Sort up ROS parameters for filter chains

src/scan_to_cloud_filter_chain.cpp

@@ -50,21 +50,22 @@ ScanToCloudFilterChain::ScanToCloudFilterChain(
   cloud_filter_chain_("sensor_msgs::msg::PointCloud2"),
   scan_filter_chain_("sensor_msgs::msg::LaserScan")
 {
-  this->declare_parameter("high_fidelity", false);
-  this->declare_parameter("notifier_tolerance", 0.03);
-  this->declare_parameter("target_frame", std::string("base_link"));
-  this->declare_parameter("incident_angle_correction", true);
-
+  rcl_interfaces::msg::ParameterDescriptor read_only_desc;
+  read_only_desc.read_only = true;
+
+  // Declare parameters
+  this->declare_parameter("high_fidelity", false, read_only_desc);
+  this->declare_parameter("notifier_tolerance", 0.03, read_only_desc);
+  this->declare_parameter("target_frame", "base_link", read_only_desc);
+  this->declare_parameter("incident_angle_correction", true, read_only_desc);
+  this->declare_parameter("laser_max_range", DBL_MAX, read_only_desc);
+
+  // Get parameters
   this->get_parameter("high_fidelity", high_fidelity_);
   this->get_parameter("notifier_tolerance", tf_tolerance_);
   this->get_parameter("target_frame", target_frame_);
   this->get_parameter("incident_angle_correction", incident_angle_correction_);
-
-  this->get_parameter_or("filter_window", window_, 2);
-  this->get_parameter_or("laser_max_range", laser_max_range_, DBL_MAX);
-  this->get_parameter_or("scan_topic", scan_topic_, std::string("tilt_scan"));
-  this->get_parameter_or("cloud_topic", cloud_topic_, std::string("tilt_laser_cloud_filtered"));
-
+  this->get_parameter("laser_max_range", laser_max_range_);
 
   filter_.setTargetFrame(target_frame_);
   filter_.registerCallback(

src/scan_to_cloud_filter_chain.hpp

@@ -58,26 +58,23 @@ class ScanToCloudFilterChain : public rclcpp::Node
   // ROS related
   laser_geometry::LaserProjection projector_; // Used to project laser scans
 
-  double laser_max_range_; // Used in laser scan projection
-  int window_;
-
-  bool high_fidelity_;                    // High fidelity (interpolating time across scan)
-  std::string target_frame_;                   // Target frame for high fidelity result
-  std::string scan_topic_, cloud_topic_;
-
   // TF
   tf2_ros::Buffer buffer_;
   tf2_ros::TransformListener tf_;
 
   message_filters::Subscriber<sensor_msgs::msg::LaserScan> sub_;
   tf2_ros::MessageFilter<sensor_msgs::msg::LaserScan> filter_;
 
-  double tf_tolerance_;
   filters::FilterChain<sensor_msgs::msg::PointCloud2> cloud_filter_chain_;
   filters::FilterChain<sensor_msgs::msg::LaserScan> scan_filter_chain_;
   rclcpp::Publisher<sensor_msgs::msg::PointCloud2>::SharedPtr cloud_pub_;
 
+  // Parameters
+  bool high_fidelity_; // High fidelity (interpolating time across scan)
+  double tf_tolerance_;
+  std::string target_frame_; // Target frame for high fidelity result
   bool incident_angle_correction_;
+  double laser_max_range_; // Used in laser scan projection
 
   ScanToCloudFilterChain(
     const rclcpp::NodeOptions & options = rclcpp::NodeOptions(),

src/scan_to_scan_filter_chain.cpp

@@ -47,17 +47,24 @@ ScanToScanFilterChain::ScanToScanFilterChain(
     "",
     this->get_node_logging_interface(), this->get_node_parameters_interface());
 
-  std::string tf_message_filter_target_frame;
-  if (this->get_parameter("tf_message_filter_target_frame", tf_message_filter_target_frame)) {
+  rcl_interfaces::msg::ParameterDescriptor read_only_desc;
+  read_only_desc.read_only = true;
 
-    this->get_parameter_or("tf_message_filter_tolerance", tf_filter_tolerance_, 0.03);
+  // Declare parameters
+  this->declare_parameter("tf_message_filter_target_frame", "", read_only_desc);
+  this->declare_parameter("tf_message_filter_tolerance", 0.03, read_only_desc);
 
+  // Get parameters
+  this->get_parameter("tf_message_filter_target_frame", tf_message_filter_target_frame_);
+  this->get_parameter("tf_message_filter_tolerance", tf_filter_tolerance_);
+
+  if (!tf_message_filter_target_frame_.empty()) {
     tf_.reset(new tf2_ros::TransformListener(buffer_));
     tf_filter_.reset(
       new tf2_ros::MessageFilter<sensor_msgs::msg::LaserScan>(
         scan_sub_, buffer_, "",
         50, this->shared_from_this()));
-    tf_filter_->setTargetFrame(tf_message_filter_target_frame);
+    tf_filter_->setTargetFrame(tf_message_filter_target_frame_);
     tf_filter_->setTolerance(std::chrono::duration<double>(tf_filter_tolerance_));
 
     // Setup tf::MessageFilter generates callback

src/scan_to_scan_filter_chain.hpp

@@ -49,7 +49,6 @@ class ScanToScanFilterChain : public rclcpp::Node
 
   message_filters::Subscriber<sensor_msgs::msg::LaserScan> scan_sub_;
   std::shared_ptr<tf2_ros::MessageFilter<sensor_msgs::msg::LaserScan>> tf_filter_;
-  double tf_filter_tolerance_;
 
   // Filter Chain
   filters::FilterChain<sensor_msgs::msg::LaserScan> filter_chain_;
@@ -58,6 +57,10 @@ class ScanToScanFilterChain : public rclcpp::Node
   sensor_msgs::msg::LaserScan msg_;
   rclcpp::Publisher<sensor_msgs::msg::LaserScan>::SharedPtr output_pub_;
 
+  // Parameters
+  std::string tf_message_filter_target_frame_;
+  double tf_filter_tolerance_;
+
 public:
   // Constructor
   ScanToScanFilterChain(