JP2023092622A - On-vehicle control device - Google Patents

Abstract

To suppress a feeling of strangeness from being given to a driver when an accelerator is turned off.SOLUTION: An on-vehicle control device, which is mounted on a vehicle and executes control of decelerating the vehicle when an accelerator is turned off, sets a reference deceleration index so that the index becomes higher as an inter-vehicle distance from a preceding vehicle becomes shorter, applies, to the reference deceleration index, a gradually changing process for changing the deceleration index when a lost condition for the preceding vehicle is satisfied, more gently in comparison with when the lost condition is not satisfied, so as to set a deceleration index, and executes deceleration control so that the vehicle decelerates at higher deceleration as the deceleration index is higher.SELECTED DRAWING: Figure 2

Description

The present invention relates to an in-vehicle control device.

Conventionally, as this type of in-vehicle control device, in a control device that performs inter-vehicle distance control for controlling the acceleration and deceleration of the host vehicle so as to maintain the inter-vehicle distance from the preceding vehicle at a predetermined target inter-vehicle distance, inter-vehicle distance control is started or canceled. There has been proposed a configuration in which the form of is changed according to the running state (see, for example, Patent Document 1).

JP-A-10-181382

While the vehicle is running based on the accelerator off operation or brake operation, when the vehicle ahead is lost and the same deceleration control as when the vehicle ahead is present is executed, the driver feels uncomfortable. may feel

A main object of the in-vehicle control device of the present invention is to prevent the driver from feeling uncomfortable when the accelerator is released.

The in-vehicle control device of the present invention employs the following means to achieve the above main object.

A first in-vehicle control device of the present invention includes:
An in-vehicle control device that is mounted in a vehicle and executes deceleration control of the vehicle when the accelerator is off,
When the accelerator is off,
The basic deceleration index is set so that the shorter the distance to the vehicle in front, the higher the deceleration.
The basic deceleration index is set by subjecting the basic deceleration index to a gradual change process that makes the change in the deceleration index slower when the lost condition of the preceding vehicle is satisfied than when the lost condition is not satisfied. death,
executing the deceleration control so that the vehicle decelerates at a higher deceleration as the deceleration index is higher;
This is the gist of it.

In the first in-vehicle control device of the present invention, when the accelerator is off, the basic deceleration index is set so that the shorter the inter-vehicle distance to the preceding vehicle is, the higher the index is, and the lost condition of the preceding vehicle is established in the basic deceleration index. The deceleration index is set by applying a gradual change process that makes the change in the deceleration index slower than when the lost condition is not satisfied, and the vehicle decelerates at a higher rate as the deceleration index increases. Execute deceleration control. As a result, when the lost condition is satisfied, the deceleration index and vehicle deceleration are changed more gently than when the lost condition is not satisfied, in response to changes in the basic deceleration index based on the distance to the vehicle ahead. can be made As a result, when the lost condition for the preceding vehicle changes from unsatisfied to satisfied and the basic deceleration index suddenly decreases, the deceleration index and the deceleration of the vehicle are prevented from suddenly decreasing, thereby preventing the driver from feeling discomfort. can give a relatively natural feeling of deceleration.

In the first in-vehicle control device of the present invention, the basic deceleration index uses, as the gradual change processing, an averaging constant that becomes larger when the lost condition is satisfied than when the lost condition is not satisfied. A smoothing process may be applied to set the deceleration index.

A second in-vehicle control device of the present invention includes:
An in-vehicle control device that is mounted in a vehicle and executes deceleration control of the vehicle when the accelerator is off,
When the accelerator is off,
The basic deceleration index is set so that the shorter the distance to the vehicle in front, the higher the deceleration.
setting a deceleration index based on the basic deceleration index when the lost condition of the preceding vehicle is not satisfied, and holding the deceleration index when the lost condition is satisfied;
executing the deceleration control so that the vehicle decelerates at a higher deceleration as the deceleration index is higher;
This is the gist of it.

In the second in-vehicle control device of the present invention, when the accelerator is off, the basic deceleration index is set so that the shorter the inter-vehicle distance to the vehicle in front is, the higher the basic deceleration index is. When the lost condition is satisfied, the deceleration index is held and deceleration control is executed so that the vehicle decelerates at a higher deceleration as the deceleration index is higher. As a result, when the lost condition is satisfied, the deceleration index of the vehicle can be suppressed from changing suddenly by holding the deceleration index with respect to the change in the basic deceleration index based on the inter-vehicle distance to the vehicle ahead. can. As a result, when the lost condition of the vehicle in front changes from unsatisfied to satisfied and the basic deceleration index rapidly decreases, the deceleration index is held to suppress the sudden decrease in deceleration of the vehicle, thereby giving the driver a sense of discomfort. can be suppressed to give a relatively natural deceleration feeling.

In the second in-vehicle control device of the present invention, when the lost condition is not satisfied when the accelerator is released, the basic deceleration index is set as the deceleration index, or the basic deceleration index is subjected to gradual change processing. The deceleration index may be set by

In the first or second in-vehicle control device of the present invention, the lost condition is a condition that the preceding vehicle does not exist within a predetermined distance, and an amount of increase per unit time in the inter-vehicle distance to the preceding vehicle is equal to or greater than a predetermined amount of increase. and at least one of the following conditions:

In the first or second in-vehicle control device of the present invention, the shorter the inter-vehicle distance to the vehicle in front, the higher, the higher the vehicle speed of the vehicle, and the higher the relative vehicle speed of the vehicle with respect to the vehicle speed of the front vehicle, the higher. The basic deceleration index may be set so that In this way, the basic deceleration index can be set more appropriately.

In the first or second in-vehicle control device of the present invention, the deceleration control may be executed such that the deceleration of the vehicle increases as the deceleration index increases and as the vehicle speed increases. good. By doing so, the deceleration of the vehicle can be controlled more appropriately.

1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 equipped with an in-vehicle control device as one embodiment of the present invention; FIG. It is a flowchart which shows an example of the processing routine at the time of accelerator off of an Example. FIG. 4 is an explanatory diagram showing an example of a basic deceleration index setting map; FIG. 5 is an explanatory diagram showing an example of an upper/lower limit deceleration setting map; Time showing an example of the status of the lost condition when the accelerator is off in the embodiment and the first comparative example, the sense of proximity index kp, the basic deceleration index kdtmp, the smoothing constant Ns, the deceleration index kd, and the target deceleration Dv*. Chart. It is a flowchart which shows an example of the processing routine at the time of accelerator off of a modification. 8 is a time chart showing an example of states of a lost condition, a sense of proximity index kp, a basic deceleration index kdtmp, a deceleration index kd, and a target deceleration Dv* when the accelerator is off in a modified example and a second comparative example;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing the outline of the configuration of an electric vehicle 20 equipped with an in-vehicle control device as one embodiment of the present invention. As illustrated, the electric vehicle 20 of the embodiment includes a driving motor 62 connected to the drive wheels, a battery 40 that exchanges electric power with the motor 62, and an electronic control unit 50 that controls the entire vehicle. In the embodiment, the electronic control unit 50 corresponds to the in-vehicle control device.

In addition to the motor 62, the battery 40, and the electronic control unit 50, the electric vehicle 20 of the embodiment includes an ignition switch 22, a GPS (Global Positioning System, Global Positioning Satellite) 24, an in-vehicle camera 26, a millimeter wave radar 28, a vehicle speed A sensor 30 , an acceleration sensor 32 , an accelerator sensor 34 , a brake sensor 36 , a battery actuator 38 , a battery 40 , a drive actuator 60 , a brake actuator 64 , a brake device 66 , a display device 68 , a meter 70 and a navigation system 80 are provided.

GPS 24 detects the position of the vehicle based on signals transmitted from multiple GPS satellites. The in-vehicle camera 26 is a camera that captures an image of the surroundings of the vehicle, and corresponds to, for example, a front camera that captures an image of the front of the vehicle, a rear camera that captures the image of the rear of the vehicle, and the like. The millimeter wave radar 28 detects the inter-vehicle distance and relative vehicle speed between the own vehicle and the vehicle ahead, and detects the inter-vehicle distance and relative vehicle speed between the own vehicle and the rear vehicle.

Vehicle speed sensor 30 detects the vehicle speed based on wheel speed and the like. The acceleration sensor 32 detects acceleration in the front-rear direction of the vehicle and acceleration in the left-right direction (lateral direction) of the vehicle. The accelerator sensor 34 detects the degree of opening of the accelerator, which is the amount of depression of the accelerator pedal by the driver. The brake sensor 36 detects a brake position or the like as the amount of depression of the brake pedal by the driver.

The battery actuator 38 detects the voltage, current and temperature of the battery 40 and manages the battery 40 based on these. The battery actuator 38 calculates a power storage rate SOC as a ratio of the remaining power storage capacity to the total power storage capacity based on the current of the battery 40 . The battery 40 is configured as a rechargeable secondary battery, and can be, for example, a lithium-ion battery, a nickel-metal hydride battery, a lead-acid battery, or the like.

The electronic control unit 50 includes a microcomputer having a CPU 51, ROM 52, RAM 53, flash memory 54, input/output ports, and communication ports. When the brake pedal is not depressed, the electronic control unit 50 controls the target driving force (positive driving force) or the target braking force ( negative driving force), and transmits the set target driving force or target braking force to the driving actuator 60 . Further, when the brake pedal is depressed, the electronic control unit 50 sets the target braking force of the braking device 66 based on the brake position from the brake sensor 36 and the vehicle speed from the vehicle speed sensor 30, and sets the set target braking force. to the brake actuator 64 .

The driving actuator 60 drives and controls the motor 62 so that the vehicle runs with the target driving force or the target braking force set by the electronic control unit 50 . For example, a synchronous generator motor or the like can be used as the motor 62 . The motor 62 is connected to the battery 40 via an inverter, and can output driving force using power supplied from the battery 40 and can supply generated power to the battery 40 .

The brake actuator 64 controls the brake device 66 so that the target braking force set by the electronic control unit 50 acts on the vehicle. The brake device 66 is configured, for example, as a hydraulically driven friction brake.

A display device 68 is incorporated, for example, in an installation panel in front of the driver's seat, and displays various information. The meter 70 is incorporated in, for example, an installation panel in front of the driver's seat.

The navigation system 80 is a system that guides the vehicle to a set destination, and includes a map information database 82 and a display section 84 . The map information database 82 stores, as map information, road distance information, road width information, type information (general road, expressway), legal speed information, and the like in each section. The display unit 84 displays map information and the like. When the destination is set, the navigation system 80 determines the travel route based on the information on the destination, the information on the current location (the current position of the own vehicle) acquired by the GPS 24, and the information stored in the map information database 82. is set, and the set travel route is displayed on the display unit 84 for route guidance.

Next, the operation of the electric vehicle 20 of the embodiment configured as described above, particularly the operation when the accelerator is off, will be described. FIG. 2 is a flowchart showing an example of an accelerator-off processing routine executed by the electronic control unit 50. As shown in FIG. This routine is repeatedly executed when the accelerator is off.

When the accelerator-off processing routine of FIG. 2 is executed, the electronic control unit 50 first determines the vehicle speed Vs of the host vehicle, the inter-vehicle distance d between the host vehicle and the vehicle ahead, and the relative vehicle speed Vr (the host vehicle relative to the vehicle ahead). (vehicle speed), inter-vehicle distance increase rate Δd, etc. are input (step S100). Here, for the vehicle speed Vs, for example, a value detected by the vehicle speed sensor 30 can be used. For the inter-vehicle distance d and the relative vehicle speed Vr, for example, values detected by the millimeter wave radar 28 can be used. In this embodiment, the millimeter wave radar 28 detects the inter-vehicle distance d for each process described later when there is no forward vehicle within a predetermined distance d1 (for example, about 500 m to 1 km) in front of the own vehicle. is set to a distance slightly longer than the predetermined distance d1. The inter-vehicle distance increase rate Δd is the amount of increase in the inter-vehicle distance d per unit time. A value obtained by dividing by can be used.

When the data are input in this manner, the input vehicle speed Vs, inter-vehicle distance d, and relative vehicle speed Vr are used to calculate a sense of proximity index kp by Equation (1) (step S110). Here, the sense of proximity index kp is an index that indicates the degree of sense of proximity that the driver feels when the vehicle is approaching the preceding vehicle. In formula (1), constant α and constant n are determined by experiments, analyses, machine learning, and the like. "Vr/d" when constant n has a value of 1 means the reciprocal of the Time To Collision (TTC), and "Vs/d" when constant α and constant n have a value of 1 is It is the reciprocal of the time (THW: Time Headway) until the own vehicle reaches the current position of the preceding vehicle. Therefore, the higher the proximity index kp, specifically, the shorter the inter-vehicle distance d, the higher the vehicle speed Vs, and the higher the relative vehicle speed Vr, the higher the driver's sense of proximity.

kp＝(Vr＋α・Vs)/dn (1)

Subsequently, a basic deceleration index kdtmp is set as a basic value of the deceleration index kd based on the proximity index kp (step S120). Here, the basic deceleration index kdtmp is applied to a basic deceleration index setting map determined in advance by experiments, analyses, and machine learning as the relationship between the sense of proximity index kp and the basic deceleration index kdtmp. can be set as FIG. 3 is an explanatory diagram showing an example of a basic deceleration index setting map. As shown in the figure, the basic deceleration index kdtmp is set to be higher within a range of 0 or more and 1 or less as the proximity index kp is higher. Specifically, the basic deceleration index kdtmp is set to a value of 0 in a region where the sense of proximity index kp is equal to or less than the value kp1, and is set to a value of 1 in a region where the sense of proximity index kp is equal to or greater than a value kp2 higher than the value kp1. In a region where the sense of proximity index kp is higher than the value kp1 and less than the value kp2, the value is set to increase from 0 to 1 as the sense of proximity index kp increases.

Then, the input inter-vehicle distance d is compared with the aforementioned predetermined distance d1 (step S130), and the inter-vehicle distance increase rate Δd is compared with a threshold value Δdref (step S140). Here, the processes of steps S130 and S140 are processes for determining whether or not the condition for the vehicle ahead being lost is satisfied. For example, if the vehicle ahead is lost on a curved road, if the vehicle ahead turns left or right or changes lanes and is lost, or if the vehicle ahead is lost due to sudden acceleration. etc. can be mentioned. In the embodiment, the case where the preceding vehicle does not exist within the predetermined distance d1 ahead of the own vehicle from the start of the accelerator release is included in the case where the preceding vehicle is lost. Specifically, the process of step S130 determines whether or not the preceding vehicle is lost within a predetermined distance d1 ahead of the host vehicle, thereby determining whether or not the preceding vehicle is lost. processing. Further, the process of step S140 is a process of determining whether or not the vehicle-front lost condition is satisfied by determining whether or not the vehicle-to-vehicle distance d between the host vehicle and the vehicle ahead is rapidly increasing.

When the inter-vehicle distance d is equal to or less than the predetermined distance d1 in step S130 and the inter-vehicle distance increase rate Δd is equal to or less than the threshold value dref in step S140, the preceding vehicle exists within the predetermined distance d1 ahead of the own vehicle and is ahead of the own vehicle. Since the inter-vehicle distance d has not rapidly increased, it is determined that the lost condition of the preceding vehicle is not satisfied (step S150), and a relatively small value Ns1 is set as the smoothing constant Ns (step S160).

After setting the smoothing constant Ns in this manner, the basic deceleration index kdtmp is smoothed using the smoothing constant Ns to set the deceleration index kd (step S190). Here, the deceleration index kd can be calculated by Equation (2) using, for example, the basic deceleration index kdtmp, the previous deceleration index (previous kd), and the smoothing constant Ns.

kd = previous kd + (kdtmp - previous kd)/Ns (2)

Subsequently, the target deceleration Dv* is set based on the vehicle speed Vs and the deceleration index kd (step S200), and the routine ends. Here, the target deceleration Dv* is obtained, for example, by setting an upper limit deceleration Dvmax and a lower limit deceleration Dvmin based on the vehicle speed Vs, and using the set upper limit deceleration Dvmax and lower limit deceleration Dvmin and the deceleration index kd. It can be calculated by Equation (3). The upper and lower deceleration limits Dvmax and lower limit deceleration limits Dvmin are determined by, for example, experimenting, analyzing, and machine learning as the relationship between the vehicle speed Vs and the upper and lower deceleration limits Dvmin. Can be applied and set. FIG. 4 is an explanatory diagram showing an example of an upper/lower limit deceleration setting map. As illustrated, the upper limit deceleration Dvmax and the lower limit deceleration Dvmin are set to increase as the vehicle speed Vs increases. This is to make the driver feel a sense of deceleration according to the vehicle speed Vs. By the processing in step S200, the target deceleration Dv* is set so that it increases as the vehicle speed V increases and as the deceleration index kd increases. Therefore, by the processing of steps S120 to S200, the higher the sense of proximity index kp, the higher the basic deceleration index kdtmp, the higher the deceleration index kd, and the higher the target deceleration Dv*.

Dv*＝Dvmax・kd＋Dvmin・(1－kd) (3)

When the target deceleration Dv* is set in this way, the target braking force of the motor 62 is set so that the vehicle is decelerated at the target deceleration Dv* by the braking force from the motor 62, and the set target braking force is transmitted to the drive actuator 60. do. The drive actuator 60 drives and controls the motor 62 so that the vehicle runs with the received target braking force. When the target deceleration Dv* is relatively large or when the charging of the battery 40 is limited, the braking force from the brake device 66 in addition to or instead of the motor 62 is applied to the vehicle at the target deceleration Dv*. A brake device 66 may be controlled in addition to or instead of the motor 62 to reduce the speed of the motor.

When the inter-vehicle distance d is longer than the predetermined distance d1 in step S130, it is determined that the preceding vehicle is not present within the predetermined distance d1 in front of the own vehicle, and that the lost condition of the preceding vehicle is established (step S170). A value Ns2 larger than the value Ns1 is set to the smoothing constant Ns (step S180), and the processes after step S190 are executed. Further, when the inter-vehicle distance increase rate Δd is less than the threshold value dref in step S140, it is determined that the inter-vehicle distance d between the host vehicle and the preceding vehicle is rapidly increasing, and the lost condition for the preceding vehicle is satisfied (step S170). A value Ns2 larger than the value Ns1 is set to the smoothing constant Ns (step S180), and the processes after step S190 are executed. Therefore, when the lost condition of the forward vehicle is satisfied, that is, when the smoothing constant Ns is set to the value Ns2, when the lost condition of the forward vehicle is not satisfied, that is, when the smoothing constant Ns is set to the value Ns1. In contrast, the deceleration index kd and the target deceleration Dv* are gently changed with respect to changes in the sense of approach index kp and the basic deceleration index kdtmp. As a result, when the preceding vehicle is lost, for example, when the preceding vehicle is lost on a curved road, or when the preceding vehicle is lost by turning left or right or changing lanes, the preceding vehicle is rapidly accelerated and lost. In such a case, the deceleration index kd and the target deceleration Dv* are suppressed from sharply decreasing due to the rapid decrease in the sense of proximity index kp and the basic deceleration index kdtmp, and the rapid decrease in deceleration of the vehicle is suppressed. It is possible to suppress giving a sense of discomfort to the driver and give a relatively natural feeling of deceleration.

FIG. 5 shows the success or failure of the lost condition when the accelerator is off, the proximity index kp, the basic deceleration index kdtmp, the smoothing constant Ns, the deceleration index kd, and the target deceleration Dv* in the embodiment and the first comparative example. It is a time chart which shows an example. In the figure, regarding the smoothing constant Ns, the deceleration index kdtmp, and the target deceleration Dv*, the solid line indicates the state of the example, and the dashed line indicates the state of the first comparative example. In the first comparative example, the smoothing constant Ns is set to the value Ns1 without considering the success or failure of the lost condition.

In the embodiment and the first comparative example, when the lost condition is not satisfied when the accelerator is off (before time t1), the value Ns1 is used as the smoothing constant Ns for the basic deceleration index kdtmp based on the proximity index kp. A deceleration index kd is set by performing a smoothing process, and a target deceleration Dv* is set based on the deceleration index kd to control the motor 62 . As a result, the deceleration index kd and the target deceleration Dv* are changed relatively quickly with respect to changes in the sense of proximity index kp and the basic deceleration index kdtmp based on changes in the inter-vehicle distance d from the vehicle in front. Deceleration can be adjusted quickly.

In the first comparative example, when the lost condition is met (time t1), such as when the vehicle in front no longer exists within a predetermined distance d1 in front of the own vehicle while the accelerator is continuously off, the proximity index kp and, in turn, Even when the basic deceleration index kdtmp suddenly decreases, the deceleration index kd is set by applying the smoothing process using the value Ns1 as the smoothing constant Ns to the basic deceleration index kdtmp. and the target deceleration Dv* also decrease rapidly. Therefore, when the vehicle ahead is lost, the deceleration of the vehicle suddenly decreases, which may give the driver a sense of discomfort. On the other hand, in the embodiment, when the lost condition is established (time t1) and the sense of proximity index kp and the basic deceleration index kdtmp rapidly decrease, the value Ns2 is smoothed to the basic deceleration index kdtmp. By setting the deceleration index kd by applying the smoothing process used as Ns, it is possible to suppress rapid decreases in the deceleration index kd and the target deceleration Dv*. As a result, when the preceding vehicle is lost, the deceleration of the vehicle can be prevented from suddenly decreasing, and the driver can be prevented from feeling uncomfortable, thereby providing a relatively natural feeling of deceleration.

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment described above, when the accelerator is off, the proximity index kp is set so that the shorter the inter-vehicle distance d to the preceding vehicle is, the higher the proximity index kp is. The basic deceleration index kdtmp is set so that it increases as kp increases. Subsequently, when the lost condition is not satisfied, the smoothing constant Ns is set to the value Ns1, and when the lost condition is satisfied, the smoothing constant Ns is set to a value Ns2 larger than the value Ns1, and the basic deceleration index kdtmp is set to A deceleration index kd is set by performing a smoothing process using a smoothing constant Ns. Then, the target deceleration Dv* is set such that the higher the deceleration index kd is, the higher the target deceleration Dv* is, and the motor 62 is controlled so that the vehicle decelerates at the target deceleration Dv*. In this way, when the lost condition is satisfied, the deceleration index kd and the target deceleration Dv* are changed more moderately than when the lost condition is not satisfied. It is possible to suppress a sudden decrease in the deceleration of the vehicle, suppress giving a sense of discomfort to the driver, and give a relatively natural feeling of deceleration.

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment, when the lost condition does not hold, the smoothing constant Ns is set to the value Ns1, and when the lost condition holds, the smoothing constant Ns is set to the value Ns1. A large value Ns2 is set, and the deceleration index kd is set by subjecting the basic deceleration index kdtmp to smoothing using the smoothing constant Ns. However, the basic deceleration index kdtmp is not limited to this, and a gradual change process is applied to the basic deceleration index kdtmp to make the change in the deceleration index kd more gradual when the lost condition is met than when the lost condition is not met. , deceleration index kd. Examples of the gradual change processing include various filter processing such as FIR (Finite Impulse Respose) filter processing, IIR (Infinite Impulse Response) filter processing, low-pass filter processing, and rate processing, in addition to smoothing processing. In various filter processes, the time constant and cutoff frequency may be changed based on whether the lost condition is satisfied.In the rate process, the rate value may be changed based on whether the lost condition is satisfied. .

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment, the accelerator-off processing routine of FIG. 2 is executed. However, instead of this, the accelerator-off processing routine of FIG. 6 may be executed. The accelerator-off processing routine of FIG. 6 differs from the accelerator-off processing routine of FIG. 2 in that the processing of steps S160, S180, and S190 is replaced with the processing of steps S300 to S320. Therefore, in the accelerator-off processing routine of FIG. 6, the same steps as those of the accelerator-off processing routine of FIG. 2 are given the same step numbers, and detailed description thereof is omitted.

In the accelerator-off processing routine of FIG. 6, when the electronic control unit 50 determines in step S150 that the lost condition of the preceding vehicle is not satisfied, it sets the basic deceleration index kdtmp set in step S120 to the deceleration index kd ( Step S310), the target deceleration Dv* is set based on the deceleration index kd (step S200), and the routine ends.

When it is determined in step S170 that the vehicle in front is lost, it is determined whether or not it is immediately after the accelerator is turned off (this is the first time to repeat this routine) (step S300). When it is determined that the accelerator has just started to be turned off, the basic deceleration index kdtmp set in step S120 is set as the deceleration index kd (step S310), and this routine ends. When it is determined that it is not immediately after the accelerator is turned off, the previous deceleration index (previous kd) is set as the deceleration index kd (step S320), and this routine ends. Therefore, when the lost condition of the preceding vehicle continues to be satisfied from the start of the accelerator off, the basic deceleration index kdtmp immediately after the start of the accelerator off is held as the deceleration index kd. Further, when the lost condition of the vehicle in front is changed from unsatisfied to satisfied while the accelerator is continuously off, the deceleration index kd immediately before the switching is held. As a result, when the preceding vehicle is lost, for example, when the preceding vehicle is lost on a curved road, or when the preceding vehicle is lost by turning left or right or changing lanes, the preceding vehicle is rapidly accelerated and lost. In such a case, the deceleration index kd is held to suppress a rapid decrease in the target deceleration Dv*, suppress a rapid decrease in the deceleration of the vehicle, and suppress a sense of discomfort from being given to the driver. It can give a natural feeling of deceleration.

FIG. 7 is a time chart showing an example of the status of the lost condition when the accelerator is off in the modified example and the second comparative example, the proximity index kp, the basic deceleration index kdtmp, the deceleration index kd, and the target deceleration Dv*. is. In the figure, regarding the deceleration index kdtmp and the target deceleration Dv*, the solid line indicates the state of the modified example, and the dashed line indicates the state of the second comparative example. In the second comparative example, the basic deceleration index kdtmp is set as the deceleration index kd without considering whether the lost condition is met.

In the modified example and the second comparative example, when the lost condition is not satisfied when the accelerator is off (before time t2), the basic deceleration index kdtmp based on the proximity index kp is set as the deceleration index kd, and this deceleration A target deceleration Dv* is set based on the index kd to control the motor 62 . As a result, the deceleration index kd and the target deceleration Dv* are rapidly changed in response to changes in the sense of proximity index kp and the basic deceleration index kdtmp based on changes in the inter-vehicle distance d from the vehicle in front, thereby decelerating the vehicle. can be adjusted quickly.

In the second comparative example, when the lost condition is met (at time t2), such as when the vehicle ahead is no longer within the predetermined distance d1 in front of the own vehicle while the accelerator is continuously off, the proximity index kp and, in turn, By setting the basic deceleration index kdtmp as the deceleration index kd even when the basic deceleration index kdtmp suddenly decreases, the deceleration index kd and the target deceleration Dv* also rapidly decrease. Therefore, when the vehicle ahead is lost, the deceleration of the vehicle suddenly decreases, which may give the driver a sense of discomfort. On the other hand, in the modified example, when the lost condition is established (time t2) and the sense of proximity index kp and, by extension, the basic deceleration index kdtmp suddenly decrease, the deceleration index kd is held to reduce the target deceleration Dv * can be suppressed from rapidly decreasing. As a result, when the preceding vehicle is lost, the deceleration of the vehicle can be prevented from suddenly decreasing, and the driver can be prevented from feeling uncomfortable, thereby providing a relatively natural feeling of deceleration.

In the electronic control unit 50 mounted on the electric vehicle 20 of the modified example described above, when the accelerator is off, the proximity index kp is set so that the shorter the inter-vehicle distance d to the preceding vehicle is, the higher the proximity index kp is. The basic deceleration index kdtmp is set so that it increases as kp increases. Subsequently, when the lost condition is not satisfied, the basic deceleration index kdtmp is set as the deceleration index kd, and when the lost condition is satisfied, the deceleration index kd is held. Then, the target deceleration Dv* is set such that the higher the deceleration index kd is, the higher the target deceleration Dv* is, and the motor 62 is controlled so that the vehicle decelerates at the target deceleration Dv*. In this way, by holding the deceleration index kd when the lost condition is established, when the preceding vehicle is lost, the deceleration of the vehicle is suppressed from rapidly decreasing, giving the driver a sense of discomfort. can be suppressed to give a relatively natural feeling of deceleration.

In the electronic control unit 50 mounted on the electric vehicle 20 of this modified example, the basic deceleration index kdtmp is set to the deceleration index kd when the lost condition is not satisfied when the accelerator is off. However, at this time, the deceleration index kd may be set by subjecting the basic deceleration index kdtmp to a smoothing process using a smoothing constant Ns (for example, a value Ns1). At this time, the basic deceleration index kdtmp may be subjected to gradual change processing other than the smoothing processing, such as various filter processing and rate processing, to set the deceleration index kd.

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment and the modified example described above, the distance d between the vehicles, the vehicle speed Vs, and the relative vehicle speed Vr are used to calculate the sense of proximity index kp according to the above-described formula (1). and However, the proximity index kp may be calculated using the inter-vehicle distance d and the vehicle speed Vs without considering the relative vehicle speed Vr. Alternatively, the proximity index kp may be calculated using the vehicle-to-vehicle distance d and the relative vehicle speed Vr without considering the vehicle speed Vs. Further, the proximity index kp may be calculated using only the vehicle-to-vehicle distance d without considering the vehicle speed Vs and the relative vehicle speed Vr.

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment and the above-described modified example, the proximity index kp is calculated based on the inter-vehicle distance d and the like, and the basic deceleration index kdtmp is calculated based on the calculated proximity index kp. shall be set. However, the basic deceleration index kdtmp may be set directly based on the inter-vehicle distance d.

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment and the modified example described above, the vehicle-to-vehicle distance d is compared with the predetermined distance d1, and the vehicle-to-vehicle distance increase rate Δd is compared with the threshold value Δdref to determine the position of the preceding vehicle. It is determined whether or not the lost condition is satisfied. However, it is also possible to determine whether or not the preceding vehicle lost condition is satisfied by comparing the inter-vehicle distance increase rate Δd with the threshold value Δdref without considering the inter-vehicle distance d. It is also possible to determine whether or not the condition for the loss of the preceding vehicle is satisfied by comparing the inter-vehicle distance d with the predetermined distance d1 without considering the inter-vehicle distance increase rate Δd. Furthermore, instead of comparing the inter-vehicle distance d with the predetermined distance d1, the value of a forward vehicle flag Fv indicating whether or not a forward vehicle exists within a predetermined distance d1 ahead of the host vehicle may be checked.

In the electronic control unit 50 mounted on the electric vehicle 20 of the embodiment and the modification described above, the target deceleration Dv* is set using the vehicle speed Vs and the deceleration index kd. However, the target deceleration Dv* may be set using only the deceleration index kd without considering the vehicle speed Vs.

In the embodiment, the electronic control unit 50 as an in-vehicle control device installed in the electric vehicle 20 having the motor 62 for running and the battery 40 has been described. However, it may be in the form of an in-vehicle control device mounted in a hybrid vehicle having an engine in addition to a motor and battery for running, or mounted in a fuel cell vehicle having a fuel cell in addition to a motor and battery for running. It may be in the form of an in-vehicle control device. In these cases, when the target deceleration Dv* is set when the accelerator is off, the motor is controlled so that the vehicle decelerates at the target deceleration Dv* by the braking force from the motor, for example, as in the case of the electric vehicle 20. can be considered. In addition, it is installed in an engine vehicle equipped with an engine without a running motor, specifically, an engine vehicle that runs by transmitting power from the engine to the driving wheels via a stepped transmission or a continuously variable transmission. It is good also as a form of the in-vehicle control device which is carried out. In this case, if the target deceleration Dv* is set when the accelerator is off, the gear ratio of the stepped transmission or the continuously variable transmission is adjusted so that the braking force of the engine brake decelerates at the target deceleration Dv*. It is conceivable to control

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the manufacturing industry of in-vehicle control devices.

20 electric vehicle, 22 ignition switch, 24 GPS, 26 in-vehicle camera, 28 millimeter wave radar, 30 vehicle speed sensor, 32 acceleration sensor, 34 accelerator sensor, 36 brake sensor, 38 battery actuator, 40 battery, 50 electronic control unit, 51 CPU , 52 ROM, 53 RAM, 54 flash memory, 60 drive actuator, 62 motor, 64 brake actuator, 66 brake device, 68 display device, 70 meter, 80 navigation system, 82 map information database, 84 display unit.

Claims (6)

An in-vehicle control device that is mounted in a vehicle and executes deceleration control of the vehicle when the accelerator is off,
When the accelerator is off,
The basic deceleration index is set so that the shorter the distance to the vehicle in front, the higher the deceleration.
The basic deceleration index is set by subjecting the basic deceleration index to a gradual change process that makes the change in the deceleration index slower when the lost condition of the preceding vehicle is satisfied than when the lost condition is not satisfied. death,
executing the deceleration control so that the vehicle decelerates at a higher deceleration as the deceleration index is higher;
In-vehicle controller. The in-vehicle control device according to claim 1,
The basic deceleration index is subjected, as the gradual change processing, to an averaging process using an averaging constant that becomes larger when the lost condition is satisfied than when the lost condition is not satisfied. to set the
In-vehicle controller. An in-vehicle control device that is mounted in a vehicle and executes deceleration control of the vehicle when the accelerator is off,
When the accelerator is off,
The basic deceleration index is set so that the shorter the distance to the vehicle in front, the higher the deceleration.
setting a deceleration index based on the basic deceleration index when the lost condition of the preceding vehicle is not satisfied, and holding the deceleration index when the lost condition is satisfied;
executing the deceleration control so that the vehicle decelerates at a higher deceleration as the deceleration index is higher;
In-vehicle controller. An in-vehicle control device according to any one of claims 1 to 3,
The lost condition includes at least one of a condition that the preceding vehicle does not exist within a predetermined distance, and a condition that the amount of increase per unit time in the inter-vehicle distance from the preceding vehicle is equal to or greater than a predetermined amount of increase.
In-vehicle controller. An in-vehicle control device according to any one of claims 1 to 4,
setting the basic deceleration index so that the shorter the inter-vehicle distance to the preceding vehicle is, the higher the index is, the higher is the vehicle speed of the vehicle, and the higher is the relative vehicle speed of the vehicle with respect to the vehicle speed of the preceding vehicle;
In-vehicle controller. An in-vehicle control device according to any one of claims 1 to 5,
executing the deceleration control so that the vehicle decelerates at a deceleration that is higher as the deceleration index is higher and as the vehicle speed is higher;
In-vehicle controller.

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