Mechanical And Control System Design Of An Omni-Directional Mobile Robot For Material Conveying

For the need of automatic flexible production line and the education of colleges, an omni-directional mobile robot for conveying materials is presented. The mechanical system and control system are introduced as two parts of the robot and analyzed by theories, while several experiments are designed.The robot is designed with layered and modular structure, including Chassis Layer, Controller Layer and Transfer Layer. It makes the robot easy to be repaired, developed and upgraded. To make the robot move flexibly in narrow space, the mobile mechanism is designed with four Mecanum wheels, which are driven by DC servo drives. The kinematics equations of the robot are derived in on-board coordinate system and world coordinate system. Transfer Layer includes two electric cylinders and one electrical transport roller. To keep the robot stable, the vertical damping mechanism is designed and installed, and it’s tested in production line.The control system is designed with layered structure to satisfy different functions. A Siemens S7-1217C PLC is used as the lower-layer controller, while a laptop computer is used as the upper-layer controller. The upper and lower layer controllers communicate with each other through the Ethernet by using OPC standard. The navigation device consists of a laser radar and a Kinect camera. The programs for logical control and motion control are designed, so that the robot can run in manual and auto modes. The robot is tested by experiments to prove the availability of control system design. The experiments include movement on straight lines and visual navigation.The robot is integrated in the automatic production line to convey materials.