The Odometry class handles odometry readings (2D pose and velocity with related timestamp) More...

#include <odometry.h>

Public Types
typedef boost::function< void(double, double)>	IntegrationFunction
	Integration function, used to integrate the odometry: More...

Public Member Functions
double	getAngular () const
	angular velocity getter More...

double	getHeading () const
	heading getter More...

double	getLinear () const
	linear velocity getter More...

double	getX () const
	x position getter More...

double	getY () const
	y position getter More...

void	init (const ros::Time &time)
	Initialize the odometry. More...

	Odometry (size_t velocity_rolling_window_size=10)
	Constructor Timestamp will get the current time value Value will be set to zero. More...

void	setVelocityRollingWindowSize (size_t velocity_rolling_window_size)
	Velocity rolling window size setter. More...

void	setWheelParams (double wheel_separation, double left_wheel_radius, double right_wheel_radius)
	Sets the wheel parameters: radius and separation. More...

bool	update (double left_pos, double right_pos, const ros::Time &time)
	Updates the odometry class with latest wheels position. More...

void	updateOpenLoop (double linear, double angular, const ros::Time &time)
	Updates the odometry class with latest velocity command. More...

Private Types
typedef bacc::accumulator_set< double, bacc::stats< bacc::tag::rolling_mean > >	RollingMeanAcc
	Rolling mean accumulator and window: More...

typedef bacc::tag::rolling_window	RollingWindow

Private Member Functions
void	integrateExact (double linear, double angular)
	Integrates the velocities (linear and angular) using exact method. More...

void	integrateRungeKutta2 (double linear, double angular)
	Integrates the velocities (linear and angular) using 2nd order Runge-Kutta. More...

void	resetAccumulators ()
	Reset linear and angular accumulators. More...

Private Attributes
double	angular_

RollingMeanAcc	angular_acc_

double	heading_

IntegrationFunction	integrate_fun_
	Integration funcion, used to integrate the odometry: More...

double	left_wheel_old_pos_
	Previou wheel position/state [rad]: More...

double	left_wheel_radius_

double	linear_
	Current velocity: More...

RollingMeanAcc	linear_acc_

double	right_wheel_old_pos_

double	right_wheel_radius_

ros::Time	timestamp_
	Current timestamp: More...

size_t	velocity_rolling_window_size_
	Rolling mean accumulators for the linar and angular velocities: More...

double	wheel_separation_
	Wheel kinematic parameters [m]: More...

double	x_
	Current pose: More...

double	y_

Detailed Description

The Odometry class handles odometry readings (2D pose and velocity with related timestamp)

Definition at line 59 of file odometry.h.

Member Typedef Documentation

typedef boost::function<void(double, double)> diff_drive_controller::Odometry::IntegrationFunction

Integration function, used to integrate the odometry:

Definition at line 64 of file odometry.h.

typedef bacc::accumulator_set<double, bacc::stats<bacc::tag::rolling_mean> > diff_drive_controller::Odometry::RollingMeanAcc

private

Rolling mean accumulator and window:

Definition at line 159 of file odometry.h.

typedef bacc::tag::rolling_window diff_drive_controller::Odometry::RollingWindow

private

Definition at line 160 of file odometry.h.

Constructor & Destructor Documentation

diff_drive_controller::Odometry::Odometry ( size_t velocity_rolling_window_size = 10 )

Constructor Timestamp will get the current time value Value will be set to zero.

Parameters

velocity_rolling_window_size Rolling window size used to compute the velocity mean

Definition at line 50 of file odometry.cpp.

Member Function Documentation

double diff_drive_controller::Odometry::getAngular ( ) const

inline

angular velocity getter

Returns: angular velocity [rad/s]

Definition at line 137 of file odometry.h.

double diff_drive_controller::Odometry::getHeading ( ) const

inline

heading getter

Returns: heading [rad]

Definition at line 101 of file odometry.h.

double diff_drive_controller::Odometry::getLinear ( ) const

inline

linear velocity getter

Returns: linear velocity [m/s]

Definition at line 128 of file odometry.h.

double diff_drive_controller::Odometry::getX ( ) const

inline

x position getter

Returns: x position [m]

Definition at line 110 of file odometry.h.

double diff_drive_controller::Odometry::getY ( ) const

inline

y position getter

Returns: y position [m]

Definition at line 119 of file odometry.h.

void diff_drive_controller::Odometry::init ( const ros::Time & time )

Initialize the odometry.

Parameters

time	Current time

Definition at line 69 of file odometry.cpp.

void diff_drive_controller::Odometry::integrateExact	(	double	linear,
		double	angular
	)

private

Integrates the velocities (linear and angular) using exact method.

Other possible integration method provided by the class.

Parameters

linear	Linear velocity m computed by encoders
angular	Angular velocity rad computed by encoders
linear
angular

Exact integration (should solve problems when angular is zero):

Definition at line 155 of file odometry.cpp.

void diff_drive_controller::Odometry::integrateRungeKutta2	(	double	linear,
		double	angular
	)

private

Integrates the velocities (linear and angular) using 2nd order Runge-Kutta.

Parameters

linear	Linear velocity m computed by encoders
angular	Angular velocity rad computed by encoders

Runge-Kutta 2nd order integration:

Definition at line 140 of file odometry.cpp.

void diff_drive_controller::Odometry::resetAccumulators ( )

private

Reset linear and angular accumulators.

Definition at line 170 of file odometry.cpp.

void diff_drive_controller::Odometry::setVelocityRollingWindowSize ( size_t velocity_rolling_window_size )

Velocity rolling window size setter.

Parameters

velocity_rolling_window_size Velocity rolling window size

Definition at line 133 of file odometry.cpp.

void diff_drive_controller::Odometry::setWheelParams	(	double	wheel_separation,
		double	left_wheel_radius,
		double	right_wheel_radius
	)

Sets the wheel parameters: radius and separation.

Parameters

wheel_separation	Separation between left and right wheels [m]
left_wheel_radius	Left wheel radius [m]
right_wheel_radius	Right wheel radius [m]

Definition at line 126 of file odometry.cpp.

bool diff_drive_controller::Odometry::update	(	double	left_pos,
		double	right_pos,
		const ros::Time &	time
	)

Updates the odometry class with latest wheels position.

Parameters

left_pos	Left wheel position [rad]
right_pos	Right wheel position [rad]
time	Current time

Returns: true if the odometry is actually updated

Get current wheel joint positions:

Estimate velocity of wheels using old and current position:

Update old position with current:

Compute linear and angular diff:

Integrate odometry:

We cannot estimate the speed with very small time intervals:

Estimate speeds using a rolling mean to filter them out:

Definition at line 76 of file odometry.cpp.

void diff_drive_controller::Odometry::updateOpenLoop	(	double	linear,
		double	angular,
		const ros::Time &	time
	)

Updates the odometry class with latest velocity command.

Parameters

linear	Linear velocity [m/s]
angular	Angular velocity [rad/s]
time	Current time

Save last linear and angular velocity:

Integrate odometry:

Definition at line 114 of file odometry.cpp.

Member Data Documentation

double diff_drive_controller::Odometry::angular_

private

Definition at line 191 of file odometry.h.

RollingMeanAcc diff_drive_controller::Odometry::angular_acc_

private

Definition at line 205 of file odometry.h.

double diff_drive_controller::Odometry::heading_

private

Definition at line 187 of file odometry.h.

IntegrationFunction diff_drive_controller::Odometry::integrate_fun_

private

Integration funcion, used to integrate the odometry:

Definition at line 208 of file odometry.h.

double diff_drive_controller::Odometry::left_wheel_old_pos_

private

Previou wheel position/state [rad]:

Definition at line 199 of file odometry.h.

double diff_drive_controller::Odometry::left_wheel_radius_

private

Definition at line 195 of file odometry.h.

double diff_drive_controller::Odometry::linear_

private

Current velocity:

Definition at line 190 of file odometry.h.

RollingMeanAcc diff_drive_controller::Odometry::linear_acc_

private

Definition at line 204 of file odometry.h.

double diff_drive_controller::Odometry::right_wheel_old_pos_

private

Definition at line 200 of file odometry.h.

double diff_drive_controller::Odometry::right_wheel_radius_

private

Definition at line 196 of file odometry.h.

ros::Time diff_drive_controller::Odometry::timestamp_

private

Current timestamp:

Definition at line 182 of file odometry.h.

size_t diff_drive_controller::Odometry::velocity_rolling_window_size_

private

Rolling mean accumulators for the linar and angular velocities:

Definition at line 203 of file odometry.h.

double diff_drive_controller::Odometry::wheel_separation_

private

Wheel kinematic parameters [m]:

Definition at line 194 of file odometry.h.

double diff_drive_controller::Odometry::x_

private

Current pose:

Definition at line 185 of file odometry.h.

double diff_drive_controller::Odometry::y_

private

Definition at line 186 of file odometry.h.

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

Public Types

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation