KR100492591B1 - Robot cleaner and his collision detection method - Google Patents

Abstract

The present invention relates to a robot cleaner and a collision detection method thereof, and to measure a linear acceleration by measuring an acceleration change as a change in electric charge amount using a MEMS technology, so that mechanical contact with the outside can be detected. To this end, the present invention is an acceleration sensor attached to any position in the axial direction of any one of the x, y, z axis of the robot cleaner body, and measuring the acceleration change as the change in the charge amount; An analog / digital converter for converting the acceleration signal into a digital signal; Compare the digital signal with preset collision data, detect a collision based on the result of the comparison, calculate a collision amount by processing the digital signal, and control the movement direction of the robot cleaner accordingly, and detect the collision. And a microcomputer that recognizes the direction of the collision in the acceleration direction and controls the operation to avoid the collision direction.

Description

Robot cleaner and collision detection method {ROBOT CLEANER AND HIS COLLISION DETECTION METHOD}

The present invention relates to a robot cleaner and a collision detection method thereof, and in particular, by measuring a change in acceleration by a change in charge amount by using a MEMS technology to measure linear acceleration, so as to detect mechanical contact with the outside.

In general, the mobile robot generates ultrasonic waves from a plurality of ultrasonic sensors attached thereto, and detects the reflected ultrasonic waves to detect a distance or a direction.

A robot cleaner, which is a representative example of a mobile robot, automatically cleans an area to be cleaned by inhaling foreign substances such as dust from the floor while driving itself in the area to be cleaned without a user's manipulation.

That is, the robot cleaner determines the distance to the obstacles such as furniture, office supplies, and walls installed in the cleaning area through a plurality of ultrasonic sensors detecting the distance and direction, and selectively drives the left and right wheel motors of the robot cleaner. Clean the cleaning area by changing direction.

1 is a longitudinal cross-sectional view showing a general robot cleaner, Figure 2 is a schematic diagram of FIG.

As shown therein, the conventional robot cleaner is equipped with a fan motor 2 for generating a suction force inside the cleaner body 1, and in front of the fan motor 2 by the fan motor 2. A filter container 4 having a built-in filter 3 for collecting dust and dirt to be sucked in is detachably installed.

In addition, the front of the filter container (4) is installed so that the suction pipe (5) is sucked in the dust or dirt sucked in, the lower end of the suction pipe (5) for sweeping up the dust or dirt of the bottom (6) The suction head 8 is provided with the brush 7 rotatably installed.

In addition, a pair of drive wheels 9 capable of forward and reverse rotation are provided below the fan motor 2 at regular intervals, and behind the suction head 8 is a rear of the cleaner body 1. Auxiliary wheel 10 is installed to support.

In addition, a charging terminal unit 12 having a charging terminal 11 is installed at a rear surface of the cleaner main body 1, and a charging terminal unit 12 is connected to a power terminal unit 14 installed at a wall surface 13 of the room. The connection terminal 15 is provided so that the charging battery 16 inside the main body 1 can be charged while the charging terminal 11 is connected to the connection terminal 15.

  In addition, an ultrasonic sensor 17 for transmitting and receiving ultrasonic waves is provided at the front center of the cleaner body 1, and the ultrasonic waves 17 are transmitted to the left and right sides of the ultrasonic sensor 17 to receive ultrasonic waves that are reflected and obstruct the obstacle. A plurality of ultrasonic sensors 31 to 35 for sensing the distance or measuring the distance to the target are installed at regular intervals as shown in FIG. 2.

A light emitting unit 19 for emitting an optical signal for guiding the charging terminal unit 12 toward the power terminal unit 14 is provided below the power terminal unit 14, and below the charging terminal unit 12. The light receiving unit 20 is installed to receive the light signal emitted from the light emitting unit 19.

In the figure, reference numeral 21 denotes a control means, and 22 denotes an exhaust port.

When cleaning using a conventional robot cleaner configured as described above, when the user presses the operation button, the power of the charging battery 16 is applied to the fan motor 2 to drive the fan motor 2, A suction force is generated in the filter container 4 by the fan motor 2 driven as described above, and dust or dirt on the bottom 6 is sucked into the suction head 8 by the suction force. Is collected by the filter (3).

In addition, the cleaning of a predetermined area is automatically performed by moving the cleaner body 1 by driving the driving wheel 9 by the control signal of the control means 21.

Meanwhile, while the automatic cleaning is performed, the voltage level of the charging battery 16 is detected through the voltage detecting unit (not shown), and the voltage level of the charging battery 16 detected by the voltage sensing unit in the control unit 21 is set. When the level is below the level, the cleaning of the automatic cleaner is stopped by the control means, while the control means 21 stores the current position in the internal memory, and then returns a control signal for returning the cleaner by the return adjustment stored in the memory. Occurs.

Therefore, when the cleaner main body 1 moves to the power supply terminal part 14 by the control signal of the control means 21, and the cleaner main body 1 approaches the power supply terminal part 14, the lower side of the power supply terminal part 14 is carried out. The optical signal emitted from the light emitting unit 19 installed in the light receiving unit 20 is received by the light receiving unit 20 provided below the charging terminal unit 12, and the control means controls the driving wheel 9 by the optical signal received from the light receiving unit 20. By the drive control, the charging terminal portion 12 approaches the power supply terminal portion 14 side.

Then, the charging terminal 11 of the charging terminal unit 12 is brought into contact with the connection terminal 15 of the power supply terminal unit 14, and the inside of the cleaner main body 1 by the power supplied by the power supply terminal unit 14. The charging battery 16 is charged.

Such a robot cleaner runs on the map information stored in itself by a given command and performs the cleaning operation. This method of performing the operation by the user's command is repeated unless the layout is changed.

However, in the case where the layout of the workspace is changed and the obstacle is changed in position, in order to control the running of the robot cleaner or the like, a map suitable for the changed layout is recreated.

FIG. 2 is a diagram illustrating an example of rectangular area mapping of a robot cleaner using a beacon in the related art, in which a robot cleaner starts from a starting point of a rectangular area where an obstacle exists and runs while avoiding an obstacle with an obstacle recognition sensor to a rangefinder. Create a path trace by

At this time, the robot vacuum cleaner receives additional information of the indoor area by receiving a signal from the beacons 41 to 47 installed at a special point while moving the indoor environment.

Therefore, the robot cleaner maps a rectangular area based on a path trace by a rangefinder and a beacon signal.

The above-described robot cleaner collides with an obstacle while traveling in an area. In general, the robot cleaner detects a collision with a bumper equipped with a mechanical spring.

When the bumper collides with an obstacle, it detects a collision by pressing a switch attached to a circuit board through a spring or blocking an infrared pickup.

However, the above-mentioned bumper has a complicated mechanism design of the spring device and only performs on / off operation. Therefore, the bumper cannot detect the strength or impact amount of the collision, and thus does not perform precise control of the moving direction of the robot according to the size of the collision. There is a problem.

The present invention has been made to solve the above problems, by measuring a linear acceleration by measuring the change in acceleration using a change in the amount of charge using the MEMS technology, the robot cleaner to detect the mechanical contact with the outside and its collision The purpose is to provide a detection method.

The present invention for achieving the above object is an acceleration sensor attached to any position in the axial direction of the robot cleaner body, any one of the x, y, z axis, and measuring the acceleration change by the change in the charge amount; An analog / digital conversion unit for converting the digital signal into a digital signal; comparing the digital signal with preset collision data, detecting a collision based on the comparison result, and then processing the digital signal to calculate a collision amount The robot cleaner may be configured to include a microcomputer that controls the moving direction of the robot cleaner, recognizes the direction of the collision in the acceleration direction when the collision is detected, and controls the driving to avoid the collision direction.

The present invention for achieving the above object, in the robot cleaner having a sensor on one side of the x, y, z axis on the main body of the robot cleaner, the acceleration by the change in the amount of charge according to the linear movement of the robot cleaner, Extracting the signal; Converting the acceleration signal into a digital signal; Comparing the linear acceleration signal converted into the digital signal with predetermined collision data; As a result of the comparison, when the linear acceleration signal is larger than the predetermined collision data, the robot cleaner detects that the collision has occurred, and then integrates the linear acceleration signal to obtain a speed and calculates the collision amount based on the speed.

Hereinafter, operations and effects of the robot cleaner and the collision detection method according to the present invention will be described in detail with reference to the accompanying drawings. First, the MEMS technology, a gyro sensor, and the like are commonly used terms, and the MEMS (Micro Electro) Mechanical system technology refers to a technology for manufacturing electromechanical devices on a small micro scale, and is mainly used for micro mirrors, switches used for RF high frequency, sensors for measuring acceleration or angular velocity, and platforms for manufacturing biochips. In the gyro sensor, when the rotational angular velocity is applied to an inertial vibrating body, an electrical signal corresponding to a Coriolis force generated in proportion to the mass, the resonance speed, and the applied angular velocity is generated. 3 is a schematic diagram of the robot cleaner of the present invention. It is a block diagram showing a castle.

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As shown in Fig. 3, the present invention includes an acceleration sensor 100 attached to an arbitrary position in any one of the x, y, and z axes of the robot cleaner main body to measure the change in acceleration as the change in charge amount; An analog / digital converter (200) for converting the acceleration signal into a digital signal; The microcomputer 300 compares the digital signal with predetermined collision data, detects a collision based on the comparison result, and then processes a predetermined amount of the digital signal to calculate a collision amount to control a moving direction of the robot cleaner accordingly. ).

4 is an operation flowchart of a collision detection method of the robot cleaner of the present invention.

As shown in FIG. 4, the present invention provides a method for extracting an acceleration signal by changing a charge amount according to a linear movement of a robot cleaner (SP1); Converting the acceleration signal into a digital signal (SP2); Comparing the linear acceleration signal converted into the digital signal with predetermined collision data (SP3); As a result of the comparison, if the linear acceleration signal is larger than the predetermined collision data, the robot cleaner detects that the collision has occurred, and then integrates the linear acceleration signal to obtain a speed, and calculates the collision amount at the speed (SP4, SP5). This operation of the present invention will be described.

First, the acceleration sensor 100 is attached to any position in the axial direction of the x, y, z axis of the robot cleaner main body, and when collided with any object, the acceleration change is measured as the change in the charge amount and the acceleration accordingly The signal is applied to the analog / digital converter 200.

Here, the acceleration sensor 100 may be replaced with a gyro sensor for measuring the rotational angular velocity by using a change in the voltage based on the pressure change of the piezoelectric element.

Accordingly, the analog / digital conversion unit 200 converts the acceleration signal into a digital signal and applies it to the microcomputer 300, and the microcomputer 300 collides the digital signal with preset collision data. After the detection, the digital signal calculates an accurate collision amount by predetermined signal processing and controls the moving direction of the robot cleaner accordingly.

That is, when the collision is detected, the microcomputer 300 recognizes the direction of the collision in the acceleration direction and controls the operation to avoid the collision direction.

More specifically, with reference to FIG. 4, first, as the robot cleaner moves, the acceleration signal is extracted due to the change in the amount of charges according to the linear movement of the robot cleaner (SP1).

Next, after converting the extracted acceleration signal into a digital signal, the digital signal is compared with predetermined collision data (SP2, SP3).

As a result of the comparison, if the linear acceleration signal is larger than the predetermined collision data, the robot cleaner detects that the collision has occurred, and then integrates the linear acceleration signal to obtain a speed and calculates the collision amount at the speed (SP4, SP5).

Thereafter, the robot cleaner determines the movement direction and moves according to the direction and the collision amount according to the collision.

In other words, when the robot cleaner collides with an obstacle, the acceleration signal is extracted by changing the amount of charge according to the linear movement of the robot cleaner, and the acceleration signal is converted into a digital signal and then converted into the digital signal. The linear acceleration signal is compared with the preset collision data, and based on the comparison result, if the linear acceleration signal is larger than the predetermined collision data, the robot cleaner detects that the collision has occurred, and then integrates the linear acceleration signal to obtain a speed. The collision amount is calculated at the speed, and the moving direction of the robot cleaner is determined.

The specific embodiments or examples made in the detailed description of the present invention are intended to clarify the technical contents of the present invention to the extent that they should not be construed as limited to these specific embodiments and should not be construed in consultation. Various changes can be made within the scope of.

As described in detail above, the present invention measures linear acceleration by measuring an acceleration change as a change in charge amount using a MEMS, a piezoelectric or a spring accelerometer, thereby precisely controlling the direction of movement of the robot by detecting mechanical contact with the outside. It works.

Figure 1 is a longitudinal cross-sectional view showing a typical robot cleaner

Figure 2 is an embodiment showing a rectangular area mapping of the robot cleaner using a conventional beacon (Beacon).

Figure 3 is a block diagram showing a schematic configuration of the robot cleaner of the present invention.

Figure 4 is a flow chart for the collision detection method of the present invention robot cleaner.

** Description of symbols for the main parts of the drawing **

100: acceleration sensor 200: analogue / digital conversion part

300: microcomputer

Claims (4)

An acceleration sensor attached to an arbitrary position in any one of the x, y, and z axes of the robot cleaner main body and measuring the change in acceleration as the change in electric charge amount; An analog / digital converter for converting the acceleration signal into a digital signal; Compare the digital signal with preset collision data, detect a collision based on the comparison result, and process the digital signal to calculate a collision amount to control a moving direction of the robot cleaner according to the result. And a microcomputer for recognizing the direction of the collision in the acceleration direction and controlling the driving to avoid the collision direction when the collision is detected. delete The method of claim 1, wherein the acceleration sensor, And a gyro sensor that measures rotational angular velocity using a change in voltage based on a change in pressure of the piezoelectric element. In the robot cleaner provided with a sensor in one of x, y and z axes on the main body of the robot cleaner, Extracting an acceleration signal due to a change in the charge amount according to the linear movement of the robot cleaner; Converting the acceleration signal into a digital signal; Comparing the linear acceleration signal converted into the digital signal with predetermined collision data; As a result of the comparison, if the linear acceleration signal is greater than the predetermined collision data, the robot cleaner detects that the collision, and then integrates the linear acceleration signal to obtain a speed, and calculates the collision amount at that speed How to detect a collision of a vacuum cleaner.