图4. 电机信号 $(F_{ M} = 35$\,N$\cdot$m, $F_{ m} = 10$\,N$\cdot$m)
Fig. 4. Switch signal of joint motor $(F_{ M} = 35$\,N$\cdot$m, $F_{ m} = 10$\,N$\cdot$m)