Vehicle control device

Abstract

To allow a vehicle to travel with an inter-vehicle distance reflecting a driver's preference.SOLUTION: A vehicle control device is used to control a vehicle which travels while switching between a manual operation mode allowing a driver to operate and an automatic operation mode without requiring driver's operation. While the vehicle travels in the manual operation mode and meets a predetermined condition including that the vehicle follows a preceding vehicle, the vehicle control device acquires a learning value by learning an inter-vehicle distance or inter-vehicle time relative to the preceding vehicle. When the vehicle travels in the automatic operation mode, the vehicle control device uses the acquired inter-vehicle distance or the inter-vehicle time relative to the preceding vehicle as the learning value. When detecting the preceding vehicle while the vehicle travels in the manual operation mode and frequency of meeting the predetermined condition is low, the vehicle control device sets the learning value to a predetermined maximum value for the learning value.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a vehicle control device. [Background technology]

[0002] Conventionally, as this type of vehicle control device, one that is used to control a vehicle that can switch between following driving operated by the driver and following driving not operated by the driver has been proposed (for example, see Patent Document 1). In this device, when the time interval between the vehicle and the preceding vehicle remains within a set range for a set period of time, the device learns the following distance for each vehicle speed. Then, during following driving not operated by the driver, the device controls the following distance between the vehicle and the preceding vehicle to be the learned following distance. It is said that this allows the vehicle to travel at a following distance that reflects the driver's preference. [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] In the above-mentioned vehicle control device, the condition that the time interval between the vehicle ahead and the vehicle in front is within the set range and continues for the set period of time is often not met, and the opportunity to learn the distance between the vehicles is limited. If the opportunity to learn the distance between the vehicles is limited, the vehicle cannot be driven at a distance that reflects the driver's preference.

[0005] The main purpose of the vehicle control device disclosed herein is to make the vehicle travel at a vehicle-to-vehicle distance that reflects the driver's preference. [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 vehicle control device according to the present disclosure includes: A vehicle control device used for controlling a vehicle that runs while switching between a manual driving mode operated by a driver and an automatic driving mode not operated by the driver, when a predetermined condition is satisfied including that the vehicle is following a preceding vehicle while running in the manual driving mode, the vehicle control device learns a distance or a time between the preceding vehicle to obtain a learned value, and when running in the automatic driving mode, the vehicle control device sets the distance or the time between the preceding vehicle to the learned value, When the preceding vehicle is detected during driving in the manual driving mode, if the frequency at which the predetermined condition is satisfied is low, the learning value is set to a predetermined value that is a maximum value of the learning value. The gist of the present invention is as follows. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing an outline of the configuration of a vehicle 20 equipped with a vehicle control device according to the present embodiment. [Diagram 2] 6 is a flowchart showing an example of a first setting routine. [Diagram 3] 10 is a flowchart showing an example of a second setting routine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of a vehicle 20 equipped with a vehicle control device of the present embodiment. The vehicle 20 includes a drive device 22, a navigation device 24, and an electronic control unit (hereinafter referred to as "ECU") 30. In addition to these, the vehicle 20 also includes a braking device such as a brake that applies a braking force, a steering device that performs steering, and the like, although not shown.

[0010] The drive device 22 includes a power source that outputs power for traveling, a transmission, and the like, and outputs the power to a drive shaft (axle and drive shaft not shown) connected to the axle.

[0011] The navigation device 24 sets a planned driving route from the current location of the vehicle (vehicle 20) to the destination based on stored map information, the current location of the vehicle from a GPS antenna, and the destination set by the user, and displays the set planned driving route on a display (not shown) to provide route guidance.

[0012] Although not shown, the ECU 30 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it includes a ROM for storing processing programs, a RAM for temporarily storing data, a non-volatile memory for storing data, and an input / output port. Signals from various sensors required for controlling the drive unit 22, the braking device, the steering device, and the like are input to the ECU 30 via an input port. Examples of signals input to the ECU 30 include the vehicle speed V from a vehicle speed sensor 32 for detecting the vehicle speed of the vehicle 20, information on the vehicle 20 and its surroundings from the surroundings recognition device 26 (for example, the distance D between the vehicle 20 and a preceding vehicle, the running position of the vehicle 20 on the lane, images of the surroundings of the vehicle 20, etc.), and an automatic driving instruction signal Sareq from the automatic driving instruction switch 28. Here, the surroundings recognition device 26 is configured with a camera, a millimeter wave radar, a quasi-millimeter wave radar, an infrared laser radar, a sonar, and the like. Control signals required for controlling the drive unit 22, the braking device, the steering device, and the like are output from the ECU 30 via an output port.

[0013] The vehicle 20 configured in this manner runs by switching between a manual driving mode in which the vehicle 20 is driven by the driver's operation and an automatic driving mode in which the vehicle 20 is driven without the driver's operation.

[0014] In the manual driving mode, the ECU 30 sets a target torque Td* based on the accelerator pedal opening and the vehicle speed V, and controls the drive device 22 to run at the target torque Td*. In the automatic driving mode, the ECU 30 sets a target vehicle speed V* based on the planned driving route from the navigation device 24, the current location of the vehicle, map information (e.g., legal speed limit), and the distance D between the vehicle and a preceding vehicle from the surrounding recognition device 26, sets the target torque Td* so that the vehicle speed V becomes the target vehicle speed V*, and controls the drive device 22 and a steering device (not shown) to run on the planned driving route at the target torque Td*. In the automatic driving mode, when the preceding vehicle is traveling and the target vehicle speed V* is higher than the vehicle speed V detected by the vehicle speed sensor 32, the ECU 30 controls the drive device 22 so that the inter-vehicle time tkd obtained by dividing the inter-vehicle distance D between the preceding vehicle and the preceding vehicle by the vehicle speed V becomes the target inter-vehicle time tkd*. The target inter-vehicle time tkd* is set to a learned value tkdl obtained by learning the inter-vehicle distance from the preceding vehicle while driving in the manual driving mode.

[0015] Next, the operation of the vehicle 20 equipped with the vehicle control device of the embodiment configured as described above, particularly the operation when setting the learning value tkdl, will be described. Fig. 2 is a flowchart showing an example of a first setting routine executed by the ECU 30. The first setting routine is repeatedly executed at predetermined time intervals (e.g., every few msec) while traveling in the manual driving mode.

[0016] When the first setting routine is executed, the CPU of the ECU 30 judges whether or not the learning condition A (predetermined condition) is satisfied (S100). Here, the learning condition A is a condition for executing learning of the inter-vehicle distance, and is satisfied when all three conditions, the prerequisite, the first following condition, and the second following condition, are satisfied. The prerequisite is a condition that the surrounding conditions such as the road and the preceding vehicle are suitable for detecting the inter-vehicle distance, and specifically, the height difference of the preceding vehicle is less than a threshold value, the preceding vehicle is not a two-wheeled vehicle, there is no traffic jam, the road surface conditions and visibility conditions are good, the road is a public road with a predetermined width or more, the road gradient is small, and it is not a merging section where lanes merge. The first following condition is a condition that the state of the vehicle 20 is suitable for executing learning, specifically, that a predetermined time has passed since the previous learning of the inter-vehicle distance, that the vehicle speed V has changed by a predetermined vehicle speed Vd or more since the previous learning of the inter-vehicle distance, that following the same preceding vehicle has continued for a predetermined time tref2 (e.g., 8 sec, 10 sec, 12 sec, etc.) or more, and that the preceding vehicle has not left. The second following condition is a condition that the vehicle 20 is traveling following the preceding vehicle, specifically, that the vehicle speed V exceeds a low vehicle speed Vlow and is below a vehicle speed Vhigh higher than the vehicle speed Vlow, that the relative speed Vr with respect to the preceding vehicle is less than a predetermined speed Vrref, that the change amount ΔV in the vehicle speed V is less than a predetermined change amount ΔVref (the vehicle speed V is constant), that the steering angle is less than a sufficiently small predetermined angle, and that the turn signal is not operating continues for a predetermined time ts or more. Therefore, the learning condition A includes a condition that the vehicle 20 follows the preceding vehicle (a second following condition).

[0017] When the learning condition A is satisfied, the inter-vehicle distance D to the preceding vehicle is divided by the vehicle speed V to obtain the inter-vehicle time tkd and stored in non-volatile memory (S110), and the number Ntd of inter-vehicle times tkd stored in the non-volatile memory is updated by incrementing it by 1 (S120). Then, it is determined whether the number Ntkd is equal to or greater than a predetermined number Ntref (e.g., 25, 30, 35, etc.) (S130). The predetermined number Ntref is a threshold value for determining whether the number Ntkd is sufficient to calculate the average inter-vehicle time tkd. When the number Ntkd is less than the predetermined number Ntref, the first setting routine is terminated.

[0018] If the number Ntkd is equal to or greater than the predetermined number Ntref in step S130, the average value of the inter-vehicle time tkd stored in the non-volatile memory is set to the learning value tkdl (S140), all inter-vehicle time tkd stored in the non-volatile memory are erased, and the number Nktd is reset to 0 (S150), and the first setting routine is terminated. Through these processes, the inter-vehicle time, i.e., the inter-vehicle distance, preferred by the driver is reflected in the learning value tkdl. When the preceding vehicle is traveling and the target vehicle speed V* is higher than the vehicle speed V detected by the vehicle speed sensor 32, the learning value tkdl thus set is set to the target inter-vehicle time tkd*, and the drive unit 22 is controlled so that the inter-vehicle time tkd becomes the target inter-vehicle time tkd*, so that the vehicle can travel at an inter-vehicle time that reflects the driver's preference, i.e., at an inter-vehicle distance that reflects the driver's preference.

[0019] Next, an operation will be described when the learning condition A is not satisfied, the number Ntkd is less than the predetermined number Ntref, or the like, and the learning value tkdl has not yet been set. Fig. 3 is a flowchart showing an example of a second setting routine executed by the ECU 30. The second setting routine is repeatedly executed at predetermined time intervals (e.g., every few msec) in parallel with the first setting routine illustrated in Fig. 2 while traveling in the manual driving mode.

[0020] When the second setting routine is executed, the CPU of the ECU 30 executes a process to determine whether or not the learning condition B is satisfied (S200). Here, the learning condition B is satisfied when the state in which the surrounding recognition device 26 detects the same preceding vehicle continues for a predetermined time tref1 (e.g., 8 sec, 10 sec, 12 sec, etc.) or more.

[0021] When the learning condition B is satisfied in step S200, it is determined whether or not the learning condition A is satisfied by the same process as in step S100 (S210). When the learning condition A is satisfied, the number of times N1 is incremented by a value of 1 and updated (S220), and when the learning condition A is not satisfied, the number of times N2 is incremented by a value of 1 and updated (S230). The number of times N1 is the number of times that the learning condition A including the second following condition is satisfied while the learning condition B is satisfied, and may be considered to indicate the number of times that the vehicle is traveling following the vehicle when the same vehicle ahead continues to exist. The number of times N2 is the number of times that the learning condition A is not satisfied while the learning condition B is satisfied, and may be considered to indicate the number of times that the vehicle is not traveling following the vehicle when the same vehicle ahead continues to exist. Then, it is determined whether or not the value obtained by adding the number of times N1 to the number of times N2 is equal to or greater than a predetermined number of times Nref (for example, 25, 30, 35, etc.) (S240). The predetermined number of times Nref is a threshold value for determining whether the number of times that the learning condition B has been satisfied is sufficient to set the learning value tdkl in step S260, which will be described later. When the value obtained by adding the number of times N2 to the number of times N1 is less than the predetermined number of times Nref, it is determined that the learning condition B is not satisfied enough to set the learning value tdkl, and the second setting routine is terminated.

[0022] When the value obtained by adding the number of times N1 and the number of times N2 in step S200 is equal to or greater than the predetermined number of times Nref, it is determined that the learning condition B is satisfied to a sufficient degree for setting the learning value tdkl, and it is determined whether or not the frequency R (=N1 / (N1+N2)) obtained by dividing the number of times N1 by the value obtained by adding the number of times N1 and the number of times N2 is less than the predetermined frequency Rref (for example, a value of 0.1, a value of 0.2, a value of 0.3, etc.) (S250). Here, the frequency R represents the frequency at which the learning condition A is satisfied when the learning condition B is satisfied. In the case of a driver who prefers aggressive driving, it is considered that the frequency of following the vehicle when there is a preceding vehicle increases, and in the case of a driver who does not prefer aggressive driving, it is considered that the frequency of following the vehicle when there is a preceding vehicle decreases. Therefore, the predetermined frequency Rref is a threshold value for determining whether or not the driver prefers aggressive driving, and step S210 is a process for determining whether or not the driver prefers aggressive driving.

[0023] If the frequency R is equal to or greater than the predetermined frequency Rref in step S250, it is determined that the driver prefers aggressive driving, and the second setting routine is terminated. If the frequency R is less than the predetermined frequency Rref, it is determined that the driver does not prefer aggressive driving, and it is determined whether or not the learning value tkdl has been set in the first setting routine (S260). If the learning value tkdl has been set in the first setting routine, the second setting routine is terminated. If the learning value tkdl has not been set in the first setting routine, a predetermined value tkdmax that is a maximum value of the inter-vehicle time tkd is set to the learning value tkdl (S270), the numbers N1 and N2 are reset to 0 (step S280), and the second setting routine is terminated. If the driver does not prefer aggressive driving, it is considered that the driver prefers a longer inter-vehicle time (inter-vehicle distance). Therefore, by setting the learning value tkdl to a predetermined value tkdmax, the driver's preferred inter-vehicle time, i.e., inter-vehicle distance, is reflected in the learning value tkdl. When the preceding vehicle is traveling and the target vehicle speed V* is higher than the vehicle speed V detected by the vehicle speed sensor 32, the learning value tkdl thus set is set to the target inter-vehicle time tkd* and the drive unit 22 is controlled so that the inter-vehicle time tkd becomes the target inter-vehicle time tkd*, so that the vehicle can travel at an inter-vehicle distance that reflects the driver's preference.

[0024] According to the vehicle control device of the embodiment described above, when learning condition B is satisfied (a preceding vehicle is detected) while driving in manual driving mode, if learning condition A (predetermined condition) is satisfied less frequently, the learning value tdkl is set to a predetermined value tdkmax that is determined in advance as the maximum value of the learning value tdkl, thereby allowing the vehicle 20 to travel at a vehicle-to-vehicle distance that reflects the driver's preference.

[0025] In the above embodiment, when the learning condition B is satisfied while driving in the manual driving mode, if the frequency at which the learning condition A is satisfied is low, the learning value tdkl is set to the maximum value of the learning value tdkl. However, the acceleration frequency at which the condition that the vehicle 20 is accelerating independently while driving in the manual driving mode is satisfied may be checked, and if the acceleration frequency is low, the learning value tdkl may be set to the maximum value of the learning value tdkl. An example of the condition at which the vehicle 20 is accelerating independently is that the increase in speed in a predetermined time is equal to or greater than a predetermined increase amount in a state where there is no preceding vehicle.

[0026] In the above embodiment, a predetermined value tkdmax that is a maximum value of the time headway tkd is set as the learned value tkdl in step S270. However, the time headway caused by a driver who does not like aggressive driving may be learned in advance by machine learning, and the learned value of the time headway calculated by machine learning may be regarded as the maximum value of the time headway tkd instead of the predetermined value tkdmax and set as the learned value tkdl.

[0027] In the above-described embodiment, in the autonomous driving mode, when the preceding vehicle is traveling and the target vehicle speed V* is higher than the vehicle speed V detected by the vehicle speed sensor 32, the ECU 30 controls the drive device 22 so that the inter-vehicle time tkd becomes the target inter-vehicle time tkd*. However, the inter-vehicle distance may be used instead of the inter-vehicle time, and the drive device 22 may be controlled so that the inter-vehicle distance becomes the target inter-vehicle distance. In this case, the learning of the inter-vehicle distance may be used as the learning value.

[0028] The following describes the relationship between the main elements of the embodiment and the main elements of the invention described in the section on solving the problems. In the embodiment, the ECU 30 corresponds to the "vehicle control device."

[0029] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0030] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0031] The present disclosure is applicable to the vehicle control device manufacturing industry and the like. [Explanation of symbols]

[0032] 22 Drive unit, 26 Surrounding recognition device, 28 Automatic driving instruction switch, 30 ECU.

Claims

[Claim 1] A vehicle control device used for controlling a vehicle that runs while switching between a manual driving mode operated by a driver and an automatic driving mode not operated by the driver, when a predetermined condition is satisfied including that the vehicle is following a preceding vehicle while running in the manual driving mode, the vehicle control device learns a distance or a time between the preceding vehicle to obtain a learned value, and when running in the automatic driving mode, the vehicle control device sets the distance or the time between the preceding vehicle to the learned value, When the preceding vehicle is detected during driving in the manual driving mode, if the frequency at which the predetermined condition is satisfied is low, the learning value is set to a predetermined value that is a maximum value of the learning value. Vehicle control device.

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