I'm not entirely sure if this is the result of RC equipment failure or a tuning issue, but me and a couple of other guys are working on autonomous flight and have encountered a problem with our throttle and our transmitter. The links should be to the exact equipment we are using with our HK Bixler.
ESC: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14871
Transmitter: http://www.hobbyking.com/hobbyking/store/__15140__Hobby_King_2_4Ghz_6Ch_Tx_Rx_V2_Mode_2_USA_Warehouse_.html
http://www.hobbyking.com/hobbyking/store/__7641__ZIPPY_Flightmax_2200mAh_3S1P_25C_X_Thin_.html
The first problem we're having is that the transmitter seems to be very finicky. After we calibrate it with the Mission Planner it appears to work fine initially (slows down/speeds up correctly), but when the throttle cuts out, the transmitter's throttle stick ceases to function until we flick the left shoulder stick forward and back once. After this the throttle stick and fine tuning knob to the right on the TX need to be forcefully pushed all the way down in order to cut the throttle.
Sometimes, the Mission Planner calibration doesn't even fix our throttle issue at all and instead causes the throttle to stay at mid-to-upper ranges until we cut the power completely, or forcefully push down on the TX's throttle stick (or use the left shoulder stick to shut the throttle off).
I think this small issue might in some way be related to the next problem we're having with the throttle cutting out during flight. We first noticed it during our attempts at Auto mode, which usually resulted in the throttle dying down and the plane spiraling downward until we recover in Manual. Unfortunately, we've recently had this same issue in Manual mode and were barely able to recover the plane before it crashed.
Currently, we think this might be an issue with the ESC. Is it possible that our problem with the TX throttling at mid-to-upper ranges only could be burning out the ESC? Or is our ESC just not up to par for what we're doing? How can we fix our TX problem?
Thanks,
Richard and Team
Replies
Well, after replacing our 20A ESC with a 35A Common Sense RC, our plane had the same issue in Auto, except as we switched to Manual the plane began to emit a fast and loud beeping sound, and gracefully crashed into the ground. We lost control of the throttle entirely and the motor seems to have cut out. Fortunately, the motor still works as we tested it afterward with our old 20A ESCs. Is it possible that there's an issue between our ESC and the APM board?
We're looking into seeing if upgrading the PPM firmware helps, but I'm not too certain that's the main issue, although it was something we had considered a while back. Since it's one of the few things we haven't put any focus into, it's worth the attempt.
Thanks for any help you guys can offer!
Also, the APM board is version 1, but would an outdated PPM encoder have these effects on Auto flight?
What version of the APM are you using? If it is a 1.x you might be running the old PPM encoder firmware, that had problems detecting certain RC input signals.
I'd try another ESC first. They're dirt cheap on ebay.