An Error Modeling Method For End-Effector Space-Curve Trajectory Of Six Degree-of-Freedom Robots

An error modeling method for six degree-of-freedom robot end effector space-curve trajectory, comprising the following steps:

• (1) selecting N trajectory points on the space-curve, wherein N is determined by specific operational task, and obtaining displacement or angular displacement of each joint based on an inverse solution model;
• (2) selecting an interpolation algorithm and performing interpolation to obtain functional relationships between joint variables and time, wherein M joint variables are selected by taking a point every 20 milliseconds (ms), and wherein a total motion time obtained by the interpolation algorithm being T(s), M is T/0.02;
• (3) taking into account of the structural errors of each joint of the robot, obtaining positive solution to obtain M corresponding robot end effector trajectory points Q;
• (4) selecting point P on an ideal trajectory so that the points Q is on a normal line that passes the point P, therefore defining an trajectory error E as the distance between the point P and the point Q, so that the problem is transformed into solving the error E based on a known ideal space trajectory curve equation and coordinates of the point Q;
• wherein when E approaches infinitesimal, planned trajectory coincide with the ideal trajectory;
• and
• (5) based on the curve equation, obtaining a tangent equation that passes the point P, calculating the coordinate of the point P, with the condition of PQ⊥PP1 (P1 Is any point of the tangent line), so as to obtain the error E.