JPS62171011A - Control method for autonomic moving robot - Google Patents

Abstract

PURPOSE:To guide a smooth and safe traveling even on a complicated road without orbit by rotating, steering and controlling a wheel based on a detection signal from a hindrance detection means, avoiding a hindrance and guiding a robot. CONSTITUTION:Twelve ultrasonic sensors 4 are disposed at an angle interval of 30 deg. on the same outer periphery of the robot main body. A ultrasonic sequence control circuit 10 drives the oscillator circuit 5 of each sensor 4 in terms of time division, and a transmitted ultrasonic wave is reflected by the hindrance and is made incident on a corresponding reception circuit 6. A timer counter group 11 measures the interval between a transmission pulse and a reception one by a corresponding counter, transmits the data to a CPU 7, and causes the CPU 7 to calculate a distance up to the hindrance. According to data from a rotational angle detection circuit 24 and from the CPU 7, a servo circuit 15 drives a DC motor 19 and turns steering shaft 22. On the basis of data from a rotational frequency detection circuit 30 and from the CPU 7, a servo circuit 16 rotates and controls a DC motor 20, and simultaneously rotates and drives wheels 2a-2d.

Description

Detailed Description of the Invention 3. IT Network Description of the Invention [Technical Field of the Invention] The present invention relates to a control system for a trackless autonomous mobile robot used in a venue or a restaurant shade.

[Prior art and its problems 1 Conventionally, track-based robots have been used as mobile robots used in offices, hospitals, hotels, restaurants, etc., but trackless robots are desired from the viewpoint of equipment costs and maintenance. .

However, trackless robots that can currently meet practical requirements have not been realized due to the complicated process of calculating the distance and direction of movement, and the lack of ability to detect obstacles along the path of movement.

[Object of the invention] This invention was made in consideration of the above-mentioned °1,
The aim is to create an autonomous mobile robot that can accurately measure the robot's movement II and direction of movement, smoothly avoid obstacles on the way even on trackless roads, and safely guide the robot to the LII'Ig location. The aim is to provide a control method for

[Main Points of Issue 1)] In order to achieve the above-mentioned [Object 1], the present invention provides a drive control means provided on the mobile robot body for controlling the rotation and steering of the wheels, and a drive control means provided on the mobile robot body for controlling the rotation and steering of the wheels. (
The Ij wheel is rotated and steered by 1 int by turning off the drive control.
, the main point is that the mobile robot body is guided while avoiding the above-mentioned obstacles.

[Configuration of Example] The present invention will be explained below based on the drawings.

Figure 1 shows the appearance of the robot;

l is a housing-shaped robot body. On the bottom of this robot body, there are four glue wheels 2 (2a to 2d) in each corner.
1! These wheels 2 have 11 steering functions. As shown in Fig. 2(a), at the standard rudder position, 2! in the +Nj direction! I (rings 2a and 2d and the rear 2 I
The lj wheels 2b and 20 each have the same axis, and the heavy wheels 2a and 2b and 2d and 20 in the front and rear force directions are oriented in one direction.

From the reference rudder position, the four single-wheel wheels 2 are
When the wheels are steered by an angle O, all wheels rotate by an angle 0 in the same direction from the reference direction (X direction), as shown in Figure 2(b).

Next, a plurality of ultrasonic sensors 4 are installed on the outer peripheral surface of the robot body l.
(4a to 4 sentences) are arranged, and one Jfi tX
The wave sensor 4 is a pair of a Mia wave transmitter ``JA5'' and an ultrasonic receiver ar'i wave sensor 4. For example, 4a shown in FIG. 3 is an ultrasonic receiver 6,
This ultrasonic receiver 6 and an ultrasonic transmitter 5 are placed at a predetermined distance (the a-sonic wave receiver 6 and the a-sonic wave transmitter 5 form a pair for emitting and injecting a K-wave as shown in the circuit described later). ), the MUe wave transmitter/transmitter of the other Miη wave transmitter/receiver 5 adjacent to and paired with this ultrasonic transmitter 5 is separated by a predetermined pressure, and the ultrasonic receiver 6 ( The ultrasonic receiver 6 is provided at the lower end of the robot main body l.

In this embodiment, as shown in FIG. 3, the ultrasonic sensors 4 are arranged in 12 sets 4a to 4 at equal angles of 30 degrees around the robot body 1 to receive ultrasonic waves from above! A6 are arranged on the same plane, the intermediate Mi sound wave transmitters 5.5 are also divided into two layers and arranged on the same axis, and the lower ultra-51 wave receivers 6 are also arranged on the same plane.

Figure 4 shows a block circuit diagram of the robot's control circuit.
7) is provided. The R-0M8 stores the control program for the CPU 7, and the RAM 9 stores data for running the robot body l.The sonic sequence control circuit 10 drives each ultrasonic receiver 5 at a time of 1. The timer counter group 11 receives the signal of each jfl i'F wave reception'jA6, and
The time difference between the transmission and reception of the n wave is detected and sent to the CPU 7. An oscillation circuit 13 is connected between each Jfl rT wave transmitter 5 and the 11-wave sequence control circuit lO, and a receiving circuit 14 is connected between each Jfl rT wave receiver 6 and the timer counter group 11.
are interposed, respectively, and these generate ultra-1'f-wave signals, cause the ultrasonic transmitter 5 to transmit ultrasonic waves, and also amplify and detect received signals.

The ultra-77-wave sequence control circuit 10 is a circuit that sequentially sends oscillation command pulses to 12 sets of oscillation circuits in a time-division manner, and simultaneously sends a trigger pulse to start counting to the timer counter group 11.

The ultrasonic waves transmitted by each ultrasonic transmitter 5 are reflected by obstacles and are incident on the corresponding pair of ultrasonic receivers 6. The output of each ultrasonic receiver 6 is amplified by a receiver 41 circuit,
The waveform is shaped into a pulse, which is input to the timer counter of the corresponding channel in the timer counter group 11.

The timer counter group 11 includes 12 sets of a sound wave sensors 4a to 4.
It consists of 12 timer counters corresponding to Il, and measures the time between the transmitted pulse and the received pulse for each ultra-H'7 wave transmission 'jA5 and each ultrasonic receiver 6.

The data is sent to the CPU 7 to calculate the distance to the obstacle.

Connected to the data bus 12 are 211 servo circuits 15.16 for steering and running, and these servo circuits 15.16.
DC motor 19.20 via driver 17.18
are connected to each other.

The DC motor 19 is rotationally controlled by a servo circuit 15 based on data from the CPU 7, and rotates a common steering shaft 22 for the wheels 2a to 2d via a steering gear 21.

A steering encoder 23 is attached to the DC motor 19, and the steering encoder 23 has a power output of 2 Aikawa.
The rotation angle detection circuit 24 receives the signal Ii-.

The rotation angle detection circuit 24 and the rotation direction determination circuit 26
It consists of a down counter 27, and the rotation direction r (separate circuit 26
The signal 1) for determining forward/reverse rotation is in the steering servo circuit 15! The count from the up/down counter 27 is given to the CPU 7 via the data bus 12 and
The steering proverbs for the 11 wheels 2a to 2d are incorporated.

On the other hand, the DC motor 20 is rotationally controlled by the servo circuit 16 based on data from the CPU 7, and
8 through I (wheels 2a to 2d are rotated simultaneously. A travel encoder 29 is attached to the DC motor 20,
The travel encoder 29 has a two-phase output, and its output signal is sent to the rotation speed detection circuit 30 and the servo circuit 16.

The rotation speed detection circuit 30 includes a rotation direction determination circuit 31 and a frequency dividing circuit 32, which converts the signal from the travel encoder 29 into a rotation direction signal 5) and an interrupt signal, respectively, and sends the signals to the CPU 7 via the data bus 12. The distance traveled by the robot body is captured.

The steering of the heavy wheels 2a to 2d taken into the CPU 7: 1X, the rotation speed, and the distance to the obstacle are stored in the RAM 9.

[Operation of the embodiment] - Generally, if we consider the trajectory of an object moving in the XY+ metaphysical plane starting from the origin (0,0) at 1=0 as shown in FIG. The position of the object at T can be calculated mathematically, but if the direction of movement of the object at each instant is 0 and the minute movement in that direction is di, then the L notation dx, d
y is dx=dl*cosO1d"1=dlas1nO...
...(2) If these six sentences are expressed using the speed ν(1) and the minute time di, dfl=ν(t)dt, so (1) formula % formula %) In fact, I- is infinite Since minute instants cannot be measured, the time is iI! : In a minute and finite predetermined time, (τ−T /
'N), calculate the direction and velocity for each All1 (sampling) L, x, and y. At this time, it can be approximated as 1- Formula (3) % Formula % (4). Here, the velocity ν(n) at each instant
and direction On in total Δ- and Co5(7n ・ν
((1), sin On · ν(n) multiplication requires measurement accuracy and processing speed,
Furthermore, considering equations (4) and (5), X=ΔΣcasOn, Y=ΔcrossΣsi+ln...
...Measure the current position of the object by approximating (6).

In the present invention, Δ is the number 11 of the driving DC motor 20.
is a function of the rotation speed of τ time, and On is the steering Jll D
q of the C motor 19 as a function of the number of rotations during time.

Figure 6 shows that the robot main body l, the rotation of the first wheels 2a to 2d,
12 is a flowchart showing a process F stage for determining which position the vehicle will be in after a predetermined XY+Lu′+il−predetermined time τ due to steering.

First, when a 1.1 inclusive request pulse is input manually from the frequency dividing circuit 32 to the CPU 7, the routine shown in FIG. Next, in step S2, the DC motor 1 of one wheel 2 is
The steering direction No. 9 is input to the CPU 7 via the rotation speed detection circuit 30. The CPU 7 calculates a common steering angle 0 of the wheels 2 from the rotational speed of the DC motor 19, and if the rotation direction of the DC motor 20 is reverse rotation, it is treated as 0=0+180° and calculates casO in step S3.

Next, the CPU 7 calculates six common travel distances of the wheels 2 from the rotational speed of the DC motor 20, and in step S4 calculates Δcross/c.
In step S5, in which the osO is calculated, this Δ 5inO is added to the previous X coordinate.

Find the current X coordinate.

Similarly, 5inO is calculated in step S6, and step S7
Finally, in step S8, this Δcross s+nO is added to the previous Yl+ mark to obtain the current Y coordinate.

This robot body l has +lj wheels 2a to 2d r fist at the same time! Steering and same time rI: Due to rotation, the direction always remains in the same direction and moves diagonally to the left and right behind the surface.

In addition, in case 1-1, 5inO is not calculated by the CPU 7, but the image is stored in the ROM 8,
In addition, the f value of ΔI is set in advance in ROM 8 by calculating (number of pulses) x (diameter of wheel) x (rotation angle/pulse) g, and the processing time for Δview・casO and Δview・5inO is set in advance. jiL can be reduced.

Next, the operation of guiding the robot from a predetermined position to a destination point while avoiding obstacles will be explained with reference to FIGS. 7 to 19. In FIG. 7, there are 12 sets of a: 'S wave sensors 4 (
The obstacle detection range in the water direction of 4a to 4 intersections is a −1, obstacles in the fan shape of area a are detected by 4a, and the distance between them is detected. Similarly, the area 4b is detected by the area 4fL.

At this time, obstacles are detected every 30 degrees around the robot body l, and data is sent to the CPU 7. Now, if the center line of area a is A, and the center line of area A is B, and the center line of the area is L, then these center lines A, B...L will extend over the entire circumference of robot body l. Obstacles can be detected with an accuracy of 115 degrees before and after. Each ultrasonic transmitter 6 detects the reflected ultrasonic wave that first enters after the paired ultrasonic transmitter 5 emits a sound wave and sends a stop pulse to the timer counter group 11, so that the timer counter group 11 is started. Each ultrasonic sensor 4 has one detection area (a, b...vertical) as the product of the count number from to stop Hi and the speed of the sound wave.
The distance fadi to the nearest obstacle is detected for each object and sent to the CPU 7 and stored in the RAM 9.

Therefore, let us now decide on the path of the robot according to the following rules.

(i) The robot has a ROM that tells it the direction in which it is trying to move.
8, and this direction vector v1 is set in the RAM 9 by a predetermined key.

(2) If an obstacle is detected in the 12 a-sentence areas by the ultra-7f wave sensor 4, then for each a-1 area, as shown in FIG. The magnitude in the direction is K: constant, d: detection distance.

l V r + l = K / d i?
...Define the vector VIn (n = 1 to 12) of the 1E river expressed by (7), and convert this formula into RO
The settings are stored in advance in Ma.

(3) The vector Va in the direction in which the robot should move while avoiding obstacles in these 12 directions is written in 1-(6) in the ROMB.
) and vl in RAMQ, the CPU 7 determines n·1 and stores it in the RAM 9.

Therefore, the CPU 7 applies J and ti to the vector of equation (8) and steers the wheels 2 via the servo circuits 15 and 16.

Rotate and move the robot body l. and 1γi
The movement of the robot main body 1 is controlled based on the travel distance 6 sentences per minute time τ mentioned above and the angle 0 at that time.

That is, as shown in FIG.
A correction vector for repulsion of F is detected via the tfla wave sensor 4, and is combined with vI in the RAM 9 using equation (8). That is, a new traveling direction vector Va in a direction to avoid obstacles is calculated by the CPU 7 and 1 (the wheels 2 are steered and driven to travel in the target direction).

The specific direction of movement will be explained below.

Figure 1θ shows the case where the robot enters a narrow road and the traveling direction vector is V[, and v[2 and VrlG are expressed as L (8) due to the reflection of ultrasonic waves from both corners of the obstacle. It is calculated by the formula and suppresses the approach speed of the robot body l (Figures 10-11).

If the robot body l is now shifted to one corner (
(Fig. 12), the CPU 7 steers the lj wheels 2 so that the correction vector V13 from the approaching corner acts more strongly than the correction vector V19 from the far distance according to equation (7), and the robot body l is pushed back to the center of the narrow road.・Rotate.

Next, when the robot passes straight through a T-junction (the traveling direction vector V is a straight path and line f), as shown in Fig. 13, the IE +E vectors Vrl and V14 from the two corners and these The correction vector Vrq from the opposite side is calculated using the above equation (8), and the path of the robot body l is corrected as shown by the dotted line, so that it is approximately in the center of the path.

Next, as shown in FIG. 14, if an obstacle protrudes from the passage wall, the robot main body l is pushed out by the correction vector v111 and smoothly passes through the obstacle in the center.

Next, as shown in FIG.
1, if it is similar to some extent, the correction vector V
r+o, Vr? Due to the difference in z, the robot main body 1 is subjected to a correction iE in a slightly opposite direction, so the robot main body 1 corrects its direction along the inclination while reducing its speed, and runs along the path in the original traveling direction v1.

Next, as shown in FIGS. 16 and 17, when traveling at a predetermined branch point, such as a T-junction, by turning 90 degrees, the distance W from the predetermined position to the T-junction is determined in advance by the rotation speed of the DC motor 20. is manually inputted into the RAM 9, and under the control of the CPU 7, the robot main body 1 is caused to travel at an initial progress vector Vl. When the rotation speed detected from the travel encoder 29 reaches the value set in the RAM 9, the DC motor 19,
The lj wheels 2 are steered via a steering gear and a steering shaft. At this time, if the position where the robot body l has stopped is shorter than the distance W of the original bending position (Fig. 16), if the correction 1 of one corner [vector V is the correction IF vector of the other corner]
IIO acts more strongly than IIO, and the robot main body l moves toward the center of the path of [1] as shown by the dotted line.

On the other hand, if the position where the robot body l has stopped is longer than the distance W (Fig. 17), the correction vector v of the other corner
r+o acts more strongly than the correction 1F vector Vl+ at the - corner, and the robot body 1 returns to the center as shown by the dotted line in the path of (1) and runs while moving.

FIG. 18 shows the movement state ff of the robot main body l traveling in an office. The correction vector created by equation (7) indicates that the port body l passes approximately at the center of the course.

Figure 19 shows a case where the robot main body 1 and a person (M) pass each other in a passageway, and the robot cannot distinguish people from obstacles in general, but when one person approaches from the front (a) Modified IF vector vr+ due to reflection from five people, decelerates or stops due to VN2 LL (b), modified vector v in the opposite direction due to the person dodging robot body l, V12 (C), robot body l also changes course in the opposite direction, resulting in a smooth passing (d).

Replaced with nl where K represents the sampling number K Ii1] I+,
R is the number of IFs smaller than l. This Sk is CPU7
The interior of the robot is smoothed to some extent, and the movement of the robot body l becomes smoother.

[Effects of the Invention] As explained in detail below, the present invention has a first drive control stage provided on the mobile robot body for controlling the rotation and steering of the wheels, and a drive control stage provided on the mobile robot body that controls the rotation and steering of the wheels. The mobile robot is equipped with an obstacle detection stage that detects the distance and direction of the obstacle, and controls the rotation and steering of the wheels by the drive control means based on the detection signal from the obstacle detection means to avoid the obstacles. Since the robot is guided by the main body, it is possible to measure the position with high precision even at low speeds, and the distance to obstacles can be accurately measured, even when guiding the robot through a passage with a complex shape. The robot can run smoothly and safely.In this way, it is effective for guiding mobile robots in various environments such as offices and hospitals1.

4. Z plane (7) IPIQi Explanation Fig. 1 is an external perspective view of an autonomous mobile robot to which the present invention is applied, Fig. 2 is a bottom view of Fig. 1, and Fig. 3 is a plane layout diagram of the AFF wave sensor. ,
Figure 4 is a block diagram of the control device of the present invention, Figure 5 is a principle diagram for calculating the displacement of a moving object, Figure 6 is a flowchart for measuring the position of the robot, and Figure 7 is the super 21 wave of Figure 3. FIG. 8 is a diagram showing the direction of the correction vector; FIG. 9 is a principle diagram showing the action of the correction vector; FIGS. 1θ to 19 are diagrams showing the operation of the present invention. It is.

l...Robot body, 2...Wheels, 4
......a TF wave sensor, 5... Ultrasonic transmitter, 6...Ml;) Transmitter/receiver, 7...
...CPU, 8...ROM, 9...R
AM, lO... Ultrasonic sequence control circuit, 1
1...Timer counter group, 12...Data bus, 13...Transmission circuit, 14...
・Reception circuit, 15.16...Servo circuit, 17
．． 18... Driver, 19°20...
DC motor, 21...Steering gear, 22...
・・Steering shaft, 23 ・・Steering encoder, 24・
...Rotation angle detection circuit 1, 26.31...
Rotation direction determination circuit, 27...Up/down counter, 28...Travel gear, 29...
Traveling encoder, 30...Rotation speed detection circuit, 3
2・−・・・・Frequency dividing circuit.

Patent applicant: Casio Computer Co., Ltd. Agent Burito Town Ill Shun 1F Diagram 1 Figure 2 Figure 3 Figure 5 Vp Figure 9 Figure 6 Figure 7 Figure 8 Figure 10 Figure 11 Figure 12 Figure 13 Figure 15 Figure 16 Figure 17 Figure 18

Claims (1)

[Claims] a mobile robot main body, a drive control means provided on the mobile robot main body to control the rotation and steering of wheels, and an obstacle detection device provided in the mobile robot main body to detect the distance and direction of obstacles in the movement path. and wherein the drive control means controls the rotation and steering of the wheels based on the detection signal from the obstacle detection means to avoid the obstacles and guide the mobile robot body. Robot control method.