For general dynamic pick and place tasks that the objects are transferred with high speed by the conveyor belt, the capability of a delta robot to track the traveling objects is very important for the efficiency. To meet the needs of precision and smooth control, a computed-torque control scheme for conveyor tracking is implemented in this paper. For higher efficiency and accuracy, computer vision system, encoder and conveyor belt region are incorporated into the control scheme. Dividing the conveyor belt into three regions, the robot is commanded to track, pick and give up according to the subregions. Conveyor belt is equipped with an encoder that provides the controller with real-time position and speed of the belt. Based upon those informations, the controller automatically compensates the end positions with respect to the belt to adjust for the position of the conveyor. Then, the conveyor tracking problem is converted to a subregional tracking problem.

In this paper, an electric transmission communication system of micro-V-groove ultra-precision CNC machine with the Mitsubishi PLC is designed. Different from the traditional method using the RS232-BD board, which has to communicate with PLC by programming offline, the system we design connects PC and PLC more directly and is more suitable for micro-V-groove ultra-precision CNC machine tool because of its real time. Embed the communication system in the CNC system, all the external devices can be monitored real-timely and the machine has run successfully.