Vehicle control device

Abstract

To provide a vehicle controller capable of towing a vehicle to be towed, and of appropriately setting timing to interrupt lane change control of a vehicle to which automatic operation control is applied.SOLUTION: A vehicle controller comprises: a towing detection unit 31 for detecting that a vehicle 11 to be towed is towed, when a vehicle 10 is subjected to automatic operation control; a determination unit 38 for determining whether or not to satisfy an interruption condition that is set based on at least one of change in a relative position between the vehicle 10 and the other vehicle traveling in an adjacent lane, during execution of lane change control executed when a predetermined condition is satisfied; and an interruption instruction unit 39 for interrupting the lane change control when the interruption condition is satisfied. The determination unit 38 releases the interruption condition when it is detected that the vehicle 10 tows the vehicle 11 to be towed rather than the interruption condition when it is not detected that the vehicle 10 tows the vehicle 11 to be towed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] The behavior of a vehicle towing another vehicle differs in some respects from the behavior of a vehicle that is not towing another vehicle. Therefore, in the automatic driving control of a vehicle towing another vehicle, it is necessary to control the vehicle taking into consideration the difference in the vehicle's behavior depending on whether or not it is towing another vehicle. Therefore, a technology has been proposed that executes different control of the vehicle depending on whether or not it is coupled to a towed vehicle (see Patent Document 1).

[0003] The driving assistance device disclosed in Patent Document 1, when detecting the connection of a towed vehicle, sets the driving mode to a second driving assistance mode with restrictions that applies only when the vehicle continues to drive in the same lane, while the second driving assistance mode, which performs automatic driving without requiring the driver to hold the steering wheel, is applied. When changing lanes, this driving assistance device then transitions the driving mode to a first driving assistance mode, which performs automatic driving with the driver requiring the driver to hold the steering wheel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6951262 Summary of the Invention [Problem to be solved by the invention]

[0005] When automatic driving control is applied to a vehicle towing a towed vehicle, it may be necessary to increase the degree of driver involvement in driving. In such cases, it is necessary to be able to appropriately set the timing for increasing the degree of driver involvement in driving.

[0006] Therefore, the present invention aims to provide a vehicle control device that is capable of towing a towed vehicle and appropriately setting the timing to interrupt lane change control of a vehicle to which automatic driving control is applied. [Means for solving the problem]

[0007] According to one embodiment, a vehicle control device is provided. The vehicle control device includes a towing detection unit that detects when the vehicle is towing a towed vehicle when the vehicle is under automatic driving control, a detection unit that detects the relative position and relative speed of the vehicle to another vehicle traveling in an adjacent lane adjacent to the lane in which the vehicle is traveling, a control unit that executes lane change control of the vehicle to change lanes from the vehicle's own lane to the adjacent lane when a predetermined condition is met, a determination unit that determines whether an interruption condition is met based on at least one of a change in the relative position and relative speed of the vehicle to the other vehicle during lane change control, and an interruption instruction unit that causes the control unit to interrupt the lane change control when the interruption condition is met. The determination unit relaxes the interruption condition when it is detected that the vehicle is towing a towed vehicle compared to the interruption condition when it is not detected that the vehicle is towing a towed vehicle. [Effects of the Invention]

[0008] The vehicle control device according to the present invention has the effect of being able to appropriately set the timing for suspending lane change control of a vehicle towing a towed vehicle and to which automatic driving control is applied. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a vehicle control system in which a vehicle control device is implemented. [Figure 2] 1 is a hardware configuration diagram of an electronic control device that is one embodiment of a vehicle control device. [Figure 3] 2 is a functional block diagram of a processor of an electronic control unit related to vehicle control processing according to the first embodiment. FIG. [Figure 4](a) and (b) are diagrams showing an example of the relationship between the hands-on request threshold when towing of the towed vehicle is not detected and the hands-on request threshold when towing of the towed vehicle is detected. [Figure 5] (a) and (b) are diagrams showing an example of the relationship between the driver change request threshold when towing of the towed vehicle is not detected and the driver change request threshold when towing of the towed vehicle is detected. [Figure 6] 4 is an operational flowchart of a vehicle control process related to a change in the degree of driver involvement in driving according to the first embodiment. [Figure 7] FIG. 10 is a functional block diagram of a processor of an electronic control unit relating to vehicle control processing according to a second embodiment. [Figure 8] FIG. 10 is a diagram showing the relationship between whether or not towing of a towed vehicle is detected and a time threshold value, which is an example of an interruption condition. [Figure 9] 10 is an operational flowchart of a vehicle control process related to a lane change according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle control device, a vehicle control method executed on the vehicle control device, and a computer program for vehicle control will be described below with reference to the drawings. This vehicle control device automatically controls the driving of a vehicle capable of towing a towed vehicle. More specifically, this vehicle control device determines whether an involvement request condition requesting the driver of the vehicle to participate in driving the vehicle is satisfied, and if it is determined that the involvement request condition is satisfied, notifies the driver of the request to participate in driving via a notification device installed in the vehicle cabin. This vehicle control device then relaxes the involvement request condition when it is detected that the vehicle is towing a towed vehicle compared to the involvement request condition when it is not detected that the vehicle is towing a towed vehicle.

[0011] FIG. 1 is a schematic configuration diagram of a vehicle control system in which a vehicle control device is implemented. FIG. 2 is a hardware configuration diagram of an electronic control device, which is one embodiment of the vehicle control device. In this embodiment, the vehicle control system 1 is mounted on a vehicle 10 and controls the vehicle 10. The vehicle control system 1 includes a camera 2, a driver monitor camera 3, a GPS receiver 4, a behavior sensor 5, a wireless communication terminal 6, a notification device 7, a storage device 8, and an electronic control unit (ECU) 9, which is an example of a vehicle control device. The camera 2, the driver monitor camera 3, the GPS receiver 4, the wireless communication terminal 6, the notification device 7, the storage device 8, and the ECU 9 are communicatively connected via an in-vehicle network that complies with a standard such as a controller area network. The behavior sensor 5 is also communicatively connected to the ECU 9. The vehicle control system 1 may further include a ranging sensor (not shown), such as a LiDAR or radar, that measures the distance from the vehicle 10 to objects present around the vehicle 10. The vehicle control system 1 may also include a navigation device (not shown) that searches for a route to a destination.

[0012] Furthermore, the vehicle 10 has equipment for towing the towed vehicle 11, such as a tow hook, and is capable of towing the towed vehicle 11.

[0013] Camera 2 is an example of an exterior sensor, and includes a two-dimensional detector configured with an array of photoelectric conversion elements, such as a CCD or C-MOS, that are sensitive to visible light, and an imaging optical system that forms an image of the area to be photographed on the two-dimensional detector. Camera 2 is mounted, for example, inside the cabin of vehicle 10 so that it faces forward of vehicle 10. Camera 2 photographs the area ahead of vehicle 10 at predetermined photographing intervals (for example, 1 / 30 to 1 / 10 seconds) and generates an image of the area ahead. The image obtained by camera 2 is an example of an exterior sensor signal that represents the situation around vehicle 10. Note that vehicle 10 may be equipped with multiple cameras with different photographing directions or focal lengths.

[0014] Every time the camera 2 generates an image, it outputs the generated image to the ECU 9 via the in-vehicle network.

[0015] The driver monitor camera 3 is an example of an in-vehicle sensor. Similar to the camera 2, the driver monitor camera 3 includes a two-dimensional detector composed of an array of photoelectric conversion elements, such as a CCD or C-MOS, that are sensitive to visible or infrared light, and an imaging optical system that forms an image of the area to be captured on the two-dimensional detector. The driver monitor camera 3 may also include a light source, such as an infrared LED, for illuminating the driver. The driver monitor camera 3 is mounted, for example, on the instrument panel or its vicinity, facing the driver so that the head of the driver seated in the vehicle 10 is included in the area to be captured, i.e., so that the driver's head can be captured. The driver monitor camera 3 captures an image of the driver at a predetermined capture interval (e.g., 1 / 30 to 1 / 10 seconds) and generates an image of the driver (hereinafter referred to as a driver image). The driver image obtained by the driver monitor camera 3 is an example of an in-vehicle sensor signal that represents the situation inside the cabin of the vehicle 10. The driver image may be a color image or a grayscale image. Every time the driver monitor camera 3 generates a driver image, it outputs the generated driver image to the ECU 9 via the in-vehicle network.

[0016] The GPS receiver 4 receives GPS signals from GPS satellites at predetermined intervals and determines the own position of the vehicle 10 based on the received GPS signals. Then, the GPS receiver 4 outputs positioning information indicating the positioning results of the own position of the vehicle 10 based on the GPS signals to the ECU 9 via the in-vehicle network at predetermined intervals. Note that the vehicle 10 may have a receiver that receives positioning signals from satellites of another satellite positioning system and determines the own position of the vehicle 10, instead of the GPS receiver.

[0017] The behavior sensor 5 is a sensor for detecting the behavior of the vehicle 10, and includes at least a torque sensor that detects the torque applied to the drive shaft of the drive wheels, and an acceleration sensor that detects the acceleration of the vehicle 10. Furthermore, the vehicle control system 1 may have a plurality of different types of behavior sensors 5. For example, the behavior sensor 5 may include a speed sensor or a gyro sensor. Each time the behavior sensor 5 generates a sensor signal representing the behavior of the vehicle 10, the behavior sensor 5 outputs the generated sensor signal to the ECU 9. Note that the sensor signal generated by the behavior sensor 5 (for example, a signal representing torque generated by a torque sensor, a signal representing acceleration / deceleration generated by an acceleration sensor, or a signal representing speed generated by a speed sensor) is an example of a vehicle behavior signal representing the behavior of the vehicle 10.

[0018] The wireless communication terminal 6 communicates wirelessly with a wireless base station in accordance with a predetermined mobile communication standard. The wireless communication terminal 6 receives map information, including high-precision maps used for autonomous driving control, from a map server via the wireless base station. The wireless communication terminal 6 then outputs the received map information to a storage device 8 via an in-vehicle network.

[0019] The notification device 7 is provided in the passenger compartment of the vehicle 10 and is a device that provides a predetermined notification to the driver by light, sound, vibration, text display, or image display. To this end, the notification device 7 has, for example, at least one of a speaker, a light source, a vibrator, or a display device. When the notification device 7 receives a notification signal indicating a predetermined notification to the driver (for example, a hands-on request or a request to take over driving) from the ECU 9, the notification device 7 notifies the driver by sound from the speaker, light emission or flashing of the light source, vibration of the vibrator, or display of a message on the display device. If the notification device 7 has two or more types of devices, the notification may be provided to the driver via each of the two or more types of devices.

[0020] The storage device 8 is an example of a storage unit, and includes, for example, a hard disk drive, a nonvolatile semiconductor memory, or an optical recording medium and an access device for the optical recording medium. The storage device 8 stores the high precision map.

[0021] Furthermore, the storage device 8 has a processor for executing processes such as updating map information and processing related to a request to read a high-precision map from the ECU 9. For example, every time the vehicle 10 travels a predetermined distance, the storage device 8 transmits a request to acquire map information together with the current position of the vehicle 10 to the map server via the wireless communication terminal 6. The storage device 8 then receives map information including a high-precision map for a predetermined area around the current position of the vehicle 10 from the map server via the wireless communication terminal 6 and stores the high-precision map included in the received map information. Furthermore, upon receiving a map read request from the ECU 9, the storage device 8 extracts an area that includes the current position of the vehicle 10 and is relatively narrower than the predetermined area from the stored high-precision map and outputs it to the ECU 9 via the in-vehicle network. The high-precision map includes information used for autonomous driving control of the vehicle 10, such as the number of lanes for each road section, individual lane widths, speed limits, road markings such as lane dividing lines, and various road signs.

[0022] The ECU 9 performs automatic driving control of the vehicle 10. Furthermore, while the ECU 9 is executing the automatic driving control of the vehicle 10, the ECU 9 determines whether or not an involvement request condition that requests involvement in driving of the vehicle is satisfied, and if the involvement request condition is satisfied, the ECU 9 requests the driver to participate in driving via the notification device 7.

[0023] The request for involvement in driving includes a request to hold the steering wheel (hands-on request) and a request to transfer control to the driver (driving handover request).

[0024] 2, the ECU 9 includes a communication interface 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 may be configured as separate circuits, or may be integrated into a single integrated circuit.

[0025] The communication interface 21 has an interface circuit for connecting the ECU 9 to other devices. Each time the communication interface 21 receives an image from the camera 2, it passes the received image to the processor 23. Each time the communication interface 21 receives a driver image from the driver monitor camera 3, it passes the received driver image to the processor 23. Furthermore, each time the communication interface 21 receives positioning information from the GPS receiver 4, it passes the positioning information to the processor 23. Furthermore, each time the communication interface 21 receives a sensor signal from the behavior sensor 5, it passes the sensor signal to the processor 23. Furthermore, the communication interface 21 passes a high-precision map read from the storage device 8 to the processor 23. Furthermore, the communication interface 21 outputs a notification signal received from the processor 23 to the notification device 7.

[0026] The memory 22 is another example of a storage unit and includes, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in the vehicle control process executed by the processor 23. For example, the memory 22 stores images of the surroundings of the vehicle 10 received from the camera 2, images of the driver received from the driver monitor camera 3, positioning information of the vehicle 10 received from the GPS receiver 4, measurements representing the behavior of the vehicle 10 represented by sensor signals received from the behavior sensor 5, and high-precision maps read from the storage device 8. The memory 22 also stores parameters such as the focal length, shooting direction, and mounting position of the camera 2, as well as various parameters for identifying an object detection classifier used to detect features, etc. The memory 22 also temporarily stores various data generated during the vehicle control process.

[0027] The processor 23 has one or more central processing units (CPUs) and their peripheral circuits. The processor 23 may further have other arithmetic circuits such as a logic unit, a numerical calculation unit, or a graphics processing unit. The processor 23 executes vehicle control processing for the vehicle 10 at predetermined intervals. Furthermore, the processor 23 changes an involvement request condition, which determines whether or not to request the driver to increase his or her level of involvement in driving, depending on whether or not the vehicle 10 is towing a towed vehicle. Furthermore, the processor 23 changes an interruption condition, which determines whether or not to interrupt a lane change process after starting the lane change process for the vehicle 10, depending on whether or not the vehicle 10 is towing a towed vehicle.

[0028] (First embodiment) 3 is a functional block diagram of the processor 23 relating to the vehicle control process according to the first embodiment. The processor 23 has a towing detection unit 31, a control unit 32, a determination unit 33, and a notification processing unit 34. Each of these units in the processor 23 is a functional module realized by, for example, a computer program running on the processor 23. Alternatively, each of these units in the processor 23 may be a dedicated arithmetic circuit provided in the processor 23.

[0029] In the first embodiment, the processor 23 determines whether an involvement request condition is satisfied while automatic driving control of the vehicle 10 is being executed, and if the involvement request condition is satisfied, notifies the driver via the notification device 7 of an involvement request requesting involvement in driving the vehicle 10. The processor 23 then changes the involvement request condition depending on whether towing of the towed vehicle 11 by the vehicle 10 is detected. Hereinafter, towing of the towed vehicle 11 by the vehicle 10 may be simply referred to as towing of the towed vehicle 11.

[0030] The towing detection unit 31 detects that the vehicle 10 is towing the towed vehicle 11. It is assumed that whether the vehicle 10 is towing the towed vehicle 11 or not remains unchanged while the vehicle 10 is in operation. Therefore, once the towing detection unit 31 determines whether the towed vehicle 11 is being towed, it may not make another determination until the ignition switch of the vehicle 10 is turned off.

[0031] For example, the towing detection unit 31 uses sensor signals obtained from the behavior sensor 5 when the vehicle 10 is in a predetermined state, which indicate measured values ​​of acceleration and torque when the vehicle 10 accelerates, to detect towing of the towed vehicle 11. The towing detection unit 31 then compares the acceleration with a towing determination threshold corresponding to the torque, and detects towing of the towed vehicle 11 if the acceleration is less than the towing determination threshold. On the other hand, the towing detection unit 31 does not detect towing of the towed vehicle 11 if the acceleration is equal to or greater than the towing determination threshold. The towing determination threshold for each torque is pre-stored in the memory 22.

[0032] The predetermined state may be, for example, a state in which the vehicle 10 is stopped at a point where there is no gradient in the traveling direction of the vehicle 10, or a state in which the vehicle 10 is traveling at a constant predetermined speed on a road that has no gradient in the traveling direction of the vehicle 10. The towing detection unit 31 may determine whether or not there is a gradient in the traveling direction of the vehicle 10 by referring to the position of the vehicle 10 indicated by the latest positioning signal from the GPS receiver 4 and a high-precision map. Furthermore, when there is no gradient in the traveling direction of the vehicle 10, the towing detection unit 31 may determine whether or not the vehicle 10 is in the predetermined state based on a sensor signal indicating the speed of the vehicle 10, which is acquired from a speed sensor, which is an example of the behavior sensor 5.

[0033] Furthermore, the towing detection unit 31 may estimate the weight of the towed vehicle 11 when it detects that the towed vehicle 11 is being towed. In this case, the towing detection unit 31 may refer to a reference table that shows the relationship between the torque and acceleration and the weight of the towed vehicle 11 to identify the weight corresponding to the measured torque and acceleration, and use the identified weight as the estimated weight of the towed vehicle 11.

[0034] In addition, if the equipment for towing the towed vehicle 11 is provided with a sensor that detects that the towed vehicle 11 is connected, the towing detection unit 31 may detect the towing of the towed vehicle 11 when the sensor signal from the sensor indicates that the towed vehicle 11 is connected.

[0035] The towing detection unit 31 notifies the control unit 32 and the determination unit 33 of the determination result as to whether or not towing of the towed vehicle 11 has been detected.

[0036] The control unit 32 controls the traveling of the vehicle 10 by referring to the high-precision map read from the storage device 8. For example, the control unit 32 controls each part of the vehicle 10 so that the vehicle 10 continues traveling within the current lane. In doing so, the control unit 32 creates a planned traveling route that passes through the current lane by referring to the high-precision map used for traveling control. For example, the control unit 32 creates a planned traveling route that passes through the center between two lane markings that divide the current lane, as shown on the high-precision map. The control unit 32 then controls each part of the vehicle 10 so that the vehicle 10 travels along the planned traveling route.

[0037] To this end, the control unit 32 detects the position of the vehicle 10 at predetermined intervals and compares the detected position of the vehicle 10 with the planned driving route. To detect the exact position of the vehicle 10, the control unit 32 compares the image generated by the camera 2 with a high-precision map used for driving control. For example, the control unit 32 assumes the position and attitude of the vehicle 10 and projects features on or around the road detected from the image onto the high-precision map, or projects features on or around the road around the vehicle 10 depicted on the high-precision map onto the image. Note that features on or around the road may be, for example, road markings such as lane markings or stop lines, or curbs. The control unit 32 then detects the position and attitude of the vehicle 10 when the features detected from the image most closely match the features depicted on the high-precision map as the exact position of the vehicle 10. Furthermore, the control unit 32 detects the lane including the vehicle's own position on the high-precision map as the vehicle's own lane. Furthermore, the control unit 32 determines that the lane markings detected at the positions closest to the vehicle 10 in the areas corresponding to the left and right sides of the vehicle 10 on the image are the lane markings that demarcate the vehicle's own lane.

[0038] The control unit 32 may determine the position at which the feature is projected on the high-precision map or image using the assumed initial values ​​of the position and attitude of the vehicle 10 and parameters of the camera 2, such as the focal length, installation height, and shooting direction. Note that the initial values ​​of the position and attitude of the vehicle 10 are the latest position of the vehicle 10 measured by the GPS receiver 4, or the position and attitude of the vehicle 10 estimated at the time of the previous self-location detection, corrected using odometry information. The control unit 32 then calculates the degree of match between the feature on or around the road detected from the image and the corresponding feature shown on the high-precision map (for example, the inverse of the sum of the squares of the distances between the corresponding feature).

[0039] The control unit 32 repeats the above process while changing the assumed position and attitude of the vehicle 10. The control unit 32 then detects the assumed position and attitude when the degree of match is greatest as the accurate position of the vehicle 10.

[0040] The control unit 32 may detect the target feature by inputting the image into a classifier that has been trained in advance to detect the target feature from the image. The control unit 32 may use, as such a classifier, a deep neural network (DNN) with a convolutional neural network (CNN)-type architecture, such as Single Shot MultiBox Detector or Faster R-CNN. Alternatively, the control unit 32 may use, as such a classifier, a DNN with a self-attention network (SAN)-type architecture, such as Vision Transformer. Alternatively, the control unit 32 may use, as such a classifier, a classifier based on another machine learning method, such as an AdaBoost classifier. Such a classifier is trained in advance according to a predetermined learning method, such as backpropagation, using a large number of training images depicting the target feature, so as to detect the target feature from the image.

[0041] The control unit 32 may measure the position of the vehicle 10 without using a high-precision map. In this case, the control unit 32 inputs an image obtained by the camera 2 into a classifier to detect left and right lane markings that demarcate the vehicle's own lane, as shown in the image. The positions of the lane markings on the image correspond one-to-one to the orientations of the cameras that generated the images. The control unit 32 estimates the positions of the lane markings on the left and right that correspond to the reference positions on the image, relative to the camera 2, for each lane marking, based on the horizontal reference positions of the pixels representing the left and right lane markings at positions closest to the bottom of the image, and parameters such as the focal length, shooting direction, and installation height of the camera 2. Furthermore, the control unit 32 determines the distance from the camera 2 to each lane marking based on the estimation results, the extension direction of the lane markings, and the shooting direction of the camera 2, thereby measuring the lateral position of the vehicle 10 within the vehicle's own lane.

[0042] If the measured position of vehicle 10 is on the planned travel route, control unit 32 determines the steering angle of vehicle 10 so that vehicle 10 moves along the planned travel route, and controls the steering of vehicle 10 to achieve the determined steering angle. Also, if the measured position of vehicle 10 is away from the planned travel route, control unit 32 determines the steering angle of vehicle 10 so that vehicle 10 approaches the planned travel route, and controls the steering of vehicle 10 to achieve the determined steering angle.

[0043] Furthermore, the control unit 32 refers to the current position of the vehicle 10 and the high-precision map to identify the speed limit for the road on which the vehicle 10 is traveling, and sets the identified speed limit as the target vehicle speed. The control unit 32 then controls each component of the vehicle 10 so that the speed of the vehicle 10 approaches the set target vehicle speed. The control unit 32 also controls the acceleration / deceleration of the vehicle 10 so that the inter-vehicle distance between the vehicle 10 and a preceding vehicle traveling ahead of the vehicle 10 in the current lane is maintained at a certain distance or greater. To this end, the control unit 32 detects other vehicles traveling around the vehicle 10 by inputting images obtained by the camera 2 into a classifier that has been trained in advance to detect other vehicles. As such a classifier, the control unit 32 can use a classifier similar to the classifier used to detect features. Alternatively, the classifier used to detect features may be trained in advance to detect other vehicles as well. In this case, the control unit 32 can detect not only features but also other vehicles by inputting images into the classifier used to detect features. The control unit 32 may then determine, among the detected other vehicles, a vehicle whose bottom edge is located within the area between two lane markings that define the vehicle's own lane on the image as a leading vehicle. Furthermore, the control unit 32 may estimate the distance between the vehicle 10 and the leading vehicle based on the position of the bottom edge of the object area in the image in which the leading vehicle is depicted, and parameters such as the shooting direction, focal length, and installation height of the camera 2. If the estimated distance to the leading vehicle is less than a certain distance, the control unit 32 sets the acceleration / deceleration of the vehicle 10 to decelerate the vehicle 10. On the other hand, if the estimated distance to the leading vehicle is equal to or greater than the certain distance, the control unit 32 sets the acceleration / deceleration of the vehicle 10 so that the speed of the vehicle 10 approaches a target speed.

[0044] Once the acceleration / deceleration is set as described above, the control unit 32 sets the accelerator opening or braking amount in accordance with the set acceleration / deceleration. In doing so, the control unit 32 may change the accelerator opening or braking amount depending on whether towing of the towed vehicle 11 is detected or not. For example, the control unit 32 may set the accelerator opening or braking amount greater when towing of the towed vehicle 11 is detected than when towing of the towed vehicle 11 is not detected.

[0045] The control unit 32 determines the fuel injection amount according to the set accelerator opening degree, and outputs a control signal corresponding to the fuel injection amount to a fuel injection device of the engine of the vehicle 10. Alternatively, the control unit 32 determines the amount of power to be supplied to the motor according to the set accelerator opening degree, and controls the motor drive circuit so that the amount of power is supplied to the motor. Alternatively, the control unit 32 outputs a control signal corresponding to the set brake amount to the brake of the vehicle 10.

[0046] Note that the control unit 32 may stop the automatic driving control or stop the vehicle 10 if the driver does not participate in the driving even after a predetermined period has elapsed since the driver was notified of a request to participate in driving. For example, if the ECU 9 does not receive a signal indicating that the steering wheel has been held from a touch sensor (not shown) provided on the steering wheel even after a predetermined period has elapsed since the hands-on request was notified, the control unit 32 may stop the automatic driving control and transfer driving control to the driver. Furthermore, if the ECU 9 does not receive a signal indicating that the steering wheel has been held from a touch sensor provided on the steering wheel or a signal indicating that the steering wheel, accelerator, or brake has been operated even after a predetermined period has elapsed since the driver handover request was notified, the control unit 32 may stop the vehicle 10.

[0047] The determination unit 33 determines whether the involvement request condition is satisfied. In this embodiment, the determination unit 33 compares the distance from the vehicle 10 to each of the left and right lane markings that separate the vehicle's own lane (hereinafter referred to as the lateral distance) with a hands-on request threshold. If either the left or right lateral distance is less than the hands-on request threshold, the determination unit 33 determines that the involvement request condition is satisfied. If the determination unit 33 determines that the involvement request condition is satisfied, it notifies the notification processing unit 34 of the determination result. The hands-on request threshold is an example of a distance threshold.

[0048] Here, the determination unit 33 sets the hands-on request threshold when towing of the towed vehicle 11 is detected to a higher value than the hands-on request threshold when towing of the towed vehicle 11 is not detected. In other words, the involvement request condition when towing of the towed vehicle 11 is detected is relaxed compared to the involvement request condition when towing of the towed vehicle 11 is not detected. For example, the determination unit 33 sets the hands-on request threshold when towing of the towed vehicle 11 is not detected to 0.2 m to 0.3 m, and sets the hands-on request threshold when towing of the towed vehicle 11 is detected to 0.4 m to 0.5 m. By setting the hands-on request threshold in this manner, it is possible to request the driver to hold the steering wheel before the vehicle 10 gets too close to a lane marking, even when the vehicle 10 is towing the towed vehicle 11.

[0049] As explained in connection with the control unit 32, the determination unit 33 may estimate the positions of the lane markings relative to the camera 2 based on the positions of the lane markings on the image detected from the image and the parameters of the camera 2. Furthermore, the determination unit 33 may obtain the lateral distance for each of the left and right sides of the vehicle 10 by subtracting the distance from the mounting position of the camera 2 to the side of the vehicle 10 from the distance from the camera 2 to the lane marking.

[0050] 4(a) and 4(b) are diagrams showing an example of the relationship between the hands-on request threshold when towing of the towed vehicle 11 is not detected and the hands-on request threshold when towing of the towed vehicle 11 is detected. In the example shown in Fig. 4(a), the vehicle 10 is not towing another vehicle. In contrast, in the example shown in Fig. 4(b), the vehicle 10 is towing the towed vehicle 11.

[0051] 4(a), if towing of the towed vehicle 11 is not detected, the first value HOnTh1 is used as the hands-on request threshold. Therefore, if towing of the towed vehicle 11 is not detected and the lateral distance L between either the left or right lane marking 401 and the vehicle 10 falls below the hands-on request threshold HOnTh1, it is determined that the involvement request condition is met and a hands-on request is notified.

[0052] In contrast, as shown in FIG. 4(b), when towing of the towed vehicle 11 is detected, the second value HOnTh2 is used as the hands-on request threshold. Therefore, when towing of the towed vehicle 11 is detected, if the lateral distance L between the vehicle 10 and either the left or right lane marking 401 falls below the hands-on request threshold HOnTh2, it is determined that the involvement request condition is met and a hands-on request is issued. The second value HOnTh2 is set to a value greater than the first value HOnTh1. Therefore, when towing of the towed vehicle 11 is detected, the involvement request condition is more likely to be met than when towing of the towed vehicle 11 is not detected. Therefore, even if the vehicle 10 is towing the towed vehicle 11, a hands-on request is issued before the vehicle 10 gets too close to the lane marking 401.

[0053] The determination unit 33 also compares the lateral distance to each of the left and right lane markings with a driver changeover request threshold. If either of the left and right lateral distances is less than the driver changeover request threshold, the determination unit 33 determines that the involvement request condition is satisfied. The driver changeover request threshold is another example of a distance threshold.

[0054] The determination unit 33 sets the driver change request threshold when towing of the towed vehicle 11 is detected to a higher value than the driver change request threshold when towing of the towed vehicle 11 is not detected. For example, the determination unit 33 sets the driver change request threshold when towing of the towed vehicle 11 is not detected to 0.1 m to 0.2 m, and sets the driver change request threshold when towing of the towed vehicle 11 is detected to 0.2 m to 0.3 m. By setting the driver change request threshold in this manner, the determination unit 33 can transfer driving control to the driver before the vehicle 10 gets too close to a lane marking, even when the vehicle 10 is towing the towed vehicle 11.

[0055] 5(a) and 5(b) are diagrams showing an example of the relationship between the driver change request threshold when towing of the towed vehicle 11 is not detected and the driver change request threshold when towing of the towed vehicle 11 is detected. In the example shown in FIG. 5(a), towing of the towed vehicle 11 is not detected. In contrast, in the example shown in FIG. 5(b), towing of the towed vehicle 11 is detected.

[0056] 5(a), when towing of the towed vehicle 11 is not detected, the first value TDTh1 is used as the driver change request threshold. Therefore, when towing of the towed vehicle 11 is not detected, if the lateral distance L between either the left or right lane marking 501 and the vehicle 10 becomes less than the driver change request threshold TDTh1, it is determined that the involvement request condition is met, and a driver change request is notified.

[0057] In contrast, as shown in FIG. 5(b), when towing of the towed vehicle 11 is detected, the second value TDTh2 is used as the driver change request threshold. Therefore, when towing of the towed vehicle 11 is detected, if the lateral distance L between either the left or right lane marking 501 and the vehicle 10 becomes less than the driver change request threshold TDTh2, it is determined that the involvement request condition is met, and a driver change request is issued. In addition, the second value TDTh2 is set to a value greater than the first value TDTh1. Therefore, when towing of the towed vehicle 11 is detected, the involvement request condition is more likely to be met than when towing of the towed vehicle 11 is not detected. Therefore, even if the vehicle 10 is towing the towed vehicle 11, a driver change request is issued before the vehicle 10 gets too close to the lane marking 501.

[0058] When the notification processing unit 34 receives the determination result that the participation request condition is satisfied from the determination unit 33, it notifies the driver via the notification device 7 of a request corresponding to the satisfied participation request condition.

[0059] As described above, when it is determined that the lateral distance is less than the hands-on request threshold, the notification processing unit 34 notifies the driver of a hands-on request via the notification device 7. Furthermore, when it is determined that the lateral distance is less than the driving change request threshold, the notification processing unit 34 notifies the driver of a driving change request via the notification device 7.

[0060] 6 is an operational flowchart of a vehicle control process related to a change in the degree of driver involvement in driving according to the first embodiment. The processor 23 may execute the vehicle control process in accordance with the following operational flowchart at predetermined intervals.

[0061] The towing detection unit 31 of the processor 23 determines whether or not towing of the towed vehicle 11 by the vehicle 10 has been detected (step S101).

[0062] If towing of the towed vehicle 11 is not detected (step S101-No), the determination unit 33 of the processor 23 sets the participation requirement condition relatively stricter (step S102). On the other hand, if towing of the towed vehicle 11 is detected (step S101-Yes), the determination unit 33 sets the participation requirement condition relatively looser (step S103).

[0063] The determination unit 33 determines whether the set participation request condition is satisfied (step S104). If the participation request condition is satisfied (step S104-Yes), the notification processing unit 34 of the processor 23 notifies the driver of a request for participation in driving that corresponds to the satisfied participation request condition via the notification device 7 (step S105).

[0064] If the involvement request condition is not satisfied in step S104 (step S104-No), or after step S105, processor 23 ends the vehicle control process.

[0065] As described above, the vehicle control device determines whether an involvement request condition, which requests the driver of the vehicle to participate in the driving of the vehicle, is satisfied, and if it is determined that the involvement request condition is satisfied, notifies the driver of the request for participation in driving via a notification device installed in the vehicle cabin. The vehicle control device then relaxes the involvement request condition when towing of the towed vehicle is detected compared to the involvement request condition when towing of the towed vehicle is not detected. Therefore, when towing of the towed vehicle is detected, the involvement request condition is more likely to be satisfied. Therefore, even when the vehicle is towing the towed vehicle, the vehicle control device can request the driver to participate in driving before the vehicle becomes unstable. As a result, the vehicle control device can appropriately set the timing to increase the degree of involvement of the driver in driving of a vehicle towing a towed vehicle and to which automatic driving control is applied.

[0066] According to a modified example, when towing of the towed vehicle 11 is detected, the determination unit 33 may adjust the hands-on requirement threshold or the driver change request threshold according to the weight of the towed vehicle 11. For example, the determination unit 33 may increase the hands-on requirement threshold or the driver change request threshold the greater the weight of the towed vehicle 11 estimated by the towing detection unit 31. In this case, the hands-on requirement threshold or the driver change request threshold may continuously increase as the estimated weight of the towed vehicle 11 increases. Alternatively, the hands-on requirement threshold or the driver change request threshold may be set in stages. In this case, the determination unit 33 increases the hands-on requirement threshold or the driver change request threshold by a predetermined step amount each time the estimated weight of the towed vehicle 11 increases by a predetermined value.

[0067] Similarly, when towing of the towed vehicle 11 is detected, the determination unit 33 may adjust the hands-on requirement threshold or the driving change requirement threshold according to the volume of the towed vehicle 11. For example, the determination unit 33 may increase the hands-on requirement threshold or the driving change requirement threshold as the volume of the towed vehicle 11 estimated by the towing detection unit 31 increases. In this case, information indicating the volume of the towed vehicle 11 may be stored in advance in the memory 22.

[0068] In this way, by adjusting the hands-on request threshold or the driving change request threshold according to the weight or volume of the towed vehicle 11, the judgment unit 33 can request the driver to take over driving at a more appropriate time before the vehicle 10 gets too close to the lane marking.

[0069] Furthermore, when towing of the towed vehicle 11 is detected, the determination unit 33 may adjust the hands-on request threshold or the driver change request threshold depending on the type of cargo carried on the towed vehicle 11. For example, the determination unit 33 may set a higher hands-on request threshold when the type of cargo carried on the towed vehicle 11 is sensitive, such as precision machinery or fragile items, which are relatively susceptible to vibration or impact, than the hands-on request threshold when the type of cargo is not sensitive. Similarly, the determination unit 33 may set a higher driver change request threshold when the type of cargo carried on the towed vehicle 11 is sensitive than the driver change request threshold when the type of cargo is not sensitive. Information indicating the type of cargo carried on the towed vehicle 11 is input via a user interface provided in the cabin of the vehicle 10 and stored in the memory 22. The determination unit 33 may determine the type of cargo carried on the towed vehicle 11 by referencing this information.

[0070] Furthermore, when towing of the towed vehicle 11 is detected, the lower the reliability of the detected lane markings that demarcate the own lane, the larger the hands-on request threshold or the driving change request threshold. In this case, the determination unit 33 may use the reliability of the lane markings output by the classifier used to detect the lane markings as the reliability.

[0071] According to another modification, the determination unit 33 may determine whether the involvement request condition is satisfied based on the behavior of the vehicle 10, the state of the driver, or the circumstances surrounding the vehicle 10, instead of the lateral distance. In this case, it is also preferable for the determination unit 33 to relax the involvement request condition when towing of the towed vehicle 11 is detected compared to the involvement request condition when towing of the towed vehicle 11 is not detected. By relaxing the involvement request condition when towing of the towed vehicle 11 is detected in this way, the determination unit 33 can request the driver to take part in driving before the vehicle 10 falls into an unstable situation due to the behavior of the vehicle 10, the state of the driver, or the circumstances surrounding the vehicle 10, even when the vehicle 10 is towing the towed vehicle 11.

[0072] For example, the determination unit 33 determines that the involvement request condition is satisfied if the speed of the vehicle 10 measured by a speed sensor, which is an example of the behavior sensor 5, is faster than the speed limit of the road on which the vehicle 10 is currently traveling by at least a predetermined speed threshold. The notification processing unit 34 then notifies the driver of a hands-on request via the notification device 7. In this case, the determination unit 33 sets the speed threshold when towing of the towed vehicle 11 is detected to a value lower than the speed threshold when towing of the towed vehicle 11 is not detected. This allows the determination unit 33 to appropriately request the driver to participate in driving when the speed of the vehicle 10 exceeds the speed limit. The determination unit 33 refers to a high-precision map to identify a road including the position of the vehicle 10 represented by the latest positioning information from the GPS receiver 4 as the road on which the vehicle 10 is traveling. The determination unit 33 then refers to a high-precision map to identify the speed limit of the road on which the vehicle 10 is traveling. Alternatively, the determination unit 33 may input the image generated by the camera 2 into a classifier that has been trained in advance to detect the speed limit indicated on a speed sign, thereby identifying the speed limit of the road on which the vehicle 10 is traveling. As such a classifier, the determination unit 33 may use a classifier similar to the classifier used to detect features, as described in the control unit 32.

[0073] Furthermore, the determination unit 33 determines that the involvement request condition is satisfied when the vehicle 10 is traveling in a section where the speed limit is less than a predetermined speed. The notification processing unit 34 then notifies the driver of a hands-on request via the notification device 7. In this case, the determination unit 33 sets the predetermined speed when towing of the towed vehicle 11 is detected to be higher than the predetermined speed when towing of the towed vehicle 11 is not detected. This allows the determination unit 33 to appropriately request the driver to participate in driving when the speed limit on the road on which the vehicle 10 is traveling is low and more careful control of the vehicle 10 is required.

[0074] Alternatively, the determination unit 33 determines that the involvement request condition is satisfied if the curvature radius of a curve located on which the vehicle 10 is traveling or within a predetermined distance (e.g., several hundred meters to 1 km) ahead is less than a predetermined curvature radius threshold. If the curvature radius of the curve is less than the predetermined curvature radius threshold, the notification processing unit 34 notifies the driver of a hands-on request via the notification device 7. Alternatively, the notification processing unit 34 may notify the driver of a driving change request via the notification device 7. In this case, the determination unit 33 sets the curvature radius threshold when towing of the towed vehicle 11 is detected to a value greater than the curvature radius threshold when towing of the towed vehicle 11 is not detected. This allows the determination unit 33 to appropriately request the driver to participate in driving depending on the curvature radius of the curve on which the vehicle 10 is traveling or is scheduled to travel. As described above, the determination unit 33 may refer to a high-precision map and identify the road including the position of the vehicle 10 indicated in the latest positioning information from the GPS receiver 4 as the road on which the vehicle 10 is traveling. Furthermore, the determination unit 33 may refer to the direction of travel of the vehicle 10 indicated by a direction sensor (not shown) mounted on the vehicle 10 and the high-precision map being used for driving control, and identify the radius of curvature of the curve included in the section from the current position of the vehicle 10 to a predetermined distance ahead on the road on which the vehicle 10 is traveling.

[0075] Alternatively, the determination unit 33 determines that the involvement request condition is satisfied if the gradient of the road on which the vehicle is traveling or in a section up to a predetermined distance ahead is equal to or greater than a predetermined gradient threshold. The notification processing unit 34 then notifies the driver of a hands-on request via the notification device 7. Alternatively, the notification processing unit 34 may notify the driver of a driving change request via the notification device 7. In this case, the determination unit 33 sets the gradient threshold when towing of the towed vehicle 11 is detected to a value smaller than the gradient threshold when towing of the towed vehicle 11 is not detected. This allows the determination unit 33 to appropriately request the driver to participate in driving depending on the gradient of the road section on which the vehicle 10 is traveling or scheduled to travel. Similarly to the above, the determination unit 33 may refer to a high-precision map and identify the road including the position of the vehicle 10 indicated in the latest positioning information from the GPS receiver 4 as the road on which the vehicle 10 is traveling. Furthermore, the determination unit 33 may refer to the direction of travel of the vehicle 10 indicated by a direction sensor (not shown) mounted on the vehicle 10 and a high-precision map to identify the gradient of the section of the road on which the vehicle 10 is traveling, from the current position of the vehicle 10 to a predetermined distance ahead.

[0076] Alternatively, the determination unit 33 determines that the involvement request condition is satisfied if the period during which the driver does not hold the steering wheel continues for a predetermined period of time that is equal to or exceeds a predetermined threshold value for that period. The notification processing unit 34 then notifies the driver of a hands-on request via the notification device 7. In this case, the threshold value for the period of time that is used when towing of the towed vehicle 11 is detected is set to a value that is smaller than the threshold value for the period of time that is used when towing of the towed vehicle 11 is not detected. Note that the determination unit 33 may determine the period of time that has elapsed since the ECU 9 last received a signal from a touch sensor on the steering wheel indicating that the steering wheel is being held.

[0077] Alternatively, the determination unit 33 determines that the involvement request condition is satisfied if the driver ignores any of the face loss warning, inattentive driving warning, closed eyes warning, or hands-off warning issued via the notification device 7 for a period of time equal to or longer than a predetermined time threshold. The notification processing unit 34 then notifies the driver of a hands-on request via the notification device 7. In this case, the time threshold when towing of the towed vehicle 11 is detected is set to a value smaller than the time threshold when towing of the towed vehicle 11 is not detected.

[0078] The determination unit 33 determines whether a facial region representing the driver's face can be detected in the driver image by inputting the driver image generated by the driver monitor camera 3 into a classifier previously trained to detect the driver's face. The determination unit 33 may use a classifier similar to the classifier used by the control unit 32 to detect features. If a facial region is not detected, the determination unit 33 determines that a face-lost state has occurred, in which the driver's face cannot be detected. If the face-lost state continues for a predetermined period of time, the determination unit 33 notifies the driver of a face-lost warning via the notification device 7. If the driver's face is detected in the generated driver image after the face-lost warning is notified, or if the driver performs a response operation in response to the face-lost warning provided in the vehicle cabin, the determination unit 33 determines that the driver has responded to the face-lost warning. On the other hand, if the driver's face is not detected in the driver image even after the face-lost warning is notified, and no response operation is performed to the face-lost warning, the determination unit 33 may determine that the driver has ignored the face-lost warning. The response operation may be performed by operating a predetermined switch provided in the vehicle cabin or by the driver making a predetermined utterance. The voice uttered by the driver is collected by a speaker provided in the vehicle cabin and output as a voice signal to the ECU 9. The processor 23 may determine whether the driver has made the predetermined utterance by performing a predetermined voice recognition process such as GMM-HMM or DNN-HMM on the voice signal.

[0079] The determination unit 33 also determines the driver's facial orientation by matching the facial region with a three-dimensional facial model. If the driver's facial orientation is outside a predetermined angular range centered on the traveling direction of the vehicle 10, the determination unit 33 determines that the driver is in an inattentive state. Alternatively, the determination unit 33 may detect the driver's gaze direction and determine that the driver is in an inattentive state if the detected gaze direction is outside the above-mentioned angular range. In this case, the determination unit 33 detects the upper and lower eyelids of either the driver's left or right eye by applying an edge detection filter to the facial region to detect horizontally continuous edges or by inputting the facial region to a classifier. Furthermore, the determination unit 33 detects the pupil center and the corneal reflection of the light source by performing template matching on the region surrounded by the upper and lower eyelids. The determination unit 33 then detects the gaze direction based on the positional relationship between the pupil center and the corneal reflection of the light source. If the inattentive state continues for a predetermined period of time, the determination unit 33 notifies the driver of an inattentive state warning via the notification device 7. If the detected face orientation or line of sight direction of the driver after the inattentive state warning is received falls within the above-mentioned angle range, that is, if the inattentive state is resolved, the determination unit 33 determines that the driver has responded to the inattentive state warning. On the other hand, if the inattentive state is not resolved even after the inattentive state warning is received, the determination unit 33 may determine that the driver has ignored the inattentive state warning.

[0080] Furthermore, the determination unit 33 calculates the degree of eye closure as the ratio of the detected distance between the upper and lower eyelids to a reference distance between the upper and lower eyelids when the driver's eyes are fully open. The reference distance is stored in advance in the memory 22. If the degree of eye closure is equal to or less than a predetermined eye closure threshold, the determination unit 33 determines that the driver is in an eye-closed state. If the eye-closed state continues for a predetermined period, the determination unit 33 notifies the driver of an eye-closed warning via the notification device 7. If the detected degree of eye closure of the driver after the eye-closed warning becomes greater than the eye-closed threshold, i.e., if the eye-closed state is resolved, the determination unit 33 determines that the driver has responded to the eye-closed warning. On the other hand, if the eye-closed state is not resolved even after the eye-closed warning is notified, the determination unit 33 may determine that the driver has ignored the eye-closed warning.

[0081] Furthermore, when the ECU 9 receives a signal from a touch sensor provided on the steering wheel indicating that the steering wheel is not being held, the determination unit 33 determines that the driver is in a hands-off state, that is, a state in which the driver is not holding the steering wheel. Then, when the ECU 9 is performing automatic driving control of the vehicle 10 at a level that requires the driver to hold the steering wheel, and the hands-off state continues for a predetermined time or longer, the determination unit 33 notifies the driver of a hands-off warning via the notification device 7. After the hands-off warning is notified, if the ECU 9 receives a signal from the touch sensor indicating that the steering wheel is being held, the determination unit 33 determines that the hands-off state has been resolved. On the other hand, if the ECU 9 does not receive a signal from the touch sensor indicating that the steering wheel is being held even after the hands-off warning is notified, the determination unit 33 may determine that the driver has ignored the hands-off warning.

[0082] The judgment unit 33 may determine whether all of the participation requirement conditions in the above-mentioned embodiment or variant are satisfied, or may determine whether any one or more of the participation requirement conditions are satisfied.

[0083] (Second embodiment) Next, a second embodiment will be described. In the second embodiment, after starting lane change processing for the vehicle 10, the processor 23 changes the interruption condition for whether or not to interrupt the lane change processing depending on whether or not the vehicle 10 is towing a towed vehicle.

[0084] FIG. 7 is a functional block diagram of the processor 23 relating to vehicle control processing according to the second embodiment. The processor 23 includes a towing detection unit 31, a lane change determination unit 35, a vehicle detection unit 36, a lane change control unit 37, a determination unit 38, and an interruption instruction unit 39. Each of these units included in the processor 23 is, for example, a functional module implemented by a computer program running on the processor 23. Alternatively, each of these units included in the processor 23 may be a dedicated arithmetic circuit provided in the processor 23. Furthermore, components that perform the same processing in the first and second embodiments are assigned the same reference numerals in the first and second embodiments. Furthermore, for details of the components in the second embodiment that correspond to those in the first embodiment, please refer to the description of the first embodiment.

[0085] As in the first embodiment, the towing detection unit 31 detects that the vehicle 10 is towing the towed vehicle 11. Then, the towing detection unit 31 notifies the lane change control unit 37 and the determination unit 38 of the towing detection result.

[0086] The lane change determination unit 35 determines whether a predetermined condition for applying lane change control to the vehicle 10 is satisfied. For example, when the driver operates a turn signal, the lane change determination unit 35 determines that the predetermined condition is satisfied. The lane change determination unit 35 then determines to apply lane change control to an adjacent lane adjacent to the vehicle's own lane in the direction indicated by the turn signal. Alternatively, the lane change determination unit 35 may determine that the predetermined condition is satisfied and apply lane change control when the vehicle's own lane and a lane heading toward the vehicle's destination are different, when the vehicle is overtaking a preceding vehicle, or when the vehicle is returning from an overtaking lane to the driving lane.

[0087] To determine whether the vehicle's own lane and the lane heading toward the destination of the vehicle 10 are different, the lane change determination unit 35 refers to the driving route to the destination of the vehicle 10, the current position of the vehicle 10, and a high-precision map, all of which are received by the ECU 9 from a navigation device (not shown). The lane change determination unit 35 then determines whether a branch point exists at which a lane heading toward the destination branches off from the road on which the vehicle 10 is currently traveling, within a section a predetermined distance from the current position of the vehicle 10. If a branch point exists, the lane change determination unit 35 determines whether the vehicle's own lane and the lane heading toward the destination are different. If the vehicle's own lane and the lane heading toward the destination are different, the lane change determination unit 35 determines to apply lane change control at least once, with the lane heading toward the destination being the target lane. As described for the control unit 32 in the first embodiment, the lane change determination unit 35 measures the exact position of the vehicle 10 by comparing the image generated by the camera 2 with the high-precision map, and identifies the lane shown on the high-precision map that includes the measured position of the vehicle 10 as the vehicle's own lane.

[0088] Furthermore, when the speed of the vehicle 10 becomes equal to or less than a predetermined speed threshold and the inter-vehicle distance between the vehicle 10 and a preceding vehicle traveling ahead of the vehicle 10 remains equal to or less than a predetermined distance for a predetermined period of time, the lane change determination unit 35 determines to apply lane change control to overtake the preceding vehicle. The predetermined period of time may be, for example, several seconds to several tens of seconds. In this case, the lane change determination unit 35 preferably sets an overtaking lane among lanes adjacent to the vehicle's own lane as the target lane to which the vehicle 10 will be changed. The lane change determination unit 35 may identify, as the preceding vehicle, a nearby vehicle that is represented in an object region located within a range corresponding to the front of the vehicle 10 on the image generated by the camera 2, among the nearby vehicles detected by the other vehicle detection unit 36. The predetermined speed threshold is set to, for example, a speed obtained by subtracting a predetermined offset value (e.g., 10 km / h to 20 km / h) from the legal speed limit or speed limit of the road on which the vehicle 10 is traveling. Therefore, the lane change determination unit 35 may set the speed threshold by referring to the current position of the vehicle 10 and the high-precision map to identify the legal speed or the speed limit of the road on which the vehicle 10 is currently traveling. Furthermore, the lane change determination unit 35 may determine the inter-vehicle distance between the vehicle 10 and the preceding vehicle based on the relative positional relationship between the vehicle 10 and the preceding vehicle detected by the other vehicle detection unit 36.

[0089] Furthermore, if the vehicle 10's own lane is an overtaking lane and the vehicle 10 has been traveling in the overtaking lane for a recent predetermined period of time, the lane change determination unit 35 determines to apply lane change control to return the vehicle 10 to the driving lane. The lane change determination unit 35 may determine whether the vehicle 10's own lane is an overtaking lane by referring to a high-precision map. In this case, the lane change determination unit 35 sets one of the driving lanes on the road on which the vehicle 10 is traveling as a target lane to which the vehicle 10 will be changed.

[0090] When the lane change determination unit 35 determines that lane change control should be applied to the vehicle 10, it notifies the other vehicle detection unit 36, the lane change control unit 37, and the determination unit 38 of the determination result and the direction (right or left) of the adjacent lane to which the vehicle 10 is to be changed, as viewed from the road on which the vehicle 10 is traveling.

[0091] The other vehicle detection unit 36 ​​detects other vehicles traveling around the vehicle 10 (hereinafter, for convenience of explanation, referred to as peripheral vehicles). Furthermore, the other vehicle detection unit 36 ​​detects the relative position and relative speed between the peripheral vehicles and the vehicle 10. In particular, the other vehicle detection unit 36 ​​detects the relative position and relative speed between the vehicle 10 and peripheral vehicles traveling in an adjacent lane (hereinafter, may be simply referred to as an adjacent lane) into which the vehicle 10 will change lanes. To this end, the other vehicle detection unit 36 ​​detects peripheral vehicles by inputting images acquired from the camera 2 into a classifier. As such a classifier, the other vehicle detection unit 36 ​​can use the same classifier as described for the control unit 32 in the first embodiment. The classifier outputs information identifying an object region including the peripheral vehicle detected in the input image and information indicating the type of the detected peripheral vehicle (e.g., passenger car, large vehicle, motorcycle, etc.).

[0092] If a nearby vehicle is detected, the other vehicle detection unit 36 ​​determines whether the nearby vehicle is traveling in an adjacent lane. Here, the position of the bottom edge of the object area including the nearby vehicle is assumed to represent the position where the nearby vehicle is in contact with the road surface. Furthermore, as described above, positions on an image correspond one-to-one to the orientation as viewed from the camera that generated the image. Therefore, the other vehicle detection unit 36 ​​can estimate the distance from the camera 2 to the nearby vehicle and the orientation from the vehicle 10 to the nearby vehicle by referring to the position of the bottom edge of the object area on the image and parameters such as the installation height and shooting direction of the camera 2. Alternatively, the other vehicle detection unit 36 ​​may estimate the distance from the camera 2 to the nearby vehicle based on the horizontal width of the object area including the nearby vehicle and a reference number of pixels on the image when the inter-vehicle distance is a reference distance, which corresponds to a reference vehicle width corresponding to the vehicle type of the nearby vehicle.

[0093] Furthermore, if the vehicle 10 is equipped with a distance measurement sensor (not shown), the other vehicle detection unit 36 ​​may detect surrounding vehicles based on the distance measurement signal. In this case, the other vehicle detection unit 36 ​​may detect surrounding vehicles by inputting the distance measurement signal to a classifier that has been trained in advance to detect surrounding vehicles from the distance measurement signal. The other vehicle detection unit 36 ​​may use a DNN with a CNN or SAN architecture as the classifier that detects surrounding vehicles from the distance measurement signal. Alternatively, the other vehicle detection unit 36 ​​may detect surrounding vehicles using other methods for detecting surrounding vehicles from the distance measurement signal. In this case, the other vehicle detection unit 36 ​​may determine the direction in which the surrounding vehicle was detected in the distance measurement signal as the direction from the vehicle 10 to the surrounding vehicle. Furthermore, the other vehicle detection unit 36 ​​may determine the distance indicated in the distance measurement signal for that direction as the estimated distance from the vehicle 10 to the surrounding vehicle.

[0094] The other vehicle detection unit 36 ​​estimates the distance from the vehicle 10 to the surrounding vehicle along a direction perpendicular to the traveling direction of the vehicle 10 based on the estimated direction and distance (hereinafter, for convenience of explanation, referred to as the inter-vehicle lateral distance). If the inter-vehicle lateral distance is within a predetermined distance range corresponding to the width of the adjacent lane at the current position of the vehicle 10, and the direction from the vehicle 10 to the surrounding vehicle is the same as the direction of the adjacent lane to which the vehicle 10 is changing lanes relative to the host vehicle lane, the other vehicle detection unit 36 ​​determines that the surrounding vehicle is traveling in the adjacent lane. The other vehicle detection unit 36 ​​may identify the predetermined distance range at the current position of the vehicle 10 by referring to a high-precision map.

[0095] Alternatively, the other vehicle detection unit 36 ​​may input the image into a classifier to detect lane markings shown in the image along with surrounding vehicles. In this case, the classifier is trained in advance so that it can also detect lane markings. The other vehicle detection unit 36 ​​then identifies, in the direction (right or left) of the merging destination, an area sandwiched between two lane markings in order from the one closest to the position of the vehicle 10 on the image, as an area showing an adjacent lane on the image. If the bottom edge of the object area showing the surrounding vehicle is included in the area corresponding to the adjacent lane, the other vehicle detection unit 36 ​​may determine that the surrounding vehicle is traveling in the adjacent lane.

[0096] The other vehicle detection unit 36 ​​performs the above processing on a series of time-series images generated by the camera 2 or a series of time-series ranging signals generated by the ranging sensor, thereby estimating the relative positions of surrounding vehicles with respect to the vehicle 10 at the time of generating each image or each ranging signal. Furthermore, the other vehicle detection unit 36 ​​determines the change in relative position of the surrounding vehicles with respect to the vehicle 10 from the relative positions of the surrounding vehicles with respect to the vehicle 10 at the time of generating each of the time-series images or ranging signals during the most recent fixed period, and estimates the relative speed of the surrounding vehicles with respect to the vehicle 10 based on the change in relative position.

[0097] If multiple surrounding vehicles are detected, the other vehicle detection unit 36 ​​may track each of the surrounding vehicles over a series of time-series images or a series of time-series distance measurement signals by applying a predetermined tracking method such as KLT tracking. Then, the other vehicle detection unit 36 ​​may estimate the relative position and relative speed of each surrounding vehicle with respect to the vehicle 10.

[0098] The other vehicle detection unit 36 ​​notifies the lane change control unit 37 and the judgment unit 38 of the relative position and relative speed of each surrounding vehicle determined to be traveling in the adjacent lane to which the lane is to be changed, with respect to the vehicle 10.

[0099] When the lane change control unit 37 is notified by the lane change determination unit 35 of the determination result that lane change control should be applied to the vehicle 10, the lane change control unit 37 executes the lane change control to cause the vehicle 10 to enter the adjacent lane. Furthermore, when the lane change control unit 37 is instructed by the interruption instruction unit 39 to interrupt the lane change control before the lane change control is completed, the lane change control unit 37 interrupts the execution of the lane change control. Then, the lane change control unit 37 controls each unit of the vehicle 10 so that the vehicle 10 continues traveling in the own lane.

[0100] When lane change control starts to be executed, the lane change control unit 37 sets a planned driving route for moving the vehicle 10 from the current lane to an adjacent lane. Once the planned driving route is set, the lane change control unit 37 controls each unit of the vehicle 10 so that the vehicle 10 travels along the planned driving route. To this end, the lane change control unit 37 measures the position of the vehicle 10 at predetermined intervals and compares the measured position of the vehicle 10 with the planned driving route. As described for the control unit 32 in the first embodiment, the lane change control unit 37 may measure the accurate position of the vehicle 10 by comparing an image acquired by the camera 2 with a high-precision map. If the measured position of the vehicle 10 is on the planned driving route, the lane change control unit 37 determines a steering angle of the vehicle 10 so that the vehicle 10 travels along the planned driving route, and controls the steering of the vehicle 10 to achieve the determined steering angle. Furthermore, if the measured position of the vehicle 10 is far from the planned driving route, the lane change control unit 37 determines the steering angle of the vehicle 10 so that the vehicle 10 approaches the planned driving route, and controls the steering of the vehicle 10 to achieve the determined steering angle.

[0101] Furthermore, if there is a nearby vehicle traveling in front of or to the side of the vehicle 10 in an adjacent lane, the lane change control unit 37 sets the acceleration / deceleration of the vehicle 10 so that the distance between the nearby vehicle and the vehicle 10 is equal to or greater than a predetermined distance threshold when the vehicle 10 enters the adjacent lane. At this time, the lane change control unit 37 refers to the relative position and relative speed of the nearby vehicle detected by the other vehicle detection unit 36. Then, if the distance between the vehicle 10 and the nearby vehicle in the traveling direction of the vehicle 10, which is calculated from the relative positions of the vehicle 10 and the nearby vehicle, is less than the distance threshold, the lane change control unit 37 decelerates the vehicle 10 so that the speed of the vehicle 10 is lower than the speed of the nearby vehicle, based on the relative speed. Furthermore, if the distance between the vehicle 10 and the nearby vehicle in the traveling direction of the vehicle 10 is equal to or greater than the distance threshold, the lane change control unit 37 may set the acceleration / deceleration based on the relative speed so that the speed of the vehicle 10 is equal to or lower than the speed of the nearby vehicle.

[0102] The lane change control unit 37 sets the accelerator opening or braking amount according to the set acceleration / deceleration. The lane change control unit 37 calculates the fuel injection amount according to the set accelerator opening, and outputs a control signal corresponding to the fuel injection amount to a fuel injection device of the engine of the vehicle 10. Alternatively, the lane change control unit 37 calculates the amount of power to be supplied to the motor according to the set accelerator opening, and controls the motor drive circuit so that the amount of power is supplied to the motor. Alternatively, the lane change control unit 37 outputs a control signal corresponding to the set braking amount to the brake of the vehicle 10.

[0103] When the vehicle 10 is traveling completely in the adjacent lane, the lane change control unit 37 terminates lane change control. At that time, the lane change control unit 37 determines whether the entire vehicle 10 is located in the adjacent lane by referring to the position of the vehicle 10 measured as described above and the high-precision map, or by referring to the two lane markings that separate the adjacent lane detected from the image. If the entire vehicle 10 is located in the adjacent lane, the lane change control unit 37 determines that the vehicle 10 is traveling completely in the adjacent lane.

[0104] While the lane change control unit 37 is performing lane change control, the determination unit 38 determines whether or not at least one of the relative position and relative speed between the vehicle 10 and a surrounding vehicle traveling in an adjacent lane to which the lane is to be changed, as detected by the other vehicle detection unit 36, satisfies a predetermined interruption condition.

[0105] For example, the determination unit 38 calculates the inter-vehicle distance between the vehicle 10 and a nearby vehicle traveling behind the vehicle 10 in an adjacent lane based on the relative positions between the nearby vehicle and the vehicle 10. The determination unit 38 determines that the interruption condition is satisfied when the inter-vehicle distance becomes less than a predetermined distance threshold. The determination unit 38 may also predict the inter-vehicle distance between the nearby vehicle and the vehicle 10 for a predetermined time period by applying a prediction process such as a Kalman filter to changes in the relative position between the nearby vehicle and the vehicle 10 over a recent predetermined period. The determination unit 38 may also determine that the interruption condition is satisfied when the inter-vehicle distance between the nearby vehicle and the vehicle 10 becomes less than the distance threshold at any predicted time point. The interruption condition may be set as a combination of the inter-vehicle distance and the relative speed between the nearby vehicle and the vehicle 10. For example, the distance threshold may be set to decrease as the speed of the nearby vehicle becomes faster than the speed of the vehicle 10 and the relative speed between the nearby vehicle and the vehicle 10 increases. Furthermore, when the speed of a nearby vehicle traveling behind vehicle 10 in an adjacent lane is faster than the speed of vehicle 10 and the relative speed between the nearby vehicle and vehicle 10 is greater than a predetermined speed threshold, the determination unit 38 may determine that the interruption condition is satisfied regardless of the inter-vehicle distance between the nearby vehicle and vehicle 10. Furthermore, the determination unit 38 may calculate a predicted time until a collision between the nearby vehicle and vehicle 10 based on a predicted result of the inter-vehicle distance between the nearby vehicle and vehicle 10. Then, when the predicted time becomes equal to or less than a predetermined time threshold, the determination unit 38 may determine that the interruption condition is satisfied.

[0106] In addition, if there are multiple surrounding vehicles traveling behind vehicle 10 in an adjacent lane, the judgment unit 38 can determine whether the interruption condition is met by performing the above processing on the surrounding vehicle closest to vehicle 10.

[0107] Furthermore, during execution of lane change control, the distance between vehicle 10 and the surrounding vehicle may suddenly become shorter due to, for example, a sudden deceleration of a surrounding vehicle traveling ahead of vehicle 10. Therefore, the determination unit 38 may determine whether the interruption condition is satisfied for a surrounding vehicle traveling ahead of vehicle 10 in the same manner as described above. However, unlike the condition for a following surrounding vehicle, the condition regarding the relative speed differs from the condition for a following surrounding vehicle; the determination unit 38 may determine that the interruption condition is satisfied when the relative speed of the surrounding vehicle with respect to vehicle 10 is slower than a predetermined speed threshold. Furthermore, the interruption condition for a surrounding vehicle traveling ahead of vehicle 10 and the interruption condition for a surrounding vehicle traveling behind vehicle 10 may be set separately.

[0108] In this embodiment, the determination unit 38 relaxes the interruption condition when it is detected that the vehicle 10 is towing the towed vehicle 11 compared to the interruption condition when it is not detected that the vehicle 10 is towing the towed vehicle 11. For example, as described above, if the interruption condition is that the inter-vehicle distance between the vehicle 10 and the surrounding vehicles is shorter than the distance threshold, the determination unit 38 increases the distance threshold when it is detected that the vehicle 10 is towing the towed vehicle 11 compared to the distance threshold when it is not detected that the vehicle 10 is towing the towed vehicle 11. Furthermore, if the interruption condition is that the relative speed of the surrounding vehicles with respect to the vehicle 10 is greater than the speed threshold, the determination unit 38 decreases the speed threshold when it is detected that the vehicle 10 is towing the towed vehicle 11 compared to the speed threshold when it is not detected that the vehicle 10 is towing the towed vehicle 11. Furthermore, if the interruption condition is that the predicted time until a collision between vehicle 10 and a surrounding vehicle is less than or equal to a time threshold, the judgment unit 38 sets the time threshold when it is detected that vehicle 10 is towing the towed vehicle 11 to a value greater than the time threshold when it is not detected that vehicle 10 is towing the towed vehicle 11.

[0109] Fig. 8 is a diagram showing the relationship between whether or not towing of the towed vehicle 11 is detected and a time threshold, which is an example of an interruption condition. In Fig. 8, the horizontal axis represents time, and the vertical axis represents the predicted time until a collision between the vehicle 10 and surrounding vehicles (Time to Collision, TTC). Chart 800 shows the change in TTC over time. In this example, it is assumed that surrounding vehicles gradually approach the vehicle 10, and as a result, the TTC shortens over time.

[0110] As shown in FIG. 8, the time threshold value Thp when towing of the towed vehicle 11 is detected is set to a value greater than the time threshold value Thn when towing of the towed vehicle 11 is not detected. Therefore, the timing t1 at which the TTC falls below the time threshold value Thp is earlier than the timing t2 at which the TTC falls below the time threshold value Thn. Therefore, lane change control is suspended earlier when towing of the towed vehicle 11 is detected than when towing is not detected. In this way, the vehicle control device according to this embodiment can suspend lane change control at an earlier timing corresponding to the sluggish behavior of the vehicle 10 due to towing of the towed vehicle 11. Therefore, this vehicle control device can appropriately set the timing at which lane change control is suspended to reduce the possibility of contact between the vehicle 10 and nearby vehicles when towing the towed vehicle 11.

[0111] When the determination unit 38 determines that the interruption condition is satisfied, it notifies the interruption instruction unit 39 of the determination result.

[0112] When the interrupt instruction unit 39 receives a determination result from the determination unit 38 that the interrupt condition has been satisfied, it notifies the lane change control unit 37 of an instruction to interrupt the lane change control.

[0113] 9 is an operational flowchart of vehicle control processing according to the second embodiment. When the lane change determination unit 35 determines that lane change control is to be applied, the processor 23 executes vehicle control processing related to lane change control in accordance with the following operational flowchart.

[0114] The towing detection unit 31 of the processor 23 determines whether or not towing of the towed vehicle 11 by the vehicle 10 has been detected (step S201).

[0115] If towing of the towed vehicle 11 is not detected (step S201-No), the determination unit 38 of the processor 23 sets the interruption condition to be relatively strict (step S202). On the other hand, if towing of the towed vehicle 11 is detected (step S201-Yes), the determination unit 38 sets the interruption condition to be relatively lenient (step S203).

[0116] The determination unit 38 of the processor 23 determines whether an interruption condition is satisfied while the lane change control unit 37 of the processor 23 is executing lane change control for the vehicle 10 (step S204). If the interruption condition is not satisfied (step S204-No), the lane change control unit 37 determines whether the movement of the vehicle 10 to the adjacent lane to which the vehicle 10 has changed has been completed (step S205). If the movement of the vehicle 10 to the adjacent lane has been completed (step S205-Yes), the processor 23 ends the vehicle control processing related to the lane change control. On the other hand, if the movement of the vehicle 10 to the adjacent lane has not been completed (step S205-No), the processor 23 repeats the processing from step S204 onwards.

[0117] In step S204, if the interruption condition is satisfied (step S204-Yes), the lane change control unit 37 interrupts the lane change control and controls the vehicle 10 to continue traveling in the own lane (step S206). After that, the processor 23 ends the vehicle control process related to the lane change control.

[0118] As described above, the vehicle control device according to the second embodiment relaxes the conditions for suspending lane change control when towing of the towed vehicle is detected compared to the conditions for suspending lane change control when towing of the towed vehicle is not detected. Therefore, this vehicle control device can suspend lane change control earlier by the amount that the vehicle's behavior becomes sluggish due to towing, and can appropriately set the timing for suspending lane change control to reduce the possibility of contact between the towed vehicle and surrounding vehicles when towing the towed vehicle.

[0119] According to this modification, similar to the modification of the first embodiment, an interruption condition may be set for each situation around the vehicle 10. For example, separate interruption conditions may be set for when the nearby vehicle traveling in the destination adjacent lane is a large vehicle and when the nearby vehicle is a non-large vehicle. However, even in this case, the determination unit 38, regardless of the type of nearby vehicle, relaxes the interruption condition when it is detected that the vehicle 10 is towing a towed vehicle 11 compared to the interruption condition when it is not detected that the vehicle 10 is towing a towed vehicle 11. The determination unit 38 then determines whether to interrupt lane change control based on the interruption condition corresponding to the type of nearby vehicle traveling in the destination adjacent lane detected by the other vehicle detection unit 36. Note that when multiple nearby vehicles traveling in the destination adjacent lane are detected, the determination unit 38 may use the interruption condition corresponding to the type of nearby vehicle closest to the vehicle 10.

[0120] Similarly, the interruption conditions may be individually set depending on the speed of the vehicle 10 when the lane change control is being executed, the speed of surrounding vehicles, the speed of the following vehicle following the vehicle 10, the lane width of the vehicle's own lane or adjacent lanes, the type of adjacent lane (e.g., overtaking lane, driving lane), the time period during which the lane change control is being executed, or the weather. In this case, similar to the modification of the first embodiment, the determination unit 38 may identify the interruption conditions to be used by referring to the speed of the vehicle 10 measured by a vehicle speed sensor, a high-precision map, weather information, or the like. Furthermore, the interruption conditions may be individually set depending on the event that triggered the lane change (e.g., changing lanes to overtake a preceding vehicle, changing lanes to move to a lane leading to a destination, etc.). In this case, the determination unit 38 may receive trigger information indicating the event that triggered the lane change from the lane change determination unit 35, and select the interruption conditions according to the trigger information. However, even in this case, the judgment unit 38 relaxes the interruption conditions when it is detected that the vehicle 10 is towing the towed vehicle 11 more than the interruption conditions when it is not detected that the vehicle 10 is towing the towed vehicle 11.

[0121] According to this modification, the determination unit 38 can appropriately set the interruption condition depending on the situation around the vehicle 10, as well as whether or not the vehicle is being towed.

[0122] Furthermore, the processor 23 may be configured to execute both the vehicle control process according to the first embodiment or its modified example and the vehicle control process according to the second embodiment or its modified example. That is, the processor 23 may have the units shown in Fig. 3 and the units shown in Fig. 7.

[0123] A computer program that realizes the functions of the processor 23 of the ECU 9 according to the above embodiment or variant may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium or an optical recording medium.

[0124] As described above, those skilled in the art can make various modifications to the embodiments within the scope of the present invention. [Explanation of symbols]

[0125] 1. Vehicle control system 10 vehicles 11 Towed vehicle 2 Cameras 3 Driver monitor camera 4 GPS receivers 5. Behavior Sensor 6. Wireless communication terminals 7 Notification device 8 Storage Devices 9 Electronic Control Unit (ECU) 21 Communication Interface 22 Memory 23 processors 31 Traction detection unit 32 Control section 33 Judgment section 34 Notification processing section 35 Lane change judgment unit 36 Other vehicle detection unit 37 Lane change control unit 38 Judgment section 39 Interruption Indicator

Claims

[Claim 1] a towing detection unit that detects that a towed vehicle is being towed when the vehicle is under automatic driving control; a detection unit that detects a relative position and a relative speed of the vehicle and another vehicle traveling in an adjacent lane adjacent to the lane in which the vehicle is traveling; a control unit that executes lane change control of the vehicle to change lanes from the own lane to the adjacent lane when a predetermined condition is satisfied; a determination unit that determines whether an interruption condition is satisfied based on at least one of a change in the relative position and the relative speed between the other vehicle and the vehicle during execution of the lane change control; an interruption instruction unit that causes the control unit to interrupt the lane change control when the interruption condition is satisfied; and the determination unit relaxes the interruption condition when it is detected that the vehicle is towing the towed vehicle more than the interruption condition when it is not detected that the vehicle is towing the towed vehicle. Vehicle control device.

Images