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Technical Paper

Yield Mapping with Digital Aerial Color Infrared (CIR) Images

Yield potential was predicted and mapped for three corn fields in Central Illinois, using digital aerial color infrared images. Three methods, namely statistical (regression) modeling, genetic algorithm optimization and artificial neural networks, were used for developing yield models. Two image resolutions of 3 and 6 m/pixel were used for modeling. All the models were trained using July 31 image and tested using images from July 2 and August 31, all from 1998. Among the three models, artificial neural networks gave best performance, with a prediction error less than 30%. The statistical model resulted in prediction errors in the range of 23 to 54%. The lower resolution images resulted in better prediction accuracy compared to resolutions higher than or equal to the yield resolution. Images after pollination resulted in better accuracy compared to images before pollination.
Technical Paper

Yield Mapping of Soybeans and Corn Using GPS

Data obtained when harvesting with a combine equipped with a yield monitor were used to develop yield maps. A prototype yield monitor was developed that uses a combination of light emitters and receivers mounted in a rectangular frame. The monitor was mounted in the combine in the top of the clean grain elevator. As grain flows through the monitor, a voltage change proportional to light reduction was recorded. This voltage was then correlated to grain flow rate. At the same time, site-specific location was recorded using the global positioning satellites (GPS) system. The location data, yield monitor output, cutting width, and combine forward speed were stored in a spreadsheet format. The data were then used to prepare the yield maps.
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Wiley SAE MOBILUS® eBook Package

Committed to being the primary source for aerospace and ground vehicle engineering resources, SAE International has added the full compilation of our Wiley eBook collections to the SAE MOBILUS® technical resource platform. Purchasable as an annual subscription and containing the titles from the Wiley Aerospace Collection, the Wiley Automotive Collection, the Wiley Computer Systems Collection, and the Wiley Cyber Security Collection.
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Wiley Computer Systems Collection Add-On

As an annual subscription, the Wiley Computer Systems Collection Add-On is available for purchase along with one or both of the following: Wiley Aerospace Collection Wiley Automotive Collection The titles from the Wiley Computer Systems Collection are included in the SAE MOBILUS® eBook Package. Titles: Real-Time Embedded Systems FlexRay and its Applications: Real Time Multiplexed Network Multiplexed Networks for Embedded Systems: CAN, LIN, FlexRay, Safe-by-Wire... Object Detection and Recognition in Digital Images: Theory and Practice Computer Vision in Vehicle Technology: Land, Sea, and Air Mobile Intelligence Other available Wiley collections: Wiley SAE MOBILUS eBook Package Wiley Aerospace Collection Wiley Automotive Collection Wiley Cyber Security Collection Add-On (purchasable with the Wiley Aerospace Collection and/or the Wiley Automotive Collection)
Technical Paper

Why Not 125 BMEP in an L-Head Truck Engine?

HIGH output per cubic inch of piston displacement is desirable not alone for the purpose of being able to transport more payload faster, but more particularly for the invariably associated byproduct of lower specific fuel consumption, and especially at road-load requirements. The only way of accomplishing this purpose is through the use of higher compression ratios, and the limiting factors for this objective are fuel distribution and the operating temperatures of the component parts. A manifold is proposed which not only definitely improves distribution at both full and road loads, but has the inherent additional advantage of reducing the formation of condensate, thus still further facilitating a reduction in road-load specific fuel consumption. Hydraulic valve lifters, obviation of mechanical and thermal distortion, and controlled water flow are the essentials in improved cooling.
Technical Paper

Weed Recognition Using Machine Vision and Color Texture Analysis

The environmental impact from herbicide utilization has been well documented in recent years. The reduction in weed control with out a viable alternative will likely result in decreased per acre production and thus higher unit production cost. The potential for selective herbicide application to reduce herbicide usage and yet maintain adequate weed control has generated significant interest in different forms of remote sensing of agricultural crops. This research evaluated the color co-occurrence texture analysis technique to determine its potential for utilization in crop groundcover identification. A program termed GCVIS (Ground Cover VISion) was developed to control an ATT TARGA 24 frame grabber; and generate HSI color features from the RGB format pixel data, HSI CCM matrices and the co-occurrence texture feature data.
Technical Paper

Wear Trends of Axial Piston Type Pumps Operating in Severe Environments

Axial piston type pumps are often exposed to severe operating conditions because of the duty cycle, the environment, or, in some situations, poor maintenance and even abuse. The detrimental effects on the pump and the hydraulic system as a result of these adverse conditions are often not known or predictable. In this study, four controlled severe operating conditions were imposed on four identical axial piston type pumps. They included 1) constant high load pressure and normal fluid temperature, 2) constant high load pressure and elevated fluid temperature, 3) cyclic load pressure and normal fluid temperature, and 4) cyclic load pressure and elevated fluid temperature. The tests were long-term; they were run continuously for up to 5000 hours. The pump wear was monitored in all cases using ferrography. In addition, the condition of the fluid was monitored and the circuit filters were examined periodically. The results of the findings are presented in this paper.
Technical Paper

Vision Assisted Tractor Guidance for Agricultural Vehicles

Computer algorithms were developed for generating the guidance parameters necessary to steer an agricultural tractor. A variety of field operations were considered in order that the guidance program be suited for general applications including travel in curved rows and following a single edge. Testing of the guidance algorithm was performed in the laboratory using simulated and videotaped images of rowcrops and tilled soil. From the images, yaw angle change of the tractor, direction value and offset error were computed. Prediction of the direction value and offset error compared well to measured values. Accuracy of the direction value was within +/- 0.5 degrees while the offset error was within +/- 0.05 meters. Good performance was observed for straight and curved rows as well as following a single edge.
Technical Paper

Virtual Instrumentation of a Soil Bin for Improved Precision

The existing instrumentation of a soil bin was retrofitted with virtual instrumentation techniques to achieve improved repeatability and more precise measurements. Current-loop sensors were added to the prime mover for improved speed control. Soil preparation operations were instrumented to determine penetrometer forces as a function of soil penetration depth, soil surface smoothness, compaction force, and soil surface elevation. Test hitch-points for agricultural implements were instrumented with wheatstone bridge force transducers. Implement depth was found with ratiometric linear transducers. Distance and speed determinations utilized an optical encoder with a resolution of 3.0 × 10-4 m. Temperature measurements were also recorded with solid state current transducers.
Technical Paper

Vickers New PVH Variable Volume Pumps

This paper outlines the design philosophy and evaluation of the new “H” series variable displacement, medium pressure, open-circuit, axial piston hydraulic pumps. The “H” series is based on previously existing, technically successful, rotating group designs, but has significant design improvements affecting the areas of: Unit Weight Envelope Size Ease of Assembly, Disassembly, Repairability and Modification Alternate Fluid Capabilities The “H” series is a family of naturally aspirated pumps nominally rated at 250 or 275 bar (3625 or 4000 psig), depending on system operating parameters. The geometric displacements of the four units in the series are as follows: 57cc (3.5 cu. in./rev.) 74cc (4.5 cu. in./rev.) 98cc (6.0 cu. in./rev.) 131cc (8.0 cu. in./rev.)
Technical Paper

Vehicle-borne Scanning for Detailed 3D Terrain Model Generation

Three-dimensional models of real world terrain have application in a variety of tasks, but digitizing a large environment poses constraints on the design of a 3D scanning system. We have developed a Mobile Scanning System that works within these constraints to quickly digitize large-scale real world environments. We utilize a mobile platform to move our sensors past the scene to be digitized - fusing the data from cm-level accuracy laser range scanners, positioning and orientation instruments, and high-resolution video cameras - to provide the mobility and speed required to quickly and accurately model the target scene.
Technical Paper

Vector Control of a Hydraulic Crane

Mobile hydraulic equipment are today operated manually to a very large extent. There are, however, some applications where substantial benefits would be obtaind if some kind of feedback and more sophisticated control was used. One such application is the control of a crane. Usually the operator controlls the flow to each of the pistons so that the crane tip is moved in the desired direction (Fig. 1). Since many mobile hydraulic valves packages have electronic input and there exists built in position transducers for the pistons, it seems to be rather straightforward to introduce vector control of the crane tip directly. That is, the operator commands controlls the direction and speed of the crane tip. Here, a control algorithm is described that allows the use of mobile electrohydraulic proportional valves while still having accurate vector control of the crane tip.
Technical Paper

Various Types of Failures in Rolling Bearings

Several papers have already been published on the subject of failure analysis of rolling bearings. These papers are very useful. However, with the advancement of bearing technology bearings are increasingly being used in more severe applications. As a result, bearings are experiencing types of failures not described in previous publications. This paper focuses on the quick diagnosis of failed rolling bearings using a magnifying glass or microscopy of low magnification with the emphasis on those failures which have not been previously described.
Technical Paper

Using Modern Technology to Improve Truck Seating

Many advancements have been made through the use of technology that give seat manufacturers the capability to provide greatly improved truck seats. Until recently the design and development of new seating was accomplished primarily through static surveys. Modern technologies available today will reduce cost, development time, and the overall effort associated with utilizing real people to develop a seating project. In many instances when these seats were placed into vehicles with actual truck drivers riding in them for many hours a day, the drivers inputs resulted in multiple revisions to the original seat to satisfy their comfort issues. With modern technologies such as computer generated seat modeling, pressure mapping, and our state of the art test equipment such as a six–axis ride simulator, it has become part of any new seat development program to acquire field ride data in specific trucks and duplicate these inputs in the test laboratory.
Technical Paper

Using Cartridge Proportional Valves for Greater Productivity

To increase productivity a new concept of proportional pressure, flow and control cartridges have been developed to enhance vehicle operation at a reasonable cost. Actuators have also been developed to stroke directional valves, or piston pumps and motors. These low power consumption devices readily interface with microprocessors. Engineers have been looking for new generations of electrohydraulic valves which will increase operator performance by simplifying the operation of vehicles with automatic controls where possible plus eliminating the brute strength manual type valving to decrease operator fatigue. Maintenance has always been a severe set back to productivity. By utilizing effective yet efficient cartridge proportional valves that are designed for simplicity of use and repair, drastic savings are shown. Previous designs were bulky and very contamination sensitive. They did the job, but were both expensive and had very high maintenance levels.
Technical Paper

Using CONCHAS-Spray to Simulate the Process of a Methanol Fueled, Direct Injection Engine

The compression, combustion, and expansion portions of a two-stroke cycle, direct methanol injection engine was simulated using the CONCHAS-Spray computer code. The input and comparison data was supplied from a Detroit Diesel Allison production engine operating on methanol fuel. Calculated values of both cranking and firing chamber pressure were lower than reported from the engine. The injected fuel did not entirely evaporate which caused regions of fuel impinging on the cylinder walls and piston face. The simulation did predict the formation and accumulation of formaldehyde in the regions of unburned fuel and is consistent with the theory that the formaldehyde does not readily decompose at low temperatures and forms from the incomplete oxidation of the fuel.
Technical Paper

Use of a Two-Stage Electrohydraulic Controller With an Axial Piston Pump

This paper presents a mathematical model of an axial piston pump/two-stage electrohydraulic controller combination. The controller uses swashplate position feedback and has been specially designed so that it is of low-to-moderate cost and so that it can respond quickly to control changes. The first stage of the controller makes use of a squeeze film damper and is dynamically stable. The model may be used for design purposes inasmuch as geometry and operating conditions can be varied over wide limits and the resulting dynamical behavior evaluated. Calculation of the dynamic response to a control current for the operating conditions and geometry of the valve shows close agreement with experiment.