WO2010139383A1

WO2010139383A1 - Method and device for controlling curve velocity of a vehicle

Info

Publication number: WO2010139383A1
Application number: PCT/EP2010/002535
Authority: WO
Inventors: Christophe Bonnet; Jens Desens; Heiner Messner; Thomas Passegger; Bernd Raichle
Original assignee: Daimler Ag
Priority date: 2009-05-30
Filing date: 2010-04-24
Publication date: 2010-12-09
Also published as: DE102009023489A1

Abstract

The invention relates to a method and a device for controlling the velocity of a vehicle. The invention is characterized in that a maximum velocity profile (100) for a route segment lying ahead is determined on the basis of digital map data. Additionally, according to the invention, a limit of the velocity of the vehicle is implemented, depending on the determined maximum velocity profile (100) such that a prescribed minimum velocity (201, 301, 401, 501) is maintained, even if said minimum velocity is greater than a velocity of the maximum velocity profile (100).

Description

METHOD AND DEVICE FOR CURVE SPEED CONTROL

A VEHICLE

The invention relates to a method and a device for speed control of a vehicle. Are known methods and devices that make an adjustment of the vehicle speed based on predictive map information. With forward-looking map information, for example, a cruise control can be improved to the extent that reacts proactively to the road and the speed of the vehicle is adjusted or reduced accordingly. The associated device is also referred to as "card speed".

The published patent application DE 10 2006 006 365 A1 discloses a method and a device for the longitudinal movement control of a vehicle, in which environmental data and / or route data are acquired and a position-dependent influencing of the vehicle on a route is taken as a basis. On the basis of digital map data, a curvature course of the route and a maximum speed course dependent thereon are determined in a forward-looking manner. The maximum speed curve is here corrected to adapt to physical load limits of the vehicle. Then, based on the corrected maximum speed course, a speed limit is performed.

Such a cruise control of a vehicle is illustrated by way of example in FIG. Fig. 1 (prior art) shows a graph in which on the y-axis 101, a vehicle speed and on the x-axis 102, the time or the distance traveled by the vehicle is plotted. The solid black line indicates the speed profile 100 of the vehicle over time or along the way. It is assumed that the speed of the vehicle is controlled by a speed control unit based on digital map data. A such control unit is for example a card or a Kartenspeicheromat. The card driver is given a set speed 103 by the driver. The vehicle thus travels speed-controlled along a route up to the point in time 105 with the setpoint speed 103. As soon as the map-control system anticipates a bend in the digital map data in the preceding route section 106-107, the vehicle's travel speed is timely advanced with a comfortable deceleration to one to drive through the curve suitable and safe speed reduced. In the present example, the curve is represented by the section 106 to 107. The setpoint speed 103, for example 100 km / h, is then reduced beginning at the time or route point 105 to the maximum possible speed for safely driving through the curve (safe maximum speed) 104, for example 30 km / h. This speed is reached in the time or path point 106 (= start of the curve) and maintained constant until the time or waypoint 107. Before the curve or after the curve in each case straight sections are assumed here. After passing through the curve from the time or waypoint 107, the vehicle is accelerated by the card system back to the setpoint speed 103 originally selected by the driver. This is reached at time 108.

The problem with the above cruise control or the use of so-called card speed is that the digital map data is never up to date. If e.g. built a new road, set up a new signage with maximum speed limits, or a road construction site is set up, it takes a while until the associated data or information in the digital map data and are thus available to the card payment. In addition, the digital map data may also contain other errors. These errors in the digital map data can then lead to disturbing (incorrect) interventions of the card system, which causes the driver an unpleasant feeling of incorrect control.

The document DE 198 16 133 A1 deals with this subject. A vehicle control device is disclosed which is intended to enable trouble-free and safe passage of a curve in front of the vehicle, independently of errors in digital map data used by the device and a faulty detected vehicle position. The device calculates a predicted pass-through speed for a curve based on a vehicle speed and a vehicle position and compares them with a maximum travel speed for the curve based on digital map data and the vehicle known vehicle position is calculated to thereby determine whether the vehicle can easily and safely drive through the curve. If the device determines that the vehicle can not easily and safely pass the turn, a warning, automatic deceleration, and / or automatic steering control is provided by a control mechanism of the device.

The device described above consequently takes into account detected errors in the digital map data in order to directly influence the control strategy, in particular the regulation of the speed. Disadvantage of this device is that errors in the digital map data are only corrected if they are discovered. The ensuing system reaction takes place partially late. Since not all errors in the digital map data can be detected with the methods or devices known in the prior art (map-based systems), the system behavior for the driver is in part incomprehensible.

The object of the invention is to provide a device and a method which reduce the disadvantages described above.

The invention results from the features of the independent claims. Advantageous developments and refinements emerge from the subclaims. Other features, applications and advantages of the invention will become apparent from the following description of embodiments of the invention which are illustrated in the figures. All features described or illustrated alone or in any combination form the subject matter of the invention, regardless of their combination in the claims or their dependency and regardless of their formulation or representation in the description or in the figures.

The inventive method for speed control of a vehicle is characterized by the fact that based on digital map data dependent on the preceding section distance top speed curve is determined and that limiting the speed of the vehicle depending on the determined maximum speed curve is made only in such a way that a limit speed is not exceeded even if it is greater than a speed of the maximum speed curve. In contrast to the prior art, it is not the goal of the present invention to recognize the errors contained in digital map data and to correct them accordingly. Rather, the invention is based on the idea of minimizing the effects of errors in digital map data on the regulation of the vehicle, in particular on the cruise control. In this case, a limit speed is defined.

The following example, which is based on all embodiments described below, is intended to illustrate the idea of the invention. It is assumed that a vehicle is equipped with a card-based payment system and travels at a setpoint speed specified by the driver for the card-and-cruise vehicle on a predetermined route. For the route section lying ahead, a maximum speed course for the safe passage through this section of the route is constantly determined. The maximum speed course takes into account at least the digital map data for the route ahead and vehicle parameters that define a safe operating envelope of the vehicle (eg maximum lateral acceleration, tires, vehicle weight, etc.). Preferably, the maximum speed profile determined for the preceding route section is determined, for example, from a curvature profile of this route section which can be taken from the digital maps. In addition, the high-speed history may take into account additional local, route-dependent maximum speed limiting features, information and / or data contained in digital map data. These are, for example, speed limits, traffic intersections, in particular T intersections, traffic junctions, railroad crossings and / or roundabouts. Such local conditions, which are usually also referred to as events, are preferably assigned constant event-specific speed values as predetermined limit speeds. Preferably, additional additional information can be used to determine the maximum speed curve, which does not result from digital map data but from other sources (eg outside temperature sensor, rain sensor, input units for manual input of information by the driver). Depending on the ascertained maximum speed curve, the speed of the vehicle is reduced to the predetermined limit speed by the card system, in due time before the turn. This limit speed is often higher than the speed that a conventional card processor would control in the presence of this card information, for example a curve. If a control intervention of the card system, ie a deceleration of the vehicle, triggered due to an error in the map data, for example. Because the map data for the preceding route for example. Provide a tight curve, but has long been omitted in reality by straightening the road , the speed of the vehicle is only reduced to the limit speed. Thus, if the vehicle travels to the supposed curve (also applies to other map features such as intersections, roundabouts, etc.), the map control slows down to the limit speed and then keeps this speed constant. Compared with the control behavior of known automatic ticket machines (see Fig. 1 and associated description), the speed set by the driver, for example 100 km / h, instead of the cornering speed 104 according to the maximum speed course of 30 km / h (see FIG 1) only reduced to the limit speed, eg 70 km / h.

If there is no card error, which will be the case in most cases, depending on the choice or specification of the limit speed, a more or less strong intervention of the driver for safe passage through the route ahead section is required. This means, to stick to the previous example, the driver must actively slow down the vehicle speed itself to 30 km / h in order to be able to drive through the curve safely. The system behavior is thus predictable. The driver can adjust to this system behavior accordingly.

The limit speed may be a predefinable constant, depending on a selected by the driver target speed of the vehicle, or be defined in dependence on the determined maximum speed course. If the limit speed is dependent on a setpoint speed of the vehicle selected by the driver, the limit speed is preferably defined by a predefinable difference from the selected setpoint speed or by a predefinable percentage of the selected setpoint speed. Furthermore, the limit speed may also be defined depending on feature classes of information contained in the digital map data, for example, a first limit speed for all the curves, a second limit speed for traffic lights, a third limit speed for intersections, a fourth limit speed for traffic gyros, a fifth limit speed for stop signs In addition, the limit speed can be defined depending on other parameters, such as local outside temperature measured by the vehicle, precipitation yes / no, driver's experience, etc. In a preferred embodiment of the method according to the invention, the vehicle is braked by a desired speed determined by the driver or a distance control system as a function of the maximum speed curve, but at most until the limit speed is reached, after which the limit speed is maintained at least temporarily, in particular as long as it is maintained. as long as the limit speed is above the maximum speed curve.

An acceleration of the vehicle, for example, to the set target speed, preferably takes place only when the speeds of the maximum speed curve for the track section lying ahead are greater than the limit speed. In this case, the acceleration of the vehicle preferably takes place as a function of the ascertained maximum speed profile.

Another object of the invention relates to a device for speed control of a vehicle. The device according to the invention comprises a first means with which a maximum speed profile can be determined on the basis of digital map data for a preceding section of the route, and a second means for regulating the speed of the vehicle with which a limitation of the speed of the vehicle can be undertaken depending on the ascertained maximum speed profile in that a limit speed is not exceeded, even if it is greater than a speed of the maximum speed course.

The above explanations for the description of the method according to the invention can be transferred analogously to the device according to the invention, so that reference is made to the above explanations of the method according to the invention for explaining the device according to the invention.

Further advantages, features and details of the invention will become apparent from the following description in which embodiments are described in detail with reference to the figures. The same, functionally identical and / or similar parts are provided in the figures with the same reference numerals. Show it:

1 is a schematic speed profile of a vehicle that has a

Speed control based on predictive map information allowed (prior art);

FIG. 2 shows a schematic speed profile of a vehicle with a cruise control according to the invention in accordance with a first exemplary embodiment; FIG.

3 shows a schematic speed profile of a vehicle with a cruise control according to the invention in accordance with a second exemplary embodiment;

4 shows a schematic speed profile of a vehicle with a cruise control according to the invention in accordance with a third exemplary embodiment; and

Fig. 5 is a schematic speed profile for a vehicle, with a speed control according to the invention according to a fourth embodiment.

Fig. 1 (prior art) has already been described in the introduction. Reference is made to the above statements at this point.

Fig. 2 is based on Fig. 1. Fig. 2 shows a speed profile 200 for a vehicle, according to a first embodiment of the invention. As in FIG. 1, in this and the following embodiments it is assumed that the vehicle is equipped with a satellite-based positioning system, for example with GPS (Global Positioning System), and that the digital map data available in the vehicle for a preceding route section 106 - 107 indicate a curve. In contrast to FIG. 1, an inventive speed control of the vehicle according to the speed profile 200 now takes place.

In the present case, based on the digital map data, the maximum speed course 100 dependent on the curvature course of the preceding road section is determined determined. In this case, methods are used as they are known in the art. The limitation of the speed of the vehicle is made depending on the determined maximum speed curve 100 such that a predetermined limit speed 201 is not exceeded. This limit speed 201 is greater in the route section 203 to 204 than the corresponding speeds of the maximum speed course 100 in the same route section.

In the present case, the vehicle speed is reduced up to the limit speed 201 with a comfortable deceleration in accordance with the ascertained maximum speed course 100. The limit speed 201 is defined in this embodiment as a function of the driver selected target speed 103 of the vehicle, the limit speed 201 is defined by a difference of 30 km / h to the selected target speed 103. The setpoint speed 103 selected or predetermined by the driver in the card-speed system is 100 km / h, so that the limit speed 201 in the present case is 70 km / h. If the curve indicated in the digital map data does not exist in reality, such an error in the map data will at most produce a reduction of the speed of the vehicle by 30 km / h instead of a deceleration of 70 km / h to 30 km / h in Fig. 1.

Nevertheless, in the present embodiment, the method according to the invention ensures complete speed regulation in the case of curves which require only a slightly lower speed than the setpoint speed 103, i. in which the speeds of the ascertained maximum speed course iOO are greater than the limit speed 201 even for a curve lying ahead.

The driver must continue to adapt the predetermined target speed 103 to the road conditions in this embodiment, as in conventional card payments, and even actively intervene below the limit speed 201 in case of need. At the same time, the driver experiences the system boundaries from time to time and learns to deal with them.

Due to the method according to the invention, errors in the digital map data can only affect up to a certain speed (limit speed 201) or cause a corresponding speed reduction. In other words, the map data includes, for example, the information that the preceding link 106 - 107 contains a curve, although in reality this curve has been long has been omitted by a straightening, so is caused by the card speed control, a speed reduction only to the limit speed 201.

The behavior of the system or device is more transparent to the driver and predictable in advance. Due to the driver's inherent duty to cooperate, the latter learns that the method according to the invention or the device according to the invention can not cope with all situations. Necessary driver interventions are perceived as natural or unsurprising in this case. The driver is thus accustomed to having to intervene actively in the speed control of the vehicle in addition to the card payment.

The speed profile of the vehicle in FIG. 2 corresponds to the setpoint speed 103 set by the driver up to the time or distance point 105/202. Between the time or distance point 202 and 203, the travel speed is reduced parallel to the maximum speed course 100 up to the limit speed 201. Between time points 203 and 204, the speed of the vehicle remains constant. Between the time or distance points 204 and 205, the vehicle is in turn accelerated to the target speed 103.

FIG. 3 shows a speed profile 300 for a vehicle according to a second exemplary embodiment. FIG. 3 is largely identical to FIG. 1. In contrast to FIG. 2, FIG. 3 illustrates the case in which the limit speed 301 is a predefinable constant. The reduction of the setpoint speed 103 from 100 km / h before the curve (section 106-107) thus takes place from the set target speed 103 along the maximum speed course 300 to an absolutely predetermined and constant limit speed 301 of 60 km / h. In this embodiment, therefore, whenever the digital map data for the route section lying ahead indicate a curve, a reduction of the vehicle speed to 60 km / h is made in advance accordingly.

The vehicle speed is reduced in Fig. 3, starting at time or waypoint 302 to the limit speed 301, which is reached in the time or waypoint 303. In the time or distance section 303-304, the driving speed is kept constant. In the time or distance section 304 - 305, the vehicle is in turn accelerated to the target speed 103. The driver is in this case the full system capability or support of the card in curves available for which a maximum speed course has been determined, the speeds of which are greater than the limit speed 301. Errors in the digital map data, for example curves that are not actually present, thus cause at most a reduction in the vehicle speed up to an absolutely predetermined constant limit speed 301. Below the limit speed 301, no interventions are made by a speed control based on digital map data by the mapmaker. Again and again, the driver experiences the system boundaries from time to time and learns to deal with them.

4 shows a schematic speed profile 400 for a vehicle, for a third embodiment of the method according to the invention. This embodiment is intended to show that the limit speed 401 can relate to any other features or information of the map data. Thus, in this case, the limit speed 401 is related to the cornering speed 104 of the maximum speed course 100. In particular, the speed profile 400 is determined in such a way that this corresponds to the upwardly shifted maximum speed profile 100 in the track section 402-405. The displacement may correspond to a fixed speed value or a value proportional to the safe cornering speed 104. Of course, the limit speed can also be defined separately for other features and information of the digital map data (intersections, level crossings, etc.).

The vehicle travels according to FIG. 4 up to the time or distance point 402 with the set speed 103 of, for example, 100 km / h which is preselected at the card computer. In the time or distance section 402-404, the vehicle is decelerated to the limit speed 401, for example, 70 km / h, which is up to Zeitbzw. Route point 404 is maintained. This means that the curve, if it actually exists in reality, would be traversed instead of the safe cornering speed 104 of for example 30 km / h with 70 km / h, which is not possible, so that in this case mandatory intervention of the Driver, ie an active braking of the vehicle is required. In the time or distance section 404-405, the vehicle is accelerated by the card system back to the target speed 103. The speed profile shown can therefore be driven in reality without driver intervention only if the digital map data are wrong with respect to the curve, and in reality there is no curve. Also in this embodiment cause errors in the digital map data at most a reduction in speed to the corresponding defined limit speed 401. The system intervention remains limited and the driver must actively intervene in the case of actually required speed reduction itself in the vehicle dynamics.

FIG. 5 shows a schematic speed profile 500 for a vehicle according to a fifth exemplary embodiment. FIG. 5 is largely identical to FIG. 1. In contrast to the preceding exemplary embodiments, the vehicle in FIG. 5 is delayed or braked in time before the time or path point 105 provided according to the maximum speed course 100. The speed reduction of the vehicle takes place here already in the time or distance point 502 and thus earlier in time than in the embodiments of Figures 2 to 4. If the limit speed 501 is reached in this case, the driver has sufficient reaction time to even actively intervene if necessary.

A corresponding speed reduction can always take place earlier than provided in the maximum speed course or only if the look-ahead has a correspondingly narrow curve or another defined feature, for example a stop sign, a junction, an intersection etc. The triggering time 502 of the speed reduction preferably depends on the vehicle condition or on the road course (for example on the vehicle speed, the vehicle acceleration, the curve radius, the type of intersection, etc.).

In FIG. 5, the vehicle speed up to the time or distance point 502 is defined by the predetermined target speed 103. At time point 502, i. clearly before the time point 105 at which a delay is provided according to the determined maximum speed curve, the vehicle speed is reduced to the limit speed 501. This is in Zeitbzw. Reached route point 503. In the time or distance section 503 to 504, the vehicle speed remains the same. From the time or distance point 504 to 505, the vehicle is in turn accelerated to the target speed 103.

The invention is therefore based on the idea to regulate the speed of the vehicle in a distance- or speed-controlled driving according to the predetermined by the driver or a distance control system target speed 103 and the speed corresponding to the determined distance-dependent To reduce maximum speed 100, if the

Maximum speed curve 100 is below the target speed 103, but the reduction of the speed is limited so that the predetermined limit speed 201 or 301 or 401 is not exceeded by the cruise control, even if the maximum speed curve 100 is below the limit speed. Of course, the driver always has the option of causing the speed limit to be undershot by operating the brakes. By the driver-side brake control, the cruise control is preferably canceled and handed over the control to the driver.

Claims

claims

A method for controlling the speed of a vehicle, in which a maximum speed profile (100) is determined on the basis of digital map data, and in which the speed of the vehicle is determined as a function of the ascertained maximum speed profile (100) in such a way that a predefined maximum speed profile (100) is determined Limit speed (201, 301, 401, 501) is not fallen below.

2. The method according to claim 1, characterized in that the limit speed (201, 301, 401, 501) is a predetermined constant.

A method according to claim 1, characterized in that the limit speed (201, 301, 401, 501) is defined in dependence on a desired speed (103) of the vehicle selected by the driver.

4. The method according to claim 3, characterized in that the limit speed (201, 301, 401, 501) by a predetermined difference to the selected target speed (103) is defined.

5. The method according to claim 3, characterized in that the limit speed (201, 301, 401, 501) by a definable percentage of the selected target speed (103) is defined.

6. The method according to claim 1, characterized in that the limit speed (201, 301, 401, 501) is defined as a function of the determined maximum speed curve (100).

7. The method according to claim 1, characterized in that the maximum speed profile (100) is dependent on local information, route-dependent information limiting a maximum speed, in particular curves, speed limits, traffic intersections, traffic junctions, railroad crossings and / or or roundabouts.

8. The method according to any one of claims 1 to 6, characterized in that the maximum speed curve (100) is determined as a function of the curvature of the route ahead section.

9. The method according to any one of claims 1 to 8, characterized in that the vehicle is braked at most until the limit speed (201, 301, 401, 501) is reached, and that the speed of the vehicle from reaching the limit speed (201, 301, 401, 501) is kept at the limit speed (201, 301, 401, 501) or at the limit speed (201, 301, 401, 501) for at least a certain period of time, as long as the limit speed (201, 301 , 401, 501) is above the maximum speed curve (100).

10. The method according to any one of claims 1 to 9, characterized in that the vehicle, the limit speed (201, 301, 401, 501) retains and only accelerated again when the speeds of the maximum speed curve (100) are larger for the track ahead , as the limit speed (201, 301, 401, 501).

11. The method according to claim 10, characterized in that the acceleration of the vehicle as a function of the maximum speed curve (100).

12. The method according to any one of the preceding claims, characterized in that the location-dependent limitation of the speed of the vehicle at an earlier time (503) is initiated than in a cruise control according to the determined maximum speed curve (100).

13. A device for speed control of a vehicle, characterized in that a first means is provided with the basis of digital map data for a preceding section of a maximum speed profile (100) can be determined, and a second means for controlling the speed of the vehicle is present with which a limitation of the speed of the vehicle depending on the ascertained maximum speed curve (100) can be undertaken such that a predetermined limit speed (201, 301, 401, 501) is not undershot, even if it is greater than a speed of the maximum speed course (100).