Constant current driving system and constant current driving method for stepping motor with fixed duty ratio

Abstract

The invention relates to the technical field of motor control, and particularly relates to a constant current driving system and a constant current driving method for a stepping motor with a fixed duty ratio. The system comprises a control unit, a driving circuit, a power circuit, a stepping motor, a current sensor and a protection circuit, wherein the control unit comprises a pulse distributor, a PWM generator and a logic arithmetic unit. The system is characterized in that the control unit also comprises a comparator, wherein the comparator, comprises an input positive end, an input negative end and an output end; the input negative end is connected with a stepping motor winding current given value; the input positive end is connected with the current sensor for receiving a stepping motor winding current feedback value; and the output end is connected with the logic arithmetic unit. The structure of the system is simple, the operation process is simple and convenient, the manufacturing cost is low, a fixed-duty ratio PWM signal is used for carrying out constant current driving on the motor, and the high-performance control on the motor is realized.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a constant current drive system and method for a stepping motor with a fixed duty ratio. Background technique [0002] Stepper motor is an actuator that converts electrical pulse signals into corresponding angular displacements. It has high control precision and flexible and convenient control methods. It has been widely used in aerospace, aviation, electronics and other fields. In the case of non-overload, the speed and stop position of the motor only depend on the frequency and number of pulse signals, and are not affected by load changes. The positioning and speed regulation of the motor are realized respectively by controlling the number of pulses and the pulse frequency. [0003] When the stepper motor rotates, when the current flowing through the motor coil exceeds the rated current, the motor will generate a high temperature rise, which may burn the motor; large cur...

AI Technical Summary

Problems solved by technology

[0017] 1. Most of them are implemented by analog or digital circuits, and A / D conversion chips are needed to collect the motor winding current, and the hardware circuit structure is complex;

[0018] 2. In the control of each shot, the PWM duty cycle needs to be calculated in real time according to the magnitude of the feedback current. The software has poor flexibility, high complexity, poor portability and scalability

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