Online optimization scheme with dual-mode controller for redundancy-resolution with torque constraints

•A dual-mode online optimization method for the redundancy-resolution with torque constraints is proposed in this paper, which extends the constraints in the kinematics level to the dynamics level.•The inequality constraints model is designed in the torque level, synthetically considered the constraints in the joint velocity and acceleration level.•Besides, a Kintro instrument is applied for redundancy-resolution first time.

In this paper, an online optimization scheme is proposed for the real time path-tracking control of the redundant robot manipulator. In the proposed scheme, the inequality constraints are extended to the torque level to avoid the torque saturation. Besides, a dual-mode optimal controller is used to yield a feasible input during each control period, to resolve the solution space decreasing problem. Then the scheme is formulated as a Quadratic Program (QP), the computationally efficient Knitro-Based solver is applied to remedy the inescapable redundancy-resolution problem. Furthermore, the comparisons based on the different path tracking simulations between the proposed method and the velocity-level schemes demonstrate that the former is safer and more applicable. The experiment on a physical robot system further verifies the physical realizability of the proposed method.