complementary_filter.cpp

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#include "ros/ros.h"
#include "std_msgs/String.h"
#include <sstream>
#include <string>
#include <iostream>
#include <math.h> 
#include <cmath>
#include <vector>

#include <boost/format.hpp> 

#include <imu_network/sensors_network.h>
#include <imu_network/filtered_imu_network.h>
#include <imu_network/filtered_imu.h>

#define MAX_MEAN_IT 25 //number of iterations to measure the mean values from gyroscopes

#define GYRO_CONVERT M_PI/180*0.069565 // conversion of gyro's values from ADC to rad/sec

using namespace std;


ros::NodeHandle* n;
ros::Publisher chatter_pub;

int sensors_number;
int first_run=0;

vector<float>gyro_angle[3];
vector<float>accel_ang_x;
vector<float>accel_ang_y;

vector<float>angle[3];
vector<float>angle_last_it[3];

vector<float>gyro_mean_vect[MAX_MEAN_IT][3]; //vectors for allocation of values of gyro for mean
vector<float>gyro_real_mean[3]; //vetor of gyro's means
vector<float>gyro_last_it[3];

float period = 1/7.35;
float alpha = 0.3;
float accel_alpha = 0.7;

int mean_it = 0;

imu_network::filtered_imu_network complementary_filter_network;

void chatterCallback(const imu_network::sensors_network::ConstPtr& msg) //callback that intercept the sensor's raw data
{
    float ax,ay,az;
    if(first_run ==0)
    {
        
        sensors_number=(int)msg->sensors_val[0].total_number;
        
        for (int i=0;i<sensors_number;i++)
        {
          //published message initialization
          imu_network::filtered_imu filtered_imu_data;
          complementary_filter_network.filtered_imu_network.push_back(filtered_imu_data);
          
          ax = msg->sensors_val[i].S_Ax;
          ay = msg->sensors_val[i].S_Ay;
          az = msg->sensors_val[i].S_Az;
          
          accel_ang_x.push_back(atan(ay/sqrt((ax*ax)+(az*az))));
          accel_ang_y.push_back(atan(ax/sqrt((ay*ay)+(az*az))));
          
          gyro_angle[0].push_back(0);
          gyro_angle[1].push_back(0);
          gyro_angle[2].push_back(0);
          
          gyro_last_it[0].push_back(0);
          gyro_last_it[1].push_back(0);
          gyro_last_it[2].push_back(0);
          
          angle_last_it[0].push_back(accel_ang_x[i]);
          angle_last_it[1].push_back(accel_ang_y[i]);
          angle_last_it[2].push_back(0);
          
          angle[0].push_back(0);
          angle[1].push_back(0);
          angle[2].push_back(0);
          
        }
    
    first_run = 1;
    return;
    }
    
    //getting the gyro's means...
    if(mean_it<MAX_MEAN_IT)
    {
        for(int i= 0;i<sensors_number;i++)
        {
          gyro_mean_vect[i][0].push_back(msg->sensors_val[i].S_Gx);
          gyro_mean_vect[i][1].push_back(msg->sensors_val[i].S_Gy);
          gyro_mean_vect[i][2].push_back(msg->sensors_val[i].S_Gz);
          gyro_real_mean[0].push_back(i);
          gyro_real_mean[1].push_back(i);
          gyro_real_mean[2].push_back(i);
        }
        mean_it++;
        return;
    }
    //getting gyros's means to compensate it (if it's needed!)
    if(mean_it==MAX_MEAN_IT)
    {
        for(int i= 0;i<sensors_number;i++)
        {
          for(int j=0;j<mean_it;j++)
          {
              gyro_real_mean[0][i]+=gyro_mean_vect[i][0][j];
              gyro_real_mean[1][i]+=gyro_mean_vect[i][1][j];
              gyro_real_mean[2][i]+=gyro_mean_vect[i][2][j];
          }
          gyro_real_mean[0][i]/=MAX_MEAN_IT;
          gyro_real_mean[1][i]/=MAX_MEAN_IT;
          gyro_real_mean[2][i]/=MAX_MEAN_IT;
          cout<<"mean_it = "<<mean_it<<" i="<<i<<" gyro_real_mean(0)="<<gyro_real_mean[0][i]<<" gyro_real_mean(1)="<<gyro_real_mean[1][i]<<" gyro_real_mean(2)="<<gyro_real_mean[2][i]<<endl;
        }
        mean_it++;      
    }
    
    float sensor_var[sensors_number][9];
    
    for(int i = 0; i<sensors_number; i++)
    {
        //sensors_values -> variable changing
        sensor_var[i][0]=msg->sensors_val[i].S_Ax;
        sensor_var[i][1]=msg->sensors_val[i].S_Ay;
        sensor_var[i][2]=msg->sensors_val[i].S_Az;
        sensor_var[i][3]=msg->sensors_val[i].S_Mx;
        sensor_var[i][4]=msg->sensors_val[i].S_My;
        sensor_var[i][5]=msg->sensors_val[i].S_Mz;
        sensor_var[i][6]=msg->sensors_val[i].S_Gx;
        sensor_var[i][7]=msg->sensors_val[i].S_Gy;
        sensor_var[i][8]=msg->sensors_val[i].S_Gz;
        
        // getting Roll & Pitch from accelerometers
        ax = sensor_var[i][0];
        ay = sensor_var[i][1];
        az = sensor_var[i][2];
        
        accel_ang_x[i] = (accel_alpha * atan(ay/sqrt((ax*ax)+(az*az)))) + ((1-accel_alpha) * angle_last_it[0][i]);
        accel_ang_y[i] = (accel_alpha * atan(ax/sqrt((ay*ay)+(az*az)))) + ((1-accel_alpha) * angle_last_it[1][i]);
        
        angle_last_it[0][i]=accel_ang_x[i];
        angle_last_it[1][i]=accel_ang_y[i];
        
        // getting Roll , Pitch & Yaw from gyroscopes
        gyro_angle[0][i] = ((sensor_var[i][6]-gyro_real_mean[0][i])) * period * GYRO_CONVERT;
        gyro_angle[1][i] = ((sensor_var[i][7]-gyro_real_mean[1][i])) * period * GYRO_CONVERT;
        gyro_angle[2][i] = ((sensor_var[i][8]-gyro_real_mean[2][i])) * period * GYRO_CONVERT;
        
        float accel_magnitude = sqrt(ax*ax + ay*ay + az*az);
                angle[0][i] = (1-alpha) * (angle[0][i] + gyro_angle[0][i]) + alpha * accel_ang_x[i];
                angle[1][i] = (1-alpha) * (angle[1][i] + gyro_angle[1][i]) + alpha * accel_ang_y[i];
                angle[2][i] = angle[2][i] + gyro_angle[2][i];

                // setting algorithm results on message variable
        complementary_filter_network.filtered_imu_network[i].linear_acceleration_x = sensor_var[i][0];
        complementary_filter_network.filtered_imu_network[i].linear_acceleration_y = sensor_var[i][1];
        complementary_filter_network.filtered_imu_network[i].linear_acceleration_z = sensor_var[i][2];
        
        complementary_filter_network.filtered_imu_network[i].angular_velocity_x = sensor_var[i][6];
        complementary_filter_network.filtered_imu_network[i].angular_velocity_y = sensor_var[i][7];
        complementary_filter_network.filtered_imu_network[i].angular_velocity_z = sensor_var[i][8];
        
        complementary_filter_network.filtered_imu_network[i].angular_displacement_x = angle[0][i];
        complementary_filter_network.filtered_imu_network[i].angular_displacement_y = angle[1][i];
        complementary_filter_network.filtered_imu_network[i].angular_displacement_z = angle[2][i];
       
        complementary_filter_network.filtered_imu_network[i].magnetometer_x = sensor_var[i][3];
        complementary_filter_network.filtered_imu_network[i].magnetometer_y = sensor_var[i][4];
        complementary_filter_network.filtered_imu_network[i].magnetometer_z = sensor_var[i][5];

        complementary_filter_network.filtered_imu_network[i].number = i;
        complementary_filter_network.filtered_imu_network[i].total_number= sensors_number;
        
        complementary_filter_network.filtered_imu_network[i].algorithm = 1;
        
        complementary_filter_network.filtered_imu_network[i].header.stamp = msg->sensors_val[i].header.stamp;
        complementary_filter_network.filtered_imu_network[i].header.frame_id = "filtered_imu_network";
        
    }
    chatter_pub.publish(complementary_filter_network);
    
}

int main(int argc, char **argv)
{   
    ros::init(argc, argv, "complementary_imu");
    n = new(ros::NodeHandle);
    ros::Subscriber sub = n->subscribe("topic_raw_data", 1000, chatterCallback);
    chatter_pub = n->advertise<imu_network::filtered_imu_network>("topic_filtered_imu", 1000);
    
    ros::spin();
    
    return 0;
}