Reserch On Key Techonologies Of Intelligent Wheat Harvester

Aiming at the slow development of wheat intelligent harvester in China,the intelligent control system of combine harvester based on microcontroller is developed.The intelligent control system mainly includes work load adaptive module,head height profiling control module、cleaning loss monitoring module and man-machine exchange module by means of DGUS screen.The working load adaptive module uses the encoder to monitor the speed of the bridge shaft,and control the operation speed with the stepping motor as the actuator to control the opening degree of the hydraulic pump.The head height profiling control module monitors the height change of the head by installing angle sensor on both sides of the head and notifies the hydraulic cylinder of the telescopic movement with the reversing valve to realize the longitudinal and transverse profiling of the head.The PVDF Piezoelectric Film sensor is used to monitor the cleaning loss.According to the established mathematical model,the lost rate of wheat harvester can be obtained.The core of the DGUS screen communication module is the DGUS screen.The synchronous communication with microcontroller is realized through serial port,and the monitoring data of sensor can be displayed in real time.At the same time,the adjustment of control parameters and the choice of operation mode can be realized.In combination with the development process of intelligent control system,through the domestic and foreign literature research,this paper researched the following four aspects of the control system one by one:(1)The whole scheme of the intelligent control system of wheat harvester is studied and planned.The whole function of the control system and the function of each sub-module are determined.(2)The design and research of intelligent control hardware system was developed.On the basis of reading the relevant research documents at home and abroad,the merits and demerits of various control schemes and sensors are studied,the specific control schemes are determined.The type of the sensor and the actuator are determined,and the hardware connection circuit diagram of the response is drawn.(3)The development and research of intelligent control software system was developed.Adopting modularization programming based on C language,the control system main program、head profiling control subroutine、work load adaptive control subroutine and communication subprogram of touch screen were respectively exploited.(4)The development of touch screen man-machine interaction system is researched in this paper.The system can realize the harvester operation mode ‘s switch and parameter tuning,as well as it can realize real-time display..In order to improve the reliability of the control system and find the basis for improvement,the harm degree of the reliability of the developed control system is analyzed with FMECA fuzzy analysis.The damage grade of each failure mode is determined,which provides the basis for improving the design and establishing preventive maintenance work.