Ergonomics in the Automotive Design Process

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6

Field of View from

Automotive Vehicles

INTRODUCTION TO FIELD OF VIEW

The objective of this chapter is to provide a background into ergonomic issues related to designing

the daylight openings (called the DLOs, which include all the window openings including wind-

shield and backlite) and other eld-of-view-providing devices such as mirrors and cameras to assure

that drivers can view the necessary visual details and objects in the roadway environment. This

chapter will present methods used in the industry to locate various eye points in the vehicle space

and draw sight lines used to measure and evaluate elds of view.

linking vehicle interiOr tO exteriOr

The eld-of-view analyses link the vehicle’s interior design to its exterior design. The interior pack-

age provides the driver’s eye locations and interior mirror. The vehicle exterior denes DLOs and

exterior mirrors. Thus, the interior and exterior designs must be developed in close coordination to

assure that drivers can see all the needed elds to drive their vehicles safely.

What is field Of vieW?

The eld of view is the extent to which the driver can see 360 degrees around the vehicle in terms

of up and down (vertical or elevation) angles and left and right (horizontal or azimuth) angles of

the driver’s line of sight to different objects outside the vehicle. (The interior eld-of-view issues

related to visibility of controls and displays are covered in Chapter 5.) Some parts of the driver’s

visual eld are obstructed due to the vehicle structure and components such as pillars, mirrors,

instrument panel, steering wheel, hood, lower edges of the window openings (called the belt line),

headrests.

Thus, what the driver can see while seated in a vehicle depends on the characteristics of (a) the

driver, (b) the vehicle, (c) the targets (e.g., pedestrians, signs, signals, lane lines), and (d) the environ-

ment (e.g., road geometry, weather, day/night). Some details and variables associated with the above

items are described below.

Driver Characteristics: The amount of visual information that a driver can obtain will depend on

the following driver characteristics: eye locations in the vehicle (dened by the eyellipses in Society

of Automotive Engineers Inc. [SAE] standard J941 [SAE, 2009]), visual capabilities (e.g., visual

contrast thresholds, visual acuity, visual elds), visual sampling behavior (e.g., eye movements),

head-turning abilities (e.g., range of comfortable head-turn angles), head movements (e.g., leaning

forward, sideways, and head turning), information-processing capabilities, and driver age (which

affects all driver capabilities).

Vehicle Characteristics: The vehicle characteristics related to the driver’s eld of view and visibility

are window-opening dimensions and glazing materials (e.g., optical and installation characteristics of

the glass), other components that can reduce visibility due to obscurations, glare and/or reections of

brighter objects (e.g., external light sources, high reectance or glossy materials on vehicle surfaces),

indirect vision devices (e.g., mirrors, sensors, cameras, and displays), wiping and defrosting systems,

and vehicle lighting and marking systems (e.g., headlamp beam patterns, signal lamps).