Determination method and determination device

Abstract

The present invention addresses the problem of providing a determination method and determination device which make it possible to appropriately determine the detection state of a detection means for an object.　Provided are a determination method and a determination device (10) wherein: calculated is a value which indicates a detection state of a distance measurement device (11), which decreases if the distance measurement device (11) detects an object, and which increases if, when an imaging device (12) images an object existing in a portion (A3) of an imaging range (A2) that overlaps with the detection range (A1) of the distance measurement device (11), the distance measurement device (11) does not detect an object existing in said portion (A3); when the calculated value is less than a first value, it is determined that the distance measurement device (11) is in a first state in which the object can be detected; and when the calculated value is not less than second value which is greater than the first value, it is determined that the distance measurement device (11) is in a second state in which the object cannot be detected.

Description

Determination method and determination device

[0001] The present invention relates to a determination method and a determination device.

[0002] An object detection device is known that includes a first detection means for detecting objects in a first region and a second detection means for detecting objects in a second region that includes at least a part of the first region, and that, when it is determined that objects in a third region that is included in the first and second regions have been detected by the second detection means, determines that the detection performance of the first detection means has deteriorated if at least one object detected by the second detection means is not detected by the first detection means (Patent Document 1).

[0003] JP 2009-243963 A

[0004] The above-described conventional technology has a problem in that a detection means that has been determined to have deteriorated object detection performance is still determined to have deteriorated detection performance even if the detection performance recovers.

[0005] The problem to be solved by the present invention is to provide a determination method and a determination device that can appropriately determine the detection state of a detection means for detecting an object.

[0006] The present invention solves the above problem by calculating a value indicating the detection state of the ranging device, which decreases when the ranging device detects an object and increases when the imaging device images an object present in a part of the imaging range that overlaps with the detection range of the ranging device and the ranging device does not detect an object present in that part, and if the calculated value is less than a first value, it is determined that the ranging device is in a first state in which it can detect an object, and if the calculated value is equal to or greater than a second value greater than the first value, it is determined that the ranging device is in a second state in which it cannot detect an object.

[0007] According to the present invention, the detection state of the object detection means can be appropriately determined.

[0008] 1 is a block diagram showing an example of an embodiment of a determination device according to the present invention; FIG. 2 is a plan view showing an example of an imaging range of an imaging device and a detection range of a distance measuring device of FIG. 1; FIG. 3 is a time chart showing an example of values ​​indicating a detection state of the distance measuring device of FIG. 1; FIG. 4 is a flowchart showing an example of a processing procedure in the determination device of FIG. 1; FIG. 5 is a flowchart (part 1) showing another example of the processing procedure in the determination device of FIG. 1; and FIG. 6 is a flowchart (part 2) showing another example of the processing procedure in the determination device of FIG. 1.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] [Configuration of Determination Device] Fig. 1 is a block diagram showing a determination device 10 according to the present invention. The determination device 10 is a group of devices for determining the detection state of an on-vehicle detection device when a vehicle is driven by autonomous driving control. All of the devices constituting the determination device 10 may be on-vehicle devices, or some of them may be provided outside the vehicle.

[0011] Autonomous driving control refers to autonomously controlling the driving behavior of a vehicle using a vehicle control device, and such driving behavior includes all driving behaviors such as acceleration, deceleration, starting, stopping, and steering. Autonomously controlling driving behavior means that the control device controls driving behavior using the vehicle's devices. The control device controls these driving behaviors within a predetermined range, and driving behaviors that are not controlled by the control device are manually operated by the driver. When the vehicle is driven manually by the driver without autonomous driving control, the control device does not autonomously control the driving behavior, and the vehicle's driving behavior is controlled by the driver's operation.

[0012] 1, the determination device 10 includes a distance measuring device 11, an imaging device 12, a state detection device 13, a display device 14, and a control device 15. The devices constituting the determination device 10 are connected by a Controller Area Network (CAN) or other in-vehicle LAN, and can exchange information with each other.

[0013] The ranging device 11 is a device that acquires the relative distance and relative speed between the ranging device 11 and an object, and examples thereof include laser radar, millimeter-wave radar, and LiDAR (Light Detection and Ranging) units. The ranging device 11 acquires position information of ranging points of objects present around the vehicle. The ranging points of the object are points on the object whose distances to the ranging device 11 are measured. The position information of the ranging points includes information on the distance from the ranging device 11 to the ranging points as well as information on the coordinates of the ranging points. The detection range within which the ranging device 11 detects the object can be set appropriately depending on the detection performance of the ranging device 11. To reduce blind spots when recognizing objects, multiple ranging devices 11 are installed at the front, right side, left side, and rear of the vehicle.

[0014] The imaging device 12 is a device that captures images of objects around the vehicle, and examples thereof include a camera equipped with an imaging element such as a CCD, an ultrasonic camera, and an infrared camera. The imaging range in which the imaging device 12 captures an image of the object can be set appropriately depending on the angle of view of the imaging device 12, and at least a portion of the imaging range overlaps with the detection range of the distance measuring device 11 when viewed from the top or side. In order to reduce blind spots when recognizing objects, multiple imaging devices 12 are installed on the vehicle's front grille, under the left and right door mirrors, near the rear bumper, etc.

[0015] The target object is an object existing on or around the road, including lane boundaries, center lines, road markings, medians, guardrails, curbs, road signs, traffic lights, and crosswalks. The target object also includes obstacles that may affect the vehicle's travel, such as automobiles other than the host vehicle, motorcycles, bicycles, and pedestrians. The detection results of the distance measuring device 11 and the imaging device 12 may be integrated or synthesized (sensor fusion) by the control device 15. This allows missing information about the target object to be supplemented.

[0016] The state detection device 13 is a sensor that detects the running state of the vehicle, and includes a vehicle speed sensor, an acceleration sensor, a yaw rate sensor, a steering angle sensor, etc. The control device 15 acquires the detection results of the distance measurement device 11, the imaging device 12, and the state detection device 13 at predetermined time intervals (for example, every 0.1 to 1 millisecond).

[0017] The display device 14 is a device for providing necessary information to the vehicle occupants, and is a liquid crystal display provided on the instrument panel, a head-up display (HUD), or other projector. The display device 14 may also include an input device (e.g., a touch panel) for the occupant to input instructions to the control device 15. The display device 14 may also include a speaker as an output device.

[0018] The control device 15 is a device that performs driving assistance through autonomous driving control and determines the detection state of the on-board detection device by controlling and cooperating with the devices that make up the determination device 10. The control device 15 is, for example, a computer, and includes a CPU (Central Processing Unit) that is a processor, a ROM (Read Only Memory) that stores programs, and a RAM (Random Access Memory) that functions as an accessible storage device. The CPU is an operating circuit that executes the programs stored in the ROM and realizes the functions of the control device 15.

[0019] The control device 15 has a determination function that determines the detection state of the on-board detection device. A program for realizing the determination function is stored in the ROM, and the determination function is realized by the CPU executing the program stored in the ROM. For convenience, Fig. 1 shows a detection unit 21, a calculation unit 22, and a determination unit 23 as functional blocks that realize the determination function. The functions of each functional block will be explained below with reference to Figs. 2 and 3.

[0020] [Functions of Functional Blocks] Fig. 2 is a plan view showing an example of a driving scene in which the control device 15 executes a detection state determination using the determination function. A road extending in the left-right direction in Fig. 2 has three lanes, L1, L2, and L3, and the vehicle travels from left to right in the drawing. In the driving scene shown in Fig. 2, a vehicle V1 equipped with the devices shown in Fig. 1 travels at position P1 on lane L2, the detection range of the distance measuring device 11 is range A1, and the imaging range of the imaging device 12 is range A2.

[0021] The detection state of the distance measuring device 11 can be determined using an image captured by the imaging device 12. As an example, if the distance measuring device 11 does not detect an object captured by the imaging device 12, it is determined that the distance measuring device 11 is in a state where it cannot detect an object. Furthermore, if the distance measuring device 11 that was determined to be in a state where it cannot detect an object detects the object again, it is determined that the distance measuring device 11 has recovered to a state where it can detect an object.

[0022] However, in the above-described determination, the determination result of the detection state of the distance measuring device 11 changes depending on the position of the object relative to the vehicle V1. For example, as shown in Fig. 2, when another vehicle V2 traveling in lane L3 is traveling at position P2 within the imaging range A2 that is not included in the detection range A1, the distance measuring device 11 is determined to be in a state where it cannot detect the object, even if it is in a state where it can detect the object. Furthermore, when the other vehicle V2 changes lanes from lane L3 to lane L2, when the distance measuring device 11 detects the other vehicle V2, it is determined that the distance measuring device 11 has recovered to a state where it can detect the object.

[0023] In this way, if the determination result of the detection state of the ranging device 11 changes frequently depending on the positional relationship between the vehicle V1 and surrounding objects, the autonomous driving control of the vehicle V1 will be repeatedly stopped and restarted, causing discomfort to the occupants of the vehicle V1. In addition to this case, if the part of the ranging device 11 that emits electromagnetic waves is covered with snow, mud, debris, etc., it will sometimes be able to detect objects within the detection range and sometimes not, causing the determination result of the detection state of the ranging device 11 to change frequently and making the autonomous driving control of the vehicle V1 intermittent. Therefore, the control device 15 according to an embodiment of the present invention calculates a value indicating the detection state of the ranging device 11 and determines the detection state of the ranging device 11 based on this value.

[0024] The detection unit 21 acquires the detection results of the distance measuring device 11, the image capturing device 12, and the state detection device 13 at predetermined time intervals (e.g., every 0.1 to 1 millisecond), and outputs the information to the calculation unit 22 and the determination unit 23 as necessary. The detection unit 21 also detects an object from the acquired detection results. For example, as shown in FIG. 2 , when the leading vehicle V3 is traveling at position P3 in lane L2, position P3 of the leading vehicle V3 is included in the detection range A1, and therefore the detection unit 21 detects the leading vehicle V3 from the detection results of the distance measuring device 11. Note that the object detection process in the detection unit 21 may be performed by the distance measuring device 11 and the image capturing device 12. In this case, the distance measuring device 11 and the image capturing device 12 output the object detection results to the calculation unit 22.

[0025] The calculation unit 22 calculates a value indicating the detection state of the ranging device 11 (hereinafter also referred to as the detection state value). The detection state value is a value used to determine the detection state of the ranging device 11, and is calculated to be low when the ranging device 11 can detect an object (hereinafter also referred to as the first state). Specifically, the first state is a state in which the ranging device 11 can properly detect an object in the detection range A1. In contrast, the detection state value is calculated to be high when the ranging device 11 cannot detect an object (hereinafter also referred to as the second state). The second state is not particularly limited, and includes a state in which the ranging device 11 cannot properly irradiate electromagnetic waves (for example, a state in which the part of the ranging device 11 that irradiates electromagnetic waves is covered with snow), a state in which the ranging device 11 cannot properly process reflected waves from an object, etc. The initial value of the detection state value is set to, for example, 0.

[0026] Based on the information output from the detection unit 21, the calculation unit 22 determines whether the running state of the vehicle V1 is in a state in which the detected state value increases (or whether the detected state value decreases), and calculates the detected state value based on this determination result. The calculation unit 22 calculates the detected state value at predetermined time intervals (for example, every 0.1 to 1 millisecond). In other words, the detected state value is a value that changes over time (over time) and is calculated depending on the time during which a condition for increasing the value is satisfied and the time during which a condition for decreasing the value is satisfied. Calculation of the detected state value begins after the ignition or accessory power of the vehicle V1 is turned on and the control device 15 is started up.

[0027] Specifically, when the ranging device 11 (or the detection unit 21) detects an object, the calculation unit 22 decreases the detection state value. For example, in the driving scene shown in Fig. 2, when the ranging device 11 detects a preceding vehicle V3 traveling at position P3, the calculation unit 22 decreases the detection state value while the ranging device 11 detects the preceding vehicle V3. Note that the position of the object detected by the ranging device 11 may be a portion where the detection range A1 and the imaging range A2 overlap (hereinafter also referred to as the target range) as long as it is within the detection range A1, or may be a portion of the detection range A1 that is not included in the imaging range A2 (for example, position P3 shown in Fig. 2).

[0028] On the other hand, when the imaging device 12 captures an image of an object present in the target range A3 indicated by the thick solid line in Fig. 2, if the distance measuring device 11 does not detect an object present in the target range A3, the calculation unit 22 increases the detection state value. For example, in the driving scene shown in Fig. 2, assuming that a leading vehicle V3 is traveling within the target range A3, if the imaging device 12 captures an image of the leading vehicle V3 and the distance measuring device 11 does not detect the leading vehicle V3 within a predetermined time after the imaging device 12 captures the image of the leading vehicle V3, the calculation unit 22 increases the detection state value while the distance measuring device 11 does not detect the leading vehicle V3. The predetermined time can be set to an appropriate value within a range in which the detection state of the distance measuring device 11 can be appropriately determined, for example, 2 to 15 seconds.

[0029] The determination unit 23 determines whether the detection state of the ranging device 11 is in the first state or the second state. Specifically, if the detection state value is less than the first value, the determination unit 23 determines that the ranging device 11 is in the first state. If the detection state value is equal to or greater than a second value greater than the first value, the determination unit 23 determines that the ranging device 11 is in the second state. The first and second values ​​can be set to appropriate values ​​within a range in which the detection state of the ranging device 11 can be appropriately determined. If the detection state value is equal to or greater than the first value and less than the second value, the determination unit 23 maintains the determination result of the detection state of the ranging device 11. In other words, if the detection state value changes from a state less than the first value to a state equal to or greater than the first value and less than the second value, the determination unit 23 determines that the ranging device 11 is in the first state. On the other hand, if the detection state value changes from a state equal to or greater than the second value to a state equal to or greater than the first value and less than the second value, the determination unit 23 determines that the ranging device 11 is in the second state. The determination unit 23 may notify the occupant of the vehicle V1 of the determination result via the display device 14.

[0030] In this way, by determining the detection state of the ranging device 11 using the detection state value, it is possible to prevent the ranging device 11 from determining that it cannot detect an object because the ranging device 11 temporarily fails to detect the object, for example, when there is another vehicle V2 traveling at position P2 within the imaging range A2 that is not within the target range A3, when the preceding vehicle V3 travels around a curve and is no longer included in the detection range A1, or when the vehicle V1 changes lanes. Furthermore, when dirt such as snow adheres to the part of the ranging device 11 that emits electromagnetic waves, the ranging device 11 may or may not be able to detect an object within the detection range A1, making it difficult to determine whether the preceding vehicle V3 is present or not. Therefore, a relatively long determination process is required to determine the detection state of the ranging device 11 based solely on the detection results of the ranging device 11. By determining the detection state of the ranging device 11 using the detection state value, it is possible to prevent an increase in the time required for this determination process.

[0031] When the detection state value becomes equal to or greater than the second value, the calculation unit 22 may not further increase the detection state value and may maintain the detection state value at the second value. In this case, when a condition for decreasing the detection state value is satisfied, the calculation unit 22 decreases the detection state value. Alternatively, when the detection state value becomes 0, the calculation unit 22 may not further decrease the detection state value and may maintain the detection state value at 0. In this case, when a condition for increasing the detection state value is satisfied, the calculation unit 22 increases the detection state value.

[0032] When the detection state value becomes equal to or greater than the second value, the control device 15 may suppress the operation of control using the ranging device 11 (e.g., autonomous driving control such as adaptive cruise control or collision damage mitigation braking). In this case, the determination unit 23 may use the display device 14 to notify the occupant of the vehicle V1 that the detection state of the ranging device 11 is in the second state and that the operation of some autonomous driving control has been suppressed. When the detection state value becomes less than the first value after determining that the detection state of the ranging device 11 is in the second state, the control device 15 may release the suppression of the operation of control using the ranging device 11. In this case, the determination unit 23 may use the display device 14 to notify the occupant of the vehicle V1 that the detection state of the ranging device 11 is in the first state and that the suppression of the operation of autonomous driving control has been released (or that autonomous driving control using the ranging device 11 has become operable).

[0033] When the detection unit 21 acquires an image captured by the imaging device 12 and detects an object from the acquired image, the detection unit 21 may determine whether the object captured by the imaging device 12 is present in the object range A3. If the detection unit 21 determines that the object captured by the imaging device 12 is present in the object range A3, the calculation unit 22 calculates a detection state value. Alternatively, if the detection unit 21 determines that the object captured by the imaging device 12 is present in the object range A3, the calculation unit 22 may determine whether the ranging device 11 has detected an object present in the object range A3. Furthermore, if the detection unit 21 determines that the object captured by the imaging device 12 is not present in the object range A3, the calculation unit 22 determines whether the ranging device 11 has detected an object present in the detection range A1.

[0034] The calculation unit 22 may increase the detection state value less when the distance measuring device 11 does not detect an object for a short period of time than when the distance measuring device 11 does not detect an object for a long period of time. This makes it possible to prevent the detection state value from increasing when the distance measuring device 11 temporarily stops detecting an object. Furthermore, the calculation unit 22 may decrease the detection state value more when the distance measuring device 11 detects an object for a long period of time than when the distance measuring device 11 detects an object for a short period of time. By promoting a change (increase or decrease) in the detection state value while the same driving scene continues, it is possible to prevent an increase in the time required for determining the detection state of the distance measuring device 11.

[0035] When the ranging device 11 detects an object, the detection unit 21 may determine whether the subtraction start time has elapsed since the ranging device 11 detected the object. The detection unit 21 acquires the time when the ranging device 11 detected the object from the time data in the control device 15, and when it determines that the subtraction start time has not elapsed since the acquired time, the calculation unit 22 does not decrease the detection state value. In contrast, when the detection unit 21 determines that the subtraction start time has elapsed since the acquired time, the calculation unit 22 decreases the detection state value. This prevents the detection state value from decreasing when dirt such as snow adheres to the part of the ranging device 11 that irradiates electromagnetic waves, making it possible to detect an object in the detection range A1 in some cases but not others. The subtraction start time can be set appropriately within a range in which the detection state of the ranging device 11 can be appropriately determined, for example, 1 to 5 seconds.

[0036] When the distance measuring device 11 detects an object, the detection unit 21 may determine whether the traveling speed of the vehicle V1 is equal to or greater than the subtraction start speed. The detection unit 21 acquires the traveling speed of the vehicle V1 from the vehicle speed sensor (state detection device 13), and when the detection unit 21 determines that the acquired traveling speed is equal to or greater than the subtraction start speed, the calculation unit 22 decreases the detection state value. On the other hand, when the detection unit 21 determines that the acquired traveling speed is less than the subtraction start speed, the calculation unit 22 does not decrease the detection state value. This prevents the detection state value from being reduced by an object in the detection range A1 when the vehicle V1 is traveling at a relatively low speed in a congested line of vehicles, when the vehicle V1 is stopped before an intersection, or the like. The subtraction start speed can be set appropriately within a range in which the detection state of the distance measuring device 11 can be appropriately determined, for example, greater than 0 km / h and equal to or less than 20 km / h.

[0037] The detection unit 21 may determine whether the traveling speed of the vehicle V1 is equal to or greater than a predetermined speed when the imaging device 12 captures an image of an object present in the target range A3 and the distance measuring device 11 does not detect the object present in the target range A3. The detection unit 21 acquires the traveling speed of the vehicle V1 from the vehicle speed sensor (state detection device 13) and, when the detection unit 21 determines that the acquired traveling speed is equal to or greater than the predetermined speed, the calculation unit 22 increases the detection state value. In contrast, when the detection unit 21 determines that the acquired traveling speed of the vehicle V1 is less than the predetermined speed, the calculation unit 22 does not increase the detection state value. This prevents the detection state value from increasing when multiple objects are present around the stopped vehicle V1 and the distance measuring device 11 cannot accurately detect the multiple objects. The predetermined speed can be set appropriately within a range in which the detection state of the distance measuring device 11 can be appropriately determined, for example, 10 to 30 km / h.

[0038] The detection unit 21 may determine whether the object detected by the distance measuring device 11 and / or the imaging device 12 is a leading vehicle V3 traveling ahead of the vehicle V1. If the detection unit 21 determines that the object is the leading vehicle V3, the calculation unit 22 calculates the inter-vehicle time from the leading vehicle V3. When the inter-vehicle time from the leading vehicle V3 is short, the amount of decrease in the detection state value is made smaller than when the inter-vehicle time is long. This makes it possible to prevent the adaptive cruise control from being erroneously resumed when the vehicle V1 is approaching the leading vehicle V3, resulting in the vehicle V1 approaching the leading vehicle V3. The inter-vehicle time is the time it takes for the vehicle V1 to reach the position of the leading vehicle V3, and is calculated by dividing the inter-vehicle distance between the vehicle V1 and the leading vehicle V3 by the traveling speed of the vehicle V1.

[0039] Fig. 3 is a time chart showing an example of a detection state value calculated by the calculation unit 22. The time charts shown in Fig. 3 are, from top to bottom, a chart showing the imaging state of the imaging device 12, a chart showing the detection state of the distance measuring device 11, a chart showing an addition determination of the detection state value, a chart showing a subtraction determination of the detection state value, a chart showing the detection state value, and a chart showing the detection state determination result, with the horizontal axis representing time. Below, an example of how the detection state value changes over time will be described using the time chart shown in Fig. 3.

[0040] First, at time T0, the control device 15 is activated, and the calculation process of the calculation unit 22 begins. In the example shown in FIG. 3 , the initial value of the detection state value is set to 0. At time T1, the imaging device 12 captures an image of the object in the target range A3, and the imaging state of the imaging device 12 changes from "not capturing" to "captured." Between time T1 and time T2, the imaging state of the imaging device 12 is "captured," while the detection state of the distance measuring device 11 remains "not detected." Because the time from time T1 to time T2 corresponds to a predetermined time, at time T2, the addition determination of the detection state value changes from "not adding" to "adding," and the detection state value begins to increase.

[0041] Between time T2 and time T3, the imaging state of the imaging device 12 is "imaging" and the detection state of the distance measuring device 11 is "not detected," so the state detection value increases in proportion to time. At time T3, the distance measuring device 11 detects an object in the target range A3, so the detection state of the distance measuring device 11 becomes "detection," and the increase in the detection state value stops. Between time T3 and time T4, the imaging state of the imaging device 12 is "imaging" and the detection state of the distance measuring device 11 is "detection," so the state detection value is maintained. However, because the time from time T3 to time T4 is shorter than the subtraction start time, the detection state value does not decrease.

[0042] At time T4, the imaging state of the imaging device 12 becomes "imaging" again, and the detection state of the distance measuring device 11 becomes "non-detection," so the detection state value begins to increase. From time T4 to time T6, the detection state value continues to increase, but because the states of the distance measuring device 11 and the imaging device 12 remain the same for a relatively long time, the amount of increase in the detection state value increases from time T5. Specifically, the amount of increase in the detection state value from time T5 to time T6 is twice the amount of increase from time T4 to time T5.

[0043] At time T6, the detection state value becomes the second value, and the detection state determination result of the distance measuring device 11 changes from "state 1" to "state 2." The detection state value does not increase any further and remains at the second value. At time T7, the distance measuring device 11 detects an object in the target range A3, and the detection state of the distance measuring device 11 becomes "detected." The addition determination of the detection state value becomes "non-addition," and the subtraction determination of the detection state value becomes "subtraction." Then, at time T8, which is the elapsed time from time T7 when the subtraction start time has elapsed, the detection state value begins to decrease.

[0044] Between time T8 and time T10, the imaging state of the imaging device 12 is "imaging" and the detection state of the distance measuring device 11 is "detection," so the state detection value decreases in proportion to time. Between time T8 and time T10, the detection state value continues to decrease, but because the states of the distance measuring device 11 and the imaging device 12 remain the same for a relatively long time, the amount of decrease in the detection state value increases from time T9. Specifically, the amount of decrease in the detection state value between time T9 and time T10 is twice the amount of decrease between time T8 and time T9.

[0045] At time T10, the detection state value becomes less than the first value, and the result of the detection state determination of the distance measuring device 11 changes from "state 2" to "state 1." Then, at time T11, the detection state value becomes 0. The detection state value does not decrease any further, and remains at 0.

[0046] 4 and 5A-5B, the information processing procedure in the determination device 10 will be described. The processing described below is repeatedly executed at predetermined time intervals (for example, every 0.1 to 1 millisecond) by a processor (CPU) provided in the control device 15.

[0047] 4 is a flowchart showing an example of a processing procedure in the determination device 10. First, in step S1, the detection unit 21 determines whether the imaging device 12 has captured an image of an object in the target range A3. If it is determined that the imaging device 12 has captured an image of an object in the target range A3, the process proceeds to step S2, where it determines whether the distance measuring device 11 has detected an object in the target range A3. On the other hand, if it is determined that the imaging device 12 has not captured an image of an object in the target range A3, the process proceeds to step S3, where it determines whether the distance measuring device 11 has detected an object.

[0048] If it is determined in step S2 that the ranging device 11 has not detected an object in the target range A3, the process proceeds to step S4, where the calculation unit 22 increases the detection state value. If it is determined in step S2 that the ranging device 11 has detected an object in the target range A3, or if it is determined in step S3 that the ranging device 11 has detected an object, the process proceeds to step S5, where the calculation unit 22 decreases the detection state value. If it is determined in step S3 that the ranging device 11 has not detected an object, the process proceeds to step S6.

[0049] In step S6, the determination unit 23 determines whether the detection state value is less than the first value. If it is determined that the detection state value is less than the first value, the process proceeds to step S7, where it is determined that the distance measuring device 11 is in the first state, and the process ends. On the other hand, if it is determined that the detection state value is equal to or greater than the first value, the process proceeds to step S8, where it determines whether the detection state value is equal to or greater than the second value. If it is determined that the detection state value is equal to or greater than the second value, the process proceeds to step S9, where it is determined that the distance measuring device 11 is in the second state, and the process ends. On the other hand, if it is determined that the detection state value is less than the second value, the process ends as is.

[0050] 5A and 5B are flowcharts showing another example of the processing procedure in the determination apparatus 10. First, in step S11, the detection unit 21 determines whether the imaging device 12 has captured an image of the object in the imaging range A2. If it is determined that the imaging device 12 has not captured an image of the object in the imaging range A2, the process proceeds to step S14. On the other hand, if it is determined that the imaging device 12 has captured an image of the object in the imaging range A2, the process proceeds to step S12.

[0051] In step S12, it is determined whether or not the object captured by the imaging device 12 is present within the target range A3. If it is determined that the object captured by the imaging device 12 is present within the target range A3, the process proceeds to step S13. On the other hand, if it is determined that the object captured by the imaging device 12 is not present within the target range A3, the process proceeds to step S14.

[0052] In step S14, it is determined whether the distance measuring device 11 has detected an object within the detection range A1. If it is determined that the distance measuring device 11 has detected an object within the detection range A1, the process proceeds to step S17. On the other hand, if it is determined that the distance measuring device 11 has not detected an object within the detection range A1, the process proceeds to step S19 in FIG. 5B.

[0053] In step S13, it is determined whether the distance measuring device 11 has detected an object in the target range A3 within a predetermined time. If it is determined that the distance measuring device 11 has detected an object in the target range A3 within the predetermined time, the process proceeds to step S17. On the other hand, if it is determined that the distance measuring device 11 has not detected an object in the target range A3 within the predetermined time, the process proceeds to step S15.

[0054] In step S15, it is determined whether the traveling speed of the vehicle V1 is equal to or greater than a predetermined speed. If it is determined that the traveling speed of the vehicle V1 is equal to or greater than the predetermined speed, the process proceeds to step S16, where the calculation unit 22 increases the detection state value. On the other hand, if it is determined that the traveling speed of the vehicle V1 is less than the predetermined speed, the process proceeds to step S19 in FIG. 5B.

[0055] In step S17, the detection unit 21 determines whether the subtraction start time has elapsed. If it is determined that the subtraction start time has elapsed, the process proceeds to step S18, where the calculation unit 22 decreases the detection state value. On the other hand, if it is determined that the subtraction start time has not elapsed, the process proceeds to step S19 in FIG. 5B.

[0056] In step S19 of FIG. 5B , the determination unit 23 determines whether the detection state value is less than the first value. If it is determined that the detection state value is less than the first value, the process proceeds to step S20, where it is determined that the distance measuring device 11 is in the first state, and the process proceeds to step S24. On the other hand, if it is determined that the detection state value is equal to or greater than the first value, the process proceeds to step S21, where it determines whether the detection state value is equal to or greater than the second value. If it is determined that the detection state value is equal to or greater than the second value, the process proceeds to step S22, where it is determined that the distance measuring device 11 is in the second state, and the process proceeds to step S24. On the other hand, if it is determined that the detection state value is less than the second value, the process proceeds to step S23. In step S23, the determination unit 23 maintains the determination state of the distance measuring device 11. Then, in step S24, the determination result is displayed on the display device 14, and the process ends.

[0057] According to this embodiment, a determination method is provided in which a control device 15 of a vehicle V1 includes a distance measuring device 11 that detects an object within a detection range A1 and an imaging device 12 that captures an image of an imaging range A2 that overlaps at least a portion of the detection range A1. The control device 15 calculates a value indicating the detection state of the distance measuring device 11, which decreases when the distance measuring device 11 detects the object and increases when the imaging device 12 captures an image of the object present in a portion A3 of the imaging range A2 that overlaps with the detection range A1 and the distance measuring device 11 does not detect the object present in the portion A3. If the value is less than a first value, the control device 15 determines that the distance measuring device 11 is in a first state in which it can detect the object. If the value is equal to or greater than a second value greater than the first value, the control device 15 determines that the distance measuring device 11 is in a second state in which it cannot detect the object. This allows the detection state of the distance measuring device 11 to be determined appropriately.

[0058] In the determination method of this embodiment, when the time during which the distance measuring device 11 does not detect the object is short, the control device 15 reduces the increase in the value compared to when the time during which the distance measuring device 11 does not detect the object is long. This makes it possible to suppress an increase in the detection state value when the distance measuring device 11 temporarily stops detecting the object.

[0059] In the determination method of this embodiment, when the distance measuring device 11 detects the object, the control device 15 does not decrease the value if the subtraction start time has not elapsed since the distance measuring device 11 detected the object. This makes it possible to prevent the detection state value from decreasing when dirt such as snow adheres to the part of the distance measuring device 11 that irradiates electromagnetic waves, making it possible to sometimes detect an object in the detection range A1 and sometimes not.

[0060] In the determination method of this embodiment, when the imaging device 12 captures an image of the object present in the portion A3 and the distance measuring device 11 does not detect the object present in the portion A3, if the traveling speed of the vehicle V1 is equal to or greater than a predetermined speed, the control device 15 increases the value. This makes it possible to prevent an increase in the detection state value when multiple objects are present around the stopped vehicle V1 and the distance measuring device 11 cannot accurately detect the multiple objects.

[0061] In the determination method of this embodiment, when the object is a preceding vehicle V3 traveling ahead of the vehicle V1, the control device 15 calculates the time interval between the vehicle V1 and the preceding vehicle V3, and when the time interval is short, reduces the amount of decrease in the value smaller than when the time interval is long. This makes it possible to prevent the adaptive cruise control from being erroneously resumed when the vehicle V1 is approaching the preceding vehicle V3, and to prevent the vehicle V1 from approaching the preceding vehicle V3.

[0062] In the determination method of this embodiment, when the distance measuring device 11 detects the object for a long time, the control device 15 increases the amount of decrease in the value compared to when the distance measuring device 11 detects the object for a short time. This promotes the decrease in the detection state value when the same driving scene continues, thereby suppressing an increase in the time required to determine the detection state of the distance measuring device 11.

[0063] Furthermore, according to this embodiment, a determination device 10 is provided that includes a distance measuring device 11 that detects an object within a detection range A1, an imaging device 12 that captures an image of an imaging range A2 that overlaps at least a portion of the detection range A1, a calculation unit 22 that calculates a value indicating the detection state of the distance measuring device 11, the value decreasing when the distance measuring device 11 detects the object and increasing when the imaging device 12 captures an image of the object present in a portion A3 of the imaging range A2 that overlaps with the detection range A1 and the distance measuring device 11 does not detect the object present in the portion A3, and a determination unit 23 that determines if the value calculated by the calculation unit 22 is less than a first value, that the distance measuring device 11 is in a first state in which the object can be detected, and if the value calculated by the calculation unit 22 is equal to or greater than a second value that is greater than the first value, that the distance measuring device 11 is in a second state in which the object cannot be detected. This allows the detection state of the distance measuring device 11 to be appropriately determined.

[0064] 10... Determination device, 11... Distance measuring device, 12... Imaging device, 13... Status detection device, 14... Display device, 15... Control device, 21... Detection unit, 22... Calculation unit, 23... Determination unit A1... Detection range, A2... Imaging range, A3... Target range, L1, L2, L3... Lane, P1, P2, P3... Position, V1... Vehicle, V2... Other vehicle, V3... Leading vehicle

Claims

1. A determination method executed by a control device of a vehicle equipped with a ranging device that detects an object within a detection range and an imaging device that images an imaging range that overlaps with at least a portion of the detection range, wherein the control device calculates a value indicating the detection state of the ranging device which decreases when the ranging device detects the object and which increases when the imaging device images the object present in a part of the imaging range that overlaps with the detection range but the ranging device does not detect the object present in that part, if the value is less than a first value, determines that the ranging device is in a first state in which it can detect the object, and if the value is equal to or greater than a second value greater than the first value, determines that the ranging device is in a second state in which it cannot detect the object.

2. The method of claim 1, wherein the control device increases the value by a smaller amount when the period during which the distance measuring device does not detect the object is short than when the period during which the distance measuring device does not detect the object is long.

3. The method of claim 1 or 2, wherein the control device does not decrease the value when the distance measuring device detects the object and the subtraction start time has not elapsed since the distance measuring device detected the object.

4. A determination method according to any one of claims 1 to 3, wherein the control device increases the value when the imaging device captures an image of the object present in the portion and the distance measuring device does not detect the object present in the portion and the vehicle's traveling speed is equal to or greater than a predetermined speed.

5. A method of determination as described in any one of claims 1 to 4, wherein the control device, when the object is a preceding vehicle traveling in front of the vehicle, calculates a time interval between the vehicle and the preceding vehicle, and when the time interval is short, reduces the amount of decrease in the value less than when the time interval is long.

6. A determination method according to any one of claims 1 to 5, wherein the control device increases the amount of decrease in the value when the distance measuring device detects the object for a long period of time compared to when the distance measuring device detects the object for a short period of time.

7. A determination device comprising: a distance measuring device that detects an object within a detection range; an imaging device that images an imaging range that overlaps with at least a portion of the detection range; a calculation unit that calculates a value indicating the detection state of the distance measuring device, the value decreasing when the distance measuring device detects the object and increasing when the imaging device images the object present in a part of the imaging range that overlaps with the detection range and the distance measuring device does not detect the object present in the part; and a determination unit that determines that the distance measuring device is in a first state in which it can detect the object if the value calculated by the calculation unit is less than a first value, and determines that the distance measuring device is in a second state in which it cannot detect the object if the value calculated by the calculation unit is equal to or greater than a second value greater than the first value.

Images