admittance_controller::AdmittanceRule Class Reference

Collaboration diagram for admittance_controller::AdmittanceRule:

Public Member Functions
	AdmittanceRule (const std::shared_ptr< admittance_controller::ParamListener > &parameter_handler)
controller_interface::return_type	configure (const std::shared_ptr< rclcpp_lifecycle::LifecycleNode > &node, const size_t num_joint, const std::string &robot_description)
	Configure admittance rule memory using number of joints.
controller_interface::return_type	reset (const size_t num_joints)
	Reset all values back to default.
void	apply_parameters_update ()
controller_interface::return_type	update (const trajectory_msgs::msg::JointTrajectoryPoint &current_joint_state, const geometry_msgs::msg::Wrench &measured_wrench, const trajectory_msgs::msg::JointTrajectoryPoint &reference_joint_state, const rclcpp::Duration &period, trajectory_msgs::msg::JointTrajectoryPoint &desired_joint_states)
const control_msgs::msg::AdmittanceControllerState &	get_controller_state ()

Public Attributes
std::shared_ptr< admittance_controller::ParamListener >	parameter_handler_
admittance_controller::Params	parameters_

Protected Member Functions
bool	calculate_admittance_rule (AdmittanceState &admittance_state, double dt)
void	process_wrench_measurements (const geometry_msgs::msg::Wrench &measured_wrench, const Eigen::Matrix< double, 3, 3 > &sensor_world_rot, const Eigen::Matrix< double, 3, 3 > &cog_world_rot)
template<typename T1 , typename T2 >
void	vec_to_eigen (const std::vector< T1 > &data, T2 &matrix)

Protected Attributes
size_t	num_joints_
std::shared_ptr< pluginlib::ClassLoader< kinematics_interface::KinematicsInterface > >	kinematics_loader_
std::unique_ptr< kinematics_interface::KinematicsInterface >	kinematics_
Eigen::Matrix< double, 6, 1 >	wrench_world_
AdmittanceState	admittance_state_ {0}
Eigen::Vector3d	cog_pos_
Eigen::Vector3d	end_effector_weight_
control_msgs::msg::AdmittanceControllerState	state_message_

Member Function Documentation

apply_parameters_update()

void admittance_controller::AdmittanceRule::apply_parameters_update

(

)

Updates parameter_ struct if any parameters have changed since last update. Parameter dependent Eigen field members (end_effector_weight_, cog_pos_, mass_, mass_inv_ stiffness, selected_axes, damping_) are also updated

calculate_admittance_rule()

bool admittance_controller::AdmittanceRule::calculate_admittance_rule ( AdmittanceState &  admittance_state, double  dt  )

protected

Calculates the admittance rule from given the robot's current joint angles. The admittance controller state input is updated with the new calculated values. A boolean value is returned indicating if any of the kinematics plugin calls failed.

Parameters

[in]	admittance_state	contains all the information needed to calculate the admittance offset
[in]	dt	controller period
[out]	success	true if no calls to the kinematics interface fail

configure()

controller_interface::return_type admittance_controller::AdmittanceRule::configure	(	const std::shared_ptr< rclcpp_lifecycle::LifecycleNode > &	node,
		const size_t	num_joint,
		const std::string &	robot_description
	)

Configure admittance rule memory using number of joints.

Configure admittance rule memory for num joints and load kinematics interface.

get_controller_state()

const control_msgs::msg::AdmittanceControllerState & admittance_controller::AdmittanceRule::get_controller_state

(

)

Set fields of state_message from current admittance controller state.

Parameters

[out]

state_message

message containing target position/vel/accel, wrench, and actual robot state, among other things

process_wrench_measurements()

void admittance_controller::AdmittanceRule::process_wrench_measurements ( const geometry_msgs::msg::Wrench &  measured_wrench, const Eigen::Matrix< double, 3, 3 > &  sensor_world_rot, const Eigen::Matrix< double, 3, 3 > &  cog_world_rot  )

protected

Updates internal estimate of wrench in world frame wrench_world_ given the new measurement measured_wrench, the sensor to base frame rotation sensor_world_rot, and the center of gravity frame to base frame rotation cog_world_rot. The wrench_world_ estimate includes gravity compensation

Parameters

[in]	measured_wrench	most recent measured wrench from force torque sensor
[in]	sensor_world_rot	rotation matrix from world frame to sensor frame
[in]	cog_world_rot	rotation matrix from world frame to center of gravity frame

update()

controller_interface::return_type admittance_controller::AdmittanceRule::update	(	const trajectory_msgs::msg::JointTrajectoryPoint &	current_joint_state,
		const geometry_msgs::msg::Wrench &	measured_wrench,
		const trajectory_msgs::msg::JointTrajectoryPoint &	reference_joint_state,
		const rclcpp::Duration &	period,
		trajectory_msgs::msg::JointTrajectoryPoint &	desired_joint_states
	)

Calculate 'desired joint states' based on the 'measured force', 'reference joint state', and 'current_joint_state'.

All transforms (e.g., world to base, sensor to base, CoG to base) are now computed directly in this function and stored in admittance_state_, removing the need for an intermediate transform struct.

Parameters

[in]	current_joint_state	current joint state of the robot
[in]	measured_wrench	most recent measured wrench from force torque sensor
[in]	reference_joint_state	input joint state reference
[in]	period	time in seconds since last controller update
[out]	desired_joint_state	joint state reference after the admittance offset is applied to the input reference

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

• ros2_controllers/admittance_controller/include/admittance_controller/admittance_rule.hpp
• ros2_controllers/admittance_controller/include/admittance_controller/admittance_rule_impl.hpp