Foreign object detection device

Abstract

To provide a technology for reducing a risk that a vehicle drives onto a detection device while maintaining a range in which intrusion of foreign matters is detectable at a necessary size, for a device that detects intrusion of foreign matters into a lower part of a vehicle via detection light.SOLUTION: A foreign matter detection device comprises: an optical transmitter which emits detection light toward a retroreflective target mounted on a bottom face of a vehicle body of a vehicle in a direction which is inclined relative to a vertical direction; and a light receiving sensor for receiving detection light reflected by the target. The foreign matter detection device is arranged on a side face of a movable device mounted on a ground surface so as to be located at a position closer to a center line of the vehicle in a lateral direction than to the target.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a foreign object detection device that detects the intrusion of a foreign object under a floor of a vehicle. [Background technology]

[0002] Patent Document 1 discloses a system for accurately detecting foreign objects present on the top surface of a housing that houses a coil in a contactless power transfer system by suppressing the effects of ambient light such as sunlight or lighting. The contactless power transfer system includes a light-emitting unit and a light-receiving unit, and detects foreign objects such as iron using detection light that passes from the light-emitting unit to the light-receiving unit. The light-emitting unit and the light-receiving unit are arranged so that the detection light passes through the top surface of the housing that houses the coil for charging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-107915 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in Patent Document 1, a detection device that detects the intrusion of foreign objects by blocking detection light is known. Such devices are sometimes used to prevent foreign objects from getting caught in a movable device, such as a ground unit of a contact-type automatic charging system, when it is activated. The ground unit of a contact-type automatic charging system is installed under the floor of a parked vehicle in a parking space or the like, and charges the vehicle by moving its movable part and connecting it to a device on the vehicle. However, if a human body or other object enters under the vehicle floor while the movable part is operating, there is a risk of injury to the movable part or the human body. Therefore, a detection device is installed to stop the operation of the movable part when it detects the intrusion of a foreign object under the vehicle floor. Detection devices are often installed close to the wheels to widen the range in which they can detect the intrusion of foreign objects, but this can easily cause the vehicle to run over the device when entering the parking space, for example.

[0005] The object of the present disclosure is to provide a technology in a device that detects the intrusion of foreign objects under the floor of a vehicle by blocking detection light, which can reduce the risk of a vehicle running over the detection device while maintaining the necessary range for detecting the intrusion of foreign objects. [Means for solving the problem]

[0006] The present disclosure relates to a foreign object detection device that detects the intrusion of a foreign object under a vehicle floor by blocking detection light. The foreign object detection device includes an optical transmitter that emits detection light in a direction inclined relative to the vertical toward a retroreflective target mounted on the underside of the vehicle body, and a light receiving sensor that receives the detection light reflected by the target. The foreign object detection device is placed on the side of a mobile device installed on the ground, at a position closer to the lateral centerline of the vehicle than the target. [Effects of the Invention]

[0007] According to the technology disclosed herein, in a device that detects the intrusion of foreign objects under the floor of a vehicle by blocking detection light, it is possible to reduce the risk of the vehicle running over the detection device while maintaining a sufficient range in which the intrusion of foreign objects can be detected. [Brief explanation of the drawings]

[0008] [Figure 1] 10 is a configuration example of a parking space comparison technique to which a foreign object detection device is applied. [Figure 2] 2 shows an example of the configuration of a parking space to which a foreign object detection device according to the present embodiment is applied. [Figure 3] 10 is another example of the configuration of a parking space to which the foreign object detection device according to the present embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0010] Consider installing a movable device, such as a ground unit for a contact-type automatic charging system, in a parking space for vehicles. Figure 1 shows an example of the configuration of a parking space in a comparative technology where a ground unit for a contact-type automatic charging system is installed. Ground unit 21 is a device in the contact-type automatic charging system that is installed on the ground, and can charge the vehicle by connecting to a device mounted on the underside of the vehicle body. Ground unit 21 is installed so as to be positioned between wheels 12 of vehicle 11 to be parked. When vehicle 11 is parked, movable unit 22 is operated toward the underside of the body to connect to a device on vehicle 11 and charge vehicle 11.

[0011] If a foreign object such as a human body gets under the floor of the vehicle 11 while the movable part 22 is operating, the human body may be caught in the movement of the movable part 22, which may result in damage to the movable part 22 or the human body. Therefore, in order to stop the operation of the movable part 22 when a foreign object gets under the floor of the vehicle 11, a foreign object detection device 31 is installed in the parking space, which detects a foreign object entering under the floor of the vehicle by blocking detection light.

[0012] The foreign object detection device 31 includes an optical transmitter and a light receiving sensor. The optical transmitter can emit detection light toward a reflective target 13 mounted on the underside of the vehicle 11. The light receiving sensor can receive the detection light reflected by the target 13. In FIG. 1, the path of the detection light is indicated by a dotted arrow. When a foreign object enters under the floor of the vehicle 11, the detection light is blocked. Then, even though the optical transmitter continues to emit detection light toward the target 13, the light receiving sensor no longer receives the reflected detection light, allowing the foreign object detection device 31 to detect the intrusion of a foreign object. In the comparative technology shown in FIG. 1, the path of the detection light is oriented vertically. This is because the target 13 and the foreign object detection device 31 are positioned directly above and below each other, so that the detection light is emitted vertically toward the target 13, which has a specularly reflective horizontal surface, and is reflected back to its original position.

[0013] The detection range within which the foreign object detection device 31 can detect the intrusion of a foreign object is the area within the underfloor space of the vehicle 11 that is sandwiched between the paths of the detection light. Therefore, at least one foreign object detection device 31 is installed on each of the right and left sides of the vehicle 11. Furthermore, to prevent foreign objects from being caught in the movable part 22 when it is in operation, the detection range must include the movable part 22's range of motion. In the comparative example, the detection light is emitted vertically directly above the foreign object detection device 31, so the detection range is the inside of the foreign object detection device 31 when viewed laterally, i.e., in the axle direction, of the vehicle 11. Therefore, the foreign object detection device 31 is positioned outside the movable part 22's range of motion. As a result, in the comparative technology, the foreign object detection device 31 is installed in close proximity to the wheels 12. However, this placement increases the risk of the wheels 12 running over the foreign object detection device 31 depending on the route the vehicle 11 takes when entering a parking space. This could damage the foreign object detection device 31 and cause it to stop functioning. Therefore, it is desirable to install the foreign object detection device 31 further inward so as not to be close to the wheels 12.

[0014] The foreign object detection device 31 of the present disclosure is provided to solve such problems. FIG. 2 shows an example configuration of a parking space to which the foreign object detection device 31 of the present disclosure is applied. As shown in FIG. 2, in the present disclosure, the foreign object detection device 31 is disposed closer to the center of the vehicle 11 in the axle direction than the target 13. The optical transmitter then irradiates the target 13 with detection light in a direction oblique to the vertical. Because the path of the detection light is oblique to the vertical direction and the target 13 is located further outward than the foreign object detection device 31 in the axle direction of the vehicle 11, the detection range expands upward. In this way, in the present disclosure, the detection range can include the movable range of the movable part 22 without the foreign object detection device 31 being disposed outside the movable range of the movable part 22.

[0015] The optimum location for installing the foreign object detection device 31 is on the side of the ground unit 21. Because the wheels 12 cannot pass over the ground unit 21 or the foreign object detection device 31, if the foreign object detection device 31 is installed outside the ground unit 21, the range over which the wheels 12 can pass will be narrowed. However, if the foreign object detection device 31 is installed inside the ground unit 21, the detection range may be narrowed to the point where it does not include the moving part 22. For this reason, the optimum location for installation is on the side of the ground unit 21.

[0016] An example configuration of the target 13 will be described. The target 13 is mounted outside the foreign object detection device 31 when viewed laterally of the vehicle 11. Furthermore, to widen the detection range, it is desirable that the target 13 be installed closer to the outside when viewed laterally of the vehicle 11. Note that while FIG. 2 only shows the positional relationship in a plane including the left-right and up-down directions of the vehicle 11, the positional relationship between the wheels 12, the target 13, the ground device 21, and the foreign object detection device 31 is different in the front-to-rear direction of the vehicle 11. Furthermore, as the target 13 for reflecting the detection light emitted obliquely back to its original position, a retroreflective target 13 as shown in FIG. 2 is envisioned. Retroreflectivity refers to the property of reflecting incident light in the same direction, and is sometimes referred to as retroreflectivity. Alternatively, as shown in FIG. 3, a target 13 mounted on the bottom of the vehicle 11 so as to face obliquely with respect to the horizontal plane may be used.

[0017] The effects of the present disclosure can also be obtained when the foreign object detection device 31 and the target 13 are swapped. In this case, the target 13 is installed on the side of the ground device 21, and the foreign object detection device 31 is mounted on the bottom of the body of the vehicle 11, in a position that is outward of the target 13 when viewed laterally. Then, by emitting detection light from the optical transmitter in a direction inclined toward the target 13, it is possible to reduce the risk of the wheels 12 running over the target 13 while ensuring the required detection range.

[0018] As described above, the foreign object detection device of the present disclosure is installed on the side of a movable device, such as a ground unit of a contact-type automatic charging system. The device then irradiates a detection light at an angle toward a target mounted on the vehicle, and detects a foreign object that has entered under the vehicle floor by blocking the detection light. By irradiating the detection light at an angle toward the target, the detection range can be maintained within the movable range of the device while reducing the risk of the wheels running over the target. [Explanation of symbols]

[0019] 11 vehicles 12 wheels 13. Target 21 Ground aircraft 22 Moving parts 31 Foreign object detection device

Claims

[Claim 1] an optical transmitter that irradiates a detection light in a direction inclined with respect to a direction perpendicular to the ground toward a retroreflective target mounted on the bottom surface of the vehicle body; a light-receiving sensor that receives the detection light reflected by the target; Equipped with a ground device of a contact-type automatic charging system that is installed on the ground and has a movable part that connects to a power receiving device of the vehicle to charge the vehicle, and is arranged on a side of the ground device so as to be closer to a lateral center line of the vehicle than the target; detecting the intrusion of a foreign object under the floor of the vehicle by blocking the detection light; Foreign object detection device.

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