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This paper presents the conceptual model and the fundamental mechanisms for software development in the context of the Brite-EuRam project Safety Related Fault Tolerant Systems in Vehicles (nick-named X-By-Wire). The objective of the X-By-Wire project is to achieve a framework for the introduction of safety related fault tolerant electronic systems without mechanical backup in vehicles. To achieve the required level of fault-tolerance, an X-By-Wire system must be designed as a distributed system comprising a number of fault-tolerant units connected by a reliable real-time communication system. For the communication system, the time-triggered TTP/C real-time communication protocol was selected. TTP/C provides fault-tolerance message transfer, state synchronization, reliable detection of node failures, a global time base, and a distributed membership service. Redundancy is used for masking failures of individual processor nodes and hardware peripherals.

The electronically-governed diesel distributor injection pump, with the proven sleeve control of injection quantity, has been in production at Bosch since 1987. Long-term development resulted in a solenoid-valve controlled injection pump. The function and component assemblies, consisting of the injection pump, solenoid valve and control unit, provide an even more flexible injection system. Of particular advantage with this type of system are the high dynamics of the fuel quantity, matching of each individual injection and the exact pump-specific fuel quantity compensation at numerous map points. Further advantages are the selection of timing and fuel injection rate independent of each other, as well as the ability to provide the correct timing even at cranking speeds. The entire system, with emphasis on the injection pump and the solenoid valve, are described for IDI engines in this paper.

In 1978, Bosch was the first supplier on the market to offer full-function antilock braking systems. In 1993, six years will have passed since Bosch delivered the first traction control system for passenger cars. In the meantime, a considerable amount of experience has been gained through ongoing development and testing. This experience enabled us to define the requirements for directional stability, optimum control strategy, maximum usage of the entire spectrum of drive torque intervention possibilities, and optimized hydraulics for automatic brake intervention. The result is Bosch ABS/ASR5, which in now being introduced to the market. This new ABS/ASR family is designed in modules, which offers high flexibility in function and assembly. Systems are available with traction improvement, or with optimized directional stability and traction. Each version is adapted to the needs of the vehicle drive layout, and adaptable to customer requirements.

A single-chip integrated barometric pressure sensor using bulk silicon micromachining will be presented in this paper. The sensor chip incorporates the complete signal evaluation and trimming of the temperature coefficients and manufacturing tolerances. Sensor chips are mounted onto 6″ × 4″ thick film substrates for batch processing during assembly and trimming. The separated, individual devices can be used for surface mounting (SMD) on a printed circuit board (PCB). Specifications for the sensor functions, as well as the assembly and packaging concept, will be discussed. Assembly, trimming and packaging are the most expensive production steps in the manufacture of sensors. In order to reduce the costs for sensors, we are introducing a standardization of sensor assembly and trimming with batch processing capability: after dicing, the integrated sensor chip is attached to a 6″ × 4″ thick film ceramic substrate with standard die-attaching glue.

This paper presents a system concept for detecting combustion misfire. The relevant research grew out of the more stringent requirements for On-Board Diagnostic systems (OBDII) mandated by the California Air Resources Board (CARB), effective as of model year 1997 onward. The system concept is based on evaluation of variations in crankshaft speed. Processes using engine roughness are applied in non-critical operating areas and/or on engines with a small number of cylinders. The modulation process is used in more critical areas. Research was done using a 12-cylinder engine and indicated the potential to comply with the California Air Resources Board's regulations for the model year (MY) 1997 and later.

This paper presents advanced planar ZrO2 oxygen sensors being developed at Robert Bosch using a modified tetragonal partially stabilized zirconia (TZP) with high ionic conductivity, high phase stability and high thermo-mechanical strength. Green tape technology combined with highly automated thickfilm techniques allows robust and cost effective manufacturing of those novel sensing elements. Standardization of assembling parts reduces the complexity of the assembly line even in the case of different sensing principles. The sensor family meets the new requirements of modern ULEV strategies like fast light off below 10 s and linear control capability as well as high quality assurance standards. High volume production will start in 1997 for European customers.

The usage of Electronic Diesel Control is increasing with todays stringent emissions regulations. This requirement also necessitates that such systems be versatile to meet the needs of the engine/vehicle manufacturer. EGR, start of injection, and fuel delivery can be electronically controlled. Depending on the design goals of the manufacturer any one or two of these can be controlled for partial and all of them for full Electronic Diesel Control. The development and application process has several critical areas. These include, development of the sensors, application of the different subsystems, failure warning and failure mode operation. All of these must be combined if design goals are to be met. As the capabilities of electronics increase it follows that electronic vehicle systems will also improve. Today impressive results have been achieved with systems that are in full or pilot production.

Modern agricultural tractors are equipped with a hitch control system. These may be mechanical-hydraulic, hydraulic-hydraulic, or electronic-hydraulic. With the variety of design options open to the tractor manufacturer, it is important to select the system which best fits the manufacturer and end user. This paper presents a comprehensive comparison of each system. Robert Bosch has had many years experience in the design and manufacture of components for hitch systems, and hopes to help designers choose the approach best suited for them.

The article describes the methods, which are employed in order to ensure high performance, safety and quality of ABS and ASR. System behaviour is evaluated and optimized by computer simulation. Moreover, a real-time simulator has been developed by which the consequences of hardware defects can be investigated systematically, Despite the increasing use of simulation the testing of vehicles remains the most important tool for system evaluation. For that purpose, a digital data acquisition system has been developed and objective evaluation criteria have been established. In order to achieve high product quality the Failure Mode and Effect Analysis (FMEA) is carried out at an early phase of development. Another prerequisite for high product quality is thorough durability and endurance testing before release of production.

Current vehicle concepts necessitate the multiple measurement of several variables required by separate electronic systems in the motor vehicle. There is the need to make sensors bus capable by the incorporation of electronic components in new definition concepts, in other words to make them multiply usable. Such bus concepts are at the present time taking concrete shape. The step of introducing electronics - especially digital - to the measuring point may simultaneously be used to considerably improve utilization of the information content of sensor structures using means of indivdual, digital correction to a greater level than has until now been technically possible. There remains the demand for high stability and reproducibility of the sensor properties over time. These signal preprocessing and information condensation processes on the spot also satisfy the need to relieve the central control units.

Commercial vehicles must convey people and goods safely and reliable, irrespective of the weather and road conditions. The ABS safety braking systems are an essential prerequisite for fulfillment of this primary task. ABS has been used in European commercial vehicles since 1981. Today there are already fittet as standard in buses to some extend. The contribution to increasing road safety is causing the European lawmakers to make ABS statutory for commercial vehicles and to make it part of their compulsory equipment. Suitable anti-lock braking systems and closed loop configurations for commercial vehicles are demonstrated by theoretical observations and technical driving trials, their axlespecific and closed-loop control characteristics are highlighted.

High performance Antilock Braking Systems (ABS) are well known to allow for very rapid pressure changes in the wheel brake cylinders. Recordings of the wheel speed during ABS control show oscillations just after the rapid pressure changes. The oscillations can not be explained by simulation if the usual stationary brake force versus slip curves are used. Thus the investigation of the oscillations requires a different approach to the modelling of the tire. As a first step in the alternative modelling of the tire the forces and moments on the running tire were measured using an experimental car. During the measurement the pressure in the wheel brake cylinder was modulated stepwise. A new Rotating Wheel Dynamometer was used to take those measurements. The results showed that the oscillations which were observed in the wheel speed could also be found in the braking force on the tire. Contrarily, the corresponding oscillations could not be found in the braking torque.

Antilock Braking Systems (ABS) and Traction Control Systems (ASR) should ensure maximum stability and steerability even under extreme driving conditions. Since high performance systems additionally improve brake distance and traction within the given physical limits, every vehicle equipped with ABS and ASR offers considerably higher active safety. ABS was introduced into the market by the Robert Bosch GmbH more than ten years ago, and more than 3 million systems have been produced by the end of 1988. Volume production of ASR began in 1987. This paper describes several high-, medium-, and low performance concepts and compares them with regard to safety and performance. Although it seems to be nearly impossible to define a cost/benefit ratio between monetary values and safety, our purpose here is to identify further development strategies through the use of a decision matrix.

Bosch's antilock braking system (ABS) is available for any type of vehicle design. It has been developed in cooperation with vehicle manufacturers and users. Safety and reliability were the eminent targets of this development. A new feature is a self-diagnostic system.

Despite the tough environmental conditions facing electronic systems in commercial vehicles, electronics is gaining ground also in these applications. In the drive sector it improves the operation of the main and auxiliary drives, upgrades fuel efficiency and reduces emission pollutant levels. It enhances safety by preventing wheel spinning in braking and acceleration. Electronic displays reduce the number of single indications otherwise needed, thus making for more clarity in information for the driver and facilitating the driver's task. Self-diagnosing and integrated emergency operation (“limp home”) capabilities are to ensure availability, a factor of special importance in commercial vehicles. A data interface standardized as widely as possible would allow add-on systems to be coupled easily and flexibly.

Alongside steering, accelerating and braking are the basic operations in the automobile which are nowadays still left to the driver to perform in their entirety. In performing these basic functions, it may come about that excessive demands are made upon a driver, these arising due to poor road conditions - rain, snow and ice - or as a result of suddenly changing traffic situations. With the introduction of anti-lock braking systems (ABS), a decisive step has been taken to increase active driving and traffic safety. The ABS prevents the lockup of the wheels during overbraking. The vehicle remains steerable and retains stable directional control. Furthermore, in many cases, a shorter braking distance is gained compared to braking with the wheels locked up. BOSCH has been manufacturing and supplying ABS for passenger cars since 1978 and for commercial vehicles and buses since 1981. ABS has proved to be an overwhelming success in practical usage.

Control of a car is lost, or considerably reduced, whenever one or more of the wheels exceed the stability limit during braking or accelerating due to excessive brake or drive slip. The problem of ensuring optimum stability, steerability and brake distance of a car during hard braking is solved by means of the well-known Anti-lock Braking System (ABS). The task to guarantee stability, steerability and optimum traction during acceleration, particularly on asymmetrical road surfaces and during cornering maneuvers, is being performed by the traction control system (ASR). Several means to provide an optimum traction control are described, e. g the control of engine torque by influencing the throttle plate and/or the ignition and/or the fuel injection.

The new generation of drive-by-wire systems currently under development has demanding requirements on the electronic architecture. Functions such as brake-by-wire or steer-by-wire require continued operation even in the presence of component failures. The electronic architecture must therefore provide fault-tolerance and real-time response. This in turn requires the operating system and the communication layer to be predictable, dependable and composable. It is well known that this properties are best supported by a time-triggered approach. A consortium consisting of German and French car manufacturers and suppliers, which aims at becoming a working group within the OSEK/VDX initiative, the OSEKtime consortium, is currently defining a specification for a time-triggered operating system and a fault-tolerant communication layer.1 The operating system and the communication layer are based on applicable interfaces of the OSEK/VDX standard.

Pre-crash functionality is defined in three functional steps: PRESET, PREFIRE and PREACT. The functional steps are described in the order of growing situation analysis performance requirements and an increasing amount of necessary system application effort. Each functional step defines its own range of view, the so-called virtual barrier. The definition of the virtual barrier is subject to various constraints in respect to sensor configuration and pre-crash performance. A more detailed description of PRESET functionality for frontal pre-crash is given together with a test example. Pre-crash sensing technology uses platform radar sensors. The platform sensors are designed for the integration of all possible functions that rely on sensor information from the close surroundings of the vehicle. This development approach guarantees a high cost efficiency, flexibility and modularity of the sensor system while still guaranteeing the full pre-crash functionality.

Until now, the use of biometric systems has not been in the public eye. The high cost of sensors and processing has meant that biometrics was previously restricted to high security access, financial transaction and law enforcement applications. However, as a result of improvements in technology, biometric sensor price and reliability have achieved levels where biometrics is being seriously considered for automotive systems. This paper introduces the field of biometrics, the key terms and processes. Fingerprint Technology and Identification by Fingerprint are discussed, as are the use and applicability of biometrics in automotive applications, including Personal Profiling, Keyless Engine Start and vehicle access authorization. The key findings of investigations over the last years are discussed.