Smart cars can “see,” but they may not “know where” they are.

LiDAR can detect surrounding obstacles, and cameras can identify lane lines, but these sensors have a common shortcoming—they can only sense “relative position” and cannot tell the vehicle its absolute coordinates on Earth.

Without global location data, vehicles cannot access high-precision maps or navigate accurately in complex environments such as overpasses and underground parking lots.

Even more challenging is that everyday weather conditions such as heavy rain, dense fog, and strong backlighting can significantly reduce the reliability of visual sensors.

For autonomous driving to truly “land,” a global positioning solution that is independent of weather, unaffected by obstructions, and always online is needed.

GNSS + IMU: A Perfect Match of Two Capabilities

The Starlink SV910 5G-V2X vehicle Ethernet gateway integrates GNSS/IMU deep-coupled navigation into a high-precision positioning and high-integration module for advanced intelligent vehicle communication , providing global “zero drift” high-precision positioning for vehicle navigation.

GNSS (Satellite Navigation Satellite System) can provide global absolute coordinates, and the error does not accumulate over time, but the update frequency is low, and the signal is easily interrupted in obstructed scenarios such as tunnels, tall buildings, and canyons.

IMU (Inertial Measurement Unit) has a fast response and can output the displacement and attitude changes of a vehicle at high frequency, but the error will drift over time when used independently.

By deeply coupling the two through fusion algorithms such as Kalman filtering, their weaknesses are complemented:

GNSS continuously corrects the drift deviation of the IMU; the IMU takes over positioning when the GNSS signal is interrupted (such as when passing through a tunnel), providing high-frequency, continuous, and reliable short-term estimation.

The result is that, regardless of the road or weather conditions, vehicles always know where they are.

Typical scenario: Not losing contact while passing through a tunnel.

Taking a vehicle passing through an urban tunnel as an example, the system’s collaboration method is as follows:

① Before entering the tunnel—GNSS completes precise positioning benchmark locking and “hands over” the current position to IMU;

② Inside the tunnel—GNSS signal disappears, IMU takes over, and the driving trajectory is calculated at high frequency based on acceleration and angular velocity;

③ After exiting the tunnel—GNSS signal is restored, the accumulated error of the IMU is immediately corrected, and the position smoothly converges to centimeter-level accuracy;

The entire process seamlessly switches the driving system, and the positioning output remains stable and available throughout.

The cornerstone of advanced intelligent driving

 

• Automatic highway on/off ramps – accurately determines whether you are currently on the main road or on a ramp, ensuring no missed or misjudgment;
• Lane-level navigation for urban roads – Select the correct lane at complex intersections and make lane-changing decisions in advance;
• Smooth autonomous driving experience – anticipating road curvature, acceleration and deceleration are more natural, and the ride is more comfortable.

These capabilities rely on a globally accurate and always-online positioning base.

Next step: Moving towards “all-scenario” base station-free positioning

With the continuous improvement of BeiDou and the large-scale application of RTK technology, high-precision positioning with lower cost and no need for ground-based augmentation networks will be achieved in the future.

This means that high-precision positioning is no longer exclusive to high-end models; ordinary passenger vehicles will gradually acquire autonomous navigation capabilities for all urban scenarios.

It’s worth mentioning that the Starlink SV910 5G-V2X vehicle Ethernet gateway, building upon the core positioning capabilities of GNSS+IMU integrated navigation , further integrates four core capabilities: high-precision positioning, dual 5G redundancy, V2X vehicle-to-everything (V2X) collaboration, and nanosecond-level time synchronization . Through the NTRIP protocol and T1/TX interface design, it boasts strong anti-interference and anti-obstruction capabilities, upgrading “precise positioning” to a comprehensive “positioning + communication + collaboration” solution. This further enhances reliable collaboration and precise positioning capabilities in autonomous driving scenarios, directly addressing industry pain points and perfectly matching the stringent requirements of scenarios such as unmanned mining trucks, unmanned container trucks, Robobuses, and unmanned vehicles in industrial parks , propelling autonomous driving from “pilot demonstrations” to “universal adoption” !