opencat_micropython

micropython implementation for esp32 of the opencat

I used Ez 3D Printed OpenCat from thingiverse: https://www.thingiverse.com/thing:3384371

Here you see the first steps it made: https://www.youtube.com/watch?v=MNgKbt5TRXs

This project is in a very early state. I did not look at the original opencat firmware, so pinout is probably different. Servo ids: FLS, FLK, BLS, BLK, FRS, FRK, BRS, BRK, T, HY, HP

F: front leg
B: back (hind) leg
T: tail
H: head
L: left
R: right
S: shoulder
K: knee
Y: yaw (left-right, shake)
P: pitch (up-down, nod)

Features:

Two Link kinematics
- used for the legs to control the servo angles
linear motion plans for all legs, tail and head:
- A motion plan is a function in time that returns the servo angles theta
- f(time)=Theta1,Theta2
- defined by a set of 2D points and the time the movement between the points should take
parameterized leg positioning >> stand():
- height: avg leg height above ground in cm [default=7]
- tilt: height difference between front and hind legs [default=0]
- roll: height difference between left and right legs [default=0]
- ground_pos: mean ground position of the legs relative to the vertical projection of the shoulders [default=0]
- spread: difference in ground position between front and hind legs [default=0]
- t: time in seconds until this position is reached [default=1]
two different gaits: walk() and tripod_gait()
- all parameters of stand() and additionally:
- n_steps: number of steps (with all 4 legs) [default=10]
- lift: hight in cm of leg above ground [default=1]
- step_size: in cm [default=8]
- direction: difference of step size between left and right to walk left/right [default: 0]
- speed: speed in cm/second [default=6]
some simple gestures (sleep, eat, nod, shake haead, wag)

Simulator:

graphical simulator that runs the same code as the robot
text filed to run repl like commadns (e.g. "cat.walk()")

My Plans:

Software (ESP32 micropython)

telnet based remote control (also include in simulator?)
walk backwards (bug prevents negative speed or step_size)
more dyamic gaits
motion plan with circular trajectories ( better walking?)
integrate head and tail to stabilize waling
integrate sensors -> requires hardware
autonomous mode (obstical avoidance) -> requires sensors
more cute gestures
sound (meow?...) with according head movement
orientation aware motion plans (requires sensors)
object recognition (on camera module)
deepsleep standby?

Hardware