Research and test of the measurement sensing device for the downforce of no-till planter row unit gauge wheels

To effectively obtain the downforce of the gauge wheels in real time,mechanical models of the interaction among the ground,gauge wheels,gauge wheel arms,and depth adjustment lever were constructed.A measuring method was proposed for monitoring the downforce through a two-dimensional radial sensing device,and a corresponding prototype was designed.Through simulation analysis of the sensing device with ANSYS,a 45°angle was determined to exist between the strain gauge axis and the sensing device axis,and the Wheatstone bridging circuit of R1+R3−R5−R7(R stands for resistance strain gauge,different figures represent the strain gauge number)and R2+R4−R6−R8 was adopted.According to performance and calibration tests for the sensing device,the maximum interaction effect between the X and Y axes was 2.52%,and the output signal was stable and consistent.The standard error of the slope of the fitting equation of the downforce calculation model is 0.008.According to the field test,the average downforce of the gauge wheels was 1148,1017,843,and 713 N,at different sowing speeds of 6,8,10,and 12 km/h,respectively.The coefficients of variation were 0.40,0.41,0.62,and 0.71,respectively.The results indicate that the downforce fluctuation of the gauge wheels became more severe with increasing planting speed.Both the strain simulation analysis and field test verified that the measurement method is accurate and reliable,the performance of the sensing device is stable,the measurement method and sensing device meet the application requirements and lay a foundation for the research of accurate and stable control of downforce of no-till planter.

Strawponic for No-Till Potato Production

Strawponic is an innovative and exotic system for growing potato on soil surface using crop straw as cover mulch. A field trial was carried out at the American University of Beirut in Lebanon to test the efficacy of this system for small potato producers. Barley (Hordeum vulgare) straw mulch at 25, 50 and 75 t/ha was used to cover potato tubers in no-till system. Potato plant number, height, number of shoots and leaves, root and shoot dry weight, and potato yield were collected. Results showed that all tested rates of straw significantly increased potato yield in comparison to the till system. Marketable yield was the highest with no-till potato at 50 and 75 t/ha compared to no-till potato at all tested surface straw rates. None of the treatments was harmful to potato plants compared to the till potato. This study could be a promising gate for production of potato for small-scale farmers.

Design and experiment of the pneumatic pressure control device for no-till planter

An adequate and uniform press wheel pressure is crucial for the homogeneous development of a crop,as it affects actual seeding depth and germination rate.The problems of uneven compaction of seed furrow and consistency of seeding depth can be caused by the pressure fluctuation of the coil-spring pressure control device(CPCD)when the no-till planter is working on the unplowed ground.In this study,a pneumatic pressure control device(PPCD)was designed for the no-till planter,the key structural parameters of air spring for press wheel pressure(PWP)stability were determined by theoretical analysis and parameter calculation.Using the gas-structure coupling finite element simulation method(FESM),the piston radius,piston angle,and cord angle of the air spring are selected as the test factors,and the vertical stiffness was used as the test index to carry out the quadratic rotation orthogonal combination test to establish the regression model of test index and factor.The bench test of the PPCD was carried out under the optimal parameter combination,piston radius of 27.2 mm,piston angle of 11.7°,and cord angle of 30.0°.The vertical stiffness verification test showed that the simulation test was consistent with the bench test result,the vertical stiffness simulation error was 7.1%,and the internal air pressure simulation error was 3.0%;The control response test showed that the average response time of the air spring inflating and deflating was 0.80 s,the maximum overshoot was 4.33%during inflation,and no pressure overshoot during deflation;Under the condition of-40-40 mm surface relief height,the PPCD could effectively reduce the pressure fluctuation compared with the CPCD,and the average reduction of the pressure fluctuation was about 25.1%.

Improving uniform scattering device for straw-smashing,back-throwing,no-tillage planter under complete straw mulching condition

With the objective of obtaining a completely straw-mulched field,when no-tillage mechanical sowing is implemented with straw smashing,delivering,and back-throwing approaches,it may be difficult to scatter the smashed straw uniformly during a succeeding wheat sowing step.This is because the previous rice straw is substantial in quantity and has a high humidity and toughness,which may easily result in non-uniform straw mulching and thus sparse and weak seedlings of wheat.Therefore a force-dispersing and uniform-scattering device was designed.With the number of scattering impellers,impeller angle,and impeller rotation speed as the main factors and the percentage of pass for the scattering width and non-uniformity of the straw mulching as the assessment indices,single-factor experiments and orthogonal regressive tests were performed,and a dual-index(percentage of pass for the scattering width and non-uniformity of the straw mulching)fitted regression equation was established.The test results suggested that the main factors(from primary to secondary)that influence the indices were the impeller rotation speed,number of scattering impellers,and impeller angle.The optimal parameter combination for the uniform scattering device was four rows of impellers with an angle of 15°,rotation speed of 1015 r/min,percentage of pass of 72.65%for the scattering width,and a non-uniformity of 13.8%in the straw mulching.This combination can be used to realize a uniform scattering of the smashed straw along the seedling rows on the after-sowing ground.According to the field investigation of the wheat growth,the wheat emergence rate was 90.7%.The research results can provide a reference for improving the uniform scattering device for a straw-smashing,back-throwing,no-tillage planter for obtaining a completely straw-mulched field,enhancing the quality of the machinery operation,and ensuring good and strong seedlings after sowing.

棉花免地膜精量播种机的设计与试验

针对棉花地膜造成的白色污染及精量播种的短板问题,文中研制了一种棉花免地膜精量播种机,集秸秆粉碎、旋耕、播种、施肥、镇压和滴灌等功能于一体。该播种机可粉碎前茬棉秆,使其均匀地抛撒在苗带上,无需铺膜,避免了残膜污染。经试验验证:在播种机前进速度为4 km/h,粉碎刀辊转速为2 200 r/min时,秸秆粉碎合格率平均值为94.38%,抛撒不均匀度为13.46%;秸秆覆盖可降低土壤坚实度,比未被秸秆覆盖的土壤坚实度平均值低30.72%,对棉花出苗起到了有利作用;株距合格指数平均值为90.94%,漏播指数平均值为2.54%,重播指数平均值为5.78%。

Performance of no-till corn precision planter equipped with row cleaners

In the continuous annual wheat-corn cropping area of North China Plain,no-till planting that promotes soil conservation and crop yield while reducing operation cost has been gradually accepted by local farmers.However,previous wheat residue is the main limiting factor affecting the performance of existing planters in placing seeds at uniform spacing and optimum depth in residue covered fields.In order to solve this problem,a kind of ground-wheel-driven row cleaner was designed,developed and mounted on row units of a four-row pneumatic precision planter.The planter has two adjacent row units equipped with the newly designed row cleaners and the other two adjacent row units equipped with the commonly used inactive row cleaners.This was used for planting at three forward speeds(4 km/h,6 km/h and 8 km/h)into half residue(HR)and whole residue(WR)plots.The amount of residue removal,seeding depth,emergence rate and indices of uniformity in seed spacing(missing-seeding index,quality of feeding index and precision index)were measured.The newly designed row cleaner performed better with regard to residue removal,with the average percentage of residue cleared as 63.0%compared to 40.3%for the inactive row cleaner.For the HR and WR plots,percentage of residue cleared of the newly designed row cleaner reached 57.1%and 68.9%respectively,suggesting that the newly designed row cleaner can work more effectively at high residue level.By contrast,with the percentage of residue cleared of the inactive row cleaner as 43.1%and 37.5%in HR and WR plots,suggesting that the inactive row cleaner just can work effectively under low residue condition.Values of missing-seeding index,QFI,precision index,coefficient of variation of depth and percent emergence for the newly designed row cleaner under whole residue level are comparable to those for the inactive row cleaner under half residue level.The result indicates that the effect of using the newly designed row cleaner is equal to that of reducing surface residue,and can help to maintain the uniformity of seed spacing and seeding depth.The newly designed row cleaner generally performed better at forward speed of 6 km/h,based on the distribution of seeds along rows and seeding depth uniformity.

Design of depth-control planting unit with single-side gauge wheel for no-till maize precision planter

No-till planters are very popular for maize seeding in fields covered with residue in annual wheat-maize double cropping system in North China Plain.However,there is no suitable depth control mechanism for existing no-till maize planters,and as a result,it is hard to obtain consistent planting depth,uniform emergence,and good passing ability at the same time.For the above reasons,a proper planting unit with a new type of depth-control mechanism was developed in this study.The mechanism consists of a single-side gauge wheel,a parallel four-bar linkage,a pair of double-disc opener,a V-shape press wheel and a depth regulator,which can adjust the planting depth from 30 mm to 90 mm to satisfy the agronomic requirement under different field conditions.Based on analysis and calculation,the width of gauge wheel was set to 50 mm while the length of parallel four-bar linkage was set to 350 mm.Field experiment was conducted and the results indicated that the newly designed planting unit with single-side gauge wheel performed well with regard to planting depth uniformity and anti-blocking ability.The planting depth uniformity and seed spacing quality were 95.45%and 91.90%,respectively,when the average height of stubble was 22.5 cm and residue amount was 0.64 kg/m^(2)in the field.It can satisfy the requirement of no-till maize planting on the cropland with residue and stubble in North China Plain.

Intelligent sowing depth regulation system based on Flex sensor and Mamdani fuzzy model for a no-till planter

Sowing depth has an important impact on the performance of no-tillage planters,it is one of the key factors to ensure rapid germination.However,the consistency of sowing depth is easily affected by the complex environment of no-tillage operation.In order to improve the performance of no-tillage planters and improve the control precision of sowing depth,an intelligent depth regulation system was designed.Three Flex sensors installed on the inner surface of the gauge wheel at 120°intervals were used to monitor the downward force exerted by the seeding row unit against ground.The peak value of the output voltage of the sensor increased linearly with the increase of the downward force.In addition,the pneumatic spring was used as a downforce generator,and its intelligent regulation model was established by the Mamdani fuzzy algorithm,which can realize the control of the downward force exerted by the seeding row unit against ground and ensure the proper seeding depth.The working process was simulated based on MATLAB-Simulink,and the results showed that the Mamdani fuzzy model performed well in changing the pressure against ground.Field results showed that when the operating speed was 6 km/h,8 km/h and 10 km/h,the error of the system’s control of sowing depth was±9 mm,±12 mm,and±22 mm,respectively,and its sowing performance was significantly higher than that of the unadjusted passive operation.

Design and experiment of the key components of the seeding monomer for high-speed corn no-till seeders

Aiming at the problems of uneven plant spacing,row spacing and sowing depth due to the collision of seeds with the tube wall or bouncing on the floor of the seed guide tube with the increase of operation speed of the current corn no-till planter,in this study,the high-speed seed belt technology was combined with the finger clip seed discharge device,a kind of high-speed no-till planter monomer was designed and installed in high-speed seed tube.At the same time,simulation analysis was made on the movement law of seeds in the seed guide tube when they fell from the finger clip seeder and the main structural parameters and the range of key parameters of the high-speed seed tube were determined.Through the prototype,the single-factor and quadratic orthogonal rotational combination test method,and the machine operating speed,the height of the high-speed seed tube and the seed guide angle were selected as the test factors in the seeding performance test.After parameter optimization,the optimal working parameters were determined:the machine forward speed was 12.18 km/h,the height of the high-speed seed tube from the ground was 42.22 mm,and the seed guide angle of the high-speed seed tube was 8.82°.The field test verified that under this parameter combination,the qualified-seeding index was 94.95%,the multiple-seeding index was 2.37%,and the missing-seeding index was 2.48%,showing stable working performance and satisfied the sowing and agronomic requirements of the no-till seeding operation.

棉花铺膜播种机设计研究

根据棉花种植的农艺要求,设计一种2BJ-2/12型铺膜播种机。应用三维设计软件SolidWorks构建铺膜播种机三维模型,完成铺膜、播种主要零部件设计及其相关参数分析,计算铺膜机构相关工作参数,分析穴播器工作过程,从而为棉花铺膜播种机设计与优化提供技术方案。

Development and evaluation of power consumption model for no-till planter based on working parameters

In order to fully understand the relationships of power consumption of no-till planter among tractor,soil properties and working parameters which affect the field operation,the power consumption model for no-till planter applied to overcome the coupling difficulties was developed in the study.Based on operation depth of no-till planter and soil properties as constraints in accordance with a certain distribution,the relationship data among traction force,forward speed and power output shaft by field test were collected and analyzed.The results showed that the relationship between traction power and power-take-off(PTO)power was negatively correlated.Under the same power consumption condition,the relationship between traction force and the PTO torque was linearly correlated,and the slope was basically consistent.Different power consumptions corresponded to different intercepts.When the forward speed was 6-7 km/h and PTO shaft rotational speed was 370-450 r/min,lower power consumption with higher working efficiency can be achieved.There was a direct correlation between total power consumption and the square of rotational speed multiplied by forward speed.The maximum correlation coefficient was found around 0.82.The findings set up a foundation for designing control system of no-till planter.

玉米全膜覆盖双垄沟播机直插式播种装置设计与仿真

设计了旱地玉米全膜覆盖双垄沟播机直插式玉米播种装置,采用凸轮和曲柄组合机构控制成穴器,实现播种时间段成穴器水平绝对速度为零。在ADAMS/View中用相对轨迹曲线生成实体的方法设计了凸轮,对直插式播种装置进行仿真分析,测试了成穴器的位移、速度、加速度,结果表明该装置满足设计要求。

棉花铺膜播种机导航路线图像检测方法

研究了棉花铺膜播种机田间作业时导航路线和田端的图像检测算法。针对自然环境下的棉花播种作业图像,采用Daubechies小波变换对处理区域进行平滑滤波;针对第1帧图像,寻找图像处理区域的垂直累计直方图的波谷,以此为基础,通过寻找局部窗口累计直方图波谷的方法,从图像底端逐行向上寻找各行候补点;对于非第1帧图像,采用当前帧与前帧导航路线相关联的方法分段寻找候补点群;最后基于过已知点Hough变换拟合出导航路线。实验证明,采用的算法可以快速、准确地检测出棉花铺膜播种作业时的导航路线及棉田田端,平均每帧图像处理时间为72.02 ms,满足铺膜播种机实际播种作业的需求。

2BQHM-2型花生覆膜穴播机的设计与试验

【目的】较好地实现花生膜上成穴、播种作业.【方法】针对花生覆膜穴播机存在的技术问题,进行2BQHM-2型气吸式花生覆膜穴播机优化设计与制造;对其关键工作部件结构及作业参数进行理论分析,然后利用UG设计分析软件完成组成部件的优化设计;通过虚拟样机技术对该机进行虚拟装配,并对成穴过程进行运动仿真分析,检验各组成部件设计的合理性及使用效果.【结果和结论】典型地区花生垄作覆膜播种田间作业性能试验表明,该机工作性能较为稳定,各部件作业顺畅,各项作业指标均能较好地达到技术要求,其作业效果与虚拟仿真测试结果相符,研究结果为覆膜穴播机的进一步优化设计提供了理论依据及技术参考.

气吸式膜上精量播种装置排种过程的仿真研究

对 2 BQM- 2型气吸式精量铺膜播种机的膜上开穴、取种、投种过程及其工作机理进行了分析 ,建立了种子运动轨迹的数学模型 ,在此基础上运用计算机仿真技术 ,动态模拟了膜上穴播的工作过程 ,找出了机组前进速度、投种角、接种漏斗偏置角变化时对种子投种精确度的影响规律 ,优化了相关设计参数 。

垂直插入式小麦覆膜穴播机的研究

针对滚轮式小麦覆膜穴播机存在的问题 ,设计了垂直插入式小麦覆膜穴播机。运用平行四杆机构原理 ,实现了成穴器——鸭嘴的直立接种、垂直入土和出土 ;采用地轮传动实现了鸭嘴插入土壤后的接近水平零位移运动 ;鸭嘴采用了定点强制开启投种。理论分析和试验表明 ,该机成穴播种机构设计合理 ,穴粒数合格率较高 ,无空穴 ,成穴器不堵土 ,不挑膜 ,穴孔合理 。

旱地玉米免耕覆盖播种技术及机具试验研究

以２ＢＱＭ—６播种机为基础，进行了６种装置的试验，研制出组合式限深刀切草器和行间压草轮配合防堵的免耕覆盖播种机具，并分析了排堵机理。

棉花双膜覆盖精量播种机的研制

为弥补传统精量播种模式存在的不足、减少作业环节和人工消耗,在分析膜上、膜下穴播优缺点的基础上,根据双膜覆盖精量播种技术的农艺要求,研制出一种棉花双膜覆盖精量播种机。通过田间对比试验,表明双膜覆盖精量播种较常规穴播出苗早2～3d,出苗率≥94%,苗株齐壮。20万hm2的生产实践表明,研制的2BMSJ-12双膜覆盖精量播种机空穴率≤3%,穴粒数合格率≥85%;窄行最小行距为9cm,能适应新疆棉花密植种植农艺要求,有助于推进新疆棉花生产全程机械化进程。

2BMFS-3型穴灌半精量玉米播种机的设计

为了适合保护性耕作的需要、解决旱田旱期播种出苗保苗的问题,达到节水、免耕、侧深施肥和半精量播种的目的,研制了与小四轮拖拉机配套的节水型免耕施肥播种机。该机能够一次性完成破茬松土、侧深施肥、穴灌、半精量播种、覆土镇压等多项作业,对麦茬地按时复播玉米等作物具有重要的意义。

滚轮式小麦覆膜穴播机的分析与评价

对滚轮式小麦覆膜穴播机的成穴机理进行了理论分析，通过对该类穴播机结构、成穴器运动轨迹、穴孔形成过程及其形状的分析，结合实际作业情况，提出了其存在的穴距不一致、易于造成空穴、挑膜严重、种孔覆土不良等问题，为新型直插式覆膜穴播机的研究提供了依据。