JP2004191289A - Method for measuring self-location of mobile body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure the self-location of a mobile body without using an optical wave surveying instrument or a reflecting prism. <P>SOLUTION: A plurality of known points A<SB>n</SB>and B<SB>n</SB>arranged in a route of movement of the mobile body are photographed by an imaging means mounted to the mobile body. The inclination α of a screen coordinate system by an imaging means to an absolute coordinate system is determined on the basis of the difference between the absolute coordinate inclination γ of line segments A<SB>n</SB>and B<SB>n</SB>in the absolute coordinate system and the local coordinate inclination β of the line segments A<SB>n</SB>and B<SB>n</SB>in the screen coordinate system. On the basis of the inclination α and absolute coordinate values of the known points A<SB>n</SB>and B<SB>n</SB>, the coordinates O of the center of a screen in the absolute coordinate system is determined. On the basis of the coordinates O of the center, it is possible to highly accurately measure the self-location P of a specific part of the mobile body. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for measuring a self-position of a moving object by image recognition.
[0002]
[Prior art]
FIG. 6 is an explanatory view showing a self-position measuring method of a moving object according to a conventional technique. That is, conventionally, as a method of measuring the self-position of the moving object, as shown in FIG. 6, a reflecting prism is installed at each of _two known points B ₁ and B ₂ , The distances L ₁ and L ₂ to the known points B ₁ and B ₂ and the angle θ between the line segment B ₁ · M and the line segment B ₂ · M are measured by the measuring device M, and the self-position is determined by the two-point included angle method. There is a way to ask. Such a method of measuring the self-position of a moving body is employed in a surveying system in a tunnel by a shield method, for example, as disclosed in Patent Document 1 below.
[0003]
[Patent Document 1]
JP-A-2001-66133
[0004]
[Problems to be solved by the invention]
However, the conventional self-position measurement method using the two-point included angle method requires a light wave measuring device M for measuring the distances L ₁ and L ₂ and the angle θ to the known points B ₁ and B ₂ , It is necessary to install a reflection prism for surveying at the known points B ₁ and B ₂ , and it is pointed out that the cost of equipment becomes high. Moreover, as the moving body A moves in the direction of the arrow V, the smaller the measurement angle θ, the lower the position measurement accuracy cannot be avoided. In addition, when a light-shielding object exists between the known points B ₁ and B ₂ and the lightwave measuring instrument M, problems such as the inability to measure its own position are pointed out.
[0005]
The present invention has been made in view of the above-described problems, and a technical problem thereof is that a self-position capable of accurately measuring the self-position of a moving object without using a light wave measuring instrument or a reflecting prism. It is to provide a measuring method.
[0006]
[Means for Solving the Problems]
As a means for effectively solving the above-mentioned technical problem, a self-position measuring method for a moving object according to the invention of claim 1 is provided by an image pickup device mounted on the moving object at a required position on a moving path of the moving object. A plurality of arranged known points are imaged, and an absolute coordinate gradient of a line connecting the plurality of known points in an absolute coordinate system and a local coordinate gradient of a line connecting the plurality of known points in the coordinate system of the screen are used. From the difference, the inclination of the screen coordinate system by the imaging means with respect to the absolute coordinate system is obtained, and the center coordinate of the screen in the absolute coordinate system is obtained from the inclination of the coordinate system of the screen and the absolute coordinate value of the known point. From the center coordinates, the self-position of the specific position of the moving body is identified.
[0007]
According to a second aspect of the present invention, in the method of the first aspect, the known point comprises a survey nail driven into a known absolute coordinate on a moving path of the moving body. Things.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a front view of a survey vehicle showing an embodiment in which a method for measuring the position of a mobile object according to the present invention is applied to a survey system by remote control, FIG. 2 is a side view of the survey vehicle, and FIG. , A block diagram of a control system, FIG. 4 is an explanatory diagram schematically showing a measurement situation according to the present embodiment, and FIG. 5 is an explanatory diagram showing a self-position measuring method according to the present invention.
[0009]
First, a surveying vehicle 10 shown in FIGS. 1 and 2 corresponds to the moving body described in claim 1, and is a movable civil engineering equipment (for example, an excavator) 3 shown in FIG. The vehicle has a surveying vehicle main body 11 that can be driven by the front wheel 11a and the rear wheel 11b so that the total station 12 and the camera 13 are mounted on the vehicle.
[0010]
As is well known, the total station 12 is a lightwave distance measuring angle gauge that automatically collimates a target formed of a reflecting prism by light waves, and measures the distance and angle of the collimated measuring point. , Is pivotally supported by the leveling table 12a so as to keep the pivot axis vertical. As shown in the block diagram of FIG. 3, the total station 12 includes a collimation control unit 121 for automatically collimating the total station 12, and a distance measurement / angle measurement operation for the total station 12 in accordance with collimation. The leveling table 12a includes a leveling control unit 123.
[0011]
The camera 13 mounted on the surveying vehicle 10 corresponds to the image pickup means described in claim 1, and employs, for example, a small CCD camera capable of continuous photographing, that is, converts an optical image into an image signal. Things. As shown in FIGS. 1 and 2, the camera 13 can be held so that the lens surface is horizontal (the optical axis is vertical), and the camera 13 is raised and lowered on the leveling table 12a via the camera support arm 13a. It is mounted so as to be able to turn together with the total station 12 by the leveling table 12a. The shooting operation of the camera 13 and the operation of the camera support arm 13a are controlled via a camera control unit 131 shown in FIG.
[0012]
In addition to the total station 12 and the camera 13 described above, the surveying vehicle 10 includes a wheel drive device 14 for driving the front wheel 11a or the rear wheel 11b, a control device 15, a modem 16, A battery, a charging device (not shown), and the like are mounted. The control device 15 is connected with the collimation control unit 121, the distance measurement / angle measurement control unit 122, the wheel driving device 14, the leveling control unit 123, the camera control unit 131, the control device 15, and the modem 16. Further, an image processing unit 132 for processing image data from the camera 13 is connected to the modem 15.
[0013]
In FIG. 3, reference numeral 20 denotes a monitoring office constructed near a survey area by the survey vehicle 10. In the monitoring office 20, operation commands to the wheel driving device 14 of the surveying vehicle 10, operation commands such as collimation, distance measurement, and angle measurement to the total station 12, photographing operation of the camera 13, and support of the camera are provided. A remote control unit 21 for remotely controlling the running of the survey vehicle 10 and the operation of the total station 12 and the camera 13 by sending an operation command or the like such as turning by the arm 13a, a survey data in the tunnel 14 by the total station 12 and a camera. A personal computer (hereinafter, abbreviated as a personal computer) 22 corresponding to the arithmetic means according to claim 1 is provided for processing image data from the computer 13 and calculating coordinates.
[0014]
A modem 23 is connected to the remote control unit 21 and the personal computer 22. Further, a monitor 25 is connected to the modem 23 via an image processing unit 24.
[0015]
The operation of the system of the present embodiment having the above-described configuration is performed as follows. First, the power of various devices in the monitoring office 20, such as the remote control unit 21 and the personal computer 22, is turned on, and the power of various devices mounted on the surveying vehicle 10 is turned on, and the devices are warmed to an operable state. Keep the machine running. On the other hand, in the surveying vehicle 10, in a standby state, the battery, which is a power source necessary for the traveling thereof and the operation of the total station 12 and the camera 13, is charged.
[0016]
On the other hand, as shown in FIG. 4, one or more targets T ₁ , T _2, ... Are attached in advance as unknown measuring points at predetermined positions of the movable civil engineering equipment 30. The targets T ₁ , T _2, ... Are composed of reflection prisms. On the road surface L completed by the civil engineering equipment 30, two survey nails _An , _Bn , _An-1 , _Bn-1 , _An-2 , _Bn- 2,. A plurality of sets are positioned at predetermined absolute coordinates and are shot at predetermined intervals.
[0017]
The surveying nails _An , _Bn , _An-1 , _Bn-1 , _An-2 , _Bn-2 ,... Are set as surveying standards, and each is made of a synthetic resin material, paint, or the like. Is colored red or blue. The absolute coordinate data of each survey nail _An , _Bn , _An-1 , _Bn-1 , _An-2 , _Bn-2 ,... Stored in memory.
[0018]
Next, the clerk of the monitoring office 20 transmits a forward command to the control device 15 of the survey vehicle 10 via the modem 23 and the modem 16 of the survey vehicle 10 by operating the remote control unit 21. 15 starts the wheel drive device 14 of the surveying vehicle 10, and the surveying vehicle 10 starts traveling on the road surface L on which the construction is completed, toward the civil engineering equipment 30 side. At this time, in response to a control command from the control device 15 in advance, the camera control unit 131 operates the camera support arm 13a such that the camera 13 is horizontal and forward.
[0019]
As the surveying vehicle 10 travels, the traveling direction situation continuously photographed by the camera 13 is transmitted from the image processing unit 132 to the monitoring office 20 via the modem 16, and transmitted from the modem 23 of the monitoring office 20 to the monitoring office 20. The image is output to the monitor 25 via the image processing unit 24 in real time. For this reason, the clerk of the monitoring office 20 can remotely control the traveling of the survey vehicle 10 by operating the remote control unit 21 while watching the image of the front of the survey vehicle displayed on the screen of the monitor 25.
[0020]
As shown in FIG. 4, the surveying vehicle 10 is located at a position where collimation, distance measurement, and angle measurement of the total station 12 with respect to targets T ₁ , T ₂ ,. When the vehicle reaches a place where a survey nail is set, for example, a place where the survey nails A _n and B _n are closest to the civil engineering equipment 30, the traveling is stopped there. Next, the staff of the monitoring office 20 transmits the self-position measurement command of the survey vehicle 10 to the control device 15 of the survey vehicle 10 via the modems 23 and 16 by operating the remote control unit 21. In this case, first, in response to a control command from the control device 15, the camera control unit 131 operates the camera support arm 13a so that the camera 13 faces vertically downward, in other words, the lens surface is horizontal. For this reason, the camera 13 projects the survey nails A _n and B _n .
[0021]
Next, surveying nails A _n that is sent to the monitoring office 20 from the camera 13 via the image processing section 132 and the modem _16, the image data and the memory stored in advance surveying nails A _n of PC 22 of B _n, B _From the absolute coordinate data of _n , the personal computer 22 calculates the absolute coordinates P of the self-position of the surveying vehicle 10 at a predetermined position (for example, the total station 12).
[0022]
The method of calculating the self-position will be described with reference to FIG. 5. As described above, the survey nails A _n and B _n are cast on the previously obtained absolute coordinates as a reference for the survey. Therefore, the coordinate values are known in the absolute coordinate system, that is, the XY coordinate system in FIG. Therefore, first, surveying nails _A n, the known absolute coordinate data of _{B n,} absolute coordinates inclination γ of the line segment _A n _{B n} in the XY coordinate system are determined.
[0023]
Next, the local coordinate inclination of the line segment A _n B _n in χψ coordinate system on the screen captured by the camera 13 (referred to tentatively as the camera coordinate system) beta is obtained. Since the camera 13 is held so that the lens surface is horizontal (the optical axis is vertical), a predetermined area immediately below the camera 13 can be accurately photographed. Does not occur. Then, the inclination α of the turning direction of the camera 13 in the absolute coordinate system (XY coordinate system) can be obtained from the difference between the absolute coordinate inclination γ and the local coordinate inclination β (α = γ−β). Here, the inclination α of the camera 13 is derived from the turning angle of the leveling table 12a.
[0024]
Next, the absolute coordinate value O of the camera center point is calculated by using the absolute coordinate values of the survey nails A _n and B _n and the inclination α of the camera 13 in the absolute coordinate system. Note that the camera center point corresponds to the center of the screen. Since the positional relationship between the camera center point and the total station 12 is fixed, the absolute coordinates P of the self-position of the total station 12 can be calculated from the distance and the angle γ between the survey nails A _n and B _n .
[0025]
According to the conventional method of obtaining the self-position by the two-point included angle method shown in FIG. 6 described above, the included angle θ decreases with the movement of the surveying vehicle (the moving body A), and the measurement accuracy may be reduced. However, according to the method described above, the known absolute coordinate data of the survey nails _An , _Bn , _An-1 , _Bn-1 , _An-2 , _Bn-2 ,. Therefore, the self-position can be measured with high accuracy. Further, unlike the related art, there is no need to periodically re-install a rear measurement target serving as a reference point for measuring the self-position of the total station 12. This eliminates the need to locate and install the rear measurement target at a known point.
[0026]
When the absolute coordinates P of the self-position of the total station 12 are obtained by the personal computer 22, the clerk of the monitoring office 20 transmits a command for the automatic distance measurement and angle measurement operation by the total station 12 from the remote control unit 21. Thus, the leveling control unit 123 first operates the leveling table 12a to hold the total station 12 horizontally. Then, the total station 12 is moved to the surveying target installed on the civil engineering equipment 30 shown in FIG. survey of target T _1, T 2 _..., and automatically collimates respectively, operate ranging and angle measuring control section 122, the distance and angle of each target T _1, to T 2 _... by the total station 12 in order Then, the survey data is transmitted from the control device 15 to the monitoring office 20 via the modem 16.
[0027]
The monitoring office 20 receives the survey data of the targets T ₁ , T _2, ... Transmitted from the total station 12 by the personal computer 22 through the modem 23 and performs arithmetic processing based on the self-position data and the direction angle of the total station 12. The position and direction of the civil engineering equipment 30 can be calculated.
[0028]
In the above-described embodiment, the present invention is applied to the case where the position and the direction of the construction vehicle and the like are tracked and the self-position of the survey vehicle to be surveyed is identified. However, the present invention can also be applied to the self-position identification of other moving objects. Needless to say,
[0029]
【The invention's effect】
According to the moving object self-position measuring method according to the first aspect of the present invention, a plurality of known points arranged on the moving path of the moving object are photographed by the imaging means mounted on the moving object, and the image is taken in the coordinate system of the screen. From the local coordinate inclination of the line connecting the plurality of known points and the absolute coordinate inclination of the line connecting the plurality of known points in the absolute coordinate system, the inclination of the coordinate system of the screen by the imaging means with respect to the absolute coordinate system is obtained. Since the center coordinates of the screen in the absolute coordinate system are obtained from the inclination and the absolute coordinate values of the plurality of known points, and the self-position of a specific portion of the moving object is measured from the center coordinates, the self- A reflective prism or the like for position measurement is unnecessary, and highly accurate self-position measurement can be performed.
[0030]
According to the self-position measuring method of the moving body according to the second aspect of the present invention, as the known point in the first or second aspect, a survey nail nailed on a known absolute coordinate in a moving path of the moving body is used. Therefore, there is no need to set up a rear measuring point target such as a reflective prism as in the case of identifying its own position with a light wave surveying instrument, and it is necessary to change the rear measuring point target every time the moving body moves. There is no.
[Brief description of the drawings]
FIG. 1 is a front view of a surveying vehicle showing an embodiment in which a method for measuring the position of a moving object according to the present invention is applied to a surveying system by remote control.
FIG. 2 is a plan view of a surveying vehicle showing an embodiment in which the method for measuring the position of a mobile object according to the present invention is applied to a surveying system by remote control.
FIG. 3 is a block diagram of a control system for implementing the method of measuring the position of a mobile object according to the present invention.
FIG. 4 is an explanatory view schematically showing a measurement situation according to the present invention.
FIG. 5 is an explanatory diagram showing a self-position measuring method according to the present invention.
FIG. 6 is an explanatory diagram showing a self-position measurement method of a moving object according to a conventional technique.
[Explanation of symbols]
10 Survey vehicle (mobile)
13 Camera (imaging means)
131 camera control unit 132 image processing unit 15 control device 20 monitoring office 21 remote control unit 22 personal computer (computing means)
_An , _Bn , _An-1 , _Bn-1 , _An-2 , _Bn-2 , ... Surveying nail O Absolute coordinate value of camera center point (center coordinate of screen)
P self-position of the absolute coordinates T _1, T ₂ ... Target α camera turning direction of inclination (the inclination of the coordinate system of the screen)
β Local coordinate gradient γ Absolute coordinate gradient

Claims (2)

An image pickup unit mounted on a moving body captures an image of a plurality of known points arranged at required positions on a moving path of the moving body, and an absolute coordinate gradient of a line connecting the plurality of known points in an absolute coordinate system, and the screen The inclination of the coordinate system of the screen by the imaging means with respect to the absolute coordinate system is obtained from the difference between the local coordinate inclination of the line connecting the plurality of known points in the coordinate system of A self-position measurement method for a moving object, comprising: obtaining center coordinates of the screen in the absolute coordinate system from absolute coordinate values of points; and identifying a self-position of a specific portion of the moving object from the center coordinates. 2. The method according to claim 1, wherein the known point comprises a survey nail located on a known absolute coordinate in a moving path of the moving body.

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