KR101293108B1 - Control method of vehicle - Google Patents

Abstract

The present invention relates to a control method of a vehicle having an adaptive cruise control system that detects a vehicle in front of the vehicle by a front sensor having a high side accuracy and adjusts a traveling speed.

To this end, the present invention is to detect the relative distance of the vehicle located in front of the vehicle with a RADAR (RAdio Detection And Ranging) sensor and LIDAR (LIght Detection And Ranging) sensor, and the angle and the incoming wave reflected from the RADAR sensor Check the difference angle of the angle reflected by the light output from the LIDAR sensor, and if it is determined that the difference angle is more than the reference angle, it is determined that the vehicle cuts in front of the vehicle (cut-in) driving speed Or detecting the width of the vehicle located in front of the vehicle at a relative distance obtained by the difference angle, the RADAR sensor, and the LIDAR sensor; It is equipped with an adaptive cruise control system that adjusts the driving speed by judging cut-in, and reduces the risk of accident by increasing the side accuracy of the front sensor. .

Adaptive cruise control system, ACC, RADAR sensor, LIDAR sensor

Description

CONTROL METHOD OF VEHICLE}

The present invention relates to a control method of a vehicle, and more particularly, to a control method of a vehicle having an adaptive cruise control system for detecting a vehicle in front by a front sensor and adjusting a traveling speed.

In general, the adaptive cruise control system (hereinafter, also referred to as "ACC") adds a regular interval driving function to a conventional cruise control function. The cruise control function means a function of constantly driving the vehicle at a predetermined speed set by the driver without using the accelerator pedal. That is, if the driver sets the cruise control mode by using the cruise control mode key or the like while driving the vehicle at a predetermined speed by using the accelerator pedal, the vehicle may be set to the cruise control mode even if the driver does not use the accelerator pedal. Speak the ability to keep pace.

As such, the cruise control function keeps the vehicle speed constant, thereby providing the convenience that the driver can drive the vehicle at a desired speed without using the acceleration and deceleration pedals. However, when driving the vehicle in the cruise control mode, there is a problem that the vehicle maintains a constant speed regardless of the presence of the vehicle ahead and may cause a traffic accident.

The Adaptive Cruise Control is proposed to prevent this problem.

In detail, the adaptive cruise control system is a system that detects a front object by using a front sensor such as a camera, and automatically controls the longitudinal behavior of the control vehicle accordingly. Such a system can reduce the stress on the driver's repetitive tasks such as acceleration, deceleration and stopping required to maintain a proper distance from the vehicle ahead when driving on the road. In addition, by automatically driving the control vehicle at a predetermined speed and automatically decelerating or accelerating according to the movement of the front object, there is an advantage that the traffic flow can be smoothly improved with the improvement of the fuel efficiency of the vehicle.

However, LIDAR (LIght Detection And Ranging) sensor, which is used as a forward detection sensor in Adaptive Cruise Control, detects the distance of an object in front of it by using light. ), And RADAR (RAdio Detection And Ranging) sensor detects the distance of an object in front of it by using radio waves, and has a problem of low lateral accuracy.

The present invention is to solve the above problems, an object of the present invention is to detect the object in front of the vehicle by using both a LIIDAR (LIght Detection And Ranging) sensor and RADAR (RAdio Detection And Ranging) sensor to the surrounding environment It is to provide a vehicle control method that can increase the lateral accuracy without being affected.

The control method of the vehicle according to an embodiment of the present invention for achieving the above object is to detect the relative distance of the vehicle located in front of the vehicle with a RADAR (RAdio Detection And Ranging) sensor and LIDAR (LIght Detection And Ranging) sensor And checking a difference angle between an angle at which the radio wave output from the RADAR sensor is reflected and an angle at which the light output from the LIDAR sensor is reflected, and when the difference angle is determined to be greater than or equal to a reference angle, the difference angle and the relative distance. Detecting the width of the vehicle located in front of the front, and if it is determined that the width is greater than the reference width, it is determined that the vehicle cuts into the front of the vehicle (step) to adjust the running speed.

When it is determined that the difference in angle is less than the reference angle, the relative distance detected by the RADAR sensor and the relative distance detected by the LIDAR sensor are averaged to calculate an average relative distance of the vehicle located in front of the vehicle, and the average relative distance It is desirable to have an adaptive cruise control system that adjusts the traveling speed according to the distance.

When the vehicle is detected only by one of the RADAR sensor and the LIDAR sensor, it is preferable to have an adaptive cruise control system for adjusting the traveling speed by using the relative distance detected by the sensor detecting the vehicle as the average relative distance. Do.

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As described in detail above, according to an aspect of the present invention, since both the LIDAR (LIght Detection And Ranging) sensor and the RADAR (RAdio Detection And Ranging) sensor detect the relative distance of the object without being affected by the surrounding environment. It is possible to provide a front sensor that can increase the lateral accuracy.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

1 is a control block diagram of a vehicle having an adaptive cruise control system according to an embodiment of the present invention.

As shown in FIG. 1, the vehicle has an ACC operation mode setting key 10 capable of switching from the normal driving mode to the adaptive cruise control mode, and a front sensor for sensing a relative speed and a relative distance of another vehicle in front of the vehicle. (11), a camera sensor 12 for knowing the type of target object present in front of the vehicle, a vehicle speed sensor 13 for detecting the traveling speed of the vehicle, and an electronic controller for controlling overall control of the system ( 14), an electronic control brake 15 for braking the vehicle, and an electronic control throttle 16 for controlling the traveling speed of the vehicle.

 The ACC operation mode setting key 10 is a switch for switching the driving mode of the vehicle from the normal driving mode to the adaptive cruise control mode (ACC), and the driver accelerates the vehicle to a desired speed by stepping on an accelerator pedal (not shown). If the ACC operation mode setting key 10 is input afterwards, the vehicle speed is controlled to be maintained at the traveling speed when the ACC operation mode setting key 10 is turned on, but the user is controlled according to the distance to the control target vehicle in front of the vehicle. The driving speed set by the user will rise or fall.

The front detection sensor 11 detects the relative speed and the relative distance of the vehicle existing in front of the vehicle and transmits it to the electronic controller 14. In the present invention, both the front detection sensor 11, the LIDAR (LIght Detection And Ranging) sensor and the RADAR (RAdio Detection And Ranging) sensor are mounted and used.

LIDAR (LIght Detection And Ranging) sensor detects the distance from the front object by using light, and measures the time when the light output from the front of the car hits the front object and reflects the return. The distance and relative speed can be detected. LIDAR (LIght Detection And Ranging) sensors have the advantage of high accuracy when detecting objects on the side of the car.

Here, the relative distance means the distance between the vehicle and the front vehicle, and the relative speed means the difference between the speed of the vehicle and the speed of the front vehicle.

RADAR (Radio Detection And Ranging) sensor detects the distance from the front object by using the radio waves, and measures the time when the radio wave output from the front of the car hits the front object and reflects it and returns. The distance and relative speed can be detected. RADAR (Radio Detection And Ranging) sensor has the advantage of being strong against the external environment (snow, rain, fog, etc.).

The camera sensor 12 may be installed toward the front of the inside of the vehicle so as to reduce the air resistance and not affect the lens by rain, snow, dust, etc., so as to photograph the front of the vehicle, and transmit the information to the electronic controller 14. By transmitting, it is possible to know the type of the object in front of the vehicle detected by the front sensor (11).

The vehicle speed sensor 13 detects the traveling speed of the vehicle and transmits the information to the electronic controller 14, and there are various types according to the measurement method. A typical example is a reed switch type sensor. A reed switch type sensor is installed near a magnet rotor and rotates the magnet rotor to change the direction of the magnetic flux passing through the reed switch. Will be.

The electronic controller 14 manages overall control of the adaptive cruise control system. Specifically, when the ACC operation mode setting key 10 is input during driving of the vehicle, the relative speed and relative distance information of the object in front of the vehicle transmitted from the front sensor 11 and the target object input from the camera sensor 12 The vehicle to be controlled is selected by integrating the information on the types of vehicles.

In addition, when the ACC operation mode setting key 10 is turned on, the electronic controller 14 controls the vehicle by using the traveling speed as the reference speed, and increases or decreases the reference speed of the vehicle according to the distance from the control target vehicle in front of the vehicle. Descended. Specifically, the electronic controller 14 controls, in principle, the electronic control throttle 16 to maintain the traveling speed of the vehicle when the ACC operation mode setting key 10 is turned on, and according to the distance from the vehicle to be controlled. Perform the same operation as

That is, the electronic controller 14 detects the vehicle speed from the vehicle speed sensor 13 when the ACC operation mode is set, and detects the safety distance from the vehicle ahead using the stop time set by the stop time setting key (not shown). . In addition, the front sensor 11 and the camera sensor 12 detects the distance to the front vehicle, that is, the distance between the vehicles. Thereafter, it is determined whether the difference between the safety distance and the vehicle distance is within a predetermined allowable range, and accordingly, the electronic control throttle 16 and the electronic control brake 15 are controlled to adjust the traveling speed of the vehicle. On the other hand, the ACC operation mode described above is described in detail in Korean Patent Laid-Open No. 2000-0055183.

On the other hand, the electronic controller 14 adjusts the traveling speed of the vehicle by using the relative distance information of the front vehicle detected by the two types of front detection sensors installed in the vehicle.

First, the electronic controller 14 checks the difference between the angle at which the radio wave output from the RADAR (Radio Detection And Ranging) sensor is reflected and the angle at which the light output from the LIDAR (LIght Detection And Ranging) sensor is reflected. When the difference in the angle is determined to be greater than or equal to the reference angle, it is determined that the detected vehicle cuts in the front of the vehicle and adjusts the driving speed. In addition, if it is determined that the difference in the angle is greater than the reference angle, the width of the vehicle located in front of the difference angle and the relative distance obtained by the RADAR sensor and the LIDAR sensor is detected. You can also adjust the running speed by judging (cut-in) in front of.

Secondly, when the electronic controller 14 calculates a relative distance from the vehicle in front of the vehicle, the electronic controller 14 uses the relative distance measured by the RADAR (RAdio Detection And Ranging) sensor and the LIDAR (LIght Detection And Ranging) sensor. The average value of the measured relative distances is estimated as the average relative distance of the front vehicle, and the driving speed of the vehicle is adjusted based on the average relative distance to the front vehicle. According to the above method, the calculated relative distance value with the front vehicle becomes more accurate.

Thirdly, the electronic control unit 14 does not detect a vehicle by a LIIDAR (LIght Detection And Ranging) sensor, but when the vehicle is detected by a RADAR (RAdio Detection And Ranging) sensor, it is assumed that the external environment is vulnerable. Adjust the driving speed of the vehicle based on the relative speed with the vehicle detected by the sensor.

The electronic control brake 15 may reduce the speed of the vehicle according to the driving of the deceleration pedal (not shown), and the electronic control throttle 16 may control the opening and closing of the vehicle according to the driving of the acceleration pedal (not shown). Can be accelerated.

2 is a schematic diagram illustrating sensing a front vehicle by a front sensor according to an embodiment of the present invention.

As shown in FIG. 2, when another vehicle 30 is cut-in while the vehicle 20 is driving and driving the adaptive cruise control system, a LIght Detection And Ranging (LIDAR) sensor is used. The relative distance a between the vehicle 20 and the front vehicle 30 is measured, and the relative distance b between the vehicle 20 and the front vehicle 30 is also measured by a RADAR (Radio Detection And Ranging) sensor. In addition, a difference angle θ between an angle at which the radio wave output from the RADAR sensor is reflected and an angle at which the light output from the LIDAR (LIght Detection And Ranging) sensor is reflected may be obtained.

At this time, when it is determined that the difference angle θ is greater than or equal to the reference angle, the electronic controller 14 determines that another vehicle 30 is interrupted in front of the vehicle 20, thereby interposing the controlled vehicle. Lifting is changed to the vehicle 30 to adjust the traveling speed. Conventionally, when detecting a front object using only a RADAR (Radio Detection And Ranging) sensor, the rear bumper corner with a large amount of reflection is recognized as the vehicle 30 so that the front part of the vehicle 30 may be cut into the lane of the vehicle 20. Although there was a risk of accident by not recognizing, according to the present invention, the vehicle 30 intervening in the front by the above-mentioned method is detected with a RADAR (RAdio Detection And Ranging) sensor and a LIDAR (LIght Detection And Ranging) sensor. The risk of accidents can be reduced by detecting cut-in vehicles.

On the other hand, if the difference angle between the radio wave reflected by the RADAR (Radio Detection And Ranging) sensor and the light reflected by the LIDAR (LIght Detection And Ranging) sensor is less than or equal to the reference angle, It is determined that the vehicle is detected, and the reference angle can be determined by the designer in consideration of an error caused by the difference between the installation positions of the two sensors.

In addition, the electronic controller 14 measures the relative distance (a) measured by the LIDAR (LIght Detection And Ranging) sensor, the relative distance (b) measured by the RADAR (RAdio Detection And Ranging) sensor, and the difference angle θ. By using this, the width (x) of the vehicle 30 that cuts in front can be obtained. The width (x) of the front vehicle obtained by the above-described method has a value greater than or equal to a certain width when cutting into the front of the vehicle 20, and thus determines that another vehicle enters the front of the vehicle 20. You may. Accordingly, the electronic control unit 14 can prevent the accident in advance by adjusting the vehicle speed.

3 is a control flowchart of a vehicle according to an embodiment of the present invention.

As shown in FIG. 3, the electronic controller 14 checks whether the ACC operation mode setting key 10 is input by the driver during normal driving of the vehicle, and when it is confirmed that the ACC operation mode setting key 10 is input. When the ACC operation mode setting key 10 is turned on, the vehicle is driven with the traveling speed as the reference speed. (S10, s20)

Next, the electronic controller 14 checks whether the vehicle is detected in front by the front sensor 11. This is because the reference speed of the vehicle must be raised or lowered according to the distance from the vehicle detected in front of the vehicle (s30).

Next, when the vehicle is detected in front of the vehicle, an angle, that is, a difference angle between the radio waves reflected by the RADAR (RAdio Detection And Ranging) sensor and the light reflected by the LIDAR (LIght Detection And Ranging) sensor, is returned. ) And the magnitude of the reference angle (θ1), or the relative distance (a) measured by the LIDAR (LIght Detection And Ranging) sensor, the relative distance (b) and the difference measured by the RADAR (RAdio Detection And Ranging) sensor Compare the size of the width (x) of the vehicle intervening in the front by the angle (θ) and the reference width (x1) (s40).

On the other hand, the reference angle (θ1) and the reference width (x1) can be determined by the designer in consideration of the error caused by the difference in the installation position of the two sensors, and based on the difference angle and width that can be determined that the vehicle in front The angle θ1 and the reference width x1 may be determined.

  Next, the electronic controller 14 determines that the difference angle θ is greater than or equal to the reference angle θ1, or if another vehicle is inserted in front of the vehicle when it is determined that the width x of the vehicle is greater than or equal to the reference width x1. It judges that it is cut-in, and selects the interrupted vehicle as a control target vehicle. In other words, the vehicle to be cut ahead is selected as the reference vehicle for speed regulation of the vehicle driving the adaptive cruise control system.

On the other hand, the electronic controller 14 determines that the difference angle θ is less than the reference angle θ1, or if the width x of the vehicle is less than the reference width x1, the vehicle in front of the vehicle to be controlled. (S60)

Next, the electronic controller 14 adjusts the vehicle speed based on the vehicle selected as the control target vehicle in the previous step. That is, the reference speed of the vehicle is raised or lowered according to the distance from the control target vehicle in front of the vehicle (s70).

1 is a control block diagram of a vehicle having an adaptive cruise control system according to an embodiment of the present invention.

Figure 2 is a schematic diagram showing detecting the front vehicle by the front sensor according to an embodiment of the present invention

3 is a control flowchart of a vehicle according to an embodiment of the present invention.

Description of the Related Art [0002]

     10: ACC operation mode setting key 11: Front sensor

     14: electronic control unit

Claims (4)

RADAR (RAdio Detection And Ranging) sensor and LIDAR (LIght Detection And Ranging) sensor detect the relative distance of the vehicle in front of the car, Check the difference angle between the angle at which the radio wave output from the RADAR sensor is reflected and the angle at which the light output from the LIDAR sensor is reflected, and If it is determined that the difference angle is more than the reference angle, the width of the vehicle located in front of the difference angle and the relative distance is detected, And if the width is determined to be greater than or equal to the reference width, determining that the vehicle is cut-in to the front of the vehicle, and controlling the traveling speed. The method of claim 1, If the difference is found to be less than the reference angle, The average relative distance of the vehicle located in front of the vehicle is calculated by averaging the relative distance detected by the RADAR sensor and the relative distance detected by the LIDAR sensor, A control method for a vehicle having an adaptive cruise control system for adjusting a traveling speed according to the average relative distance. The method of claim 2, If the vehicle is detected only by one of the RADAR sensor and LIDAR sensor, A control method of a vehicle having an adaptive cruise control system for adjusting a traveling speed by using a relative distance detected by a sensor detecting the vehicle as an average relative distance. delete

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