在感測真實物體的姿態時，我們會使用到 MPU 6050來感測當前姿態，今天我會透過六軸慣性感測器來感測物件的動作。我們知道 MPU6050 包含三軸陀螺儀、三軸加速度計，可以當作任何姿態感測使用，但因為今天並非包含磁力計，無法修正該計算時的偏移量，因此可能無法非常的精準。但若環境中沒有過多的軟磁與硬磁的干擾就沒關係。我們今天就會使用 MPU6050 來當作我們今天飛機的飛行姿態使用，今天是個非常有趣的實作，讓我們就直接開始!!!
首先我們設計一下場景與我們的飛機模型。
將我們的 Camea 放置在該 Plane 上面。調整一下它的位置。注意視角會在飛機的後方。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlaneFly : MonoBehaviour
{
public float flySpeed = 10f;
//public float turnSpeed = 100f;
void Update()
{
transform.position += transform.forward * Time.deltaTime * 1f * flySpeed;
//transform.Rotate(0, 1f * Time.deltaTime * turnSpeed, 0f, Space.Self);
}
}
#include "MPU6050_6Axis_MotionApps20.h"
//#include "MPU6050.h" // not necessary if using MotionApps include file
// Arduino Wire library is required if I2Cdev I2CDEV_ARDUINO_WIRE implementation
// is used in I2Cdev.h
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
#include "Wire.h"
#endif
// class default I2C address is 0x68
// specific I2C addresses may be passed as a parameter here
// AD0 low = 0x68 (default for SparkFun breakout and InvenSense evaluation board)
// AD0 high = 0x69
MPU6050 mpu;
// uncomment "OUTPUT_READABLE_QUATERNION" if you want to see the actual
// quaternion components in a [w, x, y, z] format (not best for parsing
// on a remote host such as Processing or something though)
//#define OUTPUT_READABLE_QUATERNION
// uncomment "OUTPUT_READABLE_EULER" if you want to see Euler angles
// (in degrees) calculated from the quaternions coming from the FIFO.
// Note that Euler angles suffer from gimbal lock (for more info, see
// http://en.wikipedia.org/wiki/Gimbal_lock)
//#define OUTPUT_READABLE_EULER
// uncomment "OUTPUT_READABLE_YAWPITCHROLL" if you want to see the yaw/
// pitch/roll angles (in degrees) calculated from the quaternions coming
// from the FIFO. Note this also requires gravity vector calculations.
// Also note that yaw/pitch/roll angles suffer from gimbal lock (for
// more info, see: http://en.wikipedia.org/wiki/Gimbal_lock)
#define OUTPUT_READABLE_YAWPITCHROLL
// uncomment "OUTPUT_READABLE_REALACCEL" if you want to see acceleration
// components with gravity removed. This acceleration reference frame is
// not compensated for orientation, so +X is always +X according to the
// sensor, just without the effects of gravity. If you want acceleration
// compensated for orientation, us OUTPUT_READABLE_WORLDACCEL instead.
//#define OUTPUT_READABLE_REALACCEL
// uncomment "OUTPUT_READABLE_WORLDACCEL" if you want to see acceleration
// components with gravity removed and adjusted for the world frame of
// reference (yaw is relative to initial orientation, since no magnetometer
// is present in this case). Could be quite handy in some cases.
//#define OUTPUT_READABLE_WORLDACCEL
// uncomment "OUTPUT_TEAPOT" if you want output that matches the
// format used for the InvenSense teapot demo
//#define OUTPUT_TEAPOT
#define INTERRUPT_PIN 2 // use pin 2 on Arduino Uno & most boards
#define LED_PIN 13 // (Arduino is 13, Teensy is 11, Teensy++ is 6)
float yaw_offset, pitch_offset, row_offset;
float yawArr, pitchArr, rowArr;
int i = 0;
bool blinkState = false;
// MPU control/status vars
bool dmpReady = false; // set true if DMP init was successful
uint8_t mpuIntStatus; // holds actual interrupt status byte from MPU
uint8_t devStatus; // return status after each device operation (0 = success, !0 = error)
uint16_t packetSize; // expected DMP packet size (default is 42 bytes)
uint16_t fifoCount; // count of all bytes currently in FIFO
uint8_t fifoBuffer[64]; // FIFO storage buffer
// orientation/motion vars
Quaternion q; // [w, x, y, z] quaternion container
VectorInt16 aa; // [x, y, z] accel sensor measurements
VectorInt16 aaReal; // [x, y, z] gravity-free accel sensor measurements
VectorInt16 aaWorld; // [x, y, z] world-frame accel sensor measurements
VectorFloat gravity; // [x, y, z] gravity vector
float euler[3]; // [psi, theta, phi] Euler angle container
float ypr[3]; // [yaw, pitch, roll] yaw/pitch/roll container and gravity vector
// packet structure for InvenSense teapot demo
uint8_t teapotPacket[14] = { '$', 0x02, 0,0, 0,0, 0,0, 0,0, 0x00, 0x00, '\r', '\n' };
// ================================================================
// === INTERRUPT DETECTION ROUTINE ===
// ================================================================
volatile bool mpuInterrupt = false; // indicates whether MPU interrupt pin has gone high
void dmpDataReady() {
mpuInterrupt = true;
}
// ================================================================
// === INITIAL SETUP ===
// ================================================================
void setup() {
// join I2C bus (I2Cdev library doesn't do this automatically)
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
Wire.begin();
Wire.setClock(400000); // 400kHz I2C clock. Comment this line if having compilation difficulties
#elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
Fastwire::setup(400, true);
#endif
// initialize serial communication
// (115200 chosen because it is required for Teapot Demo output, but it's
// really up to you depending on your project)
Serial.begin(115200);
while (!Serial); // wait for Leonardo enumeration, others continue immediately
// NOTE: 8MHz or slower host processors, like the Teensy @ 3.3V or Arduino
// Pro Mini running at 3.3V, cannot handle this baud rate reliably due to
// the baud timing being too misaligned with processor ticks. You must use
// 38400 or slower in these cases, or use some kind of external separate
// crystal solution for the UART timer.
// initialize device
//Serial.println(F("Initializing I2C devices..."));
mpu.initialize();
pinMode(INTERRUPT_PIN, INPUT);
// verify connection
//Serial.println(F("Testing device connections..."));
//Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));
// wait for ready
//Serial.println(F("\nSend any character to begin DMP programming and demo: "));
//while (Serial.available() && Serial.read()); // empty buffer
//while (!Serial.available()); // wait for data
//while (Serial.available() && Serial.read()); // empty buffer again
// load and configure the DMP
//Serial.println(F("Initializing DMP..."));
devStatus = mpu.dmpInitialize();
// supply your own gyro offsets here, scaled for min sensitivity
mpu.setXGyroOffset(220);
mpu.setYGyroOffset(76);
mpu.setZGyroOffset(-85);
mpu.setZAccelOffset(1788); // 1688 factory default for my test chip
// make sure it worked (returns 0 if so)
if (devStatus == 0) {
// Calibration Time: generate offsets and calibrate our MPU6050
mpu.CalibrateAccel(6);
mpu.CalibrateGyro(6);
mpu.PrintActiveOffsets();
// turn on the DMP, now that it's ready
// Serial.println(F("Enabling DMP..."));
mpu.setDMPEnabled(true);
// enable Arduino interrupt detection
//Serial.print(F("Enabling interrupt detection (Arduino external interrupt "));
//Serial.print(digitalPinToInterrupt(INTERRUPT_PIN));
//Serial.println(F(")..."));
attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), dmpDataReady, RISING);
mpuIntStatus = mpu.getIntStatus();
// set our DMP Ready flag so the main loop() function knows it's okay to use it
//Serial.println(F("DMP ready! Waiting for first interrupt..."));
dmpReady = true;
// get expected DMP packet size for later comparison
packetSize = mpu.dmpGetFIFOPacketSize();
} else {
// ERROR!
// 1 = initial memory load failed
// 2 = DMP configuration updates failed
// (if it's going to break, usually the code will be 1)
Serial.print(F("DMP Initialization failed (code "));
Serial.print(devStatus);
Serial.println(F(")"));
}
// configure LED for output
pinMode(LED_PIN, OUTPUT);
}
// ================================================================
// === MAIN PROGRAM LOOP ===
// ================================================================
void loop() {
// if programming failed, don't try to do anything
if (!dmpReady) return;
// read a packet from FIFO
if (mpu.dmpGetCurrentFIFOPacket(fifoBuffer)) { // Get the Latest packet
#ifdef OUTPUT_READABLE_QUATERNION
// display quaternion values in easy matrix form: w x y z
mpu.dmpGetQuaternion(&q, fifoBuffer);
Serial.print("quat\t");
Serial.print(q.w);
Serial.print("\t");
Serial.print(q.x);
Serial.print("\t");
Serial.print(q.y);
Serial.print("\t");
Serial.println(q.z);
#endif
#ifdef OUTPUT_READABLE_EULER
// display Euler angles in degrees
mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetEuler(euler, &q);
Serial.print("euler\t");
Serial.print(euler[0] * 180/M_PI);
Serial.print("\t");
Serial.print(euler[1] * 180/M_PI);
Serial.print("\t");
Serial.println(euler[2] * 180/M_PI);
#endif
#ifdef OUTPUT_READABLE_YAWPITCHROLL
// display Euler angles in degrees
mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetGravity(&gravity, &q);
mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);
//Serial.print("yaw: ");
Serial.print(ypr[0] * 180/M_PI - yaw_offset );
Serial.print(",");
yawArr += ypr[0];
//Serial.print("\tPitch: ");
Serial.print(ypr[1] * 180/M_PI - pitch_offset);
Serial.print(",");
pitchArr += ypr[1];
//Serial.print("\tRaw: ");
Serial.println(ypr[2] * 180/M_PI - row_offset);
rowArr += ypr[2];
i++;
if(i == 10)
{
yaw_offset = yawArr / 10;
pitch_offset = pitchArr / 10;
row_offset = rowArr / 10;
/*Serial.println("yaw offset: ");
Serial.print(yaw_offset);
Serial.println("pitch offset: ");
Serial.print(pitch_offset);
Serial.println("row offset: ");
Serial.print(row_offset);
Serial.println();*/
i = 0;
yawArr = 0;
pitchArr = 0;
rowArr = 0;
}
#endif
#ifdef OUTPUT_READABLE_REALACCEL
// display real acceleration, adjusted to remove gravity
mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetAccel(&aa, fifoBuffer);
mpu.dmpGetGravity(&gravity, &q);
mpu.dmpGetLinearAccel(&aaReal, &aa, &gravity);
Serial.print("areal\t");
Serial.print(aaReal.x);
Serial.print("\t");
Serial.print(aaReal.y);
Serial.print("\t");
Serial.println(aaReal.z);
#endif
#ifdef OUTPUT_READABLE_WORLDACCEL
// display initial world-frame acceleration, adjusted to remove gravity
// and rotated based on known orientation from quaternion
mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetAccel(&aa, fifoBuffer);
mpu.dmpGetGravity(&gravity, &q);
mpu.dmpGetLinearAccel(&aaReal, &aa, &gravity);
mpu.dmpGetLinearAccelInWorld(&aaWorld, &aaReal, &q);
Serial.print("aworld\t");
Serial.print(aaWorld.x);
Serial.print("\t");
Serial.print(aaWorld.y);
Serial.print("\t");
Serial.println(aaWorld.z);
#endif
#ifdef OUTPUT_TEAPOT
// display quaternion values in InvenSense Teapot demo format:
teapotPacket[2] = fifoBuffer[0];
teapotPacket[3] = fifoBuffer[1];
teapotPacket[4] = fifoBuffer[4];
teapotPacket[5] = fifoBuffer[5];
teapotPacket[6] = fifoBuffer[8];
teapotPacket[7] = fifoBuffer[9];
teapotPacket[8] = fifoBuffer[12];
teapotPacket[9] = fifoBuffer[13];
Serial.write(teapotPacket, 14);
teapotPacket[11]++; // packetCount, loops at 0xFF on purpose
#endif
// blink LED to indicate activity
blinkState = !blinkState;
digitalWrite(LED_PIN, blinkState);
delay(50);
}
}
接下來我們就將其執行看一下結果如何。結果如下 x, y, z 軸旋轉的結果。但其實基本是 yaw, pitch, roll 。
我們要先知道該實體的轉動方向，我這邊上照片讓大家瞭解一下。
首先新增兩個 Port 開啟與關閉的按鈕，同時我們要顯示該 yaw, pitch, roll 所以這邊我們先設計好 UI。這邊我設計得有些複雜，看個人喜歡進行設計就好。
開始撰寫獲取當前 yaw, pitch, roll 的方法。並且跟昨天一樣控制 Port 的開啟、關閉。我這邊廢話不多說直接上程式碼XDDD。我會提供一些有幫助的註解。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using System;
using System.IO.Ports;
using System.Threading;
using System.Globalization;
public class PlaneFly : MonoBehaviour
{
public float flySpeed = 10f;
public float turnSpeed = 100f;
public Text yaw; // show the yaw value
public Text pitch; // show the pitch value
public Text roll; // show the roll value
float[] yprflt = new float[3]; // store the yaw pitch roll float value
string[] yprstr = new string[3]; // store the yaw pitch roll string value
// port control
string portName = "COM7";
int baudRate = 115200; // need to change the baudRate!
Parity parity = Parity.None;
int dataBits = 8;
StopBits stopBits = StopBits.One;
SerialPort serialPort = null;
[SerializeField]
public int isClosedPort = 1;
void Start()
{
OpenPort();
}
void Update()
{
ReadData();
transform.position += transform.forward * Time.deltaTime * 1f * flySpeed;
//transform.Rotate(0, 1f * Time.deltaTime * turnSpeed, 0f, Space.Self);
ObjectRotation(); // set the obj rotation
}
public void OpenPort()
{
serialPort = new SerialPort(portName, baudRate, parity, dataBits,stopBits);
try{
serialPort.Open();
Debug.Log("Open port success!");
}catch(Exception ex)
{
Debug.Log(ex.Message);
}
}
public void ClosePort()
{
try{
serialPort.Close();
}catch(Exception ex)
{
Debug.Log(ex.Message);
}
}
public void ReadData()
{
if(serialPort.IsOpen)
{
string getypr = serialPort.ReadExisting(); //get the arduino output
Debug.Log(getypr);
yprstr = getypr.Split(','); // need to split the string and store to ypystr array
if(yprstr.Length == 3)
{
yaw.text = yprstr[0];
pitch.text = yprstr[1];
roll.text = yprstr[2];
}else{
Debug.LogWarning("Length is not correct!");
}
for(int i=0; i < yprstr.Length; i++)
{
yprflt[i] = float.Parse(yprstr[i]); // change string to float
}
// Thread.Sleep(50);
}
}
public void ObjectRotation()
{
transform.rotation = Quaternion.Euler(-yprflt[1], yprflt[0], -yprflt[2]);
}
}
回到 Unity 中將我們的 Button 、Text 設定好。
我們再次調整一下我們飛機的起始距離與飛行速度。 如下設計:
我們執行看看，看到飛機會往前飛行~~根據我 Yaw 旋轉的來調整飛行的方向。底下的為 yaw, pitch, roll 的數值。但還是會有些偏移，畢竟沒有加上濾波器 : >。挺有趣的XDD，最後的結果如下:
iThome鐵人賽
看影片追技術