KR100645816B1 - A device for travel distance equalization of roving robot - Google Patents

Abstract

A moving distance compensation device of a mobile robot is provided to compensate errors of moving distance due to slip or idling of a wheel by comparing movement calculated based on image data with movement calculated according to rpm data of left and right wheels. A moving distance compensation device of a mobile robot includes a wireless transmitting and receiving unit(110) transmitting and receiving a remote control signal from a user terminal, a memory(120) storing control program of the mobile robot, a wheel motor driving unit(130) moving the mobile robot, a rotation detection unit(140) detecting rotation of a wheel motor, an optical sensor unit(150) obtaining image of a ground, and a mobile robot control unit(160) correcting moving distance errors in slipping or idling a wheel by calculating and comparing movement based on data from the rotation detection unit and the optical sensor unit. The optical sensor unit has a light emitting unit(151) emitting light to the ground, a light receiving unit(152) sensing light reflected from the ground, and a conversion output unit(153) outputting image data by converting signals detected by the light receiving unit.

Description

Moving distance correction device of mobile robot {A DEVICE FOR TRAVEL DISTANCE EQUALIZATION OF ROVING ROBOT}

1 is a block diagram of a mobile robot including a movement distance correction device according to an embodiment of the present invention.

Figure 2 is a flow chart for explaining the operation of the movement distance correction apparatus of the mobile robot according to an embodiment of the present invention.

Figure 3a is a cross-sectional view for explaining the separation distance of the optical sensor unit when moving the flat ground.

Figure 3b is a cross-sectional view for explaining the separation distance of the optical sensor when moving the curved ground.

Description of the main parts of the drawing

100: mobile robot 130: wheel motor drive unit

140: rotation amount detection unit 150: light sensor unit

151 light emitting unit 152 light receiving unit

153: conversion output unit 200: mounting member

210: spring 220: sliding tube

The present invention relates to a mobile robot, and more particularly to a moving distance correction device of the mobile robot.

Robots have been developed for industrial use and as part of factory automation, or have been used to collect or collect information on behalf of humans in extreme environments that humans cannot tolerate. This field of robotics has been developed in recent years as it is used in the cutting-edge space development industry, and until recently, human-friendly home robots have been developed.

In general, a mobile robot, such as a cleaning robot, estimates its current position using encoder information installed on a wheel. In the method of estimating the position using the encoder information, an error occurs due to slippage or idle of a wheel. There is a problem.

Meanwhile, in order to solve this problem, stickers or reflecting plates having the same shape are attached to beacons at predetermined intervals in the moving area, and the beacons are recognized using a camera mounted on the mobile robot, thereby preventing errors caused by slippage or idleness of the wheels. How to calibrate was introduced.

However, the method using the beacon as described above also has a problem of accumulating the movement distance error if the brightness of the area to be moved is changed or if an object having a shape similar to the beacon is recognized.

Therefore, the present invention was created to solve the problems of the prior art as described above, the movement that can correct the movement distance error caused by the sliding or idle of the wheel based on the movement amount calculated by acquiring the image of the ground An object of the present invention is to provide a movement distance correction device for a robot.

Moving distance correction apparatus of a mobile robot according to an embodiment of the present invention for achieving the above object,

A rotation amount sensing unit for sensing an amount of rotation of the wheel motor;

An optical sensor unit attached to a bottom surface of the mobile robot to acquire an image of the ground;

A controller for correcting a moving distance according to data comparison results obtained from the rotation amount detecting unit and the optical sensor unit; Characterized in that it comprises a.

In addition, the optical sensor unit is characterized in that it is mounted to the lower end of the sliding tube capable of vertically moving so that the distance to the ground is kept constant.

According to the configuration features as described above, it is possible to correct the movement distance error caused by the slip or idle of the wheel through the comparison between the data obtained from the rotation amount sensor and the optical sensor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

First, Figure 1 shows a block diagram of a mobile robot including a movement distance correction apparatus according to an embodiment of the present invention.

As shown, the movement distance correction apparatus of the mobile robot according to an embodiment of the present invention is a wireless transmission and reception unit 110 for transmitting and receiving a signal (remote control signal) with the user terminal, a memory that stores the control program of the mobile robot Acquiring an image of the ground on the mobile robot 100 comprising a 120, a wheel motor driver 130 for the movement of the mobile robot, and a rotation amount sensing unit 140 for detecting the amount of rotation of the wheel motor. The optical sensor unit 150 is newly configured, and the mobile robot control unit 160 calculates and compares each movement amount based on the data received from the rotation amount detecting unit 140 and the optical sensor unit 150, and thus, the wheels. It is implemented to correct the movement distance error caused by slip or idle.

More specifically, the wheel motor driver 130 drives the wheel motor M in accordance with a drive control signal applied from the mobile robot controller 160, and the rotation amount detecting unit 140 is connected to each of the left and right wheel wheels. As the encoder, the rotational amount of the left and right wheels is sensed and the rotational speed data corresponding thereto is fed back to the mobile robot controller 160.

The light sensor unit 150 converts an image by converting a signal detected by the light emitter 151 that emits light toward the ground, a light receiver 152 that senses light reflected through the ground, and a light receiver 152. And a conversion output unit 153 for outputting data.

More specifically, the light emitting unit 151 converts an electric signal input from the outside into light to emit light, but various light emitting devices may be used, but the light emitting unit 151 according to the embodiment of the present invention illuminates the ground brightly. By using high brightness LEDs to keep the brightness of the ground always bright.

On the other hand, the light receiving unit 152 is for detecting the image information by receiving the light reflected through the ground, it may be an optical sensor having a good resolution at a short distance. In the general optical sensor, light emitted from the light emitting unit 151 is reflected from the ground, and the reflected light passes through the lens and is input to an image sensor composed of hundreds of pixels. It will detect the shape.

For reference, the optical sensor according to the embodiment of the present invention may be, for example, HP HDNS-2000. The HDNS-2000 is an optical sensor including a lens that collects light reflected from the ground and an image sensor that detects an image through the lens. The HDNS-2000 can capture and acquire 1500 ground images per second.

The conversion output unit 153 may be an A / D converter that receives an analog signal from the image sensor of the light receiving unit 152, converts the received signal into a digital signal, and outputs image data to the mobile robot controller 160.

On the other hand, as described above, the optical sensor unit 150 acquires an image of the ground while always maintaining a constant distance regardless of the ground state. A detailed description will be described later with reference to FIGS. 3A and 3B.

Finally, the mobile robot controller 160 not only controls the overall operation of the mobile robot, but also controls the amount of movement of the mobile robot 100 based on data received from the rotation amount detecting unit 140 and the optical sensor unit 150. Compute the distance by comparing the two calculated movements.

The mobile robot controller 160 calculates a movement amount in the x and y axes based on the rotation speed data corresponding to the rotation amounts of the left and right wheels input from the rotation amount detection unit 140. In addition, the mobile robot controller 160 calculates the amount of movement on the x and y axes by comparing the image data input from the optical sensor unit 150 with previously input image data.

The mobile robot controller 160 then corrects the moving distance by comparing the two moving amounts calculated based on the rotation speed data and the image data. At this time, the mobile robot controller 160 compares the calculated two moving amounts to correct the moving distance, and compares the calculated moving amounts based on the image data. This is because the movement amount calculated based on the rotational speed data may be more accurate than the movement amount calculated based on the rotational speed data. can do.

Therefore, when the two moving amounts calculated as a result of the comparison of the mobile robot controller 160 are different, the mobile robot controller 160 corrects the moving distance based on the calculated moving amount based on the image data.

Hereinafter, the operation of the movement distance correction device of the mobile robot will be described in more detail with reference to FIG. 2.

Figure 2 shows a flow chart for explaining the operation of the movement distance correction apparatus of the mobile robot according to an embodiment of the present invention.

Referring to FIG. 2, first, the mobile robot controller 160 outputs rotation speed data corresponding to the rotation amounts of the left and right wheels output from the rotation amount sensing unit 140 and image data output from the optical sensor unit 150. Receive (step S10).

Thereafter, the mobile robot controller 160 calculates the movement amount in the x and y axes based on the received rotational speed data, and also compares the image data input from the optical sensor unit 150 with previously input image data and x In step S20, the movement amount on the y-axis is calculated.

The mobile robot controller 160 that calculates each movement amount based on the rotational speed data and the image data checks whether the calculated two movement amounts are the same (step S30). If it is determined that the calculated two movement amounts are the same, the mobile robot controller 160 determines that the wheel slip or idle does not occur and continues the driving and at the same time the rotation amount detecting unit 140 and the optical sensor unit 150. Continue to receive data from However, if the calculated two movement amounts are found to be different, the mobile robot controller 160 corrects the movement distance by the difference between the calculated two movement amounts based on the calculated movement amount based on the image data (step S40).

After that, the mobile robot controller 160 having corrected the movement distance checks whether all movements are completed (step S50), and if it is determined that the movement is not completed, from the rotation amount detecting unit 140 and the optical sensor unit 150. The move continues while data is received, and all operations are terminated when the move is found to be complete.

3A illustrates a cross-sectional view for describing a separation distance of the optical sensor unit when moving the flat ground, and FIG. 3B illustrates a cross-sectional view for explaining the separation distance of the optical sensor unit when moving the curved ground.

As shown, the optical line unit 150 has a constant distance h from the ground at all times by the operating relationship between the mounting member 200, the spring 210, and the sliding tube 220 mounted at one end of the mobile robot 100. Will be maintained.

More specifically, the mounting member 200 is fixed to one end of the mobile robot is a basic frame to always maintain a constant separation distance (h) the optical sensor unit 150. The sliding tube 220 may flow up and down based on the mounting member 200 as an axis.

The spring 210 is mounted in the sliding tube 220 as a configuration for giving an elastic force to the sliding tube 220. The spring 210 is compressed when the ground is flat as shown in FIG. 3A, and is stretched when the ground is curved as shown in FIG. 3B to give an elastic force to the sliding tube 220.

The sliding tube 220 is capable of vertical flow according to the state of the ground with the mounting member 200 as an axis. When the mobile robot 100 is moving on the flat ground as shown in FIG. 3A, the sliding tube 220 keeps the spring 210 compressed and the sliding tube 220 in contact with the mounting member 200 and the ground. do. Therefore, the optical sensor unit 150 mounted at one end of the lower end of the sliding tube 220 acquires an image while maintaining a constant distance h from the ground at all times.

On the other hand, when the mobile robot 100 is moving the curved ground as shown in Figure 3b, because the spring 210 is extended and the sliding tube 220 comes down toward the ground, the optical sensor unit 150 is in the state of the ground Irrespective of the distance (h) can be maintained.

According to the embodiment of the present invention as described above, the movement distance generated by the slip or idle of the wheel by comparing the movement amount calculated based on the image data of the ground with the movement amount calculated from the rotational speed data of the left and right wheels There is an advantage to correct the error.

While the present invention has been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that many various obvious modifications are possible without departing from the scope of the invention from this description. Therefore, it should be interpreted by the claims described to include many such variations.

Claims (4)

A rotation amount sensing unit for sensing an amount of rotation of the wheel motor; An optical sensor unit attached to a bottom surface of the mobile robot to acquire an image of the ground; A controller for correcting a moving distance according to data comparison results obtained from the rotation amount detecting unit and the optical sensor unit; Moving distance correction device of a mobile robot, characterized in that it comprises a. The apparatus of claim 1, wherein the optical sensor unit is mounted at one end of a lower end of the sliding tube which can be vertically flowable to maintain a constant distance from the ground. The method of claim 2, wherein the optical sensor unit: A light emitting part that emits light toward the ground; A light receiving unit for detecting light reflected through the ground; A conversion output unit for converting the signal detected by the light receiving unit to output image data; Moving distance correction device of a mobile robot, characterized in that it comprises a. The apparatus of claim 1, wherein the mobile robot is a cleaning robot.

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