Trajectory Week 8

Learning Outcomes By the end of week 8 session, students will trajectory of industrial robots.

Course Outline Trajectory. Initial, via and final points. Interpretation of trajectory.

Trajectory Refers to a time history of position, velocity, and acceleration for each degree of freedom, i.e. how do we move joints with respect to time (joint coordinates). As cartesian coordinate (x,y,z) is a more desirable information from user’s perspective, inverse kinematics process is required prior to developing trajectories.

Robot Motion X Y Z t0t0 tftf t0t0 t θ3θ3 t0t0 t θ2θ2 t θ1θ1 t0t0 tftf tftf tftf t 0 = t initial t f = t final Cartesian coordinates Joint coordinates

Trajectory Planner Trajectory Generator Path & Kinematics Constraints Dynamics Constraint Cartesian Path Trajectory (joint coordinates)

Joint Coordinate Algorithm

Cartesian Coordinate Algorithm

Path planning Cartesian path Issues: obstacle avoidance, shortest path Trajectory planning, “interpolate” or “approximate” the desired path by a class of polynomial functions and generates a sequence of time-based “control set points” for the control of manipulator from the initial configuration to its destination. Steps in Robot Motion Ref. City College of New York.