upkie::cpp::actuation::bullet Namespace Reference

Bullet utility functions used in the simulation interface. More...

Classes
struct	ContactData
	Contact information for a single link. More...
struct	ExternalForce
	Parameters for a call to Bullet's applyExternalForce. More...
struct	JointProperties
	Properties for robot joints in the Bullet simulation. More...
struct	RobotSimulatorChangeDynamicsArgs
	Structure which contains the new link properties. More...
class	RobotSimulatorClientAPI
	Child class to enable modification of inertia matrices. More...

Functions
void	read_imu_data (ImuData &imu_data, b3RobotSimulatorClientAPI &bullet, int robot, const int imu_link_index, double dt)
	Compute groundtruth IMU quantities from the IMU link state. More...
btQuaternion	bullet_from_eigen (const Eigen::Quaterniond &quat)
	Convert an Eigen quaternion to a Bullet one. More...
btVector3	bullet_from_eigen (const Eigen::Vector3d &v)
	Convert an Eigen vector to a Bullet one. More...
Eigen::Quaterniond	eigen_from_bullet (const btQuaternion &quat)
	Convert a Bullet quaternion to an Eigen one. More...
Eigen::Vector3d	eigen_from_bullet (const btVector3 &v)
	Convert a Bullet vector to an Eigen one. More...
int	find_link_index (b3RobotSimulatorClientAPI &bullet, int robot, const std::string &link_name) noexcept
	Find the index of a link. More...
Eigen::Vector3d	get_position_link_in_world (b3RobotSimulatorClientAPI &bullet, int robot, int link_index) noexcept
	Get the position of a link frame in the world frame. More...
double	compute_robot_mass (b3RobotSimulatorClientAPI &bullet, int robot)
	Get the total mass of the robot. More...
Eigen::Vector3d	compute_position_com_in_world (b3RobotSimulatorClientAPI &bullet, int robot)
	Get the position of the center of mass of a robot in the world frame. More...

Variables
constexpr double	kGravity = 9.81
	Standard gravity constant used in Bullet simulations.

Detailed Description

Bullet utility functions used in the simulation interface.

Function Documentation

bullet_from_eigen() [1/2]

btQuaternion upkie::cpp::actuation::bullet::bullet_from_eigen ( const Eigen::Quaterniond &  quat )

inline

Convert an Eigen quaternion to a Bullet one.

Parameters

[in]

quat

Eigen quaternion.

Returns

Same quaternion for Bullet.

bullet_from_eigen() [2/2]

btVector3 upkie::cpp::actuation::bullet::bullet_from_eigen ( const Eigen::Vector3d &  v )

inline

Convert an Eigen vector to a Bullet one.

Parameters

[in]

v

Eigen vector.

Returns

Same vector for Bullet.

compute_position_com_in_world()

Eigen::Vector3d upkie::cpp::actuation::bullet::compute_position_com_in_world ( b3RobotSimulatorClientAPI &  bullet, int  robot  )

inline

Get the position of the center of mass of a robot in the world frame.

Parameters

[in]	bullet	Bullet client.
[in]	robot	Index of the robot.

Returns

Position of the center of mass in the world frame.

Note

This function will recompute forward kinematics.

compute_robot_mass()

double upkie::cpp::actuation::bullet::compute_robot_mass ( b3RobotSimulatorClientAPI &  bullet, int  robot  )

inline

Get the total mass of the robot.

Parameters

[in]	bullet	Bullet client.
[in]	robot	Index of the robot.

Returns

Total mass of the robot, in kilograms.

eigen_from_bullet() [1/2]

Eigen::Quaterniond upkie::cpp::actuation::bullet::eigen_from_bullet ( const btQuaternion &  quat )

inline

Convert a Bullet quaternion to an Eigen one.

Parameters

[in]

quat

Bullet quaternion.

Returns

Same vector for Eigen.

eigen_from_bullet() [2/2]

Eigen::Vector3d upkie::cpp::actuation::bullet::eigen_from_bullet ( const btVector3 &  v )

inline

Convert a Bullet vector to an Eigen one.

Parameters

[in]

v

Bullet vector.

Returns

Same vector for Eigen.

find_link_index()

int upkie::cpp::actuation::bullet::find_link_index ( b3RobotSimulatorClientAPI &  bullet, int  robot, const std::string &  link_name  )

inlinenoexcept

Find the index of a link.

Parameters

[in]	bullet	Bullet client.
[in]	robot	Index of the robot to search.
[in]	link_name	Name of the searched link.

Returns

Link index if found, -1 otherwise.

get_position_link_in_world()

Eigen::Vector3d upkie::cpp::actuation::bullet::get_position_link_in_world ( b3RobotSimulatorClientAPI &  bullet, int  robot, int  link_index  )

inlinenoexcept

Get the position of a link frame in the world frame.

Parameters

[in]	bullet	Bullet client.
[in]	robot	Index of the robot to search.
[in]	link_index	Index of the link frame.

Returns

Link index if found, -1 otherwise.

Note

This function will recompute forward kinematics.

read_imu_data()

void upkie::cpp::actuation::bullet::read_imu_data ( ImuData &  imu_data, b3RobotSimulatorClientAPI &  bullet, int  robot, const int  imu_link_index, double  dt  )

inline

Compute groundtruth IMU quantities from the IMU link state.

Parameters

[out]	imu_data	IMU data to update.
[in]	bullet	Bullet client.
[in]	robot	Bullet index of the robot model.
[in]	imu_link_index	Index of the IMU link in the robot.
[in]	dt	Simulation timestep in [s].