Experimental results on kinematic calibration of parallel manipulators using a partial pose measurement device

This paper presents kinematic calibration of parallel manipulators with partial pose measurements, using a device that measures a rotation of the end-effect or along with its position. The device contains a linear variable differential transformer, a biaxial inclinometer, and a rotary sensor. The device is designed in a modular fashion, and links of different lengths can be used. Two additional kinematic parameters required for the measurement device are discussed, kinematic relations are derived, and cost function is established to perform calibration with the proposed device. The study is performed for a six-degree-of-freedom fully parallel HexaSlide mechanism (HSM). Experimental results show significant improvement in the accuracy of the HSM.