Design Of Light Weight Manipulator For Ground Mobile Robot

Because of the development of science and technology progress, ground mobile robot can replace human to do more dangerous missions. This paper describes the design of a light weight manipulator for land mobile robot.In structural, the manipulator is designed under the idea of the use of mechanical and electrical integration; and joint internal integrated a variety of sensor systems. Due to the use of modular design, the elbow-joint and the basic-joint have exactly the same structure. Because of the manipulator's own gravity, the shoulder-joint has a similar structure, but according to its load torque to choose motors and harmonic drive models. The DOF configuration of the manipulator is rotary-pitch-pitch-pitch-yaw. To avoid the cable entanglement of manipulator in the course of its work, a big central hole in the joint was designed for the placement of the cables and plugs in the manipulator. To prevent the accident damage led by sudden death of manipulator, the joints were installed within a brake.Joint torque sensor is important sensor of flexible joint. Joint torque sensor not only provides force information for compliant manipulator control, but also can be used for joint control of the position. The torque sensor system has four strain beams, four protection beams. The strain beam's size is optimized through the static analysis of torque sensor. In four strain beams eight strain gauges are installed, comprising two Wheatstone bridge circuits. Through the process of the two-bridge output signal, the error caused by the rotating - wave generator can be eliminated.This paper established the manipulator's joint coordinate system model, and gave the forward kinematics of manipulator. Using inverse transform method, The inverse kinematics used for the optimization of base reactions can be got. With the configuration of manipulator and the range of joint motion, the manipulator's work space can be draw.Through the Newton-Euler method of iterative formula, a dynamic model of the manipulator is established. Using global optimization method, the base reaction torque is optimized, with or without the middle path between start-point and end-point.