JP5071885B2 - Vehicle obstacle detection device - Google Patents

Description

  The present invention relates to an obstacle detection device for a vehicle that controls an operation device of the vehicle according to a detection state by an obstacle detection means using a radar.

  2. Description of the Related Art Conventionally, an obstacle for a vehicle has obstacle detection means for detecting an obstacle ahead of the host vehicle, and operating equipment control means for controlling the operating equipment of the vehicle in accordance with the detected state of the obstacle by the obstacle detection means. Sensing devices are known.

  The vehicle obstacle detection device disclosed in Patent Document 1 includes a PRE CLASH SAFTY SYSTEM (PCS control) that controls an operation device such as a notification or a brake according to an obstacle detection state, and detects a predetermined driving operation state. In such a case, it has been proposed to delay the operation timing of the operating device so that the operating device is not operated in the case where an obstacle does not collide with the host vehicle if the driving state is kept as it is. That is, there are roughly two types of obstacles detected by the obstacle detection means, one is an obstacle that will be dangerous for the host vehicle if the current driving state is continued, and the other is the current driving state. Focusing on the fact that the obstacle does not collide with the host vehicle if it continues, it is not a true obstacle with a so-called collision risk, and even if an obstacle is detected, it is unnecessary to determine which obstacle This prevents a serious control. Thereby, the misrecognition of the obstacle can be prevented, and unnecessary notification and brake operation are prevented.

JP 2007-137126 A

  In Patent Document 1, it is possible to prevent erroneous recognition on an algorithm for an actual obstacle, but prevention of erroneous recognition due to the device itself is not considered. Currently, millimeter wave radars that have sharp directivity, can secure a wide band for high-speed communication, and can be miniaturized and miniaturized are effective as obstacle detection means. There is electromagnetic wave radiated above or radio wave that enters instantaneously from the gap of the radar housing, so-called electromagnetic noise, and there is a possibility that this noise detection may be mistakenly recognized as a normal reflected wave from an obstacle. is doing. This noise detection may recognize obstacles that do not actually exist, and may cause unnecessary notifications and operating devices such as brakes to operate.

  Such a countermeasure against erroneous recognition due to noise can usually determine whether or not an obstacle detected first is actually present by repeating radar detection a plurality of times. However, obstacle detection in the closest range is the most important factor in vehicle collision countermeasures. If an obstacle is detected in this area, there is no room to repeat the detection multiple times. A quick and accurate determination result of whether or not it is an object is required.

  The present invention provides an obstacle detection device for a vehicle that controls a vehicle operating device according to a detection state by an obstacle detection means using a radar, and prevents false detection caused by noise at a close distance. The purpose is to improve reliability.

According to another aspect of the present invention, there is provided an obstacle detection device for a vehicle according to obstacle detection means including radar means for detecting one or more obstacles of the own vehicle, and a detection state of each obstacle by the obstacle detection means. An obstacle determination means for determining whether or not the predetermined obstacle detected by the obstacle detection means is an obstacle detected for the first time;
Distance detecting means for detecting whether or not the distance between the obstacle detected by the obstacle detecting means and the own vehicle is within a predetermined distance, and the obstacle detected for the first time by the obstacle determining means is within a predetermined distance from the own vehicle. A radar output reduction means for reducing the radar output of the obstacle detection means at a certain time, and when the radar output reduction means operates, the received intensity of the reduced radar output from the obstacle according to the degree of reduction In the case where the obstacle does not decrease or is not received, the obstacle is excluded from the control target of the operating device control means.

  According to a second aspect of the present invention, there is provided the vehicle obstacle detection device according to the first aspect, wherein the obstacle detection means is a millimeter wave radar.

  In the vehicle obstacle detection device according to claim 3, in the invention according to claim 1 or claim 2, the operating device is a notification unit that notifies the occupant of the dangerous state. It is a notification means for notifying a dangerous state.

  According to a fourth aspect of the present invention, there is provided the vehicle obstacle detection device according to the first or second aspect, wherein the operating device is a brake means for applying a braking force to the vehicle.

  According to a fifth aspect of the present invention, there is provided the vehicle obstacle detection device according to the first or second aspect, wherein the operating device is a seat belt pretensioner that forcibly retracts the seat belt.

  According to the first aspect of the present invention, obstacle detection means including radar means for detecting one or more obstacles of the host vehicle, and the vehicle operating device according to the detection state of each obstacle by the obstacle detection means. An obstacle control means for controlling whether or not the predetermined obstacle detected by the obstacle detection means is an obstacle detected for the first time, and the obstacle detection means. Distance detecting means for detecting whether the distance between the detected obstacle and the own vehicle is within a predetermined distance; and when the obstacle detected for the first time by the obstacle determining means is within a predetermined distance from the own vehicle Radar output reduction means for reducing the radar output of the detection means, and when the radar output reduction means operates, the received intensity of the reduced radar output from the obstacle is reduced according to the degree of reduction. No, or since when received not exclude from the control target of the operation device control unit the obstacle, aims to prevent erroneous detection due to noise in the close range, it is possible to improve the reliability of obstacle detection. In other words, when the radar output is reduced, paying attention to the characteristic that the received intensity of the radar reflected from the obstacle decreases corresponding to the degree of the radar output decrease, the predetermined obstacle detected for the first time within the nearest predetermined distance When the reflected radar reception intensity is reduced corresponding to the output reduction degree of the irradiation radar, the operating device is controlled as an actual obstacle, and does not decrease corresponding to the output reduction degree of the irradiation radar. Alternatively, when not received, this obstacle is a non-existing obstacle caused by noise, and can be excluded from the control target of the operating device. In this way, the true / false judgment of the obstacle detected for the first time within a predetermined distance can be confirmed with the minimum judgment, and safe and smooth operation can be performed.

  According to the invention of claim 2, since the obstacle detection means is a millimeter wave radar, the relative speed of the obstacle can be measured directly even at the Doppler frequency, and each obstacle can be measured even when there are a plurality of obstacles. Don't mix things up. Furthermore, an obstacle detection hand that is small and advantageous in terms of cost can be obtained.

  According to the invention of claim 3, since the operating device is a notification means for notifying a passenger of a dangerous state, it is unnecessary when an obstacle detected for the first time within a predetermined distance is caused by noise. Information is avoided. For this reason, safe and smooth operation can be performed.

  According to the fourth aspect of the present invention, the operating device is a brake means that applies a braking force to the vehicle. Therefore, when an obstacle detected for the first time within the closest predetermined distance is caused by noise, an unnecessary braking force is generated. I try not to add it. For this reason, safe and smooth operation can be performed.

  According to the fifth aspect of the present invention, since the operating device is a brake means that applies a braking force to the vehicle, when an obstacle detected for the first time within a predetermined distance close to the vehicle is caused by noise, an unnecessary seat belt I am trying not to pull in. For this reason, safe and smooth operation can be performed.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a vehicle 1 including a vehicle obstacle detection device 2 according to the present invention. The obstacle detection device 2 includes a millimeter wave radar 3 as an obstacle detection means for detecting an obstacle ahead of the host vehicle 1. Millimeter waves have characteristics such as being able to have sharp directivity, ensuring a wide band for high-speed communication, and miniaturizing and micro-parts. As indicated by a thick line in FIG. 3, the detection range of the millimeter wave radar 3 is radially extended within a distance of approximately 100 m. In the present embodiment, the millimeter wave radar 3 is arranged offset to the right side from the center in the width direction of the vehicle 1, but it is not always necessary to be offset. Further, the obstacle detection means may be constituted by an infrared laser or the like.

  As shown in FIG. 2, the obstacle detection device 2 includes driving operation state detection means 5 that detects a predetermined driving operation state of the vehicle 1 by an occupant. The predetermined driving operation state means a driving operation state in which the vehicle 1 bends due to an operation of turning the steering wheel during a so-called curve or lane change, for example, when the vehicle 1 bends in the traveling direction.

  The obstacle detection device 2 includes a control unit 10 as an operation device control means for controlling an operation device of the vehicle 1 to be described later according to an obstacle detection state by the millimeter wave radar 3. The control unit 10 has a role of operating the operating device based on information from various sensors such as the driving operation state detection means 5 and the collision sensor 11.

  The obstacle detection device 2 includes an obstacle determination unit 12 that determines whether or not the obstacle detected by the millimeter wave radar 3 is an obstacle detected for the first time, the obstacle detected by the millimeter wave radar 3, and the own vehicle. A distance detecting means 13 for detecting whether the distance of the vehicle is within a predetermined distance, and a radar for reducing the radar output of the millimeter wave radar 3 when the obstacle detected for the first time by the obstacle determining means 12 is within the predetermined distance from the own vehicle. Output reduction means 14 is provided. The operating device has an alarm device 15 such as a horn for notifying a passenger of a dangerous state as a notification means. Note that the notification means may be constituted by a warning lamp on the instrument panel, a warning display on the car navigation system, or the like.

  As shown in FIG. 3, the alarm device 15 operates in a LONG alarm area A1 as a first operation timing and in a SHORT alarm area A2 as a second operation timing later than the first operation timing. It is configured. This LONG alarm area A1 has a wide area in which the obstacle 50 is detected by the millimeter wave radar 3, and the SHORT alarm area A2 is narrower than the LONG alarm area A1.

  The area in the vehicle width direction of the LONG alarm area A1 and the SHORT alarm area A2 is limited to the same area as the vehicle width L, and the front end leaves an area of ± 10% of the vehicle width L from the left and right center line. It is a mountain-shaped region extending from there to the front end of the vehicle 1 cut so as to spread rearward. In other words, the LONG alarm area A1 connects a point P1 of 40% offset from the end of the vehicle width direction end of the vehicle 1 and 2 seconds until the collision, and a point P4 of 0% offset and 0.8 seconds until the collision. The outside is cut from the line. The SHORT warning area A2 connects a point P2 at an offset of 40% from the end of the vehicle width direction end of the vehicle 1 and a point of 1.6 seconds until a collision, and a point P4 at an offset of 0% and a point of 0.8 seconds until the collision. The area outside the line is cut. In this way, the left and right corners on the front end side are cut off because it is difficult to avoid the obstacle 50 at a short distance from the host vehicle by operating the steering 3, but the obstacle 50 at a long distance and the left and right center side is This is because it is easy to operate the steering 3.

  The obstacle detection device 2 includes an operation timing SW (not shown). When the driver dislikes that the alarm device 15 frequently operates, the operation timing is always set to the SHORT alarm area A2 by setting the operation timing SW to SHORT.

  The vehicle 1 is also provided with a seat belt pretensioner 17 that removes slack in the brake means 16 that applies a braking force to the vehicle 1 and the seat belt 18 as an operating device and increases the restraining force of the occupant. However, in this embodiment, a case will be described in which the operation timing of the brake means 16 and the seat belt pretensioner 17 is not switched by the operation timing SW.

  When the millimeter wave radar 3 determines that the obstacle 50 has entered a region of a predetermined distance (point P3 of 1.0 seconds until the collision), the control unit 10 sends a signal to the brake means 16 and is relatively weak. A primary brake is activated to alert the driver. Furthermore, when the millimeter wave radar 3 determines that the obstacle 50 has further entered the region at a short distance (point P5 of 0.6 seconds until the collision), the control unit 10 sends a signal to the brake means 16, A strong secondary brake is activated to avoid a collision. The detection areas A3 and A4 of the primary brake and the secondary brake are also cut off at the left and right front end sides in the same manner as the alarm areas A1 and A2. Specifically, the primary brake area A3 is cut outside the line connecting the point of steering avoidance time of 10% offset (not shown) and the point P3 of 40% offset and 1.0 second until the collision. The region up to the tip of the vehicle 1 is a mountain-shaped region. Further, the secondary brake area A4 includes a range up to 0.2 seconds after the collision. This is a control continuation time for absorbing measurement variations of the millimeter wave radar 3, and is provided for reasons such as preventing the brake means 16 from being released after a collision.

  Although not shown, the primary brake operation timing may be switched between LONG (wide area) and SHORT (narrow area) in the same manner as the alarm device 15. Accordingly, if the current driving operation is continued, it is possible to prevent unnecessary braking force from being applied when the obstacle 50 does not collide with the host vehicle 1.

  The seat belt pretensioner 17 includes a first seat belt pretensioner 17a and a second seat belt pretensioner 17b, and the millimeter wave radar 3 causes the obstacle 50 to move at a predetermined distance (0.4 seconds until the collision). When it is detected that the vehicle has approached P6), the first seat belt pretensioner 17a pulls the seat belt 18 into a retractor (not shown) to restrain the occupant with a predetermined tension (which does not affect the collision avoidance operation). . When the collision sensor 11 detects that the vehicle has collided, the second seat belt pretensioner 17b further pulls in the seat belt 18 to restrain the occupant with a strong restraining force. The first seat belt pretensioner 17a is configured to retract the seat belt 18 by an electric motor (not shown). The second seat belt pretensioner 17b is configured to retract the seat belt 18 by an inflator such as gunpowder.

  The operation timing of the seat belt pretensioner 17 can be switched, the seat belt 18 is pulled weakly with a long detection area LONG (for example, the primary brake area A3 in FIG. 3), and the short detection area SHORT (secondary in FIG. You may make it pull in strongly in brake area A4). Thus, if the current driving operation is continued, unnecessary pulling of the seat belt 16 can be avoided when the obstacle 50 does not collide with the host vehicle 1.

  As the driving operation state detection means 5, a steering angle sensor 20 that detects a steering angle θf that indicates the steering angle of the steering 6, and a steering angular speed detection means that detects a steering angular speed dθf / dsec that indicates a change in the steering angle θf per unit time. 21 or the acceleration received in the lateral direction with respect to the traveling direction of the vehicle 1, that is, the lateral G sensor 22 for detecting the lateral G, or the steering angle for detecting the integral value per predetermined time of the steering angle θf indicating the steering angle of the steering 6 An integral value detecting means is provided. The steering angle θf and the lateral G are input to the control unit 10 with the right side being positive and the left side being negative, for example. Further, turning radius detecting means 23 for detecting that the turning radius of the vehicle 1 is not more than a predetermined value is also provided. The turning radius detection means 23 may be determined by receiving a signal from the GPS. The rudder angular velocity detection means 21 can also be used by the control unit 10.

  The driving operation state detection means 5 detects the steering angle θf, the steering angular velocity dθf / dsec, the integral value of the steering angle θf per predetermined time, the lateral G, and the turning radius R of the vehicle 1, all of which are detected. There is no need to detect, and only a part of it may be detected. Alternatively, the detection target of the driving operation state detection unit 5 may be switched in accordance with the vehicle speed or the road state, and when the detection target satisfies the condition, the operation timing of the operating device by the PCS control may be delayed. In this way, an optimal detection target can be selected according to speed and road conditions.

The obstacle detection device 2 includes obstacle position estimation means 24 for estimating and interpolating the position of the obstacle 50 when the obstacle 50 detected by the millimeter wave radar 3 is not detected for a predetermined time. While the obstacle position estimating means 24 is in operation, the PCS control of the obstacle detection device 2 is not performed to prevent malfunction.

(PCS control)
Next, the PCS control (PRE CLASH SAFTY SYSTEM) performed by the control unit 10 of the obstacle detection apparatus 2 will be described.
The control unit 10 receives the detection output from the millimeter wave radar 3 and performs calculation for estimating the position and distance of the obstacle 50. When a plurality of obstacles 50 are detected, each obstacle 50 is determined individually.

It is determined whether or not the detected predetermined obstacle 50 is in the secondary brake area A4, and if it is in the secondary brake area A4, the secondary brake is immediately executed. Similarly, if in the primary brake area A3, the primary brake weaker than the secondary brake is immediately executed.
If the obstacle 50 is in the LONG alarm area A1 or the SHORT alarm area A2, the alarm device 15 is activated immediately.

Further, the control unit 10 determines whether the absolute value of the steering angle θf is larger than α1 (for example, 90 °), whether the absolute value of the steering angular velocity dθf / dsec is larger than α2 (for example, 50 ° / sec), or whether the steering angle θf The absolute value of the integral value per predetermined time is larger than α3 (for example, 90 °), the absolute value of the lateral G is larger than α4 (for example, 6 m / sec ² ), or the turning radius R of the vehicle 1 is larger than 175 m. If any one of the conditions is satisfied, if the vehicle 1 is in a driving operation state where the vehicle 1 bends and the current driving state is continued, the obstacle will It is determined that the vehicle does not collide and the operation timing of the alarm device 15 is set to SHORT.

(Error detection judgment control)
When the detected obstacle is detected for the first time and is present within a predetermined distance, the control unit 10 of the obstacle detection device 2 determines that the obstacle is erroneously detected due to electromagnetic noise, and detects from the object of PCS control. Misdetection detection control to be excluded is performed.
As shown in FIG. 5, when a plurality of obstacles 50a and 50b are detected by the millimeter wave radar 3, the fault detection control is performed for each of the obstacles 50a and 50b. The PCS control described above is performed for 50a and 50b.

  Based on the flowchart of FIG. 4, the erroneous detection determination control performed by the control unit 10 of the obstacle detection device 2 will be described. Si (i = 1, 2,...) Indicates each step.

Obstacle detection by the millimeter wave radar 3 is started in S1, and it is determined whether or not an obstacle is detected in the next S2. Here, as shown in FIG. 5, when a plurality of obstacles are detected, an identification number is assigned to each detected obstacle, and the detected obstacle is stored in the memory in the control unit 10 to be next Move to step. Regarding the processing from the next step, determination and control are executed by specifying a predetermined obstacle, for example, the obstacle 50a closest to the host vehicle, and after the processing of the obstacle 50a is finished, It is configured to perform the determination and control of the obstacle 50b close to.
Further, based on the obstacle information stored in the memory, the obstacle position estimating means 24 described above estimates the position of the obstacle, and information on which area the predetermined obstacle exists with the passage of time is also provided. It is stored together with the identification number.
If no obstacle is detected, the obstacle detection by the millimeter wave radar 3 is continued.

  In S3, the obstacle determination means 12 determines whether or not the predetermined obstacle is the first obstacle detected based on the information stored in the memory in the control unit 10, and the identification number is detected before. If it is the first obstacle that is not provided, the process proceeds to S4. In the case of an obstacle that has been detected before and has an identification number, it is determined that the obstacle is not erroneously detected due to electromagnetic noise, and the process proceeds to S10 and PCS control is started.

  In S4, the distance detection unit 13 determines whether the distance between the host vehicle and the obstacle is within a predetermined distance D (for example, 10 m). If the distance from the obstacle is D or more, the process proceeds to S10 and PCS control is started.

  In S5, the radar output reduction means 14 irradiates the radar output of the millimeter wave radar 3 by reducing it by a predetermined level (for example, 20%) for one sampling time (100 msec). The reduction level of the radar output is set in advance by the output performance and reception performance of the millimeter wave radar 3, and is set as long as at least the reduction level is reflected in the received signal reflected from the obstacle. Is possible. Further, the level of decrease can be made variable according to the driving state, and the level of decrease can be increased as the vehicle speed increases.

If there is a reception signal reflected from the obstacle in S6, the process proceeds to S7 to determine whether or not the output of the reception signal reflected from the obstacle is the same level as the radar output reduction level.
When the output of the received signal is the same as before the radar output is lowered (S7 No), or when the received signal is not detected at all (S6 No), the reduction level of the radar output does not correspond to the output of the received signal. Therefore, it is determined that the obstacle is erroneously detected due to electromagnetic noise (S8), the obstacle is excluded from the PCS control target (S9), and the next obstacle is processed.

If the output of the received signal has decreased by the same level as the level of decrease in the radar output, it is determined that an obstacle is present at a short distance, so the process proceeds to S10 and PCS control is started.
In S10, it is determined whether the obstacle exists in the collision prediction area, that is, in any one of the LONG alarm area A1, the SHORT alarm area A2, the primary brake area A3, the secondary brake area A4, and the pretensioner operation area. If it exists, PCS control corresponding to each area is performed (S11), and the process proceeds to S12.

As described above, the alarm device 15 is activated when an obstacle is present in the LONG alarm area A1 and the SHORT alarm area A2, and the primary brake is activated to alert the driver when the obstacle is present in the primary brake area A3. At the same time, if it is in the secondary brake area A4, the secondary brake stronger than the primary brake is immediately executed. Further, when the obstacle is in a position closer to the secondary brake area A4 (see FIG. 3), the first seat belt pretensioner 17a pulls the seat belt 18 into the retractor with a force that does not affect the collision avoidance operation. To restrain the crew.
If no obstacle is present in any area, return to start.

  In S12, when a collision is detected by the collision sensor 11, the second seat belt pretensioner 17b is configured to retract the seat belt 18 with an inflator such as gunpowder and restrain the occupant with a strong restraining force. If No in S12, the process returns to the start.

  Thus, when the received intensity of the reflection radar for the predetermined obstacle detected for the first time within the closest predetermined distance does not decrease or is not received corresponding to the output reduction level of the irradiation radar, the detected obstacle is detected. Can be excluded from the control target of the operating device. Therefore, the true / false judgment of the obstacle detected for the first time within a predetermined distance can be confirmed with the minimum judgment, and safe and smooth driving can be performed.

Next, a modification in which the above embodiment is partially changed will be described.
1) In the above-described embodiment, the example in which the radar output decrease level is set to a predetermined value has been described. However, it can be changed depending on driving conditions such as the vehicle speed and external factors such as temperature and weather, as well as topography and road conditions. It is also possible to do.

2) In the above embodiment, the example in which the level of decrease in the output of the received signal reflected from the obstacle is compared with the level of decrease in the radar output as a reference has been described. The range of ± 10% of the level of decrease in the radar output May be used as a comparison reference, and the comparison reference can be made variable depending on driving conditions such as vehicle speed, external factors such as temperature, weather, topography, road conditions, and the like.

3) In the above-described embodiment, the example in which the millimeter wave radar 3 is provided as an obstacle detection unit that detects an obstacle ahead is described. However, the obstacle detection unit that detects the rear side or the rear side is also described. Control can be applied.

4) In addition, those skilled in the art can implement the present invention in various forms added with various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

It is a conceptual diagram of the vehicle provided with the obstacle detection apparatus of the vehicle which concerns on Example 1 of this invention. It is a block diagram which shows the obstruction detection apparatus of a vehicle. It is a conceptual diagram which shows the detection range of a millimeter wave radar. It is a flowchart which shows a misdetection determination control figure. It is explanatory drawing of the obstacle determination in erroneous detection determination control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Obstacle detection means 3 Millimeter wave radar 10 Control unit 12 Obstacle determination means 13 Distance detection means 14 Radar output reduction means 15 Alarm device 16 Brake means 17a First seat belt pretensioner 17b Second seat belt pretensioner 50 Obstacle object

Claims (5)

Obstacle detecting means including radar means for detecting one or more obstacles of the own vehicle, and operating equipment control means for controlling the operating equipment of the vehicle in accordance with the detection state of each obstacle by the obstacle detecting means. An obstacle detection device for a vehicle having
Obstacle determination means for determining whether the predetermined obstacle detected by the obstacle detection means is an obstacle detected for the first time;
Distance detection means for detecting whether the distance between the obstacle detected by the obstacle detection means and the host vehicle is within a predetermined distance;
A radar output reduction means for reducing the radar output of the obstacle detection means when the obstacle detected for the first time by the obstacle determination means is within a predetermined distance from the host vehicle;
When the radar output reduction means operates, if the received intensity of the reduced radar output from the obstacle does not decrease or is not received according to the degree of reduction, the obstacle is controlled by the operating device control means. An obstacle detection device for a vehicle, which is excluded from a target.   2. The obstacle detection device for a vehicle according to claim 1, wherein the obstacle detection means is a millimeter wave radar.   The vehicle obstacle detection device according to claim 1, wherein the operating device is a notification unit that notifies a passenger of a dangerous state.   The vehicle obstacle detection device according to claim 1, wherein the operating device is a brake unit that applies a braking force to the vehicle. The vehicle obstacle detection device according to claim 1, wherein the operating device is a seat belt pretensioner that forcibly retracts a seat belt.