This is about an unexpected but probably unavoidable, and hopefully somewhat interesting, distraction.
M.E.T. – Martian Emergency Team
In the last few weeks, we have been making legs, physical and virtual. We wanted to experiment with the ratios of the different leg sections to see which would yield the best results. We wanted the robot to make smaller steps, and therefore be more manoeverable, as the speed could still remain the same via the motors without having to take long steps.
We already had a robot that could walk (more or less), but now to improve it, we are taking a few steps back: in fact, we started by removing the legs completely! This might sound somewhat backwards, and it definitely felt that way for a while…
There is a lot happening in a robot’s “brain”: processing inputs coming in from various sensors at different rates, low-level outputs to control motors or other actuators, possibly combined with feedback loops. And there is the logic that actually decides what to do, keeping track of everything, maybe making simple plans and executing them. Sometimes it’s just a direct reaction to inputs (e.g. left motor power = some function of distance values), sometimes it’s much higher level, e.g. “now that we’ve visited the red corner, go back, start turning and look for something blue”. Even if you don’t worry too much about “architecture”, the question will come up eventually: how do you put all this together in software?
In 2018 we had a crazy idea: we decided to compete at Pi Wars for the first time, as Mars Exploration Team, and built our first robot, modelled after the Mars rovers, with four individually powered and steerable wheels. It was a fairly complicated design for a first experiment. It mostly worked, but it was somewhat unfinished, and we failed at most of the challenges.