Research Of Acceleration And Deceleration Algorithm Based On Single Chip Microcomputer

The research on CNC system develops from mechanics or mathematics at present, servo system also develops as an independent branch, numerical control technique does not combine with servo system completely. With the increase of acceleration when developing high-speed and high-precision CNC system, discontinuousness and non-differentiable of acceleration will result in vibration, impact and debasing of position accuracy.S-shape acceleration and deceleration (acc/dec) control algorithm has resolved the question of acceleration discontinuousness in a way, but it need solve tri-equation in order to meet the qualification at end-point, it does not realize in MCU(Micro Controller Unit) at present. There are some methods to solve the problem, such as making acceleration jumped, delaying orientation time at end-point, these methods affect high-speed and high-accuracy of CNC system exactly. When the rank of servo system rises, it need increase the rank of S-shape curve, algorithm becomes more complex, because it can not extend. Accordingly, there are some pivotal questions must be solved, including differentiable in high rank of acceleration, executable in confine condition of end-point and shortening calculation periods.To solve these problems, the dissertation presents a new acc/dec control algorithm based on moving average. The algorithm regarding the method of linear acc/dec as foundation need not solve high rank equation and realizes high rank differential of acceleration NC injunction deciphering through extending.In the paper, the control algorithm is used to injunction deciphering to basic outline curve, such as beeline, arc and helical curve. Series of moves is required for process in high-speed CNC system, adjoining feedrate of segments is calculated through its vectors variety rate in advance, and using outline error to adjust the speed. The soft of NC simulation systems based on injunction deciphering with VC++ language is established, and do research deeply on moving average number. Eventually, planning SCM(Single Chip Microcomputer) program with moving average algorithm using integer calculate mode in AC servo system, the runtime of NC injunction deciphering module is shortened to 13μs to meet the requirement of same period's control. SCM program with quadratic moving average acc/dec algorithm is used to injunction deciphering to arc and confirms algorithm's feasibility and validity.