TECHNICAL FIELD
[0001] The present invention relates to an elevator controlling apparatus that controls
car speed.
BACKGROUND ART
[0002] Conventionally, elevator apparatuses are known that modify acceleration and deceleration
rates and maximum speed of a car in response to load inside the car in order to make
maximum use of driving capacity of a motor that moves the car. The load inside the
car is detected by a weighing device that is disposed on the car. Modification of
the acceleration and deceleration rates and of the maximum speed of the car is performed
within a driving capacity of the motor and electrical machinery and equipment that
drive the motor (Patent Literature 1).
[0003] However, if an error arises in the value detected by the weighing device, there is
a risk that the acceleration and deceleration rates and the maximum speed of the car
may be set higher than the driving capacity of the motor. In that case, there is a
risk that operation of the elevator may be stopped by interruption of the electrical
power supply system due to overcurrent, or the motor being damaged by heat generation,
etc.
[0004] Conventionally, in order to prevent the occurrence of such problems due to detection
errors in the weighing device, elevator controlling apparatuses have been proposed
in which electric current to the motor is detected by an electric current detector,
and the acceleration and deceleration rates or the maximum speed of the car is lowered
if the value of electric current detected by the electric current detector exceeds
a predetermined value (Patent Literature 2).
CITATION LIST
PATENT LITERATURE
[0005]
[Patent Literature 1]
Japanese Patent Laid-Open No. 2003-238037 (Gazette)
[Patent Literature 2]
Japanese Patent Laid-Open No. 2005-280935 (Gazette)
SUMMARY OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0006] In the conventional elevator controlling apparatus that is disclosed in Patent Literature
2, the deceleration rate of the car can also be kept lower than a set value during
decelerating movement of the car in order to reduce the burden on the motor due to
the decelerating movement of the car. However, in the elevator controlling apparatus
according to Patent Literature 2, because the deceleration rate of the car modified
during the decelerating movement of the car is maintained as an unmodified low value,
the car may go past the destination floor, the stopping position of the car deviating
from the destination floor.
[0007] The present invention aims to solve the above problems and an object of the present
invention is to provide an elevator controlling apparatus that can stop a car at a
destination floor even if a deceleration rate of the car is modified during decelerating
movement.
MEANS FOR SOLVING THE PROBLEM
[0008] In order to achieve the above object, according to one aspect of the present invention,
there is provided an elevator controlling apparatus including: a speed pattern generating
portion that generates a speed pattern for performing control that accelerates and
decelerates a car to stop at a destination floor; and a deceleration rate command
portion that determines during decelerating movement of the car whether or not a deceleration
rate value of the speed pattern can be increased based on information from a torque
detector that detects torque of a driving apparatus that moves the car, the elevator
controlling apparatus being characterized in that the speed pattern generating portion
is able to reduce the deceleration rate value of the speed pattern from a first deceleration
value initially then switch over to a second deceleration value that is greater than
the first deceleration value if the deceleration rate command portion determines that
increasing the deceleration rate of the speed pattern is possible.
EFFECTS OF THE INVENTION
[0009] In an elevator controlling apparatus according to the present invention, because
the deceleration rate command portion determines whether or not the speed pattern
deceleration rate value can be increased during decelerating movement of the car based
on the information from the electric current detector, and the speed pattern generating
portion initially reduces the speed pattern deceleration rate value from the first
deceleration value, then switches over to the second deceleration value, which is
greater than the first deceleration value, if increasing the deceleration of the speed
pattern is possible, the car can be stopped at the destination floor without the stopping
position of the car deviating from the destination floor even if the deceleration
of the car is modified during the decelerating movement. Consequently, the movement
time of the car can be shortened, enabling deterioration in elevator operating service
to be suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
Figure 1 is a configuration diagram that shows an elevator according to Embodiment
1 of the present invention;
Figure 2 is a graph that shows two speed patterns that are generated by a speed pattern
generating portion from Figure 1, a speed pattern when a deceleration rate value is
a first deceleration value η, and a speed pattern when the deceleration rate value is switched over from the first
deceleration value η to a second deceleration value ζ;
Figure 3 is a flowchart that shows processing in a controlling apparatus from Figure
1 before movement of a car is started;
Figure 4 is a flowchart that shows processing in the controlling apparatus from Figure
1 during accelerating movement of the car;
Figure 5 is a flowchart that shows processing in the controlling apparatus from Figure
1 during decelerating movement of the car; and
Figure 6 is a flowchart that shows processing when adjustment of the speed pattern
is performed by the speed pattern generating portion from Figure 1.
DESCRIPTION OF EMBODIMENTS
[0011] A preferred embodiment of the present invention will now be explained with reference
to the drawings.
Embodiment 1
[0012] Figure 1 is a configuration diagram that shows an elevator according to Embodiment
1 of the present invention. In the figure, a car 2 and a counterweight 3 that can
move vertically are disposed inside a hoistway 1. A hoisting machine 4 that constitutes
a driving apparatus that moves the car 2 and the counterweight 3 is disposed in an
upper portion of the hoistway 1 .
[0013] The hoisting machine 4 has: a motor 5; and a driving sheave 6 that is rotated by
the motor 5. A main rope 7 is wound around the driving sheave 6. The car 2 and the
counterweight 3 are suspended by the main rope 7. The car 2 and the counterweight
3 are moved inside the hoistway 1 by the rotation of the driving sheave 6.
[0014] Electric power from the alternating-current power supply 8 is supplied to the motor
5. The electric power from the alternating-current power supply 8 is supplied to the
motor 5 through an electric power supply breaking portion 9, a converter 10, and an
inverter 11.
[0015] The rated electric current value is preset in the electric power supply breaking
portion 9 based on capacity of the motor 5, the converter 10, and the inverter 11.
The electric power supply breaking portion 9 disconnects a circuit that includes the
converter 10, the inverter 11, etc., from the alternating-current power supply 8 when
the electric current value from the alternating-current power supply 8 exceeds the
rated electric current value. The motor 5, the converter 10, and the inverter 11 are
protected thereby. A fuse, or a circuit breaker, for example, can be used as the electric
power supply breaking portion 9.
[0016] The converter 10 converts alternating current from the alternating-current power
supply 8 into direct current. The electric current that is converted to direct current
by the converter 10 is sent to the inverter 11. The inverter 11 adjusts the frequency
of the electric current from the converter 10. The electric current that is frequency-adjusted
by the inverter 11 is sent to the motor 5. The motor 5 rotates the driving sheave
6 at a rotational frequency that corresponds to the frequency of the electric current
from the inverter 11 on receiving electric power from the inverter 11.
[0017] The electric current value that is sent from the electric power supply breaking portion
9 to the converter 10 is detected by the electric current detector 12. The electric
current value that is detected by the electric current detector 12 changes in response
to the torque that the motor 5 generates. Consequently, the electric current detector
12 functions as a torque detector that detects the torque of the motor 5.
[0018] A speed detector 13 that generates signals that correspond to the rotation of the
driving sheave 6 is disposed on the hoisting machine 4. Since the car 2 is moved in
response to the rotation of the driving sheave 6, the speed detector 13 generates
signals that correspond to the position and speed of the car 2. An encoder, for example,
can be used as the speed detector 13. A weighing device (a car load detecting apparatus)
14 that detects the weight (i.e., load inside the car 2) of the burden (passengers,
freight, etc.) inside the car 2 is disposed on the car 2.
[0019] The respective information from the electric current detector 12, the speed detector
13, and the weighing device 14 is sent to a controlling apparatus 15 that controls
elevator operation. The controlling apparatus 15 controls the inverter 11 to control
movement of the car 2 based on the respective information from the electric current
detector 12, the speed detector 13, and the weighing device 14.
[0020] The controlling apparatus 15 has a speed pattern generating portion 16, a deceleration
rate command portion 17, and a speed controlling portion 18.
[0021] The speed pattern generating portion 16 generates a speed pattern for performing
control that accelerates and decelerates the car 2 to stop at a destination floor.
[0022] The speed pattern generating portion 16 generates the speed pattern for the car 2
based on the information from the weighing device 14 before movement of the car 2
is started. Specifically, before movement of the car 2 is started, the speed pattern
generating portion 16 finds an acceleration rate, a maximum speed, and a deceleration
rate that correspond to the respective information from the weighing device 14, and
also finds a distance (a decelerating movement distance) from when deceleration of
the car 2 is started until the car 2 is stopped based on the maximum speed and the
deceleration rate found, and generates a speed pattern for the car 2 based on the
respective acceleration rate, maximum speed, deceleration rate, and decelerating movement
distance found.
[0023] In this example, the respective values of acceleration rate, maximum speed, deceleration
rate, and decelerating movement distance that are found before movement of the car
2 is started function as an initial acceleration value
α, an initial maximum value V
0, an initial deceleration value
β, and an initial deceleration distance value S
β.
[0024] During accelerating movement of the car 2, the speed pattern generating portion 16
finds the actual acceleration value
γ of the car 2 based on the information from the speed detector 13, and determines
whether or not it is necessary to modify the speed pattern deceleration rate value
(i.e., the initial deceleration value
β) by comparing an actual acceleration value
γ and the initial acceleration value
α. The speed pattern generating portion 16 modifies the speed pattern deceleration
rate value from the initial deceleration value
β to a first deceleration value
η that is less than the initial deceleration value
β if it is determined that modification of the speed pattern deceleration rate value
is necessary, and maintains the speed pattern deceleration rate value as an unmodified
initial deceleration value
β if it is determined that modification of the speed pattern deceleration rate value
is unnecessary. The first deceleration value
η may be a preset value, and may also be a value based on the actual acceleration value
γ found.
[0025] In other words, during accelerating movement of the car 2, the speed pattern generating
portion 16 reduces the speed pattern deceleration rate value if the acceleration value
of the car 2 does not reach the initial acceleration value
α due to overloading of the motor 5, for example, in order to prevent overloading of
the motor 5 during the decelerating movement of the car 2.
[0026] Specifically, the speed pattern generating portion 16 lowers the speed pattern deceleration
rate value from the initial deceleration value
β to the first deceleration value
η if a difference between the actual acceleration value
γ that is found based on the information from the speed detector 13 and the initial
acceleration value
α is greater than or equal to a preset threshold value Δa, and maintains the unmodified
initial deceleration value
β as the speed pattern deceleration rate value if the difference between the actual
acceleration value
γ and the initial acceleration value
α is less than the threshold value Δa.
[0027] In addition, if the speed pattern deceleration rate value is modified from the initial
deceleration value
β to the first deceleration value
η, the speed pattern generating portion 16 finds a decelerating movement distance value
(a first deceleration distance value) S
η that corresponds to the first deceleration value
η after modification, and regenerates the speed pattern based on the first deceleration
value
η and the decelerating movement distance value S
η. The regeneration of the speed pattern by the speed pattern generating portion 16
is performed during accelerating movement of the car 2.
[0028] If the speed pattern deceleration rate value is reduced to the first deceleration
value
η, the deceleration rate command portion 17 determines during the decelerating movement
of the car 2 whether or not the speed pattern deceleration rate value can be increased,
based on the information from the electric current detector 12.
[0029] In other words, the deceleration rate command portion 17 determines during the decelerating
movement of the car 2 whether or not there is spare load capacity in the motor 5 by
comparing the electric current value detected by the electric current detector 12
during the decelerating movement of the car 2 and the allowable electric current value
of the motor 5. If it is determined that there is spare load capacity in the motor
5, the deceleration rate command portion 17 finds a second deceleration value
ζ that corresponds to a difference between the electric current value that is detected
by the electric current detector 12 and the allowable electric current value of the
motor 5 based on the information from the electric current detector 12. The deceleration
rate command portion 17 determines whether or not the speed pattern deceleration rate
value can be switched over to the second deceleration value
ζ from the first deceleration value
η in order to stop the car 2 at the destination floor. Moreover, the second deceleration
value
ζ is a deceleration rate value that is larger than the first deceleration value
η.
[0030] The deceleration rate command portion 17 determines that increasing the speed pattern
deceleration rate value is possible if it is determined that switching over to the
second deceleration value
ζ is possible, and determines that increasing the speed pattern deceleration rate value
is impossible if it is determined that there is no spare load capacity in the motor
5, or if it is determined that switching over to the second deceleration value
ζ is impossible.
[0031] The deceleration rate command portion 17 sends a command to increase the deceleration
of the speed pattern and information about the second deceleration value
ζ to the speed pattern generating portion 16 if it is determined that increasing the
speed pattern deceleration rate value is possible.
[0032] The speed pattern generating portion 16 performs amendment of the speed pattern based
on the information about the second deceleration value
ζ on receiving the command from the deceleration rate command portion 17. The amendment
of the speed pattern is performed by switching over to the second deceleration value
ζ after the deceleration rate value in the speed pattern is initially reduced from
the first deceleration value
η in order to maintain the stopping position of the car 2 at the destination floor.
[0033] The speed controlling portion 18 performs control over the inverter 11 that conforms
to the speed pattern while comparing changes in speed and the speed pattern of the
car 2 based on the respective information from the speed detector 13 and the speed
pattern generating portion 16.
[0034] Figure 2 is a graph that shows two speed patterns that are generated by the speed
pattern generating portion 16 from Figure 1, a speed pattern when the deceleration
rate value is the first deceleration value
η, and a speed pattern when the deceleration rate value is switched over from the first
deceleration value
η to the second deceleration value
ζ. Moreover, in Figure 2, a speed pattern is shown from a time t
0 at which deceleration of the car 2 is started until the car 2 is stopped. In the
figure, the speed of the two speed patterns A and B at time t
0 at which deceleration of the car 2 is started is the maximum speed V
0.
[0035] In the speed pattern A, when the deceleration rate value is switched over from the
first deceleration value
η to the second deceleration value
ζ, switching over from the first deceleration value
η to the second deceleration value
ζ is started at point a (speed V
1) at time t
1, passes through point b (speed V
2) at time t
2 and point c (speed V
3) at time t
3, and switching over to the second deceleration value
ζ is completed on reaching point d (speed V
4) at time t
4.
[0036] The deceleration rate value in speed pattern A. decreases continuously as it approaches
point b in a zone between point a and point b The deceleration rate value in speed
pattern A is 0 and the speed constant in a zone between point b and point c. In addition,
the deceleration rate value in speed pattern A increases continuously as it approaches
point d in a zone between point c and point d.
[0037] In speed pattern A, switching over to the second deceleration value
ζ is completed at point d, and then the speed of the car 2 reaches zero and the car
2 is stopped by passing through point e (speed V
5) at time t
5 and point f (speed V
6) at time t
6 to reach point g at time t
7.
[0038] The deceleration rate value in speed pattern A is maintained at the second deceleration
value
ζ in a zone between point d and point f. In a zone between point f and point g in speed
pattern A, the deceleration rate value decreases continuously as it approaches point
g.
[0039] Speed pattern A and speed pattern B, in which switching over to the second deceleration
value
ζ is not performed, cross each other at point e at time t
5. Consequently, the speed of the two speed patterns A and B is identical at point
e, namely V
5.
[0040] In speed pattern B, deceleration of the car 2 is started, and the deceleration rate
value reaches the first deceleration value
η, then the deceleration rate value is maintained at the first deceleration value
η until point h (speed V
8) at time t
8, the deceleration rate value decreases continuously to point h and the speed of the
car 2 reaches zero and the car 2 is stopped on reaching point i at time tg.
[0041] If the decelerating movement distance value for the car 2 according to speed pattern
A and the decelerating movement distance value for the car 2 according to speed pattern
B are equal, the car 2 is stopped at a common destination floor irrespective of which
of the two speed patterns A and B the car 2 is moved by. In order to make the decelerating
movement distance value of the car 2 according to speed pattern A and the decelerating
movement distance value of the car 2 according to speed pattern B equal, it is necessary
for an area Sp of region P that is bounded by a - b - c - d - e - a in Figure 2 and
an area Sq of a region Q that is bounded by e - h - i - g - f - e in Figure 2 to be
equal. Consequently, when speed pattern B is amended to speed pattern A in the speed
pattern generating portion 16, the area Sp of region P and the area Sq of region Q
are computed so as to be equal. In order to make the area Sp of region P and the area
Sq of region Q equal, the length of the zone between point b and point c in speed
pattern A (i.e., the length of time between time t
2 and time t
3) is adjusted.
[0042] Next, operation will be explained. Figure 3 is a flowchart that shows processing
in the controlling apparatus 15 from Figure 1 before movement of the car 2 is started.
Before movement of the car 2 is started, a speed pattern is generated by the speed
pattern generating portion 16 based on the information from the weighing device 14.
Specifically, the initial acceleration value
α, the initial maximum value V
0, and the initial deceleration value
β are first found in the speed pattern generating portion 16 based on the information
from the weighing device 14 before starting movement of the car 2 (S11). The initial
deceleration distance value S
β is subsequently found in the speed pattern generating portion 16 (S12). A speed pattern
is subsequently generated in the speed pattern generating portion 16 based on the
initial acceleration value
α, the initial maximum value V
0, the initial deceleration value
β, and the initial deceleration distance value S
β.
[0043] Figure 4 is a flowchart that shows processing in the controlling apparatus 15 from
Figure 1 during accelerating movement of the car 2. During accelerating movement of
the car 2, it is determined in the speed pattern generating portion 16 whether or
not the difference between the actual acceleration value
γ and the initial acceleration value
α is greater than or equal to the threshold value Δa (S21).
[0044] If the difference between the actual acceleration value
γ and the initial acceleration value
α is greater than or equal to the threshold value Δa, then the speed pattern deceleration
rate value is decreased from the initial deceleration value
β to the first deceleration value
η (S22), and then the decelerating movement distance value S
η is found based on the first deceleration value
η (S23). In this case, the speed pattern is regenerated in the speed pattern generating
portion 16 based on the first deceleration value
η and the decelerating movement distance S
η.
[0045] If the difference between the actual acceleration value
γ and the initial acceleration value
α is less than the threshold value Δa, on the other hand, the speed pattern deceleration
rate value is maintained at the initial deceleration value
β without being modified.
[0046] Figure 5 is a flowchart that shows processing in the controlling apparatus 15 from
Figure 1 during decelerating movement of the car 2. When decelerating movement of
the car 2 is started after the car 2 performs constant movement at the maximum speed,
whether or not the speed pattern deceleration rate value can be increased is determined
by the deceleration rate command portion 17 based on the information from the electric
current detector 12.
[0047] Specifically, in order to find the shortest time that enables switching over to the
second deceleration value
ζ, first time t
2 and time t
3 in Figure 2 are set to equal values in the deceleration rate command portion 17 (S31).
The area Sp of region P and the area Sq of region Q are then found in the deceleration
rate command portion 17 (S32), and it is determined whether or not the area Sp of
region P is less than or equal to the area Sq of region Q (S33).
[0048] If the area Sp of region P is greater than the area Sq of region Q, it is determined
by the deceleration rate command portion 17 that increasing the speed pattern deceleration
rate value is impossible, and the speed pattern deceleration rate value is maintained
at the first deceleration value
η. In that case, the above processing is repeated at intervals of a computational period
Δt of the controlling apparatus 15 until the area Sp of region P becomes less than
or equal to the area Sq of region Q.
[0049] If the area Sp of region P is less than or equal to the area Sq of region Q, it is
determined by the deceleration rate command portion 17 that increasing the speed pattern
deceleration rate value is possible, and a command to increase the deceleration rate
of the speed pattern, and information about the second deceleration value
ζ are sent from the deceleration rate command portion 17 to the speed pattern generating
portion 16.
[0050] The value of time t
3 is then found in the speed pattern generating portion 16 such that the area Sq of
region Q and the area Sp of region P are equal (S34). The value of time t
3 is expressed by time t
2 + (the area Sq - the area Sp)/speed V
3.
[0051] Amendment of the speed pattern for switching over the deceleration rate value from
the first deceleration value
η to the second deceleration value
ζ is then performed in the speed pattern generating portion 16 (S35).
[0052] Figure 6 is a flowchart that shows processing when adjustment of the speed pattern
is performed by the speed pattern generating portion 16 from Figure 1. First, the
speed pattern is amended in the zone from time t
1 to time t
2 such that the speed change from speed V
1 to speed V
2 is smooth (S41). Next, the speed pattern is amended from time t
2 such that speed V
2 and speed V
3 are constant in a zone extending to time t
3 that is found in S34 above (S42). Next, the speed pattern is amended in a zone from
time t
3 to time t
4 such that the speed change from speed V
3 to speed V
4 is smooth (S43).
[0053] In an elevator controlling apparatus of this kind, because the deceleration rate
command portion 17 determines whether or not the speed pattern deceleration rate value
can be increased during decelerating movement of the car 2 based on the information
from the electric current detector 12, and the speed pattern generating portion 16
initially reduces the speed pattern deceleration rate value from the first deceleration
value
η, then switches over to the second deceleration value
ζ, which is greater than the first deceleration value
η, if increasing the deceleration of the speed pattern is possible, the car 2 can be
stopped at the destination floor without the stopping position of the car 2 deviating
from the destination floor even if the deceleration rate of the car 2 is modified
during the decelerating movement. Consequently, the movement time of the car 2 can
be shortened, enabling deterioration in elevator operating service to be suppressed.
[0054] Because a zone exists in the speed pattern in which the deceleration rate value becomes
zero in an interval in which the deceleration rate value is switched over from the
first deceleration value
η to the second deceleration value
ζ (a zone in an interval from time t
2 to time t
3), amendment of the speed pattern can be performed easily.
[0055] Because the second deceleration value
ζ is found based on the information from the electric current detector 12, the speed
pattern deceleration rate value can be increased effectively in response to the degree
of reserve in the motor 5 relative to the load during the decelerating movement of
the car 2.
[0056] Moreover, in the above example, the speed in the zone between time t
2 and time t
3 in speed pattern A is assumed to be constant (i.e., the deceleration rate value is
assumed to be zero at all times), but the speed in the zone between time t
2 and time t
3 does not need to be constant provided that the area Sq of region Q is equal to the
area Sp of region P. For example, the speed in the zone between time t
2 and time t
3 may also be increased or decreased so as to have a constant gradient.
EXPLANATION OF NUMBERING
[0057] 1 HOISTWAY, 2 CAR, 13 ENCODER (SIGNAL GENERATING APPARATUS), 15 CAR POSITION DETECTING
PLATE (MAGNETIC SHIELDING BODY), 16 PLATE DETECTING APPARATUS (SHIELDING BODY DETECTING
APPARATUS), 18 FIRST MAGNETIC DETECTOR, 19 SECOND MAGNETIC DETECTOR, AND 20 CONTROLLING
APPARATUS.