Development of experimental paper-feeding system using crawling-like locomotion robot

The authors have investigated novel crawling-like locomotion robots that move on slippery downhill and level surface. They numerically showed that high-speed forward sliding locomotion can be generated by positively utilizing the effects of friction force acting on the ground contact point, which is underactuated however indirectly excited by synchronizing the frame rotation via entrainment effect, as well as concentrating the sliding direction via damping effect. After that, they considered to utilize the robot as an actuator by grounding it via a passive rotational joint as shown in Fig. 1 (a): a simple paper-feeding system. The wobbling length, l3 [m], is controlled to follow the desired trajectory, yd(t) = Am sin (2πfct). Through basic numerical simulations, it was confirmed that the robot’s forward motion can be successfully transformed to the paper-feeding motion as shown in Fig. 1 (b). The paper (transported object) model is specified as mpẍp = −μλc − Cpẋp, and is fed in the negative direction of the X-axis by the frictional force generated by the reciprocating motion of the robot body frame. Parametric studies showed that the feeding speed is increased with the increase of the viscosity coefficient in the body frame, c [N·s/m], but the change of the elastic coefficient, k [N/m], is less effective. It was also confirmed that the feeding speed can be controlled by adjusting the wobbling frequency, fc [Hz], and the viscosity coefficient in the paper, Cp [N·s/m]. To confirm the validity of the above numerical results, we developed a prototype paper-