US Patent 7513146 Vehicle wind tunnel balance

A vehicle supporting platform can be supported at plural locations (e.g., four locations) from below such that the platform can pivot fore to aft and side to side in response to the impact of wind on a vehicle on the platform. In a desirable form, the platform is suspended by four suspension rods or cables that loosely support the respective corners of a platform supporting structure. The platform supporting structure can be positioned in a bay beneath the floor level. Although a different number of sensors can be used, in one approach there is one aft motion sensor coupled to the front of the floor supporting frame and a wall portion of the bay and two side sensors, one adjacent to the front of the platform and the other adjacent to the rear of the platform. Both of the side sensors can be on the same side of the platform. A double ball joint can be used to couple the sensor to the structure in one embodiment to eliminate off axis loading. A structure such as a locking collar arrangement can be used in an embodiment to facilitate disconnecting the sensor from the platform.