**Background**

In the **GPS-denied** environment, inertial navigation system is the justifiable and general solution because it **do not require installation of infrastructure beforehand**. Nevertheless, the inertial navigation system (INS) calculates the relative displacement of an object that will result in **accumulated errors** due to the sensorsâ€™ drift. Under the assumption that the velocity is zero when foot is on the ground, ZUPT-aided INS modify the positioning error leveraging this pseudo-measurement.

**Contribution**

This paper improve the ZUPT-aided INS in two aspects: 1) By considering the zero velocity detecion as a hypothesis-testing problem, we propose a new test statistic; 2) To avoid excessive modification of heading angle (yaw), an asymptotic ZUPT is devised.

**Accurate zero velocity detection**: This paper takes the **difference value** of gyroscope as the test statistic, which makes the wave more sharper. The proposed method enable zero velocity detecion to maintain its accuracy **in high-dynamic motion**.
**Stable attitude modification**: The heading angle, with zero velocity update, is prone to deviation, because the excessive yaw error estimation by KF at the initial update. Therefore, the **attenuation factor** is applied to the pseudo-measurement, which alleviates the yaw fluctuation after update.