JPS61169911A - Guiding system of moving robot - Google Patents

Abstract

PURPOSE:To omit a floor surface reflecting tape or the like and to guide a robot precisely by detecting light reflected on the cylindrical reflecting surface of an object by photodetectors and correcting the route of the robot in accordance with the detected state to guide the robot to the object. CONSTITUTION:Light emitted from an infrared light emitting element 7 which is modulated by a square wave signal outputted from a modulating circuit 11 is reflected on the cylindrical reflecting surface formed on the object and detected by right and left photodetectors 8b, 8a. Output signals from the photodetectors 8a, 8b are amplified by amplifiers 12a, 12b respectively, the influence of external light is removed from the signals by BPFs 13a, 13b and the filtered signals are sent to level detecting circuits 14a, 14b. When the output signals of the BPFs 13a, 13b exceed a set level, the circuits 14a, 14b detect the state and output the detected results to a microprocessor 15. The processor 15 controls motor drivers 16a, 16b in accordance with the state signals from the circuit 14a, 14b to rotate right and left wheel motors 17b, 17a.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a guidance method for a mobile robot.

[Prior art and its problems] Conventionally, in mobile robots for transportation, mobile robots for toys, etc., a guiding method using a tape is generally used in which a light-reflecting tape is attached to the travel path and the mobile robot runs along the tape. It is being However, when the robot is guided by tape as described above, it is necessary to attach light-reflecting tape on the floor along the running path, which is extremely troublesome and also reduces the appearance of the floor. There is a problem.

Recently, pathless guidance methods such as autonomous driving using laser lighthouses and ultrasonic sensors have been considered, but these methods are still in the research stage and have problems such as high cost.

[Object of the Invention] The present invention has been made in view of the above points, and it is possible to move the robot to a target location such as a target object, home position, charging station, etc. without attaching a light reflective tape to the floor surface. It is an object of the present invention to provide a method for guiding a mobile robot that can reliably guide the robot (by providing a robot) and reduce costs.

[Main points of the invention] The present invention forms a cylindrical light reflecting surface on a target object, and
A mobile robot is provided with a light-emitting element and a light-receiving element, the light emitted from the light-emitting element is emitted forward, the light reflected by the cylindrical reflective surface of the target is received by the light-receiving element, and the light-receiving element responds to the light reception state. The robot's course is corrected so that it heads towards the target.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. First, the schematic configuration of the target object 1 and the mobile robot 2 will be explained with reference to FIG. The target object 1 is formed, for example, in a cylindrical shape, and its curved surface is mirror-finished to form a cylindrical light-reflecting surface 1a. Further, the mobile robot 2 has a recess 4 formed at the lower front surface of the robot body 3, which can fit into the cylindrical light reflecting surface 1a of the target object 1, that is, has the same curvature as the cylindrical light reflecting surface 1a. ing. A through hole 5 is formed in the center of this recess 4, and a pair of through holes 6a and 6b are provided below this through hole 5 in parallel to the left and right. Light emitting element 7, right light receiving element 8 in through hole 6a
a, a left light receiving element 8b is disposed within the through hole 6b. As shown in FIG. 2, the infrared light emitting element 7 has a light emission direction angle on the front side, and also has a right light receiving element 8a and a left light receiving element 8b.
As shown in Fig. 3, the receiving directivity angle i is on the left and right front, respectively.
qJ, some of which overlap at the front center.

Furthermore, wheels 9 are mounted on the left and right sides of the robot main body 3, and casters (not shown) are mounted on the front and rear sides.

Next, the configuration of the robot control circuit provided in the robot body 3 will be explained with reference to FIG. 4.

The infrared light emitting element 7 is, for example,
It is modulated and driven by a 100KHz square wave signal. Further, the light reception signals of the right light receiving element 8a and the left light receiving element 8b are amplified by amplifiers 12a and 12b, respectively, and then input to filters 13a and 13b.

The filters 13a and 13b are bandpass filters tuned to the modulation frequency of the modulation circuit 11, and are intended to remove the influence of external light. And the filter 13a
, 13b are outputted by level detection circuits 14a, 13b, respectively.
14b. These level detection circuits 14a, 14b
When the output signals of the filters 13a and 13b exceed the set level, this state is detected and the microprocessor 1
Output to 5. This microprocessor 15 controls the motor drivers 16a, 16b according to the signal from the level detection circuit 14a114b, and controls the right wheel motor 11a1.
The left wheel motor 17b is rotationally driven.

Next, the operation of the above embodiment will be explained with reference to the flowchart of FIG. When the mobile robot 2 moves toward the target 1 , the modulation circuit 11 first drives the infrared light emitting element 7 to emit light, and irradiates the front of the mobile robot 2 with infrared rays output from the infrared light emitting element 7 . . At this time, if the mobile robot 2 is facing the direction of the target object 1, the infrared light emitted by the infrared light emitting element 7 is reflected by the light reflecting surface 1a of the target object 1 and returned to the right light receiving element 8a or the left light receiving element 8a. Light receiving element 8
b or both. However, if the mobile robot 2 faces in a direction away from the target 1, the infrared rays emitted from the infrared light emitting element 7 will not reach the target 1, and the right light receiving element 8a1. No reflected light is incident on the left light receiving element 8b. When the microprocessor 15 in the robot control circuit shown in FIG. 4 starts the control operation, it first checks the presence or absence of light input to the optical sensor, that is, the light receiving element 8a18b, as shown in step A1 of FIG. do. That is, in step A2, it is determined whether the reflected light from the target object 1 is input to the right light receiving element 8a. If there is no light input to the right light receiving element 8a, it is determined that the mobile robot 2 is not facing the target object 1, and as shown in step A3, a drive signal is sent to the motor driver 16a to move the mobile robot 2 toward the target object 1. Turn to the left at the position. At this time, the left wheel motor 17b is stopped. The turning operation of the mobile robot 2 continues until the reflected light from the target object 1 is input to the right light receiving element 8a.

When the light input to the right light receiving element 8a is detected in step A2, the process proceeds to step A4 and the left light receiving element 8b is detected.
Determine the presence or absence of optical input to. If there is no input to the left light receiving element 8b, this means that the target object 1 has turned a little too far to the left as shown in FIG. 6(a), so step A is performed.
As shown in 5, while driving the left wheel motor 17b,
The right wheel motor 17a is stopped and the mobile robot 2 is rotated to the right. As a result, the reflected light from the target object 1 is reflected in Figure 6 (
As shown in b), the light is input to both the right light receiving element 8a and the left light receiving element 8b, and the process proceeds from step A4 to step 86, where both the right wheel motor 17a and the left wheel motor 17b are driven. A mobile robot 2 is moved forward toward a target object 1. Then the microprocessor 15
Furthermore, in step A1, the presence or absence of light input to the light receiving elements 8a and 8b is checked, and the mobile robot 20 runs TGM according to the input state. That is, first, in step 88, it is determined whether there is light input to the right light receiving element 8a, and if there is light input, the process proceeds to step A9, where it is determined whether or not there is input to the left light receiving element 8b, and if there is light input, the process proceeds to step A9. Proceed to A10. In this case, as shown in FIG. 6(b), the mobile robot 2 is correctly facing the target 1, so in step A10, the right wheel motor 17a and the left wheel motor 17b are rotationally driven, 2 is moved directly toward target 1. In addition, if it is determined in step A9 that there is no light input to the left light receiving element 8b, as shown in FIG. The wheel motor 17a is stopped and only the left wheel motor 17b is driven to turn the mobile robot 2 to the right.

Due to this rotation, the mobile robot 2 is correctly oriented in the direction of the target object 1 (and the reflected light from the target object 1 is input to both the left and right light receiving elements 8a and 8b, so the process moves from step A8 to step A9 to step AIO). Then, as described above, the right wheel motor 17a and the left wheel motor 11b are driven to move the mobile robot 2 forward toward the target object 1.

If it is determined in step 88 that there is no light input to the right light receiving element 8a, the process proceeds to step A12, where it is determined whether or not there is light input to the left light receiving element 8b. If it is determined in step A12 that there is light input to the left light receiving element 8b, it means that the mobile robot 2 is heading to the right of the target object 1 as shown in FIG. 6(C). If so, the process proceeds to step A13, where the left wheel motor 11b is stopped, and only the right wheel motor 17a is driven to turn the mobile robot 2 to the left. When the mobile robot 2 correctly faces the target object 1 by this turning, the reflected light from the target object 1 is input to both the left and right light receiving elements 8a and 8b, so steps 88 to 80 are performed. The process then proceeds to step AIG, where the right wheel motor 17a and the left wheel motor 17b are driven as described above to move the mobile robot 2 forward toward the target object 1. Thereafter, similar operations are repeated to cause the mobile robot 2 to travel toward the target object 1. Then, as shown in FIG. 7(a), when the mobile robot 2 comes into contact with a part of the target object 1, in addition to the above operation,
The cylinder (target object 1) is positioned by fitting into the recess 4 of the mobile robot 2, and the recess 4 of the mobile robot 2 and the target object 1 fit together as shown in FIG. 7(b). The infrared light emitting element 7 and the light receiving elements 8a and 8b provided in the center part A of the recess 4 are installed recessed from the surface of the recess 4, as shown in FIG. 7(c), so that the mobile robot 2 When the target object 1 and the target object 1 are fitted together, the reflected light from the light reflecting surface 1a no longer reaches the light receiving elements 8a and 8b. This state is detected in steps A8 and A12 in FIG. 5, and the right wheel motor 17a and left wheel motor 17b are stopped in step A14. , that's all for mobile robot 2
Terminates driving control.

FIG. 8 shows an example in which the present invention is applied to a hobby robot 21. The hobby robot 21 is equipped with a self-propelling function and a function of holding the tray 23 with arms 22a and 22b and raising and lowering it to a desired height. 23 is placed thereon, and a light reflecting surface 24b is formed on the outer circumferential surface of a lower cylindrical platform 24a, so that infrared rays emitted from the hobby robot 21 are reflected. Then, the hobby robot 21 takes out the designated tray 23 from s25 according to the user's command, and stores the taken out tray 23 in a predetermined position on the shelf 25. Travel control of the hobby robot 21 is performed in the same manner as in the embodiment described above.

[Effects of the Invention] As detailed above, according to the present invention, a cylindrical light reflecting surface is formed on a target object, a light emitting element and a light receiving element are provided on a mobile robot, and light emitted from the light emitting element is reflected. The light that is irradiated forward and reflected by the cylindrical reflective surface of the target is received by the light receiving element, and the robot's course is corrected according to the received light condition so that it heads toward the target. The robot can be reliably guided to a target location such as a target object, home position, charging station, etc. (by providing a target object) without attaching a light-reflecting tape. Furthermore, since the target object only forms a cylindrical light-reflecting surface, a light emitting source and its power source are not required, and the purpose can be achieved with an extremely simple configuration, which can reduce costs. .

Furthermore, since the light-reflecting surface of the target is formed in a cylindrical shape,
Positioning can be performed from any direction.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a perspective view showing the external configuration of a mobile robot and a target; FIG. 2 is a diagram showing the light emission directional characteristics of an infrared light emitting element provided in the mobile robot; Figure 3 is a diagram showing the light-receiving directional characteristics of the light-receiving element;
The figure is a block diagram showing the robot's travel control circuit, Figure 5 is a flowchart showing the travel control operation, and Figures 6 and 7 are
FIG. 8 is a diagram showing the running state of the robot for explaining the running control operation, and FIG. 8 is a perspective view showing an example in which the present invention is applied to a hobby robot. DESCRIPTION OF SYMBOLS 1... Target object, 2... Mobile robot, 3... Robot body, 4... Recessed part, 5.6a, 6b... Through hole,
7... Infrared light emitting element, 8a... Right light receiving element, 8b.
...Left light receiving element, 9...Wheel, 11...Modulation circuit,
12a, 12b...Amplifier, 13a, 13b・
7 Ilter, 14a, 14b-L, 'Bell detection circuit, 15...Microprocessor, 16a, 18b...
・Motor driver, 17a...Right wheel motor, 17b
...Left wheel motor, 21...Hobby robot, 22
a, 22b...arm, 23...tray, 24...
・Target, 25...shelf. Applicant's agent Patent attorney Takehiko Suzue Figure 4 17b 17a Figure 6

Claims (3)

[Claims] (1) A target object having a cylindrical light-reflecting surface, a light-emitting element and a light-receiving element, the light emitted from the light-emitting element is reflected by the cylindrical light-reflecting surface, the light is received by the light-receiving element, and the light is received. A mobile robot guidance method comprising: a mobile robot that corrects its course depending on the state and heads toward the target object. (2) The mobile robot has a recess that can fit into the cylindrical light reflecting surface, and the light emitting element and the light receiving element are disposed in the recess. guidance method for mobile robots. (3) Claim 2, characterized in that the light emitting element and the light receiving element are arranged at a depth from the surface of the recessed part.
Guidance method for mobile robots described in Section 2.