FIELD OF THE INVENTION
[0001] The present invention relates to a crane safety apparatus, and more particularly
to a crane safety apparatus having a plurality of image display modes and capable
of providing an operator with crane operation status settings and safe operation in
accordance with a selected image display mode.
BACKGROUND OF THE INVENTION
[0002] There has been proposed a crane safety apparatus (Japanese Patent Publication No.56-47117).
According to the function of this crane safety apparatus, various operation parameters
(boom length, boom angle, outrigger projection, jib setting, and the like) for determining
the operation status of a crane are detected with sensors. A specific load for the
operation status determined by these operation parameters is read from a digital memory
which stores therein specific loads for various operation status, the specific load
being determined in accordance with the specification of a crane. The accessed specific
load is compared with the current actual load. If the actual load becomes near the
specific load, a warning is issued, and if it becomes equal to the specific load,
the crane operation is automatically stopped. A conventional crane safety apparatus
of this type has an indication panel such as shown in Fig.1. The operation status
such as crane outrigger projection, jib setting and the like is set by using switches
mounted on the indication panel so that values representative of the current boom
length, angle and the like are displayed from time to time. A safety meter is mounted
on the upper portion of the indication panel. The safety meter displays in the form
of bar graph the safety degree of an actual load relative to the specific load for
the current crane operation status.
[0003] Such conventional technique provides warning and automatic stop for the possible
overturn, collapse, or failure of a crane. However, there is not provided a function
to regulate the operation range of a crane when considering other buildings or the
like.
[0004] Japanese Patent Laid-open Publication No.58-74496 discloses a method of regulating
the operation range of a tower type crane. According to this method, a crane boom
and an obstacle are schematically displayed on a screen so that it is possible to
detect any contact between the boom and obstacle schematically displayed on the screen.
In this case, however, for the display of an obstacle, the coordinates of the obstacle
on the screen are required to be correctly set, leading to not a simple initial setting
of the operation range.
[0005] Further, such conventional technique does not provide a function to ensure proper
and safe operation at the operation site which an operator cannot visually recognize.
[0006] Another problem associated with such conventional technique is that only the safety
degree of an actual load relative to the specific load, i.e., the safety degree of
actual operation, is provided. As a result, an operator cannot recognize sufficiently
the danger for the next possible stage and operation.
[0007] Furthermore, such conventional technique does not provide a function to selectively
display a pattern to be used for a proper crane operation suitable for particular
operation contents.
SUMMARY OF THE INVENTION
[0008] The crane safety apparatus of this invention has a memory which stores therein display
images for a plurality of crane operation modes. The display image selected by an
operator is controlled to indicate the current crane operation status in accordance
with the crane operation parameters and operator setting data.
[0009] The crane safety apparatus of this invention comprises a schematic crane mechanism
diagram displaying means for displaying a schematic diagram of a part of the crane
mechanism on a screen at the coordinate position determined by signals from sensors,
and means including a key group for fixedly displaying a predetermined zone pattern
on the screen relative to the already displayed schematic diagram, in accordance with
the crane operation status setting entered by an operator by using the key.
[0010] In a preferred embodiment of the crane safety apparatus of this invention, while
monitoring the safety degree of a crane, a schematic diagram of a part of the crane
mechanism is dynamically displayed on the screen. There are provided a main unit CPU
and display unit CPU which take partial charges of the operations necessary for the
apparatus, to thereby allow a dynamic display of the schematic diagram of the crane
mechanism on the screen while tracing a change in operation of the mechanism at high
speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
Fig.1 shows an example of an indication panel of a conventional crane safety apparatus;
Fig.2A is a block diagram showing the fundamental structure of the apparatus according
to this invention;
Fig.2B shows an example of a specific load data curve stored in the apparatus of this
invention;
Fig.2C is a block diagram showing a particular structure of the apparatus of this
invention;
Fig.3 shows a display pattern on the screen during an operation status setting mode
according to the apparatus of this invention;
Fig.4A shows a display pattern on the screen during an automatic safety monitor mode
according to the apparatus of this invention;
Fig.4B shows illustrative representations of the causes of automatic stop to be displayed
on the screen according to the apparatus of this invention;
Fig.5 shows a display pattern on the screen during an operation range setting mode
according to the apparatus of this invention;
Fig.6 shows a display pattern on the screen during a target mode according to the
apparatus of this invention;
Fig.7 shows a display pattern on the screen during a limit load - slewing angle mode
according to the apparatus of this invention;
Fig.8 shows a display pattern on the screen during a performance curve display mode
according to the apparatus of this invention;
Fig.9 shows a part of the crane total specific load table;
Fig.9B shows a display pattern on the screen during a performance table display mode
according to the apparatus of this invention;
Fig.10 is a main flow chart showing the operation sequence of the main unit;
Fig.11 is a flow chart showing a hard interrupt from the main unit;
Fig.11 is a flow chart showing a soft interrupt from the main and display units;
Fig.13 is a main flow chart showing the operation sequence of the display unit;
Fig.14 is a flow chart showing the processings of respective display modes in the
main flow chart for the display unit;
Fig.15 is a flow chart showing the hard interrupt from the display unit; and
Fig.16 is a timing chart for signals related to timer interrupt.
DESCRIPTION OF EMBODIMENT
- FUNDAMENTAL STRUCTURE OF APPARATUS -
[0013] The fundamental structure of the crane safety apparatus of this invention is shown
in Fig.2A. The crane safety apparatus is constructed of a main unit A and a display
unit B. During the operation of the apparatus, commands and data are transferred between
a main unit CPU and a display unit CPU.
[0014] Upon power-on, the crane operation status (outrigger projection step, jib step and
the like) is first required to be set. This setting is carried out at the display
unit. An operator selects an operation status setting mode from a plurality of display
modes to display a display indication (image) such as shown in Fig.3 on a display
B'' screen, and operates predetermined keys on a setting key group B' while monitoring
the display B'' screen. The display unit has a memory which stores therein graphics
data for display images such as shown in Fig.3. In accordance with a display control
program in a ROM, CPU selectively reads a display image shown in Fig.3 from the memory,
writes it in a video RAM, and displays the display image on the display B'' screen
in accordance with the data read from the video RAM. The display unit CPU fetches
the data of outrigger step setting and the like entered from a setting key by an operator,
modifies the display image so as to match the setting data, and supplies the setting
data as data D
B to the main unit A. Upon setting completion in the operation status setting mode,
the display unit enters an automatic crane safety monitor mode and displays a display
image such as shown in Fig.4A on the display B'' screen. The graphics data for the
display image such as shown in Fig.4A have already been stored in the memory, so CPU
executes a selective read and display of the graphics data.
[0015] In addition to the crane operation status setting data D
B supplied from the display unit B, the main unit A obtains from a sensor group A'
the operation parameter data (such as boom length ℓ, boom angle ϑ, slewing angle φ)
representative of the operation status of the crane mechanism which changes from time
to time as the crane is operated. These operation parameters are sent directly, or
after processed by CPU, to the display unit B as data A. The display unit B modifies
from time to time the display image on the display B'' screen in accordance with the
data A, to thereby display the current operation status of the crane.
[0016] The main unit A stores various data in accordance with each crane specification.
Such data are typically maximum specific loads for various crane operation status.
For example, a total specific load curve shown in Fig.2B is used for the operation
status settings such as with outrigger intermediate projection of (5.0 m - side direction),
without jib, and with boom length of 8.9 m. Such a total specific load curve is determined
for each of different operation status settings and boom lengths, in accordance with
each crane specification. A great number of these data are stored in ROM of the main
unit A.
[0017] In accordance with the crane operation status setting data D
B supplied from the display unit B and the crane operation status parameters changing
with time supplied from the sensor group A', the main unit A accesses ROM to obtain
the maximum specific load data for the crane operation status at that time, or compares
the maximum load value obtained by processing the data with the actual load and if
the current crane operation status is in a danger zone, a warning is issued, or/and
delivers a signal for controlling the crane mechanism A'' for automatic stop of the
crane operation.
[0018] In the memory of the display unit B, there are stored a plurality of display image
graphics data corresponding to a plurality of display modes. A display image such
as shown in Figs.5 to 9 is selected in accordance with the display mode selected by
a setting key. In addition to the automatic crane safety monitor display mode shown
in Fig.4 conventionally provided in general, an operator can use other display modes
to set the operation contents of a crane and monitor it for the effective crane operation.
The operation of other display modes will be later detailed.
[0019] The main unit A and display unit B each have a processor (CPU), and they run independently
on its own program. Transmission/reception of commands and data between the main unit
A and display unit B is allowed by an interrupt process.
- PARTICULAR STRUCTURE OF APPARATUS -
[0020] Referring to Fig.2C, the main unit CPU 200 receives the actual load data from a stress
sensor 201, and other crane operation parameter data from a slewing angle sensor 202,
boom length sensor 203, boom angle sensor 204, boom top v. angle sensor 205, jib v.
angle sensor 206, and stress sensor 208 respectively disposed at various positions
of the crane. The data from the sensors 205 and 206 disposed at the top of the boom
are collected to a top terminal 207 at the boom distal end, sent to a cord reel 210
at the boom distal end via an optical fiber cable 209, subjected to photoelectric
conversion at the cord reel, and sent to the main unit CPU 200. The display unit CPU
211 is powered from the main unit CPU 200 via a line 217. Commands and data are transferred
via bilateral serial lines 214 and 215 between the display unit CPU and main unit
CPU 200. The display 212 is a matrix type dynamic drive liquid crystal display (LCD).
An LCD is more preferable than other CRT, LED, plasma display and the like because
the crane is generally used in outdoors and because it allows a clear display image
even under strong sun light. During the night, LCD 212 is provided with back illumination.
The setting key switch group includes a plurality of touch keys corresponding in number
to a plurality of items to be set.Signals for controlling the crane mechanism are
outputted to a plunger 218, magnetic valve or the like.
- Modes of Display Unit -
(1) Operation Status Setting Mode
[0021] Referring to Fig.3, after the power is turned on, the display unit CPU automatically
enters the operation status setting mode, and displays the image such as shown in
Fig.3. This mode is indicated at 301. Numerals generally indicated at 302 represent
the boom status and they are flashing. When an operator sets desired numerals, they
stop flashing and become always illuminated. First, in order to select a desired boom
operation status, one of the ten keys on a touch panel 310A is depressed. Numeral
0 stands for the case of using only the main boom without using the jib and rooster,
numeral 1 stands for the case of using the jib with one step, numeral 3 stands for
the case of using the jib with two steps. After completion of the boom operation status
setting, numerals will flash to indicate the rightside outrigger status 303. Numeral
3 represents a maximum projection, numeral 2 an intermediate projection, numeral 1
a small projection, numeral 0 a minimum projection, numeral 4 no outrigger mounting,
and numeral 5 a running while lifting an object. Similar to the boom operation status
setting, an operator selects a desired numeral upon activation of the ten keys on
the touch panel 310A. Following the rightside outrigger setting, the leftside outrigger
status 304 is set.
[0022] The display unit CPU causes the set numeral to change its display status from flashing
to continuous illumination, and sends the set boom and outrigger status data to the
main unit CPU.
(2) Automatic Crane Safety Monitor Mode
[0023] After completion of the input operation for the operation status mode, the display
unit CPU automatically enters the automatic crane safety monitor mode for displaying
an image such as shown in Fig.4A. In accordance with the information supplied from
the main unit CPU, the display unit CPU displays the current crane operation status,
i.e., an outrigger setting 404, slewing position 405, operation radius 406, boom angle
407, lifting load 410, lifting distance 409, and boom length 402. The boom length
is schematically displayed in the form of bar 403 whose length changes in correspondence
with the actual length of the boom.
[0024] The safety limit of the current crane operation status is indicated at 411 in the
form of bar graph. The numerical representation of the safety limit is indicated at
413. The limit (maximum) load at the current crane operation status is indicated at
408. When the crane operation status becomes near the limit zone (when the bar graph
411 extends to the yellow zone), a warning is issued. When the status reaches the
limit, the crane is automatically stopped. The main unit CPU monitors the actual crane
operation status by using the data from various sensors, accesses the memory to obtain
the maximum limit load for that operation status, and checks if the accessed maximum
limit load is equal to or smaller than the actual load. If the actual load becomes
the maximum limit load for the current crane operation status, the main unit CPU delivers
a signal for locking the crane operation mechanism. During the automatic crane safety
monitor mode display, the display unit CPU visually provides an operator a crane operation
status. The crane operation status reaches a limit when it has a maximum limit load,
or when it has an operation range limit set by an operator (described later with reference
to Fig.5). Also in the latter case, a warning is issued and the crane is automatically
stopped.
[0025] One of distinctive features of this embodiment is to display an automatic stop cause
412. If the crane stops automatically during the automatic crane safety monitor display
mode, it is difficult for an operator to find at once the cause of automatic stop.
The cause of automatic stop is difficult to be found especially for the case of crane
turnover or failure caused by overload during the operation, and for the case of crane
operation during the automatic crane safety monitor mode while setting the crane operation
range or zone (described later with Fig.5). Further, if a predetermined length of
wire continues to be released over the range of its length, then a reverse winding
of the wire occurs during the crane operation. In such a case, an automatic stop is
also effected. In the automatic crane safety monitor mode of this embodiment, the
cause of automatic stop is illustratively displayed at 412 on the screen.
[0026] The illustrative representations of the causes of automatic stop are shown in Fig.4B
(a) to ((n), the representations having the following meanings. If there are a plurality
of automatic stop causes during the automatic crane safety monitor mode, the corresponding
number of representations are displayed on the screen.
Illustrative Indications |
Causes of Automatic Stop |
(a) |
automatic stop for moment (limit load) |
(b) |
automatic stop for lower angle |
(c) |
automatic stop for higher angle |
(d) |
automatic stop for most straight standing of boom |
(e) |
automatic stop for right slewing |
(f) |
automatic stop for left slewing |
(g) |
automatic stop for spiraling |
(h) |
automatic stop for releasing |
(i) |
automatic stop for radius limit |
(j) |
automatic stop for lifting distance limit |
(k) |
automatic stop for limitation of low angle |
(l) |
automatic stop for limitation of high angle |
(m) |
automatic stop for right slewing limit |
(n) |
automatic stop for left slewing limit |
[0027] The cause of automatic stop described above is displayed when certain conditions
are satisfied. For example, the cause of automatic stop for moment is assigned, when
the actual load is equal to or larger than the limit load and the lever operation
is in danger side. If the actual load is near the limit load and an operator causes
to turn down or extend the boom further, or causes the winch to wind up the wire,
these lever operations are in danger side. The main unit CPU issues a locking signal
in response to these lever operations in danger side, and the display unit CPU displays
the illustrative representation (a). Upon the automatic stop, the operator recognizes
from the displayed automatic stop cause illustrative representation (a) that the boom
cannot be turned down or extended and that the crane can be released from the danger
by other operations such as lifting the boom. As above, if the crane is turned down
and the actual load exceeds the limit load, the crane enters the automatic stop, and
the moment automatic stop cause representation is displayed. At this time, upon moving
the crane operation lever back to the neutral position, the crane automatic stop is
released and the cause representation disappears. In this condition, if the crane
operation lever is turned to the boom extension side, the automatic stop is effected
again and the moment automatic stop cause is displayed. If the crane operation lever
is turned not to the boom extension side but to the boom standing side, boom compression
side or winch winding back side, then the automatic stop and cause display are not
effected.
[0028] The crane operation in danger side is different for each automatic stop cause. The
main unit CPU has stored data representative of the direction of locking the operation
lever, respectively for each crane automatic stop cause. For example, if the automatic
stop is effected because of the boom high limit angle, the main unit CPU supplies
to the crane mechanism a signal which locks the operation lever in the direction of
lifting the boom and allows it to move in the direction of turning down the boom.
[0029] In the automatic safety monitor display mode having a number of automatic stop causes,
an operator can visually recognize the automatic stop cause so that the crane operation
is made very easy.
(3) Operation Range Limit Mode
[0030] In addition to setting the crane operation range for the crane turnover and failure
limit, the boom movable range is also set so as not to make the boom contact with
nearby buildings and the like. It is desirous if a warning is issued or the crane
is automatically stopped if the boom is moved in the direction departing from the
set movable range. In response to a depression of key A on the touch panel 310B, the
display unit CPU enters the operation range limit display mode and displays a screen
image such as shown in Fig.5. The operation range limit display mode is indicated
at 501. At the right side of the screen, the boom is schematically shown at B, and
its distal end represented by a cross is indicated at P. The schematically displayed
boom B follows the actual boom motion, and is controlled by the display unit CPU in
accordance with the operation parameters supplied from the main unit CPU. In setting
the boom operation radius limit, an operator moves the boom to the limit point (the
schematically displayed boom B also moves to the limit point). Upon depression of
key B on the touch panel 310B, the non-operation range is set at the hatched area
at the right of the boom distal end P. The operation radius R is displayed as the
operation radius limit value at 507 within a rectangular frame. In addition to the
radius limit (A) higher limit of angle (B), lower limit of angle (C), and lifting
distance limit (D) may also be set. The characteristic point of this setting is that
the boom is actually moved to the limit point and a key is depressed to set the non-operation
range, instead of calculating and setting the numerical limit value without moving
the boom to the limit point. This method of setting is advantageous in that the operation
range can be determined by moving the actual boom at the field location. The total
operation limit range covering all the limits (A) to (D) such as the radius limit
and the like is shows as (E). The boom is allowed to move within the area not hatched.
Other numerical values representative of the actual boom are also displayed on the
screen, the values including boom angle 509, actual radius 508, boom length 506, and
lifting distance 505.
[0031] At the left of the screen, a boom slewing angle range limit is displayed. A boom
B schematically displayed within an area 511 follows the actual boom motion. The boom
is moved to a boom slewing angle limit point and the boom slewing angle range limit
is set upon activation of a setting key on the touch panel. As the slewing angle range
limit, one side of the boom may be set as indicated by (F) or both sides thereof may
be set as indicated by (G). The outrigger setting status 512 previously set is also
displayed on the boom slewing display area.
[0032] For reference purpose, a lifting load 503 and maximum load 504 are displayed on the
screen.
[0033] The contents set during the operation range limit display mode are transferred in
the form of numerical data from the display CPU to the main unit CPU. Assuming that
the radius limit setting key is depressed under the conditions of the boom length
li and the boom angleϑ
i, the limit radius numerical data obtained is
. The display unit CPU displays the hatched area on the right side of R . If the
boom moves toward the outside of the set operation limit range, the main unit CPU
detects it so that a warning is issued or the crane is automatically stopped. An operator
can visually recognize the motion of the boom within the allowable operation range
as shown at (E) with respect to the non-operation range. It is a significant advantage
that an operator can forecast the next stage boom motion.
(4) Target Display Mode
[0034] Upon activation of a mode selection key on the touch panel 310B, the display unit
CPU enters the target display mode which displays a screen image such as shown in
Fig.6. This target display mode is used when an operator cannot see a lifting load
from the operator seat of the crane. Target index marks 605 and 606 indicated by solid
lines in Fig.6 are used for the setting of target points. The side of an innermost
square of the target index mark corresponds to an actual length of 15 cm, that of
the next square to an actual length of 30 cm, and that of the outermost square to
an actual length of 60 cm. First, the crane is operated to move an actual lifting
load to a target location which is set as a first target upon activation of a key
on the touch panel 310B. The first target is the origin of the coordinate system of
the screen. A lifting load position 607 is displayed on the screen at the position
apart from the origin by a certain distance. After setting the first target, an operator
can recognize from the screen the positional relation of the lifting load with the
target position without seeing the actual lifting load. It is common for a crane operation
to slew the crane and transfer a lifting load from the first point to the second point.
In such a case, the target index mark 605 is set at the first point, and the target
index mark 606 is set at the second point. The index marks 605 and 606 have independent
coordinate systems so that the distance between the target index marks 605 and 606
is not related to an actual distance therebetween. The frames indicated by a dotted
line are the effective display area of the coordinate systems of the first and second
points, the side of the frame corresponding to an actual length of, e.g., 100 cm.
The position of a lifting load within this effective area is represented by
mark. Even if the lifting load moves outside of this area, the
mark as at 607' is displayed while moving along the dotted line so that the direction
of the lifting load can be recognized by an operator. While seeing the
mark on the screen relative to the target index mark, an operator can continue the
transfer operation of the lifting load between the first and second points without
actually seeing them.
[0035] The numerical values of the distances of the lifting load to the first and second
points are displayed at the upper area of the screen at 603 and 604. For convenience
purpose, the outrigger setting 609 and slewed boom position 608 are displayed at the
lower left area of the screen. For reference purpose, there are also displayed a lifting
load 612 and maximum load 611. Reference numeral 601 indicates the display mode, and
602 indicates the safety numerical value for the crane operation during this display
mode.
[0036] The actual position of a lifting load is calculated as lifting load position data
at the main unit CPU by using the data from various sensors and the data on the crane
structure, and the lifting load position data are supplied to the display unit CPU.
Upon activation of a touch key on the display unit to set a certain position as the
origin of the target index mark 605, the display unit CPU uses the lifting load position
data at that time as the origin of the index mark 605. The display unit CPU displays
the lifting load position 607 on the screen relative to the target index mark in accordance
with a difference between the current lifting load position data and the lifting load
position data at the time of setting. If the lifting load moves outside of the outermost
square of the index mark, the display unit CPU displays the
mark along the dotted line 613 to indicate the direction of the lifting load position.
If the lifting load comes thereafter near the first or second point (i.e., comes within
the outermost square of the index mark), then the position is again displayed.
[0037] An example of the display image shown in Fig.6 provides two independent two-dimensional
target index marks. It is also possible to display three or more index marks, or three-dimensional
index marks.
(5) Limit Load - Slewing Angle Display Mode
[0038] The lifting load capacity of a crane depends on the posture of the crane structure
such as a front, rear, right and left position, so that the boom slewing of the crane
should be paid attention. When the display unit CPU enters the limit load - slewing
angle display mode upon key activation on the touch panel 310B, the display image
as shown in Fig.7 appears on the screen. A crane is schematically shown at the center
on the screen, with the outrigger setting 706 being displayed at 706. A boom is schematically
displayed at 705 for indicating the boom slewed position. A cross mark 704 at the
distal end of the schematically displayed boom 705 indicates the current distal end
of the boom. A solid line A or dotted line B indicates a safety load range area 703.
The operation is judged as safe so long as the cross mark 704 is displayed within
the area. The safety load range on the screen changes with the set outrigger conditions.
It is convenient for a crane operator to use this mode when the crane is slewed.
[0039] For reference purpose, there are also displayed on the screen, a mode indication
701, safety numerical value 702, boom length numerical value, boom operation status
708, boom angle 709, actual load 710, lifting distance 711, operation radius 712,
and maximum load 713.
(6) Performance Curve Display Mode
[0040] The typical parameter for a safety crane operation is a lifting load curve relative
to the operation radius as shown in Fig.2B. It is convenient for an operator to know
the operation safety margin by visually recognizing the current operation status from
this safety index curve. Upon activation of a mode switching key on the touch panel
310B, the display unit CPU enters the performance curve display mode and displays
a display image on the screen as shown in Fig.8. The performance curve is collectively
determined from a combination of crane operation parameters such as the outrigger
projection state, boom length, use or non-use of jib, slewing angle and the like.
The main unit CPU uses such operation parameters, accesses the previously stored specific
load data relative to the operation radius conforming with each crane specification,
and sends the specific load data to the display unit CPU. The display unit CPU displays
an operation status performance curve 803 such as shown at the rightside on the screen.
A + mark at 804 is displayed at the coordinate position determined by the current
operation radius and actual load. An operator can know the operation margin from the
position of the + mark relative to the curve. The numerical value of a marginal operation
radius is displayed at 806 near the + mark. This numerical value indication 806 moves
as the + mark 804 moves so that the operator can easily recognize this value.
[0041] For reference purpose, during the performance curve display mode, there are displayed
a current actual load 811, boom slewing status 808, outrigger setting 809, and boom
operation status 810.
(7) Performance Display Mode
[0042] There is provided a total specific load table such as shown in Fig.9A which is referred
to for the crane safety operation. This table provides specific loads relative to
operation radii conforming with each crane specification, when the outrigger setting
status and boom length are given. While referring to the table, an operator can judge
if, for example, the set outrigger and boom length are sufficient for the lifting
load and operation radius of an operation to be carried out. Upon key activation on
the touch panel 310B, the display unit CPU displays a display image as shown in Fig.9B.
This mode is referred to for an operation to be carried out so that in this mode the
crane is essentially in a stop state. An operator first uses the ten keys 310A to
enter the numeral value of a desired boom length in an area 902 where a cursor flashes.
During this mode, the entered boom length is not set as an actual boom length value.
Thereafter, the flashing cursor moves to an area 903 wherein the numerical value of
a desired slewing angle is entered. The outrigger status and the like have already
been set during the previous operation status display mode (Fig.3). Upon input of
these values, the display unit CPU receives from the main unit CPU (or the display
unit CPU itself may have such data) maximum specific load data Wt for the operation
boom angle for the given conditions, and displays them in a numerical value table
904. If the boom length and the like set for a desired operation are determined as
improper upon reference to the displayed data, the table with these numerical values
is reset, and a new boom length and the like are again entered.
[0043] For reference sake, during this mode there are displayed on the screen a mode indication
901, boom operation status 907, outrigger setting 906, and slewing angle 905.
-Operation Sequence of Apparatus -
[0044] According to the structure of the apparatus of this embodiment, the main unit and
display unit each have its own CPU which executes an operation sequence running on
a different program. The main unit control section receives the operation parameters
from sensors and the operation range setting data from the display unit control section,
calculates the actual load, operation radius, limit load and the like for the automatic
stop control of the crane mechanism, and sends the calculated data to the display
unit. The display unit control section displays the display image for a selected mode
in accordance with the data from the main unit control section, modifies the displayed
image in accordance with an input from a setting key, and sends the input setting
data to the main unit control section. The main unit and display unit control sections
carry out sequences running independently, so the transfer of commands and data therebetween
is executed upon an interrupt.
[0045] A program for sequential control of each unit CPU is stored in ROM. The display unit
has a video RAM. Display graphics data for a selected display mode are written in
the RAM the contents of which are modified as the crane operation status changes.
The graphics data stored in the video RAM are transferred to the display screen to
refresh the display image, e.g., at an interval of 150 ms.
[0046] Transmission/reception of data Da and Db by the main unit relative to the display
unit is effected by means of step synchronization (start/stop asynchronous) data communication.
Each time the main unit configures data to be transmitted to the display unit, a transmission
request interrupt is generated and the main unit CPU executes the data transmission.
The display unit generates a reception request interrupt to receive the transmitted
data. Transmission/reception of data by the display unit relative to the main unit
is performed in the similar manner.
[0047] The data representative of the crane operation status from various sensors are received
by the main unit CPU from an A/D converter. The main unit CPU receives the sensor
data upon reception of a sensor data read request interrupt at a predetermined time
interval corresponding to the operation timing of the A/D converter.
[0048] The display unit checks the key input status at a predetermined time interval and
when a key is depressed the key input data are processed.
[0049] A timer interrupt for executing a process at a predetermined time interval is supplied
to the main and display unit CPUs to execute the corresponding process.
[0050] The display unit CPU writes the graphics data in the video RAM in accordance with
the data given thereto, displays a display image on the screen, and supplies the operation
limit setting data and the like to the main unit.
[0051] In accordance with the data given to the main unit, the main unit CPU calculates
the boom radius, lifting distance, actual load and limit load, compares them with
the performance data determined in accordance with each crane specification, and outputs
a control signal to be used, e.g., for automatically stopping the crane.
(1) Main Unit Operation Sequence
[0052] In response to power-on of the apparatus or activation of a reset key, the main unit
executes the main flow sequence from S1a to S6a shown in Fig.10.
[0053] At the first step S1a, the apparatus is checked if it is in a proper state, and the
initial procedure is executed to set the CPU for ensuring the correct operation of
the following sequence. Prior to this initial procedure, an interrupt is inhibited,
and after the initial procedure, the interrupt inhibition is released at step S2a.
[0054] At the next step S3a, it is checked if there are data to be transmitted to the display
unit, and data to be received from the display. If there are data, the transmission/reception
of the data is effected. The transmitted data are received by the main unit in accordance
with a hard interrupt routine in the similar manner to receiving data from sensors.
[0055] The received and processed data are subjected to various arithmetic operations at
step S4a. Specifically, there are obtained crane operation parameters such as an actual
load, boom radius, lifting distance and the like in accordance with the boom length,
boom angle, stress and the like, and a limit load in accordance with the parameters
and limit load data previously stored in accordance with a crane specification.
[0056] Using the arithmetic operation results at step S4a, the safety degree of the crane
operation is calculated, the set operation limit value is compared with the crane
operation status, and an automatic stop process is executed at step S5a if the crane
operation is in danger or at an operation limit.
[0057] After the above sequence steps, the main unit CPU enters a HALT state at step S6a.
The main unit CPU receives a hard interrupt by an external interrupt request (IREQ)
such as data fetch, and executes an interrupt processing (the contents of Fig.11).
After the interrupt processing, the flow returns to the loop start point. If there
is no hard interrupt, the main unit CPU remains at step S6a. Although the hard interruption
is shown in Fig.10 as present between step S6a and the loop start point, it may be
provided at any step from step S3a to S6a.
[0058] In the main flow, data reception by the main unit and data transmission to the display
unit are effected upon reception of an interrupt. When new data are received or transmitted
once, there are executed a series of operations including data transmission/reception
with the display unit, data arithmetic operation, and automatic stop process.
[0059] An interrupt routine (Fig.11) starts upon reception of a hard interrupt. The interrupt
routine started by a hard interrupt includes data reception/transmission, and soft
interrupt routines 1 and 2 (Fig.12). Each time a hard interrupt is received, data
reception/transmission is carried out. If the amount of data becomes one block size
after a predetermined number of hard interrupt data receptions/transmissions, a soft
interrupt 1 start (activation) flag is set. As the soft interrupt 1 start flag is
set, the soft interrupt 1 processing of the interrupt routine is executed and a soft
interrupt 2 start flag is set. As the soft interrupt 2 start flag is set, the soft
interrupt 2 processing is executed.
[0060] The hard interrupt, soft interrupts 1 and 2 therefore have a hierarchic structure.
Data reception which is processed in a short time is performed by a hard interruption,
and during this processing another hard interrupt is inhibited. A processing which
requires a longer time is performed by the soft interrupt 1, and a processing which
requires a further longer time is performed by the soft interrupt 2. The hard interrupt
is allowed while executing the soft interrupt so that the interrupt inhibition time
is shortened, resulting in high speed data input/output processing.
[0061] Referring to Fig.11, upon reception of a hard interrupt by the main flow shown in
Fig.10, another interrupt is inhibited at step S1b. The type of interrupt is checked
at steps S2b to S9b if it is an interrupt of reception/transmission from/to the display
unit, an interrupt of reception from sensors, or a timer interrupt. In accordance
with the discriminated type, the corresponding hard interrupt processing is executed.
Specifically, the data received from the display unit are stored in a temporary storage
area, the data to be transmitted to the display unit are transferred from the temporary
storage area to the transmitter and transmitted to the display unit, or the data received
from sensors are stored in the temporary storage area. If the total data reception/transmission
amount becomes one block after a certain number of hard interrupts, the soft interrupt
1 start flag is set.
[0062] Upon completion of the soft interrupt processing, the soft interrupt 1 sequence S3b
starts (Fig.12). After this soft interrupt 1 sequence, it returns to the main flow
shown in Fig.10 (RET0).
[0063] Referring to Fig.12, at the soft interrupt 1 sequence, the soft interrupt 1 on-processing
flag is checked (step S1c). If the flag is not set and the processing is not executed,
then it is checked if the soft interrupt 1 start flag is set (step S2c). If the flag
is not set because of the data amount to be processed is insufficient, the flow advances
to step S8c. If the soft interrupt 2 is not processed and the soft interrupt 2 start
flag is not set, the flow advances via steps S9c and S10c to step S16c. At this step
S16c, the contents of the status setting register are recovered and the interrupt
inhibition set at step S1b shown in Fig.11 is released, to thereafter return to the
main flow shown in Fig.10 (RET0).
[0064] The above case illustrates that a hard interrupt occurs at the main flow, the data
are received at step S3b shown in Fig.11, and the flow returns to the main flow.
[0065] If the soft interrupt start flag is set at step S2c shown in Fig.12, the soft interrupt
1 on-processing flag is set (step S3c). Since a hard interrupt is allowed during the
soft interrupt 1 processing, the interrupt inhibition set at step S1b shown in Fig.11
is released (step S4c), and thereafter the soft interrupt 1 processing is executed
(step S5c). During the soft interrupt 1 processing, the soft interrupt 1 start flag
is reset and if the conditions are met the soft interrupt 2 start flag is set. After
executing the soft interrupt 1 processing, the hard interrupt inhibition is again
effected (step S6c) and the soft interrupt 1 on-processing flag is reset (step S7c),
to return to the loop start point at step S2c. At this time, the soft interrupt 1
start flag is being reset, the flow advances from step S2c to step S8c for the soft
interrupt 2 processing. At step S8c, if the soft interrupt 2 processing is not executed
and the soft interrupt 2 start flag is not set, then the flow advances via steps S9c
and S10c to step S16c whereat the contents of the status setting register at the start
of the interrupt are recovered and the interrupt inhibition set at step S5c is released,
to return to the main flow shown in Fig.10 (RET0).
[0066] The above case illustrates that data are received upon occurrence of a hard interrupt,
the data amount becomes one block, the soft interrupt 1 start flag is set, the soft
interrupt 1 processing for the one data block is executed, and the flow returns to
the main flow.
[0067] Since a hard interrupt is allowed during the soft interrupt 1 processing of the soft
interrupt sequence, it can be accepted during the soft interrupt 1 processing at step
S5c. When a hard interrupt occurs during the soft interrupt 1 processing at step S5c,
the hard interrupt routine is effected so that the data are received at steps S1b
to S3b shown in Fig.11. Thereafter, the flow advances to step S1c and to step S17c
shown in Fig.12 to recover the contents of the register and release the interrupt
inhibition, and returns (RET1) to the intercepted point at step S5c to thereby resume
the soft interrupt 1 processing. In the above manner, data can be received by a hard
interrupt even during the soft interrupt 1 processing.
[0068] It is assumed that the soft interrupt 2 start flag is set during the soft interrupt
1 processing. In this case, after the soft interrupt 1 processing is completed and
the soft interrupt 1 start flag is reset, the flow advances from step S2c to step
S8c for the soft interrupt 2 processing sequence. If the soft interrupt 2 processing
is not being executed, the flow advances from step S9c to S10c, and to steps S10'c,
S11c, S12c, S13c and S14c for executing the soft interrupt 2 processing and returning
to the loop start point. At this time, since the soft interrupt 2 start flag is being
reset, the flow returns via step S16c to the main flow (RET0) to terminate a series
of interrupts.
[0069] A hard interrupt is also allowed during the soft interrupt 2 processing as during
the soft interrupt 1 processing. If a hard interrupt occurs during the soft interrupt
2 processing, data are received at the flow shown in Fig.11, and the flow advances
via steps S1c, S2c, S8c and S9c to step S15c whereat the contents of the register
are recovered and the interrupt inhibition is released to return (RET2) to the intercepted
point of the soft interrupt 2 processing at step S12c.
(2) Display Unit Operation Sequence
[0070] The main flow for the display unit is shown in Fig.13. After performing an initial
procedure at step S1d in order to ensure a proper execution of the following sequence,
an interrupt inhibition is released at step S2d.
[0071] To display the crane operation status which changes from time to time on the screen,
the graphics image data for a selected display mode are written in the video RAM.
The graphics image data are read from the video RAM at a predetermined time interval,
e.g., of 150 ms to drive the display and refresh the display image on the screen.
In this embodiment, the graphics image data are stored in the video RAM as the numerical
values of coordinate points at both ends of each line segment constituting the display
image. If a display refresh flag or indication update flag is being set at step S3d,
the data in the video RAM are sent to the display to refresh the display image at
step S5d.
[0072] After the power-on or resetting, the initial display data stored in the video RAM
at the initial procedure are displayed. The display unit CPU then enters a HALT state
and does not execute the next instruction until a hard interrupt is received.
[0073] A hard interrupt to the display unit CPU is generated by a timer interrupt and a
data transmission/reception request with respect to the main unit CPU. The setting
information or transmission/reception data are received or transmitted according the
type of interrupt (Fig.15).
[0074] After the interrupt processing, the flow returns to the main flow and executes the
processing corresponding to a selected mode. The mode processings are always activated
by a hard interrupt which is also allowed during the mode processing. A hard interrupt
is inhibited only while a hard interrupt processing which requires a short time is
executed.
[0075] After a predetermined lapse of the operation start of the display unit, an operation
status input mode flag is automatically set by a timer interrupt (Fig.15). After completion
of the timer interruption processing, a judgement step S1e shown in Fig.14 is performed
and the operation status input mode processing routine is executed at step S2e. At
this routine, the graphics image data for the operation status input display image
are written in the video RAM, and thereafter the flow returns to the loop start point
at step S3d. Next, at steps S3d and S5d, the display unit CPU transfers the graphics
image data for the operation status input display image to the display screen to display
it. Then, the display unit CPU stops. An operator depresses a setting key for the
jib step while monitoring the display image, and the jib setting data are read by
the display unit CPU. Next, the display unit CPU modifies the graphics image data
in the video RAM in accordance with the jib step setting data. The graphics data for
the input operation status modified and stored in the video RAM are then displayed
on the screen at steps S3d and S5d.
[0076] The mode processing at step S2e performs the above-described display image processing
as well as other processing such as storing the transmission data of the main unit
in the temporary storage area.
[0077] The contents of processings at steps S3e to S14e are different for each mode.
[0078] The key data is read at a predetermined time interval by using the timer interrupt,
and when a key is depressed, the corresponding processing is executed.
[0079] The soft interrupt flow for the display unit has the same sequence as of the main
unit soft interrupt flow shown in Fig.12, although the contents of each step are different.
(3) Contents of Each Processing
[0080] The contents of the reception and transmission processings are each divided in the
following three processes.
[0081] Reception Processing (1): Serial data sent from the main (display) unit are sequentially
stored in a designated buffer area. When one block data are received, the data are
checked and if they are not abnormal, a start flag at Reception Processing (2) is
set. This reception processing is effected by a hard interrupt shown in Figs.11 and
15.
[0082] Reception Processing (2): The contents of the one block data sent from the main (display)
unit are checked and stored in a predetermined memory storage area at an address to
which CPU can access. This reception processing is executed by the soft interrupt
1 processing at step S5c shown in Fig.12.
[0083] Reception Processing (3): The final processing is executed from the data sent from
the main (display) unit and stored in the memory. This reception processing is executed
by the soft interrupt 2 processing at step S12c shown in Fig.12 or by the reception
data processing at step S3a in the main flow shown in Fig.10.
[0084] Transmission Processing (1): It is checked if there are data to be transmitted to
the main (display) unit. If there are data, the data are designated as being transmitted
and the transmission processing (2) is activated. This transmission processing is
executed at step S3a of the main flow shown in Fig.10 or at step S12c shown in Fig.12.
[0085] Transmission Processing (2): It is checked if a transmission is enabled. If enabled,
the transmission data are read from the memory storage area where they are stored,
converted into serial data which are then stored in a memory transmission area, and
the transmission processing (3) is activated. This transmission processing is executed
by the soft interrupt 1 processing at step S5c shown in Fig.12.
[0086] Transmission Processing (3): The data in the memory transmission area are sequentially
and serially transmitted. This transmission processing is executed at step S7b for
the data transmission processing shown in Fig.11.
[0087] As seen from Fig.13, the data transmission/reception processing by the display unit
is not included in the main flow, but the data transmission/reception is executed
at the soft interrupt 1 processing. The reason why the main flow of the main unit
includes the transmission/reception processing is as follows. The main task of the
main unit is the arithmetic operation and automatic stop operation. So long as these
operations are included in the main flow, there is no merit even if the data sent
from the display unit are soft-interrupted, but there is a demerit that the arithmetic
operation and automatic operation are delayed in their processing. Since the arithmetic
operation takes a long time and there are a number of data required for the arithmetic
operation, it is better that the arithmetic operation and automatic stop operation
are carried out not by the soft interrupt but by the main flow. On the other hand,
the display unit executes the transmission/reception processing not by the main flow
but by the soft interrupt. Since the processing time of panel switch actuation by
an operator differs greatly for each mode and the data from the main unit are used
by the soft interrupt processing, it is better that the reception processing is executed
by the soft interrupt.
[0088] Also, since the the data sent from the main unit are not generated at the main flow
but they are sent as panel switch data, it is better that the transmission processing
is executed not by the main flow but by the soft interrupt. From the above reasons
of different contents of the processings by the main and display units, the transmission/reception
processing is executed differently between the main unit and display unit.
[0089] The timer interrupt is generated every 10 ms at the main unit. There is also provided
a soft timer of 16 channels. 8 channels are used for the soft timer of the soft interrupt
1, and the other 8 channels are used as the soft timer of the soft interrupt 2. A
soft timer is constructed of a timer start/stop flag, operation counter and repetition
counter. The operation counter and respective counter of the soft timer for the soft
interrupt 1 each are constructed of one byte. and those for the soft interrupt 2 of
two bytes. The timer start/stop flag is used for the control of the soft timer operation.
The flag for the soft interrupt 1 has one byte (8 bits) each bit corresponding to
one of the eight timers. Each soft timer operates while the flag bit is "1", and stops
while the flag bit is "0". For example, after one of the bits of the timer start/stop
flag becomes "1", the operation counter is decremented by 1 each time a hard timer
interrupt occurs. When the operation counter becomes "0" which means a time-out, the
flag for the soft interrupt 1 or 2 is set and the operation counter is then set with
the count data of the repetition counter. This operation repeats until the timer start/stop
flag becomes "0". Therefore, the soft interrupt 1 timer can be set for the time duration
from 10 ms to 1.55 sec, and the soft interrupt 2 timer can control for the time duration
from 50 ms to 54.6125 min.
[0090] This soft timer interrupt is used in the following manner. The display unit receives
panel switch data at a time prior to the predetermined time. The display unit also
sets the display refresh flag, display flashing flag, initial routine timer, and the
like. The main unit sets a voice timer, initial routine timer, communication error
check timer and the like. If the timer repetition counter value is 10 and the timer
operation counter counts down from the first value, then the timer flag is set after
about 5 x (timer interrupt period) after the timer start/stop flag was set. Thereafter,
the flag is repetitively set at the interval of about 10 x (timer interrupt period)
until the timer start/stop flag is reset. The timer flag signal shown in Fig.16 is
the flag for the soft interrupt 1 or 2. This flag is reset at the time when the corresponding
processing is executed.
[0091] In the disclosed invention, the term "crane" is used to mean not only a vehicle mounted
mechanism but also other mechanism generally lifting a load with a boom, such as a
vehicle operating at an elevated stage for moving a mount type operation crane or
bucket up and down, and right and left.
1. Crane safety apparatus comprising:
sensors attached to a crane mechanism for generating sensor signals indicative
of the operational status of the crane mechanism such as boom length, boom angle,
and slewing angle;
a key board unit responsive to an operator's key operation for generating an instruction
signal;
a display device including a memory for storing graphic data to display a crane
mechanism schematic diagram and a two dimensional screen for displaying a graphic
image in accordance with the graphic data stored in the memory; and
a processor connected to said senors, key board unit and display device, wherein
said processor, in response to the signals from said sensors at predetermined intervals,
updates the graphic data of the crane mechanism schematic diagram stored in the memory
so that the crane mechanism schematic diagram graphic image on the screen represents
the crane mechanism as it is being operated, and wherein said processor, in response
to instruction signals from the key board unit, determines a positional correspondence
between a screen reference point and a preselected point of the crane mechanism schematic
diagram displayed on the screen, and writes a working range pattern, positioned with
respect to the screen reference point, into the memory so that the working range pattern
is fixedly displayed with respect to the screen reference point on the screen while
the crane mechanism schematic diagram on the screen is updated as the crane mechanism
is operated.
2. A crane safety apparatus comprising:
means for receiving a signal from a sensor which detects the operating status of
a crane mechanism;
a keypad having a key for generating a work zone instruction signal;
a two-dimensional screen;
a schematic crane mechanism diagram displaying means for dynamically displaying
a part of the schematic diagram of said crane mechanism on said screen, said displaying
means including a memory for storing the schematic diagram data of the crane mechanism,
and in response to the signal from the sensor, for modifying the stored schematic
diagram data in the memory, and for displaying the schematic diagram on the screen
by reading out the modified schematic diagram data from the memory; and
means, responsive to the work zone instruction signal generated upon a key actuation
of the keypad by an operator, for displaying a stationary predetermined zone pattern
on said screen located with respect to a preselected point of said schematic diagram
displayed on said screen at that time.
3. A crane safety apparatus according to claim 2, wherein said part of the schematic
diagram of the crane mechanism displayed on said screen is a boom diagram of said
crane, and said predetermined zone pattern is a boom operation range limit zone which
is displayed on the basis of said preselected point displayed on said screen at the
time of said key actuation.
4. A crane safety apparatus comprising:
means for receiving a signal from a sensor which detects the operating status of
a crane mechanism;
a keypad having a key for generating a work zone instruction signal;
a two-dimensional screen;
a schematic crane mechanism diagram displaying means for dynamically displaying
a part of the schematic diagram of said crane mechanism on said screen, said displaying
means including a memory for storing the schematic diagram data of the crane mechanism,
and in response to the signal from the sensor modifying the stored schematic diagram
data in the memory, and displaying the schematic diagram on the screen by reading
out the modified schematic diagram data from the memory; and
means, responsive to the work zone instruction signal generated upon a key actuation
of the keypad by an operator, for displaying a stationary predetermined zone pattern
on said screen located with respect to a preselected point on said screen, and adjusting
the display position of said schematic diagram at that time to said predetermined
point;
wherein said part of the schematic diagram of the crane mechanism displayed on
said screen is a crane lifting position diagram, and said predetermined zone pattern
is an index which indicates a distance scale within a predetermined range relative
to said preselected point.
5. A crane safety apparatus according to claim 4, wherein said crane lifting position
diagram is initially set on said screen at a predetermined position in response to
said key actuation.
6. A crane safety apparatus according to claim 4 or 5, wherein said index is a two-dimensional
closed area having as its center said crane lifting position diagram displayed on
said screen at the time of said key actuation.
7. A crane safety apparatus according to claim 6, wherein when said crane lifting position
diagram moves outside of the border of said closed area in response to the crane mechanism
operation after the initial setting, said crane lifting position diagram is displayed
near or along said border.
8. A crane safety apparatus having a main unit (A,A',A'') and a display unit (B,B',B'')
wherein:
said main unit comprises a main unit CPU (200), a terminal (207) via which a crane
operation status parameter is inputted to said main unit CPU (200), a terminal via
which command and data are transmitted/received between said main unit CPU (200) and
said display unit (B,B',B''), and a memory for storing a limit load data for each
crane operation status conforming with a crane specification;
said display unit comprises a display unit CPU (211), a display (212), a memory
for storing a pattern to be displayed on said display (212), a terminal via which
data is inputted upon a key input of data, and a terminal via which commands and data
are transmitted/received between said display unit CPU (212) and said main unit (A,A',A'');
and
said main unit CPU (200) transmits a crane operation status data to said display
unit CPU in accordance with a display mode pattern selected by said display unit (B,B',B''),
and said display unit CPU (212) controls the display pattern on said display in accordance
with said received crane operation status data.
9. A crane safety apparatus according to claim 8, wherein said main unit CPU (200) issues
a limit signal when a crane actual operation status reaches a limit which is checked
in accordance with crane control information including said stored limit load data
and/or set crane operation range limit data.
10. A crane safety apparatus according to claim 9, wherein:
said main unit CPU (200) transmits said limit signal including a limit cause when
a crane actual operation status reaches a limit which is checked in accordance with
said received crane operation status parameter, and
said display unit CPU (212) displays an indication representative of the contents
of said limit cause included in said received limit signal.
11. A crane safety apparatus comprising a main unit and a display unit for schematically
and dynamically displaying at least a part of a crane mechanism on a two-dimensional
screen, wherein:
said main unit includes a main unit CPU, a terminal for receiving at said main
unit CPU the data from a sensor which detects a crane operation status parameter,
a terminal for data transmission/reception between said main unit CPU and said display
unit, and a memory for storing limit load data for each of said crane operation status,
said limit load data satisfying the specification of said crane;
said display unit includes a display unit CPU, a display, a memory for storing
a pattern to be displayed on said display, a terminal for receiving crane mechanism
setting data inputted from an input key, and a terminal for data transmission/reception
between said display unit CPU and said main unit;
said main unit refers to said limit load data in said memory in accordance with
the data from said sensor and the said crane mechanism setting data from said display
unit, and generating a signal associated with the safety degree of said crane mechanism;
and
said display unit determines the shape and coordinate values of the schematic crane
mechanism diagram on said screen in accordance with said crane mechanism setting data
and the data from said sensor received from said main unit, and update the display
image on said screen.
12. A crane safety apparatus according to claim 11, wherein in the data input processing
by said main unit CPU and display unit CPU, the data reception processing is executed
by a hard interrupt routine during which another hard interrupt is inhibited, and
the processing after said data reception activated by said hard interrupt routine
is executed by a soft interrupt routine during which another hard interrupt is allowed.
13. A crane safety apparatus comprising display mode control means for schematically and
dynamically displaying at least a part of a crane mechanism on a two-dimensional screen,
wherein:
said display mode control means includes a main unit including a main unit CPU
and a display unit including a display unit CPU;
said main unit receives the data from a sensor which detects the operation status
of the crane and transmits said sensor data to said display unit;
said display unit displays a schematic diagram of said crane mechanism on said
display in accordance with said sensor data transmitted from said main unit, and updates
said display at a predetermined time interval to dynamically display said crane mechanism;
said display unit stores said sensor data transmitted from said main unit in a
buffer by using a hard interrupt routine during which another hard interrupt is inhibited;
and
said display unit generates the display data output for said received sensor data
by using a soft interrupt routine activated by said hard interrupt routine, a hard
interrupt being allowed during said soft interrupt routine.
14. A crane safety apparatus according to claim 13, wherein:
said soft interrupt routine includes a first soft interrupt routine and a second
soft interrupt routine;
said first soft interrupt routine responsive to generation of a predetermined block
structure of the received data for transferring said received data in a memory at
an address said display unit CPU can access; and
said second soft interrupt routine is activated by said first soft interrupt routine
and generates a display data output from said data stored in said memory.
15. A crane safety apparatus according to claim 13, wherein said display unit includes
a key for setting the status of said crane mechanism, and said display unit detects
the operation status of said key at a predetermined time interval determined by a
timer interruption to receive the data set by said key in a buffer.
16. A crane safety apparatus having means for receiving a signal from a sensor which detects
the operation status of a crane mechanism, and display means having a two-dimensional
screen, comprising:
schematic crane mechanism diagram displaying means for dynamically displaying a
part of the schematic diagram of said crane mechanism on said screen, said displaying
means responding to a signal from said sensor and determining the coordinate values
of said schematic diagram to be displayed, relative to the coordinate axes of said
screen; and
means including a key and responsive to a key actuation by an operator for the
selection of a crane operation status of said crane mechanism, for stationary displaying
a predetermined zone pattern on said screen on the basis of said schematic diagram
displayed on said screen at that time.
17. A crane safety apparatus according to claim 16, wherein said schematic diagram is
a boom of said crane, and said predetermined pattern is a boom operation range limit
zone which is displayed on the basis of said schematic diagram boom displayed on said
screen at the time of said key actuation.
18. A crane safety apparatus according to claim 16, wherein said schematic diagram is
a crane lifting position, and said predetermined pattern is an index which indicates
a distance scale within a predetermined range relative to said schematic diagram lifting
position displayed on said screen at the time of said key actuation.
19. A crane safety apparatus according to claim 18, wherein said schematic diagram lifting
position is initially set on said screen at a predetermined position in response to
said key actuation.
20. A crane safety apparatus according to claim 18 or 19, wherein said index is a two-dimensional
closed area having as its center said schematic diagram lifting position displayed
on said screen at the time of said key actuation.
21. A crane safety apparatus according to claim 20, wherein when said schematic diagram
lifting position moves outside of the border of said closed area in response to the
crane mechanism operation after the initial setting, said schematic diagram lifting
position is displayed near at and along said border.
22. A crane safety apparatus having means for receiving a signal from a sensor which detects
the operation status of a crane mechanism, and display means having a two-dimensional
screen, comprising:
displaying means for schematically displaying a boom of said crane mechanism on
said screen, said displaying means responding to a signal received from said sensor
and determining the shape of said schematic boom diagram and the coordinate values
of said schematic boom diagram on said screen at a predetermined time interval to
update a display of said schematic boom diagram on said screen; and
means responsive to an operation limit setting signal for visually discriminatively
displaying the area on said screen corresponding to the outside of said operation
range of said boom at the time of said response.
23. A crane safety apparatus according to claim 22, wherein said operation limit setting
signal is for at least one of a radius limit, higher angle limit, lower angle limit,
lifting distance limit and slewing angle limit.
24. A crane safety apparatus according to claim 22, wherein said operation limit setting
signal is for at least two of a radius limit, higher angle limit, lower angle limit
and lifting distance limit, and the visually discriminative display of said two limits
is combined on said screen.
25. A crane safety apparatus comprising:
a sensor for detecting an operation status of a crane mechanism;
a key for setting the status of said crane mechanism;
a display; and
means responsive to the data from said sensor and key for controlling a display
of a schematic diagram of said crane mechanism on said display, said control means
responding to a mode change for selectively displaying at least two schematic diagrams
of said crane mechanism.