J. Kor. Soc. Fish. Tech., 45(2), 106 113, 2009

DOI:10.3796/KSFT.2009.45.2.106

Collision risk considering the international regulations forpreventing collisions at sea, 1972

Il-Kwon KANG*, Hyung-Seok KIM, Min-Seok KIM1,

Jeong-Chang KIM2 and A-Reum LEE3

Division of Marine Production System management, Pukyong National University, Busan 608-737, Korea1Training Vessel, Pukyong National University, Busan 608-737, Korea2Research Vessel, Pukyong National University, Busan 608-737, Korea

3Dept. of Fisheries Physics, Graduate School, Pukyong National University, Busan 608-737, Korea

For the safety and cost reduction in the navigation, the automatic and intelligent system has been developed

for the vessel, and the most important factor in the system is to decide the collision risk exactly. In this

paper, we propose an advanced collision risk decision system for collision avoidance of the system. The

conventional researches using DCPA and TCPA for calculating the collision risk have a problem to produce

a same collision risk regardless of bearings for the ships, if they are located in the same distance from own

ship. To solve this problem, in addition to DCPA and TCPA, we introduce the factor of VCD(variation of

compass degree) and constant, CR which derived from COLREG 72(International Regulation for Preventing

Collision at Sea, 1972) for evaluating the collision risk including even the burden of own ship navigator due

to the encountering angle of each vessels. We decided the collision risk legally by the rule considering the

relative situation of vessels. And therefore, the proposed system has two advantages, of which one is to

produce more detail collision risk and another is to reflect the real underway situation in conformity with the

rule.

Key words : DCPA, TCPA, VCD, CR, Collision risk, Colreg 72

*Corresponding author: ikkang@pknu.ac.kr, Tel: 82-51-629-5895, Fax: 82-51-629-5885

. ECDIS

, GPS

, ARPA

.

VTS AIS

,

.

.

,

,

. ,

human error

(Kang et al., 2007). ,

,

.

,

,

(Jo et al., 2005).

.

,

DCPA

TCPA (Hasegawa,

1987).

(Hara, 1990; Hammer, 1993), Radar

(Imazu, 1984).

,

VCD(variation of compass degree)

(Kim et al., 2001).

72

14 ( ) 15

( )

.

16 ( ) 17 (

)

. , ,

,

,

, ,

.

DCPA,

TCPA, VCD , , CR

72

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,

.

.

72

,

,

.

(Lee, 1997).

if

then .

if ( )

then ( )

(1)

if

, then

.

, (2)

(Lee, 1997).

R1 if x is A1 and y is B1 then z is C1

R2 if x is A2 and y is B2 then z is C2

Rn if x is An and y is Bn then z is Cn (2)

Rn if x is An and y is Bn then z is Cn

Ri (3)

.

µRi µ(Ai and Bi Ci)(u, v, w)

[µAi(u) and µBi(v)] µCi(w) (3)

(3)

.

. (fitness) i

.

αi (4)

(5)

.

α1 µA1(x0) µB1(y0) (4)

α1 µA1(x0) µB1(y0) (5)

.

µc(z) maxx,y[µR(x,y,z) µA(x) µB(y)] (6)

.

µc min

product

.

µcn

i 1(ai µc) (7)

µcn

i 1(ai µc) (8)

,

(9) .

µ(ui) µjµ0n

∑j 1

________ (9)µ(uj)

DCPA TCPA

Mamdani

, DCPA TCPA ,

.

Fig. 1 DCPA .

.

, P : Positive, S : Small, M : Medium, B : Big

. Fig.2 Fig.3

.

.

Fig. 2 TCPA

32

, .

Fig. 3 VCD(Variation of Compass Degree)

,

. radar bearing

,

.

Fig 4 ,

DCPA, TCPA, VCD

.

, CR

72 2

,

.

.

72

Fig. 1. Membership functions of DCPA.

Fig. 2. Membership functions of TCPA.

Fig. 3. Membership functions of VCD.

1

0

PS PMS PM PMB PB

0 0.5 1 1.5 2 2.5 (n. mile)

1

0

PS PMS PM PMB PB

0 6 12 18 24 30 32 (min)

1

0

PS PMS PM PMB PB

0 0.7 1.5 22.5 30( )

Fig. 4. Membership functions of Collision Risk.

PS PMS PM PMB PB1

00 0.2 0.4 0.6 0.8 1.0

Fig. 5. Encountering situation for the direction ofapproach.

22.5

84

D

B 6 6 A

C

E

F

84

Head on H

ead

on

Crossing

Overta

king

Overtaking

Crossing

22.5

72

14 ,

.

15 ,

.

,

, .

Fig. 5

, , (head on situation),

(crossing situation),

(overtaking situation)

. Table

1 , CR ,

, ,

,

.

, ,

,

.

Fig. 6 5

,

,

.

(a)

, (b) .

Fig. 6(a) 1 head on

, 2 3

, 4

, 5

Table 1. Danger degree of CR depending on the bearing of target ship

Bearing (θ) 000 θ 006 006 θ 112.5 112.5 θ 180 180 θ 247.5 247.5 θ 354 354 θ 360

Danger degreePMB(0.8) PB(1.0) PMS(0.4) PS(0.2) PM(0.6) PMB(0.8)of CR

(a)

(b)

Fig. 6. Collision risk on the various situation(1).

72

.

2 3

(0.69), 1(0.60),

4(0.39), 5(0.36) .

2 3 2

3 ,

, 1

, 4

,

, 5 ,

,

.

, Fig. 6(b) Fig. 6(a)

,

, .

. ,

5 4

, DCPA TCPA

.

Fig. 7 Fig.

6

,

,

. (a)

, (b) .

Fig. 7(a) 3(0.69)

, 4(0.37), 1(0.36), 2

3( 0.23) . (b)

3(0.76) ,

4(0.66), 5(0.62), 2(0.42)

3(0.32) .

Fig. 7(b) 3

, 1 2

.

5

,

, ,

. 4

.

(a)

(b)

Fig. 7. Collision risk on the various situation(2).

Fig. 8 Fig. 7

,

,

.

.

3 Fig. 7

0.76 ,

, 0.85

. 4

Fig. 7 0.66

, 0.72

. 5

.

Fig. 8. The history of simulation of targets shown on the Fig. 7.

1 2

,

.

,

.

.

.

DCPA, TCPA, VCD

72

,

. ,

DCPA TCPA

.

.

.

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