chip updates: next steps to make the puppy step [updates]
So the last post we implemented the new IK system in the platform and we were able to get a few big successes that we weren’t able to get with the old IK system + software platform. Here’s a list:
° Control of stand/sit, x-position of the platform, yaw, and y-pos of the body fully from the controller with use of the joysticks
° The new kinematics is capable of a wider range of body positions and is computationally inexpensive as it uses a combination of closed form and numerical solutions instead of a single, computationally-expensive, numerical solution
° The system is now capable of incremental movements of the body and platform over-current protection without the use of a trajectory or trajectory runner
So now we want to get the platform walking, and there’s some steps we need to take to get that to happen. Right now there’s a small issue with the controls and because we aren’t using a trajectory and the points are very close together for incremental movement the platform is still a little jittery. We could implement some smoothing but for now it isn’t a huge issue. We do need to figure out a walking algorithm. We propose the following steps to do so:
° Implement a function that can generate a step trajectory for each of the legs individually, it needs to be capable of generating a step trajectory from any point to any other point in the leg’s coordinate frame
° Create a stepping order that makes sense from a controls perspective relating to the platform and previous experience/research
° Implement the control fully manually so we have full control over stepping and balance of the platform, we can implement learning later to automate the stepping
° Figure out a way to do this in multiple directions (forward, backward, and turning in both directions)
Here’s the stepping trajectory we came up with. We step both of the front legs first, transfer the weight to the front, step both of the rear legs, and then transfer the weight back center.
We’ll try to implement this soon enough within the next couple days now that the kinematics is working well.