ardupilot/libraries/AP_Motors/AP_MotorsQuad.cpp

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *       AP_MotorsQuad.cpp - ArduCopter motors library
 *       Code by RandyMackay. DIYDrones.com
 *
 */

#include "AP_MotorsQuad.h"

// setup_motors - configures the motors for a quad
void AP_MotorsQuad::setup_motors()
{
    // call parent
    AP_MotorsMatrix::setup_motors();

    // hard coded config for supported frames
    if( _flags.frame_orientation == AP_MOTORS_PLUS_FRAME ) {
        // plus frame set-up
        add_motor(AP_MOTORS_MOT_1,  90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2);
        add_motor(AP_MOTORS_MOT_2, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4);
        add_motor(AP_MOTORS_MOT_3,   0, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  1);
        add_motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  3);

    }else if( _flags.frame_orientation == AP_MOTORS_V_FRAME ) {
        // V frame set-up
        add_motor(AP_MOTORS_MOT_1,   45,  0.7981,  1);
        add_motor(AP_MOTORS_MOT_2, -135,  1.0000,  3);
        add_motor(AP_MOTORS_MOT_3,  -45, -0.7981,  4);
        add_motor(AP_MOTORS_MOT_4,  135, -1.0000,  2);

    }else if( _flags.frame_orientation == AP_MOTORS_H_FRAME ) {
        // H frame set-up - same as X but motors spin in opposite directiSons
        add_motor(AP_MOTORS_MOT_1,   45, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  1);
        add_motor(AP_MOTORS_MOT_2, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  3);
        add_motor(AP_MOTORS_MOT_3,  -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4);
        add_motor(AP_MOTORS_MOT_4,  135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2);

    } else if (_flags.frame_orientation == AP_MOTORS_VTAIL_FRAME) {
        /* Lynxmotion Hunter Vtail 400/500

           Roll control comes only from the front motors, Yaw control only from the rear motors
           roll factor is measured by the angle perpendicular to that of the prop arm to the roll axis (x)
           pitch factor is measured by the angle perpendicular to the prop arm to the pitch axis (y)

           assumptions:
                                20      20
            \      /          3_____________1
             \    /                  |
              \  /                   |
           40  \/  40            20  |  20
              Tail                  / \
                                   2   4

           All angles measured from their closest axis

           Note: if we want the front motors to help with yaw,
                 motors 1's yaw factor should be changed to sin(radians(40)).  Where "40" is the vtail angle
                 motors 3's yaw factor should be changed to -sin(radians(40))
         */

      // front right: 70 degrees right of roll axis, 20 degrees up of pitch axis, no yaw
      add_motor_raw(AP_MOTORS_MOT_1, cosf(radians(160)), cosf(radians(-70)), 0, 1);
      // back left: no roll, 70 degrees down of pitch axis, full yaw
      add_motor_raw(AP_MOTORS_MOT_2, 0, cosf(radians(160)), AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3);
      // front left: 70 degrees left of roll axis, 20 degrees up of pitch axis, no yaw
      add_motor_raw(AP_MOTORS_MOT_3, cosf(radians(20)), cosf(radians(70)), 0, 4);
      // back right: no roll, 70 degrees down of pitch axis, full yaw
      add_motor_raw(AP_MOTORS_MOT_4, 0, cosf(radians(-160)), AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2);

    }else{
        // X frame set-up
        add_motor(AP_MOTORS_MOT_1,   45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1);
        add_motor(AP_MOTORS_MOT_2, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3);
        add_motor(AP_MOTORS_MOT_3,  -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  4);
        add_motor(AP_MOTORS_MOT_4,  135, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  2);
    }
}