基于功率及转矩约束的大惯量伺服系统速度规划

Velocity Planning for Large Inertia Servo System Based on Power and Torque Constraints

针对大惯量伺服系统提出基于功率及转矩约束的速度规划,解决约束条件下响应速度慢和定位精度差的问题。提出一种基于三角函数的全程柔性加减速算法,使速度与加速度曲线连续可导。同时采用二次曲线拼接,保证不完全过程加速度仍然连续。以电动机驱动系统为模型,利用过载特性,设计基于额定功率及最大转矩双重约束下的速度规划,使约束方式在最大转矩点平滑切换,并以加减速角位移为给定,确定匀速速度与加减速时间关系,满足不同速度的加减速要求,缩短速度响应时间。基于平均速度计算单个脉冲周期,给出利于编程的左端点实现算法,并引入间隔阈值变量,大幅降低计算量,算法适用于脉冲给定的伺服驱动系统。试验结果能够验证算法的有效性,在实际应用中,算法提高了定位精度,得到很好的应用。

To improve response rate and positioning accuracy of large inertia servo system, the velocity is planned based on power and torque constraints. Globally flexible acceleration and deceleration（ad） algorithm based on trigonometric function is proposed, and a derivable and continuous velocity planning function is designed to reduce high-frequency component. Quadratic curve is employed to connect acceleration curve in incomplete process. Velocity planning algorithm is designed based on both nominal power and maximum torque constrains utilizing overload characteristic and maximum torque of the servo motor, and the condition of constrains is smoothly changed at the maximum torque point as well. The relation formula of constant speed and a＆d time is given by utilizing displacement as command signal to satisfy different requirements. Single pulse interval is calculated based on mean velocity, and a left-end curve implementation method with interval threshold is designed to reduce computation cost for computer program. This method can be also used in other pulse-given servo systems. Testing and application results demonstrates the effectiveness and reliability of the proposed methods. The presented method improves target positioning accuracy and is successfully applied in test system.