Figure 13. Electric power consumption analysis also shows that for all three kinds of friction the system expends the same power.

From

Experimental Analysis of Friction Effects Affecting the Snake Robot Segment during Rectilinear Locomotion

Ivan Virgala, Alexander Gmiterko, Peter Frankovský

American Journal of Mechanical Engineering. 2013, 1(7), 412-416 doi:10.12691/ajme-1-7-52