Full-digital subdivision high-accuracy stepper motor controller

Abstract

A full-digital fine-step high-accuracy controller for step motor is composed of single-chip microprocessor as control core, step motor control interface, power amplifier, and serial communication interface to host computer. Its control signal has standard TTL levels. Its highest frequency (1MH2) can be divided by 250, so increasing its control accuracy by 250 times.

Description

technical field [0001] The invention relates to a stepping motor control device, in particular to a control scheme and a realization method of a subdivided, all-digital stepping motor controller. Background technique [0002] Because the structure of the stepper motor is completely different from that of the DC motor and the AC motor, the control method of the stepper motor is also completely different from these two motors. The stepper motor controls the input current of the motor in the form of pulse voltage. The number of input pulses is strictly proportional to the angle of rotation of the stepper motor rotor, and the frequency of the input pulse is proportional to the rotation speed of the stepper motor. Because of the above characteristics of stepper motors, stepper motors are widely used in many precision motion mechanisms to complete the precise position control function of the system. Under the premise that the load does not exceed the rated load of the motor, the ...

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Problems solved by technology

The controller does not have the function of limiting current changes, and there is no communication interface circuit

[0007] The common features of the above three patents are: 1) Use the data table stored in the microprocessor to give the current given value data of the stepper motor through the table look-up method, and obtain the analog control voltage through digital-to-analog conversion 2) The control voltage directly supplies power to the two-phase winding of the stator of the stepper motor after power amplification, and the feedback control of the stator current is not realized, so that the output torque of the motor at high speed and low speed is inconsistent, and the stator current fluctuates greatly. 3) The two phases of the stepper motor The control system of the phase winding current is realized by analog components. Due to the poor consistency of the analog components, the characteristics of the components are greatly affected by the environmental conditions. The two-way regulator and power amplifier composed of analog components must have complete control characteristics. The same is a very difficult thing, the circuit structure is complex, and the debugging work is also very difficult 4) There is no interface part for communication with the upper control unit or computer, and it is impossible to realize the control process with relatively high intelligent requirements, and it cannot directly communicate with the upper control computer. Realize data exchange 5) There is no position detection unit, and the high-precision position control function cannot be completed alone 6) There is no limit measure for the rate of change of the stator current at the moment of power-on and power-off of the controller, which causes the motor to produce very high speed at these two moments Strong jitter phenomenon will damage precision moving parts

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