Lane dividing line detection correcting device, lane dividing line detection correcting method and automatic driving system

Abstract

Lane dividing line detection correcting device with: a maximum curvature estimation circuit (12) for estimating a maximum curvature of a road, along which a vehicle is traveling, based on vehicle sensor information; and a curvature correction circuit (13) for correcting a curvature of a lane dividing line, which has been input to the curvature correction circuit based on the maximum curvature; where the lane dividing line is represented by a white line.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a lane-parting line detection correcting device and a lane-parting line detection correcting method used in automatic control of a steering angle of a vehicle so that the vehicle can be prevented from deviating from a lane when the vehicle has deviated almost from the lane during driving, and relates to an automatic driving system having the lane-parting line detection correcting device.2. DESCRIPTION OF THE RELATED ARTHeretofore, there has been a technology for detecting a position, inclination and curvature of a lane separation line represented by a white line based on image information captured by a camera and automatically controlling the steering angle of a vehicle by using the detected position, inclination and curvature so that the vehicle cannot deviate from a lane, as disclosed in, for example, Japanese Patent Application Publication No. JP 2015-197 794 A.However, the image information captured by the camera is largely influenced by the surrounding environment, such as road surface glare from the sun, lights of an oncoming vehicle, shadows on the road surface, color, etc. As a result, when the position, inclination, and curvature of the lane separation line are detected in the environment constantly changed due to the driving, the accuracy of the detection deteriorates.With particular regard to the lane parting line, there is a need to grasp the curvature far away. In such a case, a phenomenon in which the curvature is detected to be several times larger than that of the actual road shape may occur due to erroneous detection caused by hindrance of the curvature detection by a preceding vehicle, an oncoming vehicle, etc. At the time when the steering angle of the vehicle is automatically controlled by using overestimated curvature information resulting from this erroneous detection, there is a problem that the behavior of the vehicle becomes unstable.DE 11 2014 000 532 T5 describes a curve modelling apparatus comprising a curvature calculation unit, a curvature correction unit and a node information generation unit.WO 2005 / 062 984 A2 describes a curvature estimation system which is used in a collision prediction system.US 2014 / 0 025 227 A1 describes a white line recognition camera which is used to estimate a curve shape of a road more accurately.JP 2009-230 455 A describes an apparatus for improved collision prediction with moving objects.DE 11 2010 003 874 B4 is concerned with the improved detection of road markings with restricted visibility caused by weathering, wherein a "confidence" for the near range and the far range of a recorded image is calculated.JP 2014-44 493 A describes a travel path curvature calculation apparatus, wherein suppression of instantaneous fluctuations of the calculated curvature is performed based on the number of broken lines.JP 2010-151 692 A describes a road shape prediction apparatus in which the radius of a curvature is corrected if a basic curvature radius exceeds a maximum value.SUMMARY OF THE INVENTIONSince the present invention has been made to solve the above-mentioned problem, it has an object of providing a lane-split line detection correcting device, a lane-split line detection correcting method, and an automatic driving system for stabilizing the behavior of a vehicle by correcting overestimated curvature information resulting from erroneous detection of curvature of a lane split line.To achieve the above object, the present invention provides a lane-split line detection correcting apparatus according to claim 1 To achieve the above object, the present invention also provides a lane-split line detection correcting method according to claim 13To achieve the above object, the present invention further provides an automatic driving system comprising: the lane separation line detection correcting device of claim 1; and a control circuit for controlling steering of the own vehicle based on a lane separation line having a curvature corrected by the curvature correcting circuit.Further embodiments are defined by the dependent claims.The following described subject matters which do not fall within the scope of the claims should not be regarded as part of the invention.According to the present invention, the maximum curvature of the road along which the vehicle travels is estimated based on vehicle sensor information, and based on this estimated maximum curvature, the curvature of the lane separation line that has been input is corrected. As a result, overestimated curvature caused by erroneous detection can be suppressed, and vehicle steering control using the information on the lane separation line can be stabilized.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a first embodiment of the present invention. FIG. 2 is a flowchart for illustrating an algorithm according to the first embodiment illustrated in FIG. 1. FIG. 3 is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a second embodiment of the present invention. FIG. 4 is a flowchart for illustrating an algorithm according to the second embodiment illustrated in FIG. 3. FIG. 5 is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a third embodiment of the present invention. FIG. 6 is a flowchart for illustrating an algorithm according to the third embodiment illustrated in FIG. 5. FIG. 7 is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a fourth embodiment of the present invention. FIG. 8 is a flowchart for illustrating an algorithm according to the fourth embodiment illustrated in FIG. 7. FIG. 9 is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a fifth embodiment of the present invention. FIG. 10 is a flowchart for illustrating an algorithm according to the fifth embodiment illustrated in FIG. 9. FIG. 11A is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a sixth embodiment of the present invention. FIG. 11B is a schematic diagram of a travel around a curve for illustrating a relationship between a preceding vehicle and an own vehicle according to the sixth embodiment of the present invention. FIG. 12 is a flowchart for illustrating an algorithm according to the sixth embodiment illustrated in FIG. 11. FIG. 13A is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to a seventh embodiment of the present invention. FIG. 13B is a schematic diagram of a travel around a curve for illustrating a travel course of the own vehicle according to the seventh embodiment of the present invention. FIG. 14 is a flowchart for illustrating an algorithm according to the seventh embodiment illustrated in FIG. 13. FIG. 15A is a block diagram for illustrating a configuration of a lane-separated line detection correcting device and a lane-separated line detection correcting method according to an eighth embodiment of the present invention. FIG. 15B is a schematic diagram of a travel around a curve for illustrating the travel course of the own vehicle between road edges according to the eighth embodiment of the present invention. FIG. 16 is a flowchart for illustrating an algorithm according to the eighth embodiment illustrated in FIG. 15.DETAILED DESCRIPTION OF THE EMBODIMENTSNow, with reference to the attached above drawings, a lane-split line detection correcting device, a lane-split line detection correcting method, and an automatic driving system according to a first embodiment to a ninth embodiment of the present invention will be described in detail. In each of the first to ninth embodiments, the following descriptions will be made based on the lane-divided line detection correcting means because the lane-divided line detection correcting means and the lane-divided line detection correcting method correspond to each other.First Embodiment< Of Lane Separation Line Detection Corrector 1>A lane separation line detection correcting device 1 according to a first embodiment of the present invention illustrated in FIG. 1 includes a traveling speed detection circuit 11, a maximum curvature estimation circuit 12, and a curvature correction circuit 13. the traveling speed detection circuit 11 is configured to acquire a current traveling speed from an own vehicle 2. the maximum curvature estimation circuit 12 is configured to estimate a maximum curvature of a road based on the current traveling speed acquired by the traveling speed detection circuit 11. The curvature correcting circuit 13 is configured to correct, based on the maximum curvature obtained from the maximum curvature estimating circuit 12, a curvature of a lane separation line input from a lane separation line detecting circuit 41 of an image processing device 4, and output detection information about the lane separation line to an external lane departure avoidance control device 5. The lane departure avoidance control device 5 may also be a lane departure avoidance warning device.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 2. First, the lane-separated-line detection correcting device 1 waits for input of lane-separated-line detection information from the image processing device 4 (steps S1-1 and S1-2). At the time when the lane separation line detection information is input, the maximum curvature estimation circuit 12 calculates an estimation value of the maximum curvature based on, for example, the latest or latest traveling speed that has been input last via the traveling speed detection circuit 11, and transmits the calculated estimation value as the maximum curvature to the curvature correction circuit 13 (step S 1- 3). The curvature correcting circuit 13 uses the maximum curvature to correct the curvature in the lane-parting line detection information input from the lane-parting line detecting circuit 41 (step S1-4). The lane separation line detection information including the corrected curvature is then output from the curvature correction circuit 13 to the external lane departure avoidance control device 5 (step S 1- 5).<Operation of Maximum Curvature Estimating Circuit 12>The maximum curvature estimating circuit 12 is configured to calculate an estimated value of the maximum curvature of the lane separation line based on the input traveling speed. The maximum curvature estimating circuit 12 is configured to calculate an estimated value κ of the maximum curvature based on Expression (1) and transmit the calculated estimated value κ to the curvature correcting circuit 13: where v represents a speed (m / s), R represents a minimum planar curvature radius (m), g represents a gravitational acceleration (m / s 2) and f represents a spin friction coefficient between a road surface and tires.A coefficient α is an experimentally determined value. Because a road curvature at a designed speed of a road varies depending on the country or region in which the lane separation line detection correcting device of the present invention is / is supposed to be used, a value of "1" or less is specified in accordance with this road curvature. A specified value of "1" represents the curvature at which the vehicle can travel at its actual speed without slipping.<Operation of Curvature Correcting Circuit 13>The curvature correcting circuit 13 is configured to calculate a corrected curvature L i by correcting a curvature K i in the lane-parting line detection information in accordance with Expression (2) based on the estimated value κ of the maximum curvature calculated by the maximum curvature estimating circuit 12, and output the lane-parting line detection information having the calculated curvature L i to the external lane-deviation avoidance control device 5: where L i-1 represents the curvature of the lane-parting line detection information that has been corrected last.Second Embodiment< Of Lane Separation Line Detection Corrector 1>The lane separation line detection correcting device 1 according to a second embodiment of the present invention illustrated in FIG. 3 includes a traveling speed detecting circuit 11 a, the maximum curvature estimating circuit 12, and the curvature correcting circuit 13. the traveling speed detecting circuit 11 ais configured to acquire relative speeds of preceding vehicles with respect to the own vehicle output from a vehicle detecting circuit 42 of the image processing device 4 configured to perform image processing by using an image captured by the external camera 3 as well as the current traveling speed of the own vehicle. Then, the traveling speed detection circuit 11 acalculates one of an average traveling speed and a maximum traveling speed of the preceding vehicles to be notified to the maximum curvature estimation circuit 12. The maximum curvature estimating circuit 12 is configured to estimate the maximum curvature of a travel path based on the travel speed of the own vehicle. The curvature correcting circuit 13 is configured to correct, based on the maximum curvature obtained from the maximum curvature estimating circuit 12, the curvature of the lane separation line acquired from the image processing device 4 including the lane separation line acquiring circuit 41 configured to acquire an image from the external camera 3 and acquire the lane separation line through image processing, and output the corrected lane separation line acquisition information to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 4. First, the lane-parting line detection correcting device 1 waits for input of lane-parting line detection information from the lane-parting line detecting circuit 41 of the image processing device (steps S2-1 and S2-2). At the time when the lane separation line detection information is input, the lane separation line detection circuit 11 acalculates one of an average value and a maximum value of the travel speeds of a plurality of preceding vehicles, based on the relative speeds of the plurality of preceding vehicles received from the vehicle detection circuit 42 of the image processing device 4 and the travel speed of the own vehicle input from the own vehicle 2 (step S 2- 3). For a single preceding vehicle, the relative speed of this vehicle takes on the calculation result. For no preceding vehicles, the relative speed is calculated as "0".Next, the running speed detection circuit 11 a notifies the maximum curvature estimation circuit 12 of the calculated running speed (step S 2- 4). The maximum curvature estimating circuit 12 calculates the estimated value of the maximum curvature of the road based on the average speed or maximum speed of the preceding vehicles input immediately before this notification, and transmits the calculated estimated value to the curvature correcting circuit 13 (step S2-5). The curvature correcting circuit 13 then uses the maximum curvature to correct the curvature of the lane separation line input from the lane separation line detecting circuit 41 of the image processing device 4 (step S2-6), and outputs the corrected lane separation line detection information to the external lane departure avoidance control device 5 (step S2-7).<Operation of Maximum Curvature Estimating Circuit 12>The maximum curvature estimating circuit 12 is configured to calculate the estimation value of the maximum curvature of the lane separation line based on the input average speed or maximum speed of the preceding vehicles. The maximum curvature estimating circuit 12 is configured to calculate the estimated value κ of the maximum curvature based on the expression (1) mentioned in the first embodiment, and transmit the calculated estimated value κ to the curvature correcting circuit 13.<Operation of Curvature Correcting Circuit 13>The curvature correcting circuit 13 is configured to calculate the corrected curvature L i by correcting the curvature K i in the lane separation line detection information in accordance with Expression (3) based on the maximum curvature estimated value κ calculated by the maximum curvature estimating circuit 12, and output lane separation line detection information having the calculated curvature L i to the external lane departure avoidance control device 5: where L i-1 represents the curvature of the previous corrected lane separation line detection information.Third Embodiment< Of Lane Separation Line Detection Corrector 1>The lane separation line detection correcting device 1 illustrated in FIG. 5 according to a third embodiment of the present invention includes a speed limit detection circuit 14, the maximum curvature estimation circuit 12, and the curvature correcting circuit 13. the speed limit detection circuit 14 is configured to detect a speed limit based on traffic sign / road marking information from a traffic sign detection circuit 43 of the image processing device 4 configured to perform image processing by using an image captured by the camera 3. The maximum curvature estimating circuit 12 is configured to estimate the maximum curvature of the road along which the own vehicle travels based on the detected speed limit. The curvature correcting circuit 13 is configured to correct the curvature of the lane separation line obtained from the lane separation line detecting circuit 41 of the image processing device 4 so that the curvature of the lane separation line may be limited within the maximum curvature calculated by the maximum curvature estimating circuit 12, and to output information on the lane separation line to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 6. First, the lane-parting-line detection correcting device 1 waits for input of lane-parting-line detection information from the lane-parting-line detecting circuit 41 of the image processing device 4 (steps S 3- 1 and S 3- 2). At the time when the lane separation line detection information is input, the speed limit detection circuit 14 confirms whether or not, from the traffic sign / road marking information from the traffic sign detection circuit 43 of the image processing device 4, information on the speed limit is input even only once before (steps S 3- 3 and S 3- 4). At the time when the information about the speed limit itself is input once before, the maximum curvature estimating circuit 12 calculates the maximum curvature of the road along which the own vehicle travels or travels based on this speed limit (step S3-5). Next, the curvature correcting circuit 13 corrects the curvature in the lane separation line detection information such that the curvature may be limited within the maximum curvature (step S 3- 6). Finally, the curvature correcting circuit 13 outputs the corrected lane separation line detection information to the lane departure avoidance control device 5 (step S 3- 7). On the other hand, in step S 3- 4, when the information about the speed limit itself has not been input in advance, the curvature correcting circuit 13 outputs uncorrected lane separation line detection information to the lane departure avoidance control device 5 (step S 3- 8).<Operation of Maximum Curvature Estimating Circuit 12>The maximum curvature estimating circuit 12 is configured to estimate the maximum curvature of the road based on the speed limit information input from a traffic sign. Generally, the speed limit is set lower than the designed speed of the road. Therefore, the maximum curvature estimating circuit 12 is configured to look up and output the curvature from table data of the maximum curvature at the designed speed for each input speed limit. For example, the road curvature with respect to the road design speed as indicated in the road structure order defined by the Japanese Ministry of Land, Infrastructure, Transportation and Tourism shown in Table 1 may be adopted as the table data. Table 1: Maximum curvature with respect to speed limit Table 1: Maximum curvature with respect to speed limit1201 / 5701001 / 380801 / 230601 / 120501 / 80401 / 50301 / 30201 / 15<Operation of Curvature Correcting Circuit 13>The curvature correcting circuit 13 is configured to calculate the corrected curvature L i by correcting the curvature K i in the lane separation line detection information in accordance with Expression (1) or Expression (2) based on the maximum curvature estimated value κ calculated by the maximum curvature estimating circuit 12.Fourth Embodiment< Of Lane Separation Line Detection Corrector 1>The lane separation line detection correcting device 1 according to a fourth embodiment of the present invention illustrated in FIG. 7 includes the speed limit detection circuit 14, the maximum curvature estimation circuit 12, and the curvature correction circuit 13. the speed limit detection circuit 14 is configured to obtain, from an external communication device 6, for example, a road-to-vehicle communication system, information on the speed limit of the currently traveling road. The maximum curvature estimating circuit 12 is configured to estimate the maximum curvature of the road along which the own vehicle travels based on the obtained speed limit. The curvature correcting circuit 13 is configured to correct the curvature of the lane separation line obtained from the lane separation line detecting circuit 41 of the image processing device 4 configured to perform image processing on an image captured by the camera 3 to be limited within the maximum curvature calculated by the maximum curvature estimating circuit 12, and to output information on the lane separation line to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 8. First, the lane-parting line detection correcting device 1 waits for input of lane-parting line detection information from the lane-parting line detecting circuit 41 of the image processing device 4 (steps S4-1 and S4-2). At the time when the lane separation line detection information is input, the speed limit detection circuit 14 acquires the speed limit of the road along which the vehicle is currently traveling from the external communication device 6 (step S 4- 3). At the time when the speed limit is acquired, the maximum curvature estimation circuit calculates the maximum curvature of the traveling road based on the speed limit (step S 4- 4). Next, the curvature correcting circuit 13 corrects the curvature in the lane separation line detection information so that the curvature may be limited within the maximum curvature (step S 4- 5). Finally, the curvature correcting circuit 13 outputs the corrected lane separation line detection information to the lane departure avoidance control device 5 (step S 4- 6).It should be noted that the operation of the maximum curvature estimating circuit 12 and the operation of the curvature correcting circuit 13 are the same as in the third embodiment.Fifth Embodiment< Of Lane Separation Line Detection Corrector 1>The lane separation line detection correcting device 1 illustrated in FIG. 9 according to a fifth embodiment of the present invention includes a road curvature detecting circuit 12 aand the curvature correcting circuit 13. the road curvature detecting circuit 12 ais configured to extract information on the road curvature from traffic sign information output from the traffic sign detecting circuit 43 of the image processing device 4 configured to perform image processing by using an image captured by the camera 3. The curvature correcting circuit 13 is configured to correct the curvature of the lane separation line obtained from the lane separation line detecting circuit 41 of the image processing device 4 to be restricted within the curvature extracted by the road curvature detecting circuit 12 aand to output information on the lane separation line to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 10. First, the lane-parting-line detection correcting device 1 waits for input of lane-parting-line detection information from the lane-parting-line detecting circuit 41 of the image processing device 4 (steps S 5- 1 and S 5- 2). At the time when the lane separation line detection information is input, the road curvature detection circuit 12 aconfirms whether or not information on a road curvature sign among the road sign / road marking information is input from the road sign detection circuit 43 of the image processing device 4 even once before (steps S 5- 3 and S 5- 4). At the time when information about a road curvature sign is input even once before, the road curvature detection circuit 12a extracts the information about the road curvature sign and outputs the extracted information to the curvature correction circuit 13 (step S5-5). Next, the curvature correcting circuit 13 corrects the curvature in the lane separation line detection information such that the curvature may be limited within the maximum curvature (step S 5- 6). Finally, the curvature correcting circuit 13 outputs the corrected lane separation line detection information to the lane departure avoidance control device 5 (step S 5- 7). On the other hand, in step S 5- 4, if information on a road curvature sign has not been input even once before, the curvature correcting circuit 13 outputs uncorrected lane separation line detection information to the lane departure avoidance control device 5 (step S 5- 8).Sixth Embodiment< Of Lane Separation Line Detection Corrector 1>The lane separation line detection correcting device 1 illustrated in FIG. 11A according to a sixth embodiment of the present invention includes a preceding vehicle detection circuit 15, a maximum curvature estimation circuit 12 b, and the curvature correction circuit 13. the preceding vehicle detection circuit 15 is configured to acquire a position of a preceding vehicle (front-and-rear distance and right-and-left distance) from the vehicle detection circuit 42 of the image processing device 4 configured to perform image processing by using an image captured by the camera 3. The maximum curvature estimating circuit 12 bis configured to estimate the maximum curvature of the traveling road based on the position of the preceding vehicle. The curvature correcting circuit 13 is configured to correct the curvature of the lane separation line input from the lane separation line detecting circuit 41 of the image processing device 4 to be limited within the maximum curvature calculated by the maximum curvature estimating circuit 12 band output information on the lane separation line to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 12. First, the lane-parting-line detection correcting device 1 waits for input of lane-parting-line detection information from the lane-parting-line detecting circuit 41 of the image processing device 4 (steps S6-1 and S6-2). At the time when the lane separation line detection information is input, the preceding vehicle detection circuit 15 confirms whether or not information on a preceding vehicle is currently periodically input from the vehicle detection circuit 42 of the image processing device 4 (steps S 6- 3 and S 6- 4). Then, at the time when information on a preceding vehicle is input, the preceding vehicle detection circuit 15 confirms whether or not the traveling lane is a single lane based on the input lane separation line detection information input next (step S 6- 5). If it is determined that the position information about the preceding vehicle is not input or that the traveling lane is not a single lane, it means that there are no preceding vehicles. In such a case, the curvature correcting circuit 13 outputs uncorrected lane separation line detection information (step S 6- 9). If it is determined that the traveling lane is a single lane, the maximum curvature estimation circuit 12 bestimates the maximum curvature of the traveling lane based on the position information on the preceding vehicle (step S 6- 6). If not, the processing proceeds to step S6-9, and correction of the lane separation line detection information is not performed. Next, in step S 6- 7, the curvature correcting circuit 13 corrects the curvature in the lane separation line detection information so that the curvature may be limited within the estimated maximum curvature. Finally, the curvature correcting circuit 13 outputs the corrected lane separation line detection information to the lane departure avoidance control device 5 (step S 6- 8).<Operation of Maximum Curvature Estimating Circuit 12 b>The maximum curvature estimating circuit 12 bis configured to estimate the maximum curvature of the traveling lane based on preceding vehicle detection position information in which the input position of the own vehicle is made the origin point. As illustrated in FIG. 11B, the maximum curvature estimation circuit 12 bis configured to calculate a curvature L -1[1 / m] by calculating a turning radius [m]=y / sin θ of a curve l based on a relationship between the detected position input of a preceding vehicle 2 aand a position of the own vehicle 2.Seventh Embodiment< Of Lane Separation Line Detection Corrector 1>The lane separation line detection correcting device 1 illustrated in FIG. 13A according to a seventh embodiment of the present invention includes a traveling path course detecting circuit 16, a maximum curvature estimating circuit 12 c, and the curvature correcting circuit 13. the traveling path course detecting circuit 16 is configured to acquire area information on a traveling path that has been output from a traveling path detecting circuit 44 of the image processing device 4 configured to perform image processing on an image captured by the camera 3. The maximum curvature estimating circuit 12 cis configured to estimate the maximum curvature of the traveling lane based on the acquired area information on the traveling path. The curvature correcting circuit 13 is configured to correct the curvature of the lane separation line obtained from the lane separation line detecting circuit 41 of the image processing device 4 to be limited within the maximum curvature calculated by the maximum curvature estimating circuit 12 cand output information on the lane separation line to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 14. First, the lane-parting-line detection correcting device 1 waits for input of lane-parting-line detection information from the travel path detecting circuit 44 of the image processing device 4 (steps S 7- 1 and S 7- 2). At the time when the lane separation line detection information is input, the maximum curvature estimation circuit 12 cinputs the area information on the travel path from the travel path detection circuit 44 of the image processing device 4 via the travel path course detection circuit 16, and estimates the maximum curvature of the travel lane (step S 7- 3). Next, in step S 7- 4, the curvature correcting circuit 13 corrects the curvature in the lane separation line detection information such that the curvature may be limited within the maximum curvature. Finally, the curvature correcting circuit 13 outputs the corrected lane separation line detection information to the lane departure avoidance control device 5 (step S 7- 5).<Operation of Maximum Curvature Estimating Circuit 12c>The maximum curvature estimating circuit 12 cis configured to estimate the maximum curvature of the traveling lane based on the input area information on the traveling path. As illustrated in FIG. 13B, the maximum curvature estimation circuit 12 cis configured to extract, from a detected travel path area A, a plurality of coordinate points P 1 located at the center of the width of the road, and calculate a curvature L -1[1 / m] of a curve having the distance of least square error from these coordinate points P 1 by using a least square method. This calculated curvature L -1[1 / m] is output to the curvature correcting circuit 13 as the maximum curvature.Eighth EmbodimentThe lane-parting line detection correcting apparatus 1 illustrated in FIG. 15A according to an eighth embodiment of the present invention includes the traveling path course detecting circuit 16, the maximum curvature estimating circuit 12 c, and the curvature correcting circuit 13. the traveling path course detecting circuit 16 is configured to acquire position information on road edges output from a road edge detecting circuit 81 of a data processing apparatus 8 configured to process detection data such as millimeter wave radar data and laser radar data. The maximum curvature estimating circuit 12 cis configured to estimate the maximum curvature of the traveling lane. The curvature correcting circuit 13 is configured to correct the curvature of the lane separation line obtained from the lane separation line detecting circuit 41 of the image processing device 4 to be limited within the maximum curvature calculated by the maximum curvature estimating circuit 12 cand output information on the lane separation line to the lane departure avoidance control device 5.<Operation of Lane Separation Line Detection Corrector 1>An operation flowchart of the lane separation line detection correcting device 1 is illustrated in FIG. 16. First, the lane-parting-line detection correcting device 1 waits for input of lane-parting-line detection information from the lane-parting-line detecting circuit 41 of the image processing device 4 (steps S8-1 and S8-2). At the time when the lane separation line detection information is input, the maximum curvature estimation circuit 12 cinputs, via the traveling course detection circuit 16, the position information on the road edges input from the road edge detection circuit 81 of the image processing device 4, and estimates the maximum curvature of the traveling lane (step S 8- 3). Next, in step S 8- 4, the curvature correcting circuit 13 corrects the curvature in the lane-parting line detection information such that the curvature may be limited within the maximum curvature, and outputs the corrected lane-parting line detection information to the lane-deviation avoidance control device 5 (step S 8- 5).<Operation of Maximum Curvature Estimating Circuit 12c>The maximum curvature estimating circuit 12 cis configured to estimate the maximum curvature of the traveling lane based on the input position information on the road edges. As illustrated in FIG. 15B, the maximum curvature estimation circuit 12 cis configured to extract, from the position of road edges B, a plurality of coordinate points P 2 located in the middle between both road edges, and calculate a curvature L -1[1 / m] of a curve having the distance of least square error from these coordinate points P 2 by using a least square method. The calculated curvature L -1[1 / m] is output to the curvature correcting circuit 13 as the maximum curvature.Ninth Embodiment< Of Automatic Driving System>In an automatic driving system according to a ninth embodiment of the present invention, the lane separation line detection correcting device 1 described in the first to eighth embodiments is mounted as it is. The automatic driving system includes a control unit configured to control the travel of the own vehicle 2 based on the curvature of the lane separation line corrected by the curvature correcting circuit 13 of the lane separation line detection correcting device 1.<Operation of Lane Separation Line Detection Corrector 1>The operation of the lane-separated-line detection correcting device 1 is the same as that of the lane-separated-line detection correcting devices 1 described in the first to eighth embodiments.The control unit is configured to control the travel of the own vehicle 2 based on the curvature of the lane split line corrected by the curvature correcting circuit 13 of the lane split line detection correcting device 1.< Examples of Various Embodiments>The curvature correcting circuit 13 of the first to ninth embodiments may be configured to preliminarily store a plurality of maximum curvatures from the maximum curvature estimating circuits 12, 12 band 12 cor from the road curvature detecting circuit 12 a, and to perform, when the curvature in the input lane separation line detection information exceeds the latest determined maximum curvature, correction by using the latest maximum curvature that does not exceed the above maximum curvature among the stored maximum curvatures.The curvature correcting circuit 13 may also be configured to store a plurality of maximum curvatures from the maximum curvature estimating circuits 12, 12 aand 12 cor from the road curvature detecting circuit 12 aand, when the curvature in the input lane separation line detection information exceeds the latest determined maximum curvature, perform correction by calculation, in accordance with Expression (3), of the maximum curvature at the current point among the plurality of maximum curvatures that have been stored, based on an amount of change in the maximum curvature obtained from a difference between the stored maximum curvatures.

Claims

A lane separation line detection correcting apparatus comprising: a maximum curvature estimating circuit (12) for estimating a maximum curvature of a road along which an own vehicle travels based on vehicle sensor information; and a curvature correcting circuit (13) for correcting a curvature of a lane separation line input to said curvature correcting circuit based on said maximum curvature; wherein said lane separation line is represented by a white line.The lane separation line detection correcting apparatus according to claim 1, further comprising a travel speed detecting circuit (11, 11a, 14) for detecting a target travel speed as the vehicle sensor information, wherein the maximum curvature estimating circuit estimates the maximum curvature of the road along which the own vehicle travels based on the target travel speed.The lane separation line detection correcting device according to claim 2, wherein the traveling speed detecting circuit detects a traveling speed of the own vehicle as the target traveling speed.The lane separation line detection correcting device according to claim 2, wherein the traveling speed detecting circuit detects, based on a traveling speed of each of a plurality of preceding vehicles, one of an average value and a maximum value of the traveling speeds of the plurality of preceding vehicles as the target traveling speed.The lane separation line detection correcting device according to claim 2, wherein the traveling speed detecting circuit detects a speed limit indicated by one of a road sign and a road marker as the target traveling speed.The lane-separation-line detection correcting device according to claim 2, wherein the travel speed detecting circuit detects a speed limit by communications from the outside as the target travel speed.The lane separation line detection correcting device according to claim 1, wherein the vehicle sensor information includes road curvature information indicated by a road sign.The lane separation line detection correcting apparatus according to claim 1, further comprising a preceding vehicle detecting circuit (15) for detecting a relative position, with respect to the own vehicle, of a preceding vehicle traveling along the same lane as the own vehicle as the vehicle sensor information, wherein the maximum curvature estimating circuit estimates the maximum curvature of the road along which the own vehicle travels based on the relative position of the preceding vehicle.The lane separation line detection correcting apparatus according to claim 1, further comprising a travel path course detecting circuit (16) for detecting a course of a travel path of the own vehicle as the vehicle sensor information, wherein the maximum curvature estimating circuit estimates a curvature of the travel path of the own vehicle based on the course of the travel path, and setting the estimated curvature as the maximum curvature.The lane separation line detection correcting apparatus according to claim 1, further comprising a traveling path course detecting circuit (166) for detecting position information about an edge of a traveling path of the own vehicle as the vehicle sensor information, wherein the maximum curvature estimating circuit estimates a curvature of the traveling path of the own vehicle based on the position information about the edge, and setting the estimated curvature as the maximum curvature.The lane-parting line detection correcting apparatus according to any one of claims 1-10, wherein the curvature correcting circuit is configured to preliminarily store a plurality of the maximum curvatures, and perform, when the curvature of the lane parting line input to the curvature correcting circuit exceeds one of the plurality of the most recently determined maximum curvatures, correction by using a most recently determined one of the plurality of maximum curvatures that does not exceed one of the plurality of maximum curvatures.The lane separation line detection correcting apparatus according to any one of claims 1-10, wherein the curvature correcting circuit preliminarily stores a plurality of maximum curvatures and is configured to perform, when the curvature of the lane separation line input to the curvature correcting circuit exceeds one of the plurality of the most recently determined maximum curvatures, correction by calculating a maximum curvature at a current point among the plurality of maximum curvatures that have been stored, based on a variation amount in the maximum curvature obtained from differences among the plurality of the stored maximum curvatures.A lane separation line detection correcting method comprising: estimating, by a maximum curvature estimating circuit, a maximum curvature of a road along which an own vehicle travels based on vehicle sensor information; and correcting, by a curvature correcting circuit, a curvature of a lane separation line input to the curvature correcting circuit based on the maximum curvature; wherein the lane separation line is represented by a white line.The lane separation line detection correcting method according to claim 13, further comprising: detecting, by a traveling speed detecting circuit, a target traveling speed as the vehicle sensor information; estimating, by the maximum curvature estimating circuit, the maximum curvature of the road along which the own vehicle travels based on the target traveling speed.The lane separation line detection correcting method according to claim 14, wherein the target travel speed comprises a travel speed of the own vehicle.The lane separation line detection correcting method according to claim 14, further comprising detecting, by the traveling speed detecting circuit, one of an average value and a maximum value of the traveling speeds of the plurality of preceding vehicles, based on a traveling speed of each of a plurality of preceding vehicles, as the target traveling speed.The lane separation line detection correcting method according to claim 14, further comprising detecting, by the traveling speed detecting circuit, a speed limit indicated by one of a traffic sign and a road marker as the target traveling speed.The lane separation line detection correcting method according to claim 14, further comprising detecting, by the traveling speed detection circuit, a speed limit via external communication as the target traveling speed.The lane separation line detection correcting method according to claim 13, wherein the vehicle sensor information includes road curvature information indicated by a road sign.The lane separation line detection correcting method according to claim 13, further comprising: detecting, by a preceding vehicle detecting circuit, a relative position with respect to the own vehicle, a preceding vehicle traveling along the same lane as the own vehicle as the vehicle sensor information; and estimating, by the maximum curvature estimating circuit, the maximum curvature of the road along which the own vehicle travels based on the relative position of the preceding vehicle.The lane separation line detection correcting method according to claim 13, further comprising: detecting, by a travel path course detecting circuit, a course of a travel path of the own vehicle as the vehicle sensor information; and estimating, by the maximum curvature estimating circuit, a curvature of the travel path of the own vehicle based on the course of the travel path, and setting the estimated curvature as the maximum curvature.The lane separation line detection correcting method according to claim 13, further comprising: detecting, by a traveling path course detecting circuit, position information on an edge of a traveling path of the own vehicle as the vehicle sensor information; and estimating, by the maximum curvature estimating circuit, a curvature of the traveling path of the own vehicle based on the position information on the edge, and setting the estimated curvature as the maximum curvature.The lane-parting-line detection correcting method according to any one of claims 13 - 22, wherein the curvature correcting circuit preliminarily stores a plurality of the maximum curvatures, and the lane-parting-line detection correcting method further comprises performing, by the curvature correcting circuit, when the curvature of the lane parting line input to the curvature correcting circuit exceeds one of the plurality of the most recently determined maximum curvatures, correction by using a last one of the plurality of the maximum curvatures that does not exceed one of the plurality of the maximum curvatures.The lane-parting-line detection correcting method according to any one of claims 13 - 22, wherein the curvature correcting circuit preliminarily stores a plurality of the maximum curvatures, and wherein the lane-parting-line detection correcting method further comprises performing, by the curvature correcting circuit, when the curvature of the lane parting line input to the curvature correcting circuit exceeds one of the plurality of the most recently determined maximum curvatures, correction by using a maximum curvature at a current point among the plurality of stored maximum curvatures based on an amount of variation in the maximum curvature obtained from a difference among the plurality of the stored maximum curvatures.An automatic driving system comprising: the lane separation line detection correcting device according to any one of claims 1-12; and a control circuit for controlling steering of the own vehicle based on a lane separation line having a curvature corrected by the curvature correcting circuit.

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