DE102011081148A1 - Method for operating navigation unit for motor vehicle, involves determining mean velocity depending on promptly detected course of velocity of motor vehicle - Google Patents

Abstract

The method involves determining (S2) a mean velocity depending on a promptly detected course of the velocity of the motor vehicle. An estimated velocity is determined (S4) depending on traffic condition information which correspond to a predetermined route section. Another estimated velocity is determined (S6) depending on a historically determined velocity for the predetermined route section. An expected velocity for the respective route section is determined depending on the mean velocity and a distance between the actual position of the motor vehicle and the route section. An independent claim is included for a device for operating a navigation unit.

Description

The invention relates to a method and a corresponding device for operating a navigation device for a motor vehicle.

Modern navigation systems for motor vehicles are increasingly designed to receive traffic information via traffic information channels. Such a traffic information channel is for example the Traffic Message Channel (TMC). The TMC traffic channel transmits traffic information in the inaudible ultra-short frequency (FM) band in digital form. The navigation systems can, for example, receive traffic jams via the traffic channels and thus determine routes for bypassing traffic congestion and disabilities. Some of the navigation systems are designed to determine a traffic condition forecast depending on the traffic information. This may be used to indicate to a vehicle user information about traffic conditions in the environment in which the vehicle is likely to be moving during a predictable forecast period, and / or the traffic state prognosis may be taken into account in determining an appropriate route.

The object on which the invention is based is to provide a method and a device for operating a navigation device, which contributes to qualitatively improving the provision of traffic status information for a vehicle user and / or other vehicle devices.

The object is solved by the features of the independent claims. Advantageous developments of the invention are characterized in the subclaims.

The invention is characterized by a method and a corresponding device for operating a navigation device for a motor vehicle. It is one, in particular current, average speed determined depending on a timely recorded course of the speed of the motor vehicle. Further, an estimated first speed is determined depending on traffic condition information relating to a predetermined route section. Furthermore, an estimated second speed is determined depending on a historically determined speed for the given route section. An expected speed for the respective route section is determined as a function of the average speed and of a distance between the current position of the motor vehicle and the route section and additionally depending on the first speed and / or the second speed.

Taking into account the distance of the motor vehicle from the route section and the current average speed of the motor vehicle in determining the expected speed for the route section can contribute to qualitatively improve provision of traffic state information to a vehicle user and / or other vehicle devices. The traffic information can be evaluated more reliably for the motor vehicle. The traffic information can be adjusted depending on the current state of the motor vehicle with respect to position and speed for the motor vehicle.

The timely recorded course of the speed can be determined depending on respective instantaneous speeds, which are detected during a predetermined period of time at predetermined time intervals. Preferably, the predetermined period of time approximately, for example, taking into account a calculation time and / or the time intervals, up to a current time zoom. For example, the duration may last a few minutes, for example two minutes.

In an advantageous embodiment, depending on the expected speed, a signal is generated for signaling a predicted traffic condition on the route section. Advantageously, the signal can be used to signal the predicted traffic state on the respective route section to a vehicle user, for example by means of an optical display. For example, three states can be assigned to the predicted traffic state. For example, a first state may represent a free flow of traffic. For example, the second state may represent a stagnant traffic flow, and the third state may represent a stagnant traffic, for example.

In a further advantageous embodiment, the distance represents a path distance between the route section and the position of the motor vehicle. This allows easy determination of the distance.

In a further advantageous embodiment, the historical speed is determined based on time and / or vehicle-related and / or vehicle user-related and / or vehicle group-related. This allows for the determination of the expected speed traffic conditions to take into account, which are dependent on times of the day, weekdays and seasons as well as calendrical Special features are. Furthermore, when determining the expected speed, a driving style of a specific vehicle user and / or the vehicle user can be taken into account. Furthermore, the expected speed can be determined depending on a specific vehicle group. The vehicle group may include, for example, the motor vehicles of a specific manufacturer.

In a further advantageous embodiment, the average speed and / or the first and / or the second speed are weighted differently when determining the expected speed depending on the distance between the current position of the motor vehicle and the respective route section. Advantageously, this makes it possible, when determining the expected speed, to evaluate traffic information differently depending on a distance and thus depending on a time duration until reaching the respective route section.

In a further advantageous refinement, on determining the expected speed, the weighting of the average speed and / or the first speed and / or the second speed is dependent on a group of roads that includes a respective road on which the motor vehicle is currently located. For example, a first group of streets may include urban and / or local residential and main roads. For example, a second group may include highways. A third group may include, for example, federal highways and highways. For example, a weighting factor may be determined depending on the group of the road that includes the road on which the motor vehicle is moving.

In a further advantageous embodiment, when determining the expected speed, the weighting of the average speed and / or the first speed and / or the second speed is dependent on a detected position of the motor vehicle. This makes it possible, for example, to distinguish a conscious stopping of a motor vehicle from standing in a traffic jam and to take this into account when determining the expected speed. For example, a lane recognition of the motor vehicle can be used to distinguish a short stop at the roadside from a standing in a traffic jam, where the motor vehicle is on the road. For example, the weighting factor can be adjusted depending on the determined position.

In a further advantageous embodiment, when determining the expected speed, the weighting of the average speed and / or the first speed and / or the second speed depends on a deviation between a currently detected speed for the motor vehicle or the average speed and one for the motor vehicle for the route portion estimated third speed, which is determined depending on historically recorded speeds for the route section.

The second and third estimated speeds may be determined depending on the same historically measured speeds and parameters and thus may be the same. Alternatively, the second and third estimated speeds may be determined depending on different historical speeds and thus may be different.

In a further advantageous embodiment, the historically recorded speeds are determined by a given group of motor vehicles. The group of motor vehicles may include, for example, motor vehicles of a specific motor vehicle manufacturer. This allows easy provision of historical data.

Embodiments of the invention are explained below with reference to the schematic drawings.

Show it:

1 an exemplary flowchart for a first program for operating a navigation device and

2 an exemplary flowchart for a second program for operating the navigation device.

Elements of the same construction or function are provided across the figures with the same reference numerals.

1 shows by way of example a flow chart for a first program for operating a navigation device for a motor vehicle. The navigation device may include an input unit, an output unit, a route determination unit and a position detection unit. The navigation device is coupled to a device for operating the navigation device. The device comprises, for example, a computer and a program memory in which the first program and a second program ( 2 ) are stored. The device is designed to execute the first and the second program. The first program is used to determine an expected speed v for a given route segment. Depending on the calculated expected speed v for the route section For example, a vehicle user can be signaled a traffic condition for the given route section and / or a route can be determined.

The first program is started in a step S0. The start of the program preferably takes place with a start of an active operating state of the navigation device.

In a step S2, an average speed vm of the motor vehicle is determined as a function of a timely recorded course of the speed of the motor vehicle. By way of example, the average speed vm can be determined in each case as a function of the respective instantaneous speeds for the motor vehicle detected at predetermined time intervals during a predetermined period of time. The mean velocity vm can represent, for example, an arithmetic mean of the last detected instantaneous speeds. The respective instantaneous speeds can be detected, for example, by means of a tachograph of the motor vehicle, which is coupled to the device, and then buffered in a memory of the device.

In step S4, an estimated first speed v1 is determined depending on traffic condition information relating to the predetermined route section. For this purpose, the device can be designed, for example, to receive and / or request current traffic status information via an air interface. The traffic status information may, for example, comprise information that the route section has a halting traffic flow, so that driving on the route section is possible only at a predefined reduced speed. The estimated first speed v1 can be determined for the route section, for example, depending on the reduced speed.

In step S6, an estimated second speed v2 is determined as a function of a historically determined speed for the given route section. The historically determined speed can be determined, for example, by time and place. For this purpose, the device may be designed, for example, to record a travel speed of the motor vehicle in a time-dependent and location-related manner for respective route sections and to store it in a database, for example in a database of the device. Depending on the travel speeds recorded in relation to time and place, a speed profile can be determined for the respective route section. The estimated second speed v2 can be determined, for example, as a function of the determined speed profile for the route section.

Such a speed profile can be determined for the motor vehicle. Alternatively or additionally, it is also possible that such a speed profile is determined specifically for a vehicle driver. Alternatively or additionally, it is also possible for such speed profiles to be determined in each case for a plurality of motor vehicles and / or for a plurality of vehicle drivers. The speed profiles may be directly interchanged between the various vehicles and / or sent to a central processing unit that consolidates the speed profiles and stores them in a stationary database. The speed profiles can then be retrieved as needed, for example, from the device of the motor vehicle.

In a step S10, a distance s of the motor vehicle to the predetermined route section is evaluated. If the distance s between the position of the motor vehicle and the predetermined route section is less than a predetermined first distance D1, the expected speed v is determined in a step S12 depending on the average speed vm of the motor vehicle and the estimated first speed v1. The distance s may represent a travel distance between the route section and the position of the motor vehicle.

A weighting of the mean vm and / or the first speed v1 and / or the second speed v2 in determining the expected speed vm may be different. The weighting may be dependent on a group of roads comprising a respective road on which the motor vehicle is traveling and / or depending on a current position of the motor vehicle. For example, a respective weighting factor a_i may be determined depending on the group of the road that includes the road on which the motor vehicle is moving. When weighting can thus be considered whether the motor vehicle is driving on a residential road or on a highway or on a highway.

Furthermore, the weighting may be dependent on a deviation from a currently detected speed or the average speed of the motor vehicle and a third speed estimated for the motor vehicle for the route section, which is determined as a function of speeds historically recorded for the route section. The historically recorded speeds can be determined, for example, in each case by a given group of motor vehicles. For example, the respective weighting factor a_i be adjusted depending on the determined deviation.

Furthermore, it can be taken into account in the weighting whether the motor vehicle is on a roadway in a traffic jam or has briefly stopped on a side strip. For example, a lane detection device may be used to determine if the vehicle is on the lane or on a side lane. For example, the weighting factor a_i can be adjusted depending on the detected position of the motor vehicle.

For example, the expected speed v in step S12 may be determined according to eq. 1 are determined. v = vm * a_i + v1 * (a_i-1) Eq. 1 with 0 ≤ ai ≤ 1 and i = 1 ... n
where i is a group index and n is the number of groups of streets. Each group of roads is thus assigned to one of the weighting factors a_i, whose value is preferably greater the higher an average driving speed on the roads of the respective group.

In the event that the distance s is greater than the first distance D1, it is checked in a step S14 whether the distance s is smaller than a predetermined second distance D2.

If the distance s is greater than the first distance D1 but smaller than the second distance D2, the expected speed v is determined in a step S16 as a function of the average speed vm and the first speed v1 and the distance s. For example, a function which interpolates the mean velocity vm and the estimated first velocity v1 is used to determine the expected velocity. The expected velocity v can, for example, according to Eq. 2, which represents a linear interpolation between the mean vm and the first speed v1. v = v1-vm / D2-D1 * (s-D1) + vm Eq. 2

If the distance s is greater than the second distance D2, it is checked in a step S20 whether the distance s is smaller than a predetermined third distance D3.

If the distance s is greater than the second distance D2 but smaller than the third distance D3, the expected speed v is determined in a step S22 as a function of the first speed v1 and the second speed v2 and the distance s. For example, a function that interpolates the estimated first speed v1 and the estimated second speed v2 is used to determine the expected speed v. The expected velocity v can, for example, according to Eq. 3, which represents a linear interpolation between the first speed v1 and the second speed v2.

v = v2-v1 / D3-D2 (s - D2) + v1 Eq. 3

If the distance s is greater than a predetermined third distance D3, the expected speed v is determined in a step S24 as a function of the estimated second speed. For example, the expected speed may represent the second speed.

After determining the expected speed v in step S12 or S16 or S22 or S24, the first program may be terminated in a step S26. Preferably, the program is continued in step S2, in which case the expected speed for a further route section of a predetermined route is determined and / or an updated expected speed v is determined for the same route section.

For example, it may be provided to use the determined expected speed v for an indication of a predicted traffic condition on a predetermined route.

For example, an output unit can be used to display the predicted traffic status. The output unit may comprise a screen and may for example be associated with the navigation device. The output unit can be designed, for example, to display traffic overview maps. The output unit may be configured to determine and display a traffic overview map from a map representation of an active route guidance of the navigation device, depending on a signal that is generated for signaling a predicted traffic state.

The vehicle user can predetermine a destination by means of the input unit, for example, and a route from a current position of the motor vehicle to the destination is determined, for example by the route determination unit. The determined route is subdivided into a plurality of route sections and the predicted traffic conditions are signaled for the respective route sections. Depending on the desired accuracy, a length of the route sections can be specified. The expected speed v is determined for the respective route sections.

Alternatively or additionally, it can be provided that, depending on a current position of the motor vehicle, all the route sections in a predetermined area around the motor vehicle are marked, which have a traffic jam. Alternatively or additionally, it may be provided that for freely selectable routes, which are predetermined, for example, by the vehicle user, the predicted traffic conditions are signaled on the respective route sections.

For this purpose, for example, a second program can be used. 2 shows a flowchart for the second program for operating the navigation device.

The second program is started in a step S100. The start of the second program is preferably carried out with a start of an active operating state of the navigation device. For example, variables are initialized at startup, such as counters.

The steps S102 to S124 correspond to the steps S2 to S24 of the first program.

In a step S126, depending on the expected speed v, a signal is generated to signal a predicted traffic condition on the respective route section.

The predicted traffic conditions can for example be assigned to three states. For example, a first state may represent a free flow of traffic. The second state may represent, for example, a halting traffic flow, and the third state may represent, for example, a traffic jam.

If, for example, the expected speed v is greater or only slightly smaller, for example 15 less than a predetermined upper speed, the signal can be signaled in such a way that it characterizes a first state, that is to say a flowing traffic flow. The respective route section can, for example, be displayed in green in the traffic overview map. Alternatively, it is also possible that no signal is signaled.

For example, if the determined expected speed v is noticeably less than the predetermined upper speed but greater than a predetermined lower speed, for example, the signal may be signaled to characterize the second state, that is, a stagnant traffic flow. The respective route section can be displayed, for example, in the traffic overview map in yellow color.

For example, if the determined expected speed v is less than or equal to the predetermined lower speed, for example, the signal can be signaled such that it characterizes the third state, that is, a traffic jam.

After signaling the signal, the second program may be terminated in a step S130. The program is preferably continued by means of a loop instruction S128 in step S102, in which case the expected speed v for a further route section of the predetermined route is determined. If the calculation has been made for all route sections, an updated calculation of the expected speeds v for the route sections can take place immediately or after a predetermined time.

For example, it can be provided that the traffic overview map is updated starting from a current position of the motor vehicle at predetermined time intervals, for example every 5 minutes. Alternatively or additionally, the signaling of the traffic conditions on the respective route sections in the traffic overview map can take place at predetermined times or at a freely selectable time.

LIST OF REFERENCE NUMBERS

• a_i

  weighting factor

  D1, D2, D3

  first, second, third distance

  s

  distance

  S10 ... S130

  program steps

  SIG

  signal

  v

  expected speed

  v1

  first speed

  v2

  second speed

  vm

  average speed

Claims (10)

Method for operating a navigation device for a motor vehicle, in which - an average speed (vm) is determined as a function of a timely detected course of the speed of the motor vehicle, - an estimated first speed (v1) is determined depending on traffic status information that relates to a an estimated second speed (v2) is determined as a function of a historically determined speed for the given route section and - an expected speed (v) for the respective route section is determined as a function of the average speed (vm) and of a distance (s) between the current position of the motor vehicle and the route section and as well additionally dependent on the first speed (v1) and / or the second speed (v2). Method according to Claim 1, in which, depending on the expected speed (v), a signal (SIG) is generated for signaling a predicted traffic condition on the route section. A method according to claim 1 or 2, wherein the distance (s) represents a path distance between the route section and the position of the motor vehicle. Method according to one of the preceding claims, in which the historical speed is determined based on time and / or vehicle-related and / or vehicle user-related and / or vehicle group-related. Method according to one of the preceding claims, wherein in determining the expected speed (v) depending on the distance (s) between the current position of the motor vehicle and the respective route section respectively the average speed (vm) and / or the first (v1) and / or the second speed (v2) are weighted differently. Method according to one of the preceding claims, in which, when determining the expected speed (v), the weighting of the mean speed (vm) and / or the first speed (v1) and / or second speed (v2) depends on a group of roads, which includes the road on which the motor vehicle is currently located. Method according to one of the preceding claims, wherein upon determining the expected speed (v), the weighting of the mean speed (vm) and / or the first speed (v1) and / or the second speed (v2) depends on a detected position of the motor vehicle. Method according to one of the preceding claims, in which, when determining the expected speed (v), the weighting of the mean speed (vm) and / or the first speed (v1) and / or the second speed (v2) depends on a deviation between a current speed detected speed for the motor vehicle or the average speed (vm) of the motor vehicle and an estimated for the motor vehicle for the route section third speed, which is determined depending on historically recorded for the route section speeds. Method according to claim 8, wherein the historically detected speeds are determined by a given group of motor vehicles. Device for operating a navigation device, which is designed: To determine a mean speed (vm) as a function of a timely recorded course of the speed of the motor vehicle, To determine an estimated first speed (v1) depending on traffic condition information relating to a given route section, To determine an estimated second speed (v2) depending on a historically determined speed for the given route section and To determine an expected speed (v) for the respective route section as a function of the average speed (vm) and of a distance (s) between the current position of the motor vehicle and the route section and additionally in addition to the first speed (v1) and / or the second speed (v2).

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