Information processing device, information processing method, and program

Abstract

To streamline correction processing for measurement values of a radar provided on a vehicle.SOLUTION: An information processing device according to an aspect of the present disclosure is configured to acquire a measurement value of a radar provided on a vehicle, determine whether or not the vehicle is parked or stopped, and perform correction processing on the acquired measurement value if the vehicle is determined to be parked or stopped.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a technique for correcting measurement values ​​of a radar installed in a vehicle. [Background technology]

[0002] Patent Document 1 proposes a correction method for a millimeter wave obstacle detection radar having a transmitting antenna and a receiving antenna. Specifically, Patent Document 1 proposes using radio waves that are reflected back from the transmitting antenna to the receiving antenna due to diffraction or reflection within a high frequency circuit, and correcting the distance of 0 m by using a pseudorandom code having a phase difference of the number of chips when the reflection is detected at a maximum as the reference distance of 0 m. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-046929 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a technology for improving the efficiency of correction processing for measurement values ​​of a radar installed in a vehicle. [Means for solving the problem]

[0005] An information processing device according to a first aspect of the present disclosure includes a control unit configured to acquire measurement values ​​of a radar installed in a vehicle, determine whether the vehicle is parking or stopping, and, if it is determined that the vehicle is parking or stopping, perform a correction process on the acquired measurement values.

[0006] An information processing method according to a second aspect of the present disclosure is an information processing method executed by a computer, and includes acquiring measurement values ​​of a radar installed in a vehicle, determining whether the vehicle is parking or stopping, and, if it is determined that the vehicle is parking or stopping, performing a correction process on the acquired measurement values.

[0007] A program according to a third aspect of the present disclosure is a program for causing a computer to execute an information processing method, the information processing method including acquiring measurement values ​​of a radar installed in a vehicle, determining whether the vehicle is parking or stopping, and, if it is determined that the vehicle is parking or stopping, performing a correction process on the acquired measurement values. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to improve the efficiency of correction processing for measurement values ​​of radar installed in a vehicle. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 schematically illustrates an example of a situation to which the present disclosure is applied. [Figure 2] FIG. 2 is a schematic diagram showing an example of the configuration of a radar provided in a vehicle according to the embodiment. [Figure 3A] FIG. 3A is a schematic diagram showing an example of the positional relationship between each radar of a vehicle and an object in time series. [Figure 3B] FIG. 3B shows an example of the measurement values ​​of each radar for the target object. [Figure 3C] FIG. 3C shows a schematic example of the measurement results obtained. [Figure 4] FIG. 4 is a diagram illustrating an example of a hardware configuration of the in-vehicle device according to the embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of a software configuration of the in-vehicle device according to the embodiment. [Figure 6]FIG. 6 is a flowchart illustrating an example of a processing procedure of the in-vehicle device according to the embodiment. [Figure 7] FIG. 7 is a flowchart illustrating an example of a processing procedure in a subroutine of the correction processing according to the embodiment. [Figure 8] FIG. 8 shows the state space model assumed in Bayesian estimation. [Figure 9] FIG. 9 is a schematic diagram showing an example of the arrangement of radars according to a modified example. [Figure 10] FIG. 10 is a schematic diagram showing an example of a radar configuration according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Various methods for correcting radar measurement values ​​have been proposed in the past (for example, Patent Document 1). These methods can improve the accuracy of distance measurement by radar. However, if correction processing for radar measurement values ​​is performed constantly, a problem arises in that the processing load on the information processing device (computer) increases.

[0011] In contrast, an information processing device according to a first aspect of the present disclosure includes a control unit configured to acquire measurement values ​​of a radar installed in a vehicle, determine whether the vehicle is parking or stopping, and, if it is determined that the vehicle is parking or stopping, perform correction processing on the acquired measurement values.

[0012] The influence of environmental factors such as reflections from reflective objects such as walls and changes in reflectivity due to the material of the object being measured can make radar distance measurements unstable and result in large errors in the obtained measurement values ​​(an example will be described in detail with reference to FIGS. 3A and 3B below). When a vehicle is parking or stopping, reflective objects such as walls are likely to come close to the vehicle, and there is a high possibility that various objects exist near the vehicle, making it susceptible to the influence of changes in the materials of those objects. Therefore, during parking or stopping, the vehicle is susceptible to the influence of environmental factors, and errors are likely to occur in radar distance measurements.

[0013] Therefore, the information processing device according to the first aspect of the present disclosure determines whether the vehicle is parking or stopping, and if so, performs a correction process on the measurement values, and omits the execution of the correction process during at least part of the other period (the execution or omission of the correction process during the other period may be selected as appropriate). This makes it possible to narrow the period during which the correction process on the radar measurement values ​​is executed to at least the period during which the vehicle is parking or stopping. Therefore, the information processing device according to the first aspect of the present disclosure ensures the execution of the correction process in situations where errors are likely to occur in radar distance measurements, and reduces the processing load on the information processing device by reducing the time required to execute the correction process. As a result, the efficiency of the correction process can be improved.

[0014] An embodiment according to one aspect of the present disclosure (hereinafter also referred to as "the present embodiment") will be described below with reference to the drawings. However, the present embodiment described below is merely an example of the present disclosure in all respects. Various improvements or modifications may be made without departing from the scope of the present disclosure. In implementing the present disclosure, specific configurations according to the embodiment may be adopted as appropriate. Note that while data appearing in the present embodiment is described in natural language, more specifically, it is specified using computer-recognizable pseudo-language, commands, parameters, machine language, etc.

[0015] [1 Application example] 1 is a diagram illustrating an example of a situation in which the present disclosure is applied. An in-vehicle device 1 according to this embodiment is one or more computers configured to perform distance measurement using a radar S.

[0016] In the example of FIG. 1, the in-vehicle device 1 is mounted on a vehicle V. The vehicle V is, for example, an automobile. In this embodiment, the in-vehicle device 1 is an example of an information processing device of the present disclosure. The name of the information processing device may be changed as appropriate depending on the usage situation, embodiment, etc. In the example of FIG. 1, the in-vehicle device 1 is disposed in front of the vehicle V, but the placement of the in-vehicle device 1 is not limited to this and may be determined as appropriate depending on the embodiment.

[0017] In this embodiment, the on-vehicle device 1 acquires a measurement value 3 of a radar S provided on the vehicle V. In one example, the measurement value 3 may be configured to indicate the distance from a distance reference to the object Z. The measurement value 3 of the radar S may be acquired in time series. The type of radar S is not particularly limited and may be appropriately selected depending on the embodiment. The radar S may be, for example, a distance sensor such as a millimeter-wave radar, LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), an infrared sensor, or an ultrasonic sensor. The object Z may be, for example, an obstacle, a person, another vehicle (such as an automobile, a bicycle, or a motorcycle), etc.

[0018] The in-vehicle device 1 determines whether the vehicle V is in a parking or stopping operation. A parking or stopping operation is the execution of an operation for parking or stopping the vehicle. Parking means stopping the vehicle continuously (for example, for more than 5 minutes), and stopping means stopping the vehicle for the purpose of passengers getting in or out or for a relatively short period of time (for example, within 5 minutes). In one example, whether a parking or stopping operation is in progress may be determined based on vehicle information such as turn signals, hazard lights, brakes, and a speedometer, depending on whether the vehicle V has slowed down to a certain speed or below and is heading toward a stopped state. In another example, whether a parking or stopping operation is in progress may be determined based on the acceleration value of the vehicle V (for example, whether the acceleration value has continued to decelerate for more than a predetermined time). Then, when the in-vehicle device 1 determines that the vehicle V is in a parking or stopping operation, it performs a correction process on the acquired measurement value 3.

[0019] The number of radars S provided on the vehicle V may be selected appropriately depending on the embodiment. In one example, the vehicle V may be provided with one radar S. In another example, the vehicle V may be provided with multiple radars S. In this case, the multiple radars S may be arranged so that their measurement ranges at least partially overlap. Accordingly, acquiring the measurement values ​​3 of the radars S may include acquiring the measurement values ​​3 of each radar S for an overlapping range (hereinafter also referred to as an "overlapping range") among the measurement ranges of each radar S. The on-vehicle device 1 may derive the measurement results in the overlapping range from the measurement values ​​3 of each radar S.

[0020] A method for deriving the measurement results of the overlapping range from the measurement values ​​3 of the multiple radars S may be selected appropriately depending on the embodiment. In one example, a priority area may be set for each radar S in the overlapping range (for example, in the right area of ​​the overlapping range, priority may be given to the measurement values ​​of the radar located on the right). In this case, the vehicle-mounted device 1 may adopt the measurement value 3 of the radar S assigned to the target priority area as the measurement result for the object Z present in the target priority area. In another example, the vehicle-mounted device 1 may derive the measurement result for the object Z present in the overlapping range by performing a statistical calculation (for example, an average, a weighted average, etc.) on the measurement values ​​3 of each radar S. In yet another example, the vehicle-mounted device 1 may adopt, as the measurement result for the object Z present in the overlapping range, the measurement value 3 that indicates the shortest distance from the distance reference to the object Z among the measurement values ​​3 of the multiple radars S. Note that the measurement results for the ranges other than the overlapping range may be obtained in the same manner as when making measurements using a single radar S. In one example, the measurement value of the radar S may be adopted as the measurement result as is.

[0021] The location of the radar S on the vehicle V may be determined appropriately depending on the embodiment. In the example, the radar S may be disposed at any one of the front, rear, or side of the vehicle V. In FIG. 1, the left direction of the drawing corresponds to the front of the vehicle V, and an example of a scene in which the radar S is provided at the rear of the vehicle V is shown. When multiple radars S are provided, at least two of the multiple radars S may be disposed in parallel and spaced apart in the horizontal direction so that their measurement ranges overlap. At least two of the multiple radars S may be disposed in parallel and spaced apart in the vertical direction so that their measurement ranges overlap.

[0022] FIG. 2 schematically illustrates an example of the configuration of a radar S provided on a vehicle V in this embodiment. In the example of FIG. 2, the upward direction of the drawing corresponds to the front of the vehicle V, and two radars (SA, SB) are provided on the rear of the vehicle V. The radar SA is disposed on the rear left side and has a measurement range RA on the rear left side of the vehicle V. The radar SA is configured to acquire measurement values ​​3A in time series for the measurement range RA. The radar SB is disposed on the rear right side and has a measurement range RB on the rear right side of the vehicle V. The radar SB is configured to acquire measurement values ​​3B in time series for the measurement range RB. In the example of FIG. 2, an area behind the vehicle V is an overlapping range RZ of the measurement ranges (RA, RB). Note that, hereinafter, when the radars (SA, SB) are not distinguished from each other, they are also simply referred to as "radar S," and when the measurement values ​​(3A, 3B) are not distinguished from each other, they are also simply referred to as "measurement value 3."

[0023] 3A and 3B schematically show an example of a scene in which the distance to the object Z is measured by each radar (SA, SB). FIG. 3A schematically shows an example of the relative positional relationship between each radar (SA, SB) of the vehicle V and the object Z along a time series (t=1 to t=4). FIG. 3B shows an example of the measurement values ​​(3A, 3B) of each radar (SA, SB) for the object Z. Note that the example in FIG. 3A assumes a scene in which the object Z approaches the vehicle V from behind, but it is also possible to assume a scene in which the vehicle V approaches the object Z while reversing. Alternatively, it is also possible to assume that both the object Z and the vehicle V are moving.

[0024] 3A and 3B, it is assumed that an error occurs in the measurement by radar SA at time t=3. Specifically, it is assumed that each radar (SA, SB) is configured to measure the distance to object Z by irradiating waves such as sound waves or electromagnetic waves toward object Z and measuring the waves reflected from object Z. In this case, if, due to the influence of environmental factors, each radar (SA, SB) mistakenly perceives waves other than those directly reflected from object Z as waves reflected from object Z, this may cause an error in the measurement values ​​(3A, 3B) of each radar (SA, SB).

[0025] In the example of Fig. 3A, it is assumed that at time t = 3, the radar SA erroneously measures a wave reflected from a reflecting object such as a wall as a wave directly reflected from the object Z. Accordingly, in the example of Fig. 3B, an error occurs in the measurement value 3A of the radar SA at time t = 3 by the amount corresponding to the difference between the reflection path via the reflecting object and the straight-line distance to the object Z.

[0026] When the vehicle V is parking or stopping, reflective objects such as walls are likely to come close to the vehicle V, and there is a high possibility that various objects Z are present near the vehicle V, which is easily affected by changes in the material of the objects Z. Therefore, during parking or stopping, the vehicle is easily affected by environmental factors, and errors are likely to occur in the distance measurements by each radar (SA, SB).

[0027] Therefore, in this embodiment, the in-vehicle device 1 determines whether the vehicle V is parking or stopping, and if it determines that the vehicle V is parking or stopping, performs correction processing for each radar (SA, SB). The correction processing does not need to be particularly limited as long as it can reduce the errors exemplified in Fig. 3B, and may be selected appropriately depending on the embodiment. It is preferable that the correction processing be executable in real time (i.e., it is possible to correct the measurement value at the target time without using measurement values ​​later than the target time).

[0028] In one example, the on-board device 1 may calculate, as a correction process, an estimated value of the measurement result at a target time from the measurement values ​​(3A, 3B) of each radar (SA, SB) before the target time using a statistical or probabilistic method. In the example of FIG. 3B , the estimated value at time t=k may be calculated from the measurement values ​​(3A, 3B) before time t=k (k=1, 2, 3, 4). For example, the estimated value at time t=3 may be calculated from the measurement values ​​(3A, 3B) up to time t=2.

[0029] Next, the on-board device 1 may compare the measurement values ​​(3A, 3B) of each radar (SA, SB) at the target time with the calculated estimated value. Then, based on the comparison result, the on-board device 1 may evaluate whether the measurement values ​​(3A, 3B) of each radar (SA, SB) deviate from the estimated value, and exclude the measurement values ​​(3A, 3B) of each radar (SA, SB) that deviate from the estimated value. In the example of FIG. 3B, the on-board device 1 may evaluate that the measurement value 3A of the radar SA deviates from the estimated value for the measurement values ​​(3A, 3B) at time t=3, and exclude the measurement value 3A.

[0030] 3C shows an example of measurement results obtained at each time. When there are no measurement values ​​to be excluded, the in-vehicle device 1 may derive the measurement results of the overlapping range RZ from the measurement values ​​(3A, 3B) of each radar (SA, SB), as in the case where correction processing is not performed. On the other hand, when there are measurement values ​​to be excluded, the in-vehicle device 1 may derive the measurement results of the target time from the remaining measurement values ​​other than the measurement values ​​to be excluded among the measurement values ​​(3A, 3B) of each radar (SA, SB) at the target time.

[0031] In the example of Figures 3B and 3C, the vehicle-mounted device 1 may derive measurement results at times t=1, 2, and 4 from the respective measurement values ​​(3A, 3B), and may derive a measurement result at time t=3 from the measurement value 3B. Note that deriving the measurement result at the target time from the remaining measurement values ​​may be configured by adopting, as the measurement result, the measurement value among the remaining measurement values ​​that is closest to the estimated value. In the example of Figures 3B and 3C, the vehicle-mounted device 1 may adopt, as the measurement result at time t=3, the measurement value 3B of radar SB at time t=3. Note that even if there are no measurement values ​​to exclude, the vehicle-mounted device 1 may adopt, as the measurement result, the measurement value among the measurement values ​​(3A, 3B) of each radar (SA, SB) at the target time that is closest to the estimated value.

[0032] As described above, according to the in-vehicle device 1 of this embodiment, the period during which the correction process for the measurement value 3 of the radar S is executed can be limited to the period during which the vehicle is parking or stopping. This ensures that the correction process is executed in situations where an error is likely to occur in the distance measurement by the radar S, and also reduces the time required to execute the correction process, thereby reducing the processing load on the in-vehicle device 1. As a result, the efficiency of the correction process can be improved.

[0033] In this embodiment, the in-vehicle device 1 may be configured to execute the correction process during any period other than during parking or stopping, as long as the in-vehicle device 1 is configured to omit execution of the correction process during at least a part of the period other than during parking or stopping. In one example, the in-vehicle device 1 may determine whether or not a reflecting object is close to the vehicle V. Then, even if the in-vehicle device 1 determines that a reflecting object is close to the vehicle V, the in-vehicle device 1 may execute the correction process on the acquired measurement value 3. Hereinafter, in this embodiment, it is assumed that multiple radars S are provided on the vehicle V so that their measurement ranges overlap, as exemplified in FIG. 3A.

[0034] [2 Configuration Examples] [Hardware configuration example] 4 is a diagram showing an example of the hardware configuration of the in-vehicle device 1 according to this embodiment. As shown in FIG. 4, the in-vehicle device 1 according to this embodiment includes a control unit 11, a storage unit 12, an external interface 13, an input device 14, an output device 15, and a drive 16, which are electrically connected to each other. It's a computer.

[0035] The control unit 11 includes a CPU, which is a hardware processor, RAM, ROM (Read Only Memory), cache memory, etc., and is configured to execute information processing based on programs and various data. The control unit 11 (CPU) is an example of a processor resource.

[0036] The storage unit 12 is configured with, for example, a hard disk drive, a solid state drive, or the like. The storage unit 12 is an example of a memory resource. In this embodiment, the storage unit 12 stores various information such as a program 81. The program 81 is a program for causing the in-vehicle device 1 to execute information processing (see FIGS. 6 and 7 described below) relating to a correction process for the measurement value 3 of the radar S. The program 81 includes a series of instructions for the information processing.

[0037] The external interface 13 is, for example, a USB (Universal Serial Bus) port, a dedicated port, or the like, and is an interface for connecting to an external device. The type and number of the external interfaces 13 may be determined appropriately depending on the type and number of the external devices to be connected. In this embodiment, the in-vehicle device 1 may be connected to each radar (SA, SB) via the external interface 13.

[0038] The input device 14 is a device for inputting, for example, an operation button, etc. The output device 15 is a device for outputting, for example, a display, a speaker, etc. A user can operate the in-vehicle device 1 by using the input device 14 and the output device 15. The input device 14 and the output device 15 may be integrally configured, for example, by a touch panel display, etc.

[0039] The drive 16 is a device for reading various information such as programs stored in a storage medium 91. The program 81 may be stored in the storage medium 91. The storage medium 91 is a medium that stores information such as programs by electrical, magnetic, optical, mechanical, or chemical action so that a computer or other device, machine, or the like can read the stored information. The in-vehicle device 1 may obtain the program 81 from the storage medium 91.

[0040] 4 illustrates a disk-type storage medium such as a CD or DVD as an example of the storage medium 91. However, the type of storage medium 91 is not limited to a disk type, and may be a type other than a disk. Examples of storage media other than a disk type include semiconductor memories such as flash memories. The type of drive 16 may be selected appropriately depending on the type of storage medium 91.

[0041] Regarding the specific hardware configuration of the in-vehicle device 1, components can be omitted, replaced, or added as appropriate depending on the embodiment. For example, the control unit 11 may include multiple hardware processors. The hardware processors may be configured with a microprocessor, an FPGA (field-programmable gate array), a GPU (Graphics Processing Unit), etc. At least one of the external interface 13, the input device 14, the output device 15, and the drive 16 may be omitted. The in-vehicle device 1 may be configured with multiple computers. In this case, the hardware configurations of the computers may or may not be the same. The in-vehicle device 1 may be a computer designed specifically for the service to be provided, a general-purpose computer, a mobile phone including a smartphone, a tablet PC (Personal Computer), etc.

[0042] [Software configuration example] FIG. 5 schematically shows an example of the software configuration of the in-vehicle device 1 according to this embodiment. The control unit 11 of the in-vehicle device 1 loads the program 81 stored in the storage unit 12 into the RAM. The control unit 11 then executes instructions included in the program 81 loaded into the RAM using the CPU. As a result, as shown in FIG. 5, the in-vehicle device 1 according to this embodiment operates as a computer including an acquisition unit 111, a first determination unit 112, a correction processing unit 113, a result derivation unit 114, and a second determination unit 115 as software modules. That is, in this embodiment, each software module of the in-vehicle device 1 is realized by the control unit 11 (CPU).

[0043] The acquisition unit 111 is configured to acquire measurement values ​​3 of a radar S provided on the vehicle V. In the present embodiment, the acquisition unit 111 is configured to acquire measurement values ​​3 of a plurality of radars S in time series. The first determination unit 112 is configured to determine whether the vehicle V is parking or stopping. The correction processing unit 113 is configured to perform correction processing on the acquired measurement values ​​3 when it is determined that the vehicle V is parking or stopping. The result derivation unit 114 is configured to derive measurement results in the overlapping range from the measurement values ​​3 of each radar S. The second determination unit 115 is configured to determine whether a reflecting object is close to the vehicle V. Accordingly, in the present embodiment, the correction processing unit 113 is configured to perform correction processing on the acquired measurement values ​​3 even when it is determined that a reflecting object is close to the vehicle V.

[0044] In this embodiment, an example is described in which each software module of the in-vehicle device 1 is implemented by a general-purpose CPU. However, some or all of the software modules may be implemented by one or more dedicated processors. Each module may be implemented as a hardware module. Regarding the software configuration of the in-vehicle device 1, modules may be omitted, replaced, or added as appropriate depending on the embodiment.

[0045] [3 Example of operation] FIG. 6 is a flowchart showing an example of a processing procedure of the in-vehicle device 1 according to this embodiment. The following processing procedure is an example of an information processing method. However, the following processing procedure is merely an example, and each step may be changed as much as possible. Furthermore, steps in the following processing procedure may be omitted, replaced, or added as appropriate depending on the embodiment.

[0046] <Step S10> In step S10, the control unit 11 operates as the acquisition unit 111 and acquires the measurement values ​​3 of the multiple radars S. In one example, the control unit 11 acquires the measurement values ​​(3A, 3B) of each radar (SA, SB). In this embodiment, the processing of step S10 includes acquiring the measurement values ​​3 of each radar S for the overlapping range. After acquiring the measurement values ​​3 of each radar S, the control unit 11 proceeds to the next step S12.

[0047] <Step S12> In step S12, the control unit 11 operates as the first determination unit 112 and determines whether the vehicle V is in a parking or stopping operation. In one example, the control unit 11 may determine whether the vehicle V is in a parking or stopping operation, depending on whether the vehicle V has slowed down to a certain speed or below, based on vehicle information such as blinkers, hazard lights, brakes, and a speedometer, and whether the vehicle V is in a stopped state. In another example, the control unit 11 may determine whether the vehicle V is in a parking or stopping operation, depending on the value of the acceleration of the vehicle V (for example, whether the acceleration continues to take a value in the deceleration direction for more than a predetermined time). Any method for detecting an operation for parking or stopping (for example, an operation toward parking or stopping) may be adopted as a method for determining whether the vehicle V is in a parking or stopping operation. For example, the control unit 11 may determine whether the vehicle V is in a parking or stopping operation, depending on whether the vehicle is in a transitional state toward parking or stopping. When the vehicle V is in a parking or stopping operation If it is determined that the vehicle V is not currently parking or stopping, the control unit 11 proceeds to step S16. On the other hand, if it is determined that the vehicle V is not currently parking or stopping, the control unit 11 proceeds to step S14.

[0048] <Step S14> In step S14, the control unit 11 operates as the second determination unit 115 and determines whether a reflective object is close to the vehicle V or not.

[0049] The method for detecting the proximity of a reflecting object is not particularly limited and may be appropriately selected depending on the embodiment. In one example, the vehicle V may further be provided with a camera. The control unit 11 may determine whether or not a reflecting object is close to the vehicle V by analyzing an image obtained by the camera. In another example, the closer the reflecting object is to the vehicle V, the stronger the intensity of the reflected wave from the reflecting object. Therefore, the control unit 11 may determine whether or not a reflecting object is close to the vehicle V based on the intensity of the reflected wave (signal) observed when the radar S obtains the measurement value 3. In yet another example, the vehicle V or the in-vehicle device 1 may use a GPS (Global Positioning System) measurement The storage unit 12 may be provided with a device for obtaining position information such as a radar or other device. The storage unit 12 may also store map information, which may include information indicating the position of a reflective object. In this case, the control unit 11 may determine whether a reflective object is close to the vehicle V based on the obtained position information and map information. The reflective object may be, for example, a wall, a guardrail, an iron plate (e.g., an iron plate for construction on the road surface, an iron plate at a connecting portion, etc.), an overhead structure (e.g., a road guide board, etc.), a fence in a median strip, or the side of a large vehicle (e.g., a bus, a truck, etc.).

[0050] If it is determined that a reflective object is close to the vehicle V, the control unit 11 proceeds to step S16. On the other hand, if it is determined that a reflective object is not close to the vehicle V, the control unit 11 omits the execution of step S16 and proceeds to step S18.

[0051] <Step S16> In step S16, the control unit 11 operates as a correction processing unit 113 and performs correction processing on the acquired measurement value 3. The content of the correction processing may be selected appropriately depending on the embodiment. In this embodiment, the correction processing using a statistical or probabilistic method may be adopted as the correction processing in step S16.

[0052] 7 is a flowchart showing an example of a processing procedure in a subroutine of the correction processing by the in-vehicle device 1 according to this embodiment. The correction processing of step S16 according to this embodiment may include the following processing of steps S161 to S164. However, the processing procedure shown in FIG. 7 is merely an example, and each step may be changed as much as possible. Furthermore, steps may be omitted, replaced, or added to the processing procedure shown in FIG. 7 as appropriate depending on the embodiment.

[0053] (Steps S161 and S162) In step S161, the control unit 11 calculates an estimate of the measurement result at the target time from the measurement values ​​3 of each radar S before the target time using a statistical or probabilistic method. In step S162, the control unit 11 compares the measurement values ​​3 of each radar S at the target time with the calculated estimate. In this way, the control unit 11 evaluates the likelihood of the measurement values ​​3 of each radar S using a statistical or probabilistic method.

[0054] As long as the likelihood of the measurement value 3 can be evaluated, the statistical or probabilistic method may be appropriately selected depending on the embodiment without being particularly limited. A known method may be adopted as the statistical or probabilistic method in the process of step S161. For example, the statistical or probabilistic method may be a Bayesian estimation method or an estimation method using a Kalman filter.

[0055] FIG. 8 shows a state space model assumed in the Bayesian estimation method. The state space model introduces an unobserved latent random variable x called a state, and explains the observed value y based on the state. In this embodiment, the state x corresponds to the state of the object Z (the distance to the object Z), and the observed value y corresponds to the measurement value 3 of each radar S. The state space model shown in FIG. 8 expresses that the observed value y at each time depends only on the state x at the same time. In other words, the observed value y at time t t is the state x t Assume that the state x is generated from t is the state x t-1 In Bayesian estimation, the observed value yt-1 State x for t-1 Based on the distribution of t Predicted and observed values ​​y t Regarding this prediction process, the predicted distribution of the state for the observed value y up to one time point before can be expressed by, for example, the following Equation 1.

[0056]

number

[0057]

number

[0058] When the Bayesian estimation method is adopted as a statistical or probabilistic method, the control unit 11 calculates the likelihood p(y t |x t The control unit 11 calculates the calculated likelihood p(y t |x t Depending on the value of ), it can be determined whether the measured value 3 deviates from the estimated value.

[0059] The method for determining whether the measurement value 3 deviates from the estimated value may be determined appropriately depending on the embodiment. Simply, the control unit 11 may determine whether the measurement value 3 deviates from the estimated value by comparing it with a threshold (i.e., depending on whether the likelihood is lower than the threshold). In another example, the control unit 11 may determine whether the measurement value 3 deviates from the estimated value by statistical processing (e.g., outlier determination).

[0060] The estimation method using the Kalman filter can be explained in the same way as the Bayesian estimation method, except that the state space model shown in Fig. 8 is replaced with a linear-Gaussian state space model. Therefore, even when the estimation method using the Kalman filter is adopted as a statistical or probabilistic method, the control unit 11 can determine whether the measurement value 3 deviates from the estimated value by a method similar to the above-mentioned calculation processing.

[0061] When it is determined whether or not the measurement value 3 deviates from the estimated value, the control unit 11 advances the process to the next step S163. In other words, if the evaluation is to evaluate the reliability of a measurement value 3, the estimate does not have to be derived directly. Calculating an estimate of a measurement result may involve performing an operation equivalent to deriving the estimate, even if the estimate is not directly derived.

[0062] (Step S163) In step S163, the control unit 11 determines where the process should branch depending on the result of the comparison in the process of step S162. If the process of step S162 finds that any measured value 3 is deviating from the estimated value, the control unit 11 proceeds to the next step S164. On the other hand, if any measured value 3 is not deviating from the estimated value, the control unit 11 skips the process of step S164, ends the subroutine of the correction process according to this operation example, and proceeds to step S18.

[0063] (Step S164) In step S164, the control unit 11 excludes the measurement values ​​3 of each radar S that are evaluated to deviate from the estimated value. In the example of FIGS. 3A and 3B above, the control unit 11 may evaluate that the measurement value 3A of the radar SA at time t=3 deviates from the estimated value and exclude the measurement value 3A of the radar SA from the measurement values ​​(3A, 3B) of each radar (SA, SB). Excluding the target measurement value 3 corresponds to preventing the target measurement value 3 from being reflected in the derivation of the measurement result. After excluding the deviating measurement value 3, the control unit 11 ends the subroutine of the correction process according to this operation example and proceeds to step S18.

[0064] <Step S18> 6, in step S18, the control unit 11 operates as the result derivation unit 114 and derives the measurement results in the overlapping range from the measurement values ​​3 of each radar S. A method for deriving the measurement results in the overlapping range may be selected as appropriate depending on the embodiment.

[0065] If the determinations in steps S12 and S14 are NO and the correction process in step S16 is omitted, the control unit 11 derives the measurement results for the overlapping range from the measurement values ​​3 of the multiple radars S. In one example, the control unit 11 may adopt the measurement value 3 of the radar S assigned to the target priority area as the measurement result for the object Z present in the target priority area. In another example, the control unit 11 may derive the measurement result for the object Z present in the overlapping range by performing a statistical calculation (e.g., average, weighted average, etc.) on the measurement values ​​3 of each radar S. In yet another example, the control unit 11 may adopt, as the measurement result for the object Z present in the overlapping range, the measurement value 3 that indicates the shortest distance from the distance reference to the object Z, among the measurement values ​​3 of the multiple radars S.

[0066] When the correction process of step S16 is performed and the process of step S164 is performed to exclude measurement values ​​3 that deviate from the estimated value, the control unit 11 may derive the measurement result at the target time from the remaining measurement values ​​3 other than the excluded measurement values ​​3. Except for the exclusion of measurement values ​​3 that deviate from the estimated value, the method of deriving the measurement result may be the same as when the correction process of step S16 is omitted. Alternatively, the control unit 11 may adopt the measurement value 3 that is closest to the estimated value among the remaining measurement values ​​3 as the measurement result.

[0067] If the correction process of step S16 is performed but there are no measurement values ​​3 that deviate from the estimated value and the process of step S164 is omitted, the control unit 11 may derive the measurement result of the overlapping range from the measurement values ​​3 of each radar S, as in the case where the correction process of step S16 is omitted. Alternatively, the control unit 11 may adopt the measurement value that is closest to the estimated value among the measurement values ​​3 of each radar S at the target time as the measurement result.

[0068] The measurement results for the ranges other than the overlapping range are measured in the same way as when measuring with one radar S. In one example, the control unit 11 may directly use the measurement value of the radar S as the measurement result. After deriving the measurement result, the control unit 11 proceeds to the next step S20.

[0069] <Step S20> In step S20, the control unit 11 determines whether or not to terminate the distance measurement by each radar S. The trigger for the termination may be determined appropriately depending on the embodiment. In one example, the control unit 11 may determine whether or not to terminate the distance measurement depending on whether or not the user has performed a termination operation.

[0070] If it is determined not to end the distance measurement, the control unit 11 returns the process to step S10 and executes the processes of steps S10 to S18 again. On the other hand, if it is determined to end the distance measurement, the control unit 11 ends the processing procedure according to this operation example. Note that the control unit 11 may start executing the process from step S10 at any timing (for example, in response to a start operation by the user).

[0071] [Features] In this embodiment, by the processes of steps S12 and S14, the period during which the correction process for the measurement value 3 of the radar S is performed can be narrowed down to a situation where it is determined that the vehicle V is parking or stopping or that a reflecting object is close to the vehicle V. This ensures that the correction process is performed in a situation where an error is likely to occur in the distance measurement by the radar S, and also reduces the time required to perform the correction process, thereby reducing the processing load on the in-vehicle device 1. As a result, the efficiency of the correction process can be improved.

[0072] Furthermore, in this embodiment, multiple radars S are provided with overlapping measurement ranges, thereby achieving redundancy in distance measurement. Furthermore, the redundancy in distance measurement allows correction processing to be achieved by a simple process of excluding measurement values ​​3 that deviate from the estimated value. In addition, by using an estimation method based on Bayesian estimation or a Kalman filter, the load on the correction processing can be reduced and the correction processing can be performed in real time. By adopting the measurement value 3 closest to the estimated value as the measurement result, a reliable measurement result can be obtained using a statistical or probabilistic method, thereby improving the accuracy of distance measurement.

[0073] Furthermore, by using this embodiment in a situation where the radar S is provided at the rear of the vehicle V, the accuracy of measuring the distance behind the vehicle V during parking and stopping can be ensured.

[0074] [4 Variations] Although the embodiments of the present disclosure have been described in detail above, the above description is merely an example of the present disclosure in every respect. It goes without saying that various improvements or modifications can be made without departing from the scope of the present disclosure. For example, the following modifications are possible. The following modifications can be combined as appropriate.

[0075] In the above embodiment, the number and arrangement of the radars S may be changed as appropriate. In one example, the number of radars S may be one. In another example, the number of radars S may be three or more. Even when the number of radars S is three or more, the correction process exemplified in FIG. 7 above may be adopted for the overlapping range. Furthermore, when the number of radars S provided on the vehicle V is one, or for a range other than the overlapping range among the measurement ranges of multiple radars S, any correction process other than the correction process exemplified in FIG. 7 above may be adopted. In one example, the on-vehicle device 1 may correct the measurement value 3 of the radar S by a known correction process.

[0076] 9 is a schematic diagram illustrating an example of the arrangement of radars S according to this modification. As illustrated in FIG. 9, when multiple radars S are provided, at least two radars (SA, SB) may be arranged in parallel in the vertical direction, spaced apart, so that their measurement ranges overlap. In this case, as illustrated in FIG. 9, an error may occur in the distance measurement of each radar (SA, SB) due to the influence of the road surface, etc. In the above embodiment, by adopting this arrangement, it is possible to ensure the execution of a correction process in a situation where an error is likely to occur in the distance measurement due to the influence of the road surface, etc., and to reduce the time required to execute the correction process, thereby reducing the processing load on the in-vehicle device 1.

[0077] FIG. 10 schematically illustrates an example of the configuration of a radar S according to this modification. In the example of FIG. 10, two radars (SA, SB) are arranged horizontally spaced apart from each other on either side of a camera C. In this configuration, the distance (depth) to an object shown in the captured image can be obtained by correlating the measurement results obtained by each radar (SA, SB) with the captured image obtained by the camera C. In the above embodiment, by employing this configuration, it is possible to ensure the execution of a correction process in situations where an error is likely to occur in the measurement of the distance to an object shown in the captured image, and to reduce the time required to execute the correction process, thereby reducing the processing load on the in-vehicle device 1. As shown in this modification, in the above embodiment, the radar S may be used together with other sensors.

[0078] In the above embodiment, the on-vehicle device 1 may be configured to perform multiple types of correction processes on the measurement value 3 of the radar S. At least some of the multiple types of correction processes may be selected as targets for the processes exemplified in FIG. 6 above. The remaining correction processes may be performed at any timing (or may be performed continuously). In one example, at least some of the correction processes that are targets for the processes exemplified in FIG. 6 may include the correction process exemplified in FIG. 7 above. In another example, at least some of the correction processes that are targets for the processes exemplified in FIG. 6 may not include the correction process exemplified in FIG. 7 above. In the above embodiment, the on-vehicle device 1 may be configured to perform correction processes even in situations other than those for which the determination in the process of step S12 or step S14 is YES, as long as it is configured to omit execution of correction processes in at least a part of the period.

[0079] Furthermore, in the correction process according to the above embodiment, the method for calculating the estimated value of the measurement result is not limited to the above example. In another example, the control unit 11 may calculate the estimated value of the measurement result using a physical model obtained by modeling the motion of the vehicle V and the object Z. As a specific example, the physical model may be configured to estimate the motion state (e.g., moving speed, moving direction, etc.) of the object Z from the speed and attitude (e.g., yaw rate) of the vehicle V and the measurement value 3 of the radar S. The control unit 11 may acquire various information from sensors such as a speedometer and a yaw rate sensor and the radar S, and estimate the motion state of the object Z based on the acquired information. The control unit 11 may estimate the position of the object Z at the target time from the motion state of the object Z estimated one time before the target time. Then, the control unit 11 may estimate the measurement result of the radar S for the object Z at the target time from the estimated results of the speed and attitude of the vehicle V and the position of the object Z.

[0080] In the above embodiment, the information processing in FIGS. 6 and 7 may be modified as appropriate. For example, the processing of step S14 may be omitted. Accordingly, the second determination unit 115 may be omitted from the software configuration of the on-vehicle device 1. If the measurement ranges of multiple radars S do not overlap or if there is only one radar S installed on the vehicle V, the processing of step S18 may be omitted. The processing order of steps S12 and S14 is not limited to the example shown in FIG. 6 and may be changed as desired. The processing of step S10 may be executed at any timing before the processing of step S16 or step S18 is executed. If there is only one radar S installed on the vehicle V, in step S10, the control unit 11 may acquire the measurement value 3 of one radar S.

[0081] [5 Supplementary Information] The processes and means described in this disclosure can be freely combined and implemented as long as no technical contradiction occurs.

[0082] Furthermore, a process described as being performed by one device may be shared and executed by multiple devices. Alternatively, a process described as being performed by different devices may be executed by a single device. In a computer system, the hardware configuration that realizes each function can be flexibly changed.

[0083] The present disclosure can also be realized by providing a computer program implementing the functions described in the above embodiments to a computer, and having one or more processors in the computer read and execute the program. Such a computer program may be provided to the computer via a non-transitory computer-readable storage medium connectable to the computer's system bus or via a network. Non-transitory computer-readable storage media include, for example, any type of disk, such as a magnetic disk (e.g., a floppy disk, a hard disk drive (HDD), etc.), an optical disk (e.g., a CD-ROM, a DVD disk, a Blu-ray disk), a read-only memory (ROM), a random-access memory (RAM), an EPROM, an EEPROM, a magnetic card, a flash memory, an optical card, or any type of medium suitable for storing electronic instructions. [Explanation of symbols]

[0084] 1...In-vehicle device (information processing method), V...Vehicle, 11...control unit, 12...storage unit, 13...external interface, 14...input device, 15...output device, 16...drive, 81...program, 91...storage medium, 111...acquisition section, 112...first judgment section, 113... correction processing unit, 114... result derivation unit, 115...Second judgment section, 3 (3A, 3B)...measurement value, S (SA, SB)...radar, Z...target

Claims

1. acquiring measurements from a radar installed on the vehicle; Determining whether the vehicle is parking or stopping; and When it is determined that the vehicle is parking or stopping, a correction process is performed on the acquired measurement value. a control unit configured to perform The vehicle is provided with a plurality of the radars so that their measurement ranges overlap, acquiring the measurement values ​​of the radars includes acquiring the measurement values ​​of the radars for overlapping ranges of the measurement ranges of the radars; the control unit is configured to derive a measurement result in the overlapping range from the measurement values ​​of the radars, the plurality of radar measurement values ​​are acquired in time series; The correction process includes: calculating an estimate of the measurement result at a target time from the measurement values ​​of each of the radars prior to the target time using a statistical or probabilistic method; comparing the measured value of each radar at the target time with the calculated estimated value; and excluding measurement values ​​from each of the radars that deviate from the estimated value; It is composed of deriving the measurement result comprises deriving the measurement result at the target time from remaining measurements; The vehicle further includes a camera, and the plurality of radars are arranged horizontally spaced apart from each other on either side of the camera, The control unit is configured to obtain a distance to an object appearing in the captured image by associating the measurement results obtained by each of the radars with the captured image obtained by the camera. Information processing device.

2. The statistical or probabilistic method is a Bayesian estimation method or a Kalman filter estimation method. The information processing device according to claim 1 .

3. deriving the measurement result at the target time from the remaining measurement values ​​includes adopting a measurement value among the remaining measurement values ​​that is closest to the estimated value as the measurement result; 3. The information processing device according to claim 1 or 2.

4. The control unit determining whether a reflective object is in proximity to the vehicle; and performing a correction process on the acquired measurement value even when it is determined that the reflecting object is close to the vehicle; and further configured to perform The information processing device according to claim 1 .

5. The radar is provided at the rear of the vehicle. The information processing device according to claim 1 .

6. 1. A computer-implemented information processing method, comprising: acquiring measurements from a radar installed on the vehicle; Determining whether the vehicle is parking or stopping; and When it is determined that the vehicle is parking or stopping, a correction process is performed on the acquired measurement value. Including, The vehicle is provided with a plurality of the radars so that their measurement ranges overlap, acquiring the measurement values ​​of the radars includes acquiring the measurement values ​​of the radars for overlapping ranges of the measurement ranges of the radars; The information processing method further includes deriving a measurement result in the overlapping range from measurement values ​​of the radars; the plurality of radar measurement values ​​are acquired in time series; The correction process includes: calculating an estimate of the measurement result at a target time from the measurement values ​​of each of the radars prior to the target time using a statistical or probabilistic method; comparing the measured value of each radar at the target time with the calculated estimated value; and excluding measurement values ​​from each of the radars that deviate from the estimated value; It is composed of deriving the measurement result comprises deriving the measurement result at the target time from remaining measurements; The vehicle further includes a camera, and the plurality of radars are arranged horizontally spaced apart from each other on either side of the camera, The information processing method includes obtaining a distance to an object shown in the captured image by associating a measurement result obtained by each of the radars with the captured image obtained by the camera. Information processing methods.

7. The statistical or probabilistic method is a Bayesian estimation method or a Kalman filter estimation method. The information processing method according to claim 6.

8. deriving the measurement result at the target time from the remaining measurement values ​​includes adopting a measurement value among the remaining measurement values ​​that is closest to the estimated value as the measurement result; 8. The information processing method according to claim 6 or 7.

9. determining whether a reflective object is in proximity to the vehicle; and performing a correction process on the acquired measurement value even when it is determined that the reflecting object is close to the vehicle; Further comprising: The information processing method according to any one of claims 6 to 8.

10. The radar is provided at the rear of the vehicle. The information processing method according to any one of claims 6 to 9.

11. A program for causing a computer to execute an information processing method, The information processing method includes: acquiring measurements from a radar installed on the vehicle; Determining whether the vehicle is parking or stopping; and When it is determined that the vehicle is parking or stopping, a correction process is performed on the acquired measurement value. Including, The vehicle is provided with a plurality of the radars so that their measurement ranges overlap, acquiring the measurement values ​​of the radars includes acquiring the measurement values ​​of the radars for overlapping ranges of the measurement ranges of the radars; The information processing method further includes deriving a measurement result in the overlapping range from measurement values ​​of the radars; the plurality of radar measurement values ​​are acquired in time series; The correction process includes: calculating an estimate of the measurement result at a target time from the measurement values ​​of each of the radars prior to the target time using a statistical or probabilistic method; comparing the measured value of each radar at the target time with the calculated estimated value; and excluding measurement values ​​from each of the radars that deviate from the estimated value; It is composed of deriving the measurement result comprises deriving the measurement result at the target time from remaining measurements; The vehicle further includes a camera, and the plurality of radars are arranged horizontally spaced apart from each other on either side of the camera, The information processing method includes obtaining a distance to an object shown in the captured image by associating a measurement result obtained by each of the radars with the captured image obtained by the camera. program.

12. The statistical or probabilistic method is a Bayesian estimation method or a Kalman filter estimation method. The program according to claim 11.

13. deriving the measurement result at the target time from the remaining measurement values ​​includes adopting a measurement value among the remaining measurement values ​​that is closest to the estimated value as the measurement result; 13. The program according to claim 11 or 12.

14. The information processing method includes: determining whether a reflective object is in proximity to the vehicle; and Even if it is determined that the reflecting object is close to the vehicle, the acquired measurement value is performing a correction process for the Further comprising: The program according to any one of claims 11 to 13.

15. The radar is provided at the rear of the vehicle. The program according to any one of claims 11 to 14.

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