MPU6050 6-DOF IMU & Complementary Sensor Fusion

1. Overview & Concept Definition

A Micro-Electro-Mechanical System (MEMS) integrating a 3-axis capacitive accelerometer and a 3-axis rate-of-turn gyroscope with an internal Digital Motion Processor (DMP).

2. Engineering & Industrial Significance

Provides spatial orientation, tilt angle, angular velocity, and inertial acceleration for self-balancing robots, quadcopters, and humanoid motion tracking.

3. Physical Working Principle & Transducer Dynamics

Accelerometers measure both linear dynamic acceleration and static gravitational vector $1g$ using micro-machined capacitive finger structures. Gyroscopes utilize the Coriolis force on vibrating proof masses to measure angular velocity $\omega$. Gyro integration accumulates drift error over time, while accelerometers are noisy due to mechanical vibrations. A Complementary Filter blends high-frequency gyro data with low-frequency gravity-referenced accelerometer tilt.

// C++ Complementary Filter implementation for Pitch
float pitch = 0.0f;
unsigned long lastTime = 0;

float updateComplementaryPitch(float accelX, float accelZ, float gyroRateY) {
    unsigned long now = micros();
    float dt = (now - lastTime) / 1000000.0f;
    lastTime = now;
    if (dt > 0.1f) dt = 0.01f; // Prevent startup spike

    float accelPitch = atan2(-accelX, accelZ) * 57.29578f;
    const float alpha = 0.98f;
    pitch = alpha * (pitch + gyroRateY * dt) + (1.0f - alpha) * accelPitch;
    return pitch;
}

6. Common Engineering Pitfalls & Troubleshooting

7. Applications & Physical Constraints