10種簡單的數字濾波算法(C語言源程序)

假定從8位AD中讀取數據（如果是更高位的AD可定義數據類型為int）,子程序為get_ad();?
1、限副濾波
/*? A值可根據實際情況調整
??? value為有效值，new_value為當前采樣值??
??? 濾波程序返回有效的實際值? */
#define A 10
char value;
char filter()
{
?? char? new_value;
?? new_value = get_ad();
?? if ( ( new_value - value > A ) || ( value - new_value > A )
????? return value;
?? return new_value;
}
2、中位值濾波法
/*? N值可根據實際情況調整
??? 排序采用冒泡法*/
#define N? 11
char filter()
{
?? char value_buf[N];
?? char count,i,j,temp;
?? for ( count=0;count?? {
????? value_buf[count] = get_ad();
????? delay();
?? }
?? for (j=0;j?? {
????? for (i=0;i????? {
???????? if ( value_buf[i]>value_buf[i+1] )
???????? {
??????????? temp = value_buf[i];
??????????? value_buf[i] = value_buf[i+1];?
???????????? value_buf[i+1] = temp;
???????? }
????? }
?? }
?? return value_buf[(N-1)/2];
}?????
3、算術平均濾波法
/*
*/
#define N 12
char filter()
{
?? int? sum = 0;
?? for ( count=0;count?? {
????? sum + = get_ad();
????? delay();
?? }
?? return (char)(sum/N);
}
4、遞推平均濾波法（又稱滑動平均濾波法）
/*
*/
#define N 12?
char value_buf[N];
char i=0;
char filter()
{
?? char count;
?? int? sum=0;
?? value_buf[i++] = get_ad();
?? if ( i == N )?? i = 0;
?? for ( count=0;count????? sum = value_buf[count];
?? return (char)(sum/N);
}
5、中位值平均濾波法（又稱防脈沖干擾平均濾波法）
/*
*/
#define N 12
char filter()
{
?? char count,i,j;
?? char value_buf[N];
?? int? sum=0;
?? for? (count=0;count?? {
????? value_buf[count] = get_ad();
????? delay();
?? }
?? for (j=0;j?? {
????? for (i=0;i????? {
???????? if ( value_buf[i]>value_buf[i+1] )
???????? {
??????????? temp = value_buf[i];
??????????? value_buf[i] = value_buf[i+1];?
???????????? value_buf[i+1] = temp;
???????? }
????? }
?? }
?? for(count=1;count????? sum += value[count];
?? return (char)(sum/(N-2));
}
6、限幅平均濾波法
/*
*/??
略 參考子程序1、3
7、一階滯后濾波法
/* 為加快程序處理速度假定基數為100，a=0~100 */
#define a 50
char value;
char filter()
{
?? char? new_value;
?? new_value = get_ad();
?? return (100-a)*value + a*new_value;?
}
8、加權遞推平均濾波法
/* coe數組為加權系數表，存在程序存儲區。*/
#define N 12
char code coe[N] = {1,2,3,4,5,6,7,8,9,10,11,12};
char code sum_coe = 1+2+3+4+5+6+7+8+9+10+11+12;
char filter()
{
?? char count;
?? char value_buf[N];
?? int? sum=0;
?? for (count=0,count?? {
????? value_buf[count] = get_ad();
????? delay();
?? }
?? for (count=0,count????? sum += value_buf[count]*coe[count];
?? return (char)(sum/sum_coe);
}
9、消抖濾波法
#define N 12
char filter()
{
?? char count=0;
?? char new_value;
?? new_value = get_ad();
?? while (value !=new_value);
?? {
????? count++;
????? if (count>=N)?? return new_value;
?????? delay();
????? new_value = get_ad();
?? }
?? return value;????
}
10、限幅消抖濾波法
/*
*/
略 參考子程序1、9