Function joint_limits::get_joint_limits(const std::string&, const rclcpp::node_interfaces::NodeParametersInterface::SharedPtr&, const rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr&, JointLimits&)

Function Documentation

inline bool joint_limits::get_joint_limits(const std::string &joint_name, const rclcpp::node_interfaces::NodeParametersInterface::SharedPtr &param_itf, const rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr &logging_itf, JointLimits &limits)

Populate a JointLimits instance from the node parameters.

It is assumed that parameter structure is the following: 

has_position_limits: bool
min_position: double
max_position: double
has_velocity_limits: bool
max_velocity: double
has_acceleration_limits: bool
max_acceleration: double
has_jerk_limits: bool
max_jerk: double
has_effort_limits: bool
max_effort: double
angle_wraparound: bool  # will be ignored if there are position limits

Unspecified parameters are not added to the joint limits specification. A specification in a yaml would look like this: 

<node_name>
  ros__parameters:
    joint_limits:
      foo_joint:
        has_position_limits: true
        min_position: 0.0
        max_position: 1.0
        has_velocity_limits: true
        max_velocity: 2.0
        has_acceleration_limits: true
        max_acceleration: 5.0
        has_jerk_limits: true
        max_jerk: 100.0
        has_effort_limits: true
        max_effort: 20.0
      bar_joint:
        has_position_limits: false   # Continuous joint
        angle_wraparound: true       # available only for continuous joints
        has_velocity_limits: true
        max_velocity: 4.0

Parameters:

  • joint_name – [in] Name of joint whose limits are to be fetched, e.g., “foo_joint”.

  • param_itf – [in] node parameters interface of the node where parameters are specified.

  • logging_itf – [in] node logging interface to provide log errors.

  • limits – [out] Where joint limit data gets written into. Limits specified in the parameter server will overwrite existing values. Values in limits not specified in the parameter server remain unchanged.

Returns:

True if a limits specification is found (i.e., the joint_limits/joint_name parameter exists in node), false otherwise.