IMUs

IMUs

IMU stands for Inertial Measurment Unit. While a motor encoder can be used to find how far you’ve traveled, an IMU can tell you which way the robot is facing, if it is turning, or if it is about to tip over. In VEX Robotics, the V5 3-axis Inertial Sensor combines a 3-axis gyroscope and a 3-axis accelerometer into one compact smart sensor.

How it works

Inside the IMU is a microscopic silicon chip known as a MEMS (Micro-Electro-Mechanical Systems) sensor. This chip contains small internal structures that flex and move when the robot accelerates of rotates. The IMU tracks movement across 2 sensor types:

• The Accelerometer (Linear Motion): This measures changes in speed along straight lines. Because gravity is a constant downward acceleration, the accelerometer always knows which direction is down, helping the robot stay balanced.
• The Gyroscope (Rotational Motion): This measures how fast the robot is twisting or spinning around an axis.

Picture

By combining these 2 streams of data many times per second, the IMU can calculate the robots orientation in 3D space.

Math