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author | Thomas Gubler <thomasgubler@gmail.com> | 2013-10-15 22:00:56 +0200 |
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committer | Thomas Gubler <thomasgubler@gmail.com> | 2013-10-24 17:40:03 +0200 |
commit | b21b9078e2d719bfd7af9580ac3b9b5957ef1d57 (patch) | |
tree | 32c0bffeecc3621453bc51f2bc0d2a3b007b612f /src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp | |
parent | 17e0c5053ece4cbf53e659b5f60d640beaab7d50 (diff) | |
download | px4-firmware-b21b9078e2d719bfd7af9580ac3b9b5957ef1d57.tar.gz px4-firmware-b21b9078e2d719bfd7af9580ac3b9b5957ef1d57.tar.bz2 px4-firmware-b21b9078e2d719bfd7af9580ac3b9b5957ef1d57.zip |
wip, fw attitude ctrl: split into attitude and rate, compiles, untested
Diffstat (limited to 'src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp')
-rw-r--r-- | src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp | 86 |
1 files changed, 72 insertions, 14 deletions
diff --git a/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp b/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp index 9601fa544..d2cd9cf04 100644 --- a/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp +++ b/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp @@ -47,37 +47,95 @@ ECL_YawController::ECL_YawController() : _last_run(0), + _tc(0.1f), _last_output(0.0f), + _integrator(0.0f), + _rate_error(0.0f), _rate_setpoint(0.0f), + _bodyrate_setpoint(0.0f), _max_deflection_rad(math::radians(45.0f)) { } -float ECL_YawController::control(float roll, float yaw_rate, float accel_y, float scaler, bool lock_integrator, - float airspeed_min, float airspeed_max, float aspeed) +float ECL_YawController::control_attitude(float roll, float pitch, + float speed_body_u, float speed_body_w, + float roll_rate_setpoint, float pitch_rate_setpoint) +{ + /* Calculate desired yaw rate from coordinated turn constraint / (no side forces) */ + _rate_setpoint = 0.0f; + float denumerator = (speed_body_u * cosf(roll) * cosf(pitch) + speed_body_w * sinf(pitch)); + if(denumerator != 0.0f) { //XXX: floating point comparison + _rate_setpoint = (speed_body_w * roll_rate_setpoint + 9.81f * sinf(roll) * cosf(pitch) + speed_body_u * pitch_rate_setpoint * sinf(roll)) / denumerator; + } + + /* limit the rate */ //XXX: move to body angluar rates + if (_max_rate > 0.01f) { + _rate_setpoint = (_rate_setpoint > _max_rate) ? _max_rate : _rate_setpoint; + _rate_setpoint = (_rate_setpoint < -_max_rate) ? -_max_rate : _rate_setpoint; + } + + return _rate_setpoint; +} + +float ECL_YawController::control_bodyrate(float roll, float pitch, + float pitch_rate, float yaw_rate, + float pitch_rate_setpoint, + float airspeed_min, float airspeed_max, float airspeed, float scaler, bool lock_integrator) { /* get the usual dt estimate */ uint64_t dt_micros = ecl_elapsed_time(&_last_run); _last_run = ecl_absolute_time(); - float dt = (dt_micros > 500000) ? 0.0f : dt_micros / 1000000; -// float psi_dot = 0.0f; -// float denumerator = (speed_body[0] * cosf(att_sp->roll_body) * cosf(att_sp->pitch_body) + speed_body[2] * sinf(att_sp->pitch_body)); -// if(denumerator != 0.0f) { -// psi_dot = (speed_body[2] * phi_dot + 9.81f * sinf(att_sp->roll_body) * cosf(att_sp->pitch_body) + speed_body[0] * theta_dot * sinf(att_sp->roll_body)) -// / (speed_body[0] * cosf(att_sp->roll_body) * cosf(att_sp->pitch_body) + speed_body[2] * sinf(att_sp->pitch_body)); -// } + float k_ff = math::max((_k_p - _k_i * _tc) * _tc - _k_d, 0.0f); + float k_i_rate = _k_i * _tc; - /* Calculate desired yaw rate from coordinated turn constraint / (no side forces) */ - _last_output = 0.0f; - float denumerator = (speed_body_u * cosf(roll) * cosf(pitch) + speed_body_w * sinf(pitch)); - if(denumerator != 0.0f) { //XXX: floating point comparison - _last_output = (speed_body_w * roll_rate_desired + 9.81f * sinf(roll) * cosf(pitch) + speed_body_u * pitch_rate_desired * sinf(roll)) / denumerator; + /* input conditioning */ + if (!isfinite(airspeed)) { + /* airspeed is NaN, +- INF or not available, pick center of band */ + airspeed = 0.5f * (airspeed_min + airspeed_max); + } else if (airspeed < airspeed_min) { + airspeed = airspeed_min; } + + /* Transform setpoint to body angular rates */ + _bodyrate_setpoint = -sinf(roll) * pitch_rate_setpoint * cosf(roll)*cosf(pitch) * _rate_setpoint; //jacobian + + /* Transform estimation to body angular rates */ + float yaw_bodyrate = -sinf(roll) * pitch_rate * cosf(roll)*cosf(pitch) * yaw_rate; //jacobian + + /* Calculate body angular rate error */ + _rate_error = _bodyrate_setpoint - yaw_bodyrate; //body angular rate error + + float ilimit_scaled = 0.0f; + + if (!lock_integrator && k_i_rate > 0.0f && airspeed > 0.5f * airspeed_min) { + + float id = _rate_error * k_i_rate * dt * scaler; + + /* + * anti-windup: do not allow integrator to increase into the + * wrong direction if actuator is at limit + */ + if (_last_output < -_max_deflection_rad) { + /* only allow motion to center: increase value */ + id = math::max(id, 0.0f); + } else if (_last_output > _max_deflection_rad) { + /* only allow motion to center: decrease value */ + id = math::min(id, 0.0f); + } + + _integrator += id; + } + + /* integrator limit */ + _integrator = math::constrain(_integrator, -ilimit_scaled, ilimit_scaled); + /* store non-limited output */ + _last_output = ((_rate_error * _k_d * scaler) + _integrator + (_rate_setpoint * k_ff)) * scaler; + return math::constrain(_last_output, -_max_deflection_rad, _max_deflection_rad); } |