# iOS中陀螺儀CoreMotion的用法
標(biāo)簽（空格分隔）： iOS常見疑惑解決
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以前在iphone中要得到加速度時(shí)吆倦，只能使用Accelerometer模塊得到重力加速度分量听诸，然后通過濾波得到加速度值。其實(shí)在ios中有一個(gè)陀螺儀模塊蚕泽，CoreMotion晌梨，使用更方便。
deviceMotion.m 外部引用 原始文檔
//初始化CoreMotion
CMMotionManager *motionManager = [[CMMotionManager alloc]init];
1. Accelerometer 獲取手機(jī)加速度數(shù)據(jù)
CMAccelerometerData *newestAccel = motionManager.accelerometerData;
double accelerationX = newestAccel.acceleration.x;
double accelerationY = newestAccel.acceleration.y;
double accelerationZ = newestAccel.acceleration.z;
2. Gravity 獲取手機(jī)的重力值在各個(gè)方向上的分量须妻，根據(jù)這個(gè)就可以獲得手機(jī)的空間位置仔蝌，傾斜角度等
double gravityX = motionManager.deviceMotion.gravity.x;
double gravityY = motionManager.deviceMotion.gravity.y;
double gravityZ = motionManager.deviceMotion.gravity.z;
//獲取手機(jī)的傾斜角度：
double zTheta = atan2(gravityZ,sqrtf(gravityX*gravityX+gravityY*gravityY))/M_PI*180.0;
double xyTheta = atan2(gravityX,gravityY)/M_PI*180.0;
//zTheta是手機(jī)與水平面的夾角， xyTheta是手機(jī)繞自身旋轉(zhuǎn)的角度
3. DeviceMotion 獲取陀螺儀的數(shù)據(jù) 包括角速度荒吏，空間位置等
//旋轉(zhuǎn)角速度：
CMRotationRate rotationRate = motionManager.deviceMotion.rotationRate;
double rotationX = rotationRate.x;
double rotationY = rotationRate.y;
double rotationZ = rotationRate.z;
//空間位置的歐拉角（通過歐拉角可以算得手機(jī)兩個(gè)時(shí)刻之間的夾角敛惊，比用角速度計(jì)算精確地多）
double roll = motionManager.deviceMotion.attitude.roll;
double pitch = motionManager.deviceMotion.attitude.pitch;
double yaw = motionManager.deviceMotion.attitude.yaw;
//空間位置的四元數(shù)（與歐拉角類似，但解決了萬向結(jié)死鎖問題）
double w = motionManager.deviceMotion.attitude.quaternion.w;
double wx = motionManager.deviceMotion.attitude.quaternion.x;
double wy = motionManager.deviceMotion.attitude.quaternion.y;
double wz = motionManager.deviceMotion.attitude.quaternion.z;
//通過陀螺儀模塊可以實(shí)現(xiàn)模擬賽車绰更，模擬射擊等瞧挤。
