Design of a deployable mechanism based on 7R-6R-double-loop units for mars decelerators

The increasing interest in decelerators utilized in Mars exploration has heightened the need for a decelerator with the function of deploying and a low ballistic coefficient. This paper designed a novel deployable mechanism based on 7R-6R double-loop units for Mars decelerators. First, this paper designed a new double-loop deployable unit coupled by a 7R loop and 6R loop through type synthesis based on line geometry. Then, the mobility of the mechanism was proven to be single by using screw theory. In addition, the singularity of the mechanism was investigated, which contains 3 singular configurations. Geometric conditions to avoid singular configurations were obtained in the singularity analysis. Finally, a scaled model utilized to verify the configuration and assemblability of the deployable unit was developed.