Translations:Help:FAQSpektrum:Attitude/89/en

AttitudeControl does not level my helicopter perfectly

On the ground everything seems perfect and even the first time I switch on AttitudeControl in flight on the helis levels OK. But after some time the heli is (extremely) tilted to the side when I switch on AttitudeControl again.

The AR7210BX AttitudeControl (SAFE mode) uses gyro sensors and accelerometers to build up the artificial horizon which is necessary to determine the heli's absolute position in space. This artificial horizon is highly dependent on the sensor data input and if the sensors fail, also the artificial horizon will. The sensors can especially be influenced by vibrations which cause them to show wrong data or loose some data at all. This will cause wrong calculations and in consequence cause a wrong repositioning of the heli. The gyro sensors of AR7210BX typically are very vibration resistant and you might not see the influence of vibrations in normal flight without AttitudeControl. But as the calculation of the artificial horizon mainly is a big sum of all the sensor inputs, even the smallest influence can cause an offset of the system. Additionally the accelerometers are much more sensitive to vibrations than the gyro sensors. As these are not used in normal flight most of the time, you will not see a direct influence of vibrations on them. But for the AttitudeControl these sensors have an important role and the system can only work with limited capability if these sensors fail.

• Make sure the system is perfectly aligned to the helicopter's rotation axis. Otherwise the measurements will be incorrect by principle.
• Make sure the system is not touching the helicopter's canopy and loose wires can't hit the device in flight.
• Please make sure your helicopter is running smooth and absolutely free of vibrations. Particularly with very small electric helis this is sometimes a difficult task, as there is not much mass to compensate for the vibrations and all electric components are placed very close to each other. If you see or hear any abnormalities like twitching tail or loud, vibrant noise it is very likely the AttitudeControl will not work as expected. You may try to place the AR7210BX unit at a different location on the heli or mount it with a different sort of gyro pad to compensate for those vibrations. Anyhow the best solution is to find the source of vibration, i.e. by removing tail and main blades and letting the motor run on the ground, and change defective/unbalanced parts. With the StudioXm App you can run a vibration analysis and see if there is some very high spot at a specific frequency. From this frequency you can conclude
  

• High temperature changes can cause the sensors to drift and in consequence cause the artificial horizon get offset. When it's very cold outside or very hot make sure the system can acclimatize when moving the helicopter from warm to cold or from cold to warm, before powering it up and flying.