A Loading And Unloading Manipulator Based On PLC

Recently, the need for manipulators in many factories and CNC machining centers is increasing with the development of industrial automation and the gradual increase of labor cost. The manipulator has faster and more flexible moving action, and can work under dangerous and extremely bad environment. Besides, it has a higher repeatable positioning accuracy and longer continuous working time. So if manipulators are used to do the loading and unloading work, it will greatly reduce the labor intensity of workers and the cost of production. What’s more, it will improve the production efficiency obviously.The design scheme of the manipulator is proposed according to the loading and unloading requirements, and the key parameters of the manipulator, which include the rated speed of the motor, the rated torque of the motor, the ratio of the reducer, the pitch diameter of the belt wheel and the pitch diameter of the gear, are determined through the combination of theoretical analysis and dynamic simulation. Then it is studied on the teaching, the trajectory-planning and the trajectory-executing. The main work and results are as follows:At first, the mechanical design scheme and the control design scheme of the manipulator are put forward, which contain the degrees of freedom, the trip, the maximum speed of each axis, the motor type of each axis and the transmission mode of each axis.Secondly, the key parameters of each axis are got through theoretical analysis, then the virtual prototype of each axis is built and simulated in ADAMS in order to verify the correctness of the theoretical analysis.Thirdly, the hardware of the control system is designed, including the selection of motors, the selection of controller, the selection of touch screen and the design of signal converter.Fourthly, the loading and unloading control scheme of the manipulator is designed, which contains homing, teaching, trajectory-planning and trajectory-executing. Then the HMI (Human Machine Interface) of each part is designed and the PLC programs of each part are written. And the experiment results show that the designed control scheme is effective.Finally, the research work is summarized and the content which would be improved is proposed.