GB2254590A

GB2254590A - Light deviating systems to aid vehicle manoeuvring

Info

Publication number: GB2254590A
Application number: GB9122923A
Authority: GB
Inventors: William Alexander Courtney
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-04-06
Filing date: 1991-10-29
Publication date: 1992-10-14
Anticipated expiration: 2011-10-29
Also published as: GB2254590B; GB9122923D0

Abstract

Light deviating air spoilers and airfoils for road vehicles act as view expanding optical systems thereby acting as reversing and parking aids, and include other light reflecting and refracting devices that can be combined with light deviating spoilers and airfoils to aid manoeuvering in confined spaces. The rear spoilers and airfoils described deviate light and allow the drivers visual field to be extended to include the blind spot normally offered by the bodywork at the rear of the vehicle, and consist of constructing the rear spoilers and airfoils from one or more lenses or prisms. The optical components can be constructed in a similar manner to Fresnel lenses, this allows the transparent elements to have a thin cross section. A second, opaque rear spoiler or airfoil can be added to reduce reflected light. Similar transparent spoilers and airfoils or combinations with opaque spoilers and airfoils can be added to the front or other parts of the vehicle. <IMAGE>

Description

Light Deviating Systems to aid Vehicle Manoeuvring This invention relates to road vehicles. It describes light deviating air spoilers and airfoils that offer view expanding optical systems, thereby acting as reversing and parking aids. It also includes other light reflecting and refracting devices that can be combined with light deviating spoilers to aid manoeuvring in confined spaces.

Airspoilers and airfoils are common features on road vehicles currently in production. The functional purposes of these devices are to reduce the coefficients of drag and lift for the vehicle. Also by lowering the point at which air streamlines break away from the bodywork at the rear of the vehicle the point at which the rear of the vehicle becomes soiled by road dirt thrown up by the wheels is lowered.

In recent years the reduction in fuel consumption and the corresponding reduction in air pollution which results from a reduction in drag coefficient have become increasingly important factors when marketing vehicles. Unfortunately there is a cost to be paid for these benefits. The optimum design shape and placement of the spoiler or airfoil obscures the drivers field of view. This compounds an existing problem in that the bodywork of the vehicle (door pillars, boot, bonnet etc) limit the drivers field of view. This is a particular problem when manoeuvring vehicles in restricted spaces.The cost -benefit balance between the two opposing demands of maximum visibility and minimum fuel consumption results in mass production vehicles being manufactured with rear spoilers that are not of the size and position for optimum airodynamic performance and the virtual exclusion of front bonnet or nose spoilers and airfoils from the markeL It is the object of the present invention to reduce the problems associated with current spoilers and airfoils and to provide improved optical arrangements for viewing the near surroundings of the vehicle.

The visibility problems can be reduced by constructing the spoiler wholly or partly of transparent materials. By adding optical elements to transparent air spoilers that refract or reflect light it is possible to see areas normally hidden by the bodywork. This converts a weakness of current spoiler designs into a strength. Thereby increasing their usage with corresponding environmental benefits. The optical elements which produce the deviation of the light can form part or all of the effective surface area of the spoiler. The optical elements may be lenses or prisms. Deviation without change in magnification is produced by the use of prisms. Lenses which produce negative magnification are used to increase the field of view. A combination of prisms and lenses may be used to solve a range of visual information problems.

One version of the invention can produce refraction using a thin (of the order of mm) composite of optical material. It uses a number of small prisms or lenses in a manner similar to that originally proposed by Fresnel. The transparent spoiler consisting of two sheets of material, an upper and lower sheeL The external surfaces of both sheets are preferred smooth, to minimise the accumulation of dirt or water. One sheet, upper or lower, is moulded so that its internal surface takes the form of the prisms or lenses. The other sheet can consist simply of a transparent, parallel sided laming and serves the purpose of protecting the moulded surface. If the required angle of deviation is large this can be produced by using two or more layers of deviating material.

The deviation can also be produced using spoilers or airfoils which incorporate mirrors or optically refracting prism shapes that produce total internal reflection.

The upper surface (and other surfaces as well, if necessary) can be coated with an anti reflecting layer, to reduce the reflection of unwanted light towards the drivers eyes. The extemal optical surfaces of the spoiler may also be chemically treated to minimise the adhesion of dirt to these surfaces.

The visual properties can be maintained under adverse conditions if the external surfaces are serviced by washing and wiping systems.

A second, opaque upper spoiler or airfoil can be added to assist in eliminating unwanted reflected light.

The second spoiler achieves this optical function if it is so placed that it lies along the incoming path of rays which would otherwise enter the drivers eye after being reflected in an undesirable manner from a surface of the deviating spoiler. The blind spot caused by the addition of the second spoiler can be eliminated, if desired by having a range of prisms or lenses to give a similar effect to that produced by a lens having a negative focal length.

The specific shape and angle of the spoiler to produce the required airflow effects will depend on the shape of the vehicle, performance requirements and other design variables. Those skilled in the art will be aware of the relevant shapes and dimensions required. The purpose of this invention is to describe the optical features that can be incorporated to assist in reversing and parking. The optical elements can be added in a range of configurations in order to comply with the non-optical needs.

The amount of deviation can be changed by the vehicle user if an adjustment system is incorporated to alter the angle of the plane of the spoiler to the vertical, or in the case of a multiple layer spoiler by adjusting the angle between the refracting layers. The adjustment can be done manually, or if the system is equipped with motive power the adjustment may take place remotely, in response to the operation of a switch or the like by the driver. The motive power means may be operably associated with the gear selection means, possibly using a continuously variable system so that the angle of deviation is automatically altered during the reversal manoeuvre. Alternatively, the control system could for example consist of one or more infra-red or ultra-sonic sensors that were capable of detecting the distances of obstacles or the like.A visual or audio system could be synchronised to the spoiler to supply information to the driver concerning the distance from the rear of the vehicle to the observed field of view. Systems using this version of the invention which involve motive power would be of particular benefit if the position of the spoiler for maximum aerodynamic performance did not comply with the position for required optical performance. The optimum aerodynamic characteristics are a function of the position and angle of a spoiler or airfoil that varies with speed and air pressure. The control system could be pressure or speed sensitive in order to optimize performance. The cost of obtaining the benefits of a speed or pressure sensitive system may not be justified for an opaque spoiler but become economical when the additional advantage of increased visual access is gained.The exact form of the control system employed is not an important feature of the present invention. Those skilled in the art will be aware of the many suitable methods for controlling the movement of the device.

Similar light deviating air spoiler or airfoil systems could be used to enable an observer to look into blind spots at the front or other parts of the vehicle. The deviating system could be incorporated with a spoiler on the front of the vehicle to give the combined benefit of reduced airflow resistance and improved visibility. For certain vehicle designs which incorporate a roof mounted spoiler or airfoil the incorporation of a view expanding optical system would be beneficial.

An additional problem often faced when reversing a vehicle is manoeuvring the vehicle so that it is centralised to enter the gap between two obstacles or the like whose distance apart is only slightly in excess of the width of the vehicle.

Two factors which make judgement of vehicle position difficult in these circumstances are: a) The driver has to look in two directions to see the two obstacles.

b) The judgement made is subject to a parallax error.

Methods of overcoming these problems using view expanding systems associated with air spoilers and airfoils will be described below.

Specific embodiments of these component parts of the invention will now be described.

a) The Light Deviating Rear Spoiler For simplicity and clarity it will be assumed that the spoiler consists of a flat plane parallel to the rear axle and mounted at an angle of 20 to the horizontal. The driver will be assumed to view the spoiler from an angle of 10 to the horizontal and the design will produce a refraction of the light of 20 Fig l(a) shows a typical closest distance at which the front of the bonnet of another car can be viewed without the addition of a spoiler.

Fig 1(b) shows the effect of adding a traditional opaque spoiler.

Fig 1(c) shows the effect of adding a transparent spoiler that refracts the light through an angle of 20'.

Fig 2 shows how a simple, solid prism can be used to produce the required amount of refraction. The diagram shows the refraction that would be produced for the angles shown, using a transparent material of refractive index 15. The calculations of the angles are carried out using the standard formulae for geometrical optics described in Physics textbooks.

The curved area at the front (right hand side) will have a shape that is defined by aerodynamic considerations.

Fig 3 shows a cross section of a preferred form of the spoiler that produces the same degree of refraction using a number of mini prisms. The diagram assumes for simplicity that the refraction is produced by prisms. The plane inner surfaces could be curved-i.e. they would be described as lenses. The prisms are shown on the upper layer, instead the required refracting could take place on the lower layer or be shared between both layers. For clarity the arrangement is shown as consisting of a small number of large prisms. The preferred form of the invention can be made thinner by using a large number of smaller prisms (or lenses) Fig 4 is a more detailed version of a section of fig 3. The useful refraction produced is similar to that shown in fig 2.

The surface 1 of the prism, labelled in the diagram, is parallel to the refracted ray inside the prism, for an emergent ray viewed from an angle of elevation of 10.

Angular dispersion could be corrected by using systems consisting of achromatic combinations of prisms (lenses) of different dispersive powers and refractive indices in sequence. The preferred solution is to tolerate a small amount of coloured fringes caused by dispersion and minimise this by choosing a transparent material with a low dispersive power.

Fig 4 shows the shape of prism and geometry of the rays for a cross section directly behind the driver.

The same optical principles apply as the driver looks diagonally across, towards the back of the vehicle but the geometry becomes more complex. The shape of the prisms (lenses) could be varied along a line parallel to the rear axle of the vehicle to reduce distortion of the image as seen from the driving position. This degree of sophistication is unlikely to be necessary.

Fig S shows the addition of a second opaque spoiler to reduce the amount of unwanted reflected light entering the drivers eyes. The second spoiler is labelled as 2.

The amount of reflected light can also be reduced by adding an anti reflecting coating to the optical surfaces.

Figs 6 and 7 are plan views looking down on the vehicle with the roof removed. They show show different versions of light deviating spoilers which towards the end of the spoiler produces a similar effect to a diverging lens. This enables the driver to view the area indicated by the arrows. If the interior rear view mirror currently in use is a compound mirror as described herein it would be possible to view both regions, to the left and right rear of the vehicle simultaneously.

The optical systems described in this invention are exposed to contamination from road dirt. The external optical surfaces of the spoiler may be chemically treated to minimise the adhesion of dirt to these surfaces. Washing and wiping systems similar to those used for vehicle windscreens and headlamps may be added to the optical systems. Those skilled in the art will be aware of the methods for treating the surfaces and adding washing and wiping systems.

b) A device for strnultaneotsly viewing two obstacles at extreme ends of the rear field of view This is achieved by using a compound interior mirror that consists of two mirrors, set one above the other and angled so that the extreme edges of the field of view at the back windscreen can be seen simultaneously. The mirrors can be tilted at a slight angle to each other so that they are used to view points in the field that are at the same height. Instead of using two broad mirrors a vertical set of narrow pairs of mirrors could be used. Markings, small cuts in the mirror surfaces or other visual clues could be added to aid judgement in aligning the vehicle.The width of each mirror in the compound mirror system must exceed the distance between the centre of the observers eyes, otherwise each eye will see a different view through the mirror and confusing visual information will be perceived. Figs 8 and 9 show the basic version and an exploded view of the multiple mirror version of the compound mirror.

c) A System to overcome the Parallax Error.

Without the system, light rays entering the drivers eye from the obstacles enter at different angles to those from the directions of the extreme dimensions of the vehicle.

This is illustrated in figure 10. The dashed line (1) shows the direction of a light ray which intersects with the extreme dimension, the solid line (2) shows a light ray from the inner edge of the obstacle (3) The parallax error can be overcome by using two optical devices to define a straight line that gives a view to obstacles to the rear of the vehicle and also intersects the extreme dimension of the vehicle.

The optical components could for example be a part of the light deviating air spoiler and a Fresnel lens or optical stop mounted on the rear windscreen. The Fresnel lens would then be used to deviate light from the end of the line towards the observer or the driving mirror. If a compound mirror is used to view the deviated light, the light from the direction of two extreme dimensions can be viewed simultaneously.

Fig 11 shows an obstacle (1) which is viewed through a section of the rear spoiler (2) and a Fresnel lens (3) attached to the rear windscreen. The outer edges of the region of the air spoiler seen through the Fresnel lens and the Fresnel lens define the straight line which intersects the effective exterior dimension of interesL The effective dimension could be the true dimension plus an allowance for a safely margin. (2) may have different deviating properties to other parts of the spoiler. In this case (2) enables the observer to see an area of ground shaded in the diagram (4).

If the vehicle is correctly positioned then as the vehicle is reversed the image of the obstacle seen by the observer will move to the edge of the field of view and then move out of sight before the rear of the vehicle reaches the level of the obstacle.

(5) shows the position of an obstacle which has just moved out of sight in the manner described.

If two obstacles, at opposite sides of a gap are viewed through a compound mirror (6) then the vehicle should be manoeuvred so that both images move to the edge of the field of view at the same rate. This judgement can be assisted if the compound mirror is graduated d) The Light Deviating Front Spoiler or Airfoil Front spoilers and airfoils are added to race and rally vehicles but are uncommon on mass produced road vehicles. The aerodynamic benefits of these devices are that they reduce drag and improve road holding.

They frequently have visibility disadvantages similar to those of rear spoilers. If a suitably shaped and placed light deviating spoiler is added to the nose of the vehicle it can produce aerodynamic and visibility advantages. The front spoiler may be constructed from light deviating material or be constructed from an opaque leading surface with a light deviating internal component Fig 12 shows a spoiler which consists of an opaque outer part and a light deviating inner. In this example the deviation is produced by a prism which produces total internal reflection.

e) The Light Deviating Roof Spoiler or Airfoil Roof spoilers are common on lorries and vans. They are occasionally used on other vehicles. These have similar aerodynamic advantages to front and rear spoilers but do not produce visual hindrance for the vehicle driver. They can however be used to to visual advantage if they incorporate optical systems to expand the field of view.

Claims

1. An air spoiler or airfoil which is partly or wholly transparent so that it offers less visual field restriction than a similar shaped opaque spoiler or airfoil.

2. An air spoiler or airfoil that has a shape that is optimized for aerodynamic characteristics that refracts light, in order to give view expanding assistance to the driver.

3. An air spoiler or airfoil that has a shape that is optimized for aerodynamic characteristics that reflects light, in order to give view expanding assistance to the driver.

4. A spoiler or airfoil as in claims 1,2 and 3 which includes optical elements based on Fresnel lens or prism design.

5. A spoiler or airfoil which includes multiple transparent layers.

6. A spoiler or airfoil which includes multiple transparent layers that offers smooth outer sur faces.

7. A light deviating spoiler or airfoil with one or more anti reflecting surfaces that assist in reducing unwanted reflected and scattered lighL

8. A light deviating spoiler or airfoil that has one or more surfaces that have been chemically treated to minimise the adhesion of dirt.

9. A light deviating spoiler or airfoil that can be cleaned by a wiper mechanism.

10. A light deviating spoiler or airfoil that can be wetted by a remotely controlled washing device.

11. A second, opaque spoiler or airfoil that assists in reducing unwanted reflected and scattered light when viewing the light deviating spoiler or airfoil.

12. A light deviating air spoiler or airfoil which uses two or more layers of light deviating material to produce the required amount of deviation of the lighL

13. An air spoiler or airfoil which deviates light, which can be tilted by an adjustment mecha nism, so that the deviation can be altered

14. An air spoiler or airfoil which deviates light, which includes two or more deviating compo nents which can have their relative positions altered by an adjustment mechanism, so that the deviation can be altered.

15. An air spoiler or airfoil which incorporates claims 13 and 14.

16. An air spoiler or airfoil as in claim 15 which has motive power means to allow adjustment in response to signals from an obstacle sensing system.

17. An air spoiler or airfoil as in claim 16 but including an audio or visual output system that supplies information conceming the position of the field of view of the spoiler relative to the vehicle.

18. An air spoiler or airfoil which produces changes as in claim 15 as a consequence of receiving a signal from a switch or the like related to the vehicle reverse gear or reverse gear selection means.

19. An air spoiler or airfoil which produces changes as in claim 15 which adjusts its position or angle to the vertical in response to a change in road speed.

20. An air spoiler or airfoil which produces changes as in claim 15 which adjusts its position or angle to the vertical in response to a change in airspeed in the region of the air spoiler or airfoil.

21. A light deviating air spoiler or airfoil which incorporates the phenomenon of total internal reflection to produce deviation.

22. A light deviating air spoiler or airfoil which incorporates mirrors to produce deviation.

23. A light deviating air spoiler or airfoil which produces different degrees of deviation, at different points along its length.

24. A light deviating air spoiler or airfoil which produces different degrees of deviation, at different points along a line at right angles to its length.

25. A light deviating air spoiler or airfoil which incorporates claims 23 and 24.

26. A light deviating air spoiler or airfoil which incorporates claims 23, 24 or 25 and is curved for part or all of its length.

27. An optical system, including an air spoiler or airfoil, which has two or more optical compo nents which define two points on the straight line along which a light ray, if extended back wards, away from the observer passes through one of the effective extreme dimensions of the vehicle.

28. An interior, rear view mirror which is a compound mirror, made up of at least one pair of two mirrors one above the other and at an angle to each other so that equivalent portions of the right hand and left hand rear windscreen are visible simultaneously.

29. A light deviating spoiler or spoiler system as in any of the above claims which is mounted on any other part of the vehicle.

29. A compound mirror as in claim 28 that is attached to an existing interior rear view mirror and can be swivelled out of useful view when not needed.

30. A compound mirror as in claims 28 or 29 that has graduation marks or other visual indica tions so that the relative positions of two images on the component mirrors can be compared.

31. An optical system which incorporates claims 27 and 28 or 29.

32. An optical system which incorporates claims 27, 28 or 30 and 29.

33. A device using the principles as in claims 1, 2, 3, 4, 5, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 31 and 32 which acts as a rear air spoiler.

34. A device using the principles as in claims 1, 2, 3, 4, 5, 7, 8, 9,10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 31 and 32 which can be mounted on the nose or bonnet of the vehicle.

35. A device as in claim 34 which has a protective covering on the side of the device away from the body of the vehicle.

36. As in claims 29 or 31 in which the protective covering acts as a front air spoiler or airfoil.

37. A device using the principles as in claims 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 31 and 32 which is mounted on the roof of the vehicle and is used in conjunction with other light deviating elements to give view expanding assistance to the driver.

38. A device similar to that claimed in claims 34, 35, 36 or 37 but which is mounted on any other part of the vehicle.

Amendments to the claims have been filed as follows

1. A vehicle spoiler or airfoil which deviates light using optical elements based on Fresnel lens or prism design.

2. A vehicle spoiler or airfoil which deviates light using optical elements based on Fresnel lens or prism design which is constructed from two or more transparent layers of material.

3. A spoiler or airfoil as in claims l or 2 that offers smooth outer surfaces.

4. A light deviating spoiler or airfoil with one or more anti reflecting surfaces that assist in reducing unwanted reflected and scattered light

5. A light deviating spoiler or airfoil that has one or more surfaces that have been chemically treated to minimise the adhesion of dirt.

6. A light deviating spoiler or airfoil that can be cleaned by a wiper mechanism.

7. A light deviating spoiler or airfoil that can be wetted by a remotely controlled washing device.

8. A modified version of the invention as in any of the above claims which includes a second, opaque spoiler or airfoil that assists in reducing unwanted reflected and scattered light when viewing the light deviating spoiler or airfoil.

9. An air spoiler or airfoil which deviates light, which can be tilted by an adjustment mecha nism, so that the deviation can be altered.

10. An air spoiler or airfoil which deviates light, which includes two or more deviating compo nents which can have their relative positions altered by an adjustment mechanism, so that the deviation can be faltered.

11. An air spoiler or airfoil which incorporates claims 9 and 10.

12. An air spoiler or airfoil as in claim 11 which has motive power means to allow adjustment in response to signals from an obstacle sensing system.

13. An air spoiler or airfoil as in claim 12 but including an audio or visual output system that supplies information concerning the position of the field of view of the spoiler relative to the vehicle.

14. An air spoiler or airfoil which produces changes as in claim 15 as a consequence of receiving a signal from a switch or the like related to the vehicle reverse gear or reverse gear selection means.

15. A light deviating air spoiler or airfoil which alters its position relative to the body of the vehicle in response to a change in road speed.

16. A light deviating air spoiler or airfoil which alters its position relative to the body of the vehicle in response to a change in airspeed in the region of the air spoiler or airfoil.

17. A light deviating air spoiler or airfoil which incorporates the phenomenon of total internal reflection to produce deviation.

18. A light deviating air spoiler or airfoil which incorporates mirrors to produce deviation.

19. A light deviating air spoiler or airfoil which produces different degrees of deviation, at different points along its length.

20. A light deviating air spoiler or airfoil which produces different degrees of deviation, at different points along a line at right angles to its length

21. A light deviating air spoiler or airfoil which incorporates claims 19 and 20.

22. A light deviating air spoiler or airfoil which incorporates claims 20,21 or 22 and is curved for part or all of its length.

23. An optical system, including a light deviating air spoiler or airfoil as an essential component which also has two or more optical components which define two points on the straight line along which a light ray, if extended backwards, away from the observer passes through one of the effective extreme dimensions of the vehicle.

24. An optical system, including a light deviating air spoiler or airfoil as an essential component which also includes an interior, rear view mirror which is a compound mirror, made up of at least one pair of two mirrors one above the other and at an angle to each other so that equivalent portions of the right hand and left hand rear windscreen are visible simultaneously.

25. A system as in claim 24 in which the compound mirror is attached to an existing interior rear view mirror and can be swivelled out of useful view when not needed.

26. A system as in claim 24 or 25 in which the compound mirror has graduation marks or other visual indications so that the relative positions of two images on the component mirrors can becompared, 27. A light deviating spoiler or spoiler system as in any of the above claims which is mounted on the bonnet or nose of the vehicle.

28. A light deviating spoiler or spoiler system as in 27 which has a protective covering on the light deviating elements of the spoiler on the side of the elements away from the body of the vehicle.