Detector and detection method

Abstract

To detect abnormal detection processing of a land surface.SOLUTION: A detector comprises: a point group data acquisition part acquiring point group data generated by a laser sensor; a land surface detection part acquiring estimated height of a land surface on the basis of positional information of a point group indicating the land surface extracted from the point group data; and an abnormality determination part determining that detection processing of the land surface using the laser sensor is abnormal when an absolute value of difference between reference height determined by installation position of the laser sensor and the estimated height is greater than threshold.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a detection device and a detection method. [Background technology]

[0002] Patent Document 1 describes a point cloud data collection system that acquires point cloud data including measurement data at multiple measurement points measured by a laser sensor, and when the height of a plane fitted to the measurement points calculated based on the acquired point cloud data is equal to or less than a predetermined height threshold, removes the measurement data of the measurement points that make up the plane as measurement data of measurement points on the ground, and transmits the point cloud data after the measurement data has been removed to a server. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-043475 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, in general, object detection using a laser sensor involves processing to remove points representing the ground from point cloud data measured by the laser sensor. In order to remove points representing the ground, it is necessary to accurately detect the ground. If there is an abnormality in the processing to detect the ground, it will be impossible to remove the points representing the ground, making it difficult to accurately detect objects.

[0005] Therefore, an object of the present disclosure is to detect abnormalities in the ground detection process. [Means for solving the problem]

[0006] A detection device according to one embodiment includes a point cloud data acquisition unit that acquires point cloud data generated by a laser sensor, a ground detection unit that acquires an estimated height of the ground based on position information of a point cloud indicating the ground extracted from the point cloud data, and an abnormality determination unit that determines that there is an abnormality in the ground detection process using the laser sensor when the absolute value of the difference between a reference height determined by the installation position of the laser sensor and the estimated height is greater than a threshold value.

[0007] The installation position of the laser sensor is adjusted in advance so that the ground is detected at a predetermined height. Therefore, if there is a large difference between a predetermined reference height and the estimated ground height obtained using the laser sensor, there is a high possibility that the estimated ground height is incorrect. In the detection device according to the above aspect, when the difference between the reference height and the estimated ground height is larger than a threshold, it is determined that there is an abnormality in the ground detection process, so that abnormalities in the ground detection process can be effectively detected.

[0008] The point cloud data acquisition unit may acquire first point cloud data generated by a first laser sensor that is a laser sensor and second point cloud data generated by a second laser sensor that is different from the first laser sensor, the ground surface detection unit may acquire a first estimated height of the ground surface based on position information of a point cloud indicating the ground surface extracted from the first point cloud data, and acquire a second estimated height of the ground surface based on position information of a point cloud indicating the ground surface extracted from the second point cloud data, and the abnormality determination unit may determine that there is an abnormality in the ground surface detection process using the first laser sensor when the absolute value of the difference between the reference height and the first estimated height is greater than a first threshold value and the absolute value of the difference between the first estimated height and the second estimated height is greater than a second threshold value. A large difference between the estimated height of the ground surface acquired using the first laser sensor and the estimated height of the ground surface acquired using the second laser sensor may indicate that there is an abnormality in the ground surface detection process using the first laser sensor. When the difference between the reference height and the first estimated height is greater than the first threshold value and the difference between the first estimated height and the second estimated height is greater than the second threshold value, it is determined that an abnormality has occurred in the ground detection process, thereby making it possible to detect abnormalities in the ground detection process with greater accuracy.

[0009] The detection device may further include an object detection unit that detects objects based on point cloud data, a control unit that controls the vehicle using the object detection results, and a control stop unit that stops control of the vehicle using the laser sensor when it is determined that there is an abnormality in the detection process. If there is an abnormality in the ground detection process, it may be impossible to remove the point cloud representing the ground, and it may be impossible to accurately detect objects. By stopping control of the vehicle using the point cloud data when there is an abnormality in the ground detection process, it is possible to prevent inappropriate control of the vehicle based on erroneous information.

[0010] A detection device according to another aspect includes a point cloud data acquisition unit that acquires point cloud data generated by a laser sensor, a ground detection unit that acquires an estimated inclination angle of the ground based on position information of a point cloud indicating the ground extracted from the point cloud data, and an abnormality determination unit that determines that there is an abnormality in the ground detection process using the laser sensor when the absolute value of the difference between a reference inclination angle determined by the installation attitude of the laser sensor and the estimated inclination angle is greater than a threshold value.

[0011] The installation orientation of the laser sensor is adjusted in advance so that the ground is detected at a predetermined inclination angle. Therefore, if there is a large difference between the predetermined reference inclination angle and the estimated ground inclination angle obtained using the laser sensor, there is a high possibility that the estimated ground inclination angle is incorrect. In the detection device according to the above aspect, if the difference between the reference estimated inclination angle and the estimated ground inclination angle is larger than a threshold, it is determined that there is an abnormality in the ground detection process, so that abnormalities in the ground detection process can be effectively detected.

[0012] The point cloud data acquisition unit may acquire first point cloud data generated by a first laser sensor that is a laser sensor and second point cloud data generated by a second laser sensor that is different from the first laser sensor, the ground surface detection unit may acquire a first estimated inclination angle of the ground surface based on position information of a point cloud representing the ground surface extracted from the first point cloud data, and acquire a second estimated inclination angle of the ground surface based on position information of a point cloud representing the ground surface extracted from the second point cloud data, and the abnormality determination unit may determine that there is an abnormality in the ground surface detection process using the first laser sensor when the absolute value of the difference between the reference inclination angle and the first estimated inclination angle is greater than a first threshold value and the absolute value of the difference between the first estimated inclination angle and the second estimated inclination angle is greater than a second threshold value. A large difference between the estimated inclination angle of the ground surface acquired using the first laser sensor and the estimated inclination angle of the ground surface acquired using the second laser sensor may indicate that there is an abnormality in the ground surface detection process using the first laser sensor. By determining that an abnormality has occurred in the ground detection process when the difference between the reference height and the first estimated inclination angle is greater than the first threshold value and the difference between the first estimated inclination angle and the second estimated inclination angle is greater than the second threshold value, abnormalities in the ground detection process can be detected with higher accuracy.

[0013] The vehicle may further include an object detection unit that detects objects based on the point cloud data, a control unit that controls the vehicle using the object detection results, and a control stop unit that stops control of the vehicle using the point cloud data when it is determined that there is an abnormality in the detection process. If there is an abnormality in the ground detection process, it may be impossible to remove the point cloud representing the ground, and objects may not be detected accurately. By stopping control of the vehicle using the point cloud data when there is an abnormality in the ground detection process, it is possible to prevent inappropriate control of the vehicle based on erroneous information.

[0014] A detection method according to one embodiment includes the steps of acquiring point cloud data generated by a laser sensor, acquiring an estimated height of the ground based on position information of a point cloud indicating the ground extracted from the point cloud data, and determining that there is an abnormality in the ground detection process using the laser sensor when the absolute value of the difference between the reference height determined by the installation position of the laser sensor and the estimated height is greater than a threshold value.

[0015] A detection method according to another aspect includes the steps of acquiring point cloud data generated by a laser sensor, acquiring an estimated inclination angle of the ground based on position information of a point cloud indicating the ground extracted from the point cloud data, and determining that there is an abnormality in the ground detection process using the laser sensor when the absolute value of the difference between the reference inclination angle determined by the installation attitude of the laser sensor and the estimated inclination angle is greater than a threshold value.

[0016] As described above, these detection methods can effectively detect abnormalities in the ground detection process. [Effects of the Invention]

[0017] According to various aspects of the present disclosure, an abnormality in the ground detection process can be detected. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a side view showing a vehicle equipped with a detection device. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of a detection device according to an embodiment. [Figure 3] FIG. 10 is a block diagram showing a functional configuration of a detection device according to another embodiment. [Figure 4] 1 is a flowchart illustrating a detection method according to an embodiment. [Figure 5] 10 is a flowchart illustrating a detection method according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted. The drawings may be partially simplified or exaggerated to facilitate understanding, and the dimensional ratios, angles, etc. are not limited to those shown in the drawings.

[0020] FIG. 1 is a side view showing a vehicle 1 equipped with a detection device 10 according to one embodiment. The vehicle 1 is a large vehicle such as a truck, freight vehicle, or bus, and is typically an autonomous vehicle that travels autonomously without being operated by a driver. In the following, an example will be described in which the vehicle 1 is an autonomous truck. In the following description, the forward and backward directions of the vehicle 1 are referred to as the fore-and-aft direction of the vehicle 1, and the left-to-right direction when the vehicle 1 is viewed from behind is referred to as the vehicle width direction. In addition, the direction perpendicular to the vehicle width direction and the fore-and-aft direction is referred to as the up-and-down direction.

[0021] The vehicle 1 is equipped with a laser sensor 2 and a detection device 10. As shown in FIG. 1, the laser sensor 2 is mounted on the vehicle 1, emits laser light toward an irradiation area R around the vehicle 1, receives reflected laser light, and detects the distance to an object present around the vehicle 1. The objects to be detected are obstacles such as pedestrians, bicycles, other vehicles, and fixed structures (buildings, tunnels, overpasses, signs, plants, etc.). In the embodiment shown in FIG. 1, the laser sensor 2 emits laser light ahead of the vehicle 1, but the direction of laser light emission is not limited to the forward direction. For example, the laser sensor 2 may emit laser light in all directions in a horizontal plane.

[0022] For example, a LiDAR (Laser Imaging Detection and Ranging) is used as the laser sensor 2. The LiDAR scans a laser in the vertical and horizontal directions and outputs position information of an object or environment at each measurement position in three-dimensional coordinates as point cloud data. The point cloud data is a collection of measurement points including measurement results. In other words, each measurement point of the point cloud data includes three-dimensional position information of the object.

[0023] The point cloud data output from the LiDAR includes a point cloud that indicates the ground surface G. The point cloud that indicates the ground surface G is a point cloud that indicates position information of the ground surface G. The detection device 10 removes the point cloud that indicates the ground surface G from the point cloud data, and analyzes the remaining point cloud to detect objects within the illumination region R.

[0024] The detection device 10 is mounted on the vehicle 1. The detection device 10 is a computer including a processor, a storage device, a communication device, etc. The detection device 10, for example, loads a program stored in the storage device and executes the loaded program on the processor, thereby realizing various functions described below. Note that the detection device 10 does not necessarily have to be configured as a computer that operates according to a program, and some or all of the functions of the detection device 10 may be implemented in an ASIC (Application Specific Integrated Circuit) that integrates logic circuits.

[0025] Fig. 2 is a block diagram showing the functional configuration of a detection device 10 according to one embodiment. As shown in Fig. 2, the detection device 10 includes a point cloud data acquisition unit 11, an anomaly detection unit 12, an object detection unit 13, and a control unit 14. Each functional element of the detection device 10 is accessible to a memory unit 15. The memory unit 15 is a storage device that stores at least one of a reference height Hr and a reference tilt angle Ar. The reference height Hr and the reference tilt angle Ar are set values ​​that are determined in advance according to the installation position and installation attitude of the laser sensor 2, respectively.

[0026] The point cloud data acquisition unit 11 acquires point cloud data Pc of an object in the irradiation region R generated by the laser sensor 2. The point cloud data Pc acquired by the point cloud data acquisition unit 11 is output to the abnormality detection unit 12.

[0027] The abnormality detection unit 12 detects an abnormality in the detection process of the ground G using the laser sensor 2. Causes of an abnormality in the detection process of the ground G include, for example, a positional deviation of the laser sensor 2, a malfunction of the laser sensor 2, and a malfunction in the ground filter process. As shown in FIG. 2 , the abnormality detection unit 12 includes a ground detection unit 21, an abnormality determination unit 22, and a control stop unit 23.

[0028] The ground detection unit 21 executes ground filtering processing to extract a point cloud indicating the ground G from the point cloud data Pc. The ground filtering processing is a technique for separating and removing a ground point cloud and a non-ground point cloud from the point cloud data Pc generated by the LiDAR. Known algorithms for ground filtering include a scan ground filter, a RANSAC ground filter, and a ray ground filter.

[0029] For example, in the scan ground filter, the point cloud data Pc is divided into groups horizontally and sorted by distance from the LiDAR. Next, the lowest measurement point among the sorted point clouds is selected as a candidate for the ground surface G, and measurement points nearby the candidate point for the ground surface G are searched for, and measurement points within a threshold range are classified as measurement points representing the ground surface G. By repeatedly performing the above process, a set of measurement points classified as the ground surface is extracted as a point cloud representing the ground surface G. The ground surface detection unit 21 outputs a point cloud Pt, in which the point cloud representing the ground surface G has been removed from the point cloud data Pc, to the object detection unit 13.

[0030] Furthermore, the ground detection unit 21 acquires an estimated height He of the ground G based on position information of the point cloud representing the ground G. For example, the ground detection unit 21 sets the average value of the vertical positions of each measurement point of the point cloud representing the ground G as the estimated height He of the ground G. The estimated height He of the ground G is an estimated value of the height position of the ground G obtained from the point cloud representing the ground G.

[0031] The abnormality determination unit 22 determines whether or not there is an abnormality in the detection process of the ground G using the laser sensor 2. The installation position of the laser sensor 2 is adjusted so that the ground is detected at a predetermined reference height Hr. Therefore, if the difference between the reference height Hr and the estimated height He of the ground G is large, there is a high possibility that the estimated height He is incorrect. Therefore, if the difference between the reference height Hr acquired from the storage unit 15 and the estimated height He of the ground G is larger than a threshold, the abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground G using the laser sensor 2. On the other hand, if the difference between the reference height Hr and the estimated height He of the ground G is within the threshold range, the abnormality determination unit 22 determines that there is no abnormality in the detection process of the ground G using the laser sensor 2.

[0032] The control stopping unit 23 stops the control of the vehicle 1 using the point cloud data Pc when the abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground surface G. For example, the control stopping unit 23 outputs information indicating that there is an abnormality in the detection process of the ground surface G to the object detection unit 13, and prohibits the object detection unit 13 from detecting an object.

[0033] The object detection unit 13 detects an object based on the point cloud data Pc. As shown in FIG.

[0034] The clustering unit 31 performs clustering processing on the point cloud Pt from which the points representing the ground G have been removed from the point cloud data Pc. In the clustering processing, a group of spatially adjacent points is classified into one cluster (group), and each cluster is recognized as an object. Examples of clustering processing methods that can be used include the k-means method, DBSCAN (Density-Based Spatial Clustering of Applications with Noise) method, Mean Shift method, and hierarchical clustering.

[0035] The clustering unit 31 periodically outputs position information of objects identified by the clustering process to the tracking unit 32. The objects identified by the clustering unit 31 are tracked objects. The clustering unit 31 may identify the type of tracked object based on the position, size, shape, etc. of the cluster. The clustering unit 31 periodically outputs information indicating the center position of the cluster to the tracking unit 32 as position information of the tracked object, for example.

[0036] The tracking unit 32 tracks the tracking target detected by the clustering unit 31. For example, the tracking unit 32 inputs position information of the tracking target detected by the clustering unit 31 to a Kalman filter and predicts an estimated position and speed of the tracking target. The estimated position and speed of the tracking target are periodically output to the control unit 14.

[0037] The control unit 14 controls the vehicle 1 based on the estimated position and estimated speed of the tracked object. The control unit 14 determines a target speed and a target steering angle of the vehicle 1 based on the estimated position and estimated speed of the tracked object, and controls various actuators of the vehicle 1 so that the determined target speed and target steering angle are achieved.

[0038] As described above, the detection device 10 can effectively detect an abnormality in the detection process by determining that there is an abnormality in the detection process of the ground G when the difference between the reference height Hr and the estimated height He of the ground G is greater than a threshold value. Furthermore, when it is determined that there is an abnormality in the detection process of the ground G, the control of the vehicle 1 using the point cloud data Pc generated by the laser sensor 2 is stopped. Therefore, inaccurate object detection can be prevented.

[0039] In one embodiment, the ground detection unit 21 may acquire an estimated inclination angle Ae of the ground G based on position information of a point cloud representing the ground G. For example, the estimated inclination angle Ae is the inclination angle of a plane along the point cloud representing the ground G relative to a horizontal plane. In this case, if the difference between the reference inclination angle Ar acquired from the storage unit 15 and the estimated inclination angle Ae of the ground G is greater than a threshold, the abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground G using the laser sensor 2. On the other hand, if the difference between the reference inclination angle Ar and the estimated inclination angle Ae of the ground G is within the threshold range, the abnormality determination unit 22 determines that there is no abnormality in the detection process of the ground G using the laser sensor 2.

[0040] Next, a detection device according to another embodiment will be described. Fig. 3 is a block diagram showing the functional configuration of a detection device 10A according to another embodiment. The following mainly describes differences from the detection device 10 shown in Fig. 2, and redundant explanations will be omitted.

[0041] As shown in Fig. 3, the point cloud data acquisition unit 11 acquires first point cloud data Pc1 generated by the first laser sensor 2A and second point cloud data Pc2 generated by the second laser sensor 2B. The first laser sensor 2A is a laser sensor that is monitored for abnormalities. The second laser sensor 2B is a reference laser sensor. The second laser sensor 2B emits laser light toward, for example, an area different from the irradiation area R, receives reflected laser light, and detects the distance to an object present around the vehicle 1.

[0042] The ground detection unit 21 extracts a point cloud indicating the ground G from the first point cloud data Pc1, and also extracts a point cloud indicating the ground G from the second point cloud data Pc2. The ground detection unit 21 outputs a point cloud Pt obtained by removing the point cloud indicating the ground G from the first point cloud data Pc1 to the object detection unit 13.

[0043] Furthermore, the ground detection unit 21 acquires a first estimated height He1 of the ground G based on position information of the point cloud indicating the ground G extracted from the first point cloud data Pc1. Similarly, the ground detection unit 21 acquires a second estimated height He2 of the ground G based on position information of the point cloud indicating the ground G extracted from the second point cloud data Pc2. For example, the ground detection unit 21 sets the average values ​​of the vertical positions of the point cloud indicating the ground G as the first estimated height He1 and the second estimated height He2 of the ground G.

[0044] The abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground G using the first laser sensor 2A when the difference between the reference height Hr and the first estimated height He1 is greater than a first threshold value and the difference between the first estimated height He1 and the second estimated height He2 is greater than a second threshold value. Conversely, when the difference between the reference height Hr and the first estimated height He1 is smaller than the first threshold value or the difference between the first estimated height He1 and the second estimated height He2 is smaller than the second threshold value, it determines that there is no abnormality in the detection process of the ground G using the first laser sensor 2A.

[0045] The control stopping unit 23 stops the control of the vehicle 1 using the point cloud data Pc when the abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground surface G. For example, the control stopping unit 23 outputs information indicating that there is an abnormality in the detection process of the ground surface G to the object detection unit 13, and prohibits the object detection unit 13 from detecting an object.

[0046] The clustering unit 31 performs clustering processing on the point cloud Pt obtained by removing the point cloud representing the ground surface G from the first point cloud data Pc1. The tracking unit 32 tracks the object detected by the clustering unit 31. The control unit 14 controls the vehicle 1 based on the estimated position and estimated speed of the object.

[0047] In the detection device 10A, when the difference between the reference height Hr and the first estimated height He1 is greater than the first threshold value and the difference between the first estimated height He1 and the second estimated height He2 is greater than the second threshold value, it is determined that an abnormality has occurred in the detection process of the ground G, thereby enabling abnormalities in the detection process of the ground G to be detected with higher accuracy.

[0048] In one embodiment, the ground detection unit 21 may acquire a first estimated tilt angle Ae1 of the ground G based on position information of a point cloud representing the ground G extracted from the first point cloud data Pc1, and may acquire a second estimated tilt angle Ae2 of the ground G based on position information of a point cloud representing the ground G extracted from the second point cloud data Pc2. In this case, the abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground G using the first laser sensor 2A when the absolute value of the difference between the reference tilt angle Ar and the first estimated tilt angle Ae1 acquired from the storage unit 15 is greater than a first threshold and the absolute value of the difference between the first estimated tilt angle Ae1 and the second estimated tilt angle Ae2 is greater than a second threshold. Conversely, when the absolute value of the difference between the reference tilt angle Ar and the first estimated tilt angle Ae1 is smaller than the first threshold or when the absolute value of the difference between the first estimated tilt angle Ae1 and the second estimated tilt angle Ae2 is smaller than the second threshold, the abnormality determination unit 22 determines that there is no abnormality in the detection process of the ground G using the first laser sensor 2A.

[0049] In the above-described detection device 10A, when the difference between the reference height Hr and the first estimated height He1 is greater than the first threshold value and the difference between the first estimated height He1 and the second estimated height He2 is greater than the second threshold value, it is determined that an abnormality has occurred in the detection process of the ground surface G. This makes it possible to detect an abnormality in the detection process of the ground surface G with higher accuracy.

[0050] Next, a detection method according to an embodiment will be described. Fig. 4 is a flowchart showing the detection method according to an embodiment. This detection method is executed by the detection devices 10 and 10A described above.

[0051] 4, in this detection method, the point cloud data acquisition unit 11 acquires first point cloud data Pc1 generated by the first laser sensor 2A and second point cloud data Pc2 generated by the second laser sensor 2B (step ST1). Next, the ground detection unit 21 extracts point clouds representing the ground G from the first point cloud data Pc1 and the second point cloud data Pc2 (step ST2).

[0052] Next, the ground detection unit 21 obtains a first estimated height He1 of the ground G based on the position information of the point cloud indicating the ground G extracted from the first point cloud data Pc1, and obtains a second estimated height He2 of the ground G based on the position information of the point cloud indicating the ground G extracted from the second point cloud data Pc2 (step ST3).

[0053] Next, the abnormality determination unit 22 determines whether the absolute value of the difference between the reference height Hr and the first estimated height He1 of the ground surface G is greater than a first threshold value (step ST4). If the absolute value of the difference between the reference height Hr and the first estimated height He1 is smaller than the first threshold value, there is a high possibility that there is no abnormality in the detection process of the ground surface G using the laser sensor 2, and therefore, control of the vehicle 1 is executed.

[0054] When controlling the vehicle 1, for example, the ground detection unit 21 removes the point cloud representing the ground G from the first point cloud data Pc1 (step ST6). Next, the clustering unit 31 performs a clustering process on the point cloud Pt from which the point cloud representing the ground G has been removed from the first point cloud data Pc1 (step ST7), and detects objects within the illumination region R.

[0055] Next, the tracking unit 32 tracks the detected object and acquires the estimated position and speed of the object (step ST8). Then, the control unit 14 controls the traveling of the vehicle 1 based on the detection result of the tracking unit 32 (step ST9).

[0056] On the other hand, if it is determined in step ST4 that the absolute value of the difference between the reference height Hr and the first estimated height He1 is greater than the first threshold value, the abnormality determination unit 22 determines whether the absolute value of the difference between the first estimated height He1 and the second estimated height He2 is greater than the second threshold value (step ST5).

[0057] If it is determined that the absolute value of the difference between the first estimated height He1 and the second estimated height He2 is smaller than the second threshold value, the processes of steps ST6 to ST9 are performed.

[0058] On the other hand, if it is determined in step ST5 that the absolute value of the difference between the first estimated height He1 and the second estimated height He2 is greater than the second threshold value, the control stopping unit 23 stops the control of the vehicle 1 (step ST10). For example, the control stopping unit 23 stops object detection using the first point cloud data Pc1 so that the control of the vehicle 1 is not performed.

[0059] 4, if the absolute value of the difference between the reference height Hr and the first estimated height He1 of the ground G is greater than the first threshold value and the absolute value of the difference between the first estimated height He1 and the second estimated height He2 is greater than the second threshold value, it is determined that there is an abnormality in the detection process of the ground G using the laser sensor 2 and control of the vehicle 1 is stopped, but in one embodiment, it may be determined that there is an abnormality in the detection process of the ground G using the laser sensor 2 when the absolute value of the difference between the reference height Hr and the first estimated height He1 of the ground G is greater than the first threshold value. In other words, the determination in step S5 does not necessarily have to be performed.

[0060] Next, a detection method according to another embodiment will be described. Fig. 5 is a flowchart showing the detection method according to another embodiment. This detection method is performed by the detection devices 10 and 10A described above.

[0061] 5, in this detection method, the point cloud data acquisition unit 11 acquires first point cloud data Pc1 generated by the first laser sensor 2A and second point cloud data Pc2 generated by the second laser sensor 2B (step ST11). Next, the ground surface detection unit 21 extracts point clouds representing the ground surface G from the first point cloud data Pc1 and the second point cloud data Pc2 (step ST12).

[0062] Next, the ground detection unit 21 acquires a first estimated inclination angle Ae1 of the ground G based on the position information of the point cloud representing the ground G extracted from the first point cloud data Pc1, and acquires a second estimated inclination angle Ae2 of the ground G based on the position information of the point cloud representing the ground G extracted from the second point cloud data Pc2 (step ST13).

[0063] Next, the abnormality determination unit 22 determines whether the absolute value of the difference between the reference inclination angle Ar and the first estimated inclination angle Ae1 of the ground surface G is greater than a first threshold value (step ST14). If the absolute value of the difference between the reference inclination angle Ar and the first estimated inclination angle Ae1 is smaller than the first threshold value, there is a high possibility that there is no abnormality in the detection process of the ground surface G using the laser sensor 2, and therefore, control of the vehicle 1 is executed.

[0064] When controlling the vehicle 1, for example, the ground detection unit 21 removes the point cloud representing the ground G from the first point cloud data Pc1 (step ST16). Next, the clustering unit 31 performs a clustering process on the point cloud Pt from which the point cloud representing the ground G has been removed from the first point cloud data Pc1 (step ST17), and detects objects within the irradiation area R.

[0065] Next, the tracking unit 32 tracks the detected object and acquires the estimated position and speed of the object (step ST8). Then, the control unit 14 controls the traveling of the vehicle 1 based on the detection result of the tracking unit 32 (step ST19).

[0066] On the other hand, if it is determined in step ST4 that the absolute value of the difference between the reference tilt angle Ar and the first estimated tilt angle Ae1 is greater than the first threshold value, the abnormality determination unit 22 determines whether the absolute value of the difference between the first estimated tilt angle Ae1 and the second estimated tilt angle Ae2 is greater than the second threshold value (step ST15).

[0067] If it is determined that the absolute value of the difference between the first estimated tilt angle Ae1 and the second estimated tilt angle Ae2 is smaller than the second threshold value, the processes of steps ST16 to ST19 are performed.

[0068] On the other hand, if it is determined in step ST15 that the absolute value of the difference between the first estimated tilt angle Ae1 and the second estimated tilt angle Ae2 is greater than the second threshold value, the control stopping unit 23 stops the control of the vehicle 1 (step ST20). For example, the control stopping unit 23 stops object detection using the first point cloud data Pc1 so that the control of the vehicle 1 is not performed.

[0069] 5, if the absolute value of the difference between the reference inclination angle Ar and the first estimated inclination angle Ae1 of the ground surface G is greater than the first threshold value and the absolute value of the difference between the first estimated inclination angle Ae1 and the second estimated inclination angle Ae2 is greater than the second threshold value, it is determined that there is an abnormality in the detection process of the ground surface G using the laser sensor 2, and control of the vehicle 1 is stopped. However, in one embodiment, it may be determined that there is an abnormality in the detection process of the ground surface G using the laser sensor 2 when the absolute value of the difference between the reference inclination angle Ar and the first estimated inclination angle Ae1 of the ground surface G is greater than the first threshold value. In other words, the determination in step S15 does not necessarily have to be performed.

[0070] The above describes the detection devices 10, 10A and detection methods according to various embodiments, but the invention is not limited to the above-described embodiments and various modifications can be made without departing from the spirit of the invention.

[0071] For example, in the detection device 10A, the abnormality determination unit 22 determines that there is an abnormality in the detection process of the ground G using the first laser sensor 2A when the difference between the reference height Hr and the first estimated height He1 is greater than a first threshold value and the difference between the first estimated height He1 and the second estimated height He2 is greater than a second threshold value.However, it may also be possible to determine that there is an abnormality in the detection process of the ground G when the difference between the first estimated height He1 and the second estimated height He2 is greater than a predetermined threshold value without calculating the difference between the reference height Hr and the first estimated height He1.

[0072] Although the vehicle 1 has been described as being an autonomous vehicle, the vehicle 1 does not have to be an autonomous vehicle. In this case, information relating to the position and speed of an object detected by the detection devices 10 and 10A can be used for driving assistance (such as a function for following a preceding vehicle) for the vehicle 1. The various embodiments described above can be combined within a consistent range. [Explanation of symbols]

[0073] 1...vehicle, 2...laser sensor, 2A...first laser sensor, 2B...second laser sensor, 10, 10A...detection device, 11...point cloud data acquisition unit, 13...object detection unit, 14...control unit, 21...ground detection unit, 22...abnormality determination unit, 23...control stop unit, G...ground.

Claims

1. a point cloud data acquisition unit that acquires point cloud data generated by a laser sensor; a ground detection unit that acquires an estimated height of the ground based on position information of a point cloud that indicates the ground extracted from the point cloud data; an abnormality determination unit that determines that there is an abnormality in the ground detection process using the laser sensor when an absolute value of the difference between a reference height determined by an installation position of the laser sensor and the estimated height is greater than a threshold value; A detection device comprising:

2. the point cloud data acquisition unit acquires first point cloud data generated by a first laser sensor that is the laser sensor and second point cloud data generated by a second laser sensor that is different from the first laser sensor; the ground detection unit acquires a first estimated height of the ground based on position information of a point cloud indicating the ground extracted from the first point cloud data, and acquires a second estimated height of the ground based on position information of a point cloud indicating the ground extracted from the second point cloud data; 2. The detection device according to claim 1, wherein the abnormality determination unit determines that there is an abnormality in the ground detection process using the first laser sensor when the absolute value of the difference between the reference height and the first estimated height is greater than a first threshold value and the absolute value of the difference between the first estimated height and the second estimated height is greater than a second threshold value.

3. an object detection unit that detects an object based on the point cloud data; a control unit that controls the vehicle using the object detection result; a control stopping unit that stops control of the vehicle using the point cloud data when it is determined that there is an abnormality in the detection process; The detection device according to claim 1 or 2, further comprising:

4. a point cloud data acquisition unit that acquires point cloud data generated by a laser sensor; a ground detection unit that acquires an estimated inclination angle of the ground based on position information of a point cloud that indicates the ground extracted from the point cloud data; an abnormality determination unit that determines that there is an abnormality in the ground detection process using the laser sensor when the absolute value of the difference between the reference tilt angle determined by the installation attitude of the laser sensor and the estimated tilt angle is greater than a threshold value; A detection device comprising:

5. the point cloud data acquisition unit acquires first point cloud data generated by a first laser sensor that is the laser sensor and second point cloud data generated by a second laser sensor that is different from the first laser sensor; the ground detection unit acquires a first estimated inclination angle of the ground based on position information of a point cloud indicating the ground extracted from the first point cloud data, and acquires a second estimated inclination angle of the ground based on position information of a point cloud indicating the ground extracted from the second point cloud data; 5. The detection device according to claim 4, wherein the abnormality determination unit determines that there is an abnormality in the ground detection process using the first laser sensor when the absolute value of the difference between the reference inclination angle and the first estimated inclination angle is greater than a first threshold value and the absolute value of the difference between the first estimated inclination angle and the second estimated inclination angle is greater than a second threshold value.

6. an object detection unit that detects an object based on the point cloud data; a control unit that controls the vehicle using the object detection result; a control stopping unit that stops control of the vehicle using the point cloud data when it is determined that there is an abnormality in the detection process; The detection device according to claim 4 or 5, further comprising:

7. acquiring point cloud data generated by a laser sensor; acquiring an estimated height of the ground based on position information of a point cloud indicating the ground extracted from the point cloud data; determining that there is an abnormality in the detection process of the ground using the laser sensor when an absolute value of the difference between a reference height determined by an installation position of the laser sensor and the estimated height is greater than a threshold value; A detection device comprising:

8. acquiring point cloud data generated by a laser sensor; acquiring an estimated inclination angle of the ground based on position information of a point cloud indicating the ground extracted from the point cloud data; determining that there is an abnormality in the ground detection process using the laser sensor when an absolute value of the difference between a reference tilt angle determined by an installation attitude of the laser sensor and the estimated tilt angle is greater than a threshold value; A detection method comprising:

Images