Research And Application Of Grain Level Measurement In Intelligent Grain Depot

Grain is a necessity for people's lives and an important guarantee for social stability and national security.The monitoring of grain storage mainly reflects quality and quantity.Volume regulation is one of the most important ways to regulate grain quantity.The key to volume regulation is the monitoring of grain surface height.A new method of monocular vision ranging is presented based on the research on grain storage monitoring and distance measurement technology.The distance is calculated by neural network and the double pulse of focal length and image distance provided by zoom lens.A set of grain height measuring device based on Camera technology is studied.Under the premise of real-time monitoring of the grain depot environment,the device measures the height of the grain surface.The main research of the thesis include:(1)The overall structure of the grain surface height measuring device was designed on the premise of the research status of the grain surface height measurement of grain storage and the key technology of grain storage metering.Based on the overall structure,the working process of the system is described,and the hardware design of the image acquisition module and the motor control module is performed.The zoom USB camera is used for image acquisition and the wireless transceiver is used for image transmission.Motor control module selects two-phase four-wire stepping motor and drives it by stepper motor drive module L9110 s.The Cortex-M3 processor is used as the control core.The data transmission is achieved through the infrared module and the hardware circuit design is performed on the relevant module.(2)Experiments were conducted to compare typical image sharpness algorithms in the airspace,and Brenner function was used as an image quality evaluation function.By analyzing one-dimensional search algorithm and two-dimensional search algorithm,mode search algorithm suitable for this system is selected.The algorithm steps and flow charts were given;The motor control module is designed to be driven by 8 beats to determine the excitation sequence of the stepper motor.The stepper motor is divided into five levels to control.The step angle parameters of each level is determined.The infrared module is designed.Set the infrared remote control button function.(3)Based on a large number of experiments,a database is established.Data analysis is performed on the established database,and the curve-fitting method is used to determine the piecewise function expression that satisfies the requirements,and the error comparison analysis is performed.The mapping relationship between database two-dimensional input and one-dimensional output is described by neural networks which is trained.(4)The feasibility of the system was verified by a marker experiment and a grain bank simulation experiment.Experiments were carried out under the experimental markers to determine 80 sets of distances within the range of 10-200 cm.The relative errors were calculated by curve fitting and neural network prediction respectively.The relative error of the curve fitting method was not more than 10%.The neural network prediction method was relatively.The error is strictly controlled within 3% to meet the accuracy requirements.10 groups of distance in the range of 10-200 cm repeatability experiments is carried out.The maximum variance in the calculation results is 2.615.And accuracy requirements is met.In order to verify the applicability of this system to the grain store environment,a grain warehouse model was set up to conduct experiments.The relative error under five groups of distances was calculated in the accuracy experiment,with a maximum value of 2.875%.The variance of the five groups of distances was calculated in the repeatability experiment.The maximum value is 1.85,which satisfies the accuracy requirements and stability requirements and verifies the feasibility of the system in the grain warehouse environment.Based on the research status of grain storage distance measurement,hardware and software design of grain surface height measurement device is performed.A large number of experiments verify that the system meets the requirements of accuracy and stability,and verify the feasibility of the system in a grain warehouse environment.