Kinematics and frames
Body frame and world frame, the rotation matrix between them, and the inverse kinematics that turn a velocity you want in the world into the command this drive needs.
Start in the simulator- U2.1 Two frames The robot's forward is not the world's forward. Naming the frame is half the work.
- U2.2 The rotation matrix Turning a vector from one frame into the other, in two dimensions, by hand and in code.
- U2.3 A drive that goes sideways Three degrees of freedom on the floor, and what holonomic buys you.
- U2.4 Forward kinematics From the command to the body velocity to the path over the ground.
- U2.5 Inverse kinematics The useful direction: a velocity in the world, a heading, and the command that produces it.
- U2.6 Go to a point The first useful controller: a vector to the target, straight through the inverse kinematics.
- U2.7 Project: a shape in the world Drive a square in world coordinates while the robot spins, which only a holonomic drive can do.