Vehicle control device and vehicle control method

Abstract

This vehicle control device is equipped with a signal recognition unit for recognizing the lighting state of a main light of a signal and the direction of permitted movement by an arrow light of the signal on the basis of an image captured by a camera which recognizes the peripheral environment around a vehicle, and is also equipped with a travel control unit for executing: a stopping-time deceleration control for starting a deceleration control, to be executed when stopping at a stop line, from a stopping deceleration start position, on the basis of it being possible, based on the recognition results from the signal recognition unit, to determine that the red light, which is one color of the main light, is displayed; and a primary deceleration control for decelerating at a deceleration rate which is more gradual than is the deceleration rate for the stopping-time deceleration control, from a location which is farther from the stop line than is the stopping deceleration start position, when primary control conditions are satisfied in which it is possible to determine that the red light is displayed but it is not possible to determine whether the arrow light is displayed or not on the basis of the recognition results from the signal recognition unit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2021-146929 filed in Japan on September 9, 2021, and the contents of the original application are incorporated by reference in their entirety. [Technical Field]

[0002] The present invention relates to a vehicle control device and a vehicle control method, and in particular to a technology for controlling speed in accordance with the lighting state of a traffic light. [Background technology]

[0003] Patent Document 1 discloses a driving assistance device that can accelerate the timing of assistance and reduce inconvenience to occupants in driving assistance based on the recognition result of an arrow traffic light. This driving assistance device executes a first assistance control as deceleration control when it can recognize that the red light is on but cannot recognize that the arrow signal is on. Furthermore, this driving assistance device executes a second assistance control that decelerates the vehicle at a slower deceleration than the first assistance control when it can recognize that the red light is on and that the arrow signal is on but cannot recognize the direction of the arrow signal.

[0004] By executing the second assist control, the direction of the arrow signal can be recognized, and the change in acceleration can be reduced when it is determined that deceleration control was unnecessary, thereby reducing the inconvenience to the occupants. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-76899 Summary of the Invention

[0006] The position where the arrow signal (hereinafter referred to as the arrow light) becomes visible is often closer to the traffic light than the position where the main light becomes visible. Therefore, the second assistance control is often executed later than the point where it is not possible to recognize whether the arrow light is on but it is possible to recognize that the main light is red. If the start of the second assistance control is delayed, it may be necessary to increase the deceleration rate in order to be able to stop at the stop line. If the deceleration rate of the second assistance control is increased, there is a possibility that the acceleration change will be large even if deceleration control is not necessary. As a result, it becomes difficult to prevent the occupants from being annoyed.

[0007] The present disclosure has been made based on this situation, and its purpose is to provide a vehicle control device and a vehicle control method that can start deceleration early while minimizing discomfort felt by occupants when a red light is on.

[0008] The above object is achieved by the combination of features recited in the independent claims, and the subclaims define further advantageous specific examples. The reference numerals in parentheses in the claims correspond to specific aspects described in the following embodiments as one aspect, and do not limit the technical scope of the disclosure.

[0009] One disclosure related to a vehicle control device for achieving the above object is: A vehicle control device that controls the speed of a vehicle, a signal recognition unit that recognizes the lighting state of the main lights of the traffic signals and the permitted direction of travel indicated by the arrow lights of the traffic signals based on an image captured by a camera that recognizes the surrounding environment of the vehicle; This vehicle control device is equipped with a stop deceleration control that starts deceleration control to stop at a stop line from a stop deceleration start position based on the recognition result of the signal recognition unit that it can be determined that a red light, which is one of the main lights, is on, and a travel control unit that executes primary deceleration control to decelerate at a slower deceleration rate than the stop deceleration control from a position farther from the stop line than the stop deceleration start position when a primary control condition is met, the recognition result of the signal recognition unit being that it can be determined that a red light, which is one of the main lights, is on but it cannot be determined whether a red light is on.

[0010] One disclosure relating to a vehicle control method for achieving the above object is: A vehicle control method for controlling a speed of a vehicle, comprising: Based on an image captured by a camera that recognizes the vehicle's surrounding environment, the system recognizes the lighting status of the traffic light's main lights and the permitted direction of travel indicated by the traffic light's arrow lights, This vehicle control method executes stop deceleration control, which starts deceleration control to stop at a stop line from the stop deceleration start position based on the fact that the recognition results indicate that a red light, which is one of the main lights, is on, and primary deceleration control, which decelerates at a slower deceleration rate than the stop deceleration control, from a position farther from the stop line than the stop deceleration start position when a primary control condition is met, the fact that the recognition results indicate that a red light, which is one of the main lights, is on but it is not possible to determine whether the arrow light is on.

[0011] According to this vehicle control device and vehicle control method, primary deceleration control, which is slower deceleration than deceleration by stop deceleration control, is started from a position farther from the stop line than the stop deceleration start position. One of the primary control conditions for starting primary deceleration control is that it can be determined that the red light is on, but it cannot be determined whether the arrow light is on.

[0012] The position where the main light becomes visible is often farther from the traffic light than the position where the arrow light becomes visible. In Patent Document 1, the condition for executing the second assist control is that not only the main light but also the arrow light be visible. Therefore, this vehicle control device can often start the primary deceleration control earlier than the second assist control in Patent Document 1. This makes it possible to make the deceleration in the primary deceleration control gentler. This makes it less likely that the occupants will feel uncomfortable. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing the configuration of a vehicle control device 10. [Figure 2] FIG. [Figure 3] FIG. 4 is a diagram showing a process executed by a travel control unit 73 in the first embodiment. [Figure 4] FIG. 4 is a diagram showing detailed processing of S11 in FIG. 3. [Figure 5] 10 is a diagram showing a change in speed when a vehicle 5 travels in a straight lane and stops at a stop line 92. FIG. [Figure 6] 10 is a diagram showing the speed change when a vehicle 5 travels in a left turn lane and stops at a stop line 92. FIG. [Figure 7] 10 is a diagram showing the speed change when a vehicle 5 travels in a right-turn lane and stops at a stop line 92. FIG. [Figure 8] 4 is a diagram showing a change in speed when a vehicle 5 passes through an intersection going straight. [Figure 9] 10 is a diagram showing the change in speed when a vehicle 5 turns left and passes through an intersection. [Figure 10] 10 is a diagram showing the change in speed when a vehicle 5 turns right and passes through an intersection. [Figure 11] FIG. 10 is a diagram showing a change in speed when the vehicle 5 stops at a stop line 92 without performing primary deceleration control. [Figure 12] FIG. 10 is a diagram showing a change in speed when the vehicle 5 stops at a stop line 92 without performing primary deceleration control. [Figure 13] FIG. 10 is a diagram showing a change in speed when the vehicle 5 stops at a stop line 92 without performing primary deceleration control. [Figure 14] FIG. 10 is a diagram showing a change in speed when the vehicle 5 stops at a stop line 92 without performing primary deceleration control. [Figure 15] FIG. 10 is a diagram showing a process executed by a travel control unit 73 in the second embodiment. [Figure 16] FIG. 10 is a diagram illustrating a change in speed of a vehicle 5 in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing the configuration of a vehicle control device 10. The vehicle control device 10 is mounted on a vehicle 5. There are no particular limitations on the vehicle 5 as long as it is a vehicle that travels on a road. Vehicles 5 include four-wheeled vehicles and motorcycles.

[0015] The vehicle control device 10 is a device that controls the behavior of the vehicle 5. The vehicle control device 10 performs vehicle control equivalent to autonomous driving level 3. Autonomous driving level 3 is vehicle control in which the driver is not required to monitor the surroundings under certain conditions. The vehicle control device 10 may also be configured to perform vehicle control equivalent to autonomous driving levels 2 and 1. In autonomous driving levels 2 and 1, the driver is always required to monitor the surroundings.

[0016] The vehicle control device 10 includes a periphery detection sensor 20, a position detection unit 30, a vehicle speed sensor 40, a storage unit 50, an actuator 60, and a vehicle control ECU 70. These are connected to an in-vehicle LAN 11 and communicate with each other via the in-vehicle LAN 11.

[0017] The perimeter detection sensor 20 is a sensor that detects various objects present around the vehicle 5. The objects include planar objects such as lane markings. FIG. 2 shows a camera 21 and a lidar 22 as the perimeter detection sensor 20. The camera 21 captures an image of the area in front of the vehicle 5. The camera 21 may also be configured to capture images of the sides and rear of the vehicle 5. The lidar 22 detects the positions of objects present around the vehicle 5 by projecting and receiving light. Note that in addition to or instead of the lidar 22, another sensor that detects objects present around the vehicle 5, such as a millimeter-wave radar, may be provided.

[0018] The position detection unit 30 sequentially detects the current position of the vehicle 5. The position detection unit 30 includes, for example, a GNSS receiver. The GNSS receiver receives navigation signals transmitted by navigation satellites included in the GNSS (Global Navigation Satellite System), which is a satellite navigation system, and sequentially calculates the current position based on the received navigation signals. The position detection unit 30 may also include an inertial sensor. The inertial sensor is a sensor that detects inertia occurring in the vehicle 5, and includes one or both of an acceleration sensor and an angular velocity sensor. The inertial sensor can sequentially detect changes in the relative position of the vehicle 5.

[0019] The vehicle speed sensor 40 sequentially acquires the vehicle speed V, which is the speed of the vehicle 5. The memory unit 50 is writable and stores various information. A flash memory can be used for the memory unit 50. The memory unit 50 stores a map database (hereinafter referred to as map DB). The map DB includes map information called a high-precision map. The high-precision map is a three-dimensional map, and includes traffic light information for some or all of the traffic lights 80.

[0020] FIG. 2 shows an example of a traffic light 80. The traffic light 80 shown in FIG. 2 is equipped with main lights 81, which are a red light 81R, a yellow light 81Y, and a green light 81B, in that order from right to left. In addition, an arrow light 82 is provided below the main light 81. The arrow light 82 is a light that indicates the permitted direction of travel by the direction of the arrow. The traffic light 80 shown in FIG. 2 is equipped with three arrow lights 82. The arrow light 82L is located below the green light 81B and is a left-pointing arrow light 82 indicating that a left turn is permitted. The arrow light 82S is located below the yellow light 81Y and is an upward-pointing arrow light 82 indicating that going straight is permitted. The arrow light 82R is located below the red light 81R and is a right-pointing arrow light 82 indicating that a right turn is permitted. The traffic light 80 shown in Figure 2 has three arrow lights 82, but there are also traffic lights 80 that have only one or only two arrow lights 82. There are also traffic lights 80 that have no arrow lights 82 at all.

[0021] The traffic light information includes information indicating whether the traffic light 80 is equipped with an arrow light 82, and, if the traffic light 80 is equipped with an arrow light 82, information indicating the relationship between the fixed position of the arrow light 82 and the direction of the arrow indicated by the arrow light 82 (i.e., the permitted direction of travel). The fixed position of the arrow light 82 is a fixed position based on the main light 81. The fixed position of the arrow light 82 can be indicated by which main light 81 it is under.

[0022] The map DB contains information indicating the number of lanes and the permitted direction of travel at intersections of each lane (hereinafter referred to as "lane permitted direction of travel") for at least some roads. The information indicating the permitted direction of travel of each lane may be included in a high-precision map, or may be included in a low-precision map used for route guidance during manual driving.

[0023] The actuator 60 is an actuator that causes the vehicle 5 to run and stop, and also controls the direction in which the vehicle 5 travels.

[0024] The vehicle control ECU 70 executes autonomous driving control corresponding to autonomous driving level 3. The vehicle control ECU 70 may also execute autonomous driving control corresponding to autonomous driving level 2 or 1.

[0025] The vehicle control ECU 70 can be realized by a configuration including at least one processor. For example, the vehicle control ECU 70 can be realized by a computer including a processor, nonvolatile memory, RAM, I / O, and a bus line connecting these components. The nonvolatile memory stores a program for operating a general-purpose computer as the vehicle control ECU 70. The processor executes the vehicle control program stored in the nonvolatile memory while utilizing the temporary storage function of the RAM, causing the vehicle control ECU 70 to operate as a signal recognition unit 71, a driving lane recognition unit 72, and a driving control unit 73. Execution of these operations means that a vehicle control method corresponding to the vehicle control program is being executed. The signal recognition unit 71, the driving lane recognition unit 72, and the driving control unit 73 are at least functions that the vehicle control ECU 70 executes when performing autonomous driving control equivalent to autonomous driving level 3.

[0026] The signal recognition unit 71 sequentially recognizes the lighting state of the main lights 81 of the traffic lights 80 and the permitted direction of travel indicated by the arrow lights 82 of the traffic lights 80, based on images captured by the camera 21. In detail, the signal recognition unit 71 executes the following process. The signal recognition unit 71 analyzes the images captured by the camera 21 to detect the traffic light 80 that the vehicle 5 should follow next. The traffic light 80 that the vehicle 5 should follow next is hereinafter referred to as the target traffic light. Next, the signal recognition unit 71 determines the light color that is lit in the main lights 81 of the target traffic light. The signal recognition unit 71 also determines whether or not the traffic light 80 has an arrow light 82.

[0027] Furthermore, if it is determined that there are arrow lights 82, the signal recognition unit 71 determines which arrow lights 82 are lit. Even if one or more arrow lights 82 are provided in the traffic light 80, none of the arrow lights 82 may be lit at some time. Furthermore, the signal recognition unit 71 can analyze the image captured by the camera 21 to determine the direction of the arrow of the lit arrow lights 82.

[0028] However, in this embodiment, since traffic light information can be acquired from the map DB, as long as the position where the lit arrow light 82 is fixed can be identified, it is not necessary to be able to recognize the direction of the arrow by image analysis. If the position where the lit arrow light 82 is fixed can be identified, the direction of the arrow of the lit arrow light 82 can be determined based on the traffic light information. By being able to identify the direction of the arrow of the lit arrow light 82, the travel permitted direction according to the arrow light 82 can be recognized.

[0029] The driving lane recognition unit 72 sequentially recognizes which lane the vehicle 5 is traveling in. Furthermore, the driving lane recognition unit 72 determines the permitted traveling direction of the lane in which the vehicle 5 is traveling at the target intersection. The target intersection is an intersection where passage is regulated by a target traffic light. The driving lane recognition unit 72 can recognize the lane in which the vehicle 5 is traveling by analyzing an image captured by the camera 21. The driving lane recognition unit 72 may also recognize the lane in which the vehicle 5 is traveling by using information detected by another surrounding detection sensor 20, such as the Lidar 22.

[0030] The driving lane recognition unit 72 can determine the permitted traveling direction of the lane in which the vehicle 5 is traveling at the target intersection based on the lane in which the vehicle 5 is traveling and the permitted traveling direction of that lane stored in the map DB. In addition, by recognizing the shape of a road marking 90 (see FIG. 5, etc.) that indicates the traveling direction, the driving lane recognition unit 72 can also determine the permitted traveling direction of the lane in which the vehicle 5 is traveling at the target intersection.

[0031] The driving control unit 73 controls the vehicle speed V. In addition, the driving control unit 73 may control the traveling direction of the vehicle 5. The vehicle speed V controlled by the driving control unit 73 will be described in detail. FIG. 3 shows the processing executed by the driving control unit 73. The driving control unit 73 periodically executes the processing shown in FIG. 3.

[0032] In S1, the signal recognition unit 71 determines whether it has recognized which main light 81 is on for the target traffic light. If the distance to the target traffic light is far, it cannot determine which main light 81 is on. The distance from the vehicle 5 to the target traffic light when the on main light 81 can be recognized depends on the weather, vehicle speed, the performance of the camera 21, etc. The distance from the vehicle 5 to the target traffic light when the on main light 81 can be recognized is, for example, just under 100 m. If the determination result in S1 is NO, the vehicle 5 is relatively far from the target intersection.

[0033] Therefore, if the determination result in S1 is NO, the process proceeds to S2, where road-following control is executed. Road-following control is a control in which the vehicle 5 travels along the road on which it is currently traveling at a preset vehicle speed V or a vehicle speed V that follows the vehicle ahead. After executing S2, the process returns to S1.

[0034] If the determination result in S1 is YES, the process proceeds to S3. In S3, it is determined whether the red light 81R is on. If the light color of the main light 81 recognized by the signal recognition unit 71 is yellow or blue, the determination result in S3 is NO. If the determination result in S3 is NO, the process proceeds to S4.

[0035] In S4, control is executed according to the color of the light that is on. If the color of the light that is on is blue, the vehicle is controlled to pass through the target intersection and proceed from the target intersection in the direction toward the destination. If the color of the light that is on is yellow, control is executed to stop at the target intersection. Note that if the color of the light that is on is yellow, primary deceleration control (S8) may be executed, just as in the case where the red light 81R is on and the arrow light lighting state cannot be recognized. After executing S4, the process returns to S1.

[0036] If the determination result in S3 is YES, the process proceeds to S5, where traffic light information for the target traffic light is obtained from the map database.

[0037] The above-mentioned S3 and the following S6 and S7 are conditions for determining whether or not to execute the primary deceleration control (S8) (hereinafter referred to as the primary control conditions). One condition for the primary control conditions to be met is when the recognition result of the signal recognition unit 71 determines that the red light 81R is on, but cannot determine whether the arrow light 82 is on.

[0038] In S6, it is determined from the traffic light information acquired in S5 whether the target traffic light is a traffic light 80 that has an arrow light 82 for the travel lane in which the vehicle 5 is traveling. The travel lane in which the vehicle 5 is traveling is acquired from the travel lane recognition unit 72. If the traffic light information indicates that there is no arrow light 82, the determination result in S6 is NO. Also, even if the traffic light information indicates that the target traffic light has one or more arrow lights 82, if the arrow light 82 is not for the travel lane in which the vehicle 5 is traveling, the determination result in S6 is NO. For example, if the traffic light information indicates that the target traffic light has only an arrow light 82R and the vehicle 5 is traveling in a straight or left-turn lane, the determination result in S6 is NO. If the determination result in S6 is NO, naturally, the arrow light 82 for the travel lane in which the vehicle 5 is traveling will not be illuminated. If the determination result in S6 is NO, the primary deceleration control (S8), which will be described later, is not executed.

[0039] If the traffic light information acquired in S5 indicates that the target traffic light is a traffic light 80 having an arrow light 82 in the travel lane in which the vehicle 5 is traveling, the determination result in S6 will be YES. If the determination result in S6 is YES, proceed to S7.

[0040] In S7, it is determined whether the arrow light on state has been recognized. The arrow light on state indicates which direction of travel the arrow light 82 permits is on. If the direction indicated by the lit arrow light 82 can be determined through image analysis, the determination result in S7 is YES. Alternatively, the arrow light on state may be recognized based on the fixed position of the lit arrow light 82 and the traffic light information acquired in S5. The position at which the arrow light on state can be recognized using the latter method is often farther from the target traffic light than the position at which the arrow light on state can be recognized using the former method. For example, the position at which the arrow light on state can be recognized using the former method depends on the weather, vehicle speed V, etc., but, as an example, it is a position just under 50 meters from the target traffic light. On the other hand, the position at which the arrow light on state can be recognized using the latter method is between the position at which the arrow light on state can be recognized using the former method and the position at which the lighting color of the main light can be recognized.

[0041] If the lighting state of the arrow lamp cannot be recognized, that is, if it cannot be determined whether the arrow lamp 82 is lit, the determination result in S7 is NO. If the determination result in S7 is NO, the process proceeds to S8.

[0042] In S8, primary deceleration control is executed. The primary deceleration control will be described with reference to FIG. 5. The primary deceleration control is a control for decelerating the vehicle at a slower deceleration rate than the deceleration rate achieved by the stop deceleration control from a position farther from the stop line 92 than the stop deceleration start positions Ps0 and Ps1. In the example shown in FIG. 5, the primary deceleration control is started from position Pf and ends at the stop deceleration start position Ps1. Then, the stop deceleration control is started from the stop deceleration start position Ps1.

[0043] The stop deceleration control is a deceleration control that decelerates the vehicle so as to stop at the stop line 92. As shown in FIG. 5, the deceleration in the primary deceleration control is slower than the deceleration in the stop deceleration control. Note that the deceleration means a negative acceleration. The stop deceleration start position Ps0 is the deceleration start position when stop deceleration control without primary deceleration control is performed (hereinafter referred to as stop deceleration control without primary deceleration control). The stop deceleration control without primary deceleration decelerates the vehicle at a predetermined stop deceleration that does not result in sudden deceleration. The stop deceleration start position Ps0 is the position where deceleration starts to stop the vehicle at the stop line 92 by decelerating at this deceleration. The distance traveled during the stop deceleration control can be calculated from the stop deceleration and the vehicle speed V1 before the start of deceleration. The stop deceleration start position Ps0 is determined by this distance and the position of the stop line 92.

[0044] On the other hand, the stop deceleration start position Ps1 is the position at which stop deceleration control starts when primary deceleration control is performed. The stop deceleration start position Ps1 is the position at which S8 is executed, and the time difference between executing S8 and S3 is very short. Therefore, the stop deceleration start position Ps1 can be said to be the position at which it is recognized that the red light 81R, which is the main light 81, is turned on.

[0045] The deceleration in the primary deceleration control may be slower than the deceleration in the stop deceleration control. In the example of Fig. 5, the deceleration in the primary deceleration control is a deceleration that results in a vehicle speed V2 at a position where it is estimated that the arrow lamp lighting state can be recognized. The vehicle speed V2 is determined by the distance between the position where it is estimated that the arrow lamp lighting state can be recognized and the stop line 92, and the deceleration in the stop deceleration control without primary deceleration.

[0046] Another example of the deceleration in the primary deceleration control is a deceleration that is less likely to cause discomfort to the occupant by accelerating after deceleration, as in the example of Fig. 8 described later. In other words, the deceleration is a small deceleration (for example, -0.05 G) that makes it less likely for the occupant to perceive the deceleration by the primary deceleration control and the subsequent acceleration with the same absolute value as the deceleration by the primary deceleration control.

[0047] Once the primary deceleration control has started, the process returns to S7 and continues the primary deceleration control until the arrow light is recognized as being lit. If the arrow light is recognized as being lit, the determination result in S7 becomes YES and the process proceeds to S9.

[0048] In S9, it is determined whether the light is passable. In the example of Fig. 5, the vehicle 5 is traveling in the straight lane. On the other hand, the arrow lights 82 that are lit are the arrow lights 82L and 82R, and the arrow light 82S is not lit. Therefore, in the example of Fig. 5, the determination result of S9 is NO.

[0049] In the example shown in FIG. 6, the vehicle 5 is traveling in the left-turn lane. Meanwhile, the arrow lights 82 that are turned on are the arrow lights 82S and 82R, and the arrow light 82L is not turned on. Therefore, the determination result in S9 in the example of FIG. 6 is also NO. In the example shown in FIG. 7, the vehicle 5 is traveling in the right-turn lane. Meanwhile, the arrow lights 82 that are turned on are the arrow lights 82L and 82S, and the arrow light 82R is not turned on. Therefore, the determination result in S9 in the example of FIG. 7 is also NO. If the determination result in S9 is NO, proceed to S10.

[0050] In S10, stop deceleration control is started. As a result, the vehicle 5 starts decelerating at a deceleration that stops the vehicle 5 at the stop line 92, as shown in Figures 5, 6, and 7, and stops at the stop line 92. Note that the deceleration shown in Figures 5, 6, and 7 is the same as the deceleration when stop deceleration control without primary is executed.

[0051] If the determination result in S9 is YES, the process proceeds to S11. In S11, passing speed control is executed. Passing speed control is speed control when passing through the target intersection. The processing of S11 is shown in detail in Figure 4. In Figure 4, in S111, the direction in which the vehicle 5 will proceed at the target intersection is determined. The direction in which the vehicle 5 will proceed at the target intersection can be determined from the direction defined by the driving lane in which the vehicle 5 is traveling. S111 may also be determined based on the destination point set in the autonomous driving control.

[0052] If the vehicle 5 is going straight through the target intersection, the process proceeds to S112. In S112, speed return control is performed. Speed ​​return control is a control for returning the vehicle speed to V before the primary deceleration control was started. Figure 8 shows the speed change of the vehicle 5 when speed return control is performed. In Figure 8, the vehicle 5 is traveling in the straight lane, and the arrow light 82S is on. Therefore, at the stop deceleration start position Ps1 where the arrow light on state is recognized, speed return control is started instead of stop deceleration control. In Figure 8, the acceleration in the speed return control has the same absolute value as the deceleration in the primary deceleration control. However, the absolute value of the acceleration when returning the speed does not necessarily have to be the same as the absolute value of the deceleration in the primary deceleration control.

[0053] If it is determined in S111 that the vehicle 5 will turn left, the process proceeds to S113. In S113, left-turn speed control is executed. Left-turn speed control is a control for decelerating the vehicle 5 when passing the stop line 92 so that the vehicle reaches a left-turn speed that allows it to turn left at the target intersection. Figure 9 shows the speed change of the vehicle 5 when left-turn speed control is executed. In Figure 9, the vehicle 5 is traveling in the left-turn lane, and the arrow light 82L is on. Therefore, left-turn speed control is started at the stop deceleration start position Ps1 where the arrow light on state is recognized. In left-turn speed control, the speed of the vehicle 5 does not become zero at the position of the stop line 92. Therefore, left-turn speed control decelerates the vehicle 5 more slowly than stop deceleration control.

[0054] If it is determined in S111 that the vehicle 5 is turning right, the process proceeds to S114. In S114, right-turn speed control is executed. Right-turn speed control is speed control in which the vehicle passes through the stop line 92 at a speed that allows the vehicle to stop or slow down within the target intersection. Figure 10 shows the speed change of the vehicle 5 when right-turn speed control is executed. In Figure 10, the vehicle 5 is traveling in the right-turn lane, and the arrow light 82R is on. Therefore, right-turn speed control is started at the stop deceleration start position Ps1 where the arrow light on state is recognized.

[0055] Returning to Fig. 3 for the explanation, if the determination result in S6 is NO, the process proceeds to S12. An example of proceeding to S12 will be described. In Fig. 11, the traffic light 80 does not have an arrow light 82. Therefore, the determination result in S6 is NO, and the process proceeds to S12.

[0056] 12, 13, and 14 show examples other than that shown in FIG. 11 in which primary-less stop deceleration control is executed. In FIG. 12, the vehicle 5 is traveling in the straight lane. The traffic light 80 is equipped with arrow lights 82L and 82R, but not with arrow light 82S. Therefore, in the example of FIG. 12, the determination result in S6 is NO, and the process proceeds to S12. In FIG. 13, the vehicle 5 is traveling in the left-turn lane. The traffic light 80 is equipped with arrow lights 82S and 82R, but not with arrow light 82L. Therefore, in the example of FIG. 13, the determination result in S6 is NO, and the process proceeds to S12. In FIG. 14, the vehicle 5 is traveling in the right-turn lane. The traffic light 80 is equipped with arrow lights 82L and 82S, but not with arrow light 82R. Therefore, in the example of FIG. 14, the determination result in S6 is NO, and the process proceeds to S12.

[0057] In S12, stop deceleration control without a primary is executed. Figures 11 to 14 show the change in speed of the vehicle 5 when stop deceleration control without a primary is executed. As described above, stop deceleration control without a primary is control that starts deceleration control from stop deceleration start position Ps0 and stops the vehicle at stop line 92. Because primary deceleration control is not executed, stop deceleration start position Ps0 is a position farther from the stop line 92 than stop deceleration start position Ps1 at which stop deceleration control starts when primary deceleration control is executed.

[0058] Summary of the first embodiment The vehicle control device 10 of the first embodiment described above starts primary deceleration control, which is slower deceleration than deceleration by stop deceleration control, from a position farther from the stop line 92 than the stop deceleration start positions Ps0 and Ps1 (S8). The primary control condition, which is a condition for starting the primary deceleration control, is satisfied when it can be determined that the red light 81R is on (S3: YES) but it cannot be determined whether the arrow light 82 is on (S7: NO).

[0059] The position where the main light 81 becomes visible is often farther from the traffic light 80 than the position where the lighting of the arrow light 82 becomes visible. Therefore, this vehicle control device 10 can often start the primary deceleration control earlier than the second assist control in Patent Document 1. This makes it possible to make the deceleration in the primary deceleration control gentler. This makes it less likely that the occupants will feel uncomfortable.

[0060] The signal recognition unit 71 can acquire traffic light information from a map DB. Therefore, as long as the signal recognition unit 71 can determine whether the arrow light 82 is on and the position of the lit arrow light 82 by analyzing an image, it does not need to be able to determine the direction of the arrow indicated by the lit arrow light 82. The signal recognition unit 71 can recognize the permitted direction of travel indicated by the lit arrow light 82 using the traffic light information. In image analysis, the fact that the arrow light 82 is on can often be recognized at a position farther from the traffic light 80 than the direction of the arrow indicated by the arrow light 82. Therefore, the signal recognition unit 71 can often recognize the permitted direction of travel indicated by the arrow light 82 at a position farther from the traffic light 80 compared to when not using traffic light information.

[0061] When the driving control unit 73 determines based on the map information that the target traffic light does not have the arrow light 82 for the driving lane in which the vehicle 5 is traveling (S6: NO), it can determine that the arrow light 82 is not illuminated, and therefore the primary control condition is not met. In this way, by using the map information to determine whether the primary control condition is met, it is possible to determine whether the primary control condition is met or not before the signal recognition unit 71 can recognize the arrow light 82. As a result, the stop deceleration control without a primary light can be started earlier than the stop deceleration control when the primary deceleration control is implemented. By starting the stop deceleration control without a primary light earlier, the deceleration in the stop deceleration control without a primary light can be made relatively gentle, allowing the vehicle 5 to stop at the stop line 92.

[0062] If the determination result in S7 is YES, the traveling control unit 73 starts the stop deceleration control (S10). Therefore, the stop deceleration start position Ps1 is the position where the signal recognition unit 71 can recognize the presence or absence of the arrow light 82 and the signal permission direction indicated by the arrow light 82. In this way, when it is determined that the vehicle 5 must stop at the stop line 92, the stop deceleration control can be started promptly.

[0063] When the vehicle 5 is going straight through the target intersection and the target traffic light indicates that going straight is permitted (S9: YES), the driving control unit 73 starts speed recovery control after the primary deceleration control (S112). When the vehicle 5 is going left at the target intersection and the target traffic light indicates that a left turn is permitted (S9: YES), the driving control unit 73 starts left-turn deceleration control after the primary deceleration control, in which the vehicle decelerates to a speed at which a left turn is permitted at the target intersection (S113). When the vehicle 5 is going left or right at the target intersection and the target traffic light indicates that a right turn is permitted (S9: YES), the driving control unit 73 starts right-turn deceleration control after the primary deceleration control, in which the vehicle decelerates to enter the target intersection at a speed at which a right turn is permitted (S114). In this way, speed control according to the direction of passing through the target intersection is possible after the primary deceleration control.

[0064] Second Embodiment Next, a second embodiment will be described. In the following description of the second embodiment, elements having the same reference numerals as those used previously are the same as those in the previous embodiments unless otherwise specified. Furthermore, when only a portion of the configuration is described, the previously described embodiment can be applied to the other portions of the configuration.

[0065] In the second embodiment, the driving control unit 73 does not acquire traffic light information from the map DB. Therefore, the map DB does not need to include traffic light information. Figure 15 is a flowchart showing the processing executed by the driving control unit 73 in the second embodiment.

[0066] Comparing Fig. 15 with Fig. 3, Fig. 15 does not include S5, S6, and S12 that are present in Fig. 3. This is because in the second embodiment, the driving control unit 73 does not acquire traffic light information from the map DB.

[0067] Therefore, after executing S3, the next step is to execute the determination in S7. If the determination in S7 is executed first, it is often impossible to recognize whether the arrow headlight is on or not. Therefore, the process proceeds to S8, where the primary deceleration control is executed.

[0068] In the second embodiment, which does not use map information, a situation may arise in which it is possible to determine that the red light 81R is on and that the arrow light 82 is on, but it is not possible to determine the permitted travel direction based on the arrow light 82. If it is possible to determine that the red light 81R is on and that the arrow light 82 is on, but it is not possible to determine the permitted travel direction based on the arrow light 82, the arrow light on state cannot be recognized. In this case, the determination result in S7 is NO, and primary deceleration control is executed. In other words, in the second embodiment, it is possible to determine that the red light 81R is on and that the arrow light 82 is on, but it is not possible to determine the permitted travel direction based on the arrow light 82, which is one of the primary control conditions.

[0069] In Figure 16, the state of the travel lane in which the vehicle 5 is traveling and the traffic light 80 is the same as in Figure 12. However, in the second embodiment, primary deceleration control is started from position Pf. In the first embodiment, stop deceleration control without a primary deceleration is started from stop deceleration start position Ps0. However, in the second embodiment, stop deceleration control without a primary deceleration is not executed. Then, as shown in Figure 16, stop deceleration control is started from stop deceleration start position Ps1.

[0070] In the example of Fig. 16, the traffic light 80 is equipped with arrow lights 82L and 82R. However, according to the second embodiment, even if the traffic light 80 is not equipped with any arrow lights 82, the speed change of the vehicle 5 will be the same as that in Fig. 16. Also, according to the second embodiment, even if the traffic light 80 is equipped with arrow light 82S, if the arrow light 82S is not lit, the speed change of the vehicle 5 will be the same as that in Fig. 16.

[0071] In the second embodiment, one condition for the primary control condition to be met is that it is possible to determine that the red light 81R is on and that the arrow light 82 is on, but it is not possible to determine the permitted direction of travel based on the arrow light 82. Even in this case, as shown in Fig. 16, the primary deceleration control can be started from position Pf, as in the first embodiment. Therefore, it is possible to make the deceleration in the primary deceleration control gentler.

[0072] Although the embodiments have been described above, the disclosed technology is not limited to the above-described embodiments, and the following modifications are also included in the scope of the disclosure. Furthermore, various modifications other than those described below can be made without departing from the spirit of the invention.

[0073] <Variation 1> In the embodiment, the case where vehicles keep to the left side of the road has been described. In the case where vehicles keep to the right side of the road, the terms "left" and "right" in the embodiment are interchangeable.

[0074] <Variation 2> While the primary deceleration control is being executed, a sign indicating that the primary deceleration control is being executed may be displayed on a display device located in a position recognizable by the driver of the vehicle 5. Also, signs indicating that the deceleration control at the time of stop, the speed recovery control, the speed control when turning left, and the speed control when turning right are being executed may be displayed.

[0075] <Variation 3> The vehicle control ECU 70 and the method described herein may be implemented by a special-purpose computer having a processor programmed to execute one or more functions embodied in a computer program. Alternatively, the vehicle control ECU 70 and the method described herein may be implemented by a special-purpose hardware logic circuit. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor that executes a computer program with one or more hardware logic circuits. The hardware logic circuits may be, for example, an ASIC or an FPGA.

[0076] Furthermore, the storage medium for storing the computer program is not limited to a ROM, and the program may be stored in any computer-readable, non-transitory storage medium as instructions to be executed by a computer. For example, the program may be stored in a flash memory.

[0077] Disclosure of technical ideas This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with the subsequent clause referring to the preceding clause as an alternative. Furthermore, some clauses may be written in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0078] Technical thought 1 A vehicle control device that controls the speed of a vehicle, a signal recognition unit (71) that recognizes the lighting state of the main lights of the traffic signal and the permitted direction of travel indicated by the arrow lights of the traffic signal based on an image captured by a camera that recognizes the surrounding environment of the vehicle; a travel control unit (73) that executes a stop deceleration control that starts deceleration control to be performed to stop at a stop line from a stop deceleration start position (Ps0, Ps1) based on the fact that it can be determined from the recognition result of the signal recognition unit that a red light, which is one of the main lights, is on, and a primary deceleration control that decelerates at a slower deceleration than the deceleration by the stop deceleration control from a position farther from the stop line than the stop deceleration start position when a primary control condition is satisfied, the primary control condition being that it can be determined from the recognition result of the signal recognition unit that the red light is on but it cannot be determined whether the arrow light is on; A vehicle control device comprising:

[0079] Technical thought 2 A vehicle control device according to Technical Idea 1, A vehicle control device in which the driving control unit determines that the primary control condition is met when the recognition result of the signal recognition unit can determine that the red light is on, but cannot determine whether the arrow light is on, and when it can determine based on map information that the traffic light is equipped with the arrow light.

[0080] Technical thought 3 A vehicle control device according to Technical Concept 2, The signal recognition unit is a vehicle control device that, by analyzing the image, can determine that the arrow light is on and the position of the lit arrow light, but cannot determine the direction of the arrow indicated by the lit arrow light, and when the map information includes a relationship between the position of the arrow light and the permitted direction of travel, recognizes the permitted direction of travel indicated by the lit arrow light based on the position of the lit arrow light and the map information.

[0081] Technical thought 4 A vehicle control device according to any one of Technical Ideas 1 to 3, A vehicle control device in which the driving control unit can determine that the red light is on from the recognition result of the signal recognition unit, but even if it cannot determine whether the arrow light is on or not, if it can determine based on map information that the traffic light does not have an arrow light for the driving lane in which the vehicle is traveling, it determines that the arrow light is not on and the primary control condition is not met.

[0082] Technical thought 5 A vehicle control device according to any one of technical concepts 1 to 4, A vehicle control device in which one of the primary control conditions is that it can be determined that the red light is on and that the arrow light is on, but the permitted direction of travel based on the arrow light cannot be determined.

[0083] technical thought 6 A vehicle control device according to any one of Technical Ideas 1 to 5, The vehicle control device, wherein the stop deceleration start position is a position where the signal recognition unit can recognize the presence or absence of the arrow light and the permitted direction of travel indicated by the arrow light.

[0084] Technical thought 7 A vehicle control device according to any one of Technical Ideas 1 to 6, When the vehicle is traveling straight through an intersection where there is a traffic light, and after the primary deceleration control, the driving control unit determines based on the recognition result of the signal recognition unit that the traffic light indicates that straight-through travel is permitted, the driving control unit starts speed return control to return the vehicle to the speed before the primary deceleration control was started.

[0085] Technical thought 8 A vehicle control device according to any one of Technical Ideas 1 to 7, When the vehicle turns left at an intersection where a traffic light is present, and after the primary deceleration control, the driving control unit determines based on the recognition result of the signal recognition unit that the traffic light indicates that a left turn is permitted, the vehicle control device starts left-turn deceleration control to decelerate the vehicle to a speed at which a left turn is possible at the intersection.

[0086] Technical thought 9 A vehicle control device according to any one of Technical Ideas 1 to 8, When the vehicle turns right at an intersection where a traffic light is present, and after the primary deceleration control, the driving control unit determines based on the recognition result of the signal recognition unit that the traffic light indicates that a right turn is permitted, the vehicle control device initiates right-turn deceleration control to decelerate the vehicle so that the vehicle enters the intersection at a speed at which a right turn is permitted.

Claims

1. A vehicle control device that controls the speed of a vehicle, a signal recognition unit (71) that recognizes the lighting state of the main lights of the traffic signal and the permitted direction of travel indicated by the arrow lights of the traffic signal based on an image captured by a camera that recognizes the surrounding environment of the vehicle; a travel control unit (73) that executes a stop deceleration control that starts deceleration control to stop at a stop line from a stop deceleration start position (Ps0, Ps1) based on the fact that it can be determined from the recognition result of the signal recognition unit that a red light, which is one of the main lights, is on, and a primary deceleration control that decelerates at a slower deceleration than the deceleration by the stop deceleration control from a position farther from the stop line than the stop deceleration start position when a primary control condition is satisfied, the primary control condition being that it can be determined from the recognition result of the signal recognition unit that the red light is on but it cannot be determined whether the arrow light is on; A vehicle control device comprising:

2. The vehicle control device according to claim 1, A vehicle control device in which the driving control unit determines that the primary control condition is met when the recognition result of the signal recognition unit can determine that the red light is on, but cannot determine whether the arrow light is on, and when it can determine based on map information that the traffic light is equipped with the arrow light.

3. The vehicle control device according to claim 2, The signal recognition unit is a vehicle control device that, by analyzing the image, can determine that the arrow light is on and the position of the lit arrow light, but cannot determine the direction of the arrow indicated by the lit arrow light, and when the map information includes a relationship between the position of the arrow light and the permitted direction of travel, recognizes the permitted direction of travel indicated by the lit arrow light based on the position of the lit arrow light and the map information.

4. The vehicle control device according to any one of claims 1 to 3, A vehicle control device in which the driving control unit can determine that the red light is on from the recognition result of the signal recognition unit, but even if it cannot determine whether the arrow light is on or not, if it can determine based on map information that the traffic light does not have an arrow light for the driving lane in which the vehicle is traveling, it determines that the arrow light is not on and the primary control condition is not met.

5. The vehicle control device according to any one of claims 1 to 3, The vehicle control device has as one of its fulfillment conditions the primary control condition that it can be determined that the red light is on and that the arrow light is on, but the permitted direction of travel based on the arrow light cannot be determined.

6. The vehicle control device according to any one of claims 1 to 3, The vehicle control device, wherein the stop deceleration start position is a position where the signal recognition unit can recognize the presence or absence of the arrow light and the permitted direction of travel indicated by the arrow light.

7. The vehicle control device according to any one of claims 1 to 3, When the vehicle is traveling straight through an intersection where there is a traffic light, and after the primary deceleration control, the driving control unit determines based on the recognition result of the signal recognition unit that the traffic light indicates that straight-through travel is permitted, the driving control unit starts speed return control to return the vehicle to the speed before the primary deceleration control was started.

8. The vehicle control device according to any one of claims 1 to 3, When the vehicle turns left at an intersection where a traffic light is present, and after the primary deceleration control, the driving control unit determines based on the recognition result of the signal recognition unit that the traffic light indicates that a left turn is permitted, the vehicle control device starts left-turn deceleration control to decelerate the vehicle to a speed at which a left turn is possible at the intersection.

9. The vehicle control device according to any one of claims 1 to 3, When the vehicle turns right at an intersection where a traffic light is present, and after the primary deceleration control, the driving control unit determines based on the recognition result of the signal recognition unit that the traffic light indicates that a right turn is permitted, the vehicle control device initiates right-turn deceleration control to decelerate the vehicle so that the vehicle enters the intersection at a speed at which a right turn is permitted.

10. A vehicle control method for controlling a speed of a vehicle, comprising: Based on an image captured by a camera that recognizes the surrounding environment of the vehicle, the lighting state of the main lights of the traffic signal and the permitted direction of travel indicated by the arrow lights of the traffic signal are recognized; A vehicle control method comprising: a stop deceleration control that starts deceleration control to stop the vehicle at a stop line from a stop deceleration start position (Ps0, Ps1) based on the recognition result that it can be determined that a red light, which is one of the main lights, is on; and a primary deceleration control that decelerates the vehicle at a slower deceleration rate than the stop deceleration control from a position farther from the stop line than the stop deceleration start position when a primary control condition is satisfied, the primary control condition being that it can be determined that the red light is on but it cannot be determined whether the arrow light is on.

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