# Wheat Quantity Monitoring Methods Based on Inventory Measurement and SVR Prediction Model
## 2 Measurement and Analysis of Grain Inventory Quantity  
### Steps for Checking the Quantity of Grain Stock  
The current commonly used grain quantity inspection method in Chinese warehouse clearance is shown in Figure 1. The specific implementation steps are as follows:  
Step 1: Measure the water content of the current grain through on-site sampling, check the water content of the grain in the storage and the total mass of the grain in the storage, and calculate the grain quality reduced by water reduction using Formula (1). Step 2: Measure the volume of the grain storage pile on site, and calculate the net volume of the grain pile by subtracting the volume from Formula (2). The measured volume of the grain pile is the volume of the grain pile obtained by the laser or image measurement and inspection equipment of the grain depot, and the deducted volume is the volume protruding from the bottom or side surface of the grain depot (including infrastructure facilities such as floor cages). The average density of grain depot is obtained by introducing Formula (3) for calculating the unit volume mass through field sampling, and the calculation number for measuring the current grain depot is obtained by multiplying the net volume of the grain depot and the average density of the grain depot, as shown in Formula (4). Step 3: Check the grain storage time and the book quality of stored grain, and establish the loss calculation Formula (5) to estimate the amount of natural loss according to the grain storage loss standard corresponding to the storage time. Step 4: According to the measurement calculation number, the amount of natural loss, and the quality of water reduction, calculate the original quality of the grain depot (measured quality) by using Formula (6). The final grain quantity is obtained using Formula (7). Step 5: According to the input quality of the inventory and the original quality of the grain depot, the error rate calculation Formula (8) is used to obtain the error rate of the grain depot. Step 6: Determine if there is an anomalous amount of grain in the stock in accordance with the relevant regulations on the control of the differential rate of grain in the stock. The formula for calculating the loss of moisture from the mass of a grain stock is as follows:  
\[W_{1}=W(\sigma_{1}-\sigma_{2})/(100-\sigma_{2}) \tag{1}\]  
where \(W_{1}\) is the actual book mass of the grain in storage, \(W\) is the actual book mass of the grain in storage, \(\sigma_{1}\) is the moisture content of the grain in storage, and \(\sigma_{2}\) is the measured moisture content. The formula used to calculate the net volume of the grain pile is as follows:  
\[V=V_{1}-V_{2} \tag{2}\]  
where \(V\) is the net pile volume, \(V_{1}\) is the measured pile volume, and \(V_{2}\) is the volume to be subtracted. The average density of the grain pile compensated by the introduction of the correction factor is as follows:  
\[\rho=k\rho_{1} \tag{3}\]  
where \(\rho\) is the average density of the grain pile, \(\rho_{1}\) is the measured volume weight, and \(k\) is the correction factor, which is set according to the numerical relation between the stored volume weight and the measured volume weight. Currently, the formula for calculating grain quantity widely used in the process of grain depot inspection is as follows:  
\[W_{2}=\rho V \tag{4}\]  
Figure 1: Common methods for checking the quantity of grain depots. where \(W_{2}\) is the grain quality obtained by using the average density of the grain pile after modified calculation. According to China's national standard for the physical inspection of grain stocks, natural storage loss rate for different storage years should be as follows: no more than 0.1 percent within six months, no more than 0.15 percent within six months, and no more than 0.2 percent within one year.