Driving force control method and driving force control device

Abstract

To lighten the burden on a driver which operates an accelerator pedal when there is no traffic light within a range of a predetermined distance in an ongoing direction on the road where the vehicle is traveling.SOLUTION: In a driving power control method, driving power corresponding to a quantity of manipulation on the accelerator pedal of a vehicle is generated for the vehicle (S3). It is determined whether there is a traffic light within a range of a predetermined range in a vehicle ongoing direction from the current position of the vehicle (S2, S4), and when it is determined that there is no traffic light within the range, the driving power to be generated for the vehicle which corresponds to the quantity of manipulation is made larger (S5 to S7) than when it is determined that there is a traffic light.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a driving force control method and a driving force control device. [Background technology]

[0002] Patent Document 1 describes an acceleration / deceleration control system that can obtain an acceleration / deceleration that is easy to drive by simply operating the accelerator. This system sets a target acceleration when the accelerator opening is larger than a predetermined accelerator opening, and conversely sets a target deceleration when it is smaller, and controls the throttle actuator based on these target acceleration / deceleration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-205015 Summary of the Invention [Problem to be solved by the invention]

[0004] When there are no traffic lights ahead for a while on the road on which the vehicle is traveling (for example, when traveling on a highway or a motorway), the vehicle can maintain a constant speed for a certain period of time. Even in such cases, it is a burden on the driver to continue to press the accelerator pedal against the reaction force of the accelerator pedal. The present invention aims to reduce the burden on a driver who operates an accelerator pedal when there is no traffic light within a predetermined distance of the destination of the road on which the vehicle is traveling. [Means for solving the problem]

[0005] In one aspect of the driving force control method of the present invention, a driving force corresponding to the amount of operation of the accelerator pedal of the vehicle is generated in the vehicle, and a determination is made as to whether or not there is a traffic light within a predetermined distance from the current position of the vehicle in the direction of travel of the vehicle on the road on which the vehicle is traveling.If it is determined that there is no traffic light within this range, the driving force corresponding to the amount of operation generated in the vehicle is made greater than if it is determined that there is a traffic light. [Effects of the Invention]

[0006] According to the present invention, the burden on the driver who operates the accelerator pedal when there is no traffic light within a predetermined distance of the destination of the road on which the vehicle is traveling can be reduced. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a braking / driving force control device according to an embodiment; [Figure 2] 3 is a diagram illustrating an outline of a braking / driving force control method according to an embodiment; FIG. [Figure 3] 2 is a block diagram illustrating an example of a functional configuration of a controller in FIG. 1. FIG. [Figure 4] 4 is a flowchart illustrating an example of a braking / driving force control method according to an embodiment. [Figure 5] 10(a) and 10(b) are explanatory diagrams of a modified driving force control method. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, identical or similar parts are designated by identical or similar reference numerals, and redundant explanations will be omitted. Each drawing is a schematic view, and may differ from the actual product. The embodiments shown below exemplify devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited to the devices and methods exemplified in the following embodiments. The technical concept of the present invention can be modified in various ways within the technical scope described in the claims.

[0009] (composition) Referring to Fig. 1, the host vehicle 1 is equipped with a braking / driving force control device 10 that controls the driving force and braking force generated in the host vehicle 1. The braking / driving force control device 10 controls the driving force and braking force generated in the host vehicle 1 in accordance with the amount of operation by the driver of an accelerator pedal, which is a driving force instruction operator. The braking / driving force control system 10 includes a positioning device 11, a map database 12, an external sensor 13, a vehicle sensor 14, a controller 15, and an actuator 16. In the drawings, the map database is referred to as a "map DB."

[0010] The positioning device 11 measures the current position of the vehicle 1. The positioning device 11 may include, for example, a Global Positioning System (GNSS) receiver. The GNSS receiver is, for example, a Global Positioning System (GPS) receiver, and receives radio waves from multiple navigation satellites to measure the current position of the vehicle 1. The map database 12 is a database of map information. For example, a map database provided in a car navigation system may be used as the map database 12. The controller 15 acquires information about the surrounding conditions of the current position of the vehicle from the map database 12. For example, the controller 15 acquires information about the road type of the road on which the vehicle is traveling (for example, whether it is a motorway such as an expressway or an ordinary road) and information about traffic lights installed on the road on which the vehicle is traveling from the map database 12.

[0011] The external sensor 13 detects various information (ambient environment information) about the environment surrounding the vehicle 1, for example, objects around the vehicle 1. The external sensor 13 detects the environment surrounding the vehicle 1, such as objects present around the vehicle 1, the relative position between the vehicle 1 and the object, the distance between the vehicle 1 and the object, and the direction in which the object exists. The external sensor 13 outputs the detected information about the ambient environment to the controller 15 as external environment information. For example, the external sensor 13 detects the relative positions of other vehicles and targets around the vehicle 1 relative to the vehicle 1. Here, targets include, for example, traffic lights installed on the road on which the vehicle 1 is traveling, lines on the road surface (lane markings, etc.), curbs on the shoulders of the road, guardrails, etc.

[0012] The external environment sensor 13 may include a monocular camera such as a full HD color camera. The camera captures an image including a recognition target in the environment surrounding the vehicle 1, and outputs the captured image to the controller 15 as external environment information. The external sensor 13 may also include a distance measuring device such as a laser range finder (LRF), radar, or LiDAR (Light Detection and Ranging) laser radar. The distance measuring device detects the relative position of the vehicle, which is determined by the relative distance and direction to an object present around the vehicle. The distance measuring device outputs the detected distance data to the controller 15 as external information.

[0013] The vehicle sensor 14 detects various information (vehicle information) obtained from the host vehicle 1. The vehicle sensor 14 includes, for example, a vehicle speed sensor that detects the traveling speed (vehicle speed) V of the host vehicle 1, a wheel speed sensor that detects the rotational speed of each tire equipped on the host vehicle 1, a three-axis acceleration sensor (G sensor) that detects the acceleration (including deceleration) of the host vehicle 1 in three axial directions, a steering angle sensor that detects the steering angle (including the turning angle) θs, a gyro sensor that detects the angular velocity generated in the host vehicle 1, a yaw rate sensor that detects the yaw rate γ, an accelerator sensor that detects the operation amount α of the accelerator pedal of the host vehicle 1, and a brake sensor that detects the brake operation amount by the driver.

[0014] The controller 15 is an electronic control unit (ECU) that controls the braking and driving force of the host vehicle 1. The controller 15 includes a processor 20 and peripheral components such as a storage device 21. The processor 20 may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The storage device 21 may include a semiconductor storage device, a magnetic storage device, an optical storage device, etc. The storage device 21 may include memories such as a register, a cache memory, a ROM (Read Only Memory) used as a main memory device, and a RAM (Random Access Memory). The functions of the controller 15 described below are realized by, for example, the processor 20 executing a computer program stored in the storage device 21.

[0015] The controller 15 may be formed by dedicated hardware for executing each of the information processes described below. For example, the controller 15 may include a functional logic circuit configured in a general-purpose semiconductor integrated circuit, such as a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0016] The controller 15 sets a torque command value for the driving torque or braking torque to be generated on the wheels of the host vehicle 1 in accordance with the accelerator pedal operation amount α, and drives the actuator 16 in accordance with the torque command value to generate the driving torque or braking torque on the host vehicle 1. The process of setting the torque command value by the controller 15 will be described later. The actuator 16 is a drive source connected to the wheels of the host vehicle 1, and is, for example, a drive motor, an internal combustion engine, or a brake actuator that generates a drive torque or a braking torque on the wheels of the host vehicle 1. In the following, in this embodiment, as an example, the actuator 16 is assumed to be a drive motor. The actuator 16 generates a drive force for driving the host vehicle 1 or a braking force for braking the host vehicle 1 in response to a control signal (torque command value) from the controller 15.

[0017] Next, a description will be given of the process of setting the torque command value by the controller 15. The controller 15 executes so-called one-pedal control, which performs control such that acceleration occurs when the accelerator pedal is depressed and deceleration occurs when the accelerator pedal is released. In a vehicle that implements one-pedal control (hereinafter also referred to as a one-pedal vehicle), it is possible to generate driving force or braking force to run the vehicle by simply pressing the pedal on or off. However, the present invention is not limited to one-pedal vehicles. The dashed line L1 in FIG. 2 shows an example of the characteristics of the torque command value that generates the driving torque and braking torque on the wheels of the host vehicle 1 relative to the accelerator pedal operation amount α.

[0018] When the accelerator pedal operation amount α detected by the accelerator sensor is equal to or greater than the operation amount threshold α1, the larger the operation amount α is, depending on the difference between the operation amount α and the operation amount threshold α1, the larger the positive torque command value becomes, and a larger driving torque is generated on the wheels of the host vehicle 1. When the operation amount α detected by the accelerator sensor is less than the operation amount threshold α1, the smaller the operation amount α is, depending on the difference between the operation amount α and the operation amount threshold α1, the smaller the negative torque command value (i.e., braking force, in this embodiment, regenerative braking force) becomes (i.e., the absolute value of the negative torque command value becomes larger), and a larger braking torque is generated on the wheels of the vehicle 1.

[0019] Therefore, to keep the host vehicle 1 traveling at a constant speed, the driver needs to continue to depress the accelerator pedal against the reaction force against the operation of the accelerator pedal so that the operation amount α is equal to or greater than the operation amount threshold α1. Here, for example, in the case of a one-pedal vehicle, the operation amount threshold α1 at which the drive torque and braking torque are switched is set to be larger than the accelerator operation amount that generates the drive torque in a vehicle that is not a one-pedal type, and the reaction force of the accelerator pedal increases as the operation amount α increases. Therefore, if the driver continues to depress the accelerator pedal so that the operation amount α becomes equal to or greater than the operation amount threshold α1, the burden on the driver increases because the pedal operation amount is large. That is, normally, the greater the operation amount of the accelerator pedal, the greater the pedal reaction force applied. Therefore, in order to continue to depress the accelerator pedal with a large operation amount so that the operation amount α becomes equal to or greater than the operation amount threshold α1, the driver must continue to depress the accelerator pedal against the large pedal reaction force, which increases the burden on the driver. In particular, when traveling on a road where there are no traffic lights within a predetermined distance ahead of the vehicle (for example, a motorway including an expressway), the driver must continue to depress the accelerator pedal for a long time so that the operation amount α becomes equal to or greater than the operation amount threshold α1, which increases the burden on the driver.

[0020] For this reason, the controller 15 of the embodiment determines whether or not a traffic light is present on the road on which the vehicle is traveling within a predetermined distance from the current position of the vehicle 1 in the traveling direction of the vehicle 1. If it is determined that no traffic light is present within the range, the controller 15 increases the driving force generated by the vehicle 1 in response to the detected operation amount α compared to when it is determined that a traffic light is present. Whether or not there is a traffic light within a predetermined distance from the current position of the vehicle 1 on the road on which the vehicle 1 is traveling in the direction of travel of the destination of the road on which the vehicle 1 is traveling is determined, for example, as follows: The absolute position (global position) of the vehicle 1 measured by the positioning device 11 is converted to a position on map data including position information of traffic lights stored in the map database 12, the distance from the position of the vehicle 1 on the map to the position of the traffic light closest to the vehicle 1 is calculated, and the calculated distance is compared with a predetermined distance to determine whether or not there is a traffic light within the predetermined distance in the direction of travel of the vehicle 1. Alternatively, the absolute position (global position) of the vehicle 1 measured by the positioning device 11 is converted into a position on map data including road types stored in the map database 12, and the road type of the road on which the vehicle 1 is currently traveling (for example, whether it is a motorway such as an expressway or an ordinary road) is determined from the position of the vehicle 1 on the map. If the road type of the road on which the vehicle 1 is currently traveling is a motorway, it is determined that there is no traffic light within a predetermined distance in the direction of travel of the vehicle 1, because traffic lights are not normally installed on motorways such as expressways. If the road type of the road on which the vehicle 1 is currently traveling is an ordinary road, it is determined that there is a traffic light within a predetermined distance in the direction of travel of the vehicle 1. Alternatively, based on the ETC gate passing history of the vehicle 1, it may be determined that the road type of the road on which the vehicle 1 is currently traveling is a motorway because the vehicle 1 has passed through an ETC gate installed at the entrance to the motorway but not at the exit, and it may be determined that there is no traffic light within a predetermined distance in the direction of travel of the vehicle 1. The vehicle 1 is also equipped with a camera that captures images in the direction of travel (forward), and extracts the traffic light closest to the vehicle 1 from the image captured by the camera.The distance from the position of the extracted traffic light on the image to the position of the traffic light closest to the vehicle 1 is calculated, and the calculated distance is compared with a predetermined distance to determine whether or not a traffic light is present within the predetermined distance in the direction of travel of the vehicle 1. Alternatively, if the position of a traffic light can be obtained by communication from the infrastructure side such as a traffic light, it may be determined based on the received information whether or not a traffic light is present within a predetermined distance in the traveling direction of the vehicle 1. The method of determining whether or not a traffic light is present within a predetermined distance in the traveling direction of the vehicle 1 is not limited to these and may be changed as appropriate. Hereinafter, the presence of a traffic light within a specified distance from the current position of vehicle 1 to the destination of the road on which vehicle 1 is traveling will be referred to simply as "a traffic light exists," and the absence of a traffic light within a specified distance to the destination of the road on which vehicle 1 is traveling will be referred to simply as "no traffic light exists."

[0021] For example, as shown in Fig. 2, if a torque command value having characteristic line L1 is used as the torque command value when it is determined that a traffic light is present, a correction torque Tc1 is added to the torque command value of characteristic line L1 when it is determined that no traffic light is present. A solid line L2 indicates the characteristic line of the torque command value when it is determined that no traffic light is present. This allows a larger drive torque to be generated with a smaller operation amount α, thereby reducing the burden on the driver.

[0022] Furthermore, when the torque command value is set in this manner when no traffic lights are present, if the accelerator pedal operation amount α is equal to or greater than the operation amount threshold α2, the larger the operation amount α becomes, in accordance with the difference between the operation amount α and the operation amount threshold α2, the larger the positive torque command value becomes, thereby generating a larger driving torque on the wheels of the host vehicle 1. If the operation amount α is less than the operation amount threshold α2, the smaller the operation amount α becomes, in accordance with the difference between the operation amount α and the operation amount threshold α2, the smaller the negative torque command value becomes, thereby generating a larger braking torque on the wheels of the host vehicle 1. Therefore, the operation amount threshold α2 at which the drive torque and braking torque are switched is smaller than the operation amount threshold α1 when a traffic light is present. As a result, when it is determined that there is no traffic light, the drive torque can be generated with a smaller operation amount α than when it is determined that there is a traffic light, thereby reducing the burden on the driver.

[0023] The functional configuration of the controller 15 will be described in more detail below. 3, the controller 15 includes a basic braking / driving torque setting unit 30, a correction torque setting unit 31, a torque command value calculation unit 32, and a torque control unit 33. The basic braking / driving torque setting unit 30 sets the basic braking / driving torque Tb in accordance with the accelerator pedal operation amount α detected by the accelerator sensor and the vehicle speed V of the host vehicle 1 detected by the vehicle speed sensor.

[0024] As shown in characteristic line L1 in Fig. 2, for example, when the accelerator pedal operation amount α is equal to or greater than the operation amount threshold α1, the basic braking / driving torque Tb has a larger positive value in accordance with the difference between the operation amount α and the operation amount threshold α1, and generates a larger driving torque on the wheels of the host vehicle 1. When the operation amount α is less than the operation amount threshold α1, the basic braking / driving torque Tb has a smaller negative value (i.e., a larger absolute value) in accordance with the difference between the operation amount α and the operation amount threshold α1, and generates a larger braking torque on the wheels of the host vehicle 1. Also, for example, the higher the vehicle speed V of the host vehicle 1, the greater the gradient of the basic braking / driving torque Tb set by the basic braking / driving torque setting unit 30, and the lower the vehicle speed V of the host vehicle 1, the smaller the gradient of the basic braking / driving torque Tb. For example, the basic braking / driving torque setting unit 30 sets the basic braking / driving torque Tb according to the operation amount α and the vehicle speed V using a map or a calculation formula that defines the relationship between the operation amount α, the vehicle speed V and the basic braking / driving torque Tb.

[0025] The correction torque setting unit 31 determines whether or not there is a traffic light within a predetermined distance from the current position of the vehicle 1 to the destination of the road on which the vehicle 1 is traveling, and sets the correction torque Tc according to the determination result. If such a traffic light does not exist, the vehicle can maintain a constant speed for a certain period of time. This constant speed can be referred to as "gliding" in this specification. The conditions under which gliding is possible can also be referred to as "gliding enabling conditions."

[0026] For example, the correction torque setting unit 31 may determine that the gliding enabling condition is met when the following condition (A) is met, and that the gliding enabling condition is not met when the condition (A) is not met. Condition (A): There is no traffic light within a predetermined distance from the current position of the vehicle 1 to the destination of the road on which the vehicle 1 is traveling. For example, the correction torque setting unit 31 may determine that condition (A) is met when the vehicle 1 is traveling on a motorway such as an expressway, and may determine that condition (A) is not met when the vehicle 1 is traveling on a general road.

[0027] The correction torque setting unit 31 may determine whether the vehicle 1 is traveling on a motorway or a general road based on the current position of the vehicle 1 measured based on the positioning device 11 and the map information in the map database 12, or may determine whether the vehicle 1 is traveling on a motorway or a general road based on an image captured by the camera of the external sensor 13 (for example, by recognizing road signs). For example, the correction torque setting unit 31 may determine whether or not condition (A) is met based on the current position of the vehicle 1 and the position information of the traffic light included in the map information, or may determine whether or not condition (A) is met by recognizing the traffic light on the captured image.

[0028] The correction torque setting unit 31 may further add the following conditions (B) to (D) and determine that the gliding possible condition is met if all of the conditions (A) to (D) are met, and that the gliding possible condition is not met if any of the conditions (A) to (D) are not met. Condition (B): The following condition (B1) or (B2) is met. Condition (B1): There is no preceding vehicle on the path of the host vehicle 1. Condition (B2): The time-to-collision (TTC) from the host vehicle 1 to the vehicle preceding the host vehicle 1 is equal to or greater than a first predetermined time, and the time headway (THW) from the host vehicle 1 to the vehicle preceding the host vehicle 1 is equal to or greater than a second predetermined time.

[0029] The correction torque setting unit 31 may calculate the predicted course of the vehicle 1 based on the steering angle θs detected by the steering angle sensor and the yaw rate γ detected by the yaw rate sensor, and may determine whether a preceding vehicle is present on the predicted course based on an image captured by the camera of the external sensor 13. When a preceding vehicle is present, the correction torque setting unit 31 may measure the distance between the preceding vehicle and the vehicle itself based on an image or distance measurement data from a distance measuring device, and the relative speed of the preceding vehicle relative to the vehicle itself, and calculate the arrival margin time by dividing the distance between the vehicles by the relative speed, and the headway time by dividing the distance between the vehicles by the vehicle speed V.

[0030] Condition (C): The vehicle speed V of the host vehicle 1 is equal to or greater than a predetermined speed. Condition (D): The accelerator pedal operation amount α detected by the accelerator sensor is less than the operation amount threshold α1. When the gliding enabling condition is met, the correction torque setting unit 31 sets the value of the correction torque Tc to a predetermined value "Tc1," and when the gliding enabling condition is not met, the correction torque setting unit 31 sets the value of the correction torque Tc to "0." When switching the value of the correction torque Tc, the correction torque setting unit 31 may gradually increase the value of the correction torque Tc from "0" to Tc1 and gradually decrease it from Tc1 to "0" in order to avoid abrupt torque fluctuations. The period for gradually changing the correction torque Tc may be, for example, 2 seconds.

[0031] Furthermore, if the accelerator pedal operation amount α detected by the accelerator sensor becomes equal to or greater than the operation amount threshold α1 while the correction torque Tc value is set to Tc1, the correction torque setting unit 31 sets the correction torque Tc value to 0. At this time, the correction torque setting unit 31 may gradually decrease the correction torque Tc value from Tc1 to 0 over a predetermined time period (for example, 2 seconds). By changing the value of the correction torque Tc from Tc1 to "0", the driving torque is reduced, but by gradually reducing the correction torque Tc over a predetermined time, the reduction in the correction torque Tc can be limited for a predetermined time.

[0032] The torque command value calculation unit 32 adds the correction torque Tc set by the correction torque setting unit 31 to the basic braking / driving torque Tb set by the basic braking / driving torque setting unit 30 to set the final torque command value Tf. Therefore, when the value of the correction torque Tc is "0" (i.e., when the gliding enabling condition is not met), the basic braking / driving torque Tb having the characteristic line L1 in FIG. 2 is set as the torque command value Tf. Therefore, the operation amount threshold value of the accelerator pedal operation amount α at which switching between driving torque and braking torque occurs is α1. The operation amount threshold value α1 is an example of the "first threshold value" described in the claims.

[0033] When the value of the correction torque Tc is Tc1 (that is, when the gliding enabling condition is met), the braking / driving torque having the characteristic line L2 in FIG. 2 (basic braking / driving torque Tb+correction torque Tc1) is set as the torque command value Tf. When the accelerator pedal operation amount α is equal to or greater than an operation amount threshold α2 that is smaller than the operation amount threshold α1, the torque command value Tf having the characteristic line L2 has a larger positive value in accordance with the difference between the operation amount α and the operation amount threshold α2 (i.e., the larger the difference between the operation amount α and the operation amount threshold α2), and generates a larger driving torque on the wheels of the host vehicle 1. When the operation amount α is less than the operation amount threshold α2, the torque command value Tf has a smaller negative value (i.e., a larger absolute value) in accordance with the difference between the operation amount α and the operation amount threshold α2 (i.e., the larger the difference between the operation amount α and the operation amount threshold α2), and generates a larger braking torque on the wheels of the host vehicle 1.

[0034] Therefore, the operation amount threshold value of the accelerator pedal operation amount α at which the drive torque and the braking torque are switched is α2. The operation amount threshold value α2 is an example of the "second threshold value" described in the claims. The torque control unit 33 generates a driving force or a braking force on the wheels of the host vehicle 1 by controlling the accelerator opening actuator or the brake control actuator of the actuator 16 based on the torque command value Tf. The torque control unit 33 generates a larger driving torque as the positive torque command value Tf increases, and generates a larger braking torque as the negative torque command value Tf decreases (ie, the absolute value increases).

[0035] (operation) Next, an example of a braking / driving force control method according to the embodiment will be described with reference to FIG. In step S1, the vehicle sensor 14 detects the accelerator pedal operation amount α, the vehicle speed V of the host vehicle 1, the steering angle θs, and the yaw rate γ. In step S2, the external sensor 13 acquires external information. In step S3, the basic braking / driving torque setting unit 30 sets the basic braking / driving torque Tb based on the operation amount α and the vehicle speed V.

[0036] In step S4, the correction torque setting unit 31 determines whether or not the gliding enabling condition is met based on the operation amount α, the vehicle speed V, steering angle θs, yaw rate γ, and external environment information of the host vehicle 1. If the gliding enabling condition is met (step S4: Y), the process proceeds to step S5. If the gliding enabling condition is not met (step S4: N), the process proceeds to step S6. In step S5, the correction torque setting unit 31 sets the value of the correction torque Tc to Tc1, after which the process proceeds to step S7.

[0037] In step S6, the correction torque setting unit 31 sets the value of the correction torque Tc to 0. After that, the process proceeds to step S7. In step S7, the torque command value calculation unit 32 adds the correction torque Tc to the basic braking / driving torque Tb to set the torque command value Tf. In step S8, the torque control unit 33 drives the actuator 16 based on the torque command value Tf to generate a driving force or a braking force on the wheels of the host vehicle 1. Then, the process ends.

[0038] (Variation) While the present invention has been described above as being applied to braking / driving force control of a one-pedal vehicle, it may also be applied to driving force control in response to accelerator pedal operation amount α in a vehicle that is not a one-pedal vehicle. For example, the present invention may be applied to driving force control of a vehicle in which a driving torque is generated in the wheels of the host vehicle 1 in response to accelerator pedal operation amount α, and a braking torque is generated in the wheels of the host vehicle 1 in response to brake pedal operation amount α. 5(a), for example, when the gliding enabling condition is not met, as shown by characteristic line L1 (dashed line), if the operation amount α of the accelerator pedal is equal to or greater than the operation amount threshold α1, a larger driving torque may be generated on the wheels of the host vehicle 1 in accordance with the difference between the operation amount α and the operation amount threshold α1, and if the operation amount α is less than the operation amount threshold α1, the driving torque and braking torque may be set to 0.

[0039] When the gliding possible condition is met, as shown by characteristic line L2 (solid line), if the accelerator pedal operation amount α is equal to or greater than an operation amount threshold α2 that is smaller than the operation amount threshold α1, a larger driving torque is generated on the wheels of the vehicle 1 depending on the difference between the operation amount α and the operation amount threshold α2, and if the operation amount α is less than the operation amount threshold α2, the driving torque and braking torque may be set to 0.

[0040] For example, if the gliding enabling condition is not met, a correction torque Tc of value "0" is added, and if the gliding enabling condition is met, a correction torque Tc of value Tc1 is added to a torque command value similar to the basic braking / driving torque Tb described above, and the result of this addition is limited to a lower limit value of "0", thereby generating a driving torque command value with the characteristics shown in Figure 5(a). Alternatively, characteristic maps or calculation formulas for the characteristic lines L1 and L2 may be provided, and switching may be performed depending on whether or not the gliding enabling condition is met.

[0041] See Figure 5(b). When the gliding enabling condition is not met, the increase rate of the drive torque relative to an increase in the operation amount α may be relatively small, as shown by characteristic line L1 (dashed line), and when the gliding enabling condition is met, the increase rate may be relatively large, as shown by characteristic line L2 (solid line). In this way, even if the characteristics of the drive torque are changed, when the gliding enabling condition is met, a larger drive torque can be generated with a smaller operation amount α, thereby reducing the burden on the driver.

[0042] (Effects of the embodiment) (1) The vehicle sensor 14 detects the amount of accelerator pedal operation α of the host vehicle 1. The controller 15 determines whether or not a traffic light exists within a predetermined distance from the current position of the host vehicle 1 in the traveling direction of the host vehicle 1 on the road on which the host vehicle 1 is traveling, and if it determines that no traffic light exists within this range, it increases the driving force generated in the host vehicle 1 in relation to the amount of operation α compared to when it determines that a traffic light exists. This allows a larger drive torque to be generated with a smaller amount of operation α in a situation where gliding is possible, thereby reducing the burden on the driver.

[0043] (2) When the controller 15 determines that a traffic light is present within the above range, it sets the operation amount threshold to a first threshold, and when it determines that a traffic light is not present within the above range, it sets the operation amount threshold to a second threshold that is smaller than the first threshold. When the operation amount α is equal to or greater than the operation amount threshold, the greater the operation amount α, the greater the driving force that is generated. This makes it possible to generate a driving force corresponding to the accelerator pedal depression amount α. (3) When the operation amount α is less than the operation amount threshold, the controller 15 may generate a braking force that is greater as the operation amount α is smaller. This makes it possible to generate a braking force corresponding to the accelerator pedal depression amount α.

[0044] (4) When it is determined that no traffic light is present within the above range and the operation amount α is less than the first threshold, the controller 15 may set the operation amount threshold to the second threshold. This prevents the driver from feeling uncomfortable when a large drive torque is suddenly generated due to the operation amount threshold being set to the second threshold when the accelerator pedal operation amount is relatively large.

[0045] (5) When the controller 15 determines that there is no traffic light within the above range and the arrival time from the vehicle 1 to the preceding vehicle is equal to or longer than a first predetermined time, the controller 15 may increase the driving force generated in the vehicle 1 relative to the operating amount α compared to when it determines that there is a traffic light or the arrival time is less than the first predetermined time. This allows a larger drive torque to be generated with a smaller amount of operation α in a situation where gliding is possible, thereby reducing the burden on the driver.

[0046] (6) When the controller 15 determines that there is no traffic light within the above range and the headway time from the vehicle 1 to the preceding vehicle is equal to or longer than a second predetermined time, the controller 15 may increase the driving force generated by the vehicle 1 in relation to the operating amount α compared to when it determines that there is a traffic light or when the headway time is less than the second predetermined time. This allows a larger drive torque to be generated with a smaller amount of operation α in a situation where gliding is possible, thereby reducing the burden on the driver.

[0047] (7) When the controller 15 determines that there is no traffic light within the above range and no preceding vehicle is detected, the controller 15 may increase the driving force generated in the host vehicle 1 relative to the operating amount α compared to when it determines that there is a traffic light or detects a preceding vehicle. This allows a larger drive torque to be generated with a smaller amount of operation α in a situation where gliding is possible, thereby reducing the burden on the driver.

[0048] (8) When the controller 15 determines that there is no traffic light within the above range and the traveling speed of the vehicle 1 is equal to or greater than a predetermined speed, the controller 15 may increase the driving force generated by the vehicle 1 in relation to the operating amount α compared to when the controller 15 determines that there is a traffic light or when the traveling speed is less than the predetermined speed. This allows a larger drive torque to be generated with a smaller amount of operation α in a situation where gliding is possible, thereby reducing the burden on the driver.

[0049] (9) When the operation amount threshold is set to the second threshold and the detected operation amount is equal to or greater than the first threshold, the controller 15 may set the operation amount threshold to the first threshold. This makes it possible to avoid generation of excessive drive torque. (10) The controller 15 may gradually increase the operation amount threshold from the second threshold to the first threshold over time, thereby preventing the driver from feeling uncomfortable due to a sudden torque fluctuation.

[0050] (11) The controller 15 may limit the reduction in the driving force of the vehicle 1 for a predetermined time after the detected operation amount becomes equal to or greater than the first threshold. This can prevent the driver from feeling uncomfortable due to a sudden torque fluctuation.

[0051] (12) The controller 15 determines the basic driving force to be generated in the vehicle 1 according to the operation amount α, and when it is determined that there is no traffic light within the above range, it may determine a driving force correction amount having a larger value than when it is determined that there is a traffic light, and cause the vehicle 1 to generate a driving force that is the basic driving force plus the driving force correction amount. As a result, when it is determined that no traffic light is present within the range, the driving force generated in the host vehicle 1 in response to the operation amount α is made larger than when it is determined that a traffic light is present. (13) If the controller 15 determines that no traffic light is present within the above range, the controller 15 may gradually increase the driving force correction amount over time. This prevents the driver from feeling uncomfortable due to sudden torque fluctuations. (14) The controller 15 may determine whether the road on which the vehicle 1 is traveling is an ordinary road or an expressway, and if it determines that the road on which the vehicle is traveling is an expressway, determine that there is no traffic light within a predetermined distance from the current position of the vehicle in the direction of travel of the vehicle. This makes it possible to easily determine that there is no traffic light within the predetermined distance, and suppresses an increase in the calculation load. [Explanation of symbols]

[0052] 1... host vehicle, 10... braking / driving force control device, 11... positioning device, 12... map database, 13... external sensor, 14... vehicle sensor, 15... controller, 16... actuator, 20... processor, 21... storage device, 30... basic braking / driving torque setting unit, 31... correction torque setting unit, 32... torque command value calculation unit, 33... torque control unit

Claims

1. Detecting an operation amount of an accelerator pedal of the host vehicle, and generating a driving force in the host vehicle according to the detected operation amount; determining whether or not a traffic light is present on the road on which the vehicle is traveling within a predetermined distance from the current position of the vehicle in the direction of travel of the vehicle; When it is determined that a traffic light is present within the range, the operation amount threshold is set to a first threshold; When it is determined that no traffic light is present within the range, the operation amount threshold is set to a second threshold which is smaller than the first threshold; When the detected operation amount is equal to or greater than the operation amount threshold, a larger driving force is generated in the host vehicle as the detected operation amount is larger. A driving force control method characterized by:

2. 2. The driving force control method according to claim 1, wherein when the detected operation amount is less than the operation amount threshold, the smaller the detected operation amount is, the larger the braking force generated is.

3. The driving force control method according to claim 1 or 2, characterized in that when it is determined that there is no traffic light within the range and the detected operation amount is less than the first threshold, the operation amount threshold is set to the second threshold.

4. A driving force control method according to any one of claims 1 to 3, characterized in that when it is determined that there is no traffic light within the range and the arrival time from the vehicle to the preceding vehicle is equal to or longer than a first predetermined time, the driving force generated in the vehicle in relation to the detected operating amount is made larger than when it is determined that the traffic light is present or the arrival time is less than the first predetermined time.

5. A driving force control method as described in any one of claims 1 to 4, characterized in that when it is determined that there is no traffic light within the range and the headway time from the vehicle to the preceding vehicle is equal to or greater than a second predetermined time, the driving force generated by the vehicle in relation to the detected operating amount is made larger than when it is determined that the traffic light is present or when the headway time is less than the second predetermined time.

6. A driving force control method according to any one of claims 1 to 5, characterized in that, when it is determined that no traffic light exists within the range and no preceding vehicle is detected, the driving force generated in the vehicle relative to the detected operating amount is made larger than when it is determined that the traffic light exists or a preceding vehicle is detected.

7. A driving force control method according to any one of claims 1 to 6, characterized in that when it is determined that no traffic light exists within the range and the vehicle's traveling speed is equal to or greater than a predetermined speed, the driving force generated by the vehicle in relation to the detected operating amount is made larger than when it is determined that the traffic light exists or when the traveling speed is less than the predetermined speed.

8. 3. The driving force control method according to claim 1, wherein when the operation amount threshold is set to the second threshold and the detected operation amount becomes equal to or greater than the first threshold, the operation amount threshold is set to the first threshold.

9. The driving force control method according to claim 8, wherein the operation amount threshold is gradually increased from the second threshold to the first threshold over time.

10. 10. The driving force control method according to claim 8, wherein the reduction of the driving force of the host vehicle is limited for a predetermined time after the detected operation amount becomes equal to or greater than the first threshold value.

11. determining a basic driving force to be generated in the host vehicle in accordance with the detected operation amount; When it is determined that no traffic light is present within the range, a driving force correction amount having a larger value than when it is determined that the traffic light is present within the range is determined; generating a driving force in the host vehicle that is the basic driving force plus the driving force correction amount; 11. The driving force control method according to claim 1.

12. 12. The driving force control method according to claim 11, wherein the driving force correction amount is gradually increased over time when it is determined that no traffic light is present within the range.

13. determining whether the road on which the vehicle is traveling is a general road or a highway; A driving force control method according to any one of claims 1 to 12, characterized in that, when it is determined that the road on which the vehicle is traveling is a highway for motor vehicles only, it is determined that there are no traffic lights within a predetermined distance from the current position of the vehicle in the direction of travel of the vehicle.

14. a sensor for detecting an operation amount of an accelerator pedal of the host vehicle; a power source that generates a driving force for the host vehicle according to the operation amount; a controller that determines whether or not a traffic light exists within a predetermined distance range from a current position of the host vehicle in a traveling direction of the host vehicle on a road on which the host vehicle is traveling, sets an operation amount threshold to a first threshold when it is determined that a traffic light exists within the range, sets the operation amount threshold to a second threshold which is smaller than the first threshold when it is determined that no traffic light exists within the range, and controls the power source so that the driving force generated in the host vehicle increases as the operation amount detected by the sensor increases when the detected operation amount is equal to or greater than the operation amount threshold; A driving force control device comprising:

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