TECS: revert altitude controller to old logic

- if the height rate input into TECS is finite, use that one to
update a velocity reference generator
- if the velocity reference generator reports position locked or
height rate input is not finite, then run altidue reference generator
- run altitude controller only if altitue is controlled

if height_rate_setpoint is set, only use that one to update altitdue trajectory

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
This commit is contained in:
Silvan Fuhrer 2023-03-29 13:21:11 +02:00
parent dde656f4b1
commit 460956fd33
4 changed files with 83 additions and 65 deletions

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@ -1,7 +1,9 @@
uint64 timestamp # time since system start (microseconds)
float32 altitude_sp # Altitude setpoint AMSL [m]
float32 altitude_sp_ref # Altitude setpoint reference AMSL [m]
float32 altitude_reference # Altitude setpoint reference AMSL [m]
float32 height_rate_reference # Height rate setpoint reference [m/s]
float32 height_rate_direct # Direct height rate setpoint from velocity reference generator [m/s]
float32 height_rate_setpoint # Height rate setpoint [m/s]
float32 height_rate # Height rate [m/s]
float32 equivalent_airspeed_sp # Equivalent airspeed setpoint [m/s]

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@ -134,7 +134,7 @@ TECSAirspeedFilter::AirspeedFilterState TECSAirspeedFilter::getState() const
}
void TECSAltitudeReferenceModel::update(const float dt, const AltitudeReferenceState &setpoint, float altitude,
const Param &param)
float height_rate, const Param &param)
{
// Input checks
if (!TIMESTAMP_VALID(dt)) {
@ -143,40 +143,55 @@ void TECSAltitudeReferenceModel::update(const float dt, const AltitudeReferenceS
return;
}
if (!PX4_ISFINITE(altitude)) {
altitude = 0.0f;
}
const float current_alt = PX4_ISFINITE(altitude) ? altitude : 0.f;
if (PX4_ISFINITE(setpoint.alt_rate)) {
_alt_rate_ref = setpoint.alt_rate;
} else {
_alt_rate_ref = 0.0f;
}
_velocity_control_traj_generator.setMaxJerk(param.jerk_max);
_velocity_control_traj_generator.setMaxAccelUp(param.vert_accel_limit);
_velocity_control_traj_generator.setMaxAccelDown(param.vert_accel_limit);
_velocity_control_traj_generator.setMaxVelUp(param.max_sink_rate); // different convention for FW than for MC
_velocity_control_traj_generator.setMaxVelDown(param.max_climb_rate); // different convention for FW than for MC
// Altitude setpoint reference
const bool altitude_control_enable{PX4_ISFINITE(setpoint.alt)};
_alt_control_traj_generator.setMaxJerk(param.jerk_max);
_alt_control_traj_generator.setMaxAccel(param.vert_accel_limit);
_alt_control_traj_generator.setMaxVel(fmax(param.max_climb_rate, param.max_sink_rate));
if (altitude_control_enable) {
const float target_climbrate = math::min(param.target_climbrate, param.max_climb_rate);
const float target_sinkrate = math::min(param.target_sinkrate, param.max_sink_rate);
_velocity_control_traj_generator.setVelSpFeedback(setpoint.alt_rate);
const float delta_trajectory_to_target_m = setpoint.alt - _alt_control_traj_generator.getCurrentPosition();
bool control_altitude = true;
float altitude_setpoint = setpoint.alt;
float altitude_rate_target = math::signNoZero<float>(delta_trajectory_to_target_m) *
math::trajectory::computeMaxSpeedFromDistance(
param.jerk_max, param.vert_accel_limit, fabsf(delta_trajectory_to_target_m), 0.0f);
altitude_rate_target = math::constrain(altitude_rate_target, -target_sinkrate, target_climbrate);
_alt_control_traj_generator.updateDurations(altitude_rate_target);
_alt_control_traj_generator.updateTraj(dt);
if (PX4_ISFINITE(setpoint.alt_rate)) {
// input is height rate (not altitude)
_velocity_control_traj_generator.setCurrentPositionEstimate(current_alt);
_velocity_control_traj_generator.update(dt, setpoint.alt_rate);
altitude_setpoint = _velocity_control_traj_generator.getCurrentPosition();
control_altitude = PX4_ISFINITE(altitude_setpoint); // returns true if altitude is locked
} else {
_alt_control_traj_generator.reset(0.0f, 0.0f, altitude);
_velocity_control_traj_generator.reset(0, height_rate, altitude_setpoint);
}
if (control_altitude) {
const float target_climbrate_m_s = math::min(param.target_climbrate, param.max_climb_rate);
const float target_sinkrate_m_s = math::min(param.target_sinkrate, param.max_sink_rate);
const float delta_trajectory_to_target_m = altitude_setpoint - _alt_control_traj_generator.getCurrentPosition();
float height_rate_target = math::signNoZero<float>(delta_trajectory_to_target_m) *
math::trajectory::computeMaxSpeedFromDistance(
param.jerk_max, param.vert_accel_limit, fabsf(delta_trajectory_to_target_m), 0.f);
height_rate_target = math::constrain(height_rate_target, -target_sinkrate_m_s, target_climbrate_m_s);
_alt_control_traj_generator.updateDurations(height_rate_target);
_alt_control_traj_generator.updateTraj(dt);
_height_rate_setpoint_direct = NAN;
} else {
_alt_control_traj_generator.setCurrentVelocity(_velocity_control_traj_generator.getCurrentVelocity());
_alt_control_traj_generator.setCurrentPosition(current_alt);
_height_rate_setpoint_direct = _velocity_control_traj_generator.getCurrentVelocity();
}
}
@ -190,25 +205,12 @@ TECSAltitudeReferenceModel::AltitudeReferenceState TECSAltitudeReferenceModel::g
return ref;
}
float TECSAltitudeReferenceModel::getAltitudeRateReference() const
{
return _alt_rate_ref;
}
void TECSAltitudeReferenceModel::initialize(const AltitudeReferenceState &state)
{
float init_state_alt{state.alt};
_alt_rate_ref = state.alt_rate;
const float init_state_alt = PX4_ISFINITE(state.alt) ? state.alt : 0.f;
const float init_state_alt_rate = PX4_ISFINITE(state.alt_rate) ? state.alt_rate : 0.f;
if (!PX4_ISFINITE(state.alt)) {
init_state_alt = 0.0f;
}
if (!PX4_ISFINITE(state.alt_rate)) {
_alt_rate_ref = 0.0f;
}
_alt_control_traj_generator.reset(0.0f, _alt_rate_ref, init_state_alt);
_alt_control_traj_generator.reset(0.0f, init_state_alt_rate, init_state_alt);
}
void TECSControl::initialize(const Setpoint &setpoint, const Input &input, Param &param, const Flag &flag)
@ -245,7 +247,6 @@ void TECSControl::initialize(const Setpoint &setpoint, const Input &input, Param
_debug_output.energy_balance_rate_estimate = seb_rate.estimate;
_debug_output.energy_balance_rate_sp = seb_rate.setpoint;
_debug_output.pitch_integrator = _pitch_integ_state;
_debug_output.altitude_rate_control = control_setpoint.altitude_rate_setpoint;
_debug_output.true_airspeed_derivative_control = control_setpoint.tas_rate_setpoint;
}
@ -263,7 +264,14 @@ void TECSControl::update(const float dt, const Setpoint &setpoint, const Input &
control_setpoint.tas_rate_setpoint = _calcAirspeedControlOutput(setpoint, input, param, flag);
control_setpoint.altitude_rate_setpoint = _calcAltitudeControlOutput(setpoint, input, param);
if (PX4_ISFINITE(setpoint.altitude_rate_setpoint_direct)) {
// direct height rate control
control_setpoint.altitude_rate_setpoint = setpoint.altitude_rate_setpoint_direct;
} else {
// altitude is locked, go through altitude outer loop
control_setpoint.altitude_rate_setpoint = _calcAltitudeControlOutput(setpoint, input, param);
}
SpecificEnergyRates specific_energy_rate{_calcSpecificEnergyRates(control_setpoint, input)};
@ -313,8 +321,9 @@ float TECSControl::_calcAirspeedControlOutput(const Setpoint &setpoint, const In
float TECSControl::_calcAltitudeControlOutput(const Setpoint &setpoint, const Input &input, const Param &param) const
{
float altitude_rate_output;
altitude_rate_output = (setpoint.altitude_reference.alt - input.altitude) * param.altitude_error_gain +
param.altitude_setpoint_gain_ff * setpoint.altitude_reference.alt_rate + setpoint.altitude_rate_setpoint;
altitude_rate_output = (setpoint.altitude_reference.alt - input.altitude) * param.altitude_error_gain
+ param.altitude_setpoint_gain_ff * setpoint.altitude_reference.alt_rate;
altitude_rate_output = math::constrain(altitude_rate_output, -param.max_sink_rate, param.max_climb_rate);
return altitude_rate_output;
@ -637,14 +646,15 @@ void TECS::initialize(const float altitude, const float altitude_rate, const flo
const float eas_to_tas)
{
// Init subclasses
TECSAltitudeReferenceModel::AltitudeReferenceState current_state{ .alt = altitude,
TECSAltitudeReferenceModel::AltitudeReferenceState current_state{.alt = altitude,
.alt_rate = altitude_rate};
_altitude_reference_model.initialize(current_state);
_airspeed_filter.initialize(equivalent_airspeed);
TECSControl::Setpoint control_setpoint;
control_setpoint.altitude_reference = _altitude_reference_model.getAltitudeReference();
control_setpoint.altitude_rate_setpoint = _altitude_reference_model.getAltitudeRateReference();
control_setpoint.altitude_rate_setpoint_direct =
_altitude_reference_model.getAltitudeReference().alt_rate; // init to reference altitude rate
control_setpoint.tas_setpoint = equivalent_airspeed * eas_to_tas;
const TECSControl::Input control_input{ .altitude = altitude,
@ -658,9 +668,9 @@ void TECS::initialize(const float altitude, const float altitude_rate, const flo
_debug_status.control = _control.getDebugOutput();
_debug_status.true_airspeed_filtered = eas_to_tas * _airspeed_filter.getState().speed;
_debug_status.true_airspeed_derivative = eas_to_tas * _airspeed_filter.getState().speed_rate;
_debug_status.altitude_sp_ref = _altitude_reference_model.getAltitudeReference().alt;
_debug_status.altitude_rate_alt_ref = _altitude_reference_model.getAltitudeReference().alt_rate;
_debug_status.altitude_rate_feedforward = _altitude_reference_model.getAltitudeRateReference();
_debug_status.altitude_reference = _altitude_reference_model.getAltitudeReference().alt;
_debug_status.height_rate_reference = _altitude_reference_model.getAltitudeReference().alt_rate;
_debug_status.height_rate_direct = _altitude_reference_model.getHeightRateSetpointDirect();
_update_timestamp = hrt_absolute_time();
}
@ -709,11 +719,11 @@ void TECS::update(float pitch, float altitude, float hgt_setpoint, float EAS_set
const TECSAltitudeReferenceModel::AltitudeReferenceState setpoint{ .alt = hgt_setpoint,
.alt_rate = hgt_rate_sp};
_altitude_reference_model.update(dt, setpoint, altitude, _reference_param);
_altitude_reference_model.update(dt, setpoint, altitude, hgt_rate, _reference_param);
TECSControl::Setpoint control_setpoint;
control_setpoint.altitude_reference = _altitude_reference_model.getAltitudeReference();
control_setpoint.altitude_rate_setpoint = _altitude_reference_model.getAltitudeRateReference();
control_setpoint.altitude_rate_setpoint_direct = _altitude_reference_model.getHeightRateSetpointDirect();
// Calculate the demanded true airspeed
// TODO this function should not be in the module. Only give feedback that the airspeed can't be achieved.
@ -744,9 +754,9 @@ void TECS::update(float pitch, float altitude, float hgt_setpoint, float EAS_set
_debug_status.control = _control.getDebugOutput();
_debug_status.true_airspeed_filtered = eas_to_tas * eas.speed;
_debug_status.true_airspeed_derivative = eas_to_tas * eas.speed_rate;
_debug_status.altitude_sp_ref = control_setpoint.altitude_reference.alt;
_debug_status.altitude_rate_alt_ref = control_setpoint.altitude_reference.alt_rate;
_debug_status.altitude_rate_feedforward = control_setpoint.altitude_rate_setpoint;
_debug_status.altitude_reference = control_setpoint.altitude_reference.alt;
_debug_status.height_rate_reference = control_setpoint.altitude_reference.alt_rate;
_debug_status.height_rate_direct = _altitude_reference_model.getHeightRateSetpointDirect();
}
}

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@ -155,9 +155,10 @@ public:
* @param[in] dt is the update interval in [s].
* @param[in] setpoint are the desired setpoints.
* @param[in] altitude is the altitude amsl in [m].
* @param[in] height_rate is the height rate setpoint in [m/s].
* @param[in] param are the reference model parameters.
*/
void update(float dt, const AltitudeReferenceState &setpoint, float altitude, const Param &param);
void update(float dt, const AltitudeReferenceState &setpoint, float altitude, float height_rate, const Param &param);
/**
* @brief Get the current altitude reference of altitude reference model.
@ -167,17 +168,20 @@ public:
AltitudeReferenceState getAltitudeReference() const;
/**
* @brief Get the altitude rate reference of the altitude rate reference model.
* @brief Get the Height Rate Setpoint directly from the velocity trajector generator
*
* @return Current altitude rate reference point.
* @return float direct height rate setpoint [m/s]
*/
float getAltitudeRateReference() const;
float getHeightRateSetpointDirect() const {return _height_rate_setpoint_direct; }
private:
// State
VelocitySmoothing
_alt_control_traj_generator; ///< Generates altitude rate and altitude setpoint trajectory when altitude is commanded.
float _alt_rate_ref; ///< Altitude rate reference in [m/s].
ManualVelocitySmoothingZ
_velocity_control_traj_generator; ///< generates height rate trajectory when height rate is commanded
float _height_rate_setpoint_direct{NAN}; ///< generated direct height rate setpoint
};
class TECSControl
@ -250,7 +254,7 @@ public:
*/
struct Setpoint {
TECSAltitudeReferenceModel::AltitudeReferenceState altitude_reference; ///< Altitude/height rate reference.
float altitude_rate_setpoint; ///< Altitude rate setpoint.
float altitude_rate_setpoint_direct; ///< Direct height rate setpoint.
float tas_setpoint; ///< True airspeed setpoint.
};
@ -544,9 +548,9 @@ public:
TECSControl::DebugOutput control;
float true_airspeed_filtered;
float true_airspeed_derivative;
float altitude_sp_ref;
float altitude_rate_alt_ref;
float altitude_rate_feedforward;
float altitude_reference;
float height_rate_reference;
float height_rate_direct;
enum ECL_TECS_MODE tecs_mode;
};
public:

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@ -483,7 +483,9 @@ FixedwingPositionControl::tecs_status_publish(float alt_sp, float equivalent_air
}
tecs_status.altitude_sp = alt_sp;
tecs_status.altitude_sp_ref = debug_output.altitude_sp_ref;
tecs_status.altitude_reference = debug_output.altitude_reference;
tecs_status.height_rate_reference = debug_output.height_rate_reference;
tecs_status.height_rate_direct = debug_output.height_rate_direct;
tecs_status.height_rate_setpoint = debug_output.control.altitude_rate_control;
tecs_status.height_rate = -_local_pos.vz;
tecs_status.equivalent_airspeed_sp = equivalent_airspeed_sp;