The existing space manipulator joints with permanent magnet synchronous motors (PMSMs) have many deficiencies, such as large size, low output torque, and long settling time. In this paper, the dynamic behavior of space manipulators with smart giant magnetostrictive material (GMM) joints is studied. A nonlinear dynamic model considering the magneto–thermal–mechanical coupling for the manipulator is established, and an experiment is conducted to evaluate the performance of the GMM joint. After verifying the accuracy and availability of the model, we find that comparing with the PMSM joint, manipulators with the GMM joint have better performance, which has large output torque, fast settling time, and wide temperature adaptation range. These essential investigations will be of significant benefit to the applications in space manipulators.

In the paper, a magneto-mechanic hysteresis model for giant magnetostrictive materials is suggested by considering the effect of the domain rotation and domain wall motion on the magnetization process under prestress and the applied magnetic field. The coercive force, which is magneto-mechanic dependent, is proposed instead of a pinning constant in the Jiles–Atherton model. The model can well predict the characteristics of a magnetization-applied field curve and magnetostrictive strain-applied field curve shown in the experiment, especially the “overturn phenomenon” under different compressive prestresses. Furthermore, the effect of the microstructure parameter, such as the ratio of the domain wall thickness to the internal stress wavelength, the amplitude of internal stress, the ratio of the domain wall thickness to the inclusion radius, and inclusion consistency, on coercive force under applied prestress can also be described by the model. The comparison between the results predicted by the model and experiment shows that the model is suited for a wide-ranging applied magnetic field.