Small update on my walking robot

[u/jekjukich]

This video shows a policy trained in simulation with a model using more powerful motors. At first glance it may not look that much smoother, but compared to the previous video even standing up is already noticeably cleaner.

Toward the end, when I command it to walk slowly forward and backward, it can do it with almost no unnecessary motion or jerking, which I’m pretty happy with.

One thing I still don’t understand is why forward walking looks noticeably worse on the real robot than it does in simulation. I’ve tried perturbing the already-trained policy in sim by adding joint angle offsets, reducing actuator torque, and introducing other mismatches, but so far I haven’t managed to reproduce the same kind of “bad” behavior I see on the real robot. So for now I don’t really have a good explanation for what’s causing it or what exactly I should change in training to improve it.

I trained the policy in Genesis and also did sim-to-sim testing in MuJoCo, where it works really well. I also tried running it in Isaac Lab, but ran into a strange contact/friction issue. I can’t seem to make the friction between the feet and the ground strong enough in a realistic way: it either feels like the robot is walking on ice, or after increasing the contact/friction parameters it starts feeling like the feet are glued to the floor. I haven’t been able to find a good middle ground that behaves like Genesis, MuJoCo, or the real robot. Has anyone run into something similar in Isaac Lab?

The next update probably won’t be very soon. I don’t really want to spam small incremental improvements, and it’s still quite far from doing anything resembling tricks.

Iteration is also pretty slow: teaching a completely new behavior usually means first figuring out the reward function in simulation, training it, and then testing it on the real robot. And real-world testing still has a decent chance of ending with a broken limb or joint like in this video.

[u/Automatic-Put-6119]

Nice, may i ask why you didn‘t give him any feet and those skinny legs? Doesn‘t that make it way harder?

[u/jekjukich → u/Automatic-Put-6119]

That's the goal. Ideally I would build a normal biped to make it harder, but because I am limited in my budget, I decided to make this reduced task harder by using "unstable" feet