PX4-Autopilot/src/modules/rover_mecanum/MecanumSpeedControl/MecanumSpeedControl.cpp

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#include "MecanumSpeedControl.hpp"

using namespace time_literals;

MecanumSpeedControl::MecanumSpeedControl(ModuleParams *parent) : ModuleParams(parent)
{
	_surface_vehicle_throttle_setpoint_pub.advertise();
	_surface_vehicle_speed_status_pub.advertise();
	updateParams();
}

void MecanumSpeedControl::updateParams()
{
	ModuleParams::updateParams();

	// Set up PID controllers
	_pid_speed_x.setGains(_param_ro_speed_p.get(), _param_ro_speed_i.get(), 0.f);
	_pid_speed_x.setIntegralLimit(1.f);
	_pid_speed_x.setOutputLimit(1.f);
	_pid_speed_y.setGains(_param_ro_speed_p.get(), _param_ro_speed_i.get(), 0.f);
	_pid_speed_y.setIntegralLimit(1.f);
	_pid_speed_y.setOutputLimit(1.f);

	// Set up slew rates
	if (_param_ro_accel_limit.get() > FLT_EPSILON) {
		_adjusted_speed_x_setpoint.setSlewRate(_param_ro_accel_limit.get());
		_adjusted_speed_y_setpoint.setSlewRate(_param_ro_accel_limit.get());
	}
}

void MecanumSpeedControl::updateSpeedControl()
{
	const hrt_abstime timestamp_prev = _timestamp;
	_timestamp = hrt_absolute_time();
	const float dt = math::constrain(_timestamp - timestamp_prev, 1_ms, 10_ms) * 1e-6f;

	updateSubscriptions();

	// Throttle Setpoints
	if (PX4_ISFINITE(_speed_x_setpoint) && PX4_ISFINITE(_speed_y_setpoint)) {
		Vector2f speed_setpoint = calcSpeedSetpoint();
		surface_vehicle_throttle_setpoint_s surface_vehicle_throttle_setpoint{};
		surface_vehicle_throttle_setpoint.timestamp = _timestamp;

		surface_vehicle_throttle_setpoint.throttle_body_x = RoverControl::speedControl(_adjusted_speed_x_setpoint, _pid_speed_x,
				speed_setpoint(0), _vehicle_speed_body_x, _param_ro_accel_limit.get(), _param_ro_decel_limit.get(),
				_param_ro_max_thr_speed.get(), dt);
		surface_vehicle_throttle_setpoint.throttle_body_y = RoverControl::speedControl(_adjusted_speed_y_setpoint, _pid_speed_y,
				speed_setpoint(1), _vehicle_speed_body_y, _param_ro_accel_limit.get(), _param_ro_decel_limit.get(),
				_param_ro_max_thr_speed.get(), dt);
		_surface_vehicle_throttle_setpoint_pub.publish(surface_vehicle_throttle_setpoint);

	}

	// Publish position controller status (logging only)
	surface_vehicle_speed_status_s surface_vehicle_speed_status;
	surface_vehicle_speed_status.timestamp = _timestamp;
	surface_vehicle_speed_status.measured_speed_body_x = _vehicle_speed_body_x;
	surface_vehicle_speed_status.adjusted_speed_body_x_setpoint = _adjusted_speed_x_setpoint.getState();
	surface_vehicle_speed_status.measured_speed_body_y = _vehicle_speed_body_y;
	surface_vehicle_speed_status.adjusted_speed_body_y_setpoint = _adjusted_speed_y_setpoint.getState();
	surface_vehicle_speed_status.pid_throttle_body_x_integral = _pid_speed_x.getIntegral();
	surface_vehicle_speed_status.pid_throttle_body_y_integral = _pid_speed_y.getIntegral();
	_surface_vehicle_speed_status_pub.publish(surface_vehicle_speed_status);
}

void MecanumSpeedControl::updateSubscriptions()
{
	if (_vehicle_attitude_sub.updated()) {
		vehicle_attitude_s vehicle_attitude{};
		_vehicle_attitude_sub.copy(&vehicle_attitude);
		_vehicle_attitude_quaternion = matrix::Quatf(vehicle_attitude.q);
		_vehicle_yaw = matrix::Eulerf(_vehicle_attitude_quaternion).psi();
	}

	if (_vehicle_local_position_sub.updated()) {
		vehicle_local_position_s vehicle_local_position{};
		_vehicle_local_position_sub.copy(&vehicle_local_position);
		const Vector3f velocity_in_local_frame(vehicle_local_position.vx, vehicle_local_position.vy, vehicle_local_position.vz);
		const Vector3f velocity_in_body_frame = _vehicle_attitude_quaternion.rotateVectorInverse(velocity_in_local_frame);
		_vehicle_speed_body_x = fabsf(velocity_in_body_frame(0)) > _param_ro_speed_th.get() ? velocity_in_body_frame(0) : 0.f;
		_vehicle_speed_body_y = fabsf(velocity_in_body_frame(1)) > _param_ro_speed_th.get() ? velocity_in_body_frame(1) : 0.f;
	}

	if (_surface_vehicle_speed_setpoint_sub.updated()) {
		surface_vehicle_speed_setpoint_s surface_vehicle_speed_setpoint;
		_surface_vehicle_speed_setpoint_sub.copy(&surface_vehicle_speed_setpoint);
		_speed_x_setpoint = surface_vehicle_speed_setpoint.speed_body_x;
		_speed_y_setpoint = surface_vehicle_speed_setpoint.speed_body_y;
	}
}

Vector2f MecanumSpeedControl::calcSpeedSetpoint()
{
	if (_surface_vehicle_steering_setpoint_sub.updated()) {
		surface_vehicle_steering_setpoint_s surface_vehicle_steering_setpoint{};
		_surface_vehicle_steering_setpoint_sub.copy(&surface_vehicle_steering_setpoint);
		_normalized_speed_diff = surface_vehicle_steering_setpoint.normalized_steering_setpoint;
	}

	Vector2f speed_setpoint = Vector2f(_speed_x_setpoint, _speed_y_setpoint);

	float speed_x_setpoint_normalized = math::interpolate<float>(_speed_x_setpoint,
					    -_param_ro_max_thr_speed.get(), _param_ro_max_thr_speed.get(), -1.f, 1.f);

	float speed_y_setpoint_normalized = math::interpolate<float>(_speed_y_setpoint,
					    -_param_ro_max_thr_speed.get(), _param_ro_max_thr_speed.get(), -1.f, 1.f);

	const float total_speed = fabsf(speed_x_setpoint_normalized) + fabsf(speed_y_setpoint_normalized) + fabsf(
					  _normalized_speed_diff);

	if (total_speed > 1.f) {
		const float theta = atan2f(fabsf(speed_y_setpoint_normalized), fabsf(speed_x_setpoint_normalized));
		const float magnitude = (1.f - fabsf(_normalized_speed_diff)) / (sinf(theta) + cosf(theta));
		const float normalization = 1.f / (sqrtf(powf(speed_x_setpoint_normalized,
						   2.f) + powf(speed_y_setpoint_normalized, 2.f)));
		speed_x_setpoint_normalized *= magnitude * normalization;
		speed_y_setpoint_normalized *= magnitude * normalization;
		speed_setpoint(0) = math::interpolate<float>(speed_x_setpoint_normalized, -1.f, 1.f,
				    -_param_ro_max_thr_speed.get(), _param_ro_max_thr_speed.get());
		speed_setpoint(1) = math::interpolate<float>(speed_y_setpoint_normalized, -1.f, 1.f,
				    -_param_ro_max_thr_speed.get(), _param_ro_max_thr_speed.get());
	}

	speed_setpoint(0) = fabsf(speed_setpoint(0)) > _param_ro_speed_th.get() ? speed_setpoint(0) : 0.f;
	speed_setpoint(1) = fabsf(speed_setpoint(1)) > _param_ro_speed_th.get() ? speed_setpoint(1) : 0.f;

	return speed_setpoint;
}

bool MecanumSpeedControl::runSanityChecks()
{
	bool ret = true;

	if (_param_ro_speed_limit.get() < FLT_EPSILON) {
		ret = false;
		events::send<float>(events::ID("mecanum_vel_control_conf_invalid_speed_lim"), events::Log::Error,
				    "Invalid configuration of necessary parameter RO_SPEED_LIM", _param_ro_speed_limit.get());

	}

	if (_param_ro_max_thr_speed.get() < FLT_EPSILON && _param_ro_speed_p.get() < FLT_EPSILON) {
		ret = false;
		events::send<float, float>(events::ID("mecanum_vel_control_conf_invalid_speed_control"), events::Log::Error,
					   "Invalid configuration for speed control: Neither feed forward (RO_MAX_THR_SPEED) nor feedback (RO_SPEED_P) is setup",
					   _param_ro_max_thr_speed.get(),
					   _param_ro_speed_p.get());
	}

	return ret;
}