Class defining the robot model. More...

#include <robot_model.hpp>

Public Types
typedef std::vector< double >	state_type
	Data type of the state. More...

typedef std::vector< double >	input_type
	Data type of the input. More...

Public Member Functions
	RobotModel ()

	RobotModel (const std::vector< double > &c)

	~RobotModel ()

void	eval_ode (const state_type &x, const input_type &u, state_type &dxdt, const double t)
	Evaluate the ODE. More...

void	integrate (state_type &state, const input_type &input, double t1, double t2, double init_step)
	Integrates the model over a period of time. More...

template<class MatrixT >
void	get_lin_matrices (const state_type &x_0, const input_type &u_0, MatrixT &A, MatrixT &B) const
	Gets the matrices of the linearised system. More...

template<class MatrixT >
void	get_lin_discr_matrices (const state_type &x_0, const input_type &u_0, MatrixT &Ad, MatrixT &Bd, float dt) const
	Gets the matrices of the discretised linearised system. More...

template<class VectorT , class MatrixT >
void	get_lin_discr_matrices (const VectorT &x_0, const VectorT &u_0, MatrixT &Ad, MatrixT &Bd, float dt) const
	Overloads get_lin_discr_matrices for Eigen vectors. More...

double	steady_propeller_speed (double speed) const
	Computes the propeller speed in steady state. More...

double	steady_speed (double n) const
	Computes the horizontal speed in steady state. More...

double	lat_turn_radius (double u, double delta_r) const
	Computes the lateral turning radius. More...

double	elev_turn_radius (double u, double delta_e) const
	Computes the elevation turning radius. More...

Private Member Functions
void	ode (const state_type &x, state_type &dxdt, const double t)
	ODE used to integrate the model. More...

Eigen::Matrix3d	jac_pos (double phi, double theta, double psi)
	Computes the Jacobian of the position. More...

Eigen::Matrix3d	jac_orient (double phi, double theta, double psi)
	Computes the Jacobian of the orientation. More...

double	sign (double x) const
	Returns the sign of a real number. More...

Private Attributes
std::vector< double >	c_
	Model constants. More...

double	g_
	Gravity acceleration. More...

input_type	u_
	Model inputs. More...

Detailed Description

Class defining the robot model.

The state is as follow:

$x_3 = \Phi$
$x_4 = \theta$
$x_5 = \psi$
$x_{10} = q$
$x_{11} = r$
$x_{12} = \Delta m$

The inputs are as follow:

$u_1 = \delta_r$
$u_2 = \delta_e$

Definition at line 47 of file robot_model.hpp.

Member Typedef Documentation

typedef std::vector<double> mfcpp::RobotModel::input_type

Data type of the input.

Definition at line 54 of file robot_model.hpp.

typedef std::vector<double> mfcpp::RobotModel::state_type

Data type of the state.

Definition at line 51 of file robot_model.hpp.

Constructor & Destructor Documentation

mfcpp::RobotModel::RobotModel ( )

Definition at line 32 of file robot_model.cpp.

mfcpp::RobotModel::RobotModel ( const std::vector< double > & c )

mfcpp::RobotModel::~RobotModel ( )

Definition at line 45 of file robot_model.cpp.

Member Function Documentation

double mfcpp::RobotModel::elev_turn_radius	(	double	u,
		double	delta_e
	)		const

inline

Computes the elevation turning radius.

Parameters

u	Speed of the robot
delta_e	Angle of the elevation rudder

Definition at line 251 of file robot_model.hpp.

void mfcpp::RobotModel::eval_ode	(	const state_type &	x,
		const input_type &	u,
		state_type &	dxdt,
		const double	t
	)

Evaluate the ODE.

Public version of the ODE

Parameters

x	Current state
u	Current input
dxdt	Current time derivative of the state
t	Current time

Definition at line 204 of file robot_model.cpp.

template<class MatrixT >

void mfcpp::RobotModel::get_lin_discr_matrices	(	const state_type &	x_0,
		const input_type &	u_0,
		MatrixT &	Ad,
		MatrixT &	Bd,
		float	dt
	)		const

Gets the matrices of the discretised linearised system.

The system $\dot{\Delta x} = A \Delta x + B \Delta u$ is discretised by $A_d = e^{dt.A}$ and $B_d = (\int_{0}^{dt} e^{s.A} ds) B$ .

Todo:: Update how to get B_d

MatrixT can either be Eigen::MatrixXd or Eigen::MatrixXf

Parameters

[in]	x_0	Nominal state
[in]	u_0	Nominal input
[out]	Ad	Discretised A matrix
[out]	Bd	Discretised B matrix
[in]	dt	Discretisation interval

Definition at line 148 of file robot_model.cpp.

template<class VectorT , class MatrixT >

void mfcpp::RobotModel::get_lin_discr_matrices	(	const VectorT &	x_0,
		const VectorT &	u_0,
		MatrixT &	Ad,
		MatrixT &	Bd,
		float	dt
	)		const

Overloads get_lin_discr_matrices for Eigen vectors.

VectorT can either be Eigen::VectorXd or Eigen::VectorXf MatrixT can either be Eigen::MatrixXd or Eigen::MatrixXf

Definition at line 166 of file robot_model.cpp.

template<class MatrixT >

template void mfcpp::RobotModel::get_lin_matrices	(	const state_type &	x_0,
		const input_type &	u_0,
		MatrixT &	A,
		MatrixT &	B
	)		const

Gets the matrices of the linearised system.

If the system is linearised around $ (x_0, u_0) $ , the system can be expressed for new variables $(\Delta x, \Delta u) = (x-x_0, u-u_0)$ . The ODE then becomes: $\dot{\Delta x} = A \Delta x + B \Delta u$ .

MatrixT can either be Eigen::MatrixXd or Eigen::MatrixXf

Parameters

[in]	x_0	Nominal state
[in]	u_0	Nominal input
[out]	A	A matrix
[out]	B	B matrix

Definition at line 64 of file robot_model.cpp.

void mfcpp::RobotModel::integrate	(	state_type &	state,
		const input_type &	input,
		double	t1,
		double	t2,
		double	init_step
	)

Integrates the model over a period of time.

It will update the state by integrating the dynamic model of the robot. It assumes that the inputs are constant during the integration.

It is based on the error-controlled runge_kutta54_cash_karp stepper (5th order) and uses adaptive step-size.

Parameters

[in,out]	state	Initial state to update
[in]	input	Input to the actuators
[in]	t1	Starting time of the integration
[in]	t2	Ending time of the integration
[in]	init_step	Initial step size for the integration

Definition at line 51 of file robot_model.cpp.

Matrix3d mfcpp::RobotModel::jac_orient	(	double	phi,
		double	theta,
		double	psi
	)

private

Computes the Jacobian of the orientation.

Transforms angular velocities in the global frame to the inertial frame.

Parameters

phi	First angle of the robot's orientation
theta	Second angle of the robot's orientation
psi	Third angle of the robot's orientation

Returns: Jacobian of the orientation

Definition at line 248 of file robot_model.cpp.

Matrix3d mfcpp::RobotModel::jac_pos	(	double	phi,
		double	theta,
		double	psi
	)

private

Computes the Jacobian of the position.

Transforms linear velocities in the global frame to the intertial frame.

Parameters

phi	First angle of the robot's orientation
theta	Second angle of the robot's orientation
psi	Third angle of the robot's orientation

Returns: Jacobian of the position

Definition at line 229 of file robot_model.cpp.

double mfcpp::RobotModel::lat_turn_radius	(	double	u,
		double	delta_r
	)		const

inline

Computes the lateral turning radius.

Parameters

u	Speed of the robot
delta_r	Angle of the lateral rudder

Definition at line 241 of file robot_model.hpp.

void mfcpp::RobotModel::ode	(	const state_type &	x,
		state_type &	dxdt,
		const double	t
	)

private

ODE used to integrate the model.

Parameters

x	Current state
dxdt	Current time derivative of the state
t	Current time

Definition at line 179 of file robot_model.cpp.

double mfcpp::RobotModel::sign ( double x ) const

inlineprivate

Returns the sign of a real number.

Returns: 1 if x>=0, -1 otherwise

Definition at line 261 of file robot_model.hpp.

double mfcpp::RobotModel::steady_propeller_speed ( double speed ) const

inline

Computes the propeller speed in steady state.

Note: This assumes that delta_m = 0

Parameters

speed Desired steady state speed

Definition at line 227 of file robot_model.hpp.

double mfcpp::RobotModel::steady_speed ( double n ) const

inline

Computes the horizontal speed in steady state.

Note: This assumes that the propeller speed is constant and the robot is horizontal

Parameters

n	Rotational speed of the propeller

Definition at line 234 of file robot_model.hpp.

Member Data Documentation

std::vector<double> mfcpp::RobotModel::c_

private

Model constants.

Warning: c[0] is not used to respect notation

Definition at line 175 of file robot_model.hpp.

double mfcpp::RobotModel::g_

private

Gravity acceleration.

Definition at line 178 of file robot_model.hpp.

input_type mfcpp::RobotModel::u_

private

Model inputs.

Definition at line 181 of file robot_model.hpp.

The documentation for this class was generated from the following files:

/home/corentin/thesis_ws/src/marine-farm-cpp/mf_robot_model/include/mf_robot_model/robot_model.hpp
/home/corentin/thesis_ws/src/marine-farm-cpp/mf_robot_model/src/mf_robot_model/robot_model.cpp

MFCPP 1.0	Corentin Chauvin-Hameau – 2019-2020
Coverage Path Planning for an underwater robot surveying a marine farm

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation