Robots with increased number of degree-of-freedom with single exciting force

Abstract

This paper presents the results of the development and investigation of a new class of novel multi-degree-of-freedom robots based on a new concept – the application of kinematic pairs with alternatingdegree-of-freedom (DOF) controlled by a single force or moment, changing its direction in space. Thenumber of DOF of the kinematic pairs is controlled periodically from 0 to 3, exploiting the dependenceof frictional forces on the oscillation in the contact zone of links. The advantages of this new class ofrobots include significant weight reduction, simple design and control, and specific applications in spacerobotics and soft robotic spines. In more complicated cases of trunk robots, elastic kinematic pairs areused with a number of DOF controlled by electro- or magneto-rheological fluids with viscosities thatchange as a result of applied electric or magnetic fields. Expressions for the generalized inertia matrix ofthe robots with a large number of joints have been derived using the computer algebra technique withthe subsequent automatic program code generation. As shown in this paper, such an application coulddrastically reduce the number of floating point product operations for an efficient numerical simulationof robots.