Abstract: Provided is a road surface friction coefficient measuring method and device for measuring the friction coefficient of road surfaces such as roads and runways, and which can be used by being mounted on a general car. This device has a spindle 5 detachably connected to the wheel of a travelling wheel 3 of a car, a support arm 6 oscillatably connected to the spindle, and a measuring wheel supported rotatably by the support arm.

Abstract: The multi-level vibration test system has controllable vibration attributes that enable the test engineer to precisely implement a vibration environment that is applicable to a wide range of applications and performance characteristics. The multi-level vibration test system comprises a plurality of shaker modules that are interconnected by coupling modules and optionally includes vibration input elements and/or vibration shaping elements that collectively function to enable the user to program the frequency and magnitudes that are produced by the multi-level vibration system. This novel architecture as well as the numerous implementation variations that are possible using this architecture, enable the test engineer to precisely control the vibration frequencies and magnitudes that are produced.