Vehicle

Abstract

To precisely determine an override adaptively to change in vehicle travel state / driver's steering maintaining state.SOLUTION: A vehicle 1 comprises: a steering maintaining state detection part 10 which detects the steering maintaining state of a driver of a vehicle 1; a travel state detection part 20 which detects the travel state of the vehicle 1; a torque detection part 30 which detects a torsion bar torque value of steering; and a control part 50 which makes an override determination based upon a torsion bar torque threshold set based upon the steering maintaining state and travel state, and the torsion bar torque value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] In recent years, vehicles equipped with ADAS (Advanced Driver Assistance Systems) functions that enable the vehicle itself to grasp information about its surroundings and control the vehicle on behalf of the driver have come into practical use.

[0003] For example, an ADAS function in which the vehicle steers on behalf of the driver is the LKS (Lane Keeping System), which controls the steering to prevent the vehicle from deviating from the lane in which it is traveling, and keeps the vehicle's driving position near the center of the lane. One such technology proposed is one that monitors the torsion bar torque value when the vehicle is steering to control its driving position, and if the torsion bar torque value exceeds a predetermined threshold, determines that the driver has forcibly intervened and performed a steering operation such as turning right or left or changing lanes (override determination), turns off steering control, and gives priority to the driver's steering operation (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-159781 Summary of the Invention [Problem to be solved by the invention]

[0005] When the vehicle is executing an ADAS function that steers the vehicle instead of the driver, the motor rotates the steering shaft. At this time, if the driver holds the steering wheel, a twist occurs in the steering shaft. When traveling around a curve, the driving force of the motor becomes larger than when traveling on a straight road, and the torsion generated in the steering shaft also becomes larger. Therefore, the torsion bar torque value when the vehicle is traveling on a curve is greater than the torsion bar torque value when the vehicle is traveling on a straight road. In addition, when determining whether the driver should forcibly intervene (override) based on whether the torsion bar torque value exceeds a threshold value, the steering force required per hand differs depending on the steering state (one-hand steering / two-hand steering) when the driver operates the steering wheel.

[0006] However, with the technology described in Patent Document 1 mentioned above, if the torsion bar torque value exceeds a predetermined threshold, regardless of the vehicle's driving state / driver's steering state, the steering control is turned off and priority is given to the driver's steering operation. This poses a problem in that, depending on the vehicle's driving state / driver's steering state, an override determination may be made even if the driver has no intention of overriding.

[0007] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide a vehicle that makes accurate override judgments in response to changes in the vehicle's driving state / driver's steering state. [Means for solving the problem]

[0008] Form 1: One or more embodiments of the present invention propose a vehicle that includes a steering state detection unit that detects the steering state of a vehicle driver, a driving state detection unit that detects the driving state of the vehicle, a torque detection unit that detects the torsion bar torque value of the steering, a torsion bar torque threshold value set based on the steering state and the driving state, and a control unit that makes an override determination based on the torsion bar torque value. [Effects of the Invention]

[0009] According to one or more embodiments of the present invention, it is possible to provide an effect of making an override determination with high accuracy in response to changes in the vehicle running state / driver's steering state. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a configuration of a vehicle according to an embodiment of the present invention; [Figure 2] FIG. 4 is a diagram showing a flow of an override determination process for a vehicle according to an embodiment of the present invention. [Figure 3] FIG. 4 is a diagram showing a torsion bar torque threshold value set by a control unit of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment> A vehicle 1 according to this embodiment will be described with reference to FIGS. 1 to 3. FIG.

[0012] <Vehicle 1 Configuration> As shown in FIG. 1, the vehicle 1 according to this embodiment is configured to include a steering state detection unit 10, a driving state detection unit 20, a torque detection unit 30, a steering drive unit 40, and a control unit 50.

[0013] The steering state detection unit 10 detects the steering state of the driver of the vehicle 1. The steering state detection unit 10 detects whether the driver's steering state is one-hand steering, two-hand steering, or no steering. Specifically, the steering state detection unit 10 detects the driver's steering state based on the output of sensors such as touch sensors and grip force sensors arranged at least on the left and right sides of the steering wheel, and transmits the detection results to the control unit 50 described later. More specifically, the steering state detection unit 10 determines that the driver's steering state is "one-hand steering" when either the left or right sensor output is greater than a predetermined threshold, and determines that the driver's steering state is "both-hand steering" when both left and right sensor outputs are greater than a predetermined threshold. Furthermore, when the outputs of both the left and right sensors are smaller than predetermined threshold values, the steering state detection unit 10 determines that the driver's steering state is "no steering". In addition, since the steering state detection unit 10 only needs to detect whether the driver's steering state is one-hand steering, two-hand steering, or no steering, it may detect the driver's steering state based on an image of the driver captured by a driver monitoring system, a drive recorder, etc.

[0014] The running state detection unit 20 detects the running state of the vehicle 1 . The driving state detection unit 20 detects whether the vehicle 1 is driving around a curve or on a straight road. Specifically, the driving condition detection unit 20 calculates the curvature of the road on which the vehicle 1 is currently traveling based on, for example, images of the area around the vehicle 1 or measurement results using LiDAR (Light Detection And Ranging), and detects whether the vehicle 1 is traveling on a curve or on a straight road based on the curvature, and transmits the detection result to the control unit 50 described later. More specifically, if the calculated curvature is greater than a predetermined curvature, the driving condition detection unit 20 determines that the driving condition of the vehicle 1 is "driving on a curve," and if the calculated curvature is less than the predetermined curvature, the driving condition detection unit 20 determines that the driving condition of the vehicle 1 is "driving on a straight road." In addition, since the driving state detection unit 20 only needs to detect whether the driving state of the vehicle 1 is traveling on a curve or on a straight road, it may detect the driving state of the vehicle 1 based on the output of sensors such as a yaw rate sensor, a gyro sensor, a steering angle sensor, etc.

[0015] The torque detection unit 30 detects the torsion bar torque value. Specifically, the torque detection unit 30 detects the amount of twist of the torsion bar (torsion bar torque value) using a torque sensor disposed on the torsion bar of the steering of the vehicle 1, for example, and transmits the detection result to the control unit 50.

[0016] The steering drive unit 40 rotates the steering wheel in accordance with a control signal from the control unit 50, which will be described later. Specifically, the steering drive unit 40 includes a motor that rotates the steering wheel, and drives the motor in accordance with a control signal (steering wheel angle information, etc.) received from the control unit 50 described later, thereby rotating the steering wheel by applying a driving force to the steering shaft.

[0017] The control unit 50 controls the overall operation of the vehicle 1 in accordance with a control program stored in a ROM or the like (not shown). In the present invention, the control unit 50 makes an override determination based on the torsion bar torque threshold value set based on the steering state and the running state, and the torsion bar torque value. Specifically, the control unit 50 sets a torsion bar torque threshold for making an override judgment based on the driver's steering state (one hand steering / both hands steering / no steering) received from the steering state detection unit 10 and the driving state of the vehicle 1 (driving on a curve / driving on a straight road) received from the driving state detection unit 20, and compares the torsion bar torque threshold with the current torsion bar torque value received from the torque detection unit 30 to determine whether the driver has performed a steering operation. In addition, in this embodiment, the control unit 50 executes steering control of an LKS (Lane Keeping System) that keeps the traveling position of the vehicle 1 near the center of the vehicle lane. Specifically, the control unit 50 detects a lane indicating the vehicle lane from an image captured in front of the vehicle 1, and sends a control signal to the steering drive unit 40 to control the vehicle 1's driving position so that the vehicle 1 is near the center of the vehicle lane. Furthermore, when the control unit 50 determines that the driver has forcibly intervened and performed a steering operation while the LKS is operating (override determination), it stops the steering control of the LKS and switches to steering control that prioritizes the driver's steering operation. The override determination process will be described in detail below.

[0018] <Override determination process> The override determination process of the vehicle 1 will be described with reference to FIG.

[0019] As shown in FIG. 2, the control unit 50 determines whether the LKS is in operation (step S110). Specifically, the control unit 50 detects the state of a switch for turning on / off the LKS provided in the vehicle 1, for example, to determine whether the LKS is in operation. When the control unit 50 determines that the LKS is not in operation ("NO" in step S110), it returns the process to the original state and transitions to a standby state.

[0020] On the other hand, if the control unit 50 determines that the LKS is operating ("YES" in step S110), the steering state detection unit 10 detects whether the driver's steering state is one-hand steering, two-hand steering, or no steering (step S120).

[0021] The driving state detection unit 20 detects whether the driving state of the vehicle 1 is traveling around a curve or traveling on a straight road (step S130).

[0022] The control unit 50 executes a torsion bar torque threshold value setting process (step S140). Specifically, the control unit 50 sets one of the values ​​th1 to th6 as the torsion bar torque threshold based on the driver's steering state received from the steering state detection unit 10 (step S120) and the driving state of the vehicle 1 received from the driving state detection unit 20 (step S130). As shown in FIG. 3, when the driver's steering state is "both hands on the steering wheel" and the vehicle 1 is traveling in a "curve", the torsion bar torque threshold is set to th1. When the driver's steering state is "one hand steering" and the vehicle 1 is traveling in a "curve", the torsion bar torque threshold is set to th2. Also, when the driver's steering state is "no steering" and the vehicle 1 is traveling in a "curve", the torsion bar torque threshold is set to th3. When the driver's steering state is "both hands on the steering wheel" and the vehicle 1 is traveling on a "straight road", the torsion bar torque threshold is set to th4. Also, when the driver's steering state is "one-hand steering" and the vehicle 1 is traveling on a "straight road", the torsion bar torque threshold is set to th5. Also, when the driver's steering state is "no steering" and the vehicle 1 is traveling on a straight road, the torsion bar torque threshold is set to th6. The set values ​​of the above-mentioned torsion bar torque thresholds (th1 to th6) will be described in detail later.

[0023] The torque detection unit 30 detects the current torsion bar torque value of the vehicle 1 (step S150).

[0024] The control unit 50 determines whether or not the torsion bar torque value received from the torque detection unit 30 is greater than the torsion bar torque threshold value set in step S140 (step S160). When the control unit 50 determines that the torsion bar torque value received from the torque detection unit 30 is smaller than the torsion bar torque threshold value set in step S140 ("NO" in step S160), it ends the override determination process. On the other hand, if the control unit 50 determines that the torsion bar torque value received from the torque detection unit 30 is greater than the torsion bar torque threshold value set in step S140 ("YES" in step S160), it stops the steering control of the LKS, switches to control that prioritizes the driver's steering operation (step S170), and terminates the override determination process.

[0025] <Torsion bar torque threshold setting value> The set values ​​of the above-mentioned torsion bar torque thresholds (th1 to th6) will be explained. When the vehicle is traveling on a curve, the driving force of the motor that rotates the steering wheel is greater than when the vehicle is traveling on a straight road, so the torsion that occurs in the steering shaft is greater. Therefore, in order to accurately determine whether the driver has performed an intentional steering operation (override determination), it is necessary to change the value of the torsion bar torque threshold according to the vehicle's driving condition (driving on a curve / driving on a straight road). Specifically, the torsion bar torque thresholds (th1, th2) set for making an override determination while traveling around a curve are set to values ​​greater than the torsion bar torque thresholds (th4, th5) set for making an override determination while traveling on a straight road. That is, the torsion bar torque thresholds are set so that th1>th4 and th2>th5.

[0026] When determining whether the driver should forcibly intervene (override) based on whether the torsion bar torque value exceeds the torsion bar torque threshold, the steering force required per hand differs depending on the steering state (one-hand steering / two-hand steering) when the driver operates the steering wheel. Furthermore, when forcibly intervening to perform steering operations, the driver generally performs steering operations using both hands rather than one hand. Therefore, in order to make it less likely that an override will be determined when the steering state is "one hand" than when it is "both hands," the torsion bar torque thresholds (th2, th5) set when steering with one hand are set to values ​​greater than the torsion bar torque thresholds (th1, th4) set when steering with both hands. That is, the torsion bar torque thresholds are set so that th2>th1 and th5>th4.

[0027] In addition, when the driver's steering state is "no steering," the torsion bar torque thresholds (th3, th6) set when no steering is performed are set to values ​​greater than the torsion bar torque thresholds (th2, th5) set when steering with one hand, so as to prevent the torsion bar from being erroneously determined to have been performed due to twisting of the torsion bar caused by recoil from the road surface, etc. That is, the torsion bar torque thresholds are set so that th3>th2 and th6>th5. As described above, the torsion bar torque threshold values ​​are set so that the order of each threshold value is, for example, th3>th2>th1>th6>th5>th4.

[0028] The above has been an example of the override determination process during LKS operation of vehicle 1, but for example, the above-mentioned override determination process may be executed during automatic driving operation in which steering is automatically controlled, and if it is determined that the driver has forcibly intervened and performed a steering operation (override determination), the control may be switched to one that prioritizes the driver's steering operation.

[0029] <Actions and Effects> As described above, the control unit 50 of the vehicle 1 in this embodiment performs an override judgment based on the torsion bar torque threshold value set based on the driver's steering state received from the steering state detection unit 10 and the driving state of the vehicle 1 received from the driving state detection unit 20, and the current torsion bar torque value received from the torque detection unit 30. When the control unit 50 determines that the torsion bar torque value is greater than the torsion bar torque threshold, it determines that the driver has forcibly intervened and performed a steering operation such as turning right or left or moving ahead in the lane. In other words, since the torsion bar torque value varies greatly depending on the driver's steering state and the driving state of the vehicle 1, the control unit 50 changes the value of the torsion bar torque threshold value for making an override judgment depending on the driver's steering state and the driving state of the vehicle, and performs the override judgment. This allows the vehicle 1 to make an override determination with high accuracy in response to changes in the vehicle's running state / driver's steering state.

[0030] The steering state detection unit 10 detects whether the driver's steering state is one-hand steering, two-hand steering, or no steering. The driving state detection unit 20 detects whether the vehicle 1 is driving on a curve or on a straight road. During execution of an ADAS function that controls steering on behalf of the driver, the steering shaft is rotated by the motor. When the driver holds the steering wheel while the ADAS function described above is being executed, a twist occurs in the steering shaft. When driving on a curve, the driving force of the motor is greater than when driving on a straight road, and the torsion generated in the steering shaft is also greater, so the torsion bar torque value when driving on a curve is greater than the torsion bar torque value when driving on a straight road. When a driver forcibly intervenes (overrides) and operates the steering wheel while an ADAS function is running (while LKS is running), the steering force required per hand varies depending on the driver's steering state (one-hand steering / both-hand steering). In other words, since the torsion bar torque value changes significantly depending on the driving state of the vehicle 1 and the driver's steering state, the control unit 50 changes the torsion bar torque threshold value for determining whether to override based on the vehicle's driving state (driving on a curve / driving on a straight road) and the driver's steering state (one hand steering / both hands steering / no steering), and makes the override determination. This allows for highly accurate override determination in response to changes in the vehicle's running state / driver's steering state, thereby preventing override determinations from occurring that are not intended by the driver.

[0031] <Variation 1> The control unit 50 described above sets the torsion bar torque threshold value based on the driving state (driving on a curve / driving on a straight road), but the torsion bar torque threshold value may be set for each curvature of the road on which the vehicle is traveling. That is, since the torsion bar torque value changes significantly depending on the curvature of the road on which the vehicle is traveling, the control unit 50 may set the torsion bar torque threshold value depending on the curvature of the road and the driver's steering state. This allows the torsion bar torque threshold to be set in more detail, thereby enabling override determination to be performed with even greater accuracy.

[0032] The vehicle 1 of the present invention can be realized by recording the processing of the steering state detection unit 10, the running state detection unit 20, the control unit 50, etc. on a recording medium that can be read by a computer system, and having the programs recorded on this recording medium read and executed by the steering state detection unit 10, the running state detection unit 20, and the control unit 50. The computer system here includes hardware such as an OS and peripheral devices.

[0033] Furthermore, if a WWW (World Wide Web) system is used, the "computer system" also includes the homepage provision environment (or display environment). The above program may be transmitted from a computer system that stores the program in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line.

[0034] The program may also be a program for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already stored in the computer system.

[0035] The above describes in detail an embodiment of the present invention with reference to the drawings. However, all vehicles that can be implemented by a person skilled in the art by making appropriate design modifications based on the vehicle described above as an embodiment of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention. Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that these modifications and alterations also fall within the scope of the present invention. For example, any embodiment in which a person skilled in the art has appropriately added or deleted components or modified the design, or added or omitted steps or modified conditions, is included within the scope of the present invention as long as it contains the essence of the present invention.

[0036] Furthermore, other effects and advantages brought about by the aspects described in this embodiment that are clear from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present invention. Various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be omitted from all the components shown in the embodiment. Furthermore, components from different embodiments may be combined as appropriate. [Explanation of symbols]

[0037] 1;Vehicle 10: Steering state detection unit 20: Driving condition detection unit 30: Torque detector 40: Steering drive unit 50; control section

Claims

1. a steering state detection unit that detects a steering state of a vehicle driver; a running state detection unit that detects a running state of the vehicle; a torque detection unit that detects a torsion bar torque value of the steering; a control unit that performs override determination based on a torsion bar torque threshold value set based on the steering state and the running state, and the torsion bar torque value; A vehicle characterized by comprising:

2. 2. The vehicle according to claim 1, wherein the steering state detection unit detects whether the steering state of the driver is one-hand steering, two-hand steering, or no steering.

3. 3. The vehicle according to claim 1, wherein the driving state detection unit detects whether the driving state of the vehicle is traveling on a curve or on a straight road.

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