JP3928512B2 - Preceding vehicle tracking control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a preceding vehicle follow-up control device that travels while keeping the distance between the preceding vehicle and the vehicle speed set by the driver when there is a preceding vehicle as an upper limit. It relates to control when
[0002]
[Prior art]
As a conventional preceding vehicle follow-up control device, for example, a device described in Japanese Patent Application Laid-Open No. 2000-233661 is known.
[0003]
In this conventional publication, when the inter-vehicle distance between the preceding vehicle and the following vehicle becomes small, speed control is performed so that the inter-vehicle distance with the preceding vehicle is equal to or greater than the inter-vehicle distance with the following vehicle. A technique for facilitating a rear-end collision avoidance operation is described.
[0004]
[Problems to be solved by the invention]
However, in the above prior art, since the speed control is started only when the distance between the preceding vehicle and the following vehicle becomes small, the distance between the front and rear of the host vehicle is reduced. There was a problem of giving an uncomfortable feeling.
[0005]
The present invention has been made paying attention to the above problem, and its purpose is that when the inter-vehicle distance with the following vehicle is narrowed, the relative positional relationship with the following vehicle before the inter-vehicle distance with the preceding vehicle is narrowed. It is an object of the present invention to provide a preceding vehicle follow-up control device that can be improved and can reduce the uncomfortable feeling given to the driver.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, vehicle speed detection means for detecting the vehicle speed of the host vehicle,
A preceding inter-vehicle distance detecting means for detecting an inter-vehicle distance from a preceding vehicle, a target preceding inter-vehicle distance setting means for setting a target inter-vehicle distance from the preceding vehicle, and an inter-vehicle distance between the preceding vehicle and the target preceding inter-vehicle distance Braking / driving force control means for controlling the braking force or driving force of the own vehicle, and a following inter-vehicle distance detecting means for detecting the inter-vehicle distance with the following vehicle,
In the preceding vehicle follow-up control device, the braking / driving force control means, when the inter-vehicle distance with the preceding vehicle is outside a predetermined range in which a positive / negative allowable range is added to the target inter-vehicle distance, The speed control unit that performs braking / driving force control so that the inter-vehicle distance is within the predetermined range, and the inter-vehicle distance with the preceding vehicle is within the predetermined range, and the inter-vehicle distance with the following vehicle is first. If it is less than or equal to the predetermined value, the vehicle decelerates with a constant negative acceleration, and then regains a constant positive acceleration with the same absolute value as when decelerating again. Every time And a deceleration control unit that performs deceleration control that terminates acceleration when the vehicle speed at the start of deceleration is reached.
[0007]
【The invention's effect】
In the present invention, when the inter-vehicle distance with the preceding vehicle is within the predetermined range and the inter-vehicle distance with the following vehicle is equal to or less than the first predetermined value, the vehicle decelerates with a constant negative acceleration, and again Constant positive acceleration with the same absolute value as deceleration Every time By performing deceleration control that terminates acceleration at the time when the vehicle speed at the start of deceleration is reached, it is possible to alert the subsequent vehicle to take a safe inter-vehicle distance.
[0008]
Therefore, since the relative positional relationship with the succeeding vehicle can be improved before the distance between the preceding vehicle and the preceding vehicle is reduced, the uncomfortable feeling given to the driver can be reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments for realizing the preceding vehicle follow-up control device of the present invention will be described below with reference to the first embodiment corresponding to the inventions according to claims 1, 2, 3, 4, 6, 7, 8, and 9. , 2, 3, 4, 6, 7, 8, 9 corresponding to the second embodiment, and corresponding to the inventions according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9 This will be described based on the third embodiment.
[0010]
(First embodiment)
First, the configuration will be described.
FIG. 1 is a block diagram showing the configuration of the first embodiment.
[0011]
In the figure, 1 is a control unit, 2 is a vehicle speed sensor, 3 is driver input means, 4 is front distance measurement means, 5 is rear distance measurement means, 6 is an engine ECU, 7 is a brake actuator, 8 is a throttle actuator, A horn drive circuit, 10 is a light drive circuit, and 11 is an alarm drive circuit.
[0012]
The control unit 1 includes a central processing unit (CPU) 30, a read only memory (ROM) 31, a random access memory (RAM) 32, an input circuit 12, and an output circuit 21, as shown in FIG.
[0013]
The ROM 31 stores a program and data for causing the microcomputer to function as a control unit of the preceding vehicle following control device. The ROM 31 is a memory capable of holding stored contents even when the power is off, and a rewritable ROM such as an EEPROM is preferably used. In this case, the ROM stores the parameters set by the driver, and the parameters can be used for the next and subsequent driving. The RAM 32 provides a work area for calculation by the CPU 30 and a storage area for temporarily storing various measurement values and calculation results. The input circuit 12 takes input signals from various sensors of the automobile. On the other hand, the output circuit 21 sends control signals to various actuators of the automobile.
[0014]
Returning to FIG. 1, a vehicle speed sensor 2, driver input means 3, front distance measurement means 4, rear distance measurement means 5, and engine ECU 6 are connected to the input circuit 12 of the control unit 1.
[0015]
The vehicle speed sensor 2 detects the output shaft rotational speed of the transmission, and outputs a pulse signal representing the traveling speed of the automobile according to the rotational speed.
[0016]
The driver input means 3 is for the driver to input simple numerical parameters. As the driver input means 3, a plurality of parameters prepared in advance by a driver's button operation are sequentially displayed on the liquid crystal display, and one of them is selected by the driver pressing a decision button. Although preferred, a keyboard or other input device can be used.
[0017]
The forward distance measuring means 4 is typically a laser radar, but the distance may be calculated using image processing with a millimeter wave radar, or a forward obstacle recognition CCD or a traveling road recognition CCD.
[0018]
The rear distance measuring means 5 is typically a laser radar, but the distance may be calculated using image processing with a millimeter wave radar, a back view monitor or a rear monitor CCD.
[0019]
The engine ECU 6 is connected to the input circuit 12 through an in-vehicle LAN connection, and outputs a signal indicating the throttle opening and other various data to the input circuit 12.
Note that the vehicle speed sensor 2 is not necessarily connected to the input circuit 12. For example, the vehicle speed sensor 2 may be connected to the engine ECU 6 to receive vehicle speed data from the engine ECU 6. When the engine ECU 6 is not connected to the input circuit 12 via a LAN, in addition to the vehicle speed sensor 2, a throttle sensor that detects the throttle opening or an accelerator sensor that detects the amount of depression of the accelerator is connected to the engine ECU 6.
[0020]
FIG. 3 shows a state where the host vehicle 42 is traveling at a distance A between the preceding vehicle 41 and a distance B between the following vehicle 43. In FIG. 1, the front distance calculation unit 13 of the control unit 1 calculates the inter-vehicle distance A with the preceding vehicle 41 in response to a signal from the front distance measurement means 4 at a constant interval such as 80 milliseconds. The value is stored in the RAM 32. Similarly, the rear distance calculation unit 14 calculates the inter-vehicle distance B with the succeeding vehicle 43 at regular intervals in response to a signal from the rear distance measuring means 5 and stores the value in the RAM 32.
[0021]
The front relative speed calculation unit 15 calculates the rate of change in the inter-vehicle distance A in the latest three times, that is, the difference in the inter-vehicle distance A per unit time, which is stored in the RAM 32, and stores the calculated difference in the RAM 32. On the other hand, the rear relative distance calculation unit 16 similarly calculates the relative speed with the following vehicle 43 and stores it in the RAM 32.
[0022]
In this embodiment, in addition to the front relative speed calculation unit 15 and the rear relative speed calculation unit 16, a difference change of the relative speed calculation values stored several times in the RAM 32, that is, a relative acceleration is calculated and stored in the RAM 32.
[0023]
The A ≦ a comparator 17 sends a signal to the alarm / speed adjusting means 19 when the inter-vehicle distance A is equal to or less than the predetermined value a. The predetermined value a is set to, for example, twice the braking distance according to the vehicle speed of the host vehicle 42 by the program. Alternatively, the driver can use the driver input means 3 in advance to set in advance the inter-vehicle distance that is normally required for the driver to perform the collision avoidance operation as the predetermined value a.
[0024]
Further, the predetermined value a is calculated by calculating the average inter-vehicle distance of a vehicle traveling in the adjacent lane with the laser radar directed in front of the adjacent lane, using a method as described in JP-A-5-221252. The inter-vehicle distance control device may be programmed to automatically set the average inter-vehicle distance. By adopting such a configuration, an interruption from an adjacent lane can be prevented.
[0025]
The predetermined value a is a target inter-vehicle distance, but an inter-vehicle distance error within a certain range is a value that should be allowed in control. The allowable range is defined as ± a ′. The value of a ′ is set depending on the predetermined value a, and it is convenient to use a fixed value such as 2% or 3% of the predetermined value a.
[0026]
The B ≦ b comparator 18 sends a signal to the alarm / speed adjusting means 19 when the inter-vehicle distance B is equal to or less than the first predetermined value b. The first predetermined value b is the distance from the succeeding vehicle 43 that starts the alerting activation operation when the succeeding vehicle 43 approaches, and is determined by the own vehicle speed, the relative speed with respect to the succeeding vehicle 43, and the relative acceleration. That is, when the host vehicle speed is high, a rear margin is taken, and when the approaching speed and acceleration of the succeeding vehicle 43 to the host vehicle 42 are large, the alert activation work is started more quickly. Or you may set to fixed values, such as 20m, 30m, and 40m, using the driver input means 3. FIG.
[0027]
In addition, as a parameter for forcibly ending the alert activation work, the distance that the subsequent vehicle 43 determines to be too close can be set as b2, and can be determined separately from the own vehicle speed, the relative speed with respect to the subsequent vehicle 43, and the relative acceleration. It is also convenient to use a fixed magnification such as 1/2 or 1/3 of the first predetermined value b set by the above method. Of course, it is also possible to set a fixed value using the driver input means 3.
[0028]
In addition, it is possible to set b3 as a distance that eliminates the need for the alert activation work, and can be determined separately from the own vehicle speed, the relative speed with respect to the following vehicle 43, and the relative acceleration, but the first time determined above It is also easy to use a fixed magnification such as 2 or 3 times the predetermined value b. Of course, it is also conceivable to set a fixed value using the driver input means 3.
[0029]
The driving state detection means 20 receives a signal indicating the throttle opening from the engine ECU 6 and a signal indicating the accelerator depression amount from the accelerator depression amount sensor, and detects whether or not the driver is waiting for a driving operation. For example, when there is no change in the accelerator depression amount over a certain period of time, or when there is no change in the throttle opening, it is determined that the driver is not performing a driving operation. The driving state detection means 20 detects a state in which the driver is performing a driving operation in response to a sensor that detects depression of the brake or a signal generated by the engine ECU 6 in response to the depression of the brake by the driver. be able to.
[0030]
The alarm / speed adjusting means 19 issues an alarm or performs speed adjustment processing according to signals from the A ≦ a comparator 17, the B ≦ b comparator 18, and the operation state detecting means 20. Details of the speed adjustment processing will be described later.
[0031]
The output circuit 21 is a circuit that sends signals to various actuators and the engine ECU 6 in response to signals from the alarm / speed adjusting means 19. The output circuit 21 includes an alarm driving circuit 11 for driving an alarm lamp and an alarm buzzer at the driver's seat, a light driving circuit 10 such as a headlamp, a brake lamp, and a hazard lamp, a horn driving circuit 9, a throttle actuator 8, and a brake actuator. 7 and the engine ECU 6 are connected.
[0032]
Next, the operation will be described.
[Speed adjustment processing]
FIG. 4 is a flowchart showing the flow of speed adjustment processing by the alarm / speed adjustment means 19. The process of FIG. 4 is repeated every certain time interval, for example, every 80 milliseconds, and the process is repeated again from step 101 after 80 milliseconds except that the process is exited by EXIT during the driving operation.
[0033]
In step 101, the front inter-vehicle distance A and the rear inter-vehicle distance B are calculated and stored in the RAM 32.
[0034]
In step 102, the relative speed ΔA with the preceding vehicle is calculated using the inter-vehicle distance A data stored in the RAM 32, and the relative speed ΔB with the following vehicle 43 is calculated using the inter-vehicle distance B data.
[0035]
In step 103, the front relative acceleration ΔΔA and the rear relative acceleration ΔΔB are calculated as the difference between the relative speed calculated in step 102 and the previously calculated relative speed, and stored in the RAM 32.
[0036]
In step 104, it is determined whether or not the driving operation is being performed. If the driving operation is being performed, the process proceeds to step 105. If the driving operation is not being performed, the process proceeds to step 106.
[0037]
In step 105, priority is given to the avoidance operation by the driver, the flag Fg during deceleration control is cleared, and this control is terminated.
[0038]
In step 106, it is determined whether the flag Fg during deceleration control is set. If Fg = 1, the process proceeds to step 111, and if Fg = 0, the process proceeds to step 107.
[0039]
Here, the deceleration control (step 110, step 120) as defined in the following vehicle warning operation is defined (step 110, step 120). Steps 110 and 120 correspond to a deceleration control unit. ). The flag Fg = 1 is stored in the RAM 32 when the condition for performing the following vehicle warning activation operation is satisfied. The vehicle speed V at that time is also stored as V0. The succeeding vehicle warning activation operation is described by the relationship between the vehicle speed V and V0 at that time, and the deceleration control refers to performing processing in which V has a lower speed than V0. Therefore, a state where acceleration is performed with a negative acceleration with respect to V is not necessarily called deceleration control. It is a positive / negative relationship of relative speed with respect to V0.
[0040]
Possible parameters of the operation target of the deceleration control are how much the inter-vehicle distance is increased from the inter-vehicle distance A0 with the preceding vehicle 41 at the start of the following vehicle warning activation operation, how much the vehicle speed is decelerated from the vehicle speed V0, and the vehicle speed V0. How much acceleration is decelerated from? Since each parameter determined by the distance from the succeeding vehicle 43, the own vehicle speed, the relative relationship with the succeeding vehicle 43, and the relative acceleration is a correlated parameter, a suitable parameter may be used for implementation. Alternatively, the value of b set to a fixed value such as 20 m, 30 m, or 40 m using the driver input unit 3 may be used, or a value having a correlation system with the value may be used.
[0041]
In the following, a case will be exemplified in which how much the inter-vehicle distance is increased (+ α) from the inter-vehicle distance a0 with the preceding vehicle 41 at the start of the subsequent vehicle warning activation operation is considered as an operation target parameter.
[0042]
In this case, the vehicle decelerates with a constant negative acceleration, accelerates with a constant positive acceleration having the same absolute value when it reaches half the target distance, and performs deceleration control when the vehicle speed reaches V0. finish. Similarly, it is also conceivable to perform control that once decelerates with a certain negative acceleration, stops the negative acceleration, travels for a predetermined distance, and then performs positive acceleration having the same absolute value as in the case of deceleration again. Although constant acceleration is always used here, an acceleration profile that accelerates stepwise and gradually increases acceleration may be used as long as it does not give the driver a sense of incongruity.
[0043]
When decelerating, a throttle actuator that sends a drive signal to the brake actuator 7 in FIG. 1 to operate the brake, and sends a signal to the engine ECU 6 to perform fuel cut (stops the supply of fuel to the fuel injection device). This is executed by sending a signal to 8 and closing the throttle. Conversely, when accelerating, a drive signal is sent to the brake actuator 7 so as not to brake, and a signal is sent to the engine ECU 6 to perform fuel injection (increasing the supply of fuel to the fuel injection device). It is executed by performing processing such as opening the degree.
[0044]
The speed control (step 108, step 112, step 114, step 116, step 118, step 121) is accelerated and decelerated in the same manner as described above, and the target is to maintain the inter-vehicle distance from the preceding vehicle 41 and equal the preceding vehicle speed. (Step 108, Step 112, Step 114, Step 116, Step 118, Step 121 are It corresponds to a speed control unit. ).
[0045]
In step 107, it is determined whether the inter-vehicle distance A with the preceding vehicle 41 is in the range of ± a ′ around the predetermined value a. If it is within the range, the process proceeds to step 109. If it is out of the range, the process proceeds to step 108.
[0046]
In step 108, speed control is performed so that the distance between the preceding vehicle 41 and the preceding vehicle 41 is a, and this control is terminated.
[0047]
In step 109, it is determined whether the inter-vehicle distance B with the succeeding vehicle 43 is equal to or less than a first predetermined value b. If it is equal to or smaller than the first predetermined value b, the process proceeds to step 110, and if it is larger than the first predetermined value b, this control is terminated.
[0048]
In step 110, deceleration control is performed with the flag Fg = 1 during deceleration control, and an alerting activation operation for the following vehicle 43 is started. At this time, if necessary, a signal is sent to the alarm drive circuit 11 to blink the alarm lamp in the driver's seat, or to sound an alarm buzzer, so that the driver is informed that the succeeding vehicle 43 is approaching. Further, when the relative speed with the following vehicle 43 increases, that is, when the distance B between the vehicles is increasing, the generation of an alarm is temporarily suspended and the alert activation operation for the following vehicle 43 is also suspended, and a certain time ( For example, a warning may be issued when the inter-vehicle distance B is equal to or less than the first predetermined value b.
[0049]
The alarm is processed not only for the driver of the host vehicle 42 but also for sending a signal to the light drive circuit 10 to blink the hazard lamp, sending a signal to the horn drive circuit 9 and sounding the horn, etc. It is also possible to issue an alarm to the car 43.
[0050]
In step 111, it is determined whether the inter-vehicle distance A with the preceding vehicle 41 is less than or equal to a predetermined value aa ′, that is, whether the preceding vehicle 41 is too close. If aa ′ ≦ A, the process proceeds to step 113, and if aa ′> A, the process proceeds to step 112.
[0051]
In step 112, the flag Fg during deceleration control is cleared, speed control is performed so that the distance from the preceding vehicle 41 is a, and the present control is terminated.
[0052]
In step 113, it is determined whether or not the succeeding vehicle 43 is approaching excessively. Specifically, it is determined whether the inter-vehicle distance B with the succeeding vehicle 43 is equal to or smaller than a third predetermined value b2. If B ≦ b2, the process proceeds to step 114, and if B> b2, the process proceeds to step 115.
[0053]
In step 114, the flag Fg during deceleration control is cleared, speed control is performed, and this control is terminated. Usually, since the distance with the preceding vehicle 41 is open, the operation is performed such that acceleration is performed and the distance between the following vehicle 43 is taken. Similarly, if necessary, an alarm can be issued. In this case, it is considered that the need for warning is high because the vehicle is approaching the following vehicle 43.
[0054]
In step 115, it is determined whether the inter-vehicle distance with the following vehicle 43 is open so as not to require the alert activation work. This is determined based on whether the inter-vehicle distance B with the succeeding vehicle 43 is equal to or greater than the second predetermined value b3. If B ≧ b3, the process proceeds to step 116, and if B <b3, the process proceeds to step 117.
[0055]
In step 116, the flag Fg during deceleration control is cleared, speed control is performed, and this control is terminated. Usually, since the inter-vehicle distance with the preceding vehicle 41 is open, the operation is accelerated and the inter-vehicle distance with the subsequent vehicle 43 is obtained. At this time, if the alarm is being issued, the alarm is stopped.
[0056]
In step 117, it is determined whether the inter-vehicle distance from the preceding vehicle 41 is too far. It is determined whether the inter-vehicle distance A with the preceding vehicle 41 is greater than or equal to a0 + α. If A ≧ a0 + α, the process proceeds to step 118. If A <a0 + α, the process proceeds to step 119.
[0057]
In the determination made here, the distance from the preceding vehicle 41 at that time is evaluated, and in the following step 119, the reverse distance α is evaluated from the start of the deceleration control. That is, if the current preceding vehicle speed is sufficiently faster than the deceleration control start time, there is a margin in the inter-vehicle distance A, and therefore it is determined whether or not it is necessary to cause the following vehicle 43 to be alerted.
[0058]
In step 118, the flag Fg during deceleration control is cleared, speed control is performed, and this control is terminated. Usually, since the inter-vehicle distance with the preceding vehicle 41 is open, the operation is accelerated and the inter-vehicle distance with the subsequent vehicle 43 is obtained. At this time, if the alarm is being issued, the alarm is stopped.
[0059]
In step 119, it is determined whether the deceleration control is completed. If the deceleration control has been completed, the process proceeds to step 121; otherwise, the process proceeds to step 120. In the case of the present embodiment, the control is performed so as to move backward by the target distance α, and it is determined whether or not the deceleration control is performed a predetermined number of times.
[0060]
In step 120, deceleration control is performed and this control is terminated.
[0061]
In step 121, the flag Fg during deceleration control is cleared, speed control is performed, and this control is terminated. At this time, if the alarm is being issued, the alarm is stopped.
[0062]
Since the above process is repeated every 80 milliseconds, the driver notices warnings and speed adjustments, and avoids rear-end collisions, such as turning the steering wheel to change lanes, accelerating for that, or stepping on the brakes. When the operation is performed, the driver's operation is given priority in response to the operation state detection means 20 detecting the operation.
[0063]
[Speed adjustment processing action]
FIG. 5 is a time chart showing an example of vehicle speed control.
Until the time t1 is reached, speed control is performed to keep the distance A between the preceding vehicle 41 constant. At this time, in the flowchart of FIG. 4, the flow proceeds from step 101 to step 102 to step 103 to step 104 to step 106 to step 107 to step 109. That is, it is determined in step 104 that the driving operation is not being performed, and in step 106, it is determined that Fg = 0. Subsequently, it is determined in step 107 that the inter-vehicle distance A with the preceding vehicle 41 is within the range of a ± a ′, and when the inter-vehicle distance B with the subsequent vehicle 43 is greater than the first predetermined value b in step 109. To be judged.
[0064]
At t1, the succeeding vehicle 43 has approached, so in the flowchart of FIG. 4, the process proceeds from step 101 → step 102 → step 103 → step 104 → step 106 → step 107 → step 109 → step 110. That is, it is determined in step 109 that the inter-vehicle distance B with the succeeding vehicle 43 is equal to or less than the first predetermined value b, and the flag Fg during deceleration control is set.
[0065]
From the next control cycle, the flow proceeds from step 101 → step 102 → step 103 → step 104 → step 106 → step 111 → step 113 → step 115 → step 117 → step 119 → step 120, and deceleration control is performed. Is called.
[0066]
At t2, the inter-vehicle distance A with the preceding vehicle 41 is equal to or greater than a predetermined distance. Therefore, in the flowchart of FIG. 4, step 101 → step 102 → step 103 → step 104 → step 106 → step 111 → step 113 → step 115 → step Step 117 → Proceed to Step 118. That is, in step 117, it is determined that the inter-vehicle distance A with the preceding vehicle 41 is equal to or greater than the predetermined value a0 + α. In step 118, the flag Fg during deceleration control is cleared, so The speed control is performed.
[0067]
At t3, since the inter-vehicle distance A with the preceding vehicle 41 falls within the range of the predetermined value a ± a ′, in the flowchart of FIG. 4, step 101 → step 102 → step 103 → step 104 → step 106 → step 107 → step From 109 to step 110, deceleration control is performed again.
[0068]
After t3, the above-described control from t2 to t3 is performed.
[0069]
Next, the effect will be described.
In the preceding vehicle follow-up control device of this embodiment, the effects listed below can be obtained.
[0070]
(1) Deceleration control is performed when the inter-vehicle distance A with the preceding vehicle 41 is within the range of the predetermined value a ± a ′ and the inter-vehicle distance B with the subsequent vehicle 43 is equal to or less than the first predetermined value b. Therefore, it is possible to guide the subsequent vehicle 43 to draw attention and to take a safe inter-vehicle distance. Therefore, since the relative positional relationship with the succeeding vehicle 43 can be improved before the inter-vehicle distance A with the preceding vehicle 41 is narrowed, the uncomfortable feeling given to the driver can be reduced.
[0071]
(2) Since the deceleration control is stopped and the speed control is performed when the inter-vehicle distance B with the following vehicle 43 becomes equal to or greater than the second predetermined value b3 that is larger than the first predetermined value b, The relative positional relationship of can be improved.
[0072]
(3) Since the deceleration control is stopped and the speed control is performed when the inter-vehicle distance B with the following vehicle 43 becomes equal to or smaller than the third predetermined value b2 which is smaller than the first predetermined value b, When the vehicle 42 is not aware of the deceleration, the relative positional relationship with the succeeding vehicle 43 can be improved.
[0073]
(4) Since the inter-vehicle distance A with the preceding vehicle 41 increases by α from the inter-vehicle distance a0 with the preceding vehicle 41 at the start of the rear vehicle warning start operation, the deceleration control is stopped and the speed control is performed. It is possible to reduce a sense of incongruity due to an excessively large distance A between the vehicle 41 and the vehicle. At the same time, the interruption probability of other vehicles from the adjacent lane can be reduced.
[0074]
(5) Since the deceleration control is stopped and the speed control is performed when the inter-vehicle distance A with the preceding vehicle 41 becomes equal to or less than the predetermined value aa ′, the speed control is performed when the preceding vehicle 41 decelerates. The relative positional relationship can be maintained.
[0075]
(6) Since the first to third predetermined values b, b2, b3 are determined based on the own vehicle speed, the relative speed ΔB and the relative acceleration ΔΔB with the following vehicle 43, if the own vehicle speed is fast, the rear A margin can be taken, and when the approaching speed and acceleration of the succeeding vehicle 43 to the own vehicle 42 are large, it is possible to move to the alert activation work earlier.
[0076]
(7) Since the first to third predetermined values b, b2, and b3 can be input and determined by the driver input means 3, the control load on the CPU 30 can be reduced.
[0077]
(Second embodiment)
The second embodiment is an example in which the inter-vehicle distance with the following vehicle is determined from the relative speed with respect to the following vehicle. Since the configuration of the second embodiment is the same as that of the first embodiment, detailed description thereof is omitted.
[0078]
Next, the operation will be described.
[Speed adjustment processing]
The speed adjustment process of the second embodiment will be described based on the flowchart of FIG. Since the speed adjustment process of the second embodiment is the same as that of the first embodiment shown in FIG. 4 except for step 215, only step 215 will be described.
[0079]
In step 115 of FIG. 4, it is determined whether the inter-vehicle distance with the succeeding vehicle 43 is sufficiently wide. In this process, the relative speed ΔB with the succeeding vehicle 43 needs to be in the direction of moving away. Therefore, in step 215 in FIG. 6, it is determined whether the relative speed ΔB is 0 or more as a necessary condition for satisfying step 115.
[0080]
In step 215, if it is determined that the relative speed ΔB is equal to or greater than 0, that is, the following vehicle 43 has a speed in a direction to maintain or move away from the vehicle, the process proceeds to step 116 and the flag Fg during deceleration control is cleared. Speed control is performed. At this time, if an alarm is issued, the alarm is stopped. In this embodiment, the evaluation is performed based on the relative speed ΔB with respect to the succeeding vehicle 43. However, the evaluation may be performed based on the relative acceleration ΔΔB.
[0081]
Next, the effect will be described.
(8) Since the deceleration control is stopped and the speed control is performed when the relative speed ΔB with respect to the succeeding vehicle 43 becomes 0 or more, the relative positional relationship with the succeeding vehicle 43 can be improved.
[0082]
(Third embodiment)
In the third embodiment, the deceleration control is stopped and switched to the speed control when a predetermined time has elapsed. Since the configuration of the third embodiment is the same as that of the first embodiment, detailed description thereof is omitted.
[0083]
Next, the operation will be described.
[Speed adjustment processing]
The speed adjustment process of the third embodiment will be described based on the flowchart of FIG. The speed adjustment process of the second embodiment is the same as that of the first embodiment shown in FIG. 4 except for steps 301 to 304, and therefore only steps 301 to 304 will be described.
[0084]
In step 301, it is determined whether or not the timer t has reached a predetermined time T. If the timer t has reached the predetermined time T, the process proceeds to step 303. If the timer t has not reached the predetermined time T, the process proceeds to step 302.
[0085]
In step 302, the timer t is counted up.
[0086]
In step 303, the flag Fg during deceleration control is cleared and speed control is performed.
[0087]
In step 304, the timer t is cleared and this control is terminated.
[0088]
Next, the effect will be described.
(9) Since the deceleration control is stopped and the speed control is performed when the predetermined time T elapses, driving is performed while preventing the inter-vehicle distance A from the preceding vehicle 41 from becoming more than the target inter-vehicle distance (predetermined value a). The discomfort given to the person can be reduced.
[0089]
(Other examples)
The preceding vehicle following control device of the present invention has been described based on the first to third embodiments. However, the specific configuration of the present invention is not limited to each embodiment, and Design changes and additions are allowed without departing from the spirit of the invention according to each claim.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a first embodiment.
FIG. 2 is a block diagram showing a hardware configuration of a control unit.
FIG. 3 is a diagram showing a traveling state of the own vehicle.
FIG. 4 is a flowchart showing the flow of speed adjustment processing by an alarm / speed adjustment means of the first embodiment.
FIG. 5 is a time chart showing an example of vehicle speed control in the first embodiment.
FIG. 6 is a flowchart showing the flow of speed adjustment processing by an alarm / speed adjustment means of the second embodiment.
FIG. 7 is a flowchart showing the flow of speed adjustment processing by an alarm / speed adjustment means of the third embodiment.
[Explanation of symbols]
1 Control unit
2 Vehicle speed sensor
3 Driver input means
4 Forward distance measurement means
5 Back distance measuring means
6 Engine ECU
7 Brake actuator
8 Throttle actuator
9 horn circuit
10 Write drive circuit
11 Alarm drive circuit
12 Input circuit
13 Forward distance calculator
14 Back distance calculator
15 Forward relative speed calculator
16 Rear relative speed calculator
17 A ≦ a comparator
18 B ≦ b comparator
19 Alarm / Speed adjustment means
20 Operating state detection means
21 Output circuit
30 CPU
31 ROM
32 RAM
41 preceding car
42
43 Cars following

Claims (9)

Vehicle speed detection means for detecting the vehicle speed of the vehicle;
A preceding inter-vehicle distance detecting means for detecting an inter-vehicle distance from the preceding vehicle;
A target preceding inter-vehicle distance setting means for setting a target inter-vehicle distance from the preceding vehicle;
Braking / driving force control means for controlling the braking force or driving force of the vehicle so that the inter-vehicle distance with the preceding vehicle coincides with the target preceding inter-vehicle distance;
Subsequent inter-vehicle distance detection means for detecting the inter-vehicle distance with the following vehicle,
In the preceding vehicle follow-up control device with
The braking / driving force control means includes:
When the inter-vehicle distance from the preceding vehicle is outside a predetermined range with a positive / negative allowable range added to the target inter-vehicle distance, the braking / driving force control is performed so that the inter-vehicle distance from the preceding vehicle is located within the predetermined range. A speed control unit;
When the inter-vehicle distance with the preceding vehicle is within the predetermined range and the inter-vehicle distance with the following vehicle is equal to or less than a first predetermined value, the vehicle decelerates with a constant negative acceleration, and then decelerates again. same absolute value accelerates with a constant positive acceleration with a deceleration control unit for performing deceleration control to end the acceleration at the time point when the vehicle speed when the deceleration start to the case,
A preceding vehicle follow-up control device comprising: In the preceding vehicle follow-up control device according to claim 1,
The preceding vehicle follow-up control device, wherein the deceleration control unit executes the deceleration control until an inter-vehicle distance with a succeeding vehicle is maintained or increased. In the preceding vehicle follow-up control device according to claim 1 or 2,
The preceding vehicle follow-up control device, wherein the deceleration control unit executes the deceleration control until an inter-vehicle distance with a succeeding vehicle becomes a second predetermined value that is larger than a first predetermined value. In the preceding vehicle follow-up control device according to any one of claims 1 to 3,
The preceding vehicle follow-up control device, wherein the deceleration control unit performs the deceleration control until an inter-vehicle distance with a succeeding vehicle becomes a third predetermined value smaller than a first predetermined value. In the preceding vehicle follow-up control device according to any one of claims 1 to 4,
The preceding vehicle follow-up control device, wherein the deceleration control unit executes the deceleration control until a predetermined time elapses. In the preceding vehicle follow-up control device according to any one of claims 1 to 5,
The deceleration control unit, inter-vehicle distance to the preceding vehicle, the preceding vehicle follow-up control apparatus characterized by performing the deceleration control from the inter-vehicle distance at the time of the deceleration control start to increase by a predetermined distance. In the preceding vehicle follow-up control device according to any one of claims 1 to 6,
The preceding vehicle follow-up control device, wherein the deceleration control unit executes the deceleration control until an inter-vehicle distance with a preceding vehicle is equal to or less than a target inter-vehicle distance. In the preceding vehicle follow-up control device according to any one of claims 1 to 7,
The braking / driving force control means includes a predetermined value determining unit that determines the first to third predetermined values based on the host vehicle speed, the relative speed with respect to the following vehicle, and the relative acceleration,
The preceding vehicle follow-up control device, wherein the predetermined value determination unit increases the first predetermined value as the host vehicle speed, the relative speed with respect to the following vehicle, and the relative acceleration increase. In the preceding vehicle follow-up control device according to any one of claims 1 to 7,
A preceding vehicle follow-up control device, characterized in that the driver is provided with predetermined value input means for inputting first to third predetermined values.

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