非圆车削用GMA迟滞逆补偿控制方法

为分析了非圆截面零件的加工特点及其对伺服刀架的控制要求,研究了可用于高速伺服跟踪控制的超磁致伸缩驱动器(GMA)的前馈补偿控制策略.采用经典Preisach模型对GMA的非线性迟滞进行建模,研究了模型的可逆性,推导了求逆算法,通过开环前馈补偿实验证明了逆算法的有效性.实验比较了在开环、前馈补偿和前馈补偿加PID闭环控制3种情况下,GMA对期望位移输出序列的跟踪能力.结果表明,前馈补偿将跟踪误差由开环控制时的-28.3%～24.2%减小到-1.3%～5.9%,而基于前馈补偿的PID控制则将跟踪误差进一步减小到-1.0%～1.3%,满足了伺服跟踪要求

Inverse compensate and control for GMA hysteresis in non-circular cutting

According to the characteristic of cutting process of non-circular cross-section workpieces and its control requirement for tool servo,a feed-forward compensation approach was proposed for the high-speed servo tracking control of a giant magnetostrictive actuator's(GMA'S) hysteresis by analyzing the profiles of non-circular piston's skirt and its cutting trajectory.Preisach model was employed for modeling the nonlinear hysteretic behaviour of the actuator,and the parameters of Preisach model were identified by first order descending(FOD) curves. The invertibility of Preisach model was discussed,and then the numerical expressions of the inverse Preisach model were presented for different input variations.A PID controller was designed based on the lumped parameter electrical-mechanical dynamic model of the GMA.Experimental results showed that,compared with the open-loop control,the range of tracking error was reduced from-28.3%~24.2% to-1.3%~5.9% when the feed-forward compensation was involved,and further reduced to-1.0%~1.3% by the PID controller based on the feed-forward compensation.A great improvement of tracking performance shows the effectiveness of the approach.