Expressway Overload Control Solution

1.1: Weighing Method of Ningbo Saintbond Expressway Overload Control Solution

The weighing methods of the Expressway Overload Control Solution are divided into three types: whole vehicle weighing, axle group weighing, and axle weighing.

1) Whole vehicle type Expressway Overload Control Solution. Vehicle type dynamic weighing, with a weighing platform length generally above 18 meters, can weigh passing vehicles as a whole. It has high weighing accuracy and is commonly used for dynamic weighing at highway toll stations.

2) Axis group weighing formula Expressway Overload Control Solution. Although the whole vehicle weighing equipment has high weighing accuracy, it is difficult to install due to its long scale body and limited installation site conditions. The whole vehicle weighing system has evolved into the axle group weighing system, which is a dynamic weighing system. The length of the weighing platform is usually 6-12m, making it more versatile and easy to install. Its weighing accuracy is close to that of vehicle dynamic weighing. 

3) Axle type Expressway Overload Control Solution. By obtaining the total mass of each axle of the vehicle (wheel mounted), the total load of the vehicle is accumulated. At present, axle type dynamic weighing mainly includes three methods: weighing platform, bending plate, and piezoelectric. Compared to whole vehicle and axle group weighing, axle weighing has a smaller footprint and is suitable for non-stop weighing and detection on the road.

1.2: Applicability of dynamic weighing with different axle types

Compare the weighing accuracy, weighing speed requirements, maintenance costs, service life, and basic construction quantities of three different axle weighing methods: platform type, curved plate type, and piezoelectric type. Point out the advantages and disadvantages of different axle weighing methods and apply them in engineering.

1) Weighing method of the weighing platform axle load detector. The weighing platform axle load gauge measures the weight of each axle. According to the vehicle's driving speed, perform dynamic simulation calculations through the program. The length of its weighing platform is usually 700-1000mm, commonly used for toll collection on highways. Its shortcomings include large excavation volume, difficult maintenance, easy scale jumping, and the requirement for vehicles to be in a low-speed driving state.

2) Bending plate dynamic weighing. The bending plate dynamic weighing equipment is made of bending plate sensors. Bent plate sensor is a strain gauge sensor that integrates the sensor and carrier into an internal strain gauge network, and measures weight based on the principle of deformation of the carrier after compression; It is also a type of integrated sensor structure. With the continuous development of technology, the curved plate dynamic axle load balance has become increasingly compact in size, easy to install, occupies a small area, and has a short construction period. However, it has high requirements for the road surface around the sensor, and if the road surface is damaged, the error will be significant.

3) Piezoelectric quartz dynamic weighing. The piezoelectric dynamic weighing equipment is made of piezoelectric sensors. It is a typical active sensor based on the piezoelectric effect of certain dielectric materials. When a material is deformed by force, its surface generates charges, achieving non electric weighing. There are generally three types of piezoelectric element materials used in piezoelectric sensors: piezoelectric crystals, polarized piezoelectric ceramics, and new piezoelectric materials. They all have large piezoelectric constants, good mechanical properties, good time stability, and good temperature stability, making them ideal piezoelectric materials.

At present, commonly used piezoelectric dynamic weighing detection equipment mostly uses quartz crystals or new piezoelectric materials to make piezoelectric films, such as quartz type dynamic weighing sensors, PVDF piezoelectric film sensors, etc.