DE10205039A1 - Determining intended load defined by driver and passed to vehicle drive unit, involves automatically taking into account certain boundary conditions, e.g. friction between road, wheels - Google Patents

Abstract

The method involves describing the relationship between a demanded load generator (gas pedal) deflection and a signal passed to the drive unit using different characteristics for different situation-dependent boundary conditions. At least one of the following boundary conditions is automatically taken into account; friction between road and vehicle wheels, off-road conditions, surrounding traffic, parking environment, traffic boundary conditions. AN Independent claim is also included for the following: an arrangement for implementing the inventive method.

Description

The invention relates to a method for determining a driver 's Motor vehicle by means of a load request transmitter, in particular one Accelerator pedal, predefined and suitably prepared for a vehicle Drive unit forwarded load request, the preparation of the Load request signal taking into account situational boundary conditions he follows. In particular, the relationship between a Load request transmitter deflection and that to the drive unit Transmitted load request signal can be described by a characteristic, where different characteristics for different situational boundary conditions can be provided.

In motor vehicles, the driver usually gives an accelerator pedal (also Called accelerator pedal) the specifications for the longitudinal guidance of the vehicle with regard to acceleration or deceleration (by the drag torque or Braking torque of the vehicle drive unit), as far as this by the Vehicle drivetrain can be represented before. This is typically the accelerator pedal travel or angle in the range of 0-100% using a suitable shaped characteristic curve into a driver's desired torque standardized to 0-100% Drive unit implemented. If this is for example a quantity-controlled internal combustion engine, so is the driver's desired torque by a standardized throttle valve angle or a standardized Filling value of the engine cylinder represents.

That is about the shape or the course of the characteristic Response behavior of the drive unit depends on the driver specification defined, wherein different characteristic curves can be provided that lead to a different response. For example, in the DE 199 51 119 A1 describes a method and a device for controlling a Proposed vehicle in which the driver specified Load request recorded and into a Control variable (for the vehicle drive unit) is implemented, and the named assignment by the driver through an adjustment mechanism can be changed. For example. can thus be selected a characteristic curve or the like be that by spontaneous response of the drive unit and thus distinguishes a corresponding agility of the vehicle, while a another characteristic curve or the like. good load dosing and little nervousness (with regard to deflection movements of the load request encoder).

The characteristics mentioned, which are generalized as signal processing modes Depending on the vehicle, these days are either fixed defined (either mechanically or electronically) or by means of Driver-operated switch switchable, or also Depending on driving speed and / or depending on the current Gear ratio of a gearbox provided in the vehicle drive train Defined depending on the gear to make the driver behave favorably to grant from the respective load state.

In the design of the characteristic curves (or generally the so-called signal Preparation modes according to which the load request signal is converted or prepared before it is sent to the vehicle drive unit) there is generally a conflict of goals between the desire for vehicle agility on the one hand and good dosing, driving comfort and fuel economy Driving operation on the other hand. A sporty, agile response to the Drive unit contradicts, for example, good meterability in the Parking operation and also leads to a nervous response in the Column traffic, to name just a few of the problem areas at hand.

The basically known speed-dependent characteristic curve selection already brings advantages here, but it is assumed that the vehicle Speed alone is significant in terms of Adaptation requests from the driver. However, this is not the case, for example for one dynamic traffic light start from the vehicle standstill a strong progressive, dynamic-agile characteristic would be desired, while the Parking or when maneuvering the vehicle out of a parking space also from the vehicle standstill or for the so-called Creeping a "gentle", easily metered characteristic appears desirable.

In this context, there is already a known state of the Technology, for example by DE 197 51 306 A1. According to this script, a So-called area feature for a certain area in which a vehicle drives, proven, and so-called vehicle driving force characteristics, such as the increase in throttle valve of an electronically controlled Throttle valve, modified according to the area characteristic.

The possible selection of different signal processing modes e.g. with regard to different areas is already an improvement compared to the state of the art implemented in practice today, however further improvements of the known prior art are possible, to demonstrate the task of the present invention.

• 1. der Schaltzustand eines im Antriebsstrang des Fahrzeugs vorgesehenen Drehmoment-Wandlers und/oder
• 2. der Reibwert zwischen der Fahrbahn und den Fahrzeug-Rädern und/oder
• 3. das Vorliegen von Offroadbedingungen (insbesondere unter Berücksichtigung von Längs- und Querneigungssensoren und/oder Aufbau-Beschleunigungssensoren) und/oder
• 4. der umgebende Verkehr und/oder
• 5. das Parkierumfeld und/oder
• 6. Verkehrsrandbedingungen, wie bspw. Verkehrzeichen oder eine Ampelschaltung.

For a method according to the preamble of claim 1, according to which different characteristic curves are provided for different boundary conditions, the solution to this problem is characterized in that at least one of the following boundary conditions is automatically taken into account:

• 1. the switching state of a torque converter provided in the drive train of the vehicle and / or
• 2. the coefficient of friction between the road and the vehicle wheels and / or
• 3. the existence of off-road conditions (especially taking longitudinal and bank sensors and / or body acceleration sensors into account) and / or
• 4. the surrounding traffic and / or
• 5. the parking area and / or
• 6. Traffic boundary conditions, such as traffic signs or traffic lights.

• 1. die Sichtverhältnisse für den Fahrer und/oder
• 2. der Verlauf der Fahrbahn, wobei dies in der Horizontalen und/oder unter Berücksichtigung eines Vertikal-Anteils möglich ist, und/oder
• 3. der aktuelle Fahrbahntyp.

For a method according to the preamble of claim 2, according to which different boundary conditions are taken into account in the signal conditioning - regardless of whether these are characteristic curves, the solution to this problem is characterized in that at least one of the following boundary conditions is automatically taken into account:

• 1. the visibility for the driver and / or
• 2. the course of the carriageway, this being possible horizontally and / or taking into account a vertical component, and / or
• 3. the current type of road.

In general terms, the present invention is based on the knowledge that the driver of a vehicle ideally has a response to the vehicle (or the vehicle drive unit) that is suitable for the respective driving situation and thus a situation-dependent interpretation of his accelerator pedal specifications or his load request "expressed" on the load request transmitter expected. Different driving situations can now be characterized, among other things, by the following features listed in a table, with possible sensing options, by means of which the respective driving situation can be identified, being indicated at the same time:

Basically, this table shows that by means of additional sensors and other sources of information, some of which are already available to drivers Assistance systems (such as the automatic speed control while maintaining a safety distance from the vehicle in front Vehicle) and for security systems in motor vehicles find or will find more and more use in the future, more and more Potential for a more specific and therefore more informative driving situation Detection is given. It is about the current state of the art possible, especially the so-called pedal interpretation characteristics according to the available sensors to design driving situation-specific, without a detailed specification by the driver, d. H. automatically.

It should be noted that some of the above specified boundary conditions or characteristics are already taken into account today, but mostly not in a different characteristic between one Load request transmitter actuation and the load request signal legendary way. As explained at the beginning, so far only the Driving speed and the so-called "powertrain condition", d. H. the Switching state of a provided in the drive train of the vehicle Torque converter takes into account that different Values for this different "pedal characteristics" or the like are assigned. All other boundary conditions mentioned in the table above are so far either not at all or only in the form of special regulatory interventions is taken into account without different characteristics between a pedal Deflection and the transmitted to the drive unit Load request signal to be used as a basis.

For example, the coefficient of friction between the Lane and the vehicle wheels are taken into account if a so-called drive Slip control system is active, however, then only the output power of the drive unit withdrawn without having a characteristic writable relationship between the load request transmitter deflection and the load request signal transmitted to the drive unit in Direction is changed to another characteristic. According to the invention or should the latter be done now.

For example, the distance to one has already been so far vehicle in front is taken into account if the vehicle has a automatic speed control in compliance with a Safety distance to the vehicle in front is equipped, however, then also only the output power of the drive unit withdrawn without the relationship that can be described via a characteristic curve between the load request transmitter deflection and that to the Drive unit transmitted load request signal in the direction of another characteristic will be changed. According to the invention, the latter can or should now be done.

I.e. with the effect of a changed pedal characteristic or the like or according to the invention, the traffic environment should now be taken into account. In addition to taking into account the traffic density in general, this Also sense individual vehicles moving ahead or in a lane be taken into account. Furthermore, in the same way Speed restrictions or other traffic regulating traffic signs are taken into account, such as traffic lights. Furthermore, on Parking processes, d. H. parking or parking the vehicle be reacted, preferably in such a way that then automatically an easily metered pedal characteristic curve or the like is selected.

Also with the effect of a changed pedal characteristic or the like. can or should be taken into account that or when the vehicle is on extreme road conditions, possibly even moving off-road, which basically based on the accelerations of the vehicle structure (both in Longitudinal direction and in particular in the vehicle transverse direction) but also can be determined by means of inclination sensors.

In connection with the load request transfer to the vehicle Drive unit have not yet been considered at all various boundary conditions, which are defined in independent claim 2 are listed, and which - according to the invention - to support the Driver with regard to his expectation, on a load request specification to receive a situation-specific reaction of the vehicle drive unit, in the preparation or transmission of the load request signal Can be taken into account.

This includes taking into account the current visibility for the driver in particular the type and design of the road on which the vehicle is being moved. For example, for the first criterion Night and / or fog a less dynamic response of the vehicle. Drive unit on load request increases can be selected as if the vehicle is moved during the day with clear visibility. But also the fact whether the vehicle is on a freeway or a mountain Pass route is moved, leaves a different signal processing appear recommendable. Not only a pedal characteristic curve can be used here be changed as such, but it can change the transmission behavior fundamentally changed. This is only for the sake of example Limitation to a maximum vehicle speed called.

As far as considering the type of lane is concerned, not only can be considered whether it is a running in the plane Lane or an incline or slope, but it can also find entrance whether the road is winding or winding runs straight. All of this is not only by means of suitable ones Sensors, but also by means of a known Navigation system ascertainable.

The following are just a few more examples and themselves resulting advantages for / in a (r) implementation of the invention Called procedure. So a high dynamic response when starting off be selected from a standing position, but only if there is no parking situation is present if the own lane is clear and / or if none Low friction coefficient relationships between the road and the vehicle wheels available. On the other hand, a gentle response of the vehicle Drive unit when parking the vehicle, when starting on the mountain or slope, when there is low friction and / or when there is a traffic jam Column driving can be selected. A gentle response from the accelerator pedal is also recommended in pure residential areas, in Tempo 30 zones etc., while a dynamic response when driving on the open road and is advantageous in overtaking situations. This dynamic Responsiveness can then be reduced again if Low friction conditions exist, as well as in poor visibility, when the lane is occupied, d. H. high traffic density resulting from a plurality of vehicles driving ahead Vehicles results.

In relation to the case that the relationship between a deflection of the load request transmitter / accelerator pedal and the load request signal transmitted to the vehicle drive unit can be described by a characteristic curve which in no way has to be linear, then - in general terms - certain driving Situations (S ₁ -S _n ) are each assigned optimized characteristic curves (K ₁ -K _n ). The driver can thus experience intelligent behavior of his vehicle adapted to the situation, in particular the conflict of objectives "agility versus comfort and meterability" can be effectively resolved.

In order to ensure functional transparency for the driver, the Within the framework of an advantageous development of the invention, the current one Signal processing mode, according to which the signal processing between the load request generator and the vehicle drive unit are carried out (e.g. the current characteristic curve from the scope of the fundamentally possible Characteristic curves or signal processing modes in general) to the driver, for example. be identified by the scope of the advertisement. For example. can the driver be appropriately informed that a so-called parking mode is currently active, or that a so-called city traffic mode is active after leaving the parking space or that when driving on the highway is a so-called highway mode is active. If only between a few, very elementary ones Situations (e.g. driving and parking) that can be changed for the driver clearly or in connection with others Assistance functions (e.g. activated parking aid) can be assigned independent identification not necessary.

If an adaptation or situation-specific or boundary condition-specific signal processing is to be carried out with regard to a large number of different driving situations or boundary conditions, it may be advisable for this so-called situation adaptation to be carried out smoothly to avoid discontinuities and a sudden change in the so-called pedal characteristics (or the like.) To avoid. A preferred approach for this is to continuously calculate situation probabilities (p ₁ -p _n ) (for example from 0-100% in each case) for all possible situations, which are a measure of which situation currently exists. A currently applicable characteristic curve can then, for. B. can be determined by weighted mean values of the characteristic curves. The transition between the individual situations can depend on the type of situation change via a dynamic link, e.g. B. a filter element with an adjustable time constant so that the driver is not surprised by the change in characteristics and can adapt intuitively to the new conditions. This is particularly the case when e.g. B. Changes in the characteristic curve with an accelerator pedal held constant would lead to an acceleration of the vehicle. Slow dynamics are to be used to ensure that the additional control task that results for the driver is lost as part of the fine adjustment by the driver, which is always necessary anyway.

In addition to the described change in the accelerator pedal characteristics the further possibility explained below, the basic type of Change accelerator pedal interpretation depending on the situation. Today results namely via the so-called pedal characteristic and the ultimately resulting Torque requirement of the driver dependent on the vehicle drive unit the powertrain condition of the vehicle and the current one Driving resistance indirectly a certain, but from these boundary conditions dependent vehicle response. Examples include: slope-dependent behavior of a vehicle with an automatic transmission.

Based on a control function associated with the accelerator pedal angle, e.g. B. as Part of a longitudinal dynamic management, however, can now Pedal value specification assigned a clear reaction of the vehicle be, e.g. B. a driving speed depending on the pedal angle or an acceleration and / or deceleration depending on the pedal angle. Including the vehicle's service brake system, the effective range that can be reached with the accelerator pedal is expanded. Are basically such approaches are known, the transition in accordance with the invention such signal conditioning modes and the associated selection in each case applicable characteristics or the like (e.g. speed or Acceleration is a function of the angle of the accelerator pedal or Load requestor) using the ones suggested above Situation recognition can be done based on the driving situation.

The direct specification of a Parking speed preferred regardless of incline in parking situations including one Holding the vehicle when the accelerator pedal is released. On Another example is the so-called "braking accelerator pedal", with a Acceleration proportional to pedal value with zero offset also one Deceleration function of the vehicle by releasing the pedal as a function in an independently recognized "jam-creep mode" can be implemented. The driver is spared this, permanent in traffic jam column traffic back and forth between the accelerator or accelerator pedal and a brake pedal herzuwechseln.

Basically, the present invention enables the resolution of Conflicts of goals between the agility of a motor vehicle and comfort or the operability with regard to that by means of a load request transmitter generated and processed as a suitable signal to the vehicle Drive unit transmitted load request of the vehicle driver. It follows directly an increase in driver sovereignty Vehicle guidance. Furthermore, the present invention enables this to be illustrated Additional functionalities in a cost-effective way in the growing environment Driver assistance functions and their sensors as well as on the basis of a powerful longitudinal dynamics management. A can inventive method in a manner known to those skilled in the electronic Control units are implemented, specifically for such Devices for performing a method according to the invention Protection is claimed. Finally, it should be noted that quite a lot of details also differ from the above Explanations can be designed without leaving the content of the claims.

Claims (5)

1. A method for determining the load request specified by the driver of a motor vehicle by means of a load request transmitter, in particular an accelerator pedal, and suitably processed and forwarded to a vehicle drive unit, the relationship between the load request transmitter deflection and the load request transmitter signal transmitted to the drive unit being described by a characteristic curve can be and are intended for different situational boundary conditions different characteristics, characterized in that automatically at least one of the following constraints into account:
Coefficient of friction between the road and the vehicle wheels
Off-road conditions (especially taking longitudinal and bank sensors and / or body acceleration sensors into account)
surrounding traffic
Parkierumfeld
Traffic boundary conditions (such as traffic signs or traffic lights). 2. Method for determining the load request specified by the driver of a motor vehicle by means of a load request transmitter, in particular an accelerator pedal, and suitably processed and forwarded to a vehicle drive unit, the load request transmitter signal being processed taking into account situational boundary conditions, in particular according to the preamble of claim 1 , characterized in that at least one of the following boundary conditions is automatically taken into account:
Visibility for the driver
Course of the road (in the horizontal and / or taking into account a vertical part)
Road type. 3. The method according to claim 1 or 2, characterized in that the load request signal at least under certain boundary conditions or in certain Driving situations of a specification of a specific vehicle speed or a positive and / or negative acceleration of the Corresponds to the vehicle. 4. The method according to any one of the preceding claims, characterized in that the respective Signal conditioning mode is made known to the driver of the vehicle. 5. Device for performing the method according to one of the previous claims.