Greetings everyone. I'm working on a project where a computer steers a farm tractor via GPS. Getting accurate position data is easy. My challenge has been getting accurate heading data. I have tried a MEMS gyro on the yaw axis, but it shows a lot of noise and the gyro bias drifts around. While it does help, it isn't sufficient for what I need.
Roll and Pitch are relatively easy since this is a ground vehicle, and I can use accelerometers to fix the gyro bias. Yaw is the axis I'm having trouble with. Unfortunately, I can't use magnetometers to calibrate the yaw gyro because of all the steel on a farm tractor.
How stable is the latest MEMS gyro technology? I have also looked at going to a ring laser gyro or a fiber optic gyro based IMU, but I can't find a 6-DOF package with either of those gyros. Ideally, I want a 6-DOF IMU with a TTL or RS-232 serial output.
What I'm looking for is a gyro that is stable enough that it can sit still for 5 minutes and only accumulate a few degrees of change in the estimated heading. Ideas?