Metrics and Optimization of Internal Poses for Highly Redundant Truss-Like Serialized Parallel Manipulators
This addresses kinematic challenges for specialized space assembly robots, representing an incremental improvement in optimization methods for this domain.
The paper tackles the inverse kinematics problem for over-actuated serialized Stewart platforms (Assemblers) used in autonomous in-space assembly by developing an algorithm to find feasible solutions and optimize poses to minimize actuator forces. Results from simulations show improvements in actuator forces, platform reachability, and applicability to high-payload assembly.
This paper presents a kinematic definition of a serialized Stewart platform designed for autonomous in-space assembly called an Assembler. The Assemblers architecture describes problems inherent to the inverse kinematics of over-actuated mixed kinematic systems. This paper also presents a methodology for optimizing poses. In order to accomplish this with the Assembler system, an algorithm for finding a feasible solution to its inverse kinematics was developed with a wrapper for a nonlinear optimization algorithm designed to minimize the magnitude of forces incurred by each actuator. A simulated version of an Assembler was placed into a number of representative poses, and the positions were optimized. The results of these optimizations are discussed in terms of actuator forces, reachability of the platform, and applicability to high-payload structure assembly capabilities.