Control strategy for a snake-like robot based on constraint force and verification by experiment

Abstract

This paper aims to develop a method for the locomotion of a snake-like robot, and proposes a control strategy based on the friction force between robot's body and the ground. Our concept of a control system design is that a control law should be based on the friction force as a real snake is. Both the motion equation of the robot and the friction force are derived by the Projection Method proposed by W. Blajer. The friction model is evaluated in the cost function of the control system design based on state dependent Riccati equation. As a result a derived control law takes the friction effect into account. We also build an experimental system. The effectiveness of the proposed method is verified by simulations and experiments.

A review on modelling, implementation, and control of snake robots

“…With position and/or heading control [102], [103], [104], [105], [106], [14], [16], [107], [15], [108], [17], [60], [109], [110], [10], [111], [112], [113], [114].…”

“…Directional control during lateral undulation is considered in [60,109]. The work in [110] proposes a position controller for a wheeled snake robot that takes ground friction forces into account. A similar approach is employed in [100], where deviations of the joint angles from their setpoints are used to modify the oscillatory joint motion, thereby enabling the snake robot to automatically adapt its motion to variations in the ground friction conditions.…”

A novel approach for modeling and tracking control of a passive-wheel snake robot

“…Prautsch and Mita 5 modeled a plat snake robot using Lagrangian equation and studied its tracking control performance based on Lyapunov theory. Date et al, 6,7 Watanabe et al, 8,9 Hicks and Ito, 10 and Toyoshima et al 11 modeled the snake and studied the optimized torque control of the system on the basis of classical dynamic theories. Lijieback et al [12][13][14] achieved the trajectory tracking controller design for the snake robot.…”

Two new design concepts for snake robot locomotion in unstructured environments

“…This approach is considered in [13], where the joint torques of a snake robot are specified solely in terms of the measured joint angles to achieve motion through a winding corridor, and in [14], which presents a control strategy that uses motor current measurements to adjust the shape of a snake robot moving through an elastically deformable channel. The approach is also employed in [15], which proposes a control strategy that takes ground friction forces into account, and in [16], where the deviations of the joint angles from their setpoints are used to modify the oscillatory joint motion, thereby enabling the robot to automatically adapt its motion to variations in the ground friction conditions. The works in [17]- [19] propose various gaits for motion in unstructured environments, such as climbing gaits.…”