Patent Application
20110032119
The invention relates to a driver assistance system.
Driver assistance systems are known which assist a driver in certain situations. In principle, the driver assistance system reacts to the activities carried out by the driver. The main focus is on assistance intended to control the vehicle's own dynamics. Such driver assistance systems, however, involve the risk that the driver does not feel fully occupied or experiences the intervention of the driver assistance system as a loss of control over the vehicle.
An object of the invention is to provide an alternative driver assistance system.
The aforesaid object is achieved by means of a driver assistance system which outputs information to the driver on the traffic situation in the surroundings and provides assistance, by vehicle components, in order for the driver to handle a current traffic situation, as well as a method for assisting a driver of a vehicle comprising the steps of detecting a traffic situation, and informing and assisting a driver of the vehicle by means of or via vehicle components in order for the driver to handle the traffic situation.
One exemplary embodiment is based on the generic state of the art, comprising a driver assistance system which outputs information on the surrounding traffic situation and provides assistance to the driver by means of vehicle components, in particular a steering system, a braking system, and a performance control system, in order for the driver to handle the current traffic situation.
Disclosed herein is a new, comprehensive concept for a driver assistance system called “Active Car”. It is intended to assist the driver in both his/her decision-making activities and his/her control actions. To implement such a system in the market, it is planned to make use of the fact that previous innovations in the automobile sector have been quicker to succeed if they were easy to utilize and to apply for each user and in each situation. It is thus a basic requirement that the system be easy to operate and behaves in a way that is logical to the driver. For example, the previous successful driver assistance system, ESP, intervenes in the driving behaviour of the vehicle in such a way that the driver's intention is continued to be realized to the extent permitted by the possibilities of physics. Current figures show that this kind of driver assistance is likely to be successful.
While the present driver assistance system is founded on this basis, it takes technology some decisive steps further. It is intended that the driver be informed on the current traffic situation at all times, in addition to being assisted when there is a risk of losing control over the vehicle. The main focus is not on assistance intended to control the vehicle's own dynamics, but on handling the traffic situation as a whole. One option would be the autonomous control of the vehicle in the longitudinal and transverse directions or an acoustic or visual warning to the driver. These approaches are not to be pursued since they involve the risk that the driver does not feel fully occupied or finds it difficult to associate the warning with the relevant situation.
According to another exemplary embodiment, the vehicle components can be operated by means of vehicle control elements, in particular a steering wheel, a brake pedal, and an accelerator pedal, and the information is output via said vehicle control elements. Instead of the steering wheel, brake pedal, and accelerator pedal, a joystick can be used which integrates the functions of the three aforesaid vehicle control elements, either in part or completely.
According to another exemplary embodiment, the information is output to the driver in haptic form. In this way, the driver can be reached quickly without diverting his/her attention from the traffic situation. In addition, the driver intuitively associates the warning with the relevant situation.
Moreover, one exemplary embodiment of the driver assistance system can modify the extent of the haptic warnings in accordance with the criticality of the traffic situation. In this way, the driver gets a good idea of the urgency to act.
Another exemplary embodiment focuses on that the driver assistance system changes the actuating force of the vehicle control elements, so that the perceived driving characteristics will change, thus providing a source of information to the driver. In this way, the driver is informed directly, via the vehicle control elements he/she has to operate anyway, which makes it easier for the driver to associate the information with the relevant situation.
Furthermore, it may be provided for the driver assistance system to maintain a control chain between the vehicle and the driver. In this way, the control chain which serves to control movement of the vehicle is never interrupted, thus making the driver feel that he/she is in control of the vehicle at all times.
In addition, it may be intended that the amount of assistance depends on a road type. In this way, the amount of assistance can depend on whether the car is on a city road, a highway, or a motorway, thus improving the quality of assistance since the urgency of action to be taken by the driver may depend on the road type.
Moreover, it may be intended that the amount of assistance depends on the accuracy of detection of the traffic situation. This feature also contributes to improving the quality of the information and of the assistance provided by the driver assistance system.
Furthermore, it may be intended that, in addition, a display be provided which informs the driver visually why he/she is being assisted. In this way, the driver is kept informed on the reason why assistance is needed, even if the reason is, for example, a speed limit and the relevant traffic sign has long been passed.
According to another exemplary embodiment, it may be intended that sensors be affixed to the vehicle in order to detect the traffic situation. These can include, for example, camera systems, radar sensors, and/or LiDAR sensors.
Furthermore, it may be intended that a satellite navigation receiver and/or a digital map, preferably a road map, be provided in order to detect the traffic situation.
In addition, it may be intended that the driver assistance system communicates with a traffic infrastructure and/or with other vehicles in order to detect the traffic situation. In this way, information can be transmitted to the driver assistance system which cannot be detected by the sensors described above, thus enabling even more precise information and assistance by the driver assistance system.
According to further exemplary embodiments, it may be intended that the assistance comprises an overlaid steering torque or steering angle and/or an overlaid force for actuation of the brake pedal.
Furthermore, it may be intended that the driving characteristics as they are subjectively perceived by the driver are detected and analysed. According to this exemplary embodiment, an attempt is made to foresee the behaviour of a driver and to assist him/her in handling a traffic situation.
Moreover, the present invention provides a vehicle comprising the aforesaid driver assistance system. This vehicle offers the advantages described above in an analogous manner.
The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings is the following figures:
The driver 14 receives haptic information via the vehicle control elements 20, 22, 24 in all traffic situations 10, which indicates whether he/she and/or the other road users behave(s) properly according to the valid traffic rules, and incorrect behaviour is signalled to him/her in accordance with the situation. During this process, he/she is always in control of the vehicle 16, i.e. the driver is always part of the control chain. The functionality of the driver assistance system 12 does not comprise any autonomous intervention in the control of the vehicle 16.
It is intended that the driver assistance system 12 be designed to be functional at all times, regardless of whether the car is on a motorway, highway or city road. For this purpose, an electronic road map can be used which is coupled to a GPS receiver 18 in order to differentiate between road types in a targeted manner and adapt the parameters of the driver assistance system 12. On city roads, for example, it must be taken into account that less space is available for all manoeuvres. The system must therefore intervene in vehicle control later, but stronger. Exceptions are traffic situations 10 in which haptic information is output to the driver 14 via the steering wheel 20 and relevant objects are present on both sides of the vehicle 16. Here, the driver 14 can be informed continuously.
It must be ensured, however, that the driver assistance system 12 does not guide the driver 14 away from stationary vehicles towards pavements or cycle tracks.
The aforesaid driver assistance system 12 is intended to provide haptic information to the driver 14 at all times in accordance with the traffic situation 10 via the vehicle control elements 20, 22, 24, thus intervening in the vehicle behaviour in an indirect manner. In this way, the driver is always in control of the situation, i.e. part of the control chain which serves to control movement of the vehicle, but is better informed.
It is intended that assistance be provided in nearly all fields of action of the driver 14, specifically accelerating, braking, steering, indicating direction, and operating wipers and light.
To reach the driver 14 as quickly as possible, all interventions are realized on the basis of haptic information. In addition, it may be intended that the driver be informed visually as to which dangerous situation is imminent, if possible in a discreet manner. Any autonomous braking or steering interventions should be avoided. The system primarily serves to inform the driver.
The driver assistance system 12 is intended to detect, inform on and assist in the following traffic situations 10, among others:
The accelerator pedal 24 is a Force Feedback Pedal which utilizes an actuator to apply a force, either in the same direction as or opposite to the actuating force exerted by the driver 14. In a dangerous situation, the accelerator pedal 24 is pressed against the driver's foot, or the restoring moment is reduced. It is to be considered, however, that the accelerator pedal 24 must always be designed such that autonomous acceleration is absolutely impossible.
The steering wheel 20 is coupled to an actuator which can overlay the steering torque or steering angle applied by the driver 14 with a supporting or counteracting torque or a supporting or counteracting steering angle. As an alternative, an electrical steering system can be provided to enable application of the relevant supporting torques or counter-torques to the steering wheel 20. The overlaid additional torque (or the overlaid additional angle) must be limited such that the driver 14 always has the option to override said additional torque (or said additional angle). For this purpose, the build-up speed must be limited appropriately, in addition to the absolute values.
The brake pedal 22 is provided with an actuator, or the braking system 23 is designed as an active braking system, so that braking pressure can be built up without external force being exerted by the driver 14. Since the aforesaid build-up of braking pressure cannot be overridden by the driver 14, it should be limited to 0.2 g; to inform the driver of the reason why he/she is assisted, the brake pedal 22 must not be decoupled, but must continue to be moved in accordance with the braking pressure build-up which has been specified (by the driver assistance system 12).
In addition, a visual man-machine interface is provided, which informs the driver 14 of the reason why he/she is assisted. For this purpose, a display 26 can conveniently be used, as is already installed in most large family and executive cars today. The visual indication should be as discreet as possible, except if the speed limit is exceeded (cases 4+11). Ideally, the information can only be seen by the driver 14 since otherwise the front-seat passenger might unnecessarily feel unsafe.
The duration of said increase depends mainly on an estimated reliability of the measurements made by sensors which are provided to detect the traffic situation. The force of the haptic warnings is kept limited such that the driver 14 always has the option to override them. In this way, the driver 14 is still able to control the vehicle 16 even in case of potential wrong interventions by the driver assistance system 12.
To be able to react in traffic situations 10 in which the measured data is not reliable, due to the number of measured data or to interference during the measurement, but where a situation analysis detects a dangerous situation, the counteracting force which is applied to the accelerator pedal 24 is to be reduced if a warning occurs in this type of traffic situations 10. In this way, the driver 14 still receives information on the traffic situation 10 by the sense of touch and can react immediately. In addition, the driver assistance system 12 and the driver 14 are prevented from reacting inappropriately to wrong measurements which would be interpreted as dangerous situations.
One of the main advantages of the reactive or active driver assistance system 12 is that the behaviour of said driver assistance system 12 can always be parameterized, specifically by means of the ramp function described above. In this way, an original equipment manufacturer can ensure that his vehicle 16 which is equipped with the driver assistance system 12 behaves in accordance with the corporate philosophy on the one hand. On the other, the driver 14 may be provided with suitable control elements to modify the behaviour of the driver assistance system 12 or switch it off.
Thanks to the very simple man-machine interface which is easy to understand for the driver 14, a large part of the information processing chain to be completed by the driver 14 is eliminated, thus greatly relieving him/her. In addition, the driver 14 can look in any direction to detect a potentially dangerous situation while, at the same time, another dangerous situation can be signalled to him/her. This is impossible with visual warnings and very difficult to achieve in case of acoustic warnings.
The driver assistance system can thus be parameterized using the characteristic intervention curves illustrated in
To implement the relevant warnings in an effective manner, comprehensive information relating to the surroundings must be available. Since the relative speeds in the longitudinal direction are mostly high, the sensors must have very great ranges. As a guiding value, 200-300 m should be sufficient for a function which can be properly represented, as illustrated in
An additional approach would be the use of C2I (car-to-infrastructure) communication to transmit local features of curves. These would also include friction coefficient conditions. C2C (car-to-car) communication, on the other hand, can be used to expand the ranges of the sensors or even to replace the latter. The minimum requirements made of this sensor concept would also be the ranges illustrated in
All warnings and interventions should only take place in the comfort range. Suitable emergency braking and emergency steering functions continue to be available as separate functions and are intended to be activated only in real emergencies. This limited functionality and the corresponding limitation of the accelerations which occur to the comfort range also ensure operability of the systems in nearly all weather conditions.
Two basic requirements are to be met when implementing the system. On the one hand, oncoming objects and objects which approach from behind should be validated by a second sensor system whose features are orthogonal to those of the first one. In this way, the driver could, in addition, be warned more strongly and assisted better in braking in imminent rear-end collision situations at high relative speeds. Beam sensors are sufficient in the sideways directions since there are no high relative speeds here, except in crossing situations, i.e. when crossing the path of other vehicles. In such situations, however, the driver 14 cannot be assisted by the driver assistance system 12 to a sufficient degree since the opportunities for emergency manoeuvres are very limited.
Furthermore, a hands-off detection is required in order to warn the driver 14 of passing control to the vehicle 16 since the driver 14 is always required to react adaptively in extremely dynamic dangerous situations.
For this reason, the vehicle 16 must also slow down as soon as the driver 14 lets go the steering wheel 20.
In the forward direction, it is advantageous to use a camera system in order to detect signs (right of way, speed) and traffic lights.
The use of LiDAR sensors would have the advantage that, in particular at roadwork sites, objects could also be detected which are not conductive, as is required in case of radar. In this way, it can also be ensured that site entrances marked by roadwork site markers are signalled to the driver in haptic form.
The following configurations are intended as examples for integration in a vehicle, though they are not necessarily the only ones. Based on the requirement that sensors should be selected which do not involve excessive costs, the following sensor concepts, which are shown in
As additional functions, an ACC or a steering stability feature as well as a parking assistant may be realized in one exemplary embodiment. These functions must then be switched on separately by the driver 14 and must return the regulatory function to the driver 14 as soon as the system limits are reached. The design of this return involves additional risk factors and is not intended to be part of the driver assistance system 12. Such additional functions can, however, improve the cost functionality ratio.
According to an exemplary embodiment, it is intended that information relating to the surrounding traffic situation be provided to the driver 14 by assisting him/her in maintaining a safe following distance, wherein the accelerator pedal 24 is pressed against his/her foot in accordance with the situation if the driver follows another vehicle too closely, and the vehicle 16 is decelerated autonomously in critical traffic situations in order to give even more haptic feedback to the driver 14.
According to another exemplary embodiment, it is intended that a brake pedal 22 will move more easily in order to assist in braking by increasing the brake pressure to the required value without decoupling the brake pedal 22.
According to another exemplary embodiment, it is intended that the driver 14 be assisted if he/she approaches or passes crossings too fast.
According to another exemplary embodiment, it is intended that the driver 14 be assisted in observing speed limits and that, in addition, the driver 14 be informed visually on the current speed which exceeds the maximum permissible speed.
According to another exemplary embodiment, it is intended that the driver be warned of entering a road opposite to the prescribed direction of driving.
In addition, it should be pointed out that features which have been described with reference to one of the aforesaid further developments can also be used in combination with other features of other further developments described above.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2008 007 144.7 | Jan 2008 | DE | national |
| 10 2009 006 976.3 | Jan 2009 | DE | national |
This application is the U.S. national phase application of PCT International Application No. PCT/EP2009/051091, filed Jan. 30, 2009, which claims priority to German Patent Application No. 10 2008 007 144.7, filed Jan. 31, 2008, and German Patent Application No. 10 2009 006 976.3, filed Jan. 30, 2009, the contents of such applications being incorporated by reference herein.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP09/51091 | 1/30/2009 | WO | 00 | 10/8/2010 |
