VEHICLE ASSISTANCE CONTROL DEVICE

Abstract

Vehicle assistance control device, including: a blind spot detector (70, 72) configured to detect the presence or absence of a blind spot from the vehicle's perspective in one direction of travel of the vehicle; a driving operation detector (34, 44) configured to detect a driving operation of a driver; and an electronic control unit (60) configured to perform automatic deceleration control of the vehicle based on the detection of the presence of the blind spot by the blind spot detector (70, 72), wherein the electronic control unit (60) is configured to initiate automatic deceleration control by reference to the driver's driving operation after the blind spot detector (70, 72) detects the presence of the blind spot, wherein the electronic control unit (60) is configured to initiate automatic deceleration control when a braking or steering operation by the driver is detected after the presence of the blind spot has been detected, wherein the electronic control unit (60) is configured to initiate the automatic deceleration control when a predetermined time has elapsed after the blind spot has been detected.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The invention relates to a device for assisting the driving of a vehicle such as an automobile, and in particular a device that provides driving assistance to avoid a collision caused by the sudden appearance of a pedestrian or similar (such as a cyclist) from a blind area or blind spot from the driver's perspective, for example from behind an obstacle or a building on the side of a road, or to reduce an impact in the event of a collision. 2. Description of the state of the art

[0002] Various types of systems have been proposed that provide driving assistance to avoid a collision with a pedestrian or similar object detected in the direction of travel of a vehicle. For example, if an object is detected in front of a vehicle while driving, a system disclosed in Japanese Patent Application No. 2009-286279 (JP 2009-286279 A) is configured to adjust the amount of lateral movement of the vehicle to avoid the object, according to the type of object and its speed relative to the vehicle, and to execute a driving maneuver to achieve the set lateral movement. In Japanese Patent Application No.2013-171439 A (JP 2013-171439 A) proposes determining whether a driving assistance control is performed based on a change in the degree of proximity to an object detected in front of a vehicle while driving and a change in a driving operation, and determining a method (deceleration, steering) of driving assistance. Furthermore, a driving assistance system called an "autonomous emergency braking system" (abbreviated as "AEB") is proposed. In this system, if a pedestrian or similar object is detected suddenly appearing in a vehicle's path while driving, a warning indicating a braking operation is presented to the driver, and autonomous collision avoidance braking is applied by the system if it is determined that the driver has not taken any action in response to the warning.Furthermore, in “Studies on Autonomous Driving Intelligence System according to Optimum Control Theory in view of Potential Risk”, Takahiro Hasegawa and four others, Society of Automotive Engineers of Japan, Proceedings of Academic Symposium 20145871, 2014, a system is proposed that autonomously slows down and / or steers a vehicle when a blind area or blind spot, such as an area in front of a parked vehicle located on the side of a road, is detected while the vehicle is driving, in order to avoid contact with a pedestrian or similar, or to reduce an impact, even if the pedestrian or similar actually suddenly emerges from the blind area or blind spot.

[0003] German patent application DE 11 2012 006 032 B4 discloses a driver assistance device. The driver assistance device comprises a speed zone calculation unit configured to calculate a speed zone for the host vehicle that has a possibility of the host vehicle coming into contact with the mobile object when moving in the direction of travel, based on information about the mobile object set by the information setting unit for the mobile object; a target speed calculation unit configured to calculate a target speed for the host vehicle based on a speed zone; and a target speed profile generation unit configured to...that it generates a target speed profile for decelerating the host vehicle from the current speed to the target speed for entering the blind spot, based on a target speed for entering the blind spot, which is the target speed of the host vehicle at the time of entry into a location forming the blind spot, a current speed of the host vehicle, and a target acceleration for deceleration.

[0004] German patent application DE 103 38 760 A1 discloses a motor vehicle with a Pre-Safe system comprising active and / or passive safety devices that are controlled based on information received by at least one vehicle environment detection device and one driving situation data acquisition device, and evaluated in a data evaluation unit. At least some of the active and / or passive safety devices are activated when the information from the vehicle environment detection device represents a potential collision object and the data from the driving situation data acquisition device represents driver behavior that is predefined for collision plausibility checks.

[0005] German patent application DE 10 2014 206 343 A1 discloses a method and a corresponding device for assisting a vehicle driver during an evasive maneuver. A control unit for a vehicle is described. The control unit is configured to detect an obstacle on the vehicle's current trajectory and to determine an evasive trajectory for the vehicle to avoid the obstacle. The control unit is further configured to detect an indication that the vehicle driver is initiating an evasive maneuver. Furthermore, the control unit is configured to determine a target steering angle for the vehicle's steering system based on the determined evasive trajectory, as well as the actual steering angle of the vehicle's steering system. Finally, the control unit is configured to initiate assistance for the evasive maneuver based on the target steering angle and the actual steering angle. SUMMARY OF THE INVENTION

[0006] The autonomous emergency braking (AEB) system described above, and many other conventional systems, are configured to initiate deceleration and / or steering when a pedestrian or similar object suddenly appears in the roadway and a risk of collision with the vehicle becomes apparent. However, because the system (the machine) requires a certain amount of time to gather and analyze information about the surroundings, deceleration and / or steering may not be achieved to the desired degree if a pedestrian or similar object suddenly emerges from a blind spot (from the vehicle's perspective), such as a space behind a parked vehicle, an object, or a blind intersection with poor visibility.On the other hand, in the system described in “Studies on Autonomous Driving Intelligence System according to Optimum Control Theory in view of Potential Risk”, Takahiro HASEGAWA and four others, Society of Automotive Engineers of Japan, Proceedings of the Academic Symposium 20145871, 2014, at a time when the system detects a blind spot, it is assumed that “a pedestrian or similar may suddenly appear”, and a slowing down or steering of the vehicle is performed before the pedestrian or similar is actually detected.With this arrangement, even if a pedestrian or similar object suddenly appears from the blind spot, the vehicle's speed can be reduced in advance to a speed range where the AEB can be adequately activated, or the vehicle can be steered in advance to travel along a course where it does not come into contact with the pedestrian or similar object. Thus, the steering effect of the AEB can be exerted sufficiently or to the desired extent.

[0007] As described above, a control mechanism that performs driving actions, such as slowing down or steering the vehicle, is executed solely based on the detection of a blind spot, and solely due to the possibility (a potential risk) that a pedestrian or similar object might suddenly emerge from the blind spot. When this control mechanism (called "driving assistance control based on a prediction of potential risk") is executed, the machine (the system) would intervene in the vehicle's driving, based on an assessment automatically programmed according to an artificial intelligence technology that deals with potential risk, before the pedestrian or similar object is detected, and before the risk of collision between the vehicle and the pedestrian or similar object becomes apparent.Similarly, the system's (the machine's) prediction of "potential risk" does not necessarily align with the driver's (the human's) assessment of potential risk based on perception and understanding of the environment. Furthermore, the machine does not necessarily execute operations such as slowing down or steering in response to the potential risk in the same way as the driver. Therefore, the driver might find it difficult to understand a control operation performed by the system, or the driver might experience a strange or unpleasant feeling about the system's operation, as the driver's driving intentions are not reflected at all.

[0008] As described above, the driver should avoid any feeling of unease regarding the system's control operation. Similarly, the driver will naturally experience an uneasy or uncomfortable feeling if their driving intentions are not reflected at all, even if safer vehicle operation can be achieved through the system's control.

[0009] The invention provides a driving assistance control device that performs a "driving assistance control based on a prediction of a potential risk" during a journey of the vehicle, avoiding or reducing as much as possible the strange feeling towards the operation of the system.

[0010] A driver assistance control device for a vehicle according to one aspect of the invention comprises a blind spot detector, a driving operation detector, and an electronic control unit. The blind spot detector is configured to detect the presence or absence of a blind spot from the vehicle's perspective in a direction of travel. The driving operation detector is configured to detect a driver's driving operation. The electronic control unit is configured to perform automatic deceleration control of the vehicle based on the detection of the blind spot by the blind spot detector. The electronic control unit is configured to initiate automatic deceleration control by reference to the driver's driving operation after the blind spot detector has detected the presence of the blind spot.The electronic control unit is configured to initiate automatic deceleration control if a braking or steering operation by the driver is detected after the presence of the blind spot. The electronic control unit is also configured to initiate automatic deceleration control if a predetermined time elapses after the blind spot is detected.

[0011] In the preceding aspect of the invention, a "blind spot" or "blind area" is an area or region of a blind spot or location, such as the space in front of a parked vehicle, an obstacle on the side of a road in the direction of travel of the vehicle, or a space behind a building, from the perspective of the driver of the vehicle, or an environmental detection device such as a camera or radar device installed on the vehicle. The "blind spot detector" can be a device that detects or identifies an area providing the "blind spot" or "blind area" from information about the vehicle's surroundings obtained from any devices, such as a vehicle-mounted camera or radar device capable of detecting the environments surrounding the vehicle, or a GPS system.The aforementioned "driving operation" can be any operation involved in driving the vehicle, such as pressing the brake pedal or steering by the driver. The "driving operation detector" can be any device that determines whether any significant "driving operation" has been performed and can be a detection device or a determination device that determines, for example, whether the amount of brake pedal pressure exceeded a predetermined amount or whether the steering angle exceeded a predetermined value.

[0012] With the driving assistance control device according to the above aspect, when the "blind spot" is detected while the vehicle is driving, a potential risk that a pedestrian or similar object might suddenly emerge from the blind spot is predicted, and a driving assistance control is provided according to which the vehicle is automatically slowed down. However, as described above, if the driving assistance control is carried out without reference to the driver's driving operation, the driver might experience a strange or unpleasant feeling regarding the assistance operation. Therefore, in the device of this invention, after a blind spot is detected, the electronic control unit is configured to perform an automatic deceleration with reference to the driver's driving operation.Specifically, the electronic control unit does not immediately implement automatic deceleration as a driver assistance control measure in response to the detection of a blind spot, but rather executes the driver assistance control measure, which is based on the driver's driving actions. While the driver assistance control is expected to reflect the driver's driving intention, automatic deceleration is implemented in relation to the driver's driving actions, so that the driver's driving intention is reflected in the driver assistance control measure, and it is expected that the driver's feeling of unease will be avoided or reduced.

[0013] Based on the presence of a braking or steering operation by the driver, it can be assumed that the driver has detected a blind spot, anticipates a potential risk in response to this detection, and intends to reduce the vehicle's speed or move the vehicle away from an area (where a pedestrian or similar object may suddenly appear from the blind spot) where the potential risk exists. Accordingly, in this case, automatic deceleration is performed in accordance with the driver's intention, and it is less likely or improbable that the driver will experience a strange or uncomfortable sensation from the execution of the braking by the assistance control system, which would otherwise be unexpected.If the driver does not take any action to mitigate the potential risk of a sudden collision from a blind spot, even after a certain amount of time has elapsed since the blind spot was detected, and the vehicle continues driving in the same manner, the potential risk remains unaddressed. Therefore, automatic deceleration control could also be implemented to manage the potential risk if the driver does not take any action to mitigate the potential risk of a sudden collision, even after a certain amount of time has elapsed.Thus, even if a deceleration control is unexpectedly initiated by the system instead of the driver, and the driver is not performing a driving operation that is expected to be completed within the anticipated time, the driver will recognize their error in paying attention to the blind spot when the blind spot actually approaches their own vehicle, according to the automatic deceleration, and the driver's unease regarding the automatic deceleration control will be significantly reduced compared to the case where the automatic deceleration control is initiated early, simultaneously with the detection of the blind spot.

[0014] The electronic control unit can perform automatic deceleration as a driver assistance control in any way or in any operating mode. The automatic deceleration control, as a driver assistance control according to the above, is a control to reduce the vehicle's speed in preparation for the risk or possibility that a pedestrian or similar object may suddenly emerge from a blind spot after the blind spot has been detected. Therefore, the automatic deceleration control is performed in a state where no pedestrian or similar object has been detected. If a pedestrian or similar object does suddenly enter the roadway, a collision avoidance operation can be performed by the AEB system, as described above.Accordingly, in accordance with the automatic deceleration control described above, the electronic control unit can be configured to initiate a preliminary deceleration of the vehicle before the AEB system initiates deceleration at the time the blind spot is detected, in order to more reliably avoid a collision with a pedestrian or similar object if the pedestrian or similar object suddenly emerges from the blind spot. In this case, it is desirable that the vehicle speed be sufficiently reduced at the time when an operation by the AEB system to avoid collision with the pedestrian or similar object is initiated, or when braking or steering is initiated by the driver, for the purpose of avoiding collision with the pedestrian or similar object.For this purpose, the deceleration necessary to reduce the instantaneous vehicle speed to the aforementioned vehicle speed depends on the relative distance between the entry region of a pedestrian or similar object in the vehicle's path, where the pedestrian or similar object is assumed to suddenly emerge from the detected blind spot and enter the vehicle's path. In the driving assistance control device according to the above aspect, the electronic control unit can be configured to assume that an object suddenly emerges from the blind spot and enters the vehicle's path and to calculate an entry region of the object within the path. The electronic control unit can be configured to set a target deceleration based on a relative distance between the entry region and the vehicle.The electronic control unit can be configured to perform automatic deceleration control, so that the actual deceleration of the vehicle becomes essentially the same as the target deceleration.

[0015] If the driver initiates a braking operation during an automatic deceleration control activation to bring the vehicle's actual deceleration into line with the target deceleration, it is desirable that the driver's braking operation be reflected in a movement of the vehicle. This would prevent or reduce any disconcerting feeling the driver might experience from the automatic deceleration control. Similarly, if the automatic deceleration control is activated and the driver subsequently adds a braking action, the vehicle's speed could be reduced by a degree that exceeds the driver's expectations, potentially leading to a disconcerting or uncomfortable sensation.In the driving assistance control device, as described above, the electronic control unit could be configured to apply a braking force to the vehicle to compensate for any difference between the target deceleration and the deceleration induced by the driver's braking operation when automatic deceleration control is performed. With this driving assistance control device, the driver can feel that their own braking operation is reflected in the vehicle's behavior, and the actual deceleration of the vehicle can be controlled to match the target deceleration.

[0016] In the driving assistance control device as described above, the electronic control unit can be configured to set the target deceleration based on a relative distance between the entry region and a target position set before the entry region, and a target vehicle speed of the vehicle when the vehicle reaches the target position, wherein the target position and target vehicle speed are set as a position and vehicle speed at which the vehicle speed can be reduced to substantially 0 at the time the vehicle reaches the entry region from the target position.As described in “Studies on Autonomous Driving Intelligence System according to Optimum Control Theory in view of Potential Risk”, Takahiro Hasegawa and four others, Society of Automotive Engineers of Japan, Proceedings of Academic Symposium 20145871, 2014, a position at which a deceleration of the vehicle is initiated to avoid contact with a hypothetical pedestrian or similar, wherein the position is positioned before an entry region of the pedestrian or similar in the vehicle's path, is set as a target position, and a vehicle speed at the target position, which can be reduced to essentially 0 at the time the vehicle reaches the assumed entry region of the pedestrian or similar from the target position, is set as a target vehicle speed.In this way, the target deceleration can be set depending on the relative distance between the target position and the entry region of the pedestrian or similar into the driving path and the target vehicle speed.

[0017] When the target deceleration is set to simulate deceleration when a model driver—specifically, a driver performing ideal driving—operates the vehicle, ideal vehicle operation is expected to be realized. In this respect, according to the investigations of the inventors of this invention, deceleration in which a given vehicle speed is reduced to a target vehicle speed during a movement of the vehicle from a given position to a target position during an operation by the model driver can be expressed using a virtual spring potential obtained by modeling the braking force acting on the vehicle as a repulsion or...Repulsion from a pedestrian or similar object is applied, as described in "Studies on Autonomous Driving Intelligence System according to Optimum Control Theory in view of Potential Risk," Takahiro Hasegawa et al., Society of Automotive Engineers of Japan, Proceedings of Academic Symposium 2014, 5871, 2014. In the driving assistance control device, as described above, the electronic control unit can set the target deceleration based on a virtual spring potential. The virtual spring potential can be a spring potential obtained by modeling a braking force applied to the vehicle as a repulsion from the object during a deceleration operation performed by a model driver to reduce the vehicle from a given vehicle speed to the target vehicle speed while the vehicle is moving from a given position to the target position.With the driving assistance control device configured in this way, when the automatic deceleration control is performed, an ideal vehicle operation or movement simulating an operation of the model driver can be achieved.

[0018] Meanwhile, when the blind spot detector detects a blind spot, the driver does not necessarily perceive the blind spot in the same way and will not necessarily anticipate a potential risk. Accordingly, the deceleration control of the vehicle by the driver assistance control device, as described above, may be performed as a control action unexpected by the driver. Thus, as described above, the driver assistance control device may further include a risk display device configured to display to the driver, when the blind spot is detected, the risk of an object suddenly appearing from a blind spot.When the aforementioned risk is displayed, the driver is able to anticipate a potential risk or the possibility of the object suddenly appearing and initiate deceleration or steering of the vehicle themselves, or the driver is prevented from experiencing an unsettling or uncomfortable sensation of unexpected deceleration when the automatic deceleration control is initiated. Specifically, according to the driving assistance control device as described above, an interface is provided that allows the driver to recognize the potential risk and understand how the device will handle it. The risk display device can be configured to visually indicate the risk of the object suddenly appearing.In this case, the risk display device can indicate that the risk of the object suddenly occurring increases over time. For example, an increase in the risk or the possibility of sudden occurrence can be expressed by any method, such as increasing the brightness of a risk display or increasing the flashing speed of the display.

[0019] The driving assistance control device according to the foregoing aspect may further include an accelerator pedal response force control, which applies a reaction force to the vehicle's accelerator pedal during an execution of automatic deceleration control by the electronic control unit. With the driving assistance control device thus configured, the driver feels that the accelerator pedal is heavier during an execution of automatic deceleration control, thus preventing unnecessary acceleration of the vehicle, and the driver can be informed that the deceleration control is being carried out by the device.

[0020] Thus, if, according to the foregoing aspect, the driving assistance control device performs driving assistance control based on a prediction of a potential risk or possibility of an object suddenly appearing from a blind spot at a stage where the blind spot is found, the electronic control unit performs an automatic deceleration control relating to a driving operation by the driver after a blind spot detection, so that the degree of driver involvement in driving the vehicle is increased, and the driver's strange feeling towards the control operation is expected to be avoided or reduced.Specifically, after a blind spot is detected, the automatic deceleration control is not activated independently of any driving action by the driver, but rather after waiting for a braking or steering operation by the driver, or when a predetermined time has elapsed since the blind spot detection. When the automatic deceleration control is activated at one of these times, the driver's driving behavior after the blind spot detection is monitored, and the driver's driving intention is reflected by the automatic deceleration control; therefore, a higher degree of coordination between the driver (human) and the device (machine) can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the attached drawings, in which the same reference numerals denote the same elements and in which: Fig. 1A a schematic view of a vehicle on which a vehicle driving assistance control device is installed as a preferred embodiment of the invention; Fig. 1B a block diagram showing the configuration of a system in the driver assistance control device as an embodiment of the invention; Fig. 2A a schematic view which is useful to explain a situation in which driving assistance is provided by the vehicle's driving assistance control device as the embodiment of the invention; Fig. 2B a schematic view which is useful to explain a situation in which driving assistance is provided by the vehicle's driving assistance control device as an embodiment of the invention; Fig. 2C a flowchart representing a routine that is implemented in the driving assistance control device as an embodiment of the invention; Fig. 3A a view schematically showing an example of a risk indicator indicating the presence of a potential risk (sudden appearance of a pedestrian or similar from a blind spot) which is visually displayed to the driver after a blind spot has been detected during a journey of the vehicle in the vehicle's driving assistance control device as the embodiment of the invention; Fig. 3B a display that is shown during an execution of the automatic deceleration control and a display that is shown when the automatic deceleration control is terminated, in the driving assistance control device as an embodiment of the invention; Fig. 3C a view which schematically shows an example (right side) of a display that is shown when a pedestrian or similar actually emerges from a blind spot, after detection of the blind spot, in the vehicle's driving assistance control device as the embodiment of the invention; Fig. 4A a view that schematically shows an example of changes to a potential risk indicator, a vehicle deceleration, and vehicle speed over a period of time according to the routine of Fig. 2C in the case where, after a blind spot has been detected, a driving operation carried out by the driver with respect to the blind spot is detected before a predetermined time expires; Fig. 4B a view that schematically shows an example of changes to a potential risk indicator, a vehicle deceleration, and vehicle speed over a period of time according to the routine of Fig. 2C in the case where, after a blind spot has been detected, no driving operation carried out by the driver with respect to the blind spot is recorded for a predetermined time period; Fig. 5A a schematic view of a situation in which an automatic deceleration control is carried out in the driving assistance control device of the invention, wherein the view is helpful in explaining a target position and a target speed to which reference is made when determining a target deceleration for use in the control; Fig. 5B a schematic view of a virtual spring potential obtained by modeling a braking force applied to the vehicle during a deceleration operation when a model driver reduces the vehicle speed from a given speed to a target vehicle speed during a movement of the vehicle from a given position to a target position, as a repulsion or push-off from a pedestrian or the like, with reference to the virtual spring potential when determining the target deceleration during automatic deceleration control; and Fig. 5C is a view that schematically represents an example of predicted positions of the vehicle, which are referenced when determining a target deceleration according to an automatic deceleration control. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION

[0022] Referring to Fig. 1A are in a vehicle 10, such as an automobile, in which a driving assistance control device is included as a preferred embodiment of the invention, a right and left front wheel 12FR, 12FL, a right and left rear wheel 12RR, 12RL, a driving system (of which a part in Fig. (as shown in Figure 1A), a steering device 30 for controlling the steering angle of the front wheels (a steering device for the rear wheels may also be provided) and a braking system 40 that generates a braking force in each wheel are installed. The driving system generates a braking / driving force in each wheel (from only the rear wheels, since the vehicle is a rear-wheel drive vehicle, in which in Fig. (as shown in the embodiment 1A) according to the driver pressing an accelerator pedal. The drive system is configured to transmit drive torque or rotational force from a machine and / or an electric motor (not shown; the drive system can be a hybrid drive system with both a machine and an electric motor) to rear wheels 12RR, 12RL via a (not shown) gearbox and differential gear unit 28 in normal operating mode. A power steering device can be used as the steering device 30. The power steering device transmits rotation of a steering wheel 32, operated by the driver, to tie rods 36R, 36L, while the torque is amplified or increased by means of an amplifier 34 to rotate the front wheels 12FR, 12FL.

[0023] The braking system 40 is an electronically controlled hydraulic braking system of the type in which the brake pressure in a wheel cylinder 42i (i=FR, FL, RL, RR) located at each wheel, and thus the braking force at each wheel, is adjusted by a hydraulic circuit 46 that communicates with a master cylinder 45, which is actuated in response to the driver pressing a brake pedal 44. The hydraulic circuit 46 is equipped with various valves (such as a master cylinder shut-off valve, a hydraulic pressure holding valve, and a pressure reducing valve) for selectively communicating the wheel cylinder of each wheel with the master cylinder, an oil pump, or an oil reservoir (not shown). In normal operation, the pressure from the master cylinder 45 is supplied to the corresponding wheel cylinders 42i in response to the driver pressing the brake pedal 44.As described below, when automatic deceleration control is performed after the detection of a blind spot, the various valves specified above are actuated, based on an instruction from an electronic control unit 60, so that the brake pressure in the wheel cylinder of each wheel is controlled to be equal to its set pressure, based on a detected value Pbi (i=FR, FL, RR, RL) from a corresponding pressure sensor. The braking system 40 can be of the type that pneumatically or electromagnetically applies a braking force to each wheel, or any type known to a person skilled in the art.

[0024] In the vehicle 10, in which the driving assistance control device is used as the preferred embodiment of the invention, a vehicle-mounted camera 70, a radar device 72, etc., are provided for detecting the environment around the vehicle in order to detect another vehicle around the vehicle, an obstacle, a pedestrian or similar (for example, a bicycle), the width of the road, a building, etc. Furthermore, a GPS system (vehicle navigation system) 74 can be provided, which communicates with a GPS satellite and receives various types of information, such as the environment around the vehicle and position information.

[0025] Operational control of each part of the vehicle and operational control of the driving assistance control device according to the invention are carried out by the electronic control unit 60. The electronic control unit 60 can comprise a microcomputer and a control circuit of conventional types. The microcomputer has a CPU, ROM, RAM, and an input / output interface, which are interconnected via a bidirectional common bus. The configuration and operation of each part of the driving assistance control device of the invention, as described below, can be implemented by the electronic control unit 60 according to programs. The electronic control unit 60 receives sensor readings from various sensors, which are used as parameters for the driving assistance control of the invention, which is carried out in the manner described below.For example, the electronic control unit 60 receives elements of information s1 to s3 from the vehicle's camera 70, radar device 72, GPS system 74, etc., a pressure value θb of the brake pedal, a steering angle δ, a detection value ax of a longitudinal G-sensor 65, wheel speeds or wheel rotation speeds Vwi (i=FR, FL, RR, RL), etc. The electronic control unit 60 issues a control instruction to display a risk indication to the driver, a control instruction representing a control value for use in automatic deceleration control, etc., to corresponding systems or devices.Although not shown in the drawings, the electronic control unit 60 can receive different parameters required for various controls to be carried out in the vehicle of this embodiment, for example, various detection signals such as the yaw rate γ from a gyro sensor 62 and / or the lateral acceleration Yg, and can issue various control instructions to the corresponding systems or devices.

[0026] In the system configuration of the driver assistance control device according to the invention, as shown in Fig. As shown in Figure 1B, an environment detection unit, a display system interface unit, a potential risk prediction unit, a support execution determination unit, and a coordination control unit are constructed. The environment detection unit detects the environment around the vehicle based on information from the camera, sensors, etc. When the environment detection unit detects the presence of a blind spot, as seen from the vehicle's own perspective, the information is passed to the display system interface unit, the potential risk prediction unit, and the support execution determination unit. Within the display system interface unit, a process or routine of displaying a risk indication on a display mounted in the vehicle is executed in the manner described below.The potential risk prediction unit calculates a target deceleration for use in automatic deceleration control and a control amount that implements the target deceleration using a driver model that simulates the driving behavior of a model driver. This calculation is based on blind spot position information and conditions (such as vehicle speed) of the vehicle itself, as described below. The support execution determination unit monitors the driver's driving operations, as described below, after receiving information about the presence of the blind spot and determines the timing of automatic deceleration control. Once automatic deceleration control execution is determined, the information is passed to the coordination control unit.The coordination control unit determines a control instruction based on the control amount for the automatic deceleration control, which is determined by the unit for predicting a potential risk, and a driving operation (braking operation) by the driver, and transmits the control instruction to a brake control system. Likewise, the support execution determination unit can execute a control to increase the accelerator pedal reaction force in a manner described below during the execution of the automatic deceleration control.

[0027] During an operation of the driving assistance control device of the invention, when a parked vehicle on the shoulder of a road or a corner of a building is detected while the vehicle (the driver's own vehicle) is driving, and the presence of a blind spot behind the parked vehicle or the building (in front of the vehicle or the building from the driver's own vehicle's perspective) is recognized, as schematically shown in Fig. 2A, Fig. As shown in Figure 2B, the possibility that a pedestrian or similar object might suddenly appear or emerge from the detected blind spot is considered a potential risk, and the vehicle automatically decelerates in preparation for this potential risk. However, if the device executes the automatic deceleration control immediately, solely due to blind spot detection, the driver might not understand the intention or operation of the device's control, or the intention or operation of the device's control might not align with the driver's intention. As a result, the driver's driving action might not be reflected in the vehicle's behavior, and the driver might experience a strange or uncomfortable feeling regarding the device's control operation.Thus, according to the driving assistance control implemented by the device in this embodiment, the automatic deceleration control is not executed immediately when the presence of the blind spot is detected. Instead, the presence of the potential risk is displayed to the driver, and the driver's driving action is monitored. Then, if the driver initiates a braking or steering operation in an attempt to avoid the potential risk, the device could also initiate the automatic deceleration control in accordance with the driver's action. Likewise, if the driver does not perform a braking or steering operation, even after a predetermined time has elapsed since the blind spot was detected, the automatic deceleration control can still be executed.

[0028] Referring to Fig. In step 2C, a control routine of the driving assistance control system, implemented by the device of this embodiment, initially monitors the area around the vehicle using the environmental sensing unit while the vehicle is in motion, and a blind spot detection is performed (step S1). The area around the vehicle can be monitored in any way using devices such as the vehicle-mounted camera 70, the radar device 72, and the GPS system 74 to gather information about the vehicle's surroundings. Then, if a parked vehicle, an obstacle, the corner of a building, a blind intersection (i.e., an intersection with poor visibility), or similar object is detected based on the information obtained from the camera and other devices, it can be determined that there is a blind spot behind it.

[0029] Once the presence of the blind spot has been determined, a time T, representing the elapsed time since the determination, is reset or set to 0 (T=0) in step S2. While the elapsed time T is being measured (steps S2 to S5), an attention-grabbing cue to indicate a potential risk due to the presence of the blind spot is initiated for the driver (step S3), and the driver's driving operation is monitored (step S4). The attention-grabbing cue operation might, for example, present a visual cue to draw the driver's attention to the sudden appearance of a pedestrian or similar object, as described in [reference to relevant section]. Fig. As shown in Figure 3A, the information is displayed on a (not shown) indicator located near the dashboard in front of the driver's seat. In this case, it is desirable to reinforce or emphasize the indication by increasing the brightness or flashing speed of the indicator as the time elapses immediately after the blind spot is detected, in order to indicate a gradual increase in the degree of potential risk. With this arrangement, the driver is informed that the device has detected the presence of the potential risk, and the device's intention to control the system is communicated to the driver.

[0030] In the step of monitoring the driver's driving operation (step S4), the driver's pressing of the brake pedal or the driver's steering wheel operation is monitored as a driving operation to avoid a potential risk. For example, it could be determined that the driving operation to avoid the potential risk was performed if the amount θb of the brake pedal press exceeded a predetermined value θth, or if the amount of a change in the steering angle δ of the steering wheel exceeded a predetermined angle δo in such a direction that the vehicle moves away from the blind spot.

[0031] If the driver's driving operation to avoid the potential risk is detected in this way, the automatic deceleration control is executed in response to the detection in a manner described below (step S6). Likewise, if no driving operation to avoid the potential risk is performed, automatic deceleration control is executed based on a device determination, irrespective of any attention-grabbing indication or display, if the elapsed time T exceeds the predetermined value Tth. During an execution of the automatic deceleration control, an indication that deceleration control is being performed is displayed in a given section of the instrument panel in front of the driver's seat, such as on the left side in Fig. 3B is shown. Then, when the automatic deceleration control ends, an indication of the end of the control can be displayed, as on the right side in Fig. 3B is shown.

[0032] Furthermore, during an execution of the automatic deceleration control, a control can be implemented to apply a reaction force to the accelerator pedal against its deceleration, in order to prevent unnecessary acceleration of the vehicle and to inform the driver that the deceleration control is being performed by the device. More precisely, during an execution of the automatic deceleration control, a reaction force F, expressed as below, can be applied to the accelerator pedal in such a direction as to reduce the accelerator pedal travel P to zero. F=−Ka•P

[0033] In the preceding expression (1), Ka is a positive coefficient. Specifically, the reaction force F increases when the accelerator pedal stroke P increases.

[0034] Referring to Fig. 4A and Fig. 4B summarizes the control sequence as described above. If a blind spot is detected while the vehicle is in motion, T is reset to 0, and a high-impact warning or display is initiated. The warning is gradually intensified over time by increasing the brightness or flashing speed I of the display, so that the driver can recognize and understand the potential risk detected by the device with greater reliability. Then, when the driver's driving operation is detected, as described in Fig. As shown in Figure 4A, an automatic deceleration control is executed from this point in time, so that a deceleration "a" is applied to the vehicle and the vehicle speed V is reduced. On the other hand, if the elapsed time T after a blind spot detection reaches Tth, as shown in Figure 4A, the vehicle is automatically decelerated. Fig. As shown in Figure 4B, the automatic deceleration control is executed from this point in time, even in the absence of a driving operation by the driver, so that a deceleration “a” is applied to the vehicle and the vehicle speed V is reduced.

[0035] If a pedestrian or similar object actually appears or emerges from the blind spot during the execution of the aforementioned control routine or after the automatic deceleration control has ended, deceleration control may be initiated by an AEB system, or a braking or steering operation by the driver may be anticipated. In this case, the alert can be changed from an indication of a potential risk to an indication of the actual occurrence of the risk (sudden appearance of a pedestrian or similar object).

[0036] As above with reference to Fig. 2A and Fig. As explained in Section 2B, the automatic deceleration control implemented in the device of this embodiment is a control for predicting a risk or possibility that a pedestrian or similar object may suddenly emerge from a blind spot when the presence of the blind spot is detected, and for decelerating the vehicle in advance in a state where the sudden appearance of a pedestrian or similar object has not been detected. In fact, a model driver is expected to perceive a risk of a pedestrian or similar object suddenly emerging from a blind spot when he / she detects such a blind spot, among the conditions explained in Section 2B. Fig. 2A, Fig. The system predicts the situations shown in 2B and slows the vehicle, even in a state where no pedestrian or similar object has been detected, to avoid contact with a pedestrian or similar object with greater reliability if the pedestrian or similar object suddenly appears from the blind spot. The automatic deceleration control of this embodiment can be viewed as a control system that simulates the driving of the model driver as described above.

[0037] According to the automatic deceleration control, brake control assistance is performed based on a driver model to predict potential risk. In this case, a brake control assistance system comprises the environment sensing unit, a driver model unit for predicting potential risk, and an assistance execution determination unit as described in Fig. Figure 1B shows the driver model used to predict potential risk. This model represents a target deceleration calculated from an optimization of a potential function capable of simulating a model driver's deceleration operation, an evaluation function defined by a risk evaluation expression using the potential function, and an operation magnitude expression used for control. The calculated target deceleration is converted into a pedal travel magnitude. Coordination control is then performed by comparing the pedal travel magnitude input by the driver with the pedal travel magnitude input by the assistance system and selecting the larger of the two. The selected pedal travel magnitude is then received by the vehicle. 1. Environment detection unit

[0038] If an environment detection sensor (camera) detects a parked vehicle, a space behind an object, a blind intersection without signals, or similar, the environment detection unit assumes that a pedestrian or similar object, currently invisible, will suddenly appear in front of the vehicle and transmits a marker indicating this assumption to the driver model unit to predict a potential risk. 2. Driver model for predicting potential risk

[0039] When the control marker is transmitted from the environment sensing unit to the driver model unit for predicting a potential risk, the driver model unit calculates the target deceleration for predicting a potential risk.

[0040] A repulsion potential function of a hypothetical pedestrian is defined as follows. Uped=12Kped(Xst−Xe(t))2(Xst <X(t)<Xfin) where Kped specifies a spring constant of the repulsion potential of the hypothetical pedestrian, and Xst and Xfin accordingly denote the minimum X-coordinate and the maximum X-coordinate between which the repulsion is received, and likewise denote the deceleration start position and the deceleration end position (see Fig. 5B). [Method of calculating the spring constant]

[0041] In a driving space where the sum of the potential energy generated by a virtual spring and the kinetic energy is conserved, the spring constant Kped of the repulsion potential of the hypothetical pedestrian is expressed as follows. Kped=m(V2min−V(t)2)(Xst−Xe(t))2−(Xst−Xfin)2

[0042] Here, the spring constant Kped is not constant. The spring constant Kped is characterized by the fact that it changes for each sampling period according to the position Xe of the vehicle and the approaching speed V.

[0043] Vmin, Xfin in the above equation (2) are obtained from the following equations (3), (4). Vmin=amax(−τx+τx2+2(X˜ped−Xfin)amax) Xfin=−Vminτx−V2min2amax+X˜ped

[0044] The coordinate position Xfin, at which the brake control based on the driver model ends to predict a potential risk, changes according to the position Yped of the hypothetical pedestrian, which is calculated based on the lateral interval Ypass between the own vehicle and the parked vehicle (see Fig. 5A). In the preceding equation (4), τx represents a reaction time (detection time) of the AEB and specifies a maxThe maximum acceleration of the AEB is indicated. Specifically, it is necessary to reduce the vehicle speed at the operational position Xfin to Vmin in order to avoid a collision caused by an AEB operation if a pedestrian suddenly appears in front of the vehicle. [Method of calculating a target deceleration of the driver model to predict a potential risk]

[0045] The target deceleration ax* is determined by optimizing a trade-off between the repulsion potential Uped with the hypothetical pedestrian at the predicted position of the own vehicle, which is specified by the following expression (5), and the magnitude of the target deceleration ax*. Xpx(ix,jx)=Xe(t)+V(t)tpx(jx)+12ax(ix)tpx(jx)2

[0046] The evaluation function is given here by the following equation (6). ax∗(t)=minapx(ix)∑jx=1Nx(Uped(Xpx(ix,jx))+rxax2)

[0047] In this connection, restrictions on the target slowdown are imposed by 0≤a x (ix)≤a xmax expressed. In the preceding equation (6), a slowdown is determined where the total value of Uped, which expresses the risk within a predicted time specified by the following equation (7), and the total value of the target slowdown are minimized. tpx(jx)=Δtpxjx(jx=0,1,2,…,Nx)

[0048] The target deceleration ax* of the driver model for predicting the potential risk is converted into the pedal stroke amount by the following equation (8). Pb−s=−Kffaax*−KfbPa(ax*−ax)−KfbP−V(V*−V)+b where Kffa is an acceleration FF gain, KfbPa is a proportional acceleration FB gain, KfbPV is a proportional velocity FB gain, and b is a stroke clearance.

[0049] While the foregoing description relates to the embodiment of this invention, many modifications and changes can easily be made by a person skilled in the art. It is evident that the invention is not limited to the embodiment shown, but can be applied to various devices and systems without departing from the concept of the invention.

[0050] A vehicle's driver assistance control device comprises a blind spot detector (70, 72), a driving operation detector (34, 44), and an electronic control unit (60). The blind spot detector (70, 72) is configured to detect the presence or absence of a blind spot from the vehicle's perspective in one direction of travel. The driving operation detector (34, 44) is configured to detect a driving operation by the driver. The electronic control unit (60) is configured to perform automatic deceleration control of the vehicle based on the detection of the presence of the blind spot by the blind spot detector (70, 72). The electronic control unit (60) is configured to initiate the automatic deceleration control by reference to the driver's driving operation after the blind spot detector (70, 72) has detected the presence of the blind spot.

Claims

Driving assistance control device of a vehicle, comprising: a blind spot detector (70, 72) configured to detect the presence or absence of a blind spot from the vehicle's perspective in a direction of travel of the vehicle; a driving operation detector (34, 44) configured to detect a driving operation of a driver;and an electronic control unit (60) configured to perform automatic deceleration control of the vehicle based on the detection of the presence of the blind spot by the blind spot detector (70, 72), wherein the electronic control unit (60) is configured to initiate the automatic deceleration control by reference to the driver's driving operation after the blind spot detector (70, 72) has detected its presence, wherein the electronic control unit (60) is configured to initiate the automatic deceleration control when a braking or steering operation by the driver is detected after the blind spot has been detected, wherein the electronic control unit (60) is configured to initiate the automatic deceleration control when a predetermined time has elapsed after the blind spot has been detected. Driving assistance control device according to claim 1, further comprising: a risk display device configured to display to the driver a risk of a sudden appearance of an object from the blind spot when the blind spot is detected. Driving assistance control device according to claim 2, wherein the risk display device is configured to visually indicate the risk of the sudden appearance of the object, wherein the risk display device is configured to express that the risk of the sudden appearance of the object increases with the passage of time. Driving assistance control device according to one of claims 1 to 3, wherein the electronic control unit (60) is configured to assume that an object suddenly emerges from the blind spot and enters a driving path of the vehicle, and to calculate an entry region of the object within the driving path, the electronic control unit (60) is configured to set a target deceleration based on a relative distance between the entry region and the vehicle, and the electronic control unit (60) is configured to perform the automatic deceleration control such that an actual deceleration of the vehicle becomes substantially equal to the target deceleration. Driving assistance control device according to claim 4, wherein the electronic control unit (60) is configured to apply a braking force to the vehicle to compensate for a difference between the target deceleration and a deceleration applied by a braking operation of the driver when the automatic deceleration control is performed. Driving assistance control device according to claim 4 or 5 wherein the electronic control unit (60) is configured to set the target deceleration based on a relative distance between the entry region and a target position set before the entry region, and a target vehicle speed of the vehicle when the vehicle reaches the target position, the target position and the target vehicle speed being set as a position and a vehicle speed at which the vehicle speed can be reduced to substantially 0 at a time when the vehicle reaches the entry region from the target position. Driving assistance control device according to claim 6, wherein the electronic control unit (60) sets the target deceleration based on a virtual spring potential, which is a spring potential obtained by modeling a braking force applied to the vehicle as a repulsion from the object, while a deceleration operation performed by a model driver to decelerate the vehicle from a given vehicle speed to the target vehicle speed as the vehicle moves from a given position to the target position. Driving assistance control device according to one of claims 1 to 7, further comprising an accelerator pedal reaction force control which applies a reaction force to an accelerator pedal of the vehicle during an implementation of the automatic deceleration control by the electronic control unit (60).

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