Description of the stability of the Axle Scale in motion

Description of the stability of the mobile platform scale in motion:

?The movement state of the vehicle during dynamic weighing is quite complicated. When the vehicle passes the dynamic axle load meter, the force received by the sensor includes two parts. One is the steady-state load of the vehicle, which is the weight shared by the vehicle on the current axle. The load caused; the second is the dynamic load of the vehicle, or called the transient load. There are many factors that cause dynamic load, and there are three main categories. One is the vibration caused by the vehicle's own factors; the other is the vibration caused by the uneven road surface; the third is the vibration caused by the coupling between the vehicle and the ground2. Dynamic load appears as noise during the weighing process, which is the main factor affecting weighing accuracy. To accurately reflect the measured real static axle load signal, it is necessary to minimize random noise interference. Related experiments show that the signal-to-noise ratio of the dynamic weighing signal is very low, and the amplitude of the interference noise can reach 20% or more of the real axle load. The composition is also complex, with both common mode interference and series mode interference, and the frequency distribution ranges from tens of hertz to several kilohertz].

The use of differential amplifiers can effectively common mode interference, and the use of analog RC low-pass filters can effectively reduce series mode interference, but the size of the filter parameters must be compromised. The larger the parameter, the better the interference noise, but the output signal delay The larger the value is, this is not allowed for dynamic vehicle weighing; the smaller the parameter, the better the real-time performance, but the worse the interference noise. In this way, the filtered signal still contains a considerable part of the interference signal, which must be processed by digital filtering. Therefore, the weighing accuracy of the dynamic axle load meter largely depends on the digital signal processing method, especially the excellent digital filtering algorithm.