Search Results

Lookup tables and functions are widely used in real-time embedded automotive applications to conserve scarce processor resources. To minimize the resource utilization, these lookup tables (LUTs) commonly use custom data structures. The lookup function code is optimized to process these custom data structures. The legacy routines for these lookup functions are very efficient and have been in production for many years. These lookup functions and the corresponding data structures are typically used for calibration tables. The third-party calibration tools are specifically tailored to support these custom data structures. These tools assist the calibrators in optimizing the control algorithm performance for the targeted environment for production. Application software typically contains a mix of both automatically generated software and manually developed code. Some of the same calibration tables may be used in both auto generated and hand-code [ 1 ] [ 2 ].

With the introduction of new technologies ranging from developing new alternative energy vehicles to passive and active safety systems, the automakers are responding to the increased complexity of the control system by embracing Model Based Design (MBD) and Auto-code Generation (ACG) tools for control system design. This translates into lower development costs, higher quality and faster time-to-market. The Ford Motor Company production hybrid group launched a pilot project to study the feasibility of using MBD to speed up the development and testing of the next generation Torque Monitor software. This software uses a custom data storage format, called Double Store Variable (DSV) format, for all the critical signals. Each variable contains two fields, one for storing the actual data and the second for storing a transformed copy (e.g. one's complement) of the data. This allows the software to detect run-time corruption of the data in real-time.

In an effort to improve the quality of software and take advantage of Lessons Learned, Ford Motor Company has created a generic list of software requirements to help prevent software design errors, mistakes and faults from being delivered to our customer in our vehicles. Ford's intent of publishing these requirements is to provide a basis for an SAE Recommended Practice. Ford's goal is to encourage the software community to participate in the development of a recommended practice that can benefit all software developers. These particular requirements were developed for Automotive Body Features.

The development of embedded systems in automotive environment has brought a strong expansion in the number of applications dependent of programmable devices. A failure in any of these systems may cause different types of damages. Therefore, it requires a high confidence in their operation. Many of these faults are inserted during the coding process. A tool for formal verification of the implemented code could allow the detection of possible errors that could not be encountered during the testing phase. In this paper, we propose a method for verifying software from the reduced model of the software built automatically with information from multiple traces of program executions. To illustrate the application of the proposed method a case study for an automotive electronic module that controls the windshield wiper is presented.

A highly adaptable fatigue testing computer system is presented for controlling single or multichannel test machines. The system imposes most common varieties of waveforms and also provides time synchronization between channels, such as in the case of variable amplitude biaxial load histories, and monitors various feedback signals for both data acquisition and alarm purposes. The program operates in a real-time Unix system as a separate stand-alone process. Communication with other users or the operator is done only through a reserved common block of shared memory. This feature allows control and monitoring of all tests over the computer network. A user can simply login remotely and check the test or start a data acquisition task from any workstation in the company, and then take the data files and analyze them on other computers. This paper describes the operation of the software, the methodology behind the hardware selection and the software structure.

This paper presents a description of intelligent sensor-based manufacturing, reviews previous research in this area, and identifies control system requirements necessary to support successful application of this technology. Current production control systems inhibit the successful implementation of advanced manufacturing control technologies. It is often difficult, if not impossible, to integrate new sensing technologies and advanced control algorithms with existing control platforms. To address this difficulty, hardware and software needs to support intelligent sensor-based manufacturing are discussed.

It is frequently useful to calculate the theoretical composition of the major components of vehicle exhaust. A software program has been written in Basic (or Quick Basic) which allows the convenient calculation of volume percents of CO, CO2, O2, H2, and H2O from fuel composition (H/C and O/C ratios), the water content (dew point) of the combustion air, and a chosen stoichiometry (air/fuel ratio). The program considers the Water Gas Shift reaction and the production of hydrogen under fuel rich conditions. The program is valid for both standard gasolines and oxygenated blends. Vehicle emissions data, collected to compare values calculated by the program with actual experimentally determined values from vehicle exhaust, show good agreement for measurements made at a series of air/fuel ratios ranging from lambda of 0.85-1.2.

In the last few years, there has been a considerable number of applications of microcomputer based systems in the automotive industry. Such systems have advantages in discriminating the signal from the EMI/RFI noise, through software techniques. This paper will explain how easily a system can be affected by EMI/RFI interference and briefly discuss some microprocessor software techniques on possible noise discriminating applications.

A Microcomputer Based Eight Channel Data Acquisition System has been developed for customer correlation and routine vehicle field testing applications. The eight channel system includes a self-contained signal conditioning system designed for a variety of transducer types and data frequency requirements. Calibration, signal gain, and channel zero offset adjustments can be performed under software control. The microcomputer system is based on a Motorola M6800 microprocessor and a non-volatile core memory module. The paper describes the design, development, field performance, and data processing characteristics of the system and presents specific automotive applications and field test results.

Today's electronic instrumentation is almost completely dominated by the microprocessor. Most standard techniques used to protect against electromagnetic interference have been ineffective. This paper presents a design method which allows immunity to higher levels of interference through the synergistic use of hardware and software.

The 1984 Continental Mark VII electronic instrument cluster is reviewed with emphasis on the software algorithm used to store the odometer value in the non-volatile memory. The algorithm, through the use of multiple storage locations, parity checks, and relationship checks, increases the integrity and reliability of the non-volatile memory and minimizes the loss of distance associated with partial memory failures. The criteria and rationale used to develop the algorithm is discussed along with a brief description of the operation of the algorithm.

The development and implementation of a cathode-ray tube (CRT) display automotive information center with navigation feature is described. A structured approach to the TRIPMONITOR software graphics system design is explained. It is shown that beneficial results occur when various features are grouped together into one display and operation system. Emphasis is placed on the human factors of this next generation driver's aid.

Software has becoae an inherent and critical component of electronic automotive instrumentation products. The demand for new software development has been increasing at alarming rates, To meet this demand and still provide quality software, the philosophies and methodologies of software engineering must be understood and utilized. This paper discusses the basic concepts of software engineering, the software development life cycle and software development tools and techniques. It also addresses unique points οf interest that are applicable to software engineering in the electronic automotive instrumentation environment.

This paper describes the software architecture for the Driver Information System available in the 1985 Lincoln Continental Mark VII. This CRT-based system consists of a redefineable touch screen and designated feature keys. An overview is provided describing some of the system features, including a discussion relating to the ergonomic considerations which were given to the product's overall design. Definition of, and interaction between, major components is discussed, including details pertaining to the input conditioning, multiple CPU communication, screen prioritization, and interrupt handling.

Reduced complexity, improved driveability, and increased energy efficiency are among the advantages which can be obtained through Con-board) computer control of powertrains in both conventional and electric vehicles. This paper describes the design and implementation of a control system for an advanced electric vehicle powertrain, incorporating an integrated induction motor and two speed automatic transaxle. The control system employs a distributed computer architecture utilizing a fiber optic communication system for computer coordination. The software architecture utilizes a unique combination of standard multitasking concepts and finite state automata techniques. This approach allows individual tasks to be defined and prioritized and permits data and system resources to be shared effectively. Through the use of torque and gear shift scheduling, internal combustion engine torque characteristics can be duplicated to improve driveability.

Recent advances in electronic acquisition of discrete data have opened new frontiers for the engineer. No longer is lack of data a problem, but rather, the engineer faces new challenges in productively dealing with vast quantities of numbers. The personal computer and associated software provide means to manipulate the numbers and add more value to the results of test efforts. New problems arise in the areas of monitoring test data during conduct of the experiment as indicators and instruments previously used may no longer be available. Traditional methods of reporting results can be altered to provide increased efficiency, while at the same time maintaining commonality with the presentation format of manually acquired data. Problems of how and just what data to archive must be addressed, and systems must be put in place that will allow required access to the data.

For many years, carmakers have developed unique system designs to gain a competitive advantage using some unique technology or an optimization of a design to cut costs or improve quality. This leads to continual increase in complexity, long development times and high development costs. A common platform, based on an "open architecture,'' provides a solution for many of the problems associated with the conventional automotive approach to electrical/electronic system designs. The PC industry is a prime example of how an open architecture can provide benefits to the consumer, manufacturers of software and hardware components, as well as complete system integrators. The PC, based on the initial IBM computer developed in the early eighties, has become a de facto standard that has survived 20 years of fast and dramatic changes in the fundamental technologies used within the platform.

This paper describes a new, open architecture data acquisition and calibration system, called CALVIN, developed for use in the automotive environment. The design is standards based and allows for growth with future technological breakthroughs. A major driver for the design has been the need to use commercial tools and capabilities. CALVIN, based on Windows95/NT/98 and with the careful partitioning of the hardware and software, has allowed the system to achieve the goals of de-coupling the vehicle calibration development process from the tool while allowing for the protection of user-specific intellectual property. The distributed nature of the design optimizes both the utilization cost and performance and thus, allows for an easy growth path as the environment and needs change. Automation of data acquistion and calibration is available through applications that are compatible with OLE/COM such as Visual Basic and C++.

This paper presents how Ford uses decision analysis methodology in product development. An underbody system is used to illustrate this method. The decision analysis methodology breaks down design requirements hierarchically into criteria and sub-criteria and uses a computer based tool to analyze them holistically against different alternatives to arrive at the best choice. With the decision analysis software, we were able to conduct sensitivity analysis around the baseline model to understand the robustness of our decision. We also conducted “what if” analyses on each of the criteria to understand conditions under which the choice would be different.

Suspension roll centers are currently used to establish vehicle handling characteristics such as under-steer and feel. Roll centers were developed to help understand vehicle designs on paper. Computers and mechanism simulation software allows vehicle models to be built and analyzed. Analyzing forces and moments may be a better technique as opposed to modeling suspension roll centers. A proposed method is to look directly at forces applied to the vehicle body and moments resulting from the applied forces. This force-moment method includes the effects of load transfer and tread change, which are not accounted for by geometric roll centers.