The TDS classification systems combine a side mounted tracking laser (Scandar) and an overhead mounted laser profiler to automatically generate a three dimensional profile of the vehicle. A single scanner system uses a laser that is center mounted over the lane. The dual scanner system mounts the scanners of each side of the lane to provide a more accurate width measurement. Data from the profiling scanner(s) is used to form a matrix depiction of the vehicle as seen from the overhead position of the laser. The vehicle detection process is initiated when careful examination of the profiler output indicates the presence of a vehicle. During periods when no vehicle is being detected by the laser scanner, the processor periodically polls the profiler looking for any indication of a vehicle presence. When the curtain is penetrated, the processor uses velocity information from the Scandar to determine the position of the vehicle relative to the initial location point set by the profiler. Based upon this position, the laser scanner is polled at regular predefined distance intervals (as opposed to time). A complete set of data points is transmitted from the laser scanner(s) to the signal/data processor at each sample distance. From this information a vehicle profile is generated. This process continues until the laser scanner no longer contains any indications of a vehicle. At that point the vehicle profile is terminated.
The real time flow of data from a treadle or a side mounted laser scanner provides for the determination of axle distances from the front edge of the vehicle. The length of the vehicle is determined from the number of individual data sets that are recorded.
Actual Profile - Single Lane Laser Profiler System
The functional capabilities of the various models are shown in the following table. All systems include the Scandar and use one or more overhead laser(s) for separation and width detection. Axle detection is provided by a fiber treadle or a side mounted laser scanner.
|Model Number||Overhead Lasers||Length||Width Profile||Height Profile||Axle Detection||Dual Tire Detect|