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| 1 | 基于GNSS航向微分和MEMS陀螺仪的农机轮角测量方法显示文摘【目的】设计一种农机前轮转角测量方法,代替安装复杂的连杆式轮角传感器。【方法】采用GNSS天线测量航向和速度,MEMS陀螺仪测量车身和车轮的合转动速率,计算MEMS陀螺仪与GNSS航向微分差值,获得车轮转动速率;设计自适应卡尔曼滤波器进行信息融合和校正,获得车轮转向角,并进行性能验证和田间应用试验。【结果】与连杆式轮角传感器测量结果对比,轮角测量方法的拖拉机在偏离航线2.5和1.5 m进行上线时,平均绝对误差(MAE)分别为1.13°和0.87°,均方根误差(RMSE)分别为0.90°和0.68°,上线时间分别为29.4和23.5 s;以4 km/h田间导航应用时,MAE为0.44°,RMSE为0.87°,满足拖拉机旱地作业要求。【结论】GNSS航向微分和MEMS陀螺仪轮角测量方法与连杆式轮角传感器测量性能相当,能够替代轮角传感器用于较低速农业机械导航。 | 何杰 高维炜 王辉 岳斌斌 张帆 张智刚 | 2020 | 华南农业大学学报2020，41，5： | 3 |
| 2 | Design and optimization of an automatic hydraulic steer-by-wire system for an agricultural chassis显示文摘To meet the requirements of fast steering at low vehicle speed and slow steering at high vehicle speed,the automatic steering of agricultural chassis must control both the wheel steering angle and the steering angle’s angular speed.This study applied hydraulic steer-by-wire technology to the automatic steering control of agricultural chassis.First,the transmission mechanism of the designed steering system was optimized.According to the rule of least squares,aiming at the minimum sum of squares of errors between 10 ideal outer wheel angles and real outer wheel angles,the optimal solution of hole spacing on both sides of the steering hydraulic cylinder piston rod was 925 mm.The outer wheel angle error of the optimized steering mechanism throughout the steering stroke was less than 0.15°.Additionally,a hydraulic steer-by-wire system was developed,and the parameters of its critical components were calculated.Then,the compound control strategy of the steering cylinder piston rod displacement and moving speed was formulated for this automatic steering system.The entire control system included a valve control signal calculation model,an initial velocity calculation model,a correction velocity calculation model,and an attenuation velocity calculation model,and the formulae of each model were deduced.Based on the optimized parameters and the developed control strategy,a simulation model was built in AMESim,and simulation results showed that the proposed control strategy could achieve simultaneous controls of piston rod displacement and speed at different vehicle speeds and loads.The horizontal and vertical displacements of the right wheel center were plotted for typical vehicle speeds and steering commands.The results of this study provided a new idea for the application of hydraulic steer-by-wire technology in the automatic steering of agricultural chassis. | Yinhao Jin Yanwei Yuan Licheng Zhu Decheng Wang Bo Zhao Xianfa Fang | 2022 | International Journal of Agricultural and Biological Engineering2022，15，1： | 1 |
| 3 | Development of autonomous navigation controller for agricultural vehicles显示文摘Agricultural vehicles are adopted to undertake farming tasks by traversing along crop rows in the field.Working quality depends significantly on the driving skills of the operator.Automatic guidance has been introduced into agriculture to achieve high-accuracy path tracking during the last decades,which contributes considerably to straight-line navigation.The objective of this research was to develop an autonomous navigation controller that allowed movement autonomy for various agricultural vehicles.Three wheel-type vehicles were used as the test platform featuring automatic steering,hydrostatic transmission and speed control,which included a rice transplanter,a high-clearance sprayer and a tractor.A dual-antenna RTK-GNSS receiver was attached to the vehicles to provide spatial information on both positioning and heading by using the RTX service from Trimble.A path planning method was proposed to create a straight-line reference path by giving two points,and the target path was determined according to the vehicle initial status and working assignment.Headland turning was comprehensively taken into account by listing different turn patterns in order to realize autonomous navigation at the headland.The navigation controller hardware was fabricated for program execution,data processing and information communication with peripherals.A human-machine interface was designed for the operator to complete basic setting,path planning and navigation control by providing controls.Field experiments were conducted to evaluate the performance and versatility of the newly developed autonomous navigation controller in guiding agricultural vehicles to follow straight paths and turn at the headland.Results showed that an appropriate turn pattern was automatically executed when finishing straight-line navigation.The lateral error in straight-line tracking was no more than 6 cm,6 cm and 5 cm for the rice transplanter,the high-clearance sprayer and the tractor,respectively.And the maximum lateral RMS error was 3.10 cm,4.75 cm,2.21 cm in terms of straight-line tracking,which indicated that the newly developed autonomous navigation controller was versatile and of high robustness in guiding various agricultural vehicles. | Xiang Yin Yanxin Wang Yulong Chen Chengqian Jin Juan Du | 2020 | International Journal of Agricultural and Biological Engineering2020，13，4： | 1 |
| 4 | Evaluating system of rice intensification using a modified transplanter:A smart farming solution toward sustainability of paddy fields in Malaysia显示文摘This paper presents the study reports on evaluating a new transplanting operation by taking into accounts the interactions between soil,plant,and machine in line with the System of Rice Intensification(SRI)practices.The objective was to modify planting claw(kuku-kambing)of a paddy transplanter in compliance with SRI guidelines to determine the best planting spacing(S),seed rate(G)and planting pattern that results in a maximum number of seedling,tillers per hill,and yield.Two separate experiments were carried out in two different paddy fields,one to determine the best planting spacing(S=4 levels:s_(1)=0.16 m×0.3 m,s_(2)=0.18 m×0.3 m,s_(3)=0.21 m×0.3 m,and s_(4)=0.24 m×0.3 m)for a specific planting pattern(row mat or scattered planting pattern),and the other to determine the best combination of spacing with seed rate treatments(G=2 levels:g1=75 g/tray,and g2=240 g/tray).Main SRI management practices such as soil characteristics of the sites,planting depth,missing hill,hill population,the number of seedling per hill,and yield components were evaluated.Results of two-way analysis of variance with three replications showed that spacing,planting pattern and seed rate affected the number of one-seedling in all experiment.It was also observed that the increase in spacing resulted in more tillers and more panicle per plant,however hill population and sterility ratio increased with the decrease in spacing.While the maximum number of panicles were resulted from scattered planting at s_(4)=0.24 m×0.3 m spacing with the seed rate of g1=75 g/tray,the maximum number of one seedling were observed at s_(4)=0.16 m×0.3 m.The highest and lowest yields were obtained from 75 g seeds per tray scattered and 70 g seeds per tray scattered treatment respectively.For all treatments,the result clearly indicates an increase in yield with an increase in spacing. | Redmond R.Shamshiri Bala Ibrahim Siva K.Balasundram Sima Taheri Cornelia Weltzien | 2019 | International Journal of Agricultural and Biological Engineering2019，12，2： | 1 |
| 5 | Modeling of working environment and coverage path planning method of combine harvesters显示文摘This paper mainly studied the working environment modeling and coverage path planning of combine harvesters.The boundaries of the farmland to be harvested were extracted through the farmland satellite imagery and canny algorithm.The polygon approximation method was used to fit the extracted boundaries as polygons.The edge offset of the farmland and obstacles was realized based on the principle of straight skeleton.According to the structure data of the split points which were obtained through the improved scan line algorithm,the coverage path planning of the combine harvester was realized.Moreover,the circular arc transition algorithm was used to optimize the harvesting paths to achieve the smooth turning of the combine harvester at the edge of farmland and when encountering obstacles.The simulation results show that the proposed the proposed polygon approximation method can accurately depict the boundaries of the farmland to be harvested,and reduce the amount of data to be stored.Additionally,the designed path planning method can realize the coverage path planning of the combine harvester in irregular and internal obstacle farmland. | En Lu Lizhang Xu Yaoming Li Zhong Tang Zheng Ma | 2020 | International Journal of Agricultural and Biological Engineering2020，13，2： | 1 |
| 6 | 基于云-端高精度地图的油菜无人播种作业系统设计与试验显示文摘[目的/意义]针对人工采集南方中小田边界信息操作繁琐、无人拖拉机转场作业效率低且在转弯调头处留下较大漏作业区域的问题,本研究搭建了一种基于云-端高精度地图的油菜无人播种作业系统。[方法]系统采用“无人机构建高精度地图+远程网页端规划作业路径”方法,使用无人机采集影像数据构建高精度地图,基于高精度地图框选田块实现梭行外螺旋路径自动生成,完成直播机组远程路径规划及调度作业。系统采用梭行外螺旋全覆盖路径规划方法,利用两退三切鱼尾调头方法完成梭行路径换线。为完成外螺旋路径换线,在田块边角设计了一退两切转弯换线方法,减小了油菜无人播种作业系统在转弯或调头过程产生的漏作业区域面积,进一步提升了播种作业覆盖率,并开展梭行外螺旋全覆盖路径与梭行、套行路径作业面积和作业覆盖率对比仿真试验,以Case TM1404型拖拉机搭载智能播种施肥一体机为试验平台,开展了田间试验。[结果和讨论]试验结果表明,梭行外螺旋全覆盖路径较梭行与套行作业路径,漏作业率减小18.58%~26.01%。使用无人机构建的高精度地图平面误差最大为3.23 cm,导航作业过程中最大横向偏差为7.94 cm,最大平均绝对偏差为1.85 cm,作业覆盖率为93.16%。[结论]本研究所构建的油菜无人播种作业系统有效可行,可为南方中小田块油菜无人播种作业提供技术参考。未来将探索不规则田块情况下的油菜无人播种作业模式,进一步提高系统适用性。 | 卢邦 董万静 丁幼春 孙阳 李浩鹏 张朝宇 | 2023 | 智慧农业(中英文)2023，5，4： | 0 |
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