Nonlinear Control Problems for Rest-to-Rest Maneuvers of Multi-Body Vehicles using Prismatic Actuators

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

PROJECT SUMMARY Page A This proposal describes a novel research program on nonlinear control of multi-body vehicles operating under the action of gravitational forces and control forces generated by prismatic actuators. Multi-body vehicles are mechanical systems consisting of a rigid base body that can translate and rotate in three dimensions and auxiliary bodies that are constrained to move relative to the base body and to one another. The multi-body vehicles are controlled using prismatic actuator devices, mounted on the base body. These are linear electromechanical actuators that move a proof mass along a track fixed to the base body. This is a novel actuation technology that has great potential for providing new maneuvering capabilities, namely precision translation and global attitude maneuvers, for multi-body vehicles. On the other hand, the design and operation of such multi-body vehicles present many challenges since they are not fully actuated in the sense that there are fewer control inputs than there are degrees of freedom to be controlled. Key aspects of the proposed research, from which arise the major research challenges, are: (1) the presence of controlled mechanical symmetries and their associated integrals of motion and (2) the objective of achieving arbitrary rest to rest maneuvers for the multi-body vehicles. Although some nonlinear control problems for multi-body mechanical systems are relatively simple, the problems posed in this research can not be adequately handled based on the current state of knowledge. The proposed research is the culmination of the NSF supported research of the principal investigator over the last fourteen years. It represents an extension of his previous research on nonlinear control of constrained and underactuated mechanical systems to new problems that have not previously been amenable to study using traditional nonlinear control methods. The expected contributions of the proposed research are: (1) the development of nonlinear control theory for the class of multi-body vehicles studied, (2) the development of innovative new system design and control strategies for multi-body vehicles, and (3) educational impacts through student participation in the research. The research concepts are to be applied to maneuvering vehicles operating in space or under water, and they are ideally suited for small-scale intelligent autonomous sensor systems operating in space or under water. The proposed research has the potential to provide new and enhanced maneuvering capabilities for multi-body vehicles, thereby contributing to the overall engineering infrastructure in transportation, exploration, remote sensing, and surveillance.