JP2007062403A - Following travel device of automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve comfortableness and sense of security of an occupant by suppressing bucking drive of one's own vehicle, in a following travel device of an automobile. <P>SOLUTION: The following travel device 1 comprises vehicle speed control means 17 and 18 for controlling the vehicle speed (v) of one's own vehicle W so that the inter-vehicle distance L1 between an immediately leading vehicle Wf and one's own vehicle W detected by an inter-vehicle distance detecting means 11 is kept at a target inter-vehicle distance Lt. The following travel device 1 comprises a control unit 10 for slowing down the control selectivity of the vehicle speed control means 17 and 18 when the inter-vehicle distance L2 between a vehicle Wff preceding the immediately leading vehicle and the immediately leading vehicle Wf becomes shorter than a predetermined distance inter-vehicle distance Lm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a follow-up traveling device for an automobile that causes the subject vehicle to follow the preceding vehicle while maintaining the target inter-vehicle distance between the subject vehicle and the preceding vehicle.

Conventionally, an in-vehicle camera recognizes a vehicle ahead of the host vehicle, a radar detects a distance between the host vehicle and the preceding vehicle, and an actual inter-vehicle distance between the host vehicle and the preceding vehicle is maintained at a predetermined target inter-vehicle distance. As described above, there is known an automobile follow-up traveling apparatus that causes the own vehicle to follow the preceding vehicle. In recent years, various techniques for improving and improving the ride comfort and security of passengers have been proposed for such a follow-up traveling device. For example, in Patent Document 1, in addition to the vehicle in front of the host vehicle, the vehicle in front of the host vehicle is also recognized, and the deceleration of the vehicle in front of the vehicle detected during follow-up and the relationship between the vehicle in front and the vehicle in front of the vehicle. When it is determined that the possibility of collision between the preceding vehicle and the preceding vehicle has increased from the inter-vehicle time, etc., it is determined that the possibility of collision between the own vehicle and the preceding vehicle has also increased. For example, a technique for advancing the operation timing of a seat belt device or a brake device or increasing the operation amount is disclosed.
JP 2005-31967 A

  By the way, generally, as described above, during follow-up traveling, control is performed to maintain the inter-vehicle distance between the host vehicle and the preceding vehicle at the target inter-vehicle distance. For example, the preceding vehicle travels closer to the preceding vehicle. When the front vehicle repeats sudden braking and acceleration, the host vehicle frequently performs sudden braking and acceleration, which causes a problem that passenger comfort and a sense of security are impaired. However, there is no proposal for a technique for dealing with this problem at present.

  Therefore, the present invention has the above-described problem that, in the follow-up traveling device of an automobile, the host vehicle also performs a jerky operation in conjunction with the jerky operation of the preceding vehicle as a result of maintaining the inter-vehicle distance with the preceding vehicle as the target vehicle. The problem is to deal with it and improve the ride comfort and security of passengers.

  That is, in order to solve the above-mentioned problem, the invention according to claim 1 of the present application is directed to a front vehicle recognition means for recognizing a front vehicle of the host vehicle and a target inter-vehicle distance for setting a target inter-vehicle distance between the host vehicle and the front vehicle. Setting means; inter-vehicle distance detection means for detecting the inter-vehicle distance between the preceding vehicle recognized by the forward vehicle recognition means and the host vehicle; and the inter-vehicle distance detected by the inter-vehicle distance detection means is the target inter-vehicle distance setting means. A vehicle follow-up travel device comprising vehicle speed control means for controlling the vehicle speed of the host vehicle so as to be maintained at a set target inter-vehicle distance, and forefront vehicle recognition means for recognizing a vehicle ahead of the host vehicle And a second inter-vehicle distance detecting means for detecting an inter-vehicle distance between the forward vehicle recognized by the forward vehicle recognition means and the forward vehicle recognized by the forward vehicle recognition means, and the second inter-vehicle distance Vehicle detected by distance detection means Distance is characterized in that the control sensitivity slowing means for slowing the control sensitivity of the vehicle speed control means is provided than when not in short when it becomes shorter than a predetermined inter-vehicle distance.

  Next, according to a second aspect of the present invention, in the following traveling apparatus for an automobile according to the first aspect, the target inter-vehicle distance setting means has a predetermined inter-vehicle distance detected by the second inter-vehicle distance detection means. When the vehicle distance is shorter than the target vehicle distance, the target vehicle distance is extended by a predetermined distance than when it is not shorter.

  Next, according to a third aspect of the present invention, in the following traveling apparatus for an automobile according to the second aspect, the target inter-vehicle distance setting means has a predetermined inter-vehicle distance detected by the second inter-vehicle distance detection means. After the vehicle-to-vehicle distance becomes shorter, the target vehicle-to-vehicle distance is gradually extended as the vehicle-to-vehicle distance becomes shorter.

  Next, the invention according to claim 4 is the following traveling apparatus for an automobile according to claim 2 or 3, wherein the target inter-vehicle distance setting means is the inter-vehicle distance detected by the second inter-vehicle distance detection means. Is shorter than the second predetermined inter-vehicle distance shorter than the predetermined inter-vehicle distance, the target inter-vehicle distance is further extended by the second predetermined distance.

  Next, the invention according to claim 5 is the vehicle following traveling device according to any one of claims 1 to 4, wherein the control sensitivity dulling means includes an inter-vehicle distance detected by the inter-vehicle distance detecting means. The control sensitivity of the vehicle speed control means is reduced by reducing the vehicle speed control amount of the host vehicle with respect to the deviation from the target inter-vehicle distance set by the target inter-vehicle distance setting means.

  Next, the invention according to claim 6 is the vehicle following traveling apparatus according to any one of claims 1 to 5, wherein the control sensitivity dulling means includes an inter-vehicle distance detected by the inter-vehicle distance detecting means. The control sensitivity of the vehicle speed control means is slowed by delaying the start of the vehicle speed control of the host vehicle with respect to the deviation from the target inter-vehicle distance set by the target inter-vehicle distance setting means.

  Next, according to a seventh aspect of the present invention, in the vehicle follow-up traveling device according to any one of the first to sixth aspects, the control sensitivity dulling means includes an inter-vehicle distance detected by the inter-vehicle distance detecting means. The control sensitivity of the vehicle speed control means is reduced by reducing a deviation from the target inter-vehicle distance set by the target inter-vehicle distance setting means.

  According to an eighth aspect of the present invention, in the vehicle follow-up traveling device according to any one of the first to seventh aspects, the control sensitivity dulling means has an inter-vehicle distance detected by the inter-vehicle distance detecting means. The control sensitivity of the vehicle speed control means is reduced only when it is larger than the target inter-vehicle distance set by the target inter-vehicle distance setting means.

  First, according to the first aspect of the present invention, for example, the front vehicle travels closer to the front vehicle, and as a result, the inter-vehicle distance between the front vehicle and the front vehicle is shorter than a predetermined inter-vehicle distance. Therefore, in a situation where the front vehicle is likely to drive jerkyly, the sensitivity of the vehicle speed control of the host vehicle that tries to maintain the inter-vehicle distance between the host vehicle and the preceding vehicle at the target inter-vehicle distance is reduced. Even if the vehicle performs jerky driving that repeats sudden braking and acceleration, the vehicle frequently suppresses sudden braking and acceleration, thereby improving the ride comfort and security of the occupant.

  In this case, according to the invention described in claim 2, since the sensitivity of the vehicle speed control of the host vehicle is slowed and the target inter-vehicle distance is extended by a predetermined distance, the inter-vehicle distance between the host vehicle and the preceding vehicle is increased. Even if the vehicle speed control sensitivity of the host vehicle slows down, the passenger's sense of security is ensured.

  In this case, according to the third aspect of the invention, the target inter-vehicle distance is not increased at a stretch by a predetermined distance, but the target inter-vehicle distance is reduced as the inter-vehicle distance between the preceding vehicle and the preceding vehicle decreases. Since the vehicle is gradually extended, the host vehicle is gradually separated from the preceding vehicle, and smooth follow-up running control is realized. From this point as well, the ride comfort of the occupant is improved.

  Further, according to the invention described in claim 4, the inter-vehicle distance between the preceding vehicle and the preceding vehicle becomes shorter than the second predetermined inter-vehicle distance that is shorter than the predetermined inter-vehicle distance, and the front vehicle is jerky. In a situation where driving is more likely, or in a situation where contact between the preceding vehicle and the preceding vehicle is likely to occur, the target inter-vehicle distance is further extended by the second predetermined distance. The distance between the vehicle and the vehicle can be further increased, and even if the sensitivity of the vehicle speed control of the host vehicle decreases, the passenger's sense of security is secured. The possibility of contact with the vehicle ahead can be reduced, and safety is ensured.

  Next, according to the fifth aspect of the present invention, there is shown a specific mode for slowing down the vehicle speed control sensitivity of the host vehicle. According to this, the inter-vehicle distance between the host vehicle and the preceding vehicle, the host vehicle and the front By reducing the vehicle speed control amount of the host vehicle with respect to the deviation from the target inter-vehicle distance from the vehicle, the vehicle speed control sensitivity of the host vehicle can be surely slowed down.

  Similarly, according to the invention described in claim 6, another specific mode for slowing down the vehicle speed control sensitivity of the host vehicle is shown. According to this, the inter-vehicle distance between the host vehicle and the preceding vehicle, the host vehicle, By delaying the start of the vehicle speed control of the host vehicle with respect to the deviation from the target inter-vehicle distance from the preceding vehicle, the vehicle speed control sensitivity of the host vehicle can be surely slowed down.

  Similarly, according to the seventh aspect of the present invention, there is shown another specific aspect for slowing down the vehicle speed control sensitivity of the host vehicle. According to this, the inter-vehicle distance between the host vehicle and the preceding vehicle, the host vehicle, By reducing the deviation between the target vehicle distance and the vehicle ahead, the vehicle speed control sensitivity of the host vehicle can be reliably reduced.

  According to the invention described in claim 8, the slowing down of the vehicle speed control sensitivity of the host vehicle is caused when the inter-vehicle distance between the host vehicle and the preceding vehicle is larger than the target inter-vehicle distance between the host vehicle and the preceding vehicle, that is, Since it is performed only when the host vehicle is farther than the target from the front vehicle, conversely, if the inter-vehicle distance between the host vehicle and the front vehicle is smaller than the target inter-vehicle distance between the host vehicle and the front vehicle, In other words, if the host vehicle is approaching the front vehicle beyond the target, the vehicle speed control sensitivity of the host vehicle is not slowed down. Even if there is a sudden stop, it is possible to respond to this without delay, and the possibility that the host vehicle contacts the preceding vehicle can be reduced, thus ensuring safety. Hereinafter, the present invention will be described in more detail through embodiments of the invention.

  FIG. 1 is a layout diagram of each component of an automobile follow-up traveling device 1 according to the present embodiment. This follow-up travel device 1 images a radar 11 for detecting the distance between the host vehicle W and the preceding vehicle Wf and the distance between the host vehicle W and the preceding vehicle Wff, and the front space of the host vehicle W. And a camera 12 for recognizing the forward vehicle Wf and the preceding vehicle Wff.

  Further, the follow-up traveling device 1 receives signals transmitted from other vehicles existing around the host vehicle W by inter-vehicle communication, or conversely, other vehicles existing around the host vehicle W. A vehicle-to-vehicle communication antenna 13 for transmitting a signal to the vehicle, a road-to-vehicle communication antenna 14 for exchanging signals with an antenna (not shown) provided on the side of the road by road-to-vehicle communication, A smart plate signal receiving antenna 15 for receiving a signal transmitted from an ID tag (such a number plate is referred to as a smart plate) built in a license plate of a forward vehicle Wf existing in front of the vehicle W; Contains.

  The following traveling device 1 includes a throttle actuator 17, a brake actuator 18, and a steering actuator 19 in addition to the steering angle sensor 16 for detecting the steering angle.

  FIG. 2 is a control system diagram centering on the control unit 10 of the following traveling device 1. The control unit 10 includes a signal from the radar 11, a signal from the camera 12, a signal from the vehicle-to-vehicle communication antenna 13, a signal from the road-to-vehicle communication antenna 14, and a smart plate signal receiving antenna 15. A signal and a signal from the steering angle sensor 16 are input, and control signals are output to the throttle actuator 17, the brake actuator 18, and the steering actuator 19 based on these signals. Further, the control unit 10 transmits information related to the own vehicle to the surroundings via the vehicle-to-vehicle communication antenna 13 and the road-to-vehicle communication antenna 14.

  In the present embodiment, as shown in FIG. 3, the inter-vehicle distance (first inter-vehicle distance) L1 between the host vehicle W and the front vehicle Wf, and the inter-vehicle distance (second inter-vehicle distance) between the front vehicle Wf and the preceding vehicle Wff. ) L2 is important. The first inter-vehicle distance L1 can be detected by the radar 11 as described above. The second inter-vehicle distance L2 can be detected by subtracting the first inter-vehicle distance L1 and the total length Lf of the preceding vehicle Wf from the inter-vehicle distance between the host vehicle W and the preceding vehicle Wff (operation of the control unit 10). . Here, when the millimeter wave radar is used as the radar 11, the distance between the host vehicle W and the preceding vehicle Wff can be detected by the radar 11 as described above. This is because, as shown in the figure, the millimeter wave is reflected by the road surface below the floor of the preceding vehicle Wf, reaches the vehicle Wff ahead of time, and bounces back.

  Here, when the front vehicle Wf is a large vehicle, it is difficult to cause a jerky behavior, so the total length Lf of the front vehicle Wf may be calculated as a uniform 5 m or the like. Information regarding the total length Lf of the vehicle Wf may be acquired. Or the information regarding the 2nd inter-vehicle distance L2 can also be acquired directly from the front vehicle Wf by inter-vehicle communication. In that case, a radar other than the millimeter wave radar, for example, various radars using light, radio waves, ultrasonic waves, or the like can be used as the radar 11.

  Further, as shown in FIG. 4, it is also possible to detect the total length Lf of the front vehicle Wf while traveling on a curve. That is, when it is detected by the rudder angle sensor 16 that the host vehicle W is traveling on a curve (the figure shows that the vehicle is traveling on the left curve from the direction of the front wheels 20, 20), the radar 11 is operated. The distance D2 between the front end F on the inner ring side of the front vehicle Wf and the host vehicle W, the distance D1 between the rear end R on the inner ring side of the front vehicle Wf and the host vehicle W, and the front end on the inner ring side of the front vehicle Wf. An angle Θ sandwiched between a straight line connecting F and the host vehicle W and a straight line connecting the rear end R on the inner ring side of the forward vehicle Wf and the host vehicle W is detected. A perpendicular line is drawn from the point R to the line D2, and the intersection is set to P. Then, the total length Lf of the front vehicle Wf is expressed by the following equation (1), and FP and PR are expressed by the following equations (2) and (3). Therefore, the total length Lf of the front vehicle Wf is expressed by the following equation (4). In other words, the total length Lf of the forward vehicle Wf can be detected based on the distances D1, D2 and the angle Θ (operation of the control unit 10). In accordance with this, it is also possible to detect the second inter-vehicle distance L2 between the preceding vehicle Wf and the preceding vehicle Wff while traveling along a curve.

  It is also possible to detect the total length Lf of the forward vehicle Wf from the content displayed on the license plate of the forward vehicle Wf. That is, the camera 12 is used to image a license plate (not shown) of the forward vehicle Wf. For example, if the number is “1x”, it can be determined that the vehicle is a large vehicle (large cargo, truck). If the total length Lf of the vehicle Wf is set to 12 m, for example, and the number is “3x”, it can be determined that the vehicle is a normal vehicle. Therefore, the total length Lf of the preceding vehicle Wf is set to 5 m, for example, and the number is “5x”. Then, since it can be determined that the vehicle is a small car, the total length Lf of the front vehicle Wf is set to 4.5 m, for example. In accordance with this, the numbers are “2x” (large bus), “4x” (small cargo), “6x” (small cargo), “7x” (small ordinary car, bus), “8x” (camper, etc.) In the case of “use vehicle”, “9x” (large special), and “0x” (large special), it is also possible to set the total length Lf of the preceding vehicle Wf. Further, if the number is yellow or black, it can be determined that the vehicle is a light vehicle, so the total length Lf of the front vehicle Wf is set to 3.4 m, for example.

  Further, it is possible to detect the total length Lf of the preceding vehicle Wf based on a signal (smart plate signal) transmitted from an ID tag built in the license plate of the preceding vehicle Wf. That is, the smart plate signal is received using the smart plate signal receiving antenna 15, and the total length Lf of the preceding vehicle Wf is obtained from the vehicle specification information such as the number, the total length, the total width, and the total height included in the signal. Can do.

  As shown in FIG. 5, when the second vehicle distance L2 between the forward vehicle Wf and the forward vehicle Wff is longer than the first predetermined vehicle distance Lm, that is, the forward vehicle Wf is likely to perform a jerky operation, as shown in FIG. When the situation is not normal (normal time), the first target inter-vehicle distance Lt (i) is set according to Equation 5 as the target inter-vehicle distance Lt between the host vehicle W and the preceding vehicle Wf. Here, A and B are proportional constants, and the stop inter-vehicle distance Lx is the inter-vehicle distance that should be taken when the host vehicle W and the front vehicle Wf are stopped.

Here, the function f (v) of the A term can be, for example, k · v ² . In this case, k is a proportional constant proportional to the vehicle weight, and is corrected in accordance with the number of passengers and the loading amount (more specifically, the larger the number of passengers and the loading amount, the larger the value is corrected). The function g (vf−v) of the B term can be, for example, h · (vf−v). In this case, h is a negative proportionality constant less than 0 (zero). Therefore, as the forward vehicle speed vf becomes larger than the own vehicle speed v (the more the own vehicle W tends to move away from the forward vehicle Wf), the value of the B term becomes negative and the first target inter-vehicle distance Lt (I) is set to a small value. As a result, the inter-vehicle distance deviation ΔL (referred to as a deviation ΔL (= L1-Lt) between the actual inter-vehicle distance L1 and the target inter-vehicle distance Lt, as will be described below) is apparently increased. Conversely, as the host vehicle speed v becomes greater than the forward vehicle speed vf (the host vehicle W tends to approach the forward vehicle Wf), the value of the B term increases to the plus side, and the first target inter-vehicle distance Lt (i) is set to a large value. As a result, the inter-vehicle distance deviation ΔL (= L1−Lt) is apparently reduced. In any case, the inter-vehicle distance deviation ΔL is apparently increased as an absolute value, and the target inter-vehicle distance Lt is increased according to the relative speed difference (vf−v) between the host vehicle W and the preceding vehicle Wf. It works to accelerate the convergence of the host vehicle W position.

  Further, the control unit 10 normally uses the first vehicle speed control characteristic q (i) shown in FIG. 6 as the vehicle speed control characteristic q. The vehicle speed control characteristic q generally indicates the value of the vehicle speed control amount of the host vehicle W with respect to the deviation ΔL (= L1-Lt) between the actual inter-vehicle distance L1 and the target inter-vehicle distance Lt. When ΔL is 0, the vehicle speed control amount is 0. As the inter-vehicle distance deviation ΔL increases toward the plus side, that is, as the host vehicle W moves away from the front vehicle Wf, the vehicle speed control amount increases toward the plus side, that is, the acceleration side. Conversely, as the inter-vehicle distance deviation ΔL increases toward the minus side, that is, as the host vehicle W approaches the forward vehicle Wf, the vehicle speed control amount increases toward the minus side, that is, the deceleration side. The first vehicle speed control characteristic q (i), together with a second vehicle speed control characteristic q (ii) and a third vehicle speed control characteristic q (iii), which will be described later, for example, a recording device (main memory or the like) of the control unit 10 in advance. ).

  In this case, as indicated by reference symbol (a), a dead zone is provided in which the vehicle speed control amount is zero until the inter-vehicle distance deviation ΔL reaches γ1 on the separation side and γ2 on the approach side. Further, as indicated by reference symbol (a), a slow response zone is provided in which the increment / decrement of the vehicle speed control amount is relatively small while the inter-vehicle distance deviation ΔL exceeds the dead zone a and is relatively small. As indicated by the symbol C, there is provided a sudden response zone in which the increase / decrease in the vehicle speed control amount is relatively large when the inter-vehicle distance deviation ΔL becomes relatively large beyond the slow response zone a.

  Next, as shown in FIG. 7, when the second inter-vehicle distance L2 between the forward vehicle Wf and the preceding vehicle Wff is shorter than the first predetermined inter-vehicle distance Lm, that is, the forward vehicle Wf is jerky as shown in FIG. When the vehicle is likely to drive (when approaching), the second target inter-vehicle distance Lt (ii) is set according to Equation 6 as the target inter-vehicle distance Lt between the host vehicle W and the preceding vehicle Wf. Here, the first predetermined inter-vehicle distance Lm can be, for example, (A · f (v) + Lx). As is apparent, a C term C · v · (Lm−L2) is added as compared with the first target inter-vehicle distance Lt (i). That is, the second target inter-vehicle distance Lt (ii) is extended by the C term [corresponding to claim 2]. Here, C is a proportionality constant. The value C · v · (Lm−L2) of the C term is gradually increased as the second inter-vehicle distance L2 becomes shorter after the second inter-vehicle distance L2 becomes shorter than the first predetermined inter-vehicle distance Lm. It gets bigger. In other words, the second target inter-vehicle distance Lt (ii) is gradually extended [corresponding to claim 3].

  In this case, the value of the proportionality constant B at the second target inter-vehicle distance Lt (ii) is made smaller than the value of the proportionality constant B at the first target inter-vehicle distance Lt (i). Therefore, the effect that the second target inter-vehicle distance Lt (ii) is set to a smaller value and the inter-vehicle distance deviation ΔL is apparently increased as the host vehicle W tends to move away from the preceding vehicle Wf, and The second target inter-vehicle distance Lt (ii) is set to a larger value as the host vehicle W tends to approach the front vehicle Wf, and the effect that the inter-vehicle distance deviation ΔL is apparently reduced, that is, the own vehicle The effect that the convergence of the host vehicle W position to the target inter-vehicle distance Lt is accelerated according to the relative speed difference (vf−v) between the vehicle W and the preceding vehicle Wf is reduced. In other words, the vehicle speed control sensitivity of the host vehicle W is slowed down [corresponding to claim 7].

  Further, when approaching, the control unit 10 uses the second vehicle speed control characteristic q (ii) shown in FIG. 8 as the vehicle speed control characteristic q. The second vehicle speed control characteristic q (ii) is compared with the first vehicle speed control characteristic q (i) (indicated by a dotted line in the figure), and the slow response band A and In any of the sudden response zones c, the increment / decrement of the vehicle speed control amount is reduced [corresponding to claim 8]. That is, the vehicle speed control amount of the host vehicle W is reduced, and the vehicle speed control sensitivity of the host vehicle W is slowed down [corresponding to claim 5].

  Next, as shown in FIG. 9, the control unit 10 determines that the second inter-vehicle distance Ln between the front vehicle Wf and the preceding vehicle Wff is shorter than the first predetermined inter-vehicle distance Lm. Is shorter, that is, when the forward vehicle Wf is likely to perform more jerky driving (when abnormally approaching), the third target according to Equation 7 is used as the target inter-vehicle distance Lt between the host vehicle W and the forward vehicle Wf. An inter-vehicle distance Lt (iii) is set. Here, the second predetermined inter-vehicle distance Ln can be, for example, an idle running distance (an empty running distance of the front vehicle Wf) or the like. As is apparent, the B term is deleted as compared to the second target inter-vehicle distance Lt (ii), and a D term of D · v is added instead. Here, the value of the D term is larger than the value of the B term. In other words, the third target inter-vehicle distance Lt (iii) is further extended from the second target inter-vehicle distance Lt (ii) by (D term value−B term value). ]. Here, D is a proportionality constant.

  In this case, the third target inter-vehicle distance Lt (iii) is set to a smaller value as the host vehicle W tends to move away from the preceding vehicle Wf as a result of deleting the B term, and the inter-vehicle distance deviation The third target inter-vehicle distance Lt (iii) is set to a larger value as the effect that ΔL is apparently increased and the host vehicle W tends to approach the front vehicle Wf, and the inter-vehicle distance deviation ΔL is The effect that it is apparently reduced, that is, the effect that the convergence of the position of the host vehicle W to the target inter-vehicle distance Lt is accelerated according to the relative speed difference (vf−v) between the host vehicle W and the preceding vehicle Wf is eliminated. Become. In other words, the vehicle speed control sensitivity of the host vehicle W is further reduced (corresponding to claim 7).

  Further, the control unit 10 uses the third vehicle speed control characteristic q (iii) shown in FIG. 10 as the vehicle speed control characteristic q when abnormally approaching. This third vehicle speed control characteristic q (iii) is compared with the second vehicle speed control characteristic q (ii) (indicated by a dotted line in the figure), and the dead zone a is up to γ3 when the inter-vehicle distance deviation ΔL is positive, that is, away from the vehicle. It is enlarged [corresponding to claim 8]. That is, the start of the vehicle speed control of the host vehicle W is further delayed, and the vehicle speed control sensitivity of the host vehicle W is slowed down [corresponding to claim 6]. Along with this, the amount of change in the return slow response zone (i.e., increment / decrement) is further reduced.

  Next, according to the flowchart of FIG. 11, an example of a specific operation of the follow-up running control performed by the control unit 10 will be described. First, in step S1, various signals are input, and in step S2, the presence or absence of the forward vehicle WF is determined. If there is no preceding vehicle Wf, the process returns without setting the target inter-vehicle distance Lt at step S3 and without setting the target vehicle speed control amount at step S4.

  If there is a preceding vehicle Wf, it is determined in step S5 whether or not there is a preceding vehicle Wff. When there is no preceding vehicle Wff, the target inter-vehicle distance Lt is set to the first target inter-vehicle distance Lt (i) in step S6, the inter-vehicle distance deviation ΔL (i) is calculated in step S7, and in step S8. The target vehicle speed control amount is set by the first vehicle speed control characteristic q (i) (this detailed operation will be further described later). Then, in step S9, the throttle actuator 17 (during acceleration) and the brake actuator 18 (during deceleration) are controlled so that the set target vehicle speed control amount is obtained. Thereby, the host vehicle W is caused to travel following the front vehicle Wf so that the actual inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf is maintained at the predetermined target inter-vehicle distance Lt.

  When there is the front-end vehicle Wff, it is determined in step S10 whether the second inter-vehicle distance L2 between the front vehicle Wf and the front-end vehicle Wff is shorter than the first predetermined inter-vehicle distance Lm. Next, in step S11, it is determined whether or not the second inter-vehicle distance L2 is shorter than a second predetermined inter-vehicle distance Ln. As a result, when the second inter-vehicle distance L2 is longer than the first predetermined inter-vehicle distance Lm (see FIGS. 5 and 6), the process proceeds to step S6, where the second inter-vehicle distance L2 is the first predetermined inter-vehicle distance Lm. Is shorter (see FIGS. 7 and 8), the process proceeds to step S12, and when the second inter-vehicle distance L2 is shorter than the second predetermined inter-vehicle distance Ln (see FIGS. 9 and 10), the process proceeds to step S15. move on.

  In either case, first, the target inter-vehicle distance Lt is set to the first, second, and third target inter-vehicle distances Lt (i), Lt (ii), and Lt (iii) (steps S6, S12, and S15). Distance deviations ΔL (i), ΔL (ii), ΔL (iii) are calculated (steps S7, S13, S16), and the target vehicle speed control amount is set to the first, second, and third vehicle speed control characteristics q (i), q. It is set by (ii) and q (iii) (steps S8, S14, S17). In either case, in step S9, the throttle actuator 17 (during acceleration) and the brake actuator 18 (during deceleration) are controlled so that the set target vehicle speed control amount is obtained. Thereby, the host vehicle W is caused to travel following the front vehicle Wf so that the actual inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf is maintained at the predetermined target inter-vehicle distance Lt.

  The setting operation of the target vehicle speed control amount in steps S8, S14, and S17 is performed according to the flowchart shown in FIG. First, in step S21, it is determined whether or not γ3 is set. If not (normal or approaching), it is determined in step S22 whether the inter-vehicle distance deviation ΔL is greater than γ1. If larger, in step S23, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. On the other hand, if the inter-vehicle distance deviation ΔL is smaller than γ1 in step S22, it is determined in step S24 whether the inter-vehicle distance deviation ΔL is smaller than γ2. If it is smaller, in step S23, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. However, if it is larger, it is determined that the vehicle is in the dead zone a, and the target vehicle speed control amount is determined to be 0 in step S25.

  Similarly, if γ3 is set in step S21 (during abnormal approach), it is determined in step S26 whether the inter-vehicle distance deviation ΔL is greater than γ3. If larger, in step S23, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. On the other hand, if the inter-vehicle distance deviation ΔL is smaller than γ3 in step S26, it is determined in step S24 whether the inter-vehicle distance deviation ΔL is smaller than γ2. If it is smaller, in step S23, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. However, if it is larger, it is determined that the vehicle is in the dead zone a, and the target vehicle speed control amount is determined to be 0 in step S25.

  As described above, in the present embodiment, for example, the front vehicle Wf travels close to the front vehicle Wff, and as a result, the inter-vehicle distance L2 between the front vehicle Wf and the front vehicle Wff is a predetermined inter-vehicle distance. In a situation where the vehicle is shorter than Lm (L2 <Lm) and the forward vehicle Wf is likely to perform a jerky operation (when approaching in FIG. 7), the inter-vehicle distance L1 between the host vehicle W and the forward vehicle Wf is set to the target inter-vehicle distance Lt. Since the sensitivity of the vehicle speed control of the host vehicle W to be maintained is slowed (the second vehicle speed control characteristic q (ii) in FIG. 8 and eventually the third vehicle speed control characteristic q (iii) in FIG. 10), Even if the vehicle Wf repeats sudden braking and acceleration, the host vehicle W is restrained from frequent frequent braking and rapid acceleration, improving the ride comfort and sense of security. It is done.

  In this case, the sensitivity of the vehicle speed control of the host vehicle W is slowed and the target inter-vehicle distance Lt is extended by a predetermined distance (C term: C · v · (Lm−L2)). Even if there is a margin in the inter-vehicle distance L1 with the preceding vehicle Wf and the sensitivity of the vehicle speed control of the host vehicle W is slowed down, the passenger's sense of security is ensured.

  In this case, the target inter-vehicle distance Lt is not extended at a time by a predetermined distance, but the target inter-vehicle distance Lt is gradually extended as the inter-vehicle distance L2 between the front vehicle Wf and the preceding vehicle Wff becomes shorter. Therefore (see section C), the host vehicle W is gradually separated from the front vehicle Wf, and smooth follow-up control is realized. From this point as well, the ride comfort of the occupant is improved.

  Furthermore, the inter-vehicle distance L2 between the preceding vehicle Wf and the preceding vehicle Wff becomes shorter than the second predetermined inter-vehicle distance Ln that is shorter than the predetermined inter-vehicle distance Lm (L2 <Ln), so that the front vehicle Wf is jerky. In a situation where driving is more likely, or in a situation where contact between the preceding vehicle Wf and the preceding vehicle Wff is likely to occur (at the time of abnormal approach in FIG. 9), the target inter-vehicle distance Lt is set to the second predetermined distance (D term). Therefore, even if the vehicle speed control sensitivity of the host vehicle W is slowed down, the vehicle distance L1 between the host vehicle W and the preceding vehicle Wf can be further increased. A passenger's sense of security is ensured, and even if the forward vehicle Wf comes into contact with the forward vehicle Wff, the possibility that the host vehicle W comes into contact with the forward vehicle Wf can be reduced, and safety is ensured.

  On the other hand, as one of the specific modes for slowing down the vehicle speed control sensitivity of the host vehicle W, there are an inter-vehicle distance L1 between the host vehicle W and the preceding vehicle Wf, and a target inter-vehicle distance Lt between the host vehicle W and the preceding vehicle Wf. Since the vehicle speed control amount of the host vehicle W with respect to the deviation ΔL is reduced (decrease in the amount of change in the slow response zone A and the sudden response zone U in FIGS. 8 and 10), the vehicle speed control sensitivity of the host vehicle W is ensured. Can be slowed down.

  Similarly, as another specific aspect of slowing down the vehicle speed control sensitivity of the host vehicle W, the inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf, and the target inter-vehicle distance Lt between the host vehicle W and the front vehicle Wf. Since the start of the vehicle speed control of the host vehicle W with respect to the deviation ΔL is delayed (expansion of the dead zone in FIG. 10), the vehicle speed control sensitivity of the host vehicle W can be surely slowed in this case as well. .

  Similarly, as another specific aspect for slowing down the vehicle speed control sensitivity of the host vehicle W, the inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf and the target inter-vehicle distance between the host vehicle W and the front vehicle Wf. Since the deviation ΔL from Lt is reduced (decrease in absolute value) (decrease in the value of the proportionality constant B in FIG. 7 and deletion of the B term in FIG. 9), the vehicle speed of the host vehicle W is again in this case. The control sensitivity can be surely slowed down.

  The vehicle speed control sensitivity of the host vehicle W is slowed down when the inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf is larger than the target inter-vehicle distance Lt between the host vehicle W and the front vehicle Wf. Since it is performed only when the vehicle is separated from the front vehicle Wf beyond the target (when the inter-vehicle distance deviation ΔL is positive), conversely, the inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf is the host vehicle. When the vehicle distance Wt is smaller than the target inter-vehicle distance Lt between W and the preceding vehicle Wf, that is, when the own vehicle W is approaching the front vehicle Wf more than the target (when the inter-vehicle distance deviation ΔL is negative), Since the vehicle speed control sensitivity is not slowed down, even if the host vehicle W is approaching the target vehicle Wf beyond the target even if the host vehicle Wf suddenly brakes or stops suddenly, it is delayed. The vehicle W Is less likely to come into contact with the forward vehicle Wf, and safety is ensured.

  Next, a second embodiment of the present invention will be described by extracting only the characteristic part. As illustrated in FIG. 13 (corresponding to FIG. 8) and FIG. 14 (corresponding to FIG. 10), the control unit 10 has an inter-vehicle distance deviation ΔL as a negative side as a vehicle speed control characteristic q when approaching or abnormally approaching. That is, on the approach side, the second vehicle speed control characteristic q (ii) in which the vehicle speed control amount of the host vehicle W is reduced and the vehicle speed control sensitivity of the host vehicle W is slowed down, and the start of the vehicle speed control of the host vehicle W is started. May be further delayed (γ4), and the third vehicle speed control characteristic q (iii) in which the vehicle speed control sensitivity of the host vehicle W is slowed may be used.

  The follow-up running control performed by the control unit 10 in this case is the same as that in the first embodiment shown in FIG. 11, but the setting operation of the target vehicle speed control amount is performed according to the flowchart shown in FIG.

  First, in step S31, it is determined whether or not γ3 is set. If not (normal or approaching), it is determined in step S32 whether the inter-vehicle distance deviation ΔL is greater than γ1. If so, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q in step S33. On the other hand, if the inter-vehicle distance deviation ΔL is smaller than γ1 in step S32, it is determined whether or not γ4 is set in step S34. If not (normal or approaching), it is determined in step S35 whether the inter-vehicle distance deviation ΔL is smaller than γ2. If it is smaller, in step S33, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. However, if it is larger, it is determined that the vehicle is in the dead zone a, and the target vehicle speed control amount is determined to be 0 in step S36. If γ4 is set in step S34 (when abnormally approaching), it is determined in step S38 whether the inter-vehicle distance deviation ΔL is smaller than γ4. If it is smaller, in step S33, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. However, if it is larger, it is determined that the vehicle is in the dead zone a, and the target vehicle speed control amount is determined to be 0 in step S36.

  Similarly, if γ3 is set in step S31 (during abnormal approach), it is determined in step S37 whether the inter-vehicle distance deviation ΔL is greater than γ3. If so, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q in step S33. On the other hand, if the inter-vehicle distance deviation ΔL is smaller than γ3 in step S37, it is determined whether or not γ4 is set in step S34. If not (normal or approaching), it is determined in step S35 whether the inter-vehicle distance deviation ΔL is smaller than γ2. If it is smaller, in step S33, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. However, if it is larger, it is determined that the vehicle is in the dead zone a, and the target vehicle speed control amount is determined to be 0 in step S36. If γ4 is set in step S34 (when abnormally approaching), it is determined in step S38 whether the inter-vehicle distance deviation ΔL is smaller than γ4. If it is smaller, in step S33, the target vehicle speed control amount is determined according to the vehicle speed control characteristic q. However, if it is larger, it is determined that the vehicle is in the dead zone a, and the target vehicle speed control amount is determined to be 0 in step S36.

  Next, a third embodiment of the present invention will be described by extracting only the characteristic part. As illustrated in FIG. 16 (corresponding to FIG. 7 and FIG. 9), in the third embodiment, the third target inter-vehicle distance Lt (iii) is not set, and the first vehicle Wf and the forward vehicle Wff are After the two inter-vehicle distance L2 becomes shorter than the first predetermined inter-vehicle distance Lm, only the second target inter-vehicle distance Lt (ii) is used continuously.

  Further, as illustrated in FIG. 17 (corresponding to FIGS. 8 and 10), in the third embodiment, the third vehicle speed control characteristic q (iii) is not used, and the forward vehicle Wf and the forward and backward vehicle Wff are After the second inter-vehicle distance L2 becomes shorter than the first predetermined inter-vehicle distance Lm, only the second vehicle speed control characteristic q (ii) is continuously used. In this case, in the second vehicle speed control characteristic q (ii), the dead zone a is increased to γ3 as compared with the second vehicle speed control characteristic q (ii) shown in FIG.

  In the third embodiment, the setting operation of the target vehicle speed control amount performed by the control unit 10 is the same as that in the first embodiment shown in FIG. 12, but the follow-up running control is performed according to the flowchart shown in FIG. Is called.

  First, in step S41, various signals are input, and in step S42, the presence / absence of the preceding vehicle WF is determined. If there is no preceding vehicle Wf, the process returns without setting the target inter-vehicle distance Lt at step S43 and without setting the target vehicle speed control amount at step S44.

  If there is a preceding vehicle Wf, it is determined in step S45 whether or not there is a preceding vehicle Wff. When there is no preceding vehicle Wff, the target inter-vehicle distance Lt is set to the first target inter-vehicle distance Lt (i) in step S46, the inter-vehicle distance deviation ΔL (i) is calculated in step S47, and in step S48. The target vehicle speed control amount is set by the first vehicle speed control characteristic q (i). In step S49, the throttle actuator 17 (during acceleration) and the brake actuator 18 (during deceleration) are controlled so that the set target vehicle speed control amount is obtained. Thereby, the host vehicle W is caused to travel following the front vehicle Wf so that the actual inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf is maintained at the predetermined target inter-vehicle distance Lt.

  When there is the front-end vehicle Wff, it is determined in step S50 whether the second inter-vehicle distance L2 between the front vehicle Wf and the front-end vehicle Wff is shorter than the first predetermined inter-vehicle distance Lm. As a result, when the second inter-vehicle distance L2 is longer than the first predetermined inter-vehicle distance Lm (see FIGS. 5 and 6), the process proceeds to step S46, and the second inter-vehicle distance L2 is the first predetermined inter-vehicle distance Lm. If shorter (see FIGS. 16 and 17), the process proceeds to step S51.

  In either case, first, the target inter-vehicle distance Lt is set to the first and second target inter-vehicle distances Lt (i) and Lt (ii) (steps S46 and S51), and the inter-vehicle distance deviations ΔL (i) and ΔL (ii) ) Is calculated (steps S47, S52), and the target vehicle speed control amount is set by the first and second vehicle speed control characteristics q (i), q (ii) (steps S48, S53). In either case, in step S49, the throttle actuator 17 (during acceleration) and the brake actuator 18 (during deceleration) are controlled so that the set target vehicle speed control amount is obtained. Thereby, the host vehicle W is caused to travel following the front vehicle Wf so that the actual inter-vehicle distance L1 between the host vehicle W and the front vehicle Wf is maintained at the predetermined target inter-vehicle distance Lt.

  Each of the above embodiments is the best embodiment of the present invention, but it goes without saying that various modifications and changes can be made without departing from the scope of the claims. For example, in the above-described embodiment, the first vehicle speed control characteristic q (i) used during normal time when the third inter-vehicle distance L3 between the preceding vehicle Wf and the preceding vehicle Wff is longer than the first predetermined inter-vehicle distance Lm, and the first The second vehicle speed control characteristic q (ii) used at the time of approach when the three inter-vehicle distance L3 is shorter than the first predetermined inter-vehicle distance Lm, and the abnormal distance when the third inter-vehicle distance L3 is shorter than the second predetermined inter-vehicle distance Ln. The third vehicle speed control characteristic q (iii) has been described in the case where it is registered and stored in advance in, for example, the recording device of the control unit 10, but instead of this, for example, the first vehicle speed that is a standard form is used. Only the control characteristic q (i) is registered / stored in the recording device or the like, and when the vehicle approaches or abnormally approaches, the first vehicle speed control characteristic q (i) is changed to the second vehicle speed control characteristic q (ii) each time. Or the third vehicle speed control characteristic q (iii) It is also possible to make use deformed and corrected. In addition, as means for slowing down the vehicle speed control sensitivity of the host vehicle W, the following three were mentioned: a decrease in the value of the proportional constant B, an expansion of the dead zone A, a decrease in the amount of change in the slow response zone A and the sudden response zone U. These can be applied in various combinations. In the third embodiment, as in the second embodiment, the vehicle speed control sensitivity of the host vehicle W may be slowed even when the inter-vehicle distance deviation ΔL is on the minus side, that is, on the approaching side.

  As described above in detail with reference to specific examples, the present invention frequently causes sudden braking and sudden acceleration of the own vehicle in conjunction with the forward driving even when the preceding vehicle repeats sudden braking and sudden acceleration. This is intended to improve the ride comfort and security of passengers, and is expected to have a wide range of industrial applicability in the technical field of automobile tracking systems.

FIG. 2 is a layout diagram of each component of the automobile follow-up traveling device according to the best embodiment of the present invention. It is a control system figure centering on the control unit of the said follower traveling apparatus. It is explanatory drawing of the concrete one aspect | mode which detects the inter-vehicle distance of the own vehicle and a vehicle ahead. It is explanatory drawing of the specific one aspect | mode which detects the full length of a front vehicle. It is explanatory drawing of the target inter-vehicle distance of the own vehicle and a front vehicle in case the inter-vehicle distance of a front vehicle and a front vehicle is longer than the 1st predetermined inter-vehicle distance. It is explanatory drawing which shows the characteristic (1st characteristic) of the vehicle speed control amount with respect to the inter-vehicle distance deviation in the said case. It is explanatory drawing of the target inter-vehicle distance of the own vehicle and a front vehicle in case the inter-vehicle distance of a front vehicle and a front vehicle is shorter than the 1st predetermined inter-vehicle distance. It is explanatory drawing which shows the characteristic (2nd characteristic) of the vehicle speed control amount with respect to the inter-vehicle distance deviation in the said case. It is explanatory drawing of the target inter-vehicle distance of the own vehicle and a front vehicle in case the inter-vehicle distance of a front vehicle and a front vehicle is shorter than the 2nd predetermined inter-vehicle distance. It is explanatory drawing which shows the characteristic (3rd characteristic) of the vehicle speed control amount with respect to the inter-vehicle distance deviation in the said case. It is a flowchart which shows an example of the specific operation | movement of the follow-up running control which the said control unit performs. It is a flowchart which shows one example of the target vehicle speed control amount setting operation | movement which the said control unit performs. It is explanatory drawing of the 2nd characteristic in the 2nd Embodiment of this invention. It is explanatory drawing of the 3rd characteristic in the 2nd Embodiment of this invention. It is a flowchart which shows one example of the target vehicle speed control amount setting operation | movement in the 2nd Embodiment of this invention. It is explanatory drawing of the target inter-vehicle distance of the own vehicle and the front vehicle in the 3rd Embodiment of this invention. It is explanatory drawing of the 2nd characteristic in the 3rd Embodiment of this invention. It is a flowchart which shows an example of the specific operation | movement of follow-up driving control in the 3rd Embodiment of this invention.

Explanation of symbols

1 Follow-up traveling device 10 Control unit (target inter-vehicle distance setting means, second inter-vehicle distance detection means, control sensitivity dulling means)
11 Radar (vehicle distance detection means)
12 Camera (front vehicle recognition means, forward vehicle recognition means)
13 Vehicle-to-vehicle communication antenna 14 Road-to-vehicle communication antenna 15 Smart plate signal receiving antenna 16 Steering angle sensor 17 Throttle actuator (vehicle speed control means)
18 Brake actuator (vehicle speed control means)
19 steering actuator 20 front wheel L1 first inter-vehicle distance L2 second inter-vehicle distance Lt target inter-vehicle distance W own vehicle Wf forward vehicle Wff forward vehicle

Claims (8)

Forward vehicle recognition means for recognizing a vehicle ahead of the host vehicle;
Target inter-vehicle distance setting means for setting the target inter-vehicle distance between the host vehicle and the preceding vehicle;
An inter-vehicle distance detection means for detecting an inter-vehicle distance between the preceding vehicle recognized by the forward vehicle recognition means and the host vehicle;
A follow-up traveling device for an automobile, comprising vehicle speed control means for controlling the vehicle speed of the host vehicle so that the inter-vehicle distance detected by the inter-vehicle distance detection means is maintained at the target inter-vehicle distance set by the target inter-vehicle distance setting means. There,
Front vehicle recognition means for recognizing the vehicle ahead of the vehicle,
A second inter-vehicle distance detecting means for detecting an inter-vehicle distance between the forward vehicle recognized by the forward vehicle recognition means and the forward vehicle recognized by the forward vehicle recognition means;
There is provided a control sensitivity slowing means for slowing the control sensitivity of the vehicle speed control means when the inter-vehicle distance detected by the second inter-vehicle distance detection means is shorter than the predetermined inter-vehicle distance than when it is not shortened. A follow-up traveling device for an automobile. In the vehicle following traveling device according to claim 1,
The target inter-vehicle distance setting means extends the target inter-vehicle distance by a predetermined distance when the inter-vehicle distance detected by the second inter-vehicle distance detection means is shorter than the predetermined inter-vehicle distance than when it is not shortened. An automobile follow-up traveling device characterized by that. In the automobile follow-up traveling device according to claim 2,
The target inter-vehicle distance setting means gradually increases the target inter-vehicle distance as the inter-vehicle distance decreases after the inter-vehicle distance detected by the second inter-vehicle distance detection means becomes shorter than a predetermined inter-vehicle distance. An automobile follow-up traveling device characterized by that. In the vehicle following traveling device according to claim 2 or 3,
The target inter-vehicle distance setting means sets the target inter-vehicle distance when the inter-vehicle distance detected by the second inter-vehicle distance detection means is shorter than a second predetermined inter-vehicle distance that is shorter than the predetermined inter-vehicle distance. An automobile follow-up traveling device further extending by a predetermined distance of 2. In the follow-up traveling device for an automobile according to any one of claims 1 to 4,
The control sensitivity reduction means reduces the vehicle speed control amount by reducing a vehicle speed control amount of the host vehicle with respect to a deviation between the inter-vehicle distance detected by the inter-vehicle distance detection means and the target inter-vehicle distance setting means. A follow-up traveling device for an automobile characterized in that the control sensitivity of the means is blunted. In the automobile follow-up traveling device according to any one of claims 1 to 5,
The control sensitivity reduction means delays the start of the vehicle speed control of the host vehicle with respect to the deviation between the inter-vehicle distance detected by the inter-vehicle distance detection means and the target inter-vehicle distance set by the target inter-vehicle distance setting means. A follow-up traveling device for an automobile, characterized in that the control sensitivity of the control means is blunted. In the automobile traveling device according to any one of claims 1 to 6,
The control sensitivity dulling means dulls the control sensitivity of the vehicle speed control means by reducing the deviation between the inter-vehicle distance detected by the inter-vehicle distance detection means and the target inter-vehicle distance set by the target inter-vehicle distance setting means. An automobile follow-up traveling device characterized by that. In the automobile follow-up traveling device according to any one of claims 1 to 7,
The control sensitivity dulling means dulls the control sensitivity of the vehicle speed control means only when the inter-vehicle distance detected by the inter-vehicle distance detection means is larger than the target inter-vehicle distance set by the target inter-vehicle distance setting means. A vehicle follow-up running device.

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