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PROMETHEUS - Design Technics Andras Kemeny Renault Direction de la Recherche France
ABSTRACT
JNTRODUCI'ION
PROMETHEUS, a Research Cooperation Program, uniting the primary European Automotive Companies, strives to improve Road Safety and Traffic Efficiency by developing appropriate information and communication technology. Industrial Application Projects are designed by the Function Groups, concerned with Driver Assistance by electronics systems and Vehicle to Vehicle and/or Vehicle-to-Infrastructure Communication. We describe the Function Group's activity and analyze the precompetitive research Design Process for a Cooperative Control application assessed by the corresponding Thematic Working Groups. Such an application is designed along a Topdown approach starting with defining the strategies concepts, a technical baseline, investigating critical areas and technical solutions. For the given application, requirements are analyzed for a Positioning System and a Communication Device. Specifications are determined according to reliability and safety criteria. Reconfigurable simulation software enables the validation of the various technical concepts. It also allows for the testing of driver assessment of the new product in a variety of traffic conditions. Corresponding Common European Demonstrators provide the fmal tests on testtracks in real driving conditions. The application design process relies also on Basic Research Groups activities. The underlying standardization follows in cooperation wit? Governmental and PanEuropean Authorities.
Prometheus, the Greek Titan, brought to us the sacred fire to initiate a new civilization according to greek mythology. The internal combustion engine driven automobile has a strong impact on the 20th century's civilization thanks to the autonomy and comfort given to ttxe individual driver or family who wants to miove around or travel. However, road accidents, traffic congestion, pollution come along with this new civilization. PROMETHEUS which stands for PROgraM for a European Traf€ic with Highest Efficiency and Unprecedented Safety is a large European Cooperation Program in the field of automotive electronics, ambitious like its name, striving to improve road safety and traffic efficiency. PROMETHEUS is not driven by the European Community. It is a common pre-competitive research project driven directly by the participating Automobile Companies which has the label EUREKA (Coordination Organization for European Research and Tecnological Cooperation including the Community members and Austria, Finland, Iceland, Norway, Sweden, Switzerland, and Turkey). An integral approach of the vehicle electronics brought the Automotive Companies to target the integration of the vehicle into the global information and communication network offered by the sclciety.
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INDUSTRIAL RESEARCH APPLICATIONS Applications deal with four differeat areas
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D y ” i c Vehicle Control - controls the lateral and longitudinal dynamics behavior of the vehicle according to high level control systems (cf Cooperative Control) or safety requirements.
which are : Improved Driver Information Active Driver Support Cooperative Control Traffic and Fleet Management
Sumortive Driver Information - informs the An application area is the upper level of the driver about required immediate driver action or feedback on system action. hierarchical structure of definition. An application is a set of subfunctions (or COOPERATIVE CONTROL performs when possible subfunctions and functions). cooperative manoeuvring of interdependent vehicles on all types of roads. Cooperative - IMPROVED DRIVER INFORMATION provides the driver with information on the control is based on active vehicle to vehicle vehicle to infrastructure environment, road surface, vehicle and driver and/or communication. condition.
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Obstacle Detection discriminates mving and stationary entities within the possible trajectories of the vehicle (objects) and evaluates them as obstacles according to their characteristics.
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Monitoring Environmenthad provides the driver, vehicle control systems, other road users/infrastructure with information on the immediate external vehicle operating environment (road topology, surface conditons, traffic signs and regulation, weather).
Intelligent Cruise Control CICQ - performs cooperative longitudinal control between interdependent vehicles on single lanes for harmonizing speeds and distances and reacting to significant events ahead. Intelligent Manoeuv r i n ~and Control (IMC) performs cooperative manoeuvring in order to safeguard lane changes and overtakings. Recommends appropriate behavior to the driver in order to improve safe:ty and traffic efficiency.
Intelligent Intersection Control CIIC) Monitoring; Driver - evaluates the status of the performs cooperative longitudinal control driver for vehicle control and information between interdependent vehicles at crossroads improving safety, harmonizing speeds and systems. allowing better traffic conditions. Monitorinv Vehicle - provides a status report to the driver and vehicle control systems on Medium Range Preinformation (MRP) provides the driver and vehicle: system with vehicle dynamics and operational status. relevant traffic related and envinonmental data Vision Enhancement - provides direct vision supplied by oncoming traffic or infrastructure. information to the driver i n sub-normal visibility conditions by autonomous and non- Emergency Warning EW) - waxns road users and roadside rescue information service in cooperative means. emergency case. ACTIVE DRIVER SUPPORT -SuPpOrtS the driver in an informative way or by active TRAFFIC AND FLEET MANiQGEMENT Provides the driver with route gcudance, travel intervention (copilot functions). and traffic information. Marm Determination - determines the envelope of dynamic vehicle performance Route em‘danc~- evaluates the atptimum route within which stable driving manoeuvring can to desired destination using average traffic flow data (static route guidance) or up-tedate be performed. traffic flow data (dynamic route guidance). Critical Course Determination determines the vehicle trajectory, relative to road topology and T r i ~Planning - provides the driver with a fixed and/or moving objects, leading to combination of transportation macies suited for the trip according to the travel dale and time, as collision or crossing road boundaries. well as traffic and weather conditions.
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Network and Flow Control - delivers information on traffic road distribution ; provides the driver with local route guidance and speed / lane recommendation.
information, time and mode of presentation) and Assistance Systems (tasks allocation between the Prometheus systems and the driver). To develop driver model and evaluation methods and test tools.
Commercial Fleet Management - monitoring of vehicle and freight positions to optimize the regulation of a fleet of commercial vehicles according to the demand, fleet capacity and traffic conditions.
Vehicle Safetv and Dem - ndability- to develop safety and reliability concepts based on a fuctional analysis of the driver assistance system. To design solutions for fault tolerant systems (fault tolerant distributed electrical architecture, fail safe computers and actuating Other Traffic Management applications will be systems). To define failure management and studied in cooperation with Road and City dependable software design methods. authorities. These applications cover Parking Guidance. Demand Management and Interface Infrastructure - Based System - to conceive a with Public TransDortation. fully integrated automatic computer network between on-board and roadside devices to provide the driver with information on traffic and/or environnment or to perform traffic THEMATIC PROJECTS management. An European Digital Road Map The previously described Industrial Research Task Force is in charge of organizing an Applications are analyzed along a Top-down European Road Data Base, to perform approach starting with defining strategies, benchmark test for acquisition methods and to concepts, technical baseline and technical recommend a Pan-European standard. solutions. The design of the underlying systems relies on the Thematic Working Group Communication - to develop communication activites. Each working group is concerned techniques and standards for infformation exchange between vehicles, roadside with a given field of automotive engineering. equipment and other road users, in cooperation Sensing Systems - to develop concepts and with the European Electronics Supplier systems for sensing, multisignal processing, Industry. To study and extend existing communication systems for road traffic data fusion and decision finding. These systems concern the Environmenthoad information and localization RDS (Radio Data (radar, laser telemeter, CCD and IR camera, IR System), GSM (Group Special Mobile), GPS illumination), the vehicle (gyroacoustic angular (Global Positioning System). To coordinate velocity sensor, microware speed sensor, basic research on communication technologies forces and torques) and the Driver Status and access protocols for dynamic mobile intervehicle local area networks. (driver condition and signal analysis). Actuating Systems - to develop active systems for longitudinal and lateral vehicle control (throttle - cruise control, brake, variable ratio steering, rear wheel steering). Development of concepts and devices for real time adaptative response to operational requirements and external disturbances through active chassis control.
COOPERATIVE CONTROL
For each Industrial Research Application a Design Process is performed by the corresponding Function Group.The whole precompetitive research work is covered by an 8-years Non Disclosure Agreement. We will describe here one part of the design process - the Cooperative Control Architecture - to develop common basic Specification for one application - Intelligent electronics and associated datalink. To Manoeuvring and Control (IMC), done by the harmonize existing multiplex buses to obtain a Cooperative Control Task Force. common vehicle Area Network (V.A.N.) datalink protocol to ensure system Intelligent Manoeuvring and Control - is based on monitoring relevant traffic by active Intercompatibility and technology transfer. vehicle and vehicle-madsidecommunication Man-Machine Interface - integrate-;l approach (see figure 1). to design Information Systems (selection of
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Vehicle Equipped with Communication 1. Overtaking a vehicleheveral vehicles on motorways and rural roads. Systems. 2. Lane changing on motorways/rural roads. zzm;oN 3. Entering motorway/rural roads. 4. Leaving motorways/rural roads. 5. Recommending proper lane according to speed. Operational modes are : 1. Driver Information. 2. Automatic Control.
Environment is defined as the framework in which the application has to be implemented. Figure 1 : Vehicle Equipped with Elements ofthe environment are roads and Communication System for Cooperative related infrastructure, vehicles, services, information centers, etc. For IMC, Control. environment is : Main application cases are the following 1. Roads : motorway, rural roads. scenarios : 2. All dayhight conditions. 3. All weather conditions. Hierarchical Structure
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IMC COORDINATION STRATEGIES
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GENERATORS FOR - DRIVER INFORMATION - TRAJECTORY COMMANDS
DATA 1 SIGNAL - PREPROCESSING LANE DETERMINATION - VEHICLE LOCALIZATION - RELATIVE SPEED COMPUTATION - RELATIVE POSITION COMPUTATION - OPERATIONAL SPEED LIMIT COMPUTAT. - RISK ESTIMATION ~
INTERNAL SENSORS -OWN SPEED
- OWN ACCELERATION
- OWN - OWN
POSITION DIRECTION -STEERING ANGLE
CONTROLLERS FOR -SPEED - DISTANCE -STEERING
EXTERNAL SENSORS - RELATIVE DISTANCE
- RELATIVE SPEED .. TO
NEIGHBOURS VEHICLE'S LANE POSITION - ABSOLUTE POSITION - ROAD CONDITIONS ~
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Figure 2 : IMC Hierarchical Structure.
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ACTUATORS FOR - SPEED - CONTROL - DISTANCE - CONTROL - STEERING -CONTROL
For a normal IMC functioning non equipped vehicles must, at least, have a position emitter. If not, equipped vehicles may detecte non participating vehicles and put IMC service in a degraded mode. A svstem is defined as a collection of modules (h ard w are, software, communication components, etc.) able to implement one (or some) application(s). A function is the behavior of a system with respect to the objectives. Four main fuctions have been identified for IMC : 1. IMC cluster management. 2. Generate driver information. 3. Generate trajectory. 4. Manoeuvre feasibility estimation.
Entity-Relationship-Diagram(ERD) INDICATE INCIDENT INDICATE "NORMAL" INTENTION ACQUIRE ROAD GFOMETRY ACQUIRE ROAD CONDITION INFO ACQUIRE SPEED LIMIT FROM TMC ACQUIRE DRIVER'S INTENTION GENERATE STEERING COMMAND GENERATE DISTANCE COMMAND GENERATE SPEED COMMAND ESTIMATE RISK OF MANOEUVRE MONITOR NEIGHBOURS STATES MONITOR OWN STATE DETECT OWN LANE DETERMINE AREA OF RELEVANCE DETERMINE OPERATIONAL LIMITS DETERMINE ABSOLUTE POSITION DETERMINE RELATIVE POSITION DETERMINE STEERING ANGLE DETERMINE PHYSICAL DIRECTION DETERMINE LOGICAL DIRECTION DETERMINE RELATIVE SPEEDS DETERMINE OWN SPEED DETERMINE DISTANCE
A cluster is a set of vehicles participating in the same common strategy. A strategy is a procedure for the achievement of an application goal. A hierarchical structure was set up for IMC (see figure 2). The IMC Entity-Relationship Diagram (see figure 3) shows the IMC functions specified by means of a set of subfunction. A subsystem is a part of a system which could be used independently in other systems. It corresponds always to a subfunction. The whole set of subsystems gives a coherent base to develop cooperative control applications. The Process Design includes a Technical Baseline definition. It is a self-contained concept of a system fulfilling the application objectives, based on the identification of candidate solutions among possible options. To detect critical areas and investigate technical solutions, feasability and safety aspects are considered. System Dependabilitv Operational Safety of current vehicles in Europe is well known by accident statistics. The automotive hazard exposure ratio is 7 . 5 ~ 1 0 'accidentkm ~ x vehicle. This figure takes into account a yearly 1.34 million accidents in Europe with human injuries and the estimation that each of the 110 million vehicles in Europe covers 14000 Kms a year.
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Dependability includes safety, reliability, maintainability and availability. The dependability analysis method used by the Vehicle Safety and Dependability Working Group (WG5) is based on the detenhination of the Initiator Event (I.E.) and the Undesired Event (U.E.) by a preliminary hazard analysis. With the hypothesis that the probability of human errors is much higher than that of vehicle operational faults, we estimate the initiator event probability PE by the number of times of decreasing speed per km x vehicle. Accident statistics give 5 - 10%of accidents to vehicle collisions (on lane) and 0.5 km x vehicle to the number of breaking (with a speed > 50 km/h). From the corresponding Fault Tree Analysis a Failure Probability of
all typets of accidents due to Cooperative detection of a station or the erroneous ControliFailures gives a dependability ratio of interpretation of a message should be also taken into account. the sam&order. The data volume for a vehicle is about 150-500 bits : Vehicle identity and characteristiques Position Positioning Svstem Speed A vareih of systems are already being used to AcceleratiodDeceleration locate ships, planes or automobile vehicles. Steering angle Cooperative Control Applications involve an Emergency (failure) case detection automotive network over a zone of relevance. Road identity and type Such a qone is centered on a vehicle relative to Road topology and geometry a Cooperative Control Area function. A major Road regulation informqtion transmitted from a vehicle to Road and weather conditions another 1s its position. We estimate the needed Traffic conditions accuracy on position at about 0.5 m for each Driver intention vehiclelof the zone of relevance. Such a Processed information requiredent may be seen as the result of the The global bandwith for a capture aera is about apprecia/tionof the European road traffic. 1-3 Mbps. Vehicle position is to be computed for the Radio frequency choice depends on the vehicle itself as well as for its neighbors. A availability of authorized free freqencies and neighbod is a vehicle belonging to the zone of corresponding communication technology. Several frequencies are considered presently, relevance. Assumiqg only speed Vk and position Xk are among them the band of 1-3 GHz, 5-9 GHz measure# at instants kT we can extrapolate the and around 60 GHz. position1 x(t) at an instant t between kT and Simulation (k+l) T $S x(t) = Xk + Vk (t-kT). We hav&to take into account imprecisions due A Simulator for Cooperative Automative to the swpling delay and to the measure itself. Network was developed by Renault to validate Imprecisions due to speed variation between the inter-vehicle communication concepts as two saqpling instants is limited by the well as the driver assessment of the new accelera ion (deceleration) threshold. Low-cost product in a variety of traffic conditions. For speed se sors with relative precision of 1% are this purpose a network of graphics stations is also avbilable on the market. Therefore a functioning in real time, each station ion frequency of 10 Hz seems to be representing a participating vehicle in The sampling frequency for speed Cooperative Driving. Its constitutive units are measure/ should be higher and the system a decision making engine, a communication needs tor be kpositioned periodically by (active interface (enabling communication with the or passide) infrastructure beacons. other vehicles as well as with the I infrastructure) and a 3D (three dimensional) Commu$ication System graphics computing and display unit. As the first step of decision making a safety Cooperqtive Control communication system space is computed. has to offer a unique carrier frequency for all It is a zone in which the vehicle can move emitting]and receiving mobile stations in the without immediate danger until the following zone of ielevance without central coordination. computation instant. The inter-vehicle safety distance (see figure 4) depends on the relative The nurhber of vehicles depends on traffic speed of neighbors, the reaction time of the s. In a capture area with a radius of driver (or the control system) and the can go up to 500. According to imprecision of the transmitted data : position 1 system requirements, the update rate of the f F communication system should be at about 10 - 30 Hz with a probability of non
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(correcd) reception of two consecutive
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