ros-controls · christophfroehlich · Jun 11, 2025 · Jun 10, 2025 · Jun 10, 2025
diff --git a/doc/migration.rst b/doc/migration.rst
@@ -11,3 +11,7 @@ The ``effort_controllers/GripperActionController`` and ``position_controllers/Gr
 diff_drive_controller
 *****************************
 * Parameters ``has_velocity_limits``, ``has_acceleration_limits``, and ``has_jerk_limits`` are removed. Instead, set the respective limits to ``.NAN``. (`#1653 <https://github.com/ros-controls/ros2_controllers/pull/1653>`_).
+
+pid_controller
+*****************************
+* Parameters ``enable_feedforward`` and service ``set_feedforward_control`` are removed. Instead, set the feedforward_gain to zero or a non-zero value. (`#1553 <https://github.com/ros-controls/ros2_controllers/pull/1553>`_).
diff --git a/pid_controller/doc/userdoc.rst b/pid_controller/doc/userdoc.rst
@@ -69,14 +69,6 @@ If controller parameter ``use_external_measured_states`` is true:
 
 - <controller_name>/measured_state  [control_msgs/msg/MultiDOFCommand]
 
-Services
-,,,,,,,,,,,
-
-- <controller_name>/set_feedforward_control  [std_srvs/srv/SetBool]
-
-.. warning::
-   This service is being deprecated in favour of setting the ``feedforward_gain`` parameter to a non-zero value.
-
 Publishers
 ,,,,,,,,,,,
 - <controller_name>/controller_state  [control_msgs/msg/MultiDOFStateStamped]
@@ -88,10 +80,6 @@ The PID controller uses the `generate_parameter_library <https://github.com/Pick
 
 List of parameters
 =========================
-.. warning::
-   The parameter ``enable_feedforward`` is being deprecated in favor of setting the ``feedforward_gain`` parameter to a non-zero value.
-   This might cause different behavior in the future if currently the ``feedforward_gain`` is set to a non-zero value and not activated.
-
 .. generate_parameter_library_details:: ../src/pid_controller.yaml
 
 

diff --git a/pid_controller/include/pid_controller/pid_controller.hpp b/pid_controller/include/pid_controller/pid_controller.hpp
@@ -77,8 +77,6 @@ class PidController : public controller_interface::ChainableControllerInterface
 
   using PidPtr = std::shared_ptr<control_toolbox::PidROS>;
   std::vector<PidPtr> pids_;
-  // Feed-forward velocity weight factor when calculating closed loop pid adapter's command
-  std::vector<double> feedforward_gain_;
 
   // Command subscribers and Controller State publisher
   rclcpp::Subscription<ControllerReferenceMsg>::SharedPtr ref_subscriber_ = nullptr;
@@ -87,9 +85,6 @@ class PidController : public controller_interface::ChainableControllerInterface
   rclcpp::Subscription<ControllerMeasuredStateMsg>::SharedPtr measured_state_subscriber_ = nullptr;
   realtime_tools::RealtimeBuffer<std::shared_ptr<ControllerMeasuredStateMsg>> measured_state_;
 
-  rclcpp::Service<ControllerModeSrvType>::SharedPtr set_feedforward_control_service_;
-  realtime_tools::RealtimeBuffer<bool> feedforward_mode_enabled_;
-
   using ControllerStatePublisher = realtime_tools::RealtimePublisher<ControllerStateMsg>;
 
   rclcpp::Publisher<ControllerStateMsg>::SharedPtr s_publisher_;

diff --git a/pid_controller/src/pid_controller.cpp b/pid_controller/src/pid_controller.cpp
@@ -74,8 +74,6 @@ PidController::PidController() : controller_interface::ChainableControllerInterf
 
 controller_interface::CallbackReturn PidController::on_init()
 {
-  feedforward_mode_enabled_.initRT(false);
-
   try
   {
     param_listener_ = std::make_shared<pid_controller::ParamListener>(get_node());
@@ -96,8 +94,6 @@ void PidController::update_parameters()
     return;
   }
   params_ = param_listener_->get_params();
-
-  feedforward_mode_enabled_.writeFromNonRT(params_.enable_feedforward);
 }
 
 controller_interface::CallbackReturn PidController::configure_parameters()
@@ -241,24 +237,6 @@ controller_interface::CallbackReturn PidController::on_configure(
   measured_state_values_.resize(
     dof_ * params_.reference_and_state_interfaces.size(), std::numeric_limits<double>::quiet_NaN());
 
-  auto set_feedforward_control_callback =
-    [&](
-      const std::shared_ptr<ControllerModeSrvType::Request> request,
-      std::shared_ptr<ControllerModeSrvType::Response> response)
-  {
-    feedforward_mode_enabled_.writeFromNonRT(request->data);
-
-    RCLCPP_WARN(
-      get_node()->get_logger(),
-      "This service will be deprecated in favour of setting the ``feedforward_gain`` parameter to "
-      "a non-zero value.");
-
-    response->success = true;
-  };
-
-  set_feedforward_control_service_ = get_node()->create_service<ControllerModeSrvType>(
-    "~/set_feedforward_control", set_feedforward_control_callback, qos_services);
-
   try
   {
     // State publisher
@@ -494,7 +472,10 @@ controller_interface::return_type PidController::update_and_write_commands(
   {
     for (size_t i = 0; i < measured_state_values_.size(); ++i)
     {
-      measured_state_values_[i] = state_interfaces_[i].get_value();
+      const auto measured_state = state_interfaces_[i].get_optional();
+      measured_state_values_[i] = measured_state.has_value()
+                                    ? measured_state.value()
+                                    : std::numeric_limits<double>::quiet_NaN();
     }
   }
 
@@ -512,23 +493,20 @@ controller_interface::return_type PidController::update_and_write_commands(
     if (std::isfinite(reference_interfaces_[i]) && std::isfinite(measured_state_values_[i]))
     {
       // calculate feed-forward
-      if (*(feedforward_mode_enabled_.readFromRT()))
+      // two interfaces
+      if (reference_interfaces_.size() == 2 * dof_)
       {
-        // two interfaces
-        if (reference_interfaces_.size() == 2 * dof_)
-        {
-          if (std::isfinite(reference_interfaces_[dof_ + i]))
-          {
-            tmp_command = reference_interfaces_[dof_ + i] *
-                          params_.gains.dof_names_map[params_.dof_names[i]].feedforward_gain;
-          }
-        }
-        else  // one interface
+        if (std::isfinite(reference_interfaces_[dof_ + i]))
         {
-          tmp_command = reference_interfaces_[i] *
+          tmp_command = reference_interfaces_[dof_ + i] *
                         params_.gains.dof_names_map[params_.dof_names[i]].feedforward_gain;
         }
       }
+      else  // one interface
+      {
+        tmp_command = reference_interfaces_[i] *
+                      params_.gains.dof_names_map[params_.dof_names[i]].feedforward_gain;
+      }
 
       double error = reference_interfaces_[i] - measured_state_values_[i];
       if (params_.gains.dof_names_map[params_.dof_names[i]].angle_wraparound)
@@ -599,7 +577,11 @@ controller_interface::return_type PidController::update_and_write_commands(
       state_publisher_->msg_.dof_states[i].time_step = period.seconds();
       // Command can store the old calculated values. This should be obvious because at least one
       // another value is NaN.
-      state_publisher_->msg_.dof_states[i].output = command_interfaces_[i].get_value();
+
+      const auto cmd_interface = command_interfaces_[i].get_optional();
+      state_publisher_->msg_.dof_states[i].output = cmd_interface.has_value()
+                                                      ? cmd_interface.value()
+                                                      : std::numeric_limits<double>::quiet_NaN();
     }
     state_publisher_->unlockAndPublish();
   }

diff --git a/pid_controller/src/pid_controller.yaml b/pid_controller/src/pid_controller.yaml
@@ -43,11 +43,6 @@ pid_controller:
     default_value: false,
     description: "Use external states from a topic instead from state interfaces."
   }
-  enable_feedforward: {
-    type: bool,
-    default_value: false,
-    description: "Enables feedforward gain. (Will be deprecated in favour of setting feedforward_gain to a non-zero value.)"
-  }
   gains:
     __map_dof_names:
       p: {