//离散随机线性系统的卡尔曼滤波
#include "stdio.h"
#include "math.h"
#include "stdlib.h"
int klman(int n,int m,int k,double f[],double q[], double r[],
double h[],double y[],double x[],double p[],double g[]);
static void keklm5(int n,double y[]);
int brinv(double a[],int n);
main()
{ int i,j,js;
void keklm5();
double p[3][3],x[200][3],y[200][1],g[3][1],t,s;
static double f[3][3]={{1.0,0.05,0.00125},
{0.0,1.0,0.05},
{0.0,0.0,1.0}};
static double q[3][3]={{0.25,0.0,0.0},
{0.0,0.25,0.0},
{0.0,0.0,0.25}};
static double r[1][1]={{0.25}};
static double h[1][3]={{1.0,0.0,0.0}};
for (i=0; i<=2; i++)
for (j=0; j<=2; j++) p[i][j]=0.0;
for (i=0; i<=199; i++)
for (j=0; j<=2; j++) x[i][j]=0.0;
keklm5(200,*y); //产生长度200的高斯序列
for (i=0; i<=199; i++)
{ t=0.05*i;
y[i][0]=5.0-2.0*t+3.0*t*t+y[i][0]; }
js=klman(3,1,200,*f,*q,*r,*h,*y,*x,*p,*g); //卡尔曼滤波
if (js!=0)
{ printf("\n");
printf(" t s y ");
printf("x(0) x[1] x(2) \n");
for (i=0; i<=199; i=i+5)
{ t=0.05*i; s=5.0-2.0*t+3.0*t*t;
printf("%6.2f %e %e %e %e %e\n",
t,s,y[i][0],x[i][0],x[i][1],x[i][2]); }
printf("\ninput i:");
scanf("%d",i);
}
return;
}
static void keklm5(int n,double y[]) //产生均值为0,方差为0.5^2的高斯白噪声序列
{ int i,j,m; //n为序列长度,y[]返回序列的首地址
double s,w,v,r,t;
s=65536.0; w=2053.0; v=13849.0; r=0.0;
for (i=0; i<=n-1; i++)
{ t=0.0;
for (j=0; j<=11; j++)
{ r=w*r+v; m=r/s; r=r-m*s; t=t+r/s;}
y[i]=0.5*(t-6.0);
}
return;
}
int klman(int n,int m,int k,double f[],double q[], double r[],
double h[],double y[],double x[],double p[],double g[])
{ int i,j,kk,ii,l,jj,js; //卡尔曼滤波函数
double *e,*a,*b;
extern int brinv();
e=malloc(m*m*sizeof(double));
l=m;
if (l<n) l=n;
a=malloc(l*l*sizeof(double));
b=malloc(l*l*sizeof(double));
for (i=0; i<=n-1; i++)
for (j=0; j<=n-1; j++)
{ ii=i*l+j; a[ii]=0.0;
for (kk=0; kk<=n-1; kk++)
a[ii]=a[ii]+p[i*n+kk]*f[j*n+kk];
}
for (i=0; i<=n-1; i++)
for (j=0; j<=n-1; j++)
{ ii=i*n+j; p[ii]=q[ii];
for (kk=0; kk<=n-1; kk++)
p[ii]=p[ii]+f[i*n+kk]*a[kk*l+j];
}
for (ii=2; ii<=k; ii++)
{ for (i=0; i<=n-1; i++)
for (j=0; j<=m-1; j++)
{ jj=i*l+j; a[jj]=0.0;
for (kk=0; kk<=n-1; kk++)
a[jj]=a[jj]+p[i*n+kk]*h[j*n+kk];
}
for (i=0; i<=m-1; i++)
for (j=0; j<=m-1; j++)
{ jj=i*m+j; e[jj]=r[jj];
for (kk=0; kk<=n-1; kk++)
e[jj]=e[jj]+h[i*n+kk]*a[kk*l+j];
}
js=brinv(e,m); //矩阵e求e_1
if (js==0)
{ free(e); free(a); free(b); return(js);}
for (i=0; i<=n-1; i++)
for (j=0; j<=m-1; j++)
{ jj=i*m+j; g[jj]=0.0;
for (kk=0; kk<=m-1; kk++)
g[jj]=g[jj]+a[i*l+kk]*e[j*m+kk];
}
for (i=0; i<=n-1; i++)
{ jj=(ii-1)*n+i; x[jj]=0.0;
for (j=0; j<=n-1; j++)
x[jj]=x[jj]+f[i*n+j]*x[(ii-2)*n+j];
}
for (i=0; i<=m-1; i++)
{ jj=i*l; b[jj]=y[(ii-1)*m+i];
for (j=0; j<=n-1; j++)
b[jj]=b[jj]-h[i*n+j]*x[(ii-1)*n+j];
}
for (i=0; i<=n-1; i++)
{ jj=(ii-1)*n+i;
for (j=0; j<=m-1; j++)
x[jj]=x[jj]+g[i*m+j]*b[j*l];
}
if (ii<k)
{ for (i=0; i<=n-1; i++)
for (j=0; j<=n-1; j++)
{ jj=i*l+j; a[jj]=0.0;
for (kk=0; kk<=m-1; kk++)
a[jj]=a[jj]-g[i*m+kk]*h[kk*n+j];
if (i==j) a[jj]=1.0+a[jj];
}
for (i=0; i<=n-1; i++)
for (j=0; j<=n-1; j++)
{ jj=i*l+j; b[jj]=0.0;
for (kk=0; kk<=n-1; kk++)
b[jj]=b[jj]+a[i*l+kk]*p[kk*n+j];
}
for (i=0; i<=n-1; i++)
for (j=0; j<=n-1; j++)
{ jj=i*l+j; a[jj]=0.0;
for (kk=0; kk<=n-1; kk++)
a[jj]=a[jj]+b[i*l+kk]*f[j*n+kk];
}
for (i=0; i<=n-1; i++)
for (j=0; j<=n-1; j++)
{ jj=i*n+j; p[jj]=q[jj];
for (kk=0; kk<=n-1; kk++)
p[jj]=p[jj]+f[i*n+kk]*a[j*l+kk];
}
}
}
free(e); free(a); free(b);
return(js);
}
int brinv(double a[],int n) //实矩阵A求A_1
{ int *is,*js,i,j,k,l,u,v; //函数返回标志值,若返回0,则矩阵奇异
double d,p; //若返回不为0,则表示正常返回
is=malloc(n*sizeof(int)); //a双精度二维数组,n*n存放原矩阵,返回A_1
js=malloc(n*sizeof(int)); //n矩阵a的阶数
for (k=0; k<=n-1; k++)
{ d=0.0;
for (i=k; i<=n-1; i++)
for (j=k; j<=n-1; j++)
{ l=i*n+j; p=fabs(a[l]);
if (p>d) { d=p; is[k]=i; js[k]=j;}
}
if (d+1.0==1.0)
{ free(is); free(js); printf("err**not inv\n");
return(0);
}
if (is[k]!=k)
for (j=0; j<=n-1; j++)
{ u=k*n+j; v=is[k]*n+j;
p=a[u]; a[u]=a[v]; a[v]=p;
}
if (js[k]!=k)
for (i=0; i<=n-1; i++)
{ u=i*n+k; v=i*n+js[k];
p=a[u]; a[u]=a[v]; a[v]=p;
}
l=k*n+k;
a[l]=1.0/a[l];
for (j=0; j<=n-1; j++)
if (j!=k)
{ u=k*n+j; a[u]=a[u]*a[l];}
for (i=0; i<=n-1; i++)
if (i!=k)
for (j=0; j<=n-1; j++)
if (j!=k)
{ u=i*n+j;
a[u]=a[u]-a[i*n+k]*a[k*n+j];
}
for (i=0; i<=n-1; i++)
if (i!=k)
{ u=i*n+k; a[u]=-a[u]*a[l];}
}
for (k=n-1; k>=0; k--)
{ if (js[k]!=k)
for (j=0; j<=n-1; j++)
{ u=k*n+j; v=js[k]*n+j;
p=a[u]; a[u]=a[v]; a[v]=p;
}
if (is[k]!=k)
for (i=0; i<=n-1; i++)
{ u=i*n+k; v=i*n+is[k];
p=a[u]; a[u]=a[v]; a[v]=p;
}
}
free(is); free(js);
return(1);
}