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Standard

R134a Refrigerant Charge Determination Test Method

2018-09-11
CURRENT
J3023_201809
The purpose of this document is to establish guidelines for determining the critical R134a refrigerant charge for off-road, self-propelled work machines as defined in SAE J1116 and Agricultural Tractors as defined in ANSI/ASAE S390. It will develop a minimum to maximum refrigerant charge range in which the HVAC system can maintain proper operation. Operating conditions and characteristics of the equipment will influence the optimum charge. Since these conditions and characteristics vary greatly from one application to another, careful consideration should be taken to determine the optimum R134a refrigerant charge for the HVAC system.
Standard

Auxiliary Power Unit Electrical Interface Requirements for Class Eight Trucks

2010-07-06
HISTORICAL
J2891_201007
This SAE Recommended Practice covers the design and application of a 120 VAC single phase engine based auxiliary power unit or GENSET. This document is intended to provide design direction for the single phase nominal 120 VAC as it interfaces within the truck architecture providing power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off.
Standard

Auxiliary Power Unit Electrical Interface Requirements for Class Eight Trucks

2015-12-18
CURRENT
J2891_201512
This SAE Recommended Practice covers the design and application of a 120 VAC single phase engine based auxiliary power unit or GENSET. This document is intended to provide design direction for the single phase nominal 120 VAC as it interfaces within the truck architecture providing power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off.
Standard

Identification of Self-Propelled Sweepers and Cleaning Equipment Part 2 - Machines with a Gross Vehicle Mass Up to 5000 kg

2015-03-27
CURRENT
J2130/2_201503
This SAE Standard applies to all self-propelled machines with a gross vehicle mass up to 5000 kg that are utilized to clean material from outside paved areas, parkland, floors in non-residential buildings and areas principally exposed to pedestrian traffic. Primary methods for material removal can be by mechanical, pneumatic, washing and flushing systems, or in a combination of any system.
Technical Paper

Development of an Electrohydraulic Bin Position Control System for Mobile Harvesting Equipment Using Bond Graphs

1996-08-01
961798
Many of the advances in mechatronic design and electrohydraulic controls have not been fully utilized on mobile equipment. Many operations, like the positioning storage bins on most mobile vegetable harvesting machines are controlled by the driver with a manually operated directional control valve located in the cab. Most storage bins on harvesting machines are located behind the cab, often requiring the operator to look back to view the product and reposition the bin while driving the harvester. Frequently, because of distractions or visual obstructions, the operator can not advance or reposition the storage bin during operation thus causing the incoming harvested product to “back-up” into the grading and conveying systems on the machine. When the product backs-up on the machine, overfilling and excessive product damage occurs. Using bond graph modeling and simulation, a control system to automatically position storage bins on mobile vegetable harvesting equipment was designed.
Technical Paper

Improving Mobile Equipment Performance Using New Flow and Pressure Feedback Technology

1996-08-01
961801
A recently patented transducer introduces new options for controlling and monitoring mobile equipment by measuring flow pressure, and temperature. Traditional flow transducers lack the robustness, accuracy, or responsiveness to be effectively used in actual hydraulic circuits outside the laboratory environment. Pressure transducers are used, but present packaging and cost obstacles to machine designers. Temperature sensors are also available in various subsystems in mobile equipment. Accurate monitoring or control of a fluid system depends upon dynamic measurement of the flow and pressure in a system, but at the same time it is important that the monitoring apparatus is capable of measuring small variations in relatively large flow rates. A new device has been developed in a cartridge format which solves previous limitations. The cartridge mounts easily into a manifold block, and can be produced economically.
Technical Paper

Integration of CAE Tools for Complete System Prototyping

1998-09-14
981981
A major objective of many of today's corporations is reducing time to market for new products. This goal, coupled with the fact that systems are only becoming more complex is driving many engineering organizations to employ the use of virtual prototyping, simulation and control system design software. Unfortunately, despite the promise of these tools, no single dynamic system modeling package allows the engineer to easily prototype all aspects of a complex system; mechanisms, hydraulics, pneumatics, thermodynamics, powertrains and electric drives, digital controllers, state machines and electronics. One solution to this problem is to integrate multiple CAE applications, allowing the end-user to create and manipulate a complete virtual prototype of their entire system. This paper focuses on the work The Boeing Company has done integrating its dynamic system model, simulation, and control tool set, called EASY5®, with other CAE applications.
Technical Paper

Simulation of the Loading Dynamics of a Log Forwarder

1998-09-14
982007
The main purpose of this investigation was to develop the virtual prototype of the whole log forwarder by using ADAMS dynamic system simulation software. The virtual prototype contains hydraulic systems of the loader (except the grapple), mechanisms (steering, bogie axles), tire-terrain interaction, the log loader with structural flexibility and the control systems of the loader. Then the virtual prototype was validated with a simple procedure describing loading dynamics.
Technical Paper

Vehicle Stability Control for Trucks and Buses

1998-11-16
982782
Vehicle and traffic safety improvement is one of the most important targets in the vehicle industry. The introduction of ABS for commercial vehicles, meanwhile standard in various countries, was one of the major safety improvements. This system, based on electronics, sensors and actuators shows what is achievable by controlling brakes of such heavy vehicles at the physical limits under various road conditions. With EBS (brake-by-wire) further safety features are integrated including active access of each wheel brake that allows, independent from the driver to apply the brakes to keep the vehicle stable. Electronic stability control as the overall vehicle control system integrated into EBS leads to a new generation of driver assistance concepts. The concept of Electronic Stability Control (ESC) integrated into EBS, simulation studies of vehicle behavior in critical situations, the control strategies and discussion of test results are the main content of this paper.
Technical Paper

Fire Apparatus Power Management: A Multiplexed Solution

1998-11-16
982767
Fire apparatus are a particularly sensitive vehicle application when considering the management of the electrical power and power distribution system. Modern apparatus are equipped with a multitude of control systems critical to the mission of the apparatus, including engine controls, transmission, water pump, aerial hydraulics, lighting, warning, communications and instrumentation systems. The dependency of fire apparatus on these control systems, coupled with the large electrical loading of the emergency warning and lighting systems, require that a sound power distribution and energy management system be engineered into the vehicle electrical system.
Technical Paper

A New Automatic Depth Control System for Rotary Tillers

1995-09-01
952127
Recently most of the Japanese tractors (10 - 40kw) have been equipped with an electro-hydraulic system for automatic depth and tilt control for the rotary tiller. This is a typical implement for the Japanese rice farming. The improved performance was needed to deal in the following areas. 1. In the muddy and rough soil pan condition, the tillage depth has to be kept at the satisfactory level while the engine speed stays within the operating range. 2. An automatic depth control must apply to rough tillage without using the conventional depth sensor (i.e. rotary tiller rear cover angle sensor). To meet these requirements, an automatic depth and tilt control system was developed. The two control modes (called MC-AUTO and E-AUTO) for the automatic depth control were developed by combining the conventional control method plus a load control method based on the fuzzy control theory.
Technical Paper

Hydrotonic - An Example of On-Board Eletronics Application on Agricultural Machines

1995-10-01
952274
This paper describes the stages of the introduction process of electronic control for the three-point hitch of the hydraulic system on agricultural tractors in the Brazilian market. For a perfect understanding, the basic functions of the hydraulic system, the reasons which took IOCHPE-MAXION to develop a new control system and the great challenge of introducing this new technology will be described. The stages of this development comprised: Assessment of market needs, definition and decision of the system to be adopted, seek for a technological partner, development of application/tests, advantages of the new system and, lastly, the unveiling of this new control system at the EXPOINTER 94 (*).
Technical Paper

Vehicle Control System Validation Testing

1995-11-01
952614
In order to achieve robust and reliable vehicle control system designs, it is important to follow strict testing methods. Most engineers are familiar with test requirements for individual components and devices used in a vehicle control system. Not only do the individual components need to be validated, but also the summation of all elements, including the system's software. There must exist specifications and testing requirements for the entire integrated system. The testing must be designed to validate the entire vehicle control system, so that it can deliver its intended function under a variety of operating environments, conditions and applications. System performance may be influenced by all of the other systems on the vehicle, such as type of: engine, transmission, foundation brakes, air systems, suspension, and retardation. While it is not possible to replicate all operating environments it is important to follow a plan which can effectively validate the system.
Technical Paper

Optimization of Gearbox Ratios Using Techniques for Dynamic Systems

1995-11-01
952604
The objective of this paper is to demonstrate a possibility of optimizing the fixed gear ratios of an automatic transmission by using a special modeling and simulation technique. It is a problem to design the set of ratios in general, and especially for transient driving situations. Sometimes there is a lack of systematic methods to optimize dynamic systems, and particularly vehicle powertrain systems, which is the focus of this paper. The techniques used involve a dynamic engine model and a refined gearbox model. To give each set of ratios a fair judgement, the gearbox control system is calibrated for each new set. The influence of a set of ratios on the vehicle acceleration performance and fuel economy in a given driving cycle is evaluated against an optimization criterion. Calibration of the gearbox control system is performed with stationary analysis. This is the most suitable way with respect to the input signals of gearbox control systems of today.
Technical Paper

Development of Heavy Vehicle Dynamic Stability Analysis Model Using MATLAB/SIMULINK

1995-11-01
952638
A dynamic stability analysis model of a five-axle tractor semitrailer vehicle is developed using the MATLAB/SIMULINK application tool. The linearized vehicle model is utilized to investigate the impending instability limits under various design, and operating conditions. Computer simulations are performed for step steer and a typical highway maneuver as input conditions to generate the yaw response characteristics. The model development is accomplished in a modular form to accommodate interactive re-runs of the model with design variations. SIMULINK modeling provides greater flexibility in development and incorporation of active control system modules in the model in order to investigate possible enhancement of vehicle stability limits.
Technical Paper

A Survey of 4WD Traction Control Systems and Strategies

1995-11-01
952644
Traction Control Systems improve the general safety of a vehicle by providing better handling, directional stability and traction under various driving conditions. Consumers are becoming more aware of the benefits of traction control and the automobile manufacturers are responding with vehicles incorporating various kinds of traction control systems. This paper attempts to organize the various systems by the general principles used in their implementation and strategy. The basic elements of vehicle dynamics and the tire-patch mechanics are described. The influence of other subsystems like suspension and steering on vehicle dynamics is analyzed. The need for and the schemes used for the measurement of the various dynamic parameters are delineated. The advantages and limitations of the various control strategies are also described in relation to vehicle operating conditions.
Technical Paper

Synergy in Air Dryer Performance Multiple-State Processes and Application Requirements

1995-11-01
952675
Today, most truck purchasers specify an air dryer on their new vehicles. There are a variety of product options currently available for drying and cleaning compressed air on trucks, buses, and other vehicles. Clean, dry air has become increasingly important on trucks for the operation of brakes, suspensions, fan clutches, seats, and other components. High air use vehicles, such as bulk haulers, are applications that demand new technologies to solve difficult air system problems. A number of methods can aide in the removal of water and other contaminants from compressed air systems. These methods include: aftercooling, filtration, desiccant adsorption, coalescing, centrifugal force, or some combination of these processes. Effective elimination of contaminants from the system takes additional processes. For instance, dryers which include desiccant must have sufficient purge volume and control systems to regenerate the desiccant material for optimal performance.
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