资源描述
Integrated control of agricultural tractors and implements: a review of potential opportunities relating to cultivation and crop establishment machinery
农业机械一体化系统的设计与实施: 商业机会与潜在市场 作物与环境的评估模型
Computers and Electronics in Agriculture
The quality of work and the output of a tractor-implement combination relies heavily upon the concentration and skill of the operator. Electronic systems are used increasingly to control tractor sub-systems, i.e. engine, transmission, implement hitch, external hydraulics, and driveline, and to monitor or control certain implements. However, current systems operate autonomously, relying entirely upon the operator for coordination. An integrated hierarchical control system could potentially monitor operating parameters pertinent to both the tractor and attached implements and use this information to control relevant tractor and implement sub-systems in a coordinated manner, thereby improving machine performance. Potential opportunities for the application of real-time, integrated, hierarchical control techniques to certain cultivation and crop establishment implements currently in use on European farms are reviewed. Specific implements (and their parameters) considered include primary cultivation machinery (control of working depth and working width), secondary cultivation machinery (control of working depth and seedbed quality) and crop establishment machinery (control of seeding depth and seed rate). Outline control strategies are proposed for these applications, and sensors and other hardware required to implement the control systems are identified. It is speculated that the agronomic and economic benefits which are likely to result from the implementation of the proposed technology, will enable economic justification of the proposed control systems in two to four operating seasons. These savings are likely to result from greater operational efficiency and more precise control of agronomic inputs.
Article Outline
1. Introduction
2. Control system integration
3. Cultivation machinery
3.1. Primary cultivation machinery
3.1.1. General
3.1.2. Parameters requiring control
3.1.3. Control of working depth
3.1.4. Control of working width
3.1.5. Other control opportunities
3.2. Secondary cultivation machinery
3.2.1. General
3.2.2. Parameters requiring control
3.2.3. Control of working depth
3.2.4. Control of seedbed quality
3.2.5. Other control opportunities
4. Crop establishment machinery
4.1. General
4.2. Parameters requiring control
4.3. Control of seeding depth
4.4. Control of seed rate
4.5. Other control opportunities
5. Summary and conclusions
Acknowledgements
References
Automatic end-of-line tuning for a motion inverter in agricultural tractors
Control Engineering Practice控制工程与实践学报
农田拖拉机的小空间转向研究 自动化的田边临埂转向系统设计
End-of-line tuning is a crucial step for any mass-produced system endowed with automatic controllers. As a matter of fact, due to components tolerances and spreads in the production line, the controller tuning performed on a prototype system is never optimal on the final product. In many industrial applications, though, the end-of-line tuning is performed by human testers, and this does not always guarantee an objective assessment of the closed-loop system quality. This paper proposes a systematic way to design an automatic tuning procedure for a motion-inverter controller in agricultural tractors, which allows to significantly reduce the costs of end-of-line tuning and to obtain a homogeneous manoeuvre quality in all vehicles. The proposed automatic tuning system adapts the controller parameters governing the open-loop phase of the manoeuvre until a predefined manoeuvre quality is achieved. The parameters adaptation phase is guided by an on-line objective assessment of the manoeuvre quality from measured data, which allows to automatically classify the performed manoeuvre with respect to its quality attributes. The effectiveness of the proposed approach is assessed on a prototype vehicle.
Article Outline
1. Introduction and motivation
2. System description
3. Controller description
3.1. EVD control strategy
3.2. EVP control strategy
4. Assessing the manoeuvre quality
4.1. Duration index
4.2. Discomfort index
4.3. Symmetry index
5. Automatic tuning algorithm
5.1. Sensitivity analysis
5.2. Auto-tuning algorithm implementation
6. Experimental results
7. Concluding remarks and outlook
Acknowledgements
References
Applications of empirical methods in central Italy for predicting field wheeled and tracked vehicle performance Soil and Tillage Research
Research highlights
Clay–rubber track numeric (Nr) was higher for a four rubber tracks vehicle. Clay–tire numeric (Nc) values were higher for low and medium power wheeled tractors. For mean maximum pressure (MMP) on soil to be 100 kPa, Nc,r should be more than 30. Vehicle cone index (VCI1) and MMP values were similar for low soil contact pressure. Higher Nc,r and traction performance values correspond to lowest VCI and MMP values.
Synthesis and analysis of the steering system of an adjustable tread-width four-wheel tractor
Mechanism and Machine Theory
Precision agriculture on grassland: Applications, perspectives and constraints
精准农业与草场机械:应用、视角和约束
European Journal of Agronomy
Automatic diagnosis of engine of agricultural tractors: The BED experiment
Development of an intuitive user interface for a hydraulic backhoe
液压控制系统的用户界面开发 框架与主干设计思路
Automation in Construction
Effect of vibration isolators in reduction of work stress during field operation of hand tractor Biosystems Engineering
手扶拖拉机的震动与工作舒适性的关系 操作人机工程
An Automatic Depth Control System for Online Measurement of Spatial Variation in Soil Compaction, Part 1: Sensor Design for Measurement of Frame Height Variation from Soil Surface
An Automatic Depth Control System for Online Measurement of Spatial Variation in Soil Compaction, Part 2: Modelling of the Depth Control System
Design, development and performance evaluation of a tractor-mounted bevameter
农用机械与车辆的设计要求:设计开发标准 产品效能评估
The vehicle routing problem in field logistics part I
农场/农村物流/农业物流的这辆路径问题
拖拉机产品
实施
规划
系列
农用车
CAE分析
液压设计
车辆电控系统设计
机械、车辆
汽车及零配件
工作经验
深厚的
研发
Tractors
Implementation
Planning
Series
Agricultural vehicles
CAE analysis
Hydraulic Design
Vehicle Electronic Control System
Machinery, vehicles
Motor vehicles and parts
Work experience
Deep
R & D
98 articles found for: pub-date > 2000 and tak((Tractors or (Agricultural and (Machinery or vehicles))) and ((Hydraulic Design ) or (CAE analysis ) or (Motor vehicles) or parts or R&D or (Work experience) or (Electronic Control System ) or (product and application) or (Implementation and practice)))
12 articles found for: pub-date > 2000 and tak((Tractors or (Agricultural and (Machinery or vehicles)) or (Hydraulic Design ) or (CAE analysis )) and ((Motor vehicles) or parts or Deep R&D or (Work experience) or (Electronic Control System ) or (product and application) or (sales and promotion) or (Implementation and practice) or (Planning and Series)))
An automatic depth control system for shallow manure injection, Part 1: Modelling of the depth control system
Biosystems Engineering
Injection depth has an important impact on the performance of a shallow manure injection system. Therefore, it should be maintained within narrow margins. For this purpose, an automatic electro-hydraulic depth control system was developed, which minimises the difference between the actual injection, measured by means of an ultrasonic sensor, and the desired injection depth. To minimise this difference the relative position of the shallow slurry injector attached to the four-point linkage at the back of a manure tanker was changed with respect to this tanker.
A grey box model was developed for the conversion of the voltage applied to an electronic control unit into the working depth of a shallow manure injector. A simplified and linearised model based on theoretical considerations was developed. The parameters of this model were estimated by means of frequency-domain identification techniques. This model contained all the dominant dynamics of the system that are relevant for control design. Since the dynamics of the system change during manure application, the worst case with respect to the stability of the depth control system was sought by comparing several extreme situations. The case of an empty tanker with the injector above the ground (minimal soil penetration resistance) was found to be the worst case and the model parameters were determined for this case. The resulting model contains an integrator and is of second order in the numerator, and fourth order in the denominator. Along with the non-linear time delay effect this model was found to be suitable for a model-based design of a stable and accurate injection depth controller.
Article Outline
Nomenclature
1. Introduction
2. System description
3. Determination of the model structure
3.1. The electro-hydraulic sub-system
3.2. Tanker sub-model
3.3. Global model
4. Parameter estimation
4.1. Measurement procedure
4.2. Effects of soil–injector interaction
4.3. Effects of the tanker load
4.4. Estimation of the model parameters
5. Conclusions
Acknowledgements
References
一种液压实时电控系统的故障容忍度测试与研究
Fault tolerant real time control system for steer-by-wire electro-hydraulic systems
Mechatronics机械电子工程学学报
A steer-by-wire (SBW) control system is presented with emphasis on safety issues. The applications are in articulated vehicles such as the wheel type loaders, articulated trucks, and others. The electro-hydraulic (EH) power circuit is controlled by two embedded electronic control modules (ECM), the primary ECM and backup ECM. The two ECMs monitor each others condition. If one detects fault in the other, it takes over the control functions. There are two main control algorithms that run in the ECMs in real-time: the steering valve control algorithm and the failure detection algorithm. The valve control algorithm basically generates command signal to the steering valve based on operator steering column signal as well as other machine condition sensors.
The failure detection algorithm implements a fault detection logic for both input sensors and output drivers, and flags the corresponding warning for to the operator, and take a predefined action depending on the type of the failure detected. A unique fault strategy organization is implemented by inspecting the failure behavior on both the component and the system levels. The failure detection algorithm also determines the most likely “good” sensor signal from a set of redundant sensors for each critical measurement. Based on these good sensors data, the steering control algorithm sends two output signals: the control signal to the steering EH circuit valve and the control signal to the steering wheel force feedback device (i.e. a brake or a motor) to give operator feedback about the steering conditions.
Finite state machine (FSM) concept is used to design the fault handling algorithms for both the component level and the system level failure. The probability of the system being at normal steering state or at any other steering failure state is determined. Failure mode probabilities of steering system components are also determined.
Article Outline
1. Introduction
2. Steer-by-wire control system structure
2.1. Steering systems for articulated vehicles current state of art
2.2. Proposed electro-hydraulic steering system description
2.3. Proposed system modeling
2.4. Real time steering control algorithm
2.5. Failure detection algorithm
3. Fault tolerant real time control strategy
3.1. Failure categories
3.2. Failure handling logic
3.3. Finite state machine concept
4. Failure detection and handling algorithm
5. Failure analysis
6. Test results
7. Conclusion
Appendix A. Proposed system state machine analysis
A.1. Transition probability matrix
A.2. State probability matrix
References
Experimental analysis of a motorcycle semi-active rear suspension
Control Engineering Practice
The topic of this paper is the experimental analysis and development of a control system for a semi-active suspension in a 2-wheel vehicle. The control system is implemented via a semi-active electro-hydraulic damper located in the rear suspension of a motorbike. The entire design and analysis procedure is carried out: the semi-active damper is characterized; a wide range of control strategies is recalled and an innovative semi-active algorithm (Mix-1-Stroke) based on a single-sensor layout is proposed. The strategies are then implemented in the Electronic Control Unit of the motorbike. Tests, both on test-bench and on-road, are presented. The result is the comparative analysis of a wide portfolio of different suspension control strategies, which shows the effectiveness of the Mix-1-Sensor rationale.
Article Outline
1. Introduction and problem statement
2. Description of the actuator: the semi-active damper
2.1. Remark: the dead-time τ
3. Control strategies
3.1. Sky-Hook (SH) control
3.2. Acceleration-driven-damping (ADD) control
3.3. Mix-1-sensor control
3.4. Mix-1-stroke control
4. Test-bench experiments
5. Experimental results
5.1. Remark: the damping ratio of the suspension system
6. Conclusions
Acknowledgements
References
Fault-tolerant actuators and drives—Structures, fault detection principles and applications
Annual Reviews in Control
As fault detection and fault diagnosis methods are more and more finding their way into modern industrial mechatronic products, it is now time to take the next step. Based on the research efforts for fault detection and diagnosis, a status report has been prepared for research on fault management, i.e. automatic reactions of the system to continue operation after the detection of faults. These reactions may employ hardware redundancy (i.e. switching from a faulty actuator to another, intact one) or analytical redundancy (i.e. switching from a faulty sensor to a “model sensor” or “soft sensor”).
A total fault-tolerance concept must encompass all components of a system, i.e. the actuators and drives, the process itself, the sensors as well as the controller and communication. In many cases, a degradation of functions has to be accepted after a fault has appeared. Concentrating on some widespread actuation principles, the paper will focus on electric drives and hydraulic actuators.
First, a review is given on fault-tolerance principles and general structural considerations, e.g. hot-standby and cold-standby, focusing on the scheme of an overall fault-tolerant control system. Then, fault statistics for existing actuators and drives will be presented. These fault statistics give hints on the parts of the actuators which a
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