JPH0729745B2 - Elevator speed control method - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a speed control method for an elevator controlled by a microcomputer.

[Technical background of the invention and its problems]

In a digital speed control device for an electric motor, a position detector such as a pulse generator or a brushless resolver that generates a pulse at a rotational position obtained by dividing one rotation into P equal parts is often used as a speed detector. By the way, since this position detector generates a pulse every 1 / P rotation, a reference time interval (timing) is required to detect the speed.

That is, this means that the speed detection value obtained by processing the output pulse of the position detector shows the average value at the above-mentioned reference timing, and it is not the instantaneous value at the time when the detection value is obtained. means. In addition, the detection value can be obtained only every certain period.

On the other hand, when the electric motor is controlled by the microcomputer, various processes are performed in a time-division manner, so that the speed control calculation is controlled in a certain cycle. This cycle is normally synchronized with the timing that serves as a reference for the above detection.

FIG. 2 is a block diagram showing an outline of an apparatus for controlling an electric motor in an elevator by a microcomputer, and FIG. 3 is a timing chart for explaining the operation of this apparatus.

In FIG. 2, reference numeral 1 is a speed command device for generating a speed command output, and its output signal 1 a is connected so as to be taken in by the microcomputer 2. Reference numeral 3 denotes an electric motor driving device composed of a semiconductor switch such as a giant transistor. The electric motor driving device 3 has an output power in which a voltage and a frequency applied to the electric motor 4 are changed according to a control signal 2a given by the microcomputer 2. Is applied to the electric motor 4 to drive it. Note that a three-phase induction motor is assumed here as the electric motor.

5 is a position detector for detecting the rotational position of the electric motor 4,
A pulse converter 7 receives the detection signal 5a from the position detector 5 and generates an output signal having a pulse number corresponding to the detection position and a data confirmation signal 7b for identifying whether the signal is valid or not. Is. A timer 6 gives an interrupt signal 6a to the microcomputer 2 in synchronization with the data confirmation signal 7b at a certain time interval.

Next, the operation of the control device having the above configuration will be described with reference to the timing chart of FIG.

The operation of the elevator is performed by controlling the electric motor drive device 3 at a speed determined by the speed command signal 1a output from the speed command device 1 and controlling the torque of the electric motor 4.

That is, the speed command signal 1a is given to the microcomputer 2, while the rotational position of the electric motor 4 is detected by the position detector 5 and a detection output is generated at each predetermined rotational position. Then, the detection output of the position detector 5 is given to the pulse converter 7, where the detection output is converted into the output signal 7a having the number of pulses corresponding to the detection position. Further, the pulse converter 7 simultaneously outputs a data confirmation signal 7b indicating that the output signal 7a is valid, and the microcomputer 2
Given to. The output signal from the timer 6 at a predetermined cycle
6a is output, and this is given to the microcomputer 2 as an interrupt signal. If the interrupt signal 6a indicates that it is valid when the data confirmation signal 7b is at "L" level, it is output in synchronization with the down edge of the data confirmation signal 7b.

Therefore, the microcomputer 2 performs a predetermined interrupt process every time there is this interrupt signal. If the interrupt process is (I), (II), (III) in the time chart, if the interrupt process is (I) → (II) → (II
Process in order of I). Here, assuming that the process of (I) is the allotted time for speed control calculation, the number of output pulses of the pulse converter 7 is counted during the period of (I), and the actual speed of the elevator is obtained from this. A control signal 2a that corrects the deviation between the actual speed and the speed command output is calculated and output, and given to the motor drive device 3.

Therefore, the electric motor drive device 3 drives the electric motor 4 by generating an output commensurate with the control signal 2a, so that the elevator is operated in a manner that follows the commanded speed.

Incidentally, FIG. 3 shows an example in which the timing of the data confirmation signal 7b and the timer output signal (interrupt signal) 6a are given to the microcomputer 2. Further, the interrupt cycle T (sampling time) to the microcomputer 2 is determined in consideration of the stability of the control system and the operation time of the interrupt processing contents (I), (II) and (III). Then, after the processing of (I), preset input / output processing or other necessary processing of (II) and (III) is performed, and these (I), (II), ( III) is sequentially executed during one sampling period T in speed control.

When an elevator is driven by the speed control device that performs digital speed control by the microcomputer as described above, various compensations are performed in order to suppress the resonance existing in the mechanical system and reduce the vibration given to the elevator car. Is done.

FIG. 4 is a block diagram showing an outline of an elevator control system capable of performing the vibration compensation.

In FIG. 4, reference numeral 10 denotes a speed control calculation unit that calculates a torque command value TA of the electric motor for driving the elevator from the deviation between the speed command value FRREF and the actual speed FR of the elevator. Reference numeral 11 denotes a mechanical system transmission unit including a current control system, which corresponds to the electric motor drive device 3 and the electric motor 4 in FIG. That is, its output FR
Is the actual speed of the elevator.

Now, as described above, 12 and 13 are loops provided to reduce the vibration in the car during the operation of the elevator, and 12 is the inertial system simulation unit, which uses the torque command value TA to determine the elevator machine. It calculates the speed when the system is regarded as a perfect rigid body. The deviation D-SPH between the output FRH from the inertial system simulation unit 12 and the actual speed signal FR is considered to be a factor that causes the vibration in the car of the elevator. Therefore, it suffices to control so as to eliminate the difference. Reference numeral 13 denotes a compensation calculation unit that calculates a torque command value TB for controlling vibration from the deviation (deviation between the output FRH and the actual speed signal FR) D-SPH. TL is an unbalanced load torque command value that compensates for the unbalanced load of the elevator.

In such a system, the speed control unit 10 controls the torque command value TA to eliminate the difference between the actual speed signal FR and the speed command.
Is generated, and this is added to the unbalanced load torque command value TL and the torque command value TB for suppressing the vibration of the car during operation determined by the compensation calculation unit 13 to form a control signal TM, which is the mechanical system transmission unit. By giving the voltage to the control signal TM, the output of the voltage and frequency corresponding to the control signal TM is generated and applied to the electric motor to drive the motor, and the torque corresponding to the control signal TM is generated to operate the elevator.

In FIG. 4, a portion surrounded by a broken line, that is, a loop of the vibration suppression calculation including the inertial system simulation unit 12 and the compensation calculation unit 13 is called a PIAL-B speed control calculation unit. The calculation process of the part is performed within the period (L) assigned for speed control calculation in the timing chart of FIG.

By the way, if the speed control including the vibration suppression calculation is performed by the digital control method by the above method, the speed can be detected only every certain cycle T as described above, and therefore, even if it is sufficient for the normal speed control, In the control calculation (PIAL-B speed calculation) for suppressing the vibration by capturing the minute deviation of the speed, there is a problem that the vibration suppression effect is inevitably deteriorated in the above-mentioned cycle even if the vibration frequency is particularly high. .

As a solution to this, it is conceivable to shorten the sampling period T of the speed control so as to facilitate the speed control calculation processing. However, the execution of each of (I), (II), and (III) in various interrupt processing in the microcomputer. Considering time, there is a limit.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and its purpose is to reduce the vibration of the car frequency during operation by interrupting only the process of the car vibration suppression speed control calculation in a short cycle. Another object of the present invention is to provide a speed control method for a computer-controlled elevator, which is capable of sufficiently effective suppression.

[Outline of Invention]

That is, in order to achieve the above-mentioned object, the present invention is a speed control process for generating a command for giving a target speed of elevator operation and calculating a control output of an elevator drive system necessary to obtain a speed corresponding to the command from the actual speed of the elevator. For example, various processes are interrupted by the computer at a predetermined cycle, and the speed of the elevator is simulated from the calculated control output for obtaining the target speed, and the difference between the simulated speed and the actual speed is calculated and calculated. The vibration suppression control calculation process for obtaining the correction control amount necessary to further reduce the difference is executed during the speed control process period, and the correction output obtained by the vibration suppression control calculation process is applied to the control output obtained by the speed control process. Elevator control that adds the amount and gives it to the elevator drive system as a control amount to suppress the vibration of the elevator car during speed control. In the device, the vibration suppression control calculation process is performed at each of the actual speed detection cycles of the elevator, so that the number of vibration suppression control calculations is increased so that vibrations of high vibration frequency can be sufficiently suppressed. To do.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings.

The present invention does not change the sampling period T of speed control, which is problematic to change, and only the part of the vibration suppression calculation is performed during the output period of the data confirmation signal 7b of the pulse converter 7, that is, the effective period of the speed detection signal. By doing so, the apparent sampling cycle of the vibration suppression control calculation is shortened, and the suppression effect can be sufficiently exhibited even for vibrations with high frequency.

Hereinafter, the present invention will be described with reference to FIGS. 1, 2, and 4.

According to the present invention, in controlling the speed control device shown in FIG. 2, the PIAL-B (the vibration suppression calculation loop including the inertia simulation part 12 and the compensation calculation part 13 in FIG. 4) is calculated by the microcomputer 2. The priority of the process is increased, and the interrupt priority is set so that the microcomputer 2 can be interrupted by the speed control operation in synchronization with the data confirmation signal 7b down edge except when the PIAL-B operation interrupt occurs. Moreover, the setting of the PIAL-B calculation is performed after the speed control calculation as usual.

Then, the order of processing within the speed control sampling period T is calculated according to the processing time and the priority, here, the PIAL-B calculation,
The order of (II), (I), and (III) is set, and the processing of the speed control calculation (I) is synchronized with the down edge of the data recognition signal 7b at the time other than the PIAL-B calculation interrupt.

With this setting, first, in FIG.
At t1, the microcomputer 2 is interrupted by the generation of the data confirmation signal 7b and the timer signal 6a. That is, when the timer signal 6a is generated, the timer signal 6a for the PIAL-B interrupt is simultaneously given to the microcomputer 2 in synchronization with the data confirmation signal 7b down edge output from the pulse converter 7 in FIG. Then, the microcomputer 2 enters the interruption process and executes the above-described calculation PIAL-B of the vibration suppression control of FIG. In this case, as the output signal FRH from the inertial system simulation unit 12, the value obtained by the previous speed control calculation (I) is used. still,
Initially it is zero.

Immediately after the calculation, the vibration suppression torque command value TB is output, added to the torque command value TA obtained by the previous speed control calculation (I), and given to the electric motor 4 as the torque command value TM. As a result, the electric motor 4 is torque-controlled,
Vibration suppression is controlled.

Times t2 to t3 are times when a part of the input / output mainly required for elevator control is processed. Times t3 to t4 are wait times for detecting the down edge of the data confirmation signal 7b.

Next, at the time t4, when the down edge of the data confirmation signal 7b is detected, the microcomputer 2 detects the time t4 to t5.
Normal speed control calculation is performed during. That is, the calculation for obtaining the torque command value TA in FIG. 4 is performed.

Next, from time t5 to t6, the actual speed signal FR of the elevator detected in synchronization with the data confirmation signal 7b at time t4 and the torque command value TA obtained between t4 to t5 are used to control the vibration suppression. The calculation PIAL-B is executed and the electric motor 4 is controlled as described above. t6 to t7 are the times when the input / output processing required for elevator control is performed. However, the remaining part of (II) is (II
It is processed within the calculation time of I).

After time t7, the microcomputer 2 withdraws the interrupt processing routine, and thereafter, when a new interrupt signal is input, repeats the speed control having the contents described above.

As described above, the present invention does not change the sampling period T of the normal speed control, and only the part of the control calculation PIAL-B of the vibration suppression control shows the L level of the data confirmation signal 7b indicating the time when the actual speed data of the elevator can be obtained. This is performed for each output according to the output period. Therefore, the vibration suppression control is performed with a higher frequency than other controls, so that it is possible to control so as to reduce the difference between the actual speed of the elevator and the speed that the elevator mechanical system should have at the present time. Vibration can be suppressed, and by performing this suppression correction with high frequency, a sufficient suppression effect can be obtained even for high-frequency vibration.

〔The invention's effect〕

As described above in detail, according to the present invention, since the control calculation of the vibration suppression control is performed every time the actual speed of the elevator is detected, the vibration suppression control can be performed even if the sampling cycle of the speed control system cannot be shortened. Therefore, the apparent sampling cycle is shortened. Therefore, it is possible to sufficiently suppress the high frequency vibration and to further improve the riding comfort of the elevator. It is possible to provide a method for controlling the speed of an elevator, which has effects such as

[Brief description of drawings]

FIG. 1 is a timing chart for explaining the method of the present invention, FIG. 2 is a block diagram showing a schematic configuration of an elevator speed control device by a microcomputer, and FIG. 3 is a timing for explaining the operation of a conventional device. chart,
FIG. 4 is a functional block diagram for explaining an outline of an elevator speed control system by a microcomputer. 1 ... Speed command device, 2 ... Microcomputer, 3 ...
… Motor drive device, 4 …… motor, 5 …… position detector,
6 ... Timer, 7 ... Pulse converter, 10 ... Speed control unit, 11 ... Mechanical system transmission unit, 12 ... Inertia simulation unit, 13 ... Compensation calculation unit.

Claims (1)

[Claims] 1. Various processes such as a speed control process for calculating a control output of an elevator drive system required to obtain a speed corresponding to a command for giving a target speed for elevator operation from an actual speed of the elevator, and the like. The computer is interrupted and executed at regular intervals, and the speed of the elevator is simulated from the calculated control output for obtaining the target speed, and the difference between the simulated speed and the actual speed is calculated and the difference is reduced. A vibration suppression control calculation process for obtaining a correction control amount required to perform is executed in the speed control process period, and the correction control amount calculated by the vibration suppression process is added to the control output calculated by the speed control process to drive the elevator. To control the elevator drive system and control the vibration of the elevator car during the speed control. In the elevator controller, the speed control method for an elevator, characterized in that the vibration suppression control processing was to be performed by the each of the actual speed detection period of the elevator.