JPS6258311A - Mobile robot - Google Patents

Abstract

PURPOSE:To enable a robot itself to reach correctly a target point by storing previously the distance between obstacles in the (x) and (y) directions that is different in each area and collating said distance between obstacles with the value stored previously through a range finder set on the robot. CONSTITUTION:The distances between obstacles and the area distances are displayed in a list as shown by an equation I for each area. The area name in the list is called a direction indicator and an area connection list (expression II) is obtained. Then both lists (expressions I and II) are taught to a mobile robot. The mobile robot is moved autonomously in various ways. For instance, an area connection list including both points A2 and A23 is searched at first with input of a start point AS=A2 and a target point AG=A23. Here it is decided that an answer is obtained as long as such a list is obtained. Then the procedure proceeds to another step. However no such list is available in this example, and therefore the connection list including the point A23 is searched. Thus (Y, A23, A22) are obtained and the procedure proceeds to the next process.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention relates to a mobile robot that can move while creating map information necessary for autonomous operation of a mail robot, a night-time lookout robot, etc. that runs on the floor of a building. .

[Technical background of the invention and point d]

Conventionally, when driving a mobile robot automatically, signal lines and oscillators were buried in the floor, and the mobile robot was guided along the signals, and the mobile robot received the signal from one oscillator. I was checking the location. Maku, recently,
Attempts have been made to equip a mobile robot with a visual sensor to recognize the surrounding scenery and drive the mobile robot autonomously, but this method takes time and requires a large computer. It is still far from practical use.

[Purpose of the invention]

An object of the present invention is to provide a mobile robot that can recognize its own position, find its own route to its destination, and move autonomously at high speed and at low cost.

[Summary of the invention]

The present invention relates to an autonomously controlled mobile robot, in which the activity range of the mobile robot is defined by a unit characterized by the distance between obstacles in the front-rear direction and the left-right direction of the mobile robot, which can be measured by a range finder mounted on the mobile robot. An area divided into areas and consisting of a unit area list consisting of the unit area name, the size of the unit area, the distance between the obstacles in the unit area, the direction of connection of the unit area, and the name of the connected area. This mobile robot is characterized in that a serving list is input in advance into a control computer of the mobile robot as a map of the robot's activity range.

〔Effect of the invention〕

According to the present invention, the robot can find the route from the starting point to the target point by itself and can move autonomously.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail. 1st
The figure shows a mobile robot 10 according to an embodiment of the present invention and the functions of a control device 19 (indicated by a chain line) mounted on the mobile robot 10. The mobile robot 10 is equipped with vehicle-mounted distance sensors 1, 2, two on each side on four sides. ...
, 8 are arranged, and the steering drive means 20. Wheel drive means 21
Wheels driven by 22. ..., 25 are provided.

The control device jt19 measures the distance around the mobile robot 10 using signals from each sensor from the vehicle-mounted distance sensor group 26, and recognizes the position of the mobile robot 10 together with the data in the memory unit 28.

This position data is monitored by self-position recognition result output means 29. The memory means 28 stores an area list 30 and an area association list 31 in its memory contents. The data in this memory means is stored in the route searching means 3 along with the data from the specifying means 32 for specifying the starting point and the target point.
3 to generate a branch list 34. The data of this branch list 34 and the data of the memory means 28 are inputted to the mobile robot control data vanguard means 35 to obtain the control data 36 of the mobile robot 10, and this data 36 is used to control the driving means 20 of the robot 10. Run .21. still,
These data processes are performed by a CPU and memory configuration.

Next, Figures 2 to 4. The present invention will be described in detail with reference to the collar. FIG. 2 is a diagram illustrating a method of dividing a map into unit areas, which is one of the basics of the present invention.

If the range finder on which the mobile robot is mounted measures the distance to obstacles such as front, rear, left, and right walls, the measured values will be used to calculate the unit area from A1 to 80 (as shown in Figure 2).
It can be divided into areas, which will hereinafter be simply referred to as areas.

In other words, in 81, the distance between obstacles in the X direction is lI - the distance between obstacles in the Y direction! , and in AI each lk*16
becomes.

In this way, the robot memorizes the X direction and distance between obstacles in the X direction, which vary depending on each area, in advance.

After being taught, the robot 10's position can be automatically confirmed by measuring the distance between obstacles using a range finder mounted on the robot 10, and comparing this with a stored value.

Here, the distance between obstacles and the area distance of each area will be displayed in a list as follows, and these will be referred to as an area list 30.

(As −js −Is −At −Is
)(A,,l,,l・,1B-Is) (As e l* m's #'4 1 Is
(A, , lk, It, , l, ., !,) where l k −1913 + 11° The first element in the above list is the area name, the second . The third element is
X direction, distance between obstacles in the X direction, 4th. The fifth element represents the length and distance of the area in the -X and y directions.

A method for storing a map divided into areas in this manner in a robot will be explained using FIG. 3 as an example. Here, the X direction,
For example, (xeAt*At eAs) expresses the connection of areas in a direction as a list of the directions and areas.
This shows that the regions are connected in the order of Al eAs # Am in the X direction, so this is (-X eAs
It can also be expressed as mAs * AI. The first element of the list will be referred to here as the direction indicator.

Further, this list will be referred to as the area combination list 31.

In the column of FIG. 3, the area waitstaff is as follows:

(XsAt eArt As ) CY-At -A4- As , Ate-Asy) (
X#A5 +Aa eAr eAll eA, 5Ato
)(X * Att I Att s A
lfi e A14 m Att) (xe A
lg + Att # A18 ) ()' a AL
e Ass s A19 @ AI.ノ(x, AIO
, A, l, A, , ) (Y = Ata - Att) If the above-mentioned area list 30 and area combination list 31 are taught to the mobile robot 10, all the map information will be stored.

There are various ways to autonomously move a mobile robot using this map information. A specific example will be explained with reference to the flowchart of FIG.

The moth in FIG. 4 employs a combination of a method generally called horizontal search and an inverse search method.

Now, if we input the starting point A s - AH and the target point AG - A □ in step 1, we will first search for an area collection list that includes AI and A □, and if we have such a list, we will have obtained the solution. Since this is the case, the process moves to step 36, but in this example, it does not exist, so in step 6, a search is made for an area payment list that includes A□.

(Y, A□, A□) is obtained. Also, since there is only one linked list, AG is added to the head of BG (one-branch list), resulting in B""(AI5) Cs"(Y-AI, Att).

Next, at step 121, the child list of Ct and its branch points are determined. A child list is a combined list of areas other than the parent list that includes (shares) elements included in the parent list (CI).In this example, the shared element is called a branch point.In this example, the child list of CI is (X.

Ato eAtt e '*t) e branch point is s A1
It becomes 1.

If this child list contains As (- to t), the connection of the area from the starting point to the target point has been obtained, so in step 15, the branch point A is added to the head of the branch list BG.
Add 0 and proceed to step 26.

In this example, (X, A,.e AH* Attton has A,
is not included, so return to step 8 and step 9
becomes B'-(Aat eAttton, and in step 11 Ct ” (Xe Ato # Au * Alm)
becomes.

In step 12, C3's child list (Y, A, .

Ass * An # Ato) and branch point A,. is found. Since there is no As(A,) in this child list, it becomes "" (Awe sA ****AH) C, - (YtAs, A 工 a A 16 m AI.) as in the case of C3.

Then, in step 12, find the child list of C3 and the branch point,
(X, A□, A□#A□e A14) a A14 and (X.

A, ,A, ,A, ,A, ,A, ,A,. ),
A is obtained.

These child lists do not include A s (-A, ), but since there are multiple child lists, the process moves to step 16 via steps 14 and 8. Since it is I-3, the process moves to step 19.

This completes the inverse search for finding a route starting from the target point. In this flowchart, the inverse search follows one path (
I'm trying to do it until now.

Next, move on to sequential search. First, a branch list B@ is defined in step 20. While BG creates a list of branch points from the target point, Bs creates a list of branch points from the starting point.

In step 21, the area containing As (mA, ) is determined by -ft I
Find the J strike and make this your J. Also 1 branch list Bs
Add As(wA,) to the end of and make this btj·l.

In this example, C□-(X=A*-At, As)-Btt-(
At) Cwt”(YtAs, A, mAs eAl
l,Aty)Bu-(At).

Next, in step 22, it is checked whether C1, c, cm, and C1 each have a shared element. It should be noted here that if the route is bisected at i-0, that is, the target point, check to see if there are any elements in common with the area combination lists C*' and C* (see step 17) that indicate these points. It is what happens.

In this example, there is no shared element, so find the child list and branch point of C11e and C1m, set it as C2j, and create BuJ II C
Since 1l has no child list, it is deleted, and the child list and branch point of C1t are determined as follows.

Cu = (X-Ag-At-”q-As, Ae
-Aso) -B10-(At #A@) Cxt=(X-At□ @Alg #A11 t
A14 # A11 Bu = (At −A□) Cts −(X −Ate・41st・Alg)Bus−
(A intends, A1. Then, return to step 22. C□ and C, , C□ and C1C
It is sequentially checked whether □ and C3 each have a shared element.

Since CO and Cs share A, we move to step 27 and change the shared elements A and B! In addition to the end of the list of x, let Bu-(At, A,, Am) be added.

In step 28, add B1 and BG to create the entire branch list B.
make. B is B= (At -Am -Am-AI.* 812 e
AH).

The fact that branch list B was obtained means that the starting point As(mAs)
This indicates that the route from to the target point AG (-Ass) has been decided, and each element is also a point (steering point) at which the mobile robot changes its direction of movement.

From step 29 onwards, control information for the mobile robot is created. First, find the area score eQ that includes chives, that is, A, , A, from the beginning of the elements included in branch list B, and remove the direction indicator. Delete the elements before and after At to A6 to make it 0 times. The area combination list containing m At # At is (Y, A, , A, , A・# A11 m At
), there is no area element before A, but after A there are A□,
Since there is AI, delete these and create CI = (Y-A
s , A4 , As '.-Similarly, the area joint list containing A, A, A, At
. A joined list containing ・・・・・・・・・A□ , A1
．． Find a linked list containing CI # C1 # ”・CI
seek.

By the way, the area combination list containing Alg s Alt is (Y
, bird 3. A□) However, the order of the 1-branch list is A□, A! 3 is the opposite. In this case, the direction indicator Y will be given a 1-) sign. In the end, through the work from steps 29 to 33, CI = (Y, At, A4, At)C
I” (X* At @ At IAs * At )
Cs ”(Y*A@ *A11 *All*A!.90
No. -(X,A,.,A□-An)C,-(-Y,
A□, A□) can be found. Using these C1 to C and the area list, control information for the mobile robot is created in step 35 as follows.

The robot starts from As(-At), but since the direction indicator is Y according to the area combination list C1, it advances in the y direction. The distance 111y* is the length in the y direction of 7s-4 X 1/2 +A, the length in the y direction of 10 A, the length in the direction x 1/! Calculate as.

The length of each area is determined by calling the area list using the area name.

Similarly, the distance x1 from A to A is the length of zlmA in the X direction x 1721000 x the length in the X direction of 10A.
The length in the direction + A is determined as the length in the X direction x 172. Then, in A, the robot that has been moving in the y direction until now is moving in the X direction, so control the steering wheel by 90 degrees to the right. It turns out.

As described above, it is possible to freely create control information for autonomously moving a mobile robot from a starting point to a target point.

2nd area list. As mentioned earlier, the third element is used by a mobile robot to judge its own position, but in a situation where the robot is instructed to move to a target point consisting of its current position, Used to know names. That is, the distance to the obstacle in the longitudinal and lateral directions is measured, and an area list that is a fraction of the distance is found. If there are multiple area lists, move the mobile robot back and forth, left and right to the extent that it protrudes from those areas, measure the obstacle distance in the front/back direction and lateral direction, find the area combination list that includes that area, and The current position is determined by comparing the distance to obstacles in the area adjacent to the area.

The distance to obstacles in the front, back, and lateral directions of the mobile robot is
It can be easily measured with a range finder.

FIG. 5 shows one row of ultrasonic sensors attached to the front, back, left and right sides of the mobile robot to measure the distance to each obstacle.

In FIG. 5, reference numeral 10 indicates a mobile robot, arrows indicate the direction of the robot, 11 indicates a corridor, 12 and 13 indicate obstacles such as walls, and 1 to 8 indicate ultrasonic sensors attached to the robot. Now 1
Letting the measured value of the ultrasonic sensor rli, rl, = rlv, rl, xrl,, rl, zr/,, r
17 amr is the condition in which the side surface of the robot 10 is parallel to the obstacle. Therefore, if the robot is made to move automatically until such conditions are obtained, the distance between obstacles that determine the area division will be rl, +r1. Distance between ten sensors in the width direction, rjl +rj@distance between ten longitudinal sensors,
It can be easily obtained as .

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the actual tIIIf11 of the present invention, and FIG.
The figure is a diagram explaining the division method of unit areas, which is one of the basics of the present invention. Figure 3 is a diagram explaining how to create a combined list of unit areas, which is another basic of the present invention. Figure 4 is a diagram explaining the unit area. Flowchart illustrating a sequence of methods for using region lists and unit region combination lists for autonomous control of mobile robots, Part 5
The figure is a diagram showing a method of measuring distance between obstacles. Al ~A4 IAs s r 11~r l@”-
Distance between obstacles, 1 to 8...Ultrasonic sensor, 10...
Mobile robot% 11...corridor, 12.13...wall. Agent Patent Attorney Ken Nori Chika Kikuo Takehana Figure 2 Figure 3 Figure 4 (α) Figure 4 (b)

Claims (1)

[Claims] An autonomously controlled mobile robot is divided into unit areas characterized by distances between obstacles in the front-rear direction and left-right direction of the mobile robot that can be measured with a range finder mounted on the mobile robot, and the unit area name, A unit area list consisting of the size of the unit area, the distance between the obstacles in the unit area, and an area combination list consisting of the direction of connection of the unit area and the name of the area connected to the map of the robot's activity range. A mobile robot, characterized in that it is equipped with means for inputting information into a control computer of the mobile robot in advance.