Had a bad day in the field. After having 3-4 successful missions, we gave a simple 5point mission to the rover. All was good when suddenly the car started behaving absurd. I tried getting the manual control but to no avail.
Full throttle and a bad crash with the park pavement. Lost a wheel.
I have attached the log file. If somebody could have a look and suggest what we did wrong, it would be great.
Thanks
pmaini90
ps: The crash occurs at 92.4 % mission completion if you replay it.
@pmaini90,
How about some information concerning your configuration:
Version of ArduRover2 firmware in use?
Navigation controller?
How is the navigation controller powered?
If you are using a Pixhawk, what is the voltage being applied to the servo output bus power rail?
Regards,
TCIII AVD
Hi TCIII,
its v2.46 for rover2 (sorry but isnt this forum for 2.46 
)
I am using apm2.6 with the standard power module that comes with it.
Servos are separately powered (using the power module).
I suspect it has something to do with failsafe. I am still trying to figure out the failsafe mechanism.
Also could you tell how to detect a loss connection to transmitter and what happens in that case when the rover is in auto mode.
Thanks
@pmaini90,
You stated: "Servos are separately powered (using the power module)."
The PM cannot power the servos and the APM and associated components at the same time.
Jumper J1 should not be installed and a BEC should be used to power the servos on the APM servo output power rail.
Without looking at the log, it sounds like you had a possible brown out and the APM reset itself which will cause a loss of control and the rover running wild.
I have had this happen to me on several occasions when the battery voltage was approaching the minimum and motor acceleration caused battery voltage sag below the minimum and resulted in an APM reboot.
We will look at the logs.
Regards,
TCIII AVD
Thanks for the quick reply TCIII. I much appreciate it.
Please correct me if I am wrong. The power module takes input from the battery and has two outputs.
One for the motor ESC and the other for the apm. I am using this output from the pm to power the servos and not from the output rails.
Specifically I am using the connection diagram here: copter.ardupilot.com/wiki/common … -with-apm/
I am not sure…Did I make wrong connections!!
Thanks
@pmaini90,
A log analysis indicates that you did not have a brownout or APM reset.
However at the 47.6 sec point the RC3 output (throttle?) went to 1900us while the RC3 input (throttle?) went to 900us possibly indicating a loss of the R/C signal.
You might have a failsafe issue as you have said.
Regards,
TCIII AVD
Could you please tell or point to where I could find the relevant information regarding how does the rover behave when there is a loss of signal in auto mode.
Also I am trying to figure out why did the rover go full throttle and not stop when input was 900.
Your help is much appreciated TCIII.
Thanks.
@pmaini90,
Your PM/battery configuration should be like this with J1 not installed: http://rover.ardupilot.com/wiki/common-apm25-and-26-overview/#Power_Supply_Rails_Not_Connected_Requirements_JP1_Not_Installed
I am assuming that your R/C throttle input is on the APM RC3 input?
Regards,
TCIII AVD
@pmaini90,
On my rover setups, a loss of the transmitter signal will cause the rover to go to the HOLD mode whether in Manual or Auto.
Regards,
TCIII AVD
TCIII,
the throttle is on channel 5.
PM/battery configuration is as per the link you mentioned.
I am using the “PM with servo with BEC from one ESC” configuration
I am sorry but I do not know what is hold mode. I have searched for the different modes in rover and this is what I got: rover.ardupilot.com/wiki/apmrove … sign_Modes
There are links telling how to configure 6 modes, but what are the 6 modes. Where are they to be found?
I would be grateful if you could point me to the right resource.
Thanks.
@pmaini90,
You cannot program the HOLD mode.
For my rover, if I start the Pixhawk or APM without turning on the R/C transmitter, the Pixhawk mode, after boot up, will be the HOLD mode which means it has no R/C input.
If I start the Pixhawk with the R/C transmitter on, then the Pixhawk or APM will enter the initial mode (INITIAL_MODE parameter) which is Manual (0).
If the Pixhawk or APM is in the Manual or Auto mode and it looses the R/C transmitter signal, the Pixhawk or APM will go into the HOLD mode and not respond to steering or throttle input.
When you say “the throttle is on channel 5.” Do you mean input or output?
Regards,
TCIII AVD
Thanks for the reply!
That was definitely insightful.
I am sorry that was a typo. Throttle is on APM RC3 input. The connections are as per the following link:
rover.ardupilot.com/wiki/setup/
Thanks.
@pmaini90,
I assume that your throttle output is on APM Servo Output channel 3 because that is the way it looks in the tlog?
On the second lap, at around the 47sec point the throttle output goes from around 1540us to 1900us which is indicative of the runaway and the throttle input, at the same time, goes from around 1450us to 900us which is indicative of a loss of throttle input to the APM from the receiver even though you are in the Auto mode.
The power to the APM from the PM was good up to and after the start of the runaway. However, the APM quit recording any inputs at that time indicating that maybe something happened to the APM 3.3vdc that is used by a number of components including the data logger. You might want to check and see if your 3.3vdc is okay.
Regards,
TCIII AVD
yes you are right.
My throttle is on apm output servo channel 3. Also I just noticed, the power module is also broken…the df13 connector needs repair.
So do we now know that it was due to signal loss??
If yes then that would trigger the hold mode…as you said (eh…right???). But why should the output in that case go to 1900…full throttle that is?