Vehicle control system

Abstract

To reduce the possibility that a driver of a vehicle feels unrest when deceleration control is switched to acceleration control due to a change in the signal of a traffic light.SOLUTION: A vehicle control device acquires traffic light information on the basis of information acquired by an imaging device 11, the traffic light information being information including a signal of a traffic light located ahead of a vehicle and a relative position of the traffic light to the vehicle. The vehicle control device also acquires vehicle information including a speed of the vehicle, and executes deceleration control if it is determined that the vehicle cannot pass through an intersection during execution of adoptive cruise control, and starts acceleration control when a control switch condition holds that is satisfied if the signal of the traffic light changes to a passage permission indication during the execution of the deceleration control. In the case where a specific condition holds that is satisfied if a distance to the intersection at the time when the control switch condition holds is equal to a predetermined distance threshold value or less, the vehicle control device performs acceleration through acceleration control mildly as compared to the case where the specific condition does not hold.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle control device capable of executing deceleration control and acceleration control as adaptive cruise control based on a traffic signal light display.

Background Art

[0002] Patent Document 1 describes a driving support device capable of executing deceleration support control for decelerating a vehicle independently of a driver's operation. This driving support device is configured to change an end condition of the deceleration support control according to the type of an object when there is an object in front of the vehicle's traveling route that requires the vehicle to decelerate or stop. For example, when the type of the object is another vehicle or a pedestrian, the driving support device performs deceleration support control until the vehicle completely stops, and when the type of the object is a red traffic signal, the driving support device ends the deceleration support control before the vehicle completely stops. Patent Document 1 describes that according to this driving support device, it is possible to reduce the possibility that a driver feels discomfort as compared with a configuration that performs deceleration support control in a uniform deceleration mode.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] By the way, conventionally, adaptive cruise control (ACC) is known as a driving support control for supporting a driver's driving operation of a vehicle. Adaptive cruise control executes acceleration control and deceleration control so that the vehicle speed matches a predetermined set vehicle speed when there is no preceding vehicle, and executes acceleration control and deceleration control so that the inter-vehicle distance (or inter-vehicle time) from the preceding vehicle matches a predetermined set inter-vehicle distance (or set inter-vehicle time) when there is a preceding vehicle.

[0005] Conventional adaptive cruise control systems were designed for use when vehicles are traveling on highways and expressways. However, in recent years, research and development has been conducted on vehicle control devices that enable appropriate driving using adaptive cruise control even on ordinary roads. Such vehicle control devices can be configured to perform deceleration control and acceleration control as adaptive cruise control based on the light indication of traffic signals ahead of the vehicle. Specifically, if the vehicle control device determines that it is impossible to pass through an intersection based on the light indication of the traffic signals, it will perform deceleration control to stop the vehicle at a predetermined position (for example, at the stop line of the intersection). Furthermore, if the vehicle control device determines that it is now possible to pass through the intersection when the light indication of the traffic signals changes during the execution of the deceleration control (typically from red to blue), it will interrupt the deceleration control and perform acceleration control (in other words, switch from deceleration control to acceleration control).

[0006] When acceleration control is performed with a uniform acceleration pattern, the driver may feel uneasy depending on the degree of acceleration and the timing of when the acceleration control is initiated. For example, consider a case where the vehicle control device is configured to perform acceleration control uniformly with a relatively large acceleration. In this case, if the traffic light indicator changes as described above while the vehicle is traveling relatively close to an intersection, the vehicle will be accelerated with a relatively large acceleration by the acceleration control at that point, causing the vehicle to accelerate rapidly and enter the intersection in a relatively short time. Here, for a while after the traffic light indicator changes, there is still a possibility that other vehicles and pedestrians (more precisely, other vehicles and pedestrians traveling in a direction intersecting the vehicle's lane) are present in the intersection. Therefore, in a configuration that performs acceleration control uniformly with a relatively large acceleration, the vehicle may enter the intersection with rapid acceleration without the driver having enough time to confirm whether the vehicle can safely pass through the intersection, which may cause the driver to feel uneasy. Conventional vehicle control devices (including the driver assistance device in Patent Document 1) have not considered this point at all, and there is room for improvement.

[0007] This invention was made to address the problems described above. Specifically, one of the objectives of this invention is to provide a vehicle control device that can reduce the possibility of a vehicle driver feeling uneasy when the vehicle switches from deceleration control to acceleration control due to a change in the indicator light of a traffic signal.

[0008] The vehicle control device according to the present invention (hereinafter referred to as "the present invention device") is It is mounted on the vehicle, A signal information acquisition unit acquires signal information, which includes the light indication of a signal located in front of the vehicle's path and the relative position of the signal with respect to the vehicle, based on information acquired by an imaging device (11) or a communication unit. A vehicle information acquisition unit that acquires vehicle information including the speed of the aforementioned vehicle, If, during the execution of adaptive cruise control, it is determined that it is impossible to pass through an intersection based on the traffic signal information and the vehicle information (step 345: No), the vehicle performs deceleration control as adaptive cruise control to stop the vehicle before the intersection (step 355), and if, during the execution of the deceleration control, the traffic signal indicator included in the traffic signal information changes to an indication that passage is permitted, a control switching condition is met (step 360: Yes), the vehicle interrupts the deceleration control and starts acceleration control as adaptive cruise control. It is equipped with. The aforementioned driving control unit, When the control switching condition is met, if the distance (Di) from the vehicle to the intersection is less than or equal to a predetermined distance threshold (Dth), or if the predicted arrival time required for the vehicle to reach the intersection at that time is less than or equal to a predetermined time threshold, a specific condition is met (Step 365: Yes), and the acceleration rate by the acceleration control is configured to be gentler compared to when the specific condition is not met (Step 365: No).

[0009] In the present invention, when a control switching condition (a condition met when the traffic light indicator changes to "permission to pass" while deceleration control is being executed after it is determined that it is impossible to pass through an intersection during adaptive cruise control) is met and the system switches from deceleration control to acceleration control, and a specific condition (a condition met when the distance to the intersection is below a distance threshold or the estimated arrival time is below a time threshold) is met, the degree of acceleration by the acceleration control is made gentler compared to when the specific condition is not met. With this configuration, when the control switching condition is met when the vehicle is traveling close enough to the intersection that the specific condition is met, the vehicle accelerates gently and enters the intersection after a certain amount of time. As a result, the driver can enter the intersection after thoroughly confirming whether the vehicle can safely pass through the intersection (i.e., whether there are any other vehicles or pedestrians in the intersection yet), and the possibility of the driver feeling anxious can be reduced.

[0010] Furthermore, in the present invention, when the control switching condition is met, the degree of acceleration by acceleration control is not uniformly slowed down, but rather it is configured to be slowed down only when a specific condition is met. With this configuration, if the control switching condition is met when the vehicle is traveling at a point far enough away from the intersection that the specific condition is not met, the vehicle will accelerate relatively quickly. Therefore, it is possible to reduce the possibility that the driver will feel annoyed because the vehicle will only accelerate slowly despite the relatively long distance to the intersection. In other words, in the present invention, when the control switching condition is met, the degree of acceleration by acceleration control is changed based on whether or not the specific condition is met. Therefore, appropriate acceleration control can be performed according to the distance to the intersection or the estimated time to arrive.

[0011] In one aspect of the present invention, The driving control unit is configured to reduce the degree of acceleration by the acceleration control as the distance from the vehicle to the intersection or the predicted arrival time becomes shorter when the specific condition is met.

[0012] With this configuration, the shorter the distance to the intersection or the estimated time to arrive at the intersection when certain conditions are met, the more gradually the vehicle accelerates, allowing for more appropriate acceleration control.

[0013] In one aspect of the present invention, The driving control unit is configured to increase the degree of acceleration by the acceleration control when the intersection passage condition is met after the specific condition has been met and the vehicle has passed through the intersection.

[0014] With this configuration, when a vehicle passes through an intersection while gradual acceleration control is being performed under specific conditions, the vehicle will then accelerate rapidly. This prevents the vehicle from continuing to accelerate slowly after passing through an intersection, reducing the likelihood of the driver experiencing annoyance.

[0015] In one aspect of the present invention, The aforementioned driving control unit is configured to increase the degree of acceleration over time when the conditions for passing through the intersection are met.

[0016] With this configuration, when a vehicle passes through an intersection while acceleration control with a gradual acceleration rate is being executed under specific conditions, the vehicle will then accelerate smoothly and quickly. This reduces the possibility of sudden acceleration after passing through an intersection.

[0017] In one aspect of the present invention, The aforementioned driving control unit is configured such that, when the specific condition is met, it reduces the jerk within a positive range compared to when the specific condition is not met, thereby making the degree of acceleration by the acceleration control more gradual.

[0018] With this configuration, the rate of increase in acceleration becomes gradual, allowing for appropriate acceleration control with a gradual acceleration level.

[0019] In one aspect of the present invention, When the specific condition is satisfied, the traveling control unit is configured to moderate the degree of acceleration by reducing the target acceleration within the range of positive values as compared to when the specific condition is not satisfied.

[0020] According to this configuration, since the rate of increase in the vehicle speed becomes moderate, it is possible to appropriately realize an acceleration control with a moderate degree of acceleration.

[0021] In one aspect of the present invention, When the specific condition is satisfied, the traveling control unit is configured to moderate the degree of acceleration by reducing both the jerk and the target acceleration within the range of positive values as compared to when the specific condition is not satisfied.

[0022] According to this configuration, since both the rate of increase in acceleration and the rate of increase in the vehicle speed become moderate, it is possible to appropriately realize an acceleration control with a moderate degree of acceleration.

[0023] In the above description, for the purpose of assisting the understanding of the invention, reference numerals used in the embodiments are attached in parentheses to the constituent elements of the invention corresponding to the embodiments. However, each constituent element of the invention is not limited to the embodiments defined by the above reference numerals.

Brief Description of the Drawings

Mode for Carrying Out the Invention

[0025] (Configuration) Hereinafter, a vehicle control device according to an embodiment of the present invention (hereinafter also referred to as "this embodiment") will be described with reference to the drawings. This embodiment is mounted on a vehicle. As shown in Figure 1, this embodiment comprises a vehicle control ECU 10, and a camera sensor 11, a vehicle speed sensor 12, a navigation system 13, a drive unit 21, and a braking unit 22 connected thereto. The vehicle control ECU 10 mainly comprises a microcomputer. ECU is an abbreviation for Electronic Control Unit. The microcomputer includes a CPU, ROM, RAM, and an interface (I / F), and the CPU realizes various functions by executing instructions (programs, routines) stored in ROM. Note that some of these functions may be executed by another ECU not shown. Hereinafter, a vehicle on which this embodiment is mounted will be referred to as "this vehicle".

[0026] The vehicle control ECU 10 is configured to acquire signals output or generated by these sensors and systems 11 to 13 at predetermined intervals and to control the drive unit 21 and braking unit 22 based on the acquired signals. Hereinafter, the vehicle control ECU 10 will also be simply referred to as "ECU 10".

[0027] The camera sensor 11 is installed on the back of the vehicle's inner mirror (rearview mirror). The camera sensor 11 captures images of the scenery in front of the vehicle and recognizes (detects) three-dimensional objects in front of the vehicle based on the captured image data. Three-dimensional objects include stationary objects and moving objects. Stationary objects include, for example, traffic lights, road signs, buildings, guardrails, and street trees, while moving objects include, for example, other vehicles and pedestrians. Once a three-dimensional object is recognized, the camera sensor 11 calculates the relative relationship between the vehicle and the three-dimensional object (the relative position and relative velocity of the three-dimensional object relative to the vehicle).

[0028] Furthermore, the camera sensor 11 recognizes (detects) road markings in front of the vehicle based on the above image data. Road markings include road signs (e.g., stop lines and pedestrian crossings) and lane markings. The camera sensor 11 calculates the shape of the lane (the area between two adjacent lane markings) based on the recognized lane markings.

[0029] In particular, if the detected object is a traffic light, the camera sensor 11 extracts the traffic light located in front of the vehicle's path from the detected traffic lights based on the positional relationship between the traffic light and the vehicle's lane and the orientation of the traffic light (outer shape of the traffic light), and identifies the type of light display (typically, the color of the light or an arrow signal) of the traffic light by applying known image processing to the extracted traffic light. The recognition limit distance D1, which is the maximum distance at which a traffic light can be recognized, depends on the performance of the camera sensor. In this embodiment, a camera sensor with a recognition limit distance D1 of 120 [m] is used as the camera sensor 11, but the value of D1 is not limited to this.

[0030] The camera sensor 11 outputs the information obtained in this manner to the ECU 10 as forward image information. Hereinafter, the forward image information that includes the light display of the traffic light and the relative position of the traffic light to the vehicle will be specifically referred to as "traffic light information". Traffic light information can be acquired when the distance D from the vehicle to the traffic light becomes less than or equal to the recognition limit distance D1.

[0031] The vehicle speed sensor 12 generates a signal corresponding to the vehicle's speed. The ECU 10 acquires the signal generated by the vehicle speed sensor 12 and calculates the vehicle speed v based on that signal. The vehicle speed v is an example of "vehicle information". In addition to the vehicle speed v, the ECU 10 may also be configured to acquire steering angle and / or yaw rate obtained from a steering angle sensor and / or yaw rate sensor (not shown) as vehicle information.

[0032] The navigation system 13 includes a navigation ECU (not shown), a GPS receiver and a map database (not shown) connected thereto. The GPS receiver receives GPS signals to detect the vehicle's current position (latitude and longitude). The navigation ECU determines the vehicle's current position based on the GPS signals transmitted from the GPS receiver at predetermined intervals.

[0033] The map database stores map information. This map information includes parameters that indicate the location and shape of roads (for example, the radius of curvature of the road, lane width, number of lanes, and the position of the center line of each lane), as well as information representing the location of traffic lights. The navigation ECU obtains map information of the area surrounding the vehicle's current location (hereinafter also referred to as "surrounding map information") from the map database and outputs it to the ECU 10.

[0034] The drive unit 21 is a device that applies driving force to the drive wheels to propel the vehicle. The ECU 10 controls the driving force applied to the drive wheels by controlling the operation of the drive unit 21. The type of vehicle is not particularly limited and may be, for example, an engine vehicle, a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), a fuel cell vehicle (FCEV), or an electric vehicle (BEV).

[0035] The braking device 22 is a device that applies braking force to the wheels in order to brake the vehicle. The ECU 10 controls the braking force applied to the wheels by controlling the operation of the braking device 22.

[0036] (Details of operation) The CPU of the ECU10 functions as a traffic signal information acquisition unit, a vehicle information acquisition unit, and a driving control unit by executing instructions stored in ROM. The operation of the ECU10 is described in detail below. The ECU10 calculates a target acceleration (including negative values) based on forward image information and vehicle speed v, calculates the control amount necessary to match the actual acceleration (current acceleration) to the target acceleration, and performs adaptive cruise control (hereinafter also simply referred to as "ACC") by controlling the drive unit 21 and the braking unit 22 based on the control amount (however, for the gradual deceleration control described later, the target acceleration is set to a predetermined fixed value). The ACC in this embodiment is a full-speed compatible type. The target acceleration may be calculated as the acceleration necessary to match the vehicle speed v of the vehicle to the set vehicle speed when there is no preceding vehicle, and as the acceleration necessary to match the distance (or time) between the vehicle and the preceding vehicle to the set distance (or time) when there is a preceding vehicle. In the following, ACC when there is no preceding vehicle will be referred to as "(ACC) constant speed driving control" or "(ACC) constant speed driving," and ACC when there is a preceding vehicle will be referred to as "(ACC) follow driving control" or "(ACC) follow driving."

[0037] When ACC is running and the vehicle approaches an intersection and the camera sensor 11 recognizes a traffic light, the ECU 10 obtains traffic light information from the camera sensor 11 and determines whether it is possible to pass through the intersection based on the traffic light information and the vehicle speed v. Specifically, the ECU 10 determines that it is possible to pass through the intersection if the traffic light indicator included in the traffic light information is green or an arrow signal that permits vehicles in the vehicle's lane to pass, and determines that it is impossible to pass through the intersection if the traffic light indicator is red. On the other hand, if the traffic light indicator is yellow, the ECU 10 calculates the time it will take to reach the traffic light based on the distance D from the vehicle to the traffic light and the vehicle speed v, and determines that it is possible to pass through the intersection if the time to reach the traffic light is less than or equal to a predetermined time T (for example, 3 seconds), and determines that it is impossible to pass through the intersection if the time to reach the traffic light exceeds time T.

[0038] If it is possible to pass through the intersection, the ECU10 performs constant speed driving control or follow-me driving control using ACC. On the other hand, if it is not possible to pass through the intersection, the ECU10 performs deceleration control as ACC to stop the vehicle before the intersection. Here, "before the intersection" means the position of the stop line or a predetermined distance before the pedestrian crossing if there is no preceding vehicle, and a predetermined distance before the preceding vehicle if there is a preceding vehicle.

[0039] While deceleration control is being performed, the ECU 10 determines whether the control switching condition is met based on the traffic signal information. The control switching condition is met when the traffic signal's indicator changes to a "permission to pass" indicator while the deceleration control is being performed (typically, when the indicator changes to green or an arrow signal permitting vehicles in the same lane to pass). If the control switching condition is not met, the ECU 10 continues the deceleration control that is currently being performed. On the other hand, if the control switching condition is met, the ECU 10 interrupts the deceleration control and starts acceleration control as ACC (in other words, switches from deceleration control to acceleration control).

[0040] At this time, the ECU 10 determines whether a specific condition is met based on the traffic signal information. The specific condition is met when the distance Di from the vehicle to the intersection at the time the control switching condition is met is less than or equal to a predetermined distance threshold Dth. The distance Di can be calculated based on the "relative position of the traffic signal to the vehicle" included in the traffic signal information. If the specific condition is not met (Di > Dth), the ECU 10 sets the target acceleration by acceleration control to a relatively large value within the positive range. On the other hand, if the specific condition is met (Di ≤ Dth), the ECU 10 sets the target acceleration by acceleration control to a relatively small value within the positive range for the period from the present time until the vehicle passes through the intersection. As a result, if the vehicle's position at the time the specific condition is met is relatively far from the intersection, the vehicle will accelerate quickly, thus reducing the possibility that the driver may feel annoyed due to the vehicle accelerating only slowly. On the other hand, if the vehicle is relatively close to the intersection when certain conditions are met, the vehicle will accelerate gradually. This allows the driver to fully confirm whether or not they can safely pass through the intersection (i.e., whether or not there are other vehicles or pedestrians in the intersection) before entering, thus reducing the likelihood of the driver feeling anxious.

[0041] Furthermore, after certain conditions are met, the ECU10 determines whether the intersection passage condition is met based on the traffic signal information. The intersection passage condition is the condition that is met when the vehicle passes through an intersection. If the intersection passage condition is not met, the ECU10 continues the acceleration control currently being executed (i.e., gradual acceleration). On the other hand, if the intersection passage condition is met, the ECU10 determines that the vehicle has passed through the intersection and increases the target acceleration. As a result, the vehicle accelerates quickly after passing through the intersection, which prevents the situation where the vehicle continues to accelerate slowly after passing through the intersection and reduces the possibility of the driver feeling annoyed.

[0042] Let's explain this in detail with reference to Figure 2. Figure 2 is a diagram that explains how the target acceleration by acceleration control is changed depending on whether specific conditions are met, and includes a graph that defines the relationship between the vehicle's position (horizontal axis) and vehicle speed v (vertical axis), and a diagram illustrating ACC in two cases (Case 1 and Case 2). The vehicle's position in these two cases corresponds to the horizontal axis of the graph. As shown in Figure 2, the intersection is located at position Pi. Position P1 is located at a point where the distance from position P1 to the traffic light S matches the recognition limit distance D1 (i.e., the vehicle acquires traffic light information from the camera sensor 11 when it reaches position P1). Position Pa is located at a point where the distance from position Pa to position Pi exceeds the distance threshold Dth. Position Pb is located at a point where the distance from position Pb to position Pi is less than or equal to the distance threshold Dth. Furthermore, the ECU 10 determines that it is impossible to pass through the intersection based on the traffic signal information and vehicle speed v acquired at position P1, and initiates deceleration control using ACC at position P1. Note that Figure 2 illustrates a case where there is no preceding vehicle, and it is assumed that constant speed driving control using ACC is performed in sections farther from the traffic signal S than position P1.

[0043] In Case 1, the traffic light indicator changes to blue at position Pa, thus fulfilling the control switching condition. Therefore, ECU 10 interrupts deceleration control and starts acceleration control at position Pa. At this time, the distance Di from the vehicle to the intersection (i.e., the distance from position Pa to position Pi) is greater than the distance threshold Dth, so ECU 10 determines that the specific condition is not met and sets the target acceleration by acceleration control to a relatively large value. The solid line L1 in the graph shows the relationship between the vehicle's position and vehicle speed v in Case 1. According to the solid line L1, the vehicle speed v is reduced from the set vehicle speed vs because deceleration control is started at position P1 (in other words, the vehicle switches from constant speed driving control to deceleration control). Then, at position Pa, the control switching condition is met and the specific condition is determined to be not met, so acceleration control with a relatively large acceleration is executed, and the vehicle speed v accelerates significantly in a relatively short time. As a result, the vehicle speed v reaches the set speed vs at position Pc, which is before the intersection, and is maintained at the set speed vs thereafter (i.e., constant speed control is initiated at position Pc). This allows the vehicle to pass through the intersection at a speed v equal to the set speed vs.

[0044] In contrast, in Case 2, the traffic light indicator changes to blue at position Pb, thus fulfilling the control switching condition. Therefore, the ECU 10 interrupts deceleration control and starts acceleration control at position Pb. At this time, the distance Di from the vehicle to the intersection (i.e., the distance from position Pb to position Pi) is less than or equal to the distance threshold Dth, so the ECU 10 determines that the specific condition is met and sets the target acceleration by acceleration control to a relatively small value. The solid line L2 in the graph shows the relationship between the vehicle's position and vehicle speed v in Case 2. According to the solid line L2, the vehicle speed v is reduced from the set vehicle speed vs when deceleration control is started at position P1. Then, at position Pb, the control switching condition is met and the specific condition is determined to be met, so acceleration control with a relatively small acceleration is executed, and the vehicle speed v accelerates slowly. As a result, the vehicle speed v when entering the intersection is a relatively small value. As a result, the vehicle enters the intersection after a certain amount of time has passed since the traffic light indicator changed to blue. After passing position Pi, the ECU 10 determines that the conditions for passing the intersection have been met and increases the target acceleration through acceleration control. As a result, the vehicle speed v is accelerated significantly in a relatively short time. Although not shown in Figure 2, once the vehicle speed v reaches the set vehicle speed vs through this acceleration control, the vehicle speed v is maintained at the set vehicle speed vs (i.e., constant speed driving control is initiated). There are no particular constraints on the relative magnitudes of the target acceleration due to acceleration control in Case 1 and the target acceleration due to acceleration control after passing the intersection in Case 2.

[0045] Incidentally, the lower limit (negative value) of the target acceleration for deceleration control by ACC is set to a predetermined value. As described above, if the ECU 10 determines that it is impossible to pass through an intersection based on traffic signal information and vehicle speed v, it executes deceleration control by ACC to stop the vehicle before the intersection. However, if the vehicle is traveling at a relatively high speed when the deceleration control is started, it may not be possible to secure a sufficient amount of deceleration, and the vehicle may not be able to stop properly before the intersection. For this reason, at the point where the vehicle approaches the intersection and the camera sensor 11 can recognize the traffic signal (i.e., D=D1), it is desirable that the vehicle speed v is less than or equal to the "vehicle speed at which the vehicle can stop before the intersection by deceleration control" (hereinafter, this vehicle speed at which it can stop will be referred to as "stoppable vehicle speed vth"). Therefore, if the vehicle is traveling at a vehicle speed v exceeding the stoppable vehicle speed vth at the point D>D1, the ECU 10 is configured to execute a gradual deceleration control as ACC, which is a control that slows down the vehicle, and to reduce the vehicle speed v at the point D=D1 to the stoppable vehicle speed vth. As a result, if the ECU 10 determines that it is impossible to pass through an intersection, it can appropriately stop the vehicle before reaching the intersection. The stopping speed vth depends on the recognition performance of the camera sensor 11 (i.e., the recognition limit distance D1). In this embodiment, the stopping speed vth is set to 60 km / h.

[0046] The target acceleration (an acceleration with a negative value) for the above-mentioned gradual deceleration control is predetermined and is set to -0.1[G] in this embodiment. Therefore, when the vehicle is traveling at a speed v exceeding the stopping speed vth at a point where D>D1, the point at which gradual deceleration control should be initiated can be calculated based on the target acceleration for gradual deceleration control and the current vehicle speed v. Hereinafter, the distance from the vehicle to the traffic light at the point at which gradual deceleration control should be initiated will be referred to as the "gradual deceleration start distance D2". The gradual deceleration start distance D2 can be calculated as the sum of "the distance Dd required to decelerate the current vehicle speed v to the stopping speed vth (=60[km / h]) using the target acceleration for gradual deceleration control (=-0.1[G])" and "the recognition limit distance D1 (=120[m])". The ECU 10 calculates the deceleration start distance D2 at predetermined calculation times when the vehicle is traveling at a speed v exceeding the stopping speed vth at a point where D > D1, and starts deceleration control when the distance D from the vehicle to the traffic light becomes less than or equal to the deceleration start distance D2. The ECU 10 performs deceleration control until the vehicle reaches a point where traffic light information can be acquired (i.e., until D = D1). Until the distance D from the vehicle to the traffic light becomes less than or equal to the recognition limit distance D1, the distance D may be calculated based on the surrounding map information output from the navigation ECU. In other words, the ECU 10 is configured to calculate the distance D from the vehicle to the traffic light based on the surrounding map information until traffic light information is acquired (in other words, until D ≤ D1), and after traffic light information is acquired, the distance D is calculated based on the traffic light information. However, after traffic light information is acquired, the distance D may be calculated based not only on the traffic light information but also on the surrounding map information.

[0047] Here, when the vehicle is following another vehicle using ACC while traveling at a speed v exceeding the stopping speed vth at a point where D>D1, there are cases where the preceding vehicle is decelerating at an acceleration less than the target acceleration for gradual deceleration control at a point where D≦D2 is satisfied (i.e., the deceleration pace of the preceding vehicle is faster than the deceleration pace of gradual deceleration control). In such cases, if gradual deceleration control is executed, the distance between the vehicle and the preceding vehicle will gradually decrease, making it impossible to follow the vehicle while maintaining the set distance. Therefore, in such cases, the ECU10 is configured to prioritize ACC-based follow-up control over gradual deceleration control. Specifically, when D≦D2 is satisfied while v>vth is being executed in the state of ACC-based follow-up control, if the preceding vehicle is traveling at an acceleration less than the target acceleration for gradual deceleration control, the ECU10 is configured to prioritize ACC-based follow-up control over gradual deceleration control, and if the preceding vehicle is traveling at an acceleration equal to or greater than the target acceleration for gradual deceleration control, the ECU10 interrupts the follow-up control and executes gradual deceleration control. On the other hand, the ECU10 is configured to perform gradual deceleration control when D≦D2 is satisfied while v>vth is being performed during constant speed driving control by ACC.

[0048] Furthermore, as is clear from the above explanation, at points where the distance D to the traffic light is significantly longer than the gradual deceleration start distance D2, there is no need to determine whether or not to perform gradual deceleration control (and consequently, whether or not it is possible to pass through the intersection). Therefore, the ECU 10 is configured to start the above determination only when the distance D falls below the distance at which the determination needs to be started (hereinafter, this distance will also be referred to as the "determination start distance D3"). The determination start distance D3 is set to a value that is sufficiently larger than the upper limit of the conceivable gradual deceleration start distance D2, and in this embodiment, it is set to 250 [m]. The above is a detailed explanation of the operation of the ECU 10.

[0049] (Specific operation) Next, the specific operation of ECU10 will be explained. While ACC is running, the CPU of ECU10 executes the routine shown in the flowchart of Figure 3 until the vehicle passes the intersection located ahead.

[0050] At a predetermined time, the CPU proceeds from step 300 to step 305, calculating the distance D from the vehicle to the traffic light located in front of the vehicle's path (the traffic light closest to the vehicle) based on the surrounding map information.

[0051] Next, the CPU proceeds to step 310 to determine whether the distance D is less than or equal to a predetermined starting distance D3 (=250 [m]). If D > Ds (step 310: No), the CPU returns to step 305. On the other hand, if D ≤ Ds (step 310: Yes), the CPU proceeds to step 315.

[0052] In step 315, the CPU determines whether the vehicle speed v is less than or equal to a predetermined stopping speed vth (=60 [km / h]). If v ≤ vth (step 315: Yes), the CPU proceeds to step 320. In step 320, the CPU changes the ACC control depending on whether there is a preceding vehicle. Specifically, if there is no preceding vehicle, the CPU executes constant speed driving control. On the other hand, if there is a preceding vehicle, the CPU executes follow driving control when the preceding vehicle's speed is less than or equal to the stopping speed vth, and interrupts follow driving control and executes constant speed driving control when the preceding vehicle accelerates suddenly and its speed exceeds the stopping speed vth.

[0053] Subsequently, the CPU proceeds to step 325 to determine whether or not traffic light information has been acquired (in other words, whether or not the camera sensor 11 has recognized a traffic light). If traffic light information has not been acquired (i.e., D > D1 (= 120 [m])) (step 325: No), the CPU returns to step 320. On the other hand, if traffic light information has been acquired (i.e., D ≤ D1) (step 325: Yes), the CPU proceeds to step 345, which will be described later.

[0054] On the other hand, if v > vth (step 315: No), the CPU proceeds to step 330 to determine whether the distance D calculated in step 305 is less than or equal to the slow deceleration start distance D2 (= Dd + D1). If D > D2 (step 330: No), the CPU returns to step 315. On the other hand, if D ≤ D2 (step 330: Yes), the CPU proceeds to step 335.

[0055] In step 335, the CPU performs gradual deceleration control. However, if a preceding vehicle is present and its acceleration (negative value) is less than the target acceleration for gradual deceleration control (-0.1 [G]), the CPU prioritizes follow-me control over gradual deceleration control.

[0056] The CPU then proceeds to step 340 to determine whether or not it has acquired traffic signal information. If it has not acquired traffic signal information (step 340: No), the CPU returns to step 335. On the other hand, if it has acquired traffic signal information (step 340: Yes), the CPU proceeds to step 345.

[0057] In step 345, the CPU determines whether it is possible to pass through the intersection based on the traffic signal information obtained in step 325 or step 340 and the vehicle speed v. If it is possible to pass through the intersection (step 345: Yes), the CPU proceeds to step 350 and executes constant speed driving control or follow driving control. After that (strictly speaking, after passing through the intersection), the CPU proceeds to step 395 and terminates this routine. On the other hand, if it is not possible to pass through the intersection (step 345: No), the CPU proceeds to step 355 and executes deceleration control to stop the vehicle before the intersection.

[0058] Next, the CPU proceeds to step 360 and determines whether the traffic light indicator included in the traffic light information has changed to a "permission to pass" indicator (i.e., whether the control switching condition has been met). If the light indicator has not changed to a permission to pass indicator (step 360: No), the CPU determines that the control switching condition has not been met and returns to step 355. If the light indicator does not change to a permission to pass indicator until the vehicle speed v becomes zero due to deceleration control, the vehicle will stop before the intersection. On the other hand, if the light indicator changes to a permission to pass indicator while deceleration control is being executed (step 360: Yes), the CPU determines that the control switching condition has been met and proceeds to step 365.

[0059] In step 365, the CPU calculates the distance Di from the vehicle to the intersection based on the traffic signal information and determines whether the distance Di is less than or equal to the distance threshold Dth (i.e., whether a specific condition is met). If Di > Dth (step 365: No), the CPU determines that the specific condition is not met and proceeds to step 370, setting the target acceleration to a relatively large value within the positive range and executing acceleration control. As a result, the vehicle accelerates quickly. After that (strictly speaking, after passing the intersection), the CPU proceeds to step 395 and terminates this routine. However, if there is no preceding vehicle and the vehicle speed v reaches the set vehicle speed vs before the vehicle has finished passing the intersection, the CPU switches from acceleration control to constant speed driving control (see Case 1 in Figure 2). On the other hand, if there is a preceding vehicle and the distance (or time between vehicles) to the preceding vehicle reaches the set distance (or time between vehicles) before the vehicle has finished passing the intersection, the CPU switches from acceleration control to follow driving control.

[0060] In contrast, if Di ≤ Dth (step 365: Yes), the CPU determines that a specific condition is met and proceeds to step 375, setting the target acceleration to a relatively small value within the positive range and executing acceleration control. As a result, the vehicle accelerates gradually (see Case 2 in Figure 2). After that (more precisely, after passing the intersection), the CPU proceeds to step 395 and terminates this routine. However, if there is a preceding vehicle and its acceleration is less than the target acceleration, the CPU executes follow-up driving control.

[0061] Although a vehicle control device according to the embodiment has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the object of the present invention.

[0062] For example, whether a specific condition is met may be determined not by the distance Di from the vehicle to the intersection, but by the predicted arrival time that the vehicle is expected to take to reach the intersection. Specifically, the ECU 10 may be configured to determine that the specific condition is not met if the predicted arrival time exceeds a predetermined time threshold, and to determine that the specific condition is met if the predicted arrival time is less than or equal to the time threshold. The predicted arrival time may be calculated based on the vehicle speed v and the distance Di to the intersection at the time the control switching condition is met.

[0063] Furthermore, the ECU 10 may be configured to reduce the degree of acceleration by acceleration control (i.e., to make the target acceleration and / or jerk smaller within a positive range) as the distance Di or predicted arrival time from the vehicle to the intersection at the time a specific condition is met becomes shorter.

[0064] Furthermore, when changing the acceleration mode by acceleration control based on whether or not a specific condition is met, the jerk (rate of change of acceleration) may be changed instead of the target acceleration, or both the jerk and the target acceleration may be changed. Specifically, the ECU 10 may be configured to set the jerk to a relatively large value within the positive range when the specific condition is not met, and to set the jerk to a relatively small value within the positive range when the specific condition is met. Alternatively, the ECU 10 may be configured to set both the jerk and the target acceleration to relatively large values ​​within the positive range when the specific condition is not met, and to set both the jerk and the target acceleration to relatively small values ​​within the positive range when the specific condition is met.

[0065] Similarly, when changing the acceleration mode by acceleration control after certain conditions have been met and the conditions for passing through an intersection have been met, the jerk may be changed instead of the target acceleration (i.e., the jerk may be set to a relatively large value within the range of positive values), or both the jerk and the target acceleration may be changed.

[0066] Furthermore, in the above embodiment, when the intersection passage condition was met, the target acceleration due to acceleration control was changed to a larger constant (see Figure 2). However, this target acceleration does not have to be a constant; it may be a variable that increases over time (however, a predetermined upper limit may be set for the target acceleration). If the jerk is changed instead of the target acceleration, this jerk does not have to be a constant; it may be a variable that increases over time. Also, both the jerk and the target acceleration may be variables that increase over time.

[0067] Furthermore, this implementation device may be configured not to use surrounding map information. In this case, the ECU 10 may be configured to execute the processing from step 345 onwards in Figure 3 from the time it acquires signal information from the camera sensor 11.

[0068] Furthermore, this implementation device may include a communication unit capable of vehicle-to-vehicle communication with traffic signals. In this case, the ECU 10 can acquire traffic signal information via the communication unit. This traffic signal information may include the light display of the traffic signal, information indicating when the light display will change, and location information of the traffic signal. This implementation device may also be configured not to use surrounding map information. In this case, the traffic signal information may include the light display of the traffic signal and information indicating when the light display will change. The ECU 10 may be configured to execute the processing from step 345 onwards in Figure 3 from the time it acquires traffic signal information via the communication unit.

[0069] Furthermore, the present invention may be applied when deceleration control is performed towards an intersection without traffic signals. In this case, whether or not it is possible to pass through the intersection can be determined based on whether or not other vehicles or pedestrians are present in the intersection. In addition, the control switching condition may be configured to be met when there are no other vehicles or pedestrians present in the intersection during the execution of deceleration control.

[0070] Furthermore, ACC is not limited to a full-speed range type; it may also be a type that operates within a predetermined speed range (for example, from 30 km / h to 100 km / h). [Explanation of Symbols]

[0071] 10: Vehicle control ECU, 11: Camera sensor, 12: Vehicle speed sensor, 13: Navigation system, 21: Drive system, 22: Braking system

Claims

1. It is mounted on the vehicle, A signal information acquisition unit acquires signal information, which includes the light indication of a signal located in front of the vehicle's path and the relative position of the signal with respect to the vehicle, based on information acquired by an imaging device or a communication unit. A vehicle information acquisition unit that acquires vehicle information including the speed of the aforementioned vehicle, A driving control unit that, if it is determined that it is impossible to pass through an intersection based on the traffic signal information and the vehicle information while adaptive cruise control is being performed, executes deceleration control as adaptive cruise control to stop the vehicle before the intersection, and if a control switching condition is met when the traffic signal light display included in the traffic signal information changes to a display that permits passage while the deceleration control is being performed, interrupts the deceleration control and starts acceleration control as adaptive cruise control, Equipped with, The aforementioned driving control unit, When the control switching condition is met, if the distance from the vehicle to the intersection is less than or equal to a predetermined distance threshold, or if the predicted arrival time required for the vehicle to reach the intersection at that time is less than or equal to a predetermined time threshold, the system is configured to make the degree of acceleration by the acceleration control gentler compared to when the specific condition is not met. Vehicle control system.

2. In the vehicle control device according to claim 1, The aforementioned driving control unit is configured such that the shorter the distance from the vehicle to the intersection or the shorter the predicted arrival time at the time the specific condition is met, the gentler the degree of acceleration by the acceleration control. Vehicle control system.

3. In the vehicle control device according to claim 1 or claim 2, The aforementioned driving control unit is configured to increase the degree of acceleration by the acceleration control when the intersection passage condition is met after the specific condition has been met and the vehicle has passed through the intersection. Vehicle control system.

4. In the vehicle control device according to claim 3, The aforementioned driving control unit is configured to increase the degree of acceleration over time when the conditions for passing through the intersection are met. Vehicle control system.

5. In the vehicle control device according to claim 1 or claim 2, The aforementioned driving control unit is configured such that, when the specific condition is met, it reduces the jerk within a positive range compared to when the specific condition is not met, thereby making the degree of acceleration by the acceleration control more gradual. Vehicle control system.

6. In the vehicle control device according to claim 1 or claim 2, The driving control unit is configured such that, when the specific condition is met, it reduces the target acceleration within a positive range compared to when the specific condition is not met, thereby making the degree of acceleration by the acceleration control more gradual. Vehicle control system.

7. In the vehicle control device according to claim 1 or claim 2, The aforementioned driving control unit is configured such that, when the specific condition is met, it reduces both the jerk and the target acceleration within a positive range compared to when the specific condition is not met, thereby making the degree of acceleration by the acceleration control more gradual. Vehicle control system.

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