Key Technology Research Of SMD Manipulator With Multiple Joints

The design of conventional manipulator is based on the style of one-joint-one-motor and every joint is driven by a motor. Compared to the mass of joint, the mass of the sevor motor is very big and the actuators often contribute a significant portion of the weight of manipulator outspreading. And it is a big challenge to design the little sevor motor now. As for the light manipulator design with big ratio between load and mass of joint, it is interesting to investigate the solution of compressing the components and using lesser motors to actuate more joints which can be used to decrease the mass of outspreading manipulator. This dissertation does some in-depth investigations on development of 6DOFs manipulator based on the methods of lighter manipulator design, the new mechanism of transforming, motion error model and clutch control system.Firstly, based on the structural features of the lighter manipulator and with reference to the conventional design, three methods of lighter manipulator design are proposed which are the techique of single-motor-driven, the principle of functions replacement based on dynamics, and modular design based on general bevel structrue. According to the three methods, the structural features of clutch coupling transforming mechanism are studied for joint design based on clutch working. Two joints designs based on clutch coupling transforming is introduced which axes are perpendicular to each other. The two joints are the component of a robot module with 2DoFs. A multi-joint manipulator is designed based on the robot module.Secondly, a motion model for rigid manipulator is built which joints axes are perpendicular to each other. The trajectory of the end of manipulator is studied by the kinematics of robot. The error model is built for flexible manipulator with flexible joint, and the motion error of flexible manipulator is studied under the same rules of joint motion with rigid manipulator. And the error model is built for the flexible manipulator with eccentric mass and the motion error for eccentric mass mounted in the joint is studied through comparison with the flexible manipulator with no eccentric mass in the joint.Thirdly, as for the joint structural features, manipulator performance for dynamic and kinematic is studied in the perspectives of main speed of joint, frequency characteristic and work space. The end of manipulator is simulated in the work space by software, and the frequencies of structure are obtained for control system. Forthly, with the analysis of clutch working process, a dynamic model is established for accurate control. According to the load of joint, the model of cluch with low speed and heavy load is established for the velocity modulated control system. Two parameters of control clutch system are studied. And a model for joint control is studied based on the simple clutch system. The single joint and double joints control system are simulated for position control in theory.Finally, it presents that the implementation of a new manipulator with six joints is driven by a DC motor. Two experiments and simulations which are line tracking and arc tracking are shown to verify the experimental system. And the methods for error compenstation are proposed in the structure and control system design.