Deployable structures have the advantage of being able to change their size and morphology significantly with minimal mobility. Yet, there are very limited numbers of deployable robots. This paper proposes a transformable robot by applying a threefold-symmetric Bricard linkage as the body structure. The geometries of the robot are investigated to set up relationships between its height/foot span and the joint angles of the linkage. The locomotion gaits of the robot can be realized through the deploying and folding motions of the Bricard linkage. From this, the corresponding gait controller is designed. Experimental results show that the robot can move in an arbitrary direction and follow a given path. Moreover, it is capable of moving through limited space easily by changing its configuration from folded to deployed, and vice versa. (C) 2017 Elsevier Ltd. All rights reserved.

A large variety of transformable robots were proposed in the past decades, which were mainly based on reconfigurable mechanisms. Meanwhile, deployable structures have been extensively applied to various fields, such as aerospace industry, civil engineering, and medical engineering. This paper presents a new method to integrate deployable structures to the design of transformable robots. A threefold-symmetric Bricard linkage is analyzed and used as the body structure of the robot. Gait control is then achieved by using the deploying and folding motion of the Bricard linkage. Experimental results show that the robot is capable of moving through limited space with single degree-of-freedom (DOF).