‘multi-path’ Motion of Deployable Structures

A recently developed, rigid-panel deployable antenna has shown, unexpectedly, a kind of multi-path behaviour. A physical model of the antenna deploys automatically without problems but, during retraction, it attempts to follow an alternative path and gradually locks up. Manual intervention is necessary to take the model back to its nominal retraction path, and this successfully completes the retraction process. A simple mechanical model of the antenna is analysed, and it is found that a similar type of ‘multi-path’ behaviour occurs for certain parameter values. Thus, by exploring how changes in the system parameters affect the multi-path behaviour, a way of improving the antenna design is obtained. M. Schulz and S. Pellegrino. 2