Optimizing a mechanism for best performance can be a complex task, particularly for robots that take advantage of an animal’s anatomy.

This paper studies the effect of modular torque for a snake-like robot, first analytically and then experimentally. The authors find that, in the physical robot, it is best to measure electrical current through the actuator instead of through torque, relying on the linear relationship between these quantities.

This very promising research has already resulted in a reduced version of a modular robot that substitutes fish-like mobility with snake-like mobility. This means that the authors changed the disposition of the actuators and the relationship between the individual modules composing the robot. Rezaei et al. realized that, for the actual robot, they must pay attention to the holes through which the connecting moving wires pass, since friction is created; for snake-like movements this implies a severe drag, unless they apply some means of smoothing the contact.

I highly recommend this paper to all robot researchers who specialize in animal-like designs. Other robot specialists and students will find that the analytical part is particularly illustrative of the forces acting upon the joints of a robot.