ISA Lab., CICE, CU, Korea 1

논문 : 센서 그리고 / 또는 통신을 사용한 DAS 의 성능 평가

 

요약

 

차량 주변 정보를 수집하기 위한 온 - 보드 센서들 그리고 /또는 다른 차량들과 정보 공유를 위한 차량간 통신을 사용하는 운전 보조 시스템의 정량 평가를 기술한다 .

각 시스템의 안전성 성능은 개선된 미시적인 트래픽 흐름 시뮬레이터로 정량적으로 평가되어진다 .

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1. 서론Driving assistance systems acquire surrounding information, and assist drivers by using the information.

Information acquisition methods of driving assistance systems are divided into three types categories: the system using on-board sensors only (the sensor type system), the system using communication only (the communication type system), and the system using on-board sensors and communication collaboratively (the combination type system).

The system performance of a combination type system is evaluated by simulation.

2. DAS 의 분류와 평가 방법A. Categorization of Driving assistance systems by information source

주변 정보를 얻는 3 가지 방법 : 자신의 차량으로부터 얻는 정보 , 다른 차량으로부터 얻는 정보 , 인프라구조로부터 얻는 정보 ( 그림 1, 참조 )

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B. DAS 의 평가 Microscopic Traffic Flow Simulator for Evaluation of DAS

Traffic simulator

Characteristic of drivers shall be the desired velocity and the total delay.

The total delay is the sum of a mechanical delay and a driver's delay.

The traffic simulator consists of the road model, the vehicle model, and the drivers model.

① The road model is defined by the form of a road, the number of lanes, the lane width, and the road length.

② The vehicles model is defined by vehicle types (passenger vehicles or large vehicles, etc.), the vehicle length, vehicle width, and the vehicle weight.

③ The driver model is defined by the field of view, the desire velocity, the total delay, the velocity control of vehicles, and lane-change.

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C. 평가 지표 Two indexes

① the traffic safety from the viewpoint of road administrators: the interval of the accidents that occurs on the estimated area, AAI(Average Accident Interval).

② the traffic safety from the viewpoint of drivers: the average of the traveling distance until each vehicle causes an accident on the estimated area, ANATD(Average No-Accident Traveling Distance).

 

3. 평가를 위한 센서와 통신을 사용한 DAS

A. 센서와 통신을 사용한 시스템의 개요 이 논문의 DAS 는 차량 간 통신을 사용하여 센서 정보를 공유한다 . ( 그림 2, 참조 ) The combination type system ( 그림 3, 참조 ) The driving assistance method is to give warning to the driver. The system is judging whether sub

ject vehicle is dangerous by using surrounding information. If the system is judges that subject vehicle is dangerous, the system gives warning to the driver.

DAS have a subsystem for judging danger that is called a collision warning system. The collision warning system shall consist of two subsystems, FVCWS (Forward Vehicle Collisio

n Warning System) and SCWS (Side Collision Warning System). SCWS are designed to avoid collisions that could occur when the vehicle moves in a lateral direct

ion, such as when merging or changing lanes.

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B. 평가를 위한 시뮬레이터 The simulator consists of a traffic flow part and a driving assistance system part.

The traffic flow part of this simulator is based on the model of [6].

1) 주변 정보 수집 The DAS shall have two kinds of on-board sensors which are the sensors for detecting forwa

rd vehicle and the sensors for detecting side obstacles. ( 그림 4, 참조 )

2) 충동 경고 시스템 FVCWS checks unification information using the warning assessment criteria (1).

DVT+(V2/2a-Vf2/2af) (1)

• D: following distance

• V: the velocity of the subject vehicle

• Vf: the velocity of the forward vehicle

• Free-running time T, subject vehicle deceleration a and forward vehicle deceleration af are system parameters.

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The warning conditions of SCWS shall use warning assessment criteria (2). The system decides to issue a warning when the warning assessment criteria are satisfied both laterally and longitudinally.

D (V2-V1)T (2)

• D: the distance to the other vehicle

• V1: the velocity of the subject vehicle

• V2: the velocity of the other vehicle

• T: the system parameter of free-running time

3) 경고에 대한 운전자의 행위 Warning is two kinds, the warning about collisions, and the warning about lane-change.

When the warning about the forward vehicle collision is received, a driver shall decelerate 0.15G.

When the warning about lane-change is received, lane-change shall be interrupted promptly, and return to the original lane.

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4. 센서와 통신을 사용한 DAS 의 성능평가

A. 시뮬레이션 요소 Table I, II, III, IV 참조 The simulation carried out for 40000 hour in the simulation time.

B. 시뮬레이션 결과 Figs 5 to 7 plot the average accident interval versus the penetration ratio ( 보급

률 ) in each system and each vehicle density.

Figs. 8 to 10 the average no-accident traveling distances of system-quipped vehicles (E: Equipped vehicle) and system-unequipped vehicle (UE: Unequipped vehicle) versus the penetration ratio in each system and each vehicles density.

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5. 결론

• The results are summarized as follows:

• The driving assistance system using sensors and communications has the highest safety performance in the evaluated three types of systems.

• The safety performance of the system using only communications exceeds that of the system using only sensors in the condition of more than the penetration ratio of 96%.

• The safety performance of not only system-equipped vehicles but also system-unequipped vehicles are also improved as compared with the penetration ratio of 0% when the penetration ratio is high (more than 60%).