JP4719996B2 - Object detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a so-called radar device that detects electromagnetic waves such as lasers and millimeter waves toward an object around the host vehicle and receives a reflected wave from the object to detect a relative position to the object. is there.
[0002]
[Prior art]
Conventionally, as an object detection device, for example, a device described in JP 2000-28718 A is known.
[0003]
This publication proposes an object detection device that divides a laser irradiation range into a plurality of detection areas and determines the presence of an object from the reception level of each detection area.
[0004]
In this apparatus, by comparing the added value of the reception level of the laser beam reflected in each detection area with a threshold value, it is determined whether or not an object exists in the detection area, and the relative distance from the object is determined. Therefore, it is possible to reliably detect an object.
[0005]
Here, when electromagnetic waves are transmitted to the vehicle, the reflector attached to the vehicle reflects the electromagnetic waves more strongly than other parts. Therefore, the position of the reflector is detected by the radar, and the relative position of the vehicle with respect to the host vehicle is calculated based on the detected position of the reflector.
[0006]
[Problems to be solved by the invention]
However, in the conventional object detection device, the object in the detection area is detected on the premise that the object in the detection area completely reflects the electromagnetic wave from the radar. Therefore, all the reflectors attached to the vehicle are When electromagnetic waves cannot be reflected, for example, even if a part of the vehicle falls outside the detection range and there is a reflector that is not detected, the relative position of the vehicle is calculated based only on the position of the detected reflector without considering this. Therefore, there is a problem that the calculated relative lateral position is different from the original lateral position by the amount of the reflector that is not detected.
[0007]
The present invention has been made paying attention to the above-described problems, and the object of the present invention is when a part of an object existing around the host vehicle is out of the detection range of the object detection means and cannot detect the entire object. Another object of the present invention is to provide an object detection device that can detect the relative lateral position of an object that cannot be detected as a whole with high accuracy.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the relative position of the reflector that reflects the electromagnetic wave transmitted around the host vehicle is detected. Reflector position detecting means When, Based on the detection result of the reflector position detection means, the number of reflection objects detection means for detecting the number of reflection objects that one object has, and the relative lateral position of the object based on the detection result of the reflection object position detection means. Relative lateral position calculating means for calculating, object width calculating means for calculating the width of the object based on the detection result of the reflector position detecting means, and the reflector position detecting means Based on the detection result of It is determined whether or not the condition that the object does not exist at the end of the detection range of the reflector position detection means and a part of the object is not hidden by another object present in front is satisfied. by doing, The whole object Reflector position detecting means An overall detection judging means for judging whether or not it is detected by When the previous object width calculated by the object width calculation unit and the current object width are different from each other by a predetermined value or more, the number of the previous reflections detected by the reflection number detection unit is different from the number of the current reflections. And the object width calculation means if at least one of the conditions is satisfied when the whole detection determination means determines that the whole of the object is not detected by the reflector position detection means so Calculation Based on the measured object width Calculation result of the relative lateral position calculation means And a relative lateral position correcting means for correcting.
[0009]
In the invention according to claim 2, as shown in the basic configuration diagram of FIG. The object detection apparatus according to claim 1, The object width calculated by the object width calculating unit is determined for the object determined to be detected by the entire detection determining unit. By filtering using a predetermined transfer function Stabilizing object width stabilizing means Provided , The relative lateral position correcting means is Based on the object width stabilized by the object width stabilizing means, the calculation result of the relative lateral position calculating means is corrected. Ruko And features.
[0010]
In the invention according to claim 3, as shown in the basic configuration diagram of FIG. The object detection device according to claim 2, Based on the object type determination means for determining the type of the object and the history of determination results of the object type determination means for the object determined to be detected as a whole by the whole detection determination means, Target determination means for determining whether or not the target vehicle should be detected; The object width stabilizing means includes Stabilize the object width calculated by the object width calculating unit with respect to the object determined as the target by the target determining unit. Ruko And features.
[0011]
According to a fourth aspect of the present invention, in the object detection device according to the second or third aspect, the relative lateral position correcting means is Based on the object width stabilized by the object width stabilizing means and the number of reflectors detected by the reflector number detecting means, the threshold value is a difference between the previous object width and the current object width. Set a predetermined value It is characterized by that.
[0012]
According to a fifth aspect of the present invention, in the object detection device according to the second or third aspect, the relative lateral position correcting unit includes: Based on the difference between the object width calculated by the object width calculating means and the object width stabilized by the object width stabilizing means, The calculation result of the relative lateral position calculation means is corrected.
[0013]
In invention of Claim 6, Claim 2 or claim 3 In the object detection device according to claim 1, the relative lateral position correction unit is based on the object width stabilized by the object width stabilization unit and the number of reflectors detected by the reflector number detection unit. And correcting the calculation result of the relative lateral position calculation means. It is characterized by that.
[0014]
In the invention according to claim 7, in the object detection device according to claim 2 or 3, The object width stabilizing unit is configured to stabilize the calculation result when the filter processing for stabilizing the object width calculated by the object width calculating unit is continuously performed a predetermined number of times or more. Output as width It is characterized by that.
[0015]
In the invention according to claim 8, Claim 3 In the object detection apparatus described in The object type determining unit determines the type of the object based on the object width calculated by the object width calculating unit. It is characterized by that.
[0016]
In the invention according to claim 9, Claim 3 In the object detection apparatus described in The object type determining means determines the type of the object based on the object width calculated by the object width calculating means and the number of reflecting objects detected by the reflecting object number detecting means. It is characterized by that.
[0017]
In the invention according to claim 10, Claim 3 In the object detection apparatus described in The object type determining means includes an image input means for capturing an image around the host vehicle, and an object feature recording means for recording a feature for each object type as image data, and the object captured by the image input means The type of the object is determined based on the result of comparing the image of the image and the image data for each type of the object recorded in the object feature recording unit. It is characterized by that.
[0018]
In the invention according to claim 11, in the object detection device according to claim 3, The target determining means, for each type determined for the object by the object type determination relative to the time when the object is detected by the reflector position detection means, based on the ratio of the time determined the type, Determine whether the object is a target to be detected for the vehicle It is characterized by that.
[0019]
In the invention according to claim 12, in the object detection device according to claim 3, The target determining unit is configured to calculate the time for which the type is determined for each type determined for the object by the object type determining unit with respect to the time for performing the calculation for determining the type of the object by the object type determining unit. Based on the ratio, determine whether the object is a target to be detected for the vehicle It is characterized by that.
[0023]
Operation and effect of the invention
In the invention according to claim 1, Reflector position detection means , The relative position of the reflector that reflects the electromagnetic wave transmitted around the vehicle is detected, The number of reflecting objects is detected by the reflecting object number detecting means based on the detection result of the reflecting object position detecting means, and the object is detected by the relative lateral position detecting means based on the detection result of the reflecting object position detecting means. The relative lateral position is calculated, and the object width is calculated in the object width calculation means based on the detection result of the reflector position detection means. And in the whole detection judgment means, Reflector position detection means Based on the detection result of By judging whether or not the condition that the object is not present at the end of the detection range of the reflector position detection means and that a part of the object is not hidden by another object present in front is satisfied. , The whole object Reflector position detection means Is detected by When the previous object width calculated by the object width calculating unit and the current object width are different from each other by a predetermined value or more, when the number of the previous reflector detected by the reflector number detecting unit and the number of the current reflector are different, And, when the entire detection determining means determines that the entire object is not detected by the reflector position detecting means, and satisfying at least one of the following conditions: In the relative lateral position correction means, Object width calculation means so Calculation Based on the measured object width Calculation result of relative lateral position calculation means Is corrected.
[0024]
Therefore, When the calculated previous object width and the current object width are different from each other by a predetermined value or more, when the number of detected previous reflectors and the number of current reflectors are different, and If it is determined that the entire object has not been detected, If at least one of the conditions is satisfied, Based on the already detected object width, Relative lateral position calculation means so Calculation Since the relative lateral position of the object was corrected, some of the objects around the host vehicle Reflector position detection means Even when the entire object outside the detection range cannot be detected, the relative lateral position of the object from which the entire object cannot be detected can be detected with high accuracy.
[0025]
In the invention of claim 2, ,all The object width calculated by the object width calculating unit is determined by the object width stabilizing unit for the object determined to be detected by the body detection determining unit. By filtering using a predetermined transfer function Stabilized. Then, in the relative lateral position correcting means, the calculation result of the relative lateral position calculating means is corrected based on the object width stabilized by the object width stabilizing means.
[0026]
Therefore, among the objects detected by the electromagnetic wave transmitted by the reflector position detection means, the stabilized object width is calculated for the object that can detect the entire object, and it is determined that the entire object is not detected. Based on the stabilized object width, Relative lateral position calculation means so Calculation Since the relative lateral position of the object was corrected, some of the objects around the host vehicle Reflector position detection means Even when the entire object outside the detection range cannot be detected, the lateral position of the detected object can be corrected with high accuracy based on the stabilized object width.
[0027]
In invention of Claim 3, ,all The object type is determined by the object type determination unit for the object that is determined to be detected as a whole by the body detection determination unit, and the target determination unit determines the object based on the determination result history of the object type determination unit. It is determined whether or not the vehicle is a target to be detected for the host vehicle, and the object width calculated by the object width calculating unit is stabilized in the object width stabilizing unit for the object determined as the target by the target determining unit. The Then, in the relative lateral position correcting means, the calculation result of the relative lateral position calculating means is corrected based on the object width stabilized by the object width stabilizing means.
[0028]
Therefore, among the objects detected by the electromagnetic wave transmitted by the reflector position detection means, the target that the object should detect for the host vehicle is determined based on the history of the determination result of the object type determination means for the object that can detect the whole object. If a stable object width is determined for an object determined and determined as a target, and it is determined that the entire object has not been detected, based on the stabilized object width, Relative lateral position calculation means so Calculation Since the relative lateral position of the object was corrected, some of the objects around the host vehicle Reflector position detection means Even when the entire object outside the detection range cannot be detected, the lateral position of the detected object can be corrected with higher accuracy than the invention according to claim 2 based on the stabilized object width of the target. .
[0033]
Claim 4 In the described invention, in the relative lateral position correcting means, the previous object is determined based on the object width stabilized by the object width stabilizing means and the number of reflectors detected by the reflector number detecting means. A predetermined value that is a threshold value of the difference between the width and the current object width is determined.
[0034]
Therefore, the threshold value is set based on the stabilized object width with respect to the number of reflectors, and the difference between the previous object width and the current object width needs to correct the relative lateral position. It is possible to accurately determine whether the difference is present.
[0037]
Claim 5 In the described invention, in the relative lateral position correcting means, the relative lateral position calculating means based on the difference between the object width calculated by the object width calculating means and the object width stabilized by the object width stabilizing means. The calculation result is corrected.
[0038]
Therefore, the correction amount of the relative lateral position is determined based on the difference between the stabilized object width and the object width obtained from the current detection result, and the relative lateral position can be obtained with high accuracy.
[0039]
Claim 6 In the described invention, in the relative lateral position correcting means, the relative lateral position is determined based on the object width stabilized by the object width stabilizing means and the number of reflectors detected by the reflector number detecting means. The calculation result of the calculation means is corrected.
[0040]
Therefore, the correction amount of the relative lateral position is determined based on the stabilized object width and the number of reflectors of one detection object, and the distance between the own vehicle and the detection object is long and Even when the obtained object width cannot be obtained correctly, the relative lateral position can be obtained with high accuracy.
[0041]
Claim 7 In the described invention, the object width stabilizing means is for stabilizing the object width calculated by the object width calculating means. Filtering When the calculation is continuously performed a predetermined number of times or more, the calculation result is output as a stabilized object width.
[0042]
Therefore, when the object width is stabilized, the relative lateral position can be corrected with high accuracy by not calculating the stabilized object width unless a predetermined number of calculations are performed. .
[0043]
Claim 8 In the described invention, the object width type determining means determines the object type based on the object width calculated by the object width calculating means.
[0044]
Therefore, since it is not necessary to equip other sensors or the like, the type of the object can be determined by a low-cost system configuration.
[0045]
Claim 9 In the described invention, the object type determination means determines the object type based on the object width calculated by the object width calculation means and the number of reflection objects detected by the reflection object number detection means.
[0046]
Therefore, since it is not necessary to equip with other sensors etc., it can be set as a low-cost system structure, and it can raise comparatively reliability by considering the number of reflectors.
[0047]
Claim 10 In the described invention, based on the result of comparing the image of the object captured by the image input unit and the image for each type of object recorded in the object feature recording unit in the object type determination unit. The type is determined.
[0048]
Therefore, since the object type is determined by adding image data, more accurate target identification can be performed.
[0049]
Claim 11 In the described invention, in the target determination means, the ratio of the time for which the type is determined for each type determined for the object by the object type determination means with respect to the time for detecting the object by the reflector position detection means. Based on this, it is determined whether or not the object is a target to be detected for the host vehicle.
[0050]
Therefore, since the target is determined according to the time ratio between the time when the object appears and the time when it is determined to be similar to the target, even if the object type determination is not stable, the detected object is reliably handled as the target. It can be determined whether or not.
[0051]
Claim 12 In the described invention, the target determination unit determines the type for each type determined for the object by the object type determination unit with respect to the time when the calculation for determining the type of the object is performed by the object type determination unit. Whether or not the object is a target to be detected for the host vehicle is determined based on the proportion of the time.
[0052]
Therefore, the target is determined according to the time ratio between the time when the object type determination is calculated and the time when it is determined to be similar to the target. Therefore, even if the object type determination is not stable, the detected object is reliably detected. Can be determined as a target.
[0053]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments for realizing the object detection device according to the present invention will be described in claims 1, 2, 4, 5, 6, and 6. 7 Corresponding first embodiment and claims 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 1 2 A description will be given based on the corresponding second embodiment.
[0054]
(First embodiment)
First, the configuration will be described. FIG. 2 is an automatic brake system diagram to which the object detection apparatus of the first embodiment is applied, in which 1 is a laser radar (claim 1). of 2 is a radar processing device, 5 is an external recognition device, 6 is a vehicle speed detection device, 7 is a steering angle detection device, 8 is an automatic brake control device, and 9 is a negative pressure brake booster.
[0055]
The laser radar 1 is provided at the position of the front end of the host vehicle, and transmits a vertically long beam to a reflector (preceding vehicle, infrastructure structure, etc.) in the front area of the host vehicle, A light transmission scanning unit that scans a light transmission beam in a horizontal direction within a predetermined angle range, a light receiving unit that has a horizontally long light receiving area that receives a reflected wave from the reflector, and a horizontally long light receiving area within a predetermined angle range. This is a scanning type distance measuring means having a light receiving scanning unit that scans in the vertical direction.
[0056]
The radar processing device 2 reads the scanning result (distance information) from the light receiving scanning unit of the laser radar 1 and sets the object width W and the number of reflectors n that can detect the whole of the reflectors in the front area of the vehicle. Based on stable object width W _S And the number of stable reflectors n _S And calculating the value of two-dimensional coordinates (x, y) with the origin of the own vehicle for one or a plurality of sensing objects (targets for correcting the two-dimensional coordinates with the origin of the own vehicle) This is performed by the process shown in FIG. 3 including the correction of the lateral position x. Then, the two-dimensional coordinate information of the detected object that is the processing result is output to the external recognition device 5.
[0057]
The external environment recognition device 5 is configured to detect two-dimensional coordinate information of the detected object from the radar processing device 2 and information for estimating the state quantity of the host vehicle (vehicle speed information from the vehicle speed detection device 6 and steering angle from the steering angle detection device 7). Based on the information), it recognizes whether or not the detected object is an obstacle for the host vehicle, and outputs this to the automatic brake control device 8 as external world recognition information.
[0058]
The vehicle speed detection device 6 is a device that detects a vehicle speed based on sensor signals from left and right driven wheel speed sensors, and outputs detected vehicle speed information to the external environment recognition device 5.
[0059]
The steering angle detection device 7 is a device that detects a steering angle based on a sensor signal from a front wheel steering angle sensor or the like, and outputs detected steering angle information to the external environment recognition device 5.
[0060]
When the external world recognition information input from the external world recognition device 5 satisfies the automatic brake control start condition, the automatic brake control device 8 applies a braking force command voltage to the solenoid valve of the negative pressure brake booster 9 to perform automatic brake control. When the automatic brake control termination condition is satisfied, a control command for canceling the application of the braking force command voltage to the solenoid valve of the negative pressure brake booster 9 is output.
[0061]
The negative pressure brake booster 9 applies an arbitrary braking force to the front and rear wheels, and operates according to a braking force command voltage applied from the automatic brake control device 8 to the solenoid valve.
[0062]
The radar processing device 2 and the automatic brake control device 8 are each provided with a microcomputer and its peripheral components, drive circuits for various actuators, etc., and transmit information to each other via a communication circuit.
[0063]
Next, the operation will be described.
[0064]
[Relative lateral position correction processing]
FIG. 3 is a flowchart showing the flow of the relative lateral position correction process executed by the radar processing apparatus 2 of the first embodiment. Each step will be described below. This process is performed every 100 msec.
[0065]
In step 201, the scanning result (distance information) from the laser radar 1 is read.
[0066]
In step 202, a group of data with close distance information read in step 201 (for example, a collection of 1 m or less in vertical distance and 2 m or less in horizontal distance) is grouped as one object. .
[0067]
In step 203, for each object grouped in step 202, the center coordinates of the object: x, y, the object width W, the number of reflectors of one object: n, and a flag indicating the detectability of the entire object: A (Claims) 1 Equivalent to the reflected object number detecting means, the relative lateral position calculating means, and the object width calculating means). Here, the center coordinates (x, y) of the object are obtained from the average value of the data group grouped as one object. Note that x represents the horizontal position of the object, and y represents the vertical position of the object. The object width W is obtained from the difference between the two end coordinates of the data group grouped as one object. The number n of reflections of one object is obtained as the number of areas to be reflected in the data group grouped as one object. The flag A indicating the detectability of the entire object is obtained from the fact that the object is not present at the end of scanning and that a part of the object is not hidden by other objects present in the foreground. A = 1 when satisfied, and A = 0 when these conditions are not satisfied.
[0068]
In step 204, the detected object is tracked from the center coordinates (x, y) of the object obtained in step 203 and its history. Here, tracking refers to comparing the central coordinates (x, y) of an object and its history to distinguish whether the object should be followed or newly appeared.
[0069]
In step 205, it is determined whether or not the entire object can be detected from the flag A indicating the detectability of the entire object obtained in step 203. If A = 1 (the entire object can be detected), the process proceeds to step 206. , A = 0 (the whole object cannot be detected), the process proceeds to step 207 (claims). 1 Equivalent to the whole detection determination means).
[0070]
In step 206, based on the object that can be detected entirely, the stable object width W _S And the number of stable reflectors n _S And are calculated (claims) 2,7 Equivalent to the object width stabilization means). Stable object width W _S First, the provisional object width W stabilized by the transfer function G (z) expressed by the following equation (1) using the object width W obtained in step 203 as an input. _{S_temp} Is calculated.
G (z) = 0.1z / (z−0.9) (1)
Here, z represents an advance operator. The initial value of the transfer function G (z) is set to the value of the object width W obtained by the current scanning when the process of step 206 is performed for the first time after the appearance of the object. Then, the number of times the calculation process of the expression (1) is performed for each detected object is counted, and when it is performed 10 times or more, the stabilized temporary object width W _{S_temp} Has a stable object width W _S (= W _{S_temp} ) Or else W _S = 0 (not calculated). Similarly, the number of stable reflectors n _S Is the temporary number n of reflectors stabilized by the transfer function G (z) expressed by the above equation (1) using the number n of reflectors obtained in step 203 as an input. _{S_temp} Is calculated. Note that the initial value of the transfer function G (z) is set to the value of the number of reflectors n obtained by the current scanning when the process of step 206 is performed for the first time after the appearance of the object. Then, the number of times of performing the calculation process of the expression (1) is counted for each detected object, and when it is performed 10 times or more, the number of stabilized temporary reflectors n _{S_temp} Number of stable reflectors n by rounding off the decimal point _S {= Round (n _{S_temp} )} Is calculated, otherwise n _S = 0 (not calculated). Where round (·) is the decimal point of This function performs rounding.
[0071]
In step 207, the already stable object width W _S Is calculated correctly, and if so, the process proceeds to step 208; otherwise, the process proceeds to step 212.
[0072]
In step 208, the absolute value (change in width) of the difference between the current value of the object width W obtained in step 203 and the past value of the object width W obtained 100 msec before exceeds the set threshold value 0.8Wth. (2) to determine whether or not 1, 4 Equivalent to the relative lateral position correcting means).
abs {W (z ⁰ ) -W (z ^-1 )}> 0.8Wth (2)
Here, abs {·} is a function that repeats an absolute value, and Wth is a stable object width W _S And the number of stable reflectors n _S From the following equation (3).
Wth = W _S / N _S … (3)
If the expression (2) is satisfied, the process proceeds to step 211; otherwise, the process proceeds to step 209.
[0073]
In step 209, it is determined whether or not there is a change in the number of reflectors n of one object obtained in step 203 (claims). 1 Equivalent to the relative lateral position correcting means). Here, the number of reflectors n (z ⁰ ) And the number of reflectors n (z ^-1 ) Is not zero, the process proceeds to step 211. If the difference is zero, the process proceeds to step 210.
[0074]
In step 210, the detectability of the entire object is determined based on the flag A indicating the detectability of the entire object. 1 Equivalent to the relative lateral position correcting means). If it is determined that the entire object can be detected (that is, A = 1), the process proceeds to step 212. If not (that is, A = 0), the process proceeds to step 211.
[0075]
In step 211, the stable object width W calculated in step 206 is obtained. _S Then, based on the object width W obtained by the current scanning, the lateral position x is corrected by the following equation (4). 5, 6 Equivalent to the relative lateral position correcting means).
x (z ⁰ ) = X (z ⁰ ) + Dir * (W _S -W) / 2 (4)
Here, dir has a value of ± 1, and x (z ⁰ ) −x (z ^-1 )> 0, dir = −1, x (z ⁰ ) −x (z ^-1 ) <0, dir = + 1.
[0076]
In step 212, the center coordinates (x, y) of the object are output.
[0077]
[Relative lateral position correction]
The entire object cannot be detected and is still stable. _S And the number of stable reflectors n _S 3 cannot be accurately calculated, the flow proceeds to step 201 → step 202 → step 203 → step 204 → step 205 → step 207 → step 212 in the flowchart of FIG. 3. In step 212, the horizontal position x and the vertical position y The center coordinates (x, y) of the detected object based on the detected value are output.
[0078]
The entire object can be detected and the stable object width W _S And the number of stable reflectors n _S 3 is performed, the flow proceeds from step 201 to step 202, step 203, step 204, step 205, and step 206 in the flowchart of FIG. Stable object width W based on the number of objects n _S And the number of stable reflectors n _S Is calculated.
[0079]
The entire object cannot be detected and is already stable. _S And the number of stable reflectors n _S 3 can be accurately calculated, the flow proceeds to step 201 → step 202 → step 203 → step 204 → step 205 → step 207 in the flowchart of FIG. 3, and step 208 (width changing condition) and step 209 (reflection) are performed. If neither the condition of the number of objects) nor the condition of step 210 (partial object detection condition) is satisfied, the process proceeds from step 210 to step 212 and the center coordinates of the detected object based on the detected values of the horizontal position x and the vertical position y. (X, y) is output.
[0080]
On the other hand, the entire object cannot be detected and is already stable. _S And the number of stable reflectors n _S At least one of the width change condition (step 208), the number of reflection objects change condition (step 209), and the partial object detection condition (step 210) is satisfied. Then, the process proceeds to step 211 to stabilize the object width W _S The lateral position x is corrected from the detected difference in the object width W, and the process proceeds to step 212, where the center coordinates (x, y) based on the corrected lateral position x are output.
[0081]
That is, the case where the change condition of the width of step 208 is satisfied is, for example, a case where the own vehicle approaches the detected object as shown in FIG. 4, and a reflector at the left end of the detected object when the own vehicle approaches. (Reflector) is out of detection range. Therefore, when the past value and the current value of the width W of the detected object obtained from the reflector change, the lateral position x is corrected by the change in the width that satisfies the above equation (2).
[0082]
The case where the condition for changing the number of reflectors in step 209 is satisfied is, for example, the case where the host vehicle approaches the detected object, as in FIG. 4, and the reflector at the left end of the detected object ( The reflector is out of the detection range. Then, as shown in FIG. 5, when the area of the middle reflector is large, the difference between the past value and the present value of the width of the detected object obtained from the reflector is small, and the change condition of the width of the detected object according to the above equation (2) Does not meet. Therefore, in such a case, the lateral position x is corrected by changing the number of reflectors n (3 → 2).
[0083]
The case where the object detection condition in step 210 is satisfied is, for example, as shown in FIG. 6, the distance between the detection object and the host vehicle is short, and therefore the entire width of the detection object is determined as a reflector (reflector). This is the case. In this case, even if the left end of the detected object is outside the detection range, the difference between the past value and the current value of the detected object width is small, and the condition for changing the detected object width according to the above equation (2) is not satisfied. In addition, since the entire width of the sensing object becomes a reflector, the number of reflectors But The number of reflectors is small, and the change in the number of reflectors is small, and the condition for changing the number of reflectors is not satisfied. Therefore, when the distance between the detected object and the host vehicle is short, the lateral position x is corrected by satisfying the condition that a part of the detected object is detected.
[0084]
That is, in the first embodiment, the already stable object width W _S And the number of stable reflectors n _S If the at least one of the condition for changing the width, the condition for changing the number of reflectors, and the condition for partially detecting the object is satisfied, the lateral position x of the detected object is corrected. Therefore, even if the reflection area of the reflector provided on the sensing object changes, it is not corrected for changes in the lateral position of the real object, and the number and size of the reflectors provided on the sensing object are not corrected. Therefore, it is possible to realize an object detection device that detects the lateral position x with high accuracy that is not affected by this.
[0085]
Next, the effect will be described.
[0086]
(1) In step 203, the center coordinates (x, y) of the object reflecting the electromagnetic wave transmitted around the host vehicle, the width W of the object, and the number n of reflected objects are calculated. When at least one of the width changing condition (step 208), the reflecting object number changing condition (step 209), and the object partial detection condition (step 210) is satisfied, In step 211, since the lateral position x of the detected object is corrected based on the already calculated object width W, a part of the object existing around the host vehicle is out of the detection range of the laser radar 1 and the entire object is removed. Even when it cannot be detected, the lateral position x of the object that cannot be detected as a whole can be detected with high accuracy.
[0087]
(2) The object width W stabilized in step 206 based on the object width W calculated in step 206 for the object determined to be detectable in step 205 _S Is calculated, and in step 211, the stabilized object width W _S Since the lateral position x is corrected on the basis of the object width W obtained by the current scanning, when a part of the object existing around the host vehicle is out of the detection range of the laser radar 1 and the entire object cannot be detected. The stabilized object width W _S The lateral position x of the detected object can be corrected with high accuracy based on.
[0088]
(3) In step 209, the number n (z ^-1 ) And the number n (z ⁰ ) Are different, the process proceeds to step 211 and the lateral position x is corrected, so that it is possible to eliminate erroneous correction in a state where correction is not necessary.
[0089]
(4) In step 208, the previous object width W (z ^-1 ) And the current object width W (z ⁰ ) Is different from the threshold of 0.8 Wth or more, the process proceeds to step 211 and the lateral position x is corrected. Therefore, it is possible to eliminate erroneous correction in a state where correction is not necessary.
[0090]
(5) In step 208, the stabilized object width W _S And the number of reflectors stabilized n _S Based on Wth (= W _S / N _S ) Is set to a threshold value based on the stabilized object width for the number of reflectors, and the previous object width W (z ^-1 ) And the current object width W (z ⁰ It is possible to accurately determine whether or not the difference from) is a difference that requires correction of the lateral position x.
[0091]
(6) If it is determined in step 210 that the entire object cannot be detected, the process proceeds to step 211 and the lateral position x is corrected, so that it is possible to eliminate erroneous correction in a state where correction is not necessary. .
[0092]
(7) Calculated in step 211 The Object width W and stabilized object width W _S Since the lateral position x is corrected based on the difference between the lateral position x and the lateral position x, the lateral position x can be obtained with high accuracy.
[0093]
(8) In step 206, when the calculation for stabilizing the calculated object width is continuously performed ten times or more, the object width W in which the calculation result is stabilized. _S When the object width is stabilized, the stabilized object width W is obtained unless the number of calculations is 10 times or more. _S Since it is not determined that can be calculated, the lateral position x can be corrected with high accuracy.
[0094]
(Second embodiment)
First, the configuration will be described.
FIG. 7 is an automatic braking system diagram to which the object detection device of the second embodiment is applied. In the figure, 1 is a laser radar (corresponding to the reflector position detection means of claim 3), 2 is a radar processing device, CCD camera, 4 is an image processing device, 5 is an external environment recognition device, 6 is a vehicle speed detection device, 7 is a steering angle detection device, 8 is an automatic brake control device, and 9 is a negative pressure brake booster.
[0095]
The CCD camera 3 is a progressive 3CCD camera that is provided at an upper position on the windshield of the vehicle and images the situation ahead of the host vehicle at high speed. The imaging result is sent to the image processing device 4.
[0096]
The radar processing device 2 reads the distance information of the laser radar 1 and the image data from the image processing device 4, compares the image data of the detected object stored in advance with the image data near the coordinates of the detected object, The type of the detected object (hereinafter referred to as the target) is determined, and the stable object width W based on the determined target object width W and the number of reflectors n _S And the number of stable reflectors n _S And calculating the value of the two-dimensional coordinates (x, y) with the own vehicle as the origin with respect to one or a plurality of sensing objects (targets for correcting the two-dimensional coordinates with the own vehicle as the origin) This is performed by the process shown in FIG. 8 including the correction of the lateral position x. Then, the two-dimensional coordinate information of the detected object that is the processing result is output to the external recognition device 5.
[0097]
The image processing device 4 inputs the imaging result from the CCD camera 3, creates image data of the detected object, and outputs image data information to the radar processing device 2 and the external environment recognition device 5.
[0098]
Image data information from the image processing device 4 is added to the outside recognition device 5 as input information. The other configuration is the same as that of the first embodiment shown in FIG.
[0099]
Next, the operation will be described.
[0100]
[Relative lateral position correction processing]
FIG. 8 is a flowchart showing the flow of the relative lateral position correction process executed by the radar processing apparatus 2 of the second embodiment. Each step will be described below. This process is performed every 100 msec.
[0101]
Step 301 to step 303 are the same as step 201 to step 203 in the first embodiment, and will be omitted. Step 303 corresponds to the reflecting object number detecting means, the relative lateral position calculating means, and the object width calculating means.
[0102]
Step 304 is the same as step 204, but in step 304, in addition to step 204, when the object is followed (during tracking), the appearance time t of the object is incremented.
[0103]
Step 305 is the same as step 205, but in step 305, if the entire object can be detected, the process proceeds to step 306, and if not, the process proceeds to step 314 (corresponding to the whole detection determination means in claim 3).
[0104]
In step 306, the distance √ (x ² + Y ² ) Is 40 m or more away, the process proceeds to step 307, otherwise proceeds to step 308.
[0105]
In step 307, the size of the object to be considered as a target (for example, the vehicle has a width of about 1.2 to 2.2 m, the roadside structure has a width of 0.5 m or less), and the object width W detected in step 303. For example, if the detected object width W corresponds to the width of the vehicle, T = 2 is substituted for the flag T, and the counter T2 (counter when the detected object is a vehicle) is incremented to detect When the object width W corresponds to the size of the roadside structure, T = 1 is substituted for the flag T, and the counter T1 (counter when the detected object is infrastructure) is incremented. T = 0 is assigned to the flag T, and the process proceeds to step 311. 8 Equivalent to the object type determination means). Here, the counter T1 is a value indicating the targetness when the detected object is an infrastructure, and the counter T2 is a value indicating the targetness when the detected object is a vehicle.
[0106]
In step 308, a small area based on the center coordinates (x, y) of the object obtained in step 303 is extracted from the input image of the CCD camera 3, and the central value of the luminance in the extracted image is obtained. For example, in the case of 8-bit resolution, if the central value of luminance does not fall within the range of 77 to 179, the S / N ratio is assumed to be bad, that is, the image is extremely bright or dark, and thus the reliability Is judged to be low, the process proceeds to step 309; otherwise, the process proceeds to step 310.
[0107]
In step 309, counters T1 and T2, which are values indicating targetness, are obtained from the object width W obtained in step 303 and the number n of reflections of the object. 9 Equivalent to the object type determination means). For example, when the width W is in the range of 1.2 to 2.2 m and the number of reflectors n is 3 or less, the target is recognized as a vehicle, T = 2 is substituted for the flag T, and the counter Increment T2. When the width W is 0.5 or less and the number of reflectors n is 1, the target is recognized as a roadside structure, T = 1 is substituted for the flag T, and the counter T1 is set. Increment. In other cases, T = 0 is substituted into the flag T, and the process proceeds to Step 311.
[0108]
In step 310, the image extracted in step 308 is compared with the pattern learned as a target in advance. For example, if the pattern resembles a vehicle pattern, T = 2 is substituted into the flag T and the counter T2 If the pattern is similar to the pattern of the roadside structure, T = 1 is substituted for the flag T and the counter T1 is incremented. Otherwise, T = 0 is substituted for the flag T. Step 311 (Claim 3, 10 Equivalent to the object type determination means).
[0109]
In step 311, whether or not the target is determined by the following expression is determined based on the counters T 1 and T 2 calculated in step 307, step 309, and step 310 and the time t after the object counted in step 304 is detected (claim) Term 3, 12 Equivalent to target determination means).
if (T1 >> T2) (6)
Td = (T1 / t> 0.1) (7)
elseTd = (T2 / t> 0.1) * 2 (8)
Here, (T1 / t> 0.1) in equation (7) means that Td = 1 is substituted if the conditions in parentheses are satisfied, and Td = 0 is substituted otherwise. Similarly, in the case of Expression (8), Td = 2 is substituted if the conditions in parentheses are satisfied, otherwise Td = 0 is substituted. Also, the if statement in equation (6) executes equation (7) when T1 is twice or more and larger than T2, and executes equation (8) otherwise.
[0110]
In step 312, if the Td obtained in step 311 is the same as the values of T1 and T2 obtained in step 307, step 309, and step 310, the process proceeds to step 313, and if not, the process proceeds to step 314.
[0111]
Steps 313 to 317 are the same as steps 206 to 210 in the first embodiment, and are therefore omitted.
[0112]
In step 318, if the distance from the detected object in step 303 is 38 m or less, the process proceeds to step 319, and if not, the process proceeds to step 320.
[0113]
Step 319 is the same as step 211 in the first embodiment, and will be omitted.
[0114]
In step 320, the stable object width W calculated in step 313 is obtained. _S And the number of reflectors n when stably detected calculated in step 313 _S And the correction of the lateral position x according to the following equation (9) based on the number of reflectors n obtained in step 303, and the process proceeds to step 321. 6 Equivalent to the relative lateral position correcting means).
x (z ⁰ ) = X (z ⁰ ) + Dir * (W _S / N _S ) * Abs (n _S -N) ... (9)
Here, “abs ()” is a function that repeats an absolute value, and dir has a value of ± 1 and x (z ⁰ ) −x (z ^-1 )> 0, dir = −1, x (z ⁰ ) −x (z ^-1 ) <0, dir = + 1. That is, if the distance from the detected object is large, the resolution of the laser radar 1 is lowered, and the accuracy of the calculated object width is also lowered. Therefore, highly accurate and stable object width W _S And the number of stable reflectors n _S Is used to improve the accuracy of correction.
[0115]
Since step 321 is the same as step 212 in the first embodiment, it is omitted.
[0116]
[Relative lateral position correction]
The entire object cannot be detected and is still stable. _S And the number of stable reflectors n _S 8 cannot be accurately calculated, the flow proceeds to step 301 → step 302 → step 303 → step 304 → step 305 → step 314 → step 321 in the flowchart of FIG. 8. In step 321, the horizontal position x and the vertical position y The center coordinates (x, y) of the detected object based on the detected value are output.
[0117]
The entire object can be detected and the stable object width W _S And the number of stable reflectors n _S In the flowchart of FIG. 8, in the flowchart of FIG. 8, the flow proceeds from step 301 to step 302 to step 303 to step 304 to step 305 to step 306. When the distance from the detected object is 40 m or more, If the distance from the detected object is less than 40 m and the S / N ratio in the image data near the object center coordinates is poor, the process proceeds from step 306 to step 308 to step 309. When the distance from the object is less than 40 m and the S / N ratio in the image data near the object center coordinates is good, the process proceeds from step 306 to step 308 to step 310. Then, when the counters T1 and T2 that are target-like values are calculated in either step 307, step 309, or step 310, the process proceeds to step 311 to determine whether or not the detected object is a target, and the counter T1 , T2 and the object determined as the target are the same, the process proceeds from step 312 to step 313, and the stable object is determined based on the width W of the object determined as the target and the number of reflectors n. Width W _S And the number of stable reflectors n _S Is calculated.
[0118]
The entire object cannot be detected, and the object width W is already stable. _S And the number of stable reflectors n _S 8 can be accurately calculated, the flow proceeds to step 301 → step 302 → step 303 → step 304 → step 305 → step 314 in the flowchart of FIG. 8, and step 315 (width changing condition) and step 316 (reflection) are performed. If neither the condition of the number of objects) nor the step 317 (partial object detection condition) is satisfied, the process proceeds to step 321 where the center coordinates (x, y) is output.
[0119]
On the other hand, the entire object cannot be detected and is already stable. _S And the number of stable reflectors n _S Is the time when the width change condition (step 315 ) And the number of reflectors change condition (step 316 ) And part detection conditions (steps) 317 If at least one condition is satisfied, the process proceeds to step 318. In step 318, it is determined whether or not the distance to the detected object is 38 m or less. If it is 38 m or less, the process proceeds to step 319 and the stabilization width W _S When the lateral position x is corrected from the difference between the detection width W and the detection width W exceeds 38 m, the process proceeds to step 320, where the stabilization width W _S And the number of stabilized reflectors n _S And the lateral position x is corrected from the number n of reflective objects. Thereafter, the process proceeds to step 321 to output the center coordinates (x, y) based on the corrected lateral position x.
[0120]
That is, in the second embodiment, in addition to the highly accurate detection of the lateral position x in the first embodiment, the image data from the image processing device 4 is added to the distance information of the laser radar 1 as input information. The detected object can be reliably and accurately captured, and the object width W is stabilized by distance information and image data. _S And the number of stable reflectors n _S Since the target for calculating is determined, it is possible to realize an object detection device that detects the lateral position x with high accuracy without being affected by the type of the detection object (vehicle, infrastructure structure, etc.).
[0121]
Next, the effect will be described.
[0122]
In the object detection apparatus of the second embodiment, the following effects can be obtained in addition to the effects (1) and (3) to (8) of the first embodiment.
[0123]
(9) In step 303, the center coordinates (x, y) of the object reflecting the electromagnetic wave transmitted around the vehicle, the object width W, and the number of reflectors n are calculated. In step 305, the entire object can be detected. Or In step 305, if it is determined that the whole can be detected, the type of the object is determined in step 307, step 309, or step 310. In step 311, the history of the object type determination result is displayed. In step 313, the stabilized object width W for the target determined based on _S Is calculated, When at least one of the width changing condition (step 315), the reflecting object number changing condition (step 316), and the object partial detection condition (step 317) is satisfied, Since the lateral position x of the detected object is corrected in step 319 or step 320, even if a part of the object existing around the host vehicle is out of the detection range of the laser radar 1 and the entire object cannot be detected, the target Stabilized object width W _S Therefore, the lateral position of the detected object can be corrected with higher accuracy than in the first embodiment.
[0124]
(10) In step 320, the correction amount of the lateral position x is set to the stabilized object width W. _S And the number of reflectors n of one sensing object is determined, so that the distance between the vehicle and the sensing object is far away and the object width W obtained from the current detection result cannot be obtained correctly However, the lateral position x can be obtained with high accuracy.
[0125]
(11) Since the type of the object is determined based on the object width W in step 307, it is not necessary to equip other sensors and the type of the object can be determined with a low-cost system configuration.
[0126]
(12) In step 309, since the type of the object is determined based on the object width W and the number of reflectors n, it is not necessary to equip other sensors, and a low-cost system configuration can be achieved. In addition, the reliability can be relatively improved by considering the number of reflectors n.
[0127]
(13) In step 310, the image data containing the target characteristics prepared in advance is compared with the image data in the vicinity of the center coordinates of the object, and the type of the object is determined. It can be performed.
[0128]
(14) In step 311, the ratio of the times T 1 and T 2 at which the type is determined for each type determined for the object with respect to the time t at which the calculation for determining the type of the object is performed, that is, the type determination of the object Since the target is determined according to the time ratio between the calculated time t and the times T1 and T2 that are determined to be similar to the target, even if the object type determination is not stable, the detected object is reliably set as the target. It can be determined whether or not to handle.
[0129]
(Other examples)
The object detection device of the present invention has been described based on the first embodiment and the second embodiment. However, the specific configuration is not limited to these embodiments, and each claim of the claims Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.
[0130]
For example, in the first embodiment and the second embodiment, the example in which the object detection device of the present invention is applied to an automatic brake device has been shown. However, in addition to the automatic brake device, an inter-vehicle distance control device, a constant speed travel control device, a lane, etc. The present invention can be applied to an in-vehicle control system that requires information on the relative position of an object (such as a preceding vehicle or an infrastructure structure) with respect to the host vehicle, such as a keep control device or a lane assist control device.
[0131]
In the first embodiment and the second embodiment, the case where there is one detected object has been described. However, when a plurality of objects are detected, the same processing shown in FIGS. 2 and 8 is performed on each object. Do.
[0132]
In the second embodiment, in step 311, counters T <b> 1 and T <b> 2 are times when the type is determined for each type determined for the object with respect to time t when the calculation for determining the type of the object is performed in step 311. In this example, it is determined whether or not the object is a target to be detected for the host vehicle based on the ratio of For each determined type, it may be determined whether or not the object is a target to be detected for the host vehicle based on the ratio of the counters T1 and T2, which are times when the type is determined. 11 Equivalent). In this case, since the target is determined according to the time ratio between the time when the object appears and the time when it is determined to be similar to the target, even if the object type determination is not stable, the detected object is reliably set as the target. It can be determined whether or not to handle.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of an invention according to claim 2 and an invention according to claim 3;
FIG. 2 is a diagram showing an automatic brake system to which the object detection device of the first embodiment is applied.
FIG. 3 is a flowchart showing a flow of relative lateral position correction processing executed by the radar processing apparatus of the first embodiment.
FIG. 4 is a diagram illustrating an example when the object width changes in the relative lateral position correction process according to the first embodiment;
FIG. 5 is a diagram illustrating an example of a case where the number of reflectors changes in the relative lateral position correction process of the first embodiment.
FIG. 6 is a diagram illustrating an example when the entire object cannot be detected in the relative lateral position correction process of the first embodiment.
FIG. 7 is a diagram showing an automatic brake system to which an object detection device of a second embodiment is applied.
FIG. 8 is a flowchart showing a flow of relative lateral position correction processing executed by the radar processing apparatus of the second embodiment.
[Explanation of symbols]
1 ... Laser radar (object detection means, reflector position detection means)
2. Radar processing device (object feature recording means)
3 ... CCD camera (image input means)
203, 303 ... Reflector number detection means, relative lateral position detection means, object width detection means
205, 305 ... Whole detection judgment means
206, 313 ... Object width stabilization means
208, 209, 210, 211, 319, 320 ... Relative lateral position correcting means
307, 309, 310 ... Object type determination means
311 ... Target determining means

Claims (12)

Reflector position detecting means for detecting the relative position of the reflector that reflects the electromagnetic wave transmitted around the vehicle,
Reflector number detection means for detecting the number of reflectors of one object based on the detection result of the reflector position detection means;
A relative lateral position calculating means for calculating a relative lateral position of the object based on a detection result of the reflector position detecting means;
An object width calculating means for calculating the width of the object based on the detection result of the reflector position detecting means;
Based on the detection result of the reflection object position detecting means, wherein there is no the object to the edge of the detection range of the reflective object position detection means, and by other objects present in front hidden part of the object Determining whether or not the condition is not satisfied, and determining whether or not the entire object is detected by the reflector position detecting means ,
When the previous object width calculated by the object width calculation unit and the current object width are different from each other by a predetermined value or more, the number of the previous reflections detected by the reflection number detection unit is different from the number of the current reflections. And the object calculated by the object width calculating means when at least one of the conditions is satisfied when the whole detection determining means determines that the entire object is not detected by the reflector position detecting means A relative lateral position correcting means for correcting a calculation result of the relative lateral position calculating means based on a width;
An object detection device comprising: The object detection apparatus according to claim 1,
Object width stabilization for stabilizing the object width calculated by the object width calculation means for the object determined to be detected by the whole detection determination means by filtering using a predetermined transfer function providing a means,
The relative lateral position correcting means based on the stabilized object width by the object width stabilizing means, object detecting device comprising a Turkey to correct the calculation result of the relative lateral position calculating means. The object detection device according to claim 2,
Object type determination means for determining the type of the object for the object determined to be detected as a whole by the whole detection determination means;
A target determining unit that determines whether or not the object is a target to be detected for the host vehicle based on a history of determination results of the object type determining unit ;
The object width stabilizing means, the relative said object is determined as a target by the target determining unit, an object detecting device comprising a Turkey to stabilize the object width calculated by said object width calculating means. In the object detection device according to claim 2 or 3,
The relative lateral position correcting means is based on the object width stabilized by the object width stabilizing means and the number of reflectors detected by the reflector number detecting means, the previous object width and the current object width. An object detection device characterized in that the predetermined value, which is a threshold value of the difference between the two, is determined . In the object detection device according to claim 2 or 3,
The relative lateral position correcting means calculates the relative lateral position calculating means based on the difference between the object width calculated by the object width calculating means and the object width stabilized by the object width stabilizing means. The object detection device characterized by correcting. In the object detection device according to claim 2 or 3 ,
The relative lateral position correcting means, said a stabilized object width by the object width stabilization means, and based on the a number of the reflector speed detected reflected object by the detection means, of the relative lateral position calculating means An object detection apparatus characterized by correcting a calculation result . In the object detection device according to claim 2 or 3,
The object width stabilizing unit is configured to stabilize the calculation result when the filter processing for stabilizing the object width calculated by the object width calculating unit is continuously performed a predetermined number of times or more. An object detection device characterized by outputting as a width . The object detection device according to claim 3 ,
The object type determining unit determines the type of the object based on the object width calculated by the object width calculating unit . The object detection device according to claim 3 ,
The object type determination means determines the type of the object based on the object width calculated by the object width calculation means and the number of reflection objects detected by the reflection object number detection means. Object detection device. The object detection device according to claim 3 ,
The object type determining means includes an image input means for capturing an image around the host vehicle, and an object feature recording means for recording a feature for each object type as image data, and the object captured by the image input means An object detection apparatus that determines the type of the object based on a result of comparing the image of the image and image data for each type of object recorded in the object feature recording unit . The object detection device according to claim 3,
The target determining means, for each type determined for the object by the object type determination relative to the time when the object is detected by the reflector position detection means, based on the ratio of the time determined the type, An object detection apparatus for determining whether or not the object is a target to be detected for the host vehicle . The object detection device according to claim 3,
The target determining unit is configured to calculate the time for which the type is determined for each type determined for the object by the object type determining unit with respect to the time for performing the calculation for determining the type of the object by the object type determining unit. An object detection apparatus that determines whether the object is a target to be detected for the host vehicle based on the ratio .

Images