Three different minimal modular configurations has been tested. Using only two modules, sinusoidal locomotion in straight line can be achieved. The difference of phase ( ) between the two signal determines the coordination. The speed is controlled modifying the amplitude of the sinusoidal wave.
When adding one more module in the yaw axis, three new gaits can be performed: 2D sinusoidal motion, lateral rolling and lateral shift. All of them are realized using sinusoidal waves, changing the amplitude and phase.
Lateral shift and rolling differs only on the amplitude range. When all the amplitudes are below 40, a lateral shift motion is performed. If a value greater or equal to 60 is applied, lateral rolling is achieved.
In future works, new configuration will be constructed and tested, looking for simple coordination methods. Also, genetic algorithm will be used for the calculation of the optimal parameters (amplitude, phase) of these minimal configurations.