Method for operating motor vehicle and corresponding motor vehicle

Abstract

The invention relates to a method for operating a motor vehicle (1), the motor vehicle (1) having a drive unit (3) and a plurality of drive-by-wire controllers (6). According to the invention, a central computing device (9) of the motor vehicle (1) determines an overall state on the basis of a state report transmitted by the control device (6) and actuates the drive unit (3) and / or the control device (6) as a function of the overall state. The invention also relates to a motor vehicle (1).

Description

Technical Field

[0001] The invention relates to a method for operating a motor vehicle, wherein the motor vehicle has a drive unit and a plurality of drive-by-wire control devices. The invention also relates to a motor vehicle. Background Art

[0002] The prior art discloses, for example, document DE 197 35 018 A1, which describes a system architecture for realizing functions in a motor vehicle, comprising at least two drive-by-wire systems, the control devices of which are connected to one another directly or via a bus structure.

[0003] Furthermore, document DE 197 10 082 A1 describes a drive train for a commercial vehicle, in particular for an agricultural or industrial tractor, comprising a generator driven by an internal combustion engine, at least one drive axle (the wheels of the drive axle are each driven by an associated electric motor powered by the generator), at least one steering axle (the wheels of the steering axle are steered together or individually by a steering actuator) and manual operating elements for at least steering and speed setting driving functions.

[0004] In addition, document WO 99 / 39950 A1 discloses a method for controlling or regulating a vehicle brake system according to the brake-by-wire principle, the vehicle brake system having a brake pedal with a pedal mechanism and a pedal sensor system, an electronic evaluation unit and a wheel brake module, the method comprising the following steps: detecting the driver's brake pedal actuation by at least two measuring devices, the measuring devices determining a variable characterizing the brake pedal actuation; determining the driver's braking request in the electronic evaluation unit based on the signal of the measuring device. It is proposed that the measuring device determines the same variable characterizing the brake pedal actuation to determine the braking request, and derives another measured variable for monitoring the pedal mechanism and the pedal sensor, and compares it with the brake request signal in the electronic evaluation unit. Summary of the invention

[0005] The object of the present invention is to provide a method for operating a motor vehicle which has advantages over known methods and which always enables reliable and safe operation of the motor vehicle, in particular in the case of a drive-by-wire control device without a mechanical fallback stage.

[0006] This is achieved according to the invention by a method for operating a motor vehicle having the features of claim 1. It is provided that a central computer of the motor vehicle determines an overall state based on the state reports transmitted by the control device and controls the drive unit and / or the control device as a function of the overall state.

[0007] Advantageous embodiments with suitable developments of the invention are specified in the dependent claims. It should be pointed out that the exemplary embodiments described in the description are not restrictive; rather, any variants of the features disclosed in the description, the claims and the drawings can be implemented.

[0008] The method is used for operating a motor vehicle. The motor vehicle has a power unit and a drive-by-wire control device. The power unit is used to drive the motor vehicle, i.e. to provide a drive torque intended to drive the motor vehicle. To provide the drive torque, the power unit has at least one power device, such as an internal combustion engine or a power motor. Of course, the power unit can also have a plurality of power devices, which together provide the drive torque at least temporarily. Preferably, in this case there are different types of power devices; for example, one of the power devices takes the form of an internal combustion engine and another of the power devices takes the form of a power motor.

[0009] The motor vehicle also has a plurality of drive-by-wire control devices. This refers to control devices that are operated only electrically, i.e. without a mechanical fallback stage. The drive-by-wire control devices include, for example, one or more brake-by-wire control devices, one or more steering-by-wire control devices and / or one or more shift-by-wire control devices. The control device can thus be intended for braking, steering or shifting or can perform these functions at least temporarily.

[0010] Brake-by-wire control devices are used for braking, steering-by-wire control devices are used for steering, and shift-by-wire control devices are used for shifting gears. Each brake-by-wire control device includes one or more wheel brakes with brake actuators, which are actuated purely electronically. The steering-by-wire control devices each have a steering actuator, by means of which the steering angle of the motor vehicle can be adjusted in each case, which is also actuated purely electronically.

[0011] Finally, the shift-by-wire control device has a shift actuator which is arranged in a transmission of the motor vehicle. The transmission serves to set a selected gear from a plurality of different gears or to set a corresponding transmission ratio between the power unit or one of the power units and at least one drive wheel of the motor vehicle. The shift actuator is arranged and designed to set the selected gear or the selected transmission ratio on the transmission. The shift actuator is also actuated purely electronically.

[0012] Each wire control device is arranged and designed to influence the driving operation of the motor vehicle, such as braking, steering or gear shifting. Each control device has, for example, an operating element, which is arranged in the passenger compartment of the motor vehicle and is operatively connected to an actuator of the motor vehicle completely electronically, i.e. without a mechanical backup stage. The same type of control devices can of course use the same operating elements. The wire brake control devices are thus actuated jointly by means of a brake operating device, in particular a brake pedal. The wire steering control devices have a common steering control device, in particular a common steering wheel or the like. The actuator is, for example, a wheel brake or one of a wheel brake, a steering actuator or a gear shift actuator.

[0013] In conventional motor vehicles, there is always a mechanical connection between the corresponding operating element and the corresponding actuator, at least as a backup stage. Electronic control of the corresponding actuator can be provided in addition, for example, brake boosters, power steering, etc. are operated electrically. This means that even if the power supply fails, the motor vehicle can still be operated reliably, namely by means of a mechanical backup stage, although this may require greater energy consumption.

[0014] However, the motor vehicle on which the method according to the invention is based has a plurality of drive-by-wire control devices, in which no such mechanical fallback stage is present. Nevertheless, the driving operation of the motor vehicle can still be carried out reliably and safely. For this purpose, each control device transmits a status report to the central computing device at least temporarily. Preferably, the status reports are transmitted cyclically or continuously from the respective control device to the central computing device. In the case of cyclic transmission, the intervals between successive status report transmissions are designed so that even if a malfunction suddenly occurs in the central computing device, countermeasures can be taken in sufficient time to ensure the safety of the motor vehicle.

[0015] The central computing device is preferably separated from the control device and thus constitutes an additional device of the motor vehicle. The central computing device and the control device are connected to one another in terms of communication technology, in particular via a bus system, for example via a CAN bus or a Flexray bus. However, it can also be provided that one of the control devices has a central computing device or assumes the tasks of a central computing device. In this case, however, the control device and the central computing device are formed by different circuits, so that a failure of the control device does not mean a failure of the central computing device. Particularly preferably, the central computing device is part of the control device of the power unit, which control device can also be referred to as the power unit control device. In this case, it is ensured that the power unit control device does not work and therefore the power unit does not operate in the event of a failure of the central computing device.

[0016] The central computing device receives the status reports transmitted by the control devices and determines the overall status based on the status reports. This means that the overall status depends on all status reports transmitted by the control devices. The absence of a status report from one or more control devices can also be incorporated into the overall status. The overall status can thus be associated with the status reports. The overall status describes the overall operating condition of a plurality of drive-by-wire control devices and thus of the technical equipment of the motor vehicle. The central computing device controls the power unit and / or the control device based on the overall status, in particular influencing the driving operation of the motor vehicle. This is preferably understood to mean that the central computing device transmits a control command to the power unit and / or the control device, which control command depends on the overall status.

[0017] The power device and / or the control device are in turn controlled according to the transmitted control command. Based on the control command, for example, the power device is allowed or prevented from working, or the power device is shut down. It can also be provided that based on the control command, one of the control devices is controlled to influence the driving operation of the motor vehicle, such as braking, steering or shifting.

[0018] The central computing device, which can also be referred to as a central coordinator, is therefore used to collect the status reports and summarize them into an overall status and to control at least one device of the motor vehicle, namely the power unit and / or the control device. This allows for a centralized control of the motor vehicle in order to ensure its safety at all times. In addition, the central computing device can be used to provide a consistent display to the user of the motor vehicle, which is not based on individual status reports, but on the overall status. This avoids confusing the user with different status reports of the display control devices. Overall, a safe and consistent operation of the motor vehicle is thus achieved.

[0019] An improved solution of the present invention provides that each control device performs a self-diagnosis and determines the control device operating state and / or the remaining mileage parameter of the motor vehicle based on the result of the self-diagnosis, and the control device operating state or the remaining mileage parameter is transmitted to the central computing device in the respective status report. The remaining mileage parameter is in particular the remaining mileage time or the remaining mileage distance. The remaining mileage time describes the time that can still be driven, and the remaining mileage distance describes the distance that can still be driven. Self-diagnosis is used to determine the operating state of the corresponding control device. If it is determined in the self-diagnosis that the corresponding control device can operate normally, this is recorded in the control device operating state and transmitted to the central computing device as a status report. If, on the other hand, it is determined in the self-diagnosis that there is a fault in the corresponding control device, the fault is recorded in the control device operating state.

[0020] Additionally or alternatively, in the presence of a fault, a remaining mileage parameter of the motor vehicle is determined, for example, as permitted based on legal provisions. The remaining mileage parameter is read out, for example, from a table storing the fault or the control device operating condition, based on the fault or the control device operating condition. The control device operating condition and / or the remaining mileage parameter is then transmitted to the central computing device in the form of a status report. The remaining mileage parameter, in particular the remaining mileage time or the remaining mileage distance, is measured from the first occurrence of the fault or is used from that point in time. This approach ensures that the status report transmitted by the control device always reflects the actual state of the control device. For this purpose, the self-diagnosis of each control device is preferably performed at least before the power equipment workbench, but is particularly preferably additionally performed periodically or continuously after the power equipment is started.

[0021] A further development of the invention provides that the control device is supplied with power by the power supply device, wherein the power supply device performs a self-diagnosis and determines the power supply device operating state and / or another remaining range parameter of the motor vehicle based on the result of the self-diagnosis, the power supply device operating state and the other remaining range parameter of the motor vehicle are transmitted to the central computing device in a further status report, and the central computing device takes the other status report into account when determining the overall status. The power supply device is used to supply power to the control device. If the power supply device fails, power is no longer supplied to the control device, and the control device is therefore no longer functional.

[0022] The execution process of the self-diagnosis of the power supply unit is similar to that of the control unit. The results of the self-diagnosis are summarized in the power supply unit operating condition or in another remaining mileage parameter and transmitted to the central computing device as another status report. Similar to the remaining mileage parameter, the other remaining mileage parameter is preferably another remaining mileage time or another remaining mileage distance. The central computing device receives the other status report and takes it into account when determining the overall status. In particular, the overall status is based on the power supply unit operating condition and / or another remaining mileage parameter of the motor vehicle. The other remaining mileage parameter describes the time during which the motor vehicle can be safely operated based on the self-diagnosis results. Legal provisions should be taken into account in particular. Incorporating the self-diagnosis results of the power supply unit into the determination of the overall status enables a particularly reliable and comprehensive diagnosis of the motor vehicle.

[0023] According to a further development of the invention, the overall state comprises an overall operating state determined as a function of the operating state of the control device and / or the operating state of the power supply device, and / or the overall state comprises an overall remaining range parameter determined as a function of the remaining range parameter and / or another remaining range parameter. Thus, the overall state comprises the overall operating state or the overall remaining range parameter, or both. The overall operating state is determined by the operating state of the control device and optionally by the operating state of the power supply device. Similarly, the overall remaining range parameter is determined by the remaining range parameter of the control device and optionally by another remaining range parameter of the power supply device.

[0024] For example, the overall operating condition is set to a first value corresponding to a fully functioning motor vehicle only if the control device operating condition and / or the power device operating condition indicates that the corresponding device is fully functioning. If one of the control device operating condition and / or the power device operating condition indicates a fault in the corresponding device, the overall operating condition is set to a second value indicating the fault. The overall remaining mileage parameter is preferably set to the shortest of the remaining mileage parameters and / or the further remaining mileage parameters. This ensures that the motor vehicle can operate reliably and safely throughout the remaining mileage parameters. The overall remaining mileage parameter is measured from the first occurrence of a fault in one of the devices or is used from this point on.

[0025] An improvement of the invention provides that, when the value of the control device operating condition corresponds to a functioning / functional control device and / or the value of the power device operating condition corresponds to a functioning power device, the overall operating condition is set to a first overall operating condition value; and / or, when the value of one of the control device operating conditions corresponds to a functioning malfunctioning control device and / or the value of the power device operating condition corresponds to a functioning malfunctioning power device, the overall operating condition is set to a second overall operating condition value. This has already been explained.

[0026] Only if all control device operating conditions or power supply device operating conditions indicate that the corresponding device functions normally, the overall operating condition has a first overall operating condition value. On the contrary, if only one of the control device operating conditions and / or the power supply device operating condition has a value indicating abnormal function of the device, the overall operating condition is set to a second overall operating condition value. Thus, a high safety of the motor vehicle is achieved.

[0027] A further development of the invention provides that the overall remaining range variable is set to the minimum value of the remaining range variables and / or of the further remaining range variables. This has also been pointed out. The use of the minimum value for the overall remaining range variable has the particular advantage that a remaining range variable is always displayed to the user of the motor vehicle with which the motor vehicle can still be operated reliably and safely.

[0028] An improved scheme of the present invention stipulates that the self-diagnosis of the control device and the transmission of the status report to the central computing device are performed when the power equipment is stopped, and the power equipment is allowed to operate only when the determined overall operating condition has a first overall operating condition value and / or the overall remaining mileage parameter has not been exhausted, and / or the self-diagnosis of the control device and the transmission of the status report to the central computing device are performed when the power equipment is operating, and when the determined overall operating condition has a second overall operating condition value and / or the overall remaining mileage parameter is exhausted, the power equipment and / or the control device are controlled to stop the motor vehicle.

[0029] The self-diagnosis of the control device and the transmission of the status report are therefore carried out when the power device is shut down, or when the power device is operating, or both when the power device is shut down and when the power device is operating. A shut down power device means that the power device is not ready to provide a drive torque. For example, for a shut down internal combustion engine, the ignition and / or fuel supply is interrupted. In particular, the speed of the internal combustion engine is zero. For example, for a shut down power motor, the power supply to the power motor, in particular its power electronics, is interrupted. When the power device is operating, the power device is ready to provide a drive torque, so the internal combustion engine is operating and has a non-zero speed; the power motor or its power electronics are powered.

[0030] If the power device is shut down, operation of the power device is permitted only if the overall operating condition indicates that the control device or the power supply device can operate normally and therefore the overall operating condition has a first overall operating condition value and / or the overall remaining mileage parameter has not been exhausted. If the overall operating condition does not have the first overall operating condition value or the overall remaining mileage parameter has been exhausted, operation of the power device is prevented.

[0031] Additionally or alternatively, the described approach is applied to the case where the power unit is operating. If in this case the overall operating condition does not have the first overall operating condition value and / or the overall remaining range parameter is exhausted, the power unit and / or the control device are controlled to stop the motor vehicle. Otherwise, the driving operation is allowed to continue. The advantage of this approach is that if one of the control devices fails, the motor vehicle is not allowed to start, or the driving operation of the motor vehicle is ended immediately or with a delay in the event of a failure. This ensures a high safety of the motor vehicle.

[0032] An improvement of the present invention provides that a plurality of the following devices are used as control devices: a brake-by-wire control device, a steering-by-wire control device and a shift-by-wire control device. Different control devices have been indicated. The control device preferably comprises a plurality of brake-by-wire control devices and / or a plurality of steering-by-wire control devices and / or a plurality of shift-by-wire control devices, wherein each control device is designed redundantly with respect to one another. Each of the plurality of brake-by-wire control devices is thus configured and designed for braking the same or the same plurality of wheels of a motor vehicle. Similarly, each steering-by-wire control device is configured and designed for setting the steering angle of a motor vehicle. A plurality of shift-by-wire control devices are configured and designed for operating the same transmission. With the aid of the redundant design of the control device, a high safety of the motor vehicle is achieved.

[0033] A development of the invention provides that the overall status is displayed to a user of the motor vehicle by means of a display device. The display device is, for example, an optical, acoustic and / or tactile display device. For example, the overall operating condition of the motor vehicle and / or the overall remaining range parameter are displayed to the user. The advantage of using the overall status for the display device is that a uniform and consistent display is provided to the user. This avoids the display of individual status reports from the control device, which could be inconsistent and confusing for the user.

[0034] The invention also relates to a motor vehicle, in particular to a method for carrying out the embodiments of the present description, which has a power plant and a plurality of wire control devices. A central computing device of the motor vehicle is arranged and designed to determine the overall status from the status reports transmitted by the control devices and to actuate the power plant and / or the control devices according to the overall status.

[0035] The advantages of this design or this approach for a motor vehicle have already been pointed out.Both the motor vehicle and the method for operating a motor vehicle can be improved according to the embodiments of the present description, to which reference is therefore made.

[0036] The features and feature combinations described in the description, in particular the features and feature combinations described in the following description of the figures and / or shown in the figures, can be used not only in the combination specified in each case, but also in other combinations or alone, without departing from the scope of the present invention. Therefore, embodiments which are not explicitly shown or explained in the description and / or the figures, but which are revealed from the explained embodiments or can be derived from them, are also considered to be included in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is described in more detail below with reference to the embodiments shown in the accompanying drawings, but without limiting the present invention. In the only accompanying drawing:

[0038] Figure 1 A schematic diagram of a motor vehicle having a power plant and a plurality of drive-by-wire controls is shown. DETAILED DESCRIPTION

[0039] Figure 1 A schematic diagram of a motor vehicle 1 is shown. The motor vehicle 1 has a display device 2, which is arranged in the interior of the motor vehicle 1, in particular in the passenger compartment. The display device 2 is preferably located on the dashboard of the motor vehicle 1. In addition, the motor vehicle 1 has a power device 3 and a driving assistance device 4. In addition, a power supply device 5 and a plurality of wire control devices 6 are part of the motor vehicle. There are a plurality of control devices 6 used as wire brake control devices 7 and a plurality of control devices 6 used as wire steering control devices 8. The control devices 6 are thus designed redundantly.

[0040] The control device 6 and the power supply device 5 each carry out a self-diagnosis and transmit the results of the self-diagnosis in a status report to a central computing device 9, which is also part of the motor vehicle 1. The central computing device 9 determines the overall status based on the individual status reports from the control device 6 and the power supply device 5 and controls the power device 3 and / or the control device 6 based on the overall status. In addition, it can be provided that the overall status is displayed to a user of the motor vehicle 1 via the display device 2.

[0041] This control is performed in such a way that the operation of the power device 3 is allowed or blocked depending on the overall state. "Operation" is understood as being ready to provide a drive torque intended to drive the motor vehicle. If the operation of the power device 3 is blocked, the power device cannot provide a drive torque, so that the motor vehicle 1 remains stationary. If the motor vehicle 1 is already in motion, the driving assistance device 4 can be controlled to brake the motor vehicle 1 depending on the overall state. To this end, the driving assistance device 4 controls the corresponding control device 6, more precisely the brake-by-wire control device 7. Preferably, not only one brake-by-wire control device 7, but multiple, in particular all brake-by-wire control devices 7 are controlled to brake the vehicle 1. This makes the operation of the motor vehicle 1 more reliable.

[0042] List of reference numerals:

[0043] 1Motor Vehicles

[0044] 2Display device

[0045] 3 Power equipment

[0046] 4 Driving assistance devices

[0047] 5. Power supply unit

[0048] 6-wire control device

[0049] 7 Brake-by-wire control device

[0050] 8-wire steer control

[0051] 9Central computing unit

Claims

1. A method for operating a motor vehicle (1), wherein: The motor vehicle (1) has a power device (3) and a plurality of wire control devices (6), characterized in that a central computing device (9) of the motor vehicle (1) determines an overall state based on a state report transmitted by the control device (6), and controls the power device (3) and / or the control device (6) according to the overall state.

2. The method according to claim 1, characterized in that Each control unit (6) performs a self-diagnosis and determines the control unit operating state and / or the remaining mileage parameter of the motor vehicle (1) based on the results of the self-diagnosis. The control unit operating state and the remaining mileage parameter are transmitted to the central computing unit (9) within the scope of a corresponding status report.

3. The method according to any one of the preceding claims, characterized in that The control device (6) is supplied with power by a power supply device (5), which performs a self-diagnosis and determines the power supply device operating condition and / or other remaining range parameters of the motor vehicle (1) based on the results of the self-diagnosis. The power supply device operating condition and / or other remaining range parameters of the motor vehicle are transmitted to the central computing device (9) in a further status report, and the central computing device (9) takes this further status report into account when determining the overall status.

4. The method according to any one of the preceding claims, characterized in that The overall state includes an overall operating state determined based on an operating state of the control device and / or an operating state of the power device, and / or the overall state includes an overall remaining range parameter determined based on the remaining range parameter and / or the further remaining range parameter.

5. The method according to any one of the preceding claims, characterized in that When the value of the control device operating condition corresponds to a normally functioning control device (6) and / or the value of the power device operating condition corresponds to a normally functioning power device (5), the overall operating condition is set to a first overall operating condition value; and / or, when the value of one of the control device operating conditions corresponds to a malfunctioning control device (6) and / or the value of the power device operating condition corresponds to a malfunctioning power device (5), the overall operating condition is set to a second overall operating condition value.

6. The method according to any one of the preceding claims, characterized in that The overall remaining-range variable is set to the minimum value of the remaining-range variable and / or of the further remaining-range variable.

7. The method according to any one of the preceding claims, characterized in that The self-diagnosis of the control device (6) and the transmission of the status report to the central computing device (9) are performed when the power device (3) is shut down, and the power device (3) is allowed to operate only when the determined overall operating condition has a first overall operating condition value and / or the overall remaining mileage parameter has not been exhausted, and / or the self-diagnosis of the control device (6) and the transmission of the status report to the central computing device (9) are performed when the power device (3) is operating, and when the determined overall operating condition has a second overall operating condition value and / or the overall remaining mileage parameter has been exhausted, the power device (3) and / or the control device (6) are controlled to stop the motor vehicle (1).

8. The method according to any one of the preceding claims, characterized in that A plurality of the following devices are used as the control device (6): a brake-by-wire control device (7), a steering-by-wire control device (8) and a shift-by-wire control device (9).

9. The method according to any one of the preceding claims, characterized in that The overall status is displayed to a user of the motor vehicle (1) by means of a display device (2).

10. A motor vehicle (1), in particular for carrying out the method according to one or more of the preceding claims, wherein: The motor vehicle (1) comprises a power unit (3) and a plurality of drive-by-wire control devices (6), characterized in that a central computing device (9) of the motor vehicle (1) is arranged and designed to determine an overall state based on a state report transmitted by the control device (6) and to control the power unit (3) and / or the control device (6) according to the overall state.

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