JP2006008130A - Vehicle following distance controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle following distance controller which is capable of reducing a vehicle speed smoothly and quickly upon detecting an acceleration or deceleration instruction during vehicle following distance control. <P>SOLUTION: The vehicle following distance controller has a vehicle following distance controlling means, which adjusts a current vehicle speed to bring the vehicle's speed into line with a preset speed increased or reduced in response to an acceleration request or deceleration request from a driver, and adjusts the vehicle's speed to bring a vehicle following distance to a preceding car into a preset vehicle following distance in controlling vehicle following distances. The controller also includes a means which, during the vehicle following distance control, disregards the acceleration request when detecting it and updates the preset speed to make it a current vehicle speed at the point of detecting the deceleration request when detecting the deceleration request. The controller, therefore, adjusts the vehicle's speed to the deceleration side based on the updated preset speed during the vehicle following distance control. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an inter-vehicle distance control device that uses a radar device that keeps the vehicle speed constant and tracks the front vehicle and keeps the inter-vehicle distance constant in order to prevent a rear-end collision with the front vehicle, and is particularly smooth and responsive. The present invention relates to an inter-vehicle distance control device capable of good speed control.

As a current vehicle control, many cruise devices that keep the vehicle speed constant are applied to automobiles. This cruise device is provided with a set switch for storing the current vehicle speed, an accelerator switch for accelerating and decelerating, and a coast switch for the driver, so that the throttle actuator can be opened and closed according to the driver's switch operation. I have to. Furthermore, this cruise device may be provided with an inter-vehicle distance control function for maintaining a constant inter-vehicle distance from the preceding vehicle, and these are collectively put into practical use as an inter-vehicle distance control device.

This inter-vehicle distance control device radiates millimeter waves toward the front of the vehicle, calculates inter-vehicle distance D and relative speed (V2 -V1) from the reflected wave, and is necessary based on the inter-vehicle distance from the preceding vehicle Accordingly, the throttle actuator is opened and closed to accelerate and decelerate.

FIG. 5 is a diagram for explaining acceleration and deceleration characteristics of a conventional inter-vehicle distance control device. This will be described below with reference to the drawings.

In the inter-vehicle distance control device, an optimal inter-vehicle distance D corresponding to the host vehicle speed is stored in advance as an inter-vehicle distance map in the memory. When the driver does not detect the front vehicle and the driver operates the set switch, the traveling speed at this time (referred to as the storage speed Vm) is input, and overshoot and undershoot are performed based on the storage speed Vm. In consideration of the above, a target speed VT for actually adjusting the speed of the vehicle is calculated, and constant speed running is performed. After that, when approaching a preceding vehicle that is slower than the host vehicle, readjustment is performed such that, for example, the actual speed that has been running at a constant speed has been reduced so that the inter-vehicle distance D does not fall within a predetermined value. In this case, the target speed VT is not changed, and is adjusted based on the actual speed.

As a result, the host vehicle travels while maintaining a constant distance D at the same speed as the preceding vehicle. If the driver gives an instruction to accelerate while driving at the actually measured speed V1 while maintaining the predetermined inter-vehicle distance D (turns on the accelerator switch), the inter-vehicle distance control device increases the target speed VT in accordance with the instruction. At this time, the actual measured speed V1 is lower than the target speed VT, but the inter-vehicle distance control device instructs to increase the current speed so that the actual speed matches the changed target speed VT ( Instruct the cruise ECU to open the throttle actuator).

On the other hand, if the driver gives an instruction to decelerate while driving at the actual measured speed V1 while maintaining the predetermined inter-vehicle distance D (turns on the coast switch), the inter-vehicle distance control device sets the target speed VT for smooth deceleration. Reduce gradually. At this time, control is performed to reduce the current speed so that the actual speed matches the reduced target speed VT.
In this way, smooth deceleration is achieved. The target speed VT is set to change as the accelerator switch and coast switch are kept pressed.

In addition, when a request to return to the set speed of the constant speed travel is made by the resume switch, there are some that perform the inter-vehicle distance control after requesting the set speed to the ECU. (For example, refer to Patent Document 1.)
JP-A-4-238743 ([0019], FIG. 2)

In the above-described method, when the driver operates the accelerator switch to accelerate during the inter-vehicle distance control, the inter-vehicle distance D decreases because the own vehicle speed V1 increases unless the speed V2 of the front vehicle changes. As a result, it is necessary to decelerate. That is, when the driver tries to accelerate, the inter-vehicle distance control device performs an opposite operation to decelerate.

On the other hand, when the driver requests deceleration, the driver feels that the speed of the vehicle is actually high or the distance between the vehicles is short, and it is necessary to appropriately decelerate. When the driver operates the coast switch to reduce the speed while driving at the actually measured speed V1 while maintaining the predetermined distance D, the distance control device stores the storage speed Vm stored in the memory for smooth deceleration. Based on this, the target speed VT with the speed lowered step by step is calculated. The target speed VT, which has been reduced stepwise, is compared with the actually measured speed V1, and as a result, the target speed V
When T becomes lower than the actually measured speed V1, the vehicle is actually decelerated. However, since priority is given to maintaining the inter-vehicle distance D during inter-vehicle distance control, the speed V1 of the host vehicle is affected by the speed V2 of the preceding vehicle, and the target speed VT, the stored speed Vm, and the actually measured speed V1 are not necessarily equal. I'm not necessarily doing it. If there is a speed divergence between the target speed VT and the actual speed V1 (usually, the actual speed V1 is lower or the same as the target speed VT), the target speed VT will be applied even if the driver gives a command for deceleration. Therefore, while the target speed VT is lowered to the actual speed V1, the vehicle is not actually decelerated and a time lag occurs. as a result,
Even if the storage speed Vm and the target speed VT are lowered, there is a problem that it takes time until the speed of the vehicle actually decreases. The cause of these problems is that cruise control and inter-vehicle distance control are not well suited as software.

An object of the present invention is to provide an inter-vehicle distance control device that does not accept an acceleration instruction during inter-vehicle distance control, and can smoothly and quickly decelerate when there is a deceleration instruction.

In order to achieve the above object, the present invention increases or decreases a preset set speed in accordance with a driver's acceleration request or deceleration request, and the speed of the host vehicle matches the increased or reduced set speed. In this way, the current speed of the own vehicle is adjusted to control the constant speed travel, and the speed of the own vehicle is readjusted so that the distance between the vehicle and the preceding vehicle becomes a preset distance. In the inter-vehicle distance control device having inter-vehicle distance control means for controlling the distance, the inter-vehicle distance control means prioritizes the control of the inter-vehicle distance when the acceleration request or the deceleration request is issued during the inter-vehicle distance control. It is characterized in that it is performed manually.

Further, the set speed set in advance is increased or decreased in response to the driver's acceleration request or deceleration request, and the current speed of the host vehicle is set so that the speed of the host vehicle matches the increased or decreased set speed. An inter-vehicle distance control means for controlling the inter-vehicle distance by adjusting the speed of the host vehicle to adjust the speed at a constant speed, and to readjust the speed of the host vehicle so that the inter-vehicle distance from the preceding vehicle becomes a preset inter-vehicle distance. In the inter-vehicle distance control apparatus, the inter-vehicle distance control means includes means for ignoring the acceleration request during inter-vehicle distance control.

Further, the set speed set in advance is increased or decreased in response to the driver's acceleration request or deceleration request, and the current speed of the host vehicle is set so that the speed of the host vehicle matches the increased or decreased set speed. An inter-vehicle distance control means for controlling the inter-vehicle distance by adjusting the speed of the host vehicle to adjust the speed at a constant speed, and to readjust the speed of the host vehicle so that the inter-vehicle distance from the preceding vehicle becomes a preset inter-vehicle distance. In the inter-vehicle distance control device, the inter-vehicle distance control means, when detecting the deceleration request during inter-vehicle distance control, updates the set speed as the current speed of the host vehicle when the deceleration request is detected. Means to
The speed of the own vehicle is adjusted to the deceleration side based on the updated set speed.

Further, the set speed set in advance is increased or decreased in response to the driver's acceleration request or deceleration request, and the current speed of the host vehicle is set so that the speed of the host vehicle matches the increased or decreased set speed. An inter-vehicle distance control means for controlling the inter-vehicle distance by adjusting the speed of the host vehicle to adjust the speed at a constant speed, and to readjust the speed of the host vehicle so that the inter-vehicle distance from the preceding vehicle becomes a preset inter-vehicle distance. In the inter-vehicle distance control device, the inter-vehicle distance control means includes means for changing the preset inter-vehicle distance in a larger direction when the deceleration request is detected during inter-vehicle distance control. The speed of the own vehicle is adjusted to the deceleration side according to the inter-vehicle distance.

The inter-vehicle distance control means adjusts the speed of the host vehicle based on the changed inter-vehicle distance until the ignition switch of the host vehicle is turned off.

The inter-vehicle distance control means includes inter-vehicle distance storage means that always stores the changed inter-vehicle distance. When the ignition switch of the own vehicle is turned off, the inter-vehicle distance control means is stored in the inter-vehicle distance storage means. The vehicle speed is adjusted based on the stored inter-vehicle distance.

According to the present invention, it is possible to provide an inter-vehicle distance control device that does not accept an acceleration instruction during inter-vehicle distance control, can decelerate smoothly and quickly with a decelerate instruction, and can learn the inter-vehicle distance according to the driver.

FIG. 1 is a diagram for explaining the system configuration of an inter-vehicle distance control device according to an embodiment of the present invention, and FIG. 2 explains the processing contents of a microcomputer in the case of an acceleration instruction of the inter-vehicle distance control device according to an embodiment of the present invention. It is a flowchart for doing. FIG. 3 is a flow chart for explaining the processing contents of the microcomputer in the case of a deceleration instruction of the inter-vehicle distance control device of one embodiment of the present invention. This will be described below with reference to the drawings.

Reference numeral 1 denotes a millimeter wave radar device using the Doppler effect installed in front of the own vehicle, which detects a reflected wave of a beam irradiated forward and outputs it to the subsequent stage. 2
Is a vehicle speed sensor for measuring the speed V1 of the host vehicle. Reference numeral 3 denotes an accelerator switch for instructing acceleration. 4 is a coast switch for instructing deceleration. Reference numeral 5 denotes a set switch for instructing the speed to be input to the control unit (microcomputer 61), and the vehicle speed when the switch is operated is input. 6 is a microcomputer that performs signal processing of the reflected wave detected by the radar device 1 and measures the inter-vehicle distance D and relative speed (V2 -V1) to the front vehicle, and recognizes the front vehicle based on this and performs inter-vehicle distance control. 61, ROM 62 storing various data
, A millimeter wave radar signal processing ECU configured by a memory such as a RAM 63. A cruise ECU 7 controls the speed by adjusting the throttle actuator 8 according to an instruction from the millimeter wave radar signal processing ECU 6. As a result, a certain distance between the vehicle and the front vehicle is maintained. Reference numeral 9 denotes a brake, and the inter-vehicle distance control traveling is canceled by stepping on the brake. The millimeter wave radar signal processing ECU 6 and the cruise ECU 7 are separate ECs.
Although it is comprised by U, it may comprise not only this but one ECU which put these together.

First, the acceleration instruction will be described with reference to the flowchart showing the processing contents of the microcomputer 61 in FIG. In step S1, it is determined whether or not the accelerator switch 3 is on. If the accelerator switch 3 is on, the process proceeds to step S2. If not, the process proceeds to step S6. That is, it is determined whether or not the accelerator switch 3 is operated by the driver.

In step S2, it is determined whether or not the inter-vehicle distance control is being performed based on the relative distance from the preceding vehicle. That is, control is not performed if the relative distance is sufficiently greater than or equal to a predetermined value, and control is performed if the relative distance is less than or equal to the predetermined value. If the inter-vehicle distance control is being performed, the process proceeds to step S6. If the inter-vehicle distance control is not being performed, the process proceeds to step S3. In other words, since the inter-vehicle distance is maintained in an optimal state during inter-vehicle distance control, acceleration according to the acceleration request inevitably shortens the inter-vehicle distance, and it is necessary to decelerate immediately. In such a driving operation, the crew member is in an unnatural state of repeating acceleration and deceleration, so the acceleration request is ignored. As a result, acceleration control is not performed, and the vehicle travels substantially as it is.

In step S3, the target speed VT is set to VT +1, and the process proceeds to step S4. That is, in order to perform acceleration control, the target speed VT is increased stepwise in accordance with a predetermined program. In step S4, the opening / closing angle θ of the throttle actuator 8 is set to k (V
T-V1) and the process proceeds to step S5. That is, in order to accelerate, the microcomputer 61 opens and closes the opening / closing angle θ of the throttle actuator 8 according to the difference between the target speed VT and the current vehicle speed V1.
To decide. In step S5, the cruise ECU 7 is instructed according to the determined opening / closing angle θ of the throttle actuator 8, and the process is terminated. That is, the cruise ECU 7 is instructed to open and close (usually in the opening direction because of acceleration) according to the determined opening / closing angle θ of the throttle actuator 8, and the process is ended. The throttle actuator 8 is opened and the vehicle is accelerated.

In step S6, normal inter-vehicle distance control is performed and the process ends. That is, if acceleration is performed according to the acceleration request during inter-vehicle distance control, the distance from the preceding vehicle is inevitably shortened, and deceleration is required immediately. If acceleration and deceleration are repeated in this way, the passenger feels uncomfortable, so the vehicle travels by normal inter-vehicle control ignoring the acceleration request.

Next, the case of a deceleration instruction will be described with reference to the flowchart showing the processing contents of the microcomputer 61 in FIG. In step S11, it is determined whether or not the coast switch 4 is on. If the coast switch 4 is on, the process proceeds to step S12.
Move to 16. That is, it is determined whether or not the coast switch 4 has been operated by the driver.

In step S12, it is determined whether the inter-vehicle distance control is being performed. If the inter-vehicle distance control is being performed, the process proceeds to step S13, and if the inter-vehicle distance control is not being performed, the process proceeds to step S14. That is, if the inter-vehicle distance control is not being performed, deceleration in the normal deceleration mode is performed according to the deceleration request.

In step S13, the actually measured speed V1 is substituted for the storage speed Vm and the target speed VT, and the process proceeds to step S14. In other words, if the inter-vehicle distance control is being performed, the inter-vehicle distance D is maintained in an optimum state, but the speed of the own vehicle (actually measured speed V1) in that case is the speed V2 of the preceding vehicle.
If the front car is slow, the storage speed Vm stored in the RAM 63 etc.
The speed becomes slower than the target speed VT, and a speed divergence occurs during that time. for that reason,
The vehicle is not decelerated during a period in which the measured speed V1 is lower than the target speed VT decelerated according to a predetermined program (see the solid line in FIG. 5). In order to decelerate the vehicle immediately when a deceleration request is made, the stored speed Vm and the target speed VT are made to coincide with the actually measured speed V1 as shown by the broken line in FIG. The target speed VT becomes lower than the actually measured speed V1, and deceleration can be started. That is, in this example, the speed in the inter-vehicle distance control is preferentially used.

In step S14, the target speed VT is set to VT-1, and the process proceeds to step S15.
That is, in order to perform the deceleration control, the target speed VT is decreased stepwise according to a predetermined program. In step S15, the opening / closing angle θ of the throttle actuator 8 is set to k (VT−V1), and the process proceeds to step S16. That is, the microcomputer 61 determines the opening / closing angle θ of the throttle actuator 8 according to the difference between the target speed VT and the current vehicle speed V1 in order to decelerate. According to the determined opening / closing angle θ of the throttle actuator 8, the throttle actuator 8 is opened / closed (normally in the closing direction because of deceleration), and the vehicle is decelerated.

In step S16, normal inter-vehicle distance control is performed and the process ends. That is, control that satisfies a predetermined inter-vehicle distance and a set speed is performed.

As described above, in this embodiment, no acceleration instruction is accepted during inter-vehicle distance control,
It is possible to provide an inter-vehicle distance control device capable of smoothly and immediately decelerating with a deceleration instruction.

FIG. 4 is a diagram for explaining an example of changing the inter-vehicle distance of the inter-vehicle distance control device of the second embodiment of the present invention. This will be described below with reference to the drawings.

In the first embodiment, when deceleration is instructed, the storage speed Vm and the target speed VT
Was changed to match the measured speed V1, and deceleration was performed based on that speed.
In this embodiment, the processing is not performed so as to directly change the storage speed Vm and the target speed VT, but the relationship between the vehicle speed V stored in advance in the RAM 63 or the like and the optimum inter-vehicle distance Df (referred to as inter-vehicle distance map, FIG. 4). To achieve the deceleration process.

That is, instead of lowering the storage speed Vm and the target speed VT to achieve deceleration, in FIG. 4, the inter-vehicle distance map initially composed of a thick line is used to show the optimal inter-vehicle distance Df1 at the current vehicle speed V1 in the direction of the arrow (the inter-vehicle distance is In the direction of lengthening, it is actually moved to the nearest map point). By changing the inter-vehicle distance in the direction of increasing the inter-vehicle distance map, the current inter-vehicle distance Df1 is shorter than the changed inter-vehicle distance Df2, so that the vehicle is immediately decelerated to maintain the changed inter-vehicle distance Df2. . In other words, deceleration control is not performed based on the target vehicle speed for cruise control, but deceleration control is performed using actual vehicle speed change in inter-vehicle distance control.

To change the inter-vehicle distance map, the driver operates the coast switch 4,
It is changed so that the inter-vehicle distance becomes longer. When the driver determines that the desired speed is reached, the driver releases the coast switch 4. The inter-vehicle distance corresponding to the speed of the vehicle at that time is input as the inter-vehicle distance Df2 in the map. Incidentally, as shown in FIG. 4, in the intermediate point of the speeds in which the current vehicle speed is stored in the inter-vehicle distance map, the point closest to the current vehicle speed V1 (the inter-vehicle distance corresponding to the current vehicle speed) is corrected. When the inter-vehicle distance map is used, the inter-vehicle distance corresponding to the current vehicle speed is obtained by interpolation of the two points closest to the current vehicle speed.

This changed inter-vehicle distance map is used in that state until the ignition switch is turned off. When the ignition switch is turned off, the driver may change, so that the original state (original inter-vehicle distance map) is restored. Also, if the probability that the same driver will get on is high, the changed inter-vehicle distance map is stored in a memory such as the backup RAM 63 or E ² PROM to which power is always supplied, and is changed even after the ignition switch is turned off. It is also possible to use an inter-vehicle distance map.

As described above, in this embodiment, it is possible to provide an inter-vehicle distance control device that can immediately decelerate so that the driver's desired inter-vehicle distance is obtained.

As described above, according to the present invention, an acceleration instruction is not accepted during inter-vehicle distance control, and the deceleration instruction can smoothly and quickly decelerate, and further, the inter-vehicle distance can be learned according to the driver. A control device can be provided.

It is a figure for demonstrating the system configuration | structure of the inter-vehicle distance control apparatus of one Example of this invention. It is a flowchart for demonstrating the processing content of the microcomputer in the case of the acceleration instruction | indication of the inter-vehicle distance control apparatus of one Example of this invention. It is a flowchart for demonstrating the processing content of the microcomputer in the case of the deceleration instruction | indication of the inter-vehicle distance control apparatus of one Example of this invention. It is a figure which shows the example which changes the inter-vehicle distance of the inter-vehicle distance control apparatus of the 2nd Example of this invention. It is a figure for demonstrating the acceleration and deceleration characteristics by the conventional inter-vehicle distance control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Radar apparatus 5 ... Set switch 2 ... Vehicle speed sensor 6 ... Millimeter wave radar signal processing ECU
3 ... Accelerator switch 7 ... Cruise ECU
4 ... Coast switch 8 ... Throttle actuator

Claims (6)

In response to the driver's acceleration request or deceleration request, the preset speed set in advance is increased or decreased, and the current speed of the host vehicle is adjusted so that the speed of the host vehicle matches the increased or decreased set speed. A vehicle distance control means for controlling the vehicle distance by re-adjusting the speed of the vehicle so that the distance between the vehicle and the vehicle in front of the vehicle is a preset distance between vehicles. In the inter-vehicle distance control device,
The inter-vehicle distance control means preferentially controls the inter-vehicle distance when the acceleration request or the deceleration request is made during inter-vehicle distance control. In response to the driver's acceleration request or deceleration request, the preset speed set in advance is increased or decreased, and the current speed of the host vehicle is adjusted so that the speed of the host vehicle matches the increased or decreased set speed. A vehicle distance control means for controlling the vehicle distance by re-adjusting the speed of the vehicle so that the distance between the vehicle and the vehicle in front of the vehicle is a preset distance between vehicles. In the inter-vehicle distance control device,
The inter-vehicle distance control means includes means for ignoring the acceleration request during inter-vehicle distance control. In response to the driver's acceleration request or deceleration request, the preset speed set in advance is increased or decreased, and the current speed of the host vehicle is adjusted so that the speed of the host vehicle matches the increased or decreased set speed. A vehicle distance control means for controlling the vehicle distance by re-adjusting the speed of the vehicle so that the distance between the vehicle and the vehicle in front of the vehicle is a preset distance between vehicles. In the inter-vehicle distance control device,
When the inter-vehicle distance control means detects the deceleration request during inter-vehicle distance control,
Means for updating the set speed as the current speed of the own vehicle at the time when the deceleration request is detected, and adjusting the speed of the own vehicle to the deceleration side based on the updated set speed. An inter-vehicle distance control device characterized by that. In response to the driver's acceleration request or deceleration request, the preset speed set in advance is increased or decreased, and the current speed of the host vehicle is adjusted so that the speed of the host vehicle matches the increased or decreased set speed. A vehicle distance control means for controlling the vehicle distance by re-adjusting the speed of the vehicle so that the distance between the vehicle and the vehicle in front of the vehicle is a preset distance between vehicles. In the inter-vehicle distance control device,
When the inter-vehicle distance control means detects the deceleration request during inter-vehicle distance control,
The inter-vehicle distance control device comprising means for changing the preset inter-vehicle distance in a large direction, and adjusting the speed of the own vehicle to the deceleration side according to the changed inter-vehicle distance. . 4. The inter-vehicle distance according to claim 3, wherein the inter-vehicle distance control means adjusts the speed of the own vehicle based on the changed inter-vehicle distance until the ignition switch of the own vehicle is turned off. Control device. The inter-vehicle distance control means includes inter-vehicle distance storage means for always storing the changed inter-vehicle distance, and is stored in the inter-vehicle distance storage means when the ignition switch of the own vehicle is turned on again after being turned off. 4. The inter-vehicle distance control device according to claim 3, wherein the speed of the own vehicle is adjusted based on the inter-vehicle distance.