#include <bulletrccar.h>

Inheritance diagram for gcop::Bulletrccar:

Collaboration diagram for gcop::Bulletrccar:

Classes
struct	CarState
Public Member Functions
	Bulletrccar (BulletWorld &m_world, vector< double > *zs_=0)
	~Bulletrccar ()
double	Step (Vector4d &xb, double t, const Vector4d &xa, const Vector2d &u, double h, const VectorXd p, Matrix4d A=0, Matrix42d B=0, Matrix4pd C=0)
double	Step (Vector4d &xb, const Vector2d &u, double h, const VectorXd p=0, Matrix4d A=0, Matrix42d B=0, Matrix4pd C=0)
double	Step (Vector4d &xb, const Vector2d &u, double h, const VectorXd p, const Vector4d &w, Matrix4d A=0, Matrix42d B=0, Matrix4pd C=0, Matrix4d *D=0)
bool	Reset (const Vector4d &x, double t=0)
void	setinitialstate (const CarState &inputstate, Vector4d &x)
void	setinitialstate (Vector4d &x)
	Set the car initial state as the current state.
bool	NoiseMatrix (Matrix4d &Q, double t, const Vector4d &x, const Vector2d &u, double dt, const VectorXd *p)
Public Attributes
int	rightIndex
	right of the car index in terms of x,y,z assigns the coordinate sys of car
int	upIndex
int	forwardIndex
double	carmass
	Mass of the car.
btVector3	car_halfdims
	half dimensions of car width, height, length
double	gEngineForce
	Engine Torque.
double	gBreakingForce
	Breaking Force on the vehicle.
double	maxEngineForce
	Maximum Engine force that can be applied.
double	maxBreakingForce
	Not Used.
double	gVehicleSteering
	Vehicle Steering angle.
double	steeringClamp
	Clamp on Steering angle.
double	velocityClamp
	Clamp on velocity of car.
double	wheelRadius
	Radius of wheel.
double	wheelWidth
	Width of wheel.
double	wheelFriction
	wheel friction usually large value
double	suspensionStiffness
	Stiffness of suspension. If not enough, the car will sink into ground.
double	suspensionDamping
	Damping on suspension.
double	suspensionCompression
	Compression factor decides by how much the car will compress wrto external loads.
double	rollInfluence
btScalar	suspensionRestLength
	Rest length of suspension.
btScalar	m_defaultContactProcessingThreshold
	if contact goes above this value, it will process
btVector3	wheelDirectionCS0
	direction from the car towards the wheel contact point
btVector3	wheelAxleCS
	Wheel Axle Direction.
double	gain_cmdvelocity
	Gain parameter on the commanded velocity. Can be used to convert radio commands into true velocity commands.
double	kp_torque
	Proportional gain parameter for commanding torque to get to a desired velocity.
double	kp_steer
	Steering proportional gain. Should be between 0 and 1.
double	initialz
	Initial height of the car.
btTransform	offsettrans
	To Account for the difference to coordinate system Usage: worldpose_inregcoordsys = offsettrans.inv()worldpose_bulletoffsettrans.
btTransform	offsettransinv
	The inverse of the offset transformation above.
vector< double > *	zs
	Height of the rccar only used for visualization only x and y are used in optimization.
int	count_zs
	Internal variable to find the zs count to fill the height.
bool	reset_drivevel
	Used to make sure the velocity of the chassis is used just after reset instead of vehicle vel.
btRigidBody *	m_carChassis
	Pointer to the car rigidbody.
btCollisionShape *	chassisShape
	Pointer to the car collision shape.
btRaycastVehicle *	m_vehicle
	Pointer to the raycast vehicle (Does the constraint enforcing to convert the rigidbody to a vehicle)
btCollisionShape *	m_wheelShape
	Shape of the wheels used only for display purposes.
btRaycastVehicle::btVehicleTuning	m_tuning
	Tuning parameters for the vehicle used only internally.
btVehicleRaycaster *	m_vehicleRayCaster
	Raycaster which gives the point of contact of the vehicle wheels.
BulletWorld &	m_world
CarState *	initialstate
	Initialstate if passed is stored here.

Detailed Description

A simple rear-drive Rccar model derived from Vehicle Demo using Bullet Physics Engine

This car model uses the full 6DOF state for simulation. To keep compatibility with existing 2D rccar model, this class only provides the state output as $\bm x = (x,y,\theta, v) \in\mathbb{R}^4$ . The controls for the car are given as desired steering angle and desired body velocity. These controls are converted into true controls for the bullet rccar i.e driving torque and actual steering angle through proportional control. The gains for the controller are input as parameters to the system #TODO Use full state of the car

Author: Marin Kobilarov marin(at)jhu.edu Modified: Gowtham Garimella ggarime(at)jhu.edu

Constructor & Destructor Documentation

Bulletrccar::Bulletrccar	(	BulletWorld &	m_world,
		vector< double > *	zs_ = `0`
	)

Constructor. Each bullet system takes in a world in which it lies.

Parameters:

m_world	World class in which the current system lies. Only systems in one world can interact with each other
zs_	Vector of car heights along the trajectory used for display purposes.

never deactivate the vehicle from computing collisions etc. Usually the bodies are deactivated after some time if they are not moving

create wheel connections

References gcop::Manifold< T, _n >::bnd, car_halfdims, carmass, chassisShape, forwardIndex, gcop::BulletWorld::IsZupAxis(), gcop::Rccar::l, gcop::Manifold< T, _n >::lb, gcop::BulletWorld::LocalCreateRigidBody(), m_carChassis, gcop::BulletWorld::m_dynamicsWorld, m_tuning, m_vehicle, m_vehicleRayCaster, m_wheelShape, m_world, offsettrans, offsettransinv, rightIndex, rollInfluence, steeringClamp, suspensionCompression, suspensionDamping, suspensionRestLength, suspensionStiffness, gcop::System< T, _nx, _nu, _np >::U, gcop::Manifold< T, _n >::ub, upIndex, velocityClamp, wheelAxleCS, wheelDirectionCS0, wheelFriction, wheelRadius, and wheelWidth.

gcop::Bulletrccar::~Bulletrccar ( ) [inline]

Destructor: Removes the car and its accessories from the world and deletes them

Member Function Documentation

bool Bulletrccar::NoiseMatrix	(	Matrix4d &	Q,
		double	t,
		const Vector4d &	x,
		const Vector2d &	u,
		double	dt,
		const VectorXd *	p
	)

Reimplementation of Noise matrix for specific system

bool Bulletrccar::Reset	(	const Vector4d &	x,
		double	t = `0`
	)

never deactivate the vehicle from computing collisions etc. Usually the bodies are deactivated after some time if they are not moving

create wheel connections

References car_halfdims, gcop::Bulletrccar::CarState::carangularvel, gcop::Bulletrccar::CarState::carlinearvel, carmass, gcop::Bulletrccar::CarState::cartransform, chassisShape, count_zs, forwardIndex, gBreakingForce, gEngineForce, gVehicleSteering, initialstate, initialz, gcop::BulletWorld::IsZupAxis(), gcop::BulletWorld::LocalCreateRigidBody(), m_carChassis, gcop::BulletWorld::m_dynamicsWorld, m_tuning, m_vehicle, m_vehicleRayCaster, m_world, gcop::BulletWorld::Reset(), reset_drivevel, rightIndex, rollInfluence, suspensionCompression, suspensionDamping, suspensionRestLength, suspensionStiffness, gcop::System< T, _nx, _nu, _np >::t, upIndex, wheelAxleCS, wheelDirectionCS0, wheelFriction, wheelRadius, gcop::System< T, _nx, _nu, _np >::x, and zs.

Referenced by Step().

void Bulletrccar::setinitialstate	(	const CarState &	inputstate,
		Vector4d &	x
	)

Set the intial state of the car to given full state. This overrides the reset state of the car and allows to use full state #TODO Use full stat of the car directly

References gcop::Bulletrccar::CarState::carlinearvel, gcop::Bulletrccar::CarState::cartransform, initialstate, gcop::BulletWorld::IsZupAxis(), m_carChassis, gcop::BulletWorld::m_dynamicsWorld, m_vehicle, m_world, suspensionRestLength, wheelRadius, gcop::System< T, _nx, _nu, _np >::x, and zs.

void Bulletrccar::setinitialstate ( Vector4d & x )

Set the car initial state as the current state.

References gcop::Bulletrccar::CarState::carangularvel, gcop::Bulletrccar::CarState::carlinearvel, gcop::Bulletrccar::CarState::cartransform, initialstate, gcop::BulletWorld::IsZupAxis(), m_carChassis, m_world, offsettrans, offsettransinv, gcop::System< T, _nx, _nu, _np >::x, and zs.

double Bulletrccar::Step	(	Vector4d &	xb,
		double	t,
		const Vector4d &	xa,
		const Vector2d &	u,
		double	h,
		const VectorXd *	p,
		Matrix4d *	A = `0`,
		Matrix42d *	B = `0`,
		Matrix4pd *	C = `0`
	)		`[virtual]`

Reimplementation of the step function specific to bullet rccar

Reimplemented from gcop::Rccar.

References Reset().

Referenced by Step().

double Bulletrccar::Step	(	Vector4d &	xb,
		const Vector2d &	u,
		double	h,
		const VectorXd *	p = `0`,
		Matrix4d *	A = `0`,
		Matrix42d *	B = `0`,
		Matrix4pd *	C = `0`
	)

References count_zs, gain_cmdvelocity, gEngineForce, gVehicleSteering, gcop::Rccar::h, gcop::BulletWorld::IsZupAxis(), kp_steer, kp_torque, m_carChassis, gcop::BulletWorld::m_dynamicsWorld, m_vehicle, m_world, offsettrans, offsettransinv, reset_drivevel, steeringClamp, gcop::System< T, _nx, _nu, _np >::t, gcop::System< T, _nx, _nu, _np >::x, and zs.

double Bulletrccar::Step	(	Vector4d &	xb,
		const Vector2d &	u,
		double	h,
		const VectorXd *	p,
		const Vector4d &	w,
		Matrix4d *	A = `0`,
		Matrix42d *	B = `0`,
		Matrix4pd *	C = `0`,
		Matrix4d *	D = `0`
	)