JP2009133781A - Obstacle detector for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To readily as well as accurately detect whether an object in front of a vehicle is an obstacle. <P>SOLUTION: An object detection sensor 4 detects the positional information of an object to a vehicle 1, a vehicle speed sensor 2 detects vehicle speed, and a rotational angular velocity sensor 3 detects a yaw rate. An ECU 5 estimates the expected course of the vehicle 1 from the vehicle speed and yaw rate; computes the angular velocity from the yaw rate, calculates the amount of offset of the object from the estimated, expected course; determines the risk determination range, corresponding to the computed angular velocity, based on the corresponding relationship, stored in advance; and determines that the object is an obstacle that would collide with the vehicle 1, when the amount of offset of the object lies within the risk determination range. The risk determination range is set to be shifted more in the occurrence direction of angular velocity on the front side, in the advancing direction of the vehicle 1, when angular velocity is produced, than when there angular velocity is not produced in the vehicle 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an obstacle detection device mounted on a vehicle.

  Japanese Patent Application Laid-Open No. 11-23705 discloses a relative distance calculation that calculates a relative distance between a detection value of a vehicle detection unit that detects a vehicle speed of an own vehicle and an object that exists in the traveling direction of the vehicle based on a radar detection result. The object detected by the radar based on the calculated value of the means and the calculated value of the overlap amount calculating means for calculating the overlap amount of the own vehicle and the object in the vehicle width direction of the own vehicle based on the detection result of the radar An obstacle detection device for a vehicle in which an obstacle determination means determines whether or not an obstacle is an obstacle is disclosed.

  The obstacle determination means avoids the object detected by the radar based on the overlap amount calculated by the overlap amount calculation means, the relative distance calculated by the relative distance calculation means, and the vehicle speed detected by the vehicle speed detection means. Therefore, the limit distance required between the vehicle and the object is calculated, and the first set distance determined based on the calculated distance is compared with the relative distance calculated by the relative distance calculation means. As a result of the comparison, when the relative distance is equal to or less than the first set distance, an alarm is issued by the notification means.

Japanese Patent Laid-Open No. 11-23705 JP-A-9-175295

  However, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 11-23705, for example, when there is an object (for example, a signboard or a sign) that is stationary off the road on the front extension line of a straight road that curves forward, There is a possibility that the radar of this vehicle will detect the object and the obstacle determination means will erroneously determine the object as an obstacle. In other words, when the vehicle enters the curve from the straight road, the overlap amount calculated by the overlap amount calculation means gradually decreases, but depending on the vehicle speed, the curvature of the curve and the position of the object, At the initial stage of turning, the overlap amount is not sufficiently reduced, and an object that is not an obstacle is erroneously determined as an obstacle, and an alarm is issued.

  This warning can be stopped by the vehicle's approach into the curve and the amount of overlap being sufficiently reduced, but when the warning is triggered by an object that can be clearly recognized as not being an obstacle, This makes the driver of the vehicle feel uncomfortable and annoying.

  Also, the radar detection accuracy is limited, and the overlap amount calculation means cannot calculate the overlap amount strictly. For this reason, it is necessary for the obstacle determination means to determine whether or not the object is an obstacle in consideration of the detection error of the radar, and it is extremely difficult to determine that the object is not an obstacle at the initial turning stage. Have difficulty.

  Therefore, an object of the present invention is to provide an obstacle detection device that can determine whether an object in front of a vehicle is an obstacle early and accurately.

  In order to achieve the above object, the obstacle detection apparatus of the present invention comprises an object detection means, vehicle information detection means, course estimation means, angular acceleration acquisition means, storage means, and collision determination means.

  The object detection means detects position information of the object existing ahead in the traveling direction of the vehicle with respect to the vehicle. The vehicle information detection means detects the running state information of the vehicle. The course estimation means estimates the expected course of the vehicle based on the traveling state information detected by the vehicle information detection means. The angular acceleration acquisition means acquires angular acceleration generated in the vehicle by turning the vehicle.

  The storage means stores in advance a correspondence relationship between the risk determination range for the predicted course of the vehicle and the angular acceleration generated in the vehicle. The collision determination unit obtains the position of the object with respect to the predicted path estimated by the path estimation unit from the position information detected by the object detection unit, and the risk determination range corresponding to the angular acceleration acquired by the angular acceleration acquisition unit is stored in the storage unit. The position of the object with respect to the predicted path is compared with the determined risk determination range, and the object collides with the vehicle when the position of the object with respect to the predicted path is included in the determined risk determination range. It is determined that there is an obstacle that may be. The danger judgment range is set so that the vehicle is shifted in the direction in which the angular acceleration occurs in the forward direction of the vehicle when the vehicle is experiencing angular acceleration, compared to the case where no angular acceleration is occurring. Yes.

  The vehicle information detection means may detect the vehicle speed and angular velocity of the vehicle.

  Further, the angular acceleration acquisition means may directly detect the angular acceleration generated in the vehicle, or acquire the angular acceleration by sequentially detecting the angular velocity of the vehicle and calculating the temporal change rate of the detected angular velocity. May be.

  In addition, the risk determination range when the absolute value of the angular acceleration generated in the vehicle is equal to or less than the predetermined value is set in the same manner as when the angular acceleration is not generated, and the absolute value of the angular acceleration exceeds the predetermined value. In this case, the risk determination range may be set so as to shift in the direction in which the angular acceleration is generated on the front side in the traveling direction of the vehicle as compared with the case where the angular acceleration is not generated.

  In the above configuration, the object detection means detects the position information of the object with respect to the vehicle, the course estimation means estimates the expected course of the vehicle based on the traveling state information detected by the vehicle information detection means, and the angular acceleration acquisition means When the generated angular acceleration is acquired, the collision determination unit obtains the position of the object with respect to the predicted path estimated by the path estimation unit from the position information detected by the object detection unit, and the danger corresponding to the angular acceleration acquired by the angular acceleration acquisition unit The determination range is determined based on the correspondence stored in the storage means, the position of the object with respect to the predicted course is compared with the determined risk determination range, and the position of the object with respect to the predicted path is included in the determined risk determination range. The object is determined to be an obstacle that may collide with the vehicle.

  Therefore, for example, when there is an object (eg, a signboard or a sign) that is stationary and deviated from the road on the forward extension line of the straight road that curves forward, the traveling direction of the vehicle while the vehicle is traveling on the straight road There is always an object on or in the vicinity of the extension line, and the position of the object indicated by the position information of the object coincides with or is close to the expected course of the vehicle. For this reason, while the vehicle is traveling on a straight road, the position of the object is included in the danger determination range, and the object is determined to be an obstacle.

  Subsequently, at the initial turning stage when the vehicle enters the curve from the straight road, the vehicle starts to turn while the angular acceleration occurs, and the expected course of the vehicle moves away from the object. It still exists on or near the extension line in the direction of travel, and the object is not sufficiently separated from the expected course. For this reason, if the determination of whether or not an object is an obstacle is performed using the risk determination range set in the same manner as when the vehicle is traveling straight ahead, it is determined that the object is an obstacle. There is a high possibility of being done.

  Here, when the angular acceleration is generated in the vehicle, the actual course of the vehicle is very likely to shift in the direction in which the angular acceleration is generated than the expected course. In the present invention, in consideration of the actual course of the vehicle, the vehicle is shifted in the direction of occurrence of angular acceleration on the front side in the traveling direction of the vehicle, compared with the case where angular acceleration is not occurring in the vehicle. The risk judgment range is set as follows. For this reason, in the initial turning stage in which the angular acceleration is generated in the vehicle, there is a high possibility that the object is determined not to be an obstacle out of the danger determination range. Therefore, it is possible to determine whether an object is an obstacle early and accurately.

  Further, the danger determination range may be set so as to be largely shifted in the direction in which the angular acceleration is generated as the angular acceleration generated in the vehicle increases.

  In the above configuration, since the danger determination range is shifted in accordance with the magnitude of the angular acceleration generated in the vehicle, it is possible to more accurately determine whether the object is an obstacle.

  ADVANTAGE OF THE INVENTION According to this invention, it can determine early and exactly whether the detected object becomes an obstruction.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a block diagram showing a main part of a vehicle equipped with an obstacle detection device according to an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining detection by the object detection sensor of FIG. 1, and FIG. 3 is an obstacle. FIG. 4 is a schematic diagram for explaining the tracking process, FIG. 5 is a schematic diagram for explaining the offset amount, FIG. 6 is a flowchart showing the target risk determination process of FIG. 3, and FIG. FIG. 8 is a flowchart showing the target risk continuation determination process of FIG. 3, and FIG. 8 is a schematic diagram showing a risk determination map.

  As shown in FIG. 1, a vehicle 1 according to this embodiment includes a vehicle speed sensor 2, a rotational angular velocity sensor (gyro sensor) 3, an object detection sensor 4, an ECU (Electric Control Unit) 5, a brake actuator 6, and an alarm device 7. A seat belt retractor 8. The vehicle speed sensor 2 and the rotational angular velocity sensor 3 constitute vehicle information detection means, the object detection sensor 4 constitutes object detection means, and the rotational angular velocity sensor 3 constitutes angular acceleration acquisition means.

  The vehicle speed sensor 2 detects a vehicle speed V (m / s) as travel state information of the vehicle 1 every predetermined time, and outputs the detected vehicle speed V to the ECU 5. The rotational angular velocity sensor 3 detects a yaw rate Yaw (angular velocity: rad / s) as traveling state information generated in the vehicle 1 during a turn traveling at a predetermined time with the left rotation as a positive direction, and the detected yaw rate Yaw is sent to the ECU 5. Output.

  As shown in FIG. 2, the object detection sensor 4 transmits an electromagnetic wave such as a laser or a millimeter wave radar at a predetermined time from the front end of the vehicle 1 within a range of a predetermined angle β ahead of the traveling, and the reflected wave thereof. Is received, the object (target) TG within the above range is detected, the relative speed RV between the vehicle 1 and the target TG is detected, and the position information (position data TGD) of the target TG relative to the vehicle 1 is represented by the vehicle coordinates. It is detected as coordinate values of the X coordinate and Y coordinate in the system, and the detected relative speed RV and coordinate value are output to the ECU 5. The relative speed RV is detected with the direction in which the vehicle 1 and the target TG are separated from each other as the positive direction. The vehicle coordinate system is a two-dimensional coordinate system in which the left direction of the vehicle 1 is set as the X axis positive direction and the traveling direction of the vehicle 1 is set as the Y axis positive direction. FIG. 2 illustrates a case where the presence of five targets TGa to TGe is detected. For example, position information of the target TGa is detected as coordinate values (Xa, Ya). In the following description, the horizontal position of the target TG means the X coordinate value of the target TG in the vehicle coordinate system, and the vertical position of the target TG means the Y coordinate value of the target TG in the vehicle coordinate system.

The ECU 5 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU constitutes an angular acceleration acquisition unit, a course estimation unit, and a collision determination unit, reads a program stored in a ROM as a storage unit, and executes each process described later. This program includes a risk determination map (shown in FIG. 8) showing the correspondence between the risk determination area A set for the expected course Tr of the vehicle 1 and the angular acceleration α (rad / s ² ) generated in the vehicle 1. )It is included. The CPU estimates the expected course Tr of the vehicle 1 using the vehicle speed V detected by the vehicle speed sensor 2 and the yaw rate Yaw detected by the rotational angular velocity sensor 3. Further, every time the rotational angular velocity sensor 3 detects the yaw rate Yaw, the CPU calculates an angular acceleration α that is a temporal change rate. The RAM can freely read and write the vehicle speed V detected by the vehicle speed sensor 2, the yaw rate Yaw detected by the rotational angular velocity sensor 3, the position data TGD and the relative speed RV detected by the object detection sensor 4, and the angular acceleration α calculated by the CPU. Has a storage area for storing. The detected position data TGD and the relative speed RV of the target TG are stored in association with a unique identification number ID and a collision risk flag described later. The collision risk flag is set to ON when it is determined that the vehicle 1 may collide with the target TG, and is set to OFF when it is determined that the vehicle 1 does not collide with the target TG. Is done. Further, when the CPU executes a tracking process described later and determines that the same target TG is the same, the same identification number ID is assigned to the same target TG. Further, the RAM is provided with a plurality of storage areas for accumulating and storing count values of continuation counters to be described later, and an identification number ID is associated with each storage area. Further, the latest data is sequentially updated and stored in the vehicle speed V and the yaw rate Yaw. In addition, the coordinate value and relative velocity RV data detected by the object detection sensor 4 can be sequentially stored in a time series up to a predetermined number (for example, 30), and when the predetermined number is exceeded, old data is sequentially deleted. The latest data is stored. Further, for the target TG that the CPU has already determined to not exist in front of the vehicle 1, all the position data TGD to which the identification number ID of the target TG is assigned is deleted.

  When the brake actuator 6 receives a braking instruction signal from the ECU 5, the brake actuator 6 forcibly operates disc brakes for front wheels and rear wheels (not shown) to generate a predetermined braking force on each wheel.

  The alarm device 7 is provided, for example, on an instrument panel (not shown) in the passenger compartment, and generates a buzzer sound or the like to alert the driver when receiving a notification instruction signal from the ECU 5.

  When the seat belt retractor 8 receives the seat belt lock instruction signal from the ECU 5, the seat belt retractor 8 prohibits the withdrawal of the seat belt (not shown) and maintains the restraint state of the occupant by the seat belt.

  Next, the danger determination map will be described.

  As shown in FIG. 8, in the risk determination map, a correspondence relationship between the risk determination area A with respect to the expected course Tr of the vehicle 1 and the angular acceleration α generated in the vehicle 1 is set. In FIG. 8, the vertical axis (upward is positive) is the angular acceleration α, and the horizontal axis (left direction is positive) is the offset value from the expected course Tr.

  In the risk determination area A of the present embodiment, the progress of the vehicle 1 is greater in the risk determination range when the angular acceleration α occurs in the vehicle 1 than in the risk determination range when the angular acceleration α does not occur. It is set to shift in the direction in which the angular acceleration α is generated on the front side in the direction. Further, the danger determination area A is set so that the risk determination range is largely shifted in the direction of occurrence of the angular acceleration α on the front side in the traveling direction of the vehicle 1 as the angular acceleration α generated in the vehicle 1 increases.

For example, when the angular acceleration α is not generated, the danger determination range is a range of ± P ₀ from the expected course Tr (the left threshold is P ₀ and the right threshold is −P ₀ ), and the coordinate value of the target TG When the distance (offset amount D) between (X, Y) and the predicted course Tr is −P ₀ or more and P ₀ or less (−P ₀ ≦ D ≦ P ₀ ), the target TG may collide with the vehicle 1. It is determined that it is an obstacle. Here, regardless of the occurrence of the angular acceleration α, when the offset amount D of the target TG is −P ₀ or more and P ₀ or less, the danger determination region B when determining that the target TG is an obstacle is an angle Even if the acceleration α increases or decreases, the left and right threshold values (P ₀ , −P ₀ ) of the risk determination range are constant. In contrast, the risk determination range of the risk determination area A increases in the direction in which the angular acceleration α is generated on the front side in the traveling direction of the vehicle 1 as the magnitude (absolute value) of the angular acceleration α generated in the vehicle 1 increases. The left and right thresholds increase in proportion to the angular acceleration α. That is, the danger determination area A is inclined in the left rotation direction with respect to the danger determination area B in FIG. For example, in the danger determination area A, when the angular acceleration generated in the vehicle 1 is α ₁ , the left and right thresholds of the danger determination range are P _1L , −P _1R (P _1L > P ₀ , −P _1R > −P ₀ ) and, when the angular acceleration is-.alpha. _1, the left and right threshold risk determination range _{P 2L, -P 2R (P 0} > P 2L, a _-P 0> -P _2R). If the magnitude (absolute value) of the angular acceleration α exceeds a predetermined upper limit value α ₀ , the behavior of the vehicle 1 becomes unstable, and whether or not the target TG is an obstacle depending on the relationship between the predicted course Tr and the offset amount D. Since it is difficult to accurately determine whether or not, the risk determination areas A and B are set in a range of −α ₀ or more and α ₀ or less.

  The reason why the risk determination area A is shifted as described above is as follows.

  For example, as shown in FIG. 9, when the vehicle 1 starts turning in the right direction, the target TGa existing on the left side of the expected course Tr of the vehicle 1 moves away from the origin as indicated by an arrow Qa in the state plane of FIG. The target TGb existing on the right side of the expected course Tr of the vehicle 1 approaches the origin as indicated by an arrow Qb in the state plane of FIG. For this reason, by shifting the risk determination area A as described above, the target TGa moving away from the vehicle 1 is early removed from the risk determination area A, and the target TGb approaching the vehicle 1 is included in the risk determination area A early. become. In other words, in the risk determination area A, the target TG moves away so that the risk determination range is substantially narrowed in the case of the target TGa moving away, and the risk determination range is substantially widened in the case of the approaching target TGb. Depending on whether or not it is approaching. Therefore, it is possible to determine whether the target TGa and the target TGb are obstacles early and accurately. Note that, when the angular acceleration α does not occur, such as straight running or turning with a constant curvature radius, the left and right threshold values of the danger determination range are constant.

  Next, processing executed by the ECU 5 will be described based on the flowchart of FIG.

  This process is executed every predetermined time. First, the ECU 5 reads each data (step S1). That is, the vehicle speed V detected by the vehicle speed sensor 2 and the yaw rate Yaw detected by the rotational angular velocity sensor 3 are updated and stored, and the position data TGD and the relative speed RV of all the target TGs detected by the object detection sensor 4 are stored. Remember. Further, the ECU 5 calculates and stores the angular acceleration α as a temporal change rate of the yaw rate Yaw detected by the rotational angular velocity sensor 3.

  Next, the ECU 5 executes a process for creating own vehicle data (step S2). The own vehicle data creation process is a process of estimating the expected course (estimated trajectory) Tr of the vehicle 1 using the vehicle speed V and the yaw rate Yaw read in step S1. The expected course Tr is calculated according to the following equation (1) as the radius of curvature R when the vehicle 1 turns from the current position.

  R = V / Yaw (1)

  Next, the ECU 5 executes a tracking process (step S3). The tracking process is a process of storing the target (currently detected target) TGnew corresponding to the position data TGD read in step S1 and the target TGpast detected and stored in the past in a time series. That is, it is determined whether or not the target TGnew detected this time and the target TGpast already stored are the same. If it is determined that they are the same, the position data TGDnew of the target TGnew detected this time is already stored. The same identification number ID as the identification number ID of the target TGpast is assigned and stored. Thus, by assigning the same identification number ID, the current and past position data TGD and the relative speed RV of the same target TG can be appropriately read out as necessary. On the other hand, when it is determined that the target is a new target TGnew, a new identification number ID is assigned to the position data TGDnew of the target TGnew detected this time and stored. When a new identification number ID is given, a storage area that is not currently used among a plurality of storage areas that store the count value of the continuation counter (all position data TGD of the associated identification number ID has already been erased) The new identification number ID is associated with a storage area that does not exist), and the count value of the storage area is cleared.

  Whether or not the target TGnew detected this time and the target TGpast already stored are the same is determined by, for example, subtracting the horizontal position Xk, the vertical position Yk, and the relative velocity RVk of the target TGpast stored at the time of the previous data reading. By substituting into the equation (2), the planned position (Xk + 1, Yk + 1) where the target TGpast is estimated to be present at the time of reading this data is calculated, and the calculated planned position (Xk + 1, Yk +) is calculated. It is determined whether or not the coordinate value (Xnew, Ynew) of the target TGnew read this time exists within a predetermined range from 1). When the target TGnew (Xnew, Ynew) read this time is within a predetermined range from the planned position (Xk + 1, Yk + 1), it is determined that the target TGpast and the target TGnew are the same, Determines that the target TGpast and the target TGnew are different targets.

  Xk + 1 = Xk + RVk × Δt × sin θ, Yk + 1 = Yk + RVk × Δt × cos θ (2)

  In the above equation (2), Δt is the time from the previous data reading time to the current data reading time (detection time interval of the target TG), and θ is the traveling direction of the target TGpast and the traveling of the vehicle 1. The angle formed by the direction (Y-axis direction). As for the traveling direction of the target TGpast, when the previous coordinate value (Xk, Yk) and the previous (previous) coordinate value (Xk-1, Yk-1) of the target TGpast are stored, as shown in FIG. Then, the vector direction from the previous coordinate value (Xk-1, Yk-1) to the previous coordinate value (Xk, Yk) is obtained. When the previous coordinate value (Xk-1, Yk-1) is not stored (when the target is newly detected last time), the traveling direction of the target TGpast is determined from the previous coordinate value (Xk, Yk). The vector direction toward the vehicle 1 is obtained.

  Next, the ECU 5 determines whether or not the processing of steps S5 to S8 described later has been completed for all the target TGnew read this time (step S4), and there is a target TGnew for which processing has not yet been completed. The unprocessed target TGnew is sequentially identified as the target TGnew to be processed, and the process proceeds to step S5. That is, only when the processing of step S5, step S6 and step S7, or the processing of step S5, step S6 and step S8 is executed for each target TGnew, and the processing is completed for all the targets TGnew, it will be described later. The process proceeds to step S9.

  In step S5, the ECU 5 creates obstacle data for the identified target TGnew to be processed. The obstacle data is a process of calculating a distance (offset amount Dnew of the current position) between the target TGnew (coordinate values (Xnew, Ynew)) to be processed and the expected course Tr of the vehicle 1. Specifically, as shown in FIG. 5, in the vehicle coordinate system, the distance between the coordinate value (Xnew, Ynew) of the target TGnew to be processed read in step S1 and the expected course Tr of the vehicle 1 obtained in step S2. (Offset amount Dnew of the current position) is calculated by the following equation (3) using the coordinate value (Xnew, Ynew) and the curvature radius R of the expected course Tr.

Dnew = R / | R | × ((Xnew−R) ² + Ynew ² ) ^1/2 − | R |) (3)

  Next, whether or not the collision risk flag associated with the processing target TGnew at the previous detection (the collision risk flag associated with the position data TGDpast when the processing target TGnew was previously detected) is on. It is determined whether or not (step S6). When the collision risk flag is off, the process proceeds to step S7 to execute the target risk determination process, and when the collision risk flag is on, the process proceeds to step S8 to execute the target risk continuation determination process. Even when the target TGnew to be processed is a newly detected target TG, the processing is performed assuming that the collision risk flag is off.

  In the target risk determination process (step S7), as shown in FIG. 6, the offset Dnew of the current position obtained in step S5 with respect to the target TGnew to be processed corresponds to the angular acceleration α read in step S1. It is determined whether it is included in the risk determination area A (shown in FIG. 8) (step S11). If included, the process proceeds to step S12 and the count value of the continuation counter associated with the target TGnew to be processed Is increased by 1, and the process proceeds to step S14. On the contrary, when the offset amount Dnew of the current position is not included in the danger determination area A, the process proceeds to step S13, the count value of the continuation counter associated with the target TGnew to be processed is cleared, and the process proceeds to step S14.

  In step S14, it is determined whether or not the count value of the continuation counter exceeds a predetermined threshold value N (for example, N = 4). As a result of the determination, if the count value exceeds the threshold value N, it is determined that the target TGnew to be processed is an obstacle that may collide with the vehicle 1, and the process proceeds to step S15 and the target of processing is processed. The collision risk flag associated with the position data TGDnew of the target TGnew is set to on. On the other hand, if the count value is less than or equal to the threshold value N, it is determined that the target TGnew to be processed is not the obstacle, and the process proceeds to step S16 to collide with the position data TGDnew of the target TGnew to be processed. Set the danger flag off. By executing the process in step S15 or step S16, the target risk determination process is terminated, and the process returns to step S4 in FIG.

  As described above, the target risk determination process is executed when the collision risk flag associated with the position data TGDpast when the target TGnew to be processed is detected last time is off. The collision risk flag associated with the current position data TGDnew of the target TGnew to be processed is the risk determination that the offset Dnew of the current position of the target TGnew to be processed is N times retroactively from the current time. It is set to ON only when included in the area A, and is set to OFF in other cases.

  On the other hand, in the target risk continuity determination process (step S8), as shown in FIG. 7, the offset Dnew of the current position obtained in step S5 with respect to the target TGnew to be processed is the angular acceleration read in step S1. It is determined whether or not it is included in the risk determination area A (shown in FIG. 8) corresponding to α (step S21). If not included, it is determined that the target TGnew to be processed is no longer the obstacle, In step S23, the collision risk flag associated with the position data TGDnew of the target TGnew to be processed is set to OFF. On the other hand, when the offset amount Dnew of the current position is included in the danger determination area A, it is determined that the target TGnew to be processed continues to exist as the obstacle, and the process proceeds to step S22 and the processing target is processed. The collision risk flag associated with the position data TGDnew of the target TGnew is set to ON.

  Then, by executing the process of step S22 or step S23, the target risk continuation determination process is terminated, and the process returns to step S4 of FIG.

  As described above, the target risk continuation determination process is executed when the collision risk flag associated with the position data TGDpast when the target TGnew to be processed was previously detected is on. Thus, the collision risk flag associated with the current position data TGDnew of the target TGnew to be processed is set to ON when the risk determination area A includes the offset amount Dnew of the current position of the target TGnew to be processed. Otherwise, it is set to off.

  If it is determined in step S4 that the processing in steps S5 to S8 has been completed for all the targets TGnew read this time, the process proceeds to step S9, and risk priority determination processing is executed.

  In the risk priority determination process, first, for all targets TGnew for which the collision danger flag is set to ON, the expected time (collision expected time TTC) required for the vehicle 1 to collide with the target TGnew is determined as the target TGnew and the vehicle 1 When the minimum time (estimated collision time) of all the estimated collision times TTC obtained is less than or equal to the predetermined time t1 seconds, a notification instruction signal is transmitted to the alarm device 7. The buzzer sound is generated by the alarm device 7. Further, when the shortest expected collision time is equal to or shorter than the predetermined time t2 (t2 <t1) seconds, a braking instruction signal is transmitted to the brake actuator 6 to generate a predetermined braking force on each wheel and to retract the seat belt. A seat belt lock instruction signal is transmitted to 8, and the withdrawal of the seat belt is prohibited. Note that the relative distance between the target TGnew and the vehicle 1 may be calculated from the position data TGDnew of the target TGnew, or may be directly detected by the object detection sensor 4.

  Next, referring to FIG. 9 and FIG. 10, the vehicle 1 travels on a road where a stationary target (for example, a signboard or a sign) TG exists on the forward extension line of a straight road that curves forward and is out of the road 10. The case where it does is demonstrated.

  As shown in FIG. 10, while the vehicle 1 travels straight on a straight road, the target TGa always exists on or in the vicinity of the extension line in the traveling direction of the vehicle 1, and the radius of curvature R of the expected course Tr of the vehicle 1. Becomes infinite, the expected course Tr substantially coincides with the Y axis, and the current position data TGDnew of the target TGa is located on the Y axis (on the expected course Tr). In addition, since the angular acceleration α does not occur during straight traveling, the equidistant range from the predicted course Tr toward the left and right sides is the danger determination area A. For this reason, the distance (current offset amount Dnew) between the current position data TGDnew and the expected course Tr is included in the danger determination area A. Accordingly, while the vehicle 1 is traveling on a straight road, whenever the ECU 5 detects the target TG, the ECU 5 determines that the target TG is an obstacle, and sets the collision risk flag to ON and stores it. However, in this case, since the vehicle 1 and the target TG are sufficiently separated from each other, there is a high possibility that the predicted collision time TTC exceeds t1 seconds, and the possibility that a buzzer sound is generated is low.

  Next, at the initial stage when the vehicle 1 enters the curve from the straight road, as shown in FIG. 9, the vehicle 1 starts turning, and the expected course Tr of the vehicle 1 is separated from the Y axis with a radius of curvature R. However, the target TGa still exists on the extension line in the traveling direction of the vehicle 1 or in the vicinity thereof, and the current position data TGDnew of the target TGa is located immediately on the left side of the expected course Tr. Here, since the angular acceleration α is generated in the clockwise direction in the vehicle 1 that has started turning rightward, the danger determination area A is located on the left side of the expected course Tr compared to the case where the angular acceleration α is not generated. The range becomes narrower. For this reason, the distance between the current position data TGDnew and the expected course Tr (current offset amount Dnew) is likely to deviate from the danger determination area A, and it is determined early whether the target TGa is an obstacle. And it can be done accurately. Accordingly, it is highly likely that the target TGa is determined not to be an obstacle before the predicted collision time TTC reaches t1 seconds (before the buzzer is emitted), which makes the driver of the vehicle 1 feel uncomfortable and annoying. You can suppress the feeling.

  As described above, according to this embodiment, the vehicle 1 shifts in the direction in which the angular acceleration α is generated on the front side in the traveling direction of the vehicle 1 as compared with the case where the angular acceleration α is generated in the vehicle 1. A risk determination area A is set as described above. For this reason, in the initial turning stage in which the angular acceleration α occurs in the vehicle 1, there is a high possibility that the target TG is determined to be out of the danger determination area A and not an obstacle. Therefore, it is possible to determine whether the target TG is an obstacle early and accurately.

  Further, since the danger determination area A is set so as to be largely shifted in the direction of generation of the angular acceleration α on the front side in the traveling direction of the vehicle 1 as the angular acceleration α generated in the vehicle 1 increases, The danger determination area A shifts corresponding to the magnitude of the angular acceleration α to be performed, and it is possible to more accurately determine whether or not the target TG is an obstacle.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  For example, in the above embodiment, the estimated course Tr of the vehicle 1 is estimated using the vehicle speed V detected by the vehicle speed sensor 2 and the yaw rate Yaw detected by the rotational angular velocity sensor 3, but the steering angle sensor detects the steering. The predicted course Tr may be estimated using other traveling state information such as the steering angle and the acceleration of the vehicle 1 detected by the acceleration sensor.

  In addition, although the angular acceleration α is calculated as the temporal rate of change of the yaw rate Yaw, an angular acceleration sensor that directly detects the angular acceleration α may be provided.

  In addition, although the risk determination area A that linearly shifts according to the angular acceleration α is used, a risk determination area that shifts stepwise may be used. Furthermore, the risk determination area when the absolute value of the angular acceleration α generated in the vehicle 1 is equal to or less than the predetermined value is set in the same manner as when the angular acceleration α is not generated, and the absolute value of the angular acceleration α is the predetermined value. The risk determination area when the vehicle speed exceeds the range may be set so as to shift in the direction in which the angular acceleration α is generated on the front side in the traveling direction of the vehicle 1 as compared with the case where the angular acceleration α is not generated.

  Further, in the target risk determination process and the target risk continuation determination process, the same risk determination area A is used. However, a plurality of risk determination areas may be prepared in advance, and different risk determination areas may be used in both processes. .

  In addition, the correspondence relationship between the risk determination area A with respect to the predicted course Tr of the vehicle 1 and the angular acceleration α generated in the vehicle 1 is set as a risk determination map, but instead, it may be set by a table or an arithmetic expression.

  Furthermore, in the target risk continuation determination process, when the offset amount Dnew of the current position of the target TGnew to be processed is included in the risk determination area A, the target position TGnew using the past position data TGDpast of the target TGnew to be processed is used. It may be determined whether TGnew is an obstacle. In this case, for example, the past position data TGDpast of the target TGnew to be processed is selected with the risk determination flag set to ON, and the selected past position data TGDpast (coordinate values (Xpast, Ypast)) The distance between the current vehicle 1 and the predicted course Tr of the current vehicle 1 is calculated for all the past positions selected as in the case of the current position data TGDnew, and the average value of the calculated past position offsets Dpast is calculated. Is calculated as an average value IniD of the offset amount, and it is determined whether or not the calculated average value IniD of the offset amount is included in the danger determination area A. If not included, it is determined that the target TGnew is not an obstacle. That's fine.

  The obstacle detection device of the present invention can be used by being mounted on various vehicles.

It is a block diagram which shows the principal part of the vehicle provided with the obstacle detection apparatus which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the detection by the object detection sensor of FIG. It is a flowchart which shows an obstruction detection process. It is a schematic diagram for demonstrating tracking processing. It is a schematic diagram for demonstrating offset amount. It is a flowchart which shows the target risk degree determination process of FIG. It is a flowchart which shows the target risk continuation determination process of FIG. It is a schematic diagram which shows a danger determination map. It is a schematic diagram which shows the state which the vehicle approached into the curve from the straight road. It is a schematic diagram which shows the state which a vehicle drive | works the straight road which curves ahead.

Explanation of symbols

1: Vehicle 2: Vehicle speed sensor (vehicle information detection means)
3: Rotational angular velocity sensor (vehicle information detection means, angular acceleration acquisition means)
4: Object detection sensor (object detection means)
5: ECU (angular acceleration acquisition means, storage means, course estimation means, collision determination means)
6: Brake actuator 7: Alarm device 8: Seat belt retractor

Claims (2)

Object detection means for detecting position information of the object existing in front of the traveling direction of the vehicle relative to the vehicle;
Vehicle information detection means for detecting travel state information of the vehicle;
A route estimation unit that estimates an expected route of the vehicle based on the traveling state information detected by the vehicle information detection unit;
Angular acceleration acquisition means for acquiring angular acceleration generated in the vehicle by turning of the vehicle;
Storage means in which a correspondence relationship between a risk determination range for the predicted course of the vehicle and an angular acceleration generated in the vehicle is stored in advance;
The position of the object with respect to the expected course estimated by the course estimation unit is obtained from the position information detected by the object detection unit, and a risk determination range corresponding to the angular acceleration acquired by the angular acceleration acquisition unit is stored in the storage unit. The position of the object with respect to the predicted path is compared with the determined risk determination range, and the position of the object with respect to the predicted path is included in the determined risk determination range, Collision determination means for determining that an object is an obstacle that may collide with the vehicle,
The danger determination range shifts in the direction in which the angular acceleration is generated on the front side in the traveling direction of the vehicle when the angular acceleration is generated in the vehicle than when the angular acceleration is not generated. An obstacle detection device for a vehicle, characterized in that it is set as follows. The obstacle detection device according to claim 1,
The vehicle obstacle detection device, wherein the danger determination range is set so as to be largely shifted in accordance with an increase in angular acceleration generated in the vehicle.

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