Design Of The Weighting-principle-based Application Rate Measuring-controlling System And Study Of The Signal Processing Method

Our country is an agricultural country,and agricultural economy is the foundation of national economy.China’s agriculture has been transformed from traditional agriculture to mechanized agriculture,and now it is developing towards the direction of modern precision agriculture.Precision agriculture is the practical application of modern science and technology in the field of agriculture,combining the achievements of modern information technology,biotechnology,engineering equipment technology and other disciplines and technical fields.Variable technology and variable operating machinery,including precise variable sowing and fertilization,are important parts of precision agriculture.China is making great efforts to develop the related technology and equipment for precise variable quantity operation.However,there is a lack of effective test method for the performance of this kind of machine at home and abroad.In order to monitor the dynamic performance of the external trough-wheel sowing and fertilizing machine in real time and effectively,the research group has been committed to the research and development of the weighing sowing quantity detection system in the past five years.In this paper,aiming at the defects of the original detection system of sowing amount,the mechanical structure of the detection device is optimized,and the corresponding sowing amount control and detection system is designed.The specific research contents and results are as follows:(1)single-chip microcomputer detection and control system constructionA complete master-slave communication system based on CAN bus was constructed for the newly developed seeding and fertilizing machine and seeding quantity detecting device.USES freescale series MC9S12XS128 single-chip microcomputer as control core module node,main completed the master node and PC communications,and each slave node functions,such as communication,processing and save the data from the node includes GPS for vehicle speed detection module,the weighing signal acquisition module based on AD7656 chip,groove wheel speed control and detection module.(2)research on signal processing methods of the broadcast quantity detection system.According to research by weighing type sowing quantity detection device,developed by weighing sensor signal acquisition and analysis,we design a can adapt to the field vibration of the working environment more information quantity signal processing method,the method including high frequency sampling average filtering,low-pass filtering,moving average filtering,kalman filter and the zero five steps,such as linear fitting is used to eliminate the sowing machinery in the operation of power frequency interference,high frequency vibration,random disturbance and low frequency interference,after processing the weighing sensor real-time measuring signal can be used to obtain the accumulation of sowing machinery as well as the dynamic multicast information,make evaluation on sowing machinery field performance.(3)dynamic field performance test of the sowing quantity detection system.The casing material weight keep respectively under the condition of 5 kg and 50 kg(i.e.,not material),tractors,respectively in 2 files(the average speed of 2 km/h),3(the average speed of 3 km/h)speed in the field,through calculating the dynamic system of the casing in the process of material weight values of variance and relative standards such as statistics,dynamic stability evaluation system;The maximum test variance of the system was less than 0.15kg,the average test variance was less than 0.1kg,and the average relative standard deviation was less than 5%,indicating that the dynamic process of the sowing quantity testing system had good stability and accuracy.The dynamic test results were used to evaluate the dynamic performance of sowing fertilization with high feasibility and reliability.(4)evaluation and test of field performance of seeding and fertilizing machine.Under the conditions of different driving speeds and different target sowing amount,the sowing amount detection system was applied to evaluate and test the field performance of the seeding and fertilizing machine.In the field performance test,the maximum relative error of seed cumulative sowing amount detection is 4.41%,the average relative error is 2.14%,and the variance of relative error is 1.28%.The maximum relative error,average relative error and variance of relative error are 4.88%,2.19%and 1.58%respectively.The maximum mean relative error of dynamic seeding amount was 9.83%,mean mean of mean relative error was 5.53%and mean standard deviation of relative error was less than 0.1%.The maximum average relative error of the dynamic seeding amount of compound fertilizer was 5.92%,the mean value of the average relative error was 2.68%,and the mean standard deviation of the dynamic average relative error was less than 0.1%.The dynamic seeding test results show that,when the cumulative operating area is small,the dynamic seeding detection value fluctuates greatly and the error relative to the target seeding amount is large.With the increase of the operating area,the dynamic seeding detection value will gradually stabilize and all tend to the target seeding amount.This shows that the dynamic seeding information can truly reflect the actual dynamic seeding performance and can be used as an evaluation index of dynamic performance.(5)the field experiment results show that the designed by weighing type sowing quantity monitoring system and the signal processing method of the research,field operation process can effectively eliminate the effects of various kinds of interference,access to the accumulation of sowing machinery as well as the dynamic multicast information,on the cumulative sowing quantity has good precision,dynamic seeding quantity information with the increase of operating area is grinding to the actual amount,can more reflect dynamic assignment of sowing machinery,explain the design of the sowing quantity the feasibility and reliability of the system and the signal processing method.The method of sowing quantity detection and signal processing proposed in this paper can adapt to the working conditions in the field and is expected to be applied in the intelligent transformation of the wheat sowing and fertilizer machine.