JP4595773B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and in particular, acquires relative position information between a stop position such as a stop line on a road and landmarks around the host vehicle to detect the stop position, and decelerates and stops the host vehicle with respect to the stop position. The present invention relates to a vehicle control device that performs control such as control and warning.

  A technique for detecting a stop position such as a stop line and stopping the host vehicle at a position where the stop position is detected is known. However, when the stop position is blocked by a preceding vehicle, or when driving at low visibility such as at night or in the rain, or when the stop line cannot be detected by the driver or the camera due to fading due to poor maintenance, etc. However, there is a problem that the stop position cannot be detected and the own vehicle cannot be stopped at an appropriate position.

As a technique to solve this problem, the stop position information is registered on the map and the stop position is detected. In the route from the own vehicle position information acquired by using GPS or a gyro to the destination registered by the user, A vehicle travel control device that performs deceleration processing and stop processing when a stop position is detected is detected (Patent Document 1).
JP 2000-213637 A

  However, in the above conventional technology, in order to know the distance to the stop line, it is necessary to register the stop line at the correct position (position represented by longitude and latitude) on the map and to acquire the vehicle position information accurately. Therefore, in reality, it is not easy to acquire the vehicle position information with high accuracy at an arbitrary position and register the high accuracy stop line position, and it is difficult to accurately detect the distance to the stop line. There was a problem.

  The present invention has been made to solve the above-described problems, and registration of the position information of a three-dimensional object that can confirm the relative positional relationship with the stop position together with the position information of the stop position prevents detection of the stop position. An object of the present invention is to provide a vehicle control device that can detect stop position information for the host vehicle with high accuracy even in a possible state.

In order to achieve the above object, the present invention relates to own vehicle position detecting means for detecting the position of the own vehicle with a first accuracy, and position information of landmarks serving as landmarks around the own vehicle. Landmark detection means for detecting with a second accuracy higher than the accuracy, stop position information indicating the stop position indicated by the stop line on the road , and a plurality of landmarks detected by the landmark detection means correlated with the stop position information Storage means for storing the relative position information of landmarks, and the position information of the plurality of landmarks detected by the landmark detection means after the stop position information and the relative position information are stored in the storage means, Matching judgment means for judging whether or not the relative position information of a plurality of landmarks stored in the storage means is matched; and matching by the judgment means Based on the stop position information that is determined as stop position information of the host vehicle, stop position information that correlates with the position information of the plurality of landmarks determined as Vehicle control means for controlling the vehicle.

  According to the present invention, the position of the host vehicle is detected with the first accuracy, and the position information of the landmark that is a mark around the host vehicle is detected with the second accuracy higher than the accuracy of the host vehicle position detecting means. Then, stop position information indicating the stop position and position information of a plurality of landmarks detected by the landmark detection means correlated with the stop position information are stored. After the stop position information and the position information are stored, whether or not the position information of the plurality of landmarks detected by the landmark detection means matches the position information of the plurality of landmarks stored in the storage means. The stop position information correlating with the position information of the plurality of landmarks determined to be matched is determined as the stop position information of the host vehicle, and the vehicle is controlled based on the determined stop position information.

  As described above, according to the present invention, for example, since a three-dimensional object located on the road side as a landmark is not easily affected by interruption or the like by a preceding vehicle, the stop position is detected even in a state where the stop position cannot be detected. be able to. Further, if an accurate relative positional relationship between the landmarks is obtained, there is no need for accurate position information, so there is no need to detect high-accuracy position information for registering the stop position. Can be made lower than the accuracy of the landmark detection means.

  As described above, according to the present invention, by registering the position information of the landmark that can confirm the relative positional relationship with the stop position together with the position information of the stop position, even in a state where the stop position cannot be detected. The effect that the stop position information with respect to the vehicle can be detected with high accuracy is obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the vehicle control device mounted on the vehicle of the present embodiment includes a host vehicle position sensor 10 configured by a GPS device that detects the current position of the host vehicle with a predetermined low accuracy, and a host vehicle. A landmark sensor 12 that detects landmarks around the vehicle with higher accuracy than the vehicle position sensor is provided.

  The landmark sensor 12 can be configured by, for example, a laser radar that can sense an object within a lateral position of about 10 m 50 meters ahead. The landmark sensor may be of any type as long as it can detect the position of the landmark, such as a laser radar, a stereo camera, a monocular camera, or a millimeter wave radar. It is desirable that at least one landmark is detected before the stop line.

  The own vehicle position sensor 10 and the landmark sensor 12 are connected to a control device 14 constituted by a microcomputer or the like.

  The control device 14 includes map information, a relative relationship table that stores a relative positional relationship between a plurality of landmarks detected by the landmark sensor, and a relative position that indicates a relative position between a stop line as a stop position and the plurality of landmarks. A storage device 16 for storing information and the like is connected. The control device 14 is connected to an alarm device 18 for giving an alarm when the host vehicle reaches the stop position, and a brake device 20 for performing a deceleration control when the host vehicle reaches the stop position. ing.

  From the GPS device, position data indicating the position of the host vehicle is output and input to the control device 14.

  A laser radar is configured to include a light emitting element that emits infrared light pulses and a light receiving element that receives infrared light pulses reflected from a front landmark or the like, and is attached to a front grill or a bumper of a vehicle. ing. In this laser radar, based on the arrival time of the reflected infrared light pulse until it is received by the light receiving element with respect to the time point when the light is emitted from the light emitting element, the distance r from the own vehicle to the landmark ahead and the landmark Position information represented by polar coordinates (r, θ) indicating the existence direction θ can be detected.

  Note that a gyro sensor may be used as the vehicle position sensor instead of the GPS device, and a millimeter wave radar or a camera may be used as the landmark sensor instead of the laser radar. When a laser radar is used as a landmark sensor, power poles, signs, signal pillars, guardrail pillars, reflectors, etc. can be detected as landmarks. When a camera is used as a landmark sensor Can detect, as landmarks, utility poles, signs, traffic lights, guardrails, road surface displays, and characteristic portions of building walls.

Next, a routine for executing registration processing for registering stop line position information and landmark position information according to the present embodiment will be described with reference to FIG. In a state where the host vehicle is traveling, a plurality of landmarks are detected by the landmark sensor in step 100, and positional information (r ₀ , θ ₀ ), (r ₁ , θ ₁ ), (r ₂ , θ ₂ ),... (R _n , θ _n ) are acquired. In the next step 102, the relative positional relationship between the plurality of detected landmarks is calculated based on the detected position information of the landmarks. This relative positional relationship is represented by coordinates in which the vehicle traveling direction is the z-axis and the vehicle lateral direction is the x-axis. For example, each land when the landmark closest to the host vehicle is positioned at the origin of the xz coordinate. It is expressed in the coordinates of the mark.

  In addition, you may make it use landmarks other than the landmark nearest to the own vehicle as a reference | standard landmark when calculating the relative positional relationship between landmarks.

  In the next step 104, it is determined whether or not the host vehicle has reached the stop line. If the vehicle has not reached the stop line, the correlation position calculated in step 102 is registered in the correlation table.

FIG. 3 shows the registration state of the relative positional relationship between the landmarks according to the time change. At the time t ₀ , the three lands with reference to the landmark located at (r ₀ , θ ₀ ) are shown. The relative positional relationship (0,0), (x ₀₁ , z ₀₁ ), (x ₀₂ , z ₀₂ ) between the marks is shown, and the landmark located at (r ₀ , θ ₀ ) is referenced at time t ₁ And a relative positional relationship between four landmarks including a landmark whose newly detected relative positional relationship is (x ₀₃ , z ₀₃ ). At time t ₃ , the landmark closest to the host vehicle is changed from the landmark located at (r ₀ , θ ₀ ) to the landmark located at (r ₂ , θ ₂ ). The relative positional relationship between two landmarks based on the landmark located at r ₂ , θ ₂ ) is shown. And a correlation positional relationship is registered for every time in a correlation table.

Then, after elapse of the time obtained by adding the predetermined time Δt to the current time t _n in Step 106, the process returns to Step 100 to perform the detection of the landmark and the calculation of the relative positional relationship between the landmarks again, and at every predetermined time Δt. Information indicating the relative positional relationship between landmarks is stored in a table.

When the host vehicle reaches the stop line, the position of the host vehicle detected by the host vehicle position sensor is input by inputting a signal indicating that the host vehicle has reached the stop line, or by temporarily stopping the vehicle. Is the position of the stop line, the absolute position coordinates (Xa, Za) represented by the longitude and latitude of the host vehicle (stop line) are acquired at step 108A, and the absolute position coordinates (X ₀ , Z) of the landmark are acquired at step 110A. ₀ ), (X ₁ , Z ₁ )... (X _n , Z _n ) are acquired.

At the same time, the landmark position (r _a2 , θ _a2 )... In the state where the host vehicle has reached the stop line is detected, and the stop line is set in step 110B with the position of the host vehicle set as the stop line position. Relative positions (r _a0 , θ _a0 ), (r _a1 , θ _a1 )... (R _an , θ _an ) are calculated.

  The absolute position coordinates of the landmark can be obtained by calculation based on the absolute position coordinates of the stop line and information indicating the correlation position relationship between the landmarks.

  However, when equipped with a means that can accurately acquire the relative positional relationship between the host vehicle and the stop line, such as a camera that detects the stop line, it is normal to input and pause What is necessary is just to detect a stop line at the time of driving | running | working and to acquire the relative positional relationship of a stop line and a landmark.

In step 112, the absolute position of the stop line, the absolute position of the landmark, the position of the landmark when the host vehicle is stopped on the stop line, and the relative positional relationship between the landmarks are registered in the map. The relative positional relationship table is cleared at. Each location in a state where the vehicle reaches the stop line is shown at time t ₃ in FIG.

  As described above, the relative positional relationship between the stop line and the landmark can be acquired by acquiring the position information of the landmark in a state where the vehicle position is substantially equal to the stop line position. Information indicating the correlation with the landmark can be registered in the storage device. At this time, low-accuracy position information detected by the vehicle position sensor is also acquired.

  Since the vehicle may pass a plurality of times on the same stop line, the relative positional relationship between the stop line and the landmark is acquired a plurality of times for the same stop line. For the information to be registered at the point in time, the result calculated using a statistical method may be used, or the information at the position with the highest accuracy is registered in consideration of the sensor performance. May be.

  When a camera is used as the landmark sensor, not only the landmark position information but also additional information related to the landmark height information, color, and size may be registered.

  When the landmark is sparse, information indicating the relative positional relationship may not be obtained. In this case, instead of a method of maintaining only the relative positional relationship, the position of the own vehicle and the position of the landmark may be acquired at any time and finally converted into information representing the relative positional relationship. In this case, a highly accurate relative positional relationship may not be obtained.

  In the above method, when there is no landmark ahead of the stop line, it is difficult to obtain the relative relationship between the landmark before the stop line and the stop line. In order to solve this problem, the landmark sensor is usually directed forward in the vehicle traveling direction, and the landmark is detected, and when registering the stop line and the landmark, it may be directed backward in the vehicle traveling direction. Further, the detection range of the landmark sensor may be expanded to enable omnidirectional detection.

  Next, a processing routine for predicting the stop line position using the information indicating the relative positional relationship between the stop line and the landmark registered as described above will be described. In the present embodiment, landmark matching is performed by limiting the search range as shown in FIG. Although it is possible to search the entire range without limiting the search range, in reality, the vehicle position detected by the vehicle position sensor and the error range assumed for the vehicle position sensor are considered. In addition, it is preferable that the searchable range is a range in which the landmark can be detected from the performance of the mounted landmark sensor.

When a GPS device is used as the own vehicle position sensor, as shown in FIG. 4 (1), an ellipse whose major axis direction is in the traveling direction with the current position (X _t , Z _t ) of the own vehicle as a reference. The region S is defined as a range where the host vehicle may exist, that is, a host vehicle position error range. The vehicle position error range can be represented by an ellipse having a length that is approximately the sum of the traveling distance of 30 m and the traveling distance for the second speed in the traveling direction, and a distance that is approximately 30 m in the lateral direction. Also, as shown in FIG. 4B, the search range W is the sum of the range in which the landmark can be detected from the vehicle position error range and the absolute position error of the registered information. The error range may be changed depending on the GPS reception status.

  When a sensor that detects information based on past history such as a gyro sensor is used as the vehicle position sensor, the vehicle's existence possibility range, that is, the vehicle position error, is determined from the error range corresponding to the time of position specification. Determine the range. This is because errors accumulate as time increases from the initial state.

In step 120, the vehicle position (Xt, Zt) and the vehicle position error range (σa, σb) in the X-axis and Z-axis directions are acquired. In step 122, k landmarks are detected, and each detected Landmark position information (r ₀ , θ ₀ ), (r ₂ , θ ₂ ),... (R _k , θ _k ) is acquired. Assume that the positions of the respective landmarks in the detected k landmark rows are (S ₁ , S ₂ , S ₃ ,... S _k ). In this case, an arbitrary number of landmarks may be detected.

  In the next step 124, the detection range (Fov = ± Φs, range = minRs to maxRs) stored in advance in the storage device is taken in, and the search range W on the absolute coordinates is determined.

In the next step 126, absolute positions (X _i , Z _i ), (X _{i + 1} , Z _{i + 1} ) · N of N landmarks existing within the search range W from the landmarks registered in the storage device. .. (X _{i + N} , Z _{i + N} ) are extracted, k registered landmarks are extracted from N registered landmarks in step 128, and the extracted k registered landmarks are registered landmarks A column.

In this case, when k registration landmarks are extracted from N registration landmarks, there are _N C _k combinations, and therefore _N C _k sets of registration landmark strings are extracted. The position of each landmark in the registered landmark row of each set is _defined as (M ₁ , M ₂ , M ₃ ,... M _k ).

In the next step 130, the positional relationship between the currently acquired landmark and the registered landmark, that is, the shape of the currently acquired landmark row and the shape of the registered landmark row is expressed by the following evaluation function. Use and compare. As the evaluation function, the sum of squares E _j of the distances between the landmarks is used, and the j-th set of registered landmark strings (M ₁ , M ₂ , M, of the _N C _k registered landmark strings). ₃ ,... M _k ) and the detected landmark row (S ₁ , S ₂ , S ₃ ,... S _k ), the square sum E _j of the distance between corresponding landmarks is expressed by the following equation: Calculate according to

In the next step 132, the detection landmark row is rotated by θ and the square sum E _j (θ, R) when the translation is performed by the distance R is calculated according to the above equation (2). A minimum value minE _j of E _j (θ, R) is calculated.

In step 132, it is determined whether the calculated minimum value minE _j For _N C _k-number of sets of all, if not calculated minimum minE _j For _N C _k-number of sets all to step 132 The calculation of the evaluation function is repeated until the minimum value minE _j is calculated for all the _N C _k combinations. Thus, the minimum value is calculated for each set.

  If there is no difference in the evaluation function, such as when the landmarks are arranged at equal intervals, or when there is only one detected landmark, the landmark attributes (height, color, large) Etc.), landmark attributes may be detected by a sensor, and an evaluation function using these attributes may be obtained.

  When the detected landmark row and the registered landmark row are overlapped, the evaluation function may be multiplied by a weighting coefficient in accordance with the amount of movement and the amount of rotation.

_{When the} minimum value minE _j is calculated for all of the _N C _k sets, in step 136, the number of registered landmark sequences that minimizes the minimum value minE _j is determined, and the set determined in step 138 is determined. It is determined that the landmark row is a landmark row that matches the detected landmark row. As a result, the correspondence between the detected landmark row and the registered landmark row can be confirmed, so that the position of the stop line can be obtained from the registered landmark row corresponding to the detected landmark row.

  When the position of the stop line is obtained as described above, it is determined that the host vehicle has reached the stop position, and an alarm indicating that the stop position has been reached is issued from the alarm device, and the brake device is controlled. Performs deceleration control.

  As described above, according to the present embodiment, if information indicating the relative positional relationship with the landmark, which is a three-dimensional object, is obtained, the mand mark located on the roadside is unlikely to be blocked by the preceding vehicle. Even in a state where a stop position such as a line cannot be detected, the relative distance between the host vehicle and the stop position can be obtained. Further, by registering a three-dimensional object having a reflecting plate as a landmark, the relative distance between the host vehicle and the stop position can be obtained even under poor visibility such as nighttime or rainy weather. If an accurate relative positional relationship is obtained, accurate absolute position information is not necessary, and therefore high-precision absolute position information for registering the stop position is not necessary.

It is a block diagram which shows embodiment of this invention. It is a flowchart which shows the routine which registers the positional information on a stop line, and the positional information on a landmark. It is a figure which shows the time change of the landmark detected with the landmark sensor. It is explanatory drawing explaining the procedure which judges whether registration information and the present acquisition information matched, (1) is a figure which shows the present own vehicle position and the own vehicle position error range, (2) is The figure which shows the search range based on sensor performance, (3) is a figure which shows the relationship between the registered landmark row | line | column and the landmark row | line | column acquired by detection, (4) is for demonstrating the distance evaluation between landmark row | line | columns. FIG. It is a flowchart which shows the routine which judges whether registration information and the present acquisition information matched.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Own vehicle position sensor 12 Landmark sensor 14 Control apparatus 16 Memory | storage device

Claims (1)

Own vehicle position detecting means for detecting the position of the own vehicle with a first accuracy;
Landmark detection means for detecting position information of landmarks around the own vehicle with a second accuracy higher than the accuracy of the own vehicle position detection means;
Storage means for storing stop position information indicating a stop position indicated by a stop line on the road , and relative position information of a plurality of landmarks detected by the landmark detection means correlated with the stop position information;
After the stop position information and the relative position information are stored in the storage means, the position information of the plurality of landmarks detected by the landmark detection means and the relative positions of the plurality of landmarks stored in the storage means A matching judgment means for judging whether or not the information is matched;
Stop position determination means for determining stop position information correlated with position information of a plurality of landmarks determined to be matched by the determination means as stop position information of the host vehicle;
Vehicle control means for controlling the vehicle based on the stop position information determined by the stop position determination means;
A vehicle control apparatus.

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