VStabi Pioneer of Flybarless

Translation in progress...

Main (Roll/Nick)

These are the main axis of the Copter. They are tuned together.

Expo

This adds an exponential steering characteristic to the inputs. It is useful to have a smoother center stick but still maintaining the full throw at full deflection.

Gain

This adjusts proprtional and differential Gain at the same time. This is the main adjustment to reflect the copters overall behaviour. To high gain leads to quick oszillations that often are not visible, but can be heard clearly from the motors. To low setting leads to low inherent stability and sluggish control behaviour.

The Gain shall never be 0, because the copter will loose it required stability and thus will not fly.

Agility

This adjusts the direct amount the the agility input together. Beginners start with an agility of 35, 3D Pilots may go upt to 80 or 90. The personal preference has to be adjusted individually during flight. Better start lower and progress to higer values. High agility requires quick reactions from the pilot as well.

Integral

This parameter sets the inertia of the control loop. This influences mainly the fast flying stability to keep the copter in track at high speed. If set to low it manifests in low stability against wind, and certain instability in fast forward flight. To high setting give clearly visible oszillations that may get violent.

The possible integral value is dependant on the possible gain. High gain settings allow high integral settings as well and vice versa. See it as: gain is dampening the integral.

Usually the best values are between 15 and 25 depending on the copter. Bigger copter need more than smaller ones. There is no need for tuning the integral to the edge, since even control inputs may lead to oszillations. So keep a good distance to the oszillation point.

Loop Tuning

To find out the optimum for special configurations it may be useful to try different feature combination to get best result. The defaults usually fit best.

Saturation Protect: This feature avoids control saturation. In case the system detects that there is no more throw available from the ESC´s, it reduces throttle until it regains the needed throw to stabilize the copter. This avoids out of control situations at full power.

Deep Filer: An additional filtering avoids too much noise from the sensors, allowing more gain.

Stop Support: particularly in acrobatic flightmanouvers this adds a sporty note to the control feel. It greatly reduces oszillation on heavy inputs.

Piru Correction: Bigger copters tend to run out of track on piruetting during forward flying. This option allows optimizing this allowing more flat piruettes. If activated, the copter has to be trimmed by autotrim feature, otherwise it only makes it worse. Usually its not needed to activate this.

Filter setup

The main filter is responsible for separating unwanted noise and vibrations from the real movement of the copter. VCopter uses a advanced filter topology that allows sharp separation without adding signal delay.

The filter shall be set to the lowest possible frequency, that does not degrade flight performance. The main hint are oszillations that appear if the frequency is too low. If set to high, you hear whinning or rumbling noises from the motors. Set this parameter in hover, so you can clearly watch the effect.

There is some depency to the gain parameter, so readjusting gain may influence the optimal filter setting.

From our experience, small racers need 55Hz filter frequency, while bigger copters work best with about 35Hz.

It is very convenient to put the parameter on a pot (just open the Filter Setup panel, and wiggle the pot), so you can adjust the frequency during test flying.

Yaw.

Yaw on copters is not very critical, nevertheless to high gain settings can induce excess motor driving that adds disturbances to the flight.

Model Setup Functions.

Like all other versions, you find the setup wizzard in this section. Additionally some copter specific features are included here.

Flightmode

Usually a copter drives its motors in one direction. This is called normal mode, this type of copter is not capable of sustained upside down flying.

In 3D Mode the motors are driven in both directions, and reversed if the throttle stick goes blow center. This allows flying inverted as long as you like. To do this, ESC´s are needed that allow quick reversion of the motors.

If you change the mode, keep in mind that the center position of the ESC changes to where the half throttle position was before. To make it more save this setting is taken over at startup of the NEO only. Still this a mayor change and ifg done wrong, motors may start up and cannot be switched of by the motor switch. So its strongly recommended to unmount the props during the change, and remount them not earlier that everything is working properly and safe.

Usually the ESC´s have to be reprogrammed, which is done by the motor testmode feature described below.

Output Settings

ESC Controlrate / Pulsewidth

The controlrate describes how often the ESC recives a new pulse from the NEO, and witch width is has. The default setting is a update frequency of 333HZ (every 3ms) and a pulswith in the range of 1000us to 2000us. This type of pulse is used for helicopter tail servos as well, and understood of almost every ESC.

The controlrate can be lowerd or increased up to 1000Hz (1ms). The higher the control rate the less the added signal delay and the higher the possible main gain. This allows more stability and better control reaction.

Note that if you use the default pulsewith, it only can have 333Hz or lower controlrate, because the pulse will not fit on higer rates. The result will be undefined in this case. Use the Oneshot pulswidths for higher controlrates. Note that the ESC shall have the feature integrated and activated.

We recommend 500Hz Controlrate with oneshot125, the recent ESC´s support this and it looks to work well.

There is some  chaos with the term Oneshot, which basically means, that per calculations step one pulseoutput  for all ESC´s is done. This has nothing to do with the used pulsewith. But due to some historics, this is mixed up and used as sysnonym for shorter pulses.

VCopter uses the technical pattern for oneshot anyway, independant of the selected pulsewith. Additionally VCopter is able to output the pulses without any jitter even on one calculation per output. Its something like oneshot+.

Pitch Mix

This adjusts how much of the Pitch=Throttle input is mixed to the outputs. Usually the selected 80% is fine, it leaves 20% headroom for stabilizing the copter. If the mixing is too high, the copter may get unstable at full throttle, even can go out of control. This is called control saturation.

Idle

This is the ESC output value that will never been passed to lower when motor switch is on or idle. It shall be set in a ways that the motors spin at low speed, but high enough to not have commutation problems when accelerating fron this value. Motos shall never stop completely in air, since the copter will loose stability if so.

In normal mode, a value of about -80 is fine, in 3D mode a smaller positive value has to be choosen, since on reverseing the value is reversed as well. even in 3D mode the motors shall never stop on stick center.

The value will be set at every change of the flightmode to avoid too wrong settings. So readjust after changing flightmode.

Motor Testmode

This tool fuction couples all ESC outputs directly to the throttle stick. This is intended to enter programming mode of the escs and do all needed stick programming on them.

The setting is persistent through power cycle, so its possible to start the ESC´s at full throttle which is the method to enter programming mode on most ESC´s. Please consult the manual of the ESC to find out how stick programming works.

Always unmount props in testmode, since there is no startup protection active during testmode. The motor switch has no function!

Autotrim

If the piru correction shall be used, the copter has to be trimmed. The autotrim feature will learn the hover position and allow better piruetting during flight. Usually this is not needed and gains only a small advantage.

General Remarks

The Marocell feature is available like on other NEO Versions as well, So its possible to use a foreign radio to control the copter, if it was setup by a VBar Control.

Macrocells allow som cool features which may depend on the flight control as well. Examples are tilting the motors, retracts or gimbals.

Buddyboxing is possible as well, or even controlling the gimbal by the buddys VBar Control without additional reciver. With a foreigen reciver, the buddys radio may be of other brand as well.

Rescue/Beginner

Rescue and Beginner Mode is available with VCopter as well. Rescue levels the copter from any attitude, and manages throttle. It works on 3D Copters even better, then the copter is flipped to upright in place before applying the adjusted throttle.

Beginner mode allows unexperienced users to fly the copter. It almost levels the copter if the sticks are let go. So it is avoided to gain too much speed in this mode. It can be adjusted how much input is allowed in this mode.