System Design and Improvement of Proving Test Facilities

George Kamata Manager Advanced Cruise-Assist Highway System Research Association

1. Introduction

The overall flow of system design up to this time, influenced by our examination of the concept of upstream processes, has been directed toward defining architecture, designing systems, and formulating methods of operational inspection. Study of these and related matters occupied us from 1997 to 2000.
In 2000, on-site surveys were conducted to refine the substance of our designs, make improvements in system design in light of formulated requirements and other findings, study safety and reliability issues, and feed back the requirements for practical application into these activities. The results are being organized in the form of a first version of the technical reference materials for the overall activity.
Improvements reflecting the above system design improvements were made to proving test systems. A variety of functions have also been added since 2000. This has necessitated improvements to the proving test systems for the test course even as we proceed to build the systems for the field operation tests to be conducted during 2001 and beyond.

2. Improvement of System Design

An example of lessons learned from on-site surveys will serve to illustrate this issue in system design. In looking at the shape of the road as a whole, we consider the proper distribution of equipment for provision of services, and in installing the items of equipment in their specific locations, we come up against other factors: Special precautions and methods of installing equipment, layout with respect to junction boxes, possibilities for size and placement of on-site roadside processing units, problems with installation, possibilities for advantageous use of cross-road conduits, issues for layout of wiring between devices, and so on. We made every effort to discuss the distribution of equipment and functions, the conformation of connections to optical-fiber closures, snow cover in cold climates, and other such issues on the actual site with people in the construction offices and branch offices who perform road management. These issues are covered in an organized form in the on-site survey. (Fig. 1.)

Fig. 1. Findings from On-site Surveys (Example:Services on read section of uninterrupted flow field)

The single most important factor for improvement of system design is that while spot communications will be used in the initial deployment, a future changeover to a continuous communications system is being considered. We are taking this kind of future migration into consideration while also incorporating a number of other factors in the actual design. These other factors include problems of operation and maintenance, including the installation environment, the need to devise self-diagnostic and interdependent-diagnostic, input data checking, malfunction detection, and other such functions, changes to system design parameters resulting from proving tests (specifically, reaction time, deceleration, acceptance of services, etc.), and design for safety and reliability. (Fig. 2.)

Fig. 2. Improved Design of Cruise Assist Systems

We intend to incorporate these matters into the requirements for practical application by first tackling the information provision services aspect of cooperative vehicle - highway for system start-up in 2003. We have settled upon an overall scenario that calls for gradual scaling up from that to provision of warnings, then operational support, and then later to automatic driving. The independent provision of information by the infrastructure using information boards will naturally make up an important part in the initial stages as a service provided to ordinary vehicles at large. It will also be necessary to make adjustments to resolve issues of coordination and conflict that arise when information is provided both by information boards and by cooperative vehicle - highway. The scenario for road-to-vehicle communications services envisions initial provision of services in the form of spot communications, followed by a gradual scaling up to continuous communications. We are proceeding to design the necessary systems that take these factors into account, and are also compiling this information in technical reference materials. (Fig. 3.)

Fig. 3. Support Levels of Services Incorporating Practical Requirements

3. Improvement of Test Course Test Systems

The next topic is the improvement of test systems for use on test courses. The vertical axis is formed by the improved evaluation and testing functions. Test course systems are being designed with expanded functionality that will enable verification and evaluation, for example, of road-to-vehicle communications tests, information provision services directed to multiple vehicles using two-way individual communications, information board services, services to support information provision to second parties, information services related to oncoming vehicles in connection with obstacles, and so on. They will also enable verification and evaluation of spot service functions. (Fig. 4.)

Fig. 4. Definition of Functions

4. Design of Field Operation Test Systems

The design of field operation test systems is proceeding as preparation for testing on actual roads starting in 2001. In order to enable verification of test items that could not be covered on the test course, these systems must be capable of evaluating various important issues, such as road gradient, large intersections, long-distance cruising, and localized special weather conditions encountered in cold weather areas. Most important are verification in actual traffic environments and identification of the problems involved. We are approaching this project by creating a conceptual image of the system applied in the field for evaluation of the acceptance of services provided discretely in series and in combinations, whereby a vehicle consecutively receives particular services and then multiple services in combination. Vehicles are also constantly entering and leaving the service zone. The test systems for use on actual roads are being weighed with attention to these aspects of actual traffic flowing in series, and with consideration of the kinds of services that are to be implemented for vehicles that are actually driving through. (Fig. 5.)

Fig. 5. System Design

The construction of field operation test systems should be coordinated with the deployment of services. We are identifying the functions that are necessary for facilitation of testing or test evaluation, and the functions that are needed to operate the specific tests, as part of our ongoing studies of systems that must be piggybacked onto the service functions. The figure presents an example of the study of service combinations provided on a curve on road section of uninterrupted flow field of an ordinary road, such as prevention of over shooting on curves and prevention of collisions with forward obstacles. This is a conceptual image of the framework for a system design that is configured for a combination of services. Study of the system as a whole is proceeding on the basis of co-installation of the ordinary service functions with the operation test functions. These latter include in particular the intake and output of data by systems on the vehicle side, and also the links established with the system for the purpose of overall test evaluation. (Fig. 6.)

Fig. 6. System Design

5. Conclusion
The system as described above has the substance of the system developed up to 1999, but it has additionally been given new service functions and has been improved by the superimposition of a development scenario that incorporates the requirements for practical application of the system. It has also been adjusted with a view to high-reliability design. The work done in 2000 therefore accommodates these elements for improvement of test course facilities and combines them within the general framework for a system design that is intended for field operation tests.