The Weigh-in-Motion Of Wheel Load

In recent years the situation of vehicle overload becomes more and more serious following the rapid development of the traffic and transportation. The overload causes the damage of road surface and bridges, accordingly, it worsens the road service level and traffic safety, the managements of the highway are in dire need of a sort of weigh-in-motion (WIM) systems to restrain the situation of overload. Meanwhile, in order to improve work efficiency, the WIM systems are also required to replace the existing electric vehicle weighing apparatus at the domestic locations of harbors, aerodromes, storehouses, etc. Furthermore, the overseas overload cognizance standard is different from native one that was executed during our nation natively to solve vehicle overload phenomenon. For this reason, the overload inspection equipment imported from oversea is difficult to be used according to the situation of our country. At present, when the WIM systems are studied at home,the contradiction on the identifying accuracy and vehicle passing speed can't be resolved well all along,for the disturbing factors affecting the WIM are short of systemic analysis and the inspecting signal isn't processed further. There are three targets in the paper: (1) Inspecting the signal of wheel load and vehicle velocity; (2) heightening the vehicle passing speed to accord with the request of ASTM E1318-94 specification Type III WIM systems (Notes: The precision request of ASTM E1318-94 specification Type III WIM systems is international reference standard for weigh-in-motion); (3) improving the accuracy of weigh-in-motion (WIM) to accord with the request of ASTM E1318-94 specification Type III WIM systems. Some work done in the paper is listed below: 1. Developing the vehicle velocity and wheel-position detecting system, which includes: (1) Designing vehicle velocity and wheel-position detecting circuit; (2) Developing the vehicle velocity and wheel-position detecting program; (3) Developing RS-232 communication program module; 2. Developing the wheel load signal detecting system, which includes: (1) Building the wheel load signal detecting hardware system; (2) Developing the A/D drive program for collection of wheel load signal in real time; (3) Developing the program for intercepting and disposal wheel load signal; (4) Bringing forward the arithmetic for differentiating and analyzing the extra slope of wheel load signal; 3. Bringing forward wheel load discriminate method based on experiential formula; 4. Integrating two systems and the load discriminate method mentioned above into a system of the Weigh-in-Motion of wheel load. The road-test result indicates that the passing velocity and the precision of the weigh-in-motion system of wheel load can satisfy the request of ASTM E1318-94 specification Type III WIM systems.