lp_filter.h

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//
// Created by qiayuan on 1/5/21.
//
 
#pragma once
 
#include <dynamic_reconfigure/server.h>
#include <realtime_tools/realtime_publisher.h>
#include <rm_msgs/LpData.h>
 
class LowPassFilter
{
public:
  explicit LowPassFilter(ros::NodeHandle& nh);
  explicit LowPassFilter(double cutoff_freq);
  void input(double in);
  void input(double in, ros::Time time);
  double output();
  void reset();
 
private:
  double in_[3]{};
  double out_[3]{};
 
  // Cutoff frequency for the derivative calculation in Hz.
  // Negative -> Has not been set by the user yet, so use a default.
  double cutoff_frequency_ = -1;
  // Used in filter calculations. Default 1.0 corresponds to a cutoff frequency
  // at 1/4 of the sample rate.
  double c_ = 1.;
  // Used to check for tan(0)==>NaN in the filter calculation
  double tan_filt_ = 1.;
  bool is_debug_{};
 
  ros::Time prev_time_;
  ros::Duration delta_t_;
 
  std::shared_ptr<realtime_tools::RealtimePublisher<rm_msgs::LpData>> realtime_pub_{};
};