Feature Guide: Garage Mode

Overview

Garage Mode is a feature designed to stabilise the INS when GNSS signals are unavailable, such as when a vehicle enters a garage or other enclosed area.

When enabled:

• GNSS updates are blocked once the vehicle loses satellite signal.
• After a user-defined initial delay, the INS assumes the vehicle is stationary and applies gentle velocity corrections to limit inertial drift.
• This prevents the INS from accumulating large errors in velocity while the vehicle is stationary.

Note: Garage Mode differs from the GNSS Control option:

• Garage Mode assumes the vehicle is stationary and actively stabilises velocity.

• GNSS Control only ignores unexpected GNSS measurements for a set period and does not apply velocity corrections.

Purpose

The main purpose of Garage Mode is to reduce inertial drift during periods without GNSS.

• Without GNSS, the INS relies on accelerometers and gyroscopes, which accumulate small errors over time, leading to drift.

• Garage Mode minimises this by assuming near-zero velocity when GNSS is lost.

Note: The most effective way to control drift is to use a wheel speed sensor and enable Advanced Slip. Garage Mode is intended as a secondary solution when wheel-speed inputs are unavailable.

Limitations

Garage Mode is most effective when the vehicle stops shortly after GNSS is lost, such as in a garage or parking area.

If used for extended periods while the vehicle is moving:

• The INS will slowly reduce the estimated velocity toward zero, which can create errors.

• This may occur in long tunnels, urban canyons, or other areas where GNSS is lost but the vehicle is still in motion.

Initial Delay Setting

The initial delay defines how long the INS waits after GNSS loss before assuming the vehicle is stationary:

• Short delay: For vehicles that stop almost immediately after GPS loss.

• Long delay: For vehicles that continue moving for a short period before stopping.

Best Practices

Key Points:

• Garage Mode is designed to reduce velocity drift when the vehicle comes to a stop.

• For situations where the vehicle continues moving, wheel speed input is the preferred solution.

• Always configure the initial delay to match expected stopping behaviour after GNSS loss.