Inertial sensors are powerful devices that use accelerometers and gyroscopes to measure and report an object's motion. From simple tilt sensing to full-scale autonomous navigation, inertial sensors provide the critical data needed to control movement and orientation in space. MicroStrain inertial sensors are built using Micro-Electro-Mechanical Systems (MEMS) technology and are widely used in advanced motion systems, including robotics and autonomous systems.
The term Inertial Measurement Unit (IMU) is widely used throughout the industry. It can refer generally to any inertial sensor, but it also defines a specific product class. A foundational IMU provides raw, fundamental motion data. In contrast, more advanced systems – such as a Vertical Reference Unit (VRU), Attitude and Heading Reference System (AHRS), or Inertial Navigation System (INS) – integrate additional sensors and sophisticated filtering for complete orientation and navigation solutions. These systems are also used as inertial sensors for GNSS-denied navigation, helping maintain robust motion and position accuracy even when satellite signals are limited or unavailable.
To help you find the right fit for your project, we have broken down our product types below. Each product type builds on the last, guiding you from the core sensor to a complete navigation solution.
An Inertial Measurement Unit (IMU) is the foundational sensor for understanding motion. It provides the essential raw data about an object's movement without external references.
A Vertical Reference Unit (VRU) builds upon the IMU by adding sophisticated internal filtering. The filter, MicroStrain's Auto-Adaptive Extended Kalman Filter (EKF), computes a stable orientation relative to the Earth’s gravity.
An Attitude and Heading Reference System (AHRS) advances the VRU by incorporating a magnetometer. This allows for a complete, stable 3D orientation, including heading.
An Inertial Navigation System (INS) expands an AHRS to provide a complete navigation solution that includes position and velocity, in addition to attitude and heading. In some cases, an INS model integrates a Global Navigation Satellite System (GNSS) receiver to provide a full position, velocity, and time (PVT) solution.