ISO 11067:2015 高度道路交通システム—曲線速度警告システム（CSWS）—性能要件とテスト手順 | ページ 2

2.1

subject vehicle

vehicle equipped with the CSWS and related to the topic of discussion

2.2

subject vehicle speed

longitudinal component of the subject vehicle velocity

2.3

system states

one of several stages or phases of system operation

Note 1 to entry: See Figure 1.

2.3.1

CSWS off state

state in which CSWS is off

Note 1 to entry: This state has one of the following three causes: the driver has selected the off condition, the ignition is off, or the CSWS is in failure.

2.3.2

CSWS on state

state in which CSWS is on

Note 1 to entry: This state is either in unavailable state or in available state.

2.3.3

CSWS unavailable state

system is in on state and the system has inadequate information

Note 1 to entry: The system cannot make a decision whether the warning criteria are met or not because of fault in GNSS device, lack of map data, or other reasons.

2.3.4

CSWS available state

system is in on state and the system has sufficient information to make decisions on whether the warning criteria are fulfilled or not

2.3.5

CSWS warning state

system is in available state and the warning criteria are all met

Note 1 to entry: The CSWS starts warning(s) or is operating the warning(s). The system periodically judges whether the criteria are met in order to transition to the non-warning state.

2.3.6

CSWS non-warning state

system is in available state and the warning criteria are not all met

Note 1 to entry: The system periodically judges whether the criteria are met in order to transition to the warning state.

2.4

curved road

section where the radius of curvature is less than or equal to R_C

Note 1 to entry:R_C denotes the maximum radius of curvature to be regarded as a curvature point of interest for potential warning for CSWS (see 5.2.2).

2.5

curvature point

arbitrary points on the curved road that has associated location and value of curvature

2.6

curvature point of interest

point of the curved road ahead where the distances from the subject vehicle to the curved roads are less than the look ahead distance, S_LAD

2.7

curve start point

location where the radius of curvature of the curved roadway ahead becomes less than R_C

Note 1 to entry: See 5.2.3.

2.8

curve end point

location where the radius of curvature of the curved roadway ahead becomes ≥R_C

Note 1 to entry: See 5.2.3.

2.9

target curvature point of interest

particular curvature point of interest on the roadway of the subject vehicle that CSWS is about to provide the warning to the driver

Note 1 to entry: CSWS selects the target curvature point of interest among the curvature points of interest and the curvature point of interest may vary depending upon the distance from the current location of the subject vehicle to the curvature point of interest and the current speed of the subject vehicle. If a section of the curved road has a constant radius of the curvature, the curve start point becomes the target point of interest. See 5.2.2.

2.10

distance to curvature point of interest

S_current

distance from the current position of the subject vehicle to the curvature point of interest

2.11

time to curvature point of interest

t_TC

2.12

warning threshold speed

V_WT

vehicle speed threshold that is used to determine if the CSWS warning is required

Note 1 to entry: If the vehicle speed measurement is greater than this threshold value, the CSWS provides the warning to the driver. This threshold is below the maximum speed that is defined by designed lateral acceleration to negotiate the upcoming curve.

2.13

warning end speed

V_{WT_end}

vehicle speed at which the CSWS transitions from CSWS warning state to CSWS non-warning so that the CSWS ends the warning

2.14

warning distance

S_warn

distance from the location where the warning starts to the target curvature point of interest

2.15

driver response time

t_resp

reaction time of the driver which is the time from start of the speed changing event to the time that the driver starts applying brake

2.16

minimum required deceleration

a_{d_req}

2.17

curve speed warning time

t_csw

Note 2 to entry: The value of t_CSW is selected by the manufacturer.

2.18

minimum allowed curve speed warning time

t_{csw_min}

lower threshold of the curve speed warning time

Note 1 to entry: The value of minimum allowed curve speed warning time is decided considering the amount of overspeed of the subject vehicle and the reaction delay of drivers.

2.19

minimum operating speed

V_min

minimum subject vehicle speed at which the CSWS shall operate

2.20

maximum operating speed

V_max

maximum subject vehicle speed at which the CSWS shall operate

2.21

look ahead distance

S_LAD

curve detection range of the CSWS

Note 1 to entry: For the curvature points that have radius of curvature ≤R_C and the distances from the subject vehicle to the curved roads are <S_LAD, the curvature point is considered to be a curvature point of interest.

2.22

single curve

simple curved road with a constant radius of curvature separated from other curved roads

Note 1 to entry: The clothoid can be included.

2.23

multiple curve

curved road which is a combination of two or more closely located curved roads where the curved roads are constant radius curvatures

Note 1 to entry: The clothoid can be included.

Note 2 to entry: See Table A.1.

2.24

variable radius curve

curved road with two or more radii of curvature in the same direction

Note 1 to entry: See Table A.1.

2.25

angle of curved road

AOC

central angle between the curve start point and the curve end point

Note 1 to entry: See 5.2.3 for illustrative description.

2.26

road shape points

points that is composing roads in digital map

Note 1 to entry: Roads are composed of points and links which reflect the shape and position of the road in the digital map.