You need good control of the motor RPM to drive them straight. If you used a BLDC with the joystick controlling the RPM, it would work just fine.
The idea of using the back EMF of a PM motor to sense RPM has been around for a while. There was an idea in Electronic Design or EDN a while back that used this to govern the speed of a PM motor without using a Tachometer. I think you could use this to build something that works better than the simple control scheme in present day steering controllers. Joe Smalley Rural Kitsap County WA Fiesta 48 volts NEDRA 48 volt street conversion record holder [EMAIL PROTECTED] ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, October 01, 2002 10:07 AM Subject: directional stability for tank drive > I was wondering if anyone had built a small tank drive like ev. From my use with chairs, I dont know if its the small motors or retarded programming, but they go with the slope. So, driving on the edge of the road, it pulls to the gutter. On a chair, you just move the joystick to about 10 oclock position to go in a line, but with less speed then before. > > My idea was to use a gyro to sense left and right movement and maybe rig this to the controls so it can compensate for this or for quick jerks in direction like if you hit a pot hole with one side or rut. > > Just an idea > > jeff > > richmond, va > > http://www.wheelchairmodifications.org >
