This paper discusses a path-following control of joint angles of a planar snake robot based on the port-Hamiltonian formulation. An existing controller is extended to solve the problem of the difficulty in specifying the moving direction. Furthermore, the effect of a bounded error in the input is analyzed, which provides a criterion to determine the controller parameters. The validity of the controller and the error analysis is tested via numerical simulations.

Swing-up and stabilizing control of an inverted pendulum is one of the most common experiments used for illustrating nonlinear control techniques. Since an actual inverted pendulum has a limited pivotal travel, its controller has to be designed to satisfy this constraint. However, it is difficult to design controllers for underactuated systems with state constraints, like inverted pendulums. In this paper we propose a robust control law which can swing up a translational inverted pendulum using a limited pivot travel effectively. Bearing in mind that the energy of the pendulum can be controlled according to the sign condition of pivot acceleration, we develop a control law for swinging up the pendulum which performs controlling acceleration of the pivot as well as limiting its travel. The swing-up controller consists of a lower-level controller that increases or decreases the energy of the pendulum and an upper-level controller that controls the pendulum energy to a given value by adjusting the lower-level controller using PID control techniques. The results of our simulations and experiments demonstrate the effectiveness of the proposed control law.

A key technology for a smart warehouse is the corporative control of mobile robots. This paper develops an efficient route generation method in the corporative control framework based on a future map, which has been recently proposed. For generating a route, we propose a graph, called the spatio-temporal graph, and the problem of finding a route is reduced into a shortest path problem of the graph. The effectiveness of the proposed method is demonstrated by numerical simulations.