Positioning system

Abstract

This technology provides a way to ensure positioning accuracy and robustness in positioning systems. [Solution] The positioning system for determining the position of a worker includes: an attitude sensor attached to the worker that detects a physical quantity related to changes in the worker's posture; an optical tracker device that optically detects a physical quantity representing the position of a tracker attached to the worker; and a positioning unit that determines the position of the worker by selectively using at least one of the detection results from the attitude sensor and the optical tracker device in a plurality of patterns.

Description

Technical Field

[0001] The present disclosure relates to a positioning system.

Background Art

[0002] Regarding a positioning system for positioning an operator, Patent Document 1 discloses a technique for recognizing an operation performed by an operator by using position coordinates of a body part of the operator acquired using a sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a positioning system for positioning an operator, a technique for ensuring positioning accuracy and positioning robustness is desired.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, a positioning system for positioning an operator is provided. This positioning system includes an attitude sensor that is attached to the operator and detects a physical quantity related to a change in the attitude of the operator, an optical tracker device that optically detects a physical quantity representing the position of a tracker attached to the operator, and a position specifying unit that selectively uses at least one of the detection results of the first detection result by the attitude sensor and the second detection result by the optical tracker device in a plurality of patterns to specify the position of the operator. In this configuration, the positioning system can ensure positioning accuracy and robustness by selectively using at least one of two detection results—a first detection result that is easily and reliably detected regardless of the worker's position, and a second detection result that accurately represents the tracker's position—to determine the worker's location. (2) In the above configuration, the positioning unit may selectively use at least one of the detection results in the plurality of patterns depending on the area where the worker is located. This configuration allows for the management of detection results used for positioning on an area-by-area basis while ensuring positioning accuracy and robustness in the positioning system. (3) In the above embodiment, the positioning unit may further include a receiving unit configured to receive the first detection result from the attitude sensor and the second detection result from the optical tracker device, and if only the first detection result is received by the receiving unit, the positioning unit may perform a first process to determine the worker's position using the first detection result and without using the second detection result, and if the receiving unit receives the first and second detection results which are temporally corresponding to each other, the positioning unit may perform a second process to determine the worker's position using the first and second detection results. According to this embodiment, depending on whether or not the second detection result is received, the first process which does not use the second detection result and the second process which uses the second detection result can be used in a timely manner, thereby further improving the positioning accuracy and robustness of the positioning system. Furthermore, since the first detection result is used as well as the second detection result in the second process, the position of a body part different from the body part to which the tracker is attached can be accurately determined as the position of the worker WK, thereby improving the convenience of the positioning system 10. (4) In the above embodiment, the positioning unit further identifies at least the position of the worker's feet as the position of the worker, the tracker is attached to the worker's head, and the second process is a process of identifying at least the position of the feet using the posture calculated using the first detection result and the position of the head represented by the second detection result. With this embodiment, it is possible to obtain a more accurate and useful positioning result while suppressing interference with the worker's work due to the attached tracker. (5) In the above configuration, if the position determination unit executes the first process immediately after the second process, it may determine the worker's position by using the worker's position determined in the immediately preceding second process as a reference position and calculating the displacement from the reference position using the first detection result. In this configuration, the first process can utilize the positioning result of the second process, which tends to be more accurate than that of the first process, while suppressing a decrease in positioning accuracy due to drift. As a result, the positioning accuracy in the first process can be effectively improved. This disclosure can be implemented in forms other than the positioning system described above, such as a location identification device, a positioning method, a program for implementing the positioning method, a non-temporary recording medium on which the program is recorded, or a program product. The program product may be provided, for example, as a recording medium on which the program is recorded, or as a program product that can be distributed via a network. [Brief explanation of the drawing]

[0007] [Figure 1] This is an explanatory diagram showing the schematic configuration of the positioning system in the first embodiment. [Figure 2] This is a flowchart of the location identification process in the first embodiment. [Figure 3] This figure illustrates an example of the location determination process in the first embodiment. [Figure 4] This is a flowchart of the location identification process in the second embodiment. [Figure 5]This figure illustrates an example of the location determination process in the second embodiment. [Modes for carrying out the invention]

[0008] A. First Embodiment: Figure 1 is an explanatory diagram showing the schematic configuration of the positioning system 10 in the first embodiment. The positioning system 10 is used to position a worker WK performing a task. The positioning system 10 is used at the workplace where the worker WK performs the task. In this embodiment, the workplace is a factory FC for manufacturing a vehicle VC. The tasks in this embodiment are various tasks for manufacturing the vehicle VC, and include, for example, the assembly of the vehicle VC, the installation of parts into the vehicle VC, and the inspection of the vehicle VC.

[0009] The positioning system 10 includes an attitude sensor 50, an optical tracker device 60, and a position determination device 100.

[0010] The posture sensor 50 is attached to the worker WK. In this embodiment, one posture sensor 50 is attached to the worker WK's head, left and right arms, chest, abdomen, and left and right legs. The posture sensor 50 is configured to detect physical quantities related to changes in the worker WK's posture. More specifically, the posture sensor 50 detects acceleration and angular velocity occurring in the worker WK as physical quantities related to changes in the worker WK's posture. In this embodiment, the posture sensor 50 is configured as an inertial measurement unit (IMU) equipped with a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis geomagnetic sensor. The current detection result by the posture sensor 50 is also called the "first detection result." The first detection result is associated with information indicating the timing at which the first detection result was detected. The posture sensor 50 transmits the detected first detection result to the positioning device 100.

[0011] The optical tracker device 60 comprises a tracker 61 and a base station 62. The optical tracker device 60 is configured to optically detect a physical quantity representing the position of the tracker 61 attached to the worker WK. In this embodiment, a single tracker 61 is attached to the worker WK. More specifically, in this embodiment, a single tracker 61 is attached to the head of the worker WK. The body part to which the tracker 61 is attached can be any part, but it is preferable that it be a body part that does not hinder work, such as the head. The detection result by the optical tracker device 60 is also called the second detection result. The second detection result is associated with information representing the timing at which the second detection result was detected.

[0012] The base station 62 is positioned in the factory FC near the area where worker WK performs work. In this embodiment, two base stations 62 are positioned in the factory FC. The base station 62 emits detection light at predetermined time intervals to detect the position of the tracker 61. The detection light scans within the irradiation range of the detection light. The detection light is, for example, an infrared laser. The tracker 61 has a light receiver composed of a photodiode or the like, and a communication device. The tracker 61 receives the detection light emitted from the base station 62, and when it receives the detection light, it transmits the received light information to the position identification device 100 as a second detection result. The received light information includes information representing the time from when the detection light from the base station 62 is received by the tracker 61. As a result, the position of the tracker 61 can be uniquely identified using the received light information. In this way, the received light information accurately represents the position of the tracker 61. As described above, the detection method using the base station 62 is also called the "Lighthouse method". In other embodiments, the optical tracker device 60 may optically detect physical quantities related to the position of the tracker 61 using methods other than the Lighthouse method.

[0013] The positioning device 100 is comprised of a computer comprising a processor 101, a memory 102, an input / output interface 103, and an internal bus 104. The processor 101, memory 102, and input / output interface 103 are connected via the internal bus 104 to enable bidirectional communication. A communication device 105 and a display device 106 are connected to the input / output interface 103. The communication device 105 can communicate with the attitude sensor 50 and the optical tracker device 60 by wired or wireless communication. In this embodiment, the communication device 105 corresponds to the "receiving unit" in this disclosure. The receiving unit is configured to receive a first detection result from the attitude sensor 50 and a second detection result from the optical tracker device 60. The display device 106 is comprised of, for example, a liquid crystal display and displays various information such as information related to the positioning results from the positioning system 10. Various information such as the program PG1 and the database DM is stored in the memory 102. The processor 101 executes the program PG1 to realize various functions, including those of a location identification unit 110, an area identification unit 115, a determination unit 120, and a processing unit 190.

[0014] The positioning unit 110 is configured to determine the location of worker WK by selectively using at least one of the detection results of the first detection result and the second detection result in a plurality of patterns. More specifically, the positioning unit 110 determines the location of worker WK using the detection result received by the communication device 105 as a receiving unit. In this embodiment, the positioning unit 110 selectively uses at least one of the detection results of the first detection result and the second detection result in a plurality of patterns depending on the area in which worker WK is located. The "plural patterns" here include two or more patterns from a first pattern that uses only the first detection result and does not use the second detection result, a second pattern that uses the second detection result and does not use the first detection result, and a third pattern that uses both the first and second detection results. In addition, in this disclosure, unless otherwise specified, "using the detection result" means using the "current detection result" in a timely manner. The "current detection result" means the detection result obtained at the time the positioning is performed, or at a time very close to that time. In this embodiment, the position identification unit 110 selectively uses the first pattern and the third pattern.

[0015] In this embodiment, the position identification unit 110 performs either a first process or a second process depending on the area where the worker WK is located. The first process is a positioning process that identifies the position of the worker WK using the first detection result and without using the second detection result. The second process is a positioning process that identifies the position of the worker WK using the first and second detection results. In the second process, the first and second detection results, which are temporally corresponding to each other, are used. In this embodiment, the position identification unit 110 identifies the positions of various body parts of the worker WK, including the joints, head, and feet, as the position of the worker WK. In this embodiment, the position of the feet identified by the position identification unit 110 is used as the current position of the worker WK. More specifically, the position of the midpoint of the line segment connecting the heels of both of the worker WK's feet is used as the current position of the worker WK. In other embodiments, the position of the worker WK may be identified as any body part of the worker WK, not limited to joints, head, or feet. In the following, the process of determining the position of worker WK, as in the first and second processes, will also be referred to as the "positioning process."

[0016] In the first process of this embodiment, the position determination unit 110 uses the reference position and the first detection result to determine the position of the worker WK based on the displacement from the reference position. More specifically, in the first process, the position determination unit 110 calculates the motion acceleration of the worker WK using the acceleration and posture detected by the posture sensor 50, for example, calculates the displacement from the reference position using the integral of the calculated motion acceleration, and determines the position of the worker WK based on the calculated displacement. More specifically, the displacement from the reference position is calculated by the second-order time integral of the motion acceleration. The posture of the worker WK is detected using the integral of the angular velocity, more specifically, using the integral value of the angular velocity and the acceleration. In the first process, if there is a previous position, the previous position is used as the reference position. The previous position is the position of the worker WK as the previous positioning result. The previous position may be the position as a result of positioning by the first process or the position as a result of positioning by the second process. If the first process is executed two or more times consecutively, the previous position is used cumulatively in each first process. If there is no previous position, a predetermined initial position is used as the reference position.

[0017] In addition, in the present embodiment, the position specifying unit 110 uses, as a reference position, the position of the feet of the worker WK, more specifically, the position of the midpoint of the line segment connecting the heels of both feet of the worker WK. Here, in the factory FC, the worker WK usually walks and moves with at least one of the left and right feet in contact with the ground. Therefore, when specifying the position of the worker WK based on the variation from the reference position as in the first process, by specifying the position of the feet of the worker WK as the reference position, for example, compared with the case of using the position of a body part that is likely to move regardless of walking, such as the head or wrist, as the reference position, the position of the worker WK can be specified more accurately. In addition, in the factory FC, the worker WK is likely to perform work with at least the position of one of the left and right feet fixed. Therefore, as described above, by using the position of the feet of the worker WK as the current position of the worker WK, subsequent processes by the processing unit 190 described later, for example, can be executed more appropriately. Thus, by specifying the position of the feet of the worker WK as the position of the worker WK, a more accurate and useful positioning result can be obtained.

[0018] In the second process in the present embodiment, the position specifying unit 110 specifies the position of the worker WK using the posture detected by the posture sensor 50 and the position of the tracker 61 detected by the optical tracker device 60. That is, in the present embodiment, in the second process, the position specifying unit 110 specifies the positions of the joints, head, and feet of the worker WK using the position of the head of the worker WK and the posture of the worker WK. In the second process, by using the first detection result and the second detection result in this way, it is possible to specify the position of a body part different from the body part on which the tracker 61 is mounted as the position of the worker WK. Note that in the second process, for example, the physical information of the worker WK stored in advance in the memory 102 may be used to specify the position of the worker WK. The physical information is information representing the physique of the worker WK, such as height and body width.

[0019] In the positioning process using the second detection result, like the second process, the position of the tracker 61 that can be obtained without being affected by drift is used. Also, unlike the first process, in the second process, the position of the operator WK is specified without integrating the operating acceleration, and the reference position is not used. As a result, in the positioning process using the second detection result, compared with the positioning process that does not use the second detection result like the first process, that is, the positioning process that uses the reference position, the influence of drift on the positioning result is suppressed, and the decrease in positioning accuracy is suppressed. However, the second detection result is more likely to be affected by disturbances such as obstacles that block the detection light depending on the position of the operator WK compared with the first detection result, and tends to have low robustness. Therefore, if only the positioning process using the second detection result is executed in the positioning system 10, the robustness of positioning in the positioning system 10 may decrease. Thus, in the present embodiment, by selectively using at least one of the first detection result and the second detection result, both positioning accuracy and the robustness of positioning are achieved. When the first process is executed immediately after the second process, in the first process immediately after the second process, the position of the operator WK specified in the immediately preceding second process is used as the reference position.

[0020] The area identification unit 115 identifies the area where the operator WK is located. The area identification unit 115 identifies, for example, the area where the operator WK is located using an external sensor (not shown) such as an area sensor or a camera installed in the factory FC. The external sensor is located outside the operator WK and is a sensor capable of identifying the area where the operator WK is present.

[0021] The determination unit 120 determines which of the first process and the second process to execute according to the area identified by the area identification unit 115. More specifically, the determination unit 120 refers to the database DM based on the identification information of the identified area to determine which of the first process and the second process to execute. In the database DM, the identification information of each area in the factory FC and the information representing either the first process or the second process are stored in association with each other.

[0022] The processing unit 190 performs subsequent processing using the positioning results from the positioning system 10. Subsequent processing is a process for utilizing the positioning results and includes, for example, analysis processing to analyze the positioning results and generation processing to generate a digital model based on the positioning results. In the analysis processing, the processing unit 190 analyzes, in real time or retrospectively, the appropriateness of the worker WK's state at the workplace and the appropriateness of their movement and work style by comparing, for example, the trajectory of the worker WK's movement based on the positioning results, i.e., the trajectory of the worker WK's current position, with a predetermined reference trajectory. Such analysis processing may be used, for example, for quality assurance of products produced at the workplace or for safety evaluation of work at the workplace. In addition, in the generation processing, the processing unit 190 may generate, for example, a digital model that reproduces the movement and work of the worker WK in a digital space that simulates a factory FC. The processing unit 190 may, for example, display the processing results from the subsequent processing on the display device 106. The subsequent processing may not be limited to the above.

[0023] Figure 2 is a flowchart of the location determination process. The location determination process may be performed by the processor 101 of the location determination device 100, for example, at predetermined time intervals, or at the time the first detection result is received by the communication device 105.

[0024] In step S100 of Figure 2, the area identification unit 115 identifies the area where worker WK is located. In step S105, the decision unit 120 decides whether to perform the first or second positioning process according to the area identified in step S100. In step S110, the location identification unit 110 identifies the location of worker WK by performing the positioning process determined in step S105. More specifically, in step S110, the location identification unit 110 either performs the first process using the latest first detection result received by the communication device 105, or performs the second process using the first and second detection results, which are temporally corresponding to each other and received by the communication device. Also in step S110, the location identification unit 110 records the location identified by the positioning process as a positioning result in the memory 102. In step S115, the location identification unit 110 outputs the positioning result. More specifically, in step S115, the positioning unit 110 displays the positioning result on the display device 106 or causes the processing unit 190 to execute subsequent processing.

[0025] Figure 3 illustrates an example of the position identification process in this embodiment. In Figure 3, a top view is shown of worker WK moving cyclically through positions P1, P2, P3, P4, P5, and P6 in that order. In the example in Figure 3, worker WK performs a series of tasks related to vehicle VC while moving through each position. In Figure 3, the trajectory of worker WK's movement is shown by a thick line. In the example in Figure 3, the first process is executed when worker WK is located in the first area AR1 and when worker WK is located in the third area AR3, and the second process is executed when worker WK is located in the second area AR2. In Figure 3, the first area AR1 is hatched with a dot pattern, and the second area AR2 is hatched with diagonal lines. Also in Figure 3, the boundary BD between the second area AR2 and the third area AR3 is shown by a dashed line.

[0026] In the example shown in Figure 3, the first area AR1 corresponds to the interior of the vehicle VC. The first area AR1 is located within the illumination range of the detection light from the base station 62. However, because the first area AR1 is an interior area, at least a portion of the first area AR1 becomes a blind spot in the illumination range of the detection light because the detection light is blocked by the vehicle body, such as the roof, pillars, and doors of the vehicle VC. In such blind spots, the second detection result cannot be detected, making it difficult to properly execute the second processing. Thus, the first area AR1 is an area where the second detection result is difficult to detect. Therefore, by executing the first processing when the worker WK is located in the first area AR1, it is possible to suppress the execution of the second processing in the first area AR1 where the second detection result is difficult to detect, and the worker WK can be positioned with higher accuracy.

[0027] In the example shown in Figure 3, the second area AR2 corresponds to the area outside the vehicle VC, relatively close to the vehicle VC. In a top view, the second area AR2 is positioned outside the first area AR1, surrounding it. The second area AR2 is located within the illumination range of the detection light. Furthermore, because the second area AR2 is an area outside the vehicle VC, each part within the second area AR2 is less likely to be a blind spot in the illumination range of the detection light. Thus, the second area AR2 is an area where the second detection result is more easily detected compared to the first area AR1. Therefore, by performing the second process when the worker WK is located in the second area AR2, for example, the influence of drift on the positioning result can be suppressed, and the worker WK can be positioned with higher accuracy compared to when the first process is performed in the second area AR2.

[0028] In the example shown in Figure 3, the third area AR3 corresponds to the area outside the vehicle VC, relatively far from the vehicle VC. In a top view, the third area AR3 is positioned outside the second area AR2, surrounding it. The third area AR3 is located outside the illumination range of the detection light. As a result, the second detection result is not detected in the third area AR3, making it difficult to properly execute the second process. Therefore, by executing the first process when the worker WK is located in the third area AR3, the worker WK can be positioned with higher accuracy.

[0029] As described above, the positioning system 10 in this embodiment determines the position of worker WK by selectively using at least one of the detection results: a first detection result that is easily and stably detected by the attitude sensor 50 regardless of the position of worker WK, and a second detection result that accurately represents the position of the tracker 61. This ensures positioning accuracy and robustness in the positioning system 10.

[0030] Furthermore, in this embodiment, at least one of the first detection result and the second detection result is selectively used for positioning depending on the area where the worker WK is located. Therefore, by using the appropriate detection result depending on the area where the worker WK is located, positioning accuracy and robustness of positioning can be ensured in the positioning system 10. In addition, in this embodiment, since the detection results used for positioning can be managed for each area, if an abnormality occurs in the positioning result by the positioning system 10, for example, it can be more easily identified whether the cause of the abnormality is the attitude sensor 50 or the optical tracker device 60.

[0031] Furthermore, in this embodiment, either the first process or the second process is executed depending on the area where the worker WK is located. As a result, if the worker WK is located in an area where the second detection result is difficult to detect, the first process can be executed to suppress a decrease in the robustness of positioning. On the other hand, if the worker WK is located in an area where the second detection result is easy to detect, the second process can be executed to position the worker WK with high accuracy.

[0032] Furthermore, in this embodiment, the position identification unit 110 identifies the position of worker WK in the second process using the first detection result and the second detection result. Therefore, in the second process, the position of a body part different from the body part to which the tracker 61 is attached can be identified as the position of worker WK, thereby improving the convenience of the positioning system 10. In particular, in this embodiment, in the second process, at least the position of worker WK's feet is identified using the posture of worker WK calculated using the first detection result and the position of worker WK's head represented by the second detection result. As a result, it is possible to obtain more accurate and useful positioning results while suppressing interference with the worker WK's work due to the attached tracker 61.

[0033] Furthermore, in this embodiment, when the position identification unit 110 executes the first process immediately after the second process, it uses the position of the worker WK identified in the preceding second process as a reference position and calculates the displacement from the reference position using the first detection result to identify the position of the worker WK. That is, as shown in Figure 3, at timing CH immediately after the positioning process switches from the second process to the first process, the positioning result of the preceding second process is used as the reference position for the first process. Therefore, in the first process, it is possible to utilize the positioning result of the second process, which tends to have higher accuracy than the first process, while suppressing the decrease in positioning accuracy caused by drift. As a result, the positioning accuracy in the first process can be effectively improved, and the positioning accuracy of the entire positioning system 10 can be effectively improved.

[0034] B. Second Embodiment: Figure 4 is a flowchart of the location determination process in the second embodiment. Unlike the first embodiment, in this embodiment, the location determination unit 110 executes either the first or second positioning process depending on whether or not the second detection result has been received by the communication device 105, which acts as a receiving unit, rather than depending on the area. In this embodiment, the processor 101 of the location determination device 100 does not need to function as the area determination unit 115 and the determination unit 120. Also, the database DM does not need to be stored in the memory 102. The configuration of the positioning system 10 and the location determination device 100 in the second embodiment is the same as in the first embodiment unless otherwise specified.

[0035] In step S200, the location identification unit 110 acquires the latest first detection result received by the communication device 105. In step S205, the location identification unit 110 determines whether a second detection result corresponding in time to the first detection result acquired in step S200 has been received by the communication device 105. If a second detection result has been received in step S205, the location identification unit 110 acquires that second detection result in step S210. In step S215, the location identification unit 110 executes a second process using the first detection result acquired in step S200 and the second detection result acquired in step S215. If a second detection result has not been received in step S205, the location identification unit 110 executes a first process in step S220 using the first detection result acquired in step S200. Step S225 is substantially the same as step S115 in Figure 2.

[0036] Figure 5 illustrates an example of the position determination process in the second embodiment. In the example of Figure 5, unlike the example in Figure 3, the process executed as the positioning process is switched between the first process and the second process depending on whether or not the second detection result has been received. For example, in the example of Figure 5, unlike the example in Figure 3, the first process is not continued while the worker WK moves from position P4 to P5, but rather the first process and the second process are switched as appropriate. In the second embodiment as well, the position determination unit 110, when executing the first process immediately after the second process, uses the position of the worker WK determined in the immediately preceding second process as a reference position, and determines the position of the worker WK by calculating the displacement from the reference position using the first detection result.

[0037] According to the second embodiment described above, if only the first detection result is received among the first and second detection results, the first process is executed, and if the first and second detection results, which are temporally corresponding to each other, are received, the second process is executed. Therefore, the first and second processes can be used more flexibly depending on whether or not the second detection result is received, thereby improving the positioning accuracy and robustness of the positioning system 10. In addition, since the first detection result is used in the second process as well as the second detection result, the convenience of the positioning system 10 can be improved, similar to the first embodiment. In particular, in this embodiment, in the second process, at least the position of the worker WK's feet is determined using the posture of the worker WK calculated using the first detection result and the position of the worker WK's head represented by the second detection result. As a result, it is possible to obtain a more accurate and useful positioning result while suppressing interference with the worker WK's work by the attached tracker 61.

[0038] In other embodiments, for example, a control in which positioning processing is determined for each area, as in the first embodiment, and a control in which positioning processing is determined depending on whether or not a second detection result has been received, as in the second embodiment, may be applied in combination. For example, in the examples in Figures 3 and 5, the positioning unit 110 may execute only the first processing of the two processing options in the second area AR2, and in the first area AR1, it may execute either the first or second positioning processing depending on whether or not a second detection result has been received.

[0039] C. Other embodiments: (C1) In each of the above embodiments, either the first process or the second process is performed, but is not limited to this. For example, either the first process or the third process may be performed. The third process identifies the position of worker WK using the second detection result and without using the first detection result. The third process may, for example, simply identify the position of worker WK using the position based on the second detection result, or it may identify the position of worker WK using the position based on the second detection result and predetermined posture information.

[0040] (C2) In each of the above embodiments, a single tracker 61 is attached to the worker WK. In contrast, two or more trackers 61 may be attached to the worker WK. When two or more trackers 61 are attached to the worker WK, the angular relationship between the trackers 61 can be detected from the positional relationship between the trackers 61. When two or more trackers 61 are attached to the worker WK, in the second process, the position determination unit 110 may determine the worker WK using the angular relationship between the trackers 61 in addition to, or instead of, the position of the trackers 61. More specifically, in this case, in the second process, the position determination unit 110 may, for example, use the angular relationship between the trackers 61 to correct the attitude calculated using the integral of the angular velocity detected by the attitude sensor 50, and then determine the worker WK using the corrected attitude. While the attitude calculated using the integral of angular velocity may be affected by drift, correcting the attitude using the angular relationship between the trackers 61 as described above can suppress the influence of such drift on the positioning results in the second processing. As a result, the worker WK can be positioned with higher accuracy in the second processing.

[0041] (C3) In each of the above embodiments, the positioning unit 110 may, for example, use at least one of the detection results of the first detection result and the second detection result depending on the time. More specifically, for example, when a work process including multiple tasks is repeatedly performed as one cycle, the positioning unit 110 may perform either the first process or the second process depending on the elapsed time from the start timing of the work in the cycle. In this case, it is preferable that each task included in the work process is a task whose work time does not vary easily due to factors such as the skill level of the worker WK or the external environment.

[0042] (C4) In each of the above embodiments, the positioning process identifies at least the position of the worker WK's feet, but the position of the feet does not need to be identified.

[0043] (C5) In each of the above embodiments, the position of worker WK identified in the preceding second process is used as the reference position in the first process immediately following the second process, but this is not limited to this. For example, the position of worker WK estimated using an external sensor such as a camera or an area sensor may be used as the reference position in the first process immediately following the second process.

[0044] (C6) In each of the above embodiments, factory FC is a manufacturing plant for vehicle VC, but is not limited to this. For example, factory FC may be an inspection plant for vehicle VC, or a manufacturing plant or inspection plant for various items other than vehicle VC. Furthermore, the positioning system 10 may be used not only at factory FC, but also at various workplaces where workers WK perform their work.

[0045] (C7) In each of the above embodiments, some or all of the functional units such as the position identification unit 110, area identification unit 115, determination unit 120, and processing unit 190 may be provided in an external device such as an external computer different from the position identification unit 110.

[0046] In each of the above embodiments, some or all of the functions and processes implemented in software may be implemented in hardware. Conversely, some or all of the functions and processes implemented in hardware may be implemented in software. As hardware for implementing the various functions in each of the above embodiments, various circuits such as integrated circuits and discrete circuits may be used.

[0047] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0048] 10...Positioning system, 50...Attitude sensor, 60...Optical tracker device, 61...Tracker, 62...Base station, 100...Location identification device, 101...Processor, 102...Memory, 103...Input / output interface, 104...Internal bus, 105...Communication device, 106...Display device, 110...Location identification unit, 115...Area identification unit, 120...Determination unit, 190...Processing unit

Claims

1. A positioning system for determining the location of workers, A posture sensor, which is attached to the worker and detects physical quantities related to changes in the worker's posture, An optical tracker device that optically detects a physical quantity representing the position of a tracker attached to the worker, A positioning system comprising: a positioning unit that identifies the position of the worker by selectively using at least one of the detection results from the attitude sensor and the optical tracker device in a plurality of patterns.

2. A positioning system according to claim 1, The positioning system includes a location identification unit that selectively uses at least one of the detection results in the plurality of patterns depending on the area where the worker is located.

3. A positioning system according to claim 1, further, The system includes a receiving unit configured to receive the first detection result from the attitude sensor and the second detection result from the optical tracker device, The aforementioned position identification unit is The detection results received by the receiving unit are used selectively in the plurality of patterns. If the receiving unit receives only the first detection result among the first and second detection results, it performs a first process to identify the worker's location using the first detection result and without using the second detection result. When the receiving unit receives the first detection result and the second detection result, which are temporally corresponding to each other, it performs a second process to determine the worker's position using the first detection result and the second detection result. Positioning system.

4. A positioning system according to claim 3, The position identification unit identifies at least the position of the worker's feet as the worker's position, The aforementioned tracker is attached to the worker's head, The positioning system is a process in which the second process determines the position of at least the feet using the posture calculated using the first detection result and the position of the head represented by the second detection result.

5. A positioning system according to claim 3 or 4, The positioning system includes a positioning unit that, when the first process is executed immediately after the second process, uses the position of the worker identified in the immediately preceding second process as a reference position and calculates the displacement from the reference position using the first detection result to determine the position of the worker.

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