JP2629784B2 - Synchronous control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous control device for synchronously operating two machines driven by an induction motor via an inverter device or the like.

[Conventional technology]

2. Description of the Related Art As a conventional synchronous control device of this type, a synchronous control device illustrated in a control block diagram of FIG. 2 is known. FIG. 3 shows the second
It is an output waveform of a synchro electric machine in a figure, and a relative positional relationship diagram. In FIG. 2, 1a and 1b are machines that are driven by the induction motors 2a and 2b and are driven synchronously, respectively.
In the case shown, 1a is the preceding machine 1b is the follower. Reference numerals 20a and 20b denote synchronous electric machines which are coupled to the machines 1a and 1b and are driven to rotate. In the illustrated case, 20a is a transmitter 20b and a receiver, and is a pair with each other. A sinusoidal voltage corresponding to the difference in the relative angle between the stator and rotor of each of the transmitting and receiving units is output to the stator side of the receiver 20b. Reference numeral 21 denotes a displacement detection circuit that receives the sine wave output voltage and determines the magnitude and polarity of the rotation angle difference between the rotors of the transmitter and the receiver. Reference numeral 22 denotes a motor drive circuit that receives the output of the detection circuit and controls the acceleration / deceleration of the follower motor 2b so that the rotation angle difference between the two rotors becomes zero. FIG. 3 (a) shows the waveform of the sine wave output voltage, and FIG. 3 (b) corresponds to the horizontal axis phase angle of the output voltage, that is, the rotation angle difference, based on the transmitter rotor position. 3 shows the relative relationship of the receiver rotor position in the case.

[Problems to be solved by the invention]

However, in the above-mentioned conventional system, the output voltage of the sync receiver for detecting the positional deviation between the preceding and following devices changes in a sine wave shape, and the phase angle θ of the sine wave is 2π (ra).
d) It is not possible to discriminate the position deviation corresponding to the above and below, and therefore, it is necessary to provide an n detecting means for discriminating sin θ and sin (2πn + θ) for the integer n, or to perform an operation that always satisfies 0 ≦ θ <2π. Become. For this reason, simultaneous operation after the starting points of both the preceding and following machines have been started, the operation of the two machines and their respective synchro electric machines, such as the coupling of origin coincidence, has been complicated, and the control circuit has been complicated. In view of this, the present invention
It is an object of the present invention to provide a synchronous control device that solves the above-mentioned problems by counting the output pulses of a rotary encoder.

[Means for solving the problem]

In order to achieve the above and other objects, the present invention provides a synchronous control of two machines driven by an induction motor, wherein one of the two machines is a preceding machine and the other is a follow-up machine for the preceding machine to perform a follow-up synchronous operation. In the apparatus, two-phase pulse signals of A-phase and B-phase which are respectively coupled to the two machines and rotate and have a phase difference of 90 degrees, and an origin signal of one pulse for each rotation thereof, that is, a Z-phase signal And two sets of frequency multiplication direction discriminating circuits for outputting a quadruple frequency pulse signal of the signal from the two-phase pulse signals of both encoders and discriminating the rotation direction of each encoder, Two sets of speed detection circuits for calculating the rotational speed of the encoder from the A-phase or B-phase pulse signals of each of the encoders; the Z-phase pulse signals of the two encoders; A phase difference detection circuit that calculates an origin phase difference angle between the two encoders at the time of starting the synchronization control for the follower with the quadruple frequency pulse signal corresponding to the encoder; and a phase difference angle between the origins at the time when the synchronization is completed. A phase difference setting circuit for providing a set value; an angle adjustment circuit for calculating an output difference between the phase difference detection circuit and the setting circuit; and a difference between integrated values of the quadruple frequency pulse signals corresponding to the encoders. And a difference counter circuit for subtracting the integrated value difference from the output value of the angle adjustment circuit, a first adder / subtractor for calculating the output difference between the two speed detection circuits, and a speed detection circuit of the preceding machine. Calculates the sum of the speed detection value of the preceding machine output, the position deviation of both preceding tracking machines output by the deviation counter circuit, and the difference between the speed detection values of both machines output by the first adder / subtractor. A second adder / subtractor is provided, and an output of the second adder / subtractor is used as a set speed signal of the induction motor of the follower.

[Action]

Generally, in the synchronous operation of two machines, it is necessary to equalize the speed between the moving parts to be synchronized of the two machines and to match the required specific positions in the two moving parts. Therefore, if the two machines are ordered in the order of the preceding machine and the following machine to be synchronized with the preceding machine, the synchronous control of the two machines will be performed at the same speed as the preceding machine by appropriate acceleration / deceleration control for the following machine. Control to make the deviation between the required specific positions of the preceding and following aircraft zero.
The type of control will be included. The present invention is directed to a case where the drive sources of the two machines are induction motors, and the two motors are each controlled at a variable speed by an inverter to perform synchronous control. Tracking control of both the speed and the position of the following machine with respect to the preceding machine as the sum of the detected speed of the machine, the difference between the detected speeds of the preceding machines and the deviation between the required specific positions of the two machines. Is performed so that both the speed difference term and the position deviation term at the speed set value are set to zero. The speed difference term and the position deviation term are respectively applied to the inverter via a proportional / integral (PI) adjuster so as to be input to the motor speed control system with optimal time characteristics. Here, the position deviation term is a position tracking with respect to the reference position deviation which increases the temporal integration value according to the difference between the reference positions of the preceding and following two devices at the time of starting the synchronous control for the following device and the speed difference between the two devices. This is a difference from the correction value, and is a temporal change term. In the present invention, the speed and the position specifications are determined by two sets of encoders which are coupled to the two machines in a specific positional relationship and are driven to rotate, and are output for each specified rotation angle of each encoder. A two-phase pulse signal of A-phase and B-phase generated with a phase difference of 90 degrees from each other, a reference origin signal generated at a rate of one pulse for each rotation of the encoder, that is, a Z-phase pulse signal and the two-phase pulse signal This is performed by various digital operations with the quadruple frequency pulse signal of the signal to be synthesized. That is, the speed is detected by a speed detection circuit that compares the A-phase or B-phase pulse signal period with a clock signal, and the positional deviation is included in the difference between the generation time points of the Z-phase pulse signals of both encoders. The phase difference detection circuit that counts the number of quadruple frequency pulses by the preceding encoder is detected as an angle corresponding pulse number. If the home position of the encoder does not match the required specific position of the machine corresponding to the encoder, a position signal corresponding to the difference is output as an angle corresponding pulse number from a phase difference setting circuit and the phase difference detection circuit The origin position is corrected by subtracting from the number of output pulses. Further, the position following correction value is calculated as a difference between the temporally integrated values of the two quadruple frequency pulse signals corresponding to the encoder signals of the two preceding machines, and the value is proportional to the speed difference between the two machines,
The positive and negative polarities represent a slow relationship between the two machine speeds.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a control block diagram showing an embodiment of the present invention. First
In the figure, reference numerals 1a and 1b denote machines which are driven by induction motors 2a and 2b, respectively, and are operated synchronously. In the illustrated case, 1a is a preceding machine 1b and a follower machine. Subscript a added to each component below
And b indicate that the element performs signal processing corresponding to the machines 1a and 1b, respectively. 3a and 3b are coupled to the corresponding machines and rotate, and a two-phase pulse signal of A-phase and B-phase having a phase difference of 90 degrees according to the rotation angle thereof, and each one rotation thereof The encoder outputs a one-pulse origin signal, that is, a Z-phase signal. 4a and 4b are insulating circuits, and 5a and 5b are A, B, and Z passing through the insulating circuit.
This is a shaping circuit for each phase pulse signal waveform. Reference numerals 6a and 6b denote frequency double direction discriminating circuits, which receive the A-phase and B-phase pulse signals and synthesize and output a quadruple frequency pulse signal (A + B) of the two signals, thereby outputting one pulse of the signal. The rotational resolution of the encoder is determined based on the relative relationship between the lead and delay of the 90-degree phase difference between the A-phase and B-phase pulse signals.
7a and 7b are speed detection circuits. In the case shown in the figure, the A-phase pulse signal is input, the pulse period is compared with a clock signal, and the rotation speeds fp and fc of the corresponding encoder are detected. is there. The speed can be detected in the same manner when the B-phase pulse signal is input. Reference numeral 8 denotes a phase difference detection circuit between the origins of the encoders 3a and 3b. The Z-phase pulse signals of the encoders 3a and 3b are set as clear and latch signals, respectively, within a difference period between the generation points of the two signals. By counting the number of pulses of the quadruple frequency pulse signal from the frequency double direction discriminating circuit 6a included, the phase difference α between the two encoder origins is detected as follows based on the rotation state of the encoder 3a. Things.

Nd: the number of pulses counted by the phase difference detection circuit 8 Ne: the number of pulses per rotation of the encoder 3a Also, due to mechanical misalignment at the time of assembling the required reference position of both machines and the corresponding Z-phase pulse generation reference point of each encoder. The phase difference setting circuit 13 sets a value obtained by integrating the corresponding angles for the two combinations as the correction angle γ for the phase difference α. Reference numeral 12 denotes an angle adjustment circuit for calculating the difference between the phase difference α and the correction angle γ. The angle difference between the outputs of the angle adjustment circuit is the reference point of each encoder corresponding to the position deviation between the synchronization target reference points of the two machines at the start of the synchronization control of the two machines, corrected by the angle γ as described above. This is the angle difference between them, and indicates the required correction angle for synchronization. Reference numeral 9 denotes a deviation counter circuit which counts the number of pulses between the quadruple frequency pulse signals (A + B) corresponding to the encoders 3a and 3b, and inputs the pulse number difference as an initial set value. The subtraction is performed from the number of pulses corresponding to the required correction angle from the angle adjustment circuit 12. Here, the pulse number difference between the two quadruple frequency pulse signals is proportional to the rotational speed difference between the two encoders and hence the two machines. Since the rotation angle per pulse is determined, the pulse number difference is obtained. Indicates the total displacement angle within the integration period. The total displacement angle indicates a correction angle following the required correction angle, and the output angle β of the deviation counter circuit 9, which is the difference between the two angles, indicates the remaining amount of the required correction angle at the time of counting the pulse difference. , Given below.

Here, Nc: the number of output pulses of the deviation counter circuit 9 Ne: the number of pulses per rotation of the encoder 3a 10 and 11 are proportional / integral (PI) adjusters, and the angle β and the rotation speed difference fp− The output of the adder / subtractor 15 for calculating fc is input. The sum of the rotation speed fp of the encoder 3a and the output of the two PI adjusters 10 and 11 is calculated by the addition / subtraction calculator 14, and the output fs is a speed setting signal for the induction motor 2b of the follower. Is input to the inverter device 16, and the acceleration / deceleration control for the electric motor 2b is performed. The output of the adjuster 10, which is the angle correction term of the speed setting signal, and the output of the adjuster 11, which is the speed correction term, reach zero together with the signal of the synchronous control, and the rotational speed fc of the follower is the leading speed. It becomes equal to the rotation speed fp of the machine, and the synchronous control is completed.

〔The invention's effect〕

According to the present invention, the A-phase or the B-phase generated at every prescribed rotation angle in both encoders with reference to the Z-phase pulse signal, which is the origin signal of the encoders respectively coupled to the two synchronously operated machines. By determining the position deviation between the origins of the two encoders and their respective speeds and their deviations by counting the pulse signals, the speed of the following machine is controlled so that the position deviation between the origins becomes zero. It is not necessary to adjust the reference point at the time of start-up, thereby shortening the time required for synchronization and simplifying the synchronization operation. In addition, it is possible to reliably and promptly perform the correction control for the synchronization error due to disturbance during the synchronization operation. Further, when the two machines and the respective encoders are combined and assembled, the displacement between the reference points of the two machines can be easily corrected by setting an electrical correction value from a phase difference setting circuit. Wide simplification is possible.

[Brief description of the drawings]

FIG. 1 is a control block diagram showing an embodiment of the present invention.
FIG. 3 is a control block diagram showing an embodiment of the prior art, and FIG. 3 is a diagram showing an output waveform and a relative positional relationship of the synchro electric machine in FIG. 1a …… Machine (preceding machine), 1b …… Machine (following machine), 2a, 2b
…… Induction motor, 3a, 3b… Encoder, 4a, 4b …… Insulation circuit, 5a, 5b… Shaping circuit, 6a, 6b …… Frequency multiplication direction discriminating circuit, 7a, 7b …… Speed detecting circuit, 8 … Phase difference detection circuit, 9… Deviation counter circuit, 10,11… Proportional / integral (PI) adjuster, 12… Angle adjustment circuit, 13… Phase difference setting circuit, 14,15… Addition / subtraction operation Container, 16 …… Inverter device, 2
0a: synchro electric machine (transmitter), 20b: synchro electric machine (receiver), 21: displacement detection circuit, 22: motor drive circuit.

Claims (1)

(57) [Claims] 1. A synchronous control apparatus for two machines driven by an induction motor, wherein one of the two machines is a leading machine and the other is a follow-up machine for the preceding machine, and the two machines are synchronously operated. And two sets of encoders, each of which outputs a two-phase pulse signal of A phase and B phase which rotate and have a phase difference of 90 degrees with each other and an origin signal of one pulse for each rotation thereof, that is, a Z phase signal. Output a quadruple frequency pulse signal of the two-phase pulse signals from the two encoders and determine the rotation direction of each encoder.
Sets of frequency double direction discriminating circuits, two sets of speed detecting circuits for calculating the rotational speed of the encoder from the A-phase or B-phase pulse signals of each of the encoders, the Z-phase pulse signals of the two encoders, A phase difference detection circuit for calculating an origin phase difference angle between the two encoders at the time of starting the synchronization control for the follower with the quadruple frequency pulse signal corresponding to the encoder of the machine; and the phase difference between the origins at the time of completion of the synchronization. A phase difference setting circuit for providing a set value of an angle, an angle adjustment circuit for calculating an output difference between the phase difference detection circuit and the setting circuit, and an integration between the integrated values of the quadruple frequency pulse signals corresponding to the two encoders A difference counter circuit for calculating the difference between the two, and subtracting the integrated value difference from the output value of the angle adjusting circuit; The subtraction operation unit and the preceding machine speed detecting circuit said a speed detection value of the preceding machine that outputs deviation counter preceding track position deviation between the first two aircraft that circuit outputs
And a second adder / subtractor for calculating the sum of the difference between the detected speeds of the two machines output by the adder / subtractor, and the set speed of the induction motor of the follower using the output of the second adder / subtractor. A synchronization control device characterized by being a signal.