z8rc: AS3X Flight Control Problems From Low Frequency Resonance

Wednesday, February 15, 2012

AS3X Flight Control Problems From Low Frequency Resonance

Changing the UMX Gee Bee's prop to a 5 x 2.75 reveals that AS3X can induce substantial, spurious flight control inputs just like the Blade mCP X helicopter with AS3X.

This development validates and confirms that AS3X is in fact what is inducing a loss of model control:

I first noticed a near total loss of flight control induced by AS3X when my mCP X helicopter would try to careen out of control at certain throttle settings and/or blade loads. But I didn't fully understand that the issue was caused by low frequency structural resonance until I discovered a massive improvement in heli controllability after the addition of the Z8RC boom truss modification. The Z8RC boom truss functions in the harmonic space to suppress standing sine wave resonance.

Now the UMX Gee Bee suffers from the same AS3X-induced loss of flight control in certain resonance bands. This is not typical of other 3-axis gyro systems. It appears that AS3X sensors, gains and/or logic are especially susceptible to low frequency resonance, causing compounding amplitude oscillations and loss of flight control authority. As a result of the multi-model manifestation of this problem, I am issuing the following warning:

WARNING: In certain structural resonance bands, AS3X may induce increasing flight control oscillations. An immediate change in throttle setting is advised to avoid loss of model control.

This warning should accompany further sales of AS3X-enabled models until E-Flite resolves their defective control logic.

NEUTRAL

These products did not score high or low enough to merit a buy or avoid recommendation.

RC Airplanes
3D Hobby Shop Edge 540 (41")
BlitzRCWorks Nano P-51D (21.5")
E-Flite Cap 232 (36")
E-Flite Carbon Z Yak-54
E-Flite Ultimate 20-300 10 ARF
FMS P-47D Thunderbolt (55")
Gemini RC Extra 300 (16")
Hobby King 1.5M Monster Yak-54 (59")
Mini-Air Extra 300 (16")
Parkzone Ultra Micro T-28 (16.5")

RC Helicopters
Ares Ultr-Micro MD-500D CX 100
Blade MSR
Balde MSR X
Blade Scout CX

Electrics
Duratrax Onyx LiPo Charger
E3-S-23 Micro Brushless Outrunner Motor
E-Flight Power 25
E-Flight Power 32
E-Flight Power 46
Turnigy 35-36

Radios
Spektrum Full Range Receivers

Other
AS3X
Banana Hobby 2-Axis Gyro System
Real Flight G5.5 RC Simulator
Turnigy Plush ESCs

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Searching Z8RC.com for the best match.........

Wednesday, February 15, 2012

AS3X Flight Control Problems From Low Frequency Resonance

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