What does parameter gain mean?

News2013-04-01

Part 1: ACE series Control Parameters Tuning

1. Base Parameters

1) Gain:Range: Front/back & Left/Right 40%~400%; Vertical 50%~250%
If too large, you will find the helicopter oscillating in the corresponding direction (About 5~10Hz). If too small, the helicopter will likely to be hard to control.
In GPS Atti. Mode and GPS Cruise Mode, if helicopter drifting on front/back or left/right direction for 2~5 meters, then increase 10% on the corresponding direction it drifts to until the helicopter getting oscillation. If helicopter vibrate on its vertical direction, then reduce vertical parameter by 10% until it get stable. If altitude drop and drift happens during sharp braking, then increase I -Vertical in advance parameters.

2) MAX Speed Limit:Range: Front/back 1.0~20.0 m/s & Left/Right 1.0~15.0 m/s

3) Agility:Range: 50%~200%
It determines the start-up speed from command stick, the bigger the value the faster the reaction. Increase it for sharper and quicker leveling action after command stick released. The control feeling will be stiffness and rigid if the value is too high; and sluggish leveling action and slow braking if too small.

4) Stick Delay:Range: 50%~200%
It determines the overall stick reaction speed, for example:
You push your roll stick to the maximum position your helicopter will tilt from leveling to 45 degrees, the smaller the number the quicker the transition.

2. Advance Parameters

1) Velocity Tracking:Range: Front/back & Left/Right 20.0%~250.0%; Vertical 20.0%~150.0%
The V parameter adjusts the tendency of motion during pilot commands. Higher V values cause the helicopter attitude to adjust more aggressively to obey command input. For instance, when a stick position command is given, a high V value causes the helicopter to have a relatively sharper angle in response. This allows the helicopter to reach the desired speed sooner, but sometimes the helicopter will become unstable and difficult to control. A low V value causes the helicopter to respond slower to stick position commands, even with very extreme stick positions.
One can say that the V parameter adjusts the tendency of motions, and the change of control feeling after the adjustments will be similar to the difference between using hard or soft rotor head. But V is not the sole influence on the time of respond, please note.
The V parameter adjusts the tendency of motions, and gain adjusts the feedback strength of such tendency. V is adjusted according to user preference, but gain has a theoretical best possible value.

2) I:Range: Front/Back & Left/Right & Vertical 0%~500%
The I parameter corresponds to consistent and accurate speed, or steady hovering, when the helicopter receives external disturbance. When the pilot gives a command through stick position, the helicopter might not be able to achieve the desired speed due to head wind. The larger the I value, the faster the helicopter will compensate and adjust for wind, while smaller I values may cause more time for the helicopter to reach the commanded speed.
Similarly, when the helicopter is hovering and wind blows the helicopter away from the hover point, the helicopter will gain a certain acceleration proportional to the I value to return to the hover point. The larger the I value, the sooner the helicopter will make this adjustment.
When the I value is too low, the helicopter will drift within a certain range, similar to what happens when a gain parameter is too low.

Notices:
The default values are suitable for most of the condition.

3. Suggested Parameters

how to adjust gain



Part 2: WooKoog-M series / NAZA Control Parameters Tuning

1. Basic Parameters

Usually, the default parameters are ready to go. However, different multi rotors have different gains because of different size, ESC, motor and propeller. If gain is too large, you will find the multi rotoroscillating in the corresponding direction (About 5~10Hz). If too small, the multi rotorwill likely to be hard to control. So you can still setup the basic Gain of Pitch, Roll, Yaw and Vertical manually according to your multi rotor to have a wonderful fly experience. We suggest you to change 10% to 15% of the parameter at a time.

1) Basic Gain
Pitch and Roll: To the gains of Pitch and Roll, if you release the Pitch or Roll stick after command stick, multi-rotor should be back to hovering state. If the reaction of multi-rotor in this procedure is too soft (large delay), please increase the basic gain slowly (10%-15% each time) until vibration emerges after you release the stick. Then decrease the gain a little until vibration just disappears. Now the gain is perfect, but the reaction of the attitude change is slow. You can follow the way introduced at the end of this section to tune the attitude gains.
Yaw:The way of tuning the Yaw gain is the same as the way of adjusting the Tail Gyro. If you want fast stick reaction speed, increase the gain, otherwise decrease the gain. However, the spin of multi-rotor is produced by the counter torque force, and the magnitude of which is limited. Therefore, large gain will not produce tail vibration like helicopter, but severe reaction at the start or stop of motors, which will affect the stabilization of the other directions.
Vertical: You use two methods to judge if the Vertical gain is good enough: 1) The multi-rotor can lock the altitude when the throttle stick is at center position; 2) The change of altitude is small during the flight along a route. You can increase the gain slowly (10% each time) until the vibration emerges along the vertical direction or the reaction of throttle stick is too sensitive, then decrease 20% of the gain. Now it is a suitable Vertical gain.

2) Attitude Gain
Attitude gains determine the reaction speed of attitude from command stick, the bigger the value the quicker the reaction. Increase it for sharper and quicker leveling action after command stick released. The control feeling will be stiffness and rigid if the value is too high; and sluggish leveling action and slow braking if too small.

Notices:

  • You must click Default button in first setup parameter, and subsequence firmware upgrade.
  • The vertical gain will NOT affect the manual mode.

Tips:

  • If you are a fresh player, you can tune the basic parameters first as following:
    1. Increase the basic parameters 10% at a time so as to make your multi rotor hover or light oscillate after small angular command input.
    2. Decrease the basic parameters until your multi rotor can just hover, then decrease 10% more.
  • If the basic parameters are far away from the proper value, the advanced parameters will not work.
  • Here you can make use of remote gain-tuning channels to tune the gains during the flight:
    1. Followed the instructions in “Assembly” R/C System section to connect and setup correctly;
    2. Choose the X2 or X3 channel in Remote Adjust for the gain you want to tune. One channel to one gain.
    3. The range of remote tuning is from half current value to twice current value.
  • Usually the Pitch, Roll, Attitude Pitch and Attitude Roll Gains of hexa-rotor are higher thanquad-rotor.

2. Advanced Parameters

(Olny WooKoog-M series has advanced parameters)

Usually you can ignore this step. The default values are suitable for most of the conditions, so we do NOT recommend you to change the parameters here. To some special multi rotor, experienced user can adjust the advanced parameters to have a better fly experience.

1) I
The error compensationrate in aircraft static case.

2) V.Damping
Only work in the GPS mode.
The larger the number, the brake of the aircraft will be more powerful after releasing the joystick. At the same time the maximum velocity achieved at the full-scale will become smaller.
The smaller the number, the brake of the aircraft will be more soft and need longer time. At the same time the maximum velocity achieved at the full-scale will become larger.
Too large or too small may lead to the hover instability in the GPS mode.

3) Disturbed Gain
Only for special extreme GPS circumstances. please remain default parameter.