EP2785571A1

EP2785571A1 - Safety system for a vehicle

Info

Publication number: EP2785571A1
Application number: EP12853148.0A
Authority: EP
Inventors: Carl Fredrik Ullberg; Fredrich Claezon; Mikael Lindberg
Original assignee: Scania CV AB
Current assignee: Scania CV AB
Priority date: 2011-11-28
Filing date: 2012-11-22
Publication date: 2014-10-08
Also published as: CN103958314A; SE538840C2; EP2785571A4; WO2013081533A1; SE1151130A1

Abstract

The invention relates to a safety system for a vehicle, comprising a forward looking camera (FLC) adapted to identifying and detecting circumstances and events substantially in front of the vehicle and to delivering a camera signal 2 based thereon. The safety system comprises an analysis unit 4 with a memory unit 6, a first regulating unit CU1 and a second regulating unit CU2. Said camera signal 2 is arranged to be conveyed to the analysis unit 4, and a set of safety rules for the vehicle and a set of driving rules for the vehicle are stored in the memory unit 6. The analysis unit 4 is adapted to analysing the camera signal 2 with respect to said set of safety rules for the vehicle and to delivering on the basis of the results of the analysis a first analysis signal 8 which is conveyed to said first regulating unit CU1, which is adapted to regulating one or more safety-regulated functions for the vehicle in response to first analysis signal 8. The analysis unit 4 is also adapted to analysing the camera signal 2 with respect to said set of driving rules for the vehicle and to delivering on the basis of the results of the analysis a second analysis signal 10 which is conveyed to said second regulating unit CU2, which is adapted to regulating one or more dynamic characteristics for the vehicle in response to said second analysis signal10.

Description

Title

SAFETY SYSTEM FOR A VEHICLE

Field of the invention

The present invention relates to a safety system for a vehicle according to the preamble of the independent claim.

The following terms are conventional within the field but are explained briefly below. FLC - forward looking camera - a camera on board the vehicle and directed substantially forwards.

LDW - lane departure warning - a system intended to warn of the vehicle leaving its traffic lane. This warning system is configured to minimise accidents by trying to prevent some of the commonest causes of collisions, viz. driver errors due to being distracted or too tired and therefore too inattentive.

AEBS - advanced emergency braking system - a safety system which is superordinate to other warning systems and intended to damp an unavoidable collision by the system engaging, which is achieved by automatic application of brake pressure even before the driver has begun to brake.

FCW - forward collision warning - a system intended to warn of an imminent collision and to damp or avoid it, e.g. by warning the driver, activating brakes early, inflating the seat for extra support, tightening the safety belt, etc.

BSW - blind spot warning - this system provides warning of objects at the so-called blind angle, which is the angle nearest behind the vehicle and cannot be seen by the driver by means of rearview mirrors.

ACC - adaptive cruise control - a system which uses either radar or laser to ensure that the vehicle slows down when it comes too close to a vehicle in front, with a view to subsequently accelerating when the traffic situation so allows.

Ground clearance - the distance from the ground to a vehicle's lowest point other than its wheels.

Background to the invention The way of driving a vehicle, e.g. a truck or a bus, varies depending on the vehicle's current driving situation, which is defined by its surroundings, e.g. the time of day, i.e. how light it is, the number of traffic lanes on the road and their width, any imminent intersections, traffic signals, the number of vehicles ahead and the way they are being driven, etc. These parameters which define the driving situation will affect the way the vehicle is driven.

By gathering information about the vehicle's surroundings it is possible to draw certain conclusions about the expected way of driving it and what preparedness the driver needs in a specific situation.

There is at present no known way of obtaining a comprehensive picture of the vehicle's current driving situation in order to be able to draw conclusions therefrom and help the driver to adapt the vehicle's behaviour accordingly. It is at present usual for adaptation of vehicle systems to be based entirely on internal vehicle signals, e.g. a yaw angle signal (which is a measure of the vehicle's rotational velocity about a vertical axis) or a steering wheel angle signal.

Examples are cited below of some patent specifications referring to known methods and devices within the field which also take into account information related to a vehicle's surroundings.

US 2007/182529 refers to a method for affecting the load upon the driver and describes how information to him/her can be suppressed or delayed. The load upon the driver may comprise environmental characteristics such as the current traffic situation. These characteristics may be recorded with a view to assessing the load upon the driver.

US 5,642,093 refers to a warning system for a vehicle with two CCD type cameras directed forwards to receive image data. The images are analysed with a view to achieving greater driver awareness if any "psychological stimuli" are registered, e.g. road width, bend radius, vehicles ahead, vehicles parked at the side of the road or obstacles on the road. EP 0 911 234 refers to a dynamic control system for vehicles which is intended to stabilise the vehicle's positioning when negotiating a bend or leaving a bend. As discussed above, there is a need to have a comprehensive picture of the prevailing driving situation in order thereafter to adapt the vehicle's behaviour and possibly also the driver's behaviour to cater for the current driving situation. None of the known techniques in the specifications cited above is particularly suited to using a comprehensive picture of prevailing driving situations as a basis for drawing conclusions about what the driver's expected way of driving should be and what preparedness he/she needs in the current driving situation.

The object of the present invention is therefore to propose a system for adapting a vehicle's behaviour in order to achieve safer driving appropriate to the respective driving situation.

Summary of the invention

The above objects are achieved with the invention defined by the independent claim. Preferred embodiments are defined by the dependent claims.

One aspect of the invention relates to a safety system for a vehicle, comprising a forward looking camera (FLC) adapted to identifying and detecting circumstances and events substantially in front of the vehicle and to delivering a camera signal based thereon. The safety system comprises an analysis unit with a memory unit, a first regulating unit and a second regulating unit. Said camera signal is arranged to be conveyed to the analysis unit. The memory unit stores a set of safety rules for the vehicle and a set of driving rules for the vehicle. The analysis unit is adapted to analysing the camera signal with respect to said set of safety rules for the vehicle and to delivering on the basis of the results of the analysis a first analysis signal which is conveyed to the first regulating unit, which is adapted to regulating one or more safety-related functions for the vehicle in response to said first analysis signal. The analysis unit is also adapted to analysing the camera signal with respect to said set of driving rules for the vehicle and to delivering on the basis of the results of the analysis a second analysis signal which is conveyed to said second regulating unit, which is adapted to regulating one or more dynamic characteristics for the vehicle in response to said second analysis signal.

This is of advantage in enabling a vehicle to better adapt its behaviour to prevailing traffic situations, resulting in safer vehicles and more pleasant driving for the driver. There is no need for any extra equipment such as further sensors, since existing cameras are used. A further advantage is that the camera's viewing range corresponds to that of the driver, which means that it covers approximately the same "visual field" as him/her. Thus the camera can grasp the traffic situation in much the same way as the driver.

Brief description of drawing

Figure 1 is a block diagram schematically illustrating a safety system for a vehicle in accordance with the present invention.

Detailed description of preferred embodiments of the invention

Figure 1 thus depicts a block diagram of the system according to the invention. A forward looking camera (FLC) is currently used in existing systems for vehicles such as LDW and AEBS. A camera has to be provided with a general interpretation such as a group of sensors intended to register events concerning the traffic situation substantially in front of the vehicle. According to the present invention this camera forms part of a safety system in which it is adapted to identifying and detecting circumstances and events substantially in front of the vehicle and to delivering a camera signal 2 on the basis thereof. The safety system comprises an analysis unit 4 with a memory unit 6, a first regulating unit CU1 and a second regulating unit CU2. Said camera signal 2 is arranged to be conveyed to the analysis unit 4. The memory unit 6 stores a set of safety rules for the vehicle and a set of driving rules for the vehicle. The analysis unit is adapted to analysing the camera signal with respect to said set of safety rules for the vehicle and to delivering on the basis of the results of the analysis a first analysis signal 8 which is conveyed to said first regulating unit CU1, which is adapted to regulating one or more safety-related functions for the vehicle in response to said first analysis signal. The analysis unit is also adapted to analysing the camera signal with respect to said set of driving rules for the vehicle and to delivering on the basis of the results of the analysis a second analysis signal 10 which is conveyed to said second regulating unit CU2, which is adapted to regulating one or more dynamic characteristics for the vehicle in response to said second analysis signal.

The safety rules are intended to achieve safer driving with respect to the vehicle's current driving situation. The driving rules are intended to support and facilitate the driver's driving of the vehicle according to given requirements in the prevailing driving situation.

The safety rules may comprise one or more of

- a first safety rule related to the distance to the tail lamps of one or more vehicles in front,

- a second safety rule related to density of traffic,

- a third safety rule related to movements of surrounding vehicles, and

- a fourth safety rule related to positions of surrounding vehicles.

The first safety rule may be intended to detect a plurality of tail lamps at a certain distance ahead of the vehicle which is consistently longer than the braking distance required at the vehicle's current speed. A plurality of tail lamps means that tail lamps of at least two successive vehicles are detected. The second safety rule may be intended to detect low traffic density over a certain time in combination with straight road and constant speed limit, where low traffic density means that oncoming/overtaking/overtaken vehicles are fewer than one per minute and a certain time means 5 minutes or more. The definition of low traffic density may also have other values, e.g. less than one vehicle per 30 seconds and a certain time may be 3 minutes or more. The third safety rule may be intended to detect vehicles which change lanes without flashing, drive on the wrong side, maintain deviant speeds or cross continuous lane lines. Vehicles maintaining deviant speeds means that their speed deviates from prescribed speed limits by at least +20%. The fourth safety rule may be intended to detect whether there are vehicles in lanes alongside the vehicle, which may be both to the right and the left of its current lane. The driving rules may comprise one or more of

- a first driving rule related to detected distance to obstacles,

- a second driving rule related to detected roundabouts or sharp bends,

- a third driving rule related to detected uneven road,

- a fourth driving rule related to detected even road,

- a fifth driving rule related to detected tunnels, and

- a sixth driving rule related to detected ends of tunnels. The first driving rule may be related to detecting the end of a stationary queue of vehicles or a red traffic signal in cases where the remaining distance to the queue end/traffic signal is shorter than the respective braking distance at the vehicle's current speed.

The safety-related functions relate to adaptation of the driver interface with respect to detected circumstances and events. It may be relevant to convey these functions to the driver in demanding driving situations. A demanding driving situation may for example occur when there are many vehicles and/or road-users on the road. The safety-related functions may comprise

- forward collision warning (FCW),

- tiredness warning to driver,

- blind spot warning (BSW),

- lane departure warning (LDW), and

- adaptive cruise control (ACC). The safety-related functions may be adaptation of forward collision warning (FCW) to earlier delivery of the warning, adaptation of tiredness warning to the driver to earlier delivery of warning, adaptation of blind spot warning (BSW) to setting the warning to greater sensitivity, adaptation of lane departure warning (LDW) to earlier delivery of warning or to setting the warning to greater sensitivity, or adaptation of adaptive cruise control (ACC) to a longer predetermined distance for warning when the vehicle comes too near to vehicles in front. A warning being delivered earlier or the system having a higher sensitivity or a longer warning distance means in relation to the standard settings of the various systems.

These adaptations of the safety-related functions may depend on the safety rules as follows. When a plurality of tail lamps are detected at a distance shorter than the braking distance required for the vehicle, it may be appropriate for a forward collision warning (FCW) to be delivered earlier than is set in the system. At low traffic density on a monotonous stretch of road, e.g. a straight section with constant speed limit, it may be appropriate to deliver both tiredness warnings and LDWs earlier than standard settings. In the case of vehicles running with deviant behaviour, e.g. not flashing to indicate lane change, overtaking in a deviant way, e.g. on the wrong side or across continuous lane lines, or maintaining deviant speeds which may be much slower or faster than prescribed speed limits, it may be appropriate not only to set a higher sensitivity for BSW and LDW but also a shorter predetermined distance for ACC than is conventionally deemed too close to vehicles in front. Other combinations between safety-related functions and safety rules are also conceivable.

A warning configuration may comprise ranking different types of warnings in order to be able in a demanding traffic situation to suppress or delay types of warnings which are regarded as less relevant. In the same way, the relevance of conveying the most important warnings may be raised.

The dynamic functions pertain to adaptation of the vehicle's behaviour with respect to detected circumstances and events. The dynamic functions for the vehicle may be whether/how much it turns, whether/how much it brakes, how hard its suspension is. They may be regulated by

- adapting brake pedal scaling to alter the braking effect,

- adapting the supply of power to the steering servo to facilitate turning,

- adapting the vehicle's ground clearance by means of its suspension,

- adapting the intensity of the instrument panel lighting, or

- switching off dipped headlamps. These adaptations of the dynamic functions may be combined with the driving rules as follows. When a detected distance to a stationary queue of vehicles ahead or to a red traffic signal is shorter than the vehicle's current braking distance, it may be appropriate to alter the scaling of the brake pedal in order to alter the vehicle's braking force and be able to brake harder. When a roundabout or sharp bend is detected, it may be appropriate to supply power to the steering servo or to compensate the air suspension in order to make turning easier. If running surface conditions in terms of uneven or even road are detected, it may be appropriate to alter the vehicle's ground clearance, e.g. by raising it when the road is uneven or lowering it to reduce fuel consumption when the road is even. When a tunnel is detected it may be appropriate to increase the power of the instrument lighting. If a tunnel end is detected it may be appropriate for dipped headlamps to be switched off automatically in countries which do not allow their use in daytime. Other combinations between dynamic functions and driving rules are also conceivable.

The present invention is not confined to the preferred embodiments described above. Sundry alternatives, modifications and equivalents may be used. The aforesaid embodiments are therefore not to be regarded as limiting the invention's protective scope, which is defined by the attached claims.

Claims

1. A safety system for a vehicle, comprising a forward looking camera (FLC) adapted to identifying and detecting circumstances and events substantially in front of the vehicle and to delivering a camera signal (2) based thereon,

c h a r a c t e r i s e d in that the safety system comprises an analysis unit (4) with a memory unit (6), a first regulating unit (CUl) and a second regulating unit (CU2), said camera signal (2) is arranged to be conveyed to the analysis unit (4), and a set of safety rules for the vehicle and a set of driving rules for the vehicle are stored in the memory unit (6),

the analysis unit (4) being adapted to analysing the camera signal (2) with respect to said set of safety rules for the vehicle and to delivering on the basis of the results of the analysis a first analysis signal (8) which is conveyed to said first regulating unit (CUl), which is adapted to regulating one or more safety-regulated functions for the vehicle in response to said first analysis signal (8),

and that the analysis unit (4) is also adapted to analysing the camera signal (2) with respect to said set of driving rules for the vehicle and to delivering on the basis of the results of the analysis a second analysis signal (10) which is conveyed to said second regulating unit (CU2), which is adapted to regulating one or more dynamic

characteristics for the vehicle in response to said second analysis signal (10), the safety rules comprising one or more of

- a second safety rule related to density of traffic,

- a third safety rule related to movements of surrounding vehicles,

- a fourth safety rule related to positions of surrounding vehicles, and

the driving rules comprising one or more of

- a first driving rule related to detected distance to obstacles,

- a second driving rule related to detected roundabouts or sharp bends,

- a third driving rule related to detected uneven road,

- a fourth driving rule related to detected even road,

- a fifth driving rule related to detected tunnels, and - a sixth driving rule related to detected ends of tunnels.

2. A safety system according to claim 1, characterised in that the safety-related functions pertain to adaptation of the driver interface with respect to detected circumstances and events.

3. A safety system according to claim 1, characterised in that the dynamic characteristics pertain to adaptation of the driver interface with respect to detected circumstances and events.

4. A safety system according to claim 1, characterised in that the safety-related functions comprise