DE102008039950A1 - Method for determining driving profile for road motor vehicles, involves inputting driving goal or defining trip route for trip with road motor vehicle - Google Patents

Abstract

The method involves inputting a driving goal or defining a trip route for a trip with a road motor vehicle. The method involves determining a speed profile along a part of a determined trip route, where the computation of this speed profile takes place with consideration of a topology of the trip route. Independent claims are included for the following: (1) a method for determining driving profile for road motor vehicles; and (2) a road motor vehicle.

Description

The The present invention relates to a method for determining a driving profile for Road motor vehicles. In the prior art motor vehicles are known which control devices exhibit to without actuation an accelerator pedal driving at a certain driving speed to enable. Such methods are sometimes referred to as cruise control. The driver specifies a desired speed, and the vehicle holds, as long as not, for example, the brake pedal is pressed, this speed. However, this is designed for this reference speed Driving style is not always economical. So it is possible that the vehicle on climbs the speed only under very high energy consumption and at gradients even use the engine brake to keep the speed.

Of the The present invention is therefore based on the object such To improve cruise control. Specifically, an operating point of a corresponding cruise control can be improved. This is inventively a method according to claim 1 achieved. Advantageous embodiments and variants are the subject of the dependent claims. The present invention is described with reference to commercial vehicles and especially trucks It should be noted, however, that the invention also applies to others Road motor vehicles Application can be found.

at a method according to the invention for determining a driving profile for road vehicles is first a Destination for a ride on the road vehicle entered and / or the most probable route determined. Subsequently, will determines a geographical position of the road vehicle, and determines a travel route for reaching the destination. According to the invention is a Velocity profile along at least part of the determined Driving route determined, wherein the calculation of this speed profile considering a topology of the route takes place. Instead of or next to a speed profile could also an acceleration profile for the vehicle can be determined.

In order to it is possible according to the invention, at a certain reference speed, including, for example, gradients and Gradients, also to consider curves along a particular route. In order to can be with the help of the method of the invention areas of Identify the route in which the driver set Operating point of the cruise control can affect such that a Consumption optimization takes place by avoiding braking and the push operation can be systematically expanded. To this Way forward driving can be imitated as the speed can be adjusted before inclines and crests.

Therefore, according to the invention proposed to consider the route topology in advance and also to determine the position of the vehicle. Based on this Data becomes explicitly a velocity trajectory using the method and possibly also a Sollabstandstrajektorie on the guideway to which the vehicle follows, calculated. In particular, for the determination of the velocity profile Gradient information used along the route. Preferably In this case, a calculation of the velocity profile takes place only along a part of the route, for example, in a horizon of a few hundred meters or, for example, four or five kilometers in front of the vehicle.

Preferably is a drive device for the road car considering controlled by the speed profile. It is possible that from the driver a reference speed is given and adjusted the exact vehicle speed based on the calculated speed profile becomes.

Preferably become properties when calculating the velocity profile considered a drive device of the road vehicle. In particular, an acceleration potential of the vehicle taken into account. The vehicle can control both by means of conventional speed controller or predictive Perform cruise control, the latter both the engine operation and the braking operation regulate. It is preferred to determine a position of the motor vehicle GPS positioning method used.

at Another preferred method is a travel speed of the road car taking into account the route controlled by the speed profile. More specifically, how will mentioned above, specified by the driver of the vehicle, a reference speed and the exact vehicle speed becomes dependent from the general conditions such as the route profile and also the acceleration potential of the vehicle.

Preferably are used in controlling the travel speed limits for this Driving speed set, and the speed of travel in the Controlled under these limits. So it is possible, for example, that the driver sets a reference speed and the controller an upper and a lower limit for the actual speed of the Vehicle determined. It may be at the upper limit speed especially at a legal maximum speed, which may still be reduced to the maximum in curves, this means harmless Speed is. In a curve or curvature of the road may this speed was not exceeded become. Also the bends the curve can be determined from the topology of the route. Under the Topology of the route will therefore be all route conditions the route understood, in particular slopes, slopes, bends, however, if necessary, statutory speed limits and the like. In addition, you can However, other conditions are taken into account, such as overtaking bans, Priority regulations and the like.

at the lower limit speed is preferably the other road users minimum reasonable speed in a certain place of the street.

In order to generates the procedure over the driving distance is a speed trajectory of the vehicle follows. For This method is preferably the longitudinal dynamics of the vehicle over Model described. This model can be of any type Type and only the dynamic behavior of the vehicle when using the accelerator pedal, even with an accelerator pedal = 0 position, in a specific topology, preferably also considered the free roles becomes.

As As stated above, in a preferred method, a reference speed specified. This reference speed is in particular around the desired speed given by the driver.

The above-mentioned longitudinal dynamics can be described for example by the acceleration of the vehicle with the following formula:

Where u _{e is} the accelerator pedal and α is the pitch angle of the track at the current position. The character i _total identifies the entire transmission ratio and M _{e, ref} the motor torque. The reference symbol r _w denotes the wheel ratio and the reference symbol m _red the reduced vehicle mass. Overall, the acceleration is composed here of three components, which contains the rolling resistance, the air resistance, the gear ratio, the drive torque and a corrected to the rotational inertia of components total vehicle mass. Further detailing of the model is possible as long as the necessary quality of the vehicle dynamics can be represented in this way. It is further assumed that any necessary deceleration can be adjusted via the brakes in order to keep the vehicle at the desired speed even at an arbitrary gradient. However, it would also be possible to model the braking behavior in the model by equations.

Of the Driver activates the function at a speed v, which then the desired by the driver Reference speed is. This speed can then be from an algorithm can be changed within certain limits, these limits be set by the upper and lower limit speed. The boundaries up and down are not necessarily constant, but you can location-dependent be or be based on traffic, such as one legal maximum speed, a speed and a distance of a preceding vehicle, the flow of traffic, a maximum speed in turns, one minimum speed for certain street class etc. When correcting the speed, the occurring Acceleration in dependence limited to their sign become. The acceleration limit is in certain areas limited, and between the areas through different strategies depending on the situation variable.

In order to is preferably at least temporarily an acceleration of the vehicle limited. So it is possible, for example, on downhill this Limit the acceleration of the vehicle, thus the upper limit the speed is not reached or exceeded.

Preferably, at least one case distinction is made to determine the velocity profile. Thus, preferably the velocity trajectory is generated in which at a distance of x meters the Driving distance with its parameters with the slope, curves, maximum speed limits, etc. different case distinctions, in particular with respect to the acceleration capacity of the vehicle model is subjected. Different cases can be distinguished.

The Number of these case distinctions is arbitrary, and below should a possible Set of case distinctions. This sentence represents but prefers a base set of case distinctions. First of all the case occur that at the current speed and the given pitch angle α maximum possible Acceleration by specifying a specific accelerator pedal position (eg accelerator pedal = 100%, whereby this value can be parameterized) becomes.

there the case may occur that the achievable acceleration of the Vehicle is no longer positive, that means the vehicle is no longer accelerated. In this case, the speed and / or the gear be adjusted so that a positive acceleration is possible again, this means, the target speed is lowered, or the gear is reduced or both. The decision as to what will ultimately be done is again implementation-dependent and may depend on further criteria.

It is possible, that the achievable acceleration is 0 or positive. In this Trap is thus an acceleration of the vehicle possible, and is operated up to a speed, the driving desire speed equal or a value between the current speed and the driver's desire speed is, and no acceleration more possible.

Farther the case is conceivable that with an accelerator pedal position of 0% for the current Speed a positive acceleration is possible (eg in a gradient) and the current speed below the current limit speed lies. In this case it is possible to stop the injection, and the vehicle by the downhill force to accelerate to the maximum achievable speed, however maximum up to the upper limit speed or an upper speed threshold.

If No more positive acceleration is possible by rolling out without brake application, the vehicle back to the driver's desired speed delayed become. The injection is only allowed again when through Coasting without braking intervention reaches the driver's desired speed was, or possibly shortly before. If the driver's request speed the upper limit speed, it is possible to Use brakes only when a speed of x km / h above the upper limit speed was reached.

In all other cases Is it possible, to drive the driver's request speed, provided that traffic allows. However, this case can also be split into any number of sub-cases become.

Prefers is also an acceleration of the vehicle depending an accelerator pedal position and depending on the topography calculated. It is possible a possible Acceleration for the Distance from x meters in front of the vehicle to calculate. It can be advantageous for certain topological transitions the acceleration potential additionally x meters in front of the vehicle to capture and react proactively.

This Horizon x is a free parameter of the algorithm. The horizon can be calculated online and can be different parameters, such as B. the vehicle mass, the available maximum engine torque depend on Here, for example, the case of a transition from a flat terrain to occur in a slope. In this case it is possible that Vehicle to the maximum allowed Speed, d. H. the upper limit speed before the slope to accelerate, thus increasing the slope with the minimum number Circuits and the least possible Speed loss can be overrun.

This happens when the current speed in the horizon x can no longer be kept. When doing this with the acceleration can start over again Model equations of the vehicle calculated or over a any other criteria can be set. This will be here preferably the possible Acceleration of the vehicle in a spaced from the distance Calculated area of the route.

Again, in the transition from a downhill to a flat terrain, it may be advantageous to maximize the taxiway to achieve the driver's desired speed. This is accelerated in the downhill to the limit speed, and out in flat terrain to the driver's request speed rolls. In a transition from a slope to a slope over a dome, it may be advantageous to roll out already in front of the dome when the slope behind the dome is steep and long enough to at least accelerate back to the driver's desire speed.

About the Vehicle model becomes the transition to the slope / slope scored, and the speed then z meter before the dome around reduce the amount y km / h by coasting, if it is possible to accelerate the vehicle at least to the driver's desired speed. If possible too is to accelerate the vehicle back to the upper limit speed, the speed in front of the dome can be reduced even further.

in the Case of a transition from a gradient in a slope over a sink may again be beneficial to the upper limit speed in the fall to accelerate, and keep this as long as possible in the slope. This is especially true when there are slope sections that only allow a speed below the driver's desired speed.

In Another preferred method is the velocity profile dependent on determined distances determined to other vehicles. In particular, if an ACC sensor is available, is the distance and the speed to the vehicle in front driving known. With this information, also the push operating phases can be extend. Again, you can several cases be differentiated.

in the Trap of a transition from a gradient In a level, for example, on the downhill, a passing recommendation issued when the vehicle in front is slower than the upper one Border speed, and overtaking permissible is.

If you do not overtake may, it may be advantageous at the beginning of the gradient one To increase the distance to the vehicle in front by the speed by rolling out and, if this is not possible, by braking intervention be lowered. Thus, at the end of the gradient, the distance to the vehicle in front Vehicle big enough, at the end of the gap starting from the upper limit speed (acceleration through Slope and downforce) one as possible long taxiway until reaching the driver's desired speed to enable.

at a transition from a gradient in the slope, can a passing recommendation output when the preceding vehicle is slower as the upper limit speed, and overtaking is allowed.

If you do not overtake may, it may be advantageous at the beginning of the gradient one To increase the distance to the vehicle in front by the speed by rolling out and, if this is not possible, by braking intervention be lowered. Thus, at the end of the gradient, the distance to the vehicle in front Vehicle big enough, at the end of the gap the upper limit speed (acceleration by slope and downforce) to reach and this as possible long to keep without being too close to the vehicle ahead aufzufahren.

at a transition from a slope to a slope over one Dump it may be advantageous by rolling out the speed to reduce and thus the distance to the vehicle in front to enlarge, with it in the following gradient preferably can be driven long in overrun, without the minimum distance to fall below the vehicle in front. The speed reduction in front of the dome can be doing to the case described above without distinguish a preceding vehicle, that is both the amount after and after the beginning of the reduction or time or place.

at a transition to a flat terrain in a slope it is possible to follow the vehicle in front, or the driver a passing recommendation to issue, if permissible and possible, this means, if the vehicle ahead is slower than the upper limit speed.

The However, the present invention can also be applied to vehicles without a ACC or radar sensor can be used. If not a distance meter for the Measurement of distance and speed by the preceding vehicle Traffic is blocked, it can be useful be the driver's desire speed as the maximum speed threshold, this means, to consider the upper limit speed, otherwise the procedure notoriously lower than the minimum distance to the preceding traffic can. In a further preferred method, a short-term increase in the Limit speed allowed.

This is relevant, for example, in a transition from one gradient to another Slope over a sink or even in the case of a transition from a gradient into a flat terrain. Here it is possible the upper limit speed by a certain difference without To exceed the brake intervention and this for a maximum time t_max. Such a procedure leads in particular in the case of application to a commercial vehicle to any entries in the tachometer digital driver card if t_max is below the legal limit tolerated time of, for example, one minute remains.

The The present invention is further directed to an apparatus for detection a driving profile for Road vehicles directed. This device has an input unit via which a destination for the motor vehicle is input and a position determining unit, which a position of the road vehicle determined and a memory device in which data is stored, which for a topology of a route between the position of the road vehicle and the destination are characteristic.

According to the invention the device has a processor device that configures in this way is that they have a velocity profile along at least one Part of the determined journey route is calculated, taking the calculation this speed profile considering the topology the route is taken. This is also suggested here that the desired speed given by a driver under consideration this speed profile is varied. This is preferred the processor and / or evaluation designed such that the speed profile taking into account properties a drive device of the motor vehicle is determined in the Model calculation considered is and if necessary transferred to a vehicle management computer becomes. In addition, you can also like mentioned above - more restrictions considered be like an air resistance and a rolling resistance of the vehicle.

The The present invention is further directed to a road vehicle having a directed device described above, which is a control device which has a drive device of the road vehicle dependent on of properties of the drive device controls.

Further Advantages and embodiments emerge from the attached Drawing. Showing:

1 a block diagram of a device according to the invention.

1 shows a highly simplified block diagram of a device according to the invention 1 , This device has a processor device 10 on, which on the basis of a selected by the driver reference speed v_ref drive means 8th the vehicle, if necessary. Also braking devices of the vehicle controls. More specifically, acceleration values a determined by the processor device are preferably sent to the drive device 8th output. In this case, the user via an input device 2 specify the reference velocity v_ref.

The reference number 4 refers to a position determination unit, such as a GPS receiver, which determines the position of the vehicle. This position determination unit also has a memory device 14 in which a map system including topological data for a plurality of routes is stored. The reference number 12 refers to a further input unit, by means of which the Positionsbe voting unit a destination can be specified. On the basis of this travel destination and the current position of the vehicle, the vehicle determines a route for the vehicle and topological values for this route.

These topological values are also sent to the processor device 10 and determines based on these topographic values, a speed or acceleration profile for the vehicle. The reference number 6 refers to a distance determination device with which a distance d to other, in particular preceding vehicles can be determined. These distance data d are also sent to the processor device 10 issued.

In addition, the drive device also outputs engine data D_Mot as well as an instantaneous speed v_act. However, the motor data can also be stored in a memory device of the processor device 10 be filed.

All Features disclosed in the application documents are considered to be essential to the invention as long as they are individually or in combination with respect to State of the art are new.

1

contraption

2

input device

6

Distance determiner

8th

driving means

10

processor means

12

input unit

14

memory device

d

distance data

a

acceleration values

v_ref

reference speed

v_ist

current speed

Top

topological values

D_Mot

engine data

Claims (12)

A method of determining a driving profile for road vehicles, comprising the steps of: - inputting a travel destination and / or defining a route for driving on the road vehicle; - determining a geographical position of the road vehicle; - Determination of a route to reach the destination; characterized in that a speed profile along at least part of the determined route is determined, wherein the calculation of this speed profile takes place taking into account a topology of the route. Method according to claim 1, characterized in that that a drive device for the road car considering the speed profile is controlled. Method according to at least one of the preceding claims, characterized in that in the calculation of the velocity profile characteristics of a drive device ( 8th ) of the road vehicle. Method according to at least one of the preceding Claims, characterized in that a traveling speed of the road vehicle taking into account the route the speed profile is controlled. Method according to at least one of the preceding Claims, characterized in that in the control of the driving speed Limits for This driving speed can be set, and the driving speed controlled within these limits. Method according to at least one of the preceding Claims, characterized in that for determining the velocity profile at least one case distinction is made. Method according to at least one of the preceding Claims, characterized in that a reference speed (v_ref) is given. Method according to at least one of the preceding Claims, characterized in that an acceleration of the vehicle dependent on a signal of a vehicle management computer and / or an accelerator pedal position and depending on the topology is calculated. Method according to at least one of the preceding Claims, characterized in that the velocity profile in dependence determined distances determined to other vehicles. Device for determining a driving profile for road vehicles with an input unit ( 12 ), via which a destination for the motor vehicle can be entered and a position determination unit ( 4 ), which determines a position of the road vehicle and a storage device ( 12 ) storing data indicative of a topology of a route between the position of the road vehicle and the destination; characterized in that the device comprises a processor device ( 10 ) configured to provide a velocity profile along at least one part calculated the calculated route, wherein the calculation of this speed profile takes place taking into account the topology of the route. Device according to claim 10, characterized in that the device ( 1 ) a distance determination device ( 6 ), which determines a distance (d) to other vehicles. Road vehicle with a device ( 1 ) according to claim 10 and a control device which controls a drive device of the road vehicle in dependence on characteristics of this drive device.