Cooperation device and elevator system

Abstract

To provide a cooperation device so that an autonomous traveling type movable body can safely get on / off an elevator car.SOLUTION: A cooperation device according to an embodiment comprises a step amount detection part and an operation cooperation part. The step amount detection part detects a step amount between a car floor face and a landing floor face generated when an autonomous traveling type movable body puts its own weight both on the car floor face and the landing floor face of an elevator. The operation cooperation part stops operation of the movable body and moves the car so that the car floor face matches the landing floor face when it recognizes that the step amount detected by the step amount detection part is greater than or equal to a prescribed value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a cooperative device and an elevator system. [Background technology]

[0002] Autonomous mobile robots and other mobile objects are increasingly being used within buildings for security and transporting luggage. By linking these mobile objects with elevator systems, they can travel to each floor within the building using elevator cars.

[0003] When a moving object gets into an elevator car, if the front wheels of the moving object get on the car and the front and rear wheels straddle the floor of the car and the floor of the landing, part of the weight of the moving object may be placed on the car, causing the car to move as if it sinks downward.Also, when a moving object gets off the car to a landing, if the front wheels of the moving object get off the landing and the front and rear wheels straddle the floor of the landing and the floor of the car, part of the weight of the moving object may be placed on the landing, causing the car to move as if it floats upward.

[0004] In this way, when the car moves downward or upward with the front and rear wheels of the moving body straddling the floor of the car and the floor of the landing, a step occurs between the floor of the car and the floor of the landing.

[0005] If a step occurs between the floor of the car and the floor of the landing, the moving object may be unable to proceed over the step and may stop. In view of this, there is a technology in which an imaging device installed in the car captures an image of an area including the floor of the car and the floor of the landing while passengers are getting on or off the moving object, and the captured image information is analyzed, so that if it is detected that a step has occurred between these floors and the moving object has stopped, the car is raised or lowered to eliminate the step and perform floor surface alignment (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-181793 Summary of the Invention [Problem to be solved by the invention]

[0007] However, if the difference in level between the floor of the car and the floor of the landing is large enough to cause the moving body to lose balance while moving, but not so large that it is unable to move forward and stop, the above-mentioned technology will not align the floors, and there is a problem in that it may not be possible to prevent the moving body from tipping over.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a linking device and an elevator system that allow an autonomous mobile body to safely get on and off an elevator car. [Means for solving the problem]

[0009] According to an embodiment for achieving the above object, the linking device includes a step amount detection unit and an operation linking unit. The step amount detection unit detects the amount of step between the floor surface of the elevator car and the floor surface of the landing when an autonomous traveling mobile body applies its own weight to both the floor surface of the elevator car and the floor surface of the landing. When the operation linking unit recognizes that the step amount detected by the step amount detection unit is equal to or greater than a predetermined value, it stops the operation of the mobile body and moves the car so that the floor surface of the car is aligned with the floor surface of the landing. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall view showing the configuration of an elevator system 1 according to an embodiment. [Figure 2] 2 is a block diagram showing the configuration of a moving body 20 and a linking device 30 in the elevator system 1. FIG. [Figure 3] 10 is a flowchart showing a process executed by the linked device 30. [Figure 4A]1 is a diagram showing a moving object 20 in a balanced state viewed from an imaging device 142a installed on a car door in the elevator system 1. FIG. [Figure 4B] 1 is a diagram showing a state in which an inclined moving body 20 is viewed from an imaging device 142a installed on a car door in an elevator system 1. FIG. [Figure 5A] 10 is a diagram showing a state in which the moving body 20 in a balanced state is viewed from an imaging device 142a installed obliquely above the moving direction of the moving body 20 in the elevator system 1. FIG. [Figure 5B] 10 is a diagram showing a state in which an inclined moving body 20 is viewed from an imaging device 142a installed obliquely above the moving direction of the moving body 20 in the elevator system 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an elevator system using a linking device that links the operation of an autonomous traveling mobile body with the operation of an elevator will be described as an embodiment of the present invention.

[0012] <Configuration of an elevator system according to one embodiment> 1 is an overall view showing the configuration of an elevator system 1 according to one embodiment. The elevator system 1 includes an elevator 10, an autonomous traveling vehicle 20, and a linkage device 30.

[0013] The elevator 10 comprises a hoist 12 installed above an elevator shaft 11 of a building, a rope 13 stretched across the hoist 12, a car 14 suspended from one end of the rope 13, and an elevator control panel 16 connected to the car 14 via a tail cord 15 and to the hoist 12 via a communication line. The elevator control panel 16 controls the hoist 12 and other components based on information obtained from devices inside the car 14.

[0014] A car door 141 and an imaging device 142a installed above the car door 141 are installed inside the car 14, and a landing door 171 that opens and closes in conjunction with the operation of the car door 141 is installed at a landing 17 of the building. When the car door 141 and the landing door 171 are opened, the imaging device 142a photographs a monitoring area AR that includes an area within a predetermined distance from the car door 141 inside the car 14, an area within a predetermined distance from the landing door 171 inside the landing 17 of the floor where the car 14 has landed, and an area between the car door 141 and the landing door 171.

[0015] 2 is a block diagram showing the configuration of the mobile object 20 and the linking device 30. The mobile object 20 moves to each floor of a building using a car 14, and has front wheels 21 and rear wheels 22 installed at the bottom, a drive unit 23, a mobile object wireless communication unit 24, and a mobile object control device 25. The drive unit 23 drives the rotation of the front wheels 21 and rear wheels 22. The mobile object wireless communication unit 24 communicates wirelessly with the linking device 30.

[0016] The mobile object control device 25 is configured by, for example, a CPU (Central Processing Unit) provided in a general-purpose microcomputer, and controls the driving unit 23 by installing and executing a predetermined mobile object control program.

[0017] The linking device 30 links the operation of the elevator 10 with the operation of the moving body 20, and is installed, for example, in the hall 17 in the building, the hoistway 11, or a machine room (not shown) above the hoistway 11. The linking device 30 has a memory unit 31, a linking wireless communication unit 32, and a CPU 33.

[0018] The storage unit 31 has an equilibrium state information storage unit 311 and an allowable step amount storage unit 312. The equilibrium state information storage unit 311 stores equilibrium shape information, which is shape information of the moving body 20 in an equilibrium state as seen from the imaging device 142a. The allowable step amount storage unit 312 stores an allowable step amount, which is an upper limit value of the step amount that the moving body 20 can safely overcome. The cooperative wireless communication unit 32 performs wireless communication with the moving body 20.

[0019] The CPU 33 is, for example, a CPU (Central Processing Unit) provided in a general-purpose microcomputer, and by installing and executing a predetermined cooperation control program, constitutes one or more information processing units described below. The CPU 33 has an imaging information acquisition unit 331, a step amount detection unit 332, an operation cooperation unit 333, and an input / output unit 334.

[0020] The imaging information acquisition unit 331 acquires imaging information captured by the imaging device 142a. The step amount detection unit 332 detects the amount of step between the floor surface of the car 14 and the floor surface of the hall 17 based on the imaging information acquired by the imaging information acquisition unit 331 and the shape information of the moving body 20 stored in the equilibrium state information storage unit 311.

[0021] The operation coordination unit 333 causes the elevator 10 and the mobile body 20 to perform coordinated operations based on the step amount detected by the step amount detection unit 332 and the allowable step amount stored in the allowable step amount storage unit 312 so that the mobile body 20 can safely get on and off the car 14. The input / output unit 334 inputs operation status information of the elevator 10 and the mobile body 20, and outputs operation instruction information to the elevator 10 and the mobile body 20.

[0022] Operation of an Elevator System According to an Embodiment The following describes the process performed when a moving object 20 stopped at a hall 17 gets into the car 14 to travel to another floor while the elevator system 1 is in operation. The equilibrium state information storage unit 311 of the linkage device 30 of the elevator system 1 stores in advance information about the shape of the moving object 20 in equilibrium. The allowable step amount storage unit 312 also stores in advance an allowable step amount, which is an upper limit value of the step amount indicating the height of a step that the moving object 20 can safely overcome.

[0023] 3 is a flowchart showing the processing executed by the linking device 30 when the moving object 20 gets on the car 14. The linking device 30 monitors the operating state of the moving object 20 by communicating with the moving object 20.

[0024] When the car 14 lands on the landing 17 and the car door 141 and the landing door 171 open, the mobile body control device 25 of the mobile body 20 drives the drive unit 23 to rotate the front wheels 21 and the rear wheels 22, thereby starting the operation of getting into the car 14. In addition, when the car door 141 and the landing door 171 open, the imaging device 142a starts capturing an image of the monitoring area AR.

[0025] When the imaging information acquisition unit 331 of the linkage device 30 detects that the moving object 20 is getting on the car 14 ("YES" in S1), it acquires imaging information from the imaging device 142a (S2). The imaging information acquisition unit 331 sequentially sends the acquired imaging information to the step amount detection unit 332.

[0026] Here, when the moving body 20 is moving toward the inside of the car 14 and the front wheels 21 are on the floor surface of the car 14 and the rear wheels 22 are on the floor surface of the landing 17, that is, when the moving body 20 straddles the floor surfaces of the car 14 and the landing 17 and the weight of the moving body 20 is applied to both floor surfaces, the weight of the moving body 20 causes the car 14 to move downward so as to sink, and a step is created between the floor surface of the car 14 and the floor surface of the landing 17. When this step is created, the moving body 20 is tilted with the front lowered.

[0027] The step amount detection unit 332 analyzes the acquired imaging information and, when it detects that the moving body 20 has straddled the floor surface of the elevator car 14 and the floor surface of the landing 17 ("YES" in S3), it acquires equilibrium shape information of the moving body 20 from the equilibrium state information storage unit 311 (S4).

[0028] The step amount detection unit 332 compares the acquired information on the equilibrium shape of the moving body 20 with the image information of the moving moving body 20 captured by the image capture device 142a, and determines whether the moving body 20 is tilted (S5). When the step amount detection unit 332 determines that the moving body 20 is tilted ("YES" in S5), it detects the step amount, which is the height of the step that has occurred between the floor surface of the car 14 and the floor surface of the hall 17, from the degree of tilt.

[0029] FIG. 4A is a diagram showing a state in which a moving body 20 in a balanced state is viewed from an imaging device 142a installed on a car door 141, and FIG. 4B is a diagram showing a state in which a tilted moving body 20 is viewed from the imaging device 142a.

[0030] In the balanced shape information when the moving body 20 in a balanced state is viewed from the imaging device 142a as in Fig. 4A, the length of the moving body's body in the traveling direction is recognized as L1. In contrast, in the imaging information when the tilted moving body 20 is viewed from the imaging device as in Fig. 4B, the length of the moving body's body in the traveling direction is recognized as L2. This length L2 is shorter than L1, and the greater the tilt of the moving body 20, the greater the difference between lengths L1 and L2.

[0031] Using this, the step amount detection unit 332 determines that the moving body 20 is tilted if the lengths L1 and L2 are different, and further calculates the degree of tilt of the moving body 20 based on the magnitude of the difference between the lengths L1 and L2. The step amount detection unit 332 also identifies the tilt direction of the moving body 20 by analyzing image information of the moving body 20. Furthermore, the step amount detection unit 332 detects the amount of step between the floor surface of the car 14 and the floor surface of the hall 17 and the moving direction (upward or downward) of the car 14 from the calculated degree of tilt of the moving body 20 and the identified tilt direction.

[0032] The action cooperation unit 333 determines whether the step amount detected by the step amount detection unit 332 exceeds the allowable step amount for the moving object 20 stored in the allowable step amount storage unit 312 (S6). When the action cooperation unit 333 determines that the detected step amount exceeds the allowable step amount for the moving object 20 ("YES" in S6), it recognizes that floor surface alignment processing is required to align the heights of the floor surface of the car 14 and the floor surface of the hall 17. When the action cooperation unit 333 recognizes that floor surface alignment processing is required, it transmits a stop instruction to the moving object 20 via the input / output unit 334 and the cooperation wireless communication unit 32 (S7).

[0033] In the moving body 20, the moving body control device 25 receives the stop instruction transmitted from the linking device 30 via the moving body wireless communication unit 24, and stops the rotation of the front wheels 21 and the rear wheels 22 by the drive unit 23. This causes the moving body 20 to stop.

[0034] Furthermore, when the operation cooperation unit 333 recognizes that floor surface alignment processing is necessary, it calculates the movement direction and movement amount of the car 14 for aligning the floor surfaces based on the step amount detected by the step amount detection unit 332 and the movement direction of the car 14. The operation cooperation unit 333 transmits a floor surface alignment instruction to the elevator control panel 16 together with information on the calculated movement direction and movement amount of the car 14 (S8). This floor surface alignment instruction is an instruction to move the car 14 so that the floor surface of the car 14 aligns with the floor surface of the hall 17 based on the step amount detected by the step amount detection unit 332 and the movement direction of the car 14.

[0035] When the elevator control panel 16 receives the floor alignment instruction transmitted from the linkage device 30, it moves the car 14 in accordance with the movement direction and movement amount of the car 14 attached thereto, thereby performing floor alignment.

[0036] When the elevator control panel 16 completes the floor surface alignment process, it generates a floor surface alignment completion notice and transmits it to the linkage device 30.

[0037] In the coordination device 30, the operation coordination unit 333 acquires the floor surface alignment completion notification transmitted from the elevator control panel 16 via the input / output unit 334. When the operation coordination unit 333 acquires the floor surface alignment completion notification ("YES" in S9), it transmits a travel permission notification to the moving object 20 (S10).

[0038] When the moving body 20 receives the travel permission notification from the linkage device 30, the moving body control device 25 drives the drive unit 23 to start the rotation operation of the front wheels 21 and the rear wheels 22. As a result, the moving body 20 resumes moving into the car 14.

[0039] The processing of steps S1 to S10 described above is also executed when the moving body 20 that has entered the car 14 gets off the car 14 at the destination floor. In this case, the moving body 20 moves from the car 14 toward the landing, and when the front wheels 21 rest on the floor of the landing and the weight of the moving body 20 on the floor of the car 14 decreases, the car 14 moves upward as if floating, and a step occurs between the floor of the car 14 and the floor of the landing 17. When the linking device 30 detects this step, it stops the operation of the moving body 20, causes the elevator control panel 16 to perform floor surface alignment, and then resumes the operation of the moving body 20.

[0040] In the above-mentioned step S3, when the step amount detection unit 332 does not detect that the moving body 20 has straddled the floor surface of the elevator car 14 and the floor surface of the hall 17 ("NO" in S3), the process returns to step S1.

[0041] Furthermore, in the above-mentioned step S5, when the step amount detection unit 332 determines that the moving body 20 is not tilted ("NO" in S5), or when it determines in step S6 that the detected step amount does not exceed the allowable step amount ("NO" in S6), the processing is terminated.

[0042] According to the above-described embodiment, the linking device includes a step amount detection unit that detects the amount of step between the floor surface of the elevator car and the floor surface of the landing when the autonomously traveling mobile body applies its own weight to both the floor surface of the elevator car and the floor surface of the landing, and an operation linking unit that, when it recognizes that the amount of step detected by the step amount detection unit is equal to or greater than a predetermined value, stops the operation of the mobile body and moves the car so that the floor surface of the car is aligned with the floor surface of the landing.

[0043] This allows the autonomously traveling mobile object to safely board and disembark from the elevator car by coordinating the operation of the mobile object with the operation of the elevator, even in cases where the car sinks when a heavy mobile object or a mobile object carrying heavy luggage gets on the car, or where the car floats up when such a mobile object moves from the car to a landing. In this case, there is no need to provide new devices or functions to the mobile object, and existing mobile objects can be used.

[0044] Furthermore, when the operation coordination unit recognizes that the floor of the car has been moved to match the floor of the hall, it resumes the movement of the moving body, allowing the moving body that has stopped due to the occurrence of a step to resume operation in a safe state.

[0045] Furthermore, the step amount detection unit detects the direction of movement of the car when a step occurs between the floor surface of the car and the floor surface of the landing, and the operation cooperation unit moves the car so that the floor surface of the car matches the floor surface of the landing based on the step amount and movement direction detected by the step amount detection unit, thereby allowing the elevator to perform floor surface matching processing appropriately.

[0046] In the above-described embodiment, the imaging device 142a is installed on the top of the car door 141, and the moving body 20 getting on and off the car 14 is photographed from above. However, the installation position of the imaging device 142a is not limited to this, and it may be on the side panel inside the car 14, the ceiling or wall of the landing 17, etc., as long as it can photograph the monitoring area AR.

[0047] Figure 5A is a diagram showing the state in which a moving body 20 in a balanced state is viewed from an imaging device 142b installed diagonally above the direction of movement of the moving body 20, and Figure 5B is a diagram showing the state in which a tilted moving body 20 is viewed from this imaging device 142b.

[0048] As shown in Fig. 5A, in the balanced shape information when the imaging device 142b is viewing the moving body 20 in a balanced state, the length of the moving body's body in the traveling direction is recognized as L3. In contrast, as shown in Fig. 5B, in the imaging information when the imaging device is viewing the tilted moving body 20, the length of the moving body's body in the traveling direction is recognized as L4. This length L4 is longer than L3, and the greater the tilt of the moving body 20, the greater the difference between lengths L3 and L4.

[0049] Using this, the step amount detection unit 332 determines that the moving body 20 is tilted if the lengths L3 and L4 are different, and can further calculate the degree of tilt of the moving body 20 based on the magnitude of the difference between the lengths L3 and L4. The step amount detection unit 332 can also detect the amount of step between the floor surface of the car 14 and the floor surface of the landing 17 from the calculated degree of tilt of the moving body 20.

[0050] Furthermore, the object that the step amount detection unit 332 compares when the moving body 20 is in a balanced state and when it is tilted is not limited to a line segment, but may also be the area or shape of any surface within the moving body 20 or a mark or the like affixed to the moving body 20.

[0051] Furthermore, in the above-described embodiment, the case where the step amount detection unit 332 detects the step amount based on image information obtained by photographing the moving body 20 has been described, but the present invention is not limited to this. For example, a laser transmitter (not shown) installed in the hall 17 or the car 14 may irradiate a light beam at a predetermined position on the moving body 20, and the step amount detection unit 332 may calculate the degree of inclination of the moving body 20 by detecting reflection state information such as the reflection direction of the light beam, and detect the step amount based on this.

[0052] In addition, the step amount detection unit 332 may predict the degree of inclination of the moving body 20 based on the proportion of the weight of the moving body 20 that is applied to the floor surface of the elevator car 14 and the floor surface of the landing 17, and detect the step amount based on this.

[0053] The step amount detection unit 332 may also calculate the degree of inclination of the mobile body 20 based on weight information of the mobile body 20 and loading status information of luggage loaded on the mobile body 20, and detect the step amount based on this. For example, by acquiring information in advance such as when no luggage is loaded on the mobile body 20, when luggage weighing less than a predetermined value is loaded, when luggage weighing more than a predetermined value is loaded, and so on, and taking this information into consideration when the mobile body 20 gets on or off the elevator, the step amount can be detected with high accuracy.

[0054] Furthermore, the step amount detection unit 332 may detect the amount of step between the floor surface of the car 14 and the floor surface of the landing 17, based on information about the relative positional relationship between the landing door 171 and the car door 141. For example, marks may be attached to predetermined positions on the side surfaces that appear when the car door 141 and the landing door 171 are opened, and if the corresponding positional relationship of these marks deviates from the relative positional relationship when the height of the floor surface of the car 14 and the height of the floor surface of the landing 17 are aligned, the amount of step may be detected based on the amount of deviation.

[0055] In addition, information on the amount of steps that occurred when the moving body 20 previously boarded and disembarked from the elevator 14 may be stored, and the step amount detection unit 332 may use this stored information to detect the amount of steps.

[0056] Furthermore, before the moving body 20 gets on or off the car 14, the step amount detection unit 332 may detect the amount of step between the floor surface of the current car 14 and the floor surface of the landing 17 based on the difference between the height of a predetermined position of the moving body 20 getting on or off and the height of a predetermined position of another moving body of the same type as the moving body 20 that is located within the landing 17 or the car 14, and the operation cooperation unit 333 may transmit information on the detected step amount to the elevator control panel 16 and move the car 14 based on this information, thereby performing floor surface alignment in advance before getting on or off. By performing floor surface alignment before getting on or off in this manner, the moving body 20 can get on or off the car 14 even more safely.

[0057] Furthermore, in the above-described embodiment, the mobile body control device 25 is installed inside the mobile body, but the present invention is not limited to this. A mobile body control device may be provided outside the mobile body 20, and the above-described processing may be performed by this mobile body control device communicating with the mobile body 20 and the linking device 30. This simplifies the configuration of the mobile body 20.

[0058] In the above-described embodiment, the linking device 30 is installed in a building equipped with the elevator system 1, but the present invention is not limited to this, and the elevator system may be constructed by installing the linking device 30 in a remote location from the building or on the cloud and communicatively connecting to the elevator control panel 16 and the mobile object 20 via a wide area communication network. By constructing the elevator system in this way, the linking device can collectively manage elevators in multiple buildings.

[0059] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0060] 1...Elevator system, 10...Elevator, 11...Hoistway, 12...Winching machine, 13...Rope, 14...Car, 15...Tail cord, 16...Elevator control panel, 17...Landing platform, 20...Mobile body, 21...Front wheels, 22...Rear wheels, 23...Drive unit, 24...Mobile body wireless communication unit, 25...Mobile body control device, 30...Linking device, 31...Memory unit, 32...Linking wireless communication unit, 33...CPU, 141...Cage door, 142a, 142b...Imaging device, 171...Landing platform door, 311...Equilibrium state information memory unit, 312...Tolerable step amount memory unit, 331...Imaging information acquisition unit, 332...Step amount detection unit, 333...Operation linking unit, 334...Input / output unit

Claims

1. a step amount detection unit that detects the amount of step between the floor surface of the elevator car and the floor surface of the landing when an autonomous traveling mobile body applies its own weight to both the floor surface of the elevator car and the floor surface of the landing; A coordination device comprising: an operation coordination unit that, when it recognizes that the step amount detected by the step amount detection unit is equal to or greater than a predetermined value, stops the operation of the moving body and moves the elevator so that the floor surface of the elevator matches the floor surface of the platform.

2. The coordination device according to claim 1, wherein the operation coordination unit resumes the operation of the moving body when it recognizes that the floor surface of the elevator car is aligned with the floor surface of the hall by moving the elevator car.

3. the step amount detection unit detects a moving direction of the car when a step occurs between a floor surface of the car and a floor surface of a landing, The coordination device according to claim 1, wherein the operation coordination unit moves the elevator so that the floor surface of the elevator matches the floor surface of the platform based on the step amount and movement direction detected by the step amount detection unit.

4. The linkage device of claim 1, wherein the step amount detection unit detects the step amount based on at least one of the following: image information of the moving body; information on the reflection state of light irradiated onto the moving body; the ratio of the weight of the moving body on the floor surface of the elevator car and the floor surface of the landing; weight information of the moving body; loading status information of luggage loaded onto the moving body; information on the relative positional relationship between the elevator landing door and the car door; and information on the step amount that occurred when the moving body previously boarded or disembarked the elevator car.

5. before the moving body gets on or off the car, the step amount detection unit detects the step amount between the floor surface of the car and the floor surface of the platform based on the difference between the height of a predetermined position of the moving body and the height of a predetermined position of another moving body of the same type as the moving body that is located at the platform or in the car, The coordination device according to claim 1 , wherein the operation coordination unit moves the elevator car so that a floor surface of the elevator car is aligned with a floor surface of the hall, based on the detected amount of step.

6. An elevator, an autonomously traveling mobile body that uses the elevator, and a linkage device, The linkage device includes: a step amount detection unit that detects a step amount between the floor surface of the elevator car and the floor surface of the landing, which occurs when the moving body applies its own weight to both the floor surface of the elevator car and the floor surface of the landing; an operation coordination unit that, when it recognizes that the step amount detected by the step amount detection unit is equal to or greater than a predetermined value, stops the operation of the moving body and moves the car so that the floor surface of the car matches the floor surface of the landing.

Images