bioscara_hardware_interfaces::BioscaraGripperHardwareInterface Class Reference

The bioscara gripper hardware interface class. More...

#include <gripper_hardware.hpp>

Inheritance diagram for bioscara_hardware_interfaces::BioscaraGripperHardwareInterface:

Classes
struct	gripper_config_t
	configuration structure holding the passed paramters from the ros2_control urdf More...

Public Member Functions
hardware_interface::CallbackReturn	on_init (const hardware_interface::HardwareComponentInterfaceParams &params) override
hardware_interface::CallbackReturn	on_shutdown (const rclcpp_lifecycle::State &previous_state) override
	Called on the transistion from the inactive, unconfigured and active to the finalized state.
hardware_interface::CallbackReturn	on_configure (const rclcpp_lifecycle::State &previous_state) override
	Called on the transistion from the unconfigured to the inactive state.
hardware_interface::CallbackReturn	on_cleanup (const rclcpp_lifecycle::State &previous_state) override
	Called on the transistion from the inactive to the unconfigured state.
hardware_interface::CallbackReturn	on_activate (const rclcpp_lifecycle::State &previous_state) override
	Called on the transistion from the inactive to the active state.
hardware_interface::CallbackReturn	on_deactivate (const rclcpp_lifecycle::State &previous_state) override
	Called on the transistion from the active to the inactive state.
hardware_interface::return_type	read (const rclcpp::Time &time, const rclcpp::Duration &period) override
	Reads from the hardware and populates the state interfaces.
hardware_interface::return_type	write (const rclcpp::Time &time, const rclcpp::Duration &period) override
	Writes commands to the hardware from the command interfaces.
hardware_interface::CallbackReturn	on_error (const rclcpp_lifecycle::State &previous_state) override
	Called when an error in any state or state transition is thrown.

Private Attributes
std::unique_ptr< bioscara_hardware_drivers::BaseGripper >	_gripper
	Smart pointer to the local BaseGripper.
gripper_config_t	_gripper_cfg
	configuration struct of the gripper.
float	_last_pos = std::numeric_limits<double>::quiet_NaN()
float	_vel = std::numeric_limits<double>::quiet_NaN()

Detailed Description

The bioscara gripper hardware interface class.

System interface has been chosen to allow future modifications for grippers that provide feedback. refer to the BioscaraArmHardwareInterface class for a more detailed description of the hardware life-cycle.

Member Function Documentation

on_activate()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_activate ( const rclcpp_lifecycle::State &  previous_state )

override

Called on the transistion from the inactive to the active state.

Enables PWM generation.

Parameters

previous_state

Returns

hardware_interface::CallbackReturn

on_cleanup()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_cleanup ( const rclcpp_lifecycle::State &  previous_state )

override

Called on the transistion from the inactive to the unconfigured state.

Parameters

previous_state

Returns

hardware_interface::CallbackReturn

on_configure()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_configure ( const rclcpp_lifecycle::State &  previous_state )

override

Called on the transistion from the unconfigured to the inactive state.

Parameters

previous_state

Returns

hardware_interface::CallbackReturn

on_deactivate()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_deactivate ( const rclcpp_lifecycle::State &  previous_state )

override

Called on the transistion from the active to the inactive state.

Disables PWM generation.

Parameters

previous_state

Returns

hardware_interface::CallbackReturn

on_error()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_error ( const rclcpp_lifecycle::State &  previous_state )

override

Called when an error in any state or state transition is thrown.

According to the ros2_control documentation:

‍Error handling follows the node lifecycle. If successful CallbackReturn::SUCCESS is returned and hardware is again in UNCONFIGURED state, if any ERROR or FAILURE happens the hardware ends in FINALIZED state and can not be recovered. The only option is to reload the complete plugin, but there is currently no service for this in the Controller Manager.

Since the hardware will immediatly return to the unconfigured state (source) if the error could be handled we manually call the transition functions which would normally be called to this state. Those are:

• Previous state: active
  • Deactivate hardware (on_deactivate()) -> inactive
  • Clean-Up hardware (on_cleanup()) -> unconfigured
• Previous state: inactive
  • Deactivate hardware (on_deactivate()) -> inactive
    • call the deactivate function anyway regardless if state was active or inactive.
  • Clean-Up hardware (on_cleanup()) -> unconfigured

Parameters

previous_state

Returns

hardware_interface::CallbackReturn

on_init()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_init ( const hardware_interface::HardwareComponentInterfaceParams &  params )

override

check that only one joint is defined, more mimic joints may be defined.

on_shutdown()

hardware_interface::CallbackReturn bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::on_shutdown ( const rclcpp_lifecycle::State &  previous_state )

override

Called on the transistion from the inactive, unconfigured and active to the finalized state.

When transitioning directly from active to finalized on_deactivate() is automatically called before Source Code If the previous state is either inactive or active the on_cleanup() method is called first.

Parameters

previous_state

Returns

hardware_interface::CallbackReturn

read()

hardware_interface::return_type bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::read ( const rclcpp::Time &  time, const rclcpp::Duration &  period  )

override

Reads from the hardware and populates the state interfaces.

Invokes the bioscara_hardware_drivers::Gripper::getPosition() method to read the gripper position.

Parameters

time
period

Returns

hardware_interface::return_type

write()

hardware_interface::return_type bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::write ( const rclcpp::Time &  time, const rclcpp::Duration &  period  )

override

Writes commands to the hardware from the command interfaces.

Invokes the bioscara_hardware_drivers::Gripper::setPosition() method to write the command to the gripper.

Parameters

time
period

Returns

hardware_interface::return_type

Member Data Documentation

_gripper

std::unique_ptr<bioscara_hardware_drivers::BaseGripper> bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::_gripper

private

Smart pointer to the local BaseGripper.

This will be used to either interact with the hardware or mock hardware. A smart pointer is used to guarantee destruction when the pointer is destructed. A unique pointer is used to prevent copying of the object.

_gripper_cfg

gripper_config_t bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::_gripper_cfg

private

configuration struct of the gripper.

_last_pos

float bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::_last_pos = std::numeric_limits<double>::quiet_NaN()

private

_vel

float bioscara_hardware_interfaces::BioscaraGripperHardwareInterface::_vel = std::numeric_limits<double>::quiet_NaN()

private

---

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

• lib/ros2_ws/src/dalsa_bioscara_grippers/bioscara_gripper_hardware_interface/include/bioscara_gripper_hardware_interface/gripper_hardware.hpp
• lib/ros2_ws/src/dalsa_bioscara_grippers/bioscara_gripper_hardware_interface/src/gripper_hardware.cpp