Alternative holonomic drive

[ekapalka]

Hello! I've been toying with this idea of using a trackball and joystick as a driver interface for a robot with mecanum wheels. The problem with this is that a trackball is not like a joystick. It's like a mouse (it IS a mouse, unless we can find a trackball made for some other purpose). I've been working on this in Processing, and it seems to work pretty well. I divide the screen into 360 vertical pieces, and assign each piece from 0 to 359 (with wraparound). By doing this, I can easily send a value for my simulated robot to turn to. The Processing model is great, and performs exactly as a real robot would, physics included, but in Processing, all I had to do was tell a box it's x,y, and rotation, and no real robot-applicable code was used. The problem I'm having with a real robot is that sending a specific value to rotate to is characteristic of field-centric steering (the value is the joystick angle, I think), and freedom to move without a third-person is characteristic of robot-centric steering. Is it possible to combine robot-centric strafing and field-centric rotation?