KR20050111019A - Safety steering controlling method of vehicles - Google Patents

Abstract

The present invention includes determining a driver's willingness to change lanes while driving; Determining whether the lane change is made during normal driving; Calculating a safety distance based on a speed of a vehicle driving the vehicle and road information on which the vehicle is driven; Determining whether there is a trailing vehicle within the safety distance calculated in the step in the lane that is attempting to change the lane; Calculating a relative speed with the trailing vehicle when it is determined that the trailing vehicle is within the safety distance in the step; Comparing the calculated relative speed with a preset value to determine whether a difference in relative speed with a trailing vehicle is within a safe lane change; If the driver is willing to change lanes, if there is no trailing vehicle, or if the distance from the trailing vehicle exceeds the safety distance, or if the relative speed difference with the trailing vehicle is determined to be within a safe lane change range, normal power steering Providing auxiliary steering force in proportion to the steering angle as a mode; If the driver is willing to change lanes, and if it is determined that the distance between the trailing vehicle is less than the safety distance and the relative speed difference with the trailing vehicle is within a range where a safe lane cannot be changed, a warning signal is generated by applying a control signal. Wow; Outputting a control signal such that steering assistance force generated in the driving motor of the power steering device is lowered; It provides a steering control method of a vehicle for a safe lane change comprising a.

Description

Steering control method of vehicle for safe lane change {SAFETY STEERING CONTROLLING METHOD OF VEHICLES}

The present invention relates to a steering control method of a vehicle for a safe lane change, and more particularly, when the driving vehicle changes lanes in consideration of a separation distance and a relative speed with a trailing vehicle, the lane change driving is not safe. In this case, the present invention relates to a steering control method of a vehicle for safe lane change that can suppress a lane change by increasing an operation force of a steering wheel.

When a vehicle driving on the road wants to change lanes, a driver usually visually determines whether a vehicle is trailing from left and right through side mirrors and the separation distance between trailing vehicles. Manipulate the wheel to change lanes.

However, when the operation for changing lanes while driving as described above, judging whether the image reflected through the side mirror is visually determined whether the safety is the difference between the separation distance and the actual separation distance sensationally determined by the side mirror. There is a risk of accidents due to judgment and error.

In particular, when the relative speed of the vehicle is high, the judgment through the side mirror alone makes it difficult to make a judgment.

In addition, in the case of night driving, it is difficult to determine the separation distance between the following vehicles and the relative speed of the following vehicle due to the light of the trailing vehicle reflected through the side mirror.

As such, the conventional lane change driving, which relies only on the driver's driving experience, is highly dependent on the driver's experience and condition, and thus, a method for protecting driver and passenger's safety is required.

The present invention devised to solve the above problems is to change the lane by increasing the operating force of the steering wheel when the lane change driving is not safe in consideration of the separation distance and the relative speed with the trailing vehicle when the driving vehicle to change lanes An object of the present invention is to provide a steering control method of a vehicle for a safe lane change that can be suppressed.

The present invention comprises the steps of determining the driver's willingness to change lanes while driving to achieve the above object; Determining whether the lane change is made during normal driving; Calculating a safety distance based on the speed of the vehicle being driven and the road information on which the vehicle is running; Determining whether there is a trailing vehicle within the safety distance calculated in the step in the lane that is attempting to change the lane; Calculating a relative speed with the trailing vehicle when it is determined that the trailing vehicle is within the safety distance in the step; Comparing the calculated relative speed with a preset value to determine whether the speed difference with the following vehicle is a speed difference that a lane change is safe; If the driver is willing to change lanes, if there is no trailing vehicle, or if the distance from the trailing vehicle exceeds the safety distance, or if the relative speed difference with the trailing vehicle is determined to be within a safe lane change range, normal power steering Providing auxiliary steering force in proportion to the steering angle as a mode; If the driver is willing to change lanes, and if it is determined that the distance between the trailing vehicle is less than the safety distance and the relative speed difference with the trailing vehicle is within a range where a safe lane cannot be changed, a warning signal is generated by applying a control signal. Wow; It provides a steering control method for a safe lane change comprising the step of outputting a control signal so that the steering assistance force generated in the drive motor of the power steering device is reduced.

On the other hand, the step of determining whether or not the attempt to change lanes made in the normal driving, determining whether the emergency warning light is on through the emergency warning light detection unit; Determining whether there is an irregular pattern of obstacles in front of the vehicle through the image information captured by the front CCD camera; In the above steps, it is determined that the emergency warning light is turned on or there is an irregular pattern in front of the vehicle In this case, auxiliary steering force is provided in proportion to the steering angle as a normal power steering mode. The step of determining whether this is an attempt to change lanes in the normal driving may be performed as a preceding step in the step of determining the driver's willingness to change lanes during driving, and the change belongs to the present invention.

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

Referring to FIG. 1, a system for implementing a vehicle steering control method according to the present invention is schematically illustrated.

As shown in the figure, the system for implementing the present invention vehicle steering control method, steering steering angle sensor 10 (SAS, Steering Angle Sensor), rear ultrasonic sensor 20, the turn signal detector 30 Emergency warning light detection unit 40, wheel speed sensor 50, front CCD camera 60, power steering unit 70, control unit 80, GPS receiver 85, warning sound generating means 90 It is configured to include.

First, the steering steering angle sensor 10 detects the steering angle of the steering wheel of the vehicle, converts the steering angle into a predetermined electrical signal, and outputs the same to the controller 80.

The rear ultrasonic sensor 20 is installed at the corners and middle portions of the rear bumper at predetermined intervals, and the reflected ultrasonic waves detect whether there is a trailing vehicle in the left and right lanes through the received information, and if there is a trailing vehicle, how far apart the vehicle is. , And converts it into a constant electrical signal and outputs it to the controller 80. On the other hand, the information about the separation distance with the trailing vehicle detected by the rear ultrasonic sensor 20 is used by the controller 80 to detect the relative speed with the trailing vehicle through a calculation process.

The turn signal detector 30 is connected to the control unit 80 to output on / off information of the turn signal switch to the control unit 80, and is connected to the on / off control unit according to a signal of the control unit 80.

The emergency warning light detecting unit 40 is connected to the control unit 80 and outputs on / off information of the emergency warning light switch to the control unit 80.

The wheel speed sensor 50 is installed on the wheel of the vehicle to detect the rotational speed of the wheel, converts it into a constant electrical signal and outputs it to the controller 80.

The front CCD camera 60 is installed in front of the vehicle and detects whether there are irregular patterns (blocks, waste, vinyl, etc.) besides the lanes on the road. The CCD camera 60 is a camera formed so that the captured image can be stored in the CCD semiconductor device and displayed when necessary. The CCD camera 60 stores image data input through the CCD camera 60 between the CCD camera 60 and the controller 80. An image processing apparatus (not shown) for processing and converting the same into a predetermined electrical signal is output. Such an image processing apparatus may be built in the CCD camera 60 and may be configured as a separate circuit or device.

The power steering unit 70 is a device that lightens the steering force of the steering wheel by providing steering assistance to the handle according to the steering wheel steering angle sensed by the steering steering angle sensor 10. The embodiment described herein includes an electric power steering apparatus as the power steering unit 70. The electric power steering device controls the driving force of the motor 74 by the controller 72 in proportion to the steering angle sensed by the steering steering angle sensor 10 so that the steering wheel is lightly operated as the driver desires.

The GPS receiver 85 receives GPS information and receives information on a road on which the vehicle is driving, and outputs the electrical signal to the controller 80. The GPS receiver 85 may be electrically connected to the controller 80 as a separate device and may be embedded in the controller 80. The controller 80 may drive a vehicle from information input through the GPS receiver 85. It recognizes road conditions such as general road or highway and uses them as control information.

The controller 80 includes a steering steering angle sensor 10, a rear ultrasonic sensor 20, a turn signal detector 30, an emergency warning light detector 40, a wheel speed sensor 50, and a front CCD camera 60. By using the information input from the GPS receiver 85, it is determined whether the vehicle can safely change lanes, and according to the determination result, the turn signal detector 30, the power steering unit 70, warning sound generating means Control 90. The control logic for allowing the controller 80 to receive information from the components and to perform a safe lane change driving is described in detail below (see FIG. 3).

Hereinafter, a steering control method according to the present invention will be described with reference to FIGS. 2 to 4.

Referring to FIG. 2, a vehicle steering control method according to the present invention is sequentially illustrated.

The control method of the present invention is initialized when the engine starts running with the ignition switch operating.

As shown in FIG. 2, when the steering control method of the vehicle of the present invention is started (S10), the steering steering angle sensor 10, the turn signal detector 30, and the signal detected by the front CCD camera 60 are used. The driver's willingness to change lanes is determined (S20).

When the steering wheel is steered in the direction while the one-way indicator switch is turned on, the controller 80 determines that the driver attempts to change lanes in the direction. At this time, the turn on of the turn signal switch is useful information to determine the driver's willingness to change lanes, but considering the driving habits of some drivers who change lanes without turning on the turn signals, the steering wheel is steered as the turn signal turns on. In addition, when the steering wheel is steered and the vehicle recognizes the lane and the driving direction of the vehicle as determined by the CCD camera 60, it is determined that the driver is attempting to change the lane even when the vehicle is approaching a certain slope with respect to the lane. It is desirable to.

At this time, when the driver determines that there is no willingness to change lanes, the driver maintains the normal power steering mode (S15) and forms a circular loop for determining the driver's willingness to change lanes.

If it is determined in this step that the driver is willing to change lanes, the control unit may use the signal detected by the emergency warning light detecting unit 40 and the image information captured by the front CCD camera 60 in an emergency situation. It is determined whether the lane change is attempted or whether the lane change is attempted in a normal driving state (S30).

FIG. 3 illustrates a control logic for determining whether a lane change is being attempted in a normal driving state as described above. Referring to the drawing, when the driver turns on an emergency warning light, a rapid lane change is performed in an emergency situation of the vehicle. If it is determined that the emergency warning light is turned on at this stage (S32), the steering wheel can be operated with a light feeling of operation by the operation assistance force provided by the power steering unit in the normal power steering mode (S15). The control logic then returns to the initial stage and again forms a loop to determine the driver's willingness to change lanes.

In addition, even when there are irregular patterns such as bumps and wastes in front of the vehicle, the vehicle is in an emergency situation to change the driving lane (S34). In this case, the power steering unit is provided in the normal power steering mode (S15). The operation assistance force enables the steering wheel to be operated with a light feeling of operation, and the control logic returns to the initial stage and forms a circular loop for determining the driver's willingness to change lanes (S34).

Subsequently, if it is determined that the lane change is attempted in the normal driving state in the above step, the safety distance is calculated by the subroutine (S40).

4, an example of the safety distance calculation control logic is shown. As shown in the figure, the safety distance calculation control logic is a safety distance (Ls) required for a safe lane change by road information input through the GPS receiver 85 and speed information of the vehicle detected by the wheel speed sensor 50. ) Is calculated.

The safety distance Ls should be determined in consideration of the speed of the driving vehicle and the stopping speed according to the road conditions and the driving speed. The present invention calculates the safety distance with reference to the recommendation on the safety distance proposed by the Road Traffic Safety Authority.

The Korea Highway Traffic Safety Administration shall maintain the m distance of the speed value minus 15 in the case of general roads and maintain a safe distance of 80 km / h or more and express the driving speed as m in the case of expressways. It is suggested that it is preferable. On the other hand, when the distance to the trailing vehicle is more than 20m with this recommendation, since the distance of the driver of the trailing vehicle is sufficient to respond, the safety distance is calculated based on the above two criteria. At this time, 20m, which is previously set as a reference for comparison, is referred to as a reference safety distance Ls'. This safe distance calculation method can be modified in various ways.

In the safety distance calculation step S40, in step S41 of recognizing the current driving speed of the vehicle based on the information detected by the wheel speed sensor 50, the driving speed of the current vehicle is recognized, and the road information recognition step S42. In the above, it is determined whether the road on which the vehicle is driven is a general road or a highway using the information input through the GPS receiver 85.

If the road on which the vehicle is driven is a highway or the speed of the driving vehicle is 80 km / h or more (S43), the numerical value expressed in m as the driving speed is the calculated safety distance (S44). When the road on which the vehicle is operated is a general road and the speed of the driving vehicle is less than 80 km / h, m of the value obtained by subtracting 15 from the value of the driving speed becomes a calculated safety distance (S45). For example, when the speed of the vehicle or the driving vehicle is 90km / h, the calculated safety distance is 90m, and when the speed of the driving vehicle is 70km / h on a general road, the calculated safety distance is 55m. The safety distance calculated in this way is referred to as La.

As described above, the operation logic used in the step of calculating the safety distance La calculated according to the preset logic may be variously modified by those skilled in the art, and such modifications are within the scope of the present invention.

Subsequently, the calculated safety distance La is compared with the preset comparison reference safety distance Ls' (S46), and when La <Ls', the calculated safety distance La becomes the safety distance Ls (S47), and La≥Ls'. If the reference standard safety distance Ls' becomes the safety distance Ls (S48).

When the safety distance is calculated in this step, it is determined whether there is a trailing vehicle within the safety distance in the driving lane in which the vehicle is trying to change lanes using the information detected by the rear ultrasonic sensor 20 (S50). The distance Lb from the trailing vehicle is calculated as follows.

Lb = C * t / 2

That is, it is a value obtained by dividing the required time (t) from the ultrasonic sensor to the point at which it is transmitted or received by multiplying the speed of the ultrasonic wave (C; in general conditions, C is 340 m / s).

If there is no trailing vehicle within the safety distance, the lane may be changed by operating the steering wheel with a light feeling of operation by the operation assistance force provided by the power steering unit in the normal power steering mode S15. However, if there is a trailing vehicle within the safety distance, the relative speed with the trailing vehicle is calculated based on the information detected by the rear ultrasonic sensor 20 (S60).

FIG. 5 shows an example of control logic in which a relative speed is calculated in a relative speed calculation step S60 with a trailing vehicle.

That is, the distance L1 of the trailing vehicle is measured at the time point T1 by using the time point at which the transmitted ultrasonic wave is reflected and received (S62), and the distance L2 with the trailing vehicle at the time point T2 after the predetermined period. By measuring (S64),

It can be calculated as Vr = (L1-L2) / (time difference between T1 and T2) (S66).

As described above, when the relative speed with the trailing vehicle driving in the lane where the lane change is being attempted is calculated, it is determined whether the relative speed difference is greater than or equal to the preset value (s70). In the present specification, a case in which the difference of the set relative speed is 15 km / h or more is illustrated. That is, only when the driving vehicle is 15km / h or more faster than the trailing vehicle, it is set as a safe lane change.

In the determining step, when the driving vehicle is 15km / h or more faster than the trailing vehicle and a safe lane change is possible, the steering wheel is operated by operating the steering wheel with a light operation feeling by the operation assistance provided by the power steering unit in the normal power steering mode. You can change it. However, if the relative speed difference between the driving vehicle and the trailing vehicle is less than the preset value, and it is determined that the safe lane change is impossible, the controller controls the warning sound generating means 90 to emit a warning sound and may cause the driver to change lanes. Informs that it can be (S80), by inputting a control signal to the controller of the power steering device to control the driving of the motor to lower the auxiliary operating force (S90). In other words, increasing the operating force required to operate the steering wheel prevents the driver from steering the steering wheel for driving lane changes.

Subsequently, if it is determined by the steering angle information detected by the steering steering angle sensor 10 that the driver has stopped the lane change attempt, the control logic is repeated by circulating in the normal power steering mode.

According to the present invention, when a driving vehicle attempts to change lanes, when the lane change driving is not safe in consideration of a separation distance and a relative speed with a trailing vehicle, the driver may recognize that the lane change is dangerous. In addition, since it is possible to suppress the lane change by increasing the operating force of the steering wheel, there is an effect that can prevent the risk of collision that may occur when changing the lane.

1 is a block diagram schematically showing the configuration of a steering control system of a vehicle for implementing the present invention.

2 is a flowchart sequentially illustrating a steering control method of a vehicle for safely changing lanes according to the present invention.

FIG. 3 is a flowchart illustrating a process of determining whether a lane change attempt is made in the normal driving shown in FIG. 2.

4 is a flowchart illustrating in detail the control logic for calculating the safety distance shown in FIG. 2.

FIG. 5 is a flowchart showing in detail a control logic for calculating a difference in relative speed with a trailing vehicle shown in FIG. 2.

Claims (5)

Determining the driver's willingness to change lanes while driving; Determining whether the lane change is made during normal driving; Calculating a safety distance based on a speed of a vehicle driving the vehicle and road information on which the vehicle is driven; Determining whether there is a trailing vehicle within the safety distance calculated in the step in the lane that is attempting to change the lane; Calculating a relative speed with the trailing vehicle when it is determined that the trailing vehicle is within the safety distance in the step; Comparing the calculated relative speed with a preset value to determine whether a lane change is within a safe range for a relative speed difference with a following vehicle; If the driver is willing to change lanes, if there is no trailing vehicle, or if the distance from the trailing vehicle exceeds the safety distance, or if the relative speed difference with the trailing vehicle is determined to be within a safe lane change range, normal power steering Providing a secondary steering force in proportion to the steering angle as a mode; If the driver is willing to change lanes, and if it is determined that the distance between the trailing vehicle is less than the safety distance and the relative speed difference with the trailing vehicle is within a range where a safe lane cannot be changed, a warning signal is generated by applying a control signal. Wow; Outputting a control signal such that steering assistance force generated in the driving motor of the power steering device is lowered; Steering control method of a vehicle for a safe lane change comprising a. The method of claim 1, The step of determining the driver's willingness to change lanes while driving Even when it is recognized that the turn signal is not turned on by the turn signal detecting unit, information for steering the steering wheel is input from the steering steering angle sensor, and the driving vehicle has a constant slope to the lane from the image information photographed by the front CCD camera. Steering control method of a vehicle for a safe lane change, characterized in that determined to be determined to approach the lane change. The method of claim 1, The step of determining whether the lane change is made in the normal driving, Determining whether the emergency warning light is on by using the emergency warning light detecting unit; Determining whether there is an irregular pattern of obstacles in front of the vehicle through the image information captured by the front CCD camera, In the above steps, when it is determined that the emergency warning light is turned on or there is an irregular pattern in front of the vehicle, the auxiliary steering force is provided in proportion to the steering angle as a normal power steering mode. How to control steering. The method of claim 1, The step of calculating the safety distance, Using the wheel speed sensor to recognize the speed of the vehicle being driven; Recognizing road information from information input from a GPS receiver; Calculating a safety distance La calculated according to a predetermined logic according to the speed and road information recognized in the above steps; Comparing the calculated safety distance La with a safety distance Ls' which is a reference for a preset comparison; The safety distance Ls is determined as La when La is less than Ls' in the comparing step, and the safety distance Ls is determined as Ls' when La is more than Ls'. Steering control method. The method of claim 1, The step of calculating the relative speed with the trailing vehicle, Using the received signal transmitted from the rear ultrasonic sensor and reflected from the following vehicle, Measuring a first separation distance L1 measured by a signal reflected at an initial time point T1; Measuring a second separation distance L2 measured by a signal reflected at a predetermined time T2 after a predetermined time elapses; Calculating relative speed by calculating the measured separation distance as (L1-L2) / (time difference between T1 and T2).