Static Balancing of a Class of Spatial Parallel Platform Mechanisms

Abstract

Abstract This article discusses the development of statically balanced spatial parallel platform mechanisms. A mechanism is statically balanced if its potential energy is constant for all possible configurations. This property is very important for robotic manipulators with large payloads, since it means that the mechanism is statically stable for any configuration, i.e. zero actuator forces are required whenever the manipulator is at rest. Furthermore, only inertial forces have to be sustained while the manipulator is moving. The application that motivates this research is the use of parallel platform manipulators as motion bases in commercial flight simulators, where the weight of the cockpit results in a large static load. We first present a class of spatial parallel platform mechanisms of novel architecture that is suitable for static balancing. Then sufficient conditions on the kinematic parameters that guarantee static balancing are derived for this class. Finally a particular mechanism is studied in more detail to show the practicability of its design.