JPS58179199A - Controller for stepping motor - Google Patents

Abstract

PURPOSE:To improve the stepping response of a stepping motor with a simple structure by controlling the energization of the coils of phases based on the outputs of position detectors which generate detection pulses at the mid-point between the detent positions of the motor. CONSTITUTION:When one pulse is inputted to the input terminal 23 of a start pulse, coil drive pulse of each phase for transferring the state to the detent position in response to the specified rotating direction from each phase coil drive pulse generator 17 is outputted. A coil power switching circuit 15 starts energization for moving the oil of the motor 12 to the detent position. A position detector 14 outputs a timing pulse at the mid-point between the detent positions of the motor 12. When the motor 12 is rotated and a timing pulse is outputted from the detector 14, the energization to the phase coils of the motor are switched to reverse phase energization for rotating the motor in reverse direction, the motor 12 is decelerated, and fixed to the detent positions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single step drive with closed loop control of a stepping motor.

Conventionally, open-loop control has been used to drive a stepping motor in a single step. Method of restarting energization to (2)
) When two or more phases of coils are always energized, such as in 2-2 phase excitation drive of a stepping motor, one step of the motor is further subdivided by changing the proportion of current in each phase. There is a microstep drive method that controls a motor with a resolution of divided steps (microsteps).

Method (1) is a method in which the energization time and energization stop time are determined in advance through experiments, and the energization time sequence is determined based on this. Problems such as increased vibration and step-out occur, making it extremely difficult to obtain good step response characteristics.

In addition, method (2) is open-loop control, but one step of the stepping motor is subdivided, and the motor is controlled using this resolution.The resolution of the step is also improved to prevent vibrations caused by motor load fluctuations and power supply voltage fluctuations. A good step response can be obtained by reducing the ratio by the same amount.

However, this method requires only 1 jt of coils for each phase of the motor.
Since a circuit for varying the current by steps corresponding to the step resolution of the motor is required for the number of phases of the motor, there are problems such as the circuit is complex and the cost is extremely high.

The present invention has been made to eliminate such problems, and an object of the present invention is to realize a stepping motor control device that is extremely simple and inexpensive, and has a good step response.

FIG. 1 shows the phase relationship between the stepping motor position detector and the stepping motor in the stepping motor control device according to the present invention.

In the figure, 1 is a timing disk with a slit 2, 3 is an optical phase amount detector, and 4 is a 4-phase PM type stepping motor 2.
rotor, 5 is the stator, 6 is the A and B phase of the stator, 7
are the O and D phases of the stator, and 8 to 10 are the detent positions of the stepping motor. The phase relationship between the slit 2 of the timing disk 1 and the optical position detector 3 is such that a detection pulse is output at the midpoint between the detent positions of the stepping motor by the phase adjustment device 11 of the optical position detector as shown in FIG. (adjusted so that it will be done).

FIG. 2 is an example of a drive circuit in a stepping motor control device according to the present invention. In FIG. 2, 12 is a stepping motor, 15 is a timing disk for position detection directly connected to the motor shaft, 14 is an optical position detector, 15 is a coil power switching circuit for the stepping motor, 1
6 is a Cxoluaive OR circuit (hereinafter referred to as an EOR circuit); 17 is a stepping motor coil drive pulse generation circuit for each phase; 18 is a timing pulse waveform shaping circuit;
19 is a mono staple multi vibrator (mono multi), 20 is a volume for variable output pulse width of the mono multi 19, 21 is an R-8 flip-flop, 22 is a NOR circuit, 23 is a stepping motor start pulse input terminal, 24 is a stepping motor rotation There is also a direction signal input terminal. In the state where the rotation direction signal input terminal 241C is "HIGH" or @LOW' (7) state id is input, one pulse is input to the start pulse input terminal 25, so that each phase coil drive pulse generation circuit 17 Coil drive pulses for each phase are output for instantaneous movement of the shape MM to the detent position according to the designated rotation direction. E.O.
In the R time w516, if the start signal is input, the output of the R-87 lip-flop 21 is 1HIGH-, so the output specifies the rotation direction input from the rotation direction signal input terminal 24. , the power supply switching circuit 15 starts energizing the coil of the motor 12 for movement to the next detent position. A timing disk 13 directly connected to the motor shaft and a position detector 14 for detecting a slit divided at an angle similar to the step angle of the motor on this disk output a timing pulse at the midpoint between the motor detent positions. It has been adjusted so that

When the motor rotates and a timing pulse is output from the position detector 14, the output of the R-S flip-flop 21 becomes "
The state becomes 'LOW', the KOR circuit 16 is reversed, and the energization to each phase coil of the motor is switched to reverse phase energization for rotating the motor in the reverse direction.Therefore, the rotor of the motor, which was once accelerated, starts to decelerate. When the timing pulse is input, the monomulti 19 is activated, and a preset time after the timing pulse is output, the monomulti 19 outputs a pulse, and the R-57 lip-flop 21 outputs the pulse.
The output becomes 1HIGH again, the ICOR circuit 16 is inverted again, and the coils of each phase of the motor are energized again in the same way as before the start of deceleration.

The rotor, which has been decelerated and has reached the vicinity of the next detent position, is thereby fixed at the detent position.

When the rotor reaches the next detent position, it is possible to stop the rotor without vibration by adjusting the set time of the monomulti 19 so that the speed becomes zero. Further, even if the motor 12 is rotated clockwise or counterclockwise, the same effect can be obtained because the timing pulse is output at the midpoint of the rotor's detent position.

FIG. 3 shows another example of the drive circuit in the stepping motor control device according to the present invention. In FIG. 5, the same numbers as in FIG. 2 indicate the same items.

32 is a pulse generator, and 33 is an up/down counter. When a state signal of "H GH" or "LOW" is input to the rotational direction signal input terminal 24, one trigger pulse is input to the start pulse input terminal 26, so that a signal is generated from each phase coil drive pulse generation circuit section. Coil drive pulses for each phase are output for state transition to the adjacent detent position according to the designated rotation direction. IC
Since the output of the R-37 lip-flop 21 is @HIGH after the start pulse is input to the OR circuit 16, the output specifies the rotation direction input from the rotation direction signal input terminal 24, and the coil The power supply switching circuit 15 starts energizing the coil of the motor 12 for movement to the next detent position.A timing disc 13 is connected directly to the motor shaft, and a timing disc 13 is divided at an angle similar to the step angle of the motor. The position detector 14 for detecting the detented slit is adjusted so that a timing pulse is output at the midpoint between the detent positions of the motor.When the motor starts rotating, an up/down counter cleared by the start pulse is output. 33 starts counting up.

The clock of the up/down counter 35 is the pulse generator 3.
When the timing pulse is output from the device detector 14 consisting of 2, the output of the R-87 lip 70 tube 21 is @
IIo"w", the Ic0R1 path 16 is reversed, and the energization is switched to reverse phase energization for rotating the motor in the reverse direction. Therefore, the rotor of the motor, which has been once accelerated, starts decelerating. At the same time, the up/down counter 33 starts counting down, and when the output becomes "0" (immediately after the same time interval as the time interval from the start pulse input to the timing pulse output has elapsed), the output of the R-S flip 70 knob 21 becomes "LA GH" again, and the motor coil starts to be energized in the same way as before the start of deceleration.The rotor, which has been decelerated and has reached the vicinity of the next detent position, returns to this detent position by energizing the motor coil again. Fixed without vibration.

Furthermore, even when the motor 12 rotates clockwise or counterclockwise, a timing pulse is output at the midpoint of the rotor's detent position, so there is no need to install separate detectors for each rotation direction, and circuits and control software Benefits such as being able to share information can be obtained.

When the motor power supply voltage fluctuates or when the inertial load or frictional load of the motor fluctuates, the time interval from when a timing pulse is output from the start of motor drive to when the motor reaches the next detent position fluctuates greatly. For this reason, with the drive circuit shown in FIG. 2, it is difficult to completely eliminate motor vibration in all cases. However, in the circuit of FIG. 3, since the deceleration time is automatically adjusted in each case, single-step driving of the stepping motor can be realized without vibration in all cases, which is very advantageous.

In FIG. 3, by changing the pulse period of the pulse generator 32 when the up-down counter 33 is counting up and counting down, it is possible to realize a more optimal single-step drive for the frictional load.

[Brief explanation of the drawing]

FIG. 1 shows the phase relationship between the position detector of the steering and rubbing motor and the stepping motor in the stepping motor control device according to the present invention. Figure 2 shows one of the stepping motor control devices according to the present invention.
This is an example of a circuit. FIG. 3 shows another example of the circuit of the stepping motor control device according to the present invention. Applicant: Shinshu Seiki Co., Ltd. Awa Seikosha Co., Ltd. Attorney: Patent Attorney Tsutomu Mogami Figure 1 Figure 2

Claims (1)

[Claims] 1. In a stepping motor controlled by a detection pulse from a position detector, a position detector that generates a detection pulse at a midpoint between detent positions of the stepping motor, and a coil for each phase of the stepping motor. 1. A stepping motor control device comprising an energization control circuit that controls energization of the stepping motor. 2 The energization control circuit switches the energization to the coils of each phase of the stepper motor in order to step to the momentary hold position (first energization state), and the position detector outputs a detection pulse as the stepping motor rotates. At this point, the current is switched to reverse phase energization (second energization state), and after a certain period of time, the first
2. The stepping motor control device according to claim 1, wherein energization is carried out in the same manner as in the energization state of . (v) The energization control circuit has a timer that measures the time interval from when the energization of each phase coil of the stepping motor is switched (first energization state) until the detection pulse of the position detector is output; When is output, reverse phase energization (second energization state) is performed, and after a time interval that has a constant functional relationship with the time interval measured by the timer has elapsed,
2. The stepping motor control device according to claim 1, wherein the stepping motor control device is energized again to the first energized state.