With the development of agricultural mechanization and information technology, automatic navigation tractors are becoming a more common piece of farm equipment. The accuracy of automatic navigation tractor path tracking has become critical for maximizing efficiency and crop yield. Aiming at improving path tracking control accuracy and the real-time performance of the traditional model predictive control (MPC) algorithm, the study proposed an adaptive time-domain parameter with MPC in the path tracking control of the articulated steering tractor. Firstly, the kinematics model of the articulated steering tractor was established, as well as the multi-body dynamics model by RecurDyn. Secondly, the genetic algorithm was combined with MPC. The genetic algorithm was used to calculate the optimal time domain parameters under real-time vehicle speed, vehicle posture and road conditions, and the adaptive MPC was realized. Then, path tracking simulations were conducted by combining RecurDyn and Simulink under different path types. Compared with the traditional MPC algorithm under the three paths of U-shaped, figure-eight-shaped and complex curves, the maximum lateral deviations of the modified MPC algorithm were reduced by 59.0%, 24.9% and 13.2%, respectively. At the same time, the average lateral deviation was reduced by 72%, 43.5% and 20.3%, respectively. Finally, the real path tracking tests of the articulated steering tractor were performed. The test results indicated that under the three path tracking conditions of straight line, front wheel steering and articulated steering, the maximum lateral deviation of the modified MPC algorithm was reduced by 67.8%, 44.7% and 45.1% compared with the traditional MPC. The simulation analysis and real tractor tests verified the proposed MPC algorithm, considering the adaptive time-domain parameter has a smaller deviation and can quickly eliminate the deviation and maintain tracking stability.

Previous studies on sugarcane harvester extractors have mainly focused on improving harvest quality and reducing the impurity rate and loss rate, which often ignored the issue of high energy consumption. To reduce the energy consumption of the extractor while maintaining the original impurity rate and loss rate stable, firstly, a blade element analysis method with aerodynamic theory was put forward to analyze the stress of the extractor blade, and the energy consumption equation and influencing factors of extraction were obtained. Subsequently, the computational fluid dynamics model of the exhaust extractor was established. Computational fluid dynamics (CFD) and the SST k-ω model were used to analyze the mechanism of various influencing factors on the energy consumption and internal flow characteristics of the extractor. The changes in various parameters were analyzed and discussed with respect to the resulting variations in internal pressure, velocity, vortex structure, and lift–drag coefficient of the extractor. A test bench of the extractor was built, and orthogonal tests were carried out with energy consumption, impurity rate, and loss rate as test indicators. Considering the results of the simulation and bench test comprehensively, the combination of a rotational speed of 1450 RPM, a blade number of 3, an installation angle of 25°, and a blade chord length of 200 mm was optimal for the extractor. Finally, a comparative test was carried out between the optimized extractor and the original extractor. The results demonstrated that the energy consumption of the optimized extractor was reduced by 15.49%. The impurity rate decreased by 3.51%, and the loss rate decreased by 12.39% compared to the original extractor. The study can provide a theoretical and experimental basis for designing and optimizing extractor performance.

This review has systematically assessed the critical technologies of impurity removal fans in segmental sugarcane harvesters, highlighting their impact on minimizing harvester impurity rates. The analysis was conducted from three perspectives: Firstly, the physical properties of flexible sheet-like materials were thoroughly examined, including the methodologies for material parameter measurement, the utilization of technical approaches, and the constraints of existing methods. Secondly, the operational mechanisms of impurity removal fans were elucidated, encompassing their working principles, research subjects, and technical methodologies, and compared with the mechanisms of analogous fluid machinery. Lastly, a review of the structural design and parameters of impurity removal fans was undertaken, analyzing the interplay between operational modes, structural optimization designs, and aerodynamic characteristics. The review identified key issues in the design and performance of impurity removal fans and recognized the challenges in technological advancement. Through this triadic analytical framework, the review has identified salient design and performance deficiencies within existing impurity expulsion fan technologies and has underscored the formidable challenges confronting technological evolution in this domain. Synthesizing these insights, the review proffered prospective research vectors and avant-garde technological interventions poised to augment the operational efficacy of impurity expulsion fans, with the overarching goal of enhancing the operational proficiency of sugarcane harvesting machinery.