How can we improve motor control for our robotic television camera positioners?

[horngroup]

We are many years out of school. We are building robotic positioners for television cameras. Our experience in the mechanical design is extensive. We are seeking direction in motor control. The motors which we would like to try are flat pack brushless dc motors with 5 wire on board control. The manufacturer can supply with an input which causes rotation in one direction from 0-5v and reverses from 5-10v. We use a two axis joystick as we rotate horizontally and vertically. We have trouble with our control at center rest of the joystick, as we need a "dead" spot in the center to insure 0 speed. We need to go from a "creep" speed to about 30-40 deg/sec. We would think that with allthe robotics out there this is reinventing the wheel. Any help out there?
Horngroup

 

[berkeman]

We are many years out of school. We are building robotic positioners for television cameras. Our experience in the mechanical design is extensive. We are seeking direction in motor control. The motors which we would like to try are flat pack brushless dc motors with 5 wire on board control. The manufacturer can supply with an input which causes rotation in one direction from 0-5v and reverses from 5-10v. We use a two axis joystick as we rotate horizontally and vertically. We have trouble with our control at center rest of the joystick, as we need a "dead" spot in the center to insure 0 speed. We need to go from a "creep" speed to about 30-40 deg/sec. We would think that with allthe robotics out there this is reinventing the wheel. Any help out there?
Horngroup

So zero rotation velocity is achieved around 5V? The manufacturer should have some built-in hysteresis around this center voltage, so that you get the dead spot that you want. Something like 100mV hysteresis or so. Or basically a 100mV dead zone around 5V that gives zero rotational velocity. Can they give that to you?

 

[horngroup]

Thanks for the reply. We'll check with the motor people (Maxon)