DE102019203207A1 - Operating state control of a drive device - Google Patents

Abstract

A method is provided for controlling an operating state of a drive device (3) of a vehicle (1). The method has a determination step (S1) for determining a slope of a ground (U) in front of the vehicle (1). The method also has a control step (S2) for controlling the operating state of the drive device (3) before the vehicle (1) reaches the incline on the basis of the incline determined in the determination step (S1). The control is carried out in such a way that when the incline is reached, the drive device (3) provides a drive force reserve suitable for driving over the subsurface (U) having the incline.

Description

The present invention relates to a method for controlling an operating state of a drive device of a vehicle. The invention also relates to a control device which is designed to carry out such a method, and to a vehicle with such a control device.

Conventional vehicles with an internal combustion engine, such as agricultural machinery, for example, are preferably operated at a low speed in normal driving mode. This can lead to a comparatively low fuel consumption of the internal combustion engine. At low speeds, however, a drive force reserve that the internal combustion engine can provide is relatively small. If the slope of a surface on which the vehicle is traveling increases, driving resistance also increases. The driving resistance can change to such an extent that the drive force reserve that can be provided by the internal combustion engine in the respective operating state is not sufficient to overcome the incline.

In view of the above disadvantages of the prior art, a method for controlling an operating state of a drive device of a vehicle is provided. The vehicle can be a motor vehicle, such as an agricultural machine or an automobile. The drive device can be provided and configured in or on the vehicle in order to provide more or less energy for driving the vehicle depending on its operating state. The drive device can have an internal combustion engine. It is also conceivable that the drive device has an electric motor. The drive device can also have a hybrid drive, that is to say an internal combustion engine and an electric motor.

The method has a determination step for determining a slope of a surface in front of the vehicle. The information in front of the vehicle relates to the current direction of travel of the vehicle. The slope of the subsurface is a measure of the steepness of the subsurface and relates to a section of the subsoil deviating from the horizontal.

Furthermore, the method has a control step for controlling the operating state of the drive device before the vehicle reaches the incline on the basis of the incline determined in the ascertaining step. The control is carried out in such a way that, when the incline is reached, the drive device provides a drive force reserve suitable for driving over the subsoil having the incline. The drive force reserve corresponds to a difference between the drive force that is currently required for driving the vehicle and a drive force that can be maximally output in the current operating state of the drive device.

The operating state of the drive device can be controlled in the control step in such a way that the vehicle travels at a constant speed in front of a section of the ground with an incline determined in the determination step. The operating state of the drive device can be controlled in the control step in such a way that the vehicle drives in front of and in a section of the ground with an incline and at a constant speed in a section of the ground determined in the determination step.

Controlling the operating state of the drive device can include controlling a gear ratio of a transmission of the drive device. Controlling the operating state of the drive device can include controlling a speed of a drive machine of the drive device. A speed of the drive machine can be increased, for example, before reaching the section of the ground with a gradient. A transmission ratio of the transmission can be controlled in accordance with a change in the speed of the drive machine so that the vehicle speed remains constant despite the changed speed of the drive machine.

The speed can be controlled in the control step as a function of a slope parameter that relates to the slope determined in the determination step. The gradient parameter can be approximated based on the gradient determined in the determination step. The slope parameter can relate to one or more sections or to the entire length of the section of the ground which has the slope. The ascertainment of the gradient parameter can include, for example, ascertaining an average value of the gradient of the section of the ground which has the gradient. It is conceivable that the gradient parameter is determined by means of one or more best-fit straight lines through a field of data points which correspond to the section of the subsurface that has the gradient. The slope parameter can be equal to the slope of the best-fit straight line. In the case of a plurality of best-fit straight lines, the slope parameter can be equal to the mean value of the slopes of the best-fit straight line.

If the gradient parameter is determined, as described above, based on at least one gradient of a best-fit straight line, it can be specified in degrees in which the arcsine is calculated from the respective gradient. Furthermore, how known to the person skilled in the art, the slope parameters can also be given in percent.

The speed can be increased in the control step if the slope parameter is greater than a predetermined limit value. The limit value for the gradient parameter can be set in such a way that the speed of the drive machine is not increased in the event of a slight gradient in the ground in front of the vehicle. The limit value for the slope parameter can be 5 °, for example.

• 0 bis 5,71° (entspricht 0% <= Steigungsparameter <= 10%),
• 5,72° bis 11,31° (entspricht 10% < Steigungsparameter <= 20%),
• 11,32° bis 16,7° (entspricht 20% < Steigungsparameter <= 30%), und
• größer 16,7° (entspricht 30% < Steigungsparameter)

in einem Kennfeld hinterlegt sein.The speed can be increased in the control step until a speed setpoint is reached. The speed setpoint can be determined based on the slope parameter. The speed setpoint can increase as the slope parameter increases. Different speed setpoints can be stored for different slope parameter ranges. For example, different speed setpoints for slope parameters in the range of:

• 0 to 5.71 ° (corresponds to 0% <= slope parameter <= 10%),
• 5.72 ° to 11.31 ° (corresponds to 10% <gradient parameter <= 20%),
• 11.32 ° to 16.7 ° (corresponds to 20% <incline parameter <= 30%), and
• greater than 16.7 ° (corresponds to 30% <gradient parameter)

be stored in a map.

The speed setpoint can be determined based on the speed of the vehicle in front of the section with an incline determined in the determination step. As soon as an incline is detected, the speed can be increased. A starting time and a gradient of the increase in the speed can be determined as a function of the vehicle speed, so that the speed setpoint is reached at the base of the gradient.

The speed setpoint can also change as a function of the speed for a respective slope parameter or in the respective slope parameter range. The speed setpoint can be taken from a two-dimensional map that is defined by the speed of the vehicle on one axle and the gradient parameter or the gradient parameter ranges described above on the other axis. Furthermore, a gradient for the speed increase can be freely parameterized. If the speed increase is started once, it can be run through until the speed setpoint is reached, regardless of the currently determined gradient parameter. The speed can be kept constant in the control step for a predetermined time as soon as the speed setpoint is reached.

In addition, a control device for a vehicle is provided which is designed to carry out such a method. The control device has an input interface, an operating state setting device and an output interface. The control device can be part of the engine control of the vehicle, for example.

The operating state setting device is designed to control an operating state of a drive device of the vehicle on the basis of an input variable input to the input interface before the vehicle reaches an incline. The input variable corresponds to the slope of a ground in front of the vehicle. The control device can be designed to calculate the slope parameter based on the input variable in the manner described above. The input variable can also be the slope parameter.

The control is carried out by the operating state setting device in such a way that, when the incline is reached, the drive device provides a drive force reserve suitable for driving over the subsurface having the incline.

A vehicle with such a control device is also provided. The vehicle also has a determination device connected to an input interface of the control device. The determination device is designed to determine a slope parameter that corresponds to the slope of a ground in front of the vehicle. The input interface can be connected to the determination device via a CAN bus (Controller Area Network). A transmission rate of the CAN bus can be in the range of 50 ms. The vehicle also has a drive device connected to an output interface of the control device.

The drive device has a drive machine for generating drive force and a transmission for transmitting the drive force to the wheels of the vehicle. The transmission can be a continuously variable transmission. If the transmission is a continuously variable transmission, the translation can be changed continuously, corresponding to the change in the speed of the drive machine, so that the speed of the vehicle remains constant at least before reaching the incline.

The determination device can have a radar sensor. The investigative facility can have a laser sensor or at least one camera instead of or in addition to the radar sensor. The radar sensor can be designed to determine a field of data points that correspond to the section of the ground that has the gradient. The determination device can be designed to determine the slope parameter in the manner described above based on the data points. The determination device can be designed to input the determined slope parameter to the control device as an input variable via its input interface.

• 1 zeigt schematisch ein Fahrzeug gemäß einer Ausführungsform.
• 2 zeigt schematisch ein Verfahren gemäß einer Ausführungsform.
• 3 zeigt schematisch das Fahrzeug aus 1 zum Zeitpunkt einer Ausführung eines ersten Schrittes des Verfahrens aus 2.
• 4 zeigt zeitabhängig eine Drehzahlveränderung einer Antriebsmaschine des Fahrzeugs aus 1 bei der Ausführung eines zweiten Schrittes des Verfahrens aus 2.

The vehicle can have a distance determination device which is designed to determine a distance of the vehicle to the ground having the gradient. The distance determination device can be connected to the radar sensor described above or be part of the radar sensor. The distance can be determined by the distance determination device, for example based on a reflection duration of radar waves emitted by the radar sensor.

• 1 shows schematically a vehicle according to an embodiment.
• 2 schematically shows a method according to an embodiment.
• 3 shows schematically the vehicle 1 at the time of executing a first step of the method 2 .
• 4th shows a change in the rotational speed of a prime mover of the vehicle as a function of time 1 when performing a second step of the method 2 .

The following is a vehicle 1 according to an embodiment with reference to 1 described. 1 is a schematic representation of the vehicle 1 according to one embodiment.

The vehicle 1 has a control device 2 , a drive device 3 , a sensor device 4th and wheels 5 on.

The control device 2 has an input interface 21st , an operating state setting device 22nd and an output interface 23 on. The operating state setting device 22nd is both to the input interface 21st as well as to the output interface 23 connected.

The drive device 3 has a prime mover 31 and one to the prime mover 31 connected gear 32 on.

The sensor device 4th has a detection device 41 , a distance determining device 42 and a radar sensor 43 on.

The distance determining device 42 is designed to be based on from the radar sensor 43 transmitted radar waves a distance X1 (shown in 3 ) of the vehicle 1 to a section X2 of an underground U (shown in 3 ) with an incline in the direction of travel X in front of the vehicle 1 to investigate. The distance X1 is from the distance determining device 42 based on a reflection duration from the radar sensor 43 transmitted radar waves are determined. The distance determining device 42 is designed to the determined distance X1 via the input interface 21st to the operating state setting device 22nd the control device 2 to spend.

The radar sensor 43 is designed to be an array of data points belonging to the section X2 correspond with the slope to determine and these data points to the determination device 41 to spend.

The investigative facility 41 is designed to be a slope parameter α (shown in 3 ) based on that from the radar sensor 43 to determine received data points. The investigative facility 41 is designed to be a best fit straight line X2 ' (shown in 3 ) through the field of data points. The slope parameter α corresponds to the slope of the regression line X2 ' . The investigative facility 41 is designed to use the ascertained slope parameter α via the input interface 21st to the operating state setting device 22nd the control device 2 to spend.

From the input interface 21st becomes the slope parameter α and the distance X1 to the operating state setting device 22nd the control device 2 issued. The operating state setting device 22nd is configured to an operating state of the drive device 3 to control. The operating state setting device leads to this 22nd a below in detail with reference to the 2 to 4th described procedure. The operating state of the drive device determined by this method 3 is used as a control command from the operating state setting device 22nd via the output interface 23 the control device 2 to the drive device 3 issued.

The drive device 3 is configured to be based on that provided by the controller 2 received control command to change their operating status. Furthermore, the drive device 3 so to the wheels 5 connected that they are one of the prime mover 31 generated driving force via the transmission 32 to the wheels 5 issues. The wheels 5 are designed to apply this driving force to the ground U on which the vehicle is 1 is to be transferred. The wheels 5 transmitted by the drive device 3 received driving force so on the ground U that the vehicle is on the ground in the direction of travel X emotional.

That from the operating state setting device 22nd the control device 2 procedure will now be performed with reference to the 2 to 4th described in detail below.

2 shows schematically a sequence of a method according to an embodiment. As in 2 As shown, the method has two steps, a determination step S1 and a control step S2 .

In the investigation step S1 a slope of a ground in front of the vehicle is determined in the manner described above. At the control step S2 becomes the operating state of the drive device 3 before the vehicle 1 the section X2 reached with slope, controlled on the basis of the slope determined in the determination step. The operating state is controlled so that the drive device 3 when the slope is reached, one for driving on the underground having the slope U provides suitable drive power reserve.

The determination step S1 will now be detailed with reference to 3 described. 3 shows schematically the vehicle 1 out 1 execution of a first step of the method at time t0 2 .

The vehicle 1 is located on the horizontal surface U and drives at one speed V1 in the direction of travel X on the section X2 of the subsoil U with slope to.

The vehicle is at the distance t0 at the time shown X1 that is parallel to the direction of travel X is measured from the section X2 with slope. The ones related to 1 described distance determining device 42 determines at this point in time t0 together with the radar sensor 43 the distance X1 . The determined distance X1 is from the distance determining device 42 to the input interface 21st the control device 2 issued.

The determination device also determines 41 at the illustrated time t0 together with the radar sensor 43 the slope parameter in the manner described above α leading to the slope of the section X2 corresponds. The investigative facility 41 gives the determined slope parameter α to the input interface 21st the control device 2 out.

The input interface 21st gives the distance X1 to section X2 with slope as well as the slope parameter α to the operating state setting device 22nd out.

The one on the investigation step S1 following control step S2 will now be described in detail below with reference to FIG 4th described. 4th shows a time-dependent change in the speed of the drive machine 31 of the vehicle 1 when executing the control step S2 . In 4th so is the engine speed M. the prime mover 31 plotted over time t, the illustration in 4th to in 3 time t0 shown begins.

The operating state setting device 22nd determined once they get the distance X1 and the slope parameter α based on the slope parameter α , the current vehicle speed V1 and the distance X1 how and when the operating status of the drive device 3 is to be changed. The operating state of the drive device 3 is to be controlled so that the drive device 3 when reaching the section X2 provides a drive force reserve suitable for the incline. The drive power reserve is suitable when the engine speed M. the prime mover 31 before reaching the section X2 is changed so that the vehicle 1 when reaching the section X2 , i.e. at time t2, with a constant speed V1 can continue.

Based on the slope parameter α and the current speed V1 of the vehicle 1 determines the operating state control device 22nd a speed setpoint M1 the prime mover 31 . For this purpose, there is a characteristic map in the operating state setting device 22nd deposited. Depending on how big the slope parameter is α and the current speed V1 of the vehicle 1 the speed setpoint changes M1 . The operating state setting device 22nd further determined based on the current speed V1 of the vehicle 1 and the distance X1 a point in time t1. At time t1, the engine speed becomes M. the prime mover 31 based on a current speed M0 raised. The time t1 is chosen so that the drive machine 31 the speed setpoint M1 at time t2, i.e. when the section is reached X2 , has reached. A predetermined gradient for raising the engine speed is also taken into account M. .

The operating state setting device also controls 22nd a gear ratio of the continuously variable transmission 32 so that the speed V1 of the vehicle 1 by increasing the engine speed M. does not change the current speed V1 of the vehicle 1 leads.

Has the vehicle 1 at time t2 the section X2 with slope is reached for a predetermined period of time Δt the engine speed up to a point in time t3 M. on the speed setpoint M1 kept constant. Then the engine speed M. to a lower engine speed within a period from time t3 to time t4 M2 lowered.

The speed increase in the control step S2 once started, it is run through completely, regardless of whether the sensor device 4th furthermore a slope parameter α to the input interface 21st spend or not. Is a lower engine speed again at time t4 M2 reached, the procedure begins in the determination step S1 all over again.

List of reference symbols

1

vehicle

2

Control device

21st

Input interface

22nd

Operating condition setting device

23

Output interface

3

Drive device

31

Prime mover

32

continuously variable transmission

4th

Sensor device

41

Investigative facility

42

Distance determining device

43

Radar sensor

5

bikes

α

Slope parameters

S1

Determination step

S2

Control step

M, M0 - M2

Engine speed

t0 - t4

time

Δt

predetermined period of time

U

Underground

V1

current vehicle speed

X

Direction of travel

X1

Distance to the section with an incline

X2

Section with an incline

X2 '

Best fit line

Claims (14)

A method for controlling an operating state of a drive device (3) of a vehicle (1), the method comprising the following steps: a determination step (S1) for determining a slope of a ground (U) in front of the vehicle (1), and a control step (S2) for controlling the operating state of the drive device (3) before the vehicle (1) reaches the slope on the basis of the slope determined in the determination step (S1), so that the drive device (3) when the slope is reached a for driving over the ground (U) having the incline provides a suitable drive force reserve. Procedure according to Claim 1 , wherein the operating state of the drive device (3) is controlled in the control step (S2) so that the vehicle (1) drives in front of a section (X2) of the ground (U) determined in the determination step (S1) with an incline at a constant speed (V1) . Procedure according to Claim 1 , wherein the operating state of the drive device (3) is controlled in the control step (S2) so that the vehicle (1) before and in a section (X2) of the ground (U) determined in the determination step (S1) with an incline at a constant speed (V1 ) moves. Method according to one of the Claims 1 to 3 wherein controlling the operating state of the drive device (3) comprises controlling a gear ratio of a transmission (32) of the drive device (3). Method according to one of the Claims 1 to 4th wherein controlling the operating state of the drive device (3) comprises controlling a speed (M) of a drive machine (31) of the drive device (3). Procedure according to Claim 5 , the speed (M) being controlled in the control step (S2) as a function of a slope parameter (α) which relates to the slope determined in the determining step (S1). Procedure according to Claim 6 , the rotational speed (M) being increased in the control step (S2) if the gradient parameter (α) is greater than a predetermined limit value. Procedure according to Claim 7 , the increase in speed (M) being carried out in control step (S2) until a speed setpoint (M1) is reached. Procedure according to Claim 8 , wherein the speed setpoint (M1) is determined based on the slope parameter (α). Procedure according to Claim 8 or 9 , the speed setpoint (M1) being determined based on the speed (V1) of the vehicle (1) before the section (X2) with an incline determined in the determining step (S1). Method according to one of the Claims 8 to 10 , the speed (M) being kept constant in the control step (S2) for a predetermined time (Δt) as soon as the speed setpoint (M1) is reached. Control device (2) for a vehicle (1), wherein the control device (2) has an input interface (21), an operating state setting device (22) and an output interface (23), the operating state setting device (22) being designed to be based on a the input variable entered at the input interface (21), which corresponds to a gradient of a ground (U) in front of the vehicle (1), to control an operating state of a drive device (3) of the vehicle (1) before the vehicle (1) reaches the gradient, so that when the incline is reached, the drive device (3) provides a drive force reserve suitable for driving on the ground (U) having the incline, the control device (2) being designed to perform the method according to one of the Claims 2 to 11 perform. Vehicle (1) with a control device (2) after Claim 12 , a determination device (41) connected to an input interface (21) of the control device (2) for determining a slope parameter which corresponds to the slope of a ground (U) in front of the vehicle (1), and one with an output interface (23) of the control device ( 2) connected drive device (3), the drive device (3) having a drive machine (31) for generating drive force and a gear (32) for transmitting the drive force to the wheels (5) of the vehicle (1). Vehicle (1) after Claim 13 and further comprising a distance determining device (43) which is designed to determine a distance (X1) of the vehicle (1) to the ground (U) having the incline.

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