On-Orbit Calibration of a 7-DOF Space Arm

For space manipulator, high control precision is required to realize precise operation of the target object, which directly depends on the measurement of the structure parameters. However, because of the concussion during launch and the different gravity on-orbit, the structure parameters of the space manipulator can not keep the same as on the ground. Therefore, it is important to recalibrate the space manipulator on-orbit, which becomes difficult because high precious measurement devices such as theodolite can not be used. In this paper, an on-orbit calibration method is proposed. First, the error model of the structure parameters is established. Then, the orbit calibration data is measured by the hand-eye cameras. Finally, the structure parameters can be achieved by solving the error model with least square method. The proposed method can solve the errors of the hand-eye cameras related to the hand end, and it can improve the precision of calibration.