JP3959100B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicle travel control device for detecting an object existing in an estimated trajectory of a host vehicle using a radar device or the like, and controlling the traveling state of the host vehicle according to the positional relationship between the object and the host vehicle. .

Among the data of multiple objects detected by the on-vehicle radar device, by integrating the data of objects whose positions are close to each other and the relative speed variation with respect to the host vehicle is within a predetermined range, such as a guardrail A control object recognition method for reliably identifying a control object such as a fixed object and a preceding vehicle is known from Patent Document 1 below.
JP-A-8-240660

  By the way, when a small vehicle such as a passenger car is traveling in front of the own vehicle and a large vehicle such as a carrier car is running side by side at the same speed on the side of the small vehicle, the conventional contrast object recognition method described above. Then, a small vehicle may be integrated into a large vehicle and mistakenly recognized as one vehicle. In such a case, since the position of the vehicle integrated into one vehicle is recognized as the position of the large vehicle from the difference in the size of the vehicle body, the small vehicle that is actually traveling in the estimated trajectory of the own vehicle Will not be recognized, and only a large vehicle traveling outside the estimated trajectory of the vehicle will be recognized. As a result, when the own vehicle approaches a large vehicle and a small vehicle and the large vehicle deviates from the detection range of the radar device, or the large vehicle changes its course and deviates from the detection range of the radar device, and the integration is canceled. Sometimes, a small vehicle is suddenly recognized in the estimated trajectory of the own vehicle, and there is a possibility that a delay occurs in braking for preventing a rear-end collision with the preceding vehicle.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to prevent a plurality of objects existing in front of the host vehicle from being inappropriately integrated and to perform vehicle control accurately. .

To achieve the above object, according to the first aspect of the present invention, an electromagnetic wave is transmitted toward a predetermined region in the traveling direction of the host vehicle, and a reflected wave from an object existing in the predetermined region is received. Based on at least the positions of the plurality of objects when a plurality of objects are detected within a predetermined range based on the transmission / reception results of the transmission / reception means. Integration means for combining the plurality of objects as one target object, trajectory estimation means for estimating a future travel trajectory of the own vehicle, and when the target object summarized by the integration means exists in the estimated trajectory, In a vehicle travel control device comprising vehicle control means for controlling the travel state of the host vehicle according to the positional relationship between the target object and the host vehicle, the object present in a small range closer to the host vehicle in the predetermined range of Based on the location, the position output means for outputting a representative position of one target object that has been gathered by the integrating means, said one position of the integrated plurality of objects which is the first predetermined distance or more from the representative position If one of the positions of the plurality of integrated objects exists within the estimated trajectory of the own vehicle, the one target object is separated from the estimated trajectory of the own vehicle. Separating means for separating into objects, and when the single object exists in the small range, the position output means uses the position of the single object as the representative position, and a plurality of objects in the small range. When the vehicle is present, a travel control device for a vehicle is proposed, in which a region between two objects existing at both ends in the left-right direction among the plurality of objects is output as the representative position .

  The first predetermined distances d0 and d1 are set to 3 m and 0.8 m, respectively, in the embodiment, but the values can be set as appropriate.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the integration unit is an object existing within a predetermined range based on the position of one of the plurality of objects. travel control device for a vehicle, characterized in that summarize is proposed.

According to the invention described in claim 3 , in addition to the configuration of claim 1 or 2 , in place of the separating means, two or more objects among a plurality of objects collected by the integrating means are provided. Is provided in the estimated trajectory, further comprising re-separating means for re-separating the objects whose left-right distance between the two or more objects is a second predetermined distance or more as separate target objects. A vehicle travel control device is proposed.

  The second predetermined distance d2 is set to 0.8 m in the embodiment, but the value can be set as appropriate.

According to the invention described in claim 4 , in addition to the configuration of any one of claims 1 to 3 , among a plurality of objects collected by the integration unit instead of the separation unit, Re-separating means for re-separating, as separate target objects, objects whose front-rear distance between the two or more objects is a third predetermined distance or more when two or more objects exist in the estimated trajectory; There is proposed a vehicle travel control device characterized by comprising the above.

  The third predetermined distance d3 is set to 3.0 m in the embodiment, but the value can be set as appropriate.

  The millimeter wave radar device Sr of the embodiment corresponds to the transmitting / receiving means of the present invention.

According to the configuration of claim 1, when a plurality of objects detected by the transmission / reception means are collected as one target object, if the collected objects exist across the inside and outside of the estimated trajectory of the own vehicle, Since the one target object is separated into separate target objects existing inside and outside the own vehicle's estimated trajectory, the target objects mistakenly combined into one are correctly recognized as separate target objects, and the own vehicle's estimated trajectory The vehicle control of the own vehicle based on the positional relationship between the target object existing above and the own vehicle can be accurately performed. In particular, any of the positions of the plurality of objects collected as one target object is at least a first predetermined distance from the representative position of the plurality of objects, and any of the positions of the collected objects Is present in the estimated trajectory of the own vehicle, the one target object is separated into separate target objects existing inside and outside the estimated trajectory of the own vehicle. It is possible to prevent separation from the target object.

Furthermore, since a small range is set on the side close to the own vehicle in the predetermined range and the representative position of the target object is output with reference to the position of the object existing in the small range, the representative position of the target object is as close to the own vehicle as possible. When a single object exists in a small range, the position of the single object is set as the representative position, and when a plurality of objects exist in a small range, the plurality of Since the region between two objects existing at both ends in the left-right direction is output as the representative position, the position of the target object can be appropriately set by this representative position.

According to the configuration of claim 2, since the objects existing within a predetermined range based on the position of one of the detected plurality of objects are collected as the target object, the plurality of originally separated objects are It is possible to prevent a single target object from being mistakenly collected .

According to the configuration of claim 3 , the distance in the left-right direction between two or more objects to be separated from the original target object as separate target objects because they exist in the estimated trajectory is equal to or greater than the second predetermined distance. If there is, the two or more objects are re-separated as separate target objects, so that the object existing on the estimated trajectory of the host vehicle can be more reliably separated as the target object.

According to the configuration of claim 4 , the distance in the front-rear direction between two or more objects that are to be separated from the original target object as separate target objects because they exist in the estimated trajectory is a third predetermined distance or more. If so, the two or more objects are re-separated as separate target objects, so that only objects that need to be separated as separate target objects can be more reliably separated.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 8 show a first embodiment of the present invention. FIG. 1 is an overall configuration diagram of a travel control device, and FIG. 2 is a waveform of a transmission / reception wave when an object is moving close to the transmission / reception antenna. 3 is a graph showing the detected peak signal, FIG. 4 is a block diagram showing the circuit configuration of the arithmetic processing unit of the radar device, and FIG. 5 is a diagram showing a region for separating the target vehicle, FIG. 6 is a view showing a state in which a large vehicle and a small vehicle running in parallel in front of the host vehicle are grouped as a single target vehicle, FIG. 7 is a view showing a state in which the small vehicle is separated from the once assembled large vehicle, FIG. Is a flowchart explaining the operation.

  As shown in FIG. 1, in the millimeter wave radar device Sr using FM-CW waves, the transmission operation of the oscillator 3 is modulated and controlled by the FM modulation control circuit 2 based on the timing signal input from the timing signal generation circuit 1. As shown by the solid line in FIG. 2A, a transmission wave whose frequency is modulated in a triangular wave shape is transmitted from the transmitting / receiving antenna 6 via the amplifier 4 and the circulator 5 in the horizontal direction of a predetermined detection range in front of the vehicle. For example, 9 channels are transmitted separately in different directions. When a reflected wave obtained by reflecting the FM-CW wave on an object such as a preceding vehicle is received by the transmission / reception antenna 6, the received wave is, for example, when the object approaches the own vehicle, as shown in FIG. ) On the rising side where the frequency of the transmission wave increases linearly, it appears later than the transmission wave at a frequency lower than the transmission wave, and on the lower side where the frequency of the transmission wave decreases linearly. Appears later than the transmitted wave at a higher frequency than the transmitted wave.

  The received wave received by the transmission / reception antenna 6 is input to the mixer 7 via the circulator 5. In addition to the reception wave from the circulator 5, the transmission wave distributed from the transmission wave output from the oscillator 3 is input to the mixer 7 via the amplifier 8, and the transmission wave and the reception wave are mixed by the mixer 7. Thus, as shown in FIG. 2B, the peak frequency Fup has a peak frequency Fup on the rising side where the frequency of the transmission wave increases linearly, and the peak frequency Fdn on the falling side where the frequency of the transmission wave decreases linearly. A beat signal having

  The beat signal obtained by the mixer 7 is amplified to the required level of amplitude by the amplifier 9, A / D converted by the A / D converter 10 at every sampling time, and the digitized data is stored in the memory 11 in time series. Retained. A timing signal is input to the memory 11 from the timing signal generation circuit 1, and in accordance with the timing signal, the memory 11 stores data on the rising side where the frequency of the transmission / reception wave increases and on the falling side where the frequency decreases. Will be stored in memory.

  As shown in FIG. 4, based on the data stored in the memory 11, the arithmetic processing unit (CPU) C calculates a relative distance and a relative speed with respect to an object as described later, and connect. Further, the arithmetic processing unit (CPU) C includes an object information calculation unit M1, an integration unit M2, a position output unit M3, a separation unit M4, and a trajectory estimation unit M6. The vehicle control means M5 receives the signal from the arithmetic processing unit (CPU) C and operates the alarm means 12 that prompts the driver to decelerate spontaneously and the brake actuator 13 that drives the wheel brake of the own vehicle. And control.

  The object information calculation means M1 analyzes the frequency of the beat signal data stored in the memory 11 by FFT (Fast Fourier Transform) to obtain the spectrum distribution, and based on the spectrum data, the detection level is a maximum value when the detection level is equal to or greater than a predetermined threshold value. A spectrum (peak signal) is detected. The ascending peak signal shown in FIG. 3 (a) and the descending peak signal shown in FIG. 3 (b) are detected symmetrically across the peak position when the relative speed to the object is “0”. Is done. Then, the relative distance and the relative speed of the object are calculated based on the peak frequency Fup on the rising side and the peak frequency Fdn on the descending side. Specifically, the distance to the object is calculated based on the sum of both peak frequencies Fup and Fdn, and the relative velocity with respect to the object is calculated based on the difference between both peak frequencies Fup and Fdn. The direction of the object is calculated based on the transmission direction of the transmission wave when the object is detected.

  Based on the position (relative distance and direction) of the object obtained by the object information calculation unit M1, the integration unit M2 considers a plurality of objects as one target object and integrates them. The position output means M3 outputs the representative position of the target object integrated into one. The trajectory estimation means M6 estimates the future trajectory of the host vehicle based on the vehicle speed detected by the vehicle speed sensor Sa and the yaw rate detected by the yaw rate sensor Sb. The separation unit M4 separates the target object into a plurality of target objects based on the result of comparing the position of each object constituting the target object and the estimated trajectory. The vehicle control means M5 is composed of, for example, a contact damage reduction support system. The vehicle control means M5 is a brake that is voluntarily provided to the driver so that the vehicle does not contact the preceding vehicle (that is, the target object) or damage is reduced even if the vehicle contacts the vehicle. The alarm means 12 for prompting the operation is activated, or the brake actuator 13 for performing automatic braking is activated.

  The operation of the arithmetic processing unit C will be described more specifically.

  As shown in FIGS. 5 to 7, a state is considered in which a large vehicle Vb such as a carrier car and a small vehicle Vc such as a passenger car are running in parallel at the same speed in front of the host vehicle Va. The small vehicle Vc is located in an estimated trajectory corresponding to the lane width obtained by adding a predetermined distance (1.8 m in the embodiment) to both the left and right sides of the center (one-dot chain line) of the trajectory estimated from the vehicle speed and yaw rate of the host vehicle Va. The large vehicle Vb is located outside the estimated locus. Since a large vehicle Vb made of a carrier car has a plurality of vehicles mounted thereon, the millimeter wave radar device Sr detects a plurality of objects T1 to T4 from the large vehicle Vb, detects an object T5 from the small vehicle Vc, and Another vehicle or the like (not shown) is detected as an object.

  Among the plurality of objects T1..., The plurality of objects T1 to T5 are within a predetermined range A (in the embodiment, 1.6 m on each of the left and right sides and 15 m on the front) set based on the object T1 closest to the host vehicle Va. If the detected relative speeds of the plurality of objects T1 to T5 with respect to the vehicle Va match, the plurality of objects T1 to T5 are integrated as one target object Ta surrounded by a two-dot chain line. Be recognized. The representative position of the target object Ta is the position of the object if there is a single object that exists in the small range a (see FIG. 5) with a front-rear distance of the predetermined range A within 3 m. As shown in the figure, if there are a plurality of objects T1 and T2 existing in the small range a, the center position (or the center of gravity position) of these objects T1 and T2 is set as the representative position. In this case, the representative position has a width in the left-right direction, the left end point is the position of the leftmost object T1 among the objects T1 and T2 included in the small range a, and the right end point is in the small range a. The position of the rightmost object T2 among the included objects T1 and T2 is set.

Before SL with respect to the representative position is a predetermined distance d0 forward (in 3m Example) above, and the representative position (when the representative position has a width in the lateral direction, the left end point) a predetermined distance d1 (implemented as a reference An area that is 0.8 m) or more to the left (in the direction approaching the estimated trajectory) , is within a predetermined distance (50 m in the embodiment) forward from the own vehicle Va, and is included in the estimated trajectory of the own vehicle Va If R (see FIG. 5) includes an object T5 among a plurality of integrated objects T1 to T5 as shown in FIG. 7, it is determined that the object T5 is a small vehicle Vc different from the large vehicle Vb. The target object Tb corresponding to the small vehicle Vc is separated from the original target object Ta. The predetermined distance d0 and the predetermined distance d1 are the first predetermined distance of the present invention. If there is a single object T5 present in the region R, the position of the object T5 becomes the representative position of the separated small vehicle Vc. If there are a plurality of objects T5 present in the region R, the plurality of objects The center position (or center of gravity position) is set as the representative position. In this case, the representative position has a width in the left-right direction, the left end point is the position of the leftmost object among the objects included in the region R, and the right end point is the position of the objects included in the region R. It is the position of the object that exists on the rightmost side.

  As described above, since the large vehicle Vb once mistakenly integrated as the single target object Ta can be correctly separated into the large vehicle Vb and the small vehicle Vc and recognized, the estimation of the host vehicle Va is possible. The alarm means 12 and the brake actuator 13 can be appropriately operated with respect to the small vehicle Vc existing on the trajectory.

  When separating the small vehicle Va from the large vehicle Vb, the object T5 corresponding to the small vehicle Va is separated from the objects T3 to T5 excluding the objects T1 and T2 existing in the small range a. The objects T1 and T2 that exist in the vehicle and are used for specifying the position of the large vehicle Vb are not separated as the small vehicle Va, so that useless separation can be avoided. This is because if the object T5 is included in the small range a, the representative position of the target object Ta is set as the center position of the two objects T5 and T2 located at the left and right ends, and the left end point of the representative position is This is the position of the object T5. Since the position of the object T5 that defines the left end point of the representative position is located within the estimated trajectory of the host vehicle Va, if the contact damage reduction control is performed based on the representative position, no special separation work is required. .

  Further, when the small vehicle Va is separated from the large vehicle Vb, the estimated distance of the own vehicle Va is more than the first predetermined distance (0.8 m in the embodiment) from the object T1 that defines the left end point of the representative position of the large vehicle Vb. Since the condition is that it is biased, it is possible to prevent a part of the large vehicle Vb from being erroneously separated as the small vehicle Vc.

  The flowchart of FIG. 8 summarizes the above actions.

  First, the distance, relative speed, and direction of a plurality of objects detected by the millimeter wave radar device Sr are calculated in step S1, and the plurality of objects are integrated as a single vehicle data (target object) in a predetermined range in step S2. The distance, relative speed and direction of the target object are calculated. In a subsequent step S3, the future trajectory of the host vehicle is estimated based on the vehicle speed and yaw rate of the host vehicle, and whether or not any of the plurality of objects integrated in the step S2 exists within the width of the estimated trajectory. judge. If the answer to step S3 is YES, an object present in the estimated trajectory is separated as a separate target object in step S4, and the data is flagged so that it can be identified. At this time, the original target object data calculated in step S2 is also output. In step S5, the separated separate target object is determined as a control target object (preceding vehicle), and the traveling state of the host vehicle is controlled. On the other hand, if the answer to step S3 is NO, only the data of the original target object calculated in step S2 is output, and it is determined in step S7 that the control target object (preceding vehicle) does not exist in the estimated trajectory of the own vehicle. To do.

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the arithmetic processing unit (CPU) C according to the second embodiment includes a re-separation means M4 ′ instead of the separation means M4 according to the first embodiment.

  As shown in FIG. 9, among a plurality of objects T1... Detected by the millimeter wave radar device Sr, a predetermined range A of 15 m forward and backward and 3.2 m right and left with reference to the object T1 at the closest position (see FIG. 5). ) Are integrated into a target object Ta. Since only one object T1 (Ta) exists in the small range a (see FIG. 5) on the near side 3m of the predetermined range A, the position of the object T1 (Ta) becomes the representative position of the target object Ta. 1st predetermined distance d0 (3 m in the embodiment) or more forward with respect to the representative position, and left (estimated locus) more than the first predetermined distance d1 (0.8 m in the embodiment) with respect to the representative position. In the region R (see FIG. 5) that is within a predetermined distance (50 m in the embodiment) forward from the vehicle Va and that is included in the estimated trajectory of the vehicle Va. If T4 exists, the objects T2 and T4 are separated from the original target object Ta as separate target objects Tb and Tc.

  Out of the two separated objects T2, T4 (Tb, Tc), the left and right directions are equal to or longer than a second predetermined distance d2 (0.8 m in the embodiment) with reference to the position of the object T2 (Ta) located on the near side. If the object T4 (Tc) exists in a region that is further forward than the third predetermined distance d3 (3 m in the embodiment) with reference to the position of the object T2 (Ta), the object T2 (Tb) Again, the object T4 (Tc) is separated. That is, by repeating the separation operation twice, two independent target objects Tb and Tc are separated from the original target object Ta, and each of the target objects Tb and Tc has a representative position. . Of the total three target objects Ta, Tb, Tc, the two right target objects Ta, Tb correspond to the large vehicle Vb, but the one left target object Tc corresponds to the small vehicle Vc. Appropriate for both the large vehicle Vb and the small vehicle Vc by performing vehicle control based on the two target objects Ta, Tb existing in the estimated trajectory of the three target objects Ta, Tb, Tc. The alarm means 12 and the brake actuator 13 can be activated.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the contact damage reduction support system is exemplified as the vehicle control means M5. However, the vehicle control means M5 is not limited to the contact damage reduction support system. For example, when there is no preceding vehicle, the vehicle speed is set at a predetermined vehicle speed. The present invention can also be applied to an ACC system (adaptive cruise control system) that travels and keeps a predetermined inter-vehicle distance while a preceding vehicle is present.

  In the embodiment, the millimeter wave radar device Sr is exemplified as the transmission / reception means, but other means such as a laser radar device can be adopted.

Overall configuration diagram of the travel control device Graph showing the waveform and peak frequency of transmitted / received waves when an object is moving close to the transmitting / receiving antenna Graph showing peak signal detected by detection peak determination means Block diagram showing the circuit configuration of the arithmetic processing unit of the radar device The figure which shows the field which separates the target vehicle The figure which shows the state which put together the large vehicle and small vehicle which run in front of the own vehicle as a single target vehicle The figure which shows the state which separated the small vehicle from the large vehicle once collected Flow chart explaining operation The figure corresponding to the said FIG. 6 based on 2nd Example of this invention.

Explanation of symbols

M1 Object information calculation means M2 Integration means M3 Position output means M4 Separation means M4 ′ Reseparation means M5 Vehicle control means M6 Trajectory estimation means Sr Millimeter wave radar device (transmission / reception means)
Va own car

Claims (4)

Transmission / reception means (Sr) for transmitting an electromagnetic wave toward a predetermined area in the traveling direction of the host vehicle (Va) and receiving a reflected wave from an object existing in the predetermined area;
Object information calculation means (M1) for calculating the position of the object relative to the host vehicle (Va) based on the transmission / reception result of the transmission / reception means (Sr);
An integration unit (M2) that combines the plurality of objects as one target object (Ta) based on at least the position of the plurality of objects when the plurality of objects are detected within the predetermined range (A);
Trajectory estimation means (M6) for estimating the future travel trajectory of the host vehicle (Va);
When the target object (Ta) collected by the integration means (M2) exists in the estimated locus, the traveling state of the host vehicle (Va) is controlled according to the positional relationship between the target object (Ta) and the host vehicle. Vehicle control means (M5),
In a vehicle travel control device comprising:
A representative of one target object (Ta) collected by the integration means (M2) with reference to the position of the object existing in the small range (a) on the side close to the host vehicle (Va) in the predetermined range (A). Position output means (M3) for outputting a position ;
Any one of the positions of the plurality of integrated objects is at least a first predetermined distance (d0, d1) from the representative position, and any of the positions of the plurality of integrated objects is own vehicle (Va ) Separating means for separating the one target object (Ta) into separate target objects (Ta, Tb, Tc) existing inside and outside the estimated locus of the host vehicle (Va). (M4) and equipped with a,
When there is a single object in the small range (a), the position output means (M3) uses the position of the single object as the representative position, and a plurality of objects exist in the small range (a). When the vehicle travels, a vehicle travel control device that outputs, as the representative position, a region between two objects existing at both ends in the left-right direction of the plurality of objects .   2. The vehicle according to claim 1, wherein the integration unit (M <b> 2) collects objects existing within a predetermined range (A) based on a position of one of the plurality of objects. Travel control device. Instead of the separating means (M4), when two or more objects are present in the estimated trajectory among a plurality of objects collected by the integrating means (M2), the left-right direction between the two or more objects characterized by comprising a re-separation unit (M4 ') to the distance of re-separating the second predetermined distance (d2) or more objects to each other as a separate target object (Tb, Tc), according to claim 1, wherein Item 3. The vehicle travel control device according to Item 2 . Instead of the separation means (M4), when two or more objects are present in the estimated locus among the plurality of objects collected by the integration means (M2), the front-rear direction between the two or more objects A re-separation means (M4 ') for re-separating objects having a distance equal to or greater than a third predetermined distance (d3) as separate target objects (Tb, Tc) is provided. Item 4. The vehicle travel control device according to any one of item 3 .

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