Time-optimal path tracking for articulated robot along spline curves based on master-slave strategy

Path tracking, as a subproblem in trajectory planning, is one of the most significant topics in robot researches. In this paper, a time-optimal trajectory planner is proposed, which tracks the specified B-spline path with limit jerk. This planner utilizes the master-slave strategy to plan trajectory for all axes. In the preprocessing stage, switching points are divided into two types: critical points and axis switching points. By detailed classification and S-shape velocity planning of adjacent critical points, the continuous turning problem in B-spline curves is solved. In order to reduce the global execution time under the physical constraints, an iterative optimization method is employed in the velocity profile and the bang-bang control with limit jerk is realized. The proposed algorithms are simulated on a manipulator model with three links. The result shows that the algorithms can be applied to complex B-spline path tracking and generate trajectory for each axis under jerk constraint, which reduces the vibration effectively.