Vehicle control device, vehicle control method, and program

Abstract

To provide a vehicle control device, a vehicle control method, and a program that can perform suitable automated driving control even in situations where it is necessary to consider the positional relationship with other road users while driving. [Solution] A vehicle control device comprising: an objective function determination unit that determines a combination of an objective function, formulated using auxiliary variables corresponding to predetermined scenarios assumed from the positional relationship with other traffic participants while the vehicle is in motion, with acceleration in the future as the control variable, and a limiting condition equation for setting restrictions on the future driving, according to the recognized surrounding conditions of the vehicle; and a speed determination unit that determines the driving speed of the vehicle in the future driving based on the combination of the objective function and the limiting condition equation, wherein the auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the scenario.

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a program. [Background technology]

[0002] In recent years, the practical application of autonomous driving, which automatically controls the movement of vehicles, has been progressing. Through research and development related to this autonomous driving technology, we are focusing on research and development that will further improve the safety and convenience of traffic.

[0003] Conventionally, technologies have been disclosed for vehicle control systems that perform optimal speed-related action planning by calculating state values ​​in the control of autonomous vehicles (see, for example, Patent Document 1). This conventional technology can take into account the constraints necessary for driving on public roads. However, this conventional technology did not take into account the ride comfort of the vehicle during autonomous driving.

[0004] On the other hand, in recent years, research has been conducted on automatic control when vehicles turn at intersections or cross lanes, for example, using the Multi-Profile Quadratic Programming (MPQP) method. However, in this type of automatic control, it has sometimes been difficult to calculate an appropriate driving speed that takes into account changes in the speed limit according to the vehicle's position while driving. Furthermore, when other vehicles are present in other driving lanes, it has been necessary to divide the processing of the action plan, which has sometimes increased the processing load. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-107296 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Incidentally, in autonomous driving technology, it is desirable to suppress the occurrence of jerk (a sudden, bouncy movement) that occurs due to changes in driving speed during autonomous driving in order to improve the ride comfort of the vehicle. However, conventional technology requires quantizing the jerk. And in order to continuously optimize the ride comfort during autonomous driving with conventional technology, the quantization of the jerk needs to be sufficiently fine, which results in an enormous number of quantized elements, leading to an increase in computational load, and thus an increase in the processing load related to autonomous driving.

[0007] This invention was made based on the above-mentioned problem recognition and aims to provide a vehicle control device, vehicle control method, and program that can perform suitable automated driving control even in situations where it is necessary to consider the positional relationship with other traffic participants while driving. In other words, this invention aims to achieve more suitable automated control according to the situation of the vehicle itself and other traffic participants other than the vehicle itself. And ultimately, it will contribute to the development of a sustainable transportation system. [Means for solving the problem]

[0008] The vehicle control device, vehicle control method, and program according to this invention employ the following configuration. (1) A vehicle control device according to one aspect of the present invention comprises: an objective function determination unit that determines a combination of an objective function, which is formulated using auxiliary variables corresponding to a predetermined scenario that can be assumed from the positional relationship with other traffic participants while the vehicle is in motion, with acceleration in the future as the control variable, and a limiting condition expression for setting a limit on the future driving, according to the recognized surrounding conditions of the vehicle; and a speed determination unit that determines the driving speed of the vehicle in the future driving based on the combination of the objective function and the limiting condition expression, wherein the auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the scenario.

[0009] (2): In the embodiment of (1) above, the limiting condition formula includes a condition formula for setting limits on the vehicle speed, acceleration, and jerk when the vehicle is driven, and the limiting condition formula corresponding to the vehicle speed is provided with a term that adds half of the acceleration when the vehicle is driven.

[0010] (3) In the embodiment of (2) above, the limiting condition formula further includes condition formulas for setting restrictions on following a preceding vehicle and avoiding collisions with other traffic participants, wherein the limiting condition formula corresponding to following a preceding vehicle includes a term for adjusting the driving speed of the vehicle itself.

[0011] (4) In any one embodiment of (1) to (3) above, the objective function determination unit determines a combination of a first objective function formulated using a first auxiliary variable relating to the vehicle speed limit and a first limiting condition expression corresponding to the vehicle speed when the scene is a first scene in which the speed limit of the lane in which the vehicle is traveling is changed, wherein the first limiting condition expression includes a term that adds a limit based on the first auxiliary variable and the difference in the maximum speed of the vehicle before and after the change in the speed limit.

[0012] (5) In any one embodiment of (1) to (3) above, the objective function determination unit determines a combination of a second objective function formulated using a second auxiliary variable relating to the urgency based on the positional relationship between the vehicle and the preceding vehicle and a second limiting condition expression when the scene is a second scene in which the vehicle follows a preceding vehicle, and the preceding vehicle is already the vehicle to be followed, wherein the second limiting condition expression includes a second-first limiting condition expression which has a term that adds the second auxiliary variable to the limiting condition expression which corresponds to following, and a second-second limiting condition expression which corresponds to collision avoidance and represents the position of the preceding vehicle.

[0013] (6): In the embodiment of (5) above, the objective function determination unit determines a combination of the second objective function and a third limiting condition if the scene is a second scene in which the vehicle follows the preceding vehicle, and the preceding vehicle is a new target for following, wherein the third limiting condition includes a second-third limiting condition which further includes a term that adds a third auxiliary variable related to following to the second-first limiting condition, and a second-fourth limiting condition which further includes a term that adds a third auxiliary variable to the second-second limiting condition.

[0014] (7) In any one embodiment of (1) to (3) above, the objective function determination unit determines a combination of the objective function and the limiting condition expression relating to collision avoidance if the scene is a third scene in which a collision with the other traffic participant is to be avoided, and the other traffic participant is already a target for avoidance.

[0015] (8) In the embodiment of (7) above, the objective function determination unit determines a combination of the objective function and a fourth limiting condition if the scene is a third scene in which a collision with the other traffic participant is avoided, and the other traffic participant is a new target for avoidance, wherein the fourth limiting condition is the limiting condition for collision avoidance with a term for a fourth auxiliary variable relating to collision avoidance.

[0016] (9): A vehicle control method according to one aspect of the present invention is a vehicle control method in which a computer determines, according to the recognized surrounding conditions of the vehicle, a combination of an objective function, which has acceleration in the future as a control variable and is formulated using auxiliary variables corresponding to a predetermined scenario that can be assumed from the positional relationship of the vehicle with other traffic participants while the vehicle is in motion, and a limiting condition expression for setting a limit on the future driving, and determines the driving speed of the vehicle in the future based on the combination of the objective function and the limiting condition expression, wherein the auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the scenario.

[0017] (10): A program according to one aspect of the present invention causes a computer to determine, in accordance with the recognized surrounding conditions of its own vehicle, a combination of an objective function, which is formulated using auxiliary variables corresponding to a predetermined scenario that can be assumed from the positional relationship of the vehicle with other traffic participants while the vehicle is in motion, with acceleration in the future as the control variable, and a limiting condition expression for setting restrictions on the future driving, and based on the combination of the objective function and the limiting condition expression, the program determines the driving speed of the vehicle in the future, wherein the auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the scenario. [Effects of the Invention]

[0018] According to the embodiments described in (1) to (10) above, suitable autonomous driving control can be achieved even in situations where it is necessary to consider the positional relationship with other traffic participants while driving. [Brief explanation of the drawing]

[0019] [Figure 1] This is a diagram illustrating the configuration of a vehicle system using a vehicle control device according to the embodiment. [Figure 2] This is a functional configuration diagram of the first control unit and the second control unit. [Figure 3] This figure shows an example of a basic scenario when formulating an objective function. [Figure 4] This figure shows an example of the first scenario in which an auxiliary variable is applied to the objective function. [Figure 5] This figure shows an example of the second scenario in which auxiliary variables are applied to the objective function. [Figure 6] This figure shows an example of a third scenario in which auxiliary variables are applied to the objective function. [Figure 7] This flowchart shows an example of the process flow for determining the objective function, which is performed in the objective function determination unit. [Modes for carrying out the invention]

[0020] Hereinafter, embodiments of the vehicle control device, vehicle control method, and program of the present invention will be described with reference to the drawings.

[0021] [Overall structure] Figure 1 is a diagram showing the configuration of a vehicle system 1 utilizing a vehicle control device according to an embodiment. The vehicle on which the vehicle system 1 is installed is, for example, a two-wheeled, three-wheeled, or four-wheeled vehicle, and its drive source is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using power generated by a generator connected to the internal combustion engine, or power discharged from a secondary battery or fuel cell.

[0022] Vehicle system 1 includes, for example, a camera 10, a radar device 12, a LiDAR (Light Detection and Ranging) 14, an object recognition device 16, a communication device 20, an HMI (Human Machine Interface) 30, a vehicle sensor 40, a navigation device 50, an MPU (Map Positioning Unit) 60, a driver control device 80, an automatic driving control device 100, a driving force output device 200, a brake device 210, and a steering device 220. These devices and equipment are connected to each other by multiplex communication lines such as CAN (Controller Area Network) communication lines, serial communication lines, wireless communication networks, etc. The configuration shown in Figure 1 is merely an example, and some of the configuration may be omitted, or other configurations may be added.

[0023] Camera 10 is a digital camera that utilizes a solid-state image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). Camera 10 is mounted at any location on the vehicle (hereinafter referred to as "vehicle M") on which the vehicle system 1 is installed. When imaging the area in front, camera 10 is mounted on the top of the front windshield, behind the rearview mirror, etc. Camera 10 periodically and repeatedly images the area around vehicle M. Camera 10 may also be a stereo camera.

[0024] The radar device 12 emits radio waves such as millimeter waves around the vehicle M and detects radio waves reflected by objects (reflected waves) to determine at least the position (distance and bearing) of an object. The radar device 12 can be mounted at any location on the vehicle M. The radar device 12 may also detect the position and velocity of an object using the FM-CW (Frequency Modulated Continuous Wave) method.

[0025] The LIDAR 14 irradiates light (or electromagnetic waves with a wavelength close to light) around the vehicle M and measures the scattered light. The LIDAR 14 detects the distance to the target based on the time from emission to reception. The irradiated light is, for example, pulsed laser light. The LIDAR 14 can be attached to any location on the vehicle M.

[0026] The object recognition device 16 performs sensor fusion processing on the detection results from some or all of the camera 10, radar device 12, and LIDAR 14 to recognize the position, type, speed, etc., of an object. The object recognition device 16 outputs the recognition results to the automatic driving control device 100. The object recognition device 16 may output the detection results from the camera 10, radar device 12, and LIDAR 14 directly to the automatic driving control device 100. The object recognition device 16 may be omitted from the vehicle system 1.

[0027] The communication device 20 communicates with other vehicles in the vicinity of its own vehicle M, or with various server devices via a wireless base station, for example, by using a cellular network, Wi-Fi network, Bluetooth®, DSRC (Dedicated Short Range Communication), etc.

[0028] The HMI30 displays various information to the occupants of the vehicle M and accepts input operations from the occupants. The HMI30 includes various display devices, speakers, buzzers, touch panels, switches, keys, etc.

[0029] The vehicle sensor 40 includes a vehicle speed sensor for detecting the speed of the vehicle M, an acceleration sensor for detecting acceleration, a yaw rate sensor for detecting angular velocity around the vertical axis, and an orientation sensor for detecting the orientation of the vehicle M.

[0030] The navigation device 50 includes, for example, a GNSS (Global Navigation Satellite System) receiver 51, a navigation HMI 52, and a route determination unit 53. The navigation device 50 stores first map information 54 in a storage device such as an HDD (Hard Disk Drive) or flash memory. The GNSS receiver 51 determines the position of the vehicle M based on signals received from GNSS satellites. The position of the vehicle M may be determined or supplemented by an INS (Inertial Navigation System) that utilizes the output of vehicle sensors 40. The navigation HMI 52 includes a display device, speaker, touch panel, keys, etc. The navigation HMI 52 may be partially or completely shared with the HMI 30 described above. The route determination unit 53 determines, for example, a route (hereinafter referred to as the route on the map) from the position of the vehicle M determined by the GNSS receiver 51 (or any input position) to the destination input by the occupant using the navigation HMI 52, by referring to the first map information 54. The first map information 54 is, for example, information in which the road shape is represented by links indicating roads and nodes connected by those links. The first map information 54 may also include information such as road curvature and POI (Point of Interest) information. The route on the map is output to the MPU 60. The navigation device 50 may provide route guidance using the navigation HMI 52 based on the route on the map. The navigation device 50 may be implemented, for example, by the functions of a terminal device such as a smartphone or tablet held by an occupant. The navigation device 50 may transmit the current location and destination to the navigation server via the communication device 20 and obtain a route equivalent to the route on the map from the navigation server.

[0031] The MPU 60 includes, for example, a recommended lane determination unit 61 and stores second map information 62 in a storage device such as an HDD or flash memory. The recommended lane determination unit 61 divides the map route provided by the navigation device 50 into multiple blocks (for example, every 100m with respect to the vehicle's direction of travel) and determines a recommended lane for each block by referring to the second map information 62. The recommended lane determination unit 61 makes decisions such as which lane from the left the vehicle should travel in. If there is a branching point on the map route, the recommended lane determination unit 61 determines a recommended lane so that the vehicle M can travel along a reasonable route to proceed to the branching point.

[0032] The second map information 62 is map information with higher accuracy than the first map information 54. The second map information 62 includes, for example, information on the center of lanes or information on lane boundaries. The second map information 62 may also include road information, traffic regulation information, address information (address and postal code), facility information, telephone number information, etc. The second map information 62 may be updated as needed by the communication device 20 communicating with other devices.

[0033] The driver controls 80 include, for example, an accelerator pedal, a brake pedal, a shift lever, a steering wheel, and other controls. The steering wheel does not necessarily have to be annular in shape and may be in the form of an irregularly shaped steering wheel, a joystick, buttons, etc. Sensors are attached to the driver controls 80 to detect the amount of operation or whether or not an operation is performed, and the detection results are output to the automatic driving control device 100, or to some or all of the driving force output device 200, the brake device 210, and the steering device 220.

[0034] The automatic driving control device 100 comprises, for example, a first control unit 120 and a second control unit 160. The first control unit 120 and the second control unit 160 are each realized by a hardware processor, such as a CPU (Central Processing Unit), executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as LSIs (Large Scale Integration), SOCs (System On Chip), Application Specific Integrated Circuits (ASICs), programmable logic devices (e.g., Simple Programmable Logic Devices (SPLDs) or Complex Programmable Logic Devices (CPLDs), Field Programmable Gate Arrays (FPGAs)), and GPUs (Graphics Processing Units), or by the cooperation of software and hardware. The program may be stored in advance in a storage device (a storage device equipped with a non-transient storage medium) such as the HDD or flash memory of the automatic driving control device 100, or it may be stored in a removable storage medium such as a DVD or CD-ROM, and installed in the HDD or flash memory of the automatic driving control device 100 when the storage medium (non-transient storage medium) is inserted into a drive device. The automatic driving control device 100 is an example of a "vehicle control device".

[0035] Figure 2 is a functional configuration diagram of the first control unit 120 and the second control unit 160. The first control unit 120 includes, for example, a recognition unit 130 and an action plan generation unit 140.

[0036] The first control unit 120 implements, for example, functions using AI (Artificial Intelligence) and functions using a pre-defined model in parallel. For example, the "intersection recognition" function in the first control unit 120 may be implemented by simultaneously performing intersection recognition using deep learning and recognition based on pre-defined conditions (such as pattern-matchable signals and road markings), and then scoring both and comprehensively evaluating them. This ensures the reliability of autonomous driving.

[0037] The recognition unit 130 recognizes the position and state, such as speed and acceleration, of objects around the vehicle M based on information input from the camera 10, radar device 12, and LIDAR 14 via the object recognition device 16. The position of an object is recognized as a position on an absolute coordinate system with a representative point of the vehicle M (such as the center of gravity or the center of the drive axis) as the origin, and is used for control. The position of an object may be represented by a representative point such as the center of gravity or a corner of the object, or it may be represented by a region. The "state" of an object may include the object's acceleration, jerk, or "action state" (for example, whether or not it is changing lanes or is about to change lanes).

[0038] The recognition unit 130 recognizes, for example, the lane in which the vehicle M is traveling. For example, the recognition unit 130 recognizes the driving lane by comparing the road marking pattern (for example, an arrangement of solid and dashed lines) obtained from the second map information 62 with the road marking pattern around the vehicle M recognized from the image captured by the camera 10. The recognition unit 130 may also recognize the driving lane by recognizing not only road markings, but also road boundaries (road boundaries) including road markings, shoulders, curbs, median strips, guardrails, etc. In this recognition, the position of the vehicle M obtained from the navigation device 50 and the processing results by INS may also be taken into consideration. The recognition unit 130 recognizes stop lines, obstacles, red lights, toll booths, and other road events.

[0039] When recognizing a driving lane, the recognition unit 130 recognizes the position and orientation of the vehicle M relative to the driving lane. For example, the recognition unit 130 may recognize the deviation of the vehicle M's reference point from the center of the lane, and the angle it makes with a line connecting the centers of the lanes in the direction of travel, as the relative position and orientation of the vehicle M relative to the driving lane. Alternatively, the recognition unit 130 may recognize the position of the vehicle M's reference point relative to any side edge of the driving lane (road marking or road boundary), as the relative position of the vehicle M relative to the driving lane.

[0040] The action plan generation unit 140, in principle, drives in the recommended lane determined by the recommended lane determination unit 61, and further generates a target trajectory for the vehicle M to travel in the future, automatically (without driver operation) in order to respond to the surrounding conditions of the vehicle M. The target trajectory includes, for example, a speed element. For example, the target trajectory is represented as a sequence of points (trajectory points) that the vehicle M should reach. The trajectory points are points that the vehicle M should reach at predetermined travel distances (e.g., a few meters) along the road, and separately, target speed and target acceleration at predetermined sampling times (e.g., a few tenths of a second) are generated as part of the target trajectory. The trajectory points may also be the positions that the vehicle M should reach at the sampling time for each predetermined sampling time. In this case, the information on target speed and target acceleration is represented by the intervals between trajectory points.

[0041] The action plan generation unit 140 may set autonomous driving events when generating a target trajectory. Autonomous driving events include constant speed driving events, low-speed follow driving events, lane change events, branching events, merging events, and takeover events. The action plan generation unit 140 generates a target trajectory according to the activated event.

[0042] The action plan generation unit 140 generates target speed and target acceleration according to the conditions of the lane in which the vehicle M is traveling (driving lane) and other adjacent driving lanes (adjacent lanes), as recognized by the recognition unit 130. The action plan generation unit 140 includes, for example, an objective function determination unit 142 and a speed determination unit 144. The action plan generation unit 140 generates target speed and target acceleration using the objective function determination unit 142 and the speed determination unit 144, that is, it performs an action plan related to speed (hereinafter referred to as "speed plan"). The objective function determination unit 142 determines a formulated objective function to be used when performing the speed plan, according to the conditions of the lane in which the vehicle M is traveling (driving lane) and other adjacent driving lanes (adjacent lanes), as recognized by the recognition unit 130 (hereinafter referred to as "driving conditions of the vehicle M"). The objective function is a function in which variables are formulated to address specific situations where it is necessary to consider the positional relationship with other traffic participants (e.g., people, bicycles, vehicles) while driving on public roads. The speed determination unit 144 determines a suitable driving speed for the vehicle M in the future based on the objective function determined by the objective function determination unit 142. Details regarding the objective function determination unit 142, the speed determination unit 144, and the formulation of the objective function will be described later.

[0043] The second control unit 160 controls the driving force output device 200, the braking device 210, and the steering device 220 so that the vehicle M passes through the target trajectory generated by the action plan generation unit 140 at the scheduled time.

[0044] The second control unit 160 includes, for example, an acquisition unit 162, a speed control unit 164, and a steering control unit 166. The acquisition unit 162 acquires information on the target trajectory (trajectory point) generated by the action plan generation unit 140 and stores it in memory (not shown). The speed control unit 164 controls the driving force output device 200 or the brake device 210 based on the speed elements associated with the target trajectory stored in memory. The steering control unit 166 controls the steering device 220 according to the curvature of the target trajectory stored in memory. The processing of the speed control unit 164 and the steering control unit 166 is realized, for example, by a combination of feedforward control and feedback control. As an example, the steering control unit 166 performs a combination of feedforward control according to the curvature of the road in front of the vehicle M and feedback control based on the deviation from the target trajectory.

[0045] Returning to Figure 1, the driving force output device 200 outputs driving force (torque) to the drive wheels for the vehicle to move. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, and a transmission, and an ECU (Electronic Control Unit) that controls them. The ECU controls the above configuration according to information input from the second control unit 160 or information input from the driver control unit 80.

[0046] The brake system 210 includes, for example, a brake caliper, a cylinder that transmits hydraulic pressure to the brake caliper, an electric motor that generates hydraulic pressure in the cylinder, and a brake ECU. The brake ECU controls the electric motor according to information input from the second control unit 160 or from the driver control unit 80, so that brake torque corresponding to the braking operation is output to each wheel. The brake system 210 may also include a backup mechanism that transmits hydraulic pressure generated by the operation of the brake pedal included in the driver control unit 80 to the cylinder via a master cylinder. The brake system 210 is not limited to the configuration described above, and may also be an electronically controlled hydraulic brake system that controls an actuator according to information input from the second control unit 160 to transmit hydraulic pressure from the master cylinder to the cylinder.

[0047] The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor, for example, applies force to a rack and pinion mechanism to change the direction of the steering wheels. The steering ECU drives the electric motor to change the direction of the steering wheels according to information input from the second control unit 160 or from the driver control unit 80.

[0048] [Purpose allocation] The objective function and its formulation are explained below. The objective function is formulated by deriving a state equation by assuming that the jerk (dynamic movement) of the vehicle M is constant, and this state equation is used for each predetermined scenario on a public road.

[0049] The jerk j of the vehicle M as it changes from time t to time t+1 is expressed by equation (1) below.

[0050]

number

[0051] In equation (1) above, a is acceleration. We use acceleration a as the control variable when formulating the objective function. From the jerk j expressed in equation (1) above and the general equation of motion, we derive the state equation shown in equation (2) below. The state equation in equation (2) below represents the vertical motion of the vehicle M while it is in motion.

[0052]

number

[0053] In equation (1) above, s is the position of the vehicle M, v is the velocity of the vehicle M, a is the acceleration of the vehicle M, and t is the time. The position s and velocity v are linearly related with respect to the acceleration a. In equation (1) above, the first term on the left side represents the state vector of the vehicle M at the next time t+1, the first term on the right side represents the state vector of the vehicle M at the current time t, and the second term on the right side represents the action of the vehicle M, that is, the change in the velocity of the vehicle M during its future travel. The control variable, i.e., acceleration a, is included in the state vector in equation (2) above. Here, the state vector of the vehicle M at time t+1 is "x (t+1) ", the state vector of the vehicle M at the current time t is "x t If we define a matrix as "A" and a vector as "B", then equation (2) above can be expressed as equation (3) below.

[0054]

number

[0055] For equation (3) above, the state vector x t Initial state is x0, control variable (acceleration a (t+1) ) as input to control input [a1,···,a n Given ], the behavior of the vehicle M, expressed as in equation (3) above, can be expressed as an equation equivalent to a typical Model Predictive Control (MPC), as in equation (4) below.

[0056]

number

[0057] In formulating the objective function, the control inputs in equation (4) above are [a1,···,a n The objective function is formulated for each predetermined scenario on a public road, with the target action to be sought for the vehicle M, that is, the action of the vehicle M to be optimized.

[0058] Here, the scenarios on general roads considered when formulating the objective function will be described. FIG. 3 is a diagram showing an example of the scenario that forms the basis when formulating the objective function. FIG. 3 shows an example of a plurality of scenarios assumed on a general road when the host vehicle M goes straight through an intersection. More specifically, in FIG. 3, for example, a scenario where the host vehicle M travels while following another vehicle V1 (preceding vehicle) traveling ahead in the current travel lane, or a scenario where the host vehicle M avoids another vehicle V2 (collision with the other vehicle V2) that travels in another travel lane intersecting the current travel lane and crosses ahead, a scenario where the speed limit of the current travel lane is changed, a scenario where the vehicle stops once at a stop line indicated on the current travel lane, a scenario where the host vehicle M decelerates when the other vehicle V1 turns (turns right in FIG. 3) at an intersection, etc. are assumed.

[0059] In formulating the objective function, basic functions for generating a target speed and a target acceleration, as shown in the following formulas (5) to (16), are formulated. By the way, when generating a target trajectory (here, a speed plan regarding the target speed and the target acceleration), it is preferable to consider a safety margin. The safety margin can be easily added, but in the following description, for the sake of simplicity, the consideration regarding the safety margin is omitted.

[0060] In formulating the objective function, first, a basic objective function as shown in the following formula (5) is formulated.

[0061]

Equation

[0062] The above formula (5) is an objective function that maximizes the sum of the position s of the host vehicle M at time t from time t = 1 to time t = n, that is, an objective function aimed at arriving as far and as early as possible by the host vehicle M. In the following description, for the sake of simplicity, the sum of the position s t from time t = 1 to time t = n is referred to as "total position s t ". In the above formula (5), ω t 」.t The position s at each time t is t This value represents the weight of, but in the following explanation, for the sake of simplicity, we will refer to it as the weight ω. t This does not take weight ω into consideration. t Let = 1. The objective function in equation (5) above is a linear programming model that evaluates only the distance traveled by the vehicle M.

[0063] The basic objective function defines limiting conditions for the vehicle's speed v, acceleration a, and jerk j. More specifically, it defines a limiting condition for the upper limit of speed v as shown in equation (6) below, and a limiting condition for the lower limit of speed v as shown in equation (7) below. In the following explanation, the limiting conditions for speed v will be referred to as "vehicle speed limiting conditions." Equations (6) and (7) below are examples of "conditions for setting limits on vehicle speed."

[0064]

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[0065]

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[0066] In equations (6) and (7) above, v t is the variable v representing the speed of the vehicle M at time t, a t is the variable of the acceleration a of the vehicle M at time t. In equation (6) above, v max This represents the maximum speed of the vehicle M in the speed plan.

[0067] A limiting condition is defined for the upper limit of acceleration a as shown in equation (8) below, and a limiting condition is defined for the lower limit of acceleration a as shown in equation (9) below. In the following explanation, the limiting condition for acceleration a will be referred to as the "acceleration limiting condition." Equations (8) and (9) below are examples of "conditional equations for setting limits on acceleration."

[0068]

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[0069]

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[0070] In equation (8) above, a max represents the maximum acceleration of the vehicle M in the speed plan, and in equation (9) above, a min This represents the minimum acceleration of the vehicle M in the speed plan.

[0071] A limiting condition is defined for the upper limit of jerk j as shown in equation (10) below, and a limiting condition is defined for the lower limit of jerk j as shown in equation (11) below. In the following explanation, the limiting condition for jerk j will be referred to as the "jerk limiting condition." Equations (10) and (11) below are examples of "conditioning conditions for setting limits on jerks."

[0072]

number

[0073]

number

[0074] In equation (10) above, j max represents the upper limit of the jerk of the vehicle M in the speed plan, and in equation (11) above, j min Δt represents the lower limit of the jerk of the vehicle M in the speed plan. In equations (10) and (11) above, Δt represents a discrete time step.

[0075] In the objective function shown in equation (5) above, and in the respective restriction conditions shown in equations (6) to (11) above, the time t is in the range of 1 to n, as shown in equation (12) below.

[0076]

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[0077] Furthermore, the basic objective function defines a limiting condition as shown in equation (13) below for situations where the vehicle follows another vehicle (a preceding vehicle) as the target vehicle. In the following explanation, the limiting condition for following a target vehicle will be referred to as the "following limiting condition." Equation (13) below is an example of a "condition for setting restrictions on following a preceding vehicle."

[0078]

number

[0079] In equation (13) above, v fol(t) represents the speed of the target being pursued at time t, and d fol(t) represents the actual tracking distance at time t, and the position s is as follows: t It depends linearly with respect to . In equation (13) above, d idl(t) This represents the ideal distance based on the predicted speed of the tracking target at time t. In the tracking limit condition equation shown in equation (13) above, time t is a range of a specific interval from the start to the end of tracking, as shown in equation (14) below.

[0080]

number

[0081] In equation (14) above, t fs represents the time when tracking begins, t fe This indicates the time when tracking ends.

[0082] Furthermore, the basic objective function defines a limiting condition equation like equation (15) below regarding situations where collision avoidance with other vehicles is required. In the following explanation, the limiting condition equation related to collision avoidance with other vehicles (avoidance targets) will be referred to as the "collision avoidance limiting condition equation". Equation (15) below is an example of a "conditional equation for setting restrictions regarding collision avoidance with other traffic participants".

[0083]

number

[0084] In equation (15) above, s avo(t) represents the predicted position of the avoidance target at time t. In the collision avoidance limiting condition equation shown in equation (15) above, time t is a range of a specific interval from the start to the end of the avoidance, as shown in equation (16) below. Equation (15) above is an example of "the limiting condition equation relating to collision avoidance".

[0085]

number

[0086] In equation (16) above, t as represents the time when avoidance begins, t ae This indicates the time when the avoidance process will end.

[0087] The objective function determination unit 142 determines the basic objective function formulated as shown in equation (5) above, and the respective limiting condition expressions defined as shown in equations (6) to (16) above, according to the driving conditions of the vehicle M recognized by the recognition unit 130. Here, in formulating the objective function, following limiting condition expressions as shown in equations (13) and (14) above, and collision avoidance limiting condition expressions as shown in equations (13) and (14) above are defined. As a result, the objective function determination unit 142 can determine an objective function (including limiting condition expressions) that corresponds to scenarios expected on public roads where it is necessary to consider the positional relationship with other vehicles while driving. Furthermore, in the limiting condition expressions shown in equations (6), (7), and (13) above, the control variable (acceleration a) is defined. t A term as shown in equation (17) below is added to the ). As a result, in the speed plan based on the objective function determined by the objective function determination unit 142, the change in the speed of the vehicle M becomes smoother. Equation (17) below is an example of a "term that adds 1 / 2 of the acceleration during the vehicle's movement".

[0088]

number

[0089] Incidentally, the scenarios on public roads that form the basis for formulating the objective function shown in Figure 3 include several situations in which there is concern that jerks will occur in the vehicle M due to changes in speed, that is, that the ride comfort of the vehicle M will deteriorate. In other words, it includes situations that cannot be handled even by automatic control of the vehicle M using methods such as multi-profile quadratic programming (MPQP). For example, in situations where the speed limit of the current driving lane is changed, if the driving speed is changed abruptly at the point where the speed limit changes, the ride comfort of the vehicle M will deteriorate. For example, in situations where the vehicle is driving while following a preceding vehicle (following target), if another vehicle driving in an adjacent driving lane (adjacent lane) changes lanes and enters the space between the following target and the vehicle M, and the driving speed is changed abruptly, the ride comfort of the vehicle M will deteriorate. For example, in situations where the vehicle comes to a complete stop at a stop line indicated on the current driving lane, if the driving speed is changed abruptly after approaching the stop line, the ride comfort of the vehicle M will deteriorate. However, if, for example, another vehicle traveling in an intersecting lane suddenly crosses in front of the vehicle, or a pedestrian suddenly enters the current lane, it is considered necessary to make an emergency stop, even if it means a sudden change in speed, regardless of ride comfort. Thus, the scenarios on public roads shown in Figure 3, which served as the basis for formulating the objective function, include situations where both acceleration and jerk control are necessary when the vehicle M is traveling.

[0090] In contrast, the limiting conditions defined in the basic objective function define the acceleration limiting conditions in equations (8) and (9) above, and the jerk limiting conditions in equations (10) and (11) above. In other words, the basic objective function defines the limiting conditions for acceleration a and the equations for jerk j separately. Therefore, in situations where it is necessary to control both acceleration and jerk as described above, if the limiting conditions are set to be more responsive to emergencies, the change in travel speed will be excessive. Conversely, if the limiting conditions are set to prioritize normal travel, the change in travel speed will be gradual, but there is a concern that necessary avoidance or stopping actions in emergencies will not be possible.

[0091] Therefore, we apply auxiliary variables corresponding to each scenario to the basic objective function formulated as shown in equation (5) above, and to the restriction conditions defined as shown in equations (6) to (16) above.

[0092] [First example of an auxiliary variable] The following describes the situations in which auxiliary variables are applied to the objective function and the auxiliary variables corresponding to those situations. Figure 4 shows an example of the first situation in which auxiliary variables are applied to the objective function. The first situation shown in Figure 4 is when the speed limit changes in the current lane in which the vehicle M is traveling. Figure 4 shows a situation in which the speed limit of the current lane changes from 50 km / h to 30 km / h. In this first situation, rather than abruptly changing speed at the point where the speed limit changes, it is considered preferable to gradually reduce the driving speed from the point where the speed limit changes, from the standpoint of preventing deterioration of the ride comfort of the vehicle M.

[0093] Therefore, for the basic objective function formulated as shown in equation (5) above, the auxiliary variable o t Add the following and make the objective function corresponding to the first scenario as shown in equation (18) below.

[0094]

number

[0095] In equation (18) above, the auxiliary variable o t is position s t However, the point where the speed limit changes (hereinafter referred to as "speed limit change point s") th It is a binary variable, either "0" or "1", that indicates whether or not the condition has reached ". In the following explanation, the auxiliary variable o t "Vehicle speed limit auxiliary variable o t " and a vehicle speed limit auxiliary variable o t This is an example of a "first auxiliary variable". Equation (18) above is an example of a "first objective function".

[0096] And in the first scene, position s t And, the vehicle speed limit auxiliary variable o t And, speed limit change point s th The relationship is as shown in equation (19) below.

[0097]

number

[0098] In equation (18) above, the vehicle speed limit auxiliary variable o t If you set it to "1", the total position s t becomes smaller. Therefore, in equation (18) above, the total position s t The constant C can be used to confirm that it becomes smaller. o It is preferable to set this to a sufficiently large value.

[0099] Then, in the vehicle speed limit condition equation corresponding to the first scenario, a term relating to the difference in speed limits (the second term on the right side) is added to the vehicle speed limit condition equation relating to the upper limit of speed v shown in equation (6) above, and defined as shown in equation (20) below. Equation (20) below is an example of the "first limit condition equation".

[0100]

number

[0101] In equation (20) above, vmax(1) This is the maximum speed of the vehicle M before the speed limit was changed (50 km / h in Figure 4). max This represents v max(2) This is the maximum speed of vehicle M after the speed limit has been changed (30 km / h in Figure 4). max This represents that, for example, in the first scenario shown in Figure 4, the speed limit changes to a slower position s t is point s th If it exceeds this, the vehicle speed limit auxiliary variable o t This becomes "1", and as mentioned above, the total position s t becomes smaller. At this time, in the objective function corresponding to the first scenario of equation (18) above, the second term on the right side gives the total position s t The decrease is compensated for. And the vehicle speed limit auxiliary variable o t When it becomes "1", the vehicle speed limit condition equation shown in equation (20) above triggers a change in the vehicle's speed v, and the maximum speed v max(1) From maximum speed v max(2) The process to begin will start.

[0102] In the first scenario shown in Figure 4, we showed a situation where the speed limit changes to a slower speed. Conversely, in a scenario where the speed limit increases, the maximum speed v max(2) The one with the highest top speed v max(1) It is a value greater than (maximum speed v max (High) Therefore, the vehicle speed limit auxiliary variable o t It becomes "1".

[0103] In the objective function shown in equation (18), the relation shown in equation (19), and the vehicle speed limit condition shown in equation (20), the time t is in the range of 1 to n (see equation (12)). The other limit condition conditions in the first scenario are the same as those in the basic scenario described above, so a detailed explanation is omitted.

[0104] In the first scenario, we showed an example of gradually reducing the driving speed from the point where the speed limit changes. However, it is also possible to gradually reduce the driving speed from a point a certain distance before the point where the speed limit changes, so that the driving speed reaches the changed speed at that point. In this case, the speed limit change point s th The point should be set before the point where the speed limit changes, so that it is equivalent to the first scenario described above.

[0105] [Second example of an auxiliary variable] Figure 5 shows an example of a second scenario in which an auxiliary variable is applied to the objective function. The second scenario shown in Figure 5 is a situation in which there is a mixture of situations where a rapid change in driving speed is necessary and situations where a rapid change in driving speed is unnecessary. Figure 5(a) shows a situation in which the vehicle comes to a complete stop at a stop line indicated in the current driving lane, that is, a situation in which a rapid change in driving speed is unnecessary. Figure 5(b) shows a situation in which, for example, a pedestrian P suddenly enters the current driving lane, that is, a situation in which a rapid change in driving speed is necessary. Figure 5(c) shows a situation in which, while following another vehicle V1 (a preceding vehicle) as a target, another vehicle V3 traveling in an adjacent lane changes lanes and enters between the other vehicle V1 and the vehicle M. In the scenario shown in Figure 5(c), if another vehicle V3 enters the area ahead of vehicle M on path R1, it is unnecessary to abruptly change the speed to avoid a collision. However, if another vehicle V3 enters the area ahead of vehicle M on path R2, it is considered necessary to abruptly change the speed to avoid a collision with the other vehicle V3. Thus, in the second scenario, changing the speed according to the situation at the time is considered preferable from the standpoint of preventing deterioration of the ride comfort of vehicle M.

[0106] Therefore, for the basic objective function formulated as shown in equation (5) above, the auxiliary variable e t Add the following and make the objective function corresponding to the second scenario as shown in equation (21) below.

[0107]

number

[0108] In equation (21) above, the auxiliary variable e t This variable represents the degree of urgency in relation to the position of other road users (e.g., people, bicycles, vehicles) while moving. In other words, the auxiliary variable e t This variable indicates whether or not there is a situation where it is necessary to change the driving speed rapidly. (Auxiliary variable e) t The vehicle speed limit auxiliary variable o t It is not a binary value like the above, but a variable between "0" and "1" that represents the degree of urgency to avoid a collision with other traffic participants (avoidance targets). In the following explanation, the auxiliary variable e t The "urgency auxiliary variable e" t " and the urgency auxiliary variable e t The value of this variable increases with increasing urgency (closer to "1") in order to avoid a collision with the target. t This is an example of a "second auxiliary variable." Equation (21) above is an example of a "second objective function."

[0109] Then, in the constraint equations corresponding to the second scenario, a term relating to the difference (the second term on the right-hand side) is added to both the acceleration constraint equation and the jerk constraint equation. More specifically, the acceleration constraint equation relating to the upper limit of acceleration a shown in equation (8) above is defined as equation (22) below, and the acceleration constraint equation relating to the lower limit of acceleration a shown in equation (9) above is defined as equation (23) below. The jerk constraint equation relating to the upper limit of jerk j shown in equation (10) above is defined as equation (24) below, and the jerk constraint equation relating to the lower limit of jerk j shown in equation (11) above is defined as equation (25) below.

[0110]

number

[0111]

number

[0112]

number

[0113]

number

[0114] In equation (22) above, a ptyp This represents the standard acceleration that can be expected when accelerating a vehicle (in this case, the vehicle M), and in equation (23) above, a ntyp This represents the standard acceleration (negative acceleration) that can be expected when decelerating a vehicle (in this case, the vehicle M). In equation (24) above, j ptyp This represents the standard jerk that can be expected when accelerating a vehicle (in this case, the vehicle M), and in equation (23) above, j ntyp This represents the standard jerk (negative jerk) that is generally expected when decelerating a vehicle (in this case, the vehicle M).

[0115] In the limiting conditions shown in equations (22) to (25) above, the limits on the acceleration a and jerk j of the vehicle M can be relaxed depending on the degree of urgency. And the constant C of the objective function shown in equation (21) above... e By making e a sufficiently large value, the relaxation of the restrictions in each of the restriction conditions shown in equations (22) to (25) above can be disabled. In each of the restriction conditions shown in equations (22) to (25) above, the second term on the right-hand side relating to the difference is the urgency auxiliary variable e t This relates to the urgency auxiliary variable e. t It is preferable to include the sum of these in the objective function corresponding to the second scenario shown in equation (21) above, in order to prevent the restrictions from being relaxed more than necessary by the respective restriction conditions shown in equations (22) to (25) above.

[0116] In both the objective function shown in equation (18) and the restriction conditions shown in equations (22) to (25), time t is in the range of 1 to n (see equation (12)).

[0117] Furthermore, in the vehicle speed limit condition equation corresponding to the second scenario, the following limit condition equation for following the target shown in equation (13) above is modified by adding the urgency auxiliary variable e t A term relating to (the second term on the right side) is added and defined as shown in equation (26) below, and the collision avoidance limiting condition equation relating to collision avoidance with the avoidance target shown in equation (15) above is defined as shown in equation (27) below.

[0118]

number

[0119]

number

[0120] In equation (26) above, r fol This represents the adjustment of the driving speed when following the target. In the following limit condition equation shown in equation (26) above, time t is a range of a specific interval from the start to the end of following (see equation (14) above). In equation (27) above, s fol(t) represents the position of the target being pursued at time t. In the collision avoidance limiting condition shown in equation (27) above, time t is a specific interval range from the start to the end of the avoidance (see equation (16) above). The other limiting conditions in the second scenario are the same as those in the basic scenario described above, so a detailed explanation is omitted. r fol This is an example of a "term that adjusts the driving speed of the vehicle itself." Equations (26) and (27) above are examples of "second limiting conditions." Equation (26) above is an example of "2-1 limiting conditions." Equation (27) above is an example of "2-2 limiting conditions."

[0121] Based on the objective function shown in equation (21) and the limiting conditions shown in equations (22) to (27), the vehicle M changes its driving speed according to the conditions of each of the second scenarios shown in Figure 5. More specifically, in the second scenario shown in Figure 5(a), the vehicle M gradually reduces its driving speed from before the stop line shown on the current driving lane and comes to a complete stop at the stop line. In other words, the vehicle M comes to a complete stop at the stop line. On the other hand, in the second scenario shown in Figure 5(b), when the recognition unit 130 recognizes an intruding pedestrian P, it makes an emergency stop regardless of ride comfort to avoid a collision with the pedestrian P (avoidance target). Furthermore, in the second scenario shown in Figure 5(c), the driving speed of the vehicle M is changed according to the position of another vehicle V3 that has entered between the vehicle M and the other vehicle V1 (preceding vehicle) that is following as a follow target. In other words, if another vehicle V3 enters a position ahead of vehicle M on route R1, the vehicle's speed will not change, or it will slow down gradually. If another vehicle V3 enters a position ahead of vehicle M on route R2, the vehicle's speed will be significantly reduced, or in some cases, an emergency stop will be made to avoid a collision with the other vehicle V3 (the target to be avoided).

[0122] [Third example of an auxiliary variable] Figure 6 shows an example of a third scenario in which auxiliary variables are applied to the objective function. The third scenario shown in Figure 6 is one in which it is necessary to adjust the speed of the vehicle M when merging into an adjacent lane. In this scenario shown in Figure 6, if the vehicle M merges by entering behind another vehicle V4 traveling in an adjacent lane on route R3, it is necessary to reduce the speed to ensure a safe distance from the other vehicle V4. If the vehicle M merges by entering in front of the other vehicle V4 on route R4, it is necessary to increase the speed to prevent the other vehicle V4 from having to make an emergency stop. In this third scenario as well, changing the speed according to the situation at the time is considered preferable from the standpoint of preventing deterioration of the ride comfort of the vehicle M.

[0123] Therefore, for the basic objective function formulated as shown in equation (5) above, the auxiliary variable f fol and auxiliary variable f avoIntroduce the following, and set the objective function corresponding to the third scenario as shown in the following formula (28). However, since the objective function itself maximizes the total position s t there is no change (addition of auxiliary variables).

[0124]

Equation

[0125] In the above formula (28), the auxiliary variable f fol is a binary variable of "0" or "1" representing whether the host vehicle M enters behind or in front of the other vehicle that is the following target. The auxiliary variable f avo is a binary variable of "0" or "1" representing whether the host vehicle M enters behind or in front of the other vehicle that is the avoidance target. In the following description, the auxiliary variable f fol is referred to as the "following auxiliary variable f fol ", and the auxiliary variable f avo is referred to as the "collision avoidance auxiliary variable f avo ". The following auxiliary variable f fol and the collision avoidance auxiliary variable f avo are "0" when representing entering behind, and "1" when representing entering in front.

[0126] Then, in the constraint expression corresponding to the third scenario, in the following constraint expression regarding following the following target shown in the above formula (13), add the term related to the following auxiliary variable f fol (the second term on the right side), and define it as shown in the following formula (29). Define the collision avoidance constraint expression regarding collision avoidance shown in the above formula (15) as shown in the following formulas (30) to (33).

[0127]

Equation

[0128]

Equation

[0129]

Equation

[0130] [Number]

[0131] [Number]

[0132] When the host vehicle M is traveling while following a following target or in a scene where the host vehicle M avoids an avoidance target, if the host vehicle M can enter in front of the following target or the avoidance target, according to the above formula (30) and formula (32), the following assistance variable f fol and the collision avoidance assistance variable f avo each become "1". At this time, the constant C is set to a sufficiently large value. Conversely, if the host vehicle M cannot enter in front of the following target or the avoidance target (can enter behind), according to the above formula (31) and formula (33), the following assistance variable f fol and the collision avoidance assistance variable f avo each become "0". The above formula (30) and formula (31) are examples of the "second to fourth limiting conditional expressions". The above formula (32) and formula (33) are examples of the "fourth limiting conditional expression". f avo is an example of the "fourth auxiliary variable".

[0133] In the following limiting conditional expression shown in the above formula (29) as well, the time t is within a specific interval range from the start to the end of following (see the above formula (14)). In the collision avoidance limiting conditional expressions shown in the above formula (30) to formula (33) as well, the time t is within a specific interval range from the start to the end of avoidance (see the above formula (16)). Since the other limiting conditional expressions in the third scene are the same as the limiting conditional expressions of the above-described basic scene, detailed descriptions are omitted.

[0134] Based on the objective function shown in equation (28) and the limiting conditions shown in equations (29) to (33), the vehicle M changes (adjusts) its merging speed according to the conditions of each of the third scenarios shown in Figure 6. More specifically, in the third scenario shown in Figure 6, if the vehicle M enters behind another vehicle V4 on route R3, it does not change its merging speed or slows down gradually, and if it enters in front of another vehicle V4 on route R4, it does not change its merging speed or accelerates gradually to merge into the adjacent lane.

[0135] As described above, the objective function determination unit 142 determines objective functions and auxiliary variables (including limiting conditions) corresponding to the first, second, and third scenarios, according to the driving conditions of the vehicle M recognized by the recognition unit 130. In other words, the objective function determination unit 142 discriminates scenarios that are expected on public roads where it is necessary to consider the positional relationship with other vehicles while driving, and determines objective functions and auxiliary variables (including limiting conditions) corresponding to each scenario. More specifically, the objective function determination unit 142 introduces auxiliary variables to deal with various situations expected on public roads, discriminates scenarios where the speed limit is changed, scenarios where it is necessary to balance gradual acceleration / deceleration with emergency stops, scenarios where it is necessary to adjust the driving speed, and determines objective functions and auxiliary variables (including limiting conditions) corresponding to each scenario.

[0136] There are various scenarios that can be expected on public roads where it is necessary to consider the positional relationship with other vehicles while driving, and these scenarios do not necessarily fall into one of the first, second, or third scenarios described above. For this reason, the objective function determination unit 142 may, for example, combine any two or all of the first, second, and third scenarios to determine the objective function and auxiliary variables (including limiting conditions) corresponding to that scenario. For example, the objective function determination unit 142 may combine the following limiting condition corresponding to the second scenario and the following limiting condition corresponding to the third scenario to determine the following limiting condition expressed as shown in equation (34) below as the following limiting condition corresponding to the current scenario. Equation (34) below is an example of the "third limiting condition" and the "second-to-third limiting condition". fol c is an example of a "third auxiliary variable".

[0137]

number

[0138] The speed determination unit 144 determines the future speed at which the vehicle M will travel, based on the objective function and auxiliary variables (including limiting conditions) determined by the objective function determination unit 142. In other words, the speed determination unit 144 determines the future speed according to the scenarios expected on public roads where it is necessary to consider the positional relationship with other vehicles while driving.

[0139] As a result, the action plan generation unit 140 can generate a target trajectory (target speed and target acceleration) that balances improved ride comfort and collision avoidance (in other words, improved safety) of the vehicle M, for example, in scenarios such as those shown in Figures 4 to 6. The second control unit 160 can then perform driving control (speed control) of the vehicle M in accordance with the target trajectory generated by the action plan generation unit 140.

[0140] [An example of the process for determining the objective function] Figure 7 is a flowchart showing an example of the process flow for determining the objective function, which is executed in the objective function determination unit 142. The process in this flowchart is executed repeatedly, for example, while the automatic driving control device 100 is operating. In the following description, it is assumed that the recognition unit 130 is constantly recognizing the driving status of the vehicle M.

[0141] When the objective function determination unit 142 starts processing this flowchart, it first sets the formulated basic objective function (step S100). More specifically, the objective function determination unit 142 sets the objective function shown in equation (5) above. Then, the objective function determination unit 142 sets the restriction condition expressions defined for the set basic objective function (step S102). More specifically, the objective function determination unit 142 sets the respective restriction condition expressions shown in equations (6) to (16) above.

[0142] The objective function determination unit 142 determines whether the driving situation of the vehicle M recognized by the recognition unit 130 is a situation in which the speed limit changes at a point where there is a speed limit (step S110). In other words, the objective function determination unit 142 determines whether the situation is such that the speed limit changes in the lane in which the vehicle M is currently driving, for example, as shown in the first scenario in Figure 4. If, in step S110, the recognition unit 130 determines that the driving situation of the vehicle M recognized is not a situation in which the speed limit changes at a point where there is a speed limit, the objective function determination unit 142 proceeds to step S120.

[0143] On the other hand, in step S110, if the recognition unit 130 determines that the driving situation of the vehicle M recognized is a situation where the speed limit changes at a certain point, the objective function determination unit 142 sets the vehicle speed limit auxiliary variable o in the set objective function. t Add (step S112). In other words, the objective function determination unit 142 changes the objective function shown in equation (5) above to the objective function shown in equation (18) above and resets it.

[0144] In each subsequent process, for the sake of clarity, auxiliary variables will be added, and the currently set objective function will be changed to the objective function corresponding to the added auxiliary variable and then reset.

[0145] Then, the objective function determination unit 142 replaces the vehicle speed constraint expression (step S114). More specifically, the objective function determination unit 142 replaces the vehicle speed limit expression shown in equation (6) above, which was defined in the basic objective function before resetting, with the vehicle speed constraint expression shown in equation (20) above, which corresponds to the reset objective function. Then, the objective function determination unit 142 proceeds to step S120.

[0146] The objective function determination unit 142 determines whether the driving situation of the vehicle M recognized by the recognition unit 130 is a situation in which a target vehicle is being followed exists (step S120). In other words, the objective function determination unit 142 determines whether the situation is one in which the vehicle M is driving while following a preceding vehicle (another vehicle V1) as a target vehicle, such as the second scenario shown in Figure 5(c). If, in step S120, the recognition unit 130 determines that the driving situation of the vehicle M recognized is not a situation in which a target vehicle is being followed exists, the objective function determination unit 142 proceeds to step S130.

[0147] On the other hand, in step S120, if the recognition unit 130 determines that the driving situation of its own vehicle M is a situation in which a follow target exists, the objective function determination unit 142 determines whether the follow target existed from the beginning or not (step S122). In other words, the objective function determination unit 142 determines whether the follow target is a vehicle that has already been recognized and is being followed, or a vehicle that has been newly recognized and is starting to be followed. More specifically, for example, in the second scenario shown in Figure 5(c), the objective function determination unit 142 determines whether the current follow target is another vehicle V1.

[0148] In step S122, if it is determined that the object to be followed already exists, the objective function determination unit 142 replaces the follow restriction condition and the collision avoidance restriction condition (step S124). More specifically, the objective function determination unit 142 replaces the follow restriction condition defined in the currently set objective function with the follow restriction condition shown in equation (26) above, and replaces the collision avoidance restriction condition with the collision avoidance restriction condition shown in equation (27) above. Then, the objective function determination unit 142 proceeds to step S130.

[0149] On the other hand, if it is determined in step S122 that the object to be tracked does not exist from the beginning, the objective function determination unit 142 determines the tracking auxiliary variable f fol The following limit condition expression and collision avoidance limit condition expression are replaced (step S126). More specifically, for example, in the second scenario shown in Figure 5(c), if it is determined that the current target for following has changed from other vehicle V1 to other vehicle V3 because other vehicle V3 has changed lanes and entered between other vehicle V1 and the own vehicle M, the objective function determination unit 142 adds the following auxiliary variable f to the currently set objective function. fol The objective function determination unit 142 then replaces the tracking restriction condition expression defined for the currently set objective function with the tracking restriction condition expression shown in equation (34) above, and replaces the collision avoidance restriction condition expression with the collision avoidance restriction condition expressions shown in equations (30) and (31) above. The objective function determination unit 142 then proceeds to step S130.

[0150] The objective function determination unit 142 determines whether the driving situation of the vehicle M recognized by the recognition unit 130 is a situation in which there is an object to avoid (step S130). In other words, the objective function determination unit 142 determines whether it is a situation in which it is necessary to avoid a collision with another vehicle V3 in the second scenario shown in Figure 5(c) or with another vehicle V4 in the third scenario shown in Figure 6. If, in step S130, the recognition unit 130 determines that the driving situation of the vehicle M recognized is not a situation in which there is an object to avoid, the objective function determination unit 142 proceeds to step S140.

[0151] On the other hand, in step S130, if the recognition unit 130 determines that the driving situation of its own vehicle M is a situation in which an object to be avoided exists, the objective function determination unit 142 determines whether the object to be avoided existed from the beginning or not (step S132). In other words, the objective function determination unit 142 determines whether the object to be avoided is a vehicle that has already been recognized and is being monitored for avoidance, or a vehicle that has been newly recognized and for which monitoring for avoidance will be started. More specifically, the objective function determination unit 142 determines, for example, whether it recognizes the other vehicle V3 in the second scene shown in Figure 5(c) or the other vehicle V4 in the third scene shown in Figure 6.

[0152] In step S132, if it is determined that the object to be avoided exists from the beginning, the objective function determination unit 142 replaces the collision avoidance limit condition expression (step S134). More specifically, the objective function determination unit 142 replaces the collision avoidance limit condition expression defined in the currently set objective function with the collision avoidance limit condition expression shown in equation (19) above. Then, the objective function determination unit 142 proceeds to step S140.

[0153] On the other hand, if it is determined in step S132 that the object to be avoided does not exist from the beginning, the objective function determination unit 142 determines the collision avoidance auxiliary variable f avo The collision avoidance limiting condition is replaced by adding the following (step S136). More specifically, for example, in the second scenario shown in Figure 5(c), if another vehicle V3 enters a position close to the vehicle M on the path R2, the objective function determination unit 142 adds the collision avoidance auxiliary variable f to the currently set objective function. avo The objective function determination unit 142 then replaces the collision avoidance limit condition expression defined for the currently set objective function with the collision avoidance limit condition expression shown in equations (32) and (33) above. The objective function determination unit 142 then proceeds to step S140.

[0154] The objective function determination unit 142 determines the currently set objective function and auxiliary variables (including limiting conditions) to the objective function and auxiliary variables (including limiting conditions) corresponding to the current scenario (step S140). Then, the objective function determination unit 142 returns to step S100.

[0155] Through this process, the objective function determination unit 142 determines an objective function and auxiliary variables (including limiting conditions) corresponding to the driving conditions of the vehicle M recognized by the recognition unit 130. Based on this, the speed determination unit 144 determines the future speed at which the vehicle M should travel, based on the objective function and auxiliary variables (including limiting conditions) determined by the objective function determination unit 142. The action plan generation unit 140 then generates a target trajectory (target speed and target acceleration) that balances improved ride comfort and collision avoidance (in other words, improved safety), and the second control unit 160 performs driving control (speed control) of the vehicle M according to the generated target trajectory.

[0156] As described above, according to the vehicle control device of the embodiment, the recognition unit 130 in the first control unit 120 of the automatic driving control device 100 recognizes the driving status of the vehicle M. Then, in the vehicle control device of the embodiment, the objective function determination unit 142 in the action plan generation unit 140 of the first control unit 120 of the automatic driving control device 100 determines a formalized objective function and auxiliary variables (including limiting conditions) to be used when planning the speed while driving on a public road, taking into account the positional relationship with other traffic participants (e.g., people, bicycles, vehicles), according to the driving status of the vehicle M recognized by the recognition unit 130. As a result, in the vehicle control device of the embodiment, the speed determination unit 144 in the action plan generation unit 140 of the first control unit 120 of the automatic driving control device 100 determines the future speed at which the vehicle M should travel, based on the objective function and auxiliary variables (including limiting conditions) determined by the objective function determination unit 142. In the vehicle control device of this embodiment, the action plan generation unit 140 within the first control unit 120 of the automatic driving control device 100 generates a target trajectory (target speed and target acceleration) for the vehicle M to travel in the future, and the second control unit 160 performs driving control (speed control) of the vehicle M according to the target trajectory generated by the action plan generation unit 140. As a result, the vehicle control device of this embodiment can achieve both improved ride comfort and improved safety (collision avoidance), and can drive the vehicle M automatically (without driver operation).

[0157] In this embodiment, the vehicle speed limit auxiliary variable o t , urgency auxiliary variable e t The time intervals for time t in this case were not specifically explained. However, each time interval may be the same or different. For example, the time intervals for acceleration a may be 0.1 seconds, 0.2 seconds, 0.3 seconds, ..., 5.0 seconds, and the position s t The point where the speed limit changes s th Vehicle speed limit auxiliary variable o that determines whether or not the vehicle speed has reached its limit. t The time intervals are set to 0.5 seconds, such as 0.5 seconds, 1.0 seconds, 1.5 seconds, ..., 5.0 seconds, and the urgency auxiliary variable e is used to determine the degree of urgency to avoid collisions with other traffic participants.t The time intervals for urgency e may be set to 1.0 second intervals, such as 1.0 second, 2.0 second, 3.0 second, ..., 5.0 second. By varying the time intervals in this way, the processing load on the objective function determination unit 142 in determining the objective function and auxiliary variables (including limiting conditions) can be reduced.

[0158] The embodiments described above can be expressed as follows. Hardware processor and It comprises a memory device that stores a program, The hardware processor reads and executes the program stored in the memory device, The objective function, formulated using auxiliary variables corresponding to predetermined scenarios anticipated from the positional relationship of the vehicle with other traffic participants while it is in motion, with the acceleration in the future as the control variable, and the combination of this objective function and the limiting condition equation for setting restrictions on the said future motion are determined according to the recognized surrounding conditions of the vehicle. Based on the combination of the objective function and the limiting condition, the future driving speed of the vehicle is determined. The aforementioned auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the aforementioned scenario. A vehicle control device configured in such a way.

[0159] In the embodiment, the case was described in which the objective function determination unit 142 determines a formulated objective function and auxiliary variables (including limiting conditions) in a predetermined situation where it is necessary to consider the positional relationship with other traffic participants (e.g., people, bicycles, vehicles) while driving on an ordinary road. However, the formulated objective function and auxiliary variables (including limiting conditions) described above are not limited to general roads. For example, the first scenario shown in Figure 4, the second scenario shown in Figure 5(c), and the third scenario shown in Figure 6 can also be assumed when the vehicle M is driving on an expressway. Therefore, the objective function, limiting conditions, and auxiliary variables shown in equations (5) to (34) above can be appropriately adopted even when the vehicle M is driving on an expressway. In this case, the configuration and processing of the vehicle control device (more specifically, the processing of determining the objective function executed by the objective function determination unit 142) should be equivalent to the configuration and processing of the automatic driving control device 100 in the embodiment.

[0160] Although embodiments for carrying out the present invention have been described above using examples, the present invention is not limited in any way to these embodiments, and various modifications and substitutions can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0161] 1. Vehicle System 10. Camera 12. Radar equipment 14···LIDAR 16...Object recognition device 20. Communication devices 30···HMI 40. Vehicle Sensors 50...Navigation device 51. GNSS receiver 52... Navigation HMI 53... Route determination unit 54...First Map Information 60 MPU 61... Recommended lane determination section 62...Second Map Information 80... Driver control panel 100...Automatic driving control system 120...First Control Unit 130...Recognition section 140...Action Plan Generation Department 142...Objective function determination section 144...Speed ​​determination section 160...Second Control Unit 162...Acquisition part 164... Speed ​​control unit 166... ​​Steering Control Unit 200... Driving force output device 210... Brake system 220... Steering system

Claims

1. An objective function determination unit determines, according to the recognized surrounding conditions of the vehicle, an objective function formulated using auxiliary variables corresponding to predetermined scenarios anticipated from the positional relationship with other traffic participants while the vehicle is in motion, with the acceleration in the future as the control variable, and a combination of a limiting condition expression for setting restrictions on the said future driving, A speed determination unit that determines the future driving speed of the vehicle based on the combination of the objective function and the limiting condition, Equipped with, The aforementioned auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the aforementioned scenario. Vehicle control system.

2. The aforementioned limiting condition formula includes conditional formulas for setting limits on vehicle speed, acceleration, and jerk when the vehicle is driven, The limiting condition formula corresponding to the vehicle speed includes a term that adds half of the acceleration of the vehicle during its movement. The vehicle control device according to claim 1.

3. The aforementioned restriction condition formula further includes condition formulas for setting restrictions on following a preceding vehicle and avoiding collisions with other traffic participants, The limiting condition formula corresponding to the aforementioned following includes a term for adjusting the driving speed of the vehicle itself. The vehicle control device according to claim 2.

4. The objective function determination unit determines, when the scenario is a first scenario in which the speed limit of the lane in which the vehicle is traveling is changed, a combination of a first objective function formulated using a first auxiliary variable relating to the vehicle speed limit and a first limiting condition expression corresponding to the vehicle speed. The first limiting condition formula includes a term that adds a limit based on the first auxiliary variable and the difference in the maximum speed of the vehicle before and after the change in the speed limit. A vehicle control device according to any one of claims 1 to 3.

5. The objective function determination unit determines, if the scenario is a second scenario in which the vehicle follows a preceding vehicle, and if the preceding vehicle is already the vehicle to be followed, a combination of a second objective function formulated using a second auxiliary variable relating to the urgency based on the positional relationship between the vehicle and the preceding vehicle, and a second limiting condition expression. The second limiting condition expression includes a second-first limiting condition expression having a term that adds the second auxiliary variable to the limiting condition expression corresponding to following, and a second-second limiting condition expression corresponding to collision avoidance that represents the position of the preceding vehicle. A vehicle control device according to any one of claims 1 to 3.

6. The objective function determination unit determines a combination of the second objective function and the third limiting condition expression if the scenario is a second scenario in which the vehicle follows the preceding vehicle, and the preceding vehicle is a new target for following. The third restriction expression includes a second-third restriction expression which further includes a term that adds a third auxiliary variable relating to the following to the second-first restriction expression, and a second-fourth restriction expression which further includes a term that adds the third auxiliary variable to the second-second restriction expression. The vehicle control device according to claim 5.

7. The objective function determination unit determines a combination of the objective function and the limiting condition expression relating to collision avoidance if the scenario is a third scenario in which a collision with the other traffic participant is to be avoided, and the other traffic participant is already a target for avoidance. A vehicle control device according to any one of claims 1 to 3.

8. The objective function determination unit determines a combination of the objective function and a fourth limiting condition if the scenario is a third scenario in which a collision with the other traffic participant is avoided, and the other traffic participant is a new target for avoidance. The fourth limiting condition is that the limiting condition for collision avoidance is further modified by adding a term for a fourth auxiliary variable relating to collision avoidance. The vehicle control device according to claim 7.

9. Computers The objective function, formulated using auxiliary variables corresponding to predetermined scenarios anticipated from the positional relationship of the vehicle with other traffic participants while it is in motion, with the acceleration in the future as the control variable, and the combination of this objective function and the limiting condition equation for setting restrictions on the said future motion are determined according to the recognized surrounding conditions of the vehicle. Based on the combination of the objective function and the limiting condition, the future driving speed of the vehicle is determined. The aforementioned auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the aforementioned scenario. Vehicle control method.

10. On the computer, The system determines, based on the recognized surrounding conditions of the vehicle, an objective function formulated using auxiliary variables corresponding to predetermined scenarios anticipated from the vehicle's positional relationship with other traffic participants while it is in motion, with the acceleration in the future as the control variable, and a combination of this objective function and a limiting condition equation to impose restrictions on the future driving. Based on the combination of the objective function and the limiting condition, the future driving speed of the vehicle is determined. The aforementioned auxiliary variables are variables related to vehicle speed limit, urgency, following, and collision avoidance corresponding to the aforementioned scenario. program.

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