JPH0549593B2 - - Google Patents

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 in the background art]

FIG. 4 is a block diagram showing an example of elevator speed control.

In the same figure, 1 is the elevator speed command 1a
2 is a speed command generator that generates a speed command 1a.
and a speed controller which inputs a speed signal 4a from a speed detector 4 for detecting the rotational speed of the elevator driving electric motor 3; 10 is an elevator car 7;
A load compensation signal 10a for compensating for the unbalanced torque of the car and the counterweight 9 based on the load signal 8a from the load detection device 8 that detects the live load of the car.
A load compensation circuit 5 outputs an output signal 2a of the speed controller 2, a current signal 6a from a current detector 6 that detects the current of the motor 3, and a load compensation signal 10.
11 is a power conversion device for controlling the electric motor 3 using the output signal 5a of the current controller 5. Further, 12 is a sheave connected directly to the electric motor rotating shaft or via a speed reducer, 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 figure, 21 is an operational amplifier;
22, 23, and 24 are resistors, and 25 is a capacitor, which 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 integral 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 ensure safety and improve ride comfort in elevators, unbalanced torque control is performed using the load compensation signal 10a with the brakes released (brakes applied) at startup. There are two methods: one is to control the electric motor 3 until it is stopped when the passenger lands on the floor, and then the control is stopped after the brake is released. Especially at the time of implantation,
Control continues until a certain delay time elapses after the brake is released.
This is because if the timing of stopping the control is earlier than the timing of releasing the brake, there is a risk that the car may fall.

While such control is being performed after the brake is released, if theoretically completely appropriate control is performed, the capacitor 25 of the speed controller 2 will not be charged. However, in real control systems, errors always exist. For example, there is always a deviation in the speed command signal 1a, and there is also a deviation in the operational amplifier 21 itself. Therefore, the capacitor 25 is charged while the control is being performed after the brake is released. As a result, the control current flowing through the electric motor 3 increases even though the car is stopped, causing problems such as damage to elements and generation of noise from the electric motor 3.

[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
For example, it is used as the 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,
45 and 46 are switches. operational amplifier 31,
32 and 34 constitute proportional inverting and adding circuits, and 33 constitutes an integrating circuit, respectively. Further, the switch 45 is opened when speed control is started to obtain an integral characteristic, and is closed when speed control is stopped to clear the capacitor 44. Furthermore, the switch 46 closes in synchronization with the release of the brake to permit input of a signal, and opens when the brake is released to cut off the input.

First, the operation when the elevator starts will be explained. 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, switch 45 opens and switch 46 closes, and at the same time a speed command is generated, 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 control is started at the same timing, the suspension will drop due to the action of proportional and integral characteristics at the same time as the brake is released.
A speed controller acts to prevent ejection.

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

At the time of landing, the capacitor 44 of the speed controller performs an integral action to perform highly accurate landing control while compensating for the error of unbalanced torque. The brake is first released when the elevator is close to a complete stop, and the switch 46 opens in synchronization with the brake release signal to cut off the input to the integrator. As soon as the switch 46 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 and the charge in the capacitor 44 is cleared. Furthermore, the discharge of the capacitor 44 due to the closing of the switch 45 is as follows.
Even if there is no predetermined delay time after the brake is released as described above, before the elevator is started next time,
Therefore, it can be done at any time before the brake is released.

Since the above operation is performed every time the operation is performed, the capacitor 44 is
can be prevented from being charged inappropriately.

For example, during normal landing, the speed command signal 1a for landing on the floor is almost zero, and the input signal to the integrator is small, and the change in the charging voltage of the capacitor 44 is gradual. However, due to other factors, such as when the brake is released at a position where the speed command signal for landing is large, that is, at a position where the landing error is large, the input signal to the integrator is large, so the capacitor 44 In some cases, the change in the charging voltage of The input signal to the capacitor 44 is cut off.
Since the charge is fixed, an increase in current can be prevented. This can prevent damage to the elements and generation of noise from the motor 3.

The switch shown in FIG. 1 can be implemented 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 to the integral circuit is opened and closed in synchronization with the release and release of the brake, but this signal can be transmitted, for example, to the brake operation provided in the brake device. This can be easily obtained by using a signal synchronized with the detection switch, and the timing can be obtained reliably.

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

FIG. 2 shows an example of a configuration using a logic operation circuit. In the figure, 47 and 48 are inverted logic operation elements, 4
9 and 50 are resistors, and 51 is a capacitor. The signal 47a is input in synchronization with the brake release command signal so that it becomes "1" when the brake is released and becomes "0" when it is 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 "1". To set the delay time,
If the delay time from when the brake release command signal is applied until the brake is actually released, or the delay time until the brake is released, a signal synchronized with the brake operation can be obtained.

Although the analog circuit using an operational amplifier has been described above, a similar configuration can be applied to a speed control calculation section of a 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 is cut off or made conductive in synchronization with the elevator brake release detection signal or release command signal. Performs normal integral operation or fixed integral operation. Therefore, the capacitor 44 is prevented from being improperly charged due to a deviation in the speed command signal 1a or the operational amplifier, and damage to the element and generation of noise from the motor can be prevented. Furthermore, when the elevator is stopped, the integral output is cleared to zero, allowing safe operation.

[Brief explanation of the drawing]

1 is a diagram showing an example of the configuration of the speed controller of the present invention, FIG. 2 is a diagram showing an example of a circuit for obtaining an operating signal of the switch 46 in FIG. 1, and FIG. FIG. 4 is a flowchart showing the operation of digitally calculating the integrating circuit section, FIG. 4 is a block diagram showing an example of elevator speed control, and FIG. 5 is a diagram showing an example of the configuration of the speed controller shown in FIG. 4. 1...Speed command generator, 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.

Claims (1)

[Claims] 1. In an elevator control method in which a speed signal is negatively fed back, 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, and an elevator control method is provided. When the brake is released, the integral element stops the integral operation and the integral value is fixed, and the integral value becomes zero after a predetermined time has elapsed since the elevator brake is released and before the next brake is released. Elevator speed control method. 2. The method according to claim 1, wherein release of the brake is detected by a brake operation detection switch, and the integral operation is stopped based on this. 3. The method according to claim 1, characterized in that the integral operation is stopped based on a command signal instructing release of the brake. 4. The method according to claim 1, wherein the supply of the speed command value is started in synchronization with the release of the brake. 5. Claims 1 to 5 are characterized in that the integral operation is started in synchronization with the release of the brake.
The method described in any of Section 4.