Servers by jDrones

Rover tuning cruise_throttle


(dksmall) #1

I am trying to follow the procedure here
http://ardupilot.org/rover/docs/tuning-steering-and-navigation-for-a-rover.html

I have a Pixhawk and mission planner. In step 2 how do I know how fast the rover is going? I can’t have a USB cable connected to the rover and keep up with the rover going 2 meters/sec. , while holding a laptop.


(David Boulanger) #2

Add a telemetry radio to the vehicle and computer. Also, You can play the logs back later to analyze performance .

Regards,

David R. Boulanger


(dksmall) #3

Well since I don’t have the telemetry radios, I’ll try looking at log files. It would be nice if the procedure outlined this better.

Thanks for the reply.


(David Boulanger) #4

FYI. I bought a cheap set off of Amazon. They work just find at short range. They don’t compare to a RFD or what Jdrones has but for general use I have been happy with them.

Regards,

David R. Boulanger


(dksmall) #5

Ok I ran the rover at a slow constant speed for several seconds to generate a log file. I was able to download the log file and I can review the log. Now I’m trying to figure out what to look at. The wiki instructions reference a different version of Mission Planner, i.e there is a “Graph Left” and “Graph Right” button, but the instructions reference a “Graph this data” button. Using a dropdown in the middle of the screen, I can select “Speed/Ground Speed” and I see what appears to be the GPS speed. I’m guessing this is meters/seconds. Shows what I would expect, quickly reaching 2 meters/sec and slowly climbing to 3.25 meters/sec, before I dropped the throttle. Now where can I find the throttle percentage so I can compare the the GPS speed and determine a proper value for my cruising speed?


(Thomas J Coyle III) #6

@dksmall,
I have done a lot of rover tuning over the last 4 years and I feel that you really need telemetry to do real time throttle and cruise speed tuning. All the throttle percentage parameter will do is determine whether or not you will reach the desired cruise speed. If the throttle percentage parameter is set too low, you will not reach the desired cruise speed and if it is set too high, then you might overshoot your desired cruise speed before the rover acceleration can be reduced to attain the desired cruise speed. Having to stop and read a dataflash or tlog file every run is a waste of time as far as tuning goes.
Also, without telemetry how can you tell what your sat count and HDOP values are to see if it is even worth running a waypoint course?
What do you have your LOG_BITMASK parameter set to?
Regards,
TCIII AVD


(dksmall) #7

LOG_BITMASK = 65535.

I am looking into getting a telemetry radio, they are cheaper then I would have thought. Which brings me to a question I asked in the MP forum, which was where is the throttle percentage on the HUD? Or will that magically appear once I have a radio link?


(David Boulanger) #8

Right click on the HUD and then a bunch of options will appear.

Regards,

David R. Boulanger


(dksmall) #9

Ok, got it. And I’ll order a radio and see if I can get this tuning done.