A Deployable Robot Based On The Bricard Linkage

In recent years,there has been a growing interest in the development of transformable robots,which can adjust their morphology to adapt to multiple tasks or uncertain environment for reconnaissance,rescue missions and space applications.Meanwhile,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 transformable robots based on the deployable structures.For the property that robot can transform its geometric dimension and working space largely for different tasks,this thesis is to study the transformable robots whose body is formed by a deployable structure.This thesis proposes a transformable robot by applying a threefold-symmetric Bricard linkage as the body structure.Firstly,according to the kinematic property of the linkage,the configuration and the mechanical model were designed.To traverse through the constrained environment,the geometrics of the robot were 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 was designed.Based on the kinematic model,a relationship among the displacement,configuration of the robot and the rotation angle of the motors was established.Meanwhile,control system was constructed to control the movement of the robot.Finally,the robotic prototype was assembled and three experiments were conducted.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 by changing its configuration from folded to deployed,and vice versa.The result of the thesis will be a key input to the kinematic theory of the transformable robots.It will also play as an important fundamental for the future space robots,rescue robots and service robots.