ROAD VEHICLE MOTORING AID METHOD AND SYSTEM

TECHNICAL FIELD The present invention relates to a road vehicle motoring aid method and system.

The present invention may be used to advantage in a car, to which the following description refers purely by way of example.

BACKGROUND ART

Progress in electronic systems has resulted in a steady increase over the past few years in the amount of information supplied to car drivers, and therefore in a growing need to organize and display this information for quick access by the driver without overly distracting the driver's attention from the road.

The problem of displaying information without distracting the driver's attention from the road applies in particular to GPS navigation systems, which indicate routes using data supplied by a satellite positioning device. In fact, the tendency is for drivers to focus their attention continually on the route mapped on the

GPS screen, as opposed to road traffic conditions, with obvious risks in terms of safety. It is important to note that, to monitor the GPS screen, the driver must look away from the road, and switching back and forth between the road and screen takes time for the driver's eyes to adapt to different focal lengths, which may be particularly slow in the case of elderly drivers.

By way of a solution to the problem, GPSs with a voice capability have been proposed, to communicate the route vocally to the driver. The effectiveness of voice communication, however, is limited, in that the driver still tends to monitor the GPS screen.

Another proposed solution is an HUD (Heads-Up Display) system, which projects an electronic image of the GPS-generated route information onto the windscreen of the car, so the driver can read the projected information without looking away from the windscreen, i.e. the road.

Installing an HUD system in a car, however, is an expensive process, and is therefore limited to a small number of top-range models. One of the major problems in installing an HUD system in a car is caused by flaws in the windscreen, which, though not noticeable when observing the road through the windscreen, may introduce unacceptable distortion of the projected images. As a result, the windscreen (which has an extensive surface area and highly complex curved shape) must be made to strict manufacturing specifications involving a

considerable increase in cost and rejects.

Moreover, in normal driving conditions, the driver's head and, therefore, eyes are subject to continual vertical and horizontal bobbing movements induced by vibration of the car, so the driver's eyes must keep continual track of the position of the image projected on the windscreen, thus making monitoring of the image awkward.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a road vehicle motoring aid method and system designed to eliminate the aforementioned drawbacks, an which are cheap and easy to implement. According to the present invention, there are provided a road vehicle motoring aid method and system as claimed in the accompanying Claims .

BRIEF DESCRIPTION OF THE DRAWINGS A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic side view of a car equipped with a motoring aid system in accordance with the present invention;

Figure 2 shows a schematic plan view of the Figure 1 car on open road;

Figure 3 shows a schematic plan view of the Figure 1

car on track.

PREFERRED EMBODIMENTS OF THE INVENTION

Number 1 in Figure 1 indicates a car travelling along a road 2 having a road surface 3.

Car 1 is equipped with a motoring aid system 4 comprising an electronic device 5, which generates motoring aid information as car 1 travels along road 2. Electronic device 5 typically incorporates or is connected to a GPS navigation system, which indicates the route to a given destination using data supplied by a satellite positioning device, so at least part of the information supplied by electronic device 5 relates to a route to be followed. Electronic device 5 is obviously designed to process any type of motoring aid information, such as vehicle information (travelling speed, engine speed, currently engaged gear, faults ...) or traffic condition information.

Motoring aid system 4 comprises a further electronic device 6, which receives and converts the information from electronic device 5 into a succession of typically dot-matrix graphic display images 7.

Electronic device 6 controls at least one laser projector 8 located at the front of car 1 and normally integrated in a front optical assembly of car 1. Using laser light, projector 8 projects the image 7 from electronic device 6 onto a portion of road surface 3 ahead of car 1, to enable the driver of car 1 to view

image 7 without looking away from road 2.

Motoring aid system 4 comprises a compensating device 9 for compensating the body movements of car 1 to stabilize image 7 projected by projector 8. In a first embodiment, projector 8 is float-mounted to a frame of car 1; and compensating device 9 is passive, and comprises a mechanical damper interposed between the frame and projector 8, so that projector 8 follows the movements of car 1 slowly, and is not noticeably affected by the body movements of car 1.

In a second embodiment, compensating device 9 is active, and comprises a sensor 10 for detecting the body movements of car 1; and a mechanical actuator controlled by the signal from sensor 10 to apply compensating movements, equal and opposite to the body movements of car 1, to projector 8.

In a third embodiment shown in Figure 1, compensating device 9 is active, and comprises sensor 10 for detecting the body movements of car 1; and a third electronic device 11 controlled by the signal from sensor 10 to modify image 7 by applying compensating movements, equal and opposite to the body movements of car 1, to image 7.

In one possible embodiment, projector 8 uses light of a given wavelength to project image 7 onto a portion of road surface 3; and the windscreen 12 of car 1 is treated to enhance viewing of the projector 8 wavelength, so image 7 is clearly visible by the driver without

recourse to excessively strong light to project image 7, which could annoy other road-users. A cheaper alternative than treating the whole of windscreen 12 of car 1 is to provide the driver with goggles (or additional lenses which fit onto normal glasses) treated to enhance viewing of the projector 8 wavelength.

In one possible embodiment, motoring aid system 4 comprises a further sensor 13 for determining the lay of road surface 3 ahead of car 1; and an electronic device 14 for accordingly modifying image 7 to adapt image 7 to the lay of road surface 3. In other words, sensor 13 and electronic device 14 combine to take into account whether road surface 3 is flat, uphill, or downhill. In one possible embodiment, sensor 13 may determine the inclination to the horizontal of car 1.

In one possible embodiment, motoring aid system 4 comprises a sensor 15 for determining whether the road 2 ahead of car 1 is clear. Sensor 15 is connected to projector 8, which only projects image 7 onto road surface 3 ahead of car 1 if road surface 3 is clear, thus preventing projection of image 7 onto another vehicle in front of car 1. In which case, in fact, image 7 would be illegible, and may result in reflection annoying the driver of car 1. In one possible embodiment, motoring aid system 4 determines the travelling speed of car 1, and accordingly adjusts the projection distance of image 7 (i.e. the distance between image 7 and car 1) . More specifically,

the projection distance of image 7 is adjusted in direct proportion to the travelling speed of car 1, i.e. the faster the travelling speed of car 1, the greater the projection distance of image 7. In one possible embodiment, motoring aid system 4 determines the steering angle of car 1, and accordingly adjusts the transverse position of image 7.

In Figure 2, car 1 is shown travelling along an open road 2, and image 7 projected by motoring aid system 4 comprises an ideogram indicating the direction to be followed along the desired route. In this case, electronic device 5 acquires the destination of car 1; determines the route to reach the destination; and generates information to display the route to the destination graphically on road surface 3 ahead of car 1. In addition to the ideogram, image 7 may also comprise a distance indication indicating the distance at which to perform the instruction in the ideogram.

In Figure 3, car 1 is shown on track closed to traffic, and image 7 projected by motoring aid system 4 comprises an ideal trajectory to maximize on-track speed. In this case, electronic device 5 determines the ideal trajectory, and generates information to display the ideal trajectory graphically on road surface 3 ahead of car 1. Image 7 typically comprises a line indicating the ideal trajectory, and, in _. addition to the continuous line, may also comprise a best-braking-point indication. Motoring aid system 4 as described above has

numerous advantages, by being cheap and easy to implement, and enabling information access by the driver of car 1 without distracting the driver's attention from road 2.