Class SystemInterface

Defined in File system_interface.hpp

Inheritance Relationships

Base Type

public rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface

Derived Type

public mock_components::GenericSystem (Class GenericSystem)

Class Documentation

class SystemInterface : public rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface

Subclassed by mock_components::GenericSystem

Public Functions

inline SystemInterface()

SystemInterface(const SystemInterface &other) = delete

SystemInterface 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.

SystemInterface(SystemInterface &&other) = default

virtual ~SystemInterface() = default

inline CallbackReturn init(const HardwareInfo &hardware_info, rclcpp::Logger logger, rclcpp::node_interfaces::NodeClockInterface::SharedPtr clock_interface)

Initialization of the hardware interface from data parsed from the robot’s URDF and also the clock and logger interfaces.

Parameters:

hardware_info – [in] structure with data from URDF.
clock_interface – [in] pointer to the clock interface.
logger_interface – [in] pointer to the logger interface.

Returns:

CallbackReturn::SUCCESS if required data are provided and can be parsed.

Returns:

CallbackReturn::ERROR if any error happens or data are missing.

inline virtual CallbackReturn on_init(const HardwareInfo &hardware_info)

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

Parameters:: hardware_info – [in] structure with data from URDF.
Returns:: CallbackReturn::SUCCESS if required data are provided and can be parsed.
Returns:: CallbackReturn::ERROR if any error happens or data are missing.

inline virtual std::vector<StateInterface> export_state_interfaces()

Exports all state interfaces for this hardware interface.

Old way of exporting the StateInterfaces. If a empty vector is returned then the on_export_state_interfaces() method is called. If a vector with StateInterfaces is returned then the exporting of the StateInterfaces is only done with this function and the ownership is transferred to the resource manager. The set_command(…), get_command(…), …, can then not be used.

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

Returns:: vector of state interfaces

inline virtual std::vector<hardware_interface::InterfaceDescription> export_unlisted_state_interface_descriptions()

Override this method to export custom StateInterfaces which are not defined in the URDF file. Those interfaces will be added to the unlisted_state_interfaces_ map.

Returns:: vector of descriptions to the unlisted StateInterfaces

inline virtual std::vector<StateInterface::ConstSharedPtr> on_export_state_interfaces()

Default implementation for exporting the StateInterfaces. The StateInterfaces are created according to the InterfaceDescription. The memory accessed by the controllers and hardware is assigned here and resides in the system_interface.

Returns:: vector of shared pointers to the created and stored StateInterfaces

inline virtual std::vector<CommandInterface> export_command_interfaces()

Exports all command interfaces for this hardware interface.

Old way of exporting the CommandInterfaces. If a empty vector is returned then the on_export_command_interfaces() method is called. If a vector with CommandInterfaces is returned then the exporting of the CommandInterfaces is only done with this function and the ownership is transferred to the resource manager. The set_command(…), get_command(…), …, can then not be used.

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

Returns:: vector of state interfaces

inline virtual std::vector<hardware_interface::InterfaceDescription> export_unlisted_command_interface_descriptions()

Override this method to export custom CommandInterfaces which are not defined in the URDF file. Those interfaces will be added to the unlisted_command_interfaces_ map.

Returns:: vector of descriptions to the unlisted CommandInterfaces

inline virtual std::vector<CommandInterface::SharedPtr> on_export_command_interfaces()

Default implementation for exporting the CommandInterfaces. The CommandInterfaces are created according to the InterfaceDescription. The memory accessed by the controllers and hardware is assigned here and resides in the system_interface.

Returns:: vector of shared pointers to the created and stored CommandInterfaces

inline virtual return_type prepare_command_mode_switch(const std::vector<std::string>&, const std::vector<std::string>&)

Prepare for a new command interface switch.

Prepare for any mode-switching required by the new command interface combination.

Note

This is a non-realtime evaluation of whether a set of command interface claims are possible, and call to start preparing data structures for the upcoming switch that will occur.

Note

All starting and stopping interface keys are passed to all components, so the function should return return_type::OK by default when given interface keys not relevant for this component.

Parameters:

start_interfaces – [in] vector of string identifiers for the command interfaces starting.
stop_interfaces – [in] vector of string identifiers for the command interfaces stopping.

Returns:

return_type::OK if the new command interface combination can be prepared, or if the interface key is not relevant to this system. Returns return_type::ERROR otherwise.

inline virtual return_type perform_command_mode_switch(const std::vector<std::string>&, const std::vector<std::string>&)

Perform the mode-switching for the new command interface combination.

Note

This is part of the realtime update loop, and should be fast.

Note

All starting and stopping interface keys are passed to all components, so the function should return return_type::OK by default when given interface keys not relevant for this component.

Parameters:

start_interfaces – [in] vector of string identifiers for the command interfaces starting.
stop_interfaces – [in] vector of string identifiers for the command interfaces stopping.

Returns:

return_type::OK if the new command interface combination can be switched to, or if the interface key is not relevant to this system. Returns return_type::ERROR otherwise.

virtual return_type read(const rclcpp::Time &time, const rclcpp::Duration &period) = 0

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:

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

Returns:

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

virtual return_type write(const rclcpp::Time &time, const rclcpp::Duration &period) = 0

Write the current command values to the actuator.

The physical hardware shall be updated with the latest value from the exported command interfaces.

Parameters:

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

Returns:

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

inline virtual std::string get_name() const

Get name of the actuator hardware.

Returns:: name.

inline virtual std::string get_group_name() const

Get name of the actuator hardware group to which it belongs to.

Returns:: group name.

inline const rclcpp_lifecycle::State &get_lifecycle_state() const

Get life-cycle state of the actuator hardware.

Returns:: state.

inline void set_lifecycle_state(const rclcpp_lifecycle::State &new_state)

Set life-cycle state of the actuator hardware.

Returns:: state.

inline void set_state(const std::string &interface_name, const double &value)

inline double get_state(const std::string &interface_name) const

inline void set_command(const std::string &interface_name, const double &value)

inline double get_command(const std::string &interface_name) const

inline rclcpp::Logger get_logger() const

Get the logger of the SystemInterface.

Returns:: logger of the SystemInterface.

inline rclcpp::Clock::SharedPtr get_clock() const

Get the clock of the SystemInterface.

Returns:: clock of the SystemInterface.

inline const HardwareInfo &get_hardware_info() const

Get the hardware info of the SystemInterface.

Returns:: hardware info of the SystemInterface.

Protected Attributes

HardwareInfo info_

std::unordered_map<std::string, InterfaceDescription> joint_state_interfaces_

std::unordered_map<std::string, InterfaceDescription> joint_command_interfaces_

std::unordered_map<std::string, InterfaceDescription> sensor_state_interfaces_

std::unordered_map<std::string, InterfaceDescription> gpio_state_interfaces_

std::unordered_map<std::string, InterfaceDescription> gpio_command_interfaces_

std::unordered_map<std::string, InterfaceDescription> unlisted_state_interfaces_

std::unordered_map<std::string, InterfaceDescription> unlisted_command_interfaces_

rclcpp_lifecycle::State lifecycle_state_

std::vector<StateInterface::SharedPtr> joint_states_

std::vector<CommandInterface::SharedPtr> joint_commands_

std::vector<StateInterface::SharedPtr> sensor_states_

std::vector<StateInterface::SharedPtr> gpio_states_

std::vector<CommandInterface::SharedPtr> gpio_commands_

std::vector<StateInterface::SharedPtr> unlisted_states_

std::vector<CommandInterface::SharedPtr> unlisted_commands_