EP1721071A1

EP1721071A1 - Method and arrangement for controlling a motor of a vehicle

Info

Publication number: EP1721071A1
Application number: EP05715524A
Authority: EP
Inventors: Steffen Jahn
Original assignee: Bombardier Transportation GmbH
Current assignee: Alstom Transportation Germany GmbH
Priority date: 2004-03-02
Filing date: 2005-02-25
Publication date: 2006-11-15
Also published as: GB0404558D0; GB2411739A; CN1942661A; WO2005095778A1

Abstract

Method for controlling a combustion motor (1.1) of a vehicle, in particular a rail vehicle, said motor (1.1) being mechanically connected to a gearing unit (1.2) for driving a wheel (1.3) of said vehicle and to at least one auxiliary arrangement (3) of said vehicle for providing power to said auxiliary arrangement (3), said auxiliary arrangement (3) providing at least one auxiliary function of said vehicle, wherein in a first step (5.2), a desired fuel supply signal isprovided, said desired fuel supply signal being representative of a fuel supply degree desired to be applied to said motor, in a second step (5.4), an actual motor speed of said motor (1.1) is determined, in a third step (5.8), an actual fuel supply value representing an amount of fuel to be supplied to said motor (1.1) is determined dependent on said desired fuel supply signal and on an actual auxiliary power consumption of said auxiliary arrangement (3) at said actual motor speed, said actual fuel supply value being determined to respect an upper power limit of the power to be supplied to said gearing unit (1.2) at said actual motor speed, and in a fourth step (5.12), said actual fuel supply value is used for controlling the fuel supply to said motor (1.1), and wherein said actual fuel supply value is determined dependt on said actual motor speed using a characteristic line, said characteristic line being selected, in a selection step (5.10), from a previously established set of characteristic lines, each characteristic line of said set representing a fuel supply value representative of an amount of fuel to be supplied to said motor (1.1) as a function of the motor speed of said motor (1.1).

Description

Method and arrangement for controlling a motor of a vehicle

The present invention relates to a method for controlling a combustion motor of a vehicle, in particular a rail vehicle, said motor being mechanically connected to a gearing unit for driving a wheel of said vehicle and to at least one auxiliary arrangement of said vehicle for pro- viding power to said auxiliary arrangement, said auxiliary arrangement providing at least one auxiliary function of said vehicle. In a first step, a desired fuel supply signal is provided, said desired fuel supply signal being representative of an amount of fuel desired to be supplied to said motor. In a second step, an actual motor speed of said motor is determined. In a third step, an actual fuel supply value representing an amount of fuel to be supplied to said motor is determined dependent on said desired fuel supply signal and on an actual auxiliary power consumption of said auxiliary arrangement at said actual motor speed. Said actual fuel supply value is determined to respect an upper power limit of the power to be supplied to said gearing unit at said actual motor speed. Finally, in a fourth step, said actual fuel supply value is used for controlling the fuel supply to said motor. Furthermore, the pre- sent invention relates to a control arrangement for controlling a combustion motor of a vehicle which is suitable for executing the method according to the present invention.

Such a method and control arrangement are known, for example, from the German Patent Specification No. DE 101 37 475 C1. There, a diesel engine of a rail vehicle is coupled to a gearing unit for driving the wheels of the rail vehicle and to a generator being part of an auxiliary arrangement and used for providing power to auxiliary units of the vehicle. To avoid introduction of an inadmissibly high torque into the gearing unit, fuel supply to the motor is controlled in such a manner that the difference between the actual torque provided by the motor and the actual torque introduced into the generator does not exceed an upper limit. This upper limit is defined by the maximum torque that may be introduced into the gearing unit.

To achieve this, an actual generator input torque is calculated from the generator current and the actual motor speed. To obtain a theoretical gearing unit input torque, this actual generator input torque is subtracted from a motor torque which is determined on the basis of a desired fuel supply signal received from a control lever operated by the driver of the vehicle. If this theoretical gearing unit input torque exceeds the maximum gearing unit input torque, a limited fuel supply value is used for controlling fuel supply to the motor which is inferior to the desired fuel supply value corresponding to said desired fuel supply signal. This limited fuel supply value is determined to provide a gearing unit input torque which is less than or equal to the maximum gearing unit input torque.

Although the known method provides for a limitation of the gearing unit input torque for static or slowly changing operating conditions, it has a weakness with respect to for critical dynamic situations. Such for critical dynamic situations regularly occur when components of the auxiliary arrangement, such as the compressor of an air conditioning unit, are switched off. This usually leads to a sharp drop in the power consumed by the auxiliary arrangement. Since the comprehensive calculations necessary according to the known method take a considerable amount of time until the actual fuel supply value is determined from the above comparison of calculated torques, there is a certain risk that a reaction to such critical dynamic situations may be considerably delayed. This may lead to situations where the gearing unit is subjected to an inadmissibly high torque over certain period. The consequences may be considerable damage to the gearing unit.

It is thus an object of the present invention to provide a generic method and control arrangement that, at least to some extent, overcomes the above disadvantages. It is a further object of the present invention to provide a generic method and control arrangement that ensure sufficiently rapid reactions to critical dynamic situations that may occur with sudden changes within the power consumption of the auxiliary arrangement.

The above objects are achieved starting from a method according to the preamble of claim 1 by the features of the characterizing part of claim 1. They are also achieved starting from a control arrangement according to the preamble of claim 14 by the features of the characterizing part of claim 14.

The present invention is based on the technical teaching that sufficiently rapid reactions to critical dynamic situations related to sudden changes within the power consumption of the auxiliary arrangement may be achieved if said actual fuel supply value is determined in dependence on said actual motor speed using a characteristic line, said characteristic line being selected, in a selection step during said third step, from a previously established set of characteristic lines. Each characteristic line of said set is representing a value representative of an amount of fuel to be supplied to said motor as a function of the motor speed of said motor. It will be appreciated that said amount of fuel to be supplied to said motor may represent the entire amount to be supplied to said motor. Anyway, depending on the design of the fuel supply control, said amount may also represent the amount of fuel to be supplied to each cylinder of said motor, for example.

Thus, by simply determining an actual fuel supply value from a value simply retrieved from such a characteristic line dependent on an actual motor speed extensive calculations may be avoided leading to shorter control cycles and, thus, to shorter reaction times with respect to such critical dynamic situations. In other words, in an advantageous manner, there is no need for time-consuming calculations and comparisons of torque values as a basis for the determination of said actual fuel supply value to be used for controlling the combustion motor.

It will be appreciated that each characteristic line of the set of characteristic lines may, for example, directly represent a fuel supply value as a function of the motor speed of the motor. Then, it is even possible to simply use the value taken from the selected characteristic line at a given motor speed as the actual fuel supply value. Anyway, it will be appreciated that the characteristic lines of the set of characteristic lines represents, as a function of the motor speed, any other suitable parameter having a known relation to the fuel supply value, i.e. the amount of fuel to be supplied to the motor. In the sense of the present invention, due to said known relation, such a parameter, as well, is representative of an amount of fuel to be supplied to said motor. Such a parameter may, for example, be a torque as well as a power. With said known relation it is then possible in a very simple manner to determine a corresponding fuel supply value from the value of such a parameter taken from the selected characteristic line at a given motor speed. In other words, it is possible to determine a fuel supply value using the selected characteristic line.

Preferably, at least said second, third and fourth step are continuously repeated for continuously controlling said motor. A new control cycle comprising at least said second, third and fourth step may be initiated upon each completion of a previous control cycle. Anyway, said control cycles may be initiated at given fixed or variable intervals. Preferably, at each beginning of a new control cycle, the current status of said desired fuel supply signal is verified. As an alternative, a new desired fuel supply signal is requested. It has been found that such characteristic lines may be established for different operating conditions of such a vehicle. For example, they may be established to cover at least all realistic operating conditions of said vehicle at a resolution providing a sufficiently smooth controlling operation. In other words, there may be provided a sufficiently high number of characteristic lines, each line being associated with a discrete operating condition of said vehicle, each operating condition, on the other hand, being defined by a discrete set of suitable parameters. Each set of parameters constitutes a pointer to the respective characteristic line.

The characteristic line to be used may simply be selected, in said selection step, from said set of characteristic lines according to the pointer defined by the actual parameter values of said parameter set. There is no need for any complex and time consuming calculations. Once the respective characteristic line is selected this way, the actual fuel supply value can be taken from said characteristic line dependent on the actual motor speed.

Each characteristic line may be available in any suitable form. The fuel supply value may be available as a discrete function of the motor speed. There may also be a set of discrete data pairs each containing a motor speed value and an associated fuel supply value. Of course, any other suitable representation of such a characteristic line may be used. Thus, here as well, if necessary at all, at most one simple and quick calculation has to be made to determine the correct fuel supply value.

In principle, any suitable parameter may be used for defining the different operating conditions of the vehicle. Since it has an immediate influence on the power and, thus, the torque input into the gearing unit, preferably, the operational state of the auxiliary arrangement is used as one of those parameters. Thus, preferably, said selection in said selection step is performed dependent on an operational state of said auxiliary arrangement.

To avoid any delay in reacting on the above critical dynamic situations resulting from a rapidly reduced power intake by the auxiliary arrangement, i.e. from a change in the operational state of the auxiliary arrangement, a new control cycle is preferably triggered upon the occurrence of such a change in the operational state of the auxiliary arrangement. Thus, preferably, the execution of at least said second, third and fourth step is triggered by a detection of a change in the operational state of the auxiliary arrangement. The initiation of such a new control cycle may be related to any change in the operational state of the auxiliary arrangement. Preferably, it is at least related to any change in the operational state of the auxiliary arrangement likely to result in one of the above critical dynamic situations, i.e. any change related to a quick drop in the power consumed by the auxiliary arrangement. Furthermore, preferably, the initiation of such a new control cycle is independent from the status of a previous control cycle, e.g. independent from the completion of such a previous control cycle. Preferably, it is also independent from any predetermined intervals provided for such control cycles.

With preferred simple embodiments of the method according to the present invention said auxiliary arrangement has at least a first operational state with a first power consumption of said auxiliary arrangement and a second operational state with a second power consumption of said auxiliary arrangement, said first power consumption being different from said second power consumption. Said set of characteristic lines then comprises at least a first characteristic line associated with said first operational state and at least a second charac- teristic line associated with said second operational state. In said selection step, said first characteristic line is selected if said auxiliary arrangement is in said first operational state. On the other hand, said second characteristic line is selected if said auxiliary arrangement is in said second operational state.

Preferred embodiments of the method according to the present invention providing short reaction times take into account modern motor control technology providing for fuel supply limitation and, thus, torque limitation as well via one single characteristic line for the motor itself in order to limit the mechanical and thermal load on the parts of the motor. With these embodiments said first characteristic line is representative of a first maximum fuel supply value representative of a first maximum amount of fuel to be supplied to said motor as a function of the motor speed of said motor. Said second characteristic line is representative of a second maximum fuel supply value representative of a second maximum amount of fuel to be supplied to said motor as a function of the motor speed of said motor. The desired fuel supply signal is compared to a maximum fuel supply signal, said maximum fuel supply signal being representative of the maximum fuel supply value determined at said motor speed using said characteristic line selected in the selection step. Then, said actual fuel supply value is determined in said third step from said desired fuel supply signal if said desired fuel supply signal is inferior to said maximum fuel supply signal. On the other hand, if said desired fuel supply signal is superior to said maximum fuel supply signal, said actual fuel supply value is determined in said third step from said maximum fuel supply signal. In other words, for each operational state of the auxiliary arrangement at least one such limiting characteristic line is defined. If, at a given motor speed, the amount of fuel desired to be supplied to the motor, e.g. according to a request by the driver, exceeds the maximum amount of fuel to be supplied to the motor obtained using the selected characteristic line, then said maximum amount of fuel to be supplied to the motor is used for controlling fuel supply to the motor. If this is not the case, the amount of fuel desired to be supplied to the motor is used for controlling fuel supply to the motor.

Preferred embodiments of the method according the present invention account for gearing units with different modes of operation associated with different admissible input power lev- els. In these cases said gearing unit has a first mode of operation with a first upper power limit of the power to be supplied to said gearing unit at said actual motor speed. Furthermore, said gearing unit has a second mode of operation with a second upper power limit of the power to be supplied to said gearing unit at said actual motor speed. The set of characteristic lines then comprises at least a first subset of characteristic lines comprising at least said first characteristic line. The set of characteristic lines also comprises at least a second subset of characteristic lines comprising at least said second characteristic line. In said selection step, the first subset is selected if said auxiliary arrangement is in said first operational state. On the other hand, said second subset is selected if said auxiliary arrangement is in said second operational state. Finally, in said selection step, the character- istic line is selected from the selected subset depending on the mode of operation of the gearing unit.

In other words, for each operational state of the auxiliary arrangement there is a subset of characteristic lines. Each line within the respective subset is associated to a distinct mode of operation of the gearing unit. Anyway, it will be appreciated that, with other embodiments of the present invention, it may also be provided that for each mode of operation of the gearing unit there is a subset of characteristic lines. Then, each line within the respective subset is associated to a distinct operational state of the auxiliary arrangement. The subset is then selected depending on the mode of operation of the gearing unit, while the characteristic line is selected depending on the operational state of the auxiliary arrangement. With both such embodiments it is possible to account for varying admissible input power levels as it may be the case for combined gearing units such as, for example, hydro- mechanical gearing units with a mechanical part and a hydraulic part. With further preferred embodiments of the present invention, said set of characteristic lines comprises at least a first subset of characteristic lines comprising at least said first characteristic line. Said set of characteristic lines comprises at least a second subset of characteristic lines comprising at least said second characteristic line. In said selection step, said characteristic line is selected from the respective subset dependent on said desired fuel supply signal.

It has been found that in many cases the power intake of the auxiliary arrangement is, at least in a satisfying approximation, only dependent on the on/off state of the components of the auxiliary arrangement. Thus, with advantageous embodiments of the method according to the present invention, said auxiliary arrangement comprises a plurality of auxiliary units being, at least in part, selectively operative. In this case, different combinations of auxiliary units being operative at a time represent different operational states of said auxiliary arrangement. The set of characteristic lines then comprises a subset of characteristic lines for each of said operational states, each subset comprising at least one characteristic line. In the selection step, the characteristic line to be used is selected from the subset corresponding to the currently prevailing actual operational state of said auxiliary arrangement. By this means complex calculations of the actual power intake of the auxiliary arrangement may be avoided leading to further shortened reaction times.

To restrict the total effort for setting up all the characteristic lines the number of operational states may be restricted to those combinations of auxiliary units operative at a time which may occur under normal operating conditions of the vehicle. Thus, preferably, the set of characteristic lines comprises a subset for each operational state of a first group of operational states, said first group of operational states being a fraction of all theoretically possible operational states.

There may be only one single characteristic line for any operational state of the auxiliary arrangement. For example, this may be the characteristic line for the maximum fuel supply available, i.e. admissible, at this operational state. This characteristic line for the maximum fuel supply admissible at this operational state may be used as described above for determining if the admissible maximum fuel supply value obtained from the characteristic line is to be used or if the desired fuel supply value may be used. In other cases it may be provided that, where the desired fuel supply signal is not representative of a requested maximum fuel supply, i.e. a requested maximum power, but of a certain fraction of said maximum fuel supply, the actual fuel supply value may simply be calculated from the fuel supply value taken from said characteristic line for the maximum fuel supply. This calculation may be done dependent on the desired fuel supply signal using a simple corresponding algorithm. In the most simple case, the actual fuel supply value may be determined to be a fraction of the fuel supply value taken from the characteristic line for the maximum fuel supply. Said fraction may correspond to the relation between the actual desired fuel supply and a desired maximum fuel supply, said actual desired fuel supply being represented by an actual desired fuel supply signal and said desired maximum fuel supply being represented by an desired maximum fuel supply signal.

To avoid further calculation effort and to provide for an optimized use of the gearing unit's performance potential a subset with a plurality of characteristic lines may be provided for each operational state of the auxiliary arrangement. The characteristic line to be used may then be selected according to the actual desired fuel supply signal. The number of characteristic lines to be provided is determined by the resolution necessary to provide sufficiently smooth operation characteristics. Furthermore, the selection may be done using ranges for the actual desired fuel supply signal, each range being associated with a distinct characteristic line. It may also be provided that only a certain number of distinct actual desired fuel supply signals is provided, each signal being associated with a distinct characteristic line.

Thus, according to a preferred embodiment of the present invention, each of said subsets comprises a plurality of characteristic lines, and, in said selection step, the characteristic line to be used is selected from the respective subset dependent on said desired fuel supply signal. In other words, each of said characteristic lines of said subset may be associated with a separate desired fuel supply signal.

The actual fuel supply value to be used for controlling the motor may be determined from a first fuel supply value, said first fuel supply value being determined from said selected char- acteristic line using said actual motor speed. The actual fuel supply may be calculated from said first fuel supply value using an appropriate algorithm. For example, said actual fuel supply value may be calculated from said first fuel supply value as a function of said desired fuel supply signal. Preferably, to avoid further calculation effort, said actual fuel supply value is set equal to said first fuel supply value.

All the respective selection, determination and calculation operations described above my be performed by suitable components of a control arrangement of the vehicle. Preferably, they are done by a single corresponding control unit of such a control arrangement. To smoothen the effects of rapid changes in the operational state of the auxiliary arrangement at least parts of the auxiliary arrangement may be provided with power via an energy buffer. This energy buffer damps changes in the power consumption of the parts of the auxiliary arrangement connected thereto. Thus, preferably, said auxiliary arrangement comprises a plurality of auxiliary units being, at least in part, provided with power via at least one buffer unit. This buffer unit may be of any suitable type. For example it may be of an electric type, such as a buffer battery unit or the like. It may also be of a mechanical or hydro-mechanical type, such as a hydro-mechanical drive arrangement. Of course, combinations of buffers of different types may be chosen.

To provide for the limitation of the power and, thus, the torque input into the gearing unit it is provided that each characteristic line has been set up to account for this limitation in itself. In this case no further calculations are necessary to achieve said limitation of the torque input into the gearing unit leading to very short reaction times. Preferably, the selection of the characteristic line to be used is performed, in the selection step, dependent on an operational state of the auxiliary arrangement. The respective selected characteristic line has previously been established in such a manner that, with any first fuel supply value used to fuel said motor and taken from said characteristic line at a given motor speed, the difference between the power provided by said motor at said given motor speed and a power consumed by said auxiliary arrangement in said operational state and at said given motor speed is not exceeding said upper power limit of the power to be supplied to said gearing unit at said given motor speed. Thus, in certain cases, even at a desired fuel supply signal representative of the maximum possible fueling degree a lower fueling degree is provided by said characteristic line in order to avoid overload to the gearing unit.

The present invention also relates to a control arrangement for controlling a combustion motor of a vehicle, in particular a rail vehicle. The control arrangement comprises a control unit being connectable to the motor. The motor is mechanically connected to a gearing unit for driving a wheel of the vehicle and to at least one auxiliary arrangement of the vehicle for providing power to the auxiliary arrangement. The auxiliary arrangement provides at least one auxiliary function of said vehicle. The control unit is adapted to receive a desired fuel supply signal. The desired fuel supply signal is representative of an amount of fuel desired to be supplied to said motor. The control unit is further adapted to receive an actual motor speed signal representative of an actual motor speed of the motor. It is also adapted to determine an actual fuel supply value representing an amount of fuel to be supplied to said motor dependent on said desired fuel supply signal and on an actual auxiliary power con- sumption of said auxiliary arrangement at said actual motor speed. The actual fuel supply value is determined to respect an upper power limit of the power to be supplied to said gearing unit at said actual motor speed. Finally, the control unit is adapted to use the actual fuel supply value for controlling the fuel supply to the motor. According to the invention, the control unit comprises a first memory having stored therein a set of characteristic lines.

Each characteristic line of said set represents a value representative of an amount of fuel to be supplied to the motor as a function of the motor speed of the motor. Furthermore, the control unit is adapted to select a characteristic line from said set of characteristic lines, and to determine the above actual fuel supply value in dependence on said actual motor speed signal using said selected characteristic line.

This control arrangement is suitable to execute the method according to the present invention as it has been described above. With this control arrangement the above embodiments and advantages of the method according to the present invention may be achieved as well. Thus, with respect to those embodiments and advantages, it is here referred to the above description.

Preferably, the control unit is adapted to continuously determine said actual fuel supply value for continuously controlling said motor.

The control unit may be adapted to receive an actual operational state signal, said actual operational state signal being representative of an operational state of said auxiliary ar- rangement. Then, it is also adapted to perform said selection of said characteristic line dependent on said operational state signal. Preferably, the control unit is adapted to detect a change in said actual operational state signal and to execute, in response to detection of said change, said determination of said actual fuel supply value. As an alternative, the control unit may be adapted to receive a change signal, said change signal being representa- tive of a change in said actual operational state. Then, the control unit is adapted to execute the determination of said actual fuel supply value in response to receipt of said change signal.

According to further embodiments of the control arrangement according to the present invention the auxiliary arrangement has at least a first operational state with a first power consumption of said auxiliary arrangement and a second operational state with a second power consumption of said auxiliary arrangement. The set of characteristic lines then comprises at least a first characteristic line associated with said first operational state and at least a second characteristic line associated with said second operational state. The control unit is adapted to select said first characteristic line if said actual operational state signal is indicative of said auxiliary arrangement being in said first operational state. Furthermore, it is adapted to select said second characteristic line if said actual operational state signal is indicative of said auxiliary arrangement being in said second operational state.

Preferably, the auxiliary arrangement comprises a plurality of auxiliary units being, at least in part, selectively operative, wherein different combinations of auxiliary units being operative at a time represent different operational states of said auxiliary arrangement. The control unit is then adapted to receive an actual operational state signal, said actual operational state signal being representative of an actual operational state of said auxiliary arrangement. The set of characteristic lines comprises a subset of characteristic lines for each of said operational states, each subset comprising at least one characteristic line. The control unit is adapted to select said characteristic line from the subset corresponding to said actual operational state signal. Preferably, the control unit is adapted to select the character- istic line to be used from the respective subset dependent on said desired fuel supply signal.

The present invention furthermore relates to a vehicle, in particular to a rail vehicle, comprising a combustion motor, a gearing unit and at least one auxiliary arrangement for providing at least one auxiliary function of said vehicle. The motor is mechanically connected to the gearing unit for driving a wheel of said vehicle and to the auxiliary arrangement for providing power thereto. The vehicle furthermore comprises a control arrangement according to the present invention for controlling said motor.

Preferably, said auxiliary arrangement comprises a plurality of auxiliary units being, at least in part, provided with power via at least one buffer unit to achieve the damping effect with respect to changes in the operational state of the auxiliary arrangement as it has been described above. As it has also been stated above, the buffer unit may be of any suitable design. Due to its simple implementation said buffer unit preferably comprises a battery unit.

Further embodiments of the present invention will become apparent from the dependent claims and the following description of preferred embodiments which refers to the ap- pended figures. It is shown in: Figure 1 a schematic representation of a vehicle with a preferred embodiment of a control arrangement according to the present invention for executing the method according to the present invention;

Figure 2 a flow chart of a preferred embodiment the method according to the present 5 invention executed by the control arrangement according to Figure 1 ;

Figure 3 a flow chart of another embodiment of the method according to the present invention executed by the control arrangement according to Figure 1 ;

Figure 4 a schematic representation of a vehicle with a further embodiment of a control arrangement according to the present invention for executing an embodiment ofo the method according to the present invention;

Figure 5 a flow chart of another embodiment of the method according to the present invention executed by the control arrangement according to Figure 4;

Figure 6 a flow chart of another embodiment of the method according to the present invention executed by the control arrangement according to Figure 4. 5 Figure 1 shows a schematic partial representation of a rail vehicle 1 with a preferred embodiment of a control arrangement 2 according to the present invention for executing the method according to the present invention.

The vehicle 1 comprises a combustion motor 1.1 mechanically connected to a gearing unit 1.2 for driving the wheels 1.3 of the vehicle 1. The motor 1.1 is also mechanically con-0 nected to an auxiliary arrangement 3. The auxiliary arrangement 3 provides auxiliary functions of the vehicle 1. To this end it comprises a plurality of auxiliary units such as, among others, generators 3.1 and 3.2 mechanically connected to the motor 1.1 , an air compressor 3.3 for providing pressurized air, a climate compressor 3.4 of an air-conditioning unit and cooling fans 3.5 for cooling components of the vehicle 1. The generators 3.1 and 3.2 are5 feeding a buffer unit in the form of a battery unit 3.6 which in turn provides electrical power to the components 3.3 to 3.5 of the auxiliary arrangement 3.

To avoid introduction of an inadmissibly high torque into the gearing unit 1.2, the fuel supply to the motor 1.1 is controlled in such a manner that the difference between the actual torque provided by the motor and the actual torque introduced into the generators 3.1 and 3.2 does not exceed an upper limit as will be described further below. This upper limit is defined by the maximum torque that may be introduced into the gearing unit 1.2.

As previously explained, critical dynamic situations may occur when components of the auxiliary arrangement 3, such as the air compressor 3.3 etc., are switched off. This usually leads to a sharp drop in the power consumed by the auxiliary arrangement 3 which in turn might lead to a torque input into the gearing unit 1.2 exceeding the maximum admissible torque if no sufficiently rapid reaction follows such a change in the operational state of the auxiliary arrangement 3.

To smoothen the effects of rapid changes in the operational state of the auxiliary units 3.3 to 3.5 they are provided with electrical power via the battery unit 3.6. The battery unit 3.6 damps changes in the power consumption of those auxiliary units. Anyway, if one of the generators 3.1 and 3.2 is suddenly switched off the sharp drop in the power consumed by the auxiliary arrangement may occur regardless of the presence of the battery unit 3.6.

Depending on the operational state, e.g. the on/off-state, of each of the auxiliary units 3.1 to 3.6, the auxiliary arrangement 3 has different operational states. In other words, each combination of auxiliary units 3.1 to 3.6 being operative at a time corresponds to a distinct operational state of the auxiliary arrangement 3. Each of those operational states of the auxiliary arrangement 3 is associated with a certain power consumption of the auxiliary ar- rangement 3.

The motor 1.1 is furthermore connected to a control unit 2.1 of the control arrangement 2 via a data bus 1.4. The control unit 2.1 serves to control the fuel supply to the motor 1.1. To this end it is connected via the system bus 1.4 to the fuel injection unit 1.5 of the motor 1.1. The control unit 2.1 comprises a central processing unit (CPU) 2.2 and a first memory 2.3 connected thereto. The first memory 2.3 stores a set of characteristic lines CL used for controlling the fuel supply to the motor 1.1.

Furthermore, the control unit 2.1 is connected, via the data bus 1.4, to a driver control unit 2.4. This driver control unit 2.4 provides a desired fuel supply signal DFSS dependent on the position of a driver lever 2.5 of the driver control unit 2.4. This desired fuel supply signal DFSS is representative of the fuel supply degree desired to be applied to the motor 1.1. Accordingly, it ranges between a maximum fuel supply degree, e.g. 100% of a maximum fuel supply value admissible for the motor 1.1 , and a minimum fuel supply degree, e.g. the percentage of said maximum fuel supply value for keeping the motor 1.1 running during idle running.

Each characteristic line CL in the first memory 2.3 directly represents a fuel supply value representative of an amount of fuel to be supplied to the motor 1.1 is a function of the motor speed N of the motor 1.1. Anyway, as stated above, other embodiments of the present invention may provide for characteristic lines set up, as a function of the motor speed, for any other suitable parameter associated to such a fuel supply value via a known relation. As already mentioned such parameters may be a torque or a power, for example.

The set of characteristic lines CL in the first memory 2.3 comprises a subset of characteristic lines for each operational state of the auxiliary arrangement 3 of a first group of operational states of the auxiliary arrangement 3. This first group of operational states comprises all different combinations of the auxiliary units 3.1 to 3.6 being operative at a time which may occur during normal operation of the vehicle 1. Thus, the first group of operational states is a fraction of all theoretically possible operational states of the auxiliary arrangement 3.

Each subset of characteristic lines CL comprises a plurality of characteristic lines CL. Each one of those characteristic lines in the respective subset is associated to a certain range of the desired fuel supply signal DFSS provided by the driver control unit 2.4. The number of ranges and associated characteristic lines is sufficiently high to provide a smooth controlling characteristic over the entire range of the desired fuel supply signal. In other words, there is a sufficiently high resolution to provide such smooth controlling characteristics over the entire range of the desired fuel supply signal.

To provide for the limitation of the power and, thus, the torque input into the gearing unit 1.2 each characteristic line CL has been set up to account for this limitation in itself. The respective characteristic line CL has previously been established in such a manner that, with any first fuel supply value used to fuel the motor 1.1 and taken from said characteristic line CL at a given motor speed, the difference between the power provided by the motor 1.1 at said given motor speed and a power consumed by the auxiliary arrangement 3 in said op- erational state and at said given motor speed is not exceeding said upper power limit of the power to be supplied to the gearing unit 1.2 at said given motor speed. Thus, in certain cases, even when the driver's operation of lever 2.5 causes a desired fuel supply signal DFSS representative of the maximum possible fueling degree, a lower fueling degree is provided by said characteristic line CL in order to avoid overload to the gearing unit 1.2.

In the following, the control process of the fuel supply to the motor 1.1 will be described with reference to Figures 1 and 2.

In a step 5.1 the control operation of the control arrangement 2 is initiated. Then, in a first step 5.2 of a control cycle a desired fuel supply signal DFSS is retrieved by the CPU 2.2. This may be done by requesting it via the data bus 1.4 from the driver control unit 2.4. Anyway, it will be appreciated that the desired fuel supply signal DFSS may be transmitted to the CPU 2.2 at given intervals.

In a step 5.3 of the control cycle it is determined if there has been a change in the operational state of the auxiliary arrangement 3 with respect to a previously prevailing operational state of the auxiliary arrangement 3. This determination may be performed by the CPU 2.2 itself receiving information on the operational state of each auxiliary unit 3.1 to 3.6 over the data bus 1.4 and generating a corresponding state change signal SCS. Anyway, it will be appreciated that, with other embodiments of the present invention, there may be provided a separate auxiliary arrangement state survey unit - indicated in Figure 1 by the reference numeral 6 - providing such a state change signal representative of a change in the operational state of the auxiliary arrangement 3.

If this is not the case, a motor speed signal N representative of the current motor speed of the motor 1.1 is retrieved by the CPU 2.2 in a second step 5.4 of the control cycle. This may be done by requesting it via the data bus 1.4 from a motor control unit 1.6 or a corresponding sensor of the motor 1.1. Anyway, it will be appreciated that the motor speed signal N may also be transmitted to the CPU 2.2 at given intervals.

In a step 5.5 of the control cycle, similar to step 5.3, it is again determined if there has been a change in the operational state of the auxiliary arrangement 3 with respect to a previously prevailing operational state of the auxiliary arrangement 3.

If this is not the case, an operational state signal OSS representative of the current operational state of the auxiliary arrangement 3 is determined by the CPU 2.2 in a step 5.6 of the control cycle. The CPU 2.2 performs this determination using unit operational state signals UOSS transmitted to it from the auxiliary units 3.1 to 3.6 via the data bus 1.4. This trans- mission may be initiated by requesting the respective unit operational state signal UOSS via the data bus 1.4 from the respective auxiliary unit. Anyway, it will be appreciated that the unit operational state signals UOSS may also be transmitted to the CPU 2.2 at given intervals by the auxiliary units. Furthermore, it will be appreciated that, with other embodiments of the present invention, the separate auxiliary arrangement state survey unit - indicated in Figure 1 by the reference numeral 6 -- may provide such operational state signal OSS based on unit operational state signals UOSS provided to it.

In a step 5.7 of the control cycle, similar to steps 5.3 and 5.5, it is again determined if there has been a change in the operational state of the auxiliary arrangement 3 with respect to a previously prevailing operational state of the auxiliary arrangement 3.

The steps 5.3, 5.5 and 5.7 serve to trigger a new control cycle upon detection of a change in the operational state of the auxiliary arrangement 3. To this end it is provided that it is jumped back to the first step 5.2 as soon as the existence of a state change signal SCS is detected in one of those steps 5.3, 5.5 and 5.7. Thus, extended delays in reacting to changes in the operational state of the auxiliary arrangement 3 which otherwise might lead to overload situations all the caring unit 1.2 are effectively avoided. It will be appreciated that operational state survey steps such as step 5.3 may be provided at any position in the control cycle. Anyway, it will be appreciated that, in particular with sufficiently high data transmission and processing speeds, such operational state survey steps may be omitted.

It will be appreciated that said first step 5.2, said second step 5.4 and step 5.6 may arbitrarily change their position in the above chronology. Furthermore, it will be appreciated that, with other embodiments of the present invention, those steps may also be executed at a time.

If no change in the operational state of the auxiliary arrangement 3 is detected in step 5.7 the actual fuel supply value to be used for controlling the fuel supply to the motor 1.1 is determined in a third step 5.8 of the control cycle. This actual fuel supply value is representative of the amount of fuel to be supplied to the motor 1.1.

To this end, in a first selection step 5.9 of the control cycle, the subset of characteristic lines corresponding to the actual operational state of the auxiliary arrangement 3 is selected. This selection is done using the above operational state signal OSS obtained in step 5.6. Then, in a second selection step 5.10 of the control cycle, the characteristic line CL corre- sponding to the desired fuel supply signal DFSS obtained in step 5.6 is selected from the selected subset. Finally, in a step 5.11 of the control cycle, a first fuel supply value is taken from the selected characteristic line CL using the motor speed signal N obtained in step 5.4. The actual fuel supply value to be used for controlling the motor 1.1 is then set equal to the determined first fuel supply value. Said actual fuel supply value is then used to generate a corresponding actual fuel supply signal AFSS.

Then, in a fourth step 5.12 of the control cycle, the actual fuel supply value is used for controlling the fuel supply to the motor 1.1. To this end the actual fuel supply signal AFSS is transmitted to the fuel injection unit 1.5 of the motor 1.1.

It will be appreciated that the characteristic lines may be available in the first memory 2.3 in any suitable form. The fuel supply value may be available as a discrete function of the motor speed. There may also be a set of discrete data pairs each containing a motor speed value and an associated fuel supply value. Of course, any other suitable representation of such a characteristic line may be used. The characteristic line to be used may simply be selected, in said selection step, from said set of characteristic lines according to a pointer P(OSS;DFSS) defined by the actual parameter values of a parameter set comprising the operational state signal OSS and the desired fuel supply signal DFSS or values corresponding to those signals. Once the respective characteristic line is selected this way, the actual fuel supply value can be taken from said characteristic line dependent on the actual motor speed.

Furthermore, depending on the structure of the data representing the set of characteristic lines, the first fuel supply value may also be taken directly from the first memory 2.3 using a pointer P(OSS;DFSS;N) defined by the actual parameter values of a parameter set comprising the operational state signal OSS, the desired fuel supply signal DFSS and the actual motor speed signal N or values corresponding to those signals. Thus, there is no need for any complex and time consuming calculations at all.

Finally, in a final step 5.13 of the control cycle, it is checked if there is provided stop signal to terminate the controlling operation. If this is not the case it is jumped back to the first step 5.2 of the control cycle to initiate a new control cycle. Otherwise, the controlling operation is terminated in step 5.14. Figure 3 is a flow chart of another embodiment of the method according to the present invention which may be executed by the control arrangement 2 according to Figure 1. Anyway, in this embodiment, each characteristic line CL of the set of characteristic lines in the first memory 2.3 represents a maximum fuel supply value representative of a maximum amount of fuel to be supplied to the motor 1.1 as a function of the motor speed N of the motor 1.1. The set of characteristic lines CL in the first memory 2.3 comprises a distinct characteristic line for each operational state of the auxiliary arrangement 3 of a first group of operational states of the auxiliary arrangement 3. In other words the set of characteristic lines CL in the first memory 2.3 comprises, among others, a first characteristic line repre- sentative of a first maximum fuel supply value associated with a first operational state of the auxiliary arrangement 3. Furthermore, it comprises, among others, a second characteristic line representative of a second maximum fuel supply value associated with a second operational state of the auxiliary arrangement 3.

Said first group of operational states comprises all different combinations of the auxiliary units 3.1 to 3.6 being operative at a time which may occur during normal operation of the vehicle 1. Thus, the first group of operational states is a fraction of all theoretically possible operational states of the auxiliary arrangement 3.

To provide for the limitation of the power and, thus, the torque input into the gearing unit 1.2 each characteristic line CL has been set up to account for this limitation in itself. The re- spective characteristic line CL has previously been established in such a manner that, with any maximum fuel supply value MFSV used to fuel the motor 1.1 and taken from said characteristic line CL at a given motor speed, the difference between the power provided by the motor 1.1 at said given motor speed and a power consumed by the auxiliary arrangement 3 in said operational state and at said given motor speed is not exceeding said upper power limit of the power to be supplied to the gearing unit 1.2 at said given motor speed.

In the following, the control process of the fuel supply to the motor 1.1 according to this embodiment will be described with reference to Figures 1 and 3.

In a step 5.15 the control operation of the control arrangement 2 is initiated. Then, in a first step 5.16 of a control cycle a desired fuel supply signal DFSS is retrieved by the CPU 2.2. This may be done by requesting it via the data bus 1.4 from the driver control unit 2.4. Anyway, it will be appreciated that the desired fuel supply signal DFSS may be transmitted to the CPU 2.2 at given intervals or may be permanently available at a given port of the CPU.

Other than in the embodiment of Figure 2 there is no determination if there has been a change in the operational state of the auxiliary arrangement 3 with respect to a previously prevailing operational state of the auxiliary arrangement 3. Thus, the control cycle is shortened.

In a second step 5.17 of the control cycle a motor speed signal N representative of the current motor speed of the motor 1.1 is retrieved by the CPU 2.2. This may be done by requesting it via the data bus 1.4 from a motor control unit 1.6 or a corresponding sensor of the motor 1.1. Anyway, it will be appreciated that the motor speed signal N may also be transmitted to the CPU 2.2 at given intervals or may be permanently available at a given port of the CPU.

In a step 5.18 of the control cycle an operational state signal OSS representative of the current operational state of the auxiliary arrangement 3 is determined by the CPU 2.2. The CPU 2.2 performs this determination using unit operational state signals UOSS transmitted to it from the auxiliary units 3.1 to 3.6 via the data bus 1.4. This transmission may be initiated by requesting the respective unit operational state signal UOSS via the data bus 1.4 from the respective auxiliary unit. Anyway, it will be appreciated that the unit operational state signals UOSS may also be transmitted to the CPU 2.2 at given intervals by the auxil- iary units. Furthermore, it will be appreciated that, with other embodiments of the present invention, the separate auxiliary arrangement state survey unit - indicated in Figure 1 by the reference numeral 6 - may provide such operational state signal OSS based on unit operational state signals UOSS provided to it.

It will be appreciated that said first step 5.16, said second step 5.17 and step 5.18 may ar- bitrarily change their position in the above chronology. Furthermore, it will be appreciated that, with other embodiments of the present invention, those steps may also be executed at a time.

In a third step 5.19 of the control cycle the CPU 2.2 determines an actual fuel supply signal AFSS representative for the actual fuel supply value to be used for controlling the fuel sup- ply to the motor 1.1. This actual fuel supply value is representative of the amount of fuel to be supplied to the motor 1.1. To this end, in a first selection step 5.20 of the control cycle, the characteristic line CL corresponding to the actual operational state of the auxiliary arrangement 3 is selected. This selection is done using the above operational state signal OSS obtained in step 5.18. Thus, for example, said first characteristic line is selected if the operational state signal OSS is representative of the first operational state of the auxiliary arrangement 3 or said second characteristic line is selected if the operational state signal OSS is representative of the second operational state of the auxiliary arrangement 3.

Then, in a step 5.21 of the control cycle, a maximum fuel supply value is taken from the selected characteristic line CL using the motor speed signal N obtained in step 5.17. Said maximum fuel supply value is then used to generate a corresponding maximum fuel supply signal MFSS.

In a step 5.22 of the control cycle the desired fuel supply signal DFSS obtained in the first step 5.16 is compared to said maximum fuel supply signal MFSS obtained in step 5.21.

If said desired fuel supply signal DFSS is superior to said maximum fuel supply signal MFSS, said actual fuel supply signal AFSS is set equal to said maximum fuel supply signal MFSS in a step 5.23. In other words, even if the driver's operation of lever 2.5 causes a desired fuel supply signal DFSS representative of an amount of fuel to be supplied to the motor 1.1 exceeding the admissible maximum amount of fuel to be supplied to the motor 1.1 according to said selected characteristic line CL, a lower amount of fuel is used, namely the one obtained from said selected characteristic line CL, in order to avoid overload to the gearing unit 1.2.

On the other hand, If said desired fuel supply signal DFSS is inferior to said maximum fuel supply signal MFSS, said actual fuel supply signal AFSS is set equal to said desired fuel supply signal DFSS in a step 5.24. In other words, the amount of fuel according to the driver's operation of lever 2.5 is used to fuel the motor 1.1 , since there is no danger of an overload to the gearing unit 1.2.

Then, in a fourth step 5.25 of the control cycle, the actual fuel supply value is used for controlling the fuel supply to the motor 1.1. To this end the actual fuel supply signal AFSS is transmitted to the fuel injection unit 1.5 of the motor 1.1. It will be appreciated that the characteristic lines may be available in the first memory 2.3 in any suitable form. The fuel supply value may be available as a discrete function of the motor speed. There may also be a set of discrete data pairs each containing a motor speed value and an associated fuel supply value. Of course, any other suitable representation of such a characteristic line may be used. Depending on the structure of the data representing the set of characteristic lines, the maximum fuel supply value may be taken directly from the first memory 2.3 using a pointer P(OSS;N) defined by the actual parameter values of a parameter set comprising the operational state signal OSS and the actual motor speed signal N or values corresponding to those signals. Thus, there is no need for any complex and time consuming calculations at all.

Finally, in a final step 5.26 of the control cycle, it is checked if there is provided stop signal to terminate the controlling operation. If this is not the case it is jumped back to the first step 5.16 of the control cycle to initiate a new control cycle. Otherwise, the controlling operation is terminated in step 5.27.

Figure 4 shows a schematic partial representation of a rail vehicle 1' with a preferred embodiment of a control arrangement 2 according to the present invention for executing the method according to the present invention. The rail vehicle 1', in its basic design and functionality, largely corresponds to the rail vehicle 1 of Figure 1. Thus, it is here mainly referred to the differences. Furthermore, like parts have been designated with like reference numer- als.

One difference lies within the gearing unit 1.2'. The gearing unit 1.2' is a hydro-mechanical gearing unit with a mechanical part and a hydraulic part. Depending on the operation of the respective part of the gearing unit 1.2' the gearing unit has different modes of operation associated with different admissible input power levels. Thus, the gearing unit has at least a first mode of operation with a first upper power limit of the power to be supplied to it at an actual motor speed. Furthermore, it has a second mode of operation with a second upper power limit of the power to be supplied to it at an actual motor speed. There is provided a mode of operation survey unit 1.7 connected to the CPU 2.2 via data bus 1.4. This mode of operation survey unit 1.7 provides a mode of operation signal MOS representative of the current mode of operation of the gearing unit 1.2'.

As in the embodiment described in the context of Figure 1 and 2 the set of characteristic lines CL in the first memory 2.3 comprises a subset of characteristic lines for each opera- tional state of the auxiliary arrangement 3 of a first group of operational states of the auxiliary arrangement 3. This first group of operational states comprises all different combinations of the auxiliary units 3.1 to 3.6 being operative at a time which may occur during normal operation of the vehicle 1. Thus, the first group of operational states is a fraction of all theoretically possible operational states of the auxiliary arrangement 3.

In other words the set of characteristic lines CL in the first memory 2.3 comprises, among others, a first subset of characteristic lines, each characteristic line within said first subset being representative of a first maximum fuel supply value associated with a first operational state of the auxiliary arrangement 3. Furthermore, it comprises, among others, a second subset of characteristic lines, each characteristic line within said second subset being representative of a second maximum fuel supply value associated with a second operational state of the auxiliary arrangement 3.

Another difference with respect to the embodiment of Figures 1 and 2 is that, while each subset of characteristic lines CL comprises a plurality of characteristic lines CL, each one of those characteristic lines in the respective subset is associated to a certain mode of operation of the gearing unit 1.2'.

Here as well, each characteristic line CL in the first memory 2.3 directly represents a fuel supply value representative of an amount of fuel to be supplied to the motor 1.1 is a function of the motor speed N of the motor 1.1. Anyway, as stated above, other embodiments of the present invention may provide for characteristic lines set up, as a function of the motor speed, for any other suitable parameter associated to such a fuel supply value via a known relation. As already mentioned such parameters may be a torque or a power, for example.

To provide for the limitation of the power and, thus, the torque input into the gearing unit 1.2 each characteristic line CL has been set up to account for this limitation in itself. The re- spective characteristic line CL has previously been established in such a manner that, with any first fuel supply value used to fuel the motor 1.1 and taken from said characteristic line CL at a given motor speed, the difference between the power provided by the motor 1.1 at said given motor speed and a power consumed by the auxiliary arrangement 3 in said operational state and at said given motor speed is not exceeding said upper power limit of the power to be supplied to the gearing unit 1.2' at the current mode of operation of the gearing unit 1.2' and at said given motor speed. In the following, the control process of the fuel supply to the motor 1.1 will be described with reference to Figures 4 and 5. The method according to Figure 5 largely corresponds to the method of Figure 3. Thus, it is here mainly referred to the differences. Furthermore, like steps have been designated with like reference numerals.

After having performed steps 5.15 to 5.18 as described above in the context of Figure 3, in a step 5.28 of the control cycle, the mode of operation signal MOS representative of the current mode of operation of the gearing unit 1.2' is retrieved by the CPU 2.2. This may be done by requesting it via the data bus 1.4 from the mode of operation survey unit 1.7. Anyway, it will be appreciated that the mode of operation signal MOS may also be transmitted to the CPU 2.2 at given intervals or may be permanently available at a given port of the CPU.

In a third step 5.19' of the control cycle the CPU 2.2 determines an actual fuel supply signal AFSS representative for the actual fuel supply value to be used for controlling the fuel supply to the motor 1.1. This actual fuel supply value is representative of the amount of fuel to be supplied to the motor 1.1.

To this end, in a first selection step 5.29 of the control cycle, the subset of characteristic lines corresponding to the actual operational state of the auxiliary arrangement 3 is selected. This selection is done using the above operational state signal OSS obtained in step 5.18. Then, in a second selection step 5.30 of the control cycle, the characteristic line CL corresponding to the mode of operation signal MOS obtained in step 5.28 is selected from the selected subset. Finally, in a step 5.21 of the control cycle, a maximum fuel supply value is taken from the selected characteristic line CL using the motor speed signal N obtained in step 5.17 as it has been described above in the context of Figure 3.

This maximum fuel supply value taken from the selected characteristic line CL is used to generate a maximum fuel supply signal MFSS which is then used in step 5.22 as it has been described above in the context of Figure 3. Finally, the steps 5.23 to 5.27 are performed as described above in the context of Figure 3.

It will be appreciated that the characteristic lines may be available in the first memory 2.3 in any suitable form as ahs been described above. In particular, the characteristic line to be used may simply be selected, in said selection step, from said set of characteristic lines according to a pointer P(OSS;MOS) defined by the actual parameter values of a parameter set comprising the operational state signal OSS and the mode of operation signal MOS or values corresponding to those signals. Once the respective characteristic line is selected this way, the actual fuel supply value can be taken from said characteristic line dependent on the actual motor speed N. Furthermore, depending on the structure of the data repre- senting the set of characteristic lines, the first fuel supply value may also be taken directly from the first memory 2.3 using a pointer P(OSS;MOS;N) defined by the actual parameter values of a parameter set comprising the operational state signal OSS, the mode of operation signal MOS and the actual motor speed signal N or values corresponding to those signals. Thus, there is no need for any complex and time consuming calculations at all.

With the above embodiment it is possible to account for varying admissible input power levels of the gearing unit 1.2' while effectively avoiding overload to the gearing unit 1.2'.

Figure 6 is a flow chart of another embodiment of the method according to the present invention executed by the control arrangement according to Figure 4. In the following, the control process of the fuel supply to the motor 1.1 will be described with reference to Fig- ures 4 and 6. The method according to Figure 6 largely corresponds to the method of Figure 5. Thus, it is here mainly referred to the differences. Furthermore, like steps have been designated with like reference numerals.

The only difference with respect to the method of Figure 5 lies within the mutual attribution of the characteristic lines in the first memory 2.3 and within the third step 5.19'.

The set of characteristic lines CL in the first memory 2.3 comprises a subset of characteristic lines for each mode of operation of the gearing unit 1.2'. Each one of those characteristic lines in the respective subset is associated to a certain operational state of the auxiliary arrangement 3. Similar to the previous embodiments there may be a limitation of the number of different characteristic lines CL in each subset to a first group of operational states of the auxiliary arrangement 3.

To provide for the limitation of the power and, thus, the torque input into the gearing unit 1.2 each characteristic line CL has been set up to account for this limitation in itself as has been described above. The control process of the fuel supply to the motor 1.1 largely corresponds to the method of Figure 5. Thus, it is here mainly referred to the differences. Furthermore, like steps have been designated with like reference numerals.

After having performed steps 5.15 to 5.28 as described above in the context of Figure 5, the CPU 2.2 determines, in a third step 5.19" of the control cycle, an actual fuel supply signal AFSS representative for the actual fuel supply value to be used for controlling the fuel supply to the motor 1.1. To this end, in a first selection step 5.31 of the control cycle, the subset of characteristic lines corresponding to the current mode of operation of the gearing unit 1.2' is selected. This selection is done using the above mode of operation signal MOS obtained in step 5.28. Then, in a second selection step 5.32 of the control cycle, the characteristic line CL corresponding to the operational state signal OSS obtained in step 5.18 is selected from the selected subset. Then the steps 5.21 to 5.27 are performed as described above in the context of Figure 3.

With the above embodiment it is possible, as well, to account for varying admissible input power levels of the gearing unit 1.2' while effectively avoiding overload to the gearing unit 1.2'.

The present invention has been described above in the context of embodiments with a data bus used for communication between the vehicle's components. Anyway, it will be appreciated that, with other embodiments of the present invention, the data and signals, respec- tively, may be exchanged between the components of the vehicle via direct communication links.

* * * * *

Claims

1. Method for controlling a combustion motor (1.1 ) of a vehicle, in particular a rail vehicle, said motor (1.1 ) being mechanically connected to a gearing unit (1.2; 1.2') for driving a wheel (1.3) of said vehicle and to at least one auxiliary arrangement (3) of said vehicle for providing power to said auxiliary arrangement (3), said auxiliary arrangement (3) providing at least one auxiliary function of said vehicle, wherein in a first step (5.2; 5.15), a desired fuel supply signal is provided, said desired fuel supply signal being representative of an amount of fuel desired to be supplied to said motor, in a second step (5.4; 5.17), an actual motor speed of said motor (1.1 ) is determined, in a third step (5.8; 5.19; 5.19'; 5.19"), an actual fuel supply value representing an amount of fuel to be supplied to said motor (1.1) is determined dependent on said desired fuel supply signal and on an actual auxiliary power consumption of said auxiliary arrangement (3) at said actual motor speed, said actual fuel supply value being determined to respect an upper power limit of the power to be supplied to said gearing unit (1.2; 1.2') at said actual motor speed, and in a fourth step (5.12; 5.25), said actual fuel supply value is used for controlling the fuel supply to said motor (1.1), characterized in that said actual fuel supply value is determined dependent on said actual motor speed using a characteristic line, said characteristic line being selected, in a selection step (5.10; 5.20; 5.30; 5.32), from a previously established set of characteristic lines, - each characteristic line of said set representing a value representative of an amount of fuel to be supplied to said motor (1.1 ) as a function of the motor speed of said motor (1 .1 ).

2. Method according to claim 1 , characterized by continuously repeating at least said second, third and fourth step for continuously controlling said motor (1.1 ).

3. Method according to claim 1 or 2, characterized in that said selection in said selection step is performed dependent on an operational state of said auxiliary arrangement (3).

4. Method according to claim 3, characterized in that execution of said second, third and fourth step is triggered by a detection of a change in said operational state of said auxiliary arrangement (3).

5. Method according to any one of the preceding claims, characterized in that said auxiliary arrangement (3) has at least a first operational state with a first power consumption of said auxiliary arrangement (3) and a second operational state with a second power consumption of said auxiliary arrangement (3), said set of characteristic lines comprises at least a first characteristic line associated with said first operational state and at least a second characteristic line associated with said second operational state, and, in said selection step, said first characteristic line is selected if said auxiliary ar- rangement (3) is in said first operational state, and said second characteristic line is selected if said auxiliary arrangement (3) is in said second operational state.

6. Method according to claim 5, characterized in that said first characteristic line is representative of a first maximum fuel supply value representative of a first maximum amount of fuel to be supplied to said motor (1.1 ) as a function of the motor speed of said motor (1.1). said second characteristic line is representative of a second maximum fuel supply value representative of a second maximum amount of fuel to be supplied to said motor (1.1 ) as a function of the motor speed of said motor (1.1 ), said desired fuel supply signal is compared to a maximum fuel supply signal, said maximum fuel supply signal being representative of the maximum fuel supply value taken at said motor speed from said characteristic line selected in said selection step, said actual fuel supply value is determined in said third step from said desired fuel supply signal if said desired fuel supply signal is inferior to said maximum fuel supply signal, - said actual fuel supply value is determined in said third step from said maximum fuel supply signal if said desired fuel supply signal is superior to said maximum fuel supply signal.

7. Method according to claim 5 or 6, characterized in that - said gearing unit (1.2') has a first mode of operation with a first upper power limit of the power to be supplied to said gearing unit (1.2') at said actual motor speed, said gearing unit (1.2') has a second mode of operation with a second upper power limit of the power to be supplied to said gearing unit (1.2') at said actual motor speed, - said set of characteristic lines comprises at least a first subset of characteristic lines comprising at least said first characteristic line, said set of characteristic lines comprises at least a second subset of characteristic lines comprising at least said second characteristic line, in a selection step (5.29), said first subset is selected if said auxiliary arrangement (3) is in said first operational state, and said second subset is selected if said auxiliary arrangement (3) is in said second operational state, and, in a further selection step (5.30), said characteristic line is selected from the selected subset depending on said mode of operation of said gearing unit (1.2).

8. Method according to any one of claims 5 to 7, characterized in that - said set of characteristic lines comprises at least a first subset of characteristic lines comprising at least said first characteristic line, said set of characteristic lines comprises at least a second subset of characteristic lines comprising at least said second characteristic line, and, in said selection step (5.10), said characteristic line is selected from the respec- tive subset dependent on said desired fuel supply signal.

9. Method according to any one of the preceding claims, characterized in that said auxiliary arrangement comprises a plurality of auxiliary units (3.1 , 3.2, 3.3, 3.4, 3.5, 3.6) being, at least in part, selectively operative, wherein - different combinations of auxiliary units (3.1 , 3.2, 3.3, 3.4, 3.5, 3.6) being operative at a time represent different operational states of said auxiliary arrangement (3) said set of characteristic lines comprises a subset of characteristic lines for each of said operational states, each subset comprising at least one characteristic line, and, in said selection step (5.10; 5.30), said characteristic line is selected from the subset corresponding to the currently prevailing actual operational state of said auxiliary arrangement.

10. Method according to claim 9, characterized in that said set of characteristic lines comprises a subset for each operational state of a first group of operational states, said first group of operational states being a fraction of all theoretically possible operational states.

11. Method according to claim 9 or 10, characterized in that each of said subsets com- prises a plurality of characteristic lines, and, in said selection step (5.10), said characteristic line is selected from the respective subset dependent on said desired fuel supply signal.

12. Method according to any one of the preceding claims, characterized in that said actual fuel supply value is determined from a first fuel supply value, said first fuel supply value being determined using said selected characteristic line using said actual motor speed.

13. Method according to claim 12, characterized in that said actual fuel supply value is set equal to said first fuel supply value.

14. Method according to claim 12, characterized in that said actual fuel supply value is calculated from said first fuel supply value as a function of said desired fuel supply signal.

15. Method according to any one of the preceding claims, characterized in that said auxiliary arrangement comprises a plurality of auxiliary units (3.1 , 3.2, 3.3, 3.4, 3.5, 3.6) being, at least in part, provided with power via at least one buffer unit (3.6).

16. Method according to any one of the preceding claims, characterized in that said selection of said characteristic line in said selection step (5.10; 5.20; 5.30; 5.32) is performed dependent on an operational state of said auxiliary arrangement, - said selected characteristic line has been established in such a manner that, with any first fuel supply value used to fuel said motor (1.1 ) and taken from said characteristic line at a given motor speed, the difference between the power provided by said motor (1.1) at said given motor speed and a power consumed by said auxiliary arrangement (3) in said operational state and at said given motor speed is not exceeding said upper power limit of the power to be supplied to said gearing unit (1.2; 1.2') at said given motor speed.

17. Control arrangement for controlling a combustion motor of a vehicle, in particular a rail vehicle, comprising a control unit (2.1 ) being connectable to said motor (1.1 ), said motor (1.1 ) being mechanically connected to a gearing unit (1.2; 1.2') for driving a wheel (1.3) of said vehicle and to at least one auxiliary arrangement (3) of said vehicle for providing power to said auxiliary arrangement (3), said auxiliary arrangement (3) providing at least one auxiliary function of said vehicle, said control unit (2.1 ) being adapted to receive a desired fuel supply signal, said desired fuel supply signal being rep- resentative of an amount of fuel desired to be supplied to said motor, - to receive an actual motor speed signal representative of an actual motor speed of said motor (1.1 ), to determine an actual fuel supply value representing an amount of fuel to be supplied to said motor (1.1 ) dependent on said desired fuel supply signal and on an actual auxiliary power consumption of said auxiliary arrangement (3) at said actual motor speed, said actual fuel supply value being determined to respect an upper power limit of the power to be supplied to said gearing unit (1 .2; 1.2') at said actual motor speed, and, - to use said actual fuel supply value for controlling the fuel supply to said motor (1 .1 ), characterized in that said control unit (2.1 ) comprises a first memory (2.3) having stored therein a set of characteristic lines, each characteristic line of said set representing a value repre- sentative of an amount of fuel to be supplied to said motor (1.1 ) as a function of the motor speed of said motor (1.1 ), and said control unit (2.1 ) is adapted to select a characteristic line from said set of characteristic lines, and to determine said actual fuel supply value dependent on said actual motor speed signal using said selected characteristic line.

18. Control arrangement according to claim 15, characterized in that said control unit (2.1 ) is adapted to continuously determine said actual fuel supply value for continuously controlling said motor (1.1 ).

19. Control arrangement according to claim 15 or 16, characterized in that said control unit (2.1 ) is adapted to receive an actual operational state signal, said actual operational state signal being representative of an operational state of said auxiliary arrangement (3), and to perform said selection of said characteristic line dependent on said operational state signal.

20. Control arrangement according to claim 17, characterized in that said control unit (2.1 ) is adapted to detect a change in said actual operational state signal and to execute, in response to detection of said change, said determination of said actual fuel supply value, or in that - said control unit (2.1 ) is adapted to receive the change signal, said change signal being representative of a change in said actual operational state, and to execute, in response to receipt of said change signal, said determination of said actual fuel supply value.

21 . Control arrangement according to any one of the claims 15 to 18, characterized in that said auxiliary arrangement (3) has at least a first operational state with a first power consumption of said auxiliary arrangement (3) and a second operational state with a second power consumption of said auxiliary arrangement (3), said set of characteristic lines comprises at least a first characteristic line associated with said first operational state and at least a second characteristic line associated with said second operational state, and, said control unit (2.1 ) is adapted to select said first characteristic line if said actual operational state signal is indicative of said auxiliary arrangement (3) being in said first operational state, and to select said second characteristic line if said actual operational state signal is indicative of said auxiliary arrangement (3) being in said second operational state.

22. Control arrangement according to claim 21 , characterized in that - said first characteristic line is representative of a first maximum fuel supply value representative of a first maximum amount of fuel to be supplied to said motor (1.1 ) as a function of the motor speed of said motor (1.1 ). said second characteristic line is representative of a second maximum fuel supply value representative of a second maximum amount of fuel to be supplied to said motor (1 .1 ) as a function of the motor speed of said motor (1.1 ), said control unit (2.1 ) is adapted to compare said desired fuel supply signal to a maximum fuel supply signal, said maximum fuel supply signal being representative of the maximum fuel supply value taken at said motor speed from said characteristic line selected in said selection step, - said control unit (2.1 ) is adapted to determine said actual fuel supply value from said desired fuel supply signal if said desired fuel supply signal is inferior to said maximum fuel supply signal, and said control unit (2.1 ) is adapted to determine said actual fuel supply value from said maximum fuel supply signal if said desired fuel supply signal is superior to said maximum fuel supply signal.

23. Control arrangement to claim 21 or 22, characterized in that said gearing unit (1.2') has a first mode of operation with a first upper power limit of the power to be supplied to said gearing unit (1.2') at said actual motor speed, said gearing unit (1.2') has a second mode of operation with a second upper power limit of the power to be supplied to said gearing unit (1.2') at said actual motor speed, said set of characteristic lines comprises at least a first subset of characteristic lines comprising at least said first characteristic line, said set of characteristic lines comprises at least a second subset of characteristic lines comprising at least said second characteristic line, - said control unit (2.1 ) is adapted to select said first subset if said auxiliary arrangement (3) is in said first operational state, and to select said second subset if said auxiliary arrangement (3) is in said second operational state, and, said control unit (2.1 ) is adapted to select said characteristic line from the selected subset depending on said mode of operation of said gearing unit (1.2").

24. Control arrangement according to any one of claims 21 to 23, characterized in that said set of characteristic lines comprises at least a first subset of characteristic lines comprising at least said first characteristic line, said set of characteristic lines comprises at least a second subset of characteristic lines comprising at least said second characteristic line, and, - said control unit (2.1 ) is adapted to select said characteristic line from the respective subset dependent on said desired fuel supply signal.

25. Control arrangement according to any one of claims 17 to 24, characterized in that said auxiliary arrangement (3) comprises a plurality of auxiliary units (3.1 , 3.2, 3.3, 3.4, 3.5, 3.6) being, at least in part, selectively operative, wherein different combinations of auxiliary units (3.1 , 3.2, 3.3, 3.4, 3.5, 3.6) being operative at a time represent different operational states of said auxiliary arrangement (3), said control unit (2.1 ) is adapted to receive an actual operational state signal, said actual operational state signal being representative of an actual operational state of said auxiliary arrangement (3), - said set of characteristic lines comprises a subset of characteristic lines for each of said operational states, each subset comprising at least one characteristic line, and said control unit (2.1 ) is adapted to select said characteristic line from the subset corresponding to said actual operational state signal.

26. Control arrangement according to claim 25, characterized in that said set of characteristic lines comprises a subset for each operational state of a first group of operational states, said first group of operational states being a fraction of all theoretically possible operational states.

27. Control arrangement according to claim 25 or 26, characterized in that each of said subsets comprises a plurality of characteristic lines and said control unit (2.1 ) is adapted to select said characteristic line from the respective subset dependent on said desired fuel supply signal.

28. Control arrangement according to any one of claims 17 to 27, characterized in that said control unit (2.1 ) is adapted to determine a first fuel supply value from said selected characteristic line using said actual motor speed signal, and to determine said actual fuel supply value from said first fuel supply value.

29. Control arrangement according to claim 28, characterized in that said control unit (2.1 ) is adapted to set said actual fuel supply value equal to said first fuel supply value.

30. Control arrangement according to claim 28, characterized in that said control unit (2.1 ) is adapted to calculate said actual fuel supply value from said first fuel supply value as a function of said desired fuel supply signal.

31. Control arrangement according to any one of claims 17 to 30, characterized in that said control unit (2.1 ) is adapted to select said characteristic line dependent on an operational state of said auxiliary arrangement (3), and said selected characteristic line has been established in such a manner that, with any first fuel supply value used to fuel said motor (1.1 ) and taken from said char- acteristic line at a given motor speed, the difference between the power provided by said motor (1.1 ) at said given motor speed and a power consumed by said auxiliary arrangement (3) in said operational state and at said given motor speed is not exceeding said upper power limit of the power to be supplied to said gearing unit (1.2; 1.2') at said given motor speed.

32. Vehicle, in particular rail vehicle, comprising a combustion motor (1.1), a gearing unit (1.2) and at least one auxiliary arrangement (3) for providing at least one auxiliary function of said vehicle, said motor (1.1 ) being mechanically connected to said gearing unit (1.2; 1.2') for driving a wheel (1.3) of said vehicle and to said auxiliary ar- rangement (3) of said vehicle for providing power to said auxiliary arrangement (3), characterized by a control arrangement (2) according to any one of claims 17 to 31 for controlling said motor (1.1 ).

33. Vehicle according to claim 32, characterized in that said auxiliary arrangement (3) comprises a plurality of auxiliary units (3.1 , 3.2, 3.3, 3.4, 3.5, 3.6) being, at least in part, provided with power via at least one buffer unit (3.6).

34. Vehicle according to claim 33, characterized in that said buffer unit comprises a battery unit (3.6).

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