A very fast, but also very accurate model of non-deformable tracks without grousers. More...

#include <SimpleTrackedVehiclePlugin.hh>

Public Types
typedef boost::shared_ptr< ModelPlugin >	TPtr
	plugin pointer type definition More...

Public Member Functions
	SimpleTrackedVehiclePlugin ()=default

virtual	~SimpleTrackedVehiclePlugin ()

std::string	GetFilename () const
	Get the name of the handler. More...

std::string	GetHandle () const
	Get the short name of the handler. More...

size_t	GetNumTracks (Tracks side) const
	Return the number of tracks on the given side. More...

PluginType	GetType () const
	Returns the type of the plugin. More...

void	Init () override
	Initialize the plugin. More...

void	Load (physics::ModelPtr _model, sdf::ElementPtr _sdf) override
	Called when the plugin is loaded. More...

void	Reset () override
	Reset the plugin. More...

Static Public Member Functions
static TPtr	Create (const std::string &_filename, const std::string &_name)
	a class method that creates a plugin from a file name. More...

Protected Member Functions
ignition::math::Vector3d	ComputeFrictionDirection (double _linearSpeed, double _angularSpeed, bool _drivingStraight, const ignition::math::Pose3d &_bodyPose, const ignition::math::Vector3d &_bodyYAxisGlobal, const ignition::math::Vector3d &_centerOfRotation, const ignition::math::Vector3d &_contactWorldPosition, const ignition::math::Vector3d &_contactNormal, const ignition::math::Vector3d &_beltDirection) const
	Compute the direction of friction force in given contact point. More...

double	ComputeSurfaceMotion (double _beltSpeed, const ignition::math::Vector3d &_beltDirection, const ignition::math::Vector3d &_frictionDirection) const
	Compute the velocity of the surface motion in all contact points. More...

void	DriveTracks (const common::UpdateInfo &)
	Compute and apply the forces that make the tracks move. More...

virtual std::string	GetRobotNamespace ()
	Namespace used as a prefix for gazebo topic names. More...

virtual double	GetSteeringEfficiency ()
	Steering efficiency coefficient (between 0.0 and 1.0). More...

virtual boost::optional< double >	GetTrackMu ()
	Friction coefficient in the first friction direction. More...

virtual boost::optional< double >	GetTrackMu2 ()
	Friction coefficient in the second friction direction. More...

virtual double	GetTracksSeparation ()
	Distance between the centers of the tracks. More...

void	LoadParam (const sdf::ElementPtr &_sdf, const std::string &_name, V &_target, V _defaultValue=V()) const
	Load parameter value from _sdf and store it to the given reference, using the supplied default value if the element in _sdf is not found. More...

void	LoadParam (sdf::ElementPtr &_sdf, const std::string &_name, std::string &_target, const char *_defaultValue) const
	Load parameter value from _sdf and store it to the given reference, using the supplied default value if the element in _sdf is not found. More...

virtual void	OnVelMsg (ConstPosePtr &_msg) GAZEBO_DEPRECATED(9.0)
	Callback for setting desired body velocity. More...

void	OnVelMsg (ConstTwistPtr &_msg)
	Callback for setting desired body velocity. More...

void	SetBodyVelocity (double _linear, double _angular)
	Set new target velocity for the tracks based on the desired. More...

void	SetGeomCategories ()
	Set collide categories and bits of all geometries to the required values. More...

void	SetLinkMu (const physics::LinkPtr &_link)
	Set mu and mu2 of all collisions of the given link to values given by GetTrackMu() and GetTrackMu2(). More...

virtual void	SetSteeringEfficiency (double _steeringEfficiency)
	Set steering efficiency coefficient (between 0.0 and 1.0). More...

virtual void	SetTrackMu (double _mu)
	Friction coefficient in the first friction direction. More...

virtual void	SetTrackMu2 (double _mu2)
	Friction coefficient in the second friction direction. More...

virtual void	SetTrackVelocity (double _left, double _right)
	Set new target velocity for the tracks. More...

void	SetTrackVelocityImpl (double _left, double _right) override
	Set new target velocity for the tracks. More...

void	UpdateTrackSurface () override
	Update surface parameters of the tracks to correspond to the values set in this plugin. More...

Protected Attributes
physics::LinkPtr	body
	Body of the robot. More...

unsigned int	collideWithoutContactBitmask
	This bitmask will be set to the whole vehicle body. More...

std::string	filename
	Path to the shared library file. More...

std::string	handleName
	Short name. More...

std::mutex	mutex
	Mutex to protect updates. More...

std::unordered_map< Tracks, std::string >	trackNames
	Textual lowercase names of the tracks. More...

std::unordered_map< Tracks, physics::LinkPtr >	tracks
	The tracks controlled by this plugin. More...

std::unordered_map< Tracks, double >	trackVelocity
	Desired velocities of the tracks. More...

PluginType	type
	Type of plugin. More...

Static Protected Attributes
static const unsigned int	BELT_CATEGORY = 0x20000000
	Category for tracks. More...

static const unsigned int	LEFT_CATEGORY = 0x40000000
	Category for all items on the left side. More...

static const unsigned int	ROBOT_CATEGORY = 0x10000000
	Category for the non-track parts of the robot. More...

Detailed Description

A very fast, but also very accurate model of non-deformable tracks without grousers.

Since: 8.1

The motion model is based on adjusting motion1 in ODE contact properties and on computing Instantaneous Center of Rotation for a tracked vehicle. A detailed description of the model is given in https://arxiv.org/abs/1703.04316 .

The plugin processes the following parameters, plus the common parameters defined in TrackedVehiclePlugin.

<body> Body of the vehicle to which the two tracks are connected. <left_track> The left track link's name. <right_track> The right track link's name. <left_flipper> The name of a left flipper link. Can appear multiple times. <right_flipper> The name of a right flipper link. Can appear multiple times. <collide_without_contact_bitmask> Collision bitmask that will be set to the whole vehicle (default is 1u).

Member Typedef Documentation

◆ TPtr

typedef boost::shared_ptr<ModelPlugin > TPtr

inherited

plugin pointer type definition

Constructor & Destructor Documentation

◆ SimpleTrackedVehiclePlugin()

SimpleTrackedVehiclePlugin ( )

default

◆ ~SimpleTrackedVehiclePlugin()

virtual ~SimpleTrackedVehiclePlugin ( )

virtual

Member Function Documentation

◆ ComputeFrictionDirection()

ignition::math::Vector3d ComputeFrictionDirection	(	double	_linearSpeed,
		double	_angularSpeed,
		bool	_drivingStraight,
		const ignition::math::Pose3d &	_bodyPose,
		const ignition::math::Vector3d &	_bodyYAxisGlobal,
		const ignition::math::Vector3d &	_centerOfRotation,
		const ignition::math::Vector3d &	_contactWorldPosition,
		const ignition::math::Vector3d &	_contactNormal,
		const ignition::math::Vector3d &	_beltDirection
	)		const

protected

Compute the direction of friction force in given contact point.

Parameters

[in]	_linearSpeed	Linear speed of the vehicle.
[in]	_angularSpeed	Angular speed of the vehicle.
[in]	_drivingStraight	Whether the vehicle should steer.
[in]	_bodyPose	Pose of the vehicle body.
[in]	_bodyYAxisGlobal	Direction of the y-axis of the body in world frame.
[in]	_centerOfRotation	Center of the circle the vehicle follows (Inf/-Inf if driving straight).
[in]	_contactWorldPosition	World position of the contact point.
[in]	_contactNormal	Corrected contact normal (pointing inside the track).
[in]	_beltDirection	World-frame forward direction of the belt.

Returns: Direction of the friction force in world frame.

◆ ComputeSurfaceMotion()

double ComputeSurfaceMotion	(	double	_beltSpeed,
		const ignition::math::Vector3d &	_beltDirection,
		const ignition::math::Vector3d &	_frictionDirection
	)		const

protected

Compute the velocity of the surface motion in all contact points.

Parameters

[in]	_beltSpeed	The desired belt speed.
[in]	_beltDirection	Forward direction of the belt.
[in]	_frictionDirection	First friction direction.

◆ Create()

static TPtr Create	(	const std::string &	_filename,
		const std::string &	_name
	)

inlinestaticinherited

a class method that creates a plugin from a file name.

It locates the shared library and loads it dynamically.

Parameters

[in]	_filename	the path to the shared library.
[in]	_name	short name of the plugin

Returns: Shared Pointer to this class type

References PluginT< T >::filename, gzerr, and SingletonT< SystemPaths >::Instance().

◆ DriveTracks()

void DriveTracks ( const common::UpdateInfo & )

protected

Compute and apply the forces that make the tracks move.

◆ GetFilename()

std::string GetFilename ( ) const

inlineinherited

Get the name of the handler.

References PluginT< T >::filename.

◆ GetHandle()

std::string GetHandle ( ) const

inlineinherited

Get the short name of the handler.

References PluginT< T >::handleName.

◆ GetNumTracks()

size_t GetNumTracks ( Tracks side ) const

Return the number of tracks on the given side.

Should always be at least 1 for the main track. If flippers are present, the number is higher.

◆ GetRobotNamespace()

virtual std::string GetRobotNamespace ( )

protectedvirtualinherited

Namespace used as a prefix for gazebo topic names.

◆ GetSteeringEfficiency()

virtual double GetSteeringEfficiency ( )

protectedvirtualinherited

Steering efficiency coefficient (between 0.0 and 1.0).

◆ GetTrackMu()

virtual boost::optional<double> GetTrackMu ( )

protectedvirtualinherited

Friction coefficient in the first friction direction.

◆ GetTrackMu2()

virtual boost::optional<double> GetTrackMu2 ( )

protectedvirtualinherited

Friction coefficient in the second friction direction.

◆ GetTracksSeparation()

virtual double GetTracksSeparation ( )

protectedvirtualinherited

Distance between the centers of the tracks.

◆ GetType()

PluginType GetType ( ) const

inlineinherited

Returns the type of the plugin.

Returns: type of the plugin

References PluginT< T >::type.

◆ Init()

void Init ( )

overridevirtual

Initialize the plugin.

Reimplemented from ModelPlugin.

◆ Load()

void Load	(	physics::ModelPtr	_model,
		sdf::ElementPtr	_sdf
	)

overridevirtual

Called when the plugin is loaded.

Parameters

[in]	model	Pointer to the model for which the plugin is loaded
[in]	_sdf	Pointer to the SDF for _model

Implements ModelPlugin.

◆ LoadParam() [1/2]

void LoadParam	(	const sdf::ElementPtr &	_sdf,
		const std::string &	_name,
		V &	_target,
		V	_defaultValue = `V()`
	)		const

inlineprotectedinherited

Load parameter value from _sdf and store it to the given reference, using the supplied default value if the element in _sdf is not found.

A message is written using gzmsg reporting whether the default value was used or not.

Parameters

[in]	_sdf	The SDF element of the plugin.
[in]	_name	Name of a tag inside the SDF.
[out]	_target	The reference to store the param value to.
[in]	_defaultValue	The default value.

References gzmsg, and PluginT< T >::handleName.

◆ LoadParam() [2/2]

void LoadParam	(	sdf::ElementPtr &	_sdf,
		const std::string &	_name,
		std::string &	_target,
		const char *	_defaultValue
	)		const

inlineprotectedinherited

Load parameter value from _sdf and store it to the given reference, using the supplied default value if the element in _sdf is not found.

A message is written using gzmsg reporting whether the default value was used or not. String specialization to allow accepting const char* values for std::string parameters.

Parameters

[in]	_sdf	The SDF element of the plugin.
[in]	_name	Name of a tag inside the SDF.
[out]	_target	The reference to store the param value to.
[in]	_defaultValue	The default value.

◆ OnVelMsg() [1/2]

virtual void OnVelMsg ( ConstPosePtr & _msg )

protectedvirtualinherited

Callback for setting desired body velocity.

Normally, this callback converts the x/yaw message to track velocities and calls SetTrackVelocity().

Parameters

[in] _msg Pose message from external publisher

◆ OnVelMsg() [2/2]

void OnVelMsg ( ConstTwistPtr & _msg )

protectedinherited

Callback for setting desired body velocity.

Normally, this callback converts the x/yaw message to track velocities and calls SetTrackVelocity().

Parameters

[in] _msg Twist message from external publisher

◆ Reset()

void Reset ( )

overridevirtual

Reset the plugin.

Reimplemented from ModelPlugin.

◆ SetBodyVelocity()

void SetBodyVelocity	(	double	_linear,
		double	_angular
	)

protectedinherited

Set new target velocity for the tracks based on the desired.

Parameters

[in]	_linear	Desired linear velocity of the vehicle.
[in]	_angular	Desired angular velocity of the vehicle.

◆ SetGeomCategories()

void SetGeomCategories ( )

protected

Set collide categories and bits of all geometries to the required values.

This is a workaround for https://bitbucket.org/osrf/gazebo/issues/1855 .

◆ SetLinkMu()

void SetLinkMu ( const physics::LinkPtr & _link )

protectedinherited

Set mu and mu2 of all collisions of the given link to values given by GetTrackMu() and GetTrackMu2().

Parameters

[in] _link The link whose "mu"s are to be set.

◆ SetSteeringEfficiency()

virtual void SetSteeringEfficiency ( double _steeringEfficiency )

protectedvirtualinherited

Set steering efficiency coefficient (between 0.0 and 1.0).

Parameters

[in] _steeringEfficiency The new steering efficiency.

◆ SetTrackMu()

virtual void SetTrackMu ( double _mu )

protectedvirtualinherited

Friction coefficient in the first friction direction.

Parameters

[in] _mu The new coefficient.

◆ SetTrackMu2()

virtual void SetTrackMu2 ( double _mu2 )

protectedvirtualinherited

Friction coefficient in the second friction direction.

Parameters

[in] _mu2 The new coefficient.

◆ SetTrackVelocity()

virtual void SetTrackVelocity	(	double	_left,
		double	_right
	)

protectedvirtualinherited

Set new target velocity for the tracks.

Descendant classes need to implement this function.

Parameters

[in]	_left	Velocity of left track.
[in]	_right	Velocity of right track.

◆ SetTrackVelocityImpl()

void SetTrackVelocityImpl	(	double	_left,
		double	_right
	)

overrideprotectedvirtual

Set new target velocity for the tracks.

Parameters

[in]	_left	Velocity of left track.
[in]	_right	Velocity of right track.

Implements TrackedVehiclePlugin.

◆ UpdateTrackSurface()

void UpdateTrackSurface ( )

overrideprotectedvirtual

Update surface parameters of the tracks to correspond to the values set in this plugin.

Implements TrackedVehiclePlugin.

Member Data Documentation

◆ BELT_CATEGORY

const unsigned int BELT_CATEGORY = 0x20000000

staticprotected

Category for tracks.

◆ body

physics::LinkPtr body

protected

Body of the robot.

◆ collideWithoutContactBitmask

unsigned int collideWithoutContactBitmask

protected

This bitmask will be set to the whole vehicle body.

◆ filename

std::string filename

protectedinherited

Path to the shared library file.

◆ handleName

std::string handleName

protectedinherited

Short name.

◆ LEFT_CATEGORY

const unsigned int LEFT_CATEGORY = 0x40000000

staticprotected

Category for all items on the left side.

◆ mutex

std::mutex mutex

protectedinherited

Mutex to protect updates.

◆ ROBOT_CATEGORY

const unsigned int ROBOT_CATEGORY = 0x10000000

staticprotected

Category for the non-track parts of the robot.

◆ trackNames

std::unordered_map<Tracks, std::string> trackNames

protectedinherited

Textual lowercase names of the tracks.

◆ tracks

std::unordered_map<Tracks, physics::LinkPtr> tracks

protected

The tracks controlled by this plugin.

◆ trackVelocity

std::unordered_map<Tracks, double> trackVelocity

protected

Desired velocities of the tracks.

◆ type

PluginType type

protectedinherited

Type of plugin.

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

SimpleTrackedVehiclePlugin.hh

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Member Typedef Documentation

◆ TPtr

Constructor & Destructor Documentation

◆ SimpleTrackedVehiclePlugin()

◆ ~SimpleTrackedVehiclePlugin()

Member Function Documentation

◆ ComputeFrictionDirection()

◆ ComputeSurfaceMotion()

◆ Create()

◆ DriveTracks()

◆ GetFilename()

◆ GetHandle()

◆ GetNumTracks()

◆ GetRobotNamespace()

◆ GetSteeringEfficiency()

◆ GetTrackMu()

◆ GetTrackMu2()

◆ GetTracksSeparation()

◆ GetType()

◆ Init()

◆ Load()

◆ LoadParam() [1/2]

◆ LoadParam() [2/2]

◆ OnVelMsg() [1/2]

◆ OnVelMsg() [2/2]

◆ Reset()

◆ SetBodyVelocity()

◆ SetGeomCategories()

◆ SetLinkMu()

◆ SetSteeringEfficiency()

◆ SetTrackMu()

◆ SetTrackMu2()

◆ SetTrackVelocity()

◆ SetTrackVelocityImpl()

◆ UpdateTrackSurface()

Member Data Documentation

◆ BELT_CATEGORY

◆ body

◆ collideWithoutContactBitmask

◆ filename

◆ handleName

◆ LEFT_CATEGORY

◆ mutex

◆ ROBOT_CATEGORY

◆ trackNames

◆ tracks

◆ trackVelocity

◆ type