WO1998034814A1

WO1998034814A1 - Method and device for regulating the longitudinal dynamics of a vehicle

Info

Publication number: WO1998034814A1
Application number: PCT/EP1998/000600
Authority: WO
Inventors: Alfred Eckert; Jürgen DIEBOLD; Thomas Berthold
Original assignee: Itt Manufacturing Enterprises, Inc.
Priority date: 1997-02-10
Filing date: 1998-02-04
Publication date: 1998-08-13
Also published as: DE19704854A1; AU6394498A

Abstract

The invention relates to a method and a device for regulating the longitudinal dynamics of a vehicle. To achieve this, and in particular to determine setpoints, the blinker activation of the vehicle is monitored, and, optionally, also included in the regulation and/or set point determination.

Description

Method and device for regulating the longitudinal dynamics of a vehicle

The present invention relates to a method and a device for regulating the longitudinal dynamics of a vehicle according to the preambles of the independent claims. In the broadest sense, the invention relates to a so-called "ICC system" (ICC = "Intelligent Cruise Control"). It is therefore in the same field as application 196 54 769.5 of the same applicant dated December 28, 1996, the disclosure content of which is hereby fully incorporated into this application.

ICC systems record internal and external conditions around a vehicle and determine target values for regulating the longitudinal dynamics of a vehicle in accordance with these recorded conditions. Longitudinal dynamics are understood to mean the speed and / or the acceleration or braking of the vehicle as well as variables which are related to the variables mentioned. The above-mentioned earlier, but not prepublished application by the same applicant describes, for example, a system in which various components specify target accelerations. In accordance with these target accelerations, a target vehicle acceleration is determined, which is used to control the engine. Examples of internal and external operating states of a vehicle are: the distance to a vehicle in front, the relative speed to a vehicle in front, the absolute speed of your own vehicle, the driver's request (speed, Acceleration, deceleration) etc. Examples of components that can influence the longitudinal dynamics control are: cruise control, vehicle sequence control (setting a certain relative speed or a certain distance to the vehicle in front), cornering speed control (control of the driving speed according to the lateral acceleration), accelerator pedal, etc .

Systems known hitherto have the disadvantage that they are not optimally adapted to situations which arise in particular as a result of turning, changing lanes or overtaking a driver.

The object of the invention is to provide a method and a device for regulating the longitudinal dynamics of a vehicle, with which situations such as are given by changing lanes, turning or overtaking can be dealt with in an appropriate manner.

This object is achieved with the features of the independent claims. Dependent claims are directed on preferred embodiments of the invention.

According to the invention, it is proposed to include the turn signal when regulating the longitudinal dynamics and in particular when determining target values for regulating the longitudinal vehicle dynamics. A device is provided with which the turn signal actuation can be detected and which generates a specific signal upon detection. The setpoint is then determined taking into account the turn signal. The actuation of the turn signals indicates certain driver requests. These can be integrated into the ICC regulation in a suitable manner.

Individual embodiments of the invention are described below with reference to the accompanying drawings, in which:

Fig. 1 shows a first basic embodiment of the

Invention, Fig. 2 shows a concrete structure of an inventive

Contraption,

Fig. 3 diagrams, u. Fig. 4

Fig. 1 shows in principle the structure of a control according to the invention. Reference numeral 17 denotes a device for determining at least one target value for regulating the longitudinal dynamics of the vehicle. Output variables of this device 17 can be a target distance and / or a target speed and / or a target relative speed and / or a target acceleration. These setpoints are input to a downstream control device 18 with which the vehicle engine 19 is controlled. The setpoint value determining device 17 receives input signals from various sensors. A distance sensor 11, a speed sensor 12, a pedal position sensor 13 and an image recording device 14 with associated evaluation device 15 are shown as examples. According to the invention, a turn signal actuation detection device 10 is also provided which generates a specific signal when the turn signal is confirmed and converts this signal into the setpoint values. Determining device 17 enters. In the simplest case, the turn signal actuation detection device 10 is an on / off switch which only qualitatively determines the turn signal actuation. However, it is preferable to use a detection device 10 which outputs a signal which also shows the direction of the turn signal actuation. The signal of the turn signal actuation detection device 10 would then identify three states, namely "turn signal off", "turn signal right" and "turn signal left". Such a signal can be supplied via one or more lines, analog or digital, to the setpoint value determining device 17. The turn signal actuation detection device can either query the turn signal lever on the steering wheel or the pulsing blink signal generated in response to the turn signal actuation. It can either forward one of these signals unchanged or in a processed form.

The operation of the device according to the invention is as follows: if no turn signal actuation is determined ("turn signal off"), the setpoint is determined as usual. If, on the other hand, a turn signal is detected ("turn signal right / left"), this signal is included in the setpoint determination. One way of including this signal is to generate setpoints according to predefined scenarios. These scenarios can be implemented by tables, by a suitable hardware interconnection or by software implementation. Examples are given below:

If a turn signal actuation to the left is detected ("turn signal left"), then if the vehicle sequence control is activated, the target distance to a vehicle ahead Vehicle is reduced and / or the relative speed to a preceding vehicle is increased or the target acceleration is increased. Overtaking is initiated by one or more of these measures.

In contrast to this, no acceleration process is initiated in the case of a left-hand turning process, since the overall responsibility of the driver must match the target speed of the vehicle to the turning process. The process of accelerating the vehicle for overtaking only occurs when the target speed is higher than the vehicle speed.

If a flashing to the right is detected ("right turn signal"), this can indicate a reeving or a right turn. Consequences can be the reduction of the target speed in order to brake before turning right, or the limitation of the acceleration to a maximum of zero (i.e., no positive acceleration, no speed increase).

Further advantages result if the vehicle is provided with an image recording device 14 and an evaluation device 15 connected to it. The evaluation device 15 can be designed to recognize the longitudinal direction of the carriageway and / or individual tracks on the carriageway. If the evaluation device 15 then also receives the signal from the turn signal actuation detection device 10, it learns in advance that a lane or lane change is taking place. This can advantageously be included in the recognition logic in that threshold values that have to be exceeded in order to recognize a change of lane or lane can be reduced. This makes it easier to recognize a lane or lane change possible. In addition, vehicles in adjacent lanes can also be included in advance in a follow-up order, which is more likely to be avoided when driving on the same lane without indicators.

The target value determination device 17 thus modifies target values for the vehicle control in certain operating conditions. This modification can be designed so that it does not happen suddenly, but gradually, in order to obtain a comfortable and jerk-free driving experience. The setpoints can be modified with a specific first time constant.

Furthermore, it is preferable to design the modification of the setpoints so that they are returned to their original values over time, especially when the indicator is on. This applies in particular to safety-related setpoints, for example the distance to the vehicle in front or the relative speed to this. This ensures that when the turn signal is constantly on (for example, notorious left turn signals on the motorway), setpoints are not permanently in unsafe areas. The modified nominal values are preferably returned to the original nominal values with a time constant which is longer than the time constant for modifying the nominal values. It is preferably carried out after a certain time after the turn signal has been set or after the modified setpoints have been reached.

The modified setpoints can be returned to the original setpoints when the indicator is activated to the right very slowly or not at all, because when turning right, the turning lane can be very slow.

The above statements refer to vehicles for right-hand traffic. For left-hand traffic, they are to be understood as mirror-inverted.

Fig. 2 shows an embodiment with which some of the functions mentioned above can be implemented. The implementation can take place analogously or in digital systems. 20a and 20b symbolize values which symbolize "blinker on" (20a) or "blinker off" (20b). By means of a changeover switch 20c and a subsequent evaluation 20d, these values are added up in accordance with the blinker actuation in the integrator 20e, 20f with feedback, so that a value is present at the connection 20g which is variable depending on the duration of actuation of the blinker. For example, if the value 20a for "turn signal on" is negative, there is an increasingly negative value at output 20 g when the turn signal is operated continuously. If the value for "blinker off" is positive and, in particular, is greater in magnitude than the magnitude of the previous signal, by integrating this value the output 20g is returned to its original value over time and preferably more quickly. With a suitable choice of the values 20a, 20b and the evaluation 20d, the output 20g can, for example, be added directly to the target distance and thus reduce this target distance, for example according to the formula

Distance should be _new = distance _{should be} + output _20g x K. Similarly, the upper limit of an acceleration restriction can be modified, such as by

Upper limit _new = upper limit _old x (1.0 + output ₂ o _g ) «

Output 20g can also be used to address a table.

The value of the output 20g can be limited depending on the direction by a limiter 20f.

The above-described feedback of setpoints when the turn signal is operated for a long time can be achieved by a device 21, a so-called "memory function". The output 21g of this memory function is added to the output 20g in the adder 22 and forms the output 23 with the evaluated blinker signal. The memory function 21 itself uses a signal which indicates the slope of the integration in the device 20 and which is limited to zero. In the example shown, this signal is generated in the device 24, the formation of the differential being shown here. However, the detection of the different values 20a or 20b is also sufficient. The signal representing the slope is used as the input signal of a first order low pass. Depending on the direction, this low-pass filter has two time constants, a fast one for detecting the switching on of the turn signal and a slow time constant with which the actual memory loss or the return of the modified setpoints to the original setpoints is achieved when the turn signal is operated for a long time. The device shown in FIG. 2 thus consists of an input switching part 20a to 20d, an integrator 20e to 20g, a slope calculation 24 and one

Memory function 21, wherein the outputs of integrator 20e to 20g and memory function 21 can be added to form the total output signal.

3 and 4 show individual waveforms. The individual diagrams a, b and c in FIGS. 3 and 4 each show the output 23, the output 21g of the memory function and the output 20g of the integrator. FIG. 3 relates to a memory function that has comparatively short time constants, while FIG. 4 relates to comparatively long time constants. In both cases, the curve in figure part a is the product formed in device 22 from the signal curves shown in figure parts b and c. 3c shows the output 20g. It is assumed that the turn signal is set at time 0 s and removed again at time 2 s. There is then initially a negative integration up to a value

-1, which is predetermined by the limiter 20f. After that, the value no longer changes. Only when the turn signal is reset after 2 s is the value 20a at the input of the integrator no longer present, but the positive value 20b. The result is quickly reduced to 0. The actual memory function is shown in Fig. 3b for short time constants. This is based on an embodiment which, at the moment when the integrator 20e, 20f supplies a constant value (use of the limiter 20f), starts the feedback of the modified target values to the original target values. As already mentioned above, this is too Take into account that the modification of the setpoints takes place via the signal at the output 20g that changes over time according to the setting of the turn signal. This signal (FIG. 3c) is evaluated by the signal from FIG. 3b, which decreases approximately exponentially after approx. 1 s. The curve from FIG. 3a results, and it can be seen that the modification was reduced to below 20% of its maximum deflection even before the blinking process ended (point 31 in FIG. 3a).

Fig. 4 shows the case of a "long memory". With regard to the blinker setting, the same function as in FIG. 3 was assumed (FIG. 4c corresponds to FIG. 3c). The memory function from FIG. 4b evaluating the signal from FIG. 4c, however, drops much more slowly than that shown in FIG. 3b. The result of this is that the modification of the setpoints is returned much more slowly. When the turn signal is removed after 2 s, the modification is still approximately 80% preserved (point 41 in FIG. 4a). It only disappears after approx. 3 s. Only then will the original setpoints be set again. In the embodiment shown, the duration until the original setpoint values are completely returned depends on the time constant of the memory function and on the value for integrator 20e, 20f specified by 20b.

Claims

Expectations

1. A method for controlling the longitudinal dynamics of a vehicle, in which at least one setpoint for the regulation of the longitudinal dynamics of the vehicle is determined in accordance with internal and / or external conditions, characterized in that the indicator actuation is taken into account in the control.

2. The method according to claim 1, characterized in that the turn signal actuation for determining the target value is taken into account in a distance control.

3. The method according to claim 1 or 2, characterized in that the turn signal actuation is detected and taken into account depending on the direction.

4. The method according to claim 1, 2 or 3, characterized in that setpoints for distance to a preceding vehicle and / or absolute speed of the own vehicle and / or relative speed to the preceding vehicle and / or acceleration of the own vehicle are changed upon a turn signal actuation.

5. The method according to any one of claims 1 to 4, characterized by detecting the absolute speed of the own vehicle and / or the relative speed of the own vehicle a preceding vehicle and / or the distance of the own vehicle to a preceding vehicle and / or the acceleration of the own vehicle and / or the actuation of the brake or accelerator pedal.

6. The method according to claim 4, characterized in that the change in setpoint takes place gradually in accordance with a first time constant.

7. The method according to claim 4 or 6, characterized in that the changed setpoints are gradually returned to the original setpoints when a turn signal is continuously detected.

8. The method according to claim 7, characterized in that the feedback takes place with a second time constant which is greater than the first time constant.

9. The method according to any one of claims 1 to 8 and in particular 2, characterized in that the target speed is reduced when a turn signal actuation to the right is detected.

10. The method according to any one of claims 1 to 9 and in particular 3, characterized in that when a turn signal actuation to the left is detected, the target speed is increased and / or the target acceleration is greater than zero and / or the target distance to a preceding vehicle and / or the relative speed compared to the vehicle in front is reduced.

11. The method according to any one of claims 1 to 10, characterized in that when a turn signal is activated, threshold values of a road surface recognition device are reduced.

12. Device for regulating the longitudinal dynamics of a vehicle, with a device (17) for determining at least one setpoint for regulating the longitudinal dynamics of the vehicle in accordance with internal and / or external conditions, characterized in that a device (10) for detecting the Turn signal actuation is provided, and the target value determination device (17) receives a signal generated by the turn signal actuation detection device (10) and takes this into account.

13. The apparatus according to claim 12, characterized in that the turn signal actuation detection device (10) detects the turn signal actuation depending on the direction.

14. The method according to claim 12 or 13, characterized in that the target value determining device (17) upon detection of a turn signal actuation by the detection device (10) towards target values for the absolute speed of the own vehicle and / or relative speed of the own vehicle with respect to a preceding vehicle Changes vehicle and / or distance of your own vehicle to a preceding vehicle and / or acceleration of your own vehicle.

15. Device according to one of claims 12 to 14, characterized by sensors (11 - 13) for the speed of the own vehicle and / or for the position of the gas or brake pedal and / or for the distance or the relative speed to a preceding one Vehicle, these sensors generating signals which are input into the setpoint value determining device (17).

16. Device according to one of claims 12 to 15, characterized by an image recording device (14) and a downstream image evaluation device (15) with which roadways or lane lanes can be detected, the evaluation device (15) receiving the signal from the turn signal actuation detection device ( 10) receives.