Patent ID: 8620474

Claim:
A method for controlling a robotic manipulator, comprising the steps of: storing a reference path(r s [s(t)]); determining reference increments (Î”q s [s(t)]) while following the path; providing a processor with a model of dynamics of said manipulator represented as a mathematical relation between positions of said manipulator, time derivatives of said positions, and device forces of said manipulator M Â· â…† 2 â¢ q â¡ ( t ) â…† t 2 + h â¢ ( q â¡ ( t ) , â…† q â¡ ( t ) â…† t ) = Ï„ ; and in said processor, automatically determining the reference increments based on said dynamics of the manipulator, represented in said model, while following the reference path, by determining a reference motion [Î”r s (t)] in said processor while following said path for a time increment (Î”t), by interpolation between stored positions or joint coordinates or by evaluating a stored function, and when drive forces that are necessary to realize a reference motion [Î”r s (t)] exceed tolerable drive forces (Ï„ zul ), automatically determining said reference increments [Î”q s (s(t))] so as to differ from the reference motion [Î”r s (t)] by a linear mapping Î”q s (t)=Î¦(Î”r s (t)) of the reference motion, wherein the linear mapping maps the reference increments within a predetermined tube ((1âˆ’Î¸ 1 )Â·Î”r s +Î¸ 2 Â·n Î”r +Î¸ 3 Â·b Î”r ) enclosing the reference motion [Î”r s (t)] (Ï„ zul ); and emitting a control signal at an output of the processor that controls movement of said manipulator with respect to said path; wherein M is a mass matrix; q(t) is a vector of reference positions in joint coordinates; h is a vector embodying weight, gyroscopic, and frictional forces; Ï„ is a vector of drive forces, (Î¸ 1 , Î¸ 2 , Î¸ 3 ) are parameters for deviations from the reference motion; and n Î”r , b Î”r are normal and bi-normal vectors to the reference motion.