JP2001001792A - Method and apparatus for controlling vehicle speed - Google Patents

Abstract

(57) Abstract: A vehicle speed adjustment is possible via at least one operating element of a driver in a more comfortable and transparent manner for the driver. A vehicle speed control method and device in which a reference speed is preset by an operation of an accelerator pedal by a driver, according to the reference speed, at least one adjusting element that affects the speed of the vehicle is operated. You. When the accelerator pedal is released, the reference speed is set to a preset minimum reference speed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and a device for controlling the speed of a vehicle.

[0002]

2. Description of the Related Art An example of such a method and a device for controlling the speed of a vehicle is known from DE-A 27 01 567 (U.S. Pat. No. 4,169,437). In the above patent, the drive unit of the vehicle is controlled on the basis of a preset reference (target) speed, taking into account the actual speed of the vehicle, wherein the actual speed of the vehicle is set at the preset reference speed. Approached. At this time, the reference speed is derived from the operation of the operating element operated by the driver, and the operating element includes an area for deceleration, an area for constant speed, and an area for accelerating the vehicle for presetting. , And at least three regulatory regions.
This results in a completely different pedaling characteristic and a driving behavior of the vehicle which is undesirable for the driver compared to a conventional vehicle. Therefore, this known solution is only limitedly suitable for practical use. The object of the present invention is to provide a reference speed for controlling the speed of a vehicle that is comfortable and transparent for the driver, i.e., for the driver, without significantly changing the driving behavior and pedal characteristics of the vehicle by the driver. To be unconscious of existence.

[0003]

SUMMARY OF THE INVENTION A method and apparatus for controlling the speed of a vehicle includes adjusting the speed of the vehicle.
This is possible via at least one operating element of the driver in a more comfortable and transparent manner for the driver.

[0004]

At least one adjusting element which influences the speed of the vehicle is operated according to a reference speed previously given by the driver, and the reference speed is derived according to the operation of the at least one operating element. In the vehicle speed control method and device of the present invention,
The reference speed (Vsollm) is derived from the actuation of the accelerator pedal of the vehicle, with the minimum reference speed (Vsollm)
in) is given in advance, the reference speed is returned to this minimum reference speed when the accelerator pedal is released, and / or the actuation signal of the brake pedal is evaluated and the reference speed is determined in accordance with this evaluation.

[0005] According to the invention, a reference speed for presetting a reference speed is provided which makes it possible to adjust the speed of the vehicle via at least one operating element of the driver in a more comfortable and transparent manner for the driver. A method of treatment is provided. In this case, the conventional pedal characteristics and running behavior of the vehicle are maintained to a maximum. By adjusting the speed via the accelerator pedal and the brake pedal, the driver is relieved of the burden of setting the speed, which is customary in today's independent switch-based speed control devices.

[0006] In particular, the assignment of the speed change to the accelerator operation and the assignment of the speed reduction to the operation of the brake pedal make it possible for the driver to relive the setting of the speed and to be independent of the vehicle type at the time. It is advantageous, for example, that the transmission of the vehicle is independent of whether it is automatic or manual.

[0007] In particular, it is advantageous for a low and constant reference speed to be preset, which the driver can adjust in a simple manner. This advantage has special significance when employed in so-called off-road vehicles, which allows the driver to adapt the reference speed to various land conditions in a simple manner.

It is of special significance that the standard reference speed is set again after releasing the accelerator pedal, or that the reference speed is reduced by operating the brake pedal. This contributes to increased driving safety under very comfortable driving.

[0009]

FIG. 1 is a schematic circuit diagram of a control device 10 for controlling a vehicle. In this preferred embodiment, the control device 10 includes, in particular, a driving speed regulating device or a driving speed limiting device. Control device 10
Has an input circuit 12, at least one microcomputer 14, and an output circuit 16. These components are connected to one another via a communication system 18 for data exchange. The input circuit 12 detects an input line 36 from a measuring device 38 for detecting a traveling speed, an input line 40 from an accelerator pedal measuring device 42 for detecting an operation of an accelerator pedal, and a brake operation. Is connected to the input line 50 from the measuring device 52. Furthermore, the input circuit 12 has other input lines (20 to 24) from measuring devices (26 to 30) for detecting other operating parameters of the vehicle to be evaluated within the framework of the function of the control device 10. Has been sent. These operating parameters include, for example, wheel braking pressure, engine torque, transmission ratio in the drive line, signals of circuit elements that can be operated by the driver to activate the speed control device, and the like.

At least one microcomputer 14 of the control device 10 controls at least one output line 4 in the frame of speed control (running speed adjustment or running speed limitation).
4 and at least one adjustment element 46 (eg, ABS
(Anti-lock brake control device) / brake device with ASR (traction slip control device)
Influence the braking force on at least one wheel brake of the vehicle. In some embodiments, at least one output line 32 and at least one adjustment element 34 (eg,
Via the electronic engine control), the output of the drive unit of the vehicle is affected.

The microcomputer 14 has a program incorporated therein, which controls the speed of the vehicle according to a reference speed preset by the driver, wherein the actual speed of the vehicle is controlled by a predetermined reference speed. Speed can be approached.

In this preferred embodiment, the speed control device is a speed limiter, which intervenes in at least one wheel brake of the vehicle and / or reduces engine torque. Limit the speed of the vehicle to a reference speed preset by the driver. In another application, the speed control device is a driving speed adjusting device, which is used when the vehicle speed falls below a reference value, for example, by releasing the brake or increasing the drive output, and by changing the reference speed. Is exceeded, the brake is depressed or the drive output is reduced to maintain the reference speed preset by the driver. In a preferred embodiment, the travel speed limiting device or the travel speed regulating device is mainly used in the field of off-road, especially in mountainous driving, where the speed of the vehicle is reduced by reducing the engine power and / or selectively. By applying the braking force to the wheel brakes set, the value is limited to a preset reference speed value. In particular, in such a case, the reference speed can be set as low and as constant as possible, and the driver can easily set the reference value in various situations. Can be adapted especially to various land conditions, this setting can be relived by the driver, and the speed setting reduces the burden on the driver in the same way as a conventional driving speed control device It is desirable to do.

Therefore, it has been considered that the presetting of the speed for the speed control device is performed by operating the brake pedal and the accelerator pedal by the driver. When the speed controller is activated, for example, by turning on a corresponding activation switch, it is adjusted to a preset standard reference speed. The standard reference speed is approximately 10 Km / in one embodiment.
h, but in another example it is set to a different value. By operating the brake pedal or the accelerator pedal, the driver can change the reference speed steplessly (within the range of resolution). Then, when the driver operates the accelerator pedal, the reference speed is increased, preferably to a value corresponding to one of the accelerator positions. Similarly, when the accelerator pedal is released, the reference speed is reduced. When the accelerator pedal is fully released, it is adjusted to the minimum reference speed. Releasing the accelerator pedal causes a continuous transition of the reference speed to this minimum reference speed. The minimum reference speed is the highest standard reference speed preset when the speed controller is activated. The minimum reference speed is increased by operating the accelerator pedal, corresponding to the reference speed on which the speed control is based (as long as the minimum reference speed is below the maximum value of the reference speed). Furthermore, a minimum value of the minimum reference speed is set, and the minimum value is, for example, several kilometers per hour, for example, about 5 km / h. Operating the brake pedal of the vehicle under the standard reference speed and applying the brake lowers the standard reference speed and the minimum reference speed, both possibly to their minimum values. When the accelerator pedal is operated, the reference speed and the minimum reference speed are increased again. In this case, the minimum reference speed is
At most, it can only be raised to the standard reference speed. The increase of the reference speed by the accelerator pedal is performed linearly at a constant rate in proportion to the accelerator position. The proportionality constant should be set such that the vehicle speed adjusted according to the accelerator position during acceleration of the vehicle is lower than a preset reference speed. The above relationship is determined by actual driving. However, an increase in the reference speed is only possible up to the maximum accelerator pedal position GPmax. Beyond the maximum accelerator position, the reference speed remains constant.

A possible relationship between the reference speed and the minimum reference speed is shown in FIG. In the graph shown there, the vertical axis takes the minimum reference speed Vsollmin,
The reference speed Vsoll on which the speed control is based is plotted on the horizontal axis. Furthermore, the standard reference speed Vollstar
t and the minimum value MIN of the minimum reference speed are written. Minimum value MIN and standard reference speed Vsollstart
And the minimum reference speed is the reference speed Vsol
It changes according to l. It is also possible here to consider other ways, for example, when releasing the accelerator pedal, the actual vehicle speed at that time as a new reference speed (as long as the actual vehicle speed is still below the standard reference speed Vollstart). It can also be used. As the reference speed is raised above the standard reference speed, the minimum reference speed remains limited to the standard reference speed. The same applies for the lower limit for the minimum. When the minimum reference speed is reduced by operating the brake pedal, the vehicle speed set when the brake pedal is released is used as a new minimum reference speed. However, the vehicle speed is the minimum reference speed Vsolls
Must be below the maximum value of start.

One preferred embodiment of the method described above is outlined with reference to the flow chart of FIG. This flowchart shows the program of the microcomputer 14 for implementing the method described above. This program is started when the speed control device is started, for example, by operating a switch by a driver.

In a first step 100, the reference speed Vso
11 is placed on the standard reference speed Vsollstart. Correspondingly, the minimum reference speed Vsollmin is adjusted to this value. In the next step 102, the vehicle speed Vfz, the accelerator pedal position GP, and the brake pedal position BP are read. In this case, the vehicle speed is derived in this preferred embodiment from the at least one selected wheel speed. In another example, the vehicle speed is measured directly. The accelerator position is detected by the position of the accelerator pedal (e.g., through the angle of the throttle valve), while the position of the brake pedal is also affected by the operation of the brake pedal, the detection of the operating force on the brake pedal, or by the driver. Determined by the detection of a pressure value (e.g., pressurization) in the brake device which can be operated. In another example, instead of determining the position of the brake pedal, it is sufficient to simply query the switch for "operated" or "not operated". In a subsequent inquiry step 104, it is checked whether the driver has operated the accelerator pedal, that is, whether the position of the accelerator pedal has exceeded a minimum value, for example, zero. If the minimum value has been exceeded, then in a next step 108, the reference speed Vsoll is changed as a function of the accelerator pedal GP and the minimum reference speed Vsollmin, while the minimum reference speed is (standard reference speed Vsoll).
A corresponding change is made depending on the position of the accelerator pedal (subject to the constraint of being solestart) (see, for example, FIG. 3). After step 108, step 1
The adjustment value (s) for speed control at 10 is calculated based on the reference speeds Vsoll and Vfz. In this preferred embodiment, depending on the deviation between the reference speed and the vehicle speed, the adjustment value that determines the drive torque of the drive unit of the vehicle and / or the adjustment value that determines the braking effect on the selected wheel brake is as follows: That is, the vehicle speed approaches the reference speed at least when the vehicle speed exceeds the reference speed. The adjustment value or values are sent to a corresponding adjustment device. In the next inquiry step 112, it is checked whether the speed control device has been switched off, for example, by the driver. If it has been switched off, the program is terminated; otherwise, step 10
Returned to 2. If it is confirmed in step 104 that the accelerator pedal is not operated, step 12
At 0, it is checked whether the brake pedal BP is operated. This check is performed, for example, by comparing the signal BP indicating the operation of the brake pedal with a minimum value, for example, zero, or by evaluating a switch. If the brake pedal BS has not been operated, the calculation of the adjustment value (s) is made on the basis of the actual adjustment values in step 110, while if the brake pedal has been operated, the reference speed is reduced in step 122. Based on the actuation signal, the minimum reference speed is increased in response to actuation of the brake pedal, possibly to a minimum value MIN.

The mode of operation of the method described above is outlined on the basis of the time diagram of FIG. FIG. 4a shows the reference speed Vso.
11 (solid line), the actual speed Vfz (broken line), and the minimum reference speed Vsollmin (dash-dot line) over time. FIG. 4b shows the operation of the accelerator pedal GP as an example, and FIG. 4c shows the operation of the brake pedal BP with respect to the time axis of the horizontal axis. Upon activation of the speed controller, the speed controller is operated at the standard reference speed Vsollstart according to FIG. 4a. Accordingly, the actual speed Vfz is adjusted to this reference speed. At time t0, the brake pedal BP is operated (see FIG. 4c) and released again at time t1. This means that the vehicle speed is reduced from time t0 to time t1, resulting in a corresponding reduction of the minimum reference speed and the reference speed. Between the time point t0 and the time point t2, the reference speed at the time point t1 is used as a basis for speed control, so that the vehicle speed Vfz substantially coincides with the reference speed in this region (see FIG. 4A).
The accelerator pedal is operated at time t2, and is released again at time t3. This means that the reference speed is increased at the time point t2, and the vehicle speed is controlled to follow up accordingly. The minimum reference speed is Vso at the longest
Raised to llstart. Reference speed Vsol
l can only be raised up to the maximum accelerator pedal position GPmax and thereafter remains constant. Shortly before time t3, the accelerator pedal is released again (see FIG. 4b), so that the reference speed is reduced to the minimum reference speed, here the standard reference speed. The vehicle speed is increased to a standard reference speed (see FIG. 4a). The brake pedal is operated again between time t4 and time t5, so that the reference speed is reduced from time t5. At time point t5, the accelerator pedal is released. The minimum reference speed stays at the minimum value together with the reference speed, and thereafter, speed control is performed based on these minimum values.

In another embodiment, the maximum standard value Vsoll
It does not correspond to start and is determined based on another value.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a vehicle speed control device according to the present invention.

FIG. 2 is a flowchart for presetting a reference speed in a preferred embodiment of the present invention.

FIG. 3 is a graph showing a relationship between a reference speed and a minimum reference speed according to a preferred embodiment of the present invention. The minimum reference speed Vsollmin is plotted on the vertical axis, which serves as a basis for speed control. The reference speed Vsoll is plotted on the horizontal axis.

FIGS. 4a to 4c are time charts showing operation modes in a preferred embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Control apparatus 12 Input circuit 14 Microcomputer 16 Output circuit 18 Communication system 20 ... 24,36,40,50 Input line 26 ... 30,38,42,52 Measurement device 32,34 Output line 34,46 Adjustment element

Claims (9)

[Claims] 1. The vehicle speed, wherein at least one adjusting element affecting the speed of the vehicle is operated according to a reference speed previously given by a driver, said reference speed being derived according to the operation of the at least one operating element. In the control method, the reference speed (Vsoll) is derived from the operation of the accelerator pedal of the vehicle, and the minimum reference speed (Vsollm)
in) is given beforehand, the reference speed is returned to this minimum reference speed when the accelerator pedal is released, and / or the actuation signal of the brake pedal is evaluated and the reference speed is determined in accordance with this evaluation. Is determined, and the vehicle speed is controlled. 2. The control method according to claim 1, wherein the reference speed (Vsoll) is reduced according to an operation of a brake pedal. 3. The control method according to claim 1, wherein the increase or decrease of the reference speed depends on the amount of depression of an accelerator pedal and / or a brake pedal. 4. The minimum reference speed (Vsollmin) is:
Lower limit (MIN) and maximum (Vsollstar)
The control method according to any one of claims 1 to 3, wherein the control method is increased in accordance with an operation of an accelerator pedal (GP) and decreased in accordance with an operation of a brake pedal (BP). 5. The reference speed (Vsoll) cannot be changed below a lower limit value of the minimum reference speed by operating a brake pedal, and / or the minimum speed can be changed by operating an accelerator pedal. 5. The control method according to claim 1, wherein the control speed cannot be changed above an upper limit value of the reference speed. 6. The control of the vehicle speed is performed by a speed limiter operable by a driver, and when the speed limiter is activated, the standard reference speed, preferably the maximum value of the minimum reference speed, is 6. The control method according to claim 1, wherein the value is set in advance as a value of the reference speed. 7. The control method according to claim 1, wherein the reference speed is limited to a lower minimum value. 8. A control device comprising at least one microcomputer (14) and operation of at least one adjusting element (34, 46), said microcomputer affecting the speed of the vehicle according to a preset reference speed. An output circuit (16) for generating at least one control signal for the microcomputer, and an input circuit (12) for the microcomputer to receive at least one operating signal of at least one operating element of the driver;
The above microcomputer includes at least one program, and the program includes a reference speed (Vsoll) in response to an operation signal of an accelerator pedal by a driver.
, And when the accelerator pedal is released, the reference speed (Vs
oll) to a preset minimum reference speed (Vsollm)
in) and / or evaluating the operation signal of the brake pedal and obtaining the reference speed according to the evaluation. 9. The control device according to claim 8, wherein the reference speed is limited to a lower minimum value by the program.