[JointLimits] Add Saturation Joint Limiter that uses clamping method (#971)

---------

Co-authored-by: AndyZe <[email protected]>
Co-authored-by: bijoua <[email protected]>
Co-authored-by: Guillaume Walck <[email protected]>
Co-authored-by: Christoph Fröhlich <[email protected]>
Co-authored-by: Sai Kishor Kothakota <[email protected]>
Co-authored-by: Manuel M <[email protected]>

Author: 7 people

joint_limits/CMakeLists.txt

@@ -7,12 +7,16 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "(GNU|Clang)")
 endif()
 
 set(THIS_PACKAGE_INCLUDE_DEPENDS
+  pluginlib
+  realtime_tools
   rclcpp
   rclcpp_lifecycle
+  trajectory_msgs
   urdf
 )
 
 find_package(ament_cmake REQUIRED)
+find_package(backward_ros REQUIRED)
 find_package(ament_cmake_gen_version_h REQUIRED)
 foreach(Dependency IN ITEMS ${THIS_PACKAGE_INCLUDE_DEPENDS})
   find_package(${Dependency} REQUIRED)
@@ -26,10 +30,42 @@ target_include_directories(joint_limits INTERFACE
 )
 ament_target_dependencies(joint_limits INTERFACE ${THIS_PACKAGE_INCLUDE_DEPENDS})
 
+add_library(joint_limiter_interface SHARED
+  src/joint_limiter_interface.cpp
+)
+target_compile_features(joint_limiter_interface PUBLIC cxx_std_17)
+target_include_directories(joint_limiter_interface PUBLIC
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include/joint_limits>
+)
+ament_target_dependencies(joint_limiter_interface PUBLIC ${THIS_PACKAGE_INCLUDE_DEPENDS})
+# Causes the visibility macros to use dllexport rather than dllimport,
+# which is appropriate when building the dll but not consuming it.
+target_compile_definitions(joint_limiter_interface PRIVATE "JOINT_LIMITS_BUILDING_DLL")
+
+
+add_library(joint_saturation_limiter SHARED
+  src/joint_saturation_limiter.cpp
+)
+target_compile_features(joint_saturation_limiter PUBLIC cxx_std_17)
+target_include_directories(joint_saturation_limiter PUBLIC
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include/joint_limits>
+)
+ament_target_dependencies(joint_saturation_limiter PUBLIC ${THIS_PACKAGE_INCLUDE_DEPENDS})
+# Causes the visibility macros to use dllexport rather than dllimport,
+# which is appropriate when building the dll but not consuming it.
+target_compile_definitions(joint_saturation_limiter PRIVATE "JOINT_LIMITS_BUILDING_DLL")
+
+pluginlib_export_plugin_description_file(joint_limits joint_limiters.xml)
 
 if(BUILD_TESTING)
   find_package(ament_cmake_gtest REQUIRED)
+  find_package(ament_cmake_gmock REQUIRED)
+  find_package(generate_parameter_library REQUIRED)
   find_package(launch_testing_ament_cmake REQUIRED)
+  find_package(pluginlib REQUIRED)
+  find_package(rclcpp REQUIRED)
 
   ament_add_gtest_executable(joint_limits_rosparam_test test/joint_limits_rosparam_test.cpp)
   target_link_libraries(joint_limits_rosparam_test joint_limits)
@@ -43,16 +79,31 @@ if(BUILD_TESTING)
     DESTINATION lib/joint_limits
   )
   install(
-    FILES test/joint_limits_rosparam.yaml
+    FILES test/joint_limits_rosparam.yaml test/joint_saturation_limiter_param.yaml
     DESTINATION share/joint_limits/test
   )
+
+  add_rostest_with_parameters_gmock(test_joint_saturation_limiter test/test_joint_saturation_limiter.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/joint_saturation_limiter_param.yaml
+  )
+  target_include_directories(test_joint_saturation_limiter PRIVATE include)
+  target_link_libraries(test_joint_saturation_limiter joint_limiter_interface)
+  ament_target_dependencies(
+    test_joint_saturation_limiter
+    pluginlib
+    rclcpp
+  )
+
 endif()
 
 install(
   DIRECTORY include/
   DESTINATION include/joint_limits
 )
-install(TARGETS joint_limits
+install(TARGETS
+    joint_limits
+    joint_limiter_interface
+    joint_saturation_limiter
   EXPORT export_joint_limits
   ARCHIVE DESTINATION lib
   LIBRARY DESTINATION lib

joint_limits/include/joint_limits/joint_limiter_interface.hpp

@@ -0,0 +1,250 @@
+// Copyright (c) 2024, Stogl Robotics Consulting UG (haftungsbeschränkt)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/// \author Denis Stogl
+
+#ifndef JOINT_LIMITS__JOINT_LIMITER_INTERFACE_HPP_
+#define JOINT_LIMITS__JOINT_LIMITER_INTERFACE_HPP_
+
+#include <string>
+#include <vector>
+
+#include "joint_limits/joint_limits.hpp"
+#include "joint_limits/joint_limits_rosparam.hpp"
+#include "joint_limits/visibility_control.h"
+#include "rclcpp/node.hpp"
+#include "rclcpp_lifecycle/lifecycle_node.hpp"
+#include "realtime_tools/realtime_buffer.h"
+#include "trajectory_msgs/msg/joint_trajectory_point.hpp"
+
+namespace joint_limits
+{
+using JointLimitsStateDataType = trajectory_msgs::msg::JointTrajectoryPoint;
+
+template <typename LimitsType>
+class JointLimiterInterface
+{
+public:
+  JOINT_LIMITS_PUBLIC JointLimiterInterface() = default;
+
+  JOINT_LIMITS_PUBLIC virtual ~JointLimiterInterface() = default;
+
+  /// Initialization of every JointLimiter.
+  /**
+   * Initialization of JointLimiter for defined joints with their names.
+   * Robot description topic provides a topic name where URDF of the robot can be found.
+   * This is needed to use joint limits from URDF (not implemented yet!).
+   * Override this method only if initialization and reading joint limits should be adapted.
+   * Otherwise, initialize your custom limiter in `on_limit` method.
+   *
+   * \param[in] joint_names names of joints where limits should be applied.
+   * \param[in] param_itf node parameters interface object to access parameters.
+   * \param[in] logging_itf node logging interface to log if error happens.
+   * \param[in] robot_description_topic string of a topic where robot description is accessible.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool init(
+    const std::vector<std::string> & joint_names,
+    const rclcpp::node_interfaces::NodeParametersInterface::SharedPtr & param_itf,
+    const rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr & logging_itf,
+    const std::string & robot_description_topic = "/robot_description")
+  {
+    number_of_joints_ = joint_names.size();
+    joint_names_ = joint_names;
+    joint_limits_.resize(number_of_joints_);
+    node_param_itf_ = param_itf;
+    node_logging_itf_ = logging_itf;
+
+    bool result = true;
+
+    // TODO(destogl): get limits from URDF
+
+    // Initialize and get joint limits from parameter server
+    for (size_t i = 0; i < number_of_joints_; ++i)
+    {
+      if (!declare_parameters(joint_names[i], node_param_itf_, node_logging_itf_))
+      {
+        RCLCPP_ERROR(
+          node_logging_itf_->get_logger(),
+          "JointLimiter: Joint '%s': parameter declaration has failed", joint_names[i].c_str());
+        result = false;
+        break;
+      }
+      if (!get_joint_limits(joint_names[i], node_param_itf_, node_logging_itf_, joint_limits_[i]))
+      {
+        RCLCPP_ERROR(
+          node_logging_itf_->get_logger(),
+          "JointLimiter: Joint '%s': getting parameters has failed", joint_names[i].c_str());
+        result = false;
+        break;
+      }
+      RCLCPP_INFO(
+        node_logging_itf_->get_logger(), "Limits for joint %zu (%s) are:\n%s", i,
+        joint_names[i].c_str(), joint_limits_[i].to_string().c_str());
+    }
+    updated_limits_.writeFromNonRT(joint_limits_);
+
+    auto on_parameter_event_callback = [this](const std::vector<rclcpp::Parameter> & parameters)
+    {
+      rcl_interfaces::msg::SetParametersResult set_parameters_result;
+      set_parameters_result.successful = true;
+
+      std::vector<LimitsType> updated_joint_limits = joint_limits_;
+      bool changed = false;
+
+      for (size_t i = 0; i < number_of_joints_; ++i)
+      {
+        changed |= joint_limits::check_for_limits_update(
+          joint_names_[i], parameters, node_logging_itf_, updated_joint_limits[i]);
+      }
+
+      if (changed)
+      {
+        updated_limits_.writeFromNonRT(updated_joint_limits);
+        RCLCPP_INFO(node_logging_itf_->get_logger(), "Limits are dynamically updated!");
+      }
+
+      return set_parameters_result;
+    };
+
+    parameter_callback_ =
+      node_param_itf_->add_on_set_parameters_callback(on_parameter_event_callback);
+
+    if (result)
+    {
+      result = on_init();
+    }
+
+    (void)robot_description_topic;  // avoid linters output
+
+    return result;
+  }
+
+  /**
+   * Wrapper init method that accepts pointer to the Node.
+   * For details see other init method.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool init(
+    const std::vector<std::string> & joint_names, const rclcpp::Node::SharedPtr & node,
+    const std::string & robot_description_topic = "/robot_description")
+  {
+    return init(
+      joint_names, node->get_node_parameters_interface(), node->get_node_logging_interface(),
+      robot_description_topic);
+  }
+
+  /**
+   * Wrapper init method that accepts pointer to the LifecycleNode.
+   * For details see other init method.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool init(
+    const std::vector<std::string> & joint_names,
+    const rclcpp_lifecycle::LifecycleNode::SharedPtr & lifecycle_node,
+    const std::string & robot_description_topic = "/robot_description")
+  {
+    return init(
+      joint_names, lifecycle_node->get_node_parameters_interface(),
+      lifecycle_node->get_node_logging_interface(), robot_description_topic);
+  }
+
+  JOINT_LIMITS_PUBLIC virtual bool configure(const JointLimitsStateDataType & current_joint_states)
+  {
+    return on_configure(current_joint_states);
+  }
+
+  /** \brief Enforce joint limits to desired joint state for multiple physical quantities.
+   *
+   * Generic enforce method that calls implementation-specific `on_enforce` method.
+   *
+   * \param[in] current_joint_states current joint states a robot is in.
+   * \param[in,out] desired_joint_states joint state that should be adjusted to obey the limits.
+   * \param[in] dt time delta to calculate missing integrals and derivation in joint limits.
+   * \returns true if limits are enforced, otherwise false.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool enforce(
+    JointLimitsStateDataType & current_joint_states,
+    JointLimitsStateDataType & desired_joint_states, const rclcpp::Duration & dt)
+  {
+    joint_limits_ = *(updated_limits_.readFromRT());
+    return on_enforce(current_joint_states, desired_joint_states, dt);
+  }
+
+  /** \brief Enforce joint limits to desired joint state for single physical quantity.
+   *
+   * Generic enforce method that calls implementation-specific `on_enforce` method.
+   *
+   * \param[in,out] desired_joint_states joint state that should be adjusted to obey the limits.
+   * \returns true if limits are enforced, otherwise false.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool enforce(std::vector<double> & desired_joint_states)
+  {
+    joint_limits_ = *(updated_limits_.readFromRT());
+    return on_enforce(desired_joint_states);
+  }
+
+protected:
+  /** \brief Method is realized by an implementation.
+   *
+   * Implementation-specific initialization of limiter's internal states and libraries.
+   * \returns true if initialization was successful, otherwise false.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool on_init() = 0;
+
+  /** \brief Method is realized by an implementation.
+   *
+   * Implementation-specific configuration of limiter's internal states and libraries.
+   * \returns true if initialization was successful, otherwise false.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool on_configure(
+    const JointLimitsStateDataType & current_joint_states) = 0;
+
+  /** \brief Method is realized by an implementation.
+   *
+   * Filter-specific implementation of the joint limits enforce algorithm for multiple dependent
+   * physical quantities.
+   *
+   * \param[in] current_joint_states current joint states a robot is in.
+   * \param[in,out] desired_joint_states joint state that should be adjusted to obey the limits.
+   * \param[in] dt time delta to calculate missing integrals and derivation in joint limits.
+   * \returns true if limits are enforced, otherwise false.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool on_enforce(
+    JointLimitsStateDataType & current_joint_states,
+    JointLimitsStateDataType & desired_joint_states, const rclcpp::Duration & dt) = 0;
+
+  /** \brief Method is realized by an implementation.
+   *
+   * Filter-specific implementation of the joint limits enforce algorithm for single physical
+   * quantity.
+   * This method might use "effort" limits since they are often used as wild-card.
+   * Check the documentation of the exact implementation for more details.
+   *
+   * \param[in,out] desired_joint_states joint state that should be adjusted to obey the limits.
+   * \returns true if limits are enforced, otherwise false.
+   */
+  JOINT_LIMITS_PUBLIC virtual bool on_enforce(std::vector<double> & desired_joint_states) = 0;
+
+  size_t number_of_joints_;
+  std::vector<std::string> joint_names_;
+  std::vector<LimitsType> joint_limits_;
+  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_param_itf_;
+  rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging_itf_;
+
+private:
+  rclcpp::node_interfaces::OnSetParametersCallbackHandle::SharedPtr parameter_callback_;
+  realtime_tools::RealtimeBuffer<std::vector<LimitsType>> updated_limits_;
+};
+
+}  // namespace joint_limits
+
+#endif  // JOINT_LIMITS__JOINT_LIMITER_INTERFACE_HPP_