A New Acceleration and Deceleration Algorithm and Applications

The control of acceleration and deceleration of stepper motor is one of the most key technologies of CNC system development. Acceleration is discontinuous in linear acceleration and deceleration, which caused impact in NC machining. The exponential algorithm has a strong tracking capability but weak stability at higher speed. The questions could be overcome by conventional S-curve acceleration and deceleration implementation method, but the algorithm is too complex. So a new method was proposed to implement S-curve acceleration and deceleration. This paper presents five-stage model of S curve acceleration and deceleration algorithm to satisfy the actual roller polishing machine needs. The algorithm consists of five kinematic stages: increasing acceleration stage, decreasing acceleration stage, constant-speed stage, increasing deceleration stage and decreasing deceleration stage. At the starting point and the ending point, the velocity is zero and the jerk is absolutely the maximum value J. Analysis shows that: the acceleration curve of the algorithm is a continuous curve, and there is a first-order continuous relationship between time and speed, a smooth velocity and acceleration can be obtained, which is to avoid the impact when the CNC system accelerates and decelerates or reverses. The application on roller polishing machine shows that : compared with the traditional S-curve, the algorithm can make sure the acceleration is continuous, the speed changes smoothly, the flexibility is improved and the algorithm is easy to implement.