Optimum Design And Experimental Study Of Grain Harvester Header

Rice,wheat,and other cereals are crucial staple crops in numerous regions in China.They are characterized by vast cultivation areas and significant economic importance.However,the utilization of manual or semi-mechanized harvesting methods results in low efficiency and considerable harvest losses,imposing substantial constraints on the development of the cereal industrial.It is worth noting that with the successful implementation of China’s "13th Five Year Plan",the mechanization level of national agricultural production has reached 70%.Nevertheless,traditional harvesting machines currently encounter challenges related to energy inefficiency and suboptimal harvesting performance.The header,serving as a pivotal component of the harvester,plays a decisive role in both harvest efficiency and energy utilization.Consequently,this thesis focuses on enhancing and optimizing the header in traditional harvesting machines through research.The main contents of this study are outlined as follows:(1)Based on an analysis of the research background,a thorough investigation of the contemporary status of synchronization control strategies,reel,and header body research at both domestic and international levels was conducted,leading to the formulation of the research objectives and content of this article.(2)By conducting a comprehensive comparative analysis of the merits and drawbacks of different approaches,the preliminary improvement plan of the header in this thesis was formulated.Furthermore,in alignment with the design specifications of the project,the theoretical design of vital components of the header was undertaken.This encompassed the design of the electric putter,reel and header body.(3)This thesis focuses on the control of a single push rod control within an isochronous control system.In order to overcome challenges such as the tendency of the traditional gray wolf algorithm to become trapped in local optima and exhibit premature convergence,improvements were made.The effectiveness of the enhanced algorithm was demonstrated through the application of testing functions.Additionally,a comprehensive mathematical model of the electric putter was developed,and an evaluation function was designed.Subsequently,an electric putter control system was constructed based on Krill Herd with Improved Grey Wolf Optimization(KIGWO)algorithm for tuning PI parameters.Extensive simulations analysis were performed,which confirmed the superior control performance achieved by the proposed KIGWO algorithm.These findings provide a solid foundation for future research on the isochronous control of the double putters.(4)Building upon the single putter control strategy,this thesis extends the control approach to double putter by incorporating the optimized PI parameters obtained from the previous KIGWO optimization.The primary objective of this study is to investigate the control strategy for double putter within an isochronous control system.Various control methods,including cross-coupling,PID and fuzzy PID control of the dual actuator,were developed and specifically tailored for double putter control.The distinct control approaches were subsequently integrated,and comprehensive simulations were conducted to prove evaluate the effectiveness of the proposed fusion control strategy,which combines fuzzy PID and cross-coupled techniques.The simulation results unequivocally demonstrate that the designed fusion control strategy,employing fuzzy PID and cross-coupling,outperforms other methods in terms of control accuracy and interference resistance.(5)In order to enhance the harvesting efficiency of the reel and minimize the impact on plants,this thesis utilized ADAMS to analyze the operational trajectory,speed and displacement of the reel.The simulation results were meticulously compared and analyzed,leading to the identification of the accurate operating speed ratio range for the reel.Furthermore,by integrating theoretical design principles,the optimal reel speed ratio was determined,taking into consideration the desired objectives and performance requirements of the system.(6)Through finite element analysis,the structural integrity of the designed header were assessed and confirmed to meet the required standards.Additionally,an investigation into the vibration characteristics of the header body was conducted.It was determined that the previously designed optimal reel speed ratio did not induce resonate in the header.Furthermore,the impact of other factors on the vibration of the header was analyzed.It was discovered that the excitation frequency of the threshing drum coincided with the resonant frequency of the header.Subsequently,structure enhancements were implemented to mitigate this issue,and the modified design was validated through simulation,successfully avoiding the excitation frequency.(7)With the generous support of project funding,an experimental test bench was established to explore the isochronous control of the header.The test bench was equipped with essential components,such as an electric putter,sensors,an upper computer,and an isochronous controller.Firstly,comprehensive tests were conducted to confirm the compliance of the designed control system with the project’s design requirements,with a specific focus on parameters like lifting force,stroke,and adjustment time.Secondly,a rigorous evaluation was performed to assess the effectiveness of the proposed isochronous control strategy for the electric putter.The results clearly demonstrated its superior control performance in comparison to alternative approaches.