DE102006038675A1 - Motor vehicle energy management method, involves assigning consumer to driving situation that is predicted by unit for prediction of motor vehicle, and increasing generator capacity of current generator in case of prediction of situation - Google Patents

Abstract

The method involves providing a motor vehicle with a unit for prediction of a certain driving situation. A consumer is assigned to the driving situation that is predicted by the unit for prediction of the motor vehicle. Generator capacity of a current generator is increased in case of the prediction of the driving situation, which is assigned to the consumer. A certain energy requirement is assigned to the consumer, where the requirement assigned to the situation depends upon a summed requirement of the assigned consumer. An independent claim is also included for a method for minimizing consequences of accident.

Description

The The invention relates to a method for energy management for a motor vehicle with a regulated power generator through which a plurality supplied by consumers.

From the DE 103 41 907 A1 a method for energy management for a motor vehicle is known, which is based essentially on the shutdown of superfluous or not necessarily required consumers. The method also takes into account the predictive control of on-board network components. However, such methods can only provide a satisfactory solution to the energy problem if the prediction reflects actual future supply needs. In addition, the shutdown of consumers reduces their availability.

From the DE 101 45 271 A1 An energy management device for a motor vehicle having a predictor unit for determining a power reserve or overload in an energy network of the vehicle is known. The predictor unit is configured to detect a maximum deliverable power of the generator, an actual power output of the generator, a current to the battery and a voltage of the battery, and the power reserve or overload DP from these inputs and a predetermined value for a generator utilization limit by a particular one To calculate algorithm. Also at the DE 101 45 271 A1 the shutdown of consumers reduces their availability and the quality of the overall process depends on the validity of the prediction.

Around to cover the energy needs of consumers in a motor vehicle, become common Regulated current generators used. To do the fuel consumption and the ejection of Keeping emissions low will become such a regulated electricity generator usually with relatively less Generator power operated. The lower the generator power chosen becomes, the higher is the risk that the vehicle electrical system voltage drops due to excessive energy extraction or Consumers must be shut down.

task The invention is to provide a simple method by which the availability the consumer increases becomes.

Is solved this object by a method having the features of the claim 1. Advantageous embodiments and further developments of the invention will become apparent from the dependent claims.

Especially in dangerous situations exists for the activation of safety devices of the Motor vehicle and for implementation other security measures a high energy requirement. The invention is based on the knowledge that this energy needs are closely related to the current one Driving situation is. To a reliable prediction of the energy demand to ensure hence a prediction the driving situation.

For this must the motor vehicle over Means of prediction certain driving situations. Around on the energy required in the individual driving situations close, are assigned to the driving situations consumers who in this Driving situations are typically activated and / or high Energy requirement to be operated. In the case of the prediction of a driving situation, which at least one such consumer is assigned, then According to the invention, the generator power of the regulated power generator so that increases the energy demand can be covered in the driving situation when they occur.

By the invention can already be increased generator power, before actually an elevated one Energy requirement exists. Delay and / or Start-up times can be effectively compensated.

The actual prediction The driving situation can be different from the state of the art known methods take place.

A essential group of such processes are such processes, which is known for activating passive and active security measures are. These include For example, methods for detecting an imminent impact, to Detecting an impending skidding or tipping of the motor vehicle or for detecting the falling below a safety margin or minimum braking distance. The prediction The driving situation can also be determined by means of, e.g. GPS based and / or by On-board sensor obtained, position and / or speed data of the motor vehicle, in particular if these position and / or Speed data are related to map data, which extended route information such as curve radii, gradient, speed limit etc. included. In extreme cases can then even accidents be foreseen and the energy for the then necessary protective measures be provided on time.

The invention aims particularly at providing the necessary energy supply for safety-relevant vehicle components, in particular consumers, which serve to protect the occupants in extreme situations, eg crash. Of course, the application of the invention is not limited to providing the required power supply for such vehicle components. Other consumers with typically driving situation-dependent (suspension control, active steering, adaptive cornering light) activation can benefit from an improved according to the invention energy management. For example, the prediction can be based on vehicle dynamics data.

Under Use of the invention can be a short-term high energy requirement Consumers by a short-term and thus needs-based increase in the Generator power fulfilled become.

Preferably becomes dependent on the driving situation predicted by the prediction means associated with consumers assigned a specific energy demand. In the case of prediction This driving situation can increase the generator power the regulated power generator then depending on the driving situation assigned energy demand. The energy requirement can be dimensioned in the simplest case according to the number of associated consumers become. Unless the maximum or typical energy needs of each Consumers is known, this can also be based. Preferably, then at least one consumer is a certain Assigned energy demand and assigned to a predictable driving situation Energy requirement depends much of the summed up energy needs of the associated consumers from.

alternative or additionally can in a very analogous way one by the means of prediction prädizierbaren Driving situation dependent assigned by her functions a certain energy needs become. This is particularly advantageous if at least one Function is assigned a specific energy demand and the one prädizierbaren Driving situation associated energy demand significantly from summed Energy requirement of the assigned functions depends.

The invention is particularly suitable for energy management when using a regulated power generator, which is characterized
By a dead time, which typically passes between the receipt of a request signal to increase the generator power and the actual power increase, and / or
- By a minimum dynamics, by which its increase in output per unit of time is limited.

Without the prediction according to the invention the driving situation would be a fast enough increase the generator power due to the typical dead time and / or minimum dynamics a regulated power generator can not be reached. By the invention Affects a possible dead time and / or possibly on it following time more limited Generator power, however, does not diminish or disadvantageous because earlier on an increase the generator power can be worked.

Preferably is in a motor vehicle, which in any case a prediction future driving situations, about the timely activation of pre-crash functions, is performed, no separate prediction for the Purposes of the invention carried out. Instead, in this case, preferably the results of anyway already for other purposes prediction for the Purpose of the invention used. If necessary, these results for the purpose the invention still be adapted or further processed.

Especially Advantageously, the method according to the invention can be used together with at least one active or passive security measure in one Method for reducing the consequences of accidents (pre-crash, pre-safe, pre-brake etc.) are integrated. Preferably, the increase in the Generator power at a very early stage of such a process carried out, sufficient energy supply for all subsequent phases to ensure.

Out The prior art, for example, not the following finally enumerated active or passive security measures known, their requirement respectively an elevated one Energy requirement in a driving situation with increased risk of crash condition can: central locking, ABS, suspension control, sunroof / windows shut down, Longitudinal seat adjustment / seat recliner electromechanical belt tensioner.

According to a preferred embodiment of the present invention, the method according to the invention is carried out depending on the availability of energy from at least one energy store, in particular a vehicle battery. The availability of energy from such an energy storage can then be taken into account in a prediction of the energy requirements. This can be done in particular such that energy that can be removed from the energy storage, at least partially not generated by the power generator. Thus, it can be achieved that the generator power must be increased at a later time and / or to a lesser extent. In certain situations, which would otherwise have caused an increase, generator performance in such an embodiment of the present invention may not even need to be increased at all. Thus, a homogenization of the operation of the power generator can be achieved become.

Around the availability of energy from the energy storage can, for example (if known) the state of charge, the age, the maintenance condition and / or the temperature of the energy store in a prediction of the energy requirements considered become.

The inventive method can also be developed to the effect that in the case of prediction certain driving situations, the generator power especially in terms increased on it will, one under circumstances not completely charged energy storage - as possible before the predicted Driving situation - continue to charge, in particular completely charge. The then available energy in the energy storage can then in If necessary in addition to the energy delivered directly from the generator, released become. Depending on the electrical connection, it can also be favorable if necessary, just the energy available in the energy storage to use. But it can also deliberately a redundancy situation be created because energy the energy storage removable and / or can be generated by the power generator. Especially in accident situations then, for example, the energy storage can still provide energy, if the power generator already damaged or should be separated. The same advantage is reversed.

in the The following will be with reference to the accompanying drawings a preferred embodiment of the invention. This gives more details preferred embodiments and further developments of the invention. It shows

1 the qualitative time course of the power consumption of the consumers of a motor vehicle and the generator power of a regulated current generator according to the prior art,

2 the qualitative time course of the power consumption of the consumers of a motor vehicle and the generator power of a regulated power generator using the invention.

One Motor vehicle has a large number of consumers, at least partly to protect the vehicle occupants in the event of a crash serve.

Consumers can be activated based on the detection of an impending impact. The imminence of the impact is recognized at time t1. At time t2, for the first time, an increase in the current drain from the vehicle electrical system can be measured by activating the first consumer to protect the vehicle occupants. At time t3, a maximum of the summed power consumption of the consumers is achieved. Curve 1 in 1 shows the qualitative time course of the summated electricity consumption of the consumers.

First, will in the motor vehicle of an energy management according to the state the technique went out. Accordingly, only at the time t2, to which by the activation of the first consumer an increased current drain the on-board network is detected, a request signal to increase the Generator power sent to the power generator.

Curve 2 in 1 shows the qualitative time course of the generator power of the power generator. This increases despite the receipt of the request signal at time t2 only after a dead time T_t (eg 5 ms) its generator power. In addition, the generator power only increases with a minimum dynamic range (eg 300 A / s). Corresponding to this minimum dynamics has the curve 2 for t> t2 a limited slope.

in the Result, the generator power has only increased significantly if the bulk the energy needs of consumers have already been incurred. This can therefore not be covered by the generator, but must by an energy store, for example by a corresponding dimensioned backup battery to be covered. A high capacity Buffer battery, however, brings unwanted weight into the vehicle, binds space and is associated with high costs. In the worst case Case, the backup battery is too small and the on-board voltage falls off and / or consumers can not be activated as desired. The same case may occur if the battery is insufficient loaded, aged and / or not sufficiently maintained.

2 On the other hand, in the case of the detection of an imminent impact occurring at time t1, the advantages of the invention are shown. Curve 1 again shows the qualitative time course of the summated electricity consumption of consumers. This time course corresponds to that from 1 ,

Now However, finds an inventive energy management Application. The result of the impact prediction becomes the time t1 also reported to an arithmetic unit controlling the power generator. The result of impact prediction also includes the expected time of impact.

The arithmetic unit then takes a look-up table, which is stored in a memory unit accessible to the arithmetic unit, the information which consumers in the case of the driving situation "imminent impact" to which relative time (based on the time of impact) akti fourth and what energy needs these consumers have. From this, the arithmetic unit calculates an estimated time course of the current consumption. This one is in 2 as a curve 3 (dashed) shown.

Of the Regulated power generator is based on this power consumption prediction so controlled that the generator power - if dynamically possible - always bigger or equal to the predicated Current consumption of the consumer is. Should this not be possible, The generator power is as fast as possible with maximum slew rate up to the maximum possible Generator power increased.

in the In the present case, the generator power despite existing dead time T_t and limited slew rate increased so timely that even at time t3, in which a maximum of the summed up power consumption the consumer is reached, the generator power greater than is the power taken by current consumption of the consumer. The energy demand of the consumers can thus be fully realized be covered by the generator.

Instead of the model based dose increase of the above described Generator power, the generator power can also easily after the detection of the imminence of an impact as soon as possible with maximum slew rate can be increased up to the maximum possible generator power. Also conceivable is an orientation exclusively on the prospective maximum current consumption of consumers.

It can also use the capacity and / or the state of charge of existing in the motor vehicle energy storage considered which, if appropriate, correspondingly lower requirements to the generator power.

Claims (9)

Method for energy management for a motor vehicle with a regulated power generator, which is supplied by a plurality of consumers, characterized in that the motor vehicle has means for predicting certain driving situations, that at least one predictable by the prediction means driving situation is assigned at least one consumer and in the case of the prediction of a driving situation to which at least one consumer is assigned, the generator power of the regulated power generator is increased. Method according to claim 1, characterized in that that at least one predictable Driving situation dependent assigned by it a specific energy demand will and that in case of prediction of this driving situation the increase the generator power of the regulated power generator depending on the energy requirement assigned to the driving situation takes place. Method according to claim 2, characterized in that that at least one consumer assigned a specific energy needs and that of a predictable Driving situation associated energy demand significantly from summed Energy requirement of the associated consumer depends. Method according to one of claims 1 to 3, characterized that the temporal response of the regulated power generator a Has dead time. Method according to one of claims 1 to 4, characterized that the temporal response of the regulated power generator has a minimum dynamics. Method according to one of claims 1 to 5, characterized that the means of prediction an essentially independent of the energy management vehicle function which results of the prediction for the method of energy management to be provided. Method according to one of claims 1 to 6, characterized that the increase the generator power in dependent from the availability of Energy from at least one of the motor vehicle associated energy storage is made. Method according to one of claims 1 to 7, characterized that in the case of prediction a driving situation, which at least one consumer assigned is, a motor vehicle associated energy storage further charged becomes. Method for reducing accident consequences, thereby characterized in that as part of the method for reducing accident consequences A method for energy management according to one of claims 1 to 8 performed becomes.