InterMarsnet was a proposed ESA science mission to Mars where a micro mobile robot was intended to apply instruments in the surroundings of a small lander. The microrover had to fulfil the requirements below.
The WAROMA (WAlking RObot for Mars Applications) was proposed by the A&R Section as candidate for the microrover.
Depending of the mission phase and working situation, several operation modes were identified for WAROMA.
WAROMA had excellent storage capabilities, as the legs can be placed close to the body, needed when it is stowage inside the mother spacecraft.
Nominal Walking mode
a wave gait with a duty factor (ß) of 0.5 seemed very convenient since it was the only one that reduces the interaction forces among legs and therefore the slippage phenomenon and energetic losses.
In this gait there are main two phases: the supporting-pushing phase and transfer phase.
This mode includes turning motions performed when the legs in opposite sides turn in opposite directions.
If during the transfer phase the front legs detected an obstacle, WAROMA was able to lift itself over the obstacle.
If WAROMA flipped over, happening quite possible in rough terrains, WAROMA was able to walk with the instruments down until it could recover the normal walking mode.
After turning over (see the section before), WAROMA has good recovery capabilities to come back to its nominal vertical attitude just moving appropriately one or several legs.
Unlike wheeled rovers, in the motor/leg position had to be perfectly known in this concept. The coordination of all the legs during time slots (called "gait") made use of angular position sensors on each leg. These were the possible actuation schemes envisaged for WAROMA:
The WAROMA concept was implemented in the "PROtotype of LEgged Rover" (PROLERO) activity.
In this activity the concept of WAROMA was extended with an additional set of legs (bringing the total to 6 legs) which allowed more advanced gait schemes.
PROLERO was tested in the WAROMA configuration (4 legs) at the ESA's Planetary Utilisation Facility/B (PUTB). Tests confirmed the validity of the concept.
Last update: 3 October 2006