Research On Vehicle Servo Lifting Pan-tilt

Vehicle servo lifting pan-tilt is a kind of system which is lifted mast type of bearing platform fixed in a mobile car. It can help the vehicle improve the distance of photoelectric system such as vehicle investigation, views aim and fire control during motion. At the same time, the vehicle can hid itself better and improve survivability.The development situation of servo pan-tilt and vehicle servo lifting system is systematically overview in this paper. According to the design requirement of vehicle servo lifting pan-tilt system, lifting system is screw-nut mechanism. The rotation and pitch motion are controlled by two motors separately. The concrete research contents as follows:To ensure the stability of the system, the strength of screw-nut mechanism according to the characteristics of them are checked in this paper. And the kinematics constraint equations of the three degrees of freedom system are established according to the structural characteristics of servo lifting pan-tilt system. Finite element model of key components of the system is established and static analysis is done to obtain the stress and strain of the pats. The strength and stiffness of the key parts are checked, and increasing the contact area and rounded structure can eliminate concentration stress.The mathematical model of the forward and inverse kinematics solution are derived, using the motion constraint equations. Based on the kinematics solution, the workspace of the robot is analyzed. Dynamic models of lifting system and pan-tilt system are established separately. Based on this model the driving torque is derived, which provides basis for the choice of motors and controllers.The control system adopts decentralized control, the hardware contain the upper PC computer and the lower servo control unit of each joint. The mathematical model of DC, the closed loop control models of lifting mechanism and pan-tilt are established using SimMechanics and Simulink blocks of MATLAB soft ware. Single-joint speed and position control of dual-loop simulation is finished. And the coordinate control simulation of the end of the robot is done according to the desired trajectory to check the correctness of the model.At last, using the Autodesk Inventor 2010 engineering soft ware, the models of parts are established according to the agency program and modeling progress of three-dimensional soft ware. The three-dimensional models of lifting mechanism, pan-tilt and lifting pan-tilt system are assembled by those parts.