IMU Sensor – Working & Its Applications

• When we talk about Robotics, sensors are the most important tools which make an interface between a machine and its surroundings. There is a vast number of sensors for dedicated purposes and different applications. Some of the most commonly used sensors out there are a current sensor, voltage sensor, speedometer, light sensor, and finally IMU sensor.

What is an IMU Sensor?

• IMU sensor, Inertia Measurement Unit is an electronic device that measures orientation, velocity, and gravitational forces exerted on a body by using 3 sensors: A gyroscope, a Magnetometer, and Accelerometer.
• I’m generally quite large, but with recent developments like MEMS(micro-electromechanical systems) technology, they are more commonly seen as miniaturized sensors designed for easy integration with Arduino or other microcontrollers.
• IMU sensors are normally used in the making of aircraft and also UAVs(unmanned aerial vehicles), satellites, and space vehicles. Nowadays, IMU-based GPS devices are manufactured for remote-controlled drones and planes.

Working Principle of IMU Sensor

• I work by detecting rotational movement of the three-axis, commonly known as Pitch, Roll, and YAW. To achieve such, it relies on the functionality of Accelerometers, Gyroscopes, and Magnetometers.

Accelerometers

• they are used to detect the rate of change in velocity of an object
• can only measure pitch and roll, no information about yaw

Gyroscope

• they are used to detect rotational changes or to maintain orientation

Magnetometer

• they are used to detect the gravitational force
• compared to accelerometers that can’t measure yaw since it works on a constant gravitational force, a magnetometer is a great compliment to accelerometer sensor
• Combining these three sensors gives a 9-axis of IMU that measures orientation, velocity, and gravitational force.

Applications of IMU Sensor

IMUs are most commonly used in Inertial Navigations Systems to control aircraft, ships, submarines, and other unmanned aerial vehicles. However, with its wide measurement capabilities, IMUs are still applicable for other usages as follows

• Consumer electronics; Smartphones, tablets, fitness trackers for motion sensing and orientation.
• GPS and satellite positioning systems.
• Sports technology and training applications.
• Personal transportation devices like Segway for stabilization/balancing of the vehicle.
• The above is a general list of IMU applications but so long as motion detection is required, IMU can be used.