SYSTEM AND METHOD FOR AUTOMATIC VEHICLE CONTROL

Abstract

Automatic driving control system (1) which features: a speed sensor (10) that detects vehicle speed; a yaw rate sensor (20) that detects the yaw rate of the vehicle; a yaw rate calculation unit (30) that calculates a target yaw rate required to drive the vehicle to a specific target point, and that calculates a real-time target yaw rate required to drive the vehicle to the target point by comparing a yaw rate detected in real time by the yaw rate sensor (20) with the target yaw rate; a calculation unit (40) for lateral acceleration which calculates a lateral target acceleration required to move the vehicle to the target point by using the vehicle speed and the target yaw rate, and a real-time lateral target acceleration required to move the vehicle to the target point by using the vehicle speed and the real-time target yaw rate; and a control determination unit (50) that determines whether the real-time lateral target acceleration calculated by the lateral acceleration computation unit (40) is outside the range between a predetermined upper limit threshold and a predetermined lower limit threshold of lateral acceleration, while an automatic driving mode that automatically controls the driving of the vehicle is in operation, wherein the control determination unit (50) terminates the automatic driving mode when the real-time lateral target acceleration is outside the range between the predetermined upper limit threshold and the predetermined lower limit threshold of the lateral acceleration, so that a driver can take over driving control of the vehicle.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application claims the priority and benefit under 35 USC §119(a) of Korean patent application No. 10-2014-0127377, which was filed on September 24, 2014, and which is hereby incorporated for all purposes as if it were fully disclosed herein. BACKGROUND OF THE INVENTION 1. Field of the invention

[0002] The present invention relates to an automatic driving control system and a method therefor, and in particular to an automatic driving control system that more accurately detects the driver's intention to control the driving of a vehicle by using a yaw rate and a lateral acceleration while the vehicle is driving in an automatic driving mode, in order to release the automatic driving mode in such a way as to increase the convenience and satisfaction of the driver, and a method therefor. 2. Description of the state of the art

[0003] As automobile use increases dramatically in modern society, the number of people killed or injured in traffic accidents reaches tens of thousands each year. Accordingly, to reduce the number of casualties and the economic losses caused by traffic accidents, various automotive technologies have been developed, such as advanced driver assistance systems (ADAS) that utilize state-of-the-art sensors and intelligent video equipment to help prevent accidents.

[0004] The advanced driver assistance system includes forward collision warning (FCW) technology, adaptive cruise control (ACC) technology, lane change assist technology, lane departure warning technology, and parking assist technology.

[0005] Here, the automatic driving control technology enables a vehicle to automatically detect a vehicle ahead traveling in the same direction in the lane, while the vehicle is kept in the same lane according to the driver's configuration state, and to automatically accelerate or decelerate its speed according to the speed of the vehicle ahead in order to maintain a safe distance and automatically drive at a target speed.

[0006] While the vehicle is operating in automatic driving mode using automatic driving control technology, the driver, when disengaging automatic driving mode and changing lanes—that is, when the driver intends to drive the vehicle directly—operates the steering wheel. To detect the driver's intention to perform driving control, current technology uses a torque signal generated by a torque sensor to detect steering wheel movement. However, in this method, a sufficient torque signal is only generated if the driver applies considerable force to the steering wheel. Therefore, detecting steering wheel movement by the driver is not straightforward.Furthermore, it is difficult to specify clear, objective criteria for determining a threshold value for the torque signal, and the threshold for the torque signal tends to be determined subjectively. Therefore, a method for clearly detecting the driver's intention to execute the vehicle control is required.

[0007] DE 10 2011 102 435 A1 discloses a method for operating a longitudinal driver assistance system of a motor vehicle, wherein the speed of the motor vehicle is controlled depending on at least one control data, wherein further control data include curve data relating to at least one curve to be traversed next by the motor vehicle.

[0008] DE 10 2009 018 023 A1 discloses a vehicle propulsion control system in which a control unit calculates a rating index that indicates the approach / disengagement state of a reference vehicle during a journey and stores this rating index together with a distance between the vehicles with respect to each driver in a storage device. The control unit further calculates a maximum value of the stored rating index for each distance and calculates a relational equation between the distance and the calculated maximum rating index. By correcting the relational equation, the control unit determines a speed control start determination equation that determines the start time of the automatic acceleration and / or deceleration control.

[0009] EP 2 398 681 B1 teaches a vehicle dynamics controller in which a target value is calculated as a function of the lateral force acting on the front wheel and / or the rear wheel and at least one of the lateral forces is limited to a value which is dimensioned so that the lateral acceleration of the vehicle does not exceed a permissible threshold. SUMMARY OF THE INVENTION

[0010] The invention is defined in the independent claims.

[0011] The present invention provides a system and a method for automatic driving control which more accurately detects the driver's intention to carry out driving control by using a yaw rate and a lateral acceleration while the vehicle is driving in automatic driving mode, in order to thereby release the automatic driving mode, so that the convenience and satisfaction of the driver can be increased.

[0012] According to one aspect of the present invention, an automatic vehicle control system may in particular include: a speed sensor that detects a vehicle speed; a yaw rate sensor that detects a yaw rate of the vehicle; a yaw rate calculation unit that calculates a target yaw rate required to drive the vehicle to a specific destination point, and a real-time target yaw rate required to drive the vehicle to the destination point by comparing a yaw rate detected in real time by the yaw rate sensor with the target yaw rate;a lateral acceleration calculation unit that calculates a target lateral acceleration required to move the vehicle to the target point using the vehicle speed and target yaw rate, and a real-time target lateral acceleration required to move the vehicle to the target point using the vehicle speed and real-time target yaw rate; and a control determination unit that determines whether the real-time target lateral acceleration calculated by the lateral acceleration calculation unit is outside the range between a predetermined upper limit and a predetermined lower limit for lateral acceleration while an automatic driving mode, which automatically controls the driving of the vehicle, is in operation.

[0013] According to another aspect of the present invention, an automatic driving control method may include: detecting a vehicle speed; detecting a yaw rate of the vehicle; calculating a target yaw rate required to drive the vehicle to a specific target point; calculating a target lateral acceleration required to drive the vehicle to the target point using the vehicle speed and the target yaw rate; controlling the driving of the vehicle according to the target lateral acceleration; calculating a real-time target yaw rate required to drive the vehicle to the target point by comparing a yaw rate detected in real time with the target yaw rate while an automatic driving mode is in operation to automatically control the driving of the vehicle;Calculating a real-time lateral target acceleration required to move the vehicle to the target point, using the vehicle speed and the real-time target yaw rate; and determining whether the real-time lateral target acceleration is outside the range between a predetermined upper threshold and a predetermined lower limit threshold of lateral acceleration.

[0014] In the automatic driving control system according to the present invention, it is possible to recognize the driver's intention to perform driving control more accurately by using real-time lateral target acceleration. Therefore, the driver can release the automatic driving mode at any time while an active driving control mode is in operation, thereby increasing driver convenience and satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The aforementioned and other tasks, features and advantages of the present invention will become more apparent with reference to the following detailed description, which is given in conjunction with the accompanying drawings, in which: Fig. 1 a configuration block diagram of an automatic driving control system according to the present invention; Fig. 2 an example illustrates a vehicle's trajectory and a target yaw rate required to reach the target point from the vehicle's current position; Fig. Figure 3 illustrates an example showing an upper limit threshold and a lower limit threshold of the lateral target acceleration calculated so that the vehicle reaches the target point; Fig. Figure 4 illustrates an example showing a real-time target yaw rate and a vehicle trajectory that were recalculated so that the vehicle reaches the target point while driving; and Fig. Figure 5 is a flowchart illustrating the operation of recognizing the driver's intention by using the yaw rate and lateral acceleration, and controlling the automatic driving of the vehicle in the automatic driving control system according to the present invention. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0016] Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, the same components are designated by the same reference numerals, even though they are shown in different drawings. Furthermore, a detailed description of known functions and configurations embodied therein is omitted in the following description of the present invention if doing so would make the subject matter of the present invention less clear.

[0017] Additionally, terms such as "first," "second," "A," "B," "(a)," "(b)," or the like may be used here when describing components of the present invention. These terms are used solely to distinguish one structural element from other structural elements, and a property, sequence, sequence, and the like of a corresponding structural element are not limited by the expression. It should be noted that if the description states that one component is "connected," "coupled," or "united" with another component, a third component may be "connected," "coupled," or "united" between the first and second components, even though the first component may be directly connected, coupled, or united with the second component.

[0018] Fig. Figure 1 is a configuration block diagram of an automatic driving control system according to the present invention, and Fig. Figure 2 illustrates an example showing a vehicle path and a target yaw rate so that the vehicle reaches the target point from the vehicle's current position. Fig. Figure 3 illustrates an example showing an upper limit threshold and a lower limit threshold of the lateral target acceleration calculated so that the vehicle reaches the target point, and Fig. Figure 4 illustrates an example showing a real-time target yaw rate and a vehicle trajectory that are recalculated so that the vehicle reaches the target point while driving.

[0019] The automatic driving control system 1 according to the present invention calculates a yaw rate and a lateral acceleration required for the vehicle to reach the target point in real time while the vehicle is driving in an automatic driving mode, and if the lateral acceleration is outside a range between a predetermined upper limit threshold and a lower limit threshold, determines that the driver intends to control the driving of the vehicle in order to thereby release the automatic driving mode.

[0020] The automatic driving control system 1 may include: a speed sensor 10 that detects a vehicle speed, a yaw rate sensor 20 that detects a yaw rate, a yaw rate calculation unit 30 that calculates a yaw rate, a lateral acceleration calculation unit 40 that calculates a lateral acceleration by using the vehicle speed and the yaw rate, and a control determination unit 50 that detects the driver's intention by using the lateral acceleration in order to control the operation of the automatic driving mode.

[0021] The speed sensor 10 can be mounted on the drive motor of a gearbox and can generate a speed signal according to the rotation angle of the drive motor in order to measure the vehicle speed. The speed sensor 10 can use a Hall sensor, an optical sensor, a magnetic sensor, or the like. The vehicle speed measured by the speed sensor 10 can be made available to the calculation unit 40 for lateral acceleration.

[0022] The yaw rate sensor 20 can detect a yaw rate, i.e., an angular velocity in the direction of the vehicle's vertical axis, and can include an oscillator and a detector. When an alternating voltage is applied to the yaw rate oscillator, the oscillator oscillates left and right. In such a state, when the vehicle turns at a certain angular velocity, the detector tilts in the direction perpendicular to the direction of the vibration, according to the Coriolis force, thereby outputting an alternating voltage. The waveform signal generated in the detector is simultaneously acquired to obtain the direction and magnitude of the turn, and the acquired waveform is output as an analog signal. The yaw rate sensor 20 can detect a yaw rate generated by the vehicle's current movement, that is, a reference yaw rate, which is denoted as γ. ref in Fig. 2 is displayed, and can supply this to the calculation unit 40 for lateral acceleration.

[0023] The yaw rate calculation unit 30 can define a target yaw rate γ target It calculates the yaw rate required to move the vehicle to a predetermined destination. Furthermore, the yaw rate calculation unit 30 can calculate a real-time target yaw rate γ. target real-time Calculate the distance required for the vehicle to reach the destination point while driving towards it. Here, the destination point can be a point determined in real time to guide the vehicle along the lane during automated driving, or it can be an arbitrarily determined point to guide the vehicle back to the lane if it leaves it.

[0024] First, if the target point is defined as a coordinate value (x CAM , Y CAM ) as in Fig. Figure 2 shows the yaw rate calculation unit 30 as the target yaw rate γ. target calculate the amount of energy to be generated in the vehicle when the vehicle travels to the destination point.

[0025] Additionally, the yaw rate calculation unit 30 can receive a yaw rate detected in real time by the yaw rate sensor 20 while the vehicle is traveling to the target point, and it can calculate the real-time target yaw rate γ target real-time Calculate the amount of yaw rate required for the vehicle to reach the target point with respect to the real-time yaw rate. That is, the real-time target yaw rate γ. target real-time It could be a yaw rate that has been corrected so that the vehicle reaches the target point.

[0026] The lateral acceleration calculation unit 40 can receive the velocity information and the yaw rate information from the velocity sensor 10 and the yaw rate calculation unit and can calculate the lateral acceleration.

[0027] First, if the target yaw rate γ target calculated and supplied by the yaw rate calculation unit 30, the calculation unit 40 for lateral acceleration calculates the lateral target acceleration a y-ref Calculate using the following equation 1. The lateral target acceleration a y-ref is the lateral acceleration that occurs over the vehicle's path to the target point using the yaw rate γ. target occurs. ay−ref=Vx(β˙+γ˙target)

[0028] Here, a denotes y-ref γ denotes the lateral acceleration of the target, and V denotes the vehicle speed in the x-axis direction. target refers to a differential value of the target yaw rate γ target .

[0029] Additionally, if the real-time yaw rate γ target real-timecalculated and supplied by the yaw rate calculation unit 30, while the vehicle is in automatic mode based on the target yaw rate γ target drives, the calculation unit 40 for lateral acceleration a lateral real-time target acceleration a y-demand using the following equation 2. That is, the calculation unit 40 for lateral acceleration can calculate the real-time lateral target acceleration a y-demand of the vehicle using the real-time yaw rate γ target real-time , which is calculated in real time while the vehicle is driving. ay−demand=Vx(β˙+γ˙targetreal−time)

[0030] Here, a denotes y-demand the real-time lateral target acceleration, and V x denotes a vehicle speed in the x-axis direction.

[0031] γ target real-timerefers to a differential value of the real-time directional yaw rate.

[0032] The control unit 50 can perform real-time lateral target acceleration. y-demand , calculated in the unit of calculation for lateral acceleration, are compared with a predetermined upper and lower limit threshold for lateral acceleration in order to determine whether the driver intends to drive the vehicle himself or not.

[0033] The control determination unit 50 can have the information about the upper and lower limit thresholds of the lateral acceleration, which is calculated using the following equation 3. ay−Threshold−1=ay−ref+α1ay−Threshold−2=ay−ref+α2 Here, a refers to y-Threshold-1 an upper limit threshold for lateral acceleration, and a y-Threshold-2 denotes a lower limit threshold for lateral acceleration. a y-refrefers to the lateral target acceleration, and α1 and α2 are constants for configuring the upper limit threshold a y-Threshold-1 and the lower limit threshold a y-Threshold-2 the lateral acceleration such that the lateral acceleration is contained within a predetermined range of values.

[0034] The upper limit threshold a y-Threshold-1 and the lower limit threshold a y-Tthreshold-2 Lateral acceleration must be configured taking into account a physical limit for the vehicle's acceleration and deceleration. This physical limit can include a maximum acceleration and deceleration range based on the vehicle's performance capabilities, the distance between the vehicle's current position and the destination, road conditions depending on the weather, or the driver's mental stability.

[0035] In general, the maximum acceleration and deceleration range of the vehicle can vary depending on the vehicle type and year of manufacture, if it is desirable to take these into account. The distance from the vehicle's current position to the destination point must be considered, as the time required to accelerate or decelerate varies depending on the distance. That is, in the case of a large distance, the optimal speed is set to be close to the maximum permitted speed, while in the case of a short distance, the optimal speed is set to be lower than the maximum permitted speed. Road conditions must also be taken into account, as it is not easy to stop the vehicle, and the vehicle has a tendency to skid on rainy or snowy days.The driver's mental stability must be taken into account, as some drivers may lose their composure in the event of sudden acceleration or deceleration, or they may hesitate to do so according to their disposition. Considering such a disposition, the optimal speed may be configured to be lower than the maximum permissible speed, even if the vehicle can accelerate or decelerate to the maximum permissible speed.

[0036] The lateral acceleration of the vehicle can be configured so that it does not exceed the physical limit of 0.3 g, and thus the constants α1 and α2 are configured such that the upper limit threshold a y-Threshold-1 and the lower limit threshold a y-Threshold-2 The lateral acceleration should not exceed 0.3.

[0037] If the lateral real-time target acceleration a y-demand , which is calculated in the calculation unit 40 for lateral acceleration, the control determination unit 50 can determine the real-time lateral target acceleration a y-demand with the upper limit threshold a y-Threshold-1 and the lower limit threshold a y-Threshold-2 compare the lateral acceleration, and if the real-time lateral target acceleration is a y-demand greater than the upper limit threshold a y-Threshold-1 the lateral acceleration or less than the lower limit threshold a y-Threshold-2 If the lateral acceleration is excessive, the control unit 50 can determine that the driver intends to drive the vehicle by operating the steering wheel, thereby ending the automatic driving mode for the automatic driving control of the vehicle, so that the driver takes over driving control of the vehicle.

[0038] The operation of recognizing the driver's intention using the yaw rate and lateral acceleration and controlling the automatic driving of the vehicle in the automatic driving control system 1 according to the configuration described above is described with reference to Fig. 5 described.

[0039] The speed sensor 10 detects the speed to provide speed information while the vehicle is driving in automatic mode (S500). Once the target point is determined (S510), the yaw rate calculation unit 30 calculates the target yaw rate γ. target , which is required to drive the vehicle to the destination point (S520).

[0040] The calculated yawing rate γ target and the vehicle speed information is fed to the calculation unit 40 for lateral acceleration, and the calculation unit 40 for lateral acceleration applies the yawing rate γ. targetand the vehicle speed is applied to equation 1 in order to thereby determine the lateral target acceleration a y-ref to obtain (S530).

[0041] The yaw rate sensor 20 detects the vehicle's yaw rate in real time while the vehicle is driving in automatic mode, based on the lateral target acceleration. y-ref , and the yaw rate calculation unit 30 calculates the real-time target yaw rate γ target real-time , which is required for the vehicle to reach the target point, by using the yaw rate detected by the yaw rate sensor 20 and the target yaw rate (S540).

[0042] Then the real-time yaw rate γ can be target real-time and the vehicle speed recorded in real time is used in equation 3 to calculate the real-time lateral target acceleration a y-demand to obtain (S550).

[0043] If the real-time lateral target acceleration a y-demandThe control unit 50 determines whether the lateral real-time target acceleration a is applied. y-demand in the area between the upper limit threshold a y-Threshold-1 and the lower limit threshold a y-Threshold-2 The lateral acceleration is included or not. This is determined as a consequence of the determination if the real-time lateral target acceleration is a y-demand in the area between the upper limit threshold a y-Threshold-1 and the lower limit threshold a y-Threshold-2 The control unit 50, which includes the lateral acceleration, determines that the vehicle is traveling along the configured route under automatic driving control and maintains automatic driving mode (S570). In contrast, if the real-time lateral target acceleration a y-demand greater than the upper limit threshold a y-Threshold-1 the lateral acceleration is or less than the lower limit threshold a y-Threshold-2The lateral acceleration is detected by the control unit 50, indicating that the driver intends to drive the vehicle by operating the steering wheel, and releases the automatic driving mode (S580).

[0044] The automatic driving control system 1 according to the present invention calculates the real-time yaw rate γ in real time. target real-time , to reach the target point, and calculates the real-time lateral target acceleration a y-demand by using the real-time yaw rate γ target real-time , while the vehicle is driving in automatic mode. Then the automatic driving control system 1 can interpret the driver's intention for driving control by using the real-time lateral target acceleration a y-demandThis allows the system to recognize the driver's intentions regarding driving control more accurately. This enables the driver to disable automatic driving mode at any time while the active driving control mode is in use, thereby increasing driver convenience and satisfaction.

[0045] The standard description and the standard documents mentioned in the preceding embodiments are omitted to simplify the description, and they may form part of the present description. Therefore, the addition of any part of the standard description and the standard documents to the present description, or their inclusion in the claims, is to be interpreted as belonging to the scope of the invention.

[0046] Although the embodiments of the present invention have been described for illustrative purposes, it is obvious to those skilled in the art that various modifications, additions, and substitutions are possible without departing from the scope and spirit of the invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but merely to describe it. Furthermore, the scope of the technical spirit of the present invention is limited by the embodiments. The scope of the present invention is to be interpreted, on the basis of the accompanying claims, in such a way that all the technical ideas contained within the scope equivalent to the claims belong to the present invention.

Claims

[1] Automatic driving control system (1) which features: a speed sensor (10) that detects vehicle speed; a yaw rate sensor (20) that detects the yaw rate of the vehicle; a yaw rate calculation unit (30) that calculates a target yaw rate required to drive the vehicle to a specific target point, and that calculates a real-time target yaw rate required to drive the vehicle to the target point by comparing a yaw rate detected in real time by the yaw rate sensor (20) with the target yaw rate; a calculation unit (40) for lateral acceleration which calculates a lateral target acceleration required to move the vehicle to the target point by using the vehicle speed and the target yaw rate, and a real-time lateral target acceleration required to move the vehicle to the target point by using the vehicle speed and the real-time target yaw rate; and a control determination unit (50) that determines whether the real-time lateral target acceleration calculated by the lateral acceleration computation unit (40) is outside the range between a predetermined upper limit threshold and a predetermined lower limit threshold of lateral acceleration, while an automatic driving mode that automatically controls the driving of the vehicle is in operation, wherein the control determination unit (50) terminates the automatic driving mode when the real-time lateral target acceleration is outside the range between the predetermined upper limit threshold and the predetermined lower limit threshold of the lateral acceleration, so that a driver can take over driving control of the vehicle. [2] Automatic driving control system according to claim 1, wherein the range between the predetermined upper limit threshold and the lower limit threshold is determined as a predetermined value, taking into account a physical limit of the vehicle. [3] Automatic driving control system according to claim 2, wherein the physical limit includes at least one of: the vehicle's ability to accelerate and decelerate, a distance between the vehicle's position and the destination point, road conditions depending on the weather, or the driver's mental stability. [4] Automatic driving control procedure which features: Determining vehicle speed; Detecting the vehicle's yaw rate; Calculating a target yaw rate required to move the vehicle to a specific target point; Calculating a lateral target acceleration required to move the vehicle to the target point, using the vehicle speed and the target yaw rate; Controlling the vehicle's driving according to the lateral target acceleration; Calculating a real-time target yaw rate required to drive the vehicle to the target point by comparing a yaw rate captured in real time with the target yaw rate while an automatic driving mode is in operation to automatically control the driving of the vehicle; Calculating a real-time lateral target acceleration required to move the vehicle to the target point, using the vehicle speed and the real-time target yaw rate; Determine whether the real-time lateral target acceleration is outside the range between a predetermined upper threshold and a predetermined lower limit threshold for lateral acceleration; and The automatic driving mode will end when the real-time lateral target acceleration is outside the range between the upper limit threshold and the lower limit threshold, allowing a driver to take over driving control of the vehicle. [5] Method according to claim 4, wherein the range between the upper limit threshold and the lower limit threshold is determined as a predetermined value taking into account a physical limit of the vehicle. [6] Method according to claim 5, wherein the physical boundary includes at least one of: the ability to accelerate and decelerate the vehicle, a distance between the position of the vehicle and the target point, road conditions depending on the weather or the mental stability of the driver.

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