April 22, 2009
Method for operating a device for determining a route course
The invention relates to a method for operating a device for determining a route course for a means of transportation, in particular a navigation device according to the independent claim.
Existing navigation systems today increasingly have functions that inform the user about specific location-dependent, traffic-dependent and road-relevant properties. This information is often communicated as warnings to the user via audio, voice or visual. In practice, however, these functions often result in the driver receiving the warning only when the means of locomotion is already in a critical section of the route. For example, warnings about exceeding a speed limit are often signaled only when the vehicle is already on a road section for which a speed limit should already be met.
The consequence of this is that the vehicle generally enters the affected road section at an excessive speed because the driver is completely unprepared. Mobile navigation systems have also been developed, so-called PNAs (Portable Navigation Assistant), which issue warnings based on the road network data map used and the current position of the navigation device for the user. Depending on the type of warning, additional information from the navigation device can be taken into account, which can be called up via communication channels such as radio or data channels. Here, for example, TMC (Traffic Message Channel) should be mentioned. By means of TMC, the driver receives information regarding traffic hindrances that may be relevant to the route to be traveled by him.
However, these instructions are not always optimally timed to the actual route. Further equipment features of known navigation systems are, for example, usual navigation instructions such as "turn right in 200 meters". In the case of such systems, such information is generally generated in a purely position-dependent manner by the current position of the means of locomotion being set in relation to the relevant position at which the reference actually becomes relevant.
Furthermore, ADAS (Advanced Driver Assistance Systems) is known. In the field of these systems, a distinction is made in principle between two methods. Methods that work with data from the road network database, and methods that work without data from the road network database. In the field of card-based systems, there are individual solutions, such as so-called curve detectors, which analyze the preceding curves with respect to their maximum speed to be traveled and compare this value with the current speed of the vehicle. According to the result of the speed comparison, the system generates a warning for the driver, whereby the time of the warning is not optimally tuned to the routing here.
All of these solutions, which are known from the prior art, have the disadvantage that the warning from the navigation device is not reliably generated if, in view of the current situation, it would be most advantageous for the driver.
The object of the present invention is that user instructions by means of the navigation system take place in such a way that the user is informed early so that he can react to a reasonable extent to hints of the navigation system.
To achieve the object, a device for determining a route course for a means of transportation, in particular a navigation device for a motor vehicle, operated according to the inventive method. The device on which the method according to the invention is based comprises a processor device for performing data processing tasks, position signal receiving means, in particular for GPS signals, a position determination unit for determining a position from the received position signals, an operating means, in particular with display means, for displaying the determined route course and for communication with the user of the device. The device also has access to a road network database, which also includes route-specific information.
The road network database may be included by the device by means of a storage means. However, it may also be a road network database accessible by the device at least temporarily (e.g., online) or at least temporarily retrievable (e.g., by download) to the device via a mobile data link (e.g., GSM, EDGE, UMTS, HSDPA).
To realize the operation according to the invention, the device automatically and continuously determines the instantaneous position and instantaneous speed of the means of locomotion in which the device is arranged. As a result, both the current instantaneous position and the current instantaneous speed, which can be derived, for example, from a change in the instantaneous position during a defined period of time, are available to the device for further calculations by means of the processor device.
Since the device has calculated the route for the means of transportation, taking into account the destination specified by the user, the device is able to automatically determine at least one relevant for at least a section of the route characteristic route property by accessing the road network database. The device also automatically determines the distance from the device known instantaneous position of the means of locomotion until the beginning of the above section. It is also possible for the device to include all information retrievable from the road network database (e.g., link characteristics of a link) in the data processing.
Route characteristics of sections may, for example, be properties which should cause the user of the means of transport to react in case he wishes to follow the route in compliance with all traffic regulations. For example, it could be evidence of a particularly dangerous section of the route, for the special behaviors or special attention of the user of the means of transport are required. However, it could also be an identification of a route section by means of route properties, which the user has manually assigned in order to define the route property as particularly relevant or interesting for him. Concrete, but not exhaustive, for example
To name track properties, such as speed limits, dangerous turns, dangerous sections with rock fall or debris, traffic-calmed zones and the like. Above all, those sections of the route in question, which require the driver pro-active action. The device performs continuously and automatically when detected movement of the means of transport, the determination of at least one parameter taking into account the determined distance to the above relevant section and taking into account the instantaneous speed of the means of transport and taking into account at least one line property by.
In accordance with the parameter, the automatic selection takes place between at least two operating states, wherein the communication with the user is controlled by means of the operating states. There is a control of the operating means appropriate to the respective operating state, so that in the context of the first operating state, a first visualization for the user by means of the display means is realized and in the context of the second operating state, a second visualization for the user by means of the display means is realized. The evaluation of the determined parameter can also lead to the result that no communication with the user is required.
The prior art solutions lack this dynamic and ongoing analysis of the current situation and the co-ordinate of the issuance of hints to the user that can be realized by this analysis, taking into account the realities of the route and the characteristic state characteristics of the means of locomotion. The solution according to the invention leads, as it were, to an optimization of the temporal proximity of an indication of an imminent event which is relevant for the user.
The invention thus reacts much more flexibly to the actual conditions because, in contrast to the prior art, it is not based primarily on the evaluation of static information (such as the maximum permissible speed or the current road class of a section of the route or fixed assumptions with regard to the driving behavior of the user). , The inventive method has many degrees of freedom and is open to a variety of modifications in determining the definition of a driving criterion. This makes navigation systems based on the solution according to the invention expandable and flexibly adaptable to a wide variety of application areas.
Since the notification time determined by the device practically in a forward-looking manner is chosen so that it is as meaningful and prompt as possible in relation to the event, the driver can quickly assign an important hint (eg warning) to the current route conditions and react appropriately because he was optimally sensitized to the upcoming situation by means of the device according to the invention. This can also be helpful if the driver, for example because of the excessive speed of his vehicle, comes to the conclusion that he is no longer able to react appropriately. At the very least, in such a case the driver may try to take all possible measures to avoid possible harm to him or other road users (e.g.
Rear-end collisions due to sudden braking maneuvers) averted.
Advantageous further embodiments of the invention will become apparent from the dependent claims.
At least one parameter threshold value is preferably taken into account during the evaluation. This gives the possibility to carry out a delicate evaluation of the determined parameter and to control the selection of the operating states according to the evaluation result. This gives you the opportunity to make a gradation that can capture and map even more complex situations. For example, a threshold can be used to narrow parameter-specific ranges.
The choice of a threshold value may also depend on the environmental properties (such as temperature, rain, snow, ice, etc.) and / or the track properties (such as road surface, slope, curves, etc.) and / or or the characteristics of the vehicle (such as the braking characteristics of the vehicle, ABS equipment, tires, weight, etc.).
The method according to the invention is therefore particularly preferably implemented such that it is possible to automatically modify a parameter threshold value by means of the device. The modification takes place, for example, taking into account at least one first data variable for the storage of at least one data component. This data component is used to characterize at least one property of the distance route course, such as the environmental properties. The distance course is the course of the route which is the basis of the distance to be covered and corresponds to a section of the total distance determined and to be covered by the device. Such a data component can also be used to characterize at least one property of the means of locomotion, as already indicated above.
In general, all those features should be taken into account by the device, which in any relevant form could have an influence on the tracking of the distance course by means of the means of locomotion. The modification of the threshold values is therefore not limited only to the consideration of properties relating to the environment, the route itself or the vehicle. Thus, while constant thresholds are defined in the basic method independent of environmental, route or vehicle characteristics, which provide sufficient time to take a large part of all vehicle classes into account (so that they can brake without danger, for example), further criteria for optimization are used.
Advantageously, the data variable is designed as a data vector comprising at least two data components for characterization, as explained above. It is thus easily possible, theoretically any
Subdivisions. For example, taking into account environmental characteristics, the temperature, rain, snow and ice properties could each represent a data component of a data vector with, for example, four data components. By means of, for example, array structures, this information can easily be stored in the device and queried during operation via accesses to the individual array cells by means of the software of the device.
The relevance of the data components of a data vector does not necessarily have to be identical. It is therefore provided that at least one data component comprised of the data variable or of the data vector can comprise a specific weighting. It would also be conceivable that a plurality of data components encompassed by the data variable or by the data vector comprise a common weight in order to describe the relevance of data variables or of data vectors for describing completely different properties (eg properties of surroundings and properties of the vehicle) in the context of the modification to be able to take account of a parameter threshold value. Through this modification, new thresholds can be defined which are adapted to the conditions existing in reality, allowing a more realistic communication with the user.
To simplify the internal data processing steps, it is preferable that a data component of a variable or a vector is represented by a numerical value, wherein the device forms the arithmetic mean of the numerical values for at least two existing data components and this result in the
Modification of the parameter threshold taken into account. It is important to note that if the weights do not already take appropriate scaling into account, the sum of the individual data components must be scaled accordingly, taking account of the value ranges, the weighting and the route attributes. The default value t of a parameter threshold value can be adapted, for example, to t 'according to the relationship:
t < <> = t * V (W (Sl, .., n)) * V (W (Ul,., m)) * V (Fl, .., k))
where V (X) denotes the calculation of the arithmetic mean of the weighted components (given by W) of a vector X. In the relationship exemplified above, the default value t of a parameter threshold is adjusted by the arithmetic mean of each of three weighted vectors S, U, and F, where S stands for the numerical representation of n different road characteristics, or U for m different environmental properties such as rain,
Temperature or visual condition. Instead of processing a large number of individual values, the averaging makes it possible to concentrate the essential information on a small number of data to be processed and thus also to increase the data processing speed.
Between the momentary position of the means of locomotion and the beginning of the section with the route property determined by the device, there is an optimal future vehicle position within the distance course at which the communication with the user should be made at the latest to alert the user to the determined route property. If the route property is a speed restriction, for example, an indication to the driver of the means of transportation must be made in such a way that he can still react appropriately. Therefore, the device also determines a user reference position which essentially defines that position of the means of locomotion in the future at which user communication will take place. This position is also linked to a point in time.
This point in time is the user reference time at which user communication takes place at the latest or the user reference position is reached. This position and time are continuously determined by the device with each change in the instantaneous position of the means of locomotion.
Assuming that the route property is a speed limit relevant to the route section and that the parameter represents an acceleration change which is required so that the instantaneous speed of the vehicle does not essentially exceed the speed limit after overcoming the distance, the determination of above-mentioned user pointer position and the aforementioned user guide timing implicitly by means of the device. In this case, it is still assumed that parameter threshold values are present in the form of acceleration threshold values which are likewise taken into account when determining the user reference position and / or the user information time.
Preferably, at least three parameter thresholds (e.g., acceleration thresholds) are taken into account for controlling at least four operating conditions, wherein the selection of operating conditions is also based on the result of a comparison between one of the parameter thresholds with the parameter value (e.g., negative acceleration). These measures allow the driver to preferably maintain speed limits of the prescribed manner. At the same time, the presented method offers a possibility for improving driving safety, since it becomes possible to take account of delay times (for example also the driver's reaction time).
Preferably, a first operational state is assumed by the device when the parameter value (e.g., negative acceleration) is between a first parameter threshold (e.g., acceleration threshold tl) and a second parameter threshold (e.g., acceleration threshold t2) or identical to the first parameter threshold. The threshold value can be defined such that the vehicle is still at a sufficiently great distance from the start of the relevant route section, so that, for example, there is still sufficient time to initiate a braking process. In this case, an operating state would be selected, which announces the upcoming route section, for example by means of a display on a display means, but still gives no warning.
The first operating state could be followed by a second operating state, which is assumed if the parameter value (eg negative acceleration) is substantially between the second (eg acceleration threshold t2) and a third (eg acceleration threshold t3) parameter threshold or identical to the second (acceleration threshold t2). Parameter threshold is. These threshold values could be dimensioned in such a way that the vehicle is always at a sufficiently great distance from the relevant route section when generating a user information and thus safe braking is possible, whereby the user could now be signaled in the context of the second operating state that he is using the Braking should begin (display of a proposition).
These two operating states could be followed by a third operating state, which is taken when the parameter value (e.g., negative acceleration) is substantially above the third (e.g., acceleration threshold t3) parameter threshold or is identical to the third (e.g., acceleration threshold t3) parameter threshold. This could mean that the means of locomotion is located at a critical distance to the route section, so that no more risk-free braking is possible or there is no possibility of reacting adequately. This operating state then serves to warn the driver (display of an alarm signal).
Should the device be in a fourth operating state, which is taken when the parameter value (eg negative acceleration) is substantially below the first (eg acceleration threshold tl) parameter threshold, then this could be used to allow the driver to operate without interference ( Idle state) and to observe the further movement by means of the device until a relevant event takes place, which causes the change to one of the other operating states mentioned above.
The user communication preferably takes place in accordance with one of the operating states by means of a user instruction in visual and / or acoustic and / or tactile form. This could be realized for example by means of a display means or an acoustic output or a vibration means. Depending on the wishes and personal preferences, the user could opt for one of the options through appropriate selection of the user interface.
Preferably, the device operates by means of transition thresholds for the realization of a multi-level user communication. This is intended primarily to illustrate the urgency of an indication. The device could automatically determine the transition threshold values and / or user information levels dynamically and continuously while taking into account one or more parameter threshold values.
In the context of the abovementioned second operating state (action proposal), for example, instead of an indication relating to the reduction of the speed, a multi-level warning system could be implemented, which displays indications of increasing urgency depending on the required braking power (negative acceleration, BA). This could be implemented as follows: The actual urgency of a braking event may be determined stepwise by the facility for the exemplary case of 3 acceleration thresholds (t1, t2, t3). With m = (t3 - t2) and the equation Sk = round ((BA- t2) / m), the current warning level scaling Sk is determined. "round" represents a rounding function for rounding the result of the division into an integer.
One possible application would be, for example, the use of the current warning level thus calculated as a measure of a color representation, with the highest warning level being represented in a signal color (such as red).
Another possibility for implementing a multi-level signaling is, for example, the use of a so-called software-implemented progress bar whose length represents a measure of the urgency of a required braking operation. For this purpose, a scale range is determined and a corresponding scaling is calculated according to Sk = (BA-t2) / m. The calculated value Sk then indicates the length of the progress bar, where Sk = 0 does not require braking and Sk = n requires maximum braking, assuming n is the number of notches. This flowchart is repeated continuously by the device during the navigation operation, at least as long as the means of locomotion is in motion.
Similar multilevel indication systems could also be provided in all other operating states in order to transmit the user information to be conveyed there, taking into account the urgency of the user.
Most preferably, the device coordinates the time of the user communication with further navigation-specific information. For example, in the case of audible warnings, the alert is issued only when no other voice output (such as an announced turn-off maneuver) is being made at the same time. Only at the time at which any voice output that is currently being executed is essentially ended is the warning message communicated with a suitable warning level taking into account the current instantaneous position. The following symbols are used in the following explanations:
r - route between starting point and destination point of the route,
pw - position of beginning of a section of track.
pv - Current position of the means of locomotion.
v [theta] - instantaneous speed of the means of locomotion,
a - Acceleration of the means of transport.
S - distance course between pv and pw.
d - distance between pv and pw.
Sl, ..., n = <a1, ..., an> vector with n attributes ai, which describes the properties (for example, curves, slope, road surface, etc.) of the distance course S.
W (Sl, ..., n) - weighted vector for Sl, ..., Sn, where W (Sl, ..., n) = <wl * al, ..., wn * an> gives the various attributes ai a weighting.
Ul, .., m = <ul, ..., um> vector with m attributes ui describing the properties related to environmental conditions (e.g., rain, temperature, visibility, etc.) along the distance course S.
W (Ul, .., m) - weighted vector for Ul, .., To have effect like W (Sl, ..., n).
Fl, .., k = <fl, ..., fk> - vector with k attributes f, which describes the properties relating to the vehicle (eg braking distance, weight, tires, etc.). W (Fl, .., m) - weighted vector for F l, .., Fm with effect as W (S l, ..., n) or W (Ul 3 .., m).
Hp position between pw and pv at which user communication occurs at the latest so that the driver can respond appropriately to the user advice.
Ht - time at which user communication takes place at the latest so that the driver can respond appropriately to the user information.
tl, t2 and t3 - acceleration thresholds.
R - speed limit.
TL - time until the means of locomotion reaches the position pw.
s - way
v - speed
t - time
BA - Negative acceleration to decelerate the vehicle to R until position pw.
The following figures are merely for the better understanding of the present invention, they do not limit the invention to the examples. Some of the figures are roughly schematic in order to clarify the modes of operation, active principles, technical configurations and features. In principle, any mode of operation, principle, technical design and feature shown in the figures or text may be understood to include all claims, every feature in the text and in the other figures, other modes of operation, principles, technical embodiments and features included in or resulting from this disclosure are combined freely and arbitrarily so that all conceivable combinations are to be added to the disclosure of the invention.
There are also combinations between all individual executions in the text, i. in each section of the description text, in the claims, and also combinations between different embodiments in the text, in the claims and in the figures.
Fig. 1 shows the representation of a speed limitation of the prior art;
FIG. 2 shows the display operating state according to the invention (in terms of content optically identical to FIG. 1, but visualized according to the invention;
FIG. 3 shows the suggestion operating state according to the invention
Warning level 1 (see arrow below the traffic sign);
4 shows the suggestion operating state according to the invention
Warning level 2 (see arrow below the traffic sign);
FIG. 5 shows the suggestion operating state according to the invention
Warning level 3 (see arrow below the traffic sign);
Fig. 6 shows a symbol for indicating a speed limit;
Fig. 7 shows a schematic diagram of the application of the invention;
Fig. 8 shows the possible existence of distance distance parameters;
9 shows a flow chart for the method according to the invention;
Fig. 10 shows some examples regarding the determination of system variables.
As shown in FIG. 1 and already explained in the introduction, route-relevant information such as speed limits is frequently displayed without temporal proximity and exclusively based on the instantaneous position of the means of locomotion as an indication to the user on the display means (here speed limit 50). It lacks the consideration of the temporal proximity and the actual prevailing conditions.
Figures 2 to 5 are explained in the context of the following example. The example is based on a speed alert function, which should give the driver early and adapted to his driving behavior as well as the currently prevailing environmental characteristics and route characteristics information and support to comply with speed limits. The relevant route section determined by the device is in this case a route section with a predetermined speed limit. The example therefore explains the invention from the point of view of the speed adjustments to be made by the driver on the basis of the instructions of the navigation system. However, the invention is expressly not limited to the mere application as a speed warning system.
As already explained above, the application of the invention to sections with a speed limit is only one of many possible applications which do not always have to be accompanied by a reduction in the current speed of the means of transportation.
The invention could be used, for example, as follows: A vehicle embodying the navigation system according to the invention approaches a plug section within a speed limit of R = 60 km / h (in Fig. 2 is exemplified 50 km / h displayed).
This section is currently located 700 meters from the current position of the means of transport. Part of the variables continuously determined by the facility is shown in Table 1. It is therefore recommended to consult Table 1 whenever the speed change in the example below is used to understand the change in intrinsic variables. The instantaneous position and the instantaneous speed of v [theta] = 33, 36 m / s of the means of locomotion are present continuously in the navigation system according to the invention. It now automatically determines by means of access to the road network database that a stretch of road with a speed limit of 60 km / h is imminent.
In addition, the navigation system determines the distance from d = 700 meters to the beginning of this section based on the current position of the means of transport.
Taking into account the determined distance d = 700 meters and the instantaneous speed v [theta] = 33, 36 m / s of the means of locomotion, two parameters are now determined. The first parameter is the time TL. For this time TL = (d / v [theta]) = 700 meters / 33.36 m / s = 20.98 seconds (rounded).
BA is determined as another parameter. We have BA = (v [theta] - R) / t or BA = (v [theta] - R) / (d / v [theta]). Since BA can be determined directly from the given data, the intermediate step for determining the first parameter TL could also be omitted. The background to this is that t = TL is selected for the time. If the braking process can be completed within the time TL, it is ensured that the vehicle after overcoming the distance d and thus when reaching through the
Speed limit marked section has a speed that does not exceed the speed specification at least. BA is calculated in this example as BA = 0.79 m / s <2> (rounded).
To prepare for the point in time and the manner in which the user is informed, an evaluation of this parameter BA is now started based on BA, the result of the evaluation serving as a driving criterion for the control of the operating means for outputting a message to the user of the device with regard to the relevant route property , An automatic change between at least two operating states (eg "information required" or "information not required") of the device takes place in accordance with the control criterion (eg BA exceeds or falls short of a comparison value) and the control of the operating means (eg visualization on display means included in the operating means) takes place in accordance with the operating status assumed by means of the comparison.
In this specific example, the device uses three predefined acceleration threshold values t1 to t3, which are taken into account within the scope of the control criterion and are used as a comparison value for the parameter BA. More specifically, it is checked to which threshold range the parameter BA is to be assigned. The threshold values are at tl = 1.0 m / s <2>, t2 = 2.0 m / s <2> and t3 = 3.0 m / s <2>. BA is currently 0.79 m / s <2> smaller than tl, which classifies the device as uncritical. The comparison of BA with tl, which serves as the driving criterion, therefore leads to the system-internal decision that there is no need for action. The vehicle is still far enough away from the start of the speed limit and the vehicle speed is not so high that the driver could no longer brake.
So far there is no need to give the user an indication of the speed limit ahead and unnecessarily distract him from road traffic.
It is now assumed that the driver increases the speed to 150 km / h, the distance is only 600 meters. The system-internal variables are partially set to new values (see Table 1). The inventive navigation system now informs the driver due to a change of the operating state due to the changed parameter BA (BA = 1, 74 m / s <2>), that a speed limit can be expected on the route ahead. This message could initially be done, for example, purely visually by means of a speed limit sign, which is indicated on the display means (see FIG. 2). To make it clear that the speed limit is imminent and currently not yet relevant, the sign could for example be displayed shaded gray.
There is thus no urgency for a deceleration signaled by the system, since the distance is still large enough. This display mode is characterized by BA> tl and BA <t2 is. Always in this example, the vehicle is located at a sufficiently great distance to the stretch of road, so that a safe braking is possible and still enough time remains to initiate a deceleration.
Suppose that the driver does not reduce his speed and the distance is now only 450 meters. Since the braking process now required an acceleration (BA = 2.31 m / s <2>), which is above the threshold value of t2, the system switches to another operating state. In the context of this operating state, the device determines a first display stage (warning level 1), which is realized here by way of example by the display of, for example, a green arrow (FIG. 3) below the traffic sign (FIG. 6). Thus, the user is visualized that he should initiate a deceleration of the means of transport. This operating state is characterized in that t3> BA> = t2 and on the display means a suggestion for the further procedure for the user is displayed.
The vehicle is located in a sufficiently large distance to the stretch of track, so that a more safe braking is possible and it makes sense to start braking.
Suppose that the driver now reduces the vehicle speed from 150 km / h to 130 km / h, but this is too slow, and now the distance is only 250 meters (BA = 2.81 m / s <2>). The system recognizes that despite the slight deceleration already initiated by the driver, the urgency of greater speed reduction prevails (warning level 2). Accordingly, a second warning level is activated, for example, by changing the color and / or length of the arrow described above and known from FIG. 3 (FIG. 4) in order to visualize this increased urgency to the driver. Assuming that the driver still does not respond adequately despite the indications and reduces the speed only to 100 km / h at a now prevailing distance of 105 meters to the beginning of the relevant section (BA = 2.94 m / s <2>).
Under these circumstances, the vehicle is at a critical distance to the relevant stretch of road, so that no more safe braking is possible or there is no possibility to reduce the speed so that when reaching the relevant stretch of the vehicle speed less than or equal to the speed limit vorgäbe is. The system outputs a high priority indication on the display means (Figure 5), for example by using the additional signal color red and / or further changing the geometry (e.g., the length) of the arrow below the road sign.
Suppose that the driver finally reacts adequately and reduces the speed to 70 km / h at a distance of 30 meters to the relevant section (BA = 1.80 m / s <2>). In this case, the system returns to the display state and informs the user of the speed limit in advance in accordance with FIG. 2 as described above.
Once the vehicle enters the restricted area, the usual representation of a speed limit can be made, for example by a traffic sign representing the speed limit (Figure 6).
If BA <tl, the current operating state would be set to the idle state in which no relevant display takes place.
In summary, the following operating states exist:
"Silence": No indication is given because the distance to the start position of the speed limit and instantaneous vehicle speed do not require this.
"Display": The driver is signaled by a warning that there is a speed limit on the line ahead.
"Suggestion": The driver is signaled that he must reduce his current speed.
"Alarm": The driver is signaled that only with a strong deceleration and / or not at all more appropriate and safe can the speed be reduced without risking a speeding-over.
<EMI ID = 24.1>
FIG. 7 shows the basic mode of operation of the invention on the basis of a roughly schematic sketch, which illustrates the route between start point ("start") and destination point ("destination") determined by the device according to the invention.
The device automatically and continuously determines the instantaneous position pv of the means of locomotion, which moves along the route course r determined by the device, starting from the starting point to the destination point. The automatic determination of at least one relevant to at least a section (gray hatched rectangle) of the route track property by accessing the road network database and the automatic determination of the distance d to the beginning of this section based on the instantaneous position pv of the means of transport, which along the distance course S from Means of transport is to be put back. The distance course S lies between the instantaneous position pv of the means of locomotion and the beginning pw of the route section (gray hatched rectangle).
In this example, the section (gray hatched rectangle) is a speed-limited zone with speed limit R, which should be noted. In order to achieve an improved user information, the device according to the invention determines the position Hp between pv and pw along the predicted route r at which the user instruction regarding the preceding speed limit zone must be made at the latest so that the driver can respond appropriately to the alert, to a speed overshoot to avoid. Alternatively or additionally, it is also possible to determine a point in time Ht at which no later than an indication to the driver has to be made so that he can react appropriately
For the realization of the invention, among other things, the following physical laws are implemented on the firmware side within the scope of the method: distance traveled by the vehicle after a time t:
s (t) = a / 2 * t <2> + v [theta] * t
Speed of the vehicle after a time t:
v (t) = vo + a * t
Time after which the vehicle has reached a certain speed v:
t = (v-vo) / a
Easy braking distance (without consideration of environmental and road characteristics):
s = v <2> / (2 * a)
Required time TL (time to limit) at constant speed of the vehicle on the way from pv to pw:
TL = (d / v [theta])
Required acceleration (negative and constant) a to decelerate from velocity v [theta] to R within time t:
a = (v [theta] - v) / t
where v represents the preceding allowable speed R to be observed, and a represents the so-called "break acceleration" under these circumstances.
Fig. 8 indicates the inventive use of link parameters.
It is known from the explanations above that a threshold value can also be taken into account as the triggering criterion, which can be used as a comparison value for the parameter. In the aforementioned example, four threshold values t1 to t3 were actually used. Now, the invention provides that at least one of the threshold values t1 to t3 is automatically modifiable by the device, taking into account at least one data set characterizing the distance profile curve S (gray shaded circle), wherein the data set environmental properties or route properties (gray shaded ellipse) or Fortbewegungsmitteleigenschaften (not shown).
This means that the route properties or route criteria of the distance route S or environmental criteria to be taken into account between the instantaneous position pv of the means of transportation and the starting point pw of the relevant route section are continuously determined and taken into account by the device.
These criteria can be determined by the device by means of the road network database or possibly existing sensors or other means of information on the vehicle and stored, for example, as a data vector. By way of example, the data vector S for describing the path properties of the distance profile curve S could be constructed in such a way that its attributes a1 to include different characteristic quantities for describing the route. For example, al could describe the curve situation, a2 the grade slope and a3 the characteristics of the road surface. Further criteria should be included. For the vector, S l, ..., n = <al, ..., to>.
For example, the data vector U for describing the environmental properties could be constructed such that its attributes ul to un include different characteristic quantities for describing the environmental situation. For example, ul could describe the precipitation situation, u2 the temperature situation, and u3 the visibility. Further criteria should be included. For the vector, this holds for Ul, ..., n = <ul, ..., un>.
The data vector F for describing the vehicle characteristics, for example, could be constructed so that its attributes fl to fn include different characteristic quantities for describing the vehicle. For example, fl could describe the braking distance, f2 the weight and f3 the tires. Further criteria should be included. For the vector, Fl, ..., n = <fl, ..., fn>.
It is proposed to set the vector attributes with numerical values which could, for example, serve as a reference for a table which is processed by the device.
Each vector or each attribute may include a weighting for its relevance, which is taken into account in the inventive data processing and causes the data set is taken into account in the modification of the threshold value according to the weighting factor. The device may, for example, form the arithmetic mean of the individual data record components of a data set or vector and take this result into account when modifying the threshold value. Such a weighted vector has the general form W (S l, ..., n), these being the individually weighted attributes <wl * al, ..., wn * an> includes. For example, the weighting could be realized such that a single attribute at 0% to 100% can be considered by covering a range of numbers from 0 to 100.
Taking into account, for example, the vehicle speed, various environmental conditions (weather, etc.) and the preceding route section or route profile (curves, straight line, traffic signs, etc.), a meaningful warning time Ht can be calculated. This warning time is chosen so that the driver has enough time to reduce the speed of the vehicle, so that the speed of the means of locomotion is below a speed limit relevant to the route section or a recommended speed, e.g. at bottlenecks, reached and maintained.
9 shows a flow chart for the method according to the invention, which is based primarily on firstly determining the vehicle position, the distance to a relevant route section, the instantaneous speed and a speed limit that is relevant for the route section using the data stored in the road network databases
Information and determined by means of the device position information can be determined. Subsequently, a possibly required negative acceleration BA is determined and / or the period within which the speed reduction of the instantaneous speed must be performed on the to be observed at the beginning of the section section of the user of the inventive device. For the note generation for the user, the acceleration threshold values already explained above are now included in order to create a criterion for the urgency of a user instruction and to convert the device into a corresponding operating state. The operating state then determines the required action, by means of which an indication to the user is to take place.
For the hint itself, several reference levels are again distinguished, which allow a categorization of the hint between the categories "non-urgent" and "extremely urgent".
The examples shown in FIG. 10 are self-explanatory and again show the contents of some system variables TL and BA taking into account the instantaneous velocity v [theta] and the distance d. Taking into account the given speed limit R = 70 km / h, the action or the current operating state performed by the device changes from the state "display" (example 1) via the state "rest" (example T) up to the state "suggestion" ( Example 3).
In the lower area of FIG. 10, the threshold values t 1 to t 3 are plotted along an axis. These threshold values are stored in the device and serve to classify the state into regions depending on the system parameter BA. As long as BA in the range between tl = 1, 0 m / s <2> and t2 = 1, 6 m / s <2> (example 1), the "show" state is active. For BA in the range t2 = 1, 6 m / s <2> to t3 = 4.0 m / s <2> the state "proposal" is active (example 3) and for BA> t3 = 4.0 m / s <2> the state "alarm" (no example) is active. For BA under tl = 1, 0 m / s <2> the state "rest" (example 2) is active. These statements apply to a speed limit of 70 km / h in the relevant upcoming section.