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Control of the Clutch is a complex system with multi-infactor, multi-goal and nonlinear properties, the fast tracing capability should be needed at the same time, so the fuzzy control is suitable for it. The difficulty of the clutch fuzzy control is how to analyze its stability. In this paper, the theory of Lyapunov and linear approximation is applied to analyze and design the stability of the clutch fuzzy control, which is a practical method in analysis of the stability of nonlinear systems.

Compact excavators are designed to perform a variety of functions within a small vehicle envelope. The vehicle size presents constraints on the structure as well as the hydraulic system. A unique open-center hydraulic system has been designed and developed which optimizes system performance, size, and cost. The hydraulic circuit was designed to provide smooth, reliable operation of as many as ten vehicle functions simultaneously.

This paper compares the performance of a radius lip wiper and sharp lip wiper. Both wiper styles were tested for a paired comparison of leakage, wear, and ingression resistance. The results show that using a radius lip wiper allows the fluid to adhere to the rod, giving the fluid a greater opportunity to reenter the system instead of being scraped off by the wiper and accumulating as apparent leakage. This decrease in apparent leakage does not have an adverse affect upon the wipers original intended function: preventing ingression of contamination into the hydraulic system.

This paper relates to the increase in speed and pressure ratings of piston type hydraulic pumps and motors. Such units are typically used as components in hydrostatic transmissions. Without a substantial change in basic design, the introduction of fixed losses to fulfill these ratings adversely affects the partial load efficiency of those units.

The electronics in the JCB Wheeled Loader represent an integration of the requirements of the operator, the needs for configuration on several models of loader in several languages, and the need for data collection and diagnostic capabilities. A number of challenging technologies are used in the electronics including a large custom LCD panel with backlighting, LED warning indicators, automatic 12V/24V operation, real-time clock recording of fault conditions, and CE approval. The Windows-based software tool allows settings to be altered and logged data to be viewed to monitor the operation of the loader and assist with diagnostics of faults.

In many areas, neural network technology has made a successful transition from theory to practical application, primarily due to the advances that have been made in computer technology and digital signal processing. Research at the University of Saskatchewan over the past few years has focused on applying neural network technology to fluid power systems. This paper will examine four projects that have been initiated by the authors and their graduate students which use neural networks for purposes of open loop pattern following, multiple input - multiple output control, indirect measurement of actuator displacement, and hydraulic component identification. A brief introduction to static and dynamic neural networks is given. Descriptions of the individual project objectives, the experimental implementation of neural networks to achieve these objectives, and some typical experimental results are considered.

Many mechanical systems employing fluid power use one or more valves to control fluid flow. Often these valves can be quite complex, with many inlets and exits, reversing flow, flow and pressure control, and other unique features. It is desirable to model these valves and the associated fluid and control logic circuits with software during the design phase, and explore the effect of design changes on system performance using simulation and other analyses without having to build and modify expensive prototypes. A number of commercially available software packages offer various methods for “graphically modeling” dynamic systems, and some, offer the user pre-defined libraries of hydraulic components that greatly speed the modeling process. However, the variations on valve design are unlimited, and it is often necessary to model a hydraulic valve that has not been previously defined. This paper describes an approach allowing essentially any valve configuration to be modeled.

The application of site-specific agriculture has created a rapid need for technology in the farming community. An area of particular interest is that of utilizing spatially related data to more efficiently apply crop inputs. This has commonly been accomplished through the analysis of field characteristics, the use of variable rate application of farming inputs, and the analysis of yield outputs. Global Positioning Systems have been utilized to provide the real-time location information necessary for correlation of mapping and application systems. The techniques presented in this paper describe the application of navigation systems to agriculture, as navigation overcomes many of the limitations of standard GPS systems. This navigation research has spurred the development of a coupled GPS and INS system designed to advance the state of Site-Specific Agriculture.

Precision farming involves doing the right things in the right place at the right time. Combine yield mapping systems are documenting considerable yield variation within typical fields and should encourage improved crop management for higher profits and less impact on the environment. Variety choice, pest control, drainage, soil type, soil fertility, tillage practices, crop rotation, plant stands, and topography are a few of the factors causing yield variation. Managing these causes will require a much more detailed, yet holistic approach to crop production. Precision farming tools make on-farm research easier, which should help producers make more informed management decisions.

A peculiarity of all-wheel drive off-highway vehicles is that their running abilities (cross-country mobility, tractive and velocity properties, turnability and the like) depend not only on total traction effort but also on its distribution between driving wheels. The latter is in great measure determined by actuating vehicle system and characteristics of the mechanisms installed in power dividing transmission units, i.e. in interwheel, interaxle reduction gears, and transfer cases. The characteristics of locking performance of these mechanisms regulate the circumferential force distribution between driving wheels and, respectively, a vehicle's performance indicators. Such mechanisms have been created and are being created in a multitude. The classification of power dividing mechanisms and system is given. They provide a high level of the traction performance of all-wheel drive off-highway vehicles and agricultural tractors, in particular.

As the use of electronics increases in vehicles of all kinds, multiple manufacturer compatibility issues begin to dominate the system integration. Functionality of electronics is often repeated and duplicated, increasing costs. In order to reduce costs it is some times necessary to combine the functionality of multiple units into a single package. With the combination of power amplifier electronics and microprocessors, Agile has been able to integrate several vehicle functions into an integrated package. A thorough understanding of the vehicle powertrain dynamics is a critical requirement in developing fully integrated control electronics. Development of integrated electronics begins with a full vehicle model and simulation, followed by prototyping with known electronics before a cost optimized design is proposed. Discussion in this paper will cover full vehicle simulation and assumptions to full vehicle performance and results.

Like all industries, the fluid power industry is under increasing pressure to identify and use hydraulic fluids that offer higher performance, improved fire safety, and exhibit improved environmental and toxicological behavior. Recently a novel hydrolube composition has been developed that is capable of being used in hydraulic pumps at pressures of 34.4 MPa (5000 psi) and greater*. In addition to being a Group 1 Fire Resistant Hydraulic Fluid according to the new Factory Mutual Research Corporation's testing methodology, this high-performance hydrolube also exhibits excellent biodegradability and toxicology properties. The objective of this paper is to discuss pump performance, fire resistance, and environmental and toxicology properties of this fluid..

In the application of direct fuel injection to an SI engine the fuel spray characteristics such as droplets velocity and diameter, as well as the penetration length in the combustion chamber - but especially their variation with engine speed and injected quantity - are determining criteria for a mixture formation with the required quality. These characteristics are of particular importance for high speed engines because of the large range of speed variation and become stringent for high speed two-stroke engines where a very short mixture formation time is imposed.

This paper analyzed and studied the in-cylinder flow in two engines. Both are two-stroke loop scavenging 8-cylinder in-line engines. One cylinder diameter is 150mm and the other is 160mm. For researching its loop scavenging performance, one cylinder of both engines is examined. The upper section of the cylinder above the ports is cut off and replaced by a glass one, and the cylinder head is replaced by a plexiglass plate. Then they are mounted on the test bench. A metal screen is put in the glass cylinders. Threads are tied at the screen cross points. The direction of flow in cylinder can be visualized when the air flows. A kind of instrument, named Hot Ball Anemometer, is applied to measure the air flowing speed. The diesel's loop scavenging performance can be realized and satisfactory results obtained.

For a number of years during cotton harvest in California's San Joaquin Valley, a decrease in cotton plant height was noted in the rows adjacent to the traffic path of the tractor. Studies which measured soil compaction and cotton yields for several tractor configurations were conducted over two growing seasons. The first year's study consisted of sandy and clay test plots with four tractor configurations. The highest yield was with a conventional wheel tractor with dual rear tires and front wheel drive. The plot yielded 27% more cotton in the sandy field and 14% more in the clay field over the least producing tractor plot, which was the belted track tractor. In the second year's study, the highest yield was also with a conventional wheel tractor with dual rear tires and front wheel drive. The plot produced 5% more cotton over the least producing tractor plot, also a belted track tractor. Cotton yields correlated with the soil compaction (cone penetrometer) measurements.

Traction systems for agricultural vehicles compact soil much more than the optimal density for crop yield. For this reason crop yields decrease both in the season in which compaction occurs and in subsequent years. That is why the soil compaction problem may be considered an ecological one. Among the well-known traction systems used to decrease soil compaction are; decrease of air pressure in tires, dual wheels, multi-axle wheel and crawler traction systems, improvement of tire deformation properties, etc. However, the analysis performed revealed contradictory results of using the above ways under varying operating conditions. Thus, it is not clear at what soil conditions it is appropriate to apply dual wheels, multi-axle wheel traction systems, or special appliances to increase the propulsion system's contact surface and thereby decrease its compaction. Different traction systems have varying effects on compaction for arable and sub-arable soil layers.

The effect agricultural machinery traffic on soil is minimized in various ways. Some of these techniques are very effective. By creating various designs of traction systems and by using rational parameters, it is possible to attain substantial improvement of operational properties with agricultural machinery. It is possible to increase the mobility and tractive efficiency, to decrease the soil compaction, fuel consumption, etc. This paper will show the operating conditions of tractors and agricultural machinery in Belarus and the requirements for traction systems at various periods of operation. It will also show the experience of creating and developing designs of track and half-track (rubber belted) propulsion systems for tractors and other agricultural vehicles. Such designs have been created for 60 kW tractors, harvesters and other machines. Quickly removable designs of wheel-track systems are proposed.

According to the tractor theory, the operating mass of a tractor is calculated from its traction force required to overcome the resistance of soil-cultivating implements and provisional incidental overloads. Implements' resistance changes are estimated by the coefficient of possible overload -- the ratio of maximum possible resistance to its average value, i. e. the maximum resistance value of the implement is used for calculations One of the regulating agricultural operations in the choice of tractor's operating mass is plowing. Besides, the implement's resistance change with the speed increase of the tractor's aggregate is not taken into account. The operating tractor's mass calculated by this method is by 10…20% different from the optimum operating mass.

In peak periods, producers lose valuable time due to tractor breakdowns because of parts availability and service problems. A survey of 200 producers was conducted across the Province of Saskatchewan to determine problems associated with service and availability of parts. The results show that the dealerships were becoming more responsive to the producers needs. The number of repairs per year and the cost of dealership repairs were high since 14% of respondents were using private mechanics. The number of tractors per producer nearly doubled from the 1960's estimate of two. The hydraulic components were a concern since the cost of repairs was high, and breakdowns were more frequent.

Experiments comparing hollow-core and solid large round bales of high moisture alfalfa hay (20-30 % w.b.) for drying rate on a solar-heated, forced-air dryer showed that hollow-core bales dried more than 50% faster than solid bales of equal dry matter density and moisture content. Results encourage the use of hollow-core bales to develop more compact, simpler, cost-effective designs for solar-heated, forced-air dryers to preserve premium quality hay at reasonable cost in humid climates. Three new machine items will be required, including an attachment for balers to form hollow-core round bales.