Method, device and motor vehicle for operating a motor vehicle

Abstract

The invention relates to a method for operating a motor vehicle (1), the motor vehicle having an adjusting element (22) which is displaceable, in particular continuously, between a first end position and a second end position, wherein the current position of the adjusting element (22) is monitored, wherein a deceleration torque for the motor vehicle (1) is predetermined when the current position is in a deceleration range between the first end position and a predeterminable change position, and wherein an acceleration torque for the motor vehicle (1) is predetermined when the current position is in an acceleration range between the second end position and the change position. Provision is made for monitoring the occurrence of at least one disturbance variable which influences the actual deceleration of the motor vehicle (1) caused by the deceleration torque, wherein the deceleration torque is varied as a function of the detected disturbance variable.

Description

Technical Field

[0001] The present invention relates to a method for operating a motor vehicle having an adjusting element which is displaceable, in particular steplessly, between a first end position and a second end position, wherein the current position of the adjusting element is monitored, wherein a deceleration torque for the motor vehicle is predetermined when the current position is in a deceleration range between the first end position and a predeterminable change position, and wherein an acceleration torque for the motor vehicle is predetermined when the current position is in an acceleration range between the second end position and the change position.

[0002] Furthermore, the present invention relates to a device for operating a motor vehicle, comprising a control unit.

[0003] The invention further relates to a motor vehicle having such a device. Background Art

[0004] Methods and motor vehicles of the type mentioned at the outset are known from the prior art. In particular, motor vehicles with drive motors increasingly have adjusting elements with a so-called single-pedal function. Such adjusting elements can selectively predetermine an acceleration torque or a deceleration torque. The adjusting element is movable between a first end position and a second end position, wherein switching positions are predetermined between the end positions. In order to operate the motor vehicle using the adjusting element, the current position of the adjusting element is monitored. In this case, a deceleration torque for the motor vehicle is predetermined when the current position is within a deceleration range between the first end position and the switching position, that is, when the current position of the adjusting element does not exceed the switching position. However, if the current position of the adjusting element is within an acceleration range between the switching position and the second end position, thereby exceeding the switching position, an acceleration torque for the motor vehicle is predetermined. Summary of the Invention

[0005] The method according to the present invention improves driving comfort for a motor vehicle user when the motor vehicle is decelerated using the control element. To this end, the present invention provides for monitoring the presence of at least one disturbance variable that influences the actual deceleration of the motor vehicle caused by a deceleration torque, wherein the deceleration torque is varied depending on the detected disturbance variable. In the absence of a disturbance variable, a specific deceleration torque always results in the same actual deceleration of the motor vehicle at a specific driving speed. The actual deceleration is influenced by the presence of the specific disturbance variable. For example, the actual deceleration may increase or decrease due to the disturbance variable. This increase or decrease in actual deceleration is perceptible to the motor vehicle user and is often perceived as disturbing. For example, when the position of the control element is constant, a predetermined deceleration torque is increased or decreased depending on the detected disturbance variable. Preferably, the predetermined deceleration torque, which would be determined in the absence of a disturbance variable, is varied by multiplying by a factor that is dependent on the detected disturbance variable. Preferably, the deceleration torque is varied depending on multiple simultaneously present and detected disturbance variables.

[0006] According to a preferred embodiment, the deceleration torque is modified in such a way that the modification compensates for the influence of the disturbance variable on the actual deceleration. In other words, the deceleration torque is modified, in particular increased or decreased, in such a way that the actual deceleration is the same as that which would be caused by the unchanged deceleration torque in the absence of the disturbance variable. The detected disturbance variable is thus not perceived by the user and is therefore not perceived as disturbing.

[0007] Preferably, the uphill and / or downhill slopes of the road on which the motor vehicle is traveling are monitored as disturbance variables. If the road has an uphill slope as a disturbance variable, the actual deceleration caused by the deceleration torque will increase. If the road has a downhill slope as a disturbance variable, the actual deceleration caused by the deceleration torque will decrease. Preferably, the uphill and / or downhill slopes are detected by means of a sensor device of the motor vehicle. The sensor device is, for example, a rotation rate sensor. As an alternative or in addition, the position of the motor vehicle is determined based on navigation satellite signals detected by means of a navigation unit of the motor vehicle. In order to determine the uphill and / or downhill slopes, the determined position is then compared with a map in which uphill and downhill slopes are stored for different possible positions.

[0008] According to a preferred embodiment, the wind speed and / or wind direction in the surroundings of the motor vehicle are monitored as disturbance variables. For example, wind directed against the direction of travel of the motor vehicle increases the actual deceleration caused by the deceleration torque. Conversely, wind directed in the direction of travel decreases the actual deceleration. Preferably, the wind speed and / or wind direction are detected by a wind sensor of the motor vehicle.

[0009] The load acting on the motor vehicle and / or the total weight of the motor vehicle are preferably monitored as disturbance variables. Due to an increase in the load acting on the motor vehicle or the total weight of the motor vehicle, the actual deceleration caused by the deceleration torque decreases. Preferably, the load or total weight is monitored by at least one sensor device of the motor vehicle. For example, there is a sensor device that is configured to determine the load or total weight based on the state of the vehicle's wheel suspension. The total weight of the motor vehicle can also increase due to the attachment of a trailer to the motor vehicle, thereby reducing the actual deceleration caused by the deceleration torque. Preferably, there is a sensor device that is configured to monitor whether a trailer is attached to the motor vehicle.

[0010] According to a preferred embodiment, an electric motor configured to actuate a master brake cylinder of a motor vehicle is controlled to generate at least a portion of a deceleration torque, an electric motor of a vehicle's vehicle dynamics control system is controlled to generate at least a portion of a deceleration torque, and / or a drive motor of the motor vehicle is controlled to generate at least a portion of a deceleration torque by operating the drive motor as a generator. Hereinafter, the electric motor configured to actuate the master brake cylinder is referred to as the first electric motor. The electric motor of the vehicle dynamics control system is referred to as the second electric motor. The first electric motor is configured to generate a deceleration torque by actuating the master brake cylinder and / or to amplify the deceleration torque generated by actuating a brake pedal provided in addition to the actuating element. For example, the applicant's iBooster brake actuation unit includes such an electric motor. The second electric motor is configured, for example, to actuate at least one fluid pump of a hydraulic block of the vehicle dynamics control system to generate a deceleration torque. Preferably, at least two of the first electric motor, the second electric motor, and the drive motor are controlled to jointly generate a deceleration torque.

[0011] Preferably, an electric motor designed to actuate the master brake cylinder is actuated to generate a basic deceleration torque, wherein the electric motor and / or the drive motor of the vehicle dynamics control system is actuated to compensate for the influence of disturbance variables on the actual deceleration. The basic deceleration torque is preferably a deceleration torque that would be predetermined if no disturbance variables were present. The compensating deceleration torque is generated by a second electric motor and / or the drive motor. A brake pedal, which is typically present in addition to the control element, is often coupled to the first electric motor in such a way that the position of the brake pedal changes when the master brake cylinder is actuated by the first electric motor. Compensating for the influence of disturbance variables by actuating the second electric motor and / or the drive motor results in the following advantage: the position of the brake pedal does not change due to the compensation for the influence of the disturbance variables. A change in the position of the brake pedal could be perceived as disturbing by a user of the vehicle.

[0012] The device according to the present invention for operating a motor vehicle having an adjusting element that is movable, in particular continuously, between a first end position and a second end position is characterized by a controller that is specifically designed to implement the method according to the present invention in conventional applications. This also results in the advantages already mentioned. Further preferred features and combinations of features are apparent from the preceding description. The device preferably has at least one sensor device that is communicatively connected to the controller and is designed to monitor at least one disturbance variable that causes the actual deceleration of the motor vehicle.

[0013] The motor vehicle according to the invention has an adjusting element that is particularly continuously movable between a first end position and a second end position, and is characterized by the device according to the invention. This also results in the advantages already mentioned. Further preferred features and combinations of features can be derived from the above description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is described in detail below with the aid of the accompanying drawings.

[0015] Figure 1 A motor vehicle with an adjustment element is shown in a simplified schematic diagram; and

[0016] Figure 2 A method for operating a motor vehicle using an adjusting element is shown. DETAILED DESCRIPTION

[0017] Figure 1 A simplified schematic diagram shows a motor vehicle 1. Motor vehicle 1 has four wheels 2 and 3, with wheel 2 assigned to a front axle 4 and wheel 3 assigned to a rear axle 5. Furthermore, motor vehicle 1 has a drive 6 with a generator-operable drive motor 7. Drive motor 7 is connected to wheels 2 of front axle 4 via a differential gear 8 and shafts 9, 10, and 11, so that wheels 2 can be driven by drive motor 7.

[0018] Motor vehicle 1 also has a brake system 12. Braking system 12 includes four friction brake devices 13, with a different one of these friction brake devices 13 being assigned to each of wheels 2 and 3. To actuate friction brake devices 13, braking system 12 includes a master brake cylinder 14, which is configured as a tandem master brake cylinder 14. Master brake cylinder 14 can be actuated by actuating a pedal 15. Master brake cylinder 14 can also be actuated by an electric motor 16 assigned to master brake cylinder 14. Electric motor 16 will be referred to below as first electric motor 16. Pedal 15 is coupled to first electric motor 16, or to a piston located in master brake cylinder 14, so that the position of brake pedal 15 is changed by first electric motor 16 when master brake cylinder 14 is actuated.

[0019] Braking system 12 also includes a vehicle dynamics control system 17. This system 17 includes a hydraulic block 18. This hydraulic block 18 is fluidically connected to master brake cylinder 14 via two inlet lines 19. Furthermore, this hydraulic block 18 is fluidically connected to friction brake device 13 via four outlet lines 20. Vehicle dynamics control system 17 includes an electric motor 21, which is configured to actuate at least one fluid pump (not shown) of hydraulic block 18, thereby actuating one or more friction brake devices in friction brake device 13. This electric motor 21 is hereinafter referred to as second electric motor 21.

[0020] exist Figure 1 The motor vehicle 1 shown in FIG also has an adjusting element 22. The adjusting element 22 is designed as a pedal and is continuously movable between a first end position and a second end position. The position of the adjusting element 22 in the first end position corresponds to a percentage value of 0% with reference to the adjustment travel from the first end position to the second end position, and the position of the adjusting element 22 in the second end position corresponds to a percentage value of 100%. The adjusting element 22 can be used to selectively predetermine an acceleration torque or a deceleration torque for the motor vehicle 1. When the current position of the adjusting element 22 exceeds a predeterminable switching position between the end positions, an acceleration torque is predetermined. The current position of the adjusting element 22 is then in the acceleration range. If the current position of the adjusting element 22 does not exceed the switching position, a deceleration torque is predetermined. The current position is then in the deceleration range.

[0021] Motor vehicle 1 also includes a device 23. To predetermine an acceleration torque or a deceleration torque, device 23 includes a controller 24. Controller 24 is communicatively connected to actuating element 22, first electric motor 16, second electric motor 21, and drive engine 7. If an acceleration torque is predetermined based on the current position of actuating element 22, controller 24 controls drive engine 7 to generate an acceleration torque. However, if a deceleration torque is predetermined, controller 24 controls first electric motor 16, second electric motor 21, and / or drive engine 7 to generate a deceleration torque.

[0022] The device 23 also has at least one sensor device 25, which is connected to the controller 24 in terms of communication technology. The sensor device 25 is designed to monitor the occurrence of at least one interference variable that affects the actual deceleration of the motor vehicle 1 caused by the deceleration torque. For example, the sensor device 25 monitors the uphill and / or downhill slope of the road on which the motor vehicle 1 is traveling as an interference variable. As an alternative, the sensor device 25 preferably monitors the wind speed and / or wind direction in the surroundings of the motor vehicle 1 as an interference variable. As an alternative, the sensor device 25 preferably monitors the load acting on the motor vehicle 1 and / or the total weight of the motor vehicle 1 as an interference variable. Figure 1 Only a single sensor device 25 of this type is shown in FIG. However, preferably, a plurality of sensor devices 25 are present, wherein each of these sensor devices 25 monitors a different one of the aforementioned disturbance variables.

[0023] In the following, reference Figure 2 The method for operating the motor vehicle 1 is described with the aid of a flow chart. It is assumed that the position of the actuating element 22 is in the deceleration range and is constant.

[0024] Because the current position of the adjusting element 22 is in the deceleration range, the control unit 24 determines in a first step S1 that a deceleration torque should be generated. To generate the deceleration torque, the control unit 24 then controls the first electric motor 16 in a second step S2 so that the first electric motor 16 actuates the master brake cylinder 14.

[0025] In a third step S3, sensor device 25 monitors the presence of disturbance variables. For example, sensor device 25 monitors whether the road on which motor vehicle 1 is traveling has an uphill or downhill slope as a disturbance variable. If sensor device 25 determines in step S3 that a disturbance variable is present, sensor device 25 provides information about the detected disturbance variable to controller 24 in a fourth step S4.

[0026] In a fifth step S5, the controller 24 determines, based on the information, which change in the deceleration torque is necessary to compensate for the effect of the disturbance variable on the actual deceleration of the motor vehicle 1. If an uphill slope is determined as the disturbance variable, the controller 24 determines that the deceleration torque must be reduced. If a downhill slope is determined as the disturbance variable, the controller 24 determines that the deceleration torque must be increased.

[0027] If controller 24 determines in step S5 that the deceleration torque must be reduced to compensate for the influence of the disturbance variable on the actual deceleration, reference is made to step S6. In S6, controller 24 controls first electric motor 16 so that it actuates master brake cylinder 14 to generate a reduced deceleration torque. Alternatively or additionally, controller 24 activates a braking torque blending function of brake system 12. When the braking torque blending function is activated, at least a portion of the hydraulic fluid of brake system 12 is transferred to a fluid reservoir (not shown) to reduce the deceleration torque independently of the control of first electric motor 16. If the deceleration torque is reduced solely by activating the braking torque blending function, the position of brake pedal 15 does not change when the deceleration torque is reduced.

[0028] However, if the controller 24 determines in step S5 that the deceleration torque must be increased to compensate for the effect of the disturbance variable on the actual deceleration, then reference is made to step S7. In step S7, the controller 24 controls the second electric motor 21 and / or the drive machine 7 in addition to the first electric motor 16, so that one or both of these devices generate an additional compensating deceleration torque to compensate for the effect of the disturbance variable on the actual deceleration. Because the compensating deceleration torque is generated by the second electric motor 21 and / or the drive machine 7, the position of the brake pedal 15 does not change when the braking torque is increased.

Claims

1. A method for operating a motor vehicle having an adjusting element (22) which is movable between a first end position and a second end position, wherein the current position of the adjusting element (22) is monitored, wherein a deceleration torque for the motor vehicle (1) is predetermined when the current position is in a deceleration range between the first end position and a predeterminable change position, and wherein an acceleration torque for the motor vehicle (1) is predetermined when the current position is in an acceleration range between the second end position and the change position, characterized in that Monitoring the occurrence of at least one disturbance variable, which influences an actual deceleration of a motor vehicle (1) caused by a deceleration torque, is performed, wherein the deceleration torque is changed as a function of the detected disturbance variable, wherein the deceleration torque is changed such that the influence of the disturbance variable on the actual deceleration is compensated by the change, wherein an electric motor (16) configured to actuate a master brake cylinder (14) of the motor vehicle (1) is controlled to generate at least a portion of the deceleration torque, and / or an electric motor (21) of a vehicle dynamics control system (17) of the motor vehicle (1) is controlled to generate at least a portion of the deceleration torque, and / or a drive motor (7) of the motor vehicle (1) is controlled to generate at least a portion of the deceleration torque by generator-like operation of the drive motor (7). wherein, when at least one disturbance variable is detected, an electric motor (16) configured to operate the master brake cylinder (14) is controlled to generate a basic deceleration torque, wherein the electric motor (21) of the vehicle dynamics control system (17) and / or the drive motor (7) are controlled to change the basic deceleration torque in order to compensate for the influence of the at least one disturbance variable on the actual deceleration, The basic deceleration torque is a deceleration torque predetermined when the at least one interference variable does not exist.

2. The method according to claim 1, characterized in that The uphill slope and / or downhill slope of the road on which the motor vehicle (1) is traveling is monitored as a disturbance variable.

3. The method according to claim 1 or 2, characterized in that The wind speed and / or wind direction in the surroundings of the motor vehicle (1) are monitored as disturbance variables.

4. The method according to claim 1 or 2, characterized in that A load acting on the motor vehicle (1) and / or the total weight of the motor vehicle (1) is monitored as a disturbance variable.

5. The method according to claim 1 or 2, characterized in that The adjusting element (22) is continuously movable between a first end position and a second end position.

6. A device (23) for operating a motor vehicle (1), wherein the motor vehicle (1) has an adjusting element (22) which is movable between a first end position and a second end position, characterized in that A controller (24) is specially designed to carry out the method according to any one of claims 1 to 5 in conventional applications.

7. A motor vehicle having an adjusting element (22) movable between a first end position and a second end position, characterized in that The device (23) according to claim 6.

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