On-vehicle control device

Abstract

To learn an inter-vehicle relation between an inter-vehicle time and own vehicle speed more properly.SOLUTION: An on-vehicle control device, which is loaded on a vehicle having an automatic follow-up running mode in which an own vehicle automatically runs following-up a preceding vehicle, learns, as an inter-vehicle relation between an average inter-vehicle time and an average vehicle speed which are determined from a starting point to an ending point, with respect to an inter-vehicle relation between an inter-vehicle time from a preceding vehicle when the own vehicle is in the automatic follow-up running mode and a vehicle speed of the own vehicle, where the starting point is a time point at which a relative speed of the own vehicle with respect to the preceding vehicle becomes a positive value beyond a value zero when the own vehicle follows up the preceding vehicle manually without using the automatic follow-up running mode, an intermediate point is a time point at which the relative speed becomes a negative value beyond the value zero from the starting point, and the ending point is a time point at which the relative speed becomes a positive value beyond the value zero from the intermediate point.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an in-vehicle control device, and more particularly to an in-vehicle control device mounted on an automobile having a driving mode in which the automobile automatically follows a preceding vehicle. [Background technology]

[0002] Conventionally, as an on-board control device of this type, a device has been proposed that, when the automatic following control is released and the time interval between the vehicle and the preceding vehicle remains within a set range for a set period of time, determines that the vehicle is in a following driving state by the driver, and learns a control target value for the automatic following control based on vehicle driving information according to the driver's operation (for example, see Patent Document 1). In this device, when the vehicle is in a following driving state, the time interval and the vehicle's own speed are sampled, the time interval is converted into a function of the vehicle's own speed, and the vehicle distance according to the vehicle's own speed is learned. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-178518 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned on-board control device, if the vehicle headway time remains within the set range for a set period of time, the driver is determined to be in a following driving state. This limits the opportunities for learning the vehicle headway distance, and there are cases in which the vehicle headway distance cannot be learned more appropriately.

[0005] The main object of the in-vehicle control device of the present disclosure is to more appropriately learn the inter-vehicle relationship between the inter-vehicle time and the host vehicle speed. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The on-board control device disclosed herein is an on-board control device that is installed in an automobile having an automatic following driving mode in which the automobile automatically follows the vehicle ahead, and that learns the inter-vehicle relationship between the inter-vehicle time with the preceding vehicle and the vehicle speed of the own vehicle when in the automatic following driving mode, and is characterized in that when the automobile is manually following the preceding vehicle without using the automatic following driving mode, the start point is when the relative speed of the own vehicle with respect to the preceding vehicle crosses the value of zero and becomes a positive value, the midpoint is when the relative speed from the start point crosses the value of zero and becomes a negative value, and the end point is when the relative speed from the midpoint crosses the value of zero and becomes a positive value, and the on-board control device learns the average inter-vehicle time and average vehicle speed from the start point to the end point as the inter-vehicle relationship.

[0008] In the on-board control device disclosed herein, when manually following a preceding vehicle without using the automatic following driving mode, the start point is when the relative speed of the vehicle with respect to the preceding vehicle crosses zero and becomes a positive value, the midpoint is when the relative speed from the start point crosses zero and becomes a negative value, and the end point is when the relative speed from the midpoint crosses zero and becomes a positive value, and the average vehicle time and average vehicle speed from the start point to the end point are learned as the inter-vehicle relationship. By learning the average vehicle speed and average vehicle time from the start point to the end point as the inter-vehicle relationship in this way, the inter-vehicle relationship between the inter-vehicle time and the vehicle speed can be learned more appropriately.

[0009] In the on-board control device disclosed herein, the inter-vehicle relationship may be learned when the difference between the inter-vehicle time at the start point and the inter-vehicle time of the preceding vehicle at the end point is less than a first predetermined time. This is because when the difference between the inter-vehicle time at the start point and the inter-vehicle time of the preceding vehicle at the end point is large, it is often considered that the preceding vehicle is not being followed. The inter-vehicle relationship may also be learned when the inter-vehicle time at the start point is less than a second predetermined time. This is because when the inter-vehicle time at the start point is large, it is often considered that the preceding vehicle is not being followed. Furthermore, the inter-vehicle relationship may be learned when the required time from the start point to the intermediate point is equal to or greater than a third predetermined time, and the required time from the intermediate point to the end point is equal to or greater than the third predetermined time. This is because when the required time from the start point to the intermediate point is too short, or when the required time from the intermediate point to the end point is too short, it is often not considered that the preceding vehicle is being stably followed.

[0010] In the on-board control device of the present disclosure, when traveling in the automatic following travel mode, a vehicle relationship selected from a plurality of predetermined vehicle relationships based on the learning result may be used. In this case, the selected vehicle relationship may be the one closest to the learning result, or may be the one closest to the learning result among those having a larger inter-vehicle time than the learning result. [Brief description of the drawings]

[0011] [Figure 1] 1 is a configuration diagram showing an outline of the configuration of an in-vehicle control device according to an embodiment of the present disclosure; [Diagram 2] 5 is a flowchart showing an example of an ACC recommended vehicle distance value setting process. [Diagram 3] FIG. 4 is an explanatory diagram showing an example of the relationship between the relative speed of a host vehicle with respect to a preceding vehicle and a time gap; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a schematic diagram showing the configuration of an automobile 20 as one embodiment of the present disclosure. As shown in the figure, the automobile 20 of the embodiment includes a drive device 22, a brake device (braking device) 24, a steering device 26, and an electronic control unit (hereinafter referred to as "main ECU") 30.

[0013] The drive device 22 is configured as a device that rotates and drives its output shaft 22a. For example, the drive device 22 may be equipped with a motor, an inverter, and a battery to make the automobile 20 an electric automobile, an engine, an automatic transmission, and a fuel tank to make the automobile 20 a general engine-equipped automobile, an engine, a fuel tank, a motor, an inverter, and a battery to make the automobile 20 a hybrid automobile, or a hydrogen tank, a fuel cell, a motor, and an inverter to make the automobile 20 a fuel cell vehicle. The output shaft 22a of the drive device 22 is connected to drive wheels 28a and 28b via a differential gear 27. The drive device 22 is controlled by a drive device electronic control unit (hereinafter referred to as "drive ECU") 23 equipped with a microcomputer. Signals from various sensors required for driving and controlling the drive device 22 are input to the drive ECU 23 via an input port, and various control signals for controlling the drive device 22 are output from the drive ECU 23.

[0014] The brake device 24 is configured as a well-known hydraulically driven brake device and is configured to be able to apply braking force resulting from the brake depression force applied by depressing a brake pedal 48 and braking force resulting from hydraulic pressure adjustment to the driving wheels 28a, 28b and the driven wheels 28c, 28d. The brake device 24 is driven and controlled by a brake electronic control unit (hereinafter referred to as "brake ECU") 25. The brake ECU 25 includes a microcomputer. The brake ECU 25 controls the braking force resulting from the brake depression force applied by the brake device 24 and the braking force resulting from hydraulic pressure adjustment.

[0015] The steering device 26 is mechanically connected to a steering wheel (not shown) and the drive wheels 28a, 28b via a steering shaft, and is equipped with a steering actuator. The steering device 26 steers the drive wheels 28a, 28b based on the driver's operation, and also steers the drive wheels 28a, 28b by driving the actuator based on a steering signal from the main ECU 30.

[0016] The air conditioner 29 has a refrigeration cycle and a blower fan, and performs air conditioning in the vehicle compartment when the air conditioning switch 29a is on, and does not perform air conditioning in the vehicle compartment when the air conditioning switch 29a is off.

[0017] The main ECU 30 includes a microcomputer having a CPU 31, a ROM 32, a RAM 33, a flash memory 34, and input / output ports and communication ports (not shown). For example, an on / off signal from an air conditioning switch 29a that instructs turning on / off the air conditioning device 29, an ignition signal from an ignition switch 40, a vehicle speed V from a vehicle speed sensor 41, each wheel speed from a wheel speed sensor 42, an acceleration α from an acceleration sensor 43, a yaw rate Yr from a yaw rate sensor 44, a road surface gradient θr from a gradient sensor 45, an accelerator opening Acc from an accelerator pedal position sensor 47 that detects the amount of depression of an accelerator pedal 46, and a brake pedal position BP from a brake pedal position sensor 49 that detects the amount of depression of a brake pedal 48 are input to the main ECU 30 via the input port. For example, a control signal to the steering device 26, an air conditioning control signal to the air conditioning device 29, a display control signal to a display device 70, and a communication control signal to a communication device 72 are output from the main ECU 30 via the output port. The main ECU 30 communicates with the drive ECU 23, the brake ECU 25, a shift electronic control unit (hereinafter referred to as the "shift ECU") 50, a surroundings recognition electronic control unit (hereinafter referred to as the "surroundings recognition ECU") 55, and a navigation device 60 via communication ports.

[0018] The shift ECU 50 is configured as a microcomputer, and receives a shift position signal from a shift position sensor 52 that detects the operating position of a shift lever 51. The shift ECU 50 sets the shift position based on the shift position signal from the shift position sensor 52 and a control signal from the surroundings recognition ECU 55, and transmits the set shift position to the main ECU 30.

[0019] The surrounding recognition ECU 55 is configured as a microcomputer, and receives, for example, signals indicating information about the vehicle and its surroundings from the surrounding recognition device 56 (for example, vehicle distances D1, D2 between other vehicles in front and behind the vehicle, and the vehicle's driving position in the lane on the road surface, etc.), and an automatic driving mode signal from the automatic driving switch 57. Examples of the surrounding recognition device 56 include a camera, a millimeter wave radar, a quasi-millimeter wave radar, an infrared laser radar, and a sonar. The automatic driving switch 57 is a switch for switching between a fully automatic driving mode in which all driving operations are performed automatically, an ACC driving mode in which the vehicle follows a preceding vehicle within a set vehicle speed range by ACC control (Adaptive Cruise Control), and a manual driving mode in which the driver performs driving operations. The ACC is a control in which, when there is no preceding vehicle, the vehicle automatically operates the accelerator and brakes to travel at a vehicle speed set by the driver, and when there is a preceding vehicle, the vehicle automatically operates the accelerator and brakes to travel so as to keep the distance from the preceding vehicle constant within a vehicle speed range set by the driver, so as to follow the preceding vehicle.

[0020] The navigation device 60 includes a main body 62 with a built-in control unit, a GPS antenna 64 that receives information about the current location of the vehicle, and a display 66. The control unit of the main body 62 includes a storage medium (e.g., a hard disk or SSD) in which map information and the like are stored, an input / output port, and a communication port. The map information includes service information (e.g., tourist information, parking lots, etc.) and road information for each driving section (e.g., between traffic lights and between intersections) stored as a database. The road information includes distance information, road width information, number of lanes information, area information (urban area or suburban area), type information (general road or expressway), gradient information, legal speed limit, number of traffic lights, turning radius of each curve, and the like. The display 66 is configured as a touch panel display that displays various information such as information about the current location of the vehicle and the planned driving route to the destination, and allows the user to input various instructions. When a destination is set by a user operating the display 66, the main body 62 of the navigation device 60 sets a planned driving route from the current location of the vehicle to the destination based on the map information stored in the main body 62 and the current location and destination of the vehicle obtained from the GPS antenna 64, and displays the set planned driving route on the display 66 to provide route guidance.

[0021] Next, the operation of the automobile 20 of the embodiment configured as described above, particularly the operation when setting the inter-vehicle distance in the ACC control, will be described. Fig. 2 is a flowchart showing an example of the ACC recommended inter-vehicle distance value setting process executed by the main ECU 30 of the embodiment. This ACC recommended inter-vehicle distance value setting process is repeatedly executed at predetermined time intervals.

[0022] When the ACC recommended inter-vehicle distance setting process is executed, the main ECU 30 judges whether the ACC control is off (step S100). When the ACC control is on, it is judged that the ACC recommended inter-vehicle distance value cannot be set because the ACC control is being performed, and this process is terminated. When it is judged in step S100 that the ACC control is off, it is judged whether the start point flag Fst is on (value 1) (step S110). The start point flag Fst is a flag that is turned on (value 1) when the following start condition is satisfied in this process. When it is judged that the start point flag Fst is off (value 0), it is judged whether the following start condition is satisfied (step S120). In the embodiment, the following start condition is a zero crossing condition in which the relative speed of the host vehicle with respect to the preceding vehicle crosses over the value 0 from a negative value smaller than the value 0 to a positive value smaller than the value 0. When it is judged that the following start condition is not satisfied, it is judged that the ACC recommended inter-vehicle distance value cannot be set yet, and this process is terminated.

[0023] When it is determined in step S120 that the start point flag is off and that the following start condition is satisfied, the start point flag Fst is set to on (value 1) and the inter-vehicle time Tst and the vehicle speed Vsp of the host vehicle at the start point are stored (step S130). Here, the inter-vehicle time is the distance between the preceding vehicle and the host vehicle divided by the vehicle speed V of the host vehicle.

[0024] When the inter-vehicle time Tst and the vehicle speed Vsp of the own vehicle are stored in step S130, or when it is determined that the start point flag Fst is on (value 1) in step S110, it is determined whether or not the midpoint flag Fmid is off (value 0) (step S140). The midpoint flag Fmid is a flag that is turned on (value 1) when the following midpoint condition is satisfied in this process. When it is determined that the start point flag Fst is off (value 0), it is determined whether or not the following midpoint condition is satisfied (step S150). In this embodiment, the following midpoint condition is a zero crossing condition in which the relative speed of the own vehicle with respect to the preceding vehicle crosses over the value 0 from a positive value greater than the value 0 to a negative value less than the value 0. When it is determined that the following midpoint condition is satisfied, the midpoint flag Fmid is turned on (value 1) and the inter-vehicle time Tmp and the vehicle speed Vmp at the midpoint are stored (step S160).

[0025] When the inter-vehicle time Tmp or vehicle speed Vmp at the midpoint is stored in step S160, when it is determined that the midpoint flag Fmid is on (value 1) in step S140, or when it is determined that the following midpoint condition is not satisfied in step S150, the integrated inter-vehicle time ΣT, which is an integrated value of the inter-vehicle time from the start point, the integrated vehicle speed ΣV, and the number of integrations N are calculated (step S160). Then, it is determined whether the following end condition is satisfied (step S180). In this embodiment, the following end condition is a zero-crossing condition in which the relative speed of the host vehicle with respect to the preceding vehicle crosses over the value 0 from a negative value smaller than the value 0 while the midpoint flag Fmid is on (value 1) to a positive value smaller than the value 0. When it is determined that the following end condition is not satisfied, it is determined whether the following failure condition is satisfied (step S190). Examples of the following failure conditions include a condition that the inter-vehicle time Tsp at the start point is equal to or longer than the inter-vehicle time Tmp at the midpoint, a condition that the inter-vehicle time Tsp at the start point is equal to or longer than a predetermined time (e.g., 3 seconds or more, 4 seconds or more), and a condition that the time required from the start point to the midpoint is less than a predetermined time (e.g., less than 1 second, 1.5 seconds). If it is determined that the following failure condition is not met, this process is terminated. On the other hand, if it is determined that the following failure condition is met, the integrated inter-vehicle time ΣT, integrated vehicle speed ΣV, and number of integrations N are cleared to 0, and the start point flag Fst and midpoint flag Fmid are set to off (value 0) (step S240), and this process is terminated.

[0026] When it is determined in step S180 that the following end condition is satisfied, the integrated inter-vehicle time ΣT is divided by the number of integrations N to calculate the average inter-vehicle time Tav, and the integrated vehicle speed ΣV is divided by the number of integrations N to calculate the average vehicle speed Vav (step S220), and the recommended ACC inter-vehicle distance value D is set based on the average inter-vehicle time Tav and the average vehicle speed Vav (step S230). The recommended ACC inter-vehicle distance value D can be, for example, a value obtained by multiplying the average inter-vehicle time Tav by the average vehicle speed Vav, or a nearest inter-vehicle distance that is greater than a value obtained by multiplying the average inter-vehicle time Tav by the average vehicle speed Vav among the predetermined inter-vehicle distances. Then, the integrated inter-vehicle time ΣT, the integrated vehicle speed ΣV, and the number of integrations N are cleared to a value of 0, and the start point flag Fst and the midpoint flag Fmid are set to off (value 0) (step S240), and this process ends.

[0027] FIG. 3 is an explanatory diagram showing an example of the relationship between the relative speed of the vehicle and the inter-vehicle time with respect to the preceding vehicle when the average inter-vehicle time Tav and the average vehicle speed Vav are calculated by the ACC recommended inter-vehicle time setting process. When following a preceding vehicle, if the inter-vehicle distance to the preceding vehicle increases, the driver depresses the accelerator pedal 46 to accelerate so as to reduce the inter-vehicle distance to the preceding vehicle. At this time, the relative speed with the preceding vehicle crosses the value 0 and becomes a positive value (start point Psp). If the inter-vehicle distance decreases, the driver releases the accelerator pedal 46 to decelerate and drives so as to increase the inter-vehicle distance. At this time, the relative speed with the preceding vehicle crosses the value 0 and becomes a negative value (midpoint Pmp). If the inter-vehicle distance increases, the driver depresses the accelerator pedal 46 again to accelerate so as to reduce the inter-vehicle distance. At this time, the relative speed with the preceding vehicle crosses the value 0 and becomes a positive value again (end point Pep). When following a preceding vehicle, the state continues from the start point Psp to the end point Pep via the intermediate point Pmp. At this time, the driver is considered to judge the inter-vehicle distance to be large at the start point Psp and the end point Pep, and to be small at the intermediate point Pmp. Therefore, the inter-vehicle distance preferred by the driver is considered to correspond to the inter-vehicle distance that can be taken from the start point Psp to the intermediate point Pmp. Therefore, if the average vehicle speed Vav and the average inter-vehicle time Tav from the start point Psp to the end point Pep are obtained, the average vehicle speed Vav and the average inter-vehicle time Tav will be closer to the inter-vehicle relationship preferred by the driver. In this way, by learning the average vehicle speed Vav and the average inter-vehicle time Tav from the start point Pst to the end point Pep as the inter-vehicle relationship, the inter-vehicle relationship between the inter-vehicle time and the own vehicle speed can be more appropriately learned.

[0028] Although the present disclosure has been described using the embodiment, it can be embodied in various forms. [Industrial Applicability]

[0029] The present disclosure can be used in the manufacturing industry of in-vehicle control devices, etc. [Explanation of symbols]

[0030] 20 automobile, 22 drive unit, 30 main electronic control unit, 55 surrounding recognition ECU, 56 surrounding recognition device, 57 autonomous driving switch.

Claims

1. 1. An in-vehicle control device that is mounted on an automobile having an automatic following driving mode in which the automobile automatically follows a preceding vehicle and learns a relationship between a time interval between the automobile and the preceding vehicle and a vehicle speed of the automobile in the automatic following driving mode, comprising: When the vehicle is manually following the preceding vehicle without using the automatic following driving mode, a time when the relative speed of the vehicle with respect to the preceding vehicle crosses the value 0 and becomes a positive value is set as a start point, a time when the relative speed from the start point crosses the value 0 and becomes a negative value is set as a midpoint, and a time when the relative speed from the midpoint crosses the value 0 and becomes a positive value is set as an end point, and an average inter-vehicle time from the start point to the end point is learned as an average vehicle speed and the inter-vehicle relationship.

2. An in-vehicle control device comprising:

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