KR20190061380A - multi lane radar type apparatus for measuring traffic volume and apparatus for installing the same - Google Patents

Abstract

According to the present invention, an installer for multi-lane detection radar type traffic measurement device comprises: a radar module for emitting radar waves and receiving reflected waves; a signal processing module for performing processing for obtaining necessary information through the received reflected wave; a power module which includes a battery for operating the radar module and the signal processing module; and a housing and mounting module including the above modules and attachable to an installation outside the road. An installer to automatically install the traffic measurement device on a pole at the road comprises of: a gripping portion detachably gripping the traffic measurement device; an attachment and detachment operating portion for tightening or loosening an annular or band type bracket of the traffic measurement device such that the annular or band type bracket can be attached or detached surrounding a part of a side wall of the pole; a conveying portion constructed to be able to move up and down along a side surface of the pole; and a controller portion for adjusting the operation of the conveying portion, the attachment and detachment operating portion, and the gripping portion even at a remote location by wire or wireless. Thus, the equipment operating efficiency can be greatly improved.

Description

[0001] The present invention relates to a multi-lane detection radar type traffic volume measuring apparatus and a multi-lane radar type traffic volume measuring apparatus,

More particularly, the present invention relates to a multi-lane detection radar type traffic volume measuring device capable of simultaneously recognizing and integrating traffic volume passing through a plurality of lanes of a road, and a multi-lane detection radar type traffic volume measuring device The present invention relates to an installation device configured to be easily detachable from an existing facility having a columnar shape.

The collection and arrangement of various road traffic information is necessary for the smooth operation of the roads and the accident prevention in the short term and it is a key to establish the road traffic policy in the long term. Technology and computer communication technology.

The most basic and important information in road traffic is the quantity and speed of vehicles passing through a specific road point or section from time to time, and as a means of verifying the amount or speed of a passing vehicle at such a road point, Two methods are being used.

The first method is a method in which a person manually counts directly on the field through a manual counter, and it is a method of gradually decreasing usage because it takes a lot of manpower and time. The second method is to measure the amount of traffic passing through the road using mobile traffic check equipment. And, as the equipment to automatically measure the traffic volume, it is possible to use a geomagnetic sensor and a radar detector.

The geomagnetic sensor device measures the passing traffic using the detection of the magnetic field formed when the vehicle passes through the vehicle. The radar detector uses a radar that emits radio waves of a specific frequency, for example, 24.125GHz frequency ISM band. To measure the traffic volume.

The measurement of such road traffic information may be carried out for a long period of time by installing equipment fixedly in an important traffic point. However, depending on the road condition and the circumstance around the road, It is necessary to collect traffic information by moving the branches as needed. In this case, it is necessary to collect the information collecting device such as the traffic volume at the existing installation location and install the new information collection device at a new location.

However, the geomagnetic sensor installed directly on the road has problems in three aspects.

First, because of the discomfort and danger of the installation method, a person uses a fixed mat to attach the geomagnetic sensor to the center of the vehicle, and the risk of traffic accident caused by the passing vehicle is very large. The driver can also be a big threat. Of course, the same risk exists when collecting equipment.

Secondly, since it is adhered directly to the road as an adverse effect due to road installation, there is a great risk of breakage of the geomagnetic sensor due to a large vehicle. Even if a minute crack is generated due to impact on the case, moisture penetrates into the equipment during rain. It may cause malfunction.

The third is the limit of the use by the weather, and there are many restrictions on the equipment operation depending on the influence of the weather. In other words, it is almost impossible to attach the geomagnetic sensor to the road by using the fixing mat in case of rainy weather, and when the weather or the temperature in the early winter falls below freezing, the fixing adistance of the fixing mat is weakened, Installation becomes impossible.

In addition, there is a problem in that it is difficult to make mobile equipment to be used by moving a plurality of places because there is a lot of inconvenience in moving installation even in a device using a radar probe. For example, when installing an existing radar probe on the road, it is troublesome and dangerous when attaching and detaching like a geomagnetic sensor, and in many cases, it is installed at a height of 5 m or more in order to secure a proper detection range by using a pole outside the road. In the past, additional power supply boxes and controller enclosures have been supplied and operated. However, installing such equipment on the high posts is very inconvenient, time-consuming, costly, and dangerous for operators.

Korea Patent Registration 10-1457137 Korean Patent Publication No. 10-2013-0049639

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the conventional geomagnetic sensor and conventional traffic detection methods,

A multi-lane detection radar-type traffic volume measurement device and a device for installation and recovery which can be installed outside the road, so that it is possible to avoid the danger and troubles during installation and removal, And an object thereof is to provide a mounting apparatus suitable for the above-mentioned apparatus.

The present invention also relates to a multi-lane detection radar type traffic volume measuring device having a configuration that is not in direct contact with a vehicle and is not subjected to an impact by a passing vehicle, thereby preventing damage or loss of equipment, And it is an object of the present invention to provide an installation device suitable for installation of a device.

According to another aspect of the present invention, there is provided a multi-lane detection radar type traffic volume measuring apparatus including a radar module for emitting radar waves and receiving reflected waves, a signal processing module for performing processing for obtaining necessary information through received reflected waves, A power module including a battery for operating a module and a signal processing module, and a housing and a mounting module for attaching the module to the outside of the road.

In the present invention, a radar module basically includes an antenna for transmission and reception of radar waves. The signal processing module includes a processor for obtaining traffic information including traffic volume information through processing and analysis of a signal by a reflected wave received by the radar module, And a kind of computer including hardware and a processing program such as a memory.

In the present invention, the oscillation circuit portion of the radar wave usually belongs to the radar module, but it may belong to the signal processing module and the radar module may be configured to send the radar wave.

In the present invention, the information processed and acquired by the traffic volume measuring device may be transmitted to a central control unit for collecting traffic information and integrating traffic information through a communication module and a communication network and managing the entire traffic system, and conversely, A control signal necessary for operation of the traffic volume measuring device can be inputted. At this time, the communication module may be configured as a part of a general signal processing module or as a separate element.

In the present invention, the housing and the mounting module are provided with a housing housing including a radar module, a signal processing module, and a power module so as to be suitable for installation on a column such as a pillar, a pole, And a bracket coupled to the housing and detachably mounted on the pillar on the other hand.

In the present invention, the enclosure of the housing and the mounting module may be in the form of a docking station capable of detachably mounting the radar module, the signal processing module, and the power module (battery) in a one-touch manner.

The installation device for the traffic volume measuring device of the present invention is installed in the form of enclosing a part of a side wall of a pillar type road surrounding facility of a traffic volume measuring device having an annular or band type bracket, An apparatus for removal from a sidewall,

A detaching and manipulating unit for mounting or dismounting a sidewall of a pillar-shaped road-surrounding facility, a grip unit for detachably holding the traffic-measuring apparatus itself, an annular or band-shaped bracket of the traffic- And a controller for controlling the operation of the gripper, the transferring unit, the attaching / detaching operation unit, and the gripper unit.

The conveying portion of the present invention includes an annular or band-shaped main body that surrounds a pole-like road peripheral facilities in a spaced apart state, and a conveyor which is installed on the inside of the main body to move up and down along the pole- And a movable part such as an electric wheel. For such a construction, the movable part such as the electric wheel and the main body may be tacked with an elastic object interposed therebetween, or the movable part itself may be made of a stretchable or elastic body such as a urethane resin or an air tube, A means for closing the movable part of the electric wheel or the like to be pressed onto the surface of the column-shaped facility may be provided in a state where the facility is installed on the side of the facility.

According to the multi-lane detection radar type traffic volume measuring apparatus of the present invention, it is possible to protect the vehicle from the risk of traffic accident because the person does not directly enter the road, and the risk of damage or loss of the equipment is low, The equipment operation efficiency can be greatly improved.

In addition, according to the present invention apparatus, since it is possible to measure information such as the traffic volume at the point of time to be always measured, regardless of the state of the weather, it is possible to diversify the configuration of the equipment, Thereby facilitating the movement and installation.

The installation device of the present invention can easily or efficiently install or collect the traffic volume measuring device at a high position of the columnar roadside facilities.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram schematically showing a general configuration of a traffic volume measurement system including a multi-lane detection radar type traffic volume measuring apparatus of the present invention;
Fig. 2 is a schematic diagram showing a simplified configuration of an embodiment of the measuring apparatus of the present invention,
3 is a side sectional view schematically showing the configuration of another embodiment of the measurement apparatus of the present invention,
FIG. 4 is a conceptual diagram of a usage outline schematically showing an example of a usage form of the installation apparatus of the present invention,
5 is a conceptual side view showing a conceptual configuration of an embodiment of the installation device of the present invention and a combination of the installation device and the traffic volume measurement device.
Fig. 6 is a perspective view conceptually showing the configuration of a conveyance portion of another embodiment of the installation device of the present invention. Fig.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the overall configuration of a traffic volume measurement system including a multi-lane detection radar type traffic volume measuring apparatus according to the present invention. FIG. 2 is a block diagram of a configuration of a traffic volume measuring system including a radar module, a signal processing module, Lane detection radar type traffic volume measuring device which is integrally combined and installed in a case (for example, a case).

Referring to the system configuration shown in FIG. 1, the traffic measurement device 100 is installed on a pillar installed on a road, and the antenna of the radar module is installed to direct a certain section of all the lanes of the road ahead of it. That is, the range of the radiated emission solid angle of the antenna surface of the radar module and the effective sensing distance range cover a certain section of all lanes of the measurement target road.

On the other hand, in the present invention apparatus, the installation direction of the radar antenna and the coverage area are important, and the vehicle and other vehicles can always pass adjacent to each other. In this case, the large vehicle or the preceding vehicle can shield the radar wave So that a small vehicle or a rear vehicle enters the propagation shadow zone, whereby accurate detection of the presence of a small vehicle and the number of vehicles can be restricted. This problem is more important when detecting a vehicle passing through a plurality of lanes with a single radar type traffic measurement device. Particularly, as in the present invention, not at a high position in front of the vehicle, It is necessary to use a method of temporarily minimizing the vehicle which is caught in the propagation shadow zone and can not be measured in order to measure the traffic volume accurately.

In this case, in the present invention, the multi-loop zone is set as an additional function to divide the lane section into a plurality of sections, and the traffic volume accuracy (vehicle number) of each section is measured to improve the traffic volume accuracy by software processing have.

For example, a plurality of virtual loops may be set in the interval of 30 to 100 meters in front of the measuring device so that a plurality of vehicles to be measured are detected, and a plurality of separated vehicles or a plurality of cars The traffic volume is calculated by selecting a case where the vehicle is detected as a plurality of vehicles.

Traffic information (traffic volume information) obtained by the traffic volume measuring apparatus 100 of the present invention is transmitted to a nearby access point (AP) or a hub 210 via short-range wireless communication, and the hub is connected to a communication network To the control server 220 of the traffic center, etc., and the necessary connection terminal 230 can fetch the information for use or monitor the situation.

The existing geomagnetic sensor is installed in the center of the road directly by a person, but the risk of a traffic accident is very high. However, the device of this embodiment is located outside the road as shown in the drawing. It is installed on a column for use. In such an installation location, the operator does not have to go directly into the road for installation.

Therefore, when the present embodiment is used, the operator can be safely protected by the traveling vehicle at the time of installation and removal from the risk of traffic accident, and no breakage or loss due to the traveling vehicle can be prevented since there is no contact with the traveling vehicle.

2, a radar module 10, a signal processing module 20, a power module 30, and the like are integrally formed in a box (case) 41 of a housing of a traffic measurement device and a mounting module 40 Respectively. The enclosure 41 including the respective modules is provided with a packing (not shown) in a portion in close contact with each other when assembling the hermetically sealed assembly against rain, so as to achieve a waterproof state, prevent inflow of external dust, But it is also possible to prevent problems such as short circuit and short circuit due to stacking.

The housing 41 is connected to the mounting bracket 43 and is installed on the sidewall of the pillar A of the road. To this end, the bracket 43 has a band 431 installed to surround a part of the column sidewall and a fastening means 433 such as a bolt nut in a part of the band. The gap between both ends of the band is reduced or widened through the band 431 and the bracket 43, So that it can be attached and detached.

Fig. 3 shows an embodiment of a traffic volume measuring apparatus different from that of Fig. The case 141 of the main body in which the signal processing module 120 is built in the form of a main board has insertion grooves 141a and 141b also serving as guide grooves and the radar module 110 and the battery 130 Inserted into the insertion groove in a cut-ridge shape, and can be detached and detached in a one-touch manner.

A power supply line and a signal line are provided on the bottom surface of the insertion groove of the insertion / detachment site for the functional connection between them and the cut edge contact surface corresponding to the bottom surface so that they can be connected in the form of a pin and a socket of the connector.

Packings 141c and 141d made of an elastic soft material are installed at the entrance of the insertion grooves 141a and 141b to prevent external rainwater and dust from entering. When the cartridge type modules are fully inserted into the main body case 141, the cartridge is fixed to the main body case 141 in a state in which the cartridge corresponding portion 113 is pressed by pressing the packings 141c and 141d.

Although not shown here, when inserting the cut ridge for the detachment of the one-touch type, when the elastic body such as a spring interposed between the cut ridge and the main body is compressed and fully connected, the cut ridge and the fixed body When the cartridge is fixed a little and the cartridge is further pushed toward the insertion groove for releasing the cartridge in this state, the latching portion for fixing the cartridge is released from the groove and the cartridge is cut off so as to partially protrude from the insertion groove by the restoring force of the compressed elastic body The ridge and the main body case can be formed.

 The radar module 110 basically includes a radar antenna that emits a radar wave in an external constant solid angle range and receives a reflected wave reflected from an external object. The radar module 110 includes an oscillator that generates a radio wave of a certain frequency to be radiated, To a predetermined value. The antenna component of the radar module is exposed to the outside and is directed to the road surface to be monitored even when inserted into the main body case.

The configuration of the radar module 110 is common to the existing radar technology for traffic detection in terms of basic configuration, and the reflection range of the radio wave emission range for the multi-lane detection and the range of the range is hardware control and software for the existing radar , Which is already known in the art, and a detailed description thereof will be omitted here.

The signal processing module 120 may be thought of as a kind of computer device. The radar module 110 processes the electrical signals converted by the reflected waves through a processor by a built-in processing program, temporarily stores the results in a predetermined format, accumulates the results over a predetermined period or performs other secondary processing, So that the user can obtain desired information.

For example, by using the hardware and software constituting the signal processing module 120, it is possible to identify what is a valid vehicle through signals sensed for each car line and each section and the number of vehicles passing through the corresponding area for a certain period of time Can be stored through its own storage unit and detachable auxiliary memory, and can be wirelessly transmitted to a central control station (traffic center, etc.) through an access point or a hub of the surrounding transmission network through the communication module. Therefore, traffic information can be retrieved and checked easily at any time by using the auxiliary memory detachment or wireless information communication.

The battery 130 is preferably a power module and can be maintained by a small number of people. Therefore, it is preferable to use a secondary battery having a charge capacity capable of operating for 72 hours without replacement. In addition, it is preferable to adopt a lithium ion battery or a lithium polymer battery which can increase the charging amount per unit mass so that the secondary battery is advantageous for desorption and movement of the system.

When the communication module is used, the processing program and operating condition of the processing module are corrected, updated, and reset in an external controller or a remote controller terminal that can be easily installed in a neighboring hub while leaving the present invention device at the existing installation place It can be used and can monitor function abnormality. Even if a function abnormality occurs, the module can be initialized or an error can be corrected and used.

FIG. 3 deals with a case of a cut-ridge mounting type (or a docking station type). However, the apparatus of the present invention is not easily separated by installing a radar module, a battery, a communication module such as wireless WIFI, It can be operated in a stable state.

FIG. 4 is a conceptual diagram for explaining the concept of an installation device for easily mounting, removing, or collecting the above-mentioned traffic measurement device in a facility such as a pillar of a road for easy operation.

Referring to FIG. 4, a traffic volume measuring device may be installed using a column A installed on a road for a milestone A1 installed adjacent to a point such as a bifurcation of a road or installed periodically for ventilating a destination distance At this time, the installation apparatus of the present invention is used to automatically install the traffic volume measuring apparatus without preparing a ladder or a ladder.

That is, the installation device 200 is first mounted on the lower part of the column A, and the traffic volume measurement device 100 is coupled to the installation device 200 in a state where the installation device 200 is also in the lower part of the column. In this state, the operator installs the traffic measuring device 100 at the high position of the column through the manipulation of the operator. The installation device 200 firmly fixes the traffic measurement device 100 on the column and then separates and removes the traffic measurement device 100 from the installation device 200 so that the traffic measurement device 100 can be pivoted When it is in a high position, it moves to the lower position of the column. In this state, the operator removes the mounting device from the column and moves it to the next working position.

If the existing traffic measurement device is collected from the column, the work will be done in the reverse order.

In other words, the installation device is first installed in the lower part of the column (low position) and moved to the higher position, and the traffic volume measurement device is gripped at the higher position and tightly coupled to the installation device, .

Subsequently, the installation device is moved to a lower position of the column in a state of being combined with the traffic measurement device. In the lower position, the operator separates the traffic measurement device and the installation device from the columns and collects them.

For this operation, the installation device has a controller unit (not shown) that can control the movement of the main body through wired or wireless control while being separated from the main body of the installation apparatus.

5 is a conceptual side view showing a conceptual configuration of an embodiment of the installation device of the present invention and a combination of the installation device and the traffic volume measurement device.

In this embodiment, the installation device for the traffic measurement device 100 is configured such that the bracket 143 of the traffic measurement device is mounted in the form of wrapping a part of the side wall of a pillar A-shaped peripheral facility, 100 of the traffic volume measurement apparatus 100 from the side wall of the roadside facility and includes a grip unit 240 for detachably holding the traffic volume measurement apparatus 100, an annular band (not shown) of the bracket 143 of the traffic volume measurement apparatus 100 1431) for mounting or dismounting a part of a sidewall of the facilities around the road in the form of a column, a mounting / dismounting part (250) for mounting / dismounting the mounting device (Not shown) for controlling the operation of the transfer unit 210 ', the transfer unit 210', the attaching / detaching operation unit 250, and the grip unit 240.

The grip portion 240 may be formed in various shapes, but a simple example may be a shape in which a vise is engaged with a U-shaped frame for engagement and a fastening bolt provided on one of the fastening portions. . The case of the traffic measurement device is placed between the two sides of the U-shaped frame, and the motor combined with the fastening bolt is rotated in the forward and reverse directions so that the end of the fastening bolt is tightened or loosened, The motor can be controlled by the controller.

A band 1431 installed on the sidewall of the pillar A of the road so as to surround a part of the sidewall of the pillar and a bracket 143 provided on the traffic volume measuring device for installing the traffic volume measuring device, When the bolt-nut type fastening means 1433 is used as a means for tightening the bolt-nut fastening means 1433, the attaching / detaching operation portion 250 is moved in such a manner as to reciprocate to the present position of the bolt nut of the fastening means, And a portion for tightening the bolt nut which is the fastening means. In order to drive the bolt nut, driving means such as a motor and an actuator are also provided, and these driving means can also be operated by the control of the controller. In this respect, the attaching and detaching operation portion may also have a configuration of a robot arm.

FIG. 6 is a perspective view showing another configuration of the conveyance unit in another embodiment. FIG. In this embodiment, the conveying unit includes a band-shaped main body 210 having a circular annular or angular annular shape and surrounding the facilities in the form of a pole in the form of a column, Movable parts 221 and 231 such as electric wheels that can move up and down along the facility of the vehicle, movable part frames 222 and 232 for connecting the movable part to the main body, and movable parts that can be brought close to or spaced from the column surface Tightening means (223, 233), and a motor (235) for moving the movable portion by receiving a wired or wireless signal of the remote controller.

The band-shaped body may have a cutout (not shown) on its part for attachment or detachment with the pillar, and may be opened or closed through the cutout.

The moving parts 221 and 231 such as the electric wheels and the main body 210 are rotated between the positions of the movable parts 221 and 231 so as to rotate around the column as the mounting device moves up or down along the column surface Or the movable part itself may be made of an elastic body such as a urethane resin or an air tube, or alternatively or in a state in which the movable part itself is installed on the side surface of a columnar structure, the movable part of the electric wheel or the like, And tightening means (223, 233) for tightening to the surface of the facility.

The moving part preferably has three or more wheels or driving parts distributed on the inside of the main body, and a part of the wheels may be arranged such that the rolling direction rotates the main body around the pillar. For example, as shown in FIG. 6, a hexagonal band is provided at the upper and lower portions, and these are connected to the intermediate connection frame. In each hexagonal band, three wheels are provided. Three wheels of the upper band and three wheels of the lower band are all composed of electric wheels and the lower three wheels are arranged in the direction of the clouds to move the body up and down and the upper three wheels The wheels can be operated by arranging the direction of the clouds in such a manner that the body rotates around the columns.

In other words, when moving up and down, the actuator of the tightening means is adjusted to lower the tightness of the upper three wheels through the controller, and the upper and lower wheels are moved around the lower three wheels. The actuator of the tightening means may be adjusted so as to reduce the degree of contact with the pillar of the wheels of the wheels so that the wheel can be operated by rotating the upper three wheels.

The gripping portion or the attaching / detaching operation portion of the attaching device may be detachably coupled to a frame extending portion that is not shown in FIG. 6 but is bent at the upper portion of the frame constituting the body 210 of FIG. 6 and extends inwardly in the horizontal direction.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, will be. Accordingly, the spirit of the present invention should be understood only in accordance with the following claims, and all equivalents or equivalent variations thereof are included in the scope of the present invention.

10, 110: Radar module 20, 120: Signal processing module
30, 130: power module (battery) 40: housing and mounting module
41: Enclosure 43, 143: Bracket
100: traffic volume measuring device
141: case 141a, 141b: insertion groove
141c, 141d: packing 200: mounting device
210: band type main body 221, 231:
222, 232: movable frame 223, 233: tightening means
235: motor 240:
250:

Claims (7)

A multi-lane detection radar type traffic volume measuring device,
A radar module for emitting radar waves and receiving reflected waves, a signal processing module for performing signal processing for obtaining necessary information through the reflected waves, a rechargeable battery for supplying power for operating the radar module and the signal processing module A power module including the radar module, the signal processing module, and the power module, and a housing and a mounting module that are integrally coupled to the radar module,
Wherein the radar module includes an antenna for transmitting and receiving radar waves,
The signal processing module includes a processor for obtaining traffic volume information through processing and analysis of a signal by the reflected wave received by the radar module, a memory and a signal processing program, and a communication module for exchanging information with the outside A multi-lane detection radar type traffic volume measuring device. The method according to claim 1,
Wherein the radar module and the battery are a docking station system detachably connected to the housing and the mounting module in a cartridge type manner. The method according to claim 1,
The housing and the mounting module include a housing housing including a radar module, a signal processing module, and a power module, and a bracket coupled to the housing on one side and detachably mounted on the other side of the housing,
Wherein the bracket includes a band portion that completely or partially surrounds a predetermined height of the side surface of the column and a fastening device provided at the two end portions so as to narrow or increase the distance between the two end portions of the band portion A multi-lane detection radar type traffic volume measuring device. The method according to claim 1,
Wherein the signal processing module includes a processing program,
In the process program, in counting the number of vehicles in the target area, the preceding vehicle shields the radar wave for the rear vehicle so that the rear vehicle enters the propagation shadow zone, thereby preventing the accurate detection of the number of vehicles. Wherein the multi-lane detection radar type traffic volume measuring device includes an algorithm for setting a multi-loop zone to divide a lane section into a plurality of lane sections, and to select a maximum value by measuring a traffic value (vehicle number) of each divided lane section. An installation device for installing a traffic volume measuring device having an annular or band type bracket surrounding a column on a column,
A grip portion for detachably holding the traffic volume measurement device,
Wherein the annular or band type bracket of the traffic volume measurement device is mounted or detached in a manner to surround a part of the side walls of the column,
A conveying unit configured to be able to move up and down along a side surface of the column,
And a controller for controlling operations of the transferring unit, the attaching / detaching operation unit, and the gripping unit by wire or wireless even at a position away from the transferring unit, the attaching / detaching operation unit, and the gripping unit. 6. The method of claim 5,
The conveying unit includes a main body enclosing the column in a spaced apart state, and a movable part installed inside the main body and movable up and down along the column while being in contact with a side of the column,
Further comprising adjusting means for adjusting the degree of close contact between the column surface and the movable portion. The method according to claim 6,
Wherein the movable portion has three or more electric wheels distributed on the inner side of the main body,
Wherein a part of the electric wheel is arranged so that the rolling direction is able to rotate the main body around the column.

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