Kiyohito Tokuda

Vehicle control algorithms for cooperative driving with automated vehicles and intervehicle communications

Describes the technologies of cooperative driving with automated vehicles and intervehicle communications in the Demo 2000 cooperative driving. Cooperative driving, aiming at the compatibility of safety and efficiency of road traffic, means that automated vehicles drive by forming a flexible platoon over a couple of lanes with a short intervehicle distance while performing lane changing, merging, and leaving the platoon. The vehicles for the demonstration are equipped with automated lateral and longitudinal control functions with localization data by the differential global positioning system (DGPS) and the intervehicle communication function with 5.8-GHz dedicated short range communication (DSRC) designed for the dedicated use in the demonstration. In order to show the feasibility and potential of the technologies, the demonstration was held in November 2000, on a test track with five automated vehicles. The scenario included stop and go, platooning, merging, and obstacle avoidance.

A V-band planar narrow bandpass filter using a new type integrated waveguide transition

A surface mountable planar narrow bandpass filter is proposed and demonstrated at V-band. The filter is constructed using an integrated waveguide in an alumina substrate employing a novel microstrip line to waveguide transition. The insertion loss per one transition is less than 0.1 dB over 43 to 73 GHz. A fabricated three-pole Chebyshev filter exhibits an insertion loss of 3 dB with a 3.3% bandwidth at a center frequency of 62 GHz and the return loss is better than 15 dB in the passband.

A cooperative driving system with automated vehicles and inter-vehicle communications in Demo 2000

Describes the technologies of cooperative driving with automated vehicles and inter-vehicle communications in the Demo 2000 cooperative driving. Cooperative driving, aiming at the compatibility of safety and efficiency of road traffic, here means that automated vehicles drive by forming a flexible platoon over a couple of lanes with a short inter-vehicle distance while performing lane changing, merging, and leaving the platoon. The vehicles for the demonstration are equipped with automated lateral and longitudinal control functions with localization data by the DGPS and the inter-vehicle communication function with 5.8 GHz DSRC designed for dedicated use in the demonstration. In order to show the feasibility and potential of the technologies, the demonstration was held in November, 2000 on a test track with 5 automated vehicles. The scenario included stop and go, platooning, merging and obstacle avoidance.

A 60-GHz point-to-multipoint millimeter-wave fiber-radio communication system

A 60-GHz point-to-multipoint wireless access link with data rate of 156 Mb/s incorporating 60-GHz transceiver modules and full-duplex fiber-optic millimeter-wave transmission is developed for short-range applications such as indoor wireless local area networks and intelligent transport systems. For compact system configuration, a small-size millimeter-wave transceiver module with planar antennas is developed. The transceiver module is based on broadband planar integration and packaging of millimeter-wave circuits. The RF output power is +10 dBm and the measured 3-dB antenna beamwidth is 30/spl deg/. The total size of the developed 60-GHz transceiver module, except input and output connectors, is 50 mm /spl times/ 75 mm /spl times/ 35 mm. A point-to-point full duplex fiber-optic configuration is extended to the scheme with multiple access points (APs) by using a tree coupler and a dense wavelength division multiplexing multiplexer. The AP has a simple configuration without frequency conversion. The bit error rate and packet error rate performances of the 60-GHz fiber-radio access link are evaluated. Furthermore, the effect of the extension to the scheme with multiple APs is investigated.

A Wireless Video Home-link Using 60GHz Band: Concept and Performance of the Developed System

A concept and requirements of a millimeter-wave video transmission system as a wireless home-link using 60-GHz band are described. This system can transmit broadcast television (TV) signals from TV antennas to TV set and thus can be regarded as a substitute for a feeder line. The feasibility study by investigating the systems CNR and SNR performances using MMIC-based experimental setup is also described.

A complete simulator architecture for inter-vehicle communication intersection warning systems

This paper presents the complete simulator architecture of the intersection warning system (IWS) capable of evaluating different warning systems and communication protocols. In this simulator, the network layer, the physical layer, the driver behavior, and the vehicle traffic are modeled and simulated in detail. An optional repeater is utilized at the intersection to disseminate the position, the velocity, and the acceleration information of the approaching vehicles to the road segments shadowed by buildings. The simulation results show that IWS can significantly reduce both the vehicle collision percentage and the vehicle collision speed.

Simulation of burst error models and an adaptive error control scheme for high speed data transmission over analog cellular systems

To realize high-speed data communication in a cellular system, the characteristics of mobile radio propagation paths (MRPP) and a robust error control scheme for poor circuit quality are studied. MRPP are analyzed by computer simulation, and an analysis method is described that uses a Markov model for burst errors generated by the simulation. By simulating the locus of moving vehicles, the relationship between the carrier-to-noise ratio (CNR), the fading frequency of a moving vehicle, and the three-states Markov model is obtained. An adaptive error control scheme (AECS) is developed as an effective high-speed data communication scheme in an analog cellular system. The effectiveness of the AECS is analyzed by simulating its application in a subcarrier transmission system with a 4800 b/s data transmission rate, using the three-states Markov model. The analysis method is verified and the characteristics of the AECS are evaluated using field data. >

A study of real-time and autonomous decentralized DSRC system for inter-vehicle communications

To realize the inter-vehicle communications (IVC) system, the development of a real-time and autonomous decentralized dedicated short range communication (RAD-DSRC) is necessary. In this paper, the performance of a physical layer of the RAD-DSRC system is evaluated considering the influence of the radio propagation characteristic for the IVC system. The performance of a media access control layer is also evaluated with the PL (packet loss) performance of a CSMA (carrier sense multiple access). It is clarified that the improvement of the PL for the CSMA is possible to utilize the spread spectrum technology.

Inter-vehicle communications protocol for group cooperative driving

Inter-vehicle communications technology for group cooperative driving has been studied by the Association of Electric Technology for Automobile Traffic and Driving (Japan) (JSK) since 1980. This paper presents the recent results, including an actual field test, of the group cooperative driving and the future plan for research and development of JSK.

4800 bits/s high speed data transmission over cellular system

A high speed voiceband data transmission was first sucessful over the Cellular mobile system. The data transmission speed is 4800 bit/s. The information speed is approx. 65 percents of the transmission speed when a mobile is moving. The behaviours of the signal transmission errors over a fading channel was analyzed through computer simulations. A fast pull-in MODEM, an adaptive error control scheme and a data transmission protocol were newly developped to overcome the radio fading. The experimental values of the throughput effeciency were proved to coincide with the theory.