JP2006264571A - Following stop control unit and method of controlling following stop - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve riding comfort by suppressing change of increase and decrease of deceleration to the utmost and not giving discomfort to a driver etc. when decelerating and stopping his or her own vehicle based on stop detection of preceding vehicle, and moreover not to generate unnecessary change of deceleration to the utmost. <P>SOLUTION: This control unit calculates repeatedly the distance from the preceding vehicle at an expected stop position based on the present deceleration of own vehicle 1 as the estimated stop distance between the two vehicles by a stop distance calculation means, determines repeatedly whether the estimated stop distance between the two vehicles is within tolerance from prescribed near limit stop distance between the two vehicles near the preceding vehicle to prescribed far limit stop distance between the two vehicles by a determination means. When it is determined to be within tolerance, the own vehicle 1 is decelerated while maintaining the own vehicle 1 at present deceleration speed. When it is determined out of tolerance, the own vehicle 1 is decelerated by the new deceleration speed by calculating new deceleration speed by which estimated stop distance between two vehicles falls in the tolerance, and controls the own vehicle 1 to stop following by suppressing change of increase and decrease of deceleration to the utmost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a follow-up stop control device and a follow-up stop control method for decelerating and stopping a host vehicle following a stop of traveling of a preceding vehicle.

  Conventionally, in a vehicle (own vehicle) equipped with a follow-up running system having a stop control function, the stop control is regarded as an extension of the follow-up run control, and even if the preceding vehicle decelerates to a stop, the target inter-vehicle distance and the preceding vehicle The stop control of the host vehicle is also performed by a follow-up control algorithm in which the target vehicle distance is ensured by feedback control of the acceleration / deceleration of the host vehicle based on the relative speed and the host vehicle follows the preceding vehicle.

  Specifically, based on the detection of the stop of the preceding vehicle, the normal follow-up running control is shifted to the follow-up stop control to operate the own vehicle follow-up stop control device. In the same way as in the case of, the vehicle repeatedly calculates the deceleration to stop the vehicle at the position before the target stop inter-vehicle distance set from the stop position of the preceding vehicle (the inter-vehicle distance when the preceding vehicle is stopped). The car decelerates and stops at the latest deceleration.

  In this case, the inter-vehicle distance between the preceding vehicle and the following vehicle (own vehicle) and the vehicle speed of both vehicles change as shown in FIG. 4, for example. In FIG. 4, A1 and A2 are time-dependent characteristic lines of the target inter-vehicle distance and the actual inter-vehicle distance, B1 and B2 are time-dependent characteristic lines of the preceding vehicle and the own vehicle, and ts is the stop timing of the preceding vehicle. , Te is the stop timing of the vehicle by deceleration control from ts.

  And about the deceleration of the own vehicle of ts-te, in order not to deteriorate the riding comfort during deceleration, for example, the deceleration is calculated every moment from the inter-vehicle distance when the preceding vehicle is stopped and the own vehicle movement amount. (For example, refer to Patent Document 1).

“Deceleration” is a deceleration amount (negative acceleration) per unit time, and is a unit (dimension) of −2 to the time of [km / h ² ], [m / s ² ], and the like.

Japanese Patent No. 3596493 ([Claim 1], paragraphs [0007] and [0013], FIG. 1)

  Based on the predetermined target stop inter-vehicle distance that is uniformly determined as in the prior art, it calculates the deceleration of the host vehicle from time to time, and tries to decelerate and stop the vehicle exactly at the target stop inter-vehicle distance position by the deceleration. As a result, the deceleration gradually increases or decreases based on the response characteristics of the control, etc., so the deceleration actually increases or decreases in small increments, and the vehicle behavior at the time of stopping changes to the driver's own driving behavior (braking stop) This is far from the vehicle behavior of braking stop by operation), which gives the driver a sense of incongruity and causes a very bad ride comfort. Moreover, it is not possible to stop at the target stop position accurately (just) (actually, it stops considerably before the preceding vehicle, as is apparent from FIG. 3), and wasteful change in deceleration (variable) There is also a problem of frequent control.

  The present invention suppresses the increase / decrease change of the deceleration as much as possible when decelerating and stopping the own vehicle based on the detection of the stop of the preceding vehicle, and improves the ride comfort so as not to give the driver a sense of incongruity. The purpose is to prevent unnecessary changes in speed as much as possible.

  In order to achieve the above object, the follow-up stop control device of the present invention includes stop distance calculation means for repeatedly calculating the distance from the preceding vehicle at the predicted stop position based on the current deceleration of the host vehicle as the expected stop inter-vehicle distance. Determining means for repeatedly determining whether or not the predicted stop-to-vehicle distance is within an allowable range from a predetermined near limit stop inter-vehicle distance close to the preceding vehicle to a predetermined far limit stop inter-vehicle distance; and the allowable range of the determination means The vehicle is decelerated while maintaining the current deceleration at the current deceleration, and a new deceleration within which the predicted stop distance is within the allowable range is calculated by the determination means outside the allowable range. A deceleration control means for decelerating the own vehicle at the new deceleration is provided (claim 1).

  Further, in the follow-up stop control device of the present invention, when the deceleration control means determines that the expected stop inter-vehicle distance is outside the allowable range where the expected stop inter-vehicle distance is shorter than the near limit stop inter-vehicle distance, the predicted stop inter-vehicle distance is The deceleration that becomes the distance is calculated as a new deceleration, and when the predicted stop distance is longer than the far limit stop distance, it is determined that the expected stop distance becomes the far limit stop distance. The speed is calculated as a new deceleration (claim 2).

  Next, in the follow-up stop control method of the present invention, the distance from the preceding vehicle at the predicted stop position based on the current deceleration of the host vehicle is repeatedly calculated as the predicted stop-to-vehicle distance, and the predicted stop-to-vehicle distance is calculated from the preceding vehicle. It is repeatedly determined whether or not the vehicle is within an allowable range from a predetermined near limit stop inter-vehicle distance close to a predetermined far limit stop inter-vehicle distance, and the vehicle is decelerated while maintaining the current deceleration by the determination within the allowable range. The vehicle is decelerated at the new deceleration by calculating a new deceleration in which the predicted inter-vehicle distance falls within the allowable range based on the determination outside the allowable range (Claim 3). .

  According to the first and third aspects of the present invention, when the stop of the preceding vehicle is detected, the own vehicle is set so that the target stop inter-vehicle distance is uniformly set and the stop control is performed at the position of the stop inter-vehicle distance as in the prior art. Instead of decelerating the vehicle, set the near limit stop distance and the far limit stop distance in order from the preceding vehicle, and set the distance between both limit stop distances as the allowable range of the deceleration stop position of the vehicle, and stop within this allowable range. Since the host vehicle is decelerated to control, the target stop position of the host vehicle can be given a margin, the increase / decrease change of the deceleration of the host vehicle is reduced and suppressed as much as possible, so that the driver does not feel uncomfortable As a result, it is possible to improve the ride comfort, and to prevent unnecessary changes in the deceleration as much as possible, and to significantly improve the follow-up stop control characteristic.

  Further, according to the configuration of claim 2, when it is predicted that the host vehicle will stop at a position outside the allowable range at the current deceleration, the predicted stop distance between the vehicles becomes shorter than the near limit stop distance between the vehicles, When the predicted stop position of the host vehicle is closer to the preceding vehicle than the near limit stop inter-vehicle distance, control is made so that the own vehicle stops at the position of the near limit stop inter-vehicle distance, and the expected stop inter-vehicle distance is the far limit stop. If the vehicle's expected stop position is longer than the inter-vehicle distance and the vehicle's expected stop position is further away from the preceding vehicle than the far-limit stop inter-vehicle distance position, control is performed so that the own vehicle stops at the far-end stop inter-vehicle distance position. Therefore, the change in the deceleration of the own vehicle is further reduced, the riding comfort is further improved, and a useless change in the deceleration can be further suppressed, and the follow-up stop control characteristic can be further improved.

  Next, in order to describe the present invention in more detail, an embodiment thereof will be described in detail with reference to FIGS.

  FIG. 1 is a block diagram of a follow-up stop control device for a host vehicle 1 that travels following a preceding vehicle (not shown), FIG. 2 is a flowchart for explaining the operation of FIG. 1, and FIG. Is equipped with a follow-up running system with stop control function.

  In FIG. 1, reference numeral 2 denotes a well-known distance measuring sensor composed of a laser radar, a millimeter wave radar or the like, which detects an inter-vehicle distance between the preceding vehicle and the host vehicle 1 every time, and based on the inter-vehicle distance and its time change. Outputs the relative speed of the preceding vehicle to be obtained every moment.

  A vehicle speed sensor 3 is a wheel speed sensor that detects and outputs the vehicle speed of the host vehicle 1 every moment. Reference numeral 4 denotes an operation switch unit composed of various operation switches of the own vehicle 1, and 5 denotes a sensor unit composed of various sensors for monitoring the state of the own vehicle 1 excluding the distance measuring sensor 2 and the vehicle speed sensor 3.

  Reference numeral 6 denotes an inter-vehicle distance control unit of a follow-up traveling system formed by an ECU having a microcomputer configuration. The inter-vehicle distance and relative speed of the distance measuring sensor 2 from time to time, the own vehicle speed of the vehicle speed sensor 3 and the operation switch unit 4, Following on / off signals and detection signals of the sensor unit 5 are fetched, a follow-up running control program including follow-up stop control is executed, and follow-up running control including stop distance calculation means, discrimination means, and deceleration control means described below The various means are formed.

(1) Stop distance calculation means This means repeatedly calculates the distance from the preceding vehicle at the expected stop position based on the current deceleration of the host vehicle 1 as the expected stop inter-vehicle distance after detecting the stop of the preceding vehicle.

  Specifically, when the preceding vehicle is stopped, the vehicle speed Vp of the preceding vehicle is detected every moment based on the relative speed obtained from the distance measuring sensor 2 and the vehicle speed of the vehicle speed sensor 3, and the vehicle speed Vp of the preceding vehicle is set. Since the preceding vehicle stop determination vehicle speed is less than the vehicle speed Vp_stop, it is determined to be stopped and detected.

  When the stop of the preceding vehicle is detected, the estimated stop inter-vehicle distance Dstop_est of the own vehicle 1 when the position at which the own vehicle 1 decelerates and stops at the current deceleration (predicted stop position) is obtained as the distance from the preceding vehicle. [K] is calculated from the calculation of the following equation (a).

Dstop_est [k] = D [k] −Vs [k] ² / (2 × Aref [k−1]) (a)

  In the equation (a), k is a time variable which is also the number of program repetitions, and changes to..., K-1 (previous), k (current), k + 1 (next),.

  Aref [k−1] is the latest deceleration set in the current command of the vehicle 1 (in other words, the previous deceleration (k−1)), and D [k] is obtained from the distance measuring sensor 2. The current measured inter-vehicle distance, Vs [k], is the current host vehicle speed obtained from the vehicle speed sensor 3.

(2) Discriminating means From this predetermined near limit stop inter-vehicle distance defDstopNear, where the expected stop inter-vehicle distance Dstop_est [k] calculated by the calculation of the equation (a) is close to the preceding vehicle, this near limit stop inter-vehicle distance defDstopNear It is repeatedly determined whether or not the vehicle is within an allowable range up to a predetermined far limit stop inter-vehicle distance defDstopFar.

  Here, the near limit stop inter-vehicle distance defDstopNear and the far limit stop inter-vehicle distance defDstopFar are set by an experiment or the like under conditions where the host vehicle 1 is safely stopped, and is an appropriate distance shorter and longer than the conventional target stop inter-vehicle distance. Alternatively, the near limit stop inter-vehicle distance defDstopNear may be set to the conventional target stop inter-vehicle distance, and the far limit stop inter-vehicle distance defDstopFar may be set to a distance further than that.

(3) Deceleration control means This means decelerates the vehicle while maintaining the current deceleration at the current deceleration by the determination within the allowable range of the determination means, and the expected stop of equation (a) by the determination outside the allowable range of the determination means A new deceleration in which the inter-vehicle distance Dstop_est [k] falls within the allowable range is calculated, and the host vehicle 1 is decelerated at the new deceleration.

  Specifically, when it is determined that defDstopNear ≦ Dstop_est [k] ≦ defDstopFar when decelerating at the current deceleration rate Aref [k−1], the current deceleration rate Aref [k] is changed to the current deceleration rate Aref [k]. -1] (previous deceleration Aref [k-1]), the deceleration Aref [k-1] is given to the brake control unit 7 of FIG. 1 as the current command deceleration Aref [k].

  On the other hand, when it is determined that Dstop_est [k]> defDstopFar or Dstop_est [k] <defDstopNear when the deceleration at the current deceleration rate Aref [k−1] is satisfied, for example, to satisfy defDstopNear ≦ Dstop_est [k] ≦ defDstopFar, for example, The reference stop inter-vehicle distance defDstopStand (defDstopNear <defDstopStand <defDstopFar) is set within the allowable range, and a new deceleration is calculated from the formula (a) so that the predicted stop inter-vehicle distance Dstop_est [k] becomes the reference stop inter-vehicle distance defDstopStand. The new deceleration is set as the current deceleration Aref [k], and the brake control unit 7 sends the calculated new deceleration A as the current command deceleration. ef [k] may be given, but in this embodiment, in order to further reduce the change of the deceleration is set current deceleration Aref [k] a as described below.

  That is, when decelerating at the current deceleration rate Aref [k−1], the predicted stop inter-vehicle distance Dstop_est [k] is the smallest when it is determined that the near-limit stop inter-vehicle distance defDstopNear is shorter (Dstop_est [k] <defDstopNear). As a new deceleration in which the predicted stop inter-vehicle distance Dstop_est [k] falls within the allowable range due to a change (change) in the deceleration, a deceleration where the predicted stop inter-vehicle distance Dstop_est [k] becomes the near limit stop inter-vehicle distance defDstopNear (a ) And the new deceleration is set to the current deceleration Aref [k] and given to the brake control unit 7.

  In addition, when the vehicle is decelerated at the current deceleration Aref [k−1], the predicted stop inter-vehicle distance Dstop_est [k] is the smallest when it is determined that the far-limit stop inter-vehicle distance defDstopFar becomes longer (Dstop_est [k]> defDstopFar). As a new deceleration in which the expected stop inter-vehicle distance Dstop_est [k] falls within the allowable range due to a change (change) in the deceleration, a deceleration at which the expected stop inter-vehicle distance Dstop_est [k] becomes the far limit stop inter-vehicle distance defDstopFar (a ) And the new deceleration is set to the current deceleration Aref [k] and given to the brake control unit 7.

  Next, reference numeral 8 in FIG. 1 denotes a throttle control unit. For example, by following tracking control of the inter-vehicle distance control unit 6 during traveling of the preceding vehicle, the vehicle is adjusted based on the set target inter-vehicle distance and the relative speed of the preceding vehicle. A command acceleration is given according to the speed feedback control, and the throttle actuator 9 is controlled (engine) to adjust the throttle opening so that the vehicle 1 becomes the command acceleration. A brake actuator 10 adjusts the brake cylinder pressure and the like according to the control of the brake control unit 7 so that the host vehicle 1 decelerates with the command deceleration of the inter-vehicle distance control unit 6.

  By the follow-up stop control in steps S1 to S7 in FIG. 2 based on the above configuration, the vehicle 1 travels and stops as described below.

  First, in step S1, the process proceeds from step S1 to step S2 until the preceding vehicle stoppage detection vehicle speed Vp_stop is less than the set preceding vehicle stop determination vehicle speed Vp_stop (ie, following step S2). In step S2, the command deceleration and command acceleration are selectively given to the control units 7 and 8 according to the acceleration / deceleration feedback control of the inter-vehicle distance control unit 6 in this step S2. Accordingly, the host vehicle 1 is subjected to acceleration / deceleration control so as to ensure the target inter-vehicle distance and travel following the preceding vehicle.

  Next, when the stop of the preceding vehicle is detected in step S1, the process proceeds from step S1 to step S3 (that is, the follow-up running control in step S2 is terminated and the follow-up stop control is started), and the inter-vehicle distance control unit 6 The stop distance calculation means calculates an expected stop inter-vehicle distance Dstop_est [k] at which the host vehicle 1 decelerates and stops at the current deceleration rate from the calculation of the equation (a).

  Further, the process proceeds to step S4, and the determination unit of the inter-vehicle distance control unit 6 determines whether or not the expected stop inter-vehicle distance Dstop_est [k] is within an allowable range of defDstopNear ≦ Dstop_est [k] ≦ defDstopFar.

  When it is within the allowable range, the process proceeds from step S4 to step S5, and the deceleration Aref [k] of this time is changed to the previous deceleration Aref [k-1] by the deceleration control means of the inter-vehicle distance control unit 6. The same deceleration Aref [k-1] as the previous command is given to the brake control unit 7 as the current command deceleration Aref [k], and the vehicle 1 continues to decelerate at the same deceleration.

  On the other hand, when it falls outside the allowable range, the process proceeds from step S4 to step S6.

  Then, if Dstop_est [k] <defDstopNear, the deceleration control means calculates the deceleration at which the predicted stop inter-vehicle distance Dstop_est [k] becomes the near limit stop inter-vehicle distance defDstopNear from the equation (a), and the new deceleration Is set to the current deceleration Aref [k] and given to the brake control unit 7. If Dstop_est [k]> defDstopFar, the deceleration at which the expected stop inter-vehicle distance Dstop_est [k] becomes the far limit stop inter-vehicle distance defDstopFar is set. The new deceleration is calculated from the equation (a), and the new deceleration is set to the current deceleration Aref [k] and applied to the brake control unit 7 to suppress the increase / decrease change in the deceleration as much as possible, and the expected stop inter-vehicle distance Dstop_est [k ] Is decelerated so that the distance is within the allowable range.

  Until the host vehicle 1 stops, the process returns from steps S5 and S6 to step S3 via step S7. The process is repeated from step S3 until the host vehicle 1 stops, and the stop of the host vehicle 1 is detected from the host vehicle speed. Then, the follow-up stop control is ended and the own vehicle 1 is maintained in a stopped state.

  Therefore, in the follow-up stop control based on the stop detection of the preceding vehicle TG, the expected stop inter-vehicle distance Dstop_est [k] is within the allowable range set by the near limit stop inter-vehicle distance defDstopNear and the far limit stop inter-vehicle distance defDstopFar shown in FIG. The own vehicle 1 can be decelerated and stopped so that the target stop position of the own vehicle 1 can be given a margin, so that the increase / decrease change of the deceleration of the own vehicle 1 is greater than that of the conventional control. Stop control that is suppressed as much as possible and close to the driving behavior of the driver, that is, when stop of the preceding vehicle is confirmed, the stop position (inter-vehicle distance) is determined, and close to the stop control that decelerates at a constant deceleration toward that position It can be stopped by stop control.

  Therefore, it is possible to improve the ride comfort without giving the driver a sense of incongruity, and to avoid unnecessary changes in deceleration as much as possible, and to significantly improve the follow-up stop control characteristics. it can.

  Further, in this embodiment, when the predicted stop position of the host vehicle 1 is closer to the preceding vehicle than the near limit stop inter-vehicle distance defDstopNear, the deceleration at which the host vehicle 1 stops at the position of the near limit stop inter-vehicle distance defDstopNear. When the vehicle 1 is further away from the preceding vehicle than the position at the far limit stop inter-vehicle distance defDstopFar, the own vehicle 1 is controlled to the deceleration that stops at the far limit stop inter-vehicle distance defDstopFar. The change in the deceleration of the vehicle 1 is further reduced as compared with the case where the vehicle stops at the position of the reference stop inter-vehicle distance defDstopStand, and the riding comfort is further improved, and the unnecessary change in the deceleration is further suppressed. Therefore, the follow-up stop control characteristic can be further improved.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit thereof. For example, instead of the distance measuring sensor 2, Alternatively, the present invention is similarly applied to a case where an imaging unit such as a CCD monocular camera is mounted together with the distance measuring sensor 2 and a preceding vehicle is recognized by image processing of a captured image in front of the own vehicle of the imaging unit. be able to.

  Of course, the configuration, processing procedure, and the like of the inter-vehicle distance control unit 6 may be different from those of the embodiment.

  By the way, in order to reduce the number of equipment parts of the vehicle 1, for example, the present invention can be applied to the case where the sensors 2, 3, etc. are also used as other control sensors.

It is a block diagram of one embodiment of this invention. It is a flowchart for operation | movement description of FIG. It is operation | movement explanatory drawing of the follow-up stop control of FIG. It is explanatory drawing of a prior art example.

Explanation of symbols

1 Vehicle 6 Inter-vehicle distance controller

Claims (3)

In the follow-up stop control device that decelerates and stops the own vehicle following the preceding vehicle based on the stop detection of the preceding vehicle,
Stop distance calculating means for repeatedly calculating a distance from the preceding vehicle of the predicted stop position based on the current deceleration of the host vehicle as an expected stop inter-vehicle distance;
A discriminating means for repeatedly discriminating whether or not the predicted stop inter-vehicle distance is within an allowable range from a predetermined near limit stop inter-vehicle distance close to the preceding vehicle to a predetermined far limit stop inter-vehicle distance;
The vehicle is decelerated while maintaining the current deceleration at the current deceleration by the discrimination within the permissible range of the discrimination means, and the predicted stop inter-vehicle distance is newly entered within the permissible range by the discrimination outside the permissible range of the discrimination means. And a deceleration control means for decelerating the vehicle at the new deceleration by calculating an appropriate deceleration. In the follow-up stop control device according to claim 1,
The deceleration control means calculates, as a new deceleration, a deceleration at which the predicted stop inter-vehicle distance becomes the near limit stop inter-vehicle distance when it is determined that the expected stop inter-vehicle distance is shorter than the near limit stop inter-vehicle distance. When determining that the predicted stop inter-vehicle distance is longer than the far limit stop inter-vehicle distance outside the allowable range, the deceleration at which the predicted stop inter-vehicle distance becomes the far limit stop inter-vehicle distance is calculated as a new deceleration. Tracking stop control device. Based on the stop detection of the preceding vehicle, in the follow-up stop control method of following the preceding vehicle and decelerating and stopping the own vehicle,
Repeatedly calculating the distance from the preceding vehicle at the expected stop position based on the current deceleration of the vehicle as the expected stop-to-vehicle distance,
Repeatedly determining whether or not the predicted stop vehicle distance is within an allowable range from a predetermined near limit stop vehicle distance close to the preceding vehicle to a predetermined far limit stop vehicle distance,
The vehicle is decelerated by maintaining the current deceleration at the current deceleration by the determination within the allowable range, and a new deceleration within which the predicted stop distance is within the allowable range is calculated by the determination outside the allowable range. A follow-up stop control method, wherein the vehicle is decelerated at the new deceleration.

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