Misplaced Pages

#941058

54-405: Blind spot monitors may do more than monitor the sides and rear of the vehicle. They may also include "Rear Cross-Traffic Alert", "which alerts drivers backing out of a parking space when traffic is approaching from the sides." If side view mirrors on a car are adjusted properly, there is no blind spot on the sides. This method was first documented by George Platzer in a 1995 paper presented to

108-414: A sailboat or windsurfer . This is especially true when they are heeled over ; consequently, transparent windows are sometimes sewn into the sails. Blind spots also exist around aircraft (helicopters, airships, airplanes, gliders). When the aircraft (airplane) accelerates for take off, the size of the blind spot below fuselage increases. Heavier aircraft can have up to several meters of blind spots. This

162-399: A dense fog advisory from the U.S. National Weather Service . These generally advise motorists to avoid travel until the fog dissipates or other conditions improve. Airport travel is also often delayed by low visibility, sometimes causing long waits due to approach visibility minimums and the difficulty of safely moving aircraft on the ground in low visibility. A visibility reduction

216-449: A driving mistake and claims it is even more dangerous than not using it, because it creates other blind spots directly behind the vehicle—nine reasons are listed, e.g. , when backing up—which are impossible to eliminate by a "shoulder check". Rearward invisibility is an entirely different matter. The area directly behind vehicles is the source of backup collisions , particularly involving pedestrians, children, and objects directly aft of

270-405: A horizontal plane in front of the driver. The front-end blind spots caused by this can create problems in traffic situations, such as in roundabouts , intersections , and road crossings . Front-end blind spots are influenced by the following design criteria: Most passenger cars have a diagonal pillar in the side view. The angle between the horizon and A-pillar is approximately 40 degrees with

324-535: A large truck, where the truck driver cannot see. Collisions frequently occur in no zones. A blind zone is one of several areas around heavier rolling stocks (locomotives and multiple units), where the train driver cannot see. Accidents frequently occur in blind zones. The side view mirrors of a car should be adjusted to reduce blind spots on the sides. The method is frequently overlooked in driver's education classes and takes some getting used to. Calculated elimination of blind spots by properly trained drivers

378-469: A manufacturer from maximizing visibility. These include safety, as narrower pillars cannot be made strong as easily as thicker pillars, and size restraints about aerodynamics, as taller, more vertical windshields create additional drag and reduce fuel efficiency. They also include fashion and cost, whereby design and appearance considerations can be deemed preeminent. Side radar systems offer better performance and also warn of fast-approaching vehicles entering

432-466: A more gentle impact, directing the pedestrian "up and over" rather than directly into the windscreen. This is particularly true for cars like the Mercedes-Benz A-Class which also have a low angled engine cover. Driver height can also affect visibility. An A-pillar that is split up and has a small triangle window (Front Quarter glass ) can give short driver visibility problems. In some cars,

486-438: A parking space. Specially designed cross-traffic alert warning systems have been developed to address these. As one is driving an automobile , blind spots are the areas of the road that cannot be seen while looking forward or through either the rear-view or side mirrors (expecting that the side mirrors are properly adjusted on a passenger auto – see above). The most common are the rear quarter blind spots, areas towards

540-460: A straight pillar that is not too thick. This gives the car a strong, aerodynamic body with an adequately sized front door. The sides of a panoramic windshield are curved, which makes it possible to design vertical A-pillars that give the driver maximum forward visibility. However, it is impossible to design an aerodynamic small car with a vertical A-pillar because the more vertical the A-pillar is,

594-419: A vehicle. That area has been called a "killing zone". These problems are the object of several technological solutions, including (in rough order of technological complexity, simplest first): rear-view mirror , side-view mirror , Fresnel lens , sonar , parking sensors , and backup camera . A similar problem attaches to positions left and right of a vehicle's rear bumper as the driver attempts to back out of

SECTION 10

#1732887506942

648-403: Is where b ext is the attenuation coefficient . The scattering of background light into the observer's line of sight can increase F over the distance dx . This increase is defined as b' F B ( x ) dx , where b' is a constant. The overall change in intensity is expressed as Since F B represents the background intensity, it is independent of x by definition. Therefore, It

702-489: Is a visibility of between 1 km (0.62 mi) and 2 km (1.2 mi) and haze from 2 km (1.2 mi) to 5 km (3.1 mi). Fog and mist are generally assumed to be composed principally of water droplets, haze and smoke can be of smaller particle size. This has implications for sensors such as thermal imagers (TI/ FLIR ) operating in the far-IR at wavelengths of about 10 μm, which are better able to penetrate haze and some smokes because their particle size

756-402: Is an acronym for Bl ind Spot I nformation S ystem , a system of protection developed by Volvo . Volvo's previous parent, Ford Motor Company , has since adapted the system to its Ford, Lincoln , and Mercury brands. This system was first introduced on the 2001 Volvo SCC concept car, then placed into production on the 2003 Volvo XC90 SUV and produced a visible alert when a car entered

810-399: Is capable of calculating MOR is the optical extinction analyzer (OEA). It actually calculates the optical extinction coefficient (ß) by directly measuring the decay time (aka the ring-down time constant) of injected laser light inside an optical cavity containing an ambient gas sample. The OEA is a cavity enhanced absorption spectroscopy (CEAS) technique. Briefly, the injected laser light into

864-471: Is clear from this expression that b' must be equal to b ext . Thus, the visual contrast, C V ( x ), obeys the Beer–Lambert law which means that the contrast decreases exponentially with the distance from the object: Lab experiments have determined that contrast ratios between 0.018 and 0.03 are perceptible under typical daylight viewing conditions. Usually, a contrast ratio of 2% ( C V = 0.02)

918-425: Is fast (1 Hz) and fully automated for an unattended OEA operation in the field. The geographical visibility depends on the altitude of the observation site and the topology of its surroundings. Planes and water surfaces provide a maximum range of vision, but vegetation, buildings and mountains are geographical obstacles that limit the geographical visibility. When the sky is clear and the meteorological visibility

972-408: Is generally known as the dead visual range of an aircraft. To address this, cameras are sometimes placed in the front of the aircraft to cover the missing field of view. Visibility In meteorology , visibility is the measure of the distance at which an object or light can be clearly discerned. It depends on the transparency of the surrounding air and as such, it is unchanging no matter

1026-502: Is high, the curvature of the earth limits the maximum possible geodetic visibility. The visibility from an elevated observation point down to the surface of the sea can be calculated using the Pythagorean theorem , since the line of sight and the radius of the Earth form the two legs of a right triangle . The height of the elevated point plus the Earth radius form its hypotenuse . If both

1080-448: Is inexpensive and obviates the need for costly technological solutions to that problem, provided drivers take the time to set up and use their mirrors effectively. The arrangement—pointing the side-view mirrors substantially outboard in a fixed mechanical formula—is relatively simple to achieve. Still, it takes some knowledgeable effort and getting used to it. It is reputed to be a lifesaver. However, one source considers that method

1134-539: Is limited to about 296 km. Visibility perception depends on several physical and visual factors. A realistic definition should consider the fact that the human visual system (HVS) is highly sensitive to spatial frequencies, and then to use the Fourier transform and the contrast sensitivity function of the HVS to assess visibility. The international definition of fog is a visibility of less than 1 km (3,300 ft); mist

SECTION 20

#1732887506942

1188-456: Is minor for short visual ranges but must be taken into account for ranges above 30 km. Meteorological optical range (MOR) is a measurement of visibility in kilometers. MOR is the length of path in the atmosphere required to reduce the luminous flux in a collimated beam from an incandescent lamp to 5% of its original value. There are few analytical approaches available to measure visibility (MOR) directly or indirectly. One novel instrument that

1242-405: Is often reduced somewhat by air pollution and high humidity . Various weather stations report this as haze (dry) or mist (moist). Fog and smoke can reduce visibility to near zero, making driving extremely dangerous. The same can happen in a sandstorm in and near desert areas, or with forest fires . Heavy rain (such as from a thunderstorm ) not only causes low visibility, but

1296-444: Is primarily determined by weather conditions (see visibility ) and by a vehicle's design . The parts of a vehicle that influence visibility include the windshield , the dashboard and the pillars . Good driver visibility is essential to safe road traffic . Blind spots exist in a wide range of vehicles: aircraft, cars, buses, trucks, agricultural equipment, heavy equipment, boats, ships, trams and trains. Blind spots may occur in

1350-461: Is probably the most apparent symptom of air pollution . Visibility degradation is caused by the absorption and scattering of light by particles and gases in the atmosphere . Absorption of electromagnetic radiation by gases and particles is sometimes the cause of discolorations in the atmosphere but usually does not contribute very significantly to visibility degradation. Scattering by particulates impairs visibility much more readily. Visibility

1404-455: Is reduced by significant scattering from particles between an observer and a distant object. The particles scatter light from the sun and the rest of the sky through the line of sight of the observer, thereby decreasing the contrast between the object and the background sky. Particles that are the most effective at reducing visibility (per unit aerosol mass) have diameters in the range of 0.1-1.0 μm. The effect of air molecules on visibility

1458-701: Is smaller than the wavelength; the IR radiation is therefore not significantly deflected or absorbed by the particles. With fog, occasional freezing drizzle and snow can occur. This usually occurs when temperatures are below 0 °C (32 °F). These conditions are hazardous due to ice formation, which can be deadly, particularly so because of the low visibility, which usually accompanies these conditions at under 1,000 yards. The combination of low visibility and ice formation can lead to accidents on roadways. These cold weather events are caused largely by low-lying stratus clouds . Visibility of less than 100 metres (330 ft)

1512-525: Is turned off when in reverse or park gears. On Ford products, the system was first introduced in the spring of 2009, on the 2010 Ford Fusion and Fusion Hybrid, 2010 Mercury Milan and Milan Hybrid, and 2010 Lincoln MKZ . Mitsubishi offers a Blind Spot Warning (BSW) on the Pajero Sport launched in 2016. In 2010, the Nissan Fuga / Infiniti M for the first time offered countersteering capabilities to keep

1566-514: Is used to calculate visual range. Plugging this value into the above equation and solving for x produces the following visual range expression (the Koschmieder equation): with x V in units of length. At sea level, the Rayleigh atmosphere has an extinction coefficient of approximately 13.2 × 10 m at a wavelength of 520 nm. This means that in the cleanest possible atmosphere, visibility

1620-423: Is usually reported as zero. In these conditions, roads may be closed, or automatic warning lights and signs may be activated to warn drivers. These have been put in place in certain areas that are subject to repeatedly low visibility, particularly after traffic collisions or pile-ups involving multiple vehicles. In addition, an advisory is often issued by a government weather agency for low visibility, such as

1674-451: The Society of Automotive Engineers , but the method is frequently overlooked in driver's education classes and takes some getting used to. Untrained drivers tend to adjust the side mirrors too far in, so they can see the sides of their own vehicle, but cannot see vehicles traveling alongside in adjacent lanes. Calculated elimination of blind spots by trained drivers is inexpensive and obviates

Blind spot monitor - Misplaced Pages Continue

1728-470: The absorption of light by gases and particles . Light scattered by particles outside of a particular beam may ultimately contribute to the irradiance at the target, a phenomenon known as multiple scattering . Unlike absorbed light, scattered light is not lost from a system. Rather, it can change directions and contribute to other directions. It is only lost from the original beam traveling in one particular direction. The multiple scatterings' contribution to

1782-514: The atmospheric refraction must be taken into account when calculating geodetic visibility. ICAO Annex 3 Meteorological Service for International Air Navigation contains the following definitions and note: Annex 3 also defines Runway Visual Range (RVR) as: In extremely clean air in Arctic or mountainous areas, the visibility can be up to 240 km (150 miles) where there are large markers such as mountains or high ridges. However, visibility

1836-477: The 2008 Mazda CX-9 Grand Touring and remained limited to only that highest trim level through the 2012 model year. For 2013, BSM was standard on both the CX-9 Touring and Grand Touring models. Mazda also added BSM to the redesigned 2009 Mazda 6 . Blind spot monitoring was standard equipment on the 6i and 6s Grand Touring trim levels, and was an available option on some lower trim levels. Mazda has since expanded

1890-522: The OEA built-in algorithm. To that end, the amount of light attenuated due to 1)leakage from the high-reflectivity mirrors and 2)absorption by non-aerosol species present in the gas sample is automatically accounted for by flowing the same analyzed gas sample via an aerosol filter into the cavity to measure the light extinction caused by the aerosol-free gas. More details on the OEA principle of operation can be found here . The above-described MOR determination process

1944-423: The ambient light level or time of day. It is reported within surface weather observations and METAR code either in meters or statute miles , depending upon the country. Visibility affects all forms of traffic: roads , railways , sailing and aviation . The geometric range of vision is limited by the curvature of the Earth and depends on the eye level and the height of the object being viewed. In geodesy ,

1998-542: The availability of BSM, having added it to the feature list of the Mazda2 , Mazda3 , CX-3, CX-5 , MX-5 Miata, and the upcoming CX-30 , often as part of an option package. While only a concept car, the Ford GT90 was the first vehicle to be fitted with a modern blind spot monitoring system. Currently, Ford uses the acronym BLIS for its blind spot detection. The system is active both in "drive" and "neutral" transmission gears, and

2052-430: The background and the object where F B (x) and F (x) are the intensities of the background and the object, respectively. Because the object is assumed to be perfectly black, it must absorb all of the light incident on it. Thus when x =0 (at the object), F (0) = 0 and C V (0) = 1. Between the object and the observer, F (x) is affected by additional light that is scattered into the observer's line of sight and

2106-423: The blind spot while a driver was switching lanes, using cameras and radar sensors mounted on the door mirror housings to check the blind spot area for an impending collision. Volvo won an AutoCar Safety and Technology award for the introduction of this feature. Mazda was the first Japanese automaker to offer a blind spot monitor, which they refer to as "BSM" (Blind Spot Monitoring). It was initially introduced on

2160-780: The blind spot. Blind spots also exist around trams (streetcars/trolleys) and trains (locomotives with railway carriages and multiple units). Heavier rolling stocks can have up to several meters of blind spot. This is generally known as the dead visual range of a train. To address this, cameras are sometimes placed around the train driver's cab to cover the missing field of view during coupling/decoupling between locomotives and railcars, multiple units, special railway equipments or another locomotives. Blind spots also exist around agricultural equipment (utility tractors, combine harvesters, etc.). Blind spots also exist around heavy equipment (excavators, bulldozers, wheel loaders, cranes, etc.). Blind spots also exist in front of boats and ships. When

2214-410: The boat accelerates, the bow rises, increasing the size of the blind spot. Large vessels can have up to several hundreds of meters of blind spots. This is generally known as the dead visual range of a ship. To address this, cameras are sometimes placed in the front of the vessel to cover the missing field of view. Blind spots exist where areas behind the sail are obscured from the view of a helmsman on

Blind spot monitor - Misplaced Pages Continue

2268-557: The driver to see better around the obstruction and allows the driver better depth perception. Because there is no roof connection between the A- and B-pillars, the A-pillars of a convertible automobile have to be stronger and even thicker. However, with the top down there are no B or C pillars, improving visibility behind the driver. It is best if the dashboard has a non-reflecting dark-colored surface. A small dashboard gives some reflection on

2322-440: The eyes and the object are raised above the reference plane, there are two right-angled triangles. The tangent touching the surface of the Earth or water consists of the two short legs of the two right triangles, which are added together to calculate the geometric range of vision. In geodesy the atmospheric refraction is always taken into account in the calculation, which increases the range of vision, so that even objects behind

2376-458: The front of the driver when the A-pillar (also called the windshield pillar), side-view mirror , or interior rear-view mirror block a driver's view of the road. Behind the driver, cargo, headrests, and additional pillars may reduce visibility. Proper adjusting of mirrors and using other technical solutions can eliminate or alleviate vehicle blind spots. A no zone is one of several areas around

2430-411: The high-finesse optical cavity "bounces" repeatedly, at resonance, between two opposing mirrors for a total pathlength of several kilometers until it completely decays or "rings down", primarily due to its extinction by the ambient gas sample species flowing through the cavity. After accounting for the light extinction caused by non-aerosol species, the aerosol-induced light extinction is readily derived by

2484-410: The horizon. A flatter A-pillar's advantages include reducing the overall drag coefficient and making the car body stronger in a frontal collision, at the expense of reducing driver visibility in a 180° field of view from left to right. A flatter A-pillar (and therefore windscreen) is also a factor when calculating the effects of a collision with a pedestrian. In general, a flatter angle will result in

2538-418: The inability to brake quickly due to hydroplaning . Blizzards and ground blizzards (blowing snow) are also defined in part by low visibility. To define visibility the case of a perfectly black object being viewed against a perfectly white background is examined. The visual contrast , C V (x), at a distance x from the black object is defined as the relative difference between the light intensity of

2592-427: The irradiance at x is modified by the individual particle scattering coefficient, the number concentration of particles, and the depth of the beam. The intensity change dF is the result of these effects over a distance dx . Because dx is a measure of the amount of suspended gases and particles, the fraction of F that is diminished is assumed to be proportional to the distance, dx . The fractional reduction in F

2646-462: The less space the door opening has, and the greater frontal area and coefficient of drag the vehicle will have. Examples of cars with an almost vertical A-pillar: Some modern car designs have an extremely flat A-pillar angle with the horizon. For example, the Pontiac Firebird and Chevrolet Camaro from 1993 to 2002 had a windshield angle of 68° with the vertical, which equals just 22° with

2700-443: The lower part of the windshield. A big dashboard can give a reflection on eye height. It is best if the inside of the A-pillar has a non-reflecting dark-colored surface. If the side of the window is curved there is less A-pillar reflection. Some new model cars have a very big sunroof . Sometimes the sunlight through the roof lights up the dashboard and gives a reflection in the windshield. Other design factors may prevent

2754-406: The need for expensive technological solutions to that problem, provided drivers take the time to set up and use their mirrors properly. Platzer received a patent for his blind spot monitor, and it has been incorporated into various products associated with Ford Motor Company. The blind zone mirror has been touted as "an elegant and relatively inexpensive solution" to this recognized problem. BLIS

SECTION 50

#1732887506942

2808-416: The rear of the vehicle on both sides. Vehicles in the adjacent lanes of the road that fall into these blind spots may not be visible using only the car's mirrors. Rear quarter blind spots can be: Other areas that are sometimes called blind spots are those that are too low to see behind, in front, or to the sides of a vehicle, especially those with a high seating point. This diagram shows the blocked view in

2862-401: The vehicle from colliding. Vehicle blind spot A blind spot in a vehicle or vehicle blind spot is an area around the vehicle that cannot be directly seen by the driver while at the controls, under existing circumstances. In transport , driver visibility is the maximum distance at which the driver of a vehicle can see and identify prominent objects around the vehicle. Visibility

2916-473: The windshield is fillet with the roof-line with a big radius. A fillet round A-pillar can give a tall driver visibility problems. Also sometimes the A-pillar can block the driver from seeing motorcyclists. Also, the B-pillar can block the vision of a tall driver in small 4-door cars. A driver may reduce the size of a blind spot or eliminate it by turning their head in the direction of the obstruction. This allows

#941058