SITL: fixed moment of rotated motors

This commit is contained in:
Andrew Tridgell 2016-05-01 18:06:49 +10:00
parent 60b3625950
commit 2d47ca8095
2 changed files with 35 additions and 15 deletions

View File

@ -29,37 +29,55 @@ void Motor::calculate_forces(const Aircraft::sitl_input &input,
Vector3f &rot_accel,
Vector3f &thrust) const
{
// fudge factors
const float arm_scale = radians(5000);
const float yaw_scale = radians(400);
// get motor speed from 0 to 1
float motor_speed = constrain_float((input.servos[motor_offset+servo]-1100)/900.0, 0, 1);
rot_accel.x = -radians(5000.0) * sinf(radians(angle)) * motor_speed;
rot_accel.y = radians(5000.0) * cosf(radians(angle)) * motor_speed;
rot_accel.z = yaw_factor * motor_speed * radians(400.0);
thrust(0, 0, -motor_speed * thrust_scale); // newtons NED
// the yaw torque of the motor
Vector3f rotor_torque(0, 0, yaw_factor * motor_speed * yaw_scale);
// get thrust for untilted motor
thrust(0, 0, -motor_speed);
// define the arm position relative to center of mass
Vector3f arm(arm_scale * cosf(radians(angle)), arm_scale * sinf(radians(angle)), 0);
// work out roll and pitch of motor relative to it pointing straight up
float roll = 0, pitch = 0;
// possibly roll and/or pitch the motor
if (roll_servo >= 0) {
float roll;
uint16_t servoval = input.servos[roll_servo+motor_offset];
if (roll_min < roll_max) {
roll = constrain_float(roll_min + (servoval-1000)*0.001*(roll_max-roll_min), roll_min, roll_max);
} else {
roll = constrain_float(roll_max + (2000-servoval)*0.001*(roll_min-roll_max), roll_max, roll_min);
}
Matrix3f rotation;
rotation.from_euler(radians(roll), 0, 0);
rot_accel = rotation * rot_accel;
thrust = rotation * thrust;
}
if (pitch_servo >= 0) {
float pitch;
uint16_t servoval = input.servos[pitch_servo+motor_offset];
if (pitch_min < pitch_max) {
pitch = constrain_float(pitch_min + (servoval-1000)*0.001*(pitch_max-pitch_min), pitch_min, pitch_max);
} else {
pitch = constrain_float(pitch_max + (2000-servoval)*0.001*(pitch_min-pitch_max), pitch_max, pitch_min);
}
Matrix3f rotation;
rotation.identity();
rotation.from_euler(0, radians(pitch), 0);
rot_accel = rotation * rot_accel;
thrust = rotation * thrust;
}
// possibly rotate the thrust vector and the rotor torque
if (!is_zero(roll) || !is_zero(pitch)) {
Matrix3f rotation;
rotation.from_euler(radians(roll), radians(pitch), 0);
thrust = rotation * thrust;
rotor_torque = rotation * rotor_torque;
}
// calculate total rotational acceleration
rot_accel = (arm % thrust) + rotor_torque;
// scale the thrust
thrust = thrust * thrust_scale;
}

View File

@ -49,6 +49,8 @@ QuadPlane::QuadPlane(const char *home_str, const char *frame_str) :
frame_type = "tri";
} else if (strstr(frame_str, "-tilttri")) {
frame_type = "tilttri";
// fwd motor gives zero thrust
thrust_scale = 0;
} else if (strstr(frame_str, "firefly")) {
frame_type = "firefly";
// elevon style surfaces