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In order to improve the calibration precision of 6DOF parallel mechanism, a calibration method based on external coordinate measurement is presented. The position and attitude informations of the parallel mechanism are acquired using common measuring devices and the residual equations with uniform measure are constructed. These equations can ensure the identifiability of each geometry parameter's, so no special auxiliary calibration equipments or redundant sensors are required. From the residual equations, the estimated values of geometry parameters are obtained by optimization method, and the ideal parameters are replaced by them for the parallel mechanism inverse kinematics calculation of to realize the error compensation. The simulation results show that this method can decrease the effect of measure noise, and the kinematics accuracy after calibration can reach the same order of magnitude as measurement noise since the errors of parallel mechanism's are not usually cumulated. The calibration accuracy is improved more than 5 times after error compensation by using the method. [ABSTRACT FROM AUTHOR]

Aiming at load simulating problem of the thrust vector control (TVC) system in launch vehicles, a new load simulator structure and its mathematical model are presented. The influence of main parameters on system's dynamic performance is analyzed by simulation. Building a prototype experiment system, multiple DOF load property is showed in a sweep frequency test. Simulation and experiment verify the feasibility of this load simulator structure, which lay a foundation for optimizing design parameters of the thrust vector servo mechanism and developing load simulators of heavy launch vehicles' servo systems. [ABSTRACT FROM AUTHOR]