APM,MWC,等，各种机架电机权重分析。

feitian227

丛别的网站上转过来的，做个备份。

Ardu Pirate's Motor Mixing Guidelines

Hi Pirates, based on Hein's comments, I'm going to try to explain how is the mixing of the motors done, depending on the layout/position of your ship's motors.

All mixing depends directly on the motor's positions and layout proportions. Depending on it's position each motor needs to apply different strength to pitch and roll axles. In other words, the farthest a motor is from a axle, the stronger it will have to pull.

This strength is set for each motor in the motor mixing (motors.pde) as meanings of a percentual value, that will multiply pitch and roll values used to calculate the final value for each motor.

When the percentage is 100%, it is not necessary to add any value, as we would be multiplying by 1.

Pitch and Roll Axles
Pitch and Roll axles will be used as reference to find the needed strength for each motor:



The axles layout will help to understand and locate what will the values for each motor be, and it's sign.

As for the Yaw, things are simpler, as it just depends on the rotation direction of the motor:

If Motor turns ClockWise (CW) Yaw is Negative.

If Motor turns CounterClockWise (CCW) Yaw is Positive.

I will try to explain it using exampes for the frames we commonly use:

Quad + mode
Ok, let's start with a simple Quad in + mode:


As all 4 motors are on the axles, they all will have 100% and 0% as strength values, in more detail:

Motor         Pitch         Roll         Yaw
0 Right CCW         -0%         -100%         +
1 Left CCW         +0%         +100%         +
2 Front CW        +100%         0%         -
3 Back CW        -100%         0%         -
Thus the resulting pseudo-code would have these signs and values:

rightCCW = - (0 * Pitch) - (1 * Roll) + Yaw

leftCCW = + (0 * Pitch) + (1 * Roll) + Yaw

frontCW = + (1 * Pitch) + (0 * Roll) - Yaw

backCW = - (1 * Pitch) - (0 * Roll) - Yaw

and the final code in Motors.pde, adding throttle and controlling total motor value not to get out of bounds, would be:

rightCCW = constrain(throttle - control_roll + control_yaw, minThrottle, 2000);

leftCCW = constrain(throttle + control_roll + control_yaw, minThrottle, 2000);

frontCW = constrain(throttle + control_pitch - control_yaw, minThrottle, 2000);

backCW = constrain(throttle - control_pitch - control_yaw, minThrottle, 2000);

Quad X mode
Next, Quad in X mode:



This tiem all 4 motor are rotated 45 from the axles, they all will have 71% as strength values in pitch and roll, in more detail:

Motor         Pitch         Roll         Yaw
0 FrontRight CCW         +71%         -71%         +
1 BackLeft CCW         -71%         +71%         +
2 FrontLeft CW         +71%         +71%         -
3 BackRight CW         -71%         -71%         -
Thus the resulting pseudo-code should have these signs and values:

FrontRightCCW = +(0.71 * Pitch) - (0.71 * Roll) + Yaw

BackLeftCCW = -(0.71 * Pitch) + (0.71 * Roll) + Yaw

FrontLeftCW = +(0.71 * Pitch) + (0.71 * Roll) - Yaw

BackRightCW = -(0.71 * Pitch) - (0.71 * Roll) - Yaw

BUT, as we would be lowering the overall power to 71%, and all values are the same we can simply uses 100% for all values, this way we're still keeping the same proportion of strength between motors, so there will be no difference in stability, but we will be getting all the available power.

and the final code in Motors.pde, adding throttle and controlling total motor value not to get out of bounds, would be:

FrontRightCCW = constrain(throttle + control_pitch - control_roll + control_yaw, minThrottle, 2000);

BackLeftCCW = constrain(throttle - control_pitch + control_roll + control_yaw, minThrottle, 2000);

FrontLeftCW = constrain(throttle + control_pitch + control_roll - control_yaw, minThrottle, 2000);

BackRightCW = constrain(throttle - control_pitch - control_roll - control_yaw, minThrottle, 2000);

Hexa classic mode
Next, HEXA in classic mode, with all motors at the same distance from center frame:



More in detail:

Motor         Pitch         Roll         Yaw
7 Front CW         +100%         +0%         +
2 FrontLeft CCW         +50%         +87%         -
1 BackLeft CW         -50%         +87%         +
4 FrontRight CCW         +50%         -87%         -
3 BackRight CW         -50%         -87%         +
8 Back CCW         -100%         -0%         -
Thus the resulting pseudo-code should have these signs and values:

FrontCW = + ( 1 * Pitch) + ( 0 * Roll) - Yaw

FrontLeftCCW = + (0.5 * Pitch) + (0.87 * Roll) + Yaw

BackLeftCW = - (0.5 * Pitch) + (0.87 * Roll) - Yaw

FrontRightCCW = + (0.5 * Pitch) - (0.87 * Roll) + Yaw

BackRightCW = - (0.5 * Pitch) - (0.87 * Roll) - Yaw

BackCCW = - ( 1 * Pitch) - ( 0 * Roll) + Yaw

So all 4 left and righ motors will have a pitch strength of 50% and roll of 87% while front and back will only have 100% on pitch and no effect on roll.

and the final code in Motors.pde, adding throttle and controlling total motor value not to get out of bounds, would be:

FrontCW = constrain(throttle + control_pitch - control_yaw, minThrottle, 2000);

FrontLeftCCW = constrain(throttle + (0.5 * control_pitch) + (0.87 * control_roll) + control_yaw, minThrottle, 2000);

BackLeftCW = constrain(throttle - (0.5 * control_pitch) + (0.87 * control_roll) - control_yaw, minThrottle, 2000);

FrontRightCCW = constrain(throttle + (0.5 * control_pitch) - (0.87 * control_roll) + control_yaw, minThrottle, 2000);

BackRightCW = constrain(throttle - (0.5 * control_pitch) - (0.87 * control_roll) - control_yaw, minThrottle, 2000);

BackCCW = constrain(throttle - control_pitch + control_yaw, minThrottle, 2000);

NOTE: The current NG code, is not using the 87% on roll, but 100%; in this case it is like the all four left and right motors were a bit farther away from center (13%).

Hexa H mode
Next, HEXA in H mode, with three motors on each side in a "H" shape, forming a perfect square:



More in detail:

Motor         Pitch         Roll         Yaw
1 FrontLeft CW         +100%         +100%         -
6 Left CCW         +0%         +100%         +
5 BackLeft CW         -100%         +100%         -
2 FrontRight CCW         +100%         -100%         +
3 Right CW         -0%         -100%         -
4 BackRight CCW         -100%         -100%         +
Thus the resulting pseudo-code should have these signs and values:

FrontLeftCW = + (1 * Pitch) + (1 * Roll) - Yaw

LeftCCW = + (0 * Pitch) + (1 * Roll) + Yaw

BackLeftCW = - (1 * Pitch) + (1 * Roll) - Yaw

FrontRightCCW = + (1 * Pitch) - (1 * Roll) + Yaw

BackRightCW = - (0 * Pitch) - (1 * Roll) - Yaw

BackCCW = - (1 * Pitch) - (1 * Roll) + Yaw

So in this case as all values are 100%, no value is needed, only signs.

and the final code in Motors.pde, adding throttle and controlling total motor value not to get out of bounds, would be:

FrontCW = constrain(throttle + control_pitch + control_roll - control_yaw, minThrottle, 2000);

FrontLeftCCW = constrain(throttle + control_pitch + control_roll + control_yaw, minThrottle, 2000);

BackLeftCW = constrain(throttle - control_pitch + control_roll - control_yaw, minThrottle, 2000);

FrontRightCCW = constrain(throttle + control_pitch - control_roll + control_yaw, minThrottle, 2000);

BackRightCW = constrain(throttle - control_pitch - control_roll - control_yaw, minThrottle, 2000);

BackCCW = constrain(throttle - control_pitch - control_roll + control_yaw, minThrottle, 2000);

NOTE: If the sides where to be closer to each other, a roll value would have to be added, as they would have to have less strength than pitch; and viceversa, if you got your front and back motors closer, you would have to add a pitch value.

猫咪18

确实是天书。

勿殇小天

看不懂。。。。
出手机了～http://bbs.5imx.com/bbs/viewthread.php?tid=653482&extra=page%3D1

kissghost

这种等轴距的好理解

V型 H机架等
异形机架应该怎么计算呢

APM2里面 4轴 6轴 8轴 就直接 按电机角度然后解算COS和SIN值

可是我现在搞不明白 V6型异形机架或其他非等轴距机架怎么计算

reAper07

天书:em23:

feitian227

完全一样就有点说不过去了。我两次写的东西还不完全一样呢。

不戴眼镜

我觉得其实这段代码对其他的飞控也是差不多的，大家都一样的结构。

den_18

看不懂

green

:em26:

yudhnr

天书~~:em22:

dongfang

哦，这就是那段玉兔被指责抄袭MWC的代码的地方了。不同的飞控，在把俯仰控制转换为各个电机输出动力时用的算法是不一样的。恰巧玉兔的代码和MWC的是一样的。

猫咪18

好东东，就是不懂:em17:

零意尔

:em22: :em17:

feitian227

Octo classic mode
Next, Octo in classic mode, with one motor at front and back:



More in detail:

Motor         Pitch         Roll         Yaw
0 Front CW         +100%         +0%         -
1 FrontRight CCW         +71%         -71%         +
2 Right CW         +0%         -100%         -
3 BackRight CCW         -71%         -71%         +
6 Back CW         -0%         -0%         -
7 BackLeft CCW         -71%         +71%         +
9 Left CW         +0%         +100%         -
10 FrontLeft CCW         +71%         +71%         +
Thus the resulting pseudo-code should have these signs and values:

FrontCW = + (1 * Pitch) + (0 * Roll) - Yaw

FrontRightCCW = + (0.71 * Pitch) - (0.71 * Roll) + Yaw

RightCW = + (0 * Pitch) - (1 * Roll) - Yaw

BackRightCCW = - (0.71 * Pitch) - (0.71 * Roll) + Yaw

BackCW = - (0 * Pitch) - (0 * Roll) - Yaw

BackLeftCCW = - (0.71 * Pitch) + (0.71 * Roll) + Yaw

LeftCW = + (0 * Pitch) + (1 * Roll) - Yaw

FrontLeftCCW = + (0.71 * Pitch) + (0.71 * Roll) + Yaw

and the final code in Motors.pde, adding throttle and controlling total motor value not to get out of bounds, would be:

FrontCW = constrain(throttle + control_pitch - control_yaw, minThrottle, 2000);

FrontRightCCW = constrain(throttle + (0.71 * control_pitch) - (0.71 * control_roll) + control_yaw, minThrottle, 2000);

RightCW = constrain(throttle - control_roll - control_yaw, minThrottle, 2000);

BackRightCCW = constrain(throttle - (0.71 * control_pitch) - (0.71 * control_roll) + control_yaw, minThrottle, 2000);

BackCW = constrain(throttle - control_pitch - control_yaw, minThrottle, 2000);

BackLeftCCW = constrain(throttle - (0.71 * control_pitch) + (0.71 * control_roll) + control_yaw, minThrottle, 2000);

LeftCW = constrain(throttle + control_roll - control_yaw, minThrottle, 2000);

FrontLeftCCW = constrain(throttle + (0.71 * control_pitch) + (0.71 * control_roll) + control_yaw, minThrottle, 2000);

Octo X mode
Next, Octo in "Quad" mode, 2 motors at the front, 2 at the back, 2 left and 2 right:



More in detail:

Motor         Pitch         Roll         Yaw
0 Front CW         +92%         -38%         -
1 Front CCW         +92%         +38%         +
2 Left CW         +38%         +92%         -
3 Left CCW         -38%         +92%         +
6 Right CW         -38%         -92%         -
7 Right CCW         +38%         -92%         +
9 Back CW         -92%         +38%         -
10 Back CCW         -92%         -38%         +
To be able to have full power, I'll increase values to 100%, so proportionally they will be: 92% = 100% and 38% = 42%, thus giving these values:

Thus the resulting pseudo-code should have these signs and values:

FrontCW = + (1 * Pitch) - (0.42 * Roll) - Yaw

FrontCCW = + (1 * Pitch) + (0.42 * Roll) + Yaw

LeftCW = + (0.42 * Pitch) + (1 * Roll) - Yaw

LeftCCW = - (0.42 * Pitch) + (1 * Roll) + Yaw

RightCW = - (0.42 * Pitch) - (1 * Roll) - Yaw

RightCCW = + (0.42 * Pitch) - (1 * Roll) + Yaw

BackCW = - (1 * Pitch) + (0.42 * Roll) - Yaw

BackCCW = - (1 * Pitch) - (0.42 * Roll) + Yaw

and the final code in Motors.pde, adding throttle and controlling total motor value not to get out of bounds, would be:

FrontCW = constrain(throttle + control_pitch - (0.42 * control_roll) - control_yaw, minThrottle, 2000); // Front Motor CW

FrontCCW = constrain(throttle + control_pitch + (0.42 * control_roll) + control_yaw, minThrottle, 2000); // Front Motor CCW

LeftCW = constrain(throttle + (0.42 * control_pitch) + control_roll - control_yaw, minThrottle, 2000); // Left Motor CW

LeftCCW = constrain(throttle - (0.42 * control_pitch) + control_roll + control_yaw, minThrottle, 2000); // Left Motor CCW

RightCW = constrain(throttle - (0.42 * control_pitch) - control_roll - control_yaw, minThrottle, 2000); // Right Motor CW

RightCCW = constrain(throttle + (0.42 * control_pitch) - control_roll + control_yaw, minThrottle, 2000); // Right Motor CCW

BackCW = constrain(throttle - control_pitch + (0.42 * control_roll) - control_yaw, minThrottle, 2000); // Back Motor CW

BackCCW = constrain(throttle - control_pitch - (0.42 * control_roll) + control_yaw, minThrottle, 2000); // Back Motor CCW

Files to Check when adding new motor mixing
COMMS.pde (Show_Platform_Info())
Motors.pde (motor_output())
system.pde (APM_Init())
Well Pirates, that's about it, I hope I've been able to enlighten a bit more your pirte minds! Now you can go and design your own weird shape!!

I hope you got the idea!

any comments / addings / corrections are welcome!!

Happy Landings,

Dani