DE102005002872B4 - Device and method for vehicle guidance - Google Patents

Abstract

wobei m die Anzahl der Lichtsignalanlagen bestimmt.Method for vehicle guidance by
Determining a travel time of a route,
characterized in that
- When determining the travel time an influence is taken into account by at least one traffic signal system, wherein σ _i is an average waiting time per traffic light installation, the sum of the total waiting times being multiplied by a statistical factor Λ for the total distance taking into account the coordination and density of the total distance traffic light systems, so that the estimated holding time by the traffic signals applies

where m determines the number of traffic lights.

Description

The invention relates to a method and a device for vehicle guidance.

The digital map material of navigation systems and route planners for vehicle guidance is determined according to road categories and the rules of the Highway Code (STVO) and does not take into account current traffic signal systems (LSA).

Green and red phases of the traffic light systems have an enormous impact on the travel time in the urban traffic network and lead to fluctuations or changes in the calculated travel time between 20% and 50% as a result of additional dwell times, even with normal traffic congestion. These loss of light signals caused by the traffic signals increase in proportion to the number of traffic lights per kilometer depending on coordination and intersection geometry, as well as competing and intersecting transversal traffic, such as pedestrians, public transport vehicles such as buses or trams, with driving precedence.

Measurements in city traffic show that on a 10-kilometer route in the city center, not infrequently, 40 traffic lights with 20 stops and 10 minutes of service life occur. The intersection geometry defines the ratio of green and red time and the traffic volume the length of the backwater. The arrival time of the vehicle determines the waiting time in addition to the circulation of the traffic signal system.

State of the art

These parameters caused by the traffic signal systems are currently not taken into account in route planning or vehicle guidance. Although areas with speed specifications (such as 30 km / h) and turning relationships are integrated in the algorithm for calculating the route, the influence of time-of-day-dependent loss times at the nodes of the traffic lights, static arrival times and traffic-dependent tailback periods are not. From the pamphlets DE 103 24 961 A1 . JP 08 315 290 A . EP 1 092 949 A2 methods are known in which the waiting time before a traffic light or the arrangement of a traffic light on a route in the calculation of the optimal route or fastest route to the destination flows.

task

The invention has for its object to provide a method and an apparatus for vehicle guidance, so that taken into account by traffic lights loss times in the route planning or vehicle guidance and preferably selected on a city transport network routes with minimal downtime.

This object is achieved by the features specified in claims 1 and 4 of the invention. Further developments of the invention are defined in the subclaims.

The advantage of the invention is, in particular, that in urban traffic for route planning, those traffic light systems that are on a proposed route can be taken into account.

embodiment

The invention will be explained in more detail with reference to the drawings. Show:

1 : Illustration of several routes with traffic lights

2 : schematic representation of a junction with traffic signal system

In 1 the technical design of a FCD (Floating Car Data Technology) based route planning is shown. In the first step, the average travel times on an inner-city traffic route network are recorded and the locations of the traffic signals in the digital road map material are specially marked. In the figure, intersection nodes with traffic signal system are represented by a circle and pedestrian crossings with signal system by a rectangle.

In the in 1 example chosen is between the points A and B, a road network drawn. Between both points, for example, the distances a, b and c arise.

There are three traffic lights on route a, five light signals on route b and eight traffic lights on route c. In general, this results in a specific route and a specific number of traffic lights for a specific route.

Each traffic signal system is characterized by an individual, average holding time. Depending on the turnaround time and the green time, the mean waiting time per intersection with traffic signal / n can then be estimated using the statistical time of arrival, with coordinated "green waves" and priority buses also having to be considered in the algorithm.

Δt_R

= Rotzeit pro Umlauf (Ampelzyklus)

N·Δt_R

= verlängerte Rotzeit aufgrund Rückstaus mit N grösser oder gleich 0 (N ≥ 0) und N = ganze Zahl

τ

= durch zufällige Ankunftszeit bedingte Verkürzung der Rotzeit

The holding time h at a traffic signal is composed of: h = Δt _R + N · Δt _R - τ (1) With

Δt _R

= Red time per circulation (traffic light cycle)

N · _R .DELTA.t

= extended red time due to backflow with N greater than or equal to 0 (N ≥ 0) and N = integer

τ

= shortening of the red time due to random arrival time

If the arrival time is outside the blackout period (red phase), the vehicle may pass the intersection at green. In this case, τ = Δt _R and N = 0, so that a holding time h = 0 results.

mit

λ_i

= statistischer Faktor der Lichtsignalanlage i

σ_i

= mittlere Wartezeit an der. Lichtsignalanlage i

Λ

= statistischer Faktor für die Gesamtstrecke σ _i = mittlere Wartezeit pro Lichtsignalanlage

Since N and τ are not known for the route planning, an approximation must be found for the holding time at the traffic lights. According to the invention, an estimated holding time σ of:

With

λ _i

= statistical factor of the traffic light system i

σ _i

= mean waiting time at the. Traffic light i

Λ

= statistical factor for the total distance σ _i = average waiting time per traffic signal

The average waiting time σ _i is individual for each traffic signal system. Equally individual is the statistical factor λ _i , for which the following applies: λ _i ~ k and λ _i ~ t _F / (t _R + t _F )

In this case, k corresponds to a coordination factor with which, for example, a "green wave" can be taken into account in the route planning based on FCD data (floating car data). In addition, the statistics factor λ _{i is} also proportional to the ratio of the release time (green time) t _F and the red time t _R. Ie. this factor can be used to estimate the probability with which the traffic light system i can pass without waiting time.

Since these statistic factors λ _i and σ _{i are} generally not available for every signal system, the estimation shown in equation (2) can be made for the average holding time over the entire distance AB. Accordingly, a mean waiting time of σ _{i is} used for each of the m traffic lights lying on the route AB. The sum of the total waiting times is then multiplied by the statistical factor Λ for the total distance. In this factor Λ according to the invention the coordination and density of the light signal systems of the total distance is taken into account.

In one example, it can be assumed that the mean waiting time σ _i about 20 seconds. However, if you are on a main route with "green wave", the total waiting time may be reduced to half per traffic signal, resulting in Λ = 0.5.

The estimation of the total waiting time on a route can be improved by including in the calculation whether the driver should turn left at an intersection, turn right or drive straight ahead. A corresponding sketch for this is 2 refer to. Accordingly, upon arrival at an intersection, which is represented by a circle, in principle the waiting time σ _i until the traffic light system is set to green. Depending on whether the route now plans to drive straight ahead at the intersection, turn left or turn right, there may be additional waiting times or shortening of the waiting time. Thus, for example, a "green wave" can be taken into account in the statistics factor λ _{i, 1} for straight-ahead driving. If you turn right, you may have to let pedestrians pass so that the waiting time increases, which can be taken into account with the statistics factor λ _{i, 2} . Similarly, additional latency may result in turning left by the right of oncoming straight-ahead traffic, which translates into the statistics factor λ _{i, 3} . These directional factors can be considered at each intersection, resulting in an improved estimate of the total latency using equation (2).

Claims (6)

A method for vehicle guidance by - determining a travel time of a route, characterized in that - in determining the travel time an influence is taken into account by at least one traffic signal system, wherein σ _i stands for a mean waiting time per traffic signal system, the sum of the total waiting times having a statistical factor Λ for the total distance is multiplied, which takes into account the coordination and density of the traffic lights of the total distance, so that applies to the estimated stopping time by the traffic signals

where m determines the number of traffic lights. Method according to the preceding claim, wherein a route is determined based on the travel time. Method according to one of the preceding claims, wherein a coordination factor for the consideration of a plurality of successively arranged light signal systems for determining the travel time is used. Device for vehicle guidance with - a computing device for determining a travel time of a route, characterized in that - with the computing means influencing by at least one traffic signal when determining the travel time is taken into account, wherein σ _i is an average waiting time per traffic light installation, the sum of the total waiting times being multiplied by a statistical factor Λ for the total distance taking into account the coordination and density of the total distance traffic light systems, so that the estimated holding time by the traffic signals applies

where m determines the number of traffic lights. Apparatus according to claim 4, wherein a travel route based on the travel time can be determined. Device according to one of claims 4 or 5, wherein in the computing device a plurality of successively arranged light signal systems can be considered by a coordination factor.

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