JPH0672184A - Constant speed travel device with inter-vehicle distance adjusting function - Google Patents

Abstract

PURPOSE:To provide the same traveling feeling in constant speed travel control and inter-vehicle distance adjusting control for keeping the inter-vehicle distance constant, and prevent sudden deceleration even in the case of an unexpected interruption between one's own vehicle and a front vehicle. CONSTITUTION:The inter-vehicle distance and the vehicle speed for constant speed travel are respectively set by an inter-vehicle distance setting part 151 and a vehicle speed setting part 152. On the basis of the detection signal of an inter-vehicle distance sensor 14, a vehicle judging part 25 performs vehicle judgement, and a relative speed computing part 24 computes the relative speed. On the basis of the computed relative speed and the target inter-vehicle distance computed by a target inter-vehicle distance computing part 21, an accelerating/decelerating ratio computing part 22 computes the accelerating/decelerating ratio of the own vehicle, and a target vehicle speed computing part computes the target speed corresponding to the inter-vehicle distance and relative speed. In correspondence with this target speed and the present speed detected by a vehicle speed sensor 13, a control method examining part 27 examines and selects a vehicle speed control method, and a vehicle control part 28 drives a throttle actuator 17 or a transmission controller 19 according to the selected control method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to an inter-vehicle distance control system for automatically controlling the traveling distance of a vehicle traveling ahead while the traveling distance is controlled automatically at a set traveling speed. The present invention relates to a constant speed traveling device having a distance adjusting function.

[0002]

2. Description of the Related Art In a vehicle which is controlled to travel at a constant speed at a vehicle speed set by a constant speed travel setting function, when there is a vehicle traveling ahead, the inter-vehicle distance to the vehicle in front is measured,
A constant-speed traveling device that automatically and variably controls the traveling speed of the vehicle in accordance with the measured inter-vehicle distance is disclosed in, for example, Japanese Patent Laid-Open No. 3-220.
No. 028 publication.

In this travel control device, the target travel speed is calculated and determined from the preset relationship on the basis of the measured and detected inter-vehicle distance, and from the deviation between the current vehicle speed and the calculated target vehicle speed, Acceleration / deceleration control of the traveling speed of the own vehicle is performed. However, when the inter-vehicle distance is unnecessarily large, it may be involuntarily interrupted by the preceding vehicle, and in such a case, the inter-vehicle distance decreases sharply and The sudden deceleration control is performed to give the driver a significant discomfort.

Further, in the constant speed running device for an automobile disclosed in Japanese Patent Laid-Open No. 63-269736, there is proposed a device in which an inter-vehicle distance adjusting function is added to a constant speed running control system. In this device, for example, if the current inter-vehicle distance is 30 m or more, constant speed traveling control is performed,
If the distance is 30 m or less, the inter-vehicle distance adjustment control is performed to keep the inter-vehicle distance constant.

Specifically, the throttle opening is controlled by the deviation between the target vehicle speed and the current vehicle speed during constant-speed running control, and the throttle opening is controlled by the deviation between the target vehicle and the current vehicle during the vehicle-interval adjustment control that keeps the vehicle distance constant. I control the degree.

However, the control logic of the throttle opening for performing the constant speed traveling control and the vehicle speed control for keeping the vehicle distance constant is configured differently. Therefore, in order to make the traveling feelings of the both agree with each other. Work is required. This point will be described in detail below.

The feeling felt by the driver during traveling is acceleration / deceleration due to a change in throttle opening. Therefore, if the control logic of the throttle opening is different and the actual opening / closing state of the throttle valve is different even in the same traveling state, a different traveling feeling is felt. For this reason, for example, in constant speed traveling control, the driver
Change the throttle opening when changing the set vehicle speed from 0 Km / h to 85 Km / h, and make it the same when the same speed change occurs in the inter-vehicle distance adjustment control that keeps the inter-vehicle distance constant. If the throttle opening calculation is not adjusted in advance, the driver will feel different driving feelings during the constant speed control and the constant inter-vehicle distance control.

In this pre-adjustment, whether or not the control systems are the same is adjusted by, for example, adjusting the control parameters so that the response of the control system becomes the same in frequency response and step response, and finally, in the actual vehicle. It becomes necessary to actually check the driving feeling in the test. Considering the current situation where constant speed control devices are already widespread and have a good track record of driving feeling, the throttle opening calculation of the control that keeps the distance between vehicles constant is adjusted to provide the driving feeling of constant speed driving control. Must match.

However, when the control parameter of the throttle opening calculation portion is adjusted in this way, it does not always match the characteristics required for the inter-vehicle distance adjustment control that keeps the actual inter-vehicle distance constant. It is necessary to perform a process of correcting in part (for example, target vehicle distance). In other words, by performing the work of matching the driving feeling, the development load is increased compared to the case where the same throttle opening calculation is used, and the inter-vehicle distance adjustment control characteristic that keeps the required inter-vehicle distance constant can be realized. There is a risk of disappearing,
There is a problem that a correction process must be newly added.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has the same traveling feeling for the constant speed traveling control and the vehicle-interval adjusting control for keeping the vehicle-to-vehicle distance constant, and is the same as that of the front vehicle. An object of the present invention is to provide a constant speed traveling device having an inter-vehicle distance adjusting function capable of preventing a sudden deceleration even if there is an involuntary interruption.

[0011]

In a constant speed traveling device having an inter-vehicle distance adjusting function according to the present invention, the inter-vehicle distance measuring means measures distance data with an object traveling ahead,
The relative speed calculation means calculates the relative speed based on the change in the measured inter-vehicle distance data, and the vehicle recognition means recognizes that the front object is a vehicle based on the change state of the relative speed. In such a vehicle recognition state, the difference between the inter-vehicle distance data and the set target inter-vehicle distance,
And obtain the acceleration / deceleration rate of the vehicle based on the relative speed,
The target vehicle speed is obtained by correcting the basic acceleration / deceleration rate based on the acceleration / deceleration rate and the previous target vehicle speed. The vehicle traveling speed is controlled by the vehicle speed control means based on the difference between the target vehicle speed calculated in this way and the current vehicle speed. Also, the vehicle speed is controlled so that the acceleration / deceleration rate decreases as the inter-vehicle distance increases. The correction means for correcting the acceleration / deceleration rate is provided.

[0012]

In the constant-speed traveling device having the above-mentioned structure, when the vehicle is ahead, the inter-vehicle distance is measured and the relative speed to the vehicle ahead is measured. Then, the acceleration / deceleration rate of the own vehicle is obtained from the relationship between the inter-vehicle distance and the set target inter-vehicle distance and the relative speed.
As this acceleration / deceleration rate, for example, one stored in a map can be used. After that, the current target vehicle speed is calculated from the acceleration / deceleration rate and the previously calculated target vehicle speed, and control is performed to bring the actual vehicle traveling speed closer to the target vehicle speed. As this control, opening / closing control of the engine throttle, switching of the transmission, or the like can be adopted.

Further, in the constant speed traveling device according to the second aspect, the acceleration / deceleration rate of the own vehicle is corrected so that the acceleration / deceleration rate becomes smaller as the inter-vehicle distance becomes larger corresponding to the inter-vehicle distance. It is a rough inter-vehicle distance control.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows its schematic configuration. A computer 11 that executes arithmetic control for control includes an input interface 111 that receives input information and an output interface 112 that outputs control information. The operation is performed in the CPU 113. This CP
For U113, a ROM 114 for storing programs for executing control operations and various maps for arithmetic operations and a RAM 115 for storing information based on arithmetic controls are set.

A detection signal from a vehicle speed sensor 13 which is set in relation to the wheels 12 of the vehicle and which detects a signal corresponding to the rotation speed of the wheels 12 for such a computer 11,
Further, a detection signal or the like from an inter-vehicle distance sensor 14 that measures a distance to a vehicle traveling in front is input, and further, an inter-vehicle distance from the setting unit 15 and an initial set vehicle speed are input.

The output from the computer 11 is supplied as a control command to a throttle actuator 17 for driving a throttle mechanism for controlling the rotation speed of an engine 16 for driving a vehicle, and the power from the engine 16 for wheels 12 is supplied. It is supplied as a control command to a transmission controller 19 which controls the transmission 18 to be transmitted, and the traveling speed of this vehicle is controlled to be adjusted.

FIG. 2 shows the control system of the setting section.
Reference numeral 15 is a vehicle-to-vehicle distance setting unit 151 and a vehicle-to-vehicle distance setting unit 152, each of which is configured by a switch mechanism or the like that is appropriately operated by the driver.
The information set by 151 is input to the target inter-vehicle distance calculation unit 21 configured in the computer 11, and the set inter-vehicle distance information calculated by this inter-vehicle distance calculation unit 21 is the acceleration / deceleration rate calculation unit.
Entered in 22. This target inter-vehicle distance may be changed according to the vehicle speed or the like. For example, when the vehicle speed is high, the inter-vehicle distance is set long, and when the vehicle speed is low, the inter-vehicle distance is set short.

The inter-vehicle distance sensor 14 is composed of, for example, a laser radar or the like, and a detection signal from the inter-vehicle distance sensor 14 is input to the computer 11 and the object determining unit
Supplied to 23. The object determination unit 23 is an inter-vehicle distance sensor.
The state of variation of the detection signal from 14 and the like are determined to determine whether or not an object is detected.

Further, the detection signal from the inter-vehicle distance sensor 14 is supplied to the relative speed calculating section 24, and based on the change situation of the inter-vehicle distance, more specifically, the self-interval based on the change of the inter-vehicle distance at every constant control cycle. Calculate the relative speed between the vehicle and the vehicle in front. The calculated relative speed information is supplied to the vehicle determination unit 25, and the relative speed data is constantly monitored to determine whether or not the object ahead is a vehicle. Then, the determination result is input to the acceleration / deceleration rate calculation unit 22. This vehicle determination process may be executed inside the inter-vehicle distance sensor 14.

In the acceleration / deceleration rate calculation unit 22, the target inter-vehicle distance and the relative speed, and the object determination unit 23 and the vehicle determination unit 25.
An appropriate target acceleration / deceleration rate is obtained from the determination result of. Then, the target acceleration / deceleration rate obtained by the acceleration / deceleration rate calculation unit 22 is integrated by the target vehicle speed calculation unit 26 to calculate the target vehicle speed, and then the control method examination unit 27 calculates the target vehicle speed and the target vehicle speed. By comparing with the vehicle speed, it is determined whether the normal throttle control is sufficient or whether it is necessary to control the transmission or the like. Therefore, the control method examining unit 27 is also supplied with the vehicle speed data from the vehicle speed sensor 13.

Target vehicle speed calculation unit 26 and control method examination unit 27
The output from is supplied to the vehicle speed control unit 28 together with the setting information from the vehicle speed setting unit 152. In this vehicle speed control unit 28, constant speed running control is performed in which the throttle actuator 17 of the engine 16 is driven to control the opening of the throttle valve so that the current vehicle speed detected by the vehicle speed sensor 14 matches the target vehicle speed. . When it is necessary to control the transmission 18 as well, a command is given to the transmission controller 19 to control the transmission 18.

The vehicle speed control unit 28 inputs an initial set vehicle speed by the vehicle speed setting unit 152, switches between constant speed traveling control and inter-vehicle distance control, cancels the control, and performs acceleration / deceleration control manually. It also has a function to go. Further, the switching between the constant speed traveling control and the inter-vehicle distance control may be performed without depending on the vehicle speed setting unit 152, for example, when the condition that the vehicle speed or the inter-vehicle distance is specified is satisfied.

Next, as shown in FIG.
Object determination unit 23, vehicle determination unit 25, acceleration / deceleration rate calculation unit
22, the processing in the computer 11 constituting the target vehicle speed calculation unit 26, the control method examination unit 27 and the like will be described based on the flowchart of FIG.

First, in step 201, inter-vehicle distance data is input, and in step 202, the input inter-vehicle distance data is evaluated for each control cycle, and its variation is calculated. Based on the result of calculating the variation of the inter-vehicle distance data in this way, it is determined in step 203 whether or not the degree of variation is larger than a predetermined set value, and when the degree of variation is smaller than the set value. Determines that there is an object in front (object detection state). In the next step 204, the relative speed with respect to the front object is calculated from the change in the inter-vehicle distance data, and in step 205, the calculated relative speed is stored in the buffer. Remember.

When it is determined in step 203 that the variation in the inter-vehicle distance data is large, it is determined that no object is actually present in the front (undetected state), and the process proceeds to step 206. In this step 206, the inter-vehicle distance and relative speed are set to "0".
And the fact that no object is detected is stored.

When the relative speed with respect to the vehicle ahead is stored and set in the buffer in step 205, the relative speed of each control cycle is compared in step 207 to calculate the state of variation in the relative speed. Then, in step 208, the state of this relative speed variation is compared with the set value. If the variation is small, it is determined that the object in front is a vehicle (vehicle recognition state), and in step 209 the inter-vehicle distance and The relative speed is stored and the vehicle recognition state is stored.

In step 208, if the relative speed variation is larger than the set value, it is determined that the object in front is other than the vehicle, and in step 210 the distance to the object is stored and the relative speed is set to "0". ", And the object detection state is stored. The above processing may be performed inside the inter-vehicle distance sensor 13.

When such processing is completed, the processing in the acceleration / deceleration rate calculation unit 22 is performed.
In steps 211 to 213, the acceleration / deceleration rate of the vehicle is calculated corresponding to the three states of the object undetected state, the vehicle recognized state, and the object detected state in 209 and 210, respectively.

That is, if the undetected state of the object is confirmed in step 206, the acceleration / deceleration rate at the time of non-detection is set in step 211, and the acceleration is gradually controlled up to the vehicle speed initially set by the driver. So set a small positive acceleration rate. The vehicle speed may be maintained or decelerated during a curve.

When the recognition state of the vehicle is stored in step 209, the basic acceleration / deceleration rate upon vehicle recognition is calculated in step 212. Specifically, the basic acceleration / deceleration rate is calculated based on the acceleration / deceleration rate map as shown in FIG. In this map, the horizontal axis shows the value obtained by subtracting the target vehicle distance from the current vehicle distance (whether the front vehicle is far or near), and the vertical axis shows the relative speed (close or far) with the front vehicle. It is the two-dimensional map data to be taken, and the respective acceleration / deceleration rate values at each grid point are shown.

In such a map table, a minus (-) sign represents deceleration and a plus (+) sign represents acceleration. Then, the data to be actually used is obtained by interpolating the data of each grid point.

By using such map data, although the inter-vehicle distance to the vehicle ahead is small, unnecessary deceleration control is prevented from being performed on the vehicle which the vehicle ahead is moving away from. . In addition, although there is a sufficient inter-vehicle distance to the front, when the vehicle approaches the front vehicle at a large relative speed, deceleration control is started earlier, which corresponds to the actual driving situation. Detailed vehicle distance control is performed. Further, since the acceleration / deceleration rate is continuously obtained by a uniform map, the acceleration / deceleration rate control without discontinuity is realized. For example, even if the vehicle is interrupted 16m closer than the target distance, the relative speed will be +
When it is 8, the acceleration is +2 Km / h, and unnecessary deceleration can be avoided.

After the acceleration / deceleration rate is calculated in step 212 in this way, a correction coefficient for the acceleration / deceleration rate is calculated in step 214. This correction coefficient is calculated based on the map shown in FIG. 5B, and the correction value is obtained in correspondence with the current inter-vehicle distance. That is, since a rough inter-vehicle distance control is sufficient when the inter-vehicle distance is large, the acceleration / deceleration rate is set to be small so that the comfortable control is performed to improve the riding comfort. Then, in step 215, the basic acceleration / deceleration rate is multiplied by this correction coefficient to calculate the acceleration / deceleration rate.

When the object is detected in step 210, the acceleration / deceleration rate in the object detected state is calculated in step 213 using the map of FIG. In this map, the horizontal axis indicates the current inter-vehicle distance, and the acceleration / deceleration rate is obtained according to the state of the inter-vehicle distance. Since this requires time for the processing in the relative speed calculation unit 24 and the vehicle determination unit 25, even if the vehicle is not recognized as a vehicle, it is assumed that another vehicle cuts in a short distance ahead of the own vehicle. This is to take an emergency response quickly.

When the acceleration / deceleration rates corresponding to the recognized state of the vehicle, the detected state of the object, and the undetected state of the object are thus obtained, the target vehicle speed is calculated in step 216 of FIG. This target vehicle speed is obtained by integrating the obtained acceleration / deceleration rate with respect to the target vehicle speed in the previous control cycle. Here, dt represents the control cycle.

By obtaining the target vehicle speed in this way, it is possible to prevent a sudden or discontinuous target vehicle speed from being set. Acceleration / deceleration control with a smooth feeling similar to a normal steady running state. Is done.

In step 217, limit control is performed so that the target vehicle speed thus obtained does not deviate significantly from the current vehicle speed. This is a measure to prevent the vehicle speed control unit 28 from controlling the sudden acceleration or the sudden deceleration. In this embodiment, the target vehicle speed is set below the set vehicle speed set by the driver from the viewpoint of safety.

In the control method examining section 27, the control method is selected using the area map shown in FIG. In this area map, the horizontal axis represents the difference between the target vehicle speed obtained in step 218 and the current vehicle speed. In this example, the target vehicle speed was 4 km / h or more lower than the current vehicle speed. This means that the throttle is fully closed at times and the transmission overdrive (OD) is cut (a high reduction ratio is selected) when the speed is 6 Km / h smaller. Then, each return is performed when the speed is less than 1 Km / h and less than 3 Km / h, and the reason why the hysteresis is set in this way is to reduce discontinuity when the control method is changed.

In order to realize the control using such a region map, in steps 219 to 222, the difference between the target vehicle speed obtained in step 218 and the current vehicle speed is calculated by -4 and-, respectively.
6, -3 and -1, respectively, step 21
When it is determined in 9 that the speed difference is greater than -4 Km / h, the routine proceeds to step 223, where the throttle is fully closed. If it is determined in step 220 that the speed difference is greater than -6 Km / h, then in step 224, the OD is cut.

Then, in step 221, the differential speed is
When it is determined that the speed is smaller than 3 km / h, step 22
In step 5, the OD cut is released, and when it is determined in step 222 that the differential speed has become smaller than -1 Km / h, step 226 releases the throttle fully closed control.

By performing the processing of the control method examining unit 27 as described above, the present vehicle speed does not decrease even though the target vehicle speed decreases, for example, when traveling downhill or when the vehicle speed is low. It automatically detects and controls the transmission according to this detection condition, so that a higher reduction ratio is selected and a higher deceleration is obtained. Then, such control and step 227 which has been conventionally known are performed.
The vehicle speed control targeting the target speed obtained in step 216 is performed by the constant speed control of.

[0042]

As described above, according to the constant speed traveling device having the inter-vehicle distance adjusting function according to the first aspect of the present invention, the self-vehicle is considered from the relationship between the inter-vehicle distance and the set target inter-vehicle distance and the relative speed. The target vehicle speed of this time is calculated from the acceleration / deceleration rate of the vehicle and the target vehicle speed calculated last time, and the actual vehicle traveling speed is controlled to approach the target vehicle speed. Nevertheless, the vehicle speed control logic as in the conventional constant speed traveling device can be used, and the traveling feelings of the constant speed traveling control and the inter-vehicle distance control for keeping the vehicle distance constant can be made the same. Since the acceleration / deceleration rate of the own vehicle is calculated from the relationship between the inter-vehicle distance and the set target inter-vehicle distance and the relative speed, the actual vehicle speed is determined by the inter-vehicle distance from the preceding vehicle. The control corresponds to the driving situation of, and even if there is an unexpected interruption with the preceding vehicle, it is possible to prevent a sudden deceleration.

Further, according to the constant speed traveling device having the inter-vehicle distance adjusting function of the present invention, the acceleration / deceleration rate of the own vehicle is corrected so as to correspond to the inter-vehicle distance and decrease as the inter-vehicle distance increases. Therefore, loose control can be performed in a state where the inter-vehicle distance is large, and the riding comfort can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining a constant speed traveling device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a control logic of the above embodiment.

FIG. 3 is a flowchart for explaining a processing flow in the control logic.

FIG. 4 is a flowchart illustrating a flow of processing subsequent to the processing of FIG.

FIG. 5A is a diagram showing an acceleration / deceleration basic map and FIG. 5B is a diagram showing an acceleration / deceleration rate correction map.

FIG. 6 is a diagram showing an acceleration / deceleration rate map in an object detection state.

FIG. 7 is a diagram showing an area map for selecting a control method.

[Explanation of symbols]

11 ... Computer, 13 ... Vehicle speed sensor, 14 ... Vehicle distance sensor, 15 ... Setting unit, 16 ... Engine, 17 ... Throttle actuator, 18 ... Transmission, 19 ... Transmission controller, 21 ... Target inter-vehicle distance calculation unit, 22 ...
Acceleration / deceleration rate calculation unit, 23 ... Object determination unit, 24 ... Relative speed calculation unit, 25 ... Vehicle determination unit, 26 ... Target vehicle speed calculation unit, 27 ... Control method examination unit, 28 ... Vehicle speed control unit.

Claims (2)

[Claims] 1. An inter-vehicle distance measuring means for measuring distance data to an object traveling ahead, and a relative speed calculating means for calculating a relative speed based on a change in the inter-vehicle distance data measured by the measuring means, Vehicle recognition means for recognizing that the front object is a vehicle based on the change state of the relative speed obtained by the means, a difference between the inter-vehicle distance data and the set target vehicle distance in the vehicle recognition state, and Acceleration / deceleration rate calculation means for obtaining the acceleration / deceleration rate of the vehicle based on the relative speed, target vehicle speed calculation means for obtaining the current target vehicle speed based on the acceleration / deceleration rate and the previous target vehicle speed, and the target calculated by this target vehicle speed calculation means A vehicle speed control means for controlling the vehicle traveling speed to approach the target vehicle speed on the basis of the difference between the vehicle speed and the current vehicle speed; High-speed traveling device. 2. The inter-vehicle distance lifelong generator according to claim 1, further comprising a correction unit that corrects the acceleration / deceleration rate of the vehicle so as to decrease the acceleration / deceleration rate as the inter-vehicle distance increases as the inter-vehicle distance increases. A low speed traveling device equipped with functions.