Constraint-integrated inverse kinematics method for dual-arm motion

Abstract

Dual-arm motion is a critical capability for a multi-branch space robot in on-orbit missions. To address on-orbit motion challenges specific to SRS branch configurations, a constraint-integrated inverse kinematics (CIIK) method is proposed. This method employs joint points to equivalently represent the redundant spatial robot, which comprises dual arms and a torso. An analytical expression for the inverse kinematics is derived, ensuring both accuracy and computational efficiency in the solution. Constraints are imposed on the torso through spatial vectors to mitigate the impact of constraint computations on the efficiency of inverse kinematics solutions. Furthermore, a mapping method between joint points and joint angles is proposed, which can obtain effective and smooth joint angles during continuous motion. By comparing with widely adopted inverse kinematics methods, CIIK demonstrates superior performance in terms of computational efficiency, solve rate, and joint angle continuity under unconstrained mode. Simulations and physical experiments were conducted by applying constraints to the torso. The results indicate that CIIK does not increase computation time and exhibits good solving performance in constrained mode.