A simple algorithm for determining of movement duration in task space without violating joint angle constraints

In usual robot applications, velocity and acceleration constraints are represented in joint angle space, while on the contrary, a goal is specified in task space such as the Cartesian coordinates. This fact means that a task trajectory planner itself cannot resolve the constraint problem without working together with an inverse kinematics solving method. In this paper, we present a simple method to generate a joint angle trajectory without violating the joint velocity and acceleration constraints. The key idea is to determine movement duration to solve the constraint problem. The proposed method has a strong merit in that it can use the existing task trajectory planning method and inverse kinematics solving method without re-formulating them for the constraints. The validity of the proposed method is shown by the simulation with a two-link serial manipulator executing a circle-drawing task.