Development Trends of Platform and Strapdown Inertial Navigation Systems

Inertial Navigation Systems Overview

Inertial navigation systems are mainly categorized into platform inertial navigation systems and strapdown inertial navigation systems based on different coordinate system construction methods.

A platform inertial navigation system adopts a physical stabilized platform to simulate and maintain the navigation coordinate frame. Accelerometers are installed on the gyroscope-controlled stable platform, which continuously tracks and maintains the required navigation coordinate attitude, ensuring all inertial measurements are referenced to a fixed navigation frame.

Different from platform schemes, the strapdown inertial navigation system constructs the navigation coordinate system entirely through mathematical resolving. Inertial sensors including accelerometers and gyroscopes are directly fixed on the carrier. Gyroscopes measure real-time angular motion to calculate carrier attitude changes, while accelerometer data is digitally converted into the navigation coordinate system through attitude matrix transformation.

Strapdown inertial navigation systems exhibit prominent advantages in miniaturization, cost control and structural reliability, and have become the mainstream development direction of modern inertial navigation technology. Although strapdown solutions require higher sensor precision and stronger real-time computing capability, they completely eliminate bulky and complex electromechanical platform structures. With superior vibration and shock resistance, smaller volume and lower maintenance cost, strapdown systems are highly adaptable to various vehicle, aerospace and weapon platforms.

Benefiting from the maturity of laser gyroscopes, fiber optic gyroscopes and high-speed onboard computing technology, the overall navigation performance of strapdown inertial navigation systems has been greatly improved. Since the 1980s, the research and iteration of traditional platform inertial navigation systems have basically ceased, while strapdown inertial navigation has gradually replaced platform schemes and become the dominant technical route.

Integrated Navigation Solutions

In practical engineering applications, single inertial navigation cannot fully meet long-duration high-precision requirements due to inherent error accumulation over time. In contrast, satellite navigation provides stable absolute positioning without cumulative drift but is vulnerable to signal occlusion and electromagnetic interference.

Therefore, inertial and satellite integrated navigation has become the universal practical solution. Inertial navigation offers high short-term accuracy, continuous output and full autonomy to compensate for satellite signal failure. Satellite navigation provides real-time absolute position information to calibrate inertial drift errors, suppress long-term error divergence, and achieve stable, high-precision and high-reliability continuous navigation.