Dual GPS-RTK using teensy 3.6 ?

[heliboy]

I have been looking for a good application for the new 3.5/3.6 that I got from kickstarter. Here is my plan ..

I want to make a precision heading indicator for a farming robot to replace the unreliable IMU+compass unit. I have two RTK GPS units capable of about 8mm positioning accuracy. I plan to mount them about 1 m apart on the longitudinal axis of the vehicle and use the 3.6 to compute the heading from the two GPS's on serial ports. The GPS's update at 10Hz and I think the 3.6 should be able to keep up with this rate. Then I will have the 3.6 spit out modified GPS sentences with the computed precision heading instead of the GPS heading. The autopilot can then use this to navigate. The reason is that the vehicle is very slow moving (1m/s) and the GPS heading alone is useless. The compass is also unreliable due to the large metal mass, EMI from the gas engine, and excessive vibration.

Any comments and suggestions much appreciated. Much easier to change course before coding

 

[onehorse]

We use this in the presence of multi-amp-current-carrying wires and brushed DC motors with strong and varying magnetic fields and manage 2 degree heading accuracy. This plus DPGS would make for a passable autonomous vehicle. Our plans include this IMU plus a small GPS on the vehicle, and both on a base station for local DGPS for autonomous flight. 10 cm accuracy would suffice for us; it's just a flying robot after all.

 

[heliboy]

Interesting device ! I suppose it is similar to the brick IMU. That also has a magnetometer coupled to IMU. We need better than 0.5 deg precision for land based vehicle so I want to try the dual RTK solution.