JPS60117168A - Apparatus for discriminating position of running robot - Google Patents

Abstract

PURPOSE:To accurately grasp a position, by arranging an ultrasonic transmitter receives sharp in directionality so as to shift the same by 90 deg. to perform simultaneous measurement. CONSTITUTION:The main body 1 of a running robot is allowed to run to an advance direction 8 by driving wheels 2, 3, 4, 5 thereof. When a rotary shaft 6 is rotated at the same time, ultrasonic transmitters 9, 12, 14, 16 and ultrasonic receivers 10, 13, 15, 17 attached to a transmitter receiver frame 8 are rotated in a state shifted by 90 deg. in ultrasonic transmitting and receiving directions a, b, c, d. Ultrasonic transmitting signals and ultrasonic receiving signals obtained from the ultrasonic transmitters 9, 12, 14, 16 and the ultrasonic receivers 10, 13, 15, 17 and angle data signals to the robot advance direction 18 of the ultrasonic transmitting directions (a), (b), (c), (d) are inputted to a position operation apparatus 22. The robot 1 is rectangular in the use thereof and, therefore, the position thereof can be accurately calculated on the basis of the direction and distance to a wall.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a traveling robot, and more particularly to a position recognition device that can accurately detect the position of a traveling robot.

[Background of the invention]

The robot position recognition device installed in conventional mobile robots uses a tachometer to measure the number of rotations of the wheels, calculates the traveling distance and direction of movement, and calculates the position of the mobile robot from these values. .

However, with the conventional method of measuring wheel rotation speed, the wheels lag due to the floor surface conditions on which the robot is traveling, causing errors in measuring the traveling distance and direction of travel of the robot. Since it is calculated using cumulative calculations, it has the disadvantage that the robot's position cannot be accurately recognized.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art and provide a position recognition device that can accurately recognize the position of a traveling robot.

[Summary of the invention]

The present invention recognizes the position of a running robot relative to the shape of the room in which it is running, and is equipped with a transmitter that reflects ultrasonic waves with sharp directivity and a receiver that receives them. The ultrasonic transmitter/receiver direction of the ultrasonic transmitter/receiver is set at 90°.
A plurality of ultrasonic transmitters/receivers are arranged in a staggered manner, and the plurality of ultrasonic transmitters/receivers are rotated around the same axis. By receiving the ultrasonic waves reflected from the walls of the room, the distance to the wall and the direction of the ultrasonic reflecting surface of the wall relative to the direction of movement of the robot or the reference direction are measured.

By the way, ordinary homes, offices, factories, and hospitals.

In most rooms where mobile robots are used, such as in schools, the walls between the walls are rectangular. Therefore, when a running robot is placed inside these rectangular rooms and the ultrasonic transceiver installed on the robot receives the ultrasonic waves reflected from the surrounding walls to measure the distance and direction to the wall, the distance and direction to the wall are measured. You should be able to get 4 pieces of wall data.

The present invention recognizes the position of the traveling robot relative to the rectangular shape of the room by simultaneously measuring the data from the wall shifted by 90 degrees with an ultrasonic transceiver δ device placed shifted by 90 degrees. By simultaneously obtaining direction and distance data about the four walls of the room, the robot's position can be accurately determined.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a plan view showing the configuration of a traveling robot equipped with the ultrasonic transceiver of the present invention, and FIG. 2 is a position recognition system that calculates the position of the traveling robot from the data obtained by the ultrasonic transceiver of FIG. 1. FIG. 2 is a block diagram of the device. FIG. 3 is a diagram showing a robot position recognition method, and FIG. 4 is a flowchart of an algorithm for robot position recognition. In FIG. 1, 1 is the main body of the traveling robot, 2. J 45 is a wheel for running the main body 1, 6 is a rotating device attached to the main body 1 and the illustration is omitted, and the rotating shaft is coaxial in the direction of the arrow 7. 8 is located on the upper part of the main body 1 and fixed to the rotating shaft B. A transmitter/receiver frame to which the ultrasonic transmitter/receiver is attached; 9 is an ultrasonic transmitter fixed to the transmitter/receiver frame 8 for emitting highly directional ultrasonic waves in the direction a; 10 is the ultrasonic transmitter 9; The ultrasonic receiver has its reception direction in the same direction a as the ultrasonic emission direction, and the ultrasonic wave with a sharp directivity emitted from the ultrasonic transmitter 9 in the direction α is reflected by the surface of the object 11, This is an ultrasonic receiver that receives ultrasonic waves returned in the opposite direction.

Reference numeral 12 denotes an ultrasonic transmitter for emitting ultrasonic waves with sharp directivity in a direction b that is 90° shifted from the ultrasonic transmission/reception direction α of the ultrasonic transmitter 9 and the ultrasonic receiver 10. 1
Reference numeral 3 denotes an ultrasonic receiver whose receiving direction is the same as the transmitting direction of the ultrasonic transmitter 12. Similarly, 14 is an ultrasonic transmitter that emits highly directional ultrasonic waves in the direction C opposite to 9, and 15 is an ultrasonic receiver whose reception direction is in the transmission direction C of the ultrasonic transmitter 14. It is a vessel. Similarly, 1
6 is an ultrasonic transmitter that emits highly directional ultrasonic waves in the direction d opposite to 12, and 17 is an ultrasonic receiver whose reception direction is in the transmission direction d of the ultrasonic transmitter 16. . and ultrasonic transmitter 9, 12.14.16 and ultrasonic receiver 10. '13.15.17 is fixed to the transmitter/receiver frame 8 and rotates in the direction of arrow 7 about the rotation axis 6. 18 is the traveling direction of the main body 1 of the traveling robot.

Now, in FIG. 2, 9, 12, 14, and 16 are the ultrasonic transmitters described in FIG. 1, and 10, 13, 15, and 17 are the ultrasonic receivers described in FIG. 19 is an I10 boat connected to an ultrasonic transmitter and an ultrasonic receiver. 20 is
The ultrasonic emission force Ifl of the ultrasonic transmitter 9.12.14゜16 and the ultrasonic receiver 10.13゜1j, 1 in Fig. 1
A transmitter/receiver rotation angle measuring device for measuring the angle between α, h, c, and rL force directions in the ultrasonic reception directions 7 and the advancing direction 18 of the robot body 1 (explanation in the configuration shown in FIG. 1 is omitted). However, for example, an encoder may be used.). 2
1 is I10 connected to the transmitter/receiver rotation angle measuring device 2o.
It is a port. 22 is a position calculation device such as a CPU that calculates the robot position. The I10 port 19 and the I10 port 21 and the position calculation device 22 are connected by a data bus 23.

Next, the operation will be explained. In Figure 1, the main body 1 of the traveling robot
, wheels 2, 5, 4. ．． 5 to travel in the direction of travel 18. At the same time, rotate the rotating shaft 6 counterclockwise (arrow 7
), the ultrasonic transmitter attached to the transceiver frame 8? , 12.14.16 and the ultrasonic receivers 10°13, 15.17 rotate with the ultrasonic reception direction αl bI ′ #d shifted by 90°. Ultrasonic transmitter 9, 12.14.1<i and ultrasonic receiver 1
The ultrasonic transmission signal and reception signal obtained at 0.13.15.17 are input to the robot position calculation device 22 via the I10 boat 19. On the other hand, radar rotation angle measuring device 2
The robot traveling direction of the ultrasonic transmission directions α, b, c, d of the ultrasonic transmitters 9, 12° 14, 16 and ultrasonic receivers 10, 13, 15, 17 shown in FIG. 18
The angle data signal for the I10 port 21 in FIG.
It is input to the position calculation device 22 via. Then, the position calculation device 22 performs calculation processing shown in the algorithm flowchart of FIG. 4 to determine the position of the robot. Before explaining Figure 4, we will discuss the shape of the room. Generally, moving robots are used in factories, homes, and offices.

Rooms in hospitals, schools, etc. are rectangular.

On the premise that the shape of this room is rectangular, an algorithm for recognizing the robot position performed by the position calculation device 22 will be explained with reference to FIGS. 6 and 4.

In FIG. 3, it is assumed that the rectangular room in which the robot runs is 0PQR, and that the running robot moves from point A to point B. In that case, in the 1-position calculation device 22, as shown in the fourth factor, first, the ultrasonic transmitter 9.12, 14.1 (S) and the ultrasonic receiver 10.13.15.17 in FIG. The time from when the ultrasonic wave is transmitted to when it is received is calculated based on the transmitted signal and received signal of the ultrasonic wave.This time is determined by counting the internal clock of the position calculation device 22.Next, when the ultrasonic wave is The distance t from the rotation axis 6 to the object 11 in Fig. 1 is calculated by multiplying the time from transmission to reception by the ultrasonic velocity 530φ.The position of the robot is considered in terms of the rotation axis 6.Next, transmit and receive Based on the signal from the instrument rotation angle measuring device 20, the internal clock of the 1-position calculation device 22 counts the time until the ultrasonic transceiver detects an object from the direction of movement of the robot shown in FIG. The angle θ of the object 11 in Fig. 1 with respect to the robot traveling direction 18 is calculated by multiplying by the rotational angular velocity of the device WO/! Among the angle data, search for data that is shifted by 90 degrees, that is, data obtained simultaneously by the ultrasonic transmitters 9, 12, 14, and 16 and the ultrasonic receivers 10, 13, 15, and 17 in Fig. 1. Therefore, the robot If it is located at point A of the rectangular room 0PQR in Figure 3, the distance data corresponding to the 90° shifted angle data found above is La, t
b, tc.

It is Ad. Therefore, as shown in Figure 3, the reference coordinates are determined by a line segment A that passes through the object position α at a distance LcL from point A.
Coordinates are set in which the perpendicular line OR to α is taken as the y axis, the perpendicular line op to the line segment Ah passing through the object position at the distance Ah from point A is taken as the X axis, and the intersection of OR and op is the origin O.

Therefore, the coordinates (q, yo) of point A are (ta, Lb
). Next, it is determined whether the above coordinates have been set. Then, as the coordinates are set, data tα of the distance to the object corresponding to the angle data of object detection shifted by 90° is set.
, 1b, Lc.

The shape of the room is a rectangle 0PQ at point A in Figure 3.
Predict R, and set the above x@yfm and the coordinates of the origin. If the above coordinates have already been set, that is, when calculating the coordinates of point B of the third prisoner, the distance data that corresponds to the 90° shifted angle and the distance to the wall of rectangular room 0PQR , Ag at point B, Z7. l-y
, LA and find the coordinates (x, y) of point B as (L,, 11
). Furthermore, the coordinates (x, y) of point B are replaced with the coordinates (%, yo) of the 7 starting points, the processing of the algorithm flowchart in Figure 4 is returned to the beginning, and the coordinates (x, y) of point B at the robot position are ) one after another. Using the algorithms shown in Figures 3 and 4 above, the position of the traveling robot is set to rectangle 0.
Recognize it relative to the PQR room.

Next, the coordinates (t
An example of robot travel control using data on the coordinates (4, tf) of points a, Ah) and B (x, y) will be described.

In FIG. 3, it is assumed that the robot wants to run in the Z direction at point A. Therefore, the moving direction of the robot at point A is at an angle θ
The direction is A. However, in reality, the Z direction (dotted line AZ
) and travels to point B, and the traveling direction θB at point B becomes b, where θ=tan-1'/3/n workta-1L. 7B, - 1. -1a To control the robot to run on the AZ line, the distance from point A to point B is αt, -t,)”
-+τQ-14,7-, so the next target position is A
Point D is set at a distance L from point B on Z#, and control is performed to change the traveling direction at point B from the above θB to the direction θD of the above point. Since this control is conventionally known, it will not be described in detail here. However, this example is a case where the robot is running at a substantially constant speed.

Next, the necessity of providing two or more sets of the ultrasonic transmitter and ultrasonic receiver shown in FIG. 1 with their ultrasonic transmission and reception directions shifted by 90 degrees will be described.

The position recognition of a running robot according to the present invention is a method in which the room in which the robot runs is limited to a rectangular shape, and the position of the robot is recognized based on orthogonal walls of the room. Therefore, as can be seen from the fact that data on points C and f in Fig. 3 are required to determine the coordinates (xty) of point B, at least two ultrasonic transmitters and receivers are provided, shifted by 90 degrees. There is a need. If only one ultrasonic transceiver is installed,
If it is rotated to measure distance and direction data about the walls of the room, errors will occur in the robot's position recognition.

To explain the reason, the time it takes for ultrasonic waves to reflect from a wall and return is approximately 18 m sac for a wall that is 3rrL away (6 doors in both directions), for example. Therefore, 3
It takes approximately 2Qmsees to measure data on a wall that is m away, including calculation processing time. Therefore, if the data is obtained by dividing the angle by 1 degree, it will take j8stc from measuring the data of one wall in the 5 rectangular room to measuring the data of the next orthogonal wall. During this time, if the robot is running at a speed of 30 crtp/sac, for example, the robot will move approximately 54 km
Since rust also travels, recognition of the robot's position will result in an error of 54 rust.

On the other hand, if two ultrasonic transceivers are installed with their transmitting and receiving directions shifted by 90 degrees, the time between measuring data on one wall of a rectangular room and transmitting data on another orthogonal wall will be reduced. Time is only the difference in time between the reflected ultrasound waves. For example, if the distance to a certain wall is 1 m and the distance to another perpendicular wall is 4, the time from measuring data on one wall to measuring data on another perpendicular wall is Data can be measured almost simultaneously with a time difference of only 20 m5 ec when the robots reflect from the wall, and the distance the robot travels during that time is approximately 6 mm, assuming the traveling speed is 30 c++/s, and n is a negligible error.

Furthermore, the reason why four ultrasonic transceivers were installed in this example is that if there are objects in the room and data cannot be obtained for walls in a certain direction, data for at least two walls can be obtained. This is for the purpose of

Next, the effects of this embodiment will be described. According to this embodiment, the position of the traveling robot at the time when the ultrasonic transmitter/receiver shifted by 90 degrees obtains data on the time when the ultrasonic wave is reflected from the wall of the room, the distance to the wall, and the direction. Since the vehicle is recognized relative to a rectangular room, the wheels of the conventional technology could slip due to the condition of the floor surface on which the vehicle was running, causing errors in measuring the number of rotations of the wheels and the actual distance traveled and direction of travel. Since there is no cumulative error when calculating the cumulative number of rotations of the wheels by 11,
This has the effect of accurately recognizing the robot's position.

In this example, we have explained an example in which four ultrasonic transmitters and receivers are installed at 90" intervals.The reason for installing four ultrasonic transmitters and receivers is to correspond to a rectangular room, so that the ultrasonic waves reflected from the four walls can be reflected simultaneously. This is because we want to be able to receive data.However, the coordinates (Cx, y) of position B of the traveling robot in Figure 3 are data for at least two orthogonal walls, that is, 14 @ 11 and Shun Tsugo It can be determined if either tA @tA or t is measured. Therefore, the ultrasonic transmitter/receiver of the present invention has at least two or more (two, three, 4) In other words, you can install more than one, but if there is something between the walls of a room, you may not be able to obtain data about the walls of the room, so for safety reasons, we set 4. .

In addition, the number of ultrasonic transmitters and receivers of the present invention may be set, for example, by providing two sets of 8 pieces of rough metal with 4 pieces shifted by 45 degrees, that is, 4 pieces shifted by 90 degrees, or by providing 6 sets of 12 pieces shifted by 30 degrees, that is, 6 sets of 4 pieces shifted by 90 degrees. Or, further increasing the number of sets to 4 or 5 sets, etc., is a combination of structures including a plurality of ultrasonic receivers shifted by 90 degrees, and therefore falls within the scope of the present invention. As mentioned above, increasing the number of ultrasonic transceivers is disadvantageous in terms of price, but if there are many objects between the walls of the room, data from the walls of the room can be obtained more reliably. This has the effect of accurately recognizing the robot's position.

〔Effect of the invention〕

According to the present invention, there is an effect that the position of a traveling robot can be accurately recognized. This is because rooms and hallways in homes, offices, factories, hospitals, schools, etc. are generally rectangular in shape.

Therefore, when a traveling robot equipped with the robot position recognition device of the present invention is run in a rectangular room, a plurality of ultrasonic transceivers whose ultrasonic transmitting and receiving directions are shifted by 90 degrees,
The distance and direction to the wall of the room are measured from the time from when the ultrasonic wave is emitted until it is reflected from the wall of the room and received by the receiver and the speed of the ultrasonic wave, and a rectangle is formed as shown in Figure 6. The position of the traveling robot at the time when distance and direction data for at least two perpendicular walls of the room are obtained can be recognized without accumulation of errors. When measuring, cumulatively calculating the travel distance and traveling direction, and calculating the robot's position from these values, wheel slip may occur due to the condition of the floor surface on which the robot is traveling, resulting in errors in the travel distance and traveling direction. According to the present invention, the position of a running robot can be accurately recognized with respect to a rectangular room without the drawback that the robot's position cannot be recognized correctly due to accumulated errors in calculating the robot's position. effective.

Furthermore, according to the present invention, the position of the traveling robot can be recognized relative to the shape of the surrounding room, so that the conventional traveling robot equipped with a tachometer that measures the number of rotations of the wheels will not collide with the walls of the room. In order to do this, a device such as a contact sensor that detects the shape of the surrounding room is required, but the present invention has the effect of eliminating the need for such a device.

Furthermore, the present invention has a unique effect that is particularly suitable for recognizing the position of a traveling robot in a place surrounded by rectangular walls in a room or hallway such as a general home, an office factory, a hospital, or a school.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the overall configuration of a mobile robot equipped with a position recognition device for a mobile robot according to the present invention, FIG. 2 is a block diagram of the position recognition device that calculates the position of the mobile robot, and FIG. FIG. 4 is a flowchart of the robot position recognition algorithm. 1... Robot body 2.3.4.5... Wheels 6.
... Rotation axis 8 ... Transmitter/receiver frame 9, 12.14
．． 16... Ultrasonic transmitter 10, 13.15.17.
...Ultrasonic receiver 19...I10 boat 20...Rotation angle measuring device 21 of ultrasonic transmitter/receiver...
I10 boat 22...Robot position calculation device 1 Fig. 1A 2 Fig. 9 Section 3 Fig. 4

Claims (1)

[Claims] An ultrasonic transmitter/receiver that measures the distance to an object and the direction of the object's position as viewed from the robot by emitting highly directional ultrasonic waves and receiving the ultrasonic waves reflected from the object.
A plurality of ultrasonic waves are arranged with their transmitting and receiving directions shifted by 90°,
The position of a traveling robot characterized by being equipped with an ultrasonic measuring device configured to rotate these ultrasonic transmitters and receivers around the same axis to measure the distance and direction data of objects all around the object. recognition device.