3 Locomotion controller

The locomotion controller generates the PWM signals for positioning the servos from the wave parameters: waveform, amplitude, and wavelength. Higher level systems could move the robot just specifying this parameters. Furthermore, at this stage, the movement of the robot is independent of the number of articulations. The planificator algorithm will determine the best wave and its parameters based on the terrain characteristics. For example, if the robot had to pass through a tube, an amplitude smaller than the section of the tube will be needed. If the obstacle is an step, a bigger amplitude will be used.

The architecture is shown in figure [*]. The controller is composed of three subsystems. Control table is the central part, where the angular position vectors are stored. The contents of this table determines the movement (section [*]). The position controller generates the PWM signals that are applied to the servos to set their angular position.

Figure: Architecture of the locomotion controller

Finally, the movement generator obtain the gait control table from the parameter of the wave (waveform, amplitude and wavelength). It is implemented by software, using the algorithm described in section [*].

Juan Gonzalez 2004-10-08