Research Of Load Feedback Control System Of Combine Harvester Based On ARM9 Embedded System

Combine Harvester is the important agriculture equipment wildly used in agriculture production.The application of it significantly freed farmer form the heavy working and improved the working efficiency.However,high failure rate and low reliability are still the main problems of combine harvester in China,which are often caused by overloading when combine harvester is working.As the load of combine harvester is mostly affected by its speed,well-controlled speed can effectively avoid failure caused by overload.Thus,it is very important to design a control system, which can adjust the speed according to the load.Moreover,the ARM embedded system is wildly used in many intelligent control systems and plays the important roles.Hence,this paper mainly introduced the design of Load Feedback Control System of Combine Harvester based on ARM9 microprocessor and Linux Embedded Operating System.In the paper,hardware design of the control system is separated into six modules. They are the core control module,rotation speed sensor module,analog-data-mining module,servo stepping-motor control module,sound light alarm module and human-computer interaction module.And,by using the S3C2410A microprocessor as the core control unit,the paper introduced the construction and design method of these modules in details.Then,it constructed the hardware-platform of load feedback control system.The software design is separated into two parts:hardware driver and system application software.The functions of hardware driver are input/output(I/O) port control,analog-digital(AD) sampling and external interruption(EINT).In order to assure the veracity of the data sampled from I/O port and EINT,some special filter algorithms are used in the hardware driver.As to the system application software,the paper mainly introduced the design of system control algorithm.According to the research of experimental data and control experience,the relationship between roller rotate speed and combine harvester speed is established.And,based on the relationship,two-dimensions fuzzy controller is designed which use the roller rotate speed and its changing-rate as the two input signals and the controlling plus of servo stepping-motor as the output signal.Fuzzy control query table is established by the MATLAB software after calculated all the possible input.Processor can easily find out the control data of stepping-motor from the fuzzy control query table according to different input from sensor.As a result,the computation of processor is reduced and the control effect is improved.The system debugging shows that,the design of hardware and software is very successful,combine harvester can adjust its speed according to the load betimes and the load feedback control function is available.