WO2009071369A1

WO2009071369A1 - Method for determining a route, and device therefor

Info

Publication number: WO2009071369A1
Application number: PCT/EP2008/063749
Authority: WO
Inventors: Guido Mueller; Michael Laedke
Original assignee: Robert Bosch Gmbh
Priority date: 2007-12-07
Filing date: 2008-10-14
Publication date: 2009-06-11
Also published as: DE102007059120A1

Abstract

The invention relates to a method for determining a route from a starting to a destination point, wherein a route is determined that is optimized with regard to energy consumption, for which purpose energy consumption values are associated with at least part of the map data elements illustrating a traffic grid, on the basis of which the determination of the route is made, having an acceleration-related part, and an arrangement for carrying out the method. The invention having the features of the sub-claims has the advantage of improving a route determination with the goal of the lowest possible total energy consumption.

Description

Method for determining a route and device therefor

State of the art

The invention is based on a method and a device according to the preamble of the independent claims.

Current navigation systems allow the determination of routes that represent an optimum in terms of certain criteria, such as the shortest travel time or route. In addition, certain route sections may be excluded from route determination, such as tunnels, toll roads or ferries. Furthermore, due to the consideration of digitally coded traffic reports transmitted via broadcasting, for example according to ISO 14819, a respective current traffic situation, that is to say, in particular, current traffic disruptions, can be taken into account in the route determination.

A fast route over the highway usually has a longer route than a short route, so more energy is needed to handle the longer route at higher speed during this lower engine run time. Conversely, the short route is similar in that at much lower speeds, less energy is needed to move the vehicle, but the time to travel the route is longer and the number of acceleration times is greater. Since neither the travel time nor the route length correlate directly with the energy consumption, an optimal route in terms of travel time or route will generally not represent the optimum in terms of energy consumption. Current implementations for the determination of a low-energy route follow the approach, one Optimized route to a mixture of criteria short route and fast route to determine, which is believed that it tends to use less fuel than without this criteria mixture.

From DE 196 05 458 Cl a vehicle navigation system is known which a

Determines a plurality of alternative routes from an origin to a destination and selects from these alternative routes that for a route guidance, for which the fuel consumption is the lowest. To determine the fuel consumption of each of the alternative routes, the height differences to be overcome on these routes are evaluated, with a direct

Relationship between fuel consumption and to be overcome height difference is assumed.

In EP 1 505 555 B1, a further development of the above-mentioned vehicle navigation system is described, in which additionally a time upper limit for the total travel time of the selected route is taken into account for determining the most fuel-efficient route, so that, as a result, a most fuel-efficient route is determined from the set of possible routes that do not exceed a maximum travel time. Furthermore, relative fuel consumption values are provided for gradient and gradient sections, so that an absolute fuel consumption for each partial section can be determined from a vehicle-specific average fuel consumption value and the topology-dependent relative values.

Advantages of the invention

The invention with the features of the independent claims has the advantage that a route determination is improved with the aim of the lowest possible total energy consumption.

This is achieved by virtue of the fact that at least a part of the elements of the map data representing a traffic route network, on the basis of which the Determination of the route takes place, energy consumption values are assigned, which have an acceleration-dependent share. This is based on the recognition that acceleration processes significantly influence energy consumption when driving along a route, the total energy consumption. Acceleration-dependent consumption components are particularly preferred

Nodes of the map data are assigned which nodes commonly represent intersections, freeways and other traffic junctions in a traffic route network.

Preferably, acceleration-dependent consumption components can also be assigned to edges within which a change in speed is to be expected regularly, that is to say, for example, on sections with varying speed limits or for consideration of traffic disruptions which are obtained, for example, as coded traffic reports broadcast via broadcasting or the like.

Preferably, this part of the elements and / or further elements of the map data are assigned speed-dependent energy consumption value parts. In addition to acceleration processes, in particular an actual vehicle speed has a significant influence on the

Energy consumption along a route. In particular, a transmission ratio or the number of combustion processes per track, in particular the air resistance and rolling resistance, have an effect here.

Furthermore, it is preferable to use this part of the elements and / or others

Elements of map data assigned to basic energy consumption values. Thus, even when the vehicle is stationary, energy, for example, for operating electrical consumers, such as in particular comfort equipment, such as interior air conditioning, seat heating and the like, a driver information system, which may also include an inventive navigation system for performing the method according to the invention, as well as to overcome the internal Friction of a running internal combustion engine, consumed. This base load falls predominantly in motion - A -

of the vehicle and is therefore preferably assigned both to the edges representing the sections, so also the traffic nodes as intersections representing nodes.

Advantageously, the route determination to be based on

Energy consumption values for each particular element of the map data from this element information about a typical speed or typical speed differences and stored consumption shares determined. For example, based on a typical for a considered highway section speed of, for example

130 km / h from a table or a map of this speed associated fuel consumption of, for example, 6 liters per 100 km and this value multiplied by the length of the section, resulting in the speed-dependent proportion of fuel consumption for this section. For example, an inner-city

Intersection, at which a stop of the vehicle is to be expected, associated with an energy consumption, which results from a typical energy consumption for an acceleration process from a standstill to a speed of, for example, 50 km / h.

Advantageous in the acceleration-dependent portions of energy consumption values are further influencing factors, such as in particular

- vehicle-specific influencing factors, such as type of vehicle (car, truck, ...), drive type, such as petrol, diesel, LPG, natural gas, ethanol or electric motor or hybrid drive, manual or automatic transmission, typical energy consumption values, tires Loading conditions and attachments, such as roof racks, trailers and the like and / or

- External event-dependent influencing variables, such as weather conditions, messages about traffic-relevant events such as in particular traffic disruptions and / or

- driver-specific influences, in particular a driving style of the driver (sporty / conservative / energy-saving) considered.

Advantageously, a multidimensional characteristic map for the acceleration-dependent component, which is also preferably determined for the speed-dependent energy consumption values, determines which of the respective acceleration-dependent and / or speed-dependent components / s of the energy consumption value is / are used.

In addition, it is preferable to associate the or at least some of the elements with a time-dependent energy consumption value component. Thus, a time-dependent basic energy consumption, which is caused for example by the running even at a standstill internal combustion engine such as waiting times at intersections and other base loads, advantageously taken into account.

The driving time results from a forecast of the total driving time on the basis of typical speed values for individual road sections or specific road classes.

The invention can be advantageously implemented in a navigation device for motor vehicles. It is not limited to onboard navigation. In particular, solutions for route computers on the Internet are conceivable.

drawings

Embodiments of the invention are illustrated in the figures and are explained in more detail below.

Show it Figure 1 is a block diagram of a vehicle navigation system as an example of an arrangement for carrying out the method according to the invention and

Figure 2 is a diagram of the example of the relationship between vehicle speed and speed-dependent

Energy consumption share emerges.

Description of the embodiments

In FIG. 1, the reference numeral 1 denotes the arrangement according to the invention for carrying out the method according to the invention, here without limiting the generality of the invention using the example of a navigation system for permanent or at least temporary use in a motor vehicle, ie a vehicle navigation system.

The navigation device 1 comprises, in a manner known per se, means 11 for self-locating and thus for determining a current vehicle location, for example a receiver for GPS satellite positioning signals, preferably additionally inertial sensors and the like, whereby the respective current location is determined from a combination of these signals. Via an operating device 12, which preferably has control elements, a destination can be entered by the user. As a result, a route calculation module 13, which is preferably a software module that is processed by a computer of a central controller 10 of the navigation system 1, calculates a route from the current vehicle location to the entered destination via a traffic route network represented by map data 14 stored in a mass memory 14 becomes.

The map data 14 includes elements, namely, edges representing road sections and nodes representing intersections, freeways, and other traffic nodes. These elements are assigned energy consumption values. In the case of the edges, these include one speed-dependent fraction resulting from an energy expenditure required to maintain a currently driven speed. This depends in particular on the currently driven speed itself. This will be discussed in more detail later. Furthermore, the node energy consumption values are also assigned. These include here an acceleration-dependent portion which results from the energy expenditure for accelerating the vehicle from a first speed, for example standstill, to a second speed. This proportion is dependent on numerous parameters, which will be discussed later.

Preferably, nodes can also be provided, for example, within sections of sections at locations where, for example, a speed limit on a motorway is canceled, so that acceleration processes at this point can advantageously be considered directly as acceleration. In addition, especially nodes can also

Energy consumption value shares are assigned, which result from a basic consumption at standstill of the vehicle. When the engine is running, a modern-day car consumes about 0.5 liters of gasoline per hour at a standstill, for example in front of a traffic light or a railroad crossing. This basic consumption results from the friction losses to be overcome in the engine and, moreover, the energy demand in the vehicle operated electrical consumers, a driver information system, which also includes the navigation system, a comfort equipment, such as a seat heating and interior air conditioning and, for example, the engine control.

According to the route calculation takes place in such a way that a route is determined with the lowest possible energy consumption. The exact mode of operation will be explained in more detail later and is essentially based on the fact that the calculation process takes place according to, for example, Ford Moore or Dijkstra via the energy consumption values instead of the route segment lengths, for example for the criterion shortest route. The calculated route is stored in a route memory 18 and based on a subsequent route guidance, which is determined in the course of the movement of the vehicle whose current location and aligned with the route and, if necessary, guidance instructions for following the route generated and, for example, as synthesized speech via an output device 16 be issued acoustically. Alternatively or additionally, the route can also be displayed, for example, on a display 19 in a map representation.

The navigation system 1 further advantageously has a statistics component

101, which is implemented as a software module by the computer 10. This statistical component 101 has the task to record energy-relevant data during operation of the vehicle and to adjust values stored in a parameter memory 17 according to the collected data according to standard statistical methods. For example, the evaluates

Statistics component 101 from a respective current vehicle speed and sets them to, for example, the road class of the currently traveled road in relation. Thus, it is possible to adapt the navigation system or in its parameter memory 17 to preferences of the driver regarding a speed on a road of a particular road class.

Likewise, energy consumption value shares for certain route sections or nodes can also be detected and statistically processed. For example, in this way the driving style, sporty, defensive, consumption-optimized or the like, of the vehicle driver and its influence on the energy consumption can be mapped onto the stored information.

In this navigation device 1, for example, so-called TMC traffic reports in accordance with ISO 14819, which are obtained, for example, via a radio receiver 15, can also be taken into account for the route calculation.

For this purpose, the stored energy consumption values are changed as a function of the traffic reports received for the affected sections of the route. The degree of change is preferably dependent on the nature of the Fault event and its extent or alternatively the effects of the event on the traffic flow controlled.

General basics of route calculation in today's navigation systems

In a route calculation, the routes should be able to be determined with regard to various optimization criteria, eg. As the travel time, route or as in the present case, the energy consumption. In order to make the actual optimization process independent of the criterion, the criteria values to be optimized are described by an abstract resistor.

The digitized traffic route network used for the route calculation is regularly represented by nodes and edges. The edges represent the traffic route sections (road sections) and the nodes the traffic nodes

(Intersections). At least the edges, in a preferred embodiment, the transitions in the node resistors are assigned. The edge resistance describes the travel time or distance of the edge. Within a node usually no distance is covered, so that a travel time or route does not arise. Instead, the node resistance essentially describes the maneuver to get from the input to the output edge of the node.

The sum of the resistances of the edges and nodes passing on a track gives the total resistance of the track.

M

-K total distance 2 ^ ^edge 2 ^ ^node 1 1

In the optimization test of the route calculation, a possible new route with an old, previously determined route to the destination in terms of their

Resistance compared. An optimization is performed if the new route has better resistance than the old one. This is the new Route continues to be used as a route and replaces the old one. Otherwise, the old will continue to be used and the new discarded.

Basics of energy-optimized route

The basis for the energy-optimized route is the determination of the probable energy consumption for each possible route. For driving a route, the energy consumption for maintaining the travel speed on the route is essential for the energy consumption. Assuming a nearly constant speed, the counteracting

Braking effects (rolling friction, air resistance and the like) are overcome by continuous energy supply.

In addition, another physical aspect is essential, namely the acceleration. In this case, the energy expenditure required to accelerate the vehicle from a first speed, for example from a stationary position, to a second speed is to be considered.

Thus, for the entire route, energy consumption results from the sum of the consumptions for the acceleration component and for holding the

Speed on the track.

M

EV _{total distance} = ΣEV ^B + ΣEV ^S + EV ^T / 2 /

1 1

These two aspects are influenced differently by external factors, the consideration of these influences being taken as an example in the following table.

X Only indirectly via the speed

Accordingly, for example, the energy consumption component for acceleration processes is a function fεc (a)

- Driver-specific influences, namely, depending on the driving style of the driver, vehicle-specific influences, namely, depending on the nature of

Vehicle, a type of drive, a typical energy consumption and of

Attachments and the like, and external influences, such as the weather conditions.

Accordingly, the energy consumption fraction for holding a current driving speed is a function f _E c (v) depending on the type of vehicle, a type of drive, a typical energy consumption, a tire and attachments and the like, road-specific characteristics, namely in particular a slope and external influences, such as the weather conditions.

For example, for the energy consumption component for maintaining the speed on a level path, the relationship according to FIG. 2 results. Accordingly, the energy consumption first decreases with increasing speed.

This results from the fact that at very low speeds, for example less than 25 km / h, there is no appreciable air resistance but high rolling resistance, but the vehicle is moved in a small gear and thus with a high number of combustion cycles in relation to the distance covered. In a medium speed range from here, for example, about 25 to 60 km / h, the speed-dependent energy consumption remains constant low. With increasing speed, although the energy required to overcome the air resistance increases, but the vehicle can be moved in a larger gear, resulting in a saving of energy. These two effects are superimposed here in such a way that they cancel each other out. From a speed of here, for example, 60 km / h increases by the increasing influence of air resistance steadily, from about 100 km / h, this increase can not be compensated by further upshifts, so that the increase is steeper.

For gradients or slopes, as well as depending on the other influencing variables set out, there are similar deviations in details. The sums of these curves can preferably be stored as a map associated with the map elements. Alternatively, in the

Map data and references to a single stored map or classifications to assign a particular section or part of the map to be stored. It is essential that due to the stored Data each card element, which is taken into account in the route calculation, the specific energy consumption information can be assigned specifically.

acceleration

The instantaneous energy consumption f _E v (a) can be described by a function of the acceleration. Based on a constant acceleration results in the acceleration process energy consumption according to the following formula.

- v

EV ^B = t start>

^■ f _EV {a) = - ^{Fmal a fM

/ 3 /

Where t is time and v is speed.

The function of the instantaneous energy consumption includes the dependencies with respect to the acceleration described in the table above and shown in the table. The corresponding relationships between the parameters can preferably be represented by tables due to the complex relationships. They are preferably announced to the system initially and can be adapted successively by a statistical component.

The influence of intersections and road changes is described by the speed differences at these locations. Depending on

Driving maneuvers can be set for the resistance of the probability of the required acceleration process. So with a left turn is more likely to slow down and accelerated again, as in other maneuvers. R ^B = p (M) - EV ^B = p (M) Final - v Start J a fM ^EV / 4 /

The waiting times typical for certain maneuvers are taken into account by the probability function p (M) as a function of the maneuver.

Keep the speed on the track

The instantaneous energy consumption can be described by a function of the speed. Starting from a constant speed results in an energy consumption along the route according to the following

Formula.

^ ' ^~ t ^' J EV \ y route) ^~ J EV V ^ route)

^V stretch j ^ j

Where S is the route length.

The function of the current energy consumption includes the speed dependencies shown in the table and described above. The corresponding relationships between the parameters can preferably be represented by tables due to the complex relationships. They are announced to the system Initial and can be adapted successively by a statistical component. The influence of bends and traffic disturbances along the route must be described by additional acceleration processes. It is usually slowed down before corners and it must be accelerated again afterwards. This fact takes into account the additional energy consumption according to the following formula.

77 T / S _ \ ^V distance ^{~ V} curve) f (Λ L ^V curve ^~ J EV Ψ) a / 6 / In traffic congestion, such as congestion, on the one hand, the average speed is reduced and on the other hand, it comes to additional braking and acceleration processes. Both effects have an opposite effect, on the one hand decreases and on the other hand, the energy consumption increases.

ri _j rS Traffic disruption r (1, V route traffic jam 1 ri \ 1-7 j

^ 'Traffic jam ~ J EV V Traffic jam I ^" " J EV \ ^a )''' a

It must be ensured that a disturbed track in terms of energy consumption may not be better valued, even if mathematically it might be correct. It would not be understandable if a certain section of the route is chosen exclusively if there is a traffic disturbance there.

πyS - FV 'F ^S Reier transport w ^W p ^t r ^ll m ^ll (\ ± F *, V ^V V ^S erkehrsstörung <^ ^ FV' F ^S Reier traffic \ 1 inj ^{h V} distance Verkehrsstorung _{= EV} S (Gys < gyS)

^ 'Traffic disruption ^w ^ ¹¹¹¹ ^ V' Free movement - ^ ^r traffic disruption)

The energy consumption to cover the distance corresponds to the resistance in the route calculation.

RG ^s total = EV G ^S total / 9 /

Claims

claims:

A method of determining a route from a starting point to a destination point, wherein a route optimized in terms of energy consumption is determined, including at least part of the elements of a traffic route network

Map data, on the basis of which the determination of the route takes place, energy consumption values are assigned, which have an acceleration-dependent portion.

2. Method according to claim 1, characterized in that the energy consumption values assigned to this part of the elements and / or further elements of the map data have a speed-dependent part for holding a certain speed.

3. The method according to any one of the preceding claims, characterized in that a time-dependent basic energy consumption value is taken into account.

4. The method according to claim 3, characterized in that for taking into account the time-dependent basic energy consumption value at least a part of the elements of the map data, in particular road intersections, traffic light installations and the like, basic energy consumption values and / or typical waiting times from which basic energy consumption values can be derived , assigned.

5. The method according to any one of the preceding claims, characterized in that the energy consumption values to be based on the route determination for each particular element of the map data from this element associated information about typical speed differences and stored consumption shares are determined.

6. Method according to claim 5, characterized in that the energy consumption values to be used as a basis for the route determination are determined for a particular element of the map data from this element associated information about a typical speed and consumption proportions stored therefor.

7. The method according to any one of the preceding claims, characterized in that in the acceleration-dependent portions of the energy consumption values further influencing variables, such as in particular - vehicle-specific influencing variables, in particular the type of vehicle

Drive type, typical energy consumption values, tires, load conditions and attachments and / or

- Outer event-dependent influencing variables, in particular weather conditions and / or messages about traffic-relevant events and / or - driver-specific influences, in particular a driving style of the driver

Be considered.

8. An arrangement for determining an energy consumption optimized route from a start to a destination with a controller for performing the method according to any one of the preceding claims.