CPLD-based multi-subdivision high-speed constant-torque controller of two-phase hybrid stepping motor

Abstract

The invention relates to a multi-subdivision high-speed constant-torque controller of a stepping motor. The controller is technically characterized in that: an external pulse is input into an isolation circuit which is connected with a CPLD master control chip; the CPLD master control chip is connected with a subdivision number selecting switch, a forward and backward rotation switch, a startup and shutdown switch, a current detection and over-current protection circuit, a DA conversion circuit and a crystal circuit respectively; the DA conversion circuit is connected with a current setting circuit and two paths of constant current driving circuits; the two paths of constant current driving circuits are connected with a winding of the two-phase hybrid stepping motor; and the current detection and over-current protection circuit is connected with the winding of the two-phase hybrid stepping motor. The controller has a simple structure and does not need to be externally configured with a chip, independently serves as a master control chip and is not matched with other digital processing chips for use.

Description

technical field [0001] The invention relates to a CPLD-based two-phase hybrid stepping motor multi-subdivision high-speed constant torque controller, which is a two-phase hybrid stepping motor controller. Background technique [0002] As the key part of the servo mechanism, the stepper motor generally adopts the current control mode drive system for the high-precision control system, and the subdivision drive is the best control mode. At present, the most commonly used method is to use single-chip microcomputer to design stepper motor controller. The advantages are low price, mature technology and abundant resources, but it is difficult to write in assembly language, and the program readability is not strong. Using DSP can also achieve multi-subdivision high-speed control, but DSP software programs are executed sequentially, while CPLD is connected to hardware, and the same crystal oscillator is connected externally, so the maximum speed that can be achieved is much higher t...

AI Technical Summary

Problems solved by technology

Like CPLD, FPGA is highly integrated and systematized, shortens and simplifies the process of hardware design and upgrade, and can realize multi-subdivision high-speed control. However, FPGA has abundant internal resources, and the resources are not fully utilized, which is somewhat wasteful.

From the searched papers, there are many design stepper motor controllers using a combination of single-chip microcomputer and CPLD. CPLD is only used for simple combination logic in the system. Most of the CPLDs of the MAX3000 and MAX7000 series are used. Due to the limited internal resources of this type of chip, the functions realized are only simple operation, and the operation mode up to 128 subdivisions cannot be realized.

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