Relay Control of a Morphing Tensegrity Structure with Distributed Pneumatic Actuation

It is believed that structures and actuation systems should be tightly integrated together in the future to create lightweight dynamic machines. This requires actuators to be distributed through the structure. A tensegrity structure is a very promising candidate for this future integration due to its potentially excellent stiffness and strength-to-weight ratio, and the inherent advantage of being a multi-element structure into which actuators can be embedded. In this paper, an antagonistic multi-axis control of a tensegrity structure is achieved, using a dead band controller. The controller is studied by the describing function technique, and a condition to guarantee stability is derived. The stability condition is illustrated with simulation and experimental results, and is used as a general rule to achieve stable control of the structure.