JP3721800B2 - Vehicle distance control device, vehicle distance alarm device, and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inter-vehicle control device for causing an own vehicle to travel following a preceding vehicle, an inter-vehicle alarm device for executing an alarm process for a vehicle driver based on the relationship between the own vehicle and the preceding vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a technique for improving driving safety of an automobile and reducing a driver's operation burden, an inter-vehicle distance control device that automatically follows a host vehicle to a preceding vehicle is known. The following method is a method of performing control so that an inter-vehicle deviation that is a difference between an actual inter-vehicle distance between the own vehicle and a preceding vehicle and a preset target inter-vehicle distance is eliminated. Specifically, the target acceleration is calculated based on the inter-vehicle deviation and the relative speed (the vehicle speed relative to the preceding vehicle speed), and the acceleration device and the deceleration device are controlled so that the acceleration of the vehicle becomes the target acceleration. To do.
[0003]
It can be realized in the same manner by using a value obtained by dividing the inter-vehicle distance by the speed of the own vehicle (hereinafter referred to as “inter-vehicle time”) instead of the inter-vehicle distance itself. In fact, the distance between vehicles is calculated by irradiating the preceding vehicle with a laser beam or transmission wave and detecting the time until the reflected light or reflected wave is received. The same control may be executed at the actual time and the target time using itself. Since the physical quantity corresponding to the inter-vehicle distance can be realized as described above, it is described as “inter-vehicle physical quantity” including these. However, in the explanation of the following problem to be solved, the case where the inter-vehicle distance itself is used is taken as an example.
[0004]
[Problems to be solved by the invention]
As described above, the inter-vehicular control is performed by feeding back the inter-vehicular deviation and the relative speed. For example, an accelerating apparatus and a slow decelerating apparatus ( For example, in a system that does not use the brake device itself, such as accelerator off or fuel cut, and that performs only moderate deceleration with “no acceleration”, the vehicle speed changes slowly even if the response of the deceleration control is slow. Therefore, there is no particular problem in terms of passenger comfort within the corresponding range. Also, since the preceding vehicle is decelerated strongly by the brake device, it is left to the driver of the vehicle (operation of the brake device, change of course, etc.) outside the corresponding range, so that there is no particular problem in this case.
[0005]
However, in order to perform the follow-up control corresponding to the strong deceleration of the preceding vehicle, it is necessary to provide a system including a stronger deceleration device such as a brake device. Changes in relative speed and changes in inter-vehicle deviation take a certain amount of time to appear as states, so when the preceding vehicle decelerates strongly with a brake device, detection of the deceleration behavior of the preceding vehicle is delayed, There may be a situation in which the execution timing of the deceleration control is delayed, causing an unease to the occupant.
[0006]
In this case, for example, if the feedback gain of the deceleration control and the operation threshold value of the reduction gear are set sensitively, the delay of the deceleration execution described above can be reduced. However, it is not preferable because strong deceleration control by the brake device always operates frequently and causes discomfort. Furthermore, if this method is adopted, even if the vehicle speed changes slowly, such as when cruising on the expressway described above, depending on the specific vehicle speed fluctuation cycle of the preceding vehicle, it will become a hunting tendency due to execution of unnecessary acceleration / deceleration. There is a tendency to be uncomfortable and there is no problem with the occupant's anxiety, but comfort is impaired.
[0007]
In the past, problems related to inter-vehicle control were raised, but when the inter-vehicle distance from the preceding vehicle is shorter than the predetermined alarm distance, an alarm sound or the like is issued to alert the vehicle driver. A similar problem occurs. In other words, when the preceding vehicle decelerates strongly with the brake device, it takes time to appear as a relative speed change or a change in the inter-vehicle distance, so the detection of the deceleration behavior of the preceding vehicle is delayed, and the alarm execution timing is delayed. Situations that give anxiety are also assumed.
[0008]
In this case, if the feedback gain of the above-described deceleration control and the operation threshold value of the reduction gear are set sensitively, the above-described delay in alarm execution can be reduced. However, an alarm is frequently issued in a situation where an alarm is not actually required, and this may cause a diluting alarm effect in a situation where an alarm is actually required.
[0009]
Therefore, the present invention captures the change in behavior without delay even when the preceding vehicle is strongly decelerated, and can control the deceleration at an appropriate timing, and impairs comfort by unnecessary acceleration / deceleration during steady following driving. It is a first object to execute inter-vehicle distance control that can prevent the above.
[0010]
In addition, even if the preceding vehicle decelerates strongly, the change in behavior can be detected without delay and alarm processing can be executed at an appropriate timing, as well as an inter-vehicle alarm that can prevent dilution of alarm effects due to unnecessary alarm execution. This is the second purpose.
[0011]
[Means for Solving the Problems]
The inter-vehicle control apparatus according to claim 1, wherein the inter-vehicle control unit is configured to accelerate based on an inter-vehicle deviation that is a difference between an actual inter-vehicle physical quantity and a target inter-vehicle physical quantity, and a relative speed. By driving and controlling the means and the speed reduction means, the host vehicle is caused to travel following the preceding vehicle, but this inter-vehicle distance control means calculates the inter-vehicle distance control amount calculated based on the inter-vehicle deviation and the relative speed, Only when the correction execution condition set in terms of the continuity of the relative acceleration is satisfied, Correction is performed based on the relative acceleration between the host vehicle and the preceding vehicle, and the inter-vehicle distance control is executed based on the corrected inter-vehicle control amount.
[0012]
As the actual inter-vehicle physical quantity, for example, when a configuration is adopted in which the time until the preceding vehicle is irradiated with a laser beam or a transmission wave and the reflected light or reflected wave is received is detected. As such, a value converted into an inter-vehicle distance may be used, or an inter-vehicle time divided by the vehicle speed may be used. The relative speed can be obtained by differentiating the actual inter-vehicle distance as the actual inter-vehicle physical quantity, and the relative acceleration can be obtained by differentiating the relative speed or the actual inter-vehicle distance twice.
[0013]
According to the above-described inter-vehicle distance control device according to claim 1, since the inter-vehicle distance control is executed based on the inter-vehicle distance control amount corrected based on the relative acceleration, even if the preceding vehicle decelerates strongly, the behavior change The vehicle control at an appropriate timing, that is, in this case, the deceleration control can be executed. This is because the relative acceleration reflects the degree of deceleration of the preceding vehicle.If the preceding vehicle decelerates strongly, the absolute value of the relative acceleration becomes relatively large. In this case, the host vehicle also decelerates earlier. That's fine.
[0014]
Even if the preceding vehicle decelerates strongly with a brake device, changes in relative speed and changes in inter-vehicle deviation take a certain amount of time to appear as a state. Although the detection of the deceleration behavior of the preceding vehicle is delayed and the execution timing of the initial deceleration control is delayed, it is possible to prevent the execution timing of the initial deceleration control from being delayed based on the relative acceleration that can reflect the deceleration behavior of the preceding vehicle. , Can avoid situations that cause anxiety to the passengers.
[0015]
Conversely, even when the preceding vehicle has a gradual vehicle speed fluctuation due to steady follow-up, the vehicle speed fluctuation can be reduced by correcting based on the relative acceleration so that the vehicle speed does not fluctuate more than the preceding vehicle or before the correction. This is effective in terms of preventing hunting.
[0016]
In other words, as described above, for example, if the feedback gain of the deceleration control and the operation threshold of the speed reducer are set sensitively, the delay in the speed reduction execution is reduced, but the strong speed reduction control by the brake device is always operated frequently. Even if the vehicle speed changes slowly, such as when traveling on a highway, it tends to cause hunting due to unnecessary acceleration / deceleration depending on the specific vehicle speed fluctuation cycle of the preceding vehicle. There is a loss of comfort. On the other hand, based on the relative acceleration that can reflect the deceleration behavior of the preceding vehicle, the feedback gain and the operation threshold need not be set sensitively.
[0017]
As described above, the inter-vehicle distance control device according to the present invention can detect the behavior change without delay even when the preceding vehicle is strongly decelerated, and can perform deceleration control at an appropriate timing, and can perform unnecessary addition during steady follow-up traveling. It is also possible to prevent the comfort from being impaired by the deceleration.
[0018]
The inter-vehicle control amount may be a target acceleration of the host vehicle, for example, as shown in claim 2. Of course, other than that, it may be a target torque or a target relative speed. And in the inter-vehicle distance control device of the present invention, Correction based on the relative acceleration mentioned above The Execute only when the correction execution condition set from the viewpoint of continuity of relative acceleration is satisfied The That is, measurement noise may be included in the relative acceleration obtained by differentiating the actual inter-vehicle physical quantity and the relative speed. Even if there is no such measurement noise, there is a case where it is not necessary for the own vehicle to substantially follow-up like the deceleration of the preceding vehicle for a very short time. Therefore, based on the viewpoint of continuity of relative acceleration, it is possible to remove the component of relative acceleration that does not require such control.
[0019]
Here, the continuity of the relative acceleration means that the relative acceleration has occurred for a predetermined time or more and still occurs now. Specifically, for example, claims 3 As shown in FIG. 4, the first condition that the absolute value of the weighted integrated value of the relative acceleration or the first low-pass filter processing value captured within a predetermined determination time is larger than the first threshold, and the current value of the relative acceleration or Correction is performed when both the average value in the vicinity of the current value or the second condition that the absolute value of the second low-pass filter processing value having higher responsiveness than the first low-pass filter is larger than the second threshold are satisfied. It can be considered that the execution condition is satisfied.
[0020]
The weighted integrated values used in the first condition are, for example, simple integrated values when the weight is set to “1”, and simple average values when, for example, the weight is set to “one-number of integrated values”. It is a broad concept that includes That is, it is required to have a value reflecting the relative acceleration captured within a predetermined determination time. From the same viewpoint, it may be a low-pass filter processing value. When the absolute value of the weighted integrated value or the low-pass filter processing value is larger than the first threshold value, it can be determined that the relative acceleration is continuously generated, and the measurement noise or the preceding vehicle is extremely short. It can be distinguished from a state in which the own vehicle does not need to perform follow-up control, such as time deceleration.
[0021]
On the other hand, in the second condition, it may be based on the current value of the relative acceleration itself, or may be based on an average value in the vicinity of the current value. Naturally, the vicinity of the current value is a range narrower than the integration range for calculating the integration value described above.
When the first low-pass filter processing value is used instead of the integrated value and the second low-pass filter processing value is used instead of the current value or the average value of the current values, the second low-pass filter is replaced with the first low-pass filter processing value. Set to be more responsive than the low-pass filter. In other words, since the closer values are reflected by setting the high response, the first low-pass filter processing value results in a value reflecting a relatively wide range of relative acceleration, and the second low-pass filter processing value. The filter processing value is a value reflecting a relatively narrow range, that is, a relative acceleration in the vicinity of the current value.
[0022]
Further, the predetermined determination time in the first condition described above may be constant, but for example, claims 4 If the absolute value of the relative acceleration to be taken is set to be shorter as shown in FIG. In other words, when the absolute value of the relative acceleration is small, the measurement noise of the relative acceleration signal is close to the true value, so the signal needs to be smoothed for a long time, and against the temporary slight deceleration of the preceding vehicle Does not require a large speed reduction like a brake device in the own vehicle or does not need to respond quickly. Therefore, when the absolute value of the relative acceleration is small, it may be determined using a relatively long determination time.
[0023]
Conversely, when the absolute value of relative acceleration is large, the measurement noise of the relative acceleration signal is large compared to the true value level, so it is not necessary to smooth the signal for a long time, and the deceleration of the preceding vehicle For a large deceleration, a large deceleration like a brake device is required at an early stage in the own vehicle. Therefore, when the absolute value of the relative acceleration is large, it may be determined using a relatively short determination time.
[0024]
The correction execution condition is Not established In this case, correction by relative acceleration is not performed. Specifically, the same calculation formula is used instead of changing the calculation formula for correction, but the relative acceleration at that time is zero (0). By doing so, it is practical to prevent the correction substantially.
[0025]
Further, the present invention has been made to achieve the second object in addition to the first object described above. 6 It is an inter-vehicle distance control apparatus of description. The inter-vehicle distance controller in this case further includes inter-vehicle alarm means capable of executing alarm processing for the vehicle driver when the inter-vehicle control amount becomes smaller than a predetermined alarm determination value. The inter-vehicle control amount used for the warning determination is obtained by correcting the inter-vehicle control amount calculated based on the inter-vehicle deviation and the relative speed based on the relative acceleration, and thus has the same effect as the above-described inter-vehicle control. That is, even when the preceding vehicle is strongly decelerated, the behavior change can be caught without delay and the alarm process can be executed at an appropriate timing.
In the case of the above-described inter-vehicle distance control, unnecessary acceleration / deceleration is prevented during steady follow-up traveling. In the case of this alarm, dilution of the alarm effect due to unnecessary alarm execution can be prevented. .
[0026]
By the way, since the alarm processing described above is executed on the premise of the inter-vehicle distance control, it is considered as an invention of the inter-vehicle distance control device. However, the alarm processing can also be realized as an inter-vehicle alarm device that achieves only the second object described above. For example, claims 7 As shown in FIG. 4, the difference between the physical quantity between the actual vehicle corresponding to the actual inter-vehicle distance between the own vehicle and the preceding vehicle and the target inter-vehicle physical quantity corresponding to the target inter-vehicle distance between the own vehicle and the preceding vehicle. When the inter-vehicle control amount, which is calculated based on the inter-vehicle deviation and the relative speed between the host vehicle and the preceding vehicle, for causing the host vehicle to follow the preceding vehicle and traveling is smaller than a predetermined alarm judgment value. A vehicle-to-vehicle warning device provided with vehicle-to-vehicle warning means capable of executing warning processing for a vehicle driver is assumed. And, regarding the inter-vehicle control amount to be compared with the warning determination value, the inter-vehicle control amount calculated based on the inter-vehicle deviation and the relative speed, Only when the correction execution condition set in terms of the continuity of the relative acceleration is satisfied, The correction is based on the relative acceleration between the host vehicle and the preceding vehicle. The inter-vehicle control amount in this case may be the target acceleration of the host vehicle, the target torque, or the target relative speed, as in the case of the inter-vehicle control described above.
[0027]
Even if it is not assumed that the above-described inter-vehicle distance control is executed, it is also possible to execute only the alarm processing by calculating the inter-vehicle control amount for the inter-vehicle distance control and comparing it with the alarm determination value. . The effect in this case is that even if the preceding vehicle decelerates strongly, the change in behavior can be caught without delay and alarm processing can be executed at an appropriate timing, and dilution of the alarm effect due to unnecessary alarm execution can be prevented. It is.
[0028]
Also in this case, the above-mentioned inter-vehicle distance control device is claimed in claims 3 to 3. 5 It is conceivable to apply the ideas shown in. That is , Place The first condition that the absolute value of the weighted integrated value or the low-pass filter processing value of the relative acceleration captured within a predetermined determination time is greater than the first threshold, and the absolute value of the current value of relative acceleration or the average value near the current value It may be determined that the correction execution condition is satisfied when both of the second conditions that the value is greater than the second threshold are satisfied (claims). 8 ). Further, the predetermined determination time may be set shorter as the absolute value of the relative acceleration to be captured is larger (claims). 9 ), The first threshold value may be set larger as the absolute value of the relative acceleration to be taken in is larger (claims). 10 ).
[0030]
In addition, claims 1 to 6 The inter-vehicle distance control means of the inter-vehicle distance control device according to claim 1 or claim 7 ~ 10 The function for realizing the inter-vehicle warning means of the inter-vehicle alarm device according to any of the above can be provided as a program that is activated on the computer system side, for example. In the case of such a program, for example, FD It can be used by being recorded on a computer-readable recording medium such as a magneto-optical disk, CD-ROM, hard disk, etc., and loaded into a computer system and started as required. In addition, the ROM or backup RAM may be recorded as a computer-readable recording medium, and the ROM or backup RAM may be incorporated into a computer system and used.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 mainly illustrates an inter-vehicle distance control electronic control device 2 (hereinafter referred to as “inter-vehicle control ECU”) and a brake electronic control device 4 (hereinafter referred to as “brake ECU”) to which the above-described invention is applied. It is a block diagram showing schematic structure of the various control circuits mounted in the motor vehicle shown.
[0032]
The inter-vehicle distance control ECU 2 corresponds to “inter-vehicle distance control means” and “inter-vehicle distance alarm means”, and is an electronic circuit mainly composed of a microcomputer. The current vehicle speed (Vn) signal, steering angle (str-eng, S0) A signal, a yaw rate signal, a target inter-vehicle time signal, wiper switch information, a control state signal for idle control and brake control, and the like are received from the engine electronic control unit 6 (hereinafter referred to as “engine ECU”). Then, the inter-vehicle control ECU 2 calculates inter-vehicle control and inter-vehicle alarm based on the received data.
[0033]
The laser radar sensor 3 is an electronic circuit mainly composed of a laser scanning range finder and a microcomputer, and performs differential operation on the angle and relative speed of the preceding vehicle detected by the scanning range finder and its relative speed. On the basis of the relative acceleration obtained in this way, the current vehicle speed Vn signal received from the inter-vehicle distance control ECU 2, the curve curvature radius R, etc. And the preceding vehicle information including information such as relative acceleration is transmitted to the inter-vehicle control ECU 2. The diagnostic signal of the laser radar sensor 3 itself is also transmitted to the inter-vehicle control ECU 2.
[0034]
The scanning distance measuring device scans and radiates a transmission wave or laser light within a predetermined angle range in the vehicle width direction, and based on the reflected wave or reflected light from the object, the distance between the vehicle and the front object is a scan angle. It functions as a distance measuring means that can be detected corresponding to
[0035]
Further, the inter-vehicle control ECU 2 determines the preceding vehicle to be inter-vehicle-controlled based on the own lane probability included in the preceding vehicle information received from the laser radar sensor 3 in this manner, and appropriately sets the inter-vehicle distance from the preceding vehicle. A target acceleration signal, a fuel cut request signal, an OD cut request signal, a third speed downshift request signal, and a brake request signal are transmitted to the engine ECU 6 as control command values for adjustment. It also determines whether an alarm has occurred and sends an alarm request signal. Further, a diagnosis signal, a display data signal, and the like are transmitted.
[0036]
The brake ECU 4 is an electronic circuit mainly composed of a microcomputer, and includes a steering sensor 8 that detects the steering angle of the vehicle, a yaw rate sensor 10 that detects the yaw rate, and a wheel speed sensor 12 that detects the speed of each wheel. The steering angle, the yaw rate, and the wheel speed are obtained, and these data are transmitted to the inter-vehicle control ECU 2 via the engine ECU 6. The brake ECU 4 controls a brake hydraulic pressure by driving a brake driver (not shown) according to a control command value (target acceleration, brake request) from the inter-vehicle control ECU 2 via the engine ECU 6. Further, the brake ECU 4 sounds the alarm buzzer 14 in response to an alarm request signal from the inter-vehicle control ECU 2 via the engine ECU 6.
[0037]
The engine ECU 6 is an electronic circuit mainly composed of a microcomputer, and includes a vehicle speed sensor 16 that detects the vehicle speed, a brake switch 18 that detects whether the brake is depressed, a cruise control switch 20, a cruise main switch 22, and a throttle. An opening sensor (not shown), detection signals from other sensors and switches, wiper switch information and tail switch information received via the body LAN 24 are received, and a steering angle (str -eng, S0) signal, yaw rate signal, target acceleration signal from the inter-vehicle distance control ECU 2, fuel cut request signal, OD cut request signal, 3-speed shift down request signal, brake request signal, alarm request signal, diagnosis signal, display data It is receiving the issue, and the like.
[0038]
The engine ECU 6 drives a throttle driver, a transmission driver (not shown), and the like in accordance with the operation state determined from the received signal. In addition, necessary display information is transmitted and displayed on a display device (not shown) such as an LCD via the body LAN 24, or the current vehicle speed (Vn) signal, steering angle (str-eng, S0) signal, yaw rate signal, target inter-vehicle time signal, wiper switch information signal, control state signal for idle control and brake control are transmitted to the inter-vehicle control ECU 2.
[0039]
The transmission (not shown) in this embodiment is a 5-speed automatic transmission, the 4-speed reduction ratio is set to “1”, and the 5-speed reduction ratio is smaller than the 4-speed ( For example, a so-called 4th speed + overdrive (OD) configuration is set to 0.7).
[0040]
In the present embodiment, the engine ECU 6 corresponds to “acceleration means”, and the engine ECU 6 and the brake ECU 4 correspond to “deceleration means”.
Next, processing executed by the inter-vehicle control ECU 2 will be described with reference to the flowcharts of FIGS.
[0041]
FIG. 2 is a flowchart showing the main process.
First, in the first step S110, it is determined whether the current control is being performed. If the current control is not currently being performed (S110: NO), it is determined whether the control start switch has been set (S140). If the cruise control switch 20 is turned on, the control start switch is set. If the control start switch is not set (S140: NO), the process proceeds to S1100, the acceleration / deceleration device non-control output is executed, and the alarm blower stop (S1200) is further executed. The process ends. Details of the output at the time of non-control of the acceleration / deceleration device at S1100 and the warning inter-vehicle non-control processing at S1200 will be described later.
[0042]
Further, when the control is not being performed (S110: NO) and the control start switch is set (S140: YES), the process proceeds to S130.
In S130, it is determined whether the control end switch is set. If the cruise control switch 20 is turned off, the control end switch is set. If the control end switch is set (S130: YES), the process proceeds to S1100, the acceleration / deceleration device non-control output is executed, and further, the alarm blower stop (S1200) is executed, and then the main process ends. To do.
[0043]
If the control end switch is not set (S130: NO), the target vehicle distance is calculated (S500), and then the target acceleration calculation (S600), acceleration / deceleration control (S700), and acceleration / deceleration device drive output (S800). After executing each process related to the inter-vehicle distance control, and further executing the alarm determination and alarm output process (S900), the main process is terminated.
[0044]
The above is the description of the entire processing, and the processing contents of S600 to S900 and S1100 will be described in detail. In the following description, a subroutine for each process (S600 to S800 and S1100) relating to the inter-vehicle distance control is shown in FIGS. 3 to 11, and a subroutine for the process relating to the inter-vehicle alarm (S900) is shown in FIG. The following will be described in order.
[0045]
First, the target acceleration calculation subroutine in S600 will be described with reference to the flowchart of FIG.
In first step S601, it is determined whether or not the preceding vehicle is being recognized. If the preceding vehicle is not being recognized (S601: NO), the value when the preceding vehicle has not been confirmed is set as the target acceleration (S608), and this subroutine is terminated.
[0046]
On the other hand, if the preceding vehicle is being recognized (S601: YES), the process proceeds to S602 to calculate an inter-vehicle deviation. This inter-vehicle deviation is obtained by subtracting the target inter-vehicle distance from the current inter-vehicle interval.
In step S603, the relative speed is calculated. In step S604, the relative speed is differentiated to obtain a relative acceleration. In subsequent S605, the relative acceleration is determined using the relative acceleration calculated in S604, and a relative acceleration fixed value is obtained. Details of this determination will be described later.
[0047]
In subsequent S606, the target acceleration is obtained with reference to the control map shown in FIG. 4 based on both parameters of the inter-vehicle deviation and the relative speed obtained in S602 and S603, respectively. The target acceleration in this state is called a pre-correction relative acceleration. In S607, a target acceleration is obtained by adding a value obtained by multiplying the relative acceleration fixed value obtained in S605 by a predetermined gain to the pre-correction relative acceleration obtained in S606. Thereafter, this subroutine is terminated.
[0048]
FIG. 13 schematically shows a process for obtaining the target acceleration. That is, the processing for calculating the target acceleration based on the inter-vehicle deviation and the relative speed performed in S606 is “target acceleration calculation similar to the conventional”, and is relative to the “target acceleration before correction” calculated in this way. It is a feature of this embodiment that correction based on acceleration is performed.
[0049]
Now, the detailed contents of the relative acceleration determination executed in S605 will be described. This determination of relative acceleration determines whether or not a correction execution condition set from the viewpoint of continuity of relative acceleration is satisfied, and calculates a definite value of relative acceleration according to the determination result. That is, it aims at removing the component of the relative acceleration which does not require distance control based on the viewpoint of the continuity of relative acceleration. The relative acceleration obtained by differentiating the relative speed may include measurement noise. Even if there is no such measurement noise, there is a case where it is not necessary for the own vehicle to substantially follow-up like the deceleration of the preceding vehicle for a very short time. Therefore, the relative acceleration that does not require such control is not used for control. Here, the continuity of the relative acceleration means that the relative acceleration has occurred for a predetermined time or more and still occurs now.
[0050]
Specifically, a relative acceleration integration determination value and a relative acceleration current determination value are used. Each of these determination values is calculated by the following equation.
(A) Relative acceleration integration judgment value = Relative acceleration integration value / Relative acceleration integration time
(B) Current judgment value of relative acceleration = current value of relative acceleration
The relative acceleration integrated value = Σ (relative acceleration). In this embodiment, since the relative acceleration integrated value / relative acceleration integrated time is used in calculating the relative acceleration integrated determination value, the relative acceleration per unit time within the integrated time, that is, the average value as a result. Is calculated.
[0051]
In the present embodiment, as shown in FIG. 14, the relative acceleration integration time is relatively long when the absolute value of the relative acceleration is small, and conversely when the absolute value of the relative acceleration is large. By taking a short time, a more appropriate determination is made. In other words, when the absolute value of the relative acceleration is small, the measurement noise of the relative acceleration signal is close to the true value, so the signal needs to be smoothed for a long time, and against the temporary slight deceleration of the preceding vehicle Does not require a large speed reduction like a brake device in the own vehicle or does not need to respond quickly. Therefore, when the absolute value of the relative acceleration is small, it may be determined using a relatively long integrated time as the time for determination. Conversely, when the absolute value of relative acceleration is large, the measurement noise of the relative acceleration signal is large compared to the true value level, so it is not necessary to smooth the signal for a long time, and the preceding vehicle has a large deceleration. For deceleration, a large deceleration like a brake device is required at an early stage in the own vehicle. Therefore, when the absolute value of the relative acceleration is large, it may be determined using a relatively short integration time.
[0052]
In the determination, the determination formulas for the acceleration side and the deceleration side are used, and the relative acceleration fixed value is calculated as follows depending on whether or not each determination formula is satisfied.
[Acceleration judgment]
(1) If both of the following judgment formulas (1) and (2) are satisfied, the condition is satisfied, and if either one is not satisfied, the condition is not satisfied.
[0053]
(1) Relative acceleration integration judgment value ≥ acceleration side threshold value x judgment coefficient K1
(2) Current judgment value of relative acceleration ≧ acceleration side threshold × judgment coefficient K2
(2) Relative acceleration fixed value at the time of establishment = acceleration side threshold
(3) Relative acceleration fixed value when not established = 0
The determination coefficients K1 and K2 are set in the range of 0 <K1 ≦ 1, 0 <K2 ≦ 1.
[0054]
[Deceleration side judgment]
(1) If both of the following judgment formulas (3) and (4) are satisfied, it is satisfied, and if either one is not satisfied, it is not satisfied.
(3) Relative acceleration integration judgment value ≤ deceleration side threshold value x judgment coefficient K3
(4) Current judgment value of relative acceleration ≦ deceleration side threshold × judgment coefficient K4
(2) Relative acceleration fixed value at the time of establishment = deceleration side threshold
(3) Relative acceleration fixed value when not established = 0
The determination coefficients K3 and K4 are set in the range of 0 <K3 ≦ 1, 0 <K4 ≦ 1.
[0055]
Thus, on both the acceleration side and the deceleration side, when the determination formula is not established, the relative acceleration fixed value is set to 0 so that the correction is not substantially performed.
When changing the length of the integration time depending on the absolute value of the relative acceleration, prepare a plurality of combinations of the acceleration side threshold value and the integration time and the combination of the deceleration side threshold value and the integration time used for the determination. Perform acceleration side determination and deceleration side determination for the number of combinations. Then, in order to refer to the latest information, it is inspected whether or not the accumulated time is established in order from the shortest determination, and the threshold value established for the first time is set as the relative acceleration fixed value. When all are not established, the relative acceleration fixed value = 0 is set.
[0056]
Next, the acceleration / deceleration control subroutine in S700 of FIG. 2 will be described with reference to the flowchart of FIG.
This acceleration / deceleration control is terminated by sequentially performing throttle control (S710), accelerator-off control (S720), shift-down control (S730), and brake control (S740). Each control will be described.
[0057]
First, the throttle control subroutine of S710 will be described with reference to the flowchart of FIG. In this throttle control, the value obtained by multiplying the acceleration deviation by the throttle control gain K11 is added to the previous throttle opening instruction value to obtain the current throttle opening instruction value (S711). The acceleration deviation is a value obtained by subtracting the target acceleration from the actual acceleration.
[0058]
Next, the accelerator-off control subroutine of S720 will be described with reference to the flowchart of FIG.
In the first step S721, it is determined whether or not the acceleration deviation is smaller than the reference value Aref11. If acceleration deviation <Aref11 (S721: YES), the accelerator-off operation is instructed (S723), and this subroutine is terminated.
[0059]
On the other hand, if acceleration deviation ≧ Aref11 (S721: NO), the process proceeds to S725 to determine whether the acceleration deviation is larger than the reference value Aref12. If acceleration deviation> Aref12 (S725: YES), an instruction to release the accelerator off is issued (S727), and this subroutine is terminated. If acceleration deviation ≦ Aref12 (S725: NO), Exit the subroutine.
[0060]
Next, the downshift control subroutine of S730 will be described with reference to the flowchart of FIG.
In the first step S731, it is determined whether or not the acceleration deviation is smaller than the reference value Aref21. If acceleration deviation <Aref21 (S731: YES), a shift down operation is instructed (S733), and further an accelerator off operation instruction is issued. Then (S735), this subroutine is terminated.
[0061]
On the other hand, if acceleration deviation ≧ Aref21 (S731: NO), the process proceeds to S737, where it is determined whether the acceleration deviation is larger than the reference value Aref22. If acceleration deviation> Aref22 (S737: YES), an instruction to cancel the downshift operation is issued (S727), and this subroutine is terminated. If acceleration deviation ≦ Aref22 (S737: NO), Exit the subroutine.
[0062]
Next, the brake control subroutine of S740 will be described with reference to the flowchart of FIG.
In first step S741, it is determined whether or not the acceleration deviation is smaller than the reference value Aref31. If acceleration deviation <Aref31 (S741: YES), the brake operation is instructed (S743), and the accelerator-off operation is instructed (S745). Then, the process proceeds to S751.
[0063]
On the other hand, if acceleration deviation ≧ Aref31 (S741: NO), the process proceeds to S747, where it is determined whether the acceleration deviation is larger than the reference value Aref32. If the acceleration deviation> Aref32 (S747: YES), the brake operation is instructed (S749), and the process proceeds to S751. If the acceleration deviation ≦ Aref32 (S747: NO), the process proceeds to S751. Transition.
In S751, it is determined whether or not a brake operation instruction is being issued. If the brake operation instruction is being issued (S751: YES), the process proceeds to S753, and a value obtained by multiplying the acceleration deviation by the throttle control gain K21 is added to the previous brake pressure instruction value, thereby obtaining the current brake pressure instruction value. And On the other hand, if the brake operation instruction is not in progress (S751: NO), the process proceeds to S755, and the brake pressure instruction value is set to zero.
[0064]
After the processing of S753 or S755, this subroutine is terminated.
Next, the acceleration / deceleration device drive output subroutine in S800 of FIG. 2 will be described with reference to the flowchart of FIG.
In the first step S801, it is determined whether or not an accelerator-off operation instruction has been issued. If an accelerator-off operation instruction has not been issued (S801: NO), a drive output for releasing the brake (S803) and a shift-down cancellation are issued. The driving output (S805) and the throttle opening feedback driving output (S807) are sequentially performed, and then this subroutine is terminated.
[0065]
On the other hand, if an accelerator-off operation instruction has been issued (S801: YES), it is determined whether a shift-down operation instruction has been issued. If the downshift operation instruction has not been issued (S809: NO), it is determined whether or not the brake operation instruction has been issued (S811).
[0066]
If the brake operation instruction is not issued (S811: NO), the drive output for releasing the brake (S813), the drive output for releasing the downshift (S815), and the drive output for fully closing the throttle (S815). This subroutine is terminated after sequentially performing S817). If the brake operation instruction is given (S811: YES), the drive output for fully closing the throttle (S819), the drive output for releasing the downshift (S821), and the feedback drive output of the brake pressure (S823). ) Are sequentially performed, and then this subroutine is terminated.
[0067]
On the other hand, when an affirmative determination is made in S809, that is, when there is an accelerator-off operation instruction (S801: YES) and there is a shift-down operation instruction (S809: YES), the flow proceeds to S825, and a brake operation instruction is issued. It is determined whether or not (S811).
[0068]
If the brake operation instruction is not issued (S825: NO), the drive output for releasing the brake (S827), the drive output for fully closing the throttle (S829), and the shift-down drive output (S831) are sequentially provided. Then, this subroutine is finished. If the brake operation instruction is given (S825: YES), a drive output for fully closing the throttle (S833), a shift-down drive output (S835), and a brake pressure feedback drive output (S837) are sequentially performed. Then, this subroutine is finished.
[0069]
Next, the acceleration / deceleration device non-control output subroutine in S1100 will be described with reference to the flowchart of FIG.
Since this processing is processing when the acceleration / deceleration device is not controlled, in S1101, a drive output for fully closing the throttle, a drive output for releasing the downshift in S1103, and a drive output for releasing the brake in S1105. Are sequentially performed to complete this subroutine.
[0070]
Next, the alarm determination and alarm device output processing subroutine in S900 of FIG. 2 will be described with reference to the flowchart of FIG.
In the first step S901, it is determined whether or not the target acceleration is shorter than a predetermined alarm determination value Aref41. If target acceleration <alarm determination value Aref41 (S901: YES), the alarm is sounded (S903). On the other hand, if the target acceleration ≧ the alarm determination value Aref41 (S901: NO), the alarm sounding is stopped (S905). After the processing of S903 or S905, this subroutine is terminated.
[0071]
The processing contents of the inter-vehicle control and inter-vehicle warning by the system according to the present embodiment have been described above. Next, the effect of the processing execution will be described.
In the inter-vehicle control system of the present embodiment, as shown in the flowchart of FIG. 3 or the conceptual diagram of FIG. 13, when calculating the target acceleration as the inter-vehicle control amount, the target acceleration calculated based on the inter-vehicle deviation and the relative speed. Is corrected based on the relative acceleration, and the inter-vehicle distance control is executed based on the corrected target acceleration. Therefore, even when the preceding vehicle is decelerated strongly, the behavior change can be caught without delay, and deceleration control at an appropriate timing can be executed. This is because the relative acceleration reflects the degree of deceleration of the preceding vehicle, and if the preceding vehicle decelerates strongly, the absolute value of the relative acceleration becomes relatively large. It is because it can grasp. As a result, even if the preceding vehicle decelerates strongly with the brake device, changes in relative speed and changes in inter-vehicle deviation take a certain amount of time to appear as a state. Based on this, the detection of the deceleration behavior of the preceding vehicle is delayed and the execution timing of the initial deceleration control is delayed, but the execution timing of the initial deceleration control is delayed due to the relative acceleration that can reflect the deceleration behavior of the preceding vehicle. Can be avoided, and a situation in which the passengers feel uneasy can be avoided.
[0072]
On the other hand, even when the preceding vehicle undergoes a gradual vehicle speed fluctuation due to steady tracking, it is possible to control the vehicle so that the vehicle speed does not fluctuate more than the preceding vehicle by correcting based on the relative acceleration. It is also effective in terms.
In the relative acceleration determination shown in S605 of FIG. 3, it is determined whether a correction execution condition set from the viewpoint of continuity of the relative acceleration is satisfied, and a fixed value of relative acceleration is calculated according to the determination result. Therefore, it is possible to remove a component of relative acceleration that does not require inter-vehicle control. The relative acceleration obtained by differentiating the relative speed may include measurement noise. Even if there is no such measurement noise, there is a case where it is not necessary for the own vehicle to substantially follow-up like the deceleration of the preceding vehicle for a very short time. Therefore, by determining from the viewpoint of continuity of the relative acceleration that the relative acceleration has occurred for a predetermined time and is still occurring, the relative acceleration that does not need to be controlled is not used for the control. it can.
[0073]
Further, as shown in FIG. 14, the relative acceleration integration time used for the determination is relatively long when the absolute value of the relative acceleration is small, and conversely when the absolute value of the relative acceleration is large. By taking a short time, a more appropriate determination can be made.
[0074]
Then, as shown in S901 of FIG. 12, in the alarm determination of the present embodiment, it is determined whether or not the target acceleration is shorter than a predetermined alarm determination value Aref41, and if target acceleration <alarm determination value Aref41. Only (S901: YES), the alarm is sounded (S903). As shown in FIG. 13, the target acceleration used for this alarm determination is the target acceleration calculated based on the inter-vehicle deviation and the relative speed. Is corrected based on the above. For this reason, the same effect as the above-described inter-vehicle distance control is obtained. That is, even when the preceding vehicle is strongly decelerated, the behavior change can be caught without delay and the alarm process can be executed at an appropriate timing. In the case of the above-described inter-vehicle distance control, unnecessary acceleration / deceleration is prevented during steady follow-up traveling. In the case of this alarm, dilution of the alarm effect due to unnecessary alarm execution can be prevented. .
[0075]
As described above, the present invention is not limited to such an embodiment, and can be implemented in various forms without departing from the gist of the present invention.
(1) In the above embodiment, the inter-vehicle distance is used as it is as the “inter-vehicle distance equivalent value”. However, using the time as a physical quantity corresponding to the inter-vehicle distance, the same control is performed in the detected real time and the target time. The same control may be executed for the actual inter-vehicle time and the target inter-vehicle time using the inter-vehicle time (a value obtained by dividing the inter-vehicle distance by the vehicle speed of the own vehicle) as another physical quantity. When the target inter-vehicle distance is made variable according to the vehicle speed and the target inter-vehicle distance is set almost in proportion to the vehicle speed, the target time or the target inter-vehicle time is adjusted instead of adjusting the target inter-vehicle distance. However, the same effect can be obtained.
[0076]
(2) In the relative acceleration determination in S605 of FIG. 3 in the above embodiment, since the relative acceleration integrated value / relative acceleration integrated time is used in calculating the relative acceleration integrated determination value, the relative acceleration per unit time within the integrated time, In other words, the average value was calculated as a result, but from the viewpoint of determining “continuity of relative acceleration”, the integrated time was simply multiplied by the determination coefficient without being divided by the relative acceleration integrated time. It may be a thing. However, as in the above-described embodiment, the relative acceleration fixed value is set to the smaller of the relative acceleration integrated determination value and the current relative acceleration determination value (in the case of acceleration-side determination) or relative acceleration relative determination value. In the method of selecting the larger of the current acceleration judgment values (in the case of deceleration side judgment), it is necessary to set the same level as the current judgment value to be selected, so it is appropriate to use the average value It is.
[0077]
Further, as the current determination value, a value obtained by multiplying the current value by the determination coefficient is used, but this may be an average value in the vicinity of the current value instead of the current value itself. Furthermore, the first low-pass filter processing value is used in place of the integrated value, the second low-pass filter processing value is used in place of the current value, and the second low-pass filter has a higher response than the first low-pass filter. It is also possible to cope with the problem by setting the property (a value closer to that is reflected).
[0078]
(3) The alarm processing in the above embodiment is executed on the premise of inter-vehicle distance control, but can also be realized as an apparatus that executes only inter-vehicle alarm. In that case, in the flowchart of FIG. 2, S700, S800, and S1100 are deleted, the target acceleration is calculated in S600, and then the process proceeds to the alarm determination / alarm device output process in S900.
[0079]
(4) In the alarm processing in the above embodiment, the target acceleration that is the inter-vehicle control amount and the alarm determination value Aref41 are compared (see S901 in FIG. 12). This can also be applied to a configuration in which a warning process for a vehicle driver is executed when becomes smaller than a predetermined warning judgment value. That is, when the warning determination value is set based on at least the relative speed, the warning determination value may be set based on the relative acceleration between the host vehicle and the preceding vehicle. In other words, if the conventional arithmetic expression for the alarm determination value includes a term based on the actual inter-vehicle physical quantity and a term based on the relative speed, a term based on the relative acceleration is added to the term. In this case as well, since the warning judgment value is set based on the relative acceleration sensitive to the behavior change of the preceding vehicle, even if the preceding vehicle decelerates strongly, the behavior change can be captured without delay at the appropriate timing. Thus, the alarm processing can be executed and the dilution of the alarm effect due to unnecessary alarm execution can be prevented.
[Brief description of the drawings]
FIG. 1 is a system block diagram of an inter-vehicle distance controller according to an embodiment.
FIG. 2 is a flowchart showing a main process of inter-vehicle distance control.
FIG. 3 is a flowchart showing a target acceleration calculation subroutine executed during main processing.
FIG. 4 is an explanatory diagram of a control map used for target acceleration calculation.
FIG. 5 is a flowchart showing an acceleration / deceleration control subroutine executed during main processing.
FIG. 6 is a flowchart showing a throttle control subroutine executed during acceleration / deceleration control.
FIG. 7 is a flowchart showing an accelerator-off control subroutine executed during acceleration / deceleration control.
FIG. 8 is a flowchart showing a downshift control subroutine executed during acceleration / deceleration control.
FIG. 9 is a flowchart showing a brake control subroutine executed during acceleration / deceleration control.
FIG. 10 is a flowchart showing an acceleration / deceleration device drive output subroutine executed during main processing.
FIG. 11 is a flowchart showing an output subroutine at the time of non-control of the acceleration / deceleration device executed during the main process.
FIG. 12 is a flowchart showing an alarm determination and alarm output process subroutine executed during the main process.
FIG. 13 is a block diagram showing a correction method using relative acceleration.
FIG. 14 is an explanatory diagram showing an integrated value, a current value, an integrated time, a final value, and the like of relative acceleration.
[Explanation of symbols]
2. Electronic control device for inter-vehicle distance control (inter-vehicle control ECU)
3 ... Laser radar sensor
4 ... Brake electronic control unit (brake ECU)
6. Engine electronic control unit (engine ECU)
8 ... Steering sensor
10 ... Yaw rate sensor
12 ... Wheel speed sensor
14 ... Alarm buzzer
16 ... Vehicle speed sensor
18 ... Brake switch
20 ... Cruise control switch
22 ... Cruise main switch
24 ... Body LAN

Claims (12)

Acceleration means and deceleration means for accelerating and decelerating the host vehicle;
The inter-vehicle deviation, which is the difference between the actual inter-vehicle physical quantity that is the physical quantity corresponding to the actual inter-vehicle distance between the host vehicle and the preceding vehicle, and the target inter-vehicle physical quantity that is the physical quantity corresponding to the target inter-vehicle distance between the own vehicle and the preceding vehicle, and Based on the relative speed between the vehicle and the preceding vehicle, by driving and controlling the acceleration means and the deceleration means, an inter-vehicle control means for causing the host vehicle to follow the preceding vehicle and travel,
In the inter-vehicle control device comprising:
The inter-vehicle distance control means calculates the inter-vehicle control amount calculated based on the inter-vehicle deviation and the relative speed only when a correction execution condition set in terms of the continuity of the relative acceleration is satisfied, and the own vehicle and the preceding vehicle. Is corrected based on the relative acceleration to the vehicle, and the vehicle distance control is executed based on the corrected vehicle distance control amount. The inter-vehicle control apparatus according to claim 1, wherein
The inter-vehicle control amount is a target acceleration of the host vehicle;
An inter-vehicle control device characterized by the above. The inter-vehicle control apparatus according to claim 1 , wherein
The first condition that the absolute value of the weighted integrated value of the relative acceleration or the first low-pass filter processing value captured within the predetermined determination time is larger than the first threshold, and the current value of the relative acceleration or an average near the current value When the second condition that the absolute value of the value or the second low-pass filter processing value having higher responsiveness than the first low-pass filter is larger than the second threshold is satisfied, the correction execution condition is satisfied Judging that
An inter-vehicle control device characterized by the above. In the inter-vehicle control apparatus according to claim 3 ,
The predetermined determination time is set shorter as the absolute value of the relative acceleration to be taken is larger,
An inter-vehicle control device characterized by the above. In the inter-vehicle control apparatus according to any one of claims 1 to 4 ,
The inter-vehicle distance control means, when the correction execution condition is not satisfied, sets the relative acceleration used for correction to zero (0) so that the correction is not substantially performed.
An inter-vehicle control device characterized by the above. In the inter-vehicle control apparatus according to any one of claims 1 to 5 ,
further,
An inter-vehicle alarm means capable of executing an alarm process for a vehicle driver when the inter-vehicle control amount is smaller than a predetermined alarm determination value;
An inter-vehicle control device characterized by the above. The inter-vehicle deviation, which is the difference between the actual inter-vehicle physical quantity that is the physical quantity corresponding to the actual inter-vehicle distance between the host vehicle and the preceding vehicle, and the target inter-vehicle physical quantity that is the physical quantity corresponding to the target inter-vehicle distance between the own vehicle and the preceding vehicle, and When the inter-vehicle control amount calculated based on the relative speed between the vehicle and the preceding vehicle and causing the host vehicle to follow the preceding vehicle is smaller than a predetermined alarm judgment value, In the inter-vehicle alarm device comprising inter-vehicle alarm means capable of executing alarm processing,
The inter-vehicle control amount is calculated based on the inter-vehicle control amount calculated based on the inter-vehicle deviation and the relative speed only when a correction execution condition set in terms of the continuity of the relative acceleration is satisfied. It is corrected based on the relative acceleration with the car,
An inter-vehicle warning device characterized by The inter-vehicle warning device according to claim 7 ,
The first condition that the absolute value of the weighted integrated value of the relative acceleration or the first low-pass filter processing value captured within the predetermined determination time is larger than the first threshold, and the current value of the relative acceleration or an average near the current value When the second condition that the absolute value of the value or the second low-pass filter processing value having higher responsiveness than the first low-pass filter is larger than the second threshold is satisfied, the correction execution condition is satisfied Judging that
An inter-vehicle warning device characterized by The inter-vehicle warning device according to claim 8 ,
The predetermined determination time is set shorter as the absolute value of the relative acceleration to be taken is larger,
An inter-vehicle warning device characterized by The inter-vehicle warning device according to claim 8 or 9 ,
The first threshold value is set to be larger as the absolute value of the relative acceleration to be captured is larger.
An inter-vehicle warning device characterized by The computer-readable recording medium which recorded the program for functioning a computer system as a distance control means of the distance control apparatus in any one of Claims 1-6 . A computer-readable recording medium a program for causing the computer system to function as a vehicle alarm means headway warning apparatus according to any one of claims 7-10.

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