Vehicle controller

Abstract

To provide a vehicle controller for appropriately controlling vehicle speed when driving near a merging point.SOLUTION: A vehicle controller 100 comprises: a sign recognition unit 111 which recognizes a road sign installed in a forwarding direction in association with a travel path of a self vehicle; a travel path recognition unit 112 which recognizes a curved road on the basis of curvature of the travel path in the forwarding direction; a speed setting unit 113 which sets target traveling speed of the self vehicle; and a traveling control unit 114 which controls an actuator AC so that the self vehicle travels at the set target traveling speed. When the curved road is recognized by the travel path recognition unit 112 while the self vehicle is traveling on a merging lane which merges with a main road and the road sign is recognized by the sign recognition unit 111 on the curved road, the speed setting unit 113 sets the target traveling speed as first target traveling speed. When the self vehicle enters the main road, the speed setting unit sets the target traveling speed as a second target traveling speed different from the first target traveling speed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that controls the traveling of a host vehicle at a point where a merging lane merges into a main lane. [Background technology]

[0002] Conventionally, as this type of device, a device that controls vehicle speed based on the speed limit displayed on road signs or road markings is known (see, for example, Patent Document 1). The device described in Patent Document 1 recognizes the speed limit displayed on the road signs or road markings based on a captured image of the area in front of the vehicle, and controls the vehicle speed based on the recognized speed limit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-128790 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a road sign is installed near a merging point where a vehicle merges with a main line of a highway, it is difficult to determine based on a captured image whether the road sign corresponds to the main line. Therefore, simply recognizing information about the road sign based on a captured image, as in the device described in Patent Document 1, may not adequately control the vehicle speed near the merging point. [Means for solving the problem]

[0005] A vehicle control device according to one aspect of the present invention includes a sign recognition unit that recognizes road signs installed ahead in the traveling direction in association with a traveling path of the host vehicle, a traveling path recognition unit that recognizes a curvature of the traveling path ahead in the traveling direction, a speed setting unit that sets a target traveling speed of the host vehicle on the traveling path, a traveling actuator, and a traveling control unit that controls the traveling actuator so that the host vehicle travels at the target traveling speed set by the speed setting unit. The traveling path recognition unit recognizes a curved road based on the curvature of the recognized traveling path. When the traveling path recognition unit recognizes a curved road while the host vehicle is traveling on a merging lane that merges into a main lane and the sign recognition unit recognizes a road sign on the curved road, the speed setting unit sets the target traveling speed to a first target traveling speed based on the road sign, and when the host vehicle enters the main lane, sets the target traveling speed to a second target traveling speed different from the first target traveling speed. Effect of the Invention

[0006] According to the present invention, it is possible to appropriately control the vehicle speed when traveling near a merging point. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a schematic configuration of a main part of a vehicle control device according to an embodiment of the present invention; [Figure 2A] FIG. 2 is a diagram showing an example of a driving scene of the host vehicle; [Figure 2B] Graph showing the curvature of the merging lane in Figure 2A. [Diagram 3] FIG. 11 is a diagram showing another example of a driving scene of the host vehicle. [Figure 4A] FIG. 11 is a diagram showing another example of a driving scene of the host vehicle. [Figure 4B] Graph showing the curvature of the merging lane in FIG. 4A. [Figure 5A] FIG. 11 is a diagram showing another example of a driving scene of the host vehicle. [Figure 5B] FIG. 11 is a diagram showing another example of a driving scene of the host vehicle. [Figure 6] 4 is a flowchart showing an example of a process executed by a controller in FIG. 1. [Figure 7]FIG. 11 is a diagram showing another example of a driving scene of the host vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 7. A vehicle control device according to an embodiment of the present invention can be applied to a vehicle having an automatic driving function, that is, an automatic driving vehicle. The vehicle to which the vehicle control device according to the present embodiment is applied may be called the host vehicle to distinguish it from other vehicles. The host vehicle may be any of an engine vehicle having an internal combustion engine (engine) as a driving source, an electric vehicle having a driving motor as a driving source, and a hybrid vehicle having an engine and a driving motor as driving sources. The host vehicle can run not only in an automatic driving mode in which no driving operation by the driver is required, but also in a manual driving mode in which the driver operates the vehicle.

[0009] Fig. 1 is a block diagram showing a schematic configuration of a main part of a vehicle control device 100 according to an embodiment of the present invention. As shown in Fig. 1, the vehicle control device 100 includes a controller 10, a communication unit 1 communicatively connected to the controller 10, a positioning sensor 2, a vehicle speed sensor 3, a camera 4, an input device 5, an output device 6, an acceleration sensor 7, and an actuator AC.

[0010] The communication unit 1 communicates with various servers (not shown) via networks including wireless communication networks such as the Internet and mobile phone networks, and acquires map information, traffic information, and the like from the servers periodically or at any timing. Networks include not only public wireless communication networks but also closed communication networks provided for each predetermined management area, such as wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), and the like. The acquired map information is output to the storage unit 12 and updated as needed.

[0011] The positioning sensor 2 receives a positioning signal transmitted from a positioning satellite. The positioning satellite is an artificial satellite such as a GPS satellite or a quasi-zenith satellite. The current traveling position (latitude, longitude, altitude) of the host vehicle 101 is measured using the positioning information received by the positioning sensor 2. The positioning sensor 2 is used to detect the position of the host vehicle 101. Instead of the positioning sensor 2, a distance detection sensor (radar, lidar, etc.) that detects the distance from the host vehicle 101 to an object (an object installed on a road) can also be used to detect the position of the host vehicle 101. In this case, the position of the host vehicle 101 is detected based on the position information of the object installed on the road obtained from the map information stored in the memory unit 12 and the distance information to the object obtained by the positioning sensor 2. As the positioning sensor 2, a combination of receiving a positioning signal and a distance detection sensor may be used. The vehicle speed sensor 3 detects the vehicle speed of the host vehicle 101. The acceleration sensor 7 detects the acceleration in the left-right direction (lateral acceleration) of the host vehicle 101. The acceleration sensor 7 may detect acceleration of the host vehicle 101 in the front-rear direction (longitudinal direction) and the up-down direction (vertical direction).

[0012] The camera 4 has an imaging element (image sensor) such as a CCD or a CMOS. The camera 4 may be a monocular camera or a stereo camera. The camera 4 captures images of the surroundings of the vehicle 101. The camera 4 is attached, for example, to a predetermined position at the front of the vehicle 101, and continuously captures images of the space in front of the vehicle 101 to obtain image data of the object (hereinafter referred to as captured image data or simply captured image).

[0013] The input device 5 is a general term for devices that accept input operations by the driver. For example, the input device 5 includes buttons, switches, displays with touch panel functions, and the like that are installed at predetermined positions in the vehicle (for example, the steering wheel or the center console).

[0014] The output device 6 is a general term for devices that output information to the driver. For example, the output device 6 includes a display and a speaker that are installed in a predetermined position in the vehicle and provide information (image information and audio information) to the driver.

[0015] The actuators AC are driving actuators for controlling the driving of the host vehicle 101. When the driving source for driving is an engine, the actuators AC include a throttle actuator for adjusting the opening degree of a throttle valve (throttle opening degree) of the engine. When the driving source for driving is a driving motor, the actuators AC include the driving motor. The actuators AC also include a brake actuator for operating the braking device of the host vehicle 101 and a steering actuator for driving the steering device.

[0016] The controller 10 is composed of an electronic control unit (ECU). More specifically, the controller 10 includes a computer having an arithmetic unit 11 such as a CPU (microprocessor), a storage unit 12 such as a ROM, a RAM, and other peripheral circuits (not shown) such as an I / O interface. Note that although a plurality of ECUs with different functions, such as an engine control ECU, a travel motor control ECU, and a braking device ECU, can be provided separately, the controller 10 is shown in FIG. 1 as a collection of these ECUs for the sake of convenience.

[0017] The memory unit 12 stores highly accurate, detailed map information (referred to as high-accuracy map information). The high-accuracy map information includes road position information, road shape (curvature, etc.) information, road gradient information, intersection and branch point position information, number of lanes information, lane width and position information for each lane (information on lane center positions and lane position boundary lines), position information of landmarks (traffic lights, buildings, etc.) as markers on the map, road sign information (positions, types, regulation information, etc.), and road surface profile information such as road surface unevenness. The memory unit 12 also stores various control programs, thresholds used in the programs, and other information.

[0018] The calculation unit 11 has, as functional configurations, a sign recognition unit 111, a roadway recognition unit 112, a speed setting unit 113, and a driving control unit 114. The sign recognition unit 111 detects road signs included in an image capture range, specifically, road signs installed ahead in the traveling direction (rear side in the traveling direction) in association with the traveling road of the host vehicle 101, based on the captured image obtained by the camera 4. The sign recognition unit 111 recognizes information on the detected road signs, for example, information on the type (warning sign or regulatory sign) and content of the road sign, and the position where the road sign was recognized (hereinafter referred to as the recognized position), based on the captured image, and stores the recognized information in the storage unit 12. The sign recognition unit 111 may recognize information on the road signs installed ahead in the traveling direction in association with the traveling road of the host vehicle 101, from the map information stored in the storage unit 12.

[0019] The road recognition unit 112 recognizes the curvature of the road ahead of the vehicle 101 in the traveling direction. Specifically, the road recognition unit 112 calculates the curvature of the road included in the imaging range based on the captured image obtained by the camera 4. The road recognition unit 112 may calculate the curvature of the road based on the yaw rate, yaw angle, pitch rate, pitch angle, roll rate, and roll angle of the vehicle 101 during traveling, which are detected by an in-vehicle sensor (not shown) of the vehicle 101. The road recognition unit 112 may also acquire the curvature of the road from map information stored in the storage unit 12. Furthermore, the road recognition unit 112 may estimate the curvature of the road based on the lateral acceleration detected by the acceleration sensor 7 and the vehicle speed detected by the vehicle speed sensor 3. The road recognition unit 112 recognizes a curved road based on the curvature of the road ahead of the vehicle 101 in the traveling direction.

[0020] FIG. 2A is a diagram showing an example of a driving scene of the vehicle 101. FIG. 2B is a graph showing a curvature K of the merging lane AL1 in FIG. 2A. FIG. 2A shows a scene in which the vehicle 101 drives on a lane AL1 (hereinafter referred to as a merging lane) merging into a two-lane expressway HW. The lanes LN1 and LN2 in FIG. 2A are the two lanes on the right side of the expressway HW. The merging lane AL1 includes a curved road whose curvature changes to be maximum at a position VP, and a straight road (hereinafter referred to as an acceleration lane) that is provided adjacent to the lane LN1 beyond the curved road (on the far side in the traveling direction). A road sign (speed limit sign) SG11 indicating that the maximum vehicle speed is limited to 60 km / h is installed on the curved road of the merging lane AL1.

[0021] The speed setting unit 113 sets a target travel speed of the host vehicle 101 on a travel route including a merging lane and an expressway as shown in FIG. 2A. When the host vehicle 101 is traveling on a merging lane merging into an expressway, the travel route recognition unit 112 recognizes a curved road and the sign recognition unit 111 recognizes a speed limit sign on the curved road. The speed setting unit 113 recognizes that the speed limit sign recognized by the sign recognition unit 111 applies to the host vehicle 101 traveling on the merging lane (more specifically, the section from the installation position of the speed limit sign to the end position of the acceleration lane). That is, the speed setting unit 113 recognizes that the maximum vehicle speed of the host vehicle 101 is limited to the speed limit specified by the speed limit sign during the period from when the host vehicle 101 passes the speed limit sign to when the host vehicle 101 enters the expressway. Then, the speed setting unit 113 sets the target travel speed of the host vehicle 101 to the speed limit specified by the speed limit sign (hereinafter referred to as speed V1). Thereafter, when the curvature K of the road recognized by the road recognition unit 112 becomes less than a predetermined value, the speed setting unit 113 determines that the vehicle 101 has entered the acceleration lane beyond the curved road of the merging lane (the vehicle 101 will soon enter the expressway), and sets the target driving speed of the vehicle 101 to a speed V2 different from the speed V1. The speed V2 is a target driving speed input by the user via the input device 5 when using an automatic driving function (or a driving assistance function) such as constant speed driving. The storage unit 12 stores information indicating the speed V2 (hereinafter, referred to as set speed information). When the target driving speed is not input by the user, the speed setting unit 113 may acquire the speed limit designated by the speed limit sign as the speed V2 based on the speed limit sign recognized by the sign recognition unit 111 after the vehicle 101 has entered the acceleration lane. The speed limit may be acquired from map information stored in the storage unit 12, or a default limit value of the highway may be applied.

[0022] 3, 4A, 4B, 5A, and 5B are diagrams showing other examples of driving scenes of the host vehicle 101. The driving scene in FIG. 3 is similar to the driving scene in FIG. 2A, but the speed limit sign SG2 is provided near the end position of the curved road, that is, near the start position of the acceleration lane. When the sign recognition unit 111 recognizes a speed limit sign provided at the start position of the acceleration lane or within a predetermined distance in the traveling direction from the start position, the speed setting unit 113 recognizes that the speed limit sign applies not only to the host vehicle 101 traveling in the merging lane, but also to the host vehicle 101 after entering the expressway. In other words, the speed setting unit 113 recognizes that the maximum vehicle speed of the host vehicle 101 is limited to the speed limit specified by the speed limit sign not only during the period from when the host vehicle 101 passes the speed limit sign until it enters the expressway, but also after the host vehicle 101 enters the expressway.

[0023] Fig. 4A shows a scene in which the host vehicle 101 is traveling on a merging lane AL2 that includes a first curved road (section CI1-CO1) and a second curved road (section CI2-CO2). Fig. 4B is a graph showing a curvature K of the merging lane AL2 in Fig. 4A.

[0024] When a straight road DL (sections CO1-CI2) with a curvature K less than a predetermined value is included, as in the merging lane AL2 shown in FIG. 4A, the speed setting unit 113 may erroneously recognize the straight road DL as an acceleration lane. In that case, the speed setting unit 113 erroneously determines that the speed limit sign SG2 is installed near the start position of the acceleration lane. As a result, the speed limit sign SG2 should only be applied to the host vehicle 101 traveling on the merging lane AL2, but it is also applied to the host vehicle 101 after it has entered the expressway HW, as in the traveling scene of FIG. 3.

[0025] Therefore, the speed setting unit 113 determines that the host vehicle 101 has entered an acceleration lane when the state in which the curvature K of the road ahead in the traveling direction recognized by the road recognition unit 112 is less than a predetermined value continues for a predetermined distance. The above-mentioned predetermined distance is set to a value larger than the length of the straight road DL so as not to erroneously recognize a section in which the curvature K is less than the predetermined value, such as a straight road DL, as an acceleration lane. The speed setting unit 113 may determine that the host vehicle 101 has entered an acceleration lane when the state in which the curvature K of the road ahead in the traveling direction is less than the predetermined value continues for a predetermined time. Moreover, this predetermined time may be changed depending on the current traveling speed of the host vehicle 101.

[0026] The travel path recognition unit 112 may obtain the curvature of the merging lane from the map information stored in the memory unit 12, and recognize the end position of the curved road included in the merging lane based on the curvature K, and the speed setting unit 113 may determine whether the host vehicle 101 has entered the acceleration lane based on the end position. When the merging lane AL2 includes multiple curved roads as in the example of FIG. 4A, the travel path recognition unit 112 recognizes the end position of the curved road at the innermost side in the traveling direction. When the speed setting unit 113 determines that the host vehicle 101 has entered the acceleration lane, it switches the target travel speed of the host vehicle 101 from speed V1 to speed V2.

[0027] FIG. 5A shows an overhead view of a multi-level road where a merging lane AL3 merges with an expressway HW, and FIG. 5B shows a schematic diagram of the multi-level road in FIG. 5A as seen from the right side (the lower side of FIG. 5A). As described above, the speed limit sign SG3 installed near the start position of the acceleration lane is usually applied not only to the host vehicle 101 traveling on the merging lane AL3, but also to the host vehicle 101 after entering the expressway HW. However, when the acceleration lane is a slope as shown in FIG. 5B, the speed limit sign SG3 installed in the acceleration lane is applied to the host vehicle 101 traveling on the acceleration lane, but is not applied to the host vehicle 101 after entering the expressway HW. Therefore, when the roadway recognition unit 112 recognizes a speed limit sign near the start position of the acceleration lane, the speed setting unit 113 determines whether the acceleration lane is a slope. When the speed setting unit 113 determines that the acceleration lane is a slope, it recognizes that the speed limit sign applies to the host vehicle 101 traveling in the merging lane and does not apply to the host vehicle 101 after entering the expressway. Note that the speed setting unit 113 recognizes that the acceleration lane is a slope when the gradient of the acceleration lane is equal to or greater than a predetermined threshold. The gradient of the acceleration lane is recognized by the roadway recognition unit 112 based on the image captured by the camera 4 or the map information stored in the memory unit 12.

[0028] The traveling control unit 114 controls the traveling speed of the host vehicle 101 based on the target traveling speed set by the speed setting unit 113. Specifically, the traveling control unit 114 controls the actuator AC so that the host vehicle 101 travels at the target traveling speed set by the speed setting unit 113.

[0029] Fig. 6 is a flowchart showing an example of a process executed by the controller 10 of Fig. 1. The process shown in this flowchart is repeated at predetermined intervals while the host vehicle 101 is traveling in the autonomous driving mode, for example.

[0030] As shown in FIG. 6, first, in step S1, the current position (current traveling position) of the vehicle 101 is acquired based on the positioning information received by the positioning sensor 2 and the map information stored in the memory unit 12. In step S2, a road sign recognition process is performed based on the image captured by the camera 4 or the map information stored in the memory unit 12. In step S3, it is determined whether or not a speed limit sign was recognized in step S2. If the result in step S3 is affirmative, in step S5, a flag FLRG is set to 1. The flag FLRG is information indicating whether or not a speed limit sign was recognized with 1 (TRUE) or 0 (FALSE), and is stored in the memory unit 12. In step S6, the target traveling speed is set to the speed limit (speed V1) specified by the speed limit sign recognized in step S2. Specifically, the speed limit information SL is updated with the speed V1. The speed limit information SL is information indicating the target traveling speed of the vehicle 101, and is stored in the memory unit 12. On the other hand, if the result in step S3 is NO, the flag FLRG is set to 0 in step S4, and the process proceeds to step S7.

[0031] In step S7, it is determined whether the vehicle 101 is traveling on a merging lane. If the result in step S7 is positive, it is determined in step S8 whether the curvature of the road ahead in the traveling direction is equal to or greater than a predetermined value based on the image captured by the camera 4 or the map information stored in the storage unit 12. If the result in step S8 is positive, in step S9, the flag FCI is set to 1, the flag FCO is set to 0, and the flag FC is set to 1. The flag FCI is information that indicates whether the vehicle 101 has passed the start position of a curved road (point CI in the example of FIG. 3) with 1 (TRUE) or 0 (FALSE). The flag FCO is information that indicates whether the vehicle 101 has passed the end position of the curved road (point CO in the example of FIG. 3) after passing the start position of the curved road with 1 (TRUE) or 0 (FALSE). The flag FC is information that indicates whether the vehicle 101 has passed the end position of the curved road while traveling on the merging lane with 1 (TRUE) or 0 (FALSE). The flags FCI, FCO, and FC are stored in the storage unit 12 and are initialized to 0 in advance. If the result in step S8 is negative, then in step S10, it is determined whether or not the flag FCI is 1. That is, it is determined whether or not the host vehicle 101 has passed the start position of a curved road. If the result in step S10 is negative, then it is determined that the host vehicle 101 is traveling on a straight road (including a straight road between curved roads as shown in FIG. 4A), and the process proceeds to step S12. If the result in step S10 is positive, then it is determined that the host vehicle 101 has passed the start position of a curved road and then passed the end position of the curved road, and in step S11, the flag FCO is set to 1. At this time, the flag FCI is initialized to 0. Next, in step S12, it is determined whether or not the flag FLRG is 1. If the result in step S12 is negative, then it is determined whether or not the flag FCO is 1 in step S13. If the result in step S13 is positive, it is determined that the vehicle 101 recognized a speed limit sign at the end of the curved road or on the straight road (acceleration lane) behind it, and in step S21, the flag FL is set to 0. On the other hand, if the result in step S13 is negative, in step S14, it is determined whether the flag FC is 1. If the result in step S14 is positive, it is determined that a speed limit sign was recognized while the vehicle 101 was traveling on a curved road, and in step S16, the flag FL is set to 1, and the process ends.The flag FL is information for adjusting the timing at which the setting of the target traveling speed of the host vehicle 101 is switched from the speed V1 to the speed V2. When the flag FL is set to 1 (TRUE), the traveling speed control based on the speed V1 is performed until the host vehicle 101 enters the main line (expressway), and when the host vehicle 101 enters the main line, the target traveling speed of the host vehicle 101 is switched from the speed V1 to the speed V2, and the traveling speed control based on the speed V2 is started. On the other hand, when the flag FL is set to 0 (FALSE), the traveling speed control based on the speed V1 is continued even after the host vehicle 101 enters the main line (expressway). On the other hand, when the result in step S14 is negative, that is, when a speed limit sign is recognized in a state in which the host vehicle 101 has not passed a curved road even once, it is determined in step S15 whether the lane in which the host vehicle 101 is traveling is inclined. If the result in step S15 is YES, it is determined that a speed limit sign has been recognized while the vehicle 101 is traveling in an inclined acceleration lane as shown in FIG. 5A and FIG. 5B, and the flag FL is set to 1 in step S16, and the process is terminated. On the other hand, if the result in step S15 is NO, the process is terminated. As a result, when a speed limit sign has been recognized in the acceleration lane, if the acceleration lane is a slope, the speed limit sign is applied only to the vehicle 101 traveling in the acceleration lane. On the other hand, if the acceleration lane in which the speed limit sign has been recognized is not a slope, the speed limit sign is applied not only to the vehicle 101 traveling in the acceleration lane, but also to the vehicle 101 traveling on the expressway. The flag FL is initialized to 0 in advance.

[0032] If the result in step S7 is negative, that is, if it is determined that the host vehicle 101 is traveling on a main line (expressway), then in step S17, the flags FCI, FC0, and FC are initialized to 0. In step S18, it is determined whether or not the flag FLRG is 1. If the result in step S18 is positive, that is, if a speed limit sign is recognized while the host vehicle 101 is traveling on the main line, then the process proceeds to step S21, where the flag FL is set to 0 and the process ends. If the result in step S18 is negative, then in step S19, it is determined whether or not the flag FL is 1. If the result in step S19 is negative, then the process proceeds to step S21. If the result in step S19 is positive, then in step S20, the speed limit information SL is updated with the speed V2, and then the process proceeds to step S21. In this way, when the flag FL is set to 1, the target traveling speed of the host vehicle 101 is switched from the speed V1 to the speed V2 when the host vehicle 101 enters the main line. In addition, when the determination in step S7 indicates that the curvature of the road ahead in the traveling direction is less than a predetermined value for a predetermined distance or a predetermined time, it may be determined that the host vehicle 101 traveling in the acceleration lane will soon enter the main lane (expressway), and the process may proceed to step S17. As a result, while the host vehicle 101 is traveling in the acceleration lane, the target traveling speed of the host vehicle 101 is switched from speed V1 to speed V2, and the host vehicle 101 can smoothly enter the main lane.

[0033] The traveling control unit 114 controls the actuator AC based on the speed limit information SL that is updated by repeatedly executing the process of Fig. 6. More specifically, the traveling control unit 114 controls the actuator AC so that the vehicle speed detected by the vehicle speed sensor 3 does not exceed the target traveling speed indicated by the speed limit information SL.

[0034] The operation of the vehicle control device 100 according to this embodiment can be summarized as follows. In the driving scene of FIG. 2A, when a road sign SG11 installed on the road ahead in the traveling direction is recognized, the speed limit information SL is updated with the speed limit (speed V1) designated by the road sign SG11 (S1 to S3, S5, S6). In this case, the vehicle control device 100 judges that the speed limit sign SG11 applies only to the host vehicle 101 traveling on the merging lane (S7, S8, S9, S12, S13, S14, S16). While the curvature of the road ahead in the traveling direction is equal to or greater than a predetermined value, that is, while the host vehicle 101 is traveling on a curved road, the traveling speed control based on the speed V1 is continued (S1 to S4, S7, S8, S9, S12). Then, when the host vehicle 101 enters the main line, the speed limit information SL is updated to the speed V2 indicated by the set speed information stored in the storage unit 12 (S1 to S4, S7, S17, S18, S19, S20, S21). As a result, the host vehicle 101 travels at the speed limit (speed V1) specified by the road sign SG11 until entering the main line, and when entering the main line, travels according to the target travel speed (speed V2) commanded in advance by the user.

[0035] On the other hand, in the driving scene of Fig. 4A, when a speed limit sign SG2 installed on a straight road DL between the first curve road and the second curve road of the merging lane AL2 is recognized, the speed limit information SL is updated with the speed limit (speed V1) specified by the speed limit sign SG2 (S1 to S3, S5, S6). In the driving scene of Fig. 4A, a straight road DL is recognized ahead of the host vehicle 101 in the traveling direction, but a second curve road exists ahead of it, so the vehicle control device 100 determines that the straight road DL is not an acceleration lane, and determines that the speed limit sign SG2 applies only to the host vehicle 101 traveling in the merging lane (S7, S8, S10, S12, S13, S14, S16). As a result, the driving speed control based on the speed V1 is continued. Thereafter, when the vehicle 101 passes through the second curved road and enters the main road, the speed limit information SL is updated with the speed V2 (S1 to S4, S7, S17, S18, S19, S20, S21).

[0036] 3, when a speed limit sign SG12 installed near the start position of the acceleration lane of the merging lane AL1 is recognized, the speed limit information SL is updated with the speed limit (speed V1) specified by the speed limit sign SG12 (S1 to S3, S5, S6). Since the acceleration lane of the merging lane AL1 is not inclined, the vehicle control device 100 determines that the speed limit sign SG12 applies not only to the host vehicle 101 traveling on the merging lane AL1, but also to the host vehicle 101 after entering the expressway HW (S7, S8, S10, S11, S12, S13, S21). As a result, the traveling speed control based on the speed V1 continues even after entering the expressway HW (S1 to S4, S7, S17, S18, S19, S21). On the other hand, in the traveling scene of Fig. 5A, when the speed limit sign SG3 installed in the acceleration lane (slope) of the merging lane AL3 is recognized, the vehicle control device 100 judges that the speed limit sign SG3 applies to the host vehicle 101 traveling in the acceleration lane, and does not apply to the host vehicle 101 after entering the expressway HW (S1 to S3, S5, S6, S7, S8, S10, S12, S13, S14, S15, S16). As a result, the traveling speed control based on the speed limit (speed V1) specified by the speed limit sign SG3 is continued until the host vehicle 101 enters the expressway HW. When the host vehicle 101 enters the expressway HW, the target traveling speed is switched from speed V1 to speed V2, and the traveling speed control based on speed V2 is started (S1 to S4, S7, S17, S18, S19, S20, S21).

[0037] According to this embodiment, the following advantageous effects can be obtained. (1) The vehicle control device 100 includes a sign recognition unit 111 that recognizes road signs installed ahead in the traveling direction in association with the traveling road of the host vehicle 101, a traveling road recognition unit 112 that recognizes the curvature of the traveling road ahead in the traveling direction, a speed setting unit 113 that sets a target traveling speed of the host vehicle 101 on the traveling road, an actuator AC, and a traveling control unit 114 that controls the actuator AC so that the host vehicle 101 travels at the target traveling speed set by the speed setting unit 113. The traveling road recognition unit 112 further recognizes a curved road based on the curvature of the recognized traveling road. When the vehicle 101 is traveling on a merging lane merging into a main lane (expressway), the travel lane recognition unit 112 recognizes a curved road and the sign recognition unit 111 recognizes a road sign on the curved road, the speed setting unit 113 sets the target travel speed to a first target travel speed (speed V1) based on the road sign, and then, when the vehicle 101 enters the main lane, sets the target travel speed to a second target travel speed (speed V2) different from speed V1. This allows the vehicle 101 to smoothly enter the main lane from the merging lane according to the speed limit sign installed on the merging lane, even if the merging lane includes a curved road. As a result, the safety of traffic near the merging point can be improved.

[0038] (2) After the travel path recognition unit 112 recognizes a curved road, if the state where the curvature of the road is less than a predetermined value continues for a predetermined time or distance, the travel path recognition unit 112 determines that the vehicle 101 is traveling in the acceleration lane, that is, the vehicle 101 will soon enter an expressway, and changes the target travel speed from speed V1 to speed V2. This makes it possible to suppress travel speed control based on a speed limit sign installed in a merging lane when the vehicle 101 enters the acceleration lane. In addition, it is possible to prevent suppression of travel speed control based on a speed limit sign installed in a merging lane on a straight road DL included in a curved road (sections CI1 to CO2) such as the merging lane AL2 in FIG. 4A.

[0039] (3) The travel path recognition unit 112 further recognizes the gradient of the travel path ahead in the traveling direction. When the sign recognition unit 111 recognizes a road sign while the host vehicle 101 is traveling on the merging lane, the speed setting unit 113 determines whether the gradient of the travel path recognized by the travel path recognition unit 112 is equal to or greater than a predetermined threshold, and when it is determined that the gradient is equal to or greater than the predetermined threshold, changes the target travel speed from speed V1 to speed V2. This makes it possible to appropriately control the travel speed of the host vehicle 101 in accordance with the speed limit sign installed on the merging lane, even in a merging lane where the acceleration lane is a slope as shown in FIG. 5A.

[0040] The above embodiment can be modified in various ways. Some modified examples will be described below. In the above embodiment, the camera 4 as an imaging unit is used to detect the surroundings (forward) of the vehicle 101, but the in-vehicle detector may have any configuration as long as it detects the surroundings of the vehicle 101. For example, the in-vehicle detector may be a radar or a lidar. In the above embodiment, signs and the like included in the image captured by the camera 4 are detected, but the sign recognition unit may detect signs and the like based on information obtained by the radar or the lidar.

[0041] In the above embodiment, the roadway recognition unit 112 recognizes the curvature and gradient of the roadway ahead in the traveling direction. However, the roadway recognition unit may recognize a toll gate installed on the roadway ahead in the traveling direction based on the captured image of the camera 4, or the map information stored in the storage unit 12 and the position of the vehicle 101 detected by the positioning sensor 2. FIG. 7 is a diagram showing another example of a traveling scene of the vehicle 101. In FIG. 7, a toll gate TG is provided on the merging lane AL4, and a speed limit sign SG4 is installed on the front side of the toll gate TG in the traveling direction. In the traveling scene of FIG. 7, when the sign recognition unit 111 recognizes the speed limit sign SG4, the speed setting unit 113 determines whether or not the toll gate TG is recognized on the roadway ahead in the traveling direction by the roadway recognition unit 112. When a toll gate TG is recognized on the road ahead in the traveling direction, the speed setting unit 113 recognizes that the speed limit sign SG4 applies to the host vehicle 101 before passing through the toll gate TG, but does not apply to the host vehicle 101 after passing through the toll gate TG. Then, the speed setting unit 113 sets the target traveling speed to the speed limit (speed V1) specified by the speed limit sign SG4 until the host vehicle 101 passes through the toll gate TG, and when the host vehicle 101 passes through the toll gate TG, changes the target traveling speed from speed V1 to speed V2.

[0042] In the above embodiment, when the vehicle 101 enters the acceleration lane in a driving scene such as that shown in FIG. 2A, the speed setting unit 113 sets the target driving speed to the speed V2 indicated by the set speed information stored in the storage unit 12. When the set speed information is not stored in the storage unit 12, the speed setting unit 113 acquires the speed limit designated by the speed limit sign recognized by the sign recognition unit 111 as the speed V2 after the vehicle 101 enters the acceleration lane. However, due to occlusion by a vehicle ahead, the sign recognition unit 111 may not be able to recognize the speed limit sign associated with the road ahead of the vehicle 101 in the traveling direction from the captured image of the camera 4. In such a case, the speed setting unit 113 cannot acquire the information on the speed V2, and is unable to switch the target driving speed well. Therefore, the speed setting unit may output request information (audio information or image information) requesting input of a command value of the speed V2 to the output device 6, and acquire the command value of the speed V2 input by the user via the input device 5 in response to the request. More specifically, when the vehicle 101 is traveling in the merging lane, the speed setting unit outputs the request information via the output device 6 when the curvature of the travel lane recognized by the travel lane recognition unit 112 is less than a predetermined value for a predetermined time or distance and no new road sign is recognized by the sign recognition unit 111. When the command value of the speed V2 is input by the user via the input device 5 in response to the output of the request information, the speed setting unit changes the target travel speed from the speed V1 to the speed V2 based on the command value. This makes it possible to appropriately perform travel speed control in the acceleration lane even when the set speed information is not stored in the storage unit 12. In addition, when the curvature of the road recognized by the road recognition unit 112 remains less than a predetermined value for a predetermined time or distance and no new road signs are recognized by the sign recognition unit 111, instead of requesting input of a command value for speed V2, the speed setting unit may obtain information about a speed limit sign associated with the road ahead in the direction of travel of the vehicle 101 from the map information stored in the memory unit 12, and obtain the speed limit specified by the speed limit sign as speed V2.Alternatively, information on the legal speed limit set for the road ahead in the traveling direction of the vehicle 101 may be obtained from the map information stored in the memory unit 12, and the legal speed limit may be obtained as the speed V2.

[0043] In the above embodiment, the vehicle control device 100 is applied to an autonomous vehicle, but the vehicle control device 100 can be applied to vehicles other than autonomous vehicles. For example, the vehicle control device 100 can be applied to a manually driven vehicle equipped with an ADAS (Advanced driver-assistance systems).

[0044] Further, in the above embodiment, an example in which the process of FIG. 6 is executed while the vehicle 101 is traveling in the automatic driving mode has been shown, but the process of FIG. 6 may be executed while the vehicle 101 is traveling in the manual driving mode. In that case, the traveling control unit 114 controls the output device 6 as the notification unit together with the actuator AC or instead of the actuator AC based on the speed limit information SL that is updated by repeatedly executing the process of FIG. 6. Note that the output device 6 as the notification unit may be controlled together with the actuator AC while traveling in the automatic driving mode. That is, the control unit may control at least one of the notification unit and the traveling actuator based on a road sign. For example, the control unit controls the output device 6 (display) so that the speed limit indicated by the speed limit information SL is notified to the occupant by an image. Also, for example, the control unit controls the output device 6 (speaker) so that the speed limit indicated by the speed limit information SL is notified to the occupant by voice.

[0045] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. The above-mentioned embodiment and one or more modifications can be arbitrarily combined, and modifications can be combined with each other. [Explanation of symbols]

[0046] 1 communication unit, 2 positioning sensor, 3 vehicle speed sensor, 4 camera, 5 input device, 6 output device, 7 acceleration sensor, 10 controller, 11 calculation unit, 12 memory unit, 100 vehicle control device, 111 sign recognition unit, 112 road recognition unit, 113 speed setting unit, 114 driving control unit, AC actuator

Claims

1. a sign recognition unit that recognizes road signs installed ahead in the traveling direction of the host vehicle in association with the traveling route of the host vehicle; A roadway recognition unit that recognizes a curvature of the roadway ahead in the traveling direction; a speed setting unit that sets a target travel speed of the host vehicle on the travel route; A traveling actuator; a travel control unit that controls the travel actuator so that the host vehicle travels at the target travel speed set by the speed setting unit, The roadway recognition unit further recognizes a curved road based on the curvature of the recognized roadway, a speed setting unit that sets the target traveling speed to a first target traveling speed based on the road sign when the traveling path recognition unit recognizes the curved road while the vehicle is traveling on a merging lane merging into a main road and the sign recognition unit recognizes the road sign on the curved road, and that sets the target traveling speed to a second target traveling speed different from the first target traveling speed when the vehicle enters the main road.

2. 2. The vehicle control device according to claim 1, The vehicle control device is characterized in that, after the curved road is recognized by the roadway recognition unit, when the state in which the curvature is less than the specified value continues for a specified time or distance, the speed setting unit determines that the vehicle will enter the main line, and changes the target driving speed from the first target driving speed to the second target driving speed.

3. 2. The vehicle control device according to claim 1, The roadway recognition unit further recognizes a toll booth installed on the roadway, a speed setting unit that sets the target traveling speed to the first target traveling speed when the sign recognition unit recognizes the road sign while the host vehicle is traveling in the merging lane, determines whether the toll gate has been recognized by the traveling path recognition unit, and changes the target traveling speed from the first target traveling speed to the second target traveling speed when the host vehicle passes through the toll gate when the toll gate has been recognized by the traveling path recognition unit.

4. 2. The vehicle control device according to claim 1, The roadway recognition unit further recognizes a gradient of the roadway, a speed setting unit that sets the target traveling speed to the first target traveling speed when the sign recognition unit recognizes the road sign while the vehicle is traveling on the merging lane, and determines whether a gradient of the traveling road recognized by the traveling road recognition unit is equal to or greater than a predetermined threshold, and when it is determined that the gradient is equal to or greater than the predetermined threshold, changes the target traveling speed from the first target traveling speed to the second target traveling speed when the vehicle enters the main lane.

5. 2. The vehicle control device according to claim 1, an input device for inputting commands from a user; an output device that outputs request information requesting input of a command value of the second target traveling speed, The speed setting unit is outputting the request information via the output device when, while the host vehicle is traveling on the merging lane, a state in which the curvature of the road recognized by the road recognition unit is less than the predetermined value continues for a predetermined time or a predetermined distance and a new road sign is not recognized by the sign recognition unit; a command value for the second target driving speed being input to the input device in response to the output of the request information, the target driving speed being changed from the first target driving speed to the second target driving speed based on the command value.

6. 2. The vehicle control device according to claim 1, Further comprising a storage unit for storing map information; the speed setting unit changes the target traveling speed from the first target traveling speed to the second target traveling speed obtained based on the map information stored in the memory unit when, while the vehicle is traveling in the merging lane, the curvature of the traveling road remains less than the predetermined value for a predetermined time or a predetermined distance and no new road sign is recognized by the sign recognition unit.

Images