A versatile strap product that comprises two main shoulder straps, at the rear of which, four fixation points connect several belts to the main shoulder straps. Among the belts, four elastic belts are attached to the fixation points to secure objects carried. The belts comprise horizontalvertical belts, which are interwoven perpendicularly to form a web.

We proposed a positioning integrated gyroscope (PIG) with a unit price of less than US$3,000. A pilot test was conducted in the tunnel section. The positioning error of the MEMS gyroscope was 4,300 meters at a moving distance of 7.8 kilometers,because there was no GNSS signal in the tunnel. The signal of GNSS module only uses the built-in IMU for positioning, the maximum error is also 348 meters. We move 7.8 kilometers, the error is 89 meters73 meters, the overall error are MEMS (55), GNSS (4.5),the team＇s module (1.1), the internationally marketed inertial FOG (0.9).