During my PhD research, I was investigating how to apply legged robots for planetary exploration. I am fascinated by the idea of letting machines go where no human has ever gone before and increase the knowledge and understanding of the worlds that surround us. Probably the best example in this context is the SpaceBok robot, which has been developed as part of a student project which I supervised.
I was interested in locomotion strategies for walking on celestial bodies. One that stroke me as exciting was the use of “jumping” gaits. Gaits with extended flight phases are quite useful as soon as you move into lower-than-earth gravity environments. Although they also introduce new challenges such as the stabilization of the robot during flight.
For space robotics, it is essential to demonstrate the capabilities of a system in environments that is mimicking actual conditions in some way. Thus, we performed locomotion experiments with SpaceBok on real Martian analog soil at RUAG, Switzerland. For this purpose, we changed the feet of the robot to avoid sinkage, and provide high traction. As a result, we could show that the robot is capable of climbing even the steepest inclinations possible in the testbed (25degrees).
There are more challenges in exploring environments in which humans cannot just quickly intervene and save the robot. For example, mars rovers often got stuck in sand, which caused severe disruption and, in some cases, even the end of the mission. Legged robots have the advantage that they can use their limbs to “probe” the environment to assess the safety of a foothold. Similar to what humans would do as well.
Related to that is also the idea that we could use our limbs to not only assess the safety of a foothold but use it as some sort of measurement device. In this example, the robot can determine the roughness of concrete, which, in the next step, can be used to classify damages.
The robot needs to have the ability to recharge autonomously to be completely independent of human intervention. A fully docking station can realize this. In this case, the robot was also purged with an inert gas (required for use in explosive environments).