Vehicle control device

Abstract

A vehicle control device (100) is provided with: a sign recognition unit (111) that recognizes a road sign provided forward in the direction of travel in association with the path of travel of a host vehicle; a travel path recognition unit (112) that recognizes a curve on the basis of the curvature of a travel path ahead in the direction of travel; a speed setting unit (113) that sets a target travel speed of the host vehicle; and a travel control unit (114) that controls the actuator (AC) so that the host vehicle travels at the set target travel speed. The speed setting unit (113) sets the target travel speed to a first target travel speed when the vehicle travels on a merging lane where the vehicle merges on the trunk road, and when the vehicle travels on the merging lane where the vehicle travels on the trunk road, the traveling road recognition unit (112) recognizes a curve, and when the vehicle travels on the merging lane, the sign recognition unit (111) recognizes a road sign on the curve, the speed setting unit (113) sets the target travel speed to a second target travel speed. The target travel speed is set to a second target travel speed different from the first target travel speed.

Description

Technical Field

[0001] The present invention relates to a vehicle control device for controlling the travel of a vehicle at a location where a merging lane merges with a main road. Background Art

[0002] As such a device, there is a device that controls the vehicle speed according to the speed limit displayed on a road sign or road surface marking (for example, see Patent Document 1). In the device described in Patent Document 1, the speed limit displayed on the road sign or road surface marking is recognized based on the captured image in front of the vehicle, and the vehicle speed is controlled according to the recognized speed limit.

[0003] However, when a road sign is installed near a merging point where a vehicle merges with a main road of an expressway, it is difficult to determine whether the road sign corresponds to the main road from a captured image. Therefore, if the device described in Patent Document 1 recognizes only the information of the road sign from a captured image, it may not be possible to properly control the vehicle speed near the merging point.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-128790 (JP 2005-128790 A). Summary of the invention

[0007] A vehicle control device according to one technical solution of the present invention comprises: a sign recognition unit that recognizes a road sign provided ahead in the traveling direction in association with a traveling path of the vehicle; a traveling path recognition unit that recognizes the curvature of the traveling path ahead in the traveling direction; a speed setting unit that sets a target traveling speed of the vehicle on the traveling path; a traveling actuator; and a traveling control unit that controls the traveling actuator so that the vehicle travels at the target traveling speed set by the speed setting unit. The traveling path recognition unit recognizes a curve based on the recognized curvature of the traveling path. When the traveling path recognition unit recognizes a curve when the vehicle is traveling in a merging lane merging with a main road, and when the sign recognition unit recognizes a road sign on the curve, the speed setting unit sets the target traveling speed to a first target traveling speed based on the road sign, and when the vehicle enters the main road, the target traveling speed is set to a second target traveling speed different from the first target traveling speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The objects, features and advantages of the present invention will be further clarified through the following description of the embodiments in conjunction with the accompanying drawings.

[0009] Figure 1 This is a block diagram schematically showing a main part configuration of a vehicle control device according to an embodiment of the present invention.

[0010] Figure 2A This is a diagram showing an example of a driving scene of the host vehicle.

[0011] Figure 2B It is shown Figure 2A A graph of the curvature of the merging lane.

[0012] Figure 3 This is a diagram showing another example of the driving scene of the host vehicle.

[0013] Figure 4A This is a diagram showing another example of the driving scene of the host vehicle.

[0014] Figure 4B It is shown Figure 4A A graph of the curvature of the merging lane.

[0015] Figure 5A This is a diagram showing another example of the driving scene of the host vehicle.

[0016] Figure 5B This is a diagram showing another example of the driving scene of the host vehicle.

[0017] Figure 6 It is shown by Figure 1 A flowchart of an example of a process performed by a controller.

[0018] Figure 7 This is a diagram showing another example of the driving scene of the host vehicle. DETAILED DESCRIPTION

[0019] Below, refer to Figures 1 to 7 The embodiments of the present invention are described. The vehicle control device of the embodiments of the present invention can be applied to vehicles with an automatic driving function, that is, automatic driving vehicles. It should be noted that sometimes, the vehicle to which the vehicle control device of the present embodiment is applied is referred to as the present vehicle, as distinguished from other vehicles. The present vehicle can 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 present vehicle can not only travel in an automatic driving mode that does not require the driver's driving operation, but also travel in a manual driving mode in which the driver performs driving operations.

[0020] Figure 1 1 is a block diagram schematically showing the main structure of the vehicle control device 100 according to the embodiment of the present invention. Figure 1 As shown, the vehicle control device 100 includes a controller 10 and a communication unit 1, 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, which are respectively connected to the controller 10 so as to be communicable therewith.

[0021] The communication unit 1 communicates with various servers (not shown) through a network including a wireless communication network represented by the Internet, a mobile phone network, etc., and obtains map information and traffic information from the server regularly or at any time. The network includes not only a public wireless communication network, but also a closed communication network set up in each specified management area, such as a wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), etc. The obtained map information is output to the storage unit 12 and updated at any time.

[0022] 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 positioning sensor 2 uses the received positioning information to determine the current driving position (latitude, longitude, altitude) of the vehicle 101. The positioning sensor 2 is used to detect the position of the vehicle 101. Instead of the positioning sensor 2, a distance detection sensor (radar, laser radar, etc.) that detects the distance from the vehicle 101 to an object (an object set on the road) can also be used to detect the position of the vehicle 101. In this case, the position of the vehicle 101 is detected based on the position information of the object set on the road obtained from the map information stored in the storage unit 12 and the distance information to the object obtained by the positioning sensor 2. As the positioning sensor 2, a sensor that receives a positioning signal and a distance detection sensor can also be used in combination. The vehicle speed sensor 3 detects the vehicle speed of the vehicle 101. The acceleration sensor 7 detects the acceleration (lateral acceleration) of the vehicle 101 in the left and right directions. It should be noted that the acceleration sensor 7 can also detect acceleration in the front-rear direction (longitudinal direction) and the up-down direction (vertical direction) of the host vehicle 101 .

[0023] The camera 4 has a photographing element (image sensor) such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor). The camera 4 may be a single-lens camera or a stereo camera. The camera 4 photographs the surroundings of the vehicle 101. The camera 4 is, for example, installed at a predetermined position in front of the vehicle 101, and continuously photographs the space in front of the vehicle 101 to obtain image data of the object (hereinafter referred to as photographed image data or simply photographed image).

[0024] The input device 5 is a general term for a device that receives input operations from the driver. For example, the input device 5 includes buttons, switches, and a display with a touch panel function that are provided at a predetermined position in the vehicle (eg, a steering wheel or a center console).

[0025] The output device 6 is a general term for a device that outputs information to the driver. For example, the output device 6 includes a display, a speaker, etc. that are installed at a predetermined position in the vehicle and provide information (image information, sound information) to the driver.

[0026] The actuator AC is a driving actuator for controlling the driving of the vehicle 101. When the driving source is an engine, the actuator AC includes a throttle actuator for adjusting the opening of the throttle valve of the engine (throttle opening). When the driving source is a driving motor, the driving motor is included in the actuator AC. The brake actuator for operating the brake device of the vehicle 101 and the steering actuator for driving the steering device are also included in the actuator AC.

[0027] The controller 10 includes an electronic control unit (ECU). More specifically, the controller 10 includes a computer having a computing unit 11 such as a CPU (microprocessor), a storage unit 12 such as a ROM (read-only memory) and a RAM (random access memory), and other peripheral circuits not shown in the figure, such as an I / O interface. It should be noted that although multiple ECUs with different functions, such as an engine control ECU, a travel motor control ECU, and a brake device ECU, can be independently provided, for the sake of convenience, in Figure 1 , the controller 10 is shown as a collection of these ECUs.

[0028] The storage unit 12 stores high-precision detailed map information (referred to as high-precision map information). The high-precision map information includes road location information, road shape information (curvature, etc.), road slope information, intersection or fork location information, lane number information, lane width and each lane location information (lane center location, lane location boundary information), location information of landmarks (signals, buildings, etc.) as marks on the map, road sign information (location, type, restriction information), and road surface contour information such as the unevenness of the road surface. The storage unit 12 also stores various control programs, thresholds used in the programs, and other information.

[0029] The computing unit 11 includes a sign recognition unit 111, a travel path recognition unit 112, a speed setting unit 113, and a travel control unit 114 as functional structures. The sign recognition unit 111 detects road signs included in the shooting range based on the captured image obtained by the camera 4, and specifically detects road signs set in front of the travel direction (toward the travel direction) in association with the travel path of the host vehicle 101. The sign recognition unit 111 recognizes information about the detected road signs based on the captured image, such as information about the type of road signs (warning signs, restriction signs), content, and the position where the road signs are recognized (hereinafter referred to as the recognition position), and stores the recognized information in the storage unit 12. The sign recognition unit 111 can also recognize information about road signs set in front of the travel direction in association with the travel path of the host vehicle 101 from the map information stored in the storage unit 12.

[0030] The travel path recognition unit 112 recognizes the curvature of the travel path ahead of the host vehicle 101 in the direction of travel. Specifically, the travel path recognition unit 112 calculates the curvature of the travel path included in the shooting range based on the captured image obtained by the camera 4. It should be noted that the travel path recognition unit 112 can also calculate the curvature of the travel path based on the yaw rate or yaw angle, pitch rate, pitch angle, roll rate, and roll angle of the host vehicle 101 in the process of travel detected by the vehicle-mounted sensor of the host vehicle 101 (not shown). In addition, the travel path recognition unit 112 can also obtain the curvature of the travel path from the map information stored in the storage unit 12. Furthermore, the travel path recognition unit 112 can also estimate the curvature of the travel path based on the lateral acceleration detected by the acceleration sensor 7 and the vehicle speed detected by the vehicle speed sensor 3. The travel path recognition unit 112 recognizes a curve based on the curvature of the travel path ahead of the host vehicle 101 in the direction of travel.

[0031] Figure 2A 1 is a diagram showing an example of a travel scene of the host vehicle 101 . Figure 2B It is shown Figure 2A Graph of the curvature K of the merging lane AL1. Figure 2A 2 shows a scene in which the host vehicle 101 is traveling in a lane (hereinafter referred to as a merging lane) AL1 merging with a two-lane highway HW. Figure 2A Lanes LN1 and LN2 are the two right lanes of the expressway HW. The merging lane AL1 includes a curve whose curvature changes in a manner that reaches the maximum at position VP, and a straight road (hereinafter also referred to as an acceleration lane) provided so as to be adjacent to the lane LN1 at the front end (deep side in the direction of travel) of the curve. A road sign (speed limit sign) SG11 indicating that the maximum speed limit is 60 km / h is provided at the curve of the merging lane AL1.

[0032] The speed setting unit 113 sets the speed of the vehicle 101 in the following manner: Figure 2AThe target driving speed for the merging lane and the driving path of the expressway shown. When the vehicle 101 is traveling in the merging lane merging into the expressway, the driving path recognition unit 112 recognizes a curve, and when the sign recognition unit 111 recognizes a speed limit sign at the curve, the speed setting unit 113 recognizes that the speed limit sign recognized by the sign recognition unit 111 is applicable to the vehicle 101 traveling in the merging lane (more specifically, the section from the setting position of the speed limit sign to the end position of the acceleration lane). That is, it is recognized that the maximum speed of the vehicle 101 is limited to the speed limit specified by the speed limit sign during the period from the time when the vehicle 101 passes the speed limit sign until it enters the expressway. In addition, the speed setting unit 113 sets the target driving speed of the vehicle 101 to the speed limit specified by the speed limit sign (hereinafter referred to as speed V1). Afterwards, when the curvature K of the driving path identified by the driving path recognition unit 112 is less than a specified value, the speed setting unit 113 determines that the vehicle 101 has entered the acceleration lane at the front end of the curve of the merging lane (the vehicle 101 is about to enter the expressway), and thus sets the target driving speed of the vehicle 101 to a speed V2 that is different from the speed V1. The speed V2 is the target driving speed input via the input device 5 when the user uses an automatic driving function (or a driving assistance function) such as constant speed driving. The storage unit 12 stores information showing the speed V2 (hereinafter referred to as the set speed information). When the user does not input the target driving speed, the speed setting unit 113 can also obtain the speed limit specified by the speed limit sign as the speed V2 based on the speed limit sign identified by the sign recognition unit 111 after the vehicle 101 enters the acceleration lane. It should be noted that the speed limit can also be obtained from the map information stored in the storage unit 12, and sometimes the default limit value of the expressway is also applied.

[0033] Figure 3 , Figure 4A , Figure 4B , Figure 5A as well as Figure 5B This is a diagram showing another example of a travel scene of the host vehicle 101 . Figure 3 Driving scenes and Figure 2A The driving scene is the same as that of the vehicle 101, but the speed limit sign SG2 is set near the end position of the curve, that is, near the start position of the acceleration lane. When the sign recognition unit 111 recognizes a speed limit sign set at the start position of the acceleration lane or within a specified distance from the start position in the traveling direction, the speed setting unit 113 recognizes that the speed limit sign is applicable not only to the vehicle 101 traveling in the merging lane, but also to the vehicle 101 after entering the expressway. That is, not only during the period from when the vehicle 101 passes the speed limit sign until entering the expressway, but also after the vehicle 101 enters the expressway, it is recognized that the maximum speed of the vehicle 101 is limited to the speed limit specified by the speed limit sign.

[0034] Figure 4A 2 shows a scene in which the host vehicle 101 travels in the merging lane AL2 including the first curve (section CI1 to CO1) and the second curve (section CI2 to CO2). Figure 4B It is shown Figure 4A Graph of the curvature K of the merging lane AL2.

[0035] like Figure 4A In the case where the merging lane AL2 shown in the figure includes a straight road DL (section CO1-CI2) with a curvature K less than a specified value, the speed setting unit 113 may mistakenly recognize the straight road DL as an acceleration lane. In this case, the speed setting unit 113 mistakenly recognizes that the speed limit sign SG2 is set near the start position of the acceleration lane. As a result, the speed limit sign SG2 should only apply to the host vehicle 101 traveling in the merging lane AL2, but it will be Figure 3 The same driving scenario is also applicable to the vehicle 101 after entering the highway HW.

[0036] Therefore, the speed setting unit 113 determines that the vehicle 101 has entered the acceleration lane when the curvature K of the driving road ahead in the traveling direction identified by the driving road recognition unit 112 is less than the specified value for a specified distance. The above-mentioned specified distance is set to a value greater than the length of the straight road DL to avoid misidentifying the section where the curvature K is less than the specified value, such as the straight road DL, as the acceleration lane. It should be noted that the speed setting unit 113 can also determine that the vehicle 101 has entered the acceleration lane when the curvature K of the driving road ahead in the traveling direction is less than the specified value for a specified time. In addition, the specified time can also be changed according to the current driving speed of the vehicle 101.

[0037] It should be noted that the travel path recognition unit 112 can also obtain the curvature of the merging lane from the map information stored in the storage unit 12, and recognize the end position of the curve included in the merging lane based on the curvature K. The speed setting unit 113 determines whether the vehicle 101 has entered the acceleration lane based on the end position. For example, when the vehicle 101 passes the end position, the speed setting unit 113 determines that the vehicle 101 has entered the acceleration lane. It should be noted that if Figure 4A As in the example of , when the merging lane AL2 includes a plurality of curves, the travel path recognition unit 112 recognizes the end position of the curve on the deepest 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 the speed V1 to the speed V2.

[0038] Figure 5A FIG. 2 shows a bird's-eye view of a three-dimensional road where the merging lane AL3 merges with the expressway HW. Figure 5B The diagram schematically shows the Figure 5A Observe the lower side of Figure 5A As described above, the speed limit sign SG3 set near the start position of the acceleration lane is generally applicable not only to the vehicle 101 traveling in the merging lane AL3 but also to the vehicle 101 after entering the expressway HW. Figure 5B As shown, when the acceleration lane is a ramp, the speed limit sign SG3 set in the acceleration lane is applicable to the vehicle 101 traveling in the acceleration lane, but not applicable to the vehicle 101 after entering the expressway HW. Therefore, the speed setting unit 113 determines whether the acceleration lane is a ramp when the speed limit sign is recognized by the driving path recognition unit 112 near the start position of the acceleration lane. When the speed setting unit 113 determines that the acceleration lane is a ramp, it recognizes that the speed limit sign is applicable to the vehicle 101 traveling in the merging lane, but not applicable to the vehicle 101 after entering the expressway. It should be noted that when the slope of the acceleration lane is above a specified threshold, the speed setting unit 113 recognizes that the acceleration lane is a ramp. The slope of the acceleration lane is recognized by the driving path recognition unit 112 based on the image captured by the camera 4 or the map information stored in the storage unit 12.

[0039] The travel control unit 114 controls the travel speed of the host vehicle 101 based on the target travel speed set by the speed setting unit 113. Specifically, the travel control unit 114 controls the actuators AC so that the host vehicle 101 travels at the target travel speed set by the speed setting unit 113.

[0040] Figure 6 It is shown by Figure 1 The flowchart is a flowchart of an example of a process executed by the controller 10. The process shown in the flowchart is repeatedly performed in units of predetermined cycles, for example, while the vehicle 101 is traveling in the automatic driving mode.

[0041] like Figure 6As shown, first, in step S1, the current position (current driving position) of the vehicle 101 is obtained based on the positioning information received by the positioning sensor 2 and the map information stored in the storage unit 12. In step S2, the road sign recognition process is performed based on the captured image of the camera 4 or the map information stored in the storage unit 12. In step S3, it is determined whether the speed limit sign is recognized in step S2. When step S3 is affirmative (S3: Yes), in step S5, the flag FLRG is set to 1. The flag FLRG is information that indicates whether the speed limit sign is recognized using 1 (TRUE) and 0 (FALSE), and is stored in the storage unit 12. In step S6, the target driving 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 driving speed of the vehicle 101, and is stored in the storage unit 12. On the other hand, when the decision of step S3 is negative (S3: No), in step S4, the flag FLRG is set to 0, and the process proceeds to step S7.

[0042] In step S7, it is determined whether the vehicle 101 is traveling in the merging lane. When step S7 is affirmative (S7: Yes), in step S8, it is determined whether the curvature of the road ahead in the traveling direction is greater than a specified value based on the image captured by the camera 4 or the map information stored in the storage unit 12. When step S8 is affirmative (S7: Yes), 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 uses 1 (TRUE) and 0 (FALSE) to indicate whether the vehicle 101 has passed the starting position of the curve ( Figure 3 In the example, it is information of location CI). The flag FCO is used to indicate whether the vehicle 101 has passed the end position of the curve after passing the start position of the curve ( Figure 3 In the example of location CO, the marker FC is information indicating whether the vehicle 101 has passed a curve while driving in the merging lane using 1 (TRUE) and 0 (FALSE). It should be noted that the markers FCI, FCO, and FC are stored in the storage unit 12 and are pre-initialized to 0. When step S8 is negative (S8: No), in step S10, it is determined whether the marker FCI is 1. That is, it is determined whether the vehicle 101 has passed the starting position of the curve. When step S10 is negative (S10: No), it is determined that the vehicle 101 is on a straight road (also including Figure 4AWhen the vehicle 101 is traveling on a straight road (such as a straight road between two curves), the process proceeds to step S12. When step S10 is affirmative (S10: Yes), it is determined that the vehicle 101 has passed the end position of the curve after passing the start position of the curve, 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 the flag FLRG is 1. When step S12 is negative (S12: No), the process ends. When step S12 is affirmative (S12: Yes), in step S13, it is determined whether the flag FCO is 1. When step S13 is affirmative (S13: Yes), it is determined that the vehicle 101 has recognized a speed limit sign at the end position of the curve or on the straight road (acceleration lane) on the deep side thereof, and in step S21, the flag FL is set to 0. On the other hand, when step S13 is negative (S13: No), in step S14, it is determined whether the flag FC is 1. When step S14 is affirmative (S14: Yes), it is determined that the vehicle 101 has recognized the speed limit sign while traveling on a curve. In step S16, the flag FL is set to 1 and the processing is terminated. The flag FL is information for adjusting the timing of switching the setting of the target traveling speed of the vehicle 101 from speed V1 to speed V2. When the flag FL is set to 1 (TRUE), the traveling speed control based on speed V1 is performed until the vehicle 101 enters the main road (highway). When the vehicle 101 enters the main road, the target traveling speed of the vehicle 101 is switched from speed V1 to speed V2, and the traveling speed control based on speed V2 is started. On the other hand, when the flag FL is set to 0 (FALSE), the traveling speed control based on speed V1 is continued even after the vehicle 101 enters the main road (highway). On the other hand, when step S14 is negative (S14: No), that is, when the vehicle 101 recognizes the speed limit sign without passing the curve once, in step S15, it is determined whether the lane in which the vehicle 101 is traveling is inclined. When step S15 is positive (S15: Yes), it is determined that the vehicle 101 is in such a way that the lane in which the vehicle 101 is traveling is inclined. Figure 5A and Figure 5B When a speed limit sign is recognized while the vehicle 101 is traveling in the inclined acceleration lane shown in the figure, in step S16, the flag FL is set to 1 and the processing is terminated. On the other hand, when step S15 is negative (S15: No), the processing is terminated. Thus, when a speed limit sign is recognized in the acceleration lane, when the acceleration lane is a ramp, the speed limit sign is only applicable to the vehicle 101 traveling in the acceleration lane. On the other hand, when the acceleration lane where the speed limit sign is recognized is not a ramp, the speed limit sign is applicable not only to the vehicle 101 traveling in the acceleration lane, but also to the vehicle 101 traveling on the highway. It should be noted that the flag FL is initialized to 0 in advance.

[0043] When step S7 is negative (S7: No), that is, when it is determined that the vehicle 101 is traveling on a main road (highway), in step S17, the flags FCI, FC0, and FC are initialized to 0. In step S18, it is determined whether the flag FLRG is 1. When step S18 is positive (S18: Yes), that is, when the vehicle 101 recognizes the speed limit sign while traveling on the main road, the process proceeds to step S21, the flag FL is set to 0, and the process ends. When step S18 is negative (S18: No), in step S19, it is determined whether the flag FL is 1. When step S19 is negative (S19: No), the process proceeds to step S21. When step S19 is positive (S19: Yes), in step S20, after updating the speed limit information SL with the speed V2, the process proceeds to step S21. Thus, when the flag FL is set to 1, when the vehicle 101 enters the main road, the target driving speed of the vehicle 101 is switched from speed V1 to speed V2. It should be noted that, in the determination of step S7, when the curvature of the road ahead in the traveling direction is less than a specified value for a specified distance or a specified time, it can be determined that the vehicle 101 traveling in the acceleration lane is about to enter the main road (highway), and the process proceeds to step S17. Thus, when the vehicle 101 is traveling in the acceleration lane, the target driving speed of the vehicle 101 is switched from speed V1 to speed V2, and the vehicle 101 can smoothly enter the main road.

[0044] The driving control unit 114 performs the Figure 6 More specifically, the travel control unit 114 controls the actuator AC so that the vehicle speed detected by the vehicle speed sensor 3 does not exceed the target travel speed indicated by the speed limit information SL.

[0045] The operation of the vehicle control device 100 according to this embodiment is summarized as follows. Figure 2AIn a driving scenario, when a road sign SG11 set on the driving road ahead in the direction of travel is recognized, the speed limit information SL is updated with the speed limit (speed V1) specified by the road sign SG11 (S1 to S3, S5, S6). In this case, the vehicle control device 100 determines that the speed limit sign SG11 is only applicable to the vehicle 101 traveling in the merging lane (S7, S8, S9, S12, S13, S14, S16). While the curvature of the driving road ahead in the direction of travel is greater than a specified value, that is, while the vehicle 101 is traveling on a curve, the driving speed control based on the speed V1 is continued (S1 to S4, S7, S8, S9, S12). Furthermore, when the vehicle 101 enters the main road, the speed limit information SL is updated with the speed V2 indicated by the set speed information stored in the storage unit 12 (S1 to S4, S7, S17, S18, S19, S20, S21). Thus, the vehicle 101 travels at the speed limit (speed V1) designated by the road sign SG11 until entering the main road, and travels at the target travel speed (speed V2) designated in advance by the user when entering the main road.

[0046] On the other hand, Figure 4A In the driving scenario, when the speed limit sign SG2 set on the straight road DL between the first curve and the second curve of the merging lane AL2 is recognized, the speed limit information SL (S1 to S3, S5, S6) is updated with the speed limit (speed V1) specified by the speed limit sign SG2. Figure 4A In the driving scenario, although the straight road DL is identified in front of the vehicle 101 in the direction of travel, there is a second curve in front of it. Therefore, the vehicle control device 100 determines that the straight road DL is not an acceleration lane, and determines that the speed limit sign SG2 is only applicable to the 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 continues. Afterwards, when the vehicle 101 passes the second curve 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).

[0047] In addition, Figure 3In the driving scenario, when the speed limit sign SG12 set near the starting position of the acceleration lane of the merging lane AL1 is identified, 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). Because the acceleration lane of the merging lane AL1 is not inclined, the vehicle control device 100 determines that the speed limit sign SG12 is not only applicable to the vehicle 101 traveling in the merging lane AL1, but also to the vehicle 101 after entering the highway HW (S7, S8, S10, S11, S12, S13, S21). As a result, the driving speed control based on the speed V1 is continued even after entering the highway HW (S1 to S4, S7, S17, S18, S19, S21). On the other hand, in Figure 5A In the driving scenario, when the speed limit sign SG3 set in the acceleration lane (ramp) of the merging lane AL3 is recognized, the vehicle control device 100 determines that the speed limit sign SG3 is applicable to the vehicle 101 traveling in the acceleration lane, and is not applicable to the vehicle 101 after entering the highway HW (S1 to S3, S5, S6, S7, S8, S10, S12, S13, S14, S15, S16). As a result, the driving speed control based on the speed limit (speed V1) specified by the speed limit sign SG3 is continued until the vehicle 101 enters the highway HW. When the vehicle 101 enters the highway HW, the target driving speed is switched from speed V1 to speed V2, and the driving speed control based on speed V2 is started (S1 to S4, S7, S17, S18, S19, S20, S21).

[0048] According to this embodiment, the following effects can be achieved.

[0049] (1) The vehicle control device 100 includes: a sign recognition unit 111 that recognizes a road sign provided ahead in the traveling direction and associated with the traveling path of the host vehicle 101; a traveling path recognition unit 112 that recognizes the curvature of the traveling path ahead in the traveling direction; a speed setting unit 113 that sets a target traveling speed of the host vehicle 101 on the traveling path; 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 path recognition unit 112 further recognizes a curve based on the recognized curvature of the traveling path. When the vehicle 101 is traveling in a merging lane merging with a main road (highway), the speed setting unit 113 sets the target driving speed to a first target driving speed (speed V1) based on the road sign when the driving path recognition unit 112 recognizes a curve and the sign recognition unit 111 recognizes a road sign on the curve. Then, when the vehicle 101 enters the main road, the target driving speed is set to a second target driving speed (speed V2) different from the speed V1. Thus, even if the merging lane includes a curve, it is possible to enter the main road from the merging lane in a good manner according to the speed limit sign set in the merging lane. As a result, the safety of traffic near the merging point can be improved.

[0050] (2) After the travel path recognition unit 112 recognizes a curve, if the curvature of the curve is less than a specified value for a specified time or a specified distance, the vehicle 101 is judged to be traveling in the acceleration lane, i.e., the vehicle 101 is about to enter the expressway, and the target travel speed is changed from speed V1 to speed V2. In this way, when the vehicle 101 enters the acceleration lane, the travel speed control based on the speed limit sign set in the merging lane can be suppressed. In addition, in the case of Figure 4A In the straight road DL included in the curve (section CI1 to CO2) such as the merging lane AL2, the travel speed control based on the speed limit sign set in the merging lane is prevented from being suppressed.

[0051] (3) The driving path recognition unit 112 also recognizes the slope of the driving path ahead in the traveling direction. When the vehicle 101 is traveling in the merging lane, when the road sign is recognized by the sign recognition unit 111, the speed setting unit 113 determines whether the slope of the driving path recognized by the driving path recognition unit 112 is greater than a predetermined threshold value. When it is determined that the slope is greater than the predetermined threshold value, the target driving speed is changed from speed V1 to speed V2. Figure 5A In this way, even when the acceleration lane is a merging lane with a slope, the travel speed of the host vehicle 101 can be appropriately controlled according to the speed limit sign set in the merging lane.

[0052] The above-mentioned embodiment can be modified into various forms. Several modified examples are described below. In the above-mentioned embodiment, the camera 4 as the shooting unit detects the conditions around (in front of) the vehicle 101, but as long as the conditions around the vehicle 101 are detected, the structure of the vehicle-mounted detector can be in any form. For example, the vehicle-mounted detector can also be a radar or a laser radar. In addition, in the above-mentioned embodiment, the signs and the like contained in the image captured by the camera 4 are detected, but the sign recognition unit can also detect the signs and the like based on the information obtained by the radar or the laser radar.

[0053] In addition, in the above-mentioned embodiment, the travel path recognition unit 112 recognizes the curvature and slope of the travel path ahead in the travel direction. However, the travel path recognition unit may also recognize a toll booth set up on the travel path ahead in the travel direction based on the image captured by the camera 4 or the map information stored in the storage unit 12 and the position of the host vehicle 101 detected by the positioning sensor 2. Figure 7 This is a diagram showing another example of a travel scene of the host vehicle 101 . Figure 7 There is a toll booth TG in the merging lane AL4, and a speed limit sign SG4 is set in front of the toll booth TG in the direction of travel. Figure 7 In the driving scenario, when the speed limit sign SG4 is recognized by the sign recognition unit 111, the speed setting unit 113 determines whether the driving path recognition unit 112 has recognized the toll station TG on the driving path ahead in the driving direction. When the toll station TG is recognized on the driving path ahead in the driving direction, the speed setting unit 113 recognizes that the speed limit sign SG4 is applicable to the vehicle 101 before passing through the toll station TG, and is not applicable to the vehicle 101 after passing through the toll station TG. Furthermore, until the vehicle 101 passes through the toll station TG, the speed setting unit 113 sets the target driving speed to the speed limit (speed V1) specified by the speed limit sign SG4, and when the vehicle 101 passes through the toll station TG, the speed setting unit 113 changes the target driving speed from speed V1 to speed V2.

[0054] In addition, in the above embodiment, Figure 2AIn such a driving scene, when the host vehicle 101 enters the acceleration lane, the speed setting unit 113 sets the target driving speed to the speed V2 indicated by the setting speed information stored in the storage unit 12. In addition, when the setting speed information is not stored in the storage unit 12, the speed setting unit 113 obtains the speed limit specified by the speed limit sign as the speed V2 based on the speed limit sign recognized by the sign recognition unit 111 after the host vehicle 101 enters the acceleration lane. However, sometimes the sign recognition unit 111 cannot recognize the speed limit sign associated with the driving road ahead of the traveling direction of the host vehicle 101 from the captured image of the camera 4 due to the obstruction of the vehicle ahead, etc. In such a case, the speed setting unit 113 cannot obtain the information of the speed V2 and cannot perform the switching of the target driving speed well. Therefore, the speed setting unit can also output the request information (sound information or image information) requesting the input of the command value of the speed V2 to the output device 6, and obtain the command value of the speed V2 input by the user via the input device 5 according to the request. More specifically, when the host 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 traveling road recognized by the traveling road recognition unit 112 is less than the prescribed value for a prescribed time or a prescribed distance and the sign recognition unit 111 does not recognize a new road sign. When the user inputs a command value of the speed V2 via the input device 5 in response to the output of the request information, the speed setting unit changes the target traveling speed from the speed V1 to the speed V2 based on the command value. Thus, even when the setting speed information is not stored in the storage unit 12, the traveling speed control in the acceleration lane can be appropriately performed. It should be noted that the speed setting unit may also obtain information on a speed limit sign associated with the traveling road ahead of the host vehicle 101 in the traveling direction from the map information stored in the storage unit 12 when the curvature of the traveling road recognized by the traveling road recognition unit 112 is less than the prescribed value for a prescribed time or a prescribed distance and the sign recognition unit 111 does not recognize a new road sign, instead of requesting the input of the command value of the speed V2, and obtain the speed limit specified by the speed limit sign as the speed V2. Alternatively, information on the legal speed set for the road ahead in the traveling direction of the host vehicle 101 may be obtained from the map information stored in the storage unit 12, and the legal speed may be obtained as the speed V2.

[0055] In addition, in the above embodiment, the vehicle control device 100 is applied to an autonomous vehicle, but the vehicle control device 100 can also be applied to vehicles other than autonomous vehicles. For example, the vehicle control device 100 can also be applied to a manually driven vehicle equipped with an ADAS (Advanced driver-assistance system).

[0056] In addition, in the above embodiment, the vehicle 101 is shown to be executing the automatic driving mode while traveling. Figure 6 An example of processing, but Figure 6 The processing can also be performed when the vehicle 101 is traveling in the manual driving mode. In this case, the driving control unit 114 performs the following steps according to the above process: Figure 6 The speed limit information SL updated by the processing is controlled together with the actuator AC or instead of the actuator AC to serve as the notification unit. It should be noted that the output device 6 serving as the notification unit can also be controlled together with the actuator AC when driving in the automatic driving mode. That is, the control unit can also control at least one of the notification unit and the driving actuator according to the road signs. For example, the control unit controls the output device 6 (display) so that the speed limit shown by the speed limit information SL is notified to the occupants in the form of images. In addition, for example, the output device 6 (speaker) is controlled so that the speed limit shown by the speed limit information SL is notified to the occupants by sound.

[0057] The above description is merely an example, and the above embodiment and modified examples do not limit the present invention unless the features of the present invention are impaired. One or more of the above embodiment and modified examples can be arbitrarily combined, and the modified examples can be combined with each other.

[0058] According to the present invention, the vehicle speed can be appropriately controlled when traveling near a merging point.

[0059] The present invention has been described above in conjunction with preferred embodiments, but it should be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of the claims.

Claims

1. A vehicle control device, characterized in that: have: A sign recognition unit (111) for recognizing a road sign provided ahead in the traveling direction and associated with the traveling road of the vehicle; A travel path recognition unit (112) for recognizing the curvature of the travel path ahead in the travel direction; A speed setting unit (113) for setting a target travel speed of the host vehicle on the travel path; Actuator for travel (AC); and a travel control unit (114) for controlling the travel actuator (AC) so that the host vehicle travels at the target travel speed set by the speed setting unit (113); The travel path recognition unit (112) further recognizes a curve based on the recognized curvature of the travel path. The speed setting unit (113) sets the target driving speed to a first target driving speed based on the road sign when the driving path recognition unit (112) recognizes the curve when the vehicle is traveling in a merging lane merging into a main road, and when the road sign is recognized by the sign recognition unit (111) at the curve, and sets the target driving speed to a second target driving speed different from the first target driving speed when the vehicle enters the main road.

2. The vehicle control device according to claim 1, characterized in that: When the curvature is less than the specified value for a specified time or a specified distance after the curve is identified by the driving path identification unit (112), the speed setting unit (113) determines that the vehicle has entered the main road and changes the target driving speed from the first target driving speed to the second target driving speed.

3. The vehicle control device according to claim 1, characterized in that: When the vehicle passes the end position of the curve after the travel path recognition unit (112) recognizes the curve, the speed setting unit (113) determines that the vehicle has entered the main road and changes the target travel speed from the first target travel speed to the second target travel speed.

4. The vehicle control device according to claim 3, characterized in that: When the driving path recognition unit (112) recognizes a plurality of the curves, the speed setting unit (113) determines that the vehicle has entered the main road when the vehicle passes the end position of the curve on the deepest side in the direction of travel, and changes the target driving speed from the first target driving speed to the second target driving speed.

5. The vehicle control device according to claim 1, characterized in that: The travel path recognition unit (112) further recognizes a toll booth located on the travel path. When the road sign is recognized by the sign recognition unit (111) while the vehicle is traveling in the merging lane, the speed setting unit (113) sets the target driving speed to the first target driving speed, and determines whether the driving path recognition unit (112) has recognized the toll station. When the driving path recognition unit (112) recognizes the toll station, the target driving speed is changed from the first target driving speed to the second target driving speed when the vehicle passes through the toll station.

6. The vehicle control device according to claim 1, characterized in that: The travel path recognition unit (112) further recognizes the slope of the travel path. The speed setting unit (113) sets the target driving speed to the first target driving speed when the road sign is recognized by the sign recognition unit (111) while the host vehicle is traveling in the merging lane, and determines whether the slope of the driving road recognized by the driving road recognition unit (112) is above a specified threshold value. When it is determined that the slope is above the specified threshold value, the target driving speed is changed from the first target driving speed to the second target driving speed when the host vehicle enters the main road.

7. The vehicle control device according to claim 1, characterized in that: Also available: An input device (5) for inputting instructions from a user; and an output device (6) for outputting request information for inputting a command value of the second target driving speed, The speed setting unit (113) outputs the request information via the output device when the curvature of the driving path identified by the driving path identification unit (112) is less than the specified value for a specified time or a specified distance while the host vehicle is driving in the merging lane, and the sign identification unit (111) does not identify a new road sign. When the command value of the second target traveling speed is input to the input device (5) in response to the output of the request information, the speed setting unit (113) changes the target traveling speed from the first target traveling speed to the second target traveling speed based on the command value.

8. The vehicle control device according to claim 1, characterized in that: It also includes a storage unit (12) for storing map information. The speed setting unit (113) changes the target driving speed from the first target driving speed to the second target driving speed obtained based on the map information stored in the storage unit (12) when the curvature of the driving road is less than the specified value for a specified time or a specified distance while the vehicle is driving in the merging lane and the sign recognition unit (111) does not recognize a new road sign.

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