Based On Fuzzy Pid Control Stepper Motor Positioning System,

This paper introduces an automatic position setting system of stepping motor based on the chip microcomputer and fuzzy PID control. In order to make this system have extensive uses, we use a simple man-machine interactive system, and in this system the choosing of function modules and controlling parameters can be inputted from the keyboard. So, this system can realize not only the high accuracy position but also the multiform function control. By the way of software of chip microcomputer instead of the conventional ring-shaped allotter in the system, we can design a high efficient and energy-saving drive scheme of stepping motor; By the way of serial communication between the microcomputer and the computer, we can achieve a remote monitoring and real-time system to the stepping motor; By the way of the variable-frequency control and PID control, we can make the stepping motor run efficiently; By the design of optically coupled circuit, we can enhance the ability of anti-interference of this system.During the control process, in order to improve the partial and integral performance we choose different proportion factor kp, integral quotient Tj, differential quotient Td according to variable error e and error rate of change △e. When |e| is much greater, in order to accelerate the response speed of system, avoid making the integral saturated due to the short-term fluctuation of e and avoid great overshoot of the system, the only P control could be adopted. When |e| is moderate, for the sake of decreasing overshoot and ensure the response speed, the PD control could be adopted. When |ej is much smaller, in order to enhance the ability of anti-interference and avoid oscillation of system, the PID control could be adopted.And if the stepping motor runs at the constant rate at the frequency lower than the limiting frequency, it leads to the much longer working time. In order to improve this state, a new method called acceleration and deceleration control is necessary. We run the stepping motor at the low speed and accelerate with no desynchronizing to the status of working at constant speed. Before it reach the target location, thestepping motor runs at the reduction speed. At last the motor stops at the target location, and the overswing is avoided.In a example of an Automatic Position Setting System of Robotic Arm Based On The Stepping Motor Controlled By The Chip Microcomputer, the results of experiment show that the system which is extracted in this paper, can accurately detect the position of measured object and identify. And the system performance index meets the challenge of design.