Study On A Modular Robotic Anthropopathic Arm Based On The Sarrus Linkage

Modular robotic arms of multitudinous types have been employed in many fields, such as manufacturing, automation, service, military and so on. Traditional modular robotic arms are mostly composed of joint modules and link modules. There are three types of one-DOF joint modules: pivot joint module, rotational joint module and prism joint module. Link modules are fixed, which have no independent driving equipments. Modules that are able to act as both joints and links are employed in modular robotic arms to improve their versatility and flexibility.A novel modular robotic arm based on the Sarrus linkage is proposed in the thesis, in accordance with the needs of the development of modular robotic arm. As the Sarrus linkage is able to transfer motions and connect two adjacent modules, its application in robotic arms can widen their workspace and strengthen their flexibility. In this paper, the kinematics characters of the Sarrus linkage is first studied; then, the mathematic model of the robotic arm is built, and its kinematics features are also analysized, with both theoretical and simulation methods; at last, the experimental model of the arm is made up. The results demonstrated the rationality of employing the Sarrus linkage in robotic arm, and testified the validity of the design of the mechanical structure and control system of the modular robotic arm.The main contents of the thesis are as follows:(1)Basic theoretical study of the Sarrus linkage was made, including its DOF, kinematics, dynamics and so on. The analysis comes to the conclusions that the Sarrus linkage is a 1 DOF spatial mechanism, and it is able to export rotational motion, translational motion and winding motion—the combination of the former two motions. This section is the preparation for the application of the Sarrus linkage in robotic arms.(2)The models of modular robotic arms based on the Sarrus linkage are designed, including robotic modules and robots of different configurations. The robots are composed of the Sarrus module and two kinds of link modules, and they can be divided into two types: robots composed of only the Sarrus modules and robots composed of different modules.(3)The kinematics characters of the modular robotic arm based on the Sarrus linkage are studied, and the mathematical and simulation model of the arm are also built. The analysis comes to the conclusion that the idea of designing robotic arms of this kind is reasonable and advisable.(4)The experimental model of the modular robotic arm based on the Sarrus linkage is built up, and the conclusions of the experiment demonstrated that the former theoretical and simulation study of the robotic arm was correct, they also proved the idea of employing the Sarrus linkage in robotic arms was reasonable, as well as the design of the mechanical structure and control system of the modular robotic anthropopathic arm based on the Sarrus linkage.