Robust control of a brachiating robot

Abstract

Abstract-This paper investigates the robust control of an underactuated brachiating robot. The control schemes are motivated by the applications that require robots to move through lattice structures, such as the inspection and maintenance of power transmission lines and towers. Inspired by the pendulum-like movements in gibbons' arboreal locomotion, the controllers are designed to synchronize the brachiator with a virtual oscillator. Two schemes are proposed: a modeldependent feedback linearization scheme and a sliding-mode scheme that is independent of the system model. The numerical results illustrate that the proposed schemes are robust to the arbitrary initial configurations of the brachiator and the limitation in the motor torque at the elbow joint. They are able to perform successful fast swing-up and dynamic brachiating in a unified control framework. Furthermore, both controllers enable the underactuated robot to brachiate along a structural member with an upward slope.

A Nonlinear Optimal Control Approach for Multi-DOF Brachiation Robots

“…On the other side, functioning of these robotic systems in an underactuation mode signi¯es that these robots are fault tolerant in the case of actuators' failures and that they continue to perform reliably their tasks even if speci¯c actuators are subjected to a fault. [10][11][12] So far, several nonlinear control methods have been proposed for these robotic systems. [13][14][15] There have been several attempts to treat the related control problem with the use of global linearization-based techniques or with the use of robust control methods such as sliding-mode control.…”

Robust Control Synthesis and Verification for Wire-Borne Underactuated Brachiating Robots Using Sum-of-Squares Optimization

“…Pchelkin et al [9] presented an optimization framework to generate trajectories for energy efficient brachiation of a 24-DoF Gorilla robot on horizontal ladder bars. A modelfree sliding mode control scheme was presented in [10], [11] for brachiating along a rigid structural member with an upward slope. More recently, a three-link brachiation robot was presented in [12], which used an iterative LQR algorithm for trajectory generation and a combination of a cascaded PID control and an input-output linearization controller to track desired trajectories and swing along monkey bars.…”