JPS61101380A - Method of controlling speed of elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for controlling the speed of an elevator.

[Technical background of the invention and problems of the background art] FIG. 4 is a block diagram showing an example of elevator speed control.

In the figure, 1 is a speed command generator that generates a speed command 1a for the elevator, and 2 is an input of a speed signal 4a from a speed detector 4 for detecting the speed command 1a and the rotational speed of an electric motor 3 for driving the elevator. 10 is an elevator, and a load signal 8a from a load detection device 8 that detects the load of the car 7 is used to compensate for the unbalanced torque of the car and the counterweight 9. i! A load compensation circuit 5 outputs an i-compensation signal 10a, 5 is an output signal 2a of the speed controller 2, and a current detector 6 detects the current of the electric motor 3.
A current controller 11 inputs a current signal 6a and a load compensation signal 10a from the current controller 5, and a power converter 11 for controlling the electric machine 3 using the output signal 5a of the current controller 5. or,
12 is a sheave connected directly or via a reduction rock to the electric motor rotating shaft; 13 is a main rope connecting the car 7 and the counterweight 9 via the sheave 12; and 14 is a brake device.

FIG. 5 is a diagram showing an example of the configuration of the speed controller 2 in FIG. 4. In the same figure, 21 is an operational amplifier, 22.23.2
A resistor 4 and a capacitor 25 constitute a proportional-integral circuit. 26 is a switch for clearing the accumulation in the capacitor 25 when the control is stopped. The speed controller configured with proportional integrals as shown in FIG.
It is extremely suitable for elevator control systems that require highly accurate speed control and floor landing control.

However, in order to improve riding comfort in an elevator, there is a method in which the brake is released (brake applied) at startup, and unbalanced torque control is performed using the load compensation signal 10a, and then the brake is released. When landing on the floor, a method is used in which the electric motor 3 is controlled to a stopped state, and the control is stopped after the brake is released.

During such control when the brake is released, the capacitor 25 of the speed controller 2, which is configured by proportional integration, becomes unrelated to proper control due to the deviation of the speed command signal 1a and the deviation of the operational amplifier 21 itself. This problem may cause inappropriate torque to be generated when the brake is released at startup, or the control current may increase after the brake is released at landing.

[Purpose of the invention]

It is an object of the present invention to provide a speed control method that improves the above-mentioned problems by changing the control timing of the speed controller configured by proportional integration.

[Summary of the invention]

The present invention prevents improper integral operation by controlling the integral operation of a speed controller according to the state of the brake of an elevator brake device.

[Embodiments of the invention]

FIG. 1 shows an example of the configuration of a speed controller used to implement the method according to the present invention. This speed controller is used, for example, as speed controller 2 in the system shown in FIG. In FIG. 1, 31 to 34 are operational amplifiers, 35 to 43 are resistors, 44 is a capacitor, and 45 and 46 are switches. Operational amplifier 31゜32.34 is a proportional inverting addition circuit, 33
constitute an integrating circuit. Further, the switch 45 is opened when speed control is started to provide an integral characteristic, and closed when speed control is stopped to clear the capacitor 44. Furthermore, switch 4
6 closes in synchronization with the release of the brake to permit signal input, and opens when the brake is released to cut off the input. − First, we will explain the operation when the elevator starts.

Unbalanced torque control is started in the brake released state by the load compensation signal 10a, and then the brake is released.

In synchronization with the release of the brake, the switch 45 opens and the switch 46 closes, and at the same time a speed command is generated, a signal 1a is input, and speed control is started using proportional-integral characteristics. At the start of speed control, charging of the capacitor 44 is started from zero. Furthermore, even if unbalanced torque compensation is not performed, if the control is started at the same timing, the speed controller will act as soon as the brake is released to prevent dropping or jumping out due to the action of the proportional and integral characteristics. do.

Next, a description will be given of when the implantation stops.

In the body cylinder, high-precision landing control is performed by compensating for the error of unbalanced torque due to the integral action of the capacitor 44 of the speed controller. When the elevator is close to a complete stop, the brake is first released, and the switch 46 opens in synchronization with the brake release signal, cutting off the input to the integrator. switch 4
At the same time as the capacitor 6 is opened, the amount of charge in the capacitor 44 is fixed to the value at that time. After a further delay time, the switch 45 closes to clear the charge in the capacitor 44. Furthermore, switch 4
The discharge of the capacitor 44 due to the opening of step 5 does not need to be performed at a predetermined delay time after the release of the brake as described above, but may be performed at any time before the next time the elevator is started and therefore before the release of the brake.

Since the above operation is performed every time the vehicle is driven, it is possible to prevent the capacitor 44 from being improperly charged due to a deviation in the speed command signal 1a or the operational amplifier.

For example, during normal landing, the speed command signal 1 for landing
a becomes almost zero, the input signal to the integrator is small, and the charging voltage of the integrator 44 changes slowly. However, due to other factors, such as when the brake is released at a position where the ζth speed command signal of landing is large, that is, a position where the landing error is large, the input signal to the integrator is large, and the capacitor 44 The change in the charging voltage may be very large, and the current command value to the electric motor n3 may increase, causing the electric current to become excessively diverted.
According to the present invention, the input signal to the integrator is cut off at the same time as the brake is released, and the charging of the capacitor 44 is fixed, so an increase in current can be prevented.

The switch shown in FIG. 1 can be realized using contacts such as relays, but it can also be constructed using electronic elements such as field effect transistors.

In the example shown in FIG. 1, the switch 46 that cuts off the input signal of the integrating circuit is opened and opened U''d in synchronization with the opening and release of the brake. This can be easily obtained by using a signal synchronized with the brake operation detection switch, and the timing can be obtained reliably.

If the brake device does not have an operation detection switch, this can also be achieved using a brake release command signal.

FIG. 2 shows an example of a configuration using a logic operation circuit. 4 in the diagram
7.48 is an inversion logic operation element, four.

5o is a resistor, and 51 is a capacitor. Signal 47a synchronizes with the brake release command signal and when released ++ 1 ++
, input so that it becomes "O" when released.

The resistor 49 and the capacitor 51 are a delay circuit for generating on and off delay times, and the resistor 50 is an input limiting resistor. With this circuit, the output signal 48a operates with a delay of a delay time with respect to the input brake release command signal 47a. The switch 44 may be configured to be turned on by the output signal II I ++.

If the delay time is set so that it is the delay time from when the brake release command signal is given until the brake is actually released, or until the brake is released, the signal can be synchronized with the brake operation. I can do about 10 things.

The above explanation was based on an analog circuit using an operational amplifier, but
A similar configuration can be applied to the speed control calculation section of the digital circuit.

FIG. 3 shows a flowchart when a programmed computer is caused to perform the same function as the integrating circuit constituted by the operational amplifier 33 of FIG. 1.

As shown in the figure, by determining the integral input permission signal, it is determined whether to read a new input signal or set the input signal to zero. The integral operation is stopped by zero of the input signal, and the previous output value is fixed.

Although the elevators that perform special controls such as unbalanced torque control and stop control have been described above, they can also be applied to other applications that require similar operations.

〔Effect of the invention〕

As described above, in the present invention, in an elevator speed controller configured with proportional-integral characteristics, the input of the integral circuit can be cut off or turned on in synchronization with the elevator brake release command signal or release command signal. Accordingly, the normal operation of the integral or the fixed operation of the integral is performed. Therefore, the capacitor 44 is prevented from being improperly charged due to a deviation in the speed command signal 1a or the operational amplifier. Furthermore, when the elevator is stopped, the integral output is always cleared to zero, ensuring safe operation.

[Brief explanation of the drawing]

1 is a diagram illustrating an example of the configuration of the speed controller of the present invention, FIG. 2 is a diagram illustrating an example of a circuit for obtaining an operating signal for the switch 46 in FIG. 1, and FIG. FIG. 4 is a block diagram showing an example of elevator speed control. FIG. 5 is a diagram showing an example of the configuration of the speed controller shown in FIG. 4. 1...Speed command generation device, 2...Speed controller, 3.
...Electric motor, 4...Speed detector, 31-34...Operation amplifier, 35-43, 49.50...Resistor, 44
゜51...Capacitor, 45.46...Switch,
47°48...Logic operation element. Applicant's agent: Seiji Inomata, Figure 1, Figure 2, Figure 5, Fan

Claims (1)

[Claims] 1. In an elevator control method in which a speed signal is negatively returned, compared with a speed command value, and speed control is performed based on the comparison result, an integral element is added to the speed control calculation, A method for controlling the speed of an elevator, characterized in that when the brake of the elevator is released, the integral element stops the integral operation and the integral value is fixed. 2. The method according to claim 1, wherein release of the brake is detected by a brake operation detection switch, and based on this, the integral operation is stopped. 3. The method according to claim 1, wherein the integral operation is stopped based on a command signal instructing release of the brake. 4. The method according to claim 1, wherein the integral value is set to zero after a predetermined time has elapsed since the brake has been released and before the brake is next released. 5. The method according to claim 1, wherein the supply of the speed command value is started in synchronization with the release of the brake. 6. The method according to any one of claims 1 to 5, characterized in that the integral operation is started in synchronization with the release of the brake.