5 Configuration 3: Three-modules star

Figure: The three-modules star configuration.

The last configuration tested was a three-modules star, shown in Figure. The modules form a star of three points with an angular distance of $120^{0}$.

It can move on a 2D surface, in three directions, as well as performing rotations in the yaw axis. If two adjacent modules are in phase and the opposite has $\bigtriangleup\phi\in[100,150]$, it moves on a straight in the direction of the module out of phase. However, this movement is very surface-dependant.

When the increment of phase between the three modules is $120^{o}$, for example, $\phi_{1}=0$, $\phi_{2}=120^{o}$ and $\phi_{3}=240^{o}$, the robot performs a slow rotation in the yaw axis.