机械手时间最优脉动连续轨迹规划算法

Time-optimal and Jerk-continuous Trajectory Planning Algorithm for Manipulators

为使机械手的作业效率达到最优,同时确保运动的平稳性,提出一种新的最优轨迹规划方法。通过逆运动学运算得到与任务空间轨迹对应的关节空间位置序列,采用7次B样条曲线插值方法构造启动和停止运动参数可控,且速度、加速度和脉动均连续的关节轨迹。将机械手运动学约束转化为B样条曲线的控制顶点约束,采用序列二次规划方法求解最优运动时间节点,进而规划出满足非线性运动学约束的时间最优脉动连续轨迹。仿真和试验结果表明,提出的轨迹规划方法为关节控制器提供理想的轨迹,使机械手在最短的时间平稳地跟踪任务空间的任意指定轨迹。

In order to optimize the productivity and ensure the running stability of manipulators, a new optimal trajectory planning algorithm is proposed. Position series in joint space are obtained by applying inverse kinematic algorithm to a specified trajectory in task space, and B-splines of seven degree are exploited to interpolate joint position series and generate joint trajectories with continuous velocity, acceleration and jerk, as well as controllable start-stop kinematic parameters. By converting kinematic constraints of manipulators to constraints on control points of B-splines, optimal time nodes are solved by using sequential quadratic programming strategy, then time-optimal and jerk-continuous trajectories which satisfy nonlinear kinematic constraints are planned. Simulating and experimental results show that the proposed trajectory planning algorithm provides ideal trajectories for joint controller, and ensures manipulators to track any specified trajectory in task space stably with the minimum traveling time.