JP2000211829A - Elevator control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an unbalance load sensor for an elevator at starting, enhance the maintainability, stop the elevator car stably at the reference position irrespective of riding passengers, and establish a high speed responsiveness at the time of starting. SOLUTION: This elevator control device including a speed control system to put the sensed speed of an AC motor 80 identical to a speed command is composed of a car stop position sensing means 120 to sense the position of an elevator car 110, a rotating direction judging means 400 to judge the rotating direction of the motor on the basis of pulses emitted from an encoder 140, and a position control system having a calculating means 410 to calculate the rotating angle (position) of the motor upon counting the encoder pulses by reference to the car stopped position given by the sensing means 120 and a position control means 420 to work so as to compensate the deviation of the obtained position from the reference signal. On the basis of the encoder pulses, the position control is executed continuously from the start command for elevator to its having moved to the destination floor, and the car is held in the correct position of the stop floor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator control device, and more particularly to a technique for smoothly starting an elevator.

[0002]

2. Description of the Related Art Conventional elevators are disclosed in
As described in Japanese Patent Publication No. 403, a load sensor detects a load amount corresponding to a position of a hoistway of an elevator cable and a compensating rope, and based on the detection, adds a load compensation signal to a current command signal. A torque for suppressing fluctuation was generated to prevent jumping and dropping at the time of startup.

[0003]

In the conventional elevator control, since the position fluctuation is compensated by the load sensor, it is necessary to adjust the load sensor under specific conditions. Maintenance and inspection are required, and the car is stopped at the stop position via the load sensor, so that only intermittent position control can be performed. In some cases, the fluctuation at the time of startup becomes large, which may affect the riding comfort.

SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to eliminate an unbalanced load sensor at the time of starting an elevator, improve maintainability, and further stably restrain the elevator at a reference position regardless of a passenger who gets in the vehicle. To increase the responsiveness of the

[0005]

The object of the present invention is to detect a car stop position when an elevator touches a floor, determine the rotation direction of an induction motor from an encoder pulse, and generate an encoder pulse based on the car stop position. The rotation angle (position) of the induction motor is calculated by counting, and a position control system that operates to compensate for the deviation between the reference signal of the car stop position and the position (rotation angle) is provided. This is solved by performing position control continuously based on the encoder pulse and holding the car at the stop position of the stop floor until the elevator moves toward the target floor after the start. In addition, a stop position of a car at the time of landing of an elevator is detected, a rotation direction of the electric motor is determined from an encoder pulse, and a position signal obtained from a rotor of a synchronous motor is synchronized with a signal of a rotary encoder to detect a magnetic pole position. A signal is formed, a rotation angle (position) of the synchronous motor is calculated based on a change point of the level of the magnetic pole position detection signal, and a reference signal of the car stop position based on the car stop position and the position (rotation angle) And a position control system that operates to compensate for the deviation from the start position of the elevator based on the magnetic pole position detection signal from when the elevator start command is issued until the elevator moves toward the target floor. The solution is to do it continuously and hold the car in the stop position on the stop floor.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an elevator control device according to an embodiment of the present invention. This embodiment is an example in which the present invention is applied to an induction motor as an AC motor. FIG.
1, the three-phase commercial power supply 10 is connected to a rectifier (converter) 20 that converts an AC voltage into a DC voltage. The DC voltage obtained from the rectifier 20 is smoothed by the smoothing capacitor 30. The DC voltage obtained by the smoothing capacitor 30 is converted into a variable voltage / variable frequency AC voltage by the PWM inverter 40 and applied to the induction motor 80. The rotor of the induction motor 80 is connected to the mesh wheel 90 via a transmission mechanism such as a gear. A rope is wound around the mesh wheel 90, and a counterweight 100 and a car 110 are connected to both ends of the rope. The induction motor 80 generates a driving force (rotational energy) corresponding to an imbalance between the load capacity of the car 110 and the counterweight 100, converts the energy into vertical kinetic energy of the elevator via the mesh wheel 90, and The basket moves up and down. The up-and-down movement of the elevator moves toward a stop floor by a control means described later, and when the elevator reaches a predetermined position with respect to the stop floor, a deceleration command is given to the induction motor 80 to shift to a deceleration mode. In this case, the induction motor 80 is braked by a generator brake (not shown in FIG. 1) or regenerative braking (when the rectifier 20 is replaced by a converter), and when the car 110 arrives at the stop position on the destination floor, the coil The excitation power supplied to the electric motor 60 is turned off, and the rotor of the induction motor 80 is locked by the desk brake 70. When the occupant gets into the car, the start button (destination button) 130 is pressed, and the door is closed, the excitation power supply 50 is turned on, and when the excitation current flows through the coil 60, the brake 70 is released. In this case, depending on the sign of the difference between the load amount of the car 110 and the counterweight 100, the car 110 starts moving upward or downward. That is, when the loading capacity of the car 110 is heavier than the weight of the counterweight 100, the car 110 moves downward.

In the present embodiment, an appropriate starting torque that balances the unbalanced portion between the time when the start button 130 is pressed and the brake 70 is released and the time when the elevator moves toward the destination floor is quickly increased. The motor is generated by the induction motor 80, and the stop position is maintained so as not to vibrate up and down, so that the motor is started quickly and smoothly. This is achieved by the following configuration. First, when the car stops and the car brake 110 is applied to fix the car 110 at a predetermined position, a car stop position signal is generated from the car stop position sensor 120 based on the stop position.
The car stop position signal is input to the reference position generation means 430, and generates a reference position command θ *. The following position control is executed so that the car 110 is held at the reference position. Due to the unbalanced load, the car 110
Moves, the rotation direction of the electric motor is detected from the state of the phases of the A and B phase pulses having a phase difference of 90 degrees from each other generated from the encoder 140 directly connected to the rotor of the induction motor 80. The direction of movement of the car 110 is determined from the rotation direction. The rotation direction of the induction motor 80 depends on the A of the encoder when the encoder 140 is attached to the motor.
The phase relationship may be determined by utilizing the phase relationship between the phase and B-phase pulses. In other words, when the car 110 moves downward, the loading capacity of the car 110 is larger than the weight of the counterweight 100, so that the induction motor 80 generates a traction force such that the car moves upward. As described above, in the opposite case, the car 110 is lighter, so that it moves downward and the induction motor 80 is drawn, so that a braking force for preventing the induction motor 80 is generated. The speed control ω _rr * is formed by the position control means 420. Here, the feedback signal θ to the position control means 420 is determined for each of the sign and the magnitude. The sign is determined by the motor rotation direction judging means 400. The sign is a positive sign in the upper case and a negative sign in the lower case. The amount of movement of the car 110 is determined by the position (rotation angle) calculating means 410 based on the number of pulses of the encoder 140 (the number of pulses within a specified time Ts) based on the car stop position signal.
Or the width of the encoder 140 (predetermined clock cycle Δt)
Is measured and determined. The signals of the position θ and the reference position θ * are input to the minus terminal and the plus terminal of the adder / subtractor 513, respectively. The speed command ωrr * formed by the position control means 420 is input to the speed command switching means 440. The speed command switching unit 440 also receives the speed command ωr * issued from the speed command generation unit 210 of the control unit that controls the normal operation. Here, the control means for controlling the normal operation includes an acceleration command generating means 200 for issuing an acceleration command, and a speed command generating means 210 for generating a speed command ωr * based on the acceleration command. The switching condition between the two by the speed command switching means 440 is a position deviation Δ
It is determined by the magnitude of the absolute value of θ (= θ * −θ). That is, when Δθ is equal to or more than the specified value (Δθ) min, the motor rotation direction determination unit 400, the position (rotation angle) calculation unit 410, the car stop position sensor 120, the reference position generation unit 430, and the addition / subtraction unit 513 are described. The activation compensation control system composed of the position control means 420 operates, and the car 110
And the rotational angular velocity ω of the induction motor 80 obtained from the speed detecting means 220.
m is input to the plus terminal and the minus terminal of the adder / subtractor 510, and the deviation Δω between the speed command ωrr * and the rotational angular speed ωm
Occurs. The deviation Δω is input to the speed control means 230 to generate a torque command τ *. The torque command τ * is input to the plus terminal of the adder / subtractor 514, and the instantaneous torque τ obtained from the torque estimator 240 is input to the minus terminal. The instantaneous torque τ (= k · It · φ2) is obtained from the torque estimation unit 240 using the torque current It obtained by the excitation current / torque current detection unit 300 and the secondary magnetic flux calculation unit 270 and the secondary magnetic flux φ2. Here, the primary current (the current flowing through the primary winding of the AC motor 80) detected by the exciting current / torque current detecting means 300 from the current sensors 81 and 82 is converted to a primary angular frequency ω (= ωm + ωs: slip angular frequency). ) Is converted to a two-phase DC current using an instantaneous phase ψ (= ∫ωdt) obtained by integrating the torque current It and the exciting current Im. The secondary magnetic flux φ2 is obtained by using the exciting current Im and the secondary time constant T2 of the AC motor 80,
In the secondary magnetic flux calculating means 270, M · Im / (1 + T2
S) It is obtained by calculating << s: Laplace operator, M: exciting inductance >>. Above torque command τ
* And a deviation Δτ (= τ * −τ) between the instantaneous torque τ generated from the induction motor 80 is input to the torque control means 250, and the torque control means 250 outputs the torque current command It to eliminate the torque deviation Δτ. * Occurs. On the other hand, the exciting current command Im * is output from the exciting current command generating means 260 according to a start signal issued from the start button 130. The torque current command It * and the excitation current command Im * thus obtained are respectively added to and subtracted from the adders / subtracters 511 and 51.
2, the torque current It and the excitation current Im detected by the excitation current / torque current detection means 300 are input to the respective minus terminals. The torque current deviation ΔIt and the excitation current deviation ΔIm are input to the current control means 280 to generate voltage commands Vt *, Vm *.
This voltage command is obtained by the PWM signal generating means 290 and the magnitude of the primary voltage command V1 ｛= √ (Vt *) ² + (Vm
*) ² ｝, AC primary voltage command from instantaneous phase （(for 3 phases)
Vu, vv, and vw are generated, compared with a triangular wave (carrier), a PWM signal is generated, and applied to the gate of the power switching element of the PWM inverter 40. With this PWM signal, the PWM inverter 40 obtains a variable voltage / variable frequency voltage, which is applied to the induction motor 80, and
Generates a torque for stopping the motor at the stop position.

FIG. 2 shows a flow of a series of the startup compensation processing of this embodiment. The passenger pushes the destination direction button from the floor side, the door opens, and the passenger enters the car 1
10 and the start button (button on the destination floor) 130 of the elevator is pressed (process 10A). The main circuit contactor (not shown in FIG. 1) is turned on, and the PWM inverter 4
A DC voltage is applied to 0 (process 10B). Start button 1
The starting signal generated from the excitation current command generating means 2
60, a predetermined exciting current command I is supplied to the induction motor 80.
m * (Normally, even if a rated load torque is applied, an excitation current command near the rated value is given in order to generate a torque corresponding to this torque at high speed. A magnetic flux is generated inside the induction motor 80 (process 10C). Next, based on the information of the car stop position sensor 120 which determines the stop position of the car, the reference position generating means 4 is used.
At 30, the stop position of the car is set as a reference position command θ * (process 10D). At this point, the preparation for operating the position control system is completed.
0, and the brake 70 is released (process 1).
0E). By this operation, the car 110 moves up and down in accordance with the load capacity and the unbalanced load of the counterweight 100. Generally, the weight of the counterweight 100 is determined so that it can be balanced to about half of the load capacity of the occupant.
Moves upward, and for more than half of the capacity, the car 110 moves downward. Here, it is assumed that the case where the car 110 moves upward is normal rotation, and the case where the car 110 moves downward is reverse rotation (process 10F). This rotation direction is determined from the phase relationship between the A-phase signal and the B-phase signal of the encoder pulse, as shown in FIG. FIG. 3 shows a state at the time of rising of the A-phase signal.
The determination is made based on whether the level of the B-phase signal is '1 (high level)' or '0 (low level)'. That is, in the former case, the rotation direction is forward, and in the latter case, the rotation direction is reverse. If it is above, it is necessary to generate a braking force on the induction motor 80. Here, assuming that the reference position command θ * is zero, the speed command ωrr obtained from the position control means 420
The sign of the position (rotation angle) θ must be determined so that * becomes negative (process 10G). Here, assuming that the time of '1 (high level)' is positive, the position deviation Δθ (= θ * −θ = −θ <0) obtained from the adder / subtractor 513 is negative, and this deviation Δθ and the position control system The speed command ωrr * obtained from the product of the gains Gp becomes negative, and becomes a speed command for suppressing the rotation of the induction motor 80. That is, it is prevented that the car 110 moves upward due to the generation of the braking force.
Conversely, when the car 110 attempts to move downward, the sign of the position θ becomes negative and the sign of the position deviation Δθ becomes positive (= θ * −θ = −θ> 0). The sign of the generated speed command ωrr * is positive, and an acceleration force (traction force) is generated, so that the car 110 is prevented from descending (process 10H). The above operation is based on the position deviation Δ
The processing is repeated until θ falls within the predetermined range Δθmin (processing 10I, 10K). The gain of the position control system is set by the exciting current flowing through the coil 60 of the brake 70 so that the response time is 1/10 or less of the response time for opening and closing the braking force. As a result, even when the brake 70 is released, the car 110 is instantaneously maintained at the reference position.
This processing is executed, and the position deviation is set to a predetermined range Δθmin.
If it is within the range, the induction motor 80 is driven according to the speed command ωr * generated from the speed command generating means 210, and the car 110 is moved to the target floor designated by the start button 130. At this time, the operation of the speed control system and the like during normal operation is described in, for example, Japanese Patent Application No. 8-40916, and description thereof will be omitted.

As described above, according to the present embodiment, the car 11
The starting can be performed without adding an unbalanced load sensor (unbalanced load sensor) between the load amount of 0 and the counterweight 100. As a result, it is possible to realize a thin elevator drive system with a short axial length, and to further reduce the installation space. Also, adjustment, maintenance and inspection of the sensor are not required. Further, conventionally, compensation is performed only when the imbalance load exceeds a specified value, but in the present embodiment,
High-precision position correction determined by the resolution of the encoder can be performed, and the ride caused by the crew before the start-up or the like does not shake. Further, by increasing the gain of the position control system, the car can be moved toward the destination floor almost simultaneously with the closing of the door.

The above is a method of operating by switching to the normal speed control system based on the position deviation. However, the input signal of the torque control means 250 or the current control means 280, that is, the torque deviation, the fluctuation of the current deviation Is within the specified range,
A similar effect can be obtained by switching to a normal speed control system for operation. This is because in this state, the torque or current necessary for position compensation is appropriately given.

FIG. 4 shows another embodiment of the present invention. This embodiment is an example of a case where an elevator is driven using a permanent magnet type synchronous motor. The difference from the embodiment of FIG. 1 lies in the magnetic pole position detecting means 411 and the reference position generating method. Therefore, the description will be focused on this point. Magnetic pole position detecting means 4
The details of the configuration of FIG. 11 are shown in FIG. 5, and the operation will be described with reference to the time chart of FIG. The position detector 141 of FIG.
, Three phases of induced voltages generated by the synchronous motor 83 are detected, and based on this, digital signals Pu, Pv, and Pw having levels of “1” and “0” as shown in FIG. 6 are generated. Differential pulses are generated from the 60 ° position detection signal generation means 411a from the rising and falling points of these three signals. This signal appears as the 60 ° position detection signal shown in FIG. Here, a case is shown in which the magnetic pole position is set to 0 ° based on the rising point of the signal Pu. This signal is taken into the magnetic pole position detecting means 411b every 60 °, and generates a phase θn (n: 1 to 6) every 60 °. This signal is generated to increase by one period (360 °) and return to the original position. The angle between each 60 sections is
Integral operation (Σωn · Δ) between the clock signal (period 1 / Δt) and the rotational angular velocity ωn obtained from the velocity detecting means 220
t) is obtained by performing the rotation angle detection means 411c in the 60 ° section. The magnetic pole position θ at the present time is obtained by the rotation angle position calculation means 411d based on the rotation direction determination signal of the synchronous motor 83 and the signals obtained from the magnetic pole position detection means 411b and the rotation angle detection means 411c. The reference position signal θ * is a rotation angle position calculating means 411d at the time when the car stop position detection signal issued from the car stop position sensor 120 obtained when the elevator stops is changed from '0' to '1' level. From the magnetic pole position signal θ obtained from. If the position control is executed after the desk brake 70 is released based on the reference position θ * and the magnetic pole position θ obtained by the above method, the car 110 can be kept at a predetermined reference position. The operation of the position control is the same as that described in the embodiment of FIG. Here, the information on the magnetic pole position needs to be stored in a memory by a battery backup so that it can be retained even in the event of a power failure. In the processing below the speed control system, the difference from the induction motor of FIG. 1 is that the command Id * of the d-axis current component is set to zero, and the phase of the modulated wave of the PWM signal is always at the magnetic pole position. The point is that a PWM signal is generated with a synchronized phase. This is a basic principle for driving the synchronous motor, and thus will not be described.

In this embodiment, the magnetic pole position of the synchronous motor can always be obtained with high precision from the stop state of the elevator.
There is no torque fluctuation, the stop position can be maintained, and a quick-response start can be realized. Further, even when the power supply is interrupted due to a power outage or the like, the memory power supply can be backed up by a battery, a large-capacity capacitor, or the like.

Since the magnetic pole position detection method described in the present embodiment is not a method unique to an elevator, it goes without saying that it can be applied to a general permanent magnet type synchronous motor starting method.

[0014]

As described above, according to the present invention,
Since an unbalanced load sensor is not necessary, the shaft length of the motor is shortened, and the installation space for the elevator is reduced.In the conventional example, the unbalanced load only occurs when an unbalanced load exceeding the specified range occurs. In order to perform the compensation at the time of starting by the load sensor, at the time of getting on, the swing of the car and the like occur, whereas in the present invention, since the position control determined by the resolution of the encoder is performed, even if the passenger fluctuates, it is always The car can be stopped at a predetermined position, whereby a comfortable ride can be achieved. Furthermore, since there is no need to mount, check, adjust, and the like the unbalanced load sensor, maintenance is improved, and maintainability can be improved. In addition, since the position control is processed sufficiently earlier than the brake release time constant, the elevator can be started almost at the same time as the door closes, realizing a stable position control system and increasing the responsiveness at the time of starting the elevator. Can be. Also in synchronous motors,
Since the magnetic pole position can always be detected with high accuracy, torque fluctuations can be reduced, a stable position control system can be realized, and quick response at the time of starting the elevator can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an elevator control device according to an embodiment of the present invention.

FIG. 2 is a flowchart of a startup reward process according to the present invention.

FIG. 3 is an explanatory diagram of a method for detecting a rotation direction of a motor.

FIG. 4 is a configuration diagram of another embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating a unit for detecting a rotation angle (position) in FIG. 4;

FIG. 6 is a time chart for explaining the operation of FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Commercial power supply, 20 ... Rectifier, 30 ... Smoothing capacitor, 40 ... PWM inverter, 50 ... Excitation power supply, 81,
82 ... current sensor, 60 ... coil, 70 ... desk brake, 80 ... induction motor, 83 ... synchronous motor, 90 ... mesh wheel, 100 ... counterweight, 110 ... car, 12
0: Car stop position sensor, 130: Start button, 200
... Acceleration command means, 210 ... Speed command generation means, 220
... speed detecting means, 230 ... speed controlling means, 240 ... torque estimating means, 140 ... encoder, 141 ... position detector, 200 ... acceleration command generating means, 210 ... speed command generating means, 220 ... speed detecting means, 230 ... speed Control means, 240: torque estimation means, 250: torque control means, 260: excitation current command generation means, 270: secondary magnetic flux calculation means, 280: current control means, 290: PWM signal generation means, 300: excitation current / torque Current detection means, 4
00: motor rotation direction determination means, 410: position (rotation angle) calculation means, 411: magnetic pole position (rotation angle) calculation means, 420: position control means, 430: reference position generation means, 440: speed command switching means, 510 , 511,
512, 513, 514 ... adder / subtractor

Claims (7)

[Claims] 1. An AC motor for moving a car of an elevator, and a PWM inverter for controlling the AC motor, for generating a speed command for the AC motor, while generating a speed command from a rotary encoder attached to the AC motor. An elevator control device having a speed control system for detecting the speed of the AC motor based on the applied pulse and matching the speed with the speed command, wherein the encoder detects a car stop position when the elevator touches the floor, and the encoder The rotation direction of the electric motor is determined from the pulse, the encoder pulse is counted based on the car stop position, and the rotation angle (position) of the electric motor is calculated. The reference signal of the car stop position and the position (rotation) Angle) and a position control system that operates to compensate for the deviation from the angle An elevator control device, wherein position control is continuously performed based on the encoder pulse until the elevator moves toward a target floor, and the car is held at a stop position on a stop floor. 2. The position control system according to claim 1, wherein:
Car stop position detection means for detecting a car position when the elevator touches down, motor rotation direction determination means for determining the rotation direction of the motor from encoder pulses having a 90-degree phase difference emitted from the rotary encoder, Position (rotation angle) calculation means for calculating the rotation angle (position) of the electric motor by counting the encoder pulses based on the car stop position obtained from the car stop position detection means, and a reference signal for the car stop position An elevator control apparatus comprising: a position control unit that operates to compensate for a deviation between the position and the position (rotation angle). 3. A synchronous motor for moving a car of an elevator, and a PWM inverter for controlling the synchronous motor, for generating a speed command for the synchronous motor, while issuing a speed command from a rotary encoder attached to the synchronous motor. An elevator control device having a speed control system for detecting the speed of the AC motor based on the applied pulse and matching the speed with the speed command, wherein the encoder detects a car stop position when the elevator touches the floor, and the encoder Determine the rotation direction of the motor from the pulse, synchronize the position signal obtained from the rotor of the synchronous motor with the signal of the rotary encoder to form a magnetic pole position detection signal, the change point of the level of the magnetic pole position detection signal Calculate the rotation angle (position) of the motor based on the reference, and stop the car based on the car stop position A position control system that operates to compensate for the deviation between the position reference signal and the position (rotation angle) is provided, from when an elevator start command is issued to when the elevator moves toward a target floor. An elevator control device, wherein position control is continuously performed based on the magnetic pole position detection signal, and the car is held at a stop position on a stop floor. 4. The position control system according to claim 3, wherein:
Car stop position detection means for detecting a car position when the elevator touches down, motor rotation direction determination means for determining the rotation direction of the motor from encoder pulses having a 90-degree phase difference emitted from the rotary encoder, Position detecting means for detecting the position of the rotor of the synchronous motor, and a position signal of the position detecting means synchronized with a signal of the rotary encoder to form a magnetic pole position detection signal, and a change point of the level of the magnetic pole position detection signal Magnetic pole position (rotation angle) calculating means for calculating the rotation angle (position) of the electric motor with reference to the reference, a reference signal of the car stop position obtained from the stop position detecting means, and the magnetic pole position (rotation angle) calculating means Characterized by having position control means operable to compensate for a deviation from the motor rotation angle (position) obtained from the motor. Motor controller. 5. The position control device according to claim 2, wherein a speed command switching means is provided, and the position control is performed until a deviation between a reference signal of the car stop position and the motor rotation angle (position) falls within a predetermined range. An elevator control device, wherein a speed command formed by the means is used as a speed command of the speed control system, and when the deviation falls within a predetermined range, the speed command is switched to a speed command during normal operation. 6. The position control system according to claim 1, wherein a current control system is added to an output of the speed control system, and when a variation of a deviation of the current control system falls within a predetermined range. An elevator control device characterized by switching from a speed command to a speed command during normal operation by the speed control system. 7. The method according to claim 1, wherein a torque control system is added to an output of the speed control system, and when a variation of a deviation of the torque control system falls within a predetermined range, the torque control system outputs a speed command from the position control system. An elevator control device characterized by switching to a speed command during normal operation by a speed control system.