Obstacle detection system and obstacle detection method

Abstract

To provide an obstacle detection system capable of improving accuracy of detecting an obstacle.SOLUTION: The obstacle detection system includes an object detection unit for detecting an object in a predetermined detection range in a traveling direction on a course, a positional deviation detection unit for detecting a positional deviation from a reference direction of the object detection unit with respect to the traveling direction, a setting unit for setting a warning range in the predetermined detection range based on the reference direction of the object detection unit, and a correction unit for correcting the warning range based on the positional deviation detected by the positional deviation detection unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an obstacle detection system and an obstacle detection method for detecting an obstacle. [Background technology]

[0002] Obstacle detection devices are typically attached to hard, sturdy objects such as automobiles and automated transport robots. Various proposals have been made regarding obstacle detection (see Patent Documents 1 to 13). Basically, the mounting position of an obstacle detection device remains constant after installation, and positional changes, such as height and tilt, of the obstacle detection device generally occur in conjunction with the body to which it is attached. Furthermore, when the position of the obstacle detection device changes, corrections are made to the obstacle detection process based on information about the positional change of the body to which it is attached. On the other hand, when an obstacle detection device is attached to an object with an unstable mounting position, such as a human body or a handheld device, the positional change of the obstacle detection device and the positional change of the body to which it is attached do not necessarily coincide. Therefore, even if a correction process is performed using information about the positional change of the body to which it is attached, the correction may be insufficient, resulting in a problem of reduced obstacle detection accuracy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 62-166809 [Patent Document 2] Japanese Patent Application Publication No. 2-196973 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-339595 [Patent Document 4] Japanese Patent Application Laid-Open No. 2003-279640 [Patent Document 5] International Publication No. 2005-046542 [Patent Document 6] Japanese Patent Application Laid-Open No. 2006-242650 [Patent Document 7] Japanese Patent Application Laid-Open No. 2006-305214 [Patent Document 8] Japanese Patent Application Laid-Open No. 2006-276595 [Patent Document 9] Japanese Patent Application Laid-Open No. 2008-099049 [Patent Document 10] Japanese Patent Application Laid-Open No. 2009-199583 [Patent Document 11] Japanese Patent Application Publication No. 2016-221022 [Patent Document 12] Patent Publication No. 2021-189800 [Patent Document 13] Japanese Patent Publication No. 2023-130545 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure has been made in view of the above, and aims to provide an obstacle detection system and an obstacle detection method that can improve the accuracy of obstacle detection. [Means for solving the problem]

[0005] The obstacle detection system of the present disclosure includes an object detection unit for detecting an object within a predetermined detection range in the direction of travel on a path, a position deviation detection unit for detecting a position deviation from a reference direction of the object detection unit relative to the direction of travel, a setting unit for setting a warning range within the predetermined detection range based on the reference direction of the object detection unit, and a correction unit for correcting the warning range based on the position deviation detected by the position deviation detection unit.

[0006] The obstacle detection method disclosed herein includes the steps of detecting an object within a predetermined detection range in the direction of travel on a path, detecting a positional deviation from a reference direction relative to the direction of travel, setting a warning range within the predetermined detection range based on the reference direction, and correcting the warning range based on the detected positional deviation. [Effects of the Invention]

[0007] According to the obstacle detection system and obstacle detection method of the present disclosure, it is possible to improve the accuracy of obstacle detection. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an overview of an obstacle detection system 1 according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating a functional block configuration of an obstacle detection system 1 according to a first embodiment. [Figure 3] FIG. 2 is a diagram illustrating a layout of a sensor array 30 according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating a reference direction of an object detection unit according to the first embodiment. [Figure 5] FIG. 4 is a diagram illustrating a horizontal detection range of an object detection unit according to the first embodiment. [Figure 6] FIG. 4 is a diagram illustrating a detection range in the vertical direction of an object detection unit according to the first embodiment. [Figure 7] 10A to 10C are diagrams illustrating horizontal correction of a warning range according to the first embodiment. [Figure 8] 10A to 10C are diagrams illustrating correction of the warning range in the vertical direction according to the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating correction of each point in the warning range according to the first embodiment. [Figure 10] 10A to 10C are diagrams illustrating specific examples of warnings according to the first embodiment and a comparative example. [Figure 11] 10A to 10C are diagrams illustrating a specific example of a warning when the warning range according to the first embodiment is corrected in the vertical direction. [Figure 12] 10A to 10C are diagrams illustrating a specific example of a warning when the warning range according to the first embodiment is corrected in the horizontal direction. [Figure 13] FIG. 4 is a diagram illustrating the relationship of distance between a user and an obstacle according to the first embodiment. [Figure 14]5A to 5C are diagrams illustrating the relationship between transmitted waves and received waves of the sensor array 30 according to the first embodiment. [Figure 15] FIG. 10 is a flowchart illustrating correction of a warning range according to the first embodiment. [Figure 16] FIG. 10 is a flowchart illustrating notification of warning information according to the first embodiment. [Figure 17] FIG. 10 is a diagram illustrating adjustment of a warning range according to the second embodiment. [Figure 18] 11A and 11B are diagrams illustrating an example in which ultrasonic sensors are provided as periphery detection units in periphery directions other than the traveling direction according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and their description will not be repeated in principle.

[0010] Embodiment 1 1 is a diagram illustrating an overview of an obstacle detection system 1 according to the first embodiment. Referring to FIG. 1, the obstacle detection system 1 includes a main body 10 and a control unit 100.

[0011] The main body 10 is attached to a hat, helmet, hair band, goggles, eyeglasses, necklace, belt, or the like worn by the user. The main body 10 includes an inertial sensor 12, an output unit 20, a sensor array 30, and a communication interface unit 40. The control unit 100 is connected to the main body 10 via the communication interface unit 40 via a wired or wireless connection so as to be communicatively connected. For example, the control unit 100 may be a smartphone or a tablet. Note that, in this example, a configuration in which the main body 10 and the control unit 100 are provided as separate entities will be described, but the present invention is not limited to this configuration and they may be provided as a single device.

[0012] Fig. 2 is a diagram illustrating a functional block configuration of obstacle detection system 1 according to the first embodiment. Referring to Fig. 2, inertial sensor 12, which is a position deviation detection unit, includes angular velocity sensor (gyro sensor) 14 and acceleration sensor 16. Angular velocity sensor (gyro sensor) 14 is used to detect a position deviation from a reference direction with respect to the traveling direction. Acceleration sensor 16 detects a change in the moving speed of an object.

[0013] The output unit 20 includes a buzzer or speaker 22 and a vibrator 24. When an obstacle is detected, warning information is issued from the buzzer or speaker 22. The vibrator 24 has a vibration function and issues the warning information using this vibration function. The buzzer or speaker 22 may be replaced by a wireless earphone or a wireless headphone.

[0014] The sensor array 30, which is an object detection unit, includes a plurality of ultrasonic sensors 32, 34 arranged in an array for detecting objects within a predetermined detection range in the traveling direction on the course. The ultrasonic sensor 34 is an ultrasonic sensor for transmitting, and outputs ultrasonic waves. The ultrasonic sensor 32 is an ultrasonic sensor for receiving, and receives, as received waves, waves reflected from the ultrasonic waves output from the ultrasonic sensor 34. By arranging a plurality of ultrasonic sensors, the sensor array 30 can receive reflected waves from objects as received waves and identify the position of the object (a three-dimensional position relative to the sensor array 30) based on a combination of the received waves.

[0015] The control unit 100 includes an input interface unit 110, a storage unit 120, a CPU 130, and a communication interface unit 140. The CPU (Central Processing Unit) 130 executes programs stored in the storage unit 120 to realize various functional blocks.

[0016] The input interface unit 110 is a keyboard, mouse, touch panel, etc. (not shown) that are provided so that an administrator or user can operate and input data.

[0017] The storage unit 120 stores various parameters, setting information, and various programs used in the obstacle detection system 1. In this example, the storage unit 120 includes warning range information 122 for setting a warning range, information about the reference position of the sensor array 30, and various information 124 about the detection range and threshold value.

[0018] The communication interface unit 140 executes communication processing with the communication interface unit 40 of the main body unit 10 via wired or wireless communication, thereby enabling data exchange.

[0019] The CPU 130 includes a plurality of functional blocks. Specifically, the CPU 130 includes a positional deviation calculation unit 131, a setting unit 132, a correction unit 133, a setting registration unit 134, a determination unit 135, a notification unit 136, a measurement unit 137, an adjustment unit 138, and a positional deviation determination unit 139.

[0020] The positional deviation calculation unit 131 calculates the positional deviation of the sensor array 30 from the reference direction of the sensor array 30 relative to the moving direction of the user based on information from the inertial sensor 12 .

[0021] The setting unit 132 sets a warning range within a predetermined detection range based on the reference direction of the sensor array 30 .

[0022] The correction unit 133 corrects the warning range based on the positional deviation calculated by the positional deviation calculation unit 131.

[0023] The setting registration unit 134 registers in the storage unit 120 various data input via the input interface unit 110 in order for the setting unit 132 to set a warning range. As an example, the setting registration unit 134 receives values ​​of the user's height and shoulder width input via the input interface unit 110 and stores them in the storage unit 120 as warning range information 122. Note that the information in the storage unit 120 may be obtained from an external server.

[0024] The determination unit 135 determines whether or not to issue a warning for an object in the warning range set by the setting unit 132.

[0025] The notification unit 136 notifies warning information based on the determination result of the determination unit 135. The measurement unit 137 measures the traveling speed of the object detection unit based on information from the inertial sensor 12.

[0026] The adjustment unit 138 adjusts the warning range based on the measurement result of the measurement unit 137. The positional deviation determination unit 139 determines whether the positional deviation calculated by the positional deviation calculation unit 131 exceeds a predetermined value, and if it exceeds the predetermined value, instructs the notification unit 136 to output guidance information. The notification unit 136 notifies the guidance information in accordance with the instruction.

[0027] FIG. 3 is a diagram illustrating the layout of the sensor array 30 according to the first embodiment. Referring to FIG. 3A, this example illustrates an example in which nine ultrasonic sensors are arranged in an array. For example, ultrasonic waves are transmitted from the central ultrasonic sensor 34, and the remaining eight ultrasonic sensors 32 receive reflected waves from the object as received waves, thereby identifying the object's position (three-dimensional position relative to the sensor array 30). Referring to FIG. 3B, the inertial sensor 12 and the sensor array 30 may be arranged side by side on a substrate. Referring to FIG. 3C, an example in which the ultrasonic sensor is arranged on the front side of the substrate and the inertial sensor 12 is arranged on the back side of the substrate is illustrated. Referring to FIG. 3D, a two-tiered substrate may be provided, with the sensor array 30 arranged on the upper substrate and the inertial sensor 12 on the lower substrate. By integrating the ultrasonic sensor and the inertial sensor 12, the relative positions of the sensors are maintained constant, enabling stable operation. This configuration allows the sensor array 30 and the inertial sensor 12 to be efficiently attached to a hat, helmet, or the like. Alternatively, a small and lightweight MEMS (Micro Electro Mechanical Systems) ultrasonic sensor may be used.

[0028] 4 is a diagram illustrating the reference direction of the object detection unit according to the first embodiment. Referring to FIG. 4, this example shows a case where the traveling direction and the reference direction coincide with each other. For simplicity of explanation, this example assumes that when a cap or helmet is worn in the reference position, the vertical direction of the array surface is preset to be oriented in the same direction as the traveling direction of the user.

[0029] The reference direction is set such that the array surface of the sensor array 30 is used as the reference plane, with the direction perpendicular to this reference plane being the Y axis, the vertical direction perpendicular to the Y axis and extending up and down relative to the user being the Z axis, and the horizontal direction perpendicular to the Y axis and extending left and right relative to the user being the X axis.

[0030] 5 is a diagram illustrating the horizontal detection range of the object detection unit according to the first embodiment. Referring to FIG. 5, in this example, the detection range AR of the sensor array 30 in the XY plane is shown with reference to a reference direction. Note that the reference direction and the traveling direction coincide with each other. Specifically, the sensor array 30 has a sector-shaped detection range AR with a predetermined angle in the horizontal direction.

[0031] In this example, a warning area PA is set within the detection area AR. Specifically, the warning area PA is set as a 3D cubic shape, for example. Specifically, the warning area PA is set as a cubic shape with upper points P1 to P4 and lower points Q1 to Q4. The width D in the X direction and the length L in the Y direction of the warning area PA are shown. The width D is set as the value of the shoulder width + α, where α is a preset buffer value. The length L is preset to a distance shorter than the maximum distance of the detection area of ​​the sensor array 30.

[0032] 6 is a diagram illustrating the vertical detection range of the object detection unit according to the first embodiment. Referring to FIG. 6, in this example, the detection range AR of sensor array 30 in the ZY plane is shown with reference to a reference direction. Note that the reference direction and the traveling direction coincide with each other. Specifically, sensor array 30 has a sector-shaped detection range AR with a predetermined angle in the vertical direction.

[0033] In this example, a warning area PA is set within the detection area AR. Specifically, the warning area PA is set as a 3D cubic shape, for example. Specifically, the warning area PA is set as a cubic shape with upper points P1 to P4 and lower points Q1 to Q4. The height H in the Z direction and the length L in the Y direction of the warning area PA are shown. The height H is set as the value of height + β, where β is a preset buffer value. The length L is preset to a distance shorter than the maximum distance of the detection area of ​​the sensor array 30. Therefore, the warning area PA is set as a three-dimensional area having predetermined detection ranges in both the horizontal and vertical directions.

[0034] In this example, the warning area PA is set in a 3D cubic shape, but the shape is not limited to this and may be spherical. The distance of the detection area is set in advance based on the sensitivity and performance of the ultrasonic sensors. In addition, the predetermined angle is set in advance based on the number of ultrasonic sensors arranged in the sensor array 30, etc., in accordance with the field of view of each ultrasonic sensor. In this example, the detection area is set in advance, but the detection area may be adjusted to an appropriate range by calibration of the ultrasonic sensors in the sensor array 30, etc.

[0035] The warning range PA (length L, width D, height H) is set based on warning range information 122 stored in advance in storage unit 120.

[0036] 7 is a diagram illustrating horizontal correction of the warning area according to the first embodiment. Referring to FIG. 7, this example describes a case where the vertical direction of the array surface of sensor array 30 (the front direction of the device), which is the reference direction of the object detection unit attached to a hat, helmet, or the like, is misaligned with the user's traveling direction in the horizontal direction. Here, a case where a positional deviation θh occurs in the horizontal direction is illustrated. The warning area PA is set in a state inclined with respect to the traveling direction in accordance with the positional deviation θh.

[0037] In this example, the warning range is corrected when there is a positional deviation θh between the reference direction and the traveling direction in the horizontal direction. Specifically, the warning range PA is corrected along the traveling direction by the amount of the positional deviation θh with respect to the traveling direction to set the warning range PAh. In this example, a case is shown in which the warning range PAh is set by correcting points P1-P4 and points Q1-Q4 to new points P1h-P4h and points Q1h-Q4h by the positional deviation θh.

[0038] 8 is a diagram illustrating vertical correction of the warning area according to the first embodiment. With reference to FIG. 8, in this example, a case will be described in which the vertical direction of the array surface of sensor array 30 (the front direction of the device), which is the reference direction of the object detection unit attached to a hat, helmet, or the like, is misaligned with the user's traveling direction in the vertical direction. Here, a case is shown in which a positional deviation θv occurs in the vertical direction. The warning area PA is set in a state inclined with respect to the traveling direction in accordance with the positional deviation θv.

[0039] In this example, the warning range is corrected when a positional deviation θv occurs between the reference direction and the direction perpendicular to the traveling direction. Specifically, the warning range PA is corrected along the traveling direction by the amount of the positional deviation θv with respect to the traveling direction to set the warning range PAv. In this example, the warning range PAv is set by correcting points P1-P4 and points Q1-Q4 to new points P1v-P4v and points Q1v-Q4v by the positional deviation θv.

[0040] FIG. 9 is a diagram illustrating correction of each point in the warning range according to the first embodiment. 9(A), for example, the coordinates (x, y) of point P1 before correction are corrected to point P1h (xh, yh) in accordance with the horizontal positional deviation θh. Specifically, a position rotated by θh from point P1 using a rotation matrix is ​​set as point P1h. The other points P2 to P4 are similarly corrected to set points P2h to P4h in the horizontal direction. Note that points Q1 to Q4 are also similarly set as points Q1h to Q4h. This sets the warning range ARh.

[0041] 9(B), for example, the coordinates (y, z) of point P1 before correction are corrected to point P1v (yv, zv) according to the vertical positional deviation θv. Specifically, a position rotated by θv from point P1 using a rotation matrix is ​​set as point P1v. The other points P2 to P4 are corrected in the same way to set points P2v to P4v in the vertical direction. Note that points Q1v to Q4 are also set in the same way. This sets the warning range ARv.

[0042] Although the above description is directed to a case where the reference direction is misaligned with the direction of travel in the horizontal or vertical direction, the present invention is equally applicable to a case where misalignment occurs in both the horizontal and vertical directions.

[0043] FIG. 10 is a diagram illustrating a specific example of an alarm according to the first embodiment and a comparative example. FIG. 10A is a diagram illustrating a conventional warning range as a comparative example.

[0044] Conventionally, the detection range AR detected by the object detection unit and the warning range were set to the same range, and an alarm was issued whenever an obstacle was detected within the detection range. In other words, in this case, an alarm was issued even for objects that were not in a position that would pose an obstacle to the user.

[0045] 10B is a diagram illustrating a warning range according to the first embodiment. FIG. In the first embodiment, the warning range PA is set in the vertical direction of the detection range AR, so that it is possible to set it so that no warning is issued even if an obstacle is located at a position higher than the user's height.

[0046] Referring to FIG. 10(C), a conventional warning range is described as a comparative example. Conventionally, the detection range AR detected by the object detection unit and the warning range were set to the same range, and an alarm was issued whenever an obstacle was detected within the detection range. In other words, in this case, an alarm was issued even for objects that were not in a position that would pose an obstacle to the user.

[0047] 10(D) shows a diagram illustrating a warning range according to the first embodiment. FIG. In the first embodiment, the warning range PA is set in the horizontal direction of the detection range AR, so it is possible to set it so that an alarm is not issued even if an obstacle is located at a position more than shoulder width away from the user.

[0048] FIG. 11 is a diagram illustrating a specific example of a warning when the warning range according to the first embodiment is corrected in the vertical direction.

[0049] 11(A) shows a case where the vertical direction of the array surface of the sensor array 30 (the front direction of the device), which is the reference direction of the object detection unit according to the first embodiment, is shifted vertically from the user's traveling direction. In this case, the warning range may also be shifted vertically. Therefore, due to the shift in the warning range, an obstacle that was not originally intended may be detected and an alarm may be issued.

[0050] Referring to Figure 11(B), in this example, by correcting the warning range PA to the warning range PAv as described in Figure 8, it is possible to appropriately issue an alarm to an obstacle that is aligned with the user's traveling direction.

[0051] FIG. 12 is a diagram illustrating a specific example of a warning when the warning range according to the first embodiment is corrected in the horizontal direction.

[0052] 12(A) shows a case where the vertical direction of the array surface of sensor array 30 (the front direction of the device), which is the reference direction of the object detection unit according to the first embodiment, is misaligned horizontally with the direction of travel of the user. In this case, the warning range may also be misaligned horizontally.

[0053] Therefore, there is a possibility that an obstacle in the traveling direction will not be detected due to a deviation in the warning range.

[0054] Referring to Figure 12(B), in this example, by correcting the warning range PA to the warning range PAh as described in Figure 7, it is possible to appropriately issue an alarm to an obstacle that is aligned with the user's direction of travel.

[0055] 13A and 13B are diagrams illustrating the relationship between the distance between the user and an obstacle according to the first embodiment. Referring to Fig. 13A, a case is shown in which an obstacle OBJ is detected in a warning range PA. Referring to Fig. 13B, a case is shown in which the distance between the obstacle OBJ and the user becomes even shorter in the warning range PA.

[0056] FIG. 14 is a diagram illustrating the relationship between the transmitted wave and the received wave of the sensor array 30 according to the first embodiment.

[0057] Referring to FIG. 14(A), the sensor array 30 outputs a transmission wave and detects the distance to an object based on the time from when the transmission wave is output until when the received wave, which is a reflected wave, is received.

[0058] 13(A), a case is shown in which a transmission wave is output and the sensor array 30 receives a reception wave from an obstacle OBJ in response to the transmission wave. Furthermore, a case is shown in which the sensor array 30 also receives a reception wave from the ground in addition to the obstacle OBJ.

[0059] Referring to FIG. 14(B), sensor array 30 outputs a transmission wave and detects the distance to an object based on the time from when the transmission wave is output until when a received wave, which is a reflected wave, is received.

[0060] 13(B), a transmission wave is output and the sensor array 30 receives a reception wave from an obstacle OBJ in response to the transmission wave. As the distance to the obstacle OBJ decreases, the time it takes to follow the reception wave from the obstacle becomes shorter.

[0061] On the other hand, the state of the received waves from the ground other than the obstacle OBJ does not change. Therefore, it is possible to remove the received waves from objects (ground) whose distance does not change based on whether or not the distance changes, and to issue an alarm in accordance with the received waves from objects (obstacles) whose distance changes. Note that in this example, a case has been described in which the state of the received waves from the ground does not change, but the same can be applied to received waves from the ceiling.

[0062] FIG. 15 is a flowchart illustrating correction of the warning range according to the first embodiment. 15, setting unit 132 sets a warning range in a predetermined detection range based on the reference direction of sensor array 30, based on warning range information 122 (step S2). Specifically, warning range PA, which is a 3D cubic shape with length L, width D, and height H, is set based on the reference direction in accordance with the method described in FIGS. 5 and 6.

[0063] Next, the positional deviation calculation unit 131 acquires information from the inertial sensor 12, which is a positional deviation detection unit, via the communication interface unit 40 (step S4). Next, the positional deviation calculation unit 131 calculates the positional deviation between the reference direction of the sensor array 30 and the traveling direction of the user based on the information from the inertial sensor 12 (step S6). Specifically, based on the information from the angle sensor 14 of the inertial sensor 12, the positional deviation calculation unit 131 calculates the positional deviations θh and θv between the traveling direction and the reference direction, which are set so that the direction perpendicular to the reference plane of the sensor array 30 is the Y axis, the vertical direction perpendicular to the Y axis and extending up and down with respect to the user is the Z axis, and the horizontal direction perpendicular to the Y axis and extending left and right with respect to the user is the X axis.

[0064] Next, the positional deviation determination unit 139 determines whether the positional deviation calculated by the positional deviation calculation unit 131 is within a predetermined value (step S8).

[0065] In step S8, if it is determined that the positional deviation is within a predetermined value (YES in step S8), positional deviation determination unit 139 instructs correction unit 133 to correct the warning range (step S10). Specifically, correction unit 133 corrects the warning range PA along the traveling direction based on positional deviations θh and θv in accordance with the method described with reference to FIGS.

[0066] Next, the correction unit 133 determines whether the process is to be completed (step S12). In step S12, if the correction unit 133 determines that the process is not to be completed (NO in step S12), the process returns to step S4 and the above correction process is repeated.

[0067] On the other hand, in step S12, if it is determined that the processing is to be ended (YES in step S12), the correction unit 133 ends the processing (END). For example, if the power is turned off, it may be determined that the processing is to be ended.

[0068] Furthermore, in step S8, if it is determined that the positional deviation is not within the predetermined value (NO in step S8), positional deviation determination unit 139 instructs notification unit 136 to output guidance information. Notification unit 136 notifies the guidance information via output unit 20 in accordance with the instruction. Then, the process proceeds to step S12. Subsequent processes are similar.

[0069] When the positional deviation is not within the predetermined value, it means that the warning range cannot be corrected within the detection range.

[0070] For example, if the reference direction of the main unit 10 attached to a hat, helmet, or the like worn by a user is significantly offset from the traveling direction, the detection range itself is significantly offset, making it impossible to correct the warning range along the traveling direction. In such cases, it is possible to provide guidance information to the user to align the hat or helmet in the correct direction. Specifically, the output unit 20 may provide guidance information to return the hat or helmet to the reference position using the positional deviations θh and θv. For example, a speaker may be used to provide messages such as "Please move θh to the left" or "Please move θv downward." Alternatively, the guidance information may be provided by using a buzzer to sound an error or by using the vibrator 24 to vibrate, or a combination of these may be used.

[0071] The obstacle detection system according to the first embodiment can improve the accuracy of obstacle detection because the warning range is constantly corrected based on information from the position deviation detection unit.

[0072] Furthermore, if the user's traveling direction is not significantly different from the reference direction of the main unit 10, the warning range is automatically corrected along the traveling direction, which is convenient for the user. Furthermore, if the user's traveling direction is significantly different from the reference direction of the main unit 10, guidance information is output to prompt the user to return to the correct position, thereby improving the accuracy of obstacle detection.

[0073] FIG. 16 is a flowchart illustrating notification of warning information according to the first embodiment. 16, sensor array 30, which is an object detection unit, outputs ultrasonic waves at a predetermined cycle (step S30). Sensor array 30 also receives reflected waves as received waves and outputs them to determination unit 135.

[0074] The determination unit 135 determines whether or not there is a received wave that is equal to or greater than a predetermined threshold value among the received waves output from the sensor array 30 (step S32). The threshold value can be determined using the various information 124 in the storage unit 120.

[0075] In step S32, if the determination unit 135 determines that there is no received wave equal to or greater than the predetermined threshold value (NO in step S32), the process returns to step S30 and the above processing is repeated.

[0076] On the other hand, if it is determined in step S32 that there is a received wave equal to or greater than the predetermined threshold value (YES in step S32), determination unit 135 determines whether or not the received wave is within the warning range (step S34). Specifically, determination unit 135 determines whether or not the received wave is from an object within the warning range corrected by correction unit 133. Specifically, it determines whether or not the received wave is from an object within the warning range corrected as described with reference to FIGS. 11 and 12.

[0077] Next, in step S34, if the determination unit 135 determines that the received wave is within the warning range (YES in step S34), it determines whether the received wave is a reflected wave from somewhere other than the ground or ceiling (step S36). Specifically, as explained in Fig. 14, if the distance of the received wave does not change, it can be determined that the received wave is a reflected wave from the ground or ceiling. On the other hand, if the distance of the received wave changes, it can be determined that the received wave is from an obstacle other than a reflected wave from the ground or ceiling.

[0078] In step S36, if the determination unit 135 determines that the received wave is a reflected wave from somewhere other than the ground or the ceiling (YES in step S36), it outputs warning information (step S38). Specifically, the determination unit 135 instructs the notification unit 136 to output the warning information from the notification unit 136 via the output unit 20. Specifically, the warning information may be a message such as "Danger!" that is output using a speaker. Alternatively, the warning information may be output by at least one of a warning sound using a buzzer or vibration using the vibrator 24, or a combination of these may be used.

[0079] Then, the determination unit 135 determines whether or not to end the process (step S40). In step S40, if the determination unit 135 determines not to end the process (NO in step S40), the process returns to step S30 and the above process is repeated.

[0080] On the other hand, in step S40, when the determination unit 135 determines that the processing should be ended (YES in step S40), the processing is ended (END). For example, when the power is turned off, it may be determined that the processing should be ended.

[0081] On the other hand, in step S34, if the determination unit 135 determines that the received wave is not within the warning range (NO in step S34), the process returns to step S30 and the above processing is repeated.

[0082] On the other hand, in step S36, if the determination unit 135 determines that the wave is a reflected wave from the ground or the ceiling (NO in step S36), the process returns to step S30 and the above processing is repeated.

[0083] The obstacle detection system according to the first embodiment can appropriately issue warning information when an obstacle is detected within the warning range. If the reference direction of the main body 10 and the traveling direction do not deviate significantly, the warning range is automatically corrected along the traveling direction, and if there is an obstacle in the traveling direction, warning information is appropriately issued, which is convenient for the user.

[0084] Embodiment 2 FIG. 17 is a diagram illustrating adjustment of the warning range according to the second embodiment.

[0085] Referring to FIG. 17(A), a case is shown in which the user is walking in the direction of travel.

[0086] Referring to FIG. 17(B), a case is shown in which the user is running and moving in the forward direction.

[0087] In this example, the warning range is adjusted according to the user's moving speed. Specifically, the inertial sensor 12 includes an acceleration sensor 16. Therefore, it is possible to measure the moving speed of the main body 10 based on information from the acceleration sensor 16.

[0088] The measuring unit 137 measures the moving speed of the main body unit 10 based on information from the acceleration sensor 16 of the inertial sensor 12 .

[0089] The adjustment unit 138 adjusts the warning range in accordance with the movement speed of the main body unit 10, which is the measurement result of the measurement unit 137. Specifically, if the movement speed of the main body unit 10 is fast, the length L of the warning range is increased. As a result, if the user's movement speed is fast, the length L of the warning range is set to be long, so that the presence of an obstacle can be notified at an appropriate timing so that the user does not come into contact with the obstacle.

[0090] On the other hand, the length L of the warning range may be shortened when the moving speed of the main body 10 is slow. In this way, when the moving speed of the user is slow, the length L of the warning range is set to be short, so that the warning can be given at an appropriate timing to prevent the user from coming into contact with an obstacle.

[0091] In this example, a method for adjusting the length L of the warning range in accordance with the moving speed has been described, but the width D or height H, which is limited to the length L, may also be adjusted according to the situation. For example, the width D and height H of the warning range may be increased when the moving speed is fast, and may be decreased when the moving speed is slow. Also, for example, the user may use the input interface unit 110 to adjust the length, width, and height as desired.

[0092] Embodiment 3 An obstacle detection system according to a third embodiment will be described in the case where ultrasonic sensors are provided as surrounding detection units in surrounding directions other than the traveling direction.

[0093] FIG. 18 is a diagram illustrating an example in which ultrasonic sensors are provided as periphery detection units in periphery directions other than the traveling direction according to the third embodiment.

[0094] Referring to FIG. 18(A), for example, an ultrasonic sensor is provided facing the ground direction as a direction other than the user's traveling direction.

[0095] In this case, the ultrasonic sensor can output ultrasonic waves to the ground and measure the height position from the ground.

[0096] For example, it is possible to set a warning range by measuring the height position from the ground.

[0097] In the above, a method has been described in which height is input in advance using the input interface unit 110 and stored in the memory unit 120, but it is also possible to automatically measure and set the height of the warning range by measuring the height position from the ground.

[0098] Referring to FIG. 18(B), for example, an ultrasonic sensor is provided facing the ceiling direction as a direction other than the moving direction of the user.

[0099] In this case, the ultrasonic sensor can output ultrasonic waves in the direction of the ceiling and measure the distance from the ceiling surface.

[0100] For example, it is possible to issue a warning when the distance to the ceiling is within a predetermined distance.

[0101] It is also possible to provide ultrasonic sensors in the opposite direction behind the user or in the left and right directions other than the direction of travel of the user, so as to issue warning information from blind spots other than the direction of travel.

[0102] In the above embodiment, the object detection unit has been described as using ultrasound to detect objects, but this is not limited to this and a method of detecting objects based on at least one of light, radio waves, sound waves, or image data may also be adopted.

[0103] Furthermore, although the above description has been given of a method for measuring the moving speed using the acceleration sensor 16, the present invention is not limited to this, and the moving speed may be measured using, for example, a global positioning system (GPS). Furthermore, the position information and information relating to positional deviation may be associated and registered using the GPS. When the user moves to the corresponding position information again, the associated information relating to positional deviation may be used to set the warning range.

[0104] The embodiments disclosed herein are intended to be combined as appropriate within the scope of compatibility. The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0105] 1 Obstacle detection system, 10 main body, 12 inertial sensor, 14 angle sensor, 16 acceleration sensor, 20 output section, 22 speaker, 24 vibrator, 30 sensor array, 32, 34 ultrasonic sensor, 40 communication interface section, 100 control unit, 110 input interface section, 120 memory section, 122 warning range information, 124 various information, 130 CPU, 131 position deviation calculation section, 132 setting section, 133 correction section, 134 setting registration section, 135 judgment section, 136 notification section, 137 measurement section, 138 adjustment section, 139 position deviation judgment section, 140 communication interface section.

Claims

1. an object detection unit for detecting an object within a predetermined detection range in the traveling direction on the course; a positional deviation detection unit for detecting a positional deviation of the object detection unit from a reference direction with respect to the traveling direction; a setting unit that sets a warning range within the predetermined detection range based on a reference direction of the object detection unit; a correction unit that corrects the warning range based on the positional deviation detected by the positional deviation detection unit.

2. The obstacle detection system according to claim 1 , further comprising a setting registration unit for registering information for setting the warning range by the setting unit.

3. a determination unit that determines whether to issue a warning to the object in the warning range; The obstacle detection system according to claim 1 , further comprising: a notification unit that issues warning information based on the determination result of said determination unit.

4. 4. The obstacle detection system according to claim 3, wherein the notification unit notifies the warning information by at least one of sound, vibration, and message information.

5. The determination unit Estimating whether the object in the warning range is the ground or the ceiling; The obstacle detection system according to claim 3 , wherein the system determines whether to issue a warning for the object other than the estimated ground or ceiling in the warning range.

6. The obstacle detection system according to claim 1 , wherein the object detection unit detects the object based on at least one of light, radio waves, sound waves, and image data.

7. the object detection unit includes a plurality of ultrasonic sensors arranged in an array, The obstacle detection system of claim 1 , wherein each of the ultrasonic sensors is a Micro Electro Mechanical Systems (MEMS) device.

8. 8. The obstacle detection system according to claim 7, wherein the position deviation detection unit includes an inertial sensor capable of measuring angular velocity and acceleration.

9. The obstacle detection system of claim 8 , wherein the plurality of ultrasonic sensors and the inertial sensor are integrally molded.

10. 2. The obstacle detection system according to claim 1, wherein the object detection unit and the positional deviation detection unit are attached to a member that is detachable from the human body.

11. 11. The obstacle detection system according to claim 10, further comprising a communication unit that enables information exchange between the object detection unit and the positional deviation detection unit attached to the member, and the setting unit and the correction unit provided separately from the member.

12. a measurement unit that measures a traveling speed of the object detection unit in a traveling direction on the course; The obstacle detection system according to claim 1 , further comprising an adjustment unit that adjusts the warning range based on the measurement result of the measurement unit.

13. The obstacle detection system according to claim 12 , wherein the measurement unit includes a GPS.

14. The obstacle detection system according to claim 1 , further comprising a surroundings detection unit for detecting the object in a direction different from the traveling direction.

15. the surroundings detection unit detects a position of the object detection unit in a height direction from the ground, The obstacle detection system according to claim 14 , wherein the setting unit sets the warning range based on a position of the object detection unit in a height direction from the ground.

16. a positional deviation determination unit that determines whether the positional deviation exceeds a predetermined value; The obstacle detection system according to claim 1 , wherein the notification unit notifies guidance information based on the determination result of the position deviation determination unit.

17. detecting an object within a predetermined detection range in a traveling direction on a course; detecting a positional deviation from a reference direction relative to the traveling direction; setting a warning range in the predetermined detection range based on a reference direction; and correcting the warning range based on the detected position deviation.

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