CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part (CIP) of
U.S. Patent Application No. 13/885,720, filed May 16, 2013, pending, which is the U.S. national phase of PCT International Patent Application
No.
PCT/US2011/066122 filed December 20, 2011, which claims the benefit of
U.S. Provisional Patent Application No. 61/424,888, filed December 20, 2010, and
U.S. Provisional Patent Application No. 61/435,558, filed January 24, 2011, the entire contents of each of which are hereby incorporated by reference in this
application.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
BACKGROUND OF THE INVENTION
[0003] The invention relates to work platforms and, more particularly, to a work platform
including an obstruction sensing system to reduce the possibility of collision with
an obstruction or structure.
[0004] Lift vehicles including aerial work platforms, telehandlers such as rough terrain
telescoping fork trucks with work platform attachments, and truck mounted aerial lifts
are known and typically include an extendible flexible configuration boom, which may
be positioned at different angles relative to the ground, and a work platform at an
end of the boom. On or adjacent the platform, there is typically provided a control
console including various control elements that may be manipulated by the operator
to control such functions as boom angle, boom extension, rotation of the boom and/or
platform on a vertical axis, engine or other type of power source, and where the lift
vehicle is of the self-propelled type, there are also provided steering, drive speed
and direction and braking controls.
[0005] A safety hazard can occur in a lift vehicle including a work platform when an operator
is positioned between the platform and a structure that may be located overhead or
behind the operator, among other places. Collision avoidance is also desirable with
objects around the platform for example glass surfaces, aircraft structures, and other
more fragile or delicate structures.
BRIEF SUMMARY OF THE INVENTION
[0006] A camera sensor or the like may be mounted to the aerial work platform to observe
the platform, the area around the platform, and the operator. The system processes
data from the sensor to determine whether the operator is present and if the operator
is in a proper operating position and also to determine the proximity of objects above,
behind and to the sides of and below the platform. Based on data from the sensor,
a control module permits, modifies or prevents operation and/or manipulation of the
platform.
[0007] In an exemplary embodiment, a work platform is combined with a system for detecting
obstacles. The work platform includes a control panel with operating components that
control a position of the platform. The combined work platform and system include
a sensor mounted in a vicinity of the platform that monitors at least one of an operator
area, the platform, and an area around the platform, and a processor receiving a signal
from the sensor that processes the signal to determine at least one of a position
of an operator on the platform and a proximity of objects in the area around the platform.
A control module communicating with the processor and the operating components modifies
control signals from the control panel based on communication with the processor.
[0008] The processor may determine that the operator is not present or is not in a proper
operating position, and the control module may be programmed to prevent operation
of the platform that would cause motion of the platform. An override switch may be
connected with the control module, where the control module may be programmed to permit
operation of the platform at very slow or creep speed based on activation of the override
switch. The processor may determine that the operator is leaning over the control
panel, and the control module may be programmed to stop active functions and prevent
further operation of the platform that would cause motion of the platform. The processor
may determine that the operator is leaning over the control panel for a predetermined
time, and the control module may be programmed to reverse a last operating function
of the platform. The processor may determine that the operator is present and in a
proper operating position and that there are no objects in the area around the platform,
and the control module may be programmed to permit normal operation of the platform.
[0009] In one embodiment, the sensor may be programmed to distinguish the area around the
platform between a warning zone and a danger zone, where the danger zone is closer
to the platform than the warning zone. The processor may determine that an object
is present in the warning zone, and the control module may be programmed to permit
operation of the platform at creep speed based on the determination that the object
is present in the warning zone. The processor may determine that an object is present
in the danger zone, and the control module may be programmed to prevent operation
of the platform based on the determination that the object is present in the danger
zone. The sensor may be programmed to adjust a depth of at least one of the warning
zone and the danger zone based on operating characteristics of the platform. Exemplary
operating characteristics may include a number of operators on the platform, a direction
in which the platform is traveling, and a speed of the platform. The control module
may detect a speed of the platform, wherein the processor is programmed to process
signals from the sensor relating to the platform speed toward one of the objects in
the area of the platform. In this context, the control module may be programmed to
slow active functions at a rate relative to the speed at which the platform is approaching
the one of the objects in the area of the platform. The control module may be programmed
to reduce a commanded operation speed based on a proximity to one of the objects in
the area of the platform.
[0010] The sensor may include multiple sensing elements secured in the vicinity of the platform.
In one arrangement, the platform may include a platform railing, where the sensor
is mounted on the platform railing. The sensor may be one of an optical sensor, a
radar sensor, and an acoustic sensor. The sensor may be attached to a manipulation
device such as a pan and/or tilt mechanism or a mirror that displaces or rotates the
sensor field of view.
[0011] In another exemplary embodiment, an aerial work platform includes a control panel
including operator controls for manipulating the platform, a control module communicating
with the operator controls and controlling manipulation of the platform based on signals
from the control panel, and an obstruction sensing system. The obstruction sensing
system includes a sensor mounted in a vicinity of the platform that monitors an operator
area, the platform, and an area around the platform, and a processor receiving a signal
from the sensor that processes the signal to determine a position of an operator on
the platform and a proximity of objects in the area around the platform. The control
module is in communication with the processor and is programmed to modify control
signals from the operator controls based on communication with the processor.
[0012] In yet another exemplary embodiment, a method of controlling an aerial work platform
includes the steps of (a) monitoring with a sensor mounted in a vicinity of the platform
an operator area, the platform, and an area around the platform; (b) detecting with
a processor receiving a signal from the sensor a position of an operator on the platform
and a proximity of objects in the area around the platform; and (c) a control module
modifying control signals from an operator control panel based on communication with
the processor and based on the detection in step (b). Step (c) may be practiced by
preventing operation of the platform when an operator is not present or is not in
a proper operating position. Step (b) may be practiced to determine whether the operator
is leaning over a control panel for a predetermined period of time, and step (c) may
be practiced by preventing operation of the platform during the predetermined period
of time and after the predetermined period of time, reversing a last operating function
of the platform. Step (c) may be practiced by permitting operation of the platform
at creep speed when an object is detected in the warning zone, and by preventing operation
of the platform when an object is detected in the danger zone.
[0013] In yet another embodiment there is provided a combined work platform and system for
detecting proximate obstacles, the work platform including a control panel with operating
components that control a position of the platform, the combined work platform and
system comprising:
a sensor mounted in a vicinity of the platform, the sensor monitoring at least one
of an operator area, the platform, and an area around the platform;
a processor receiving a signal from the sensor, the processor processing the signal
to determine at least one of a position of an operator on the platform and a proximity
of objects in the area around the platform; and
a control module communicating with the processor and the operating components and
modifying control signals from the control panel based on communication with the processor.
[0014] Aptly the processor determines that the operator is not present or is not in a proper
operating position, and the control module is programmed to prevent operation of the
platform that would cause motion of the platform.
[0015] Aptly the combined work platform and system comprises an override switch connected
with the control module, wherein the control module is programmed to permit operation
of the platform at creep speed based on activation of the override switch.
[0016] Aptly the processor determines that the operator is leaning over the control panel,
and the control module is programmed to stop active functions and prevent further
operation of the platform that would cause motion of the platform.
[0017] Aptly the processor determines that the operator is leaning over the control panel
for a predetermined time, and the control module is programmed to reverse a last operating
function of the platform.
[0018] Aptly the processor determines that the operator is present and in a proper operating
position and that there are no objects in the area around the platform, and the control
module is programmed to permit normal operation of the platform.
[0019] Aptly the sensor is programmed to distinguish the area around the platform between
a warning zone and a danger zone, the danger zone being closer to the platform than
the warning zone, and wherein the processor determines that an object is present in
the warning zone, and the control module is programmed to permit operation of the
platform at creep speed based on the determination that the object is present in the
warning zone.
[0020] Aptly the processor determines that an object is present in the danger zone, and
the control module is programmed to stop active functions and prevent further operation
of the platform that would cause motion of the platform based on the determination
that the object is present in the danger zone.
[0021] Aptly the combined work platform and system further comprises an override switch
connected with the control module, wherein the control module is programmed to permit
operation of the platform at creep speed based on activation of the override switch.
[0022] Aptly the sensor is programmed to adjust a depth of at least one of the warning zone
and the danger zone based on operating characteristics of the platform.
[0023] Aptly the operating characteristics comprise a number of operators on the platform,
a direction in which the platform is traveling, and a speed of the platform.
[0024] Aptly the control module detects a speed of the platform, and wherein the processor
is programmed to process signals from the sensor relating to the platform speed toward
one of the objects in the area of the platform, the control module being programmed
to slow active functions at a rate relative to the speed at which the platform is
approaching the one of the objects in the area of the platform.
[0025] Aptly the control module is programmed to reduce a commanded operation speed based
on a proximity to one of the objects in the area of the platform.
[0026] Aptly the sensor comprises multiple sensing elements secured in the vicinity of the
platform.
[0027] Aptly the platform comprises a platform railing, and wherein the sensor is mounted
on the platform railing.
[0028] Aptly the sensor comprises one of an optical sensor, a radar sensor, and an acoustic
sensor.
[0029] Aptly the combined work platform and system further comprises a manipulation device
to which the sensor is attached.
[0030] Aptly the manipulation device comprises a pan and/or a tilt mechanism.
[0031] Aptly the manipulation device comprises a mirror that displaces or rotates the sensor
field of view.
[0032] In yet another embodiment there is provided an aerial work platform comprising:
a control panel including operator controls for manipulating the platform;
a control module communicating with the operator controls and controlling manipulation
of the platform based on signals from the control panel; and
an obstruction sensing system comprising:
a sensor mounted in a vicinity of the platform, the sensor monitoring an operator
area, the platform, and an area around the platform, and
a processor receiving a signal from the sensor, the processor processing the signal
to determine a position of an operator on the platform and a proximity of objects
in the area around the platform,
wherein the control module is in communication with the processor and is programmed
to modify control signals from the operator controls based on communication with the
processor.
[0033] Aptly the sensor is programmed to distinguish the area around the platform between
a warning zone and a danger zone, the danger zone being closer to the platform than
the warning zone, and wherein the control module is programmed to control operation
of the platform differently depending on whether objects are detected in the warning
zone or the danger zone.
[0034] Aptly the control module is programmed to prevent operation of the platform when
the operator is not present or is not in a proper operating position and when an object
is detected in the danger zone, wherein the control module is programmed to permit
operation of the platform at creep speed when an object is detected in the warning
zone, and wherein the control module is programmed to permit normal operation of the
platform when no object is detected in the warning zone or the danger zone and when
the operator is present and in the proper operating position.
[0035] Aptly the sensor comprises multiple sensing elements secured in the vicinity of the
platform.
[0036] In yet another embodiment there is provided a method of controlling an aerial work
platform, the method comprising:
- (a) monitoring with a sensor mounted in a vicinity of the platform an operator area,
the platform, and an area around the platform;
- (b) detecting with a processor receiving a signal from the sensor a position of an
operator on the platform and a proximity of objects in the area around the platform;
and
- (c) a control module modifying control signals from an operator control panel based
on communication with the processor and based on the detection in step (b).
[0037] Aptly step (c) is practiced by preventing operation of the platform when an operator
is not present or is not in a proper operating position.
[0038] Aptly step (b) is practiced to determine whether the operator is leaning over a control
panel for a predetermined period of time, and wherein step (c) is practiced by preventing
operation of the platform during the predetermined period of time and after the predetermined
period of time, reversing a last operating function of the platform.
[0039] Aptly the area around the platform includes a warning zone and a danger zone, the
danger zone being closer to the platform than the warning zone, and wherein step (c)
is practiced by permitting operation of the platform at creep speed when an object
is detected in the warning zone, and by preventing operation of the platform when
an object is detected in the danger zone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] These and other aspects and advantages will be described in detail with reference
to the accompanying drawings, in which:
FIG. 1 shows an exemplary aerial lift vehicle including a work platform;
FIG. 2 is a perspective view of the work platform and obstruction sensing system according
to preferred embodiments of the invention;
FIGS. 3-16 show the platform and the non-adaptive and adaptive areas monitored by
the sensor; and
FIGS. 17-21 show an exemplary pan/tilt mechanism and functionality for the sensor
unit.
DETAILED DESCRIPTION OF THE INVENTION
[0041] FIG. 1 illustrates an exemplary typical aerial lift vehicle including a vehicle chassis
2 supported on vehicle wheels 4. Although the vehicle shown includes a telescoping
boom, the invention is equally applicable to other vehicles including, for example,
articulated booms without telescoping or extendable booms. A turntable and counterweight
6 are secured for rotation on the chassis 2, and an extendible (flexible arrangement)
boom assembly is pivotably attached at one end to the turntable 6. An aerial work
platform 10 is attached at an opposite end of the extendible boom 8. The illustrated
lift vehicle is of the self-propelled type and thus also includes a driving/control
system (illustrated schematically in FIG. 1 at 12) and a control console 14 on the
platform 10 with various control elements that may be manipulated by the operator
to control such functions as boom angle, boom extension, rotation of the boom and/or
platform on a vertical axis, and engine, steering, drive speed and direction and braking
controls, etc.
[0042] FIG. 2 shows the combined work platform 10 and system 20 for detecting obstructions
such as obstacles around the platform including overhead obstacles. A sensor 22 is
mounted in a vicinity of the platform and monitors at least one of an operator area,
the platform, and an area around the platform. The sensor 22 may be a stereo camera
sensor that provides a data stream consisting of pixel data (RGB value and range)
to a computer or processor 24 mounted on the platform 10. An exemplary stereo camera
sensor is MultiSense S21 available from Carnegie Robotics. Those of ordinary skill
in the art will appreciate alternative sensors that may be suitable, and the invention
is not meant to be limited to a specific sensor type.
[0043] The obstruction sensing system 20 may include multiple sensors 22 that are cooperable
together and mounted in various areas in the vicinity of the platform 10. In an exemplary
construction, the platform 10 includes a platform railing, and the sensor 22 is mounted
on the platform railing. Mounting on the platform provides for a static view of the
platform through the full range of boom articulation. Sensors may alternatively or
additionally be mounted to boom structure to allow for a larger field of view of the
platform and/or mounted to platform support structure other than the railing. For
example, as shown, the sensor 22 may be mounted on a dedicated bracket 23 secured
to the platform, or the sensor 22 may be secured adjacent the control panel 14.
[0044] The computer or processor 24 processes the pixel range data to determine at least
one of a position of an operator on the platform 10 and a proximity of objects in
the area around the platform 10. A control module 26 in the control panel 14 forms
part of the driving/control system 12 and communicates with the processor 24 to control
operation of the platform based on a signal from the processor 24. In some arrangements,
the control module 26 communicates with the driving/control system 12, which controls
overall operation of the machine. In this arrangement, the control module 26 may gather
input from control devices such as joysticks, switches, etc. and communicate operator
commands to the driving/control system 12.
[0045] In some embodiments, the processor 24 determines whether the operator is not present
or is not in a proper operating position, and if so, the control module 26 is programmed
to prevent operation of the platform 10. That is, if the operator is not detected,
the computer 24 sends a data message to the control module 26 that prevents motion
or operation, or stops all active functions of the work platform 10. The system may
also include an override button 28, where the platform 10 may be operated at creep
speed if the override button 28 is activated.
[0046] The processor 24 may determine that the operator is leaning over the control panel
14, in which case, the control module 26 is programmed to prevent operation of the
platform 10. If the processor 24 determines that the operator is leaning over the
control panel for a predetermined time, the control module 26 is programmed to reverse
a last operating function of the platform. In this instance, the system may also sound
an alarm and turn on a warning beacon.
[0047] Indicator lamps 29 may be secured to the platform railing and around the control
panel to communicate system status to the operator. Exemplary locations for the indicator
lamps 29 are shown in FIG. 2. The control module 26 may cause the indicator lamps
29 to illuminate when the control module 26 is in any way affecting machine control.(e.g.,
when the sensors 22 indicate that the machine is getting too close to an obstacle).
[0048] FIGS. 3-8 show exemplary sensing areas for detecting the proximity of objects above,
behind, below and to the sides of the platform 10. The sensor 22 is programmed to
distinguish the area around the platform between a warning zone (Zone A) 30 and a
danger zone (Zones B and C) 32, where the danger zone 32 is closer to the platform
10 than the warning zone 30 as shown. If the processor 24 determines that an object
is present in the warning zone, the control module 26 is programmed to permit operation
of the platform 10 at creep speed. If the processor 24 determines that an object is
present in the danger zone 32, the control module 26 is programmed to prevent operation
of the platform 10 (i.e., stop all active functions and/or prevent the start or continuation
of any operation). At any time when the control module 26 prevents operation of the
platform 10 that would cause motion of the platform 10, activation of the override
switch 28 will permit operation of the platform 10 at creep speed. If the processor
24 determines that the operator is present and in a proper operating position and
that there are no objects in the area around the platform 10 (i.e., in proximity defined
by proscribed zones), the control module 26 permits normal, unrestricted operation
of the platform 10. If no operator is present, operation of the platform that would
cause motion of the platform is prevented unless overridden with the override switch
28.
[0049] Because the processor 24 is interpreting shape and distance from an obstacle in real
time, the processor 24 can be programmed to estimate direction and speed of movement
of the platform in relation to recognized obstacles. The processor 24 can be programmed
to take action even when those obstacles are outside of the warning zone 30. For example,
the processor 24 can be programmed to signal the driving/control system 12 to slow
down machine functions such as drive when the processor 24 recognizes that the operator
is driving the machine at full speed in the direction of potential obstacle. As another
example, the boom functions (or drive function) can be slowed down more aggressively
if the processor determines that the machine is moving fast toward a collision point.
[0050] With reference to FIGS. 5-8, the warning zone 30 and the danger zone 32 may be configured
as adaptive zones, where based on the picture of the surrounding environment, the
control module 26 can adjust the size and shape of the respective zones 30, 32. Adaptive
zones are calculated by the control module based on sensor system/controller ability
to recognize, among other things, the number of people in the platform, or the combination
of people and materials (tools, equipment) present in the platform. FIGS. 7 and 8
illustrate results of the controller module calculation. In FIGS. 5 and 6, the zones
30, 32 are adapted according to a specific operator. In FIG. 7, the zones 30, 32 are
adapted according to the presence of two operators, and in FIG. 8, the zones are adapted
according to an operator and equipment on the platform.
[0051] Various methods may be used for reducing the platform speed based on detected object
distance. In a "speed limiting" method, a limit for the maximum commandable speed
is set based on the distance to the detected object (see, e.g., FIGS. 5-13). In a
"speed reducing" method, the operator input is scaled down based on the distance to
the detected obstacle (see, e.g., FIGS. 14-16). These two methods may result in different
machine behavior.
[0052] The zones may be adapted to speed and direction of machine movement. Zones can be
adjusted to become deeper if it is determined that the machine is moving faster than
a threshold speed, or the zones can be "deeper" in the main direction of travel when
activating the swing or other direction function. The control module may adjust the
sensors to penetrate deeper into the direction of the side of platform. FIGS. 9-13
show variations in a depth of the warning zone and/or the danger zone based on platform
speed and direction. More specifically, FIG. 9 shows the platform traveling to the
right with each of the right side warning zone and danger zone having an increased
depth. FIG. 10 shows the platform descending with the warning and/or danger zones
having an increased depth in the direction of platform movement. The system may be
programmed to adjust the depth of the zones based on the speed of the platform. FIGS.
11-13 show a proportionally increased depth with increasing platform speed.
[0053] In a related context, the adaptive zones may incorporate proportional speed reduction
zones as shown in FIGS. 14-16. In FIG. 14, the percent of commanded speed is reduced
according to the proximity of the potential obstacle to the platform. The speed reduction
zones are shown in discrete steps but may alternatively be continuous. In FIG. 15,
the proportional speed reduction zones are combined with the zones adapted for speed
and direction. In FIG. 15, the platform is traveling to the right, and the depth of
the zones is modified accordingly. In FIG. 16, an object is detected in the 60% zone
with the platform traveling to the right. The function speed is reduced to 60% of
the commanded speed.
[0054] Communication between the sensor 22 and the processor 24 may be via digital packets
(CANbus) or discrete signaling (digital or analog output). Other forms of digital
communication may be used, allowing the sensor to provide information needed to evaluate
environmental awareness. Examples include, without limitation, Ethernet, I2C, RS232/485,
digital pulse width modulation (PWM), etc. The control module 26 interprets the data
to determine if and how the machine should react to the sensor data. The processor
24 based on signals from the sensors 22 can determine if they need to be cleaned via
a built-in test (BIT). The sensing elements 22 can be based on optical, radar or acoustic
(ultrasonic) sensing. The sensing elements 22 can be a single device or multiple devices
with the same or complementary technologies. This provides redundancy and tolerance
to a range of environmental conditions, contamination on the sensors, and objects
to be detected. Sensors may be passive (stereo camera, single camera) or active (light
detection and ranging (LiDAR), laser detection and ranging (LADAR), 3D vision sensor),
radar or acoustic (ultrasonic). Any suitable type of sensor(s) may be used, and the
invention is not meant to be limited to the described exemplary embodiments. Alternative
sensor arrangements that achieve the same functionality are also contemplated including,
for example, sensors that react to an emitter (via electromagnetic waves or other
signals), reflective tape (on the machine and/or incorporated into the operator's
protective gear), etc.
[0055] With reference to FIGS. 17-21, the sensor 22 (camera, LiDAR, RADAR, etc.) can be
manipulated either by mechanical rotation (pan/tilt) of the entire sensor using a
suitable pan/tilt mechanism 34 (an exemplary pan/tilt mechanism is the Multisense
S21 available from Carnegie Robotics), or by mechanical displacement/rotation of the
field of view via a polygon reflector 36, single reflector 38, pair of reflectors
40 (optical mirror(s) for camera and LiDAR, metal plate(s) for radar and acoustic),
etc. The manipulation device can be controlled either by the processor 24, control
module 26, sensor 22, or be self-contained in the manipulation device. Manipulating
a sensor or sensor field of view allows each sensor to cover more of the surrounding
area around the platform and/or boom structure.
[0056] The platform and obstruction sensing system endeavor to avoid collisions between
the moving platform and obstacles in the vicinity of the platform. The proactive system
according to preferred embodiments is advantageous as compared to reactive systems
that make adjustments after an obstacle has made contact with the operator and/or
platform structure.
[0057] While the invention has been described in connection with what is presently considered
to be the most practical and preferred embodiments, it is to be understood that the
invention is not to be limited to the disclosed embodiments, but on the contrary,
is intended to cover various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
1. A combined work platform and system for detecting proximate obstacles, the work platform
including a control panel with operating components that control a position of the
platform, the combined work platform and system comprising:
a sensor mounted in a vicinity of the platform, the sensor monitoring at least one
of an operator area, the platform, and an area around the platform;
a processor receiving a signal from the sensor, the processor processing the signal
to determine at least one of a position of an operator on the platform and a proximity
of objects in the area around the platform; and
a control module communicating with the processor and the operating components and
modifying control signals from the control panel based on communication with the processor.
2. A combined work platform and system according to claim 1,
wherein the processor determines that the operator is not present or is not in a proper
operating position, and the control module is programmed to prevent operation of the
platform that would cause motion of the platform.
3. A combined work platform and system according to claim 2,
wherein the processor determines that the operator is leaning over the control panel,
and the control module is programmed to stop active functions and prevent further
operation of the platform that would cause motion of the platform.
4. A combined work platform and system according to claim 3,
wherein the processor determines that the operator is leaning over the control panel
for a predetermined time, and the control module is programmed to reverse a last operating
function of the platform.
5. A combined work platform and system according to claim 1,
wherein the sensor is programmed to distinguish the area around the platform between
a warning zone and a danger zone, the danger zone being closer to the platform than
the warning zone, and wherein the processor determines that an object is present in
the warning zone, and the control module is programmed to permit operation of the
platform at creep speed based on the determination that the object is present in the
warning zone.
6. A combined work platform and system according to claim 5,
wherein the processor determines that an object is present in the danger zone, and
the control module is programmed to stop active functions and prevent further operation
of the platform that would cause motion of the platform based on the determination
that the object is present in the danger zone.
7. A combined work platform and system according to claim 2 or claim 6, further comprising
an override switch connected with the control module, wherein the control module is
programmed to permit operation of the platform at creep speed based on activation
of the override switch.
8. A combined work platform and system according to claim 5,
wherein the sensor is programmed to adjust a depth of at least one of the warning
zone and the danger zone based on operating characteristics of the platform.
9. A combined work platform and system according to claim 8,
wherein the operating characteristics comprise a number of operators on the platform,
a direction in which the platform is traveling, and a speed of the platform.
10. A combined work platform and system according to claim 1,
wherein the control module detects a speed of the platform, and wherein the processor
is programmed to process signals from the sensor relating to the platform speed toward
one of the objects in the area of the platform, the control module being programmed
to slow active functions at a rate relative to the speed at which the platform is
approaching the one of the objects in the area of the platform.
11. A combined work platform and system according to claim 1,
wherein the control module is programmed to reduce a commanded operation speed based
on a proximity to one of the objects in the area of the platform.
12. A method of controlling an aerial work platform, the method comprising:
(a) monitoring with a sensor mounted in a vicinity of the platform an operator area,
the platform, and an area around the platform;
(b) detecting with a processor receiving a signal from the sensor a position of an
operator on the platform and a proximity of objects in the area around the platform;
and
(c) a control module modifying control signals from an operator control panel based
on communication with the processor and based on the detection in step (b).
13. A method according to claim 12, wherein step (c) is practiced by preventing operation
of the platform when an operator is not present or is not in a proper operating position.
14. A method according to claim 13, wherein step (b) is practiced to determine whether
the operator is leaning over a control panel for a predetermined period of time, and
wherein step (c) is practiced by preventing operation of the platform during the predetermined
period of time and after the predetermined period of time, reversing a last operating
function of the platform.
15. A method according to claim 13, wherein the area around the platform includes a warning
zone and a danger zone, the danger zone being closer to the platform than the warning
zone, and wherein step (c) is practiced by permitting operation of the platform at
creep speed when an object is detected in the warning zone, and by preventing operation
of the platform when an object is detected in the danger zone.