Research And Design Of The Antenna Mount Based On A Parallel Mechanism

Many different styles of antenna mount have great function in antenna dynamic tracking. The OVER-TOP tracking and collector ring problems degrade the ability of dynamic tracking and the dependability of antenna systems. The six degrees of freedom Stewart platform is good at high stiffness and low weight, no blind area and collector ring, could greatly improve the dynamic tracking ability and dependability, reduce the cost of system. The research works based on Stewart platform, a serial works had been putted on configuration, structure design and re-checking, calibration, and accuracy analysis.Through the kinematics analysis of the machine, the structure and workspace of the Stewart parallel mechanism was got, the principle of large angle rotation pose was also analyzed. The speed of Stewart parallel mechanism is analyzed carefully, the compare had been done between normal antenna mount, and the result showed the new mechanism has no blind area.Secondly, the structure of Stewart parallel mechanism was designed, and the kinetics analysis was done by ADAMS, the stiffness and intensity of bars was analyzed by AnsysWorkbench. The control system was also finished. The position error of joint and the length error of bars is analyzed by Monte Carlo method. The calibration is finished with genetic algorithm, The joint error is calibrated by laser tracker, and the precision of pose is highly improved. The sample show the new mechanism meets the requirements.At last, The workspace of the mechanism with fault tolerant strategy was analyzed.and the fault-tolerant strategy of adjusting mechanism is put forward based on redundant DOF. The DOF of the mechanism with single link fault is analyzed, and the change of the workspace is comparised, it is a new method for improving the reliability of the mount.