A control device and method for a stepping motor

Abstract

The invention belongs to the field of electromechanical control, and in particular relates to a control device and method for a stepping motor. The device is composed of a computer, a single-chip microcomputer, a control signal photoelectric isolation circuit, a linear unregulated power supply, an output current control circuit, a drive circuit, a winding current acquisition circuit, a reference voltage comparison circuit, and a feedback signal photoelectric isolation circuit. The communication between the computer and the single-chip computer is realized. For the remote setting of stepper motor parameters, the single-chip microcomputer controls the high-precision rotation of the stepper motor drive circuit to the stepper motor according to the set parameters, and at the same time collects the current signal fed back by the winding current acquisition circuit and the actual number of walking pulses, thus realizing high-power stepping High-precision control of the motor.

Description

technical field [0001] The invention belongs to the field of electromechanical control, and in particular relates to a control device and method for a stepping motor. Background technique [0002] Due to the characteristics of low speed, high torque, and non-accumulation of errors, stepper motors are widely used in precision testing equipment such as high-precision translation platforms and high-precision electric turntables. [0003] At present, most of the control methods of stepper motors adopt the open-loop control method with a single function. Its disadvantages are as follows: [0004] 1) The accuracy and stability of the driving pulse frequency are not high enough, which causes the inconsistency of the energization cycle of each phase winding, resulting in low control accuracy; [0005] 2) The drive pulse frequency cannot be changed arbitrarily according to the load demand and motor speed requirements, resulting in resonance between the natural frequency of the syst...

AI Technical Summary

Problems solved by technology

[0004] 1) The accuracy and stability of the driving pulse frequency are not high enough, which causes the inconsistency of the energization cycle of each phase winding, resulting in low control accuracy;

[0005] 2) The drive pulse frequency cannot be changed arbitrarily according to the load demand and motor speed requirements, resulting in resonance between the natural frequency of the system and the drive frequency, resulting in chatter and howling;

[0006] 3) The subdivision control of the traditional method is usually realized by manually adjusting the subdivision dial switch of the driver, and real-time program control modification cannot be performed as required;

[0007] 4) Since the driving current of the traditional control device is small and cannot be programmed and modified after setting, it is difficult to directly drive the high-power motor. At present, most of the methods used are to increase the torque by sacrificing the speed through the transmission mode of screw or worm gear to increase the torque. Achieving large load driving capacity, but this method will introduce meshing errors and backlash between the teeth of the mechanical structural parts, which will reduce the motion accuracy. In order to solve the problem of motion accuracy, most designers use an encoder as a feedback method , but this undoubtedly increases the design cost and control difficulty;

[0008]5) Most drivers have half-current self-locking and full-current self-locking functions, that is, half of the current value or the full current passing through the winding when the motor is at rest The value makes the motor lock and does not rotate, but when the user needs to manually rotate the motor, the control circuit needs to be powered off, which is inconvenient to operate

[0009] Due to the above technical problems, stepper motors have certain limitations in the application field of precision test equipment. It is difficult to ensure the driving capability and motion accuracy of high-power stepper motors at the same time, and it is also difficult to pass software in the system integration of test equipment. Program control realizes the modification of the user's own actual demand parameters, which is not convenient for automatic control under system integration

Images