KR20210064906A - Movable fire detector - Google Patents

Abstract

According to an embodiment of the present invention, provided is an IoT based mobile fire detector, which is portable and easy to move, does not require specialized personnel for installation and measurement, and can detect a fire in an industrial construction site early. The mobile fire detector according to an embodiment of the present invention includes: a sensor module disposed at an end of a pull-out member to detect fire-related information; a support for positioning the housing at a set height from the ground; and a communication unit which transmits sensing information detected by the sensor module to a control system in real time, and receives instruction information from the control system.

Description

MOVABLE FIRE DETECTOR

The present invention relates to a mobile fire detector, and by applying a module that can detect a fire in an industrial construction site early, it is an Internet of Things (IOT)-based mobile fire detector that recognizes the situation immediately in case of a fire and facilitates initial response. it's about

Most of the disasters caused by fire, explosion, and suffocation at construction sites are caused by welding welding, using heating and electric heaters, and electric leakage. Disasters caused by fires at construction sites are not very frequent, but they require a lot of attention because they cause a decrease in the durability of the construction and a lot of casualties.

However, construction sites are vulnerable to fire accidents because each work is performed simultaneously in various work processes and in several spaces. In addition, there are many cases of working in a place with insufficient ventilation and in an enclosed space, and the insufficient monitoring function of the fire monitor is also analyzed as the cause.

However, the domestic fire detector market is still mainly formed of low-cost sensors such as thermal sensors. Such a fire detection system measures oxygen, carbon dioxide, temperature, flame, etc., and it is difficult to find a study on a system that transmits and controls accident scene data in real time.

Accordingly, although the Internet of Things (IoT)-based fire management system has been actively conducted in recent years, it is impossible to move it by installing a sensor on a simple wall, and it is inconvenient to install it every time because it requires professional manpower for measurement. .

In addition, in relation to most of the construction site fires, when the construction completion rate exceeds 60%, the frame work is finished, and the interior and exterior finishing materials are installed, so a fire detector installed on a wall or a column has a problem in reality.

Since the contents described in the above-mentioned background are only prepared for understanding the background of the present invention, it may include contents other than those already known to those skilled in the art.

Patent Document 1: Registered Patent No. 10-0973297 Patent Document 2: Registered Utility Model No. 20-0390989 Patent Document 3: Registered Utility Model No. 20-0450081

Embodiments of the present invention are portable and easy to move, do not require professional personnel to install and measure, and to provide an Internet of Things (IoT)-based mobile fire detector capable of early detection of fires in industrial construction sites. .

A movable fire detector according to an embodiment of the present invention includes a pull-out member mounted on the housing so as to be drawn out from the inside of the housing; a sensor module disposed at an end of the pull-out member to detect fire-related information; a support for positioning the housing at a set height from the ground; and a communication unit for transmitting the sensing information sensed by the sensor module to a control system in real time and receiving instruction information from the control system.

In the movable fire detector according to an embodiment of the present invention, the pull-out member may include: a first pull-out member drawn out toward an upper side of the housing; and a second take-out member drawn out toward a lower side of the housing, wherein the sensor module may be disposed at an upper end of the first take-out member and a lower end of the second take-out member.

In the mobile fire detector according to an embodiment of the present invention, the sensor module includes at least one selected from a smoke sensor, a fine dust sensor, a thermocouple sensor, a flame detection sensor, and a gas sensor, and the gas sensor includes CO, CO2, Or it can sense O2.

The movable fire detector according to an embodiment of the present invention further includes a photographing unit provided in a main body disposed on one side of the housing, and the photographing unit includes at least one of an RGB camera, an infrared camera, a sound detection unit, and a motion detection sensor can do.

In the mobile fire detector according to the embodiment of the present invention, the communication unit may transmit the information sensed by the photographing unit to the control system and receive information from the control system.

A mobile fire detector according to an embodiment of the present invention includes information detected by the sensor module and the photographing unit; and a controller for controlling the operation of a speaker, a display, or a warning light according to the information received from the communication unit.

In the mobile fire detector according to an embodiment of the present invention, the controller includes information detected by the sensor module and the photographing unit; And, according to the information received from the communication unit, an evacuation process for surrounding evacuation may be performed in the first early warning state, and a fire reporting process may be performed through the control system in the second confirmed alert state.

In the mobile fire detector according to an embodiment of the present invention, the display unit may display information detected by the sensor module, information received from the control system, and video call information in real time.

In the mobile fire detector according to an embodiment of the present invention, the speaker may notify a preset emergency sound, evacuation information, or fire information, or transmit information received from the control system.

In the mobile fire detector according to the embodiment of the present invention, the warning light may express a color step by step according to information sensed by the sensor module and information received from the control system.

In the mobile fire detector according to the embodiment of the present invention, further comprising a GPS sensor for detecting the corresponding location information, the communication unit may transmit the location information to the control system in real time.

In the mobile fire detector according to the embodiment of the present invention, the pull-out member may have at least two telescopic pipe structures, respectively.

The movable fire detector according to an embodiment of the present invention may further include a horizontal sensing unit for detecting and notifying a horizontal state of the main body and a vertical state of the pull-out member.

The movable fire detector according to an embodiment of the present invention may further include a main body rotating unit for moving the main body along the periphery of the housing so that the photographing unit can photograph the periphery of the housing.

The movable fire detector according to an embodiment of the present invention may further include a module rotating unit configured to rotate the sensor module to sense the periphery of the pull-out member.

The movable fire detector according to an embodiment of the present invention may further include a light exposed at an end of the pull-out member.

In the mobile fire detector according to the embodiment of the present invention, a scale indicating a length may be displayed on the pull-out member.

In the mobile fire detector according to the embodiment of the present invention, the telescopic pipes may have a preset unit length.

In the mobile fire detector according to an embodiment of the present invention, the telescopic pipes may have different colors to enable external identification.

In the mobile fire detector according to an embodiment of the present invention, the support has a telescopic pipe structure and has a structure that is lengthened or shortened, and at least three of them may be configured to contact the ground.

According to embodiments of the present invention, as an early fire detector to which a portable early fire detection module is applied, it is possible to more accurately and quickly deliver a situation by providing primary danger warning information and providing secondary confirmation warning information.

In addition, it is possible to accurately determine the situation and give accurate instructions by applying the technology to detect changes in numerical values such as oxygen and carbon dioxide in the work site more quickly than the information such as smoke, flame, and heat collected through existing alarms in the field.

In addition, it is possible to reduce enormous property damage due to fire and economic and industrial damage due to the erroneous operation of a fire engine, and it is possible to report a fire through the network in the early stage of a fire, and it is possible to reduce damage caused by fire.

In addition, through the concentration of smoke detectors, flame detectors, carbon monoxide, carbon dioxide, oxygen, fine dust (PM2.5), etc., the primary early warning: when one or two of the sensors are operating (oxygen and carbon monoxide), early warning and Execute the evacuation of personnel in the area, and 2nd confirmed alarm: 3~4 modules of the detectors are activated (1st alarm + smoke detector, carbon dioxide), so you can immediately report a fire through the management and control center and evacuate the surrounding personnel have.

In addition, it is easy to enter the shortest distance for rapid fire suppression and analyze the cause of the fire with on-site monitoring and control through camera, identification and rescue of the remaining personnel in the surrounding environment through infrared and motion detection, and identification of the first accident location through GPS.

In particular, a sensor module equipped with a fine dust sensor, thermocouple sensor, and flame detection sensor is attached to the upper and lower parts of the frame to detect smoke and flames that are generated at the beginning of a fire, and fine dust and gases (such as carbon monoxide, carbon dioxide, and oxygen) ) can be analyzed from the upper and lower sides to increase reliability, and immediate on-site response can be realized by identifying whether a fire has occurred.

In addition, an RGB camera, an infrared camera, and a motion sensor are attached to the main body to determine the presence or absence of survivors in situations where evacuation is required. A warning sound and light can spread the disaster situation and induce evacuation.

In addition, a GPS sensor is installed in the main body or housing to induce a smooth on-site response by transmitting the location to the fire department in the event of a fire, and by visualizing the data acquired through the sensor module through the touch screen LCD panel (display unit) It can inform users and support the management (storage and retrieval, etc.) of measured information, and support the control center and video call, so that misinformation and fire situations can be immediately disseminated.

In addition, by extending the fire detector in the vertical direction, it is possible to improve the mobility, which is a problem of the existing fire alarm, and to solve the problem that requires a professional manpower when installing the sensor.

In addition, it is possible to secure higher reliability by using a sensor module equipped with a wide range of sensors such as fine dust, flame detection, and heat, and induce real-time interaction between the site and the control center based on IoT, and whether there are any remaining people in the event of an evacuation. It is possible to implement an automatic notification system in case of confirmation and fire.

The above-mentioned effects according to the embodiments of the present invention are not limited to the described contents, and may further include all effects predictable from the specification and drawings.

1 is a front view showing a state before unfolding a mobile fire detector according to an embodiment of the present invention.
2 (a) and (b) are a plan view and a bottom view showing a state before unfolding the mobile fire detector according to an embodiment of the present invention.
3 is a front view showing a state in which the movable fire detector is unfolded according to an embodiment of the present invention.
4 is a rear view showing a state in which the movable fire detector is unfolded according to an embodiment of the present invention.
5 is a partially enlarged front view of a mobile fire detector according to an embodiment of the present invention.
6 is a partially enlarged rear view of a mobile fire detector according to an embodiment of the present invention.
7 is a schematic configuration diagram of a mobile fire detector according to an embodiment of the present invention.
8 (a) and (b) are a partial front view and a perspective view of a mobile fire detector according to another embodiment of the present invention.
9 is a partial schematic cross-sectional view of a mobile fire detector according to another embodiment of the present invention.

It should be understood that the present invention is not limited to the specific embodiments described below, and includes all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

The terms used herein are used to describe specific embodiments, and are not intended to limit the present invention. A singular expression may include a plural expression unless the context clearly dictates otherwise.

Terms such as “include” or “have” mean that there is a possibility to further include other components or actions in addition to the components or actions described in the specification. Terms such as first, second, etc. are not intended to limit the components, and are for the purpose of distinguishing one component from other components.

Hereinafter, an embodiment of a mobile fire detector according to the present invention will be described in detail with reference to the accompanying drawings. Here, the drawings according to the embodiment of the present invention and the description thereof have been described for understanding the spirit of the present invention. In addition, in describing the present invention, detailed descriptions of structures and processes related to known techniques will be omitted.

1 is a front view showing a state before unfolding a mobile fire detector according to an embodiment of the present invention.

Referring to FIG. 1 , the mobile fire detector largely includes a housing 110 , a main body 100 , and a support 115 , and an outer surface of the main body 100 has a display unit 135 and a photographing unit 140 . , a sound sensing unit 130 , a horizontal sensing unit 125 , and a speaker 105 , and the photographing unit 140 may include an RGB camera 141 and an infrared camera 142 .

The photographing unit 140 may include a separate motion detection sensor, and the infrared camera 142 may also perform the function of the motion detection sensor. In addition, a separate GPS sensor 150 may be disposed in the main body 100 or the housing 110 .

First, the housing 110 is disposed vertically in the center, and the main body 100 is coupled to the outer peripheral surface of the upper end of the housing 110 . That is, the upper end of the housing 110 has a structure that penetrates the main body 100 from the bottom to the top.

The support 115 is composed of at least three, the upper end of which is hinged to the housing 110 or the main body 100, and the lower end is configured to contact the ground, and the housing 110 has the support 115 ) to which the fixing member 120 is fixed is attached.

The RGB camera 141 may photograph a situation in front or photograph a user's face during a video call, and the horizontal sensing unit 125 shows the horizontal state of the main body 100 or the housing 110, , the speaker 105 may transmit a preset voice or a warning sound to the surroundings.

In addition, the infrared camera 142 is a charge-coupled device (CCD) camera having sufficient sensitivity to infrared, and captures the position of a person or an animal in a dark place. In addition, a near-infrared light source using a laser and an integrated infrared sensor using an image intensifier (II) may be applied.

2 (a) and (b) are a plan view and a bottom view showing a state before unfolding the mobile fire detector according to an embodiment of the present invention.

Referring to FIGS. 2A and 2B , a warning light 200 is formed to protrude from the upper rear surface of the main body 100 , and a first draw-out member 301 is provided at the upper center of the housing 110 . and a sensor module 310 is disposed at an upper end of the first take-out member 301 .

In addition, the second take-out member 302 is disposed at the lower center of the housing 110 , and the sensor module 310 is disposed at the lower end of the second take-out member 302 .

In an embodiment of the present invention, the sensor module 310 for detecting fire-related information can improve the fire detection reliability and speed by detecting the lower and upper floors of the workplace, respectively. For example, a fire may occur in the lower part or in the upper part, and even if it occurs in the lower part, since smoke or heat moves to the upper part, the detection performance may be improved according to the position of the sensor module.

It will be described in more detail with reference to FIGS. 3 and 4 .

3 is a front view showing a state in which the movable fire detector is unfolded according to an embodiment of the present invention.

1 and 3 , the lead-out member 300 includes a first take-out member 301 and a second take-out member 302, and the lead-out member 300 and the support 115 have a telescopic pipe structure. It has a structure that lengthens or shortens.

In addition, the first take-out member 301 is drawn out from the inside of the housing 110 to the upper side and has a structure that is elongated to the upper side, and the second draw-out member 302 is drawn out from the lower side inside the housing 110 to the lower side. It has an elongated structure.

The lower end of the support 115 is spread in all directions around the housing 110 to position the main body 100 and the housing 110 at a set height from the ground. A sensor module 310 is configured at an upper end of the first take-out member 301 and a lower end of the second take-out member 302, respectively.

First, referring to FIGS. 3 and 7 , the sensor module 310 includes a smoke sensor 751 , a fine dust sensor 146 , a thermocouple sensor 145 , a flame detection sensor 144 , and a gas sensor 143 . It may include at least one selected, and may include all of them. Here, the gas sensor 143 may detect carbon monoxide, carbon dioxide, and oxygen, and the gas sensor may be configured in plurality.

As described above, the sensor module 310 is disposed in the upper and lower layers of air, and the height thereof is adjusted to detect fire in various ways at various work sites, thereby improving detection accuracy. In addition, the sensor module 310 can detect a fire early by applying various sensors compared to the conventional method.

4 is a rear view showing a state in which the mobile fire detector is unfolded according to an embodiment of the present invention, and compared with FIGS. 1 to 3, characteristic differences will be mainly described, and detailed descriptions of the same and similar parts will be omitted.

Referring to FIG. 4 , a scale 400 may be further formed on the first take-out member 301 and the second take-out member 302 to easily determine the length or height thereof. In addition, the first take-out member 301 and the second take-out member 302 are each composed of at least two telescopic pipes, and they are each made to have different colors so that a user or operator can easily determine the height thereof. and can be easily identified from a distance.

In the embodiment of the present invention, the first lead-out member 301 is configured in three stages, and the second lead-out member 302 is configured in two stages, and the number may be changed according to design specifications. In addition, the second extraction member 302 may not be configured, and the sensor module 310 may be configured at the lower end of the housing 110 .

In addition, since the display unit 135 and the photographing unit 140 are configured in the main body 100, the height of the main body 100 is preferably arranged at a height that an operator can easily operate, and the display unit 135 may be configured as a touch panel.

5 is a partially enlarged front view of a mobile fire detector according to an embodiment of the present invention.

Referring to FIG. 5 , the RGB camera 141 and the infrared camera 142 are disposed on the display unit 135 , and the motion detection sensor 753 illustrated in FIG. 7 may be additionally disposed. A sound sensing unit 130 , a horizontal sensing unit 125 , and a speaker 105 are arranged under the display unit 135 , and their positions may be variously changed.

The horizontal sensing unit 125 can measure not only the horizontal level but also the vertical level, and can easily detect the verticality of the withdrawing member 300, and when the ground is inclined, the main body 100 and the withdrawing member ( 300) can be adjusted horizontally and vertically.

6 is a partially enlarged rear view of a mobile fire detector according to an embodiment of the present invention.

4 and 6, the warning light 200 is provided on one side of the upper surface of the main body 100, and the warning light 200 has green, yellow, and red colors from the bottom.

Depending on the fire warning level, a green light, a yellow light, and a red light can be activated to visually inform the operator of the fire level. In addition, there is no limitation on the installation position of the warning light 200 , and may be formed along the circumference of the main body 100 .

7 is a schematic configuration diagram of a mobile fire detector according to an embodiment of the present invention.

Referring to FIG. 7 , the mobile fire detector includes a detection unit 720 , and the detection unit 720 includes a horizontal detection unit 125 , a sensor module 310 , a photographing unit 140 , and a GPS sensor 150 . , a sound detection unit 720 , and the sensor module 310 includes a smoke sensor 751 , a dust sensor 146 , a thermocouple sensor 145 , a flame detection sensor 144 , and a gas sensor 143 . may include

In addition, the photographing unit 140 may include an RGB camera 141 , an infrared camera 142 , and a motion detection sensor 753 .

The notification unit 700 includes a speaker 105 and a warning light 200 , the communication unit 740 performs wired/wireless communication with an external system, and the external system 730 includes a control system 731 and a communication terminal. at least one of (732).

In addition, a structure including a main body rotating unit 900 for rotating the main body and a module rotating unit 800 rotating the sensor module, showing an operating principle thereof will be described with reference to FIGS. 8 and 9 .

The communication unit 740 may transmit the sensing information sensed by the sensing unit 720 to the external system 730 in real time, and may receive instruction information from the external system 730 in real time.

The controller 777 controls the operation of the notification unit 700 and the display unit 135 in real time according to the sensing information detected by the sensing unit 720 and the instruction information received from the communication unit 740 to control the operation of the on-site can direct

In particular, the controller 777 performs an evacuation process to evacuate the surroundings in the first early warning state according to the detection information detected by the detection unit 720 and the instruction information received from the communication unit 740 . In the evacuation process, a warning sound may be transmitted through the speaker 105 or an announcement for evacuation may be transmitted, and the warning lamp 200 may also be lit in yellow or red.

In addition, the controller 777 performs a fire reporting process through the external system 730 in the second confirmed alarm state according to the detection information detected by the detection unit 720 and the instruction information received from the communication unit 740 . do. In the fire reporting process, detection information about the surrounding situation is transmitted, and a request for actual fire suppression is performed. Here, an announcement for evacuation may be transmitted, and the warning light 200 may also be lit in red.

The display unit 135 displays the sensing information detected by the sensing unit 720, the instruction information/received information received from the external system 730, and video call information in real time, and displays various field conditions in real time. , and the user can select and process information through a display unit (eg, a touch screen).

The controller 777 generates a sound according to the detection information detected by the detection unit 720 through the speaker 105 of the notification unit 700 and the received information/instruction information received from the external system 730 . It can be transmitted in real time.

In addition, the controller 777 controls the color (green/indicated) step by step according to the detection information detected by the detection unit 720 through the warning light 200 and the received information/instruction information received from the external system 730 . yellow/red) can be expressed in real time.

The GPS sensor 150 of the sensing unit 720 detects the corresponding location information, and the communication unit 740 transmits the location information to the external system 730 in real time to implement rapid fire suppression.

8 (a) and (b) are a partial front view and a perspective view of a mobile fire detector according to another embodiment of the present invention.

Referring to FIG. 8 , the sensor module 310 is disposed at the end of the first take-out member 301 , the sensors are arranged along the circumference of the sensor module 310 , and the light 820 is disposed at the center of the end surface. More can be installed.

The sensors may include first, second, third, fourth, and fifth sensors 851 , 852 , 853 , 854 , 855 , which respectively include a smoke sensor, a fine dust sensor, a thermocouple sensor, a flame detection sensor, and a gas sensor. It may be a sensor, and the gas sensor may detect concentrations of carbon monoxide, carbon dioxide, and oxygen.

In the embodiment of the present invention, the module rotating unit 800 includes a motor 805 and a gear 810, and the motor 805 rotates the sensor module 310 according to an operation signal of the controller 777. can Accordingly, the sensor module 310 can more quickly and stably detect the surrounding fire danger state.

9 is a partial schematic cross-sectional view of a mobile fire detector according to another embodiment of the present invention.

The main body rotating part 900 may be further configured inside the main body 100 . The main body rotating unit 900 includes a motor 905 and a gear 910 , and the motor rotates the main body 100 around the housing 110 through the gear according to an operation signal of the controller 777 . So it can be rotated.

Accordingly, the photographing unit 140 provided in the main body 100 can stably detect the surrounding fire danger state in real time, recognize the situation of the work site more widely, and display the current situation on the display unit 135, Through the speaker 105 and the warning light 200, it is possible to easily and quickly notify.

Although the embodiments of the present invention have been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , changes, deletions, additions, etc. will be able to easily suggest other embodiments, but this will also fall within the scope of the present invention.

100: body 105: speaker
110: housing 115: support
125: horizontal sensing unit 130: sound sensing unit
135: display unit 140: photographing unit
141: RGB camera 143: gas sensor
144: flame detection sensor 145: thermocouple sensor
146: dust sensor 150: GPS sensor
142: infrared camera 301: first extraction member
302: second take-out member 300: take-out member
310: sensor module 400: scale
700: notification unit 720: detection unit
751: smoke sensor 753: motion detection sensor
777: controller 200: warning light
730: external system 731: control system
732: communication terminal 740: communication unit
800: module rotating part 805: motor
810: gear 820: light
900: body rotating part

Claims (20)

a pull-out member mounted to the housing so as to be drawn out from the inside of the housing;
a sensor module disposed at an end of the pull-out member to detect fire-related information;
a support for positioning the housing at a set height from the ground; and
a communication unit that transmits the sensing information detected by the sensor module to a control system in real time and receives instruction information from the control system; A portable fire detector comprising a. The method of claim 1,
The withdrawal member is
a first pull-out member drawn out toward the upper side of the housing; and
a second pull-out member drawn out toward the lower side of the housing; including,
and the sensor module is disposed at an upper end of the first take-out member and a lower end of the second take-out member. The method of claim 1,
The sensor module is
At least one selected from a smoke sensor, a fine dust sensor, a thermocouple sensor, a flame detection sensor, and a gas sensor,
The gas sensor is a mobile fire detector, characterized in that for detecting CO, CO2, or O2. The method of claim 1,
a photographing unit provided in a body disposed on one side of the housing; further comprising,
The photographing unit includes at least one of an RGB camera, an infrared camera, a sound detection unit, and a motion detection sensor. 5. The method of claim 4,
The communication unit transmits the information detected by the photographing unit to the control system, and the mobile fire detector, characterized in that for receiving the information from the control system. 5. The method of claim 4,
information detected by the sensor module and the photographing unit; and a controller for controlling the operation of a speaker, a display, or a warning light according to the information received from the communication unit. A mobile fire detector further comprising a. 7. The method of claim 6,
the controller
information detected by the sensor module and the photographing unit; and according to the information received from the communication unit,
In the state of the first early warning, the evacuation process is performed to evacuate the surrounding area,
A mobile fire detector, characterized in that the fire reporting process is performed through the control system in the second confirmed alarm state. 7. The method of claim 6,
The display unit is a mobile fire detector, characterized in that for displaying information detected by the sensor module, information received from the control system, and video call information in real time. 7. The method of claim 6,
The speaker notifies a preset emergency sound, evacuation information, or fire information, or transmits information received from the control system. 7. The method of claim 6,
The warning light is a mobile fire detector, characterized in that the color is expressed in stages according to the information sensed by the sensor module and the information received from the control system. The method of claim 1,
GPS sensor for detecting the corresponding location information; further comprising,
The mobile fire detector, characterized in that the communication unit transmits the location information to the control system in real time. The method of claim 1,
Each of the withdrawing members has at least two telescopic pipe structures. 5. The method of claim 4,
a horizontal sensing unit for detecting and notifying a horizontal state of the main body and a vertical state of the pull-out member; A mobile fire detector further comprising a. The method of claim 1,
a module rotating unit for rotating the sensor module to sense the periphery of the withdrawing member; A mobile fire detector further comprising a. 5. The method of claim 4,
a main body rotating unit for moving the main body along the periphery of the housing so that the photographing unit can photograph the periphery of the housing; A mobile fire detector further comprising a. The method of claim 1,
a light disposed at an end of the lead-out member; A mobile fire detector further comprising a. The method of claim 1,
The mobile fire detector, characterized in that the scale indicating the length is displayed on the pull-out member. 13. The method of claim 12,
The telescopic pipes are mobile fire detectors, characterized in that having a predetermined unit length. 13. The method of claim 12,
The telescopic pipes are mobile fire detectors, characterized in that they have different colors to enable external identification. The method of claim 1,
The support has a telescopic pipe structure and has a structure that is lengthened or shortened, and at least three mobile fire detectors are configured to be in contact with the ground.

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