Task space angular velocity blending for real-time trajectory generation

A method of controlling a robot manipulator moving toward a target frame F.sub.0 with a target velocity v.sub.0 comprising a linear target velocity .nu. with an angular target velocity .omega..sub.0 to smoothly and continuously divert said robot manipulator to a subsequent frame F.sub.1, said target frame being associated with a target transition time T.sub.0 and said subsequent frame being associated with a subsequent transition time T.sub.1, said method comprising the steps of:

• determining a global transition velocity v.sub.1 necessary to move said manipulator from said target frame F.sub.0 to said subsequent frame F.sub.1 within said subsequent transition time T.sub.1, said global transition velocity comprising a linear transition velocity .nu..sub.1 and an angular transition velocity .omega..sub.1 ;
• defining a blend time interval 2.tau..sub.0 within which the global velocity of said robot manipulator is to be changed from a global target velocity v.sub.0 to said global transition velocity v.sub.1 and dividing said blend time interval 2.tau..sub.0 into discrete time segments .delta.t;
• during each one of said discrete time segments .delta.t of said blend interval 2.tau..sub.0 ;
• (a) computing a blended global velocity v of said manipulator as a blend of said global target velocity v.sub.0 and said global transition velocity v.sub.1, said blended global velocity v being at least approximately equal to said target global velocity v.sub.0 at the beginning of said blend time interval and at least approximately equal to said global transition velocity v.sub.1 at the end of said blend time interval, said blended global velocity v comprising a blended angular velocity .omega. and a blended linear velocity .nu., and
• (b) rotating said manipulator by an incremental rotation corresponding to an integration of said blended angular velocity .omega. over one discrete time segment .delta.t.