无轨电动采摘车的研究与应用

我国温室内作物采摘收获主要是人工作业,没有辅助的配套设施设备,劳动消耗大、效率低。虽然目前相继推出有轨道的采摘车,但由于温室种植面积大,轨道的成本占比重较大。针对以上问题,开发了无轨道电动采摘车,实现了温室作业通道内无轨道采摘。该无轨采摘车主要由行走转移底盘、液压升降机构、工作平台、液压举升及控制部分等构成。该采摘车在温室狭窄的作业通道内运行,进行无轨道采摘作业,具有结构简单、操作容易、零排放及无污染等优点。经过实际生产试验,相对人工作业,工作效率可提高6~7倍。     

The impact of water and agriculture policy scenarios on irrigated farming systems in Italy: An analysis based on farm level multi-attribute linear programming models

The objective of this paper is to evaluate the impacts of agriculture and water policy scenarios on the sustainability of selected irrigated farming systems in Italy, in the context of the forthcoming implementation of the directive EC 60/2000. Directive EC 60/2000 (Water Framework Directive) is intended to represent the reference norm regulating water use throughout Europe. Five main scenarios were developed reflecting aspects of agricultural policy, markets and technologies: Agenda 2000, world market, global sustainability, provincial agriculture and local community. These were combined with two water price levels, representing stylised scenarios for water policy. The effects of the scenarios on irrigated systems were simulated using multi-attribute linear programming models representing the reactions of the farms to external variables defined by each scenario. The output of the models consists of economic, social and environmental indicators aimed at quantifying the impact of the scenarios on different aspects of sustainability relevant for irrigated farming systems. Five Italian irrigated farming systems were considered: cereal, rice, fruit, vegetables and citrus. The results show the diversity of irrigated systems and the different effects that water pricing policy may produce depending on the agricultural policy, market and technological scenarios. They also highlight a clear trade-off between socio-economic sustainability and environmental (water, nitrogen, pesticide) sustainability. Water pricing will have, in most cases, less impact than agricultural markets and policy scenarios, though it appears to be an effective instrument for water regulation in the least intensive irrigated systems considered. This emphasises the need for a differentiated application of the Water Framework Directive at the local level as well as a more careful balance of water conservation, agricultural policy and rural development objectives.     

Urea-SCR系统尿素喷射数据驱动预测控制研究

为了同时实现较高的NOx转化效率和较低的NH3逃逸量这一矛盾的排放控制需求,基于数据驱动预测控制技术设计了一款urea-SCR系统尿素喷射控制器。数据来自某型号柴油机台架ETC瞬态循环测试试验,控制器直接由四输入及两输出(预测输出和约束输出)耦合激励再分离得出。基于系统的实际物理特性,在控制问题描述中明确考虑了输入输出量的时域约束。考虑到相对参考无偏的控制需求,预测方程采用增量型。台架测试表明,激励工况下,控制器能够满足优化问题提出的排放控制目标;非激励瞬态工况下,对于工况变化不确定性引起的干扰,控制器具有较好的鲁棒性。     

农业装备自动控制技术研究综述

随着信息与控制理论的发展，自动化控制技术在农业装备领域广泛应用，促进农业生产的智能化、现代化与规模化。运动控制和作业控制是智能农机自动控制技术的两大核心内容，为无人农机在复杂环境下的高精度自主导航安全行驶和精准作业提供保障。速度控制与转向控制是智能农机运动控制的基础，导航跟踪控制是智能农机运动控制的主要内容。本文阐述了智能农机速度控制与转向控制的研究进展，总结归纳了基于几何模型、基于运动学模型和不依赖于模型的自动导航跟踪运动控制方法。然后，着重分析了智能农机在耕、种、管、收等各环节的作业机构控制以及多机协同作业控制方法。最后，指出构建更加精准的农机数学模型，研究面向复杂场景的先进底盘运动控制技术，发展人工智能与控制理论深度融合的农机控制技术以及提升农机农艺相结合的多机协同控制技术是未来智能农机自动控制技术的发展方向。     

改进的滴灌双向流道结构参数对水力性能影响

为了在现有滴灌管(带)生产设备加工成型,改进了滴灌双向流道结构.针对这一新型流道,探索分析流道结构参数对其水力性能的影响.以流道4个关键结构参数为因素,基于正交试验设计方法,设计16组方案并制作流道样件,进行水力性能试验.采用极差分析和方差分析研究各结构参数对水力性能的影响效应.利用多元线性回归,建立流态指数和流量系数与4个结构参数的回归模型.结果表明,流道过水宽度,对流态指数的影响最显著,分水件与边壁距离的影响最小;分水件与边壁距离对流量系数的影响最大.回归模型效果显著,且准确度较高,可用于流道流态指数、流量系数的预测,研究结果可为新型双向流道的参数化设计及其结构优化,提供一定的理论指导.     

基于逐步优化算法的太子河流域水库生态调度研究

针对太子河流域面临水资源短缺、生态环境退化现象,建立汛期以旬、非汛期以月为调度时段的水库生态调度模型,提出3种联合调度方案,并采用逐步优化算法求解,结果表明,在满足各区间用水户现状用水的条件下,各控制断面流量均能满足生态流量的要求。     

基于北斗卫星导航的秸秆机械化还田作业管理系统

为满足秸秆机械化还田作业精准化管理的需要,解决还田工作中作业面积统计困难、现场核查工作量大、全局管理难以实现等若干现实问题,设计了基于北斗卫星导航的秸秆机械化还田作业精准管理系统。系统集成北斗卫星导航定位、物联网、地理信息系统等信息技术,通过北斗卫星导航农业机械车载信息终端,实时采集、处理秸秆还田作业中的定位和状态数据,获取还田现场的高清影像。通过建立作业管理信息系统,实现作业监控、地块识别、面积量测、质量评估、指标统计和指挥调度等功能。试验结果表明,系统可以有效实现轨迹监控、灵活调度、分类统计分析,提高了秸秆还田机械化作业效率。同时,地块识别率和地块面积统计达到了作业精度要求,可以满足秸秆机械化还田作业的需要。     

Application of a simulation model for assessing integration of smallholder shifting cultivation and sheep production in Yucatán, Mexico

Simulation models are effective tools to examine interactions between livestock, cropping systems, households, and natural resources. Our study objective was to use an integrated livestock and crop model to assess the outcomes from selected suites of management decisions observed in smallholder sheep-cropping systems of Yucatán, Mexico. The scenarios contrasted specialized systems versus mixed farming, and evaluated the outcomes of increased crop-livestock integration. Mixed enterprise scenarios involving sheep provided more income than specialized enterprises, and capitalized on a lower price of on-farm maize grain, efficient utilization of surplus labor, and availability of common land. Labor and management income was greatest for the unintegrated and partially integrated crop and livestock scenarios. It was more profitable for producers to sell excess grain and maize stover, and use common land to feed the livestock, suggesting that increased integration does not always result in improved outcomes. The results are consistent with a system not yet pushed to the point where integration is inevitable. For all sets of scenarios, the model structure was able to accommodate subtle management differences to produce appropriate biophysical, labor, and economic outcomes. We conclude there is potential to use similar model development methods to describe other crop-livestock systems, thus providing tools for learning, scenario analysis, and impact assessment.     

明流输水隧洞局部坡降变更后的水力学问题

分析了实际工程中长直明流输水隧洞在施工成型后由于测量控制、地质构造或机械操作方面的原因，造成的局部洞轴线偏移和低坡衔接偏差，总结了由此而引起的各种水力学问题，并提出了修复的对策和必要的工程处理方案。     

多功能果园作业平台安全性研究进展

多功能果园作业平台主要应用于梨、苹果等容易因碰撞造成表皮损伤的鲜果采摘,同时兼有果品运输、枝干修剪及疏花疏果等运载平台功能,可显著提高果农工作效率和降低劳动强度。近年来,随着我国果园轻简化管理技术的推广应用,多功能果园作业平台设备快速发展,因平台上作业属于半高空和高空作业,其安全性备受关注。基于多功能果园作业平台的通过性、升降机构、自动调平技术及防侧翻4个方面的研究进展,介绍了履带式及轮式行走装置的优缺点及在国内外的具体应用,套缸式、剪叉式、曲臂式及链式升降机构应用场景,自动调平技术的研究进展及在果园应用中的调平水平、平台侧翻评价指标,以及利用该指标进行侧翻预警和主动防侧控制的方法,并提出多功能果园作业平台农机农艺融合、导航技术及智能机械手等多技术融合方向发展趋势,以期为提高作业平台的技术水平及安全性提供参考。      

Agriculture,population, environment and balanced regional development: A modelling project in Poland

This paper considers a regional agricultural development programme, assuming intensive water systems and irrigation constructions and a build-up of agricultural production. In order to analyse possible future developments and policies, a number of mathematical computerised models were created. These models are briefly characterised, together with their joint functioning as a system of models for multi-aspect regional planning, balancing the various values—economic, social and environmental—involved in any socio-economic development related to agriculture. In particular, a detailed regional agricultural model is presented, along with its mode of operation and an example of the results. The interrelationship of basic development-triggered values and objectives is illustrated by means of these results.     

DéciBlé, a software package for wheat crop management simulation

DéciBlé is a simulation tool intended to support the design and evaluation of technical management for the wheat crop. Crop management is here considered from a strategic planning point of view, as the choice of technical decision rules for the whole growing period rather than day-by-day decisions for each operation. DéciBlé simulates the consequences for technical operations and crop production of a set of decision rules over a wide range of possible contexts (regions, year-to-year weather variation, fields, etc.). It is a simulation in which two models interact: a decision and a crop model. The decision model represents the decision rules through a specific formalisation and generates the operations for each context. The crop model is a set of modules simulating plant development, crop environment and yield accumulation implied by these operations in this context through the generation of loss functions or risk estimates. The crop model consists of a set of empirical models based on agronomic diagnosis and experimental references widely used in France. A general validation of DéciBlé is carried out using observed data from a network of field trials. The wheat development stages are simulated within 4 days of the observed dates in more than 80% of the cases and the yield components and final yield with differences of less than 15% from the real values in more than 75% of the cases. We discuss (i) the causes of unsatisfactory predictions and the prospects for improving the various modules of the crop model; (ii) the use of the simulator in some decision problems; and (iii) the position of DéciBlé among the existing models for crop management decision help, emphasising the originality of the method of decision representation.     

电动拖拉机快速原型平台测控系统设计与试验

针对目前对电动拖拉机试验平台测控系统的设计方法较少的问题,提出了一种可重构测控系统的设计方法.根据拖拉机旋耕机组的工作特性要求,搭建了一种串联式混合电动拖拉机快速原型试验平台.该平台采用双电机独立驱动结构,结合dSPACE和Matlab/Simulink建立了实时测量控制系统,提出了通信模块化和控制策略模块化的设计方法...     

灌溉渠系运行计算机模拟技术的开发

借鉴日本以及其他国家在灌溉渠系水管理方面的成果和经验，结合我国灌区的实际情况，建立了较完整的渠系运行模型，编制了具有一定通用性和可扩充性的计算机模拟软件。实践表明，该软件对于测试和评价渠系的力学特性、工程控制特性和管理调度特性是有效的，它为改进灌区水管理提供了一个科学、简便、可行的技术手段。     

Conserving natural resources in olive orchards on sloping land: Alternative goal programming approaches towards effective design of cross-compliance and agri-environmental measures

Olive farming on sloping land in southern Europe is facing multiple challenges and it is reasonable to believe that farmers will opt for the abandonment of some systems and intensification or change to organic production of other systems. The issues at stake surpass financial farm viability and two EU policy instruments - cross-compliance and agri-environmental measures (AEM) - are available to address environmental objectives. This paper explores how cross-compliance and AEM policy options may lead to shifts in olive production systems and their social and environmental effects in Trás-os-Montes, NE Portugal over 25 years under two sets of conditions of uncertainty: decision-making by land users and market scenarios. Uncertainty in decision-making is addressed by employing five alternative goal programming models. The models include Linear Programming (LP), Weighted Goal Programming (WGP) and MINMAX Goal Programming (MINMAX GP), the GP variants of which are moreover formulated from a societal (S) and farmer (F) perspective. Uncertainty in market prospects is addressed by projecting olive oil and labour prices and trends in farm subsidies, distinguishing four price combinations in market scenarios. The models were validated by their capability to reproduce the initial configuration of olive production systems. Six policy options are evaluated under the complete ranges of uncertainty factors in a total of 6 × 5 × 4 = 120 model runs. Results show overall large effects of farmer decision-making and market scenarios. The cross-compliance and AEM policy instruments have an unequivocal effect on environmental performance and help to maintain work in rural areas. However, farmer income levels are insensitive to the policies, all work is absorbed by family labour and important environmental issues linked to more intensive systems such as pollution are not addressed. In a case study with the WGP (F) model which best reproduced the initial configuration of production systems, cross-compliance was moreover found to burden farmers under adverse market conditions, while AEM contributed to farmer’s objectives under favourable market conditions. A solution would be to focus cross-compliance regulations on intensive systems and offer appropriate AEM for traditional or abandoned orchards. Both policy instruments proved effective, but there is scope for removing substantial overlap between them.     

Modelling the interactions between regional farming structure, nitrogen losses and environmental regulation

Changes in the structure of agriculture are known to affect emissions of environmental pollutants from agriculture. Such changes are often driven by structural changes in agricultural production, so structural changes are likely to have indirect effects on emissions. In a pilot study, we consider how linking two complementary simulation models might be used to explore these effects. The agent-based AgriPoliS model was used to simulate the structural dynamics of agricultural production. The results from AgriPoliS were passed via a number of intermediate models to the Farm-N model, which was used to estimate the nitrogen surplus and losses from each farm for each year.The modelling complex was exercised by simulating the effects of two plausible policy scenarios for each of 14 years. The initial sizes and types of farms were based on statistics from a region in Denmark and the farms were randomly distributed within this region. The reference scenario (REF) implemented the current area-based Common Agricultural Policy payments for Denmark. The 1 LU scenario applied the additional constraint that a minimum area of 1 ha land had to be available for the application of the manure produced by one livestock unit.Substantial changes in the structure of agricultural production were shown for both scenarios. The effect on the regional nitrogen surpluses was predicted to differ between scenarios and the contribution of the different farm types to change with time. Predicted ammonia emission changed with time and differed between the scenarios, whereas the Danish fertiliser and manure legislation meant that nitrate leaching remained fairly stable.The implementation of additional environmental legislation significantly changed the trajectory of structural adjustment processes. Results emphasize the complex interplay between structural changes, losses of nitrogen, and environmental regulation.It is concluded that the effects of structural change on environmental emissions can be usefully explored by linking agent-based models of farmers’ investment decisions with other models describing nutrient losses from the farm and that such modelling can play a useful role in designing effective environmental policies for agriculture. However, the approach demands the availability or collection of many region-specific data and this could create a barrier to its use.     

阻力控制系统负载模拟器的设计

负载模拟器是进行动力机械室内模拟试验的必要设备。本文针对以往负载模拟器设计方案存在问题,在拖拉机阻力控制系统动态特性室内模拟试验台的设计中提出了改进设计方案,对一般动力机械负载模拟器的设计有普遍参考价值。     

涌泉灌双向流流道稳流器工作机理与水力性能分析

为了研究双向流稳流器流道结构的水力特性,以其内部双向流形成装置和结构参数为研究对象,取流道结构参数八字形分水件张角α,V字形挡水件张角β、八字形分水件中部过水孔宽度d为因素安排试验方案,利用激光精雕技术制作稳流器样机进行水力试验,测得0.05~0.21 MPa等9个不同压力对应的流量值,应用多元回归拟合其流态指数在0.476~0.501,其水力性能良好;同时采用水力学计算方法,计算当稳流器工作水头分别在5~15 m时,流道总局部损失系数为18.3~19.8,大约是1组传统流道形式局部损失系数的4~10倍,从水力学计算的角度表明双向流流道消能效果的优越性;采用Minitab软件的Gauss-Newton算法进行多元回归,迭代次数设为200次,建立流态指数与结构参数之间的回归方程,通过显著性检验和相关系数检验结论一致,均显示回归效果具有统计学意义,且各因子的系数均有意义,为其流道参数化设计、结构优化以及在农业工程中的研发与应用提供了理论依据.     

Optimum irrigation and pond operation to move away from exclusively rainfed agriculture: the Boru Dodota Spate Irrigation Scheme, Ethiopia

Under rainfed agriculture without supplementary supply, crop failure due to erratic rainfall has become a common phenomenon in many regions of Ethiopia. Spate irrigation development with storage provision at the 5,000 ha Boru Dodota Spate Irrigation Scheme is one of the initiatives to move away from exclusively rain-dependent agriculture. This initiative has faced several challenges. Lack of design experience and failure to fully grasp the unpredictable nature of the spate flow caused the Boru Dodota Spate Irrigation Scheme to be implemented without considering the necessity of storage ponds. In addition, absence of a systematic approach to assist planners has resulted in non-optimal design of ponds’ capacity and operation. The study, on which this article is based, aimed at optimum storage operation to irrigate the maximum possible area with the existing ponds’ capacity and available water resource. During the study, the surface storage and irrigation scheme planning model was developed and used to analyze several pond operation scenarios in Boru Dodota Spate Irrigation Scheme. The main findings were as follows: (1) Supplementing the rainfall with the operation of the existing 19 ponds that enable weekly irrigation frequency results in irrigating at least 6,600 ha. (2) An increase in the number of ponds does not always guarantee an increase in the size of irrigated land because the water resources, the operation, and management are defining factors. (3) It is not economical to only rely on spate flow for irrigation as even with 200 ponds, a maximum of 1,250 ha could be irrigated.     

Decision-making processes for crop management on African farms. Modelling from a case study of cotton crops in northern Cameroon

Recent work on decision processes on French farms and irrigated systems in Africa has shown that farmers plan their cyclical (recurrent) technical operations, and that one can model this planning process. Taking the case of cotton crop management in North Cameroon, we show that with certain adjustments, modelling of this kind can also be done for rainfed crop farming in Africa. The adjustments are needed to take account of the differences in social status between different fields on one farm and the implications of the fact that farm work is primarily manual. This produces decision models with a similar structure to that described for technical management of an annual crop break in a temperate climate using mechanised implements. Not only do these models give us a detailed understanding of the variability of farming practices, we can also classify them into categories according to weather scenarios yield level as a function of weather scenario. We show that one can attribute farms to these types of model using simple indicators concerning work organisation. By analysing North Cameroon farmers' decision processes for managing cotton crops we can thus produce an effective tool for organising technical supervision of farmers at the regional level: advisers can work with these decision model types by measuring some simple indicators at farm level to predict which types of model are applicable, without the onerous work of constructing individual decision models.