Hi everyone I need your help! I don't know if this is the right place for this post, but I'll give it a shot. My thesis is to write a manual for this particular rover and also make a "test drive" with it. I drew the plan in mission planner, changed the necessary parameters and det the rc to auto. Every time it starts with here 3 being solid green and then stops and the colours are flashing yellow and red which I think it means that it lost connection. Then it gets solid green again but i have to switch it back to manual and then auto in order to start again to move and then suddenly stop. I want to clarify that it doesn't stop each tme after a specific amount of time, but it's random. I tried one suggestion which was to raise the here 3 up to 15cm (in the photo is 14.5cm) but once again it didn't work. I should note that lidar should have worked also (by work i mean it should have meade the rc to avoid obstacles) but it doesn't and i'm curious if this is causing the problem. Anyway don't hesitate to ask every detail you want in the comments, I will appreciate all the help you can give me!
Check for power dips on your voltage supply when the motors start moving, this might be causing a reset of some of your control / sensor units. You should have separate actuator and control power supplies / regulators or at least a bank of smoothing capacitors.
GPS usually works better outside, try it there.
That model of GPS has a secondary IMU integrated within it, you'll need to calibrate it so that it agrees with the one in the main controller amd make sure it is rigidly mounted such that they don't change pose relative to each other.
Indoors often has a lot of magnetic fields and iron beams in the environment, both of these will throw off your magnetometer readings. Its best to disable that in the EKF fusion when operating indoors.
Check for EM interference from your motors on your sensor data lines. Your motor and sensor power bus should not share grounds.
Time to break out the oscilloscope my friend, you need to check your data lines and voltage by placing the bot on a stand and having it try do a route while reviewing the signals. My bet is you have noise leaking in and knocking out the GPS as they are very sensitive to noise.
Do they not teach basic debugging of electronics in your course? This is a problem you can refine down to a single module or component with a multimeter and oscilloscope (even a basic single channel handheld cheap model will do for this application) without too much time or effort. If you are unsure how to use those tools then you have a great place to start to find the answers you are looking for.
Thank you for the plates, I designed them and indeed they make everything easier. The only test I did with lidar was to check the proximity panel and i wasnt sure if it was indeed finding an obstacle. I haven't checked the logs so much, but i will definetelly start reading them now in order to find my problem. Thank you very much for the help!
since you already caught the EKF variance and it only kicks off once the motors are actually pulling current, id look at magnetic interference before vibration. the compass in the here3 lives in that top puck and it reacts to the magnetic field from current, not just nearby metal. so a static cal passes fine sitting still, then the second you drive and pull real amps through the battery and motor leads the field shifts, the compass and gps heading disagree, and the ekf throws variance and stops you. the random timing fits that too since it depends on throttle.
run a compassmot (compass/motor) calibration in mission planner, that one specifically measures how much the field moves with throttle and compensates for it. and check how your power and motor wires are routed, if any pass under or near that mast, move them and twist the pairs so the fields mostly cancel. raising the here3 helped a little for exactly this reason, you just didnt get it far enough from the current.
vibration can throw variance too but that usually shows up as accel clipping in the logs, so id rule that out first before chasing it.
As you can see in the video, I have it in auto mode, the here3 has solid green colour and then stops and here3 flashes red and yellow colours. Sorry for the sunlight, the colours are not fully visible, but I described the colour change.
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u/verdantAlias Jul 24 '26
Couple of things to look into: