Active Control of Four-Bar Tensegrity-Membrane Systems

Tensegrity-membrane systems are deployable structures that can be utilized in space applications such as solar sails and radar systems. This work addresses the control design for four-bar tensegrity-membrane systems. The tendons act as actuators, and the system can be controlled by changing the rest-lengths of the tendons. Lagrange’s method is used to model the system, and the equations of motion are expressed as a set of differential-algebraic equations (DAE). For control design, the equations of motion of the system in the DAE form are converted into the form of second order ordinary differential equations based on coordinate partitioning and coordinate mapping. Since the number of control inputs is less than the number of state variables, these systems can be classified as underactuated nonlinear systems. The collocated partial feedback linearization (PFL) technique is implemented to design a nonlinear controller. Simulation results of the closed-loop system under initial perturbation are presented, and the performance of the controller is discussed.