KR19980059395A - Position controller and method by position controller - Google Patents

Abstract

The present invention relates to the position control of the stacker crane (S / C), and in particular, in an automatic warehouse facility, the encoder converts the number of pulses into distance to determine the speed pattern at each edge, and also counts the pulses to control the high precision position. The present invention relates to a position control apparatus and method using a position controller adapted to a field, and includes: a PLC (10) for receiving a command for a target position from a computer and outputting the same; and a target position through the PLC (10). A position controller 20 for calculating a speed pattern and a deceleration point and outputting the speed pattern and a deceleration point to the PLC 10, and an inverter 30 for switching the speed by receiving a speed pattern command of the PLC 10; And a motor 40 driven as the inverter 30 is speed-changed, and outputs a pulse count value to the PLC 10 when the striker is turned on at a target position to control the PLC 10. Motor 40 By including the encoder 50 to stop, the present invention uses the position controller and the encoder to convert the distance into pulses and convert the pulses into distances to determine the speed, and count the points at the right position as the number of pulses to stop. By doing so, precise position control is possible, and the error does not occur because the fork is not moved out of the fork position, thereby reducing the loss of production.

Description

Position controller and method by position controller

The present invention relates to the position control of the stacker crane (S / C), and in particular, in an automatic warehouse facility, the encoder converts the number of pulses into distance to determine the speed pattern at each edge, and also counts the pulses to control the high precision position. The present invention relates to a position control apparatus and method by a position controller suitable for the field.

1 is a block diagram of a conventional position control apparatus. As shown in FIG. 1, a PLC 10 for precomputing a low-speed switching stage by receiving a command from a control panel and a speed control signal of the PLC 10 are illustrated. Inverter 20 for adjusting the speed received by the input, and the motor 30 is controlled to drive speed in accordance with the speed control of the inverter 20, the operation thereof will be described with reference to FIG.

When a command is issued to the programmable logic controller (PLC) 10 from the operation panel, the PLC 10 calculates the low-speed switching year in advance and keeps it in the correct position, and the PLC 10 of the inverter 20 The speed is controlled to the exact position. At this time, since it is stopped by the timer, reliability cannot be secured at the exact position.

In addition, when the sensor is turned on by the striker, it is fixed by the timer. At this time, the stop degree of each edge is different and it is fixed by using two sensors. If the equipment is used for a long time, it will be overrun and difficult to use in the place requiring precise position control of the equipment. In addition, there will be a difference in the position to stop when moving forward and backward, resulting in unstable storage of cargo. It is difficult to plan.

As described above, in the conventional position control device, since the position is fixed by the timer when the sensor is turned on by the striker, the stop degree of each edge is different and the position is fixed by using two sensors. fork) If the equipment is out of position during operation and the equipment is used for a long time, it is overrun and difficult to use in the place requiring precise position control of the equipment. And, due to this there was a problem that the stabilization and productivity of the facility is reduced.

Accordingly, an object of the present invention is to determine the speed by converting the distance into pulses and converting the pulses into distances using position controllers and encoders, and counting the points at the exact positions as the number of pulses to stop the precise position control. Solves the problem.

As a specific means of the present invention for achieving the above object, a position controller receives a command for a target position through a sequencer, calculates a speed pattern and a deceleration point, and outputs it to the sequencer, wherein the sequencer is an inverter with a speed pattern command. By controlling the drive of the motor by adjusting the speed of

1 is a block diagram of a conventional position control apparatus.

2 is a waveform diagram of a conventional position control.

3 is a block diagram of a position control apparatus according to the position controller of the present invention.

4 is a waveform diagram of position control by the position controller of the present invention;

Figure 5 is a signal flow diagram of a position control method by the position controller of the present invention.

* Explanation of symbols for main parts of the drawings

10: PLC 10A: Sequence

20: position controller 30: inverter

40: motor 50: encoder

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram of a position control apparatus according to the position controller of the present invention. As shown in FIG. 3, a PLC 10 for receiving a command for a target position from a computer and outputting the command is outputted to the target position through the PLC 10. A position controller 20 for calculating a speed pattern and a deceleration point and outputting the speed pattern and a deceleration point to the PLC 10, and an inverter 30 for switching the speed by receiving a speed pattern command of the PLC 10; And a motor 40 driven as the inverter 30 is speed-changed, and outputs a pulse count value to the PLC 10 when the striker is turned on at a target position to control the PLC 10. It is configured to include an encoder 50 for stopping the motor 40, the operation and effect thereof will be described with reference to FIG.

When the command for the target position is transmitted to the sequencer 10A of the PLC 10 in the computer not shown, and the position controller 20 is inquired of the target position, the position controller 20 determines the velocity pattern ( pattern) and the deceleration point are calculated to give information to the sequencer 10A, and the sequencer 10A drives the motor 40 through the inverter 30.

Also, when the striker is turned on at the target position, the sequencer 10A directly receives the count value from the encoder 50 and stops the position controller 20. The position controller 20 stops the bank data, There is a parameter of exact position range (YYC) and destination point (DP) data to determine the velocity pattern of the target position, and information about each position by YYC (exact position range) shown in (b) of FIG. The DP shown in (C) is output at the end of the final purpose, and the sequencer 10A is directly input to stop the pulse value after the exact striker is turned on.

Therefore, when the position controller 20 calculates the speed pattern and the deceleration point and outputs it to the PLC 10, the drive is controlled by controlling the speed through the inverter 30, and when the striker is turned on, the encoder ( 50 outputs a pulse count value to the sequence 10A of the PLC 10 to stop driving of the motor.

5 is a signal flow diagram of a position control method according to the position controller of the present invention, in which a PLC receives a command command of a computer and counts YYC (correct position range) (S1-S2), wherein If the pulse value is 20, DP (Destination Point) is generated by the position controller, and the position sensor is turned on by the PLC (S3-S5), and the speed pulse is counted by the PLC to stop the motor. It consists of the steps (S6-S7).

As described in detail above, the present invention uses a position controller and an encoder to convert distances into pulses, convert pulses into distances, determine speed, and precisely control position by counting and stopping points at the exact positions as pulses. It does not occur during the fork operation in the home position, so that no error occurs, thereby reducing the loss of production.

Claims (4)

The PLC 10 receives a command for a target position from a computer and outputs it, and receives a command for the target position through the PLC 10 to calculate a speed pattern and a deceleration point, and output the same to the PLC 10. A position controller 20, an inverter 30 for switching speed by receiving the speed pattern command of the PLC 10, a motor 40 driven as the inverter 30 is speed switched, and a target position. And a encoder 50 which outputs a pulse count value to the PLC 10 when the striker is on and stops the motor 40 under the control of the PLC 10. Position control device. The position control apparatus of claim 1, wherein the inverter (30) switches speed to high speed, medium speed, low speed, and watch speed. The position controller according to claim 1, wherein the position controller (20) generates a DP (Destination Point) only at a final destination position and controls the vehicle to enter the watch mode. When the PLC receives a command command of the computer and counts YYC (fixed position range) (S1-S2), if the pulse value of the YYC is 20, a DP (Destination Point) is generated by the position controller. The position sensor is turned on by the PLC (S3-S5), and the speed-controlled pulse is counted by the PLC to stop the motor (S6-S7). Position control method.