Object detection device

Abstract

An object detection device according to the present disclosure is installed such that an opening / closing door of an elevator and surroundings of the door are detection regions, and comprises: a three-dimensional distance image sensor that receives reflected light, from each point in the detection regions, of light emitted from a light-emitting unit, and acquires a measured distance which is information about the distance to each of the points and a measured reflection intensity which is intensity information of the reflected light; a correction unit that corrects the measured distance in accordance with a correction function for correcting the measured distance on the basis of the measured distance and the measured reflection intensity; and a detection unit that detects an object around the door on the basis of the corrected measured distance.

Description

Object detection device

[0001] The present disclosure relates to object detection devices, and more particularly to object detection devices for elevator doors.

[0002] Conventionally, there has been known an object detection device that uses a sensor installed near the elevator door to detect objects around the door to prevent passengers from getting caught or pulled in when the elevator doors are opening or closing. The sensor in such an object detection device uses, for example, an optical beam sensor.

[0003] Furthermore, if three-dimensional information about the area around the elevator doors can be acquired, objects around the elevator doors can be detected with higher accuracy. For example, Patent Document 1 describes an object detection device that infers three-dimensional information from two-dimensional information captured by a camera, thereby detecting passengers being pulled in.

[0004] Japanese Patent Publication No. 2021-6486

[0005] In order to perform the analogy of three-dimensional information in Patent Document 1, basic information such as the dimensions of the interior of the elevator must be input in advance for each site where the camera is installed.

[0006] In contrast, by using a time-of-flight (TOF) three-dimensional range image sensor, for example, it is possible to directly obtain three-dimensional information of the detection area without having to input information for each installation site or perform complex image analysis. However, with a TOF three-dimensional range image sensor, if an object is present close to the sensor, reflected light from the object may become stray light inside the camera, causing deviations in the detected distance values.

[0007] When attempting to detect objects around elevator doors using a 3D range image sensor, the 3D range image sensor needs to be installed close to the door surface, but if the 3D range image sensor is installed close to the door surface, it is conceivable that reflected light from the door will be strongly incident on the 3D range image sensor, especially when the doors are fully closed or opening and closing. Therefore, simply using a 3D range image sensor in an elevator object detection device makes it difficult to detect objects around elevator doors with high accuracy, and there is a risk of false detection or missed detection of objects due to deviations in distance values ​​caused by the influence of reflected light.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and provides an object detection device for elevator doors that uses a 3D range image sensor and is improved to reduce the influence of reflected light from surrounding objects and enable high-accuracy object detection.

[0009] The object detection device disclosed herein is equipped with a three-dimensional distance image sensor that is installed so that the opening and closing doors of an elevator and the area around the doors form a detection area, and receives reflected light from each point within the detection area in response to light emitted from a light-emitting unit, thereby obtaining a measured distance, which is distance information to each point, and a measured reflection intensity, which is intensity information of the reflected light; a correction unit that corrects the measured distance according to a correction function that corrects the measured distance depending on the measured distance and the measured reflection intensity; and a detection unit that detects objects around the doors based on the corrected measured distance.

[0010] Alternatively, the object detection device of the present disclosure comprises a three-dimensional distance image sensor that is installed so that the opening and closing doors of an elevator and the area around the doors form a detection area, receives reflected light from each point within the detection area in response to light emitted from a light-emitting unit, and acquires a measured distance, which is distance information to each point, and a measured reflection intensity, which is intensity information of the reflected light; a door state detection unit that detects the open / closed state of the door; and a light intensity limiting unit that, based on the open / closed state of the door, reduces the amount of light emitted from the light-emitting unit in the direction of the opening or closing door when the opening or closing door enters the imaging range of the three-dimensional distance image sensor.

[0011] According to the present disclosure, the measurement error of a 3D range image sensor caused by the influence of reflected light from objects around a door can be corrected using a correction function, thereby enabling objects around the door to be detected with high accuracy even when using a 3D range image sensor.

[0012] Fig. 1 is a schematic diagram showing an overview of an elevator system according to a first embodiment of the present disclosure and a building in which the elevator system is installed. Fig. 2 is a schematic diagram showing an object detection device and the vicinity of an entrance / exit of a car of the elevator system according to the first embodiment of the present disclosure. Fig. 3 is a diagram showing the relationship between the measured reflection intensity measured by a three-dimensional range image sensor and a measurement error. Fig. 4 is a flowchart for explaining the procedure of a correction function calculation process by a correction function calculation unit of the object detection device according to the first embodiment of the present disclosure.

[0013] Hereinafter, an embodiment of an object detection device according to the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and the description thereof will be simplified or omitted.

[0014] Embodiment 1. Figure 1 is a schematic diagram showing an overview of an elevator system according to Embodiment 1 and a building in which the elevator system is installed. As shown in Figure 1, the elevator system 1 includes a hoistway 2 that runs vertically through multiple floors in the building. A machine room 4 is provided directly above the hoistway 2. A hoisting machine 6 is installed in the machine room 4, and a main rope 5 is wound around the hoisting machine 6. A car 7 is suspended by the main rope 5 so that it can rise and fall within the hoistway 2.

[0015] On each floor of the building, a landing 8 is provided opposite the elevator shaft 2. At the entrance of each landing 8, a landing door 9 and a landing door frame 10 arranged on the outer periphery of the landing door 9 are provided. The landing door 9 is movable in the direction of the frontage of the entrance of the landing 8. The entrance of the landing 8 is opened and closed by the movement of the landing door 9. The movement of the landing door 9 is performed in conjunction with the movement of a door panel 12, which will be described later.

[0016] A car door device 11 is provided at the entrance of the car 7. The car door device 11 includes a pair of door panels 12 and a drive machine 13. The pair of door panels 12 are provided at the entrance of the car 7 so as to be perpendicular to the direction of getting on and off to the car 7. The direction of getting on and off to the car 7 is the direction of getting on or off to the car 7, and in Figure 1 it is the left-right direction on the paper. The drive machine 13 moves the pair of door panels 12 in opposite directions to each other and horizontally along a plane perpendicular to the getting on and off direction, thereby opening and closing the door panels 12.

[0017] A control panel 14 is installed in the machine room 4. The control panel 14 is electrically connected to the hoisting machine 6 and the driving machine 13, and controls the operations of the hoisting machine 6 and the driving machine 13. The control panel 14 also performs integrated control of the entire elevator system 1.

[0018] During normal operation of the elevator system 1, the control panel 14 controls the drive of the hoisting machine 6. The car 7 moves up and down in the hoistway 2 in response to the drive of the hoisting machine 6. When the car 7 arrives at the landing 8 of the destination floor, the control panel 14 sends a command to the driving machine 13 to open the pair of door panels 12. The driving machine 13 receives the command from the control panel 14 and drives the pair of door panels 12 in the door-opening direction. Thereafter, the control panel 14 sends a signal to the driving machine 13 to close the pair of door panels 12, and the driving machine 13 drives the pair of door panels 12 in the door-closing direction based on the received command. Note that the landing doors 9 are also opened and closed in conjunction with the movement of the pair of door panels 12.

[0019] The elevator system 1 includes an object detection device 20. The object detection device 20 is capable of detecting objects present inside the car 7 and at the landing 8 at the floor where the car 7 is stopped, and functions as part of a safety device. Details of the object detection device 20 will be described later.

[0020] FIG. 2 is a schematic diagram showing the vicinity of the entrance / exit of the car 7 and the object detection device 20 of the elevator system 1 according to this embodiment. FIG. 2 shows a perspective view of the portion near the entrance / exit of the car 7. As shown in FIG. 2, a floor 7a, a top frame 7b, and a pair of side frames 7c and 7d are formed near the entrance / exit of the car 7. The floor 7a is an internal floor of the car 7. The top frame 7b and the pair of side frames 7c and 7d form a three-sided frame surrounding the entrance / exit of the car 7. Each of the pair of side frames 7c and 7d has a side frame surface adjacent to each of a pair of door panels 12. For example, the side frame surface of the side frame 7c and the side frame surface of the side frame 7d face each other. A gap exists between the pair of side frames 7c and 7d and the pair of door panels 12, allowing the pair of door panels 12 to open and close.

[0021] The object detection device 20 includes a three-dimensional distance image sensor 21 and a detection processor 22. While there is no limitation on the installation position of the detection processor 22, in this embodiment, the detection processor 22 is provided on the ceiling of the car 7. The three-dimensional distance image sensor 21 is installed, for example, in a position on the upper frame 7b above the mating surfaces of the ends of the pair of door panels 12 in the door closing direction, so that the lower side of the three-dimensional distance image sensor 21 is the detection area. The detection area is near the door panels 12 inside the car 7 and the landing doors 9 of the landing 8, and includes at least the mating surfaces of the pair of door panels 12, a portion of the floor 7a, and one of the pair of sleeve frames 7c, 7d. The mounting angle and installation position of the three-dimensional distance image sensor 21 are not limited as long as distance information between the mating surfaces of the pair of door panels 12 and the portion of the floor 7a and one of the pair of sleeve frames 7c, 7d can be obtained.

[0022] Although not shown, the three-dimensional range image sensor 21 includes a light-emitting unit and a detection unit that detects the light reflected from objects at each point in the detection area in response to the light emitted from the light-emitting unit. The three-dimensional range image sensor 21 acquires distance information to each point in the detection area and outputs it as a measured distance, and also outputs information on the intensity of the reflected light from each point as a measured reflection intensity, and transmits the measured distance and measured reflection intensity to the detection processor 22.

[0023] The detection processor 22 determines whether or not a detection object exists within the detection area based on the output from the 3D distance image sensor 21. Note that the detection object here is, for example, an object that is present in the vicinity of the door panel 12 and the landing door 9 (hereinafter also simply referred to as "door") and that may be caught or pulled in, and may include, for example, a user, the user's luggage, clothing, etc. The detection processor 22 is electrically connected to the control panel 14 and is configured to be able to send and receive information.

[0024] Fig. 2 is a block diagram showing the functions of the object detection device 20. As shown in Fig. 3, the detection processor 22 has a door state detection unit 23, a storage unit 24, a correction function calculation unit 25, a correction unit 26, and a detection unit 27.

[0025] The door state detection unit 23 acquires the door open / closed state, which is information on the open / closed state of the door panel 12 and the landing door 9, from the control panel 14.

[0026] The storage unit 24 stores the measured distance and measured reflection intensity sent from the 3D range image sensor 21 in association with the open / closed state of the door detected by the door state detection unit 23. In other words, the storage unit 24 stores the measured distance and reflection intensity detected by the 3D range image sensor 21 in a certain open / closed state of the door together with information on the open / closed state of the door at the time of detection.

[0027] The correction function calculation unit 25 calculates a correction function using the actual distance to each point in the detection area in a certain door open / closed state, and the measured distance and measured reflection intensity corresponding to the certain door open / closed state stored in the storage unit 24. The method of calculating the correction function will be described in detail later.

[0028] The correction unit 26 corrects the measured distance according to a correction function corresponding to the door open / close state, based on the door open / close state detected by the door state detection unit 23 and the measured distance and measured reflection intensity transmitted from the three-dimensional distance image sensor 21.

[0029] The detection unit 27 executes the detection process. Specifically, the detection unit 27 determines whether or not a detection target exists in the detection area based on the measured distance corrected by the correction unit 26. If it is determined that a detection target exists, the detection unit 27 transmits information indicating that the detection target has been detected to the control panel 14.

[0030] If the control panel 14 receives detection information of a detection object from the detection processor 22 before the pair of door panels 12 open, it will stop sending a command to open the pair of door panels 12. If the control panel 14 receives detection information of a detection object from the detection processor 22 before the pair of door panels 12 close, it will stop sending a command to close the pair of door panels 12. Alternatively, instead of stopping sending a command to open or close the pair of door panels 12, the control panel 14 will send a command to the driver 13 to stop the operation of opening or closing the pair of door panels 12.

[0031] Next, we will explain how the correction function calculation unit 25 calculates the correction function. Since the three-dimensional range image sensor 21 detects the distance to an object based on light reflected from the object, errors may occur in the measured distance due to the influence of ambient light. In particular, the measured distance obtained when the door panel 12 is located near the three-dimensional range image sensor 21, such as when the door is closed, may contain measurement errors due to stray light caused by intense reflected light from the door panel 12. The correction function is used to correct such measurement errors.

[0032] Fig. 3 is a diagram showing the relationship between the measured reflection intensity measured by the 3D range image sensor and the measurement error. In Fig. 3, the horizontal axis represents the measured reflection intensity, and the vertical axis represents the measurement error, i.e., the deviation of the measured distance to each point from the actual distance. Fig. 3 shows the measurement results for three measurement points a, b, and c, which are distances from the 3D range image sensor 21, among the points within the detection area.

[0033] As shown in Fig. 3, there is a certain correlation between the distance to the measurement point, the reflection intensity, and the measurement error, and the distance deviation is uniquely determined for the distance to the measurement point and the reflection intensity. Therefore, in this embodiment, the relationship between the reflection intensity, the distance to the measurement point, and the distance deviation is found as shown in Fig. 3, and a correction function is calculated based on this relationship.

[0034] More specifically, the correction function calculation unit 25 acquires the measured distance and measured reflection intensity corresponding to, for example, the door fully open state from the storage unit 24. When the door is fully open, the output of the three-dimensional range image sensor 21 is acquired when the door panel 12 is not present near the three-dimensional range image sensor 21, and therefore the output of the three-dimensional range image sensor 21 is less likely to include distance deviations due to stray light caused by the door panel 12. Therefore, the correction function calculation unit 25 uses each measured distance to any measurement point when the door is fully open as a reference distance.

[0035] The correction function calculation unit 25 then acquires from the memory unit 24 the measured distances and measured reflection intensities for multiple door open / closed states from the start of the door closing operation to the door fully closed state. Next, for any measurement point within the detection area, the difference between the measured distance during the door closing operation or when the door is fully closed and the measured distance when the door is fully open (i.e., the reference distance) is calculated. While there are no limitations on the measurement points, locations that do not move due to the door opening / closing operation, such as the armrests 7c and 7d, are preferred. By setting multiple arbitrary measurement points and performing measurements at each measurement point, a correction function that defines the relationship shown in FIG. 3 can be calculated. In this embodiment, the correction function is calculated for each door open / closed state. The correction function for each door open / closed state is a function that receives the measured distance and measured reflection intensities measured by the 3D range image sensor 21 as inputs and outputs the distance deviation to be corrected.

[0036] The calculated correction function may be one that uses pre-stored relationships between the measured distance and the measured reflection intensity of each point within the detection area and the deviation from the measured distance to provide, by interpolation, the distance deviation for the measured distance and measured reflection intensity newly acquired by the 3D range image sensor 21. Alternatively, the correction function may be one that calculates parameters of a predetermined smooth function using the least squares method or the like based on the pre-recorded relationships between the measured distance and the measured reflection intensity of each point within the detection area and the deviation from the distance, and provides the distance deviation corresponding to the newly acquired measured distance and measured reflection intensity as the output of the smooth function.

[0037] 4 is a flowchart illustrating the procedure of the correction function calculation process performed by the correction function calculation unit. The operation of the correction function calculation process shown in FIG. 4 is executed at a predetermined timing. Here, the "preset timing" may be, for example, immediately after the installation of the three-dimensional range image sensor 21.

[0038] 4 , first, in step S01, the door state detection unit 23 detects that the door is fully open. If the door is fully open in step S01, then in step S02, the 3D range image sensor 21 acquires the measured distance and the measured reflection intensity, and outputs the acquired measurement information to the storage unit 24.

[0039] Next, in step S03, a command to start the door closing operation is output from the control panel 14, and in response to the command, the driver 13 starts closing the door. Next, in step S04, the door state detection unit 23 detects the door open / closed state and outputs the result to the memory unit 24.

[0040] Next, in step S05 , the three-dimensional distance image sensor 21 acquires the measured distance and the measured reflection intensity, and outputs the acquired measurement information to the storage unit 24 .

[0041] Next, in step S06, the correction function calculation unit 25 acquires from the memory unit 24 the measured distance and the measured reflection intensity stored in association with the door open / close state acquired in step S04, calculates a correction function for the door open / close state acquired in step S04, and outputs it to the correction unit 26.

[0042] Next, in step S07, it is determined whether or not calculation of the correction function for the door fully closed state has been completed. If it is determined in step S07 that calculation of the correction function for the door fully closed state has not been completed, the process returns to step S03, and steps S03 to S07 are repeated. On the other hand, if it is determined in step S07 that calculation of the correction function for the door fully closed state has been completed, the calculation process of the correction function is completed, and the current process is terminated.

[0043] The calculated correction function is associated with the door open / closed state when the correction function was calculated and output to the correction unit 26. The correction unit 26 corrects the measured distance using the correction function corresponding to the door open / closed state when the measured distance was measured, using the measured distance and measured reflection intensity measured by the 3D range image sensor 21 as parameters. Note that "corresponding to the door open / closed state" here does not mean that the door open / closed state when the measured distance was measured and the door open / closed state corresponding to the correction function are completely the same. In this case, it is sufficient that a correction function corresponding to a door open / closed state close to the door open / closed state when the measured distance was measured is used to correct the measured distance.

[0044] As described above, according to this embodiment, object detection device 20 can calculate a correction function for correcting the measured distance based on the measured distance and measured reflection intensity output from 3D range image sensor 21, and thereby correct the measured distance. Therefore, even when used in an environment prone to strong reflected light, such as an object detection device for elevator doors, it is possible to prevent false detection or missed detection of an object due to measurement errors caused by the influence of reflected light.

[0045] In this embodiment, the object detection device 20 has a correction function calculation unit 25 that calculates a correction function, and the correction function can be calculated using the measured distance when the door is fully open as a reference distance. Because the correction function calculation unit 25 can calculate the correction function from actual measurement data while the door is open or closed, it is no longer necessary to input information such as the internal dimensions of the car 7 in advance for each installation site, and the versatility of the object detection device 20 can be improved.

[0046] However, the object detection device 20 may not have the functionality of a correction function calculation unit, but may store a separately calculated correction function. In this case, the correction function can be used to correct the measured distance of the 3D distance image sensor 21, and false detection of an object due to the influence of reflected light can be suppressed.

[0047] Alternatively, instead of the measured distance when the door is fully open, the actual measured value of the distance to each measurement point may be stored in advance, and this actual measured value may be used as the reference distance for calculating the deviation of the measured distance.

[0048] In addition, in this embodiment, a correction function is calculated for each of a plurality of door open / closed states, and the correction unit 26 corrects the measured distance using the correction function corresponding to the door open / closed state. However, this embodiment is not limited to this, and may be configured to calculate correction functions corresponding to three states, for example, a door fully open state, a door fully closed state, and a door in the middle of opening or closing. Alternatively, a single correction function may be calculated without distinguishing between the door open / closed states.

[0049] Furthermore, in the present embodiment, the door state detection unit 23 is configured to acquire the door open / closed state from the control panel 14, but is not limited to this, and the door state detection unit 23 may be configured to detect the door open / closed state based on, for example, the measured distance and measured reflection intensity from the three-dimensional range image sensor 21. In this case, for example, based on the measured distance sent from the three-dimensional range image sensor 21, the average distance to a specific area of ​​the pair of door panels 12 is calculated, and the door open / closed state can be detected based on the calculated average distance.

[0050] In the present embodiment, the timing for calculating the correction function by the correction function calculation unit 25 has been described as the timing when the three-dimensional range image sensor 21 is installed. However, the timing for calculating the correction function is not limited to this. For example, in addition to the timing when the three-dimensional range image sensor 21 is installed, the correction function calculation process may be performed periodically at regular intervals after the installation of the three-dimensional range image sensor 21. This makes it possible to deal with changes over time in the characteristics of the three-dimensional range image sensor 21, changes in the design of the car or the platform, and the like.

[0051] In this embodiment, the elevator doors are double-hinged, and the 3D range image sensor 21 is disposed above the mating surface of the door panel 12 on the upper frame 7b of the car 7. However, the installation position of the 3D range image sensor 21 is not limited to this. For example, if the elevator door panel is single-hinged, the 3D range image sensor 21 may be disposed above the end side in the door closing direction. The 3D range image sensor 21 may also be disposed on the landing 8 side, for example, on the upper frame of the three-sided frame of the landing door frame 10. In this case, the 3D range image sensor 21 may be disposed at each of the multiple landings 8 of the elevator.

[0052] Furthermore, in this embodiment, a configuration has been described in which the detection processor 22 and the control panel 14 are electrically connected and commands to the drive machine 13 are executed via the control panel 14, but a configuration in which the detection processor 22 and the drive machine 13 are directly connected and information on the detection of a detection target is transmitted from the detection processor 22 to the drive machine 13. Furthermore, in this embodiment, a case has been described in which the detection processor 22 is installed on the ceiling of the car 7, but the installation location of the detection processor 22 is not limited, and it may be installed in the machine room 4, for example.

[0053] Embodiment 2 An object detection device of embodiment 2 has the same configuration as object detection device 20 of embodiment 1, except that it has a function of reducing the amount of light emitted from the light emitting unit of the three-dimensional range image sensor.

[0054] More specifically, the object detection device of this embodiment includes a light amount limiting unit that functions to reduce the amount of light emitted from the light emitting unit. The light amount limiting unit limits the amount of light emitted from the light emitting unit depending on whether the door is open or closed. For example, the light amount limiting unit stores in advance a limit value for the amount of light emitted for the door open or closed state, and limits the amount of light emitted from the light emitting unit in accordance with this limit value.

[0055] For example, a limit value for the amount of light emitted from the light-emitting unit is set in response to the door open / close state in which the effect of the amount of light reflected from the door panel 12 on the output of the 3D distance image sensor 21 becomes so strong that it cannot be ignored, and the amount of correction for the measured distance exceeds a threshold. Note that this limit value may limit only the amount of light emitted in a specific direction.

[0056] For example, the light amount limiting unit may be configured to limit the current supplied to the light emitting unit, thereby controlling the light emitted in the direction of the door panel 12. Alternatively, a shield may be inserted just before the light emitting unit to block part of the light irradiated in the direction of the door panel, depending on the door open / close state and the limit value of the irradiated light amount.

[0057] The correction function corresponding to the door open / closed state in which a limit value is set for the amount of light irradiated by the light emitting unit is calculated using the measurement distance measured with the amount of light emitted according to the limit value.

[0058] If stray light from the door panel 12 or the like is excessively strong during measurement by the 3D range image sensor 21, the amount of correction by the correction function will be large. If the amount of correction becomes too large, the reliability of the correction value will also decrease. In contrast, with the object detection device of this embodiment, the amount of light projected onto the door panel 12 or the like can be limited to a small amount when the door is open or closed, when the influence of stray light is expected to be strong. Therefore, the influence of stray light on the 3D range image sensor 21 can be minimized and the amount of correction can be reduced, allowing for detection of the object to be detected with higher accuracy.

[0059] In this embodiment, the case where the amount of light emitted from the light-emitting unit is limited when the correction amount due to the correction function becomes large has been described. However, the function of limiting the amount of light emitted in embodiment 2 can also be applied to object detection devices other than the object detection device of embodiment 1 that do not have the function of measuring the measurement distance using a correction function. In this case, for example, when the opening or closing door panel 12 enters the imaging range of the 3D range image sensor, the light amount limiting unit reduces the amount of light emitted in the direction of the 3D range image sensor and the opening or closing door. This makes it possible to minimize the effects of stray light.

[0060] The above describes in detail preferred embodiments, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0061] In the above embodiments, when the number, quantity, amount, range, etc. of each element is mentioned, the object detection device of this disclosure is not limited to the mentioned number unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in these embodiments are not necessarily essential to this invention unless otherwise specified or clearly specified in principle.

[0062] DESCRIPTION OF SYMBOLS 1 Elevator system, 2 Hoistway, 5 Main rope, 6 Hoisting machine, 7 Cage, 7a Floor, 7b Upper frame, 7c Side frame, 7d Side frame, 8 Landing, 9 Landing door, 10 Landing door frame, 11 Cage door device, 12 Door panel, 13 Drive machine, 14 Control panel, 20 Object detection device, 21 Three-dimensional distance image sensor, 22 Detection processor, 23 Door state detection unit, 24 Memory unit, 25 Correction function calculation unit, 26 Correction unit, 27 Detection unit

Claims

1. a three-dimensional distance image sensor that is installed so that the elevator doors that open and close and the surroundings of the doors form a detection area, receives reflected light from each point within the detection area in response to light irradiated from a light emitting unit, and obtains a measured distance, which is distance information to each point, and a measured reflection intensity, which is intensity information of the reflected light; a correction unit that corrects the measured distance according to a correction function that corrects the measured distance depending on the measured distance and the measured reflection intensity; A correction function calculation unit for calculating the correction function; A detection unit that detects an object around the door based on the corrected measured distance; An object detection device comprising:

2. a three-dimensional distance image sensor that is installed so that the elevator doors that open and close and the surroundings of the doors form a detection area, receives reflected light from each point within the detection area in response to light irradiated from a light emitting unit, and obtains a measured distance, which is distance information to each point, and a measured reflection intensity, which is intensity information of the reflected light; A door state detection unit that detects an open / closed state of the door; a light amount limiting unit that reduces an amount of light emitted from the light emitting unit toward the opening or closing door when the opening or closing door enters an imaging range of the three-dimensional range image sensor based on an opening or closing state of the door; An object detection device comprising:

3. A door state detection unit that detects an open / closed state of the door; a storage unit that acquires and stores the measured distance and the measured reflection intensity from the three-dimensional range image sensor when the door is in a fully closed state, a fully open state, or a state in which the door is being opened or closed; Equipped with The correction function calculation unit calculates the correction function based on the measured distance and the measured reflection intensity stored in the storage unit. The object detection device according to claim 1 .

4. The object detection device described in claim 3, characterized in that the correction function calculation unit calculates the correction function based on the difference between the measured distance of each point when the door is fully open and the measured distance of each point when the door is fully closed and in the open / closed state, and the measured reflection intensity.

5. The storage unit stores in advance distance information to each of the points in the detection area, The object detection device according to claim 3, characterized in that the correction function calculation unit calculates the correction function based on the difference between the distance information of each point recorded in the memory unit and the measured distance, and the measured distance and the measured reflection intensity of each point.

6. The correction function calculation unit calculates the correction function for each open / closed state of the door, The object detection device according to any one of claims 3 to 5, wherein the correction unit corrects the measured distance using the correction function corresponding to the open / closed state of the door detected by the door state detection unit.

7. 6. The object detection device according to claim 1, further comprising a light amount limiting unit that reduces the amount of light emitted from the light emitting unit based on the open / closed state of the door.