Virtual Class to implement when integrating a stand-alone sensor into ros2_control. More...

#include <sensor_interface.hpp>

Inheritance diagram for hardware_interface::SensorInterface:

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Collaboration diagram for hardware_interface::SensorInterface:

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Public Member Functions
	SensorInterface (const SensorInterface &other)=delete
	SensorInterface copy constructor is actively deleted.

	SensorInterface (SensorInterface &&other)=default

virtual CallbackReturn	on_init (const HardwareInfo &hardware_info)
	Initialization of the hardware interface from data parsed from the robot's URDF.

virtual std::vector< StateInterface >	export_state_interfaces ()=0
	Exports all state interfaces for this hardware interface.

virtual return_type	read (const rclcpp::Time &time, const rclcpp::Duration &period)=0
	Read the current state values from the actuator.

virtual std::string	get_name () const
	Get name of the actuator hardware.

const rclcpp_lifecycle::State &	get_state () const
	Get life-cycle state of the actuator hardware.

void	set_state (const rclcpp_lifecycle::State &new_state)
	Set life-cycle state of the actuator hardware.

Protected Attributes
HardwareInfo	info_

rclcpp_lifecycle::State	lifecycle_state_

Detailed Description

Virtual Class to implement when integrating a stand-alone sensor into ros2_control.

The typical examples are Force-Torque Sensor (FTS), Interial Measurement Unit (IMU).

Methods return values have type rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface::CallbackReturn with the following meaning:

Returns: CallbackReturn::SUCCESS method execution was successful.; CallbackReturn::FAILURE method execution has failed and and can be called again.; CallbackReturn::ERROR critical error has happened that should be managed in "on_error" method.

The hardware ends after each method in a state with the following meaning:

UNCONFIGURED (on_init, on_cleanup): Hardware is initialized but communication is not started and therefore no interface is available.

INACTIVE (on_configure, on_deactivate): Communication with the hardware is started and it is configured. States can be read.

FINALIZED (on_shutdown): Hardware interface is ready for unloading/destruction. Allocated memory is cleaned up.

ACTIVE (on_activate): States can be read.

Constructor & Destructor Documentation

◆ SensorInterface()

hardware_interface::SensorInterface::SensorInterface ( const SensorInterface & other )

delete

SensorInterface copy constructor is actively deleted.

Hardware interfaces are having a unique ownership and thus can't be copied in order to avoid failed or simultaneous access to hardware.

Member Function Documentation

◆ export_state_interfaces()

virtual std::vector< StateInterface > hardware_interface::SensorInterface::export_state_interfaces ( )

pure virtual

Exports all state interfaces for this hardware interface.

The state interfaces have to be created and transferred according to the hardware info passed in for the configuration.

Note the ownership over the state interfaces is transferred to the caller.

Returns: vector of state interfaces

Implemented in ros2_control_demo_example_14::RRBotSensorPositionFeedback, and ros2_control_demo_example_5::ExternalRRBotForceTorqueSensorHardware.

◆ get_name()

virtual std::string hardware_interface::SensorInterface::get_name ( ) const

inlinevirtual

Get name of the actuator hardware.

Returns: name.

◆ get_state()

const rclcpp_lifecycle::State & hardware_interface::SensorInterface::get_state ( ) const

inline

Get life-cycle state of the actuator hardware.

Returns: state.

◆ on_init()

virtual CallbackReturn hardware_interface::SensorInterface::on_init ( const HardwareInfo & hardware_info )

inlinevirtual

Initialization of the hardware interface from data parsed from the robot's URDF.

Parameters

[in] hardware_info structure with data from URDF.

Returns: CallbackReturn::SUCCESS if required data are provided and can be parsed.; CallbackReturn::ERROR if any error happens or data are missing.

Reimplemented in ros2_control_demo_example_14::RRBotSensorPositionFeedback, and ros2_control_demo_example_5::ExternalRRBotForceTorqueSensorHardware.

◆ read()

virtual return_type hardware_interface::SensorInterface::read	(	const rclcpp::Time &	time,
		const rclcpp::Duration &	period
	)

pure virtual

Read the current state values from the actuator.

The data readings from the physical hardware has to be updated and reflected accordingly in the exported state interfaces. That is, the data pointed by the interfaces shall be updated.

Parameters

[in]	time	The time at the start of this control loop iteration
[in]	period	The measured time taken by the last control loop iteration

Returns: return_type::OK if the read was successful, return_type::ERROR otherwise.

Implemented in ros2_control_demo_example_14::RRBotSensorPositionFeedback, and ros2_control_demo_example_5::ExternalRRBotForceTorqueSensorHardware.

◆ set_state()

void hardware_interface::SensorInterface::set_state ( const rclcpp_lifecycle::State & new_state )