Travel support control device and travel support control method

Abstract

To provide a travel support control device and travel support control method which can restrain excessive avoidance behavior while avoiding collision against a front object of an own vehicle.SOLUTION: A travel support control device calculates target distance between an own vehicle and an object which exists in front of the own vehicle and sets rearward distance of approach prohibition area which is set in rear of the object on the basis of speed of the own vehicle and the target distance and controls the speed of the own vehicle so that the distance between the own vehicle and the target approaches the target distance while preventing the own vehicle from being entered into the approach prohibition area.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to a driving support control device and a driving support control method.

Background Art

[0002] In recent years, a driving support system that supports the speed or steering of a vehicle has been put into practical use. For example, in the technology of Patent Document 1, a prohibited entry area is set around an object, and the speed or steering is controlled so as not to enter the prohibited entry area, thereby controlling to avoid a collision with the object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology of Patent Document 1, when a preceding vehicle that is traveling while maintaining a certain inter-vehicle distance decelerates, the host vehicle immediately performs an avoidance operation so as not to enter the prohibited entry area. Therefore, since it reacts sensitively to a slight deceleration of the preceding vehicle, the riding comfort deteriorates. Further, when another vehicle cuts in front of the host vehicle from an adjacent lane, an excessive avoidance operation by deceleration or steering is performed to leave the prohibited entry area set near the host vehicle, and the riding comfort deteriorates.

[0005] Therefore, an object of the present disclosure is to provide a driving support control device and a driving support control method that can reliably avoid a collision with an object in front of the host vehicle while suppressing an excessive avoidance operation.

Means for Solving the Problems

[0006] The driving support control device according to the present disclosure is A host vehicle, a target setting unit that calculates a target distance between the host vehicle and an object existing in front of the host vehicle, a prohibited entry area setting unit that sets a prohibited entry area at least behind the object, and a vehicle control unit that controls the speed of the host vehicle so that the distance between the host vehicle and the object approaches the target distance while preventing the host vehicle from entering the prohibited entry area. The prohibited entry area setting unit sets a rear distance of the prohibited entry area set behind the object based on the speed of the host vehicle and the target distance.

[0007] The driving support control device according to the present disclosure includes a target setting step of calculating a target distance between a host vehicle and an object existing in front of the host vehicle, a prohibited entry area setting step of setting a prohibited entry area at least behind the object, and a vehicle control step of controlling the speed of the host vehicle so that the distance between the host vehicle and the object approaches the target distance while preventing the host vehicle from entering the prohibited entry area. In the prohibited entry area setting step, a rear distance of the prohibited entry area set behind the object is set based on the speed of the host vehicle and the target distance.

Advantages of the Invention

[0008] According to the traveling support control device and the traveling support control method according to the present disclosure, the target distance and the rear distance of the entry prohibition area are set individually, and while preventing the host vehicle from entering the entry prohibition area, the speed of the host vehicle is controlled so that the distance between the host vehicle and the object approaches the target distance. Therefore, when the host vehicle does not enter within the range of the rear distance of the entry prohibition area, the speed of the host vehicle can be controlled in consideration of the riding comfort so that the distance approaches the target distance. When the host vehicle may enter within the range of the rear distance of the entry prohibition area, the speed of the host vehicle can be controlled so that the host vehicle does not surely enter within the range of the rear distance of the entry prohibition area. Further, since the rear distance of the entry prohibition area is set based on the speed of the host vehicle and the target distance, it is possible to balance the improvement of the riding comfort and the certainty of collision avoidance in consideration of the traveling state of the host vehicle and the setting state of the target distance. Therefore, it is possible to surely avoid a collision with an obstacle in front of the host vehicle, suppress an excessive avoidance operation, and improve the riding comfort.

Brief Description of the Drawings

[0009]

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Mode for Carrying Out the Invention

[0010] 1. Embodiment 1 The driving support control device 50 according to Embodiment 1 will be described with reference to the drawings. In the present embodiment, the driving support control device 50 is provided in the host vehicle.

[0011] As shown in FIG. 1, the host vehicle includes a peripheral monitoring device 31, a position detection device 32, a vehicle state detection device 33, a map information database 34, a wireless communication device 35, a driving support control device 50, a drive control device 36, a power unit 8, an electric steering device 7, an electric brake device 9, and a human interface device 37, etc.

[0012] The peripheral monitoring device 31 is a device such as a camera or a radar that monitors the periphery of the host vehicle. For the radar, a millimeter-wave radar, a lidar, an ultrasonic radar, etc. are used. The wireless communication device 35 performs wireless communication with a base station or peripheral devices using a cellular wireless communication standard such as 4G or 5G. The wireless communication device 35 performs wireless communication with a roadside unit and peripheral vehicles, etc.

[0013] The position detection device 32 is a device that detects the current position (latitude, longitude, altitude) of the host vehicle, and a GPS antenna or the like that receives a signal output from an artificial satellite such as GNSS (Global Navigation Satellite System) is used. Note that various methods such as a map matching method, a dead reckoning method, and a method using detection information around the host vehicle may be used for detecting the current position of the host vehicle.

[0014] The map information database 34 stores road information such as road shape (e.g., number of lanes, position of each lane, shape of each lane, type of each lane, road type, speed limit, shape of intersections, etc.), road signs (speed limit signs and their speed limits, stop signs, etc.), road markings (stop lines, crosswalks, etc.), toll booths (entrance position of toll booths, passing speed of toll booths, etc.), and traffic lights. The map information database 34 is mainly composed of a storage device. Note that the map information database 34 may be provided in an external server connected to the network, and the driving support control device 50 may acquire necessary road information from the external server via the wireless communication device 35.

[0015] As the drive control device 36, a power control device, a brake control device, an automatic steering control device, a light control device, etc. are provided. The power control device controls the output of the power units 8 such as internal combustion engines and motors. The brake control device controls the braking operation of the electric brake device 9. The automatic steering control device controls the electric steering device 7. The light control device controls turn indicators, hazard lamps, etc.

[0016] The vehicle state detection device 33 is a detection device that detects the state of the host vehicle such as the driving state and the running state of the host vehicle. In the present embodiment, the vehicle state detection device 33 detects the speed, acceleration, yaw rate, steering angle, lateral acceleration, etc. of the host vehicle as the running state of the host vehicle. For example, as the vehicle state detection device 33, a speed sensor that detects the rotational speed of the wheels, an acceleration sensor, an angular velocity sensor, a steering angle sensor, etc. are provided.

[0017] As the driving state of the host vehicle, acceleration / deceleration operations, steering angle operations, and lane change operations by the driver are detected. For example, as the vehicle state detection device 33, an accelerator position sensor, a brake position sensor, a steering angle sensor (steering wheel angle sensor), a steering torque sensor, a turn indicator position switch, etc. are provided.

[0018] The human interface device 37 is a device that receives driver input such as speakers, display screens, and input devices, and transmits information to the driver.

[0019] 1-1. Driving support control device 50 The driving support control device 50 includes processing units such as an information acquisition unit 51, a target setting unit 52, an entry prohibited area setting unit 53, and a vehicle control unit 54. Each process of the driving support control device 50 is realized by a processing circuit provided in the driving support control device 50. Specifically, as shown in FIG. 2, the driving support control device 50 includes an arithmetic processing device 90 such as a CPU (Central Processing Unit), a storage device 91, and an input / output device 92 that inputs and outputs external signals to and from the arithmetic processing device 90.

[0020] As the arithmetic processing device 90, an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), a GPU (Graphics Processing Unit), an AI (Artificial Intelligence) chip, various logic circuits, and various signal processing circuits may be provided. Further, as the arithmetic processing device 90, a plurality of the same type or different types may be provided, and each process may be executed in a shared manner. As the storage device 91, various storage devices such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), and a hard disk are used.

[0021] The input / output device 92 is provided with a communication device, an A / D converter, an input / output port, a drive circuit, etc. The input / output device 92 is connected to a peripheral monitoring device 31, a position detection device 32, a vehicle state detection device 33, a map information database 34, a wireless communication device 35, a drive control device 36, a human interface device 37, etc., and communicates with these devices.

[0022] Then, each process such as those from each processing unit 51 to 54 included in the driving support control device 50 is realized by the arithmetic processing device 90 executing software (program) stored in the storage device 91 and cooperating with other hardware of the driving support control device 50 such as the storage device 91 and the input / output device 92. Note that setting data such as stage table data used by each of the processing units 51 to 54 is stored in a storage device 91 such as an EEPROM.

[0023] 1-1-1. Information acquisition unit 51 The information acquisition unit 51 acquires information on the host vehicle and information on objects existing around the host vehicle. The object is set to an object or a landmark existing in front of the host vehicle.

[0024] For example, as shown in FIG. 3, the object is set to another vehicle (hereinafter referred to as the preceding vehicle) traveling in front of the travel lane in which the host vehicle is traveling.

[0025] Also, as shown in FIG. 4, the object is set to another vehicle (preceding vehicle) traveling in front of the lane to which the host vehicle is moving. In this case, there are cases such as when changing lanes, merging lanes, or branching lanes.

[0026] Also, as shown in FIG. 5, the object is set to another vehicle (preceding vehicle) moving from an adjacent lane to in front of the host vehicle. In this case, there are cases such as when changing lanes, merging lanes, or branching lanes.

[0027] In this embodiment, the information acquisition unit 51 acquires at least the speed v of the host vehicle, the speed vtgt of the target object, the distance d between the host vehicle and the target object, and the relative speed vrel of the target object with respect to the host vehicle. The relative speed vrel is the relative speed obtained by subtracting the speed v of the host vehicle from the speed vtgt of the target object (vrel = vtgt - v).

[0028] The information acquisition unit 51 acquires the driving state of the host vehicle as information of the host vehicle. In this embodiment, the information acquisition unit 51 acquires the position, moving direction, speed, acceleration, etc. of the host vehicle based on the position information of the host vehicle acquired from the position detection device 32 and the host vehicle state acquired from the vehicle state detection device 33.

[0029] Based on the position information of the host vehicle acquired from the position detection device 32, the information acquisition unit 51 acquires road information around the host vehicle from the map information database 34. The road information to be acquired includes road shape (e.g., number of lanes, position of each lane, shape of each lane, type of each lane, road type, speed limit, shape of intersection, etc.), road signs (speed limit signs and their speed limits, stop signs, etc.), road markings (stop lines, crosswalks, etc.), toll gate information (entrance position of toll gate, passing speed of toll gate, etc.), traffic signal and other road information. The shape of each lane includes the center position of the lane, the width of the lane, the curvature of the lane, etc. The shape of the lane is set at each point along the front-rear direction of the lane. The type of each lane includes the main lane, merge lanes that merge into the main lane, etc. Also, the shape of the lane includes the start position of the merge lane, the end position of the merge lane, and the length of the merge lane.

[0030] In addition, the information acquisition unit 51 detects the shape and type of lane markings such as white lines and road shoulders acquired from the surrounding monitoring device 31, and determines the shape and position of each lane, the number of lanes, the type of each lane, etc. based on the detected shape and type of lane markings such as those of the road. The shape of each lane includes the center position of the lane, the width of the lane, the curvature of the lane, etc. The type of each lane includes the main lane, merge lanes, etc.

[0031] In addition, based on the detection information acquired from the surrounding monitoring device 31, the information acquisition unit 51 acquires information on road signs, road markings, traffic lights, and toll gates. The information acquisition unit 51 may acquire the current state of traffic lights and the like from the outside via wireless communication.

[0032] The information acquisition unit 51 acquires information on other vehicles around the host vehicle. In the present embodiment, based on the detection information acquired from the surrounding monitoring device 31 and the position information of the host vehicle acquired from the position detection device 32, the information acquisition unit 51 acquires the relative position, relative speed, and distance of other vehicles with respect to the host vehicle, as well as the position, moving direction, speed, and acceleration of other vehicles. In addition to other vehicles, the information acquisition unit 51 also acquires information such as obstacles, pedestrians, and traffic regulations such as lane regulations.

[0033] The information acquisition unit 51 may acquire, by communication from outside the host vehicle, the driving state of other vehicles (position, moving direction, speed, etc. of other vehicles), as well as road information (lane information, etc.) and traffic information (obstacles, congestion level, etc.) around the host vehicle. For example, the information acquisition unit 51 may acquire the driving state of other vehicles, as well as road information and traffic information around the host vehicle, from other vehicles or a server to which other vehicles have uploaded information, via wireless communication or the like. Further, from a roadside device such as a camera that monitors the road conditions, etc., via wireless communication or the like, the driving state of other vehicles, as well as road information and traffic information in the monitoring area, may be acquired.

[0034] Based on the position of the host vehicle, the information acquisition unit 51 acquires lane information corresponding to the lane in which the host vehicle is traveling. Further, based on the position of each other vehicle, the information acquisition unit 51 acquires lane information corresponding to the lane in which each other vehicle is traveling. The acquired lane information includes the shape, position, and type of the lane, as well as the lane information of the surrounding lanes.

[0035] 1-1-2. Target setting unit 52 The target setting unit 52 calculates a target distance d* between the host vehicle and an object existing in front of the host vehicle.

[0036] In this embodiment, the target setting unit 52 sets a target distance d* based on the speed v of the host vehicle or the speed vtgt of the target object. When the speed v of the host vehicle is used, Equation (1) is used, and when the speed vtgt of the target object is used, Equation (2) is used.

Number

Number

[0037] Here, Thw is the inter-vehicle time. Dstop is the target distance when the target object is stopped, and is referred to as the stopping distance.

[0038] In this embodiment, the target setting unit 52 refers to step table data in which relationships are set between a plurality of levels of the length of the target distance, a plurality of specified values of inter-vehicle times preset corresponding to each of the plurality of levels, and a plurality of specified values of stopping distances, reads out the specified value of the inter-vehicle time and the specified value of the stopping distance corresponding to the currently set level, and sets them as the inter-vehicle time Thw and the stopping distance Dstop.

[0039] For example, as shown in FIG. 6, the plurality of levels are set to long, medium, and short, and in the step table data, three specified values of inter-vehicle times Thw_L, Thw_M, Thw_S corresponding to the three levels, and three specified values of stopping distances Dstop_L, Dstop_M, Dstop_S are set. Here, the relationship is Thw_L > Thw_M > Thw_S, and the relationship is Dstop_L > Dstop_M > Dstop_S.

[0040] In this embodiment, the target setting unit 52 sets a target speed v* of the host vehicle based on the speed vtgt of the target object. For example, as shown in the following equation, the target setting unit 52 sets the target speed v* of the host vehicle to the speed vtgt of the target object. For example, the speed vtgt of the target object is calculated by adding the relative speed vrel of the target object with respect to the host vehicle to the speed v of the host vehicle.

Number

[0041] 1-1-3. Entry Prohibited Area Setting Unit 53 The entry prohibited area setting unit 53 sets an entry prohibited area at least behind the object. The entry prohibited area setting unit 53 sets a rear distance dlim of the entry prohibited area set behind the object based on the speed v of the host vehicle and the target distance d*.

[0042] The entry prohibited area setting unit 53 sets the rear distance dlim of the entry prohibited area to be smaller than the target distance d*, and increases the reduction amount of the rear distance dlim of the entry prohibited area with respect to the target distance d* as the speed v of the host vehicle increases.

[0043] In the present embodiment, as shown in the following formula, the entry prohibited area setting unit 53 sets, as the rear distance dlim of the entry prohibited area, the distance obtained by subtracting the distance obtained by multiplying the speed v of the host vehicle by the margin time Tmrg from the target distance d*.

Equation

[0044] The rear distance dlim of the entry prohibited area can be made shorter than the target distance d* by the multiplication distance of the speed v of the host vehicle and the margin time Tmrg.

[0045] In the present embodiment, the target setting unit 52 refers to step table data in which a relationship between a plurality of steps of the degree of the length of the target distance and a plurality of preset specified values of margin times corresponding to each of the plurality of steps is set, reads out the specified value of the margin time corresponding to the currently set step, and sets it as the margin time Tmrg.

[0046] For example, as shown in FIG. 6, the plurality of stages are set to long, medium, and short, and in the stage table data, specified values Tmrg_L, Tmrg_M, and Tmrg_S of three margin times are set corresponding to the three stages. Here, the relationship is Tmrg_L > Tmrg_M > Tmrg_S. Alternatively, it may be set such that as the inter-vehicle time Thw becomes longer, the ratio of the margin time Tmrg to the inter-vehicle time Thw increases, such as Tmrg_L / Thw_L > Tmrg_M / Thw_M > Tmrg_S / Thw_S.

[0047] 1-1-4. Vehicle control unit 54 The vehicle control unit 54 controls the speed of the host vehicle so that the distance between the host vehicle and the object approaches the target distance d* while preventing the host vehicle from entering the prohibited entry area.

[0048] In the present embodiment, the vehicle control unit 54 uses a dynamic vehicle model representing the behavior of the host vehicle, calculates predicted values de of the distance at each future time point and predicted values ve of the speed of the host vehicle at each future time point, and under the constraint condition that the host vehicle does not enter the range of the rear distance dlim of the prohibited entry area, solves an optimization problem having an evaluation function J for evaluating the distance deviation between the target distance d* and the predicted value de of the distance and the speed deviation between the target speed v* and the predicted value ve of the speed, calculates a command value aref of the acceleration at each future time point, and controls the speed v of the host vehicle based on the command value aref of the acceleration.

[0049] The constrained optimization problem is formulated as follows. The following formula represents that a control input u that minimizes the evaluation function J is obtained. Here, x is the vehicle state quantity, and x0 is the initial value of the vehicle state quantity x. Also, x' is the predicted value of the vehicle state quantity x. f(x, u) is a vector-valued function related to the dynamic vehicle model. g is a constraint condition that constrains the vehicle state quantity x and the control input u, and the optimization problem is solved while satisfying the constraint condition. Note that the positive and negative of the evaluation function may be inverted to be a maximization problem that maximizes the evaluation function.

Equation

[0050] The vehicle state quantity x and the control input u are set as follows. Here, de is the predicted value of the distance, ve is the predicted value of the speed of the host vehicle, and ae is the predicted value of the acceleration of the host vehicle. Also, [...] T represents the transpose matrix. [Number]

[0051] The dynamic vehicle model can be expressed as follows. Here, Ta is the response delay of the drive control device with respect to the acceleration command value aref. [Number]

[0052] The vehicle control unit 54 uses the dynamic vehicle model to calculate the predicted value de of the distance and the predicted value ve of the speed of the host vehicle from the current time t = 0 to the future time point up to the prediction period Th. The vehicle control unit 54 solves an optimization problem of obtaining the control input u that minimizes the evaluation function J that evaluates each of the distance deviation and the speed deviation under the constraint condition that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area at every predetermined calculation period Tper, and calculates the solution as the acceleration command value aref.

[0053] At this time, the number of prediction time points is N. The number of time points N is obtained by N = Th / Tper. The period from the current time t = 0 to the future time point up to the prediction period Th is called the "horizon".

[0054] The evaluation function J is expressed as follows. Here, h(k) is a vector-valued function regarding the evaluation items at each prediction time point k (k = 0, ···, N - 1), and h(N) is a vector-valued function regarding the evaluation items at the prediction time point N. r(k) is the target value at each prediction time point k (k = 0, ···, N - 1), and r(N) is the target value at the prediction time point N. W and WN are weight matrices, which are diagonal matrices having the weights for the respective evaluation items in the diagonal components.

Number

[0055] ?The vehicle control unit 54 sets the vector value functions h(k) and h(N) related to the evaluation items as follows. Here, de(k) is the predicted value de of the distance at each prediction time point k (k = 0, ···, N). ve(k) is the predicted value ve of the speed of the host vehicle at each prediction time point k (k = 0, ···, N). Aref(k) is the command value of the acceleration at each prediction time point k (k = 0, ···, N).

Number

[0056] The vehicle control unit 54 sets the target values r(k) and r(N) for the vector value functions h and hN related to the evaluation items using the target distance d* and the target speed v* of the host vehicle.

Number

[0057] The vehicle control unit 54 sets a constraint condition such that the predicted value de(k) of the distance at each prediction time point k is equal to or greater than the rear distance dlim so that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area, as shown in the following equation.

Number

[0058] The vehicle control unit 54 evaluates the deviation between the vector-valued function h(k) and the target value r(k), and the deviation between the vector-valued function h(N) and the target value r(N) using the evaluation function J. The vehicle control unit 54 solves an optimization problem of obtaining a control input u that minimizes the evaluation value of each deviation under the constraint condition that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area at each predetermined calculation cycle, and sets the command value aref(k) of the acceleration at each prediction time k of the obtained solution as the command value aref(t) of the acceleration at each future time t. Since the process of solving the optimization problem itself is a known technique, detailed description thereof is omitted.

[0059] The vehicle control unit 54 sets the command value aref of the acceleration corresponding to the current time from the command value aref(t) of the acceleration at each future time t, calculates the command value of the output of the power unit 8 and the command value of the braking force of the electric brake device 9 based on the command value aref of the acceleration, and transmits each command value to the power control device and the brake control device.

[0060] The power control device controls the output of the power unit 8 such as the internal combustion engine and the motor according to the command value of the output. The brake control device controls the braking operation of the electric brake device 9 according to the command value of the braking force.

[0061] <Control behavior> An example of the control behavior is shown in FIG. 7. The upper graph in FIG. 7 shows the information related to the distance between the host vehicle and the object (preceding vehicle), and the lower graph in FIG. 7 shows the information related to the speed of the host vehicle. Until the time t01, the host vehicle and the preceding vehicle are traveling at a constant speed, and the distance d between the host vehicle and the preceding vehicle is maintained at the target distance d*. The rear distance dlim of the entry prohibited area is set shorter than the target distance d* by the multiplication distance of the speed v of the host vehicle and the margin time Tmrg.

[0062] From time t01, the leading vehicle is decelerating rapidly. In the example of Fig. 7, the target distance d* is set in proportion to the speed vtgt of the leading vehicle using Equation (2). Therefore, the target distance d* decreases in proportion to the speed vtgt of the leading vehicle, and the rear distance dlim of the no-entry area decreases in response to the decrease in the speed vtgt of the leading vehicle. Also, the target speed v* of the host vehicle is set to the speed vtgt of the leading vehicle. Therefore, the target speed v* decreases in the same way as the deceleration of the speed vtgt of the leading vehicle.

[0063] After the start of rapid deceleration of the leading vehicle, in a state not restricted by the constraint condition of the rear distance dlim of the no-entry area, the command value aref of the acceleration is decreased so that the speed v and the distance d of the host vehicle follow the target speed v* and the target distance d*, and the speed v and the distance d of the host vehicle are decreasing. However, due to the following delay, the speed v of the host vehicle exceeds the target speed v* and the speed vtgt of the leading vehicle, and the distance d exceeds the target distance d*. Since the distance d is the integral value of the relative speed between the speed v of the host vehicle and the speed vtgt of the leading vehicle, the decrease amount of the distance d with respect to the target distance d* becomes large after the start of deceleration of the leading vehicle with a delay, and at time t02, the distance d has decreased to the rear distance dlim of the no-entry area.

[0064] After time t02, since the command value aref of the acceleration is calculated under the constraint condition of the rear distance dlim of the no-entry area, the command value aref of the acceleration is calculated so that the host vehicle does not enter the range of the rear distance dlim of the no-entry area. Therefore, the command value aref of the acceleration is further decreased, and the speed v of the host vehicle is further decreased.

[0065] After time t03, the distance d begins to exceed the rear distance dlim of the no-entry area, and the speed v and the distance d of the host vehicle gradually converge to the target speed v* and the target distance d*.

[0066] At time t02, some time has passed since the deceleration of the preceding vehicle and the start of the deceleration of the host vehicle, and the deceleration of the host vehicle is in progress. Therefore, even if deceleration is performed so that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area, it does not give the driver a strong sense of discomfort. Accordingly, it is possible to realize a comfortable control that surely avoids a collision with the preceding vehicle and does not overly react to the deceleration of the preceding vehicle.

[0067] 1-1-5. Flowchart Next, the schematic processing procedure (vehicle driving support method) of the driving support control device 50 according to the present embodiment will be described using the flowchart shown in FIG. 8. The processing of the flowchart in FIG. 8 is executed, for example, at every predetermined calculation cycle. Note that the processing of steps that are unnecessary at the execution time is skipped as appropriate.

[0068] In step S11, as described above, the information acquisition unit 51 determines whether there is an object to be controlled for distance around the host vehicle. If there is, the process proceeds to step S12, and if not, the process ends.

[0069] In step S12, as described above, the information acquisition unit 51 acquires the information of the host vehicle and the information of the object existing around the host vehicle.

[0070] In step S13, as described above, the target setting unit 52 calculates the target distance d* between the host vehicle and the object existing in front of the host vehicle. Further, the target setting unit 52 sets the target speed v* of the host vehicle based on the speed vtgt of the object.

[0071] In step S14, as described above, the entry prohibited area setting unit 53 sets an entry prohibited area at least behind the object. The entry prohibited area setting unit 53 sets the rear distance dlim of the entry prohibited area set behind the object based on the speed v and the target distance d* of the host vehicle.

[0072] In step S15, as described above, the vehicle control unit 54 controls the speed of the host vehicle so that the distance between the host vehicle and the object approaches the target distance d* while preventing the host vehicle from entering the prohibited entry area.

[0073] 2. Embodiment 2 Next, the driving support control device 50 according to Embodiment 2 will be described. The components having the same configuration as those in Embodiment 1 described above will not be described. The basic configuration of the driving support control device 50 according to the present embodiment is the same as that in Embodiment 1, but the method of setting the rear distance dlim of the prohibited entry area is different from that in Embodiment 1.

[0074] In the present embodiment, the prohibited entry area setting unit 53 increases the rear distance dlim of the prohibited entry area as the relative speed vrel of the object obtained by subtracting the speed v of the host vehicle from the speed vtgt of the object increases in the negative direction, and shortens the rear distance dlim of the prohibited entry area as the relative speed vrel increases in the positive direction.

[0075] According to this configuration, as the relative speed vrel increases in the negative direction and the decreasing speed of the distance d increases, the host vehicle can be decelerated earlier by increasing the rear distance dlim of the prohibited entry area, ensuring the distance d, and more reliably preventing a collision with the object. Also, by starting deceleration earlier, the peak of the deceleration can be suppressed, improving the riding comfort. On the other hand, as the relative speed vrel increases in the positive direction and the increasing speed of the distance d increases, the possibility of a collision with the object decreases, so even if the rear distance dlim of the prohibited entry area is shortened, there is no possibility of a collision with the object.

[0076] The prohibited entry area setting unit 53 increases the rear distance dlim of the prohibited entry area as the relative acceleration arel of the object obtained by subtracting the acceleration a of the host vehicle from the acceleration atgt of the object increases in the negative direction, and shortens the rear distance dlim of the prohibited entry area as the relative acceleration arel increases in the positive direction.

[0077] According to this configuration, as the relative acceleration arel increases in the negative direction and the deceleration acceleration of the distance d increases, by increasing the rear distance dlim of the prohibited entry area, the host vehicle can be decelerated early, the distance d can be ensured, and a collision with the object can be more reliably prevented. Also, by starting deceleration early, the peak of the deceleration can be suppressed, improving the riding comfort. On the other hand, as the relative acceleration arel increases in the positive direction and the acceleration of the distance d increases, the possibility of a collision with the object decreases, so even if the rear distance dlim of the prohibited entry area is shortened, there is no possibility of colliding with the object.

[0078] In this embodiment, the prohibited entry area setting unit 53 sets the rear distance dlim of the prohibited entry area using the following formula. Here, kv is a coefficient for the relative speed, set to a negative value, and ka is a coefficient for the relative acceleration, set to a negative value.

Equation

[0079] Note that the setting of the rear distance dlim of the prohibited entry area according to the relative acceleration arel may not be performed. Also, instead of kv×vrel, a function such as map data or a mathematical formula in which the relationship between the relative speed vrel and the added value with respect to the target distance d* is set may be used. Instead of ka×arel, a function such as map data or a mathematical formula in which the relationship between the relative acceleration arel and the added value with respect to the target distance d* is set may be used.

[0080] <Control Behavior> Fig. 9 shows an example of control behavior. The upper graph in Fig. 9 shows information related to the distance between the host vehicle and the target object (preceding vehicle), and the lower graph in Fig. 9 shows information related to the speed of the host vehicle. The preceding vehicle is traveling at a constant speed vtgt, the speed v of the host vehicle is greater than the speed vtgt of the preceding vehicle, and the relative speed vrel is negative. The host vehicle is approaching the preceding vehicle from behind the preceding vehicle. The target distance d* is set in proportion to the speed vtgt of the preceding vehicle using Equation (2). Since the speed vtgt of the preceding vehicle is constant, the target distance d* is constant.

[0081] Since the relative speed vrel is negative, the rear distance dlim of the entry prohibited region is greater than the target distance d* according to the magnitude of the relative speed vrel. As the speed v of the host vehicle approaches the speed vtgt of the preceding vehicle and the magnitude of the relative speed vrel decreases, the increase amount of the rear distance dlim of the entry prohibited region with respect to the target distance d* decreases.

[0082] At time t11, the distance d has decreased to the rear distance dlim of the entry prohibited region. After time t11, since the command value aref of the acceleration is calculated under the constraint condition of the rear distance dlim of the entry prohibited region, the command value aref of the acceleration is increased in the negative direction so that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited region, and the speed v of the host vehicle further decreases. Therefore, the host vehicle can be decelerated early so that the distance d does not decrease too much with respect to the magnitude of the relative speed vrel, the distance d can be secured, and the collision with the target object can be more reliably prevented. In addition, by starting deceleration early, the peak of the deceleration can be suppressed, and the riding comfort can be improved.

[0083] 3. Embodiment 3 Next, the travel support control device 50 according to Embodiment 3 will be described. Description of the constituent parts similar to those in the above Embodiment 1 will be omitted. The basic configuration of the travel support control device 50 according to the present embodiment is the same as that in Embodiment 1, but a plan generation unit 55 is further provided, and accordingly, the processing of the entry prohibition area setting unit 53 and the vehicle control unit 54 is different from that in Embodiment 1. FIG. 10 shows a block diagram of the travel support control device 50 according to the present embodiment.

[0084] <Planning generation unit 55> The planning generation unit 55 calculates the transient target distance dplan*(t) at each future time point t until the distance d reaches the target distance d*, and the transient target speed vplan*(t) at each future time point t until the speed v of the host vehicle reaches the target speed v*.

[0085] In the present embodiment, the planning generation unit 55 performs a filtering process on the target distance d* at the virtual time representing each future time point t from the present to the time point in the future by the planning period, and calculates the transient target distance dplan*(t) at each future time point t.

[0086] For example, the calculation shown in the following formula is performed. Here, s is the Laplace operator, F(s) is the transfer function representing the filtering process, d*(s) represents the Laplace-transformed target distance d*, and L -1 represents the inverse Laplace transform. Note that a discretized formula is used in the actual calculation formula.

Equation

[0087] For the filtering process, various low-pass filter processes are used. For example, a moving average process with multiple stages (for example, 3 stages or 4 stages) is used for the filtering process.

[0088] In this embodiment, the plan generation unit 55 calculates the transient target speed vplan*(t) at each future time point t based on the time derivative value of the transient target distance dplan*(t) and the target speed v* at each future time point t in the virtual time representing each future time point t from the current time to the time point of the planning period ahead.

[0089] For example, the calculation shown in the following formula is performed. Here, s represents the differential operation. Note that a discretized formula is used in the actual calculation formula.

Equation

[0090] Note that the plan generation unit 55 calculates the time derivative value of the initial output value of the filter process at the current time t = 0 such that the transient target speed vplan*(0) at the current time t = 0 matches the speed v of the current host vehicle, calculates the initial output value of the filter process at the current time t = 0 such that the transient target distance dplan*(0) at the current time t = 0 matches the current distance d, and at the current time t = 0, sets the initial internal calculation value of the filter process such that the time derivative value of the output value of the filter process matches the time derivative value of the initial output value and the output value of the filter process matches the initial output value.

[0091] The calculation of the transient target distance dplan* and the transient target speed vplan* is executed, for example, when a new object is set, or when the state of the object changes, or when a specific condition is satisfied.

[0092] <Prohibited entry area setting unit 53> The prohibited entry area setting unit 53 calculates the rear distance dlim(t) of the prohibited entry area at each future time point t based on the target distance d* and the transient target distance dplan*(t) at each future time point t.

[0093] In this embodiment, the prohibited entry area setting unit 53 sets, as the rear distance dlim(t) of the prohibited entry area at each future time point t, the smaller value between the target distance d* and the transient target distance dplan*(t) at each future time point t, as shown in the following equation.

Equation

[0094] Alternatively, the prohibited entry area setting unit 53 may set, as the rear distance dlim(t) of the prohibited entry area at each future time point t, the distance obtained by subtracting the distance obtained by multiplying the speed v of the host vehicle by the margin time Tmrg from the smaller value between the target distance d* and the transient target distance dplan*(t) at each future time point t, as shown in the following equation.

Equation

[0095] <Vehicle control unit 54> In this embodiment, the vehicle control unit 54 controls the speed v of the host vehicle so that the host vehicle does not enter the range of the rear distance dlim of the prohibited entry area at each future time point, while the distance d approaches the transient target distance dplan* at each future time point and the speed v of the host vehicle approaches the transient target speed vplan* at each future time point.

[0096] In this embodiment, the vehicle control unit 54 uses a dynamic vehicle model representing the behavior of the host vehicle to calculate the predicted value de of the distance at each future time point and the predicted value ve of the speed of the host vehicle at each future time point. Under the constraint condition that the host vehicle does not enter the range of the rear distance dlim of the prohibited entry area at each future time point, the vehicle control unit 54 solves an optimization problem having an evaluation function for evaluating the distance deviation between the predicted value de of the distance at each future time point and the transient target distance dplan* at each future time point, and the speed deviation between the predicted value ve of the speed of the host vehicle at each future time point and the transient target speed vplan* at each future time point, to calculate the command value aref of the acceleration at each future time point, and controls the speed v of the host vehicle based on the command value aref of the acceleration.

[0097] In the vehicle control unit 54, the following equations are different from those in the first embodiment, but the other equations are the same as those in the first embodiment.

[0098] In the present embodiment, as shown in the following equation, the vehicle control unit 54 sets target values r(k) and r(N) for the vector value functions h(k) and h(N) regarding the evaluation items by using the transient target distance dplan* at each future time point and the transient target speed vplan* at each future time point.

Equation

[0099] Here, based on the transient target distance dplan*(t) at each future time point t, the transient target distance dplan*(k) at each corresponding prediction time point k is set, and based on the transient target speed vplan*(t) at each future time point t, the transient target speed vplan*(k) at each corresponding prediction time point k is set.

[0100] The vehicle control unit 54 sets a constraint condition such that the predicted value de(k) of the distance at each prediction time point k is equal to or greater than the rear distance dlim(k) at each prediction time point k so that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area at each future time point, as shown in the following equation.

Equation

[0101] Here, based on the rear distance dlim(t) of the entry prohibited area at each future time point t, the rear distance dlim(k) of the entry prohibited area at each corresponding prediction time point k is set.

[0102] <Control Behavior> An example of the control behavior is shown in FIG. 11. The upper graph in FIG. 11 shows information related to the distance between the host vehicle and the object (preceding vehicle), and the lower graph in FIG. 11 shows information related to the speed of the host vehicle. FIG. 11 shows the behavior after another vehicle changes lanes (cuts in) in front of the host vehicle as shown in FIG. 5.

[0103] At time t20, another vehicle changes lanes in front of the host vehicle, the other vehicle is set as an object, a target distance d* is set, and speed control is started. The target distance d* is set in proportion to the speed vtgt of the preceding vehicle using Equation (2). Since the speed vtgt of the preceding vehicle is constant, the target distance d* is constant. Also, the target speed v* of the host vehicle is set to the speed vtgt of the preceding vehicle.

[0104] At time t20, the speed v of the host vehicle is greater than the speed vtgt of the preceding vehicle. The transient target distance dplan* at each future time point until the distance d reaches the target distance d* and the transient target speed vplan* at each future time point until the speed v of the host vehicle reaches the target speed v* are calculated. The transient target distance dplan* at each future time point is smaller than the target distance d*, and the transient target distance dplan* at each future time point is set as the rear distance dlim of the no-entry region at each future time point.

[0105] Then, the command value aref of the acceleration is calculated under the constraint condition of the rear distance dlim (transient target distance dplan*) of the no-entry region, and the command value aref of the acceleration is calculated so that the host vehicle does not enter the range of the rear distance dlim of the no-entry region. As a result, the distance d is controlled along the rear distance dlim (transient target distance dplan*) of the no-entry region, and the speed v of the host vehicle is controlled along the transient target speed vplan*.

[0106] Since the transient target distance dplan* set as the rear distance dlim of the no-entry region is a plan of the target distance until the distance d reaches the target distance d*, even if the transient target distance dplan* is set as a constraint condition, it is possible to suppress excessive acceleration and deceleration of the host vehicle and perform planned and appropriate acceleration and deceleration. Therefore, even when another vehicle cuts in front of the host vehicle, it is possible to surely avoid a collision with the preceding vehicle and realize a comfortable control without excessively accelerating and decelerating with respect to the preceding vehicle.

[0107] Next, using the flowchart shown in FIG. 12, the general processing procedure (vehicle driving support method) of the driving support control device 50 according to the present embodiment will be described. The processing of the flowchart in FIG. 12 is executed, for example, at every predetermined calculation cycle. Note that the processing of steps that are unnecessary at the execution time is skipped as appropriate.

[0108] In step S21, as described above, the information acquisition unit 51 determines whether there is an object to be controlled for distance around the host vehicle. If there is, the process proceeds to step S22. If not, the process ends.

[0109] In step S22, as described above, the information acquisition unit 51 acquires the information of the host vehicle and the information of the object existing around the host vehicle.

[0110] In step S23, as described above, the target setting unit 52 calculates the target distance d* between the host vehicle and the object existing in front of the host vehicle. Further, the target setting unit 52 sets the target speed v* of the host vehicle based on the speed vtgt of the object.

[0111] In step S24, as described above, the plan generation unit 55 calculates the transient target distance dplan*(t) at each future time point t until the distance d reaches the target distance d*, and the transient target speed vplan*(t) at each future time point t until the speed v of the host vehicle reaches the target speed v*.

[0112] In step S25, as described above, the entry prohibited area setting unit 53 sets an entry prohibited area at least behind the object. The entry prohibited area setting unit 53 calculates the rear distance dlim(t) of the entry prohibited area at each future time point t based on the target distance d* and the transient target distance dplan*(t) at each future time point t.

[0113] In step S26, as described above, the vehicle control unit 54 controls the speed v of the host vehicle so that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area at each future point in time, while the distance d approaches the transient target distance dplan* at each future point in time, and the speed v of the host vehicle approaches the transient target speed vplan* at each future point in time.

[0114] <Other Embodiments> (1) In each of the above embodiments, the case where the object is set as the preceding vehicle in front of the host vehicle has been described as an example. However, the object may be set as various objects such as a stationary object or a stop position existing in front of the host vehicle. The stationary object is set as a stationary vehicle, an obstacle, etc. existing in front of the host vehicle. The stop position is set as various stop lines (for example, a stop line for a temporary stop, a stop line for a crosswalk, a stop line for an intersection), a stop line of a traffic signal, or a stop position due to various factors. In this case, since the speed vtgt of the object is 0, the target speed v* is set to 0.

[0115] (2) In Embodiment 3, the entry prohibited area setting unit 53 may calculate the lower limit value Tlim(t) of the inter-vehicle time at each future point in time t as an alternative parameter representing the rear distance dlim of the entry prohibited area at each future point in time based on the rear distance dlim(t) of the entry prohibited area at each future point in time t and the transient target speed vplan*(t) at each future point in time t.

[0116] For example, as shown in the following formula, the entry prohibited area setting unit 53 divides the value obtained by subtracting the stop distance Dstop from the rear distance dlim(t) of the entry prohibited area at each future point in time t by the transient target speed vplan*(t) at each future point in time t to calculate the lower limit value Tlim(t) of the inter-vehicle time at each future point in time. The stop distance Dstop is the target distance when the object is stationary.

Equation

[0117] Then, the vehicle control unit 54 controls the speed v of the host vehicle so that the headway time Thw of the host vehicle calculated based on the distance d and the speed v of the host vehicle does not become smaller than the lower limit value Tlim of the headway time at each future time point, while the distance d approaches the transient target distance dplan* at each future time point and the speed v of the host vehicle approaches the transient target speed vplan* at each future time point.

[0118] Specifically, the vehicle control unit 54 uses a dynamic vehicle model representing the behavior of the host vehicle to calculate the predicted value de of the distance at each future time point and the predicted value ve of the speed of the host vehicle at each future time point, and under the constraint condition that the predicted value Thwe of the headway time of the host vehicle at each future time point calculated based on the predicted value de of the distance at each future time point and the predicted value ve of the speed at each future time point does not become smaller than the lower limit value Tlim(t) of the headway time at each future time point, it solves an optimization problem having an evaluation function for evaluating the distance deviation between the predicted value de of the distance at each future time point and the transient target distance dplan*, and the speed deviation between the predicted value ve of the speed of the host vehicle at each future time point and the transient target speed vplan* at each future time point, calculates the command value aref of the acceleration at each future time point, and controls the speed of the host vehicle based on the command value aref of the acceleration.

[0119] As shown in the following formula, the vehicle control unit 54 divides the value obtained by subtracting the stop distance Dstop from the predicted value de(k) of the distance at each prediction time point k by the predicted value ve(k) of the speed at each prediction time point k to calculate the predicted value Thwe(k) of the headway time at each prediction time point k.

Equation

[0120] As shown in the following formula, the vehicle control unit 54 sets a constraint condition such that the predicted value Thwe(k) of the headway time at each prediction time point k is equal to or greater than the lower limit value Tlim(k) of the headway time at each prediction time point k so that the predicted value Thwe(k) of the headway time at each prediction time point k does not become smaller than the lower limit value Tlim(k) of the headway time at each prediction time point k.

Equation

[0121] (3) In each of the above embodiments, the vehicle control unit 54 has been described by taking as an example the case of solving an optimization problem to control the speed of the host vehicle. In Embodiments 1 and 2, the vehicle control unit 54 may control the speed v of the host vehicle so that the distance d approaches the target distance d* while preventing the host vehicle from entering the entry prohibited area by using a control method other than solving the optimization problem. For example, the vehicle control unit 54 changes the command value aref of the acceleration so that the distance d approaches the target distance d* by feedback control, and when there is a possibility that the host vehicle may enter the entry prohibited area, the vehicle control unit 54 may change the command value aref of the acceleration so that the host vehicle does not enter the entry prohibited area.

[0122] In Embodiment 3, the vehicle control unit 54 may control the speed v of the host vehicle so that the host vehicle does not enter the range of the rear distance dlim of the entry prohibited area at each future time point, while the distance d approaches the transient target distance dplan* at each future time point and the speed v of the host vehicle approaches the transient target speed vplan* at each future time point, by using a control method other than solving the optimization problem. For example, the vehicle control unit 54 changes the command value aref of the acceleration so that the distance d approaches the transient target distance dplan* at each future time point and the speed v of the host vehicle approaches the transient target speed vplan* at each future time point by feedback control, and when there is a possibility that the host vehicle may enter the range of the rear distance dlim of the entry prohibited area at each future time point, the vehicle control unit 54 may change the command value aref of the acceleration so that the host vehicle does not enter the entry prohibited area.

[0123] Although various exemplary embodiments and examples are described, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable to the embodiments alone or in various combinations. Accordingly, numerous variations not illustrated are envisioned within the scope of the technology disclosed in this specification. For example, it is assumed to include cases where at least one component is modified, added, or omitted, and further cases where at least one component is extracted and combined with components of other embodiments.

Description of Reference Numerals

[0124] 50: Driving support control device, 52: Target setting unit, 53: Entry prohibited area setting unit, 54: Vehicle control unit, 55: Plan generation unit, a: Acceleration of own vehicle, aref: Command value of acceleration, arel: Relative acceleration, atgt: Acceleration of object, d*: Target distance, d: Distance, de: Predicted value of distance, dlim: Rear distance of entry prohibited area, dplan*: Transitional target distance, v: Speed of own vehicle, v*: Target speed, ve: Predicted value of speed of own vehicle, vplan*: Transitional target speed, vrel: Relative speed, vtgt: Speed of object, J: Evaluation function, Thwe: Predicted value of inter-vehicle time, Tlim: Lower limit value of inter-vehicle time, Tmrg: Margin time

Claims

1. A target distance calculation unit that calculates a target distance between the host vehicle and an object existing in front of the host vehicle, An entry prohibition area setting unit that sets an entry prohibition area at least behind the object, A vehicle control unit that controls the speed of the host vehicle so that the distance between the host vehicle and the object approaches the target distance while preventing the host vehicle from entering the entry prohibition area, and The entry prohibition area setting unit is a driving support control device that sets a rear distance of the entry prohibition area set behind the object based on the speed of the host vehicle and the target distance.

2. The driving support control device according to claim 1, wherein the entry prohibition area setting unit sets, as the rear distance of the entry prohibition area, a distance obtained by multiplying the speed of the host vehicle by a delay time and subtracting the result from the target distance.

3. The driving support control device according to claim 2, wherein the entry prohibition area setting unit refers to step table data in which a relationship between a plurality of steps corresponding to the degree of the length of the target distance and a plurality of specified values of delay times preset for each of the plurality of steps is set, reads out the specified value of the delay time corresponding to the currently set step, and sets the delay time.

4. The driving support control device according to claim 1, wherein the entry prohibition area setting unit increases the rear distance of the entry prohibition area as the relative speed of the object, which is obtained by subtracting the speed of the host vehicle from the speed of the object, becomes larger in the negative direction, and decreases the rear distance of the entry prohibition area as the relative speed becomes larger in the positive direction.

5. The driving support control device according to claim 4, wherein the entry prohibition area setting unit increases the rear distance of the entry prohibition area as the relative acceleration of the object, which is obtained by subtracting the acceleration of the host vehicle from the acceleration of the object, becomes larger in the negative direction, and decreases the rear distance of the entry prohibition area as the relative acceleration becomes larger in the positive direction.

6. A plan generation unit that calculates a transient target distance at each future time point until the distance reaches the target distance and a transient target speed at each future time point until the speed of the host vehicle reaches the target speed, and The driving support control device according to claim 1, wherein the entry prohibition area setting unit calculates the rear distance of the entry prohibition area at each future time point based on the target distance and the transient target distance at each future time point.

7. The traveling support control device according to claim 6, wherein the entry prohibition area setting unit sets the smaller value of the target distance and the transient target distance at each future time point as the rear distance of the entry prohibition area at each future time point.

8. The traveling support control device according to claim 6, wherein the entry prohibition area setting unit sets, as the rear distance of the entry prohibition area at each future time point, a distance obtained by subtracting a distance obtained by multiplying the vehicle speed of the host vehicle by a delay time from the smaller value of the target distance and the transient target distance at each future time point.

9. The traveling support control device according to any one of claims 6 to 8, wherein the vehicle control unit controls the speed of the host vehicle so that the host vehicle does not enter the range of the rear distance of the entry prohibition area at each future time point, while the distance approaches the transient target distance at each future time point and the speed of the host vehicle approaches the transient target speed at each future time point.

10. Based on the rear distance of the entry prohibition area at each future time point and the transient target speed at each future time point, the entry prohibition area setting unit calculates a lower limit value of the inter-vehicle time at each future time point as an alternative parameter representing the rear distance of the entry prohibition area at each future time point. The traveling support control device according to claim 6, wherein the vehicle control unit controls the speed of the host vehicle so that the inter-vehicle time of the host vehicle calculated based on the distance and the speed of the host vehicle does not become smaller than the lower limit value of the inter-vehicle time at each future time point, while the distance approaches the transient target distance at each future time point and the speed of the host vehicle approaches the transient target speed at each future time point.

11. The entry prohibition area setting unit divides, by the transient target speed at each future time point, a value obtained by subtracting the stop distance, which is the target distance when the object is stopped, from the rear distance of the entry prohibition area at each future time point, to calculate the lower limit value of the inter-vehicle time at each future time point. The traveling support control device according to claim 10, wherein the vehicle control unit divides a value obtained by subtracting the stop distance from the distance by the speed of the host vehicle to calculate the inter-vehicle time.

12. A target distance calculation step of calculating a target distance between the host vehicle and an object existing in front of the host vehicle; An entry prohibition area setting step of setting an entry prohibition area at least behind the object; A vehicle control step of controlling the speed of the host vehicle so that the distance between the host vehicle and the object approaches the target distance while preventing the host vehicle from entering the prohibited entry area; A driving support control method for determining a rear distance of the prohibited entry area set behind the object based on the speed of the host vehicle and the target distance in the prohibited entry area setting step.

Images