I'm working on a Bixler with APM2 (w/ airspeed inputs) and am having a hard time with throttle control.
In manual mode the throttle works fine as long as my inputs are smooth, but I have noticed that if I make a step change in throttle (closed to full instantly) the motor will fail to start. This is not an issue when the receiver is wired directly to the ESC (an EFlite 40A).
When using RTL/Auto modes on the APM we've had problems with throttle not picking up. When using airspeed data the plane will maintain minimum speed, but will descend without adding throttle. With airspeed disabled the plane attempts to maintain altitude but will stall. I suspect that the ardupilot is commanding a step change in throttle and the motor is not powering up.
Does anyone have any advice on how to deal with this issue? There is a throttle slew rate parameter I may play with to see if that alleviates the problem.
Thanks for any insight you can provide.
Have you calibrated the ESC when it is hooked to the APM2. What you are describing is a ESC that does not understand the high and low signal values from the Reciever/APM
Thanks for the response. It turns out it was a bad motor. We went out flying to try the throttle slew control, and the motor just quit starting up and made some awful sounds. New motor was installed today and test flown...everything works perfectly.
BTW, we just posted a updated Bixler Parameters file in the manual, which has now been tested with ArduPlane 2.40. It's here.
Great. I've been hoping that would come soon. Thanks Chris.