Sensor calibration device and sensor calibration method

Abstract

To provide technology that makes it possible to carry out calibration of a laser sensor mounted to a laser scanner with good accuracy in correspondence to the actual measurement object without using a jig, etc., and properly adjusting the laser light irradiation angle of the laser sensor.SOLUTION: There is provided a sensor calibration device for carrying out calibration processing on a laser sensor. The sensor calibration device comprises: a sensor data measurement unit for measuring the sensor data acquired by the laser sensor; a map creation and position attitude detection unit for creating map data representing the environment surrounding the laser sensor and detecting the position and attitude of the laser sensor; a map evaluation unit for evaluating the quality of the created map data; and a sensor parameter adjustment unit for adjusting the sensor parameter of the laser sensor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technique for performing calibration of a sensor. [Background technology]

[0002] When acquiring measurement data using various scanner devices, in order to obtain highly accurate measurement data, it is essential to appropriately calibrate the sensors mounted on the scanner devices.

[0003] As one of such techniques, a technique for calibrating a laser sensor mounted on a laser scanner is known (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-156165 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-055311 Summary of the Invention [Problem to be solved by the invention]

[0005] In the techniques described in Patent Documents 1 and 2, when calibrating a sensor mounted on a scanner device, a jig with a known shape is used as a calibration target. Therefore, when calibrating a laser sensor mounted on a laser scanner using the techniques described in Patent Documents 1 and 2, a dedicated jig with a known shape must be separately prepared, which poses a problem of increased costs.

[0006] Furthermore, when calibrating the laser sensor using the techniques described in Patent Documents 1 and 2, it is necessary to use a dedicated jig with a known shape, which makes the work of performing the calibration cumbersome, and since the jig and the actual object to be measured are different, there are problems in that it is not possible to perform calibration with high precision.

[0007] On the other hand, it is difficult to accurately calibrate the laser sensor mounted on the laser scanner in accordance with the actual object to be measured, the environment, etc. (hereinafter collectively referred to as the "object to be measured") without using a dedicated jig with a known shape, and to appropriately adjust the irradiation angle of the laser light from the laser sensor using existing technology, and the development of new technology has been awaited.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a technology that enables accurate calibration of a laser sensor mounted on a laser scanner in accordance with the actual object to be measured, without using a jig or the like, and that makes it possible to appropriately adjust the irradiation angle of the laser light of the laser sensor. [Means for solving the problem]

[0009] A sensor calibration device according to the present invention is a device that performs calibration processing on a laser sensor, and includes a sensor data measurement unit that measures sensor data acquired by the laser sensor, a map creation / position and attitude detection unit that creates map data representing the environment around the laser sensor and detects the position and attitude of the laser sensor, a map evaluation unit that evaluates the quality of the created map data, and a sensor parameter adjustment unit that adjusts the sensor parameters of the laser sensor.

[0010] Other problems and solutions disclosed in the present application will be made clear in the detailed description and drawings. [Effects of the Invention]

[0011] According to the present invention, it is possible to accurately calibrate a laser sensor mounted on a laser scanner in accordance with the actual object to be measured without using a jig or the like, and to appropriately adjust the irradiation angle of the laser light from the laser sensor. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an example of a hardware configuration of an entire system including a sensor calibration device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of functional blocks of the sensor calibration device. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of a laser sensor. [Figure 4] FIG. 10 is a diagram illustrating an example of how deviation occurs in sensor data. [Figure 5] 10 is a flowchart illustrating an example of the overall flow of processing executed by the sensor calibration device. [Figure 6] FIG. 10 is a diagram illustrating an outline of a sensor data measurement process. [Figure 7] FIG. 1 is a diagram illustrating an outline of map creation and position and orientation detection processing. [Figure 8] FIG. 10 is a diagram illustrating an outline of a map evaluation process. [Figure 9] FIG. 10 is a diagram illustrating an overview of a sensor parameter adjustment process. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the following description, an "interface apparatus" may refer to one or more interface devices, which may be at least one of the following: One or more I / O (Input / Output) interface devices. The I / O (Input / Output) interface devices are interface devices for at least one of the I / O device and a remote display computer. The I / O interface device for the display computer may be a communications interface device. The at least one I / O device may be a user interface device, for example, either an input interface device such as a keyboard and pointing device, or an output interface device such as a display device. One or more communication interface devices. The one or more communication interface devices may be one or more homogeneous communication interface devices (e.g., one or more NICs (Network Interface Cards)) or two or more heterogeneous communication interface devices (e.g., an NIC and an HBA (Host Bus Adapter)).

[0014] In the following description, "memory" refers to one or more memory devices, which are an example of one or more storage devices, and may typically be a primary storage device. At least one memory device in the memory may be a volatile memory device or a non-volatile memory device.

[0015] In the following description, an "auxiliary storage device" may refer to one or more auxiliary storage devices, which are an example of one or more storage devices. The auxiliary storage device may typically be a non-volatile storage device (e.g., a persistent storage device), and specifically may be, for example, a hard disk drive (HDD), a solid state drive (SSD), a non-volatile memory express (NVME) drive, or a storage class memory (SCM).

[0016] In the following description, the term "storage device" may refer to at least one memory, including a memory and an auxiliary storage device.

[0017] Furthermore, in the following description, a "processor" may refer to one or more processor devices. The at least one processor device may typically be a microprocessor device such as a CPU (Central Processing Unit), but may also include other types of processor devices such as a GPU (Graphics Processing Unit). The at least one processor device may be single-core or multi-core. The at least one processor device may also be a processor core. The at least one processor device may also be a broader processor device such as a circuit that is a collection of gate arrays written in a hardware description language that performs some or all of the processing (e.g., an FPGA (Field-Programmable Gate Array), a CPLD (Complex Programmable Logic Device), or an ASIC (Application Specific Integrated Circuit)).

[0018] Furthermore, in the following description, functions may be described using the expression "xxx unit." However, the functions may be realized by one or more computer programs (hereinafter simply referred to as "programs") executed by a processor, by one or more hardware circuits (e.g., FPGAs or ASICs), or by a combination thereof. When a function is realized by a program executed by a processor, the specified processing is performed using a storage device and / or an interface device, etc., as appropriate, and therefore the function may be considered to be at least a part of the processor. Processing described using a function as the subject may be processing performed by a processor or a device having the processor. A program may be installed from a program source. The program source may be, for example, a computer that distributes the program or a computer-readable recording medium (e.g., a non-transitory recording medium). The description of each function is merely an example; multiple functions may be combined into one function, or one function may be divided into multiple functions.

[0019] In the following description, information that provides an output for an input may be described using expressions such as "yyy table," but the information may be a table of any data structure, or may be a neural network that generates an output for an input, or a learning model such as a genetic algorithm or random forest. In other words, to indicate that the information does not depend on the data structure, a "yyy table" may be referred to as "yyy information." In the following description, the structure of each table is an example, and one table may be divided into two or more tables, or all or part of two or more tables may be one table.

[0020] In the following description, a process may be described using a "program" as the subject, but the process described using a program as the subject may also be a process performed by a processor or a device having that processor. Two or more programs may be realized as one program, or one program may be realized as two or more programs.

[0021] In the following description, a "sensor calibration device" or a "sensor system" may be a system (e.g., a cloud computing system) implemented on a group of physical computing resources (e.g., a cloud platform), or a system (e.g., an on-premise system) configured with one or more physical computers. When the device or system "displays" display information, it may mean that the display information is displayed on a display device possessed by the computer, or that the computer transmits the display information to a display computer (in the latter case, the display information is displayed by the display computer).

[0022] In addition, the following description of the embodiments will be given using as examples a sensor calibration device that performs a process (hereinafter also referred to as a "calibration process") to appropriately adjust the irradiation angle of the laser light from the laser sensor, and a sensor system that includes at least the laser sensor and the sensor calibration device, and that subsequently eliminates errors (hereinafter also referred to as "angle errors") in the irradiation angle when the laser sensor irradiates laser light, which occur during the manufacture of the laser sensor due to poor accuracy in hardware aspects such as the dimensional accuracy of each component that makes up the laser sensor and the assembly accuracy of the laser sensor, through software processing.

[0023] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0024] In the following description, the same or similar components will be designated by common reference numerals, and redundant description may be omitted.

[0025] Furthermore, when there are multiple elements having the same or similar functions, the multiple elements may be described by using the same reference numeral with different subscripts to distinguish between them. On the other hand, when there is no need to distinguish between the multiple elements, the subscripts may be omitted.

[0026] <Configuration example of sensor system 100> First, a configuration example of a sensor calibration device 110 and a sensor system 100 including at least the sensor calibration device 110 will be described with reference to FIGS.

[0027] Fig. 1 is a diagram schematically illustrating an example of the overall hardware configuration of a sensor system 100 that includes at least a sensor calibration device 110. Fig. 2 is a diagram illustrating an example of functional blocks of the sensor calibration device 110. Fig. 3 is a diagram schematically illustrating an example of the configuration of a laser sensor 120.

[0028] (Example of the overall system configuration) As illustrated in FIG. 1, the sensor system 100 according to this embodiment includes at least one sensor calibration device 110 and at least one laser sensor 120 as components.

[0029] The sensor calibration device 110 is a computer system that can appropriately adjust the irradiation angle of the laser light from the laser sensor 120 by performing a calibration process on the laser sensor 120, and is realized by at least one computer device or server device having the respective configurations described below.

[0030] Furthermore, an example of the laser sensor 120 is a general laser sensor constituting a sensor unit (not shown) of a 2D laser scanner (not shown), which includes at least a laser light source 21 that irradiates laser light toward the reflective surface of a mirror 22, a mirror 22 that reflects the laser light toward the surface of the subject 23, a light receiving unit (not shown) that receives scattered light generated when the laser light reflected by the reflective surface of the mirror 22 is diffusely reflected on the surface of the subject 23, an encoder (not shown) that encodes the scattered light received by the light receiving unit, and a motor (not shown) that drives the light receiving unit, encoder, etc., as shown in the schematic configuration of FIG. If the above-mentioned angle error occurs during the manufacture of the laser sensor 120 due to inaccuracies in the hardware aspects, such as the dimensional accuracy of the above-mentioned components that make up the laser sensor 120 and the assembly accuracy of the laser sensor 120, a deviation will occur in the sensor data acquired by the laser sensor 120, as illustrated in Figure 4, which reflects the deviation between the actual irradiation direction of the laser light emitted from the laser light source 21 and the angle measured by the encoder.

[0031] The sensor calibration device 110 and the laser sensor 120 are connected to each other via an appropriate communication network (hereinafter simply referred to as "network") 50 such as a dedicated line or the Internet so that they can communicate data with each other, thereby collectively constituting a sensor system 100. Note that the sensor calibration device 110 and the laser sensor 120 are connected to the network 50 via wired connections via well-known communication devices (not shown), but they may also be connected wirelessly.

[0032] Furthermore, user terminals (not shown), such as laptop PCs, tablets, and smartphones owned by users of the sensor system 100 (e.g., users or operators of the sensor system 100), may be connected to the sensor calibration device 110 and the laser sensor 120 constituting the sensor system 100 via an appropriate network 50, such as the Internet or a dedicated line, so as to be able to communicate data with each other. In this case, each user terminal and the network 50 may be connected wirelessly or by wire.

[0033] Furthermore, other computer devices, server devices, etc. (hereinafter also referred to as "other devices") may be connected to the sensor calibration device 110 and the laser sensor 120 constituting this sensor system 100 so as to be able to perform data communications via the network 50. In this case, the other devices and the network 50 may be connected by wire or wirelessly via well-known communication equipment (not shown).

[0034] 1 and 2, the sensor calibration device 110 constituting the sensor system 100 has been described as being composed of one device. However, for example, the sensor calibration device 110 may be composed of multiple devices.

[0035] In addition, in the present embodiment, as illustrated in FIG. 1 , the sensor calibration device 110 and the laser sensor 120 constituting the sensor system 100 have been described as being separate devices. However, the sensor calibration device 110 and the laser sensor 120 may be configured as the same device. In this case, for example, the sensor calibration device 110 may be configured to include some or all of the functions performed by the laser sensor 120. Furthermore, for example, the laser sensor 120 may be configured to include some or all of the functions performed by the sensor calibration device 110.

[0036] In addition, in the present embodiment, the sensor calibration device 110 and the laser sensor 120, which constitute the sensor system 100, and various other devices such as a user terminal and other devices have been described as being separate devices. However, the sensor calibration device 110 and / or the laser sensor 120 and various other devices may be configured as the same device. In this case, the sensor system 100 may be configured as, for example, a computer system including some or all of these various devices. Furthermore, for example, the sensor system 100 may be configured to include some or all of the functions performed by these various devices.

[0037] (Example of hardware configuration of sensor calibration device 110) Next, an example of the hardware configuration of the sensor calibration device 110 that constitutes the sensor system 100 will be described with reference to FIG.

[0038] 1, the sensor calibration device 110 is realized by a computer having at least a storage device including a memory 112 and an auxiliary storage device 113, an interface device including at least a communication interface 114, and a processor 111 connected to them. In the sensor calibration device 110, the interface device may include an input interface 115 and / or an output interface 116.

[0039] The following description will be given assuming that the sensor calibration device 110 is realized by a single general-purpose computer device having one or more processors 111, one or more memories 112, one or more auxiliary storage devices 113, one or more communication interfaces (hereinafter also referred to as "communication I / F") 114, one or more input interfaces (hereinafter also referred to as "input I / F") 115, one or more output interfaces (hereinafter also referred to as "output I / F") 116, and wired or wireless communication lines connecting them.

[0040] The auxiliary storage device 113 is an auxiliary storage device made up of a nonvolatile storage element such as a flash memory. Specific examples of the auxiliary storage device 113 include a solid state drive (SSD) and a hard disk drive (HDD). The auxiliary storage device 113 stores at least a sensor calibration program (not shown). The sensor calibration program is a computer program for implementing functions required by the sensor calibration device 110. The auxiliary storage device 113 stores various computer programs including the sensor calibration program.

[0041] That is, when the sensor calibration program is executed by the processor 111, the functions of each functional unit of the sensor calibration device 110, such as a sensor data measurement unit 121, a map creation / position and orientation detection unit 122, a map evaluation unit 123, and a sensor parameter adjustment unit 124, which will be described later, are realized. In other words, by executing the sensor calibration program by the processor 111, various processes are performed, including a process for measuring sensor data acquired by the laser sensor 120 (hereinafter also referred to as "sensor data measurement process"), a process for simultaneously estimating the position of the laser sensor 120 and creating an environmental map for the laser sensor 120 (hereinafter also referred to as "SLAM (Simultaneous Localization and Mapping) process"), which will be described later in relation to Figures 5 to 9, a process for calculating the subsequent position and orientation of the laser sensor 120 using the first frame of the measurement data of the laser sensor 120 as the origin (hereinafter also referred to as "map creation / position and orientation detection process"), a process for evaluating the quality of the map data created by the map creation / position and orientation detection process (hereinafter also referred to as "map evaluation process"), and a process for optimizing the irradiation direction a of the laser light irradiated from the laser light source 21 and the orientation n of the mirror 22, which are adjustment parameters of the laser sensor 120, using the position and orientation calculated by the map creation / position and orientation detection process and the measurement data of the laser sensor 120 (hereinafter also referred to as "sensor parameter adjustment process").

[0042] The sensor calibration program is provided to the sensor calibration device 110 from various removable media such as a CD-ROM or a flash memory or via the network 50, and is stored in a non-volatile auxiliary storage device 113, which is a non-transitory storage medium. Therefore, it is preferable that the sensor calibration device 110 has an interface for reading data from the removable media.

[0043] The sensor calibration program may also be installed from a program source. The program source may be, for example, a program distribution computer or a computer-readable recording medium. The sensor calibration program may also be composed of a device driver, an operating system, various application programs located at higher layers than those, and a library that provides common functions to these programs. Furthermore, two or more programs may be realized as one sensor calibration program, or one sensor calibration program may be realized as two or more programs.

[0044] The memory 112 is a main storage device mainly made up of volatile storage elements such as RAM (Random Access Memory). The memory 112 also includes a ROM made up of nonvolatile storage elements. The ROM stores unchanging programs (e.g., BIOS) and the like. The memory 112 temporarily stores data representing various information read from the auxiliary storage device 113 and various data acquired via the communication interface 114 and / or the input interface 115.

[0045] The processor 111 is a processor device such as a CPU (Central Processing Unit) and various co-processors. The processor 111 loads various computer programs, including a sensor calibration program, into the memory 112 and executes them, thereby performing overall control of the sensor calibration device 110 itself and also managing the control unit 11 that performs various processes such as calculation processing and determination processing.

[0046] The interface device includes a communication interface 114 that controls a communication unit 14 described below, and an I / O (Input / Output) interface that includes an input interface 115 that controls an input unit 51 described below, and an output interface 116 that controls an output unit 61 described below.

[0047] The communication interface 114 is a network interface device that controls communication with the laser sensor 120 and other devices in accordance with a predetermined protocol.

[0048] The input interface 115 is an interface to which input devices such as a keyboard 151, a mouse 152, a touch panel, etc. are connected and which receives input from an operator.

[0049] The output interface 116 is an interface to which various display devices 161 such as a liquid crystal display or a touch screen, or an output device such as a printer (not shown), are connected, and which outputs the results of program execution in a format that can be viewed by an operator.

[0050] The sensor calibration device 110 may be an independent device or an embedded device.

[0051] (Example of functional block of sensor calibration device 110) Next, an example of various functional blocks included in the sensor calibration device 110 will be described with reference to Fig. 2. Note that each block described below does not represent a hardware configuration, but represents a functional block.

[0052] The sensor calibration device 110 is mainly composed of functional blocks: a control unit 11 realized by the aforementioned processor 111; a memory unit 13 realized by the aforementioned storage devices (112, 113); a communication unit 14 realized by the aforementioned communication interface 114; and a user interface unit 15 realized by the aforementioned input interface 115 and output interface 116.

[0053] The control unit 11 executes various data processing operations based on the programs and data stored in the storage unit 13 and the data acquired by the communication unit 14. The control unit 11 also functions as an interface between the storage unit 13 and the communication unit 14.

[0054] As shown in FIG. 2, the control unit 11 has the following functional blocks: a sensor data measurement unit 121, a map creation / position and orientation detection unit 122, a map evaluation unit 123, and a sensor parameter adjustment unit .

[0055] The sensor data measurement unit 121 executes a sensor data measurement process, the details of which will be described later with reference to FIGS.

[0056] The map creation and position / orientation detection unit 122 executes map creation and position / orientation detection processing, the details of which will be described later with reference to FIGS.

[0057] The map evaluation unit 123 executes a map evaluation process, the details of which will be described later with reference to FIGS.

[0058] The sensor parameter adjustment unit 124 executes a sensor parameter adjustment process, the details of which will be described later with reference to FIGS.

[0059] The control unit 11 is configured using a processor 111, and can realize these functional blocks by executing the above-mentioned sensor calibration program. Note that the control unit 11 may be configured using a logic circuit such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) instead of the processor 111. The control unit 11 may also be configured by combining the processor 111 and a logic circuit.

[0060] The storage unit 13 is configured using a storage device, for example, consisting of a memory 112 and an auxiliary storage device 113, and stores a program that supplies various processing instructions to the control unit 11, and data representing various information used in the processing executed by the control unit 11.

[0061] The control unit 11 can execute various processes by reading and writing these data to the storage unit 13.

[0062] The communication unit 14 is responsible for communication processing with other devices such as the laser sensor 120 and user terminals via the network 50. The communication unit 14 is configured using, for example, a NIC (Network Interface Card) or an HBA (Host Bus Adapter).

[0063] The user interface unit 15 includes the functional blocks of an input unit 51 and an output unit 61.

[0064] The input unit 51 is responsible for input-related processing, such as accepting input operations from the user, among other processes related to the user interface. The input unit 51 is configured using input devices such as a keyboard 151, a mouse 152, a touch panel, etc., and detects various operations from the user.

[0065] Among the processes related to the user interface, the output unit 61 is responsible for output-related processes such as displaying various screens on the display device 161 and outputting audio. The output unit 61 is configured using various display devices 161 such as a liquid crystal display or a touch screen.

[0066] It should be noted that the inclusion of the input unit 51 and / or the output unit 61 is not essential when, for example, remotely logging in to the sensor calibration device 110 from another external device such as a user terminal, or when receiving input information from an external device or providing output information to an external device via the communication interface 114. In this case, the sensor calibration device 110 may have a web server function and receive access from an external device using a predetermined protocol.

[0067] That is, each component of the sensor calibration device 110 is realized by hardware including a processor 111, storage devices such as a memory 112 and an auxiliary storage device 113, wired or wireless communication lines and interface devices (151, 152, 161) that connect them, and software stored in the storage devices (112, 113) that supplies processing instructions to the computing unit (processor 111).

[0068] The above description of the functions of the sensor calibration device 110 has been given assuming that each function of the sensor calibration device 110 is implemented integrally by a single computer. However, each function may be implemented by a plurality of interconnected computers and / or server devices. Furthermore, the sensor calibration device 110 may be configured to include a general-purpose computer such as a laptop PC and a web browser installed thereon, or may be configured to include a web server or various portable devices.

[0069] The sensor calibration device 110 is a computer system configured on one physical computer or on multiple logically or physically configured computers, and may operate on a virtual computer constructed on multiple physical computer resources. For example, functional units such as the sensor data measurement unit 121, map creation / position and orientation detection unit 122, map evaluation unit 123, and sensor parameter adjustment unit 124 may each operate on a separate physical or logical computer, or multiple units may be combined to operate on a single physical or logical computer.

[0070] Furthermore, the above description of each function is merely an example, and multiple functions may be combined into one function, or one function may be divided into multiple functions.

[0071] Furthermore, the sensor calibration device 110 may have other functions in addition to the above functions. For example, the sensor calibration device 110 may be configured to include some of the various functions of the laser sensor 120, as described above.

[0072] <Processing flow example> Next, the above-mentioned processes executed by the sensor calibration device 110 will be described with reference to FIGS.

[0073] (sensor calibration process) FIG. 5 is a flowchart 500 showing an example of the overall flow of the sensor calibration process executed by the sensor calibration device 110.

[0074] As described above, this sensor calibration process is executed by the sensor calibration device 110 to eliminate the angular error in the irradiation angle of the laser light of the laser sensor 120 by sufficiently converging it, and to appropriately adjust the irradiation angle of the laser light of the laser sensor 120.

[0075] In step S501, the control unit 11 of the sensor calibration device 110 causes the sensor data measurement unit 121 to execute sensor data measurement processing. As described above, this sensor data measurement processing is processing related to measuring sensor data acquired by the laser sensor 120. Specifically, as illustrated in FIG. 6, the sensor data measurement processing is performed by rotating the laser sensor 120 on the spot to acquire data for one revolution. Note that in the sensor data measurement processing, it is not necessary to measure the orientation of the laser sensor 120. This is because the orientation of the laser sensor 120 is detected and corrected in the map creation and position / orientation detection processing in step S502. Furthermore, with regard to the shape of the environment in which the sensor data is measured, although vertical walls are an essential constraint, measurement can be performed in environments of various shapes without considering other constraints. In this way, the sensor data is measured. Upon completing the processing in step S501, the control unit 11 of the sensor calibration device 110 proceeds to step S502.

[0076] In step S502, the control unit 11 of the sensor calibration device 110 executes map creation and position and orientation detection processing using the map creation and position and orientation detection unit 122. As described above, this map creation and position and orientation detection processing is processing for the laser sensor 120, that is, processing for simultaneously performing position estimation and environmental map creation, and calculating the subsequent position and orientation of the laser sensor 120 using the first frame of measurement data of the laser sensor 120 as the origin. Here, in the SLAM processing executed in step S502, as illustrated in FIG. 7, a problem occurs in that map data do not overlap each other due to the influence of angle error of the laser sensor 120 when generating environmental map data (hereinafter also simply referred to as "map data"). 7, the map creation and position / orientation detection unit 122 matches sensor data near 0 degrees and near 360 degrees, and measures an accurate angle error by calculating the angle error ratio α=B / A, where A is the angle of 360 degrees after map creation and B is the angle resulting from the matching of the map data between 0 degrees and 360 degrees. Then, the measured angle error is appropriately corrected, and this corrected map data is created. As a result of the map creation and position / orientation detection process in step S502, SLAM processing is executed for the laser sensor 120, and the subsequent position and orientation of the laser sensor 120 are calculated using the first frame of the measurement data of the laser sensor 120 as the origin. After completing the process in step S502, the control unit 11 of the sensor calibration device 110 proceeds to step S503.

[0077] In step S503, the control unit 11 of the sensor calibration device 110 causes the map evaluation unit 123 to execute map evaluation processing. As described above, this map evaluation processing is processing related to evaluating the quality of the map data created by the SLAM processing in step S502. Specifically, as illustrated in FIG. 8, the corrected map data is subjected to processing such as taking an average value in a specific direction to calculate an average map, and then the difference between the map before averaging and the average map is evaluated. In this way, the quality of the map data is evaluated. When the processing in step S503 is completed, the control unit 11 of the sensor calibration device 110 proceeds to step S504.

[0078] In step S504, the control unit 11 of the sensor calibration device 110 causes the sensor parameter adjustment unit 124 to execute a sensor parameter adjustment process. As described above, this sensor parameter adjustment process is a process related to optimization of the irradiation direction a of the laser light irradiated from the laser light source 21 and the orientation n of the mirror 22, which are adjustment parameters of the laser sensor 120, using the position and orientation calculated in the map creation and position and orientation detection process in step S502 and the measurement data of the laser sensor 120. Specifically, as illustrated in FIG. 9 , the irradiation direction a of the laser light and the orientation n of the mirror 22 are optimized by fixing the corrected angle and moving the irradiation direction a of the laser light and the orientation n of the mirror 22 so that the corrected map data approaches the average map. Note that both the irradiation direction a of the laser light and the orientation n of the mirror 22 are calculated based on data measured at various positions and orientations.

[0079] This sensor parameter adjustment process is performed using the following (Equation 1): As described above, a is the irradiation direction of the laser light emitted from the laser light source 21, and n is the orientation of the mirror 22.

[0080]

number

[0081] As a result, the irradiation direction a of the laser light irradiated from the laser light source 21 and the orientation n of the mirror 22, which are adjustment parameters of the laser sensor 120, are optimized using the position and orientation calculated by the map creation / position and orientation detection process in step S502 and the measurement data of the laser sensor 120. As a result, for example, a deviation between the actual irradiation direction a of the laser light irradiated from the laser light source 21 and the angle measured by the encoder is eliminated. Upon completing the process in step S504, the control unit 11 of the sensor calibration device 110 proceeds to step S505.

[0082] In step S505, the control unit 11 of the sensor calibration device 110 executes a process to determine whether the angular error in the irradiation angle of the laser beam from the laser sensor 120 has converged for the sensor data whose sensor parameters have been adjusted in step S504. If it is determined in step S505 that the angular error has not yet converged (step S505: No), the process returns to step S502 and executes the processes of steps S502 to S504 again to sufficiently converge the angular error in the irradiation angle of the laser beam from the laser sensor 120. This is because by repeatedly executing the processes of steps S502 to S504, the parameters can be optimized with high precision in the sensor parameter adjustment process of step S504. In this case, the processes of steps S502 to S504 are repeatedly executed until it is determined in step S505 that the angular error in the irradiation angle of the laser beam from the laser sensor 120 has converged (step S505: Yes). On the other hand, if it is determined in step S505 that the angular error in the laser light irradiation angle of the laser sensor 120 has converged (step S505: Yes), the control unit 11 of the sensor calibration device 110 terminates the sensor calibration process shown in the flowchart 500 of Figure 5.

[0083] In this way, the sensor calibration device 110 according to this embodiment calibrates the laser sensor 120 without using a jig or the like by executing in this order the sensor data measurement process, the map creation and position and orientation detection process, the map evaluation process, and the sensor parameter adjustment process, which respectively constitute steps S501 to S504 in the sensor calibration process illustrated in Fig. 5. As a result, the sensor calibration device 110 can accurately calibrate the laser sensor 120 mounted on the laser scanner in a form suited to the actual measurement target, without using a jig or the like, and can appropriately adjust the irradiation angle of the laser light from the laser sensor 120.

[0084] The above-described embodiment of the present invention can be summarized as follows.

[0085] (1) The sensor calibration device 110 is a device that performs a calibration process on the laser sensor 120, and includes a sensor data measurement unit 121 that measures sensor data acquired by the laser sensor 120, a map creation / position and orientation detection unit 122 that creates map data representing the environment around the laser sensor 120 and detects the position and orientation of the laser sensor 120, a map evaluation unit 123 that evaluates the quality of the created map data, and a sensor parameter adjustment unit 124 that adjusts sensor parameters of the laser sensor 120. As a result, the sensor calibration device 110 can accurately calibrate the laser sensor 120 mounted on a laser scanner in a manner suited to the actual measurement target, without using a jig or the like, and can appropriately adjust the irradiation angle of the laser light from the laser sensor 120.

[0086] (2) The calibration process is a process for appropriately adjusting the irradiation angle of the laser light from the laser sensor 120.

[0087] (3) The calibration process is a process that uses software processing to subsequently eliminate angle errors that represent errors in the irradiation angle when the laser sensor 120 irradiates laser light, which occur due to poor accuracy in the hardware aspects during the manufacturing of the laser sensor 120.

[0088] (4) The calibration process is performed in accordance with the actual measurement target and / or measurement environment without using a jig or the like.

[0089] (5) The map creation and position / orientation detection unit 122 estimates the position of the laser sensor 120 and creates map data simultaneously by SLAM (Simultaneous Localization and Mapping) processing.

[0090] (6) The map creation and position / orientation detection unit 122 calculates the subsequent position and orientation of the laser sensor 120, using the first frame of measurement data of the laser sensor 120 as the origin.

[0091] (7) The map creation and position / orientation detection unit 122 estimates the physical parameters of the laser sensor 120 based on the sensor data acquired while changing the position and / or orientation of the laser sensor 120, and calculates the actual irradiation direction a of the laser light.

[0092] (8) The sensor parameter adjustment unit 124 adjusts the sensor parameters of the laser sensor 120 by performing an optimization process on the sensor parameters.

[0093] (9) The sensor parameters include at least the irradiation direction a of the laser light emitted from the laser light source 21 of the laser sensor 120.

[0094] (10) The sensor parameters include at least the orientation n of the mirror 22 of the laser sensor 120.

[0095] The present invention is not limited to the above-described embodiment, and can be implemented using any components without departing from the spirit of the present invention.

[0096] Each of the above-described embodiments is merely an example, and the present invention is not limited to these details as long as the features of the invention are not impaired. Furthermore, although various embodiments have been described above, the present invention is not limited to these details, and not all of these details are necessarily essential to the solution of the present invention. Other aspects conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0097] In the above figures, the control lines and information lines shown are those that are considered necessary for explanation, and do not necessarily show all the control lines and information lines that are necessary for implementation. For example, it can be assumed that in reality, almost all components are interconnected.

[0098] Furthermore, the above-described layout of each functional unit of the sensor system 100, the sensor calibration device 110, the laser sensor 120, etc. is merely an example. The layout of each functional unit can be changed to an optimal layout in terms of the performance, processing efficiency, communication efficiency, etc. of the hardware and software included in the sensor system 100, the sensor calibration device 110, the laser sensor 120, etc.

[0099] Furthermore, the aforementioned configurations, functions, processing units, processing means, etc. may be realized in part or in whole by hardware, for example by designing them as integrated circuits, or may be realized in software by having processor 111 interpret and execute a program that realizes each function. [Explanation of symbols]

[0100] 100...Sensor system 110...sensor calibration device, 120...laser sensor

Claims

1. A sensor calibration device that performs a calibration process on a laser sensor, a sensor data measurement unit that measures sensor data acquired by the laser sensor; a map creation and position / orientation detection unit that creates map data representing the environment around the laser sensor and detects the position and orientation of the laser sensor; a map evaluation unit for evaluating the quality of the created map data; a sensor parameter adjustment unit that adjusts sensor parameters of the laser sensor; A sensor calibration device comprising:

2. 2. The sensor calibration device according to claim 1, The calibration process is a process of appropriately adjusting the irradiation angle of the laser light from the laser sensor.

3. 3. The sensor calibration device according to claim 2, The calibration process is a process of a sensor calibration device in which angle errors, which represent errors in the irradiation angle when the laser sensor irradiates laser light and which arise due to inaccuracies in the hardware surface during the manufacture of the laser sensor, are eliminated after the fact through software processing.

4. 2. The sensor calibration device according to claim 1, A sensor calibration device in which the calibration process is performed in a manner that is appropriate for the actual measurement target and / or measurement environment, without using a jig or the like.

5. 2. The sensor calibration device according to claim 1, The map creation / position and orientation detection unit is a sensor calibration device that simultaneously estimates the position of the laser sensor and creates the map data by SLAM (Simultaneous Localization and Mapping) processing.

6. 6. The sensor calibration device according to claim 5, The map creation and position / orientation detection unit calculates the subsequent position and orientation of the laser sensor using the first frame of measurement data of the laser sensor as the origin.

7. 3. The sensor calibration device according to claim 2, The map creation / position and orientation detection unit estimates the physical parameters of the laser sensor based on sensor data acquired while changing the position and / or orientation of the laser sensor, and calculates the actual irradiation direction of the laser light.

8. 2. The sensor calibration device according to claim 1, The sensor parameter adjustment unit adjusts the sensor parameters of the laser sensor by performing an optimization process on the sensor parameters.

9. 2. The sensor calibration device according to claim 1, The sensor parameters include at least an irradiation direction of a laser beam emitted from a laser light source of the laser sensor.

10. 2. The sensor calibration device according to claim 1, The sensor calibration device, wherein the sensor parameters include at least an orientation of a mirror of the laser sensor.

11. A sensor calibration method for performing a calibration process on a laser sensor, comprising: a computer having at least a processor and a storage device, a sensor data measurement unit that measures the sensor data acquired by the laser sensor; a map creation and position / orientation detection unit that creates map data representing the environment around the laser sensor and detects the position and orientation of the laser sensor; a map evaluation unit evaluating the quality of the created map data; The sensor parameter adjustment unit adjusts the sensor parameters of the laser sensor. Sensor calibration method.

12. a processor; Storage device and At least In a computer that performs a calibration process for a laser sensor, measuring sensor data acquired by the laser sensor; Creating map data representing the environment around the laser sensor and detecting the position and orientation of the laser sensor; Evaluating the quality of the generated map data; Adjust the sensor parameters of the laser sensor causing the computer to execute the steps of: Computer program.

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