JPH04165503A - Method and device for controlling driving device - Google Patents

Abstract

PURPOSE:To prevent the runaway of a driving device even in the case the connection of a detector is mistaken by comparing the driving direction derived, based on a detecting signal with the driving direction given by a driving signal, and inverting the phase of the detecting signal, when both of them are different. CONSTITUTION:When the driving of a servomotor 50 is started, a connection discriminator 24 interrupts tentatively a servo-loop and inspects the connection state of an encoder 52. In the case the connection is erroneous, a phase inverting signal 'H' is outputted and a phase inverter 22 is allowed to invert the phase of a detecting signal of the encoder 52, the wiring is corrected as a software, and the control can be executed in the same way as the connection is executed normally. In such a manner, even if the connection of the encoder 52 is erroneous, of such an accident as a servomotor 50 runs away and a mechanical system is damaged can be prevented, and also, the servomotor 50 can be controlled normally without executing the wiring once again.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for controlling a drive device that digitally controls and drives a servo motor or the like.

[Prior Art] Speed motors are widely used as drive sources for robots and various types of automatic Ia gates. Control of such robots and automatic machines generally involves detecting the speed and position of the controlled object, feeding back these detected values to the operating unit including the servo motor, and modifying the amount of operation, that is, the drive of the servo motor. I have to. When performing feedback control, an encoder is attached to the servo motor to output a pair of detection signals with a 90 degree phase difference, and the rotation speed, rotation amount, and rotation direction of the servo motor are detected and the control target is detected. I am trying to find the speed and position.

[Problem to be Solved by the Invention] However, if the encoder is incorrectly connected to the control unit, the two feeder signals (signals A and B) output from the encoder that are 90 degrees different in phase may be mistakenly sent to the control unit. When an appropriate drive command is given, the servo motor runs out of control until the controlled object reaches the end of its stroke, causing damage to the mechanical system. In order to prevent such runaway of the servo motor, it is necessary to thoroughly check the wiring condition when connecting the encoder, and if the wiring is incorrect, the wiring must be rewired.

The present invention has been made in order to eliminate the drawbacks of the prior art, and aims to provide a method and device for controlling a drive device that prevents the drive device from running out of control even if the wiring of the detector is incorrect. The purpose is

[Means to solve the problem]

In order to achieve the above object, a method for controlling a drive device according to the present invention detects a signal indicating the drive state of the drive device, and controls the drive device by feedbanking this detection signal to a drive signal applied to the drive device. In the method, the drive direction of the drive device is determined based on the detection signal, the drive direction is compared with the drive direction given by the drive signal, and when the two differ, the phase of the detection signal is inverted. , the drive direction of the drive device determined based on the detection signal is made to match the drive direction given by the drive signal.

The phase of the detection signal may be inverted by cutting off the feed-hack of the detection signal to the drive signal when the drive device starts driving, and driving the drive device for a predetermined time or by a predetermined amount.

Further, the control device for a drive device according to the present invention includes a drive detector that detects a drive state of the drive device and outputs a pair of detection signals having a phase difference, and a drive detector that outputs a pair of detection signals that are output from the drive detector. a direction discriminator that determines and outputs the drive direction of the drive device based on the direction discriminator; a phase inverter that inverts the phase of the pair of detection signals input to the direction discriminator; The drive direction of the drive device and the drive direction given to the drive device are compared to determine whether the connection of the drive detector is correct or incorrect, and if the connection of the drive detector is incorrect, a phase inversion signal is sent to the phase inverter. and a connection discriminator that inverts the phase of the pair of detection signals input to the direction discriminator.

[Effect]

In the present invention configured as described above, when the drive direction of the drive device obtained by the detection signal fed to the operation section is opposite to the drive direction caused by the drive signal given to the drive device, the detection signal is The phase of the detection signal is inverted, assuming that the output detector is incorrectly wired. This allows you to modify the wiring using software without having to rewire the wiring.
The drive direction obtained from the detection signal and the drive direction instructed by the drive signal can be matched, and runaway of the drive device can be prevented and damage to the mechanical system can be avoided.

In addition, when inverting the detection signal, the drive unit! By cutting off the feedback of the detection signal to the drive signal at the start of driving, not only can incorrect wiring be corrected more safely, but also the i-color range of malfunction can be made smaller.

〔Example〕

A preferred embodiment of the control method and control device for a drive device according to the present invention will be described in detail according to the attached concavity.

FIG. 1 is a block diagram of a control device that controls a drive device according to an embodiment of the present invention.

The control device 10 includes an adder 12 into which a signal of a target position 1 of a controlled object (not shown) is input, and a position error amplifier 14 connected to the output side of the adder 12. Then, the position error amplifier 14 amplifies the deviation between the target position of the controlled object outputted by the adder 12 and the detected actual position, and outputs a pulse or analog speed command to the servo amplifier 40.

The control device 10 also includes an amplifier down counter 18 connected to the adder 12 via a switch 16, and a direction discriminator 20 connected to the input side of the up/down counter 18.
, a phase inverter 22 that receives the output signal of the encoder 52 and outputs a signal to the direction discriminator 20, and a connection discriminator 24. The connection discriminator 24 opens and closes the switch 16, and receives the target position signal and the output signal of the up/down counter 18.Based on these signals, the encoder 52
A phase inversion signal for inverting the phase of the signal outputted by is sent to the phase inverter 22.

As shown in FIG. 2, the phase inverter 22 consists of an exclusive OR circuit, and receives the signal A output from the encoder 52 to one input terminal of the exclusive OR circuit.
, B (pulse 1), and the phase inverted signal output from the connection discriminator 24 is input to the other input terminal.

The output side of the exclude-OR circuit is connected to the input pin of the latch circuit 2B constituting the direction discriminator 20.

On the other hand, the other signal (pulse 2) output from the encoder 52 is input to the D2 input of the latch circuit 28. Further, the output signal of the Q4 output bin of the latch circuit 28 is input to the D3 input of the latch circuit 28, and the output signal of the Q2 output bin is input to the D1 input of the latch circuit 28. ing. Therefore, the latch circuit 28 outputs the input states of the D1 to D4 person bins at that time to the corresponding Q and -Q4 output bins according to the rising edge of the input clock pulse, and then maintains this state, so that the Q2 output bin is The D1 input pin, which takes the output as an input, receives the contents of the D2 input pin one clock earlier, and similarly, the contents of the D1 input pin one clock earlier are input to the D1 input pin. Therefore, when the latch circuit 28 is latched by the rising edge of the clock pulse, the content of the input bin is outputted to the output bin Q by one clock, and the content of the input bin D at the time of latching is output to the output bin Q2. is output, and the contents of the D4 input pin one clonk before are output to the Q output bin, and the contents of the D4 input pin at the time of latching are output to the Q output bin.

The direction determiner 20 includes a latch circuit 28 and a decoding circuit 30.
and two NAND circuits 32 and 34.

The decoding circuit 30 has the Q, , Q2, QU, and Q4 output bins of the latch circuit 28 connected to the A, B, C, and D input pins, and determines the state of these output bins (H"° or " A count amplifier signal or a countdown signal is output to the up/down counter 18 in accordance with the up/down counter 18. In other words, the 1.8.7.14 output bin of the decoding circuit 30 outputs a pulse that causes the up/down counter 8 to count and amplify. The input side of a NAND circuit 32 that outputs is connected to the 4.2.13.11 output pin, and the input end of a NAND circuit 34 that outputs a pulse that causes the up/down counter 18 to count down is connected to the 4.2.13.11 output pin. In synchronization with the input clock pulse, a pulse is output from one of the output bins connected to the NAND circuits 32 and 34 depending on the input state of the A-D input pin.

The servo amplifier 40 that receives the speed command from the position error amplifier 14 calculates the rotational speed of the servo motor 50 from the adder 42 to which the output signal of the position error amplifier 14 is input and the output signal of the encoder 52 and inputs it to the adder 42. It consists of a rotational speed calculator 46 and a speed deviation amplifier 44 that amplifies the output of the adder 42. And servo amplifier 4
The output of 0, that is, the output of the speed deviation amplifier 44, is given to a servo motor 50 as a driving device constituting the operating section.

An encoder 52 is attached to the servo motor 50. In response to the rotation of the servo motor 50, the encoder 52 outputs detection signals A and B consisting of a pair of rectangular pulses that are 90 degrees out of phase and indicate the driving state of the servo motor 50.

Incidentally, as shown by the broken line in FIG.
4 may be detected by the encoder 52.

The operation of the embodiment configured as described above is as follows.

In the description of the embodiment, it is assumed that when the servo motor 50 rotates in the forward direction, the encoder 52 outputs a detection signal in which the signal A leads the signal B in phase as shown in FIG. 4(A). . When the connection of the encoder 52 is normal, when the servo motor 50 rotates forward, the signal A is input to the exclusive OR circuit which is the phase inversion H22, and the Dt input pin of the launch circuit 28 of the direction discriminator 20 is input. At the same time, the direction discriminator 20 causes the amplifier down counter J8 to count and amplify when the signal input to the D4 input of the launch circuit 28 is ahead of the signal input to the D2 input. A pulse is output, and when the signal input to the D2 input is ahead of the signal input to the D4 input, a signal is output to cause the amplifier down counter 18 to count down.

When the control device 10 receives, for example, a drive command to rotate the servo motor 50 forward (rotation in the direction in which the amplifier down counter 18 counts and amps) from an input device (not shown), the connection discriminator 24 turns off the switch 16. The servo loop is cut off and the phase inversion signal "L"° is sent to the exclusive OR circuit which is the phase inversion 522 (step 60.61 in FIG. 3).
0 indicates a position command that does not cause the servo motor 50 to run out of control even if the encoder 52 is incorrectly connected (for example, the count value of the amplifier down counter 18 is +50).
) is applied to the position error amplifier 14 (step 62).

The position error amplifier 14 inputs a speed command signal consisting of a pulse signal corresponding to the given position to the speed error amplifier 44 via the adder 42 of the servo amplifier 40. The speed deviation amplifier 44 amplifies the input speed command signal and supplies it to the servo motor 50 to drive it.

When the servo motor 50 rotates, the encoder 52 detects the rotation and outputs a pair of pulse signals A and B having a phase difference of 90 degrees, as shown in FIG. The signal is sent to the phase inverter 22. Further, the rotation speed calculator 46 of the servo amplifier 40 calculates the rotation speed of the servo motor 50 from the signals A and B output from the encoder 52 and sends it to the adder 42 . The adder 42 calculates the difference between the speed command given from the position deviation amplifier 14 and the actual rotation speed of the servo motor 50 calculated by the rotation speed calculator 46, and sends the difference to the speed deviation amplifier 44. Then, the speed deviation amplifier 44 drives the servo motor 50 based on the output signal of the adder 42 so that the rotation speed of the servo motor 50 becomes the speed of the speed command output from the position deviation amplifier 14.

On the other hand, phase inverter (exclusive OR circuit) 22
, one of the signals A and B output from the encoder 52 is input to one input terminal, and the direction discriminator 200 launch circuit 2
8 D2 input pin The other person inputs. Since the exclusive-OR circuit 22 receives the phase inverted signal "°L°" output from the connection discriminator 24 at the other input terminal, the pulse I (signal A, B ), it outputs a signal with the same phase as pulse 1 to the sub-circuit 28. In other words, the exclusive-knob OR circuit 22 is configured so that the pulse 1 is "L".
”, it outputs “L”’ and “Ho”.

When this happens, °゛H'' is output.

As mentioned above, the latch circuit 28 has a
The contents of the Dz input pin before the clock are Q, the contents of the D2 input pin when latched to the output pin are Q, the contents of the Dz input pin are 1 clock ahead of the output pin, and the contents of the input pin are Q, and the contents of the input pin are Q when the output pin is latched. The contents of the D4 person input are output. Therefore, the launch circuit 28 is connected to D4, which is the input port 1 of the direction discriminator 20.
The encoder pulse 1 inputted to the human input terminal via the exclusive OR circuit 22 is converted from the encoder pulse 2 inputted to the input port D2, which is the input port 2 of the direction discriminator 20, as shown in FIG. If the phase is delayed by 90 degrees from the phase shown, the output states of the Q and -Q4 output pins will be as shown in the figure when latched by the clock pulse.

When the output of the latch circuit 28 is input to the A-D input bin, the decoding circuit 30 of the direction determining device 20 selects an output bin to output a pulse in accordance with the input state of each input bin. That is, the decoding circuit 30 examines the input state of each input bin with the A input bin as the least significant bit and the D input bin as the most significant bit. If it is like this, output the pulse from the 13 output bin. This results in N
The AND circuit 34 outputs a countdown pulse to the up/down counter 18 as shown in FIG. 4(B).

Hereinafter, in the same manner, the direction determination B20 is performed by the child circuit 28.
D2. When the input state of the D4 input terminal is as shown in FIG. 6, a countdown pulse is output to the up/down counter 18 as shown in FIG. 4(B).

On the other hand, the connection discriminator 24 monitors the counting state of the amplifier down counter 18, and when the amplifier down counter I8 counts down, it determines that the connection of the encoder 52 is wrong, and the exclusive・Output the phase inversion signal "H" to the OR circuit (Step 3.64 in Figure 3) and return to step 62.

When the exclusive OR circuit 22 receives the phase inversion signal "H" from the connection discriminator 24, the exclusive OR circuit 22 inverts the phase of the encoder pulse 1 input to the other input terminal and outputs the D4 input terminal of the latch circuit 28. Therefore, the signal input to the input port 1 or input bin of the direction determination circuit 20 is a signal with the phase of encoder pulse 1 inverted, and the signal input to the input port 2, D2 input bin, is a signal with the phase of encoder pulse 1 inverted. The phase is 90 degrees ahead of that of pulse 2. That is, the state of the signal input to the input bin of the latch circuit 28, which is the input port 1.2 of the direction determination circuit 20, becomes as shown in the upper part of FIG.
is connected normally, and the output states of the Q1 to Q4 output bins become as shown in the figure.

As a result, the direction discriminator 20 uses the lever 1' times #! 30 is
(2) A pulse is output from one of the 8.7.14 output pins, and the NAND circuit 32 outputs a count-up pulse to the up-down counter 18 as shown in FIG. 4(C). Therefore, the connection determination 2g24 determines that the connection is OK when the up/down counter 18 counts up.Pro 3.65)
Close the switch 16 and connect the servo loop. Then, the control device IO inputs the output of the X adder 12 to the position error amplifier I4, and shifts to a normal control state.

In addition, when the connection of the encoder 52 is normal, and the connection discriminator 24 is outputting the phase inverted signal "L", the input ports 1 and 2 of the direction discriminator 20 are connected as shown in FIG. 4(D). A signal like this is input, and the NAN of the direction discriminator 20
The D recovery 32 outputs a count up signal. Therefore, the connection discriminator 24 determines that the connection of the encoder 52 is normal, closes the switch I6, connects the servo loop, and shifts to the normal control state.

As described above, in the embodiment, the connection discriminator 24 temporarily interrupts the servo loop to inspect the connection state of the encoder 52 when the servo motor 50 starts driving, and if the connection is incorrect, performs phase inversion. A signal "H" is output to invert the phase of the detection signal of the encoder 52 to the phase inverter 22, and the wiring is corrected using software so that it can be controlled in the same way as if it were normally connected. . Therefore, in the embodiment, even if the encoder 52 is incorrectly connected, it is possible to prevent the servo motor 50 from running out of control and causing damage to the mechanical system, and moreover, the servo motor 50 can be connected without rewiring. Can be controlled normally. Furthermore, in the embodiment, since the servo roof is temporarily shut off when the servo motor 50 starts driving and the wiring state is inspected, even if the wiring is incorrect, the range of malfunction of the servo motor 50 is small. Miswiring can be corrected more safely using software.

In addition, in FIG. 1, when the position error amplifier 14 outputs an analog speed command, when the servo motor 50 starts driving, the connection discriminator 24 turns off the switch I6 and, for example, sets the servo motor 50 to 3. A predetermined low speed command that moves the controlled object by 1 mm is outputted to the position deviation amplifier 14 by supplying current, while the connection discriminator 24 checks the increase or decrease in the count value of the up/down counter 18 and outputs it to the encoder. 52 is judged to be good or bad.

Further, in the embodiment described above, the case where the rotation speed of the servo motor 50 is determined by inputting the detection signal of the encoder 52 to the rotation speed calculator 46 was explained. - The output signal of the 54 may be input to the adder 42. Further, in the above embodiment, the case where the drive device is the servo motor 5o has been described, but the drive device may be a hydraulic cylinder or the like. In the embodiment described above, the encoder 52 is used as a detector to detect the driving state of the servo motor 50. An inducton, differential transformer, etc. may also be used.

The fifth time is a bronc diagram of another example.

In FIG. 5, the control device 10 is provided with a switch 16 between the addition 112 and the amplifier down counter 18, which is opened and closed by the connection discriminator 24, as in the previous embodiment. In addition, the control device W10 includes a position error amplifier 1.
4, a speed deviation amplifier 72 connected to the output side of the adder 70, and a differential calculator 74 that differentiates the count value of the up/down counter 1B to obtain the rotational speed of the servo motor 50. , this micromolecule J calculator 7
4 and a switch 76 provided between the up/down counter 18.

Speed deviation amplifier 72 outputs a current command signal to f-flow amplifier 80 as an output signal of control device 10 . The current amplifier 8o amplifies the output signal of the speed deviation amplifier 72, supplies the commanded current to the servo motor 5o, and drives the servo motor 5o. Note that, like the switch 16, the switch 76 is opened and closed by the connection discriminator 24 when the servo motor 50 starts driving.

In the embodiment configured in this way, as in the previous embodiment, when the servo motor 50 starts driving, the connection discriminator 2
4 turns off the switch 16.76 to interrupt the servo loop, and the speed deviation amplifier 72 supplies the current amplifier 80 with a predetermined voltage/A.
(Torque) command is given for a predetermined period of time (for example, 0.5 seconds), during which time the connection discriminator 24 changes the increase/decrease in the up/down counter 18 to detect the connection state of the encoder 52. Perform similar processing. Further, in this embodiment, since the feedback signal for determining the speed deviation is also cut off when the servo motor 5o is driven, safer control with a positive value can be achieved.

〔Effect of the invention〕

As explained above, according to the present invention, when the drive direction of the drive device obtained by the detection signal feed-hacked to the operation unit is opposite to the drive direction by the drive signal given to the drive device, the detection In order to invert the phase of the detection signal by assuming that the connection of the detector that outputs the signal is incorrectly wired, the drive direction obtained from the detection signal and the drive direction instructed by the drive signal will be lost without rewiring. This can prevent the drive device from running out of control and cause damage to the i-mechanical system.9 When inverting the detection signal, when the drive device starts driving, By cutting off the feedback, not only can incorrect wiring be corrected more safely using software, but also the range of malfunction can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control device for controlling a drive device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing details of the direction discriminator and phase inverter of the embodiment, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a timing chart explaining the operation of the embodiment, FIG. 5 is a block diagram of another embodiment, and FIGS. 6 and 7 are latch circuits of the direction discriminator according to the embodiment. FIG. 3 is a diagram showing the relationship between input and output. 10 Control device, 16.76-Switch, 1st Amplifier down counter, 20 One-way discriminator, 22 = Phase inverter, 24- Connection discriminator 40 Servo amplifier,
50 --m- drive device (servo motor), 52 ---
Drive detector (encoder).

Claims (3)

[Claims] (1) In a method for controlling a drive device in which a signal indicating a drive state of the drive device is detected and this detection signal is fed back to a drive signal given to the drive device, the drive direction of the drive device is determined based on the detection signal. , this drive direction is compared with the drive direction given by the drive signal, and when the two differ, the phase of the detection signal is inverted, and the drive direction of the drive device determined based on the detection signal is determined by the drive direction. A method for controlling a drive device, characterized in that the drive direction is made to coincide with a drive direction given by a signal. (2) The inversion of the phase of the detection signal cuts off the feedback of the detection signal to the drive signal when the drive device starts driving, and drives the drive device for a predetermined time or by a predetermined amount. 2. The method of controlling a drive device according to claim 1, wherein the method is performed by: (3) a drive detector that detects the drive state of the drive device and outputs a pair of detection signals having a phase difference; and a drive direction of the drive device based on the pair of detection signals output by this drive detector. a direction discriminator that determines and outputs the direction discriminator, a phase inverter that inverts the phase of the pair of detection signals input to the direction discriminator, and a drive direction of the drive device determined by the direction discriminator and a direction that is applied to the drive device. determine whether the connection of the drive detector is correct or incorrect by comparing the drive direction with the drive direction determined, and if the connection of the drive detector is incorrect, provide a phase inversion signal to the phase inverter and input it to the direction discriminator. A control device for a drive device, comprising: a connection discriminator that inverts the phases of the pair of detection signals.