JP4794268B2 - Radar accuracy prediction device - Google Patents

Description

The present invention relates to a radar accuracy prediction apparatus that detects an object around a vehicle.

2. Description of the Related Art Conventionally, an ambient object recognition apparatus that detects an object around a vehicle and displays the object is known (see, for example, Patent Document 1). In this conventional method, an object around the vehicle is detected by a radar device assuming that the vehicle travels in a parking lot, and is excluded as noise other than detection points along a direction parallel or perpendicular to the traveling direction of the vehicle. By doing so, the detection accuracy of the object is improved.
JP 2002-228734 A (page 4-6, FIG. 1-9)

  By the way, the device disclosed in Patent Document 1 detects the surface position of a parked vehicle that is traveling in a parking lot and close to the host vehicle, and detects other vehicles while traveling on a road. However, it is impossible to deal with a decrease in detection accuracy in such applications. For example, when the distance between the host vehicle and another vehicle is more than a certain distance, the other vehicle is detected as a point. Therefore, in the method of Patent Document 1, it is possible to determine whether or not the detection result is noise. Can not. Therefore, it is convenient if a user such as a driver can be notified of such erroneous detection, that is, when the detection accuracy decreases and the reliability of the detection result decreases.

The present invention was created in view of the above points, and an object of the present invention is to provide a radar accuracy prediction apparatus capable of notifying the user of a decrease in accuracy when detecting an object around the vehicle. It is in.

In order to solve the above-described problems, a radar accuracy prediction apparatus according to the present invention includes a radar apparatus that detects an object around the host vehicle, a vehicle information acquisition unit that acquires vehicle information including a traveling direction and a travel position of the host vehicle, and An accuracy determining means for determining the accuracy of object detection by the radar device, an accuracy information storing means for storing information related to the accuracy determined by the accuracy determining means together with the vehicle information acquired by the vehicle information acquiring means, and an accuracy information storing means An accuracy prediction unit that predicts the detection accuracy of the radar device corresponding to the front of the host vehicle in the traveling direction based on the information stored in the vehicle, and a prediction result notification unit that performs predetermined notification based on the prediction result of the accuracy prediction unit; The accuracy determined by the accuracy determination means includes accuracy indicating the presence / absence of detection and position accuracy indicating the degree to which the position in the angular direction swings, Degree determination means, the detection operation of the last plurality of times, accuracy is lowered when the same object of continuous detection is interrupted, the angle direction between the position at the location and time before that at the present time The accuracy of object detection is determined on the assumption that the greater the degree of blur is, the lower the position accuracy is. As a result, information on a location where the detection accuracy of the radar device has been reduced in the past is accumulated, and the accuracy of the radar device is reduced at that location in advance when traveling next time. Can be notified.

In addition, it is possible to perform accuracy prediction using both the accuracy and the position accuracy that are important when accurately detecting objects around the host vehicle.

  Further, it is desirable that the above-described prediction result notifying means performs notification notifying that the accuracy reduction is predicted by the accuracy predicting means. Thereby, only the minimum information useful for the user can be notified.

  Moreover, it is desirable that the notification by the prediction result notifying unit described above includes the length of the section in which the accuracy decrease is predicted by the accuracy predicting unit. As a result, the user himself / herself can grasp a section in which the user needs attention.

  The vehicle further includes map data storage means storing a road shape corresponding to the travel position of the vehicle. As vehicle information, the travel position of the host vehicle read from the map data storage means is used instead of the travel position of the host vehicle. It is desirable to use a corresponding road shape. As a result, the road shape can be known for a road that has traveled for the first time regardless of the past number of travels, and the accuracy of the radar apparatus can be predicted for such a road.

In addition, the accuracy determination means described above is arranged outside the vehicle, and a radar device, vehicle information acquisition means, accuracy prediction means, and prediction result notification means are mounted on the vehicle. Also, an information record capable of inserting / extracting information input / output between the accuracy determination means arranged outside the vehicle and the radar device, vehicle information acquisition means, accuracy prediction means, and prediction result notification means mounted on the vehicle. It is desirable to use a medium. Alternatively, the input / output of information between the accuracy determination unit arranged outside the vehicle described above and the radar device mounted on the vehicle, the vehicle information acquisition unit, the accuracy prediction unit, and the prediction result notification unit may be performed by communication. desirable. As a result, a part of the processing can be performed using a personal computer or a server outside the vehicle, so that the processing performed in the in-vehicle device can be performed using a processing device having a relatively low processing capability. Become.

  A radar accuracy prediction apparatus according to an embodiment to which the present invention is applied will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a radar accuracy prediction apparatus according to an embodiment. A radar accuracy prediction apparatus shown in FIG. 1 includes a radar processing module 10, a position calculation unit 12, a vehicle information acquisition unit 14, a vehicle determination unit 16, a detection history DB (database) 20, a radar accuracy determination unit 30, a radar accuracy DB 32, a path. The information extraction unit 40, the radar accuracy prediction unit 42, the output control unit 50, and the display device 52 are included.

  The radar processing module 10 is installed at a plurality of locations on the front, rear, left, and right sides of the host vehicle, and detects other objects (mainly other vehicles) included in a predetermined detection range. Based on the output signal of the radar processing module 10, the position calculation unit 12 calculates the direction in which the other object exists and the distance to the other object as the position of the other object. For example, the radar processing module 10 transmits millimeter wave FM signals (radar waves) whose frequency changes with time from a plurality of transmission / reception antennas and receives reflected waves from other objects in the detection range. A signal obtained by synthesizing the transmission signal and the reception signal is output. The position calculation unit 12 calculates the distance to another object by analyzing the frequency of the beat component included in the output signal of the radar processing module 10. By calculating the distance and comparing the levels of the combined signal for each of a plurality of transmitting and receiving antennas having different directions, the direction of another object can be known. Note that the operating principles of the radar processing module 10 and the position calculation unit 12 vary depending on the wavelength of the detection signal used, the structure of the antenna, and the like, but in this embodiment, if the direction and distance to other objects are known, Therefore, any type of radar processing module that can achieve this object may be used. Further, the position calculation unit 12 may be provided in the radar processing module 10.

  The vehicle information acquisition unit 14 acquires the current position and traveling direction of the host vehicle as vehicle information. For example, a GPS device is connected, and the vehicle information acquisition unit 14 acquires the current position and traveling direction of the host vehicle from the GPS device. Alternatively, a navigation device may be connected, and the current position and traveling direction of the host vehicle may be acquired from the navigation device. When the navigation device is used, the current position of the vehicle after the vehicle position correction by the map matching process or the like can be acquired, so that the accuracy of the acquired vehicle information can be improved.

  The vehicle determination unit 16 performs vehicle detection by determining whether or not this object is a vehicle based on the direction and distance to the object calculated by the position calculation unit 12. For example, since the vehicle information acquisition unit 14 knows the current position and traveling direction of the host vehicle, the vehicle determination unit 16 knows whether the object calculated by the position calculation unit 12 is a stationary object or a moving object. In the case of a moving body, it is determined that this object is a vehicle. Vehicles include motorcycles and other special vehicles in addition to four-wheeled vehicles such as passenger cars and trucks.

  The detection history DB 20 stores a history of vehicle detection by the vehicle determination unit 16. The radar accuracy determination unit 30 determines the radar accuracy at that time for other vehicles detected by the vehicle determination unit 16 based on the detection history information stored in the detection history DB 20. In the present embodiment, the radar accuracy is expressed using two parameters of “accuracy” and “position accuracy”. “Accuracy” indicates whether or not the vehicle of interest has been detected. For the last 32 scans (one scan corresponds to one detection operation at a certain time), the accuracy increases when the same vehicle is continuously detected, and the detection of the same vehicle is interrupted. Is less accurate. “Position accuracy” is the degree of blurring of the position in the angular direction between the position n at the current time and the position n−1 at the previous time (the degree to which the direction of the reflected wave received by the radar processing module 10 fluctuates). ). The larger the cumulative value, the lower the position accuracy.

  Radar accuracy data (radar accuracy data) determined by the radar accuracy determination unit 30 is stored in the radar accuracy DB 32. Specifically, when old (previous) radar accuracy data corresponding to the position n at the current time is already stored in the radar accuracy DB 32, the radar accuracy data is updated to the latest contents. Further, when old (previous) radar accuracy data corresponding to the position n at the current time is not stored in the radar accuracy DB 32, newly obtained radar accuracy data is newly stored.

  2 and 3 are diagrams illustrating specific examples of vehicle determination by the vehicle determination unit 16. 2 and 3, G is the own vehicle, A is the other vehicle around the own vehicle G and traveling within the detection range of the radar processing module 10, B is a convenience store beside the road, and C is V indicates a vending machine installed on the side of the road, and D indicates a road sign installed on the side of the road. In addition, S1 and S2 indicate regions that are determined to be likely to exist corresponding to the detected other vehicle A.

  As shown in FIG. 2, when there is nothing on the side of the road on which the host vehicle G is traveling, the detection accuracy of the other vehicle A existing behind becomes higher. On the other hand, as shown in FIG. 3, when there is a convenience store B, a vending machine C, a road sign D, or the like beside the road on which the host vehicle G is traveling, depending on the degree of reflection of the radar wave by these. The radar accuracy of the vehicle A that is originally a detection target is lowered.

  The radar accuracy determination unit 30 stores radar accuracy data including the own vehicle position and the traveling direction as well as the direction in which the radar accuracy has decreased at that time in the radar accuracy DB 32. FIG. 4 is a diagram illustrating a direction in which the radar accuracy has decreased. Centering on the own vehicle G, any one of the four types of front, rear, right side, and left side is selected as the direction in which the radar accuracy is lowered. For example, in the example shown in FIG. 3, when the vehicle A existing “backward” is detected from the own vehicle G and both the accuracy and the position accuracy at the time of detection of the vehicle A are reduced, the vehicle A is shown in FIG. 5. The content radar accuracy data (radar accuracy data at position n) is generated and updated or newly stored in the radar accuracy DB 32. In FIG. 5, “front”, “right”, “left”, and “rear” correspond to “front”, “right side”, “left side”, and “rearward” shown in FIG. 4. In addition, “◯” indicates a normal state in which the radar accuracy (accuracy and position accuracy) has not decreased, and “Δ” indicates a state in which the radar accuracy has decreased. The radar accuracy data is stored by the radar accuracy DB 32 when the radar accuracy is deteriorated in any one of “front”, “right side”, “left side”, and “rear”. It is not done if the is not lowered.

  The route information extraction unit 40 acquires route information on which the host vehicle travels. For example, when a navigation device is connected, along the travel route when the vehicle travels straight on the currently traveling road from the position and traveling direction of the vehicle, or along the travel route set by the route search process When route guidance is being performed, route information specifying the travel route is extracted by the route information extraction unit 40.

  The radar accuracy prediction unit 42 reads out radar accuracy data corresponding to the travel route that the host vehicle is about to enter from the radar accuracy DB 32, and predicts the radar accuracy for a certain section (for example, 500 m). The output control unit 50 creates a predetermined alarm screen using the prediction result from the radar accuracy prediction unit 42 and displays it on the display device 52. For example, as shown in FIG. 6, when the vehicle approaches a place where the radar accuracy decreases behind the host vehicle (see FIG. 3) when the host vehicle enters, the radar accuracy prediction unit 42 predicts the radar accuracy decrease. The output control unit 50 displays an alarm message such as “There is a possibility that the rearward detection may not be sufficiently performed. Be careful about the rear.” In parallel with this display operation, a predetermined notification sound may be output from a speaker (not shown).

  When the radar accuracy data shown in FIG. 7 is obtained along the travel route set by the route search, assuming that the position of the host vehicle has reached the position n, the output control unit 50 , 300m The right direction may not be detected sufficiently. Be careful about the right direction. "

  The radar processing module 10, the position calculation unit 12 described above, the vehicle information acquisition unit 14 as vehicle information acquisition means, the radar accuracy determination unit 30 as accuracy determination means, the radar accuracy DB 32 as accuracy information storage means, the radar The accuracy prediction unit 42 corresponds to the accuracy prediction unit, and the output control unit 50 and the display device 52 correspond to the prediction result notification unit, respectively.

  The radar accuracy prediction apparatus of this embodiment has such a configuration, and the operation thereof will be described next. FIG. 8 is a flowchart showing an operation procedure for detecting other vehicles around the host vehicle and updating the radar accuracy DB 32 during traveling. The vehicle determination unit 16 determines whether a vehicle is detected within the detection range of the radar processing module 10 based on the calculation result of the position calculation unit 12 (step 100). If not detected, a negative determination is made and the determination in step 100 is repeated. When a vehicle is detected, an affirmative determination is made in the determination of step 100, and the vehicle determination unit 16 updates the history of the detection history DB 20 (step 101). The radar accuracy determination unit 30 determines the radar accuracy based on the data stored in the detection history DB 20 (step 102), and updates the radar accuracy DB 32 (step 103).

  FIG. 9 is a flowchart showing an operation procedure of alarm display relating to radar accuracy performed in parallel with the update of the radar accuracy DB 32. The route information extraction unit 40 extracts route information (step 200), and the radar accuracy prediction unit 42 predicts the radar accuracy ahead of the traveling direction of the host vehicle based on the extracted route information (step 201). Further, the radar accuracy prediction unit 42 determines whether or not the predicted data accuracy is lower than the normal value (step 202). If there is no portion where the radar accuracy has decreased in front of the traveling direction of the host vehicle, a negative determination is made, and the process returns to step 200 to repeat the operation of acquiring route information. Further, when there is a portion where the radar accuracy has decreased in front of the traveling direction of the host vehicle, an affirmative determination is made in the determination of step 202, and then the output control unit 50 creates and displays a predetermined alarm screen. (Step 203).

  As described above, in the radar accuracy prediction apparatus according to the present embodiment, radar accuracy data related to a location where the radar accuracy has been lowered in the past is accumulated in the radar accuracy DB 32, and the next time the vehicle travels in advance. In addition, it is possible to notify the user that the radar accuracy is reduced at that location. In particular, it is possible to notify only minimum information that is useful to the user by notifying the fact that a decrease in accuracy is predicted. Further, by including the length of the section in which the accuracy is predicted to be reduced in this notification, the user himself / herself can grasp the section that requires the user's attention.

  FIG. 10 is a diagram showing a modification of the radar accuracy prediction apparatus shown in FIG. The radar accuracy prediction apparatus shown in FIG. 10 differs from the configuration shown in FIG. 1 in that a map DB (database) 60 as map data storage means is added. The map DB 60 stores map data including information on road shapes such as intersections. Based on the detection result calculated by the position calculation unit 12, the traveling direction of the host vehicle acquired by the vehicle information acquisition unit 14, and the road shape read from the map DB 60, the vehicle determination unit 16 Detect other vehicles present. As for the road shape, straight lines, curves (curvature), intersections (number of intersecting roads), etc. are listed, and any road shape corresponding to the travel position is extracted from the map DB 60. The radar accuracy determination unit 30 determines the radar accuracy at that time when another vehicle is detected by the vehicle determination unit 16, and if the radar accuracy is lowered, the traveling direction of the host vehicle and the road shape are determined. Is used as a search key to search whether or not the radar accuracy data corresponding to this search key is stored in the radar accuracy DB 32 and update the radar accuracy DB 32 to the latest contents. Further, the radar accuracy prediction unit 42 reads a road shape corresponding to the route information ahead of the traveling direction of the host vehicle extracted by the route information extracting unit 40 from the map DB 60, and based on the traveling direction and the road shape of the host vehicle. It is determined whether or not there is a portion where the radar accuracy has decreased corresponding to the road shape ahead of the traveling direction of the host vehicle. When there is a lowered portion, a predetermined alarm screen is created and displayed by the output control unit 50.

  In this way, when there is a stationary object that is installed in accordance with the road condition (road shape) such as an intersection such as a traffic light or a road sign by using the road shape instead of the traveling position of the host vehicle. In addition, it is possible to accurately detect the correspondence between a stationary object around the road and a decrease in radar accuracy. In particular, when the road shape is determined based on the map data stored in the map DB 60, the road shape can be known even for roads that have never traveled regardless of the number of past travels. It becomes possible to predict whether or not the accuracy is lowered before traveling.

FIG. 11 is a diagram illustrating a configuration of a radar accuracy prediction apparatus according to another embodiment. The radar accuracy prediction apparatus shown in FIG. 11 includes a radar accuracy prediction apparatus 100 and a radar accuracy DB update apparatus 200. The radar accuracy prediction apparatus 100 has a configuration in which the vehicle determination unit 16, the detection history DB 20, and the radar accuracy determination unit 30 are removed from the radar accuracy prediction apparatus shown in FIG. 1 and a memory card IF (interface) unit 70 is added. ing. The radar accuracy DB update device 200 includes the configuration (vehicle determination unit 16, detection history DB 20, radar accuracy determination unit 30), radar accuracy DB 32A, and memory card IF unit 80 that are removed. The radar accuracy data having the same contents is stored in the two radar accuracy DBs 32 and 32A. The radar accuracy DB update device 200 is installed outside the vehicle and can be realized using a personal computer, for example.

  Information is input / output between the radar accuracy prediction apparatus 100 and the radar accuracy DB update apparatus 200 by using a common memory card 90 that can be attached to the memory card IF units 70 and 80. In the radar accuracy prediction device 100, when information about the newly detected object is output from the position calculation unit 12, this information is input to the vehicle determination unit 16 in the radar accuracy DB update device 200 via the memory card 90. Is done. Further, when vehicle detection is performed by the vehicle determination unit 16 and the radar accuracy DB 32A is updated by the radar accuracy determination unit 30 as a result, the update result is sent to the radar in the radar accuracy prediction apparatus 100 via the memory card 90. It is sent to the accuracy DB 32 and the update result is reflected.

  As described above, since the vehicle detection and the radar accuracy determination can be performed by the radar accuracy DB update apparatus 200 using a personal computer or the like outside the vehicle, it is possible to reduce the burden of processing performed in the in-vehicle device. It is possible to shorten the processing time for accuracy prediction. In addition, although the case where the input / output of information between the radar accuracy prediction apparatus 100 and the radar accuracy DB update apparatus 200 is performed using the memory card 90 has been described, other recording such as MD (mini disk) and CD-RW is performed. You may make it carry out using a medium. In this case, a read / write device for these recording media may be provided instead of the memory card IF units 70 and 80.

FIG. 12 is a diagram illustrating a modification of the radar accuracy prediction apparatus illustrated in FIG. 11. The radar accuracy prediction apparatus shown in FIG. 12 includes a radar accuracy prediction apparatus 100A and a radar accuracy DB update server 200A, and these are connected by a communication line via a network 300. The radar accuracy prediction apparatus 100 </ b> A has a configuration in which the memory card IF unit 70 is replaced with a communication processing unit 72 with respect to the radar accuracy prediction apparatus 100 illustrated in FIG. 11. The communication processing unit 72 performs line connection with the network 300 by wireless communication such as a mobile phone (not shown). Further, the radar accuracy DB update server 200A has a configuration in which the memory card IF unit 80 is replaced with a communication processing unit 82 with respect to the radar accuracy DB update device 200 shown in FIG. The communication processing unit 82 performs line connection with the network 300 via a dedicated line or a general-purpose line.

The radar accuracy prediction apparatus shown in FIG. 12 performs vehicle detection and radar accuracy determination in the radar accuracy DB update server 200A using the radar detection result sent from the radar accuracy prediction apparatus 100A and vehicle information corresponding thereto. Is basically the same as the apparatus shown in FIG. Moreover, the radar accuracy DB update server 200A performs vehicle detection and updates of radar accuracy data using a lot of information sent from the radar accuracy prediction apparatus 100A provided in each of a plurality of vehicles.

  In this way, vehicle detection, radar accuracy data update, and the like can be performed outside the vehicle by the radar accuracy DB update server 200A, so that the burden of processing performed in the in-vehicle device can be reduced, and radar accuracy prediction can be performed. Processing time can be shortened. Further, the radar accuracy DB update server 200A outside the vehicle can perform radar accuracy determination based on information sent from a plurality of vehicles and distribute the result to each vehicle. Radar accuracy prediction can be performed. In addition, radar accuracy data is accumulated when other vehicles travel even on roads where the host vehicle has never traveled, so radar accuracy prediction can be performed even on roads that have never traveled. Is possible.

It is a figure which shows the structure of the radar accuracy prediction apparatus of one Embodiment. It is a figure which shows the specific example of the vehicle determination by a vehicle determination part. It is a figure which shows the specific example of the vehicle determination by a vehicle determination part. It is a figure which shows the direction where the radar accuracy fell. It is a figure which shows the specific example of radar accuracy data. It is a figure which shows the vehicle which approachs the location where radar accuracy falls. It is a figure which shows the specific example of the radar accuracy data along a driving path. It is a flowchart which shows the operation | movement procedure which detects other vehicles around the own vehicle during driving | running | working, and updates radar accuracy DB. It is a flowchart which shows the operation | movement procedure of the alarm display regarding the radar accuracy performed in parallel with update of radar accuracy DB. It is a figure which shows the modification of the radar accuracy prediction apparatus shown in FIG. It is a figure which shows the structure of the radar accuracy prediction apparatus of other embodiment. It is a figure which shows the modification of the radar accuracy prediction apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Radar processing module 12 Position calculation part 14 Vehicle information acquisition part 16 Vehicle determination part 20 Detection history DB (database)
30 Radar accuracy determination unit 32, 32A Radar accuracy DB
40 Route Information Extraction Unit 42 Radar Accuracy Prediction Unit 50 Output Control Unit 52 Display Device 60 Map DB
70, 80 Memory card IF (interface) unit 72, 82 Communication processing unit 90 Memory card 100, 100A Radar accuracy prediction device 200 Radar accuracy DB update device 200A Radar accuracy DB update server 300 Network

Claims (7)

A radar device for detecting objects around the vehicle;
Vehicle information acquisition means for acquiring vehicle information including the traveling direction and travel position of the host vehicle;
Accuracy determination means for determining the accuracy of object detection by the radar device;
Accuracy information storage means for storing information relating to the accuracy determined by the accuracy determination means together with the vehicle information acquired by the vehicle information acquisition means;
Accuracy prediction means for predicting the detection accuracy of the radar device corresponding to the front of the traveling direction of the host vehicle based on the information stored in the accuracy information storage means;
A prediction result notification means for performing a predetermined notification based on a prediction result by the accuracy prediction means;
The accuracy determined by the accuracy determination means includes accuracy indicating the presence / absence of detection and position accuracy indicating the degree to which the position in the angular direction swings,
In the most recent detection operation, the accuracy determination means decreases the accuracy when continuous detection of the same object is interrupted, and between the position at the current time and the position at the previous time. A radar accuracy prediction apparatus, wherein the accuracy of object detection is determined on the assumption that the positional accuracy is lower as the degree of blur in the angular direction is larger. In claim 1,
The radar accuracy prediction apparatus according to claim 1, wherein the prediction result notifying unit notifies the user of a case where a decrease in accuracy is predicted by the accuracy prediction unit. In claim 2,
The radar accuracy prediction apparatus according to claim 1, wherein the notification by the prediction result notification means includes a length of a section in which accuracy reduction is predicted by the accuracy prediction means. In any one of Claims 1-3,
Map data storage means for storing a road shape corresponding to the travel position of the vehicle;
A radar accuracy prediction apparatus using, as the vehicle information, a road shape corresponding to the travel position of the host vehicle read from the map data storage means instead of the travel position of the host vehicle. In any one of Claims 1-4
With arranging the precision determination unit outside the vehicle, the radar device, the vehicle information acquisition unit, the accuracy predicting unit, the prediction result notification unit radar accuracy prediction apparatus characterized by mounted on a vehicle. In claim 5,
Input / output of information between the accuracy determination means arranged outside the vehicle and the radar device mounted on the vehicle, the vehicle information acquisition means, the accuracy prediction means, and the prediction result notification means can be inserted / removed A radar accuracy prediction apparatus using a simple information recording medium. In claim 5,
Communication of input / output of information between the accuracy determination unit arranged outside the vehicle and the radar device mounted on the vehicle, the vehicle information acquisition unit, the accuracy prediction unit, and the prediction result notification unit A radar accuracy prediction apparatus characterized by performing.

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