Strange issue - Mode switches to RTL itself. - Discussions

I have the latest ArduPilot Mega with the Oilpan installed on my Glider and have

I am experiencing a strange issue, that has happened on 3 instances, when the mode switched to RTL by itself. ALl instances were on ground, and the motor went to full throttle and I had no control from the TX. Switched off and switched back on and it was all good again.

Here is my setup : I use a Futaba 10C with a R6008HS Rx . Ch1 is Aileron, Ch2 is Elevator and Ch3 is throttle. CH5 is conencted to the CH8 In on the ArduPilot Mega board.

CH5 is used by a 3 position switch and i configured the actions of it via CLI as below :L

Up - Manual

CTR - FBW-A

Down - RTL

All 3 instances of the autopilot going into RTL were when the switch was in Manual mode.

Also, on all instances, nothing was touched on the TX ( no accidintal flipping of switch etc )

I checked the logs , they do have MOD: RTL as the last Mode change which proves that the autipilot did go into RTL.

I do have Throttle Failsafe enabled, with a PWM of 1030 and it works OK.

I have tried to read through ALL avaialble documentations and can only think of the follwoing :

A. Cannot be because of RX going into failsafe - because it would kick stabilize mode in FS and not RTL

B. Can happen if somehow the RX went into a brownout - ie sent no signal on CH5 . This should kick in RTL mode. I was able to check this by pulling out the CH5 cable in manual mode. It went into RTL.

Cannot think of why this should happen. I had checked all connections and they were tight and good and paid special attention to the CH5 cable and its not loose.

I would really like some help with this. Though I have had several flights, i feel very uneasy about this, and when the Autopilot goes into RTL, the motor comes to life, and can be injurious, as well as i can loose my plane, if it happens in the air.

Any help/ideas would be much, much appreciated.

Thanks !

I suspect it could be static. Here is what i remember on the 3 instances
1. The first instance happened at my home, the day I configured the Throttle failsafe. After i booted the board, the motor started and went to full power ( as in RTL mode ). Nothing on the TX would stop, and i had to eventually disconnect.

2. THe second instance happened on the field when, just before launch the motor came to life but in less than a second went back - like a short burst of throttle. Though afterwards it functioned fine and i did a flight too without resetting the board.

3. The third instance too happened on field, when I was showing the board to someone and the TX was kept 5 feet away, and the motor came to life ( luckily no one was hurt ) .

I checked the following :
a. Logs said MOD: RTL confirming that the motor came to life because the ArduPilot went into RTL mode
b. Checked all solder joints, seem OK and tight
c. checked the cables/wires/connectors all were snug, and no matter how i moved them, i wasnt able to replicate the issue
d. Checked the ESC temperature if it had something to do with but nothing i found did it.

The only issue i can think of is either static - as all 3 times i may have had my hand close to the usb port ( close to the Ch8 IN ) OR perhaps the software somehow crashing..

Any input would be really appreciated, as i am very worried and holding off from further flights till an able to find an answer to this.

Thanks !

Replies

Developer

Doug Weibel February 15, 2011 at 4:35pm

Is your low throttle position close to 1030? If so maybe it was an issue of the your throttle value drifting below.
FPVGenie February 15, 2011 at 4:42am

I suspect it could be static. Here is what i remember on the 3 instances
1. The first instance happened at my home, the day I configured the Throttle failsafe. After i booted the board, the motor started and went to full power ( as in RTL mode ). Nothing on the TX would stop, and i had to eventually disconnect.

2. THe second instance happened on the field when, just before launch the motor came to life but in less than a second went back - like a short burst of throttle. Though afterwards it functioned fine and i did a flight too without resetting the board.

3. The third instance too happened on field, when I was showing the board to someone and the TX was kept 5 feet away, and the motor came to life ( luckily no one was hurt ) .

I checked the following :
a. Logs said MOD: RTL confirming that the motor came to life because the ArduPilot went into RTL mode
b. Checked all solder joints, seem OK and tight
c. checked the cables/wires/connectors all were snug, and no matter how i moved them, i wasnt able to replicate the issue
d. Checked the ESC temperature if it had something to do with but nothing i found did it.

The only issue i can think of is either static - as all 3 times i may have had my hand close to the usb port ( close to the Ch8 IN ) OR perhaps the software somehow crashing..

Any input would be really appreciated, as i am very worried and holding off from further flights till an able to find an answer to this.

Thanks !

This reply was deleted.