Research On ZYNQ-based Intelligent Cutting Machine Speed Control Method

With the development of science and technology,motion control technology has been widely used in CNC machine tools,cutting machines and other fields.In the processing of cutting machine,a series of movements such as feeding,starting and stopping and trajectory conversion of the tool can be controlled to effectively improve the processing efficiency and cutting accuracy.This design combines the FPGA technology,according to the working principle of the cutting machine on the stepper motor control research,focusing on the research of the stepper motor motion control system.Specifically,the main research contents are as follows:(1)Stepping motor control algorithm analysis.The commonly used control algorithms are T-type acceleration and deceleration,S-type acceleration and deceleration,exponential acceleration and deceleration,and PID control algorithms,and the corresponding motion equations are deduced according to their mathematical models and implemented on the FPGA.These algorithms are compared and analysed,and their advantages and disadvantages as well as the scope of application are pointed out.(2)In terms of hardware design,a key deactivation module is designed for the problem of jitter when the key switch is closed;in the control link,an LCD display module is designed to reflect the motion process of the stepper motor;in the feedback link,an encoder module is designed to get the number of pulses of the actual motion of the stepper motor;and at the same time,a UART serial communication module is designed to achieve the communication between the FPGA and the host computer.machine.(3)In the software design,for the traditional T-type acceleration and deceleration algorithm at this stage,the problem of the deceleration point is not easy to determine,and puts forward a deceleration point adaptive T-type acceleration and deceleration algorithm.The algorithm adopts the idea of "splitting and complementing" to derive the time of the deceleration point,and designs the deceleration point adaptive determination module on the FPGA with the iterative divider as the core.Experimental results show that the improved T-type acceleration and deceleration algorithm can automatically determine the position of the deceleration point,and by comparing the time with the ideal deceleration point,the minimum accuracy of the algorithm to determine the deceleration point is 98%,which meets the requirements of real-time;by comparing the ideal curve with the actual curve,it can be seen that the actual motor speed curve is smoother and the rotational speed error is smaller.(4)Aiming at the current stage of the S-type acceleration and deceleration algorithm formula is complex,and it is difficult to implement on the FPGA,a real-time generation method of S-type acceleration and deceleration algorithm is proposed.The algorithm is based on the binary quadratic equation to construct the model of S-type curve and derive the motion equation of each stage of the S-type algorithm.The real-time generation module with CORDIC algorithm as the core is designed on FPGA,which calculates the required number of pulses by itself at the arrival of each pulse firing cycle.The experimental results show that the improved S-type acceleration and deceleration algorithm operates with smooth curves and high accuracy.Meanwhile,the improved Stype acceleration and deceleration algorithm can automatically determine the time of the deceleration point.