Motor vehicle deceleration data acquisition and processing apparatus and methodology

Abstract

The decelerating movement of a vehicle during a skid test is sensed by an accelerometer which provides an analog signal representative of the deceleration to a computer where the analog signal is periodically sampled and converted into a digital deceleration signal for storing in a computer memory. Alternatively, the decelerating movement of the vehicle may be sensed by a radar speed detector providing digital signals representative of the initial speed and final speed of a time increment to a computer processor which records and stores the digital speed signals in computer memory to be later recalled to produce a digital deceleration signal. The computer processor effects storing of the digital deceleration signals in the computer memory at the beginning of a skid test when the magnitude of the signals exceeds a predetermined threshold level as sensed by a threshold level detector or, alternatively, when a mercury position switch is operated by the deceleration force. Subsequently, the stored deceleration data is retrieved from the computer memory by the processor for performing selected mathematical operations on the data to derive information such as the coefficient of friction encountered by the skidding vehicle, the length of the skid, and the time duration of the skid. The results of the mathematical operations may be displayed on a digital display panel or printed on a tape to provide a permanent record.

Dependencies are inferred from the claim text.