KR101280784B1 - Lane keeping method and lane keeping system - Google Patents

Abstract

The present invention relates to a lane keeping method and system, which converts an input steering torque signal into a pulse modulated signal and outputs a steering torque signal converted into a pull modulated signal to a steering system to perform steering torque control. It features.

According to the present invention, it is possible to control the fine steering torque and provide a smooth steering feeling to the driver.

Steering torque signal, pulse modulation, lane keeping

Description

Lane keeping method and system {LANE KEEPING METHOD AND LANE KEEPING SYSTEM}

One embodiment of the present invention is directed to a lane keeping method and system. More specifically, the present invention relates to a steering torque signal conversion technology that enables fine steering torque control and provides a smooth steering feeling to the driver, and a lane keeping technology using the same.

Conventionally, a lane keeping system (LKS) has been developed to detect lane departure through a camera and enable lane keeping.

The lane keeping system is configured to apply steering torque calculated by calculating steering torque to prevent lane departure from a detected lane departure to a steering system such as an electric power steering system. Allow control to take place.

In the conventional lane keeping system, when the steering torque calculated to prevent lane departure is applied to the steering system 150, steering torque control is performed even if the steering torque increases due to mechanical play or friction near the steering wheel center. There is a problem in that a control dead zone (Dead-Zone) is formed, which is a time domain in which the steering angle that occurs according to the present invention is hardly changed. The problem that such a control dead zone is formed prevents fine steering torque control and makes the driver feel a sudden steering torque, thereby failing to provide a smooth steering feeling. More seriously, it may cause a lane departure and cause an accident.

In this background, an object of the present invention is to enable fine steering torque control that allows a steering angle change to occur even with a slight increase in steering torque, and to provide a smooth steering feeling to the driver.

In addition, another object of the present invention, to enable fine steering torque control, to provide a smooth steering feeling to the driver to provide a safe lane keeping function.

One embodiment of the present invention, the lane departure detection unit for detecting a lane departure based on the image through the camera; A steering torque signal generator for calculating steering torque in a direction of preventing the detected lane departure and generating a steering torque signal for the calculated steering torque; A steering torque signal conversion unit converting the generated steering torque signal into a pulse modulation signal form through a pulse modulation method; And a steering torque signal applying unit for applying the steering torque signal converted into the pull modulated signal form to the steering system.

One embodiment of the present invention, the lane departure detection step for detecting a lane departure based on the image through the camera; A steering torque signal generation step of calculating steering torque in a direction of preventing the detected lane departure and generating a steering torque signal for the calculated steering torque; A steering torque signal conversion step of converting the generated steering torque signal into a pulse modulation signal form through a pulse modulation method; And a lane keeping control step of performing steering control for lane keeping based on the steering torque signal converted into the pulse modulated signal form.

Another embodiment of the present invention, the signal input unit for receiving a steering torque signal; A signal converter for converting the input steering torque signal into a pulse modulated signal through a pulse modulation method; And a signal output unit configured to output a steering torque signal converted into the pull modulated signal form.

As described above, according to the present invention, the steering torque signal is converted into a pulse modulation method and used for steering torque control, thereby enabling fine steering torque control that allows a steering angle change to occur even with a slight increase in steering torque. It has the effect of providing a smooth steering feeling.

According to the present invention, the steering torque signal is converted into a pulse modulation method and used for steering torque control for the lane keeping function, thereby enabling fine steering torque control and providing a smooth steering feeling to the driver, thereby providing a safe lane keeping function. It is effective to provide.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

1 is a block diagram of a lane keeping system 100 according to an embodiment of the present invention.

Referring to FIG. 1, a lane keeping system 100 according to an exemplary embodiment of the present invention may include a lane departure detection unit 110 for detecting a lane departure based on an image through a camera. The steering torque signal generation unit 120 calculates a steering torque in a direction of preventing the lane departure, and generates a steering torque signal for the calculated steering torque, and modulates the generated steering torque signal into a pulse modulation (PM: Pulse). Through a modulation method, a steering torque signal converting unit 130 for converting a pulse modulated signal form and a steering torque signal applying unit 140 for applying a steering torque signal converted to a pull modulated signal form to the steering system 150 are provided. And the like.

Lane keeping system 100 according to an embodiment of the present invention is also referred to as Lane Keeping Assist System (LKAS).

The steering torque signal generation unit 120 generates a steering torque signal for the steering torque calculated by calculating steering torque based on the magnitude and direction for preventing the lane departure according to the detected degree of lane departure. . In this case, the generated steering torque signal is a signal for steering torque that increases in magnitude for a predetermined time, as shown in FIGS. 6 and 7.

The aforementioned steering torque signal converter 130 may convert the generated steering torque signal into a pulse width modulated signal type among the pulse modulated signal types through a pulse width modulation (PWM) method among the pulse modulated methods. have.

At this time, the pulse width Duty of the steering torque signal converted into the pulse width modulation signal form is a value obtained by dividing the magnitude of the steering torque signal generated by the steering torque signal generator 120 by the torque saturation magnitude of the generated steering torque signal. Can be proportional to

When the steering torque signal applying unit 140 described above applies the steering torque signal generated by the steering torque signal generating unit 120 to the steering system 150 as shown in FIG. 6, the steering torque is increased. Even if the steering angle generated by the steering torque control hardly changes the time domain is formed. The time domain thus formed is referred to as "control dead zone." Such a control dead zone may occur due to mechanical play or friction near the center of the steering wheel, and the steering angle hardly changes even when the steering torque is increased, so that the driver may feel a sudden steering torque change. 6, when the steering torque in the steering torque signal is in the range of 0 Nm to about 2.8 Nm (control dead zone), there is no change in the steering angle, and when the steering torque becomes larger than about 2.8 Nm, the steering angle increases abruptly. It is to disable torque control. The problem of making such fine steering torque control impossible is that the driver does not feel the steering torque gradually increasing slightly in the range of 0 Nm to approximately 2.8 Nm, and the steering torque is felt only when the steering torque increases approximately 2.8 Nm. It may not provide a smooth steering feel to the vehicle and, more seriously, may cause lane departure and cause an accident.

 In the lane keeping system 100 according to an exemplary embodiment of the present invention proposed to solve these problems, the steering torque signal applying unit 140 controls the steering torque signal generated by the steering torque signal generating unit 120. The steering torque signal converting unit 130 converts the steering torque signal generated by the steering torque signal generating unit 120 into a pulse modulated signal without applying it to 150, and the steering torque signal applying unit 140 By applying the steering torque signal converted into the pulse modulation signal form to the steering system 150, even if the steering torque increases, the steering angle generated by the steering torque control is hardly changed. "Can be removed. In other words, when the steering torque is increased, it is possible to enable fine steering torque control that allows the steering angle to change accordingly. As a result, the driver may feel a smooth steering torque change, thereby providing a smooth steering feeling.

The above-described steering torque signal conversion unit 130 converts the steering torque signal generated by the steering torque signal generation unit 120 into a pulse modulation signal form through a pulse modulation method. Through one pulse width modulation (PWM) method, the steering torque signal can be converted into a pulse width modulation signal. At this time, the pulse width Duty in the steering torque signal converted into the pulse width modulation signal form is the torque saturation of the steering torque signal generated by generating the magnitude of the steering torque in the steering torque signal generated by the steering torque signal generator 120. It can be proportional to the value divided by (Torque Saturation).

2 is an exemplary view of implementing the lane keeping system 100 according to an embodiment of the present invention. The lane keeping system 100 may be implemented as an electronic control unit (ECU), which is referred to as a LKS ECU (Lane Keeping System Electronic Control Unit, 200, hereinafter referred to as "LKS ECU"). This is called.

Referring to FIG. 2, when the driver makes a driver input through the switch 220 to use the lane keeping function, the LCS ECU 200 starts to perform the lane keeping function, and includes a vision system 210 including a camera. Receives lane information of both lanes detected from the mobile terminal. At the same time, the LKS ECU 200 may be equipped with various in-vehicle sensors (e.g., vehicle speed sensor, yaw rate sensor, steering angle sensor 270, etc.) or various in-vehicle systems (e.g., ABS / ESC 140, MDPS 250). ), EMS 260, etc.) receives vehicle information including at least one of a lateral velocity, a longitudinal velocity, a yaw rate, a heading angle, and the like.

Referring to FIG. 2, and also with reference to FIG. 3 illustrating a situation in which a vehicle is prevented from lane departure by the lane keeping system 100 and lane keeping is provided, the LKS ECU 200 may include input lane information and Detects that the vehicle 300 leaves the lane 310 by using the vehicle information, calculates and generates a steering torque for allowing the vehicle 300 to maintain the lane 310, and interlocks with the MDPS 250. The steering torque signal for the steering torque generated in this way is converted into a pulse modulated signal (e.g., pulse width modulated signal), and the steering torque signal converted into a pulse modulated signal (e.g., pulse width modulated signal) is used. By performing steering torque control, the vehicle 300 may maintain the lane 310 to travel. The LCS ECU 200 may display the lane keeping state on the display 230 in the vehicle 300 while performing the lane keeping function such that the driver may check the current driving state of the vehicle 300. .

Information or signals may be transferred between the devices shown in FIG. 2 through a vehicle communication network such as a control area network (CAN).

4 is a flowchart schematically illustrating a lane keeping method provided by the lane keeping system 100 according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the lane keeping method provided by the lane keeping system 100 according to an exemplary embodiment includes a lane departure detecting step S400 of detecting a lane departure based on an image through a camera and detecting the lane departure. Steering torque signal generation step (S402) of calculating the steering torque in the direction of preventing the lane departure, and generating a steering torque signal for the calculated steering torque, and pulse modulation generated through the pulse modulation method A steering torque signal converting step (S404) for converting into a modulated signal form, and a lane maintaining control step (S406) for performing steering control for lane keeping based on the steering torque signal converted into a pulse modulating signal form.

As described above, according to the exemplary embodiment of the present invention, the steering torque signal is converted into a pulse modulation method and used for steering torque control for the lane keeping function, thereby enabling fine steering torque control, thereby providing a smooth steering feeling to the driver. By providing a safe lane keeping function is effective.

5 is a block diagram of a steering torque signal conversion apparatus 500 according to another embodiment of the present invention.

Referring to FIG. 5, the steering torque signal conversion apparatus 500 according to another embodiment of the present invention may include a signal input unit 510 for receiving a steering torque signal 5100 and a pulse modulation (PM) scheme. The signal converter 520 converts the input steering torque signal 5100 into a pulse modulated signal, and the signal output unit 530 outputs a steering torque signal 5200 converted into a pull modulated signal. Include.

The signal conversion unit 520 described above may convert the input steering torque signal 5100 into a pulse width modulation signal in the form of a pulse modulation signal by using a pulse width modulation (PWM) method. Can be converted to a form.

The pulse width Duty of the steering torque signal 5200 converted by the signal converter 520 into the pulse width modulation signal form is the steering torque signal 5100 inputted with the magnitude of the input steering torque signal 5100. It can be proportional to the value divided by the torque saturation of the In addition, the steering torque signal 5200 converted by the signal converter 520 into the pulse width modulated signal may have a period of a constant value (for example, 100 ms).

The steering torque signal conversion apparatus 500 according to another embodiment of the present invention may be applied to the lane keeping system 100 described above with reference to FIGS. 1 to 4. In this case, the above-described signal input unit 510 may receive a steering torque signal 5100 for the provision torque calculated in the direction of preventing lane departure detected by the camera. The signal output unit 530 may output the steering torque signal 5200 converted into a pulse modulation signal form to the steering system 150.

FIG. 6 shows the steering angle change according to the steering torque signal 5100 during steering torque control when the steering torque signal 5100 is applied to the steering system 150 without being converted into a pulse modulation signal form as in the related art. FIG. 7 is a diagram illustrating an example of converting a steering torque signal 5100 into a pulse width modulation (PWM) signal using a steering torque signal conversion device 500 according to another embodiment of the present invention, and forming a pulse width modulation signal. A steering angle change based on a steering torque signal 5100 when steering torque control is performed based on a steering torque signal 5200 converted into Rs.

In FIG. 6, the upper graph is a graph showing the steering torque signal 5100 with respect to the steering torque, and the lower graph is a graph showing the steering angle change according to the steering torque signal 5100.

Referring to FIG. 6, even if the steering torque is increased, a time region in which the steering angle generated by the steering torque control is hardly changed is formed. The time domain thus formed is referred to as "control dead zone." Such a control dead zone may occur due to mechanical play or friction near the center of the steering wheel, and the steering angle hardly changes even when the steering torque is increased, so that the driver may feel a sudden steering torque change. Referring to FIG. 6, in the steering torque signal 5100 in the range of 0 Nm to approximately 2.8 Nm (control dead zone), there is no change in steering angle according to steering torque, and the steering angle becomes larger than approximately 2.8 Nm. It is suddenly increased, which makes fine steering torque control impossible. The problem of making such fine steering torque control impossible is that the driver does not feel the steering torque gradually increasing slightly in the range of 0 Nm to approximately 2.8 Nm, and the steering torque is felt only when the steering torque increases approximately 2.8 Nm. It may not provide a smooth steering feel to the vehicle and, more seriously, may cause lane departure and cause an accident.

These problems may be solved as shown in FIG. 7 using the steering torque signal conversion apparatus 500 according to another embodiment of the present invention.

In FIG. 7, the upper graph is a graph showing the input steering torque signal 5100, and the middle graph is a steering in which the input steering torque signal 5100 is converted into a pulse width modulation signal through a pulse width modulation method. A graph showing a torque signal 5200, and a graph below shows a steering angle change according to a steering torque signal 5200 converted into a pulse width modulated signal.

Referring to FIG. 7, without applying the steering torque signal 5100 to the steering system 150 as it is, the steering torque signal conversion apparatus 500 converts the input steering torque signal 5100 into a pulse modulated signal form. By applying the steering torque signal 5200 converted in the form of pulse modulation signal to the steering system 150, even when the steering torque is increased, the steering angle generated by the steering torque control is hardly changed. Zone) "can be removed. In other words, when the steering torque is increased, it is possible to enable fine steering torque control that allows the steering angle to change accordingly. As a result, the driver may feel a smooth steering torque change, thereby providing a smooth steering feeling.

In the steering torque signal 5200 converted into the pulse width modulation signal type shown in FIG. 7, the pulse width Duty is obtained by inputting the magnitude of the steering torque in the steering torque signal 5100 input from the signal input unit 510. It may be proportional to the value divided by the magnitude of the torque saturation of the steering torque signal 5100. This can be confirmed through FIG. 8.

As described above, according to another embodiment of the present invention, the steering torque signal is converted into a pulse modulation method and used for steering torque control, thereby enabling fine steering torque control that allows a steering angle change to occur even with a slight increase in steering torque. In addition, the driver has an effect of providing a smooth steering feeling.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented in one independent hardware, each or all of the components are selectively combined to perform some or all of the functions combined in one or a plurality of hardware. It may be implemented as a computer program having a. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program may be stored in a computer readable storage medium and read and executed by a computer, thereby implementing embodiments of the present invention. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a block diagram of a lane keeping system according to an embodiment of the present invention;

2 is an exemplary view illustrating a lane keeping system according to an embodiment of the present invention;

3 is an exemplary diagram in which a vehicle is prevented from lane departure by lane keeping by a lane keeping system according to an exemplary embodiment of the present invention.

4 is a flowchart illustrating a lane keeping method according to an embodiment of the present invention;

5 is a block diagram of an apparatus for converting a steering torque signal according to another embodiment of the present invention;

6 is a view showing a steering angle change according to a steering torque signal in the conventional steering torque control;

7 is a view illustrating a steering angle change according to a steering torque signal when steering torque control is performed by converting a steering torque signal into a pulse width modulated signal using a steering torque signal converting apparatus according to another embodiment of the present invention;

8 is a diagram illustrating a steering torque signal converted into a pulse width modulated signal.

Description of the Related Art

100: lane keeping system

110: lane departure detection unit

120: steering torque signal generation unit

130: steering torque signal conversion unit

140: steering torque signal applying unit

150: steering system

500: steering torque signal converter

510: signal input

520: signal conversion unit

530: signal output unit

5100: steering torque signal

5200: steering torque signal converted into pulse width modulated signal

Claims (4)

Lane departure detection unit for detecting a lane departure based on the image through the camera; A steering torque signal generator for calculating steering torque in a direction of preventing the detected lane departure and generating a steering torque signal for the calculated steering torque; A steering torque signal conversion unit for converting the generated steering torque signal into a pulse width modulation signal through a pulse width modulation (PWM) method; And A steering torque signal applying unit for applying the steering torque signal converted into the spread width modulation signal form to the steering system, The pulse width Duty of the steering torque signal converted into the pulse width modulated signal form is And the magnitude of the generated steering torque signal is proportional to a value obtained by dividing the generated steering torque signal by the torque saturation magnitude of the generated steering torque signal. The method of claim 1, The steering torque signal converter, And a steering torque signal is converted into a pulse width modulated signal so that a steering angle changes according to the calculated steering torque change in a control dead zone. delete Lane departure detection step of detecting a lane departure based on the image through the camera; A steering torque signal generation step of calculating steering torque in a direction of preventing the detected lane departure and generating a steering torque signal for the calculated steering torque; A steering torque signal conversion step of converting the generated steering torque signal into a pulse width modulation signal form through a pulse width modulation (PWM) method; And And a lane keeping control step of performing steering control for lane keeping based on the steering torque signal converted into the spread width modulation signal form. The pulse width Duty of the steering torque signal converted into the pulse width modulated signal form is And a magnitude of the generated steering torque signal is proportional to a value obtained by dividing the generated steering torque signal by the torque saturation magnitude of the generated steering torque signal.

Images