kalman_imu_data.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 <kfilter/ekfilter.hpp>
#include <kfilter/kvector.hpp>

//messages 

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


#define MAX_MEAN_IT 64 //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;


class imuEKF_sp : public Kalman::EKFilter<double,0,false,false,false>
{
    public:
        
        imuEKF_sp() 
        {
          setDim(6, 0, 6, 3, 3);
          Period = 0.025;
        }
        
    protected:
        
        void makeA()
        {
          for (int i = 0 ; i<6 ; i++)
          {
              for(int j = 0 ; j<6 ; j++)
              {
                if(i==j) A(i,j)=1.0;
                else A(i,j) = 0.0;
              }
          }
          A(0,1) = Period;
          A(2,3) = Period;
          A(4,5) = Period;
          
        }
        void makeH()
        {
          for(int i=0;i<3;i++)
          {
              for(int j=0;j<6;j++)
              {
                H(i,j)=0.0;
              }
          }
          H(0,1)=1.0;
          H(1,3)=1.0;
          H(2,5)=1.0;
          
        }
        void makeV()
        {
          for(int i=0;i<3;i++)
          {
              for(int j=0;j<3;j++)
              {
                if(i==j) V(i,j)=1.0;
                else V(i,j)=0.0;
              }
          }
          
        }
        void makeR()
        {
          for(int i=0;i<3;i++)
          {
              for(int j=0;j<3;j++)
              {
                if(i==j) R(i,j)=75*M_PI/180; // 75 dps in rad/s
                    else R(i,j)=0.0;
              }
          }
          
        }
        void makeW()
        {
          
          for(int i=0;i<6;i++)
          {
              for(int j=0;j<6;j++)
              {
                if(i==j) W(i,j) = 1.0;
                else W(i,j) = 0.0;
              }
          }
          
        }
        void makeQ()
        {
          for(int i=0;i<6;i++)
          {
              for(int j=0;j<6;j++)
              {
                if(i==j) Q(i,j) = 1.0;
                else Q(i,j) = 0.0;
              }
          }
          
        }
        void makeProcess()
        {
          Vector x_(x.size());
          x_(0) = x(0) + x(1)*Period;
          x_(1) = x(1);
          x_(2) = x(2) + x(3)*Period;
          x_(3) = x(3);
          x_(4) = x(0) + x(5)*Period;
          x_(5) = x(5);
          
          x.swap(x_);
        }
        void makeMeasure()
        {
          Vector z(3);
          z(0)=x(1);
          z(1)=x(3);
          z(2)=x(5);
        }
        
        double Period;
        
};

vector<imuEKF_sp> kalman_imu;

imuEKF_sp::Vector _z(3);
imuEKF_sp::Vector _u;

vector<ros::Time>time_stamp;
vector<float>gyro_valx;
vector<float>gyro_valy;
vector<float>gyro_valz;

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



int sensors_number;
int first_run=0;
int marker_id;
int mean_it = 0;

imu_network::filtered_imu_network kalman_data_network;

void chatterCallback(const imu_network::sensors_network::ConstPtr& msg)
{
    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 kalman_imu_data;
          kalman_data_network.filtered_imu_network.push_back(kalman_imu_data);
          
          time_stamp.push_back(msg->sensors_val[i].header.stamp);
          gyro_valx.push_back(msg->sensors_val[i].S_Gx*GYRO_CONVERT);
          gyro_valy.push_back(msg->sensors_val[i].S_Gy*GYRO_CONVERT);
          gyro_valz.push_back(msg->sensors_val[i].S_Gz*GYRO_CONVERT);

          imuEKF_sp kalman_initializer;
          kalman_imu.push_back(kalman_initializer);
          
          imuEKF_sp::Vector _x(6);
          
          imuEKF_sp::Matrix _P0(6,6);
          
          _x(0)=0.0;
          _x(1)=0.0;
          _x(2)=0.0;
          _x(3)=0.0;
          _x(4)=0.0;
          _x(5)=0.0;
          
          for (int a = 0; a<6;a++)
          {
              for (int b=0;b<6;b++)
              {
                if (a==b) _P0(a,b)=10.3;
                else _P0(a,b)=0.0;
              }
          }
          kalman_imu[i].init(_x,_P0);
        }
        first_run = 1 ;  
        return;
    }
    
    imuEKF_sp::Vector _x(6);
    
    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++)
    {
        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;
        
        _z(0)=(msg->sensors_val[i].S_Gx-gyro_real_mean[0][i])*GYRO_CONVERT;
        _z(1)=(msg->sensors_val[i].S_Gy-gyro_real_mean[1][i])*GYRO_CONVERT;
        _z(2)=(msg->sensors_val[i].S_Gz-gyro_real_mean[0][i])*GYRO_CONVERT;
        
        kalman_imu[i].step(_u,_z);
        
        imuEKF_sp::Vector result(6);
        result = kalman_imu[i].getX();
    //storing the values inside message variables...
    kalman_data_network.filtered_imu_network[i].linear_acceleration_x = sensor_var[i][0];
    kalman_data_network.filtered_imu_network[i].linear_acceleration_y = sensor_var[i][1];
    kalman_data_network.filtered_imu_network[i].linear_acceleration_z = sensor_var[i][2];
       
    kalman_data_network.filtered_imu_network[i].angular_velocity_x = result(1);
    kalman_data_network.filtered_imu_network[i].angular_velocity_y = result(3);
    kalman_data_network.filtered_imu_network[i].angular_velocity_z = result(5);
        
    kalman_data_network.filtered_imu_network[i].angular_displacement_x = result(0);
    kalman_data_network.filtered_imu_network[i].angular_displacement_y = result(2);
    kalman_data_network.filtered_imu_network[i].angular_displacement_z = result(4);
        
    kalman_data_network.filtered_imu_network[i].magnetometer_x = sensor_var[i][3];
    kalman_data_network.filtered_imu_network[i].magnetometer_y = sensor_var[i][4];
    kalman_data_network.filtered_imu_network[i].magnetometer_z = sensor_var[i][5];
        
    kalman_data_network.filtered_imu_network[i].number= i;
    kalman_data_network.filtered_imu_network[i].total_number=sensors_number;
        
    kalman_data_network.filtered_imu_network[i].algorithm = 0;
    
    kalman_data_network.filtered_imu_network[i].header.stamp = msg->sensors_val[i].header.stamp;
    kalman_data_network.filtered_imu_network[i].header.frame_id = "filtered_imu_network";
        
    }
    chatter_pub.publish(kalman_data_network);
    
}

int main(int argc, char **argv)
{   
    ros::init(argc, argv, "kalman_imu_raw");
    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;
}