Dynamic control for manipulator

In combination with a control system for a multiple link manipulator having a central processing unit having adequate storage and computational capabilities for generating motion signals indicative of the desired motion of each link, a linear dynamic control loop for generating actuator signals for activating actuators moving the individual links with the desired motion and sensors detecting the position and motion of said links for generating feedback signals to said central processing unit and said linear dynamic control loop, a method for correcting said actuator signals for the nonlinear dynamics of the manipulator characterized by:

• dividing the multiple links of the multiple link manipulator into a first set comprising a predetermined number of links and a second set comprising the remaining links;
• computing a first set of correction factors for said remaining links using recursive Newton-Euler dynamics in response to said desired motion signals and said feedback signals;
• computing a second set of correction factors for said predetermined number of links using Lagrangian dynamics in response to said desired motion signals, said feedback signals and said first set of correction factors;
• summing said correction factors of said first and second set of correction factors with their associated actuator signals to generate corrected actuator signals corrected for the nonlinear dynamics of the manipulator links;
• and
• activating the individual actuators of the manipulator with said corrected actuator signals to move their associated link with the desired motion.

A control system for a multiple link manipulator having a base and a plurality of actuators, at least one actuator associated with each manipulator link, for moving its associated link in response to input signals, said control system comprising:

• sensor means associated with each manipulator link for generating feedback signals indicative of the actual position and motion of each manipulator link;
• central processing unit means having adequate storage and computation means responsive to a stored program and said feedback signals for generating motion signals indicative of the desired motion of the individual manipulator links;
• a linear dynamic control loop responsive to said desired motion signals and said feedback signals for generating said input signals activating said plurality of actuators to move their associated link with the desired motion;
• a nonlinear dynamic control loop responsive to said desired motion signals and said feedback signals for generating correction factor signals for each of the actuators compensating for the nonlinear dynamics of the manipulator, said nonlinear dynamics control loop computing said correction factors for a predetermined number of actuators, using Lagrangian dynamics and computing said correction factors for the remaining actuators using recursive Newton-Euler dynamics;
• and
• means for individually summing said correction factors with the input signals to generate corrected input signals, corrected for the nonlinear dynamics of the manipulator.