我用arduino uno和mpu6050控制sg90舵机 ，使舵机随着mpu6050的转动而转动，代码范围设置的是0-90°，传感器转动时，舵机可以跟着转动，但是传感器一停下，舵机就自动回归原位。求解。
```#include "Wire.h"
#include "I2Cdev.h"
#include "MPU6050.h"
/*舵机*/#include <Servo.h>
Servo myservo; //创建一个舵机控制对象
MPU6050 accelgyro;
unsigned long now,
lastTime = 0;float dt; //微分时间
int16_t ax, ay, az, gx, gy, gz; //加速度计和陀螺仪的原始数据
float aax=0, aay=0,aaz=0, agx=0, agy=0, agz=0; //角度变量
long axo = 0, ayo = 0, azo = 0; //加速度计偏移量
long gxo = 0, gyo = 0, gzo = 0; //陀螺仪偏移量
float pi = 3.1415926; float AcceRatio = 16384.0; //加速度计比例系数
float GyroRatio = 131.0; //陀螺仪比例系数
uint8_t n_sample = 8; //加速度计滤波算法采样个数
float aaxs[8] = {0}, aays[8] = {0}, aazs[8] = {0}; //x,y轴采样队列
long aax_sum, aay_sum,aaz_sum; //x,y轴采样和
float a_x[10]={0}, a_y[10]={0},a_z[10]={0} ,g_x[10]={0} ,g_y[10]={0},g_z[10]={0};
float Px=1, Rx, Kx, Sx, Vx, Qx; //x轴卡尔曼变量float Py=1, Ry, Ky, Sy, Vy, Qy; //y轴卡尔曼变量
float Pz=1, Rz, Kz, Sz, Vz, Qz; //z轴卡尔曼变量int16_t value; //定义一个整形变量用于存放读取到的信号值
bool blinkState = false;
void setup(){
Wire.begin(); Serial.begin(115200);
accelgyro.initialize(); //初始化 unsigned short times = 200; //采样次数
for(int i=0;i<times;i++)
{ accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz); //读取六轴原始数值
axo += ax; ayo += ay; azo += az;
gxo += gx; gyo += gy; gzo += gz; }
axo /= times; ayo /= times; azo /= times; //计算加速度计偏移
gxo /= times; gyo /= times; gzo /= times; //计算陀螺仪偏移
Serial.println("Initializing I2C devices..."); //显示变量名
accelgyro.initialize();
Serial.println("Testing device connections..."); //显示通信连接名
Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed"); //显示传感器是否成功连接
myservo.attach(9); // 该舵机由arduino第九脚控制}
void loop(){
unsigned long now = millis(); //当前时间
dt = (now - lastTime) / 1000.0; //微分时间
lastTime = now; //上一次采样时间 accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz); //读取六轴原始数值
float accx = ax / AcceRatio; //x轴加速度
float accy = ay / AcceRatio; //y轴加速度
float accz = az / AcceRatio; //z轴加速度 aax = atan(accy / accz) * (-180) / pi; //y轴对于z轴的夹角
aay = atan(accx / accz) * 180 / pi; //x轴对于z轴的夹角
aaz = atan(accz / accy) * 180 / pi; //z轴对于y轴的夹角
aax_sum = 0; // 对于加速度计原始数据的滑动加权滤波算法
aay_sum = 0; aaz_sum = 0;
for(int i=1;i<n_sample;i++)
{
aaxs[i-1] = aaxs[i];
aax_sum += aaxs[i] * i;
aays[i-1] = aays[i];
aay_sum += aays[i] * i;
aazs[i-1] = aazs[i];
aaz_sum += aazs[i] * i; }
aaxs[n_sample-1] = aax;
aax_sum += aax * n_sample;
aax = (aax_sum / (11*n_sample/2.0)) * 9 / 7.0; //角度调幅至0-90°
aays[n_sample-1] = aay; //此处应用实验法取得合适的系数
aay_sum += aay * n_sample; //本例系数为9/7
aay = (aay_sum / (11*n_sample/2.0)) * 9 / 7.0;
aazs[n_sample-1] = aaz;
aaz_sum += aaz * n_sample;
aaz = (aaz_sum / (11*n_sample/2.0)) * 9 / 7.0;
float gyrox = - (gx-gxo) / GyroRatio * dt; //x轴角速度
float gyroy = - (gy-gyo) / GyroRatio * dt; //y轴角速度
float gyroz = - (gz-gzo) / GyroRatio * dt; //z轴角速度
agx += gyrox; //x轴角速度积分
agy += gyroy; //y轴角速度积分
agz += gyroz;
/* kalman start */ Sx = 0; Rx = 0; Sy = 0; Ry = 0; Sz = 0; Rz = 0;
for(int i=1;i<10;i++)
{
//测量值平均值运算
a_x[i-1] = a_x[i]; //即加速度平均值 Sx += a_x[i]; a_y[i-1] = a_y[i]; Sy += a_y[i]; a_z[i-1] = a_z[i]; Sz += a_z[i]; } a_x[9] = aax;
Sx += aax; Sx /= 10; //x轴加速度平均值
a_y[9] = aay; Sy += aay; Sy /= 10; //y轴加速度平均值
a_z[9] = aaz; Sz += aaz; Sz /= 10;
for(int i=0;i<10;i++)
{
Rx += sq(a_x[i] - Sx); Ry += sq(a_y[i] - Sy); Rz += sq(a_z[i] - Sz); } Rx = Rx / 9; //得到方差 Ry = Ry / 9;
Rz = Rz / 9; Px = Px + 0.0025; // 0.0025在下面有说明...
Kx = Px / (Px + Rx); //计算卡尔曼增益 agx = agx + Kx * (aax - agx); //陀螺仪角度与加速度计速度叠加
Px = (1 - Kx) * Px; //更新p值
Py = Py + 0.0025; Ky = Py / (Py + Ry); agy = agy + Ky * (aay - agy); Py = (1 - Ky) * Py; Pz = Pz + 0.0025; Kz = Pz / (Pz + Rz); agz = agz + Kz * (aaz - agz); Pz = (1 - Kz) * Pz;
Serial.print(agx);Serial.print(",");
Serial.print(agy);Serial.print(",");
Serial.print(agz);Serial.println();
myservo.write(agx); // 指定舵机转向的角度
delay(15);
-
```