Gear Shift Patterns in Uncertain Terrestrial Locomotion Systems

Abstract

The paper focusses on various gear shift patterns in an uncertain terrestrial locomotion system, i.e., in a wormlike locomotion system (WLLS). A WLLS in this theory is understood as a system living in a straight line (one dominant linear dimension) with no active (i.e., driving) legs nor wheels. A mechanical model comprises a chain of discrete mass points (1) connected by viscoelastic force actuators and (2) having ground interaction via spikes which make the velocities unidirectional. A spike means any device which realizes this restriction. The distances between two consecutive mass points are changed by an adaptive controller. In combination with the ground contact spikes, this results in an undulatory locomotion of the system. Optimal gaits which achieve a defined number and succession of resting mass points as well as the resulting velocity are developed in numerical investigations. We present a gait shifting procedure incorporating a combination of speed adjustment and gait change that enables optimal crawling for predefined limits of actuator or spike force load.