JP2008065418A - Autonomous running device, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an autonomous running device which can measure a distance to an obstacle correctly without using a sensor means. <P>SOLUTION: The autonomous running device is equipped with; a first sensor means 3 which sequentially measures distances to the obstacle 2; a second sensor means 9 which measures a fixed distance to the obstacle; first and second sensor distance decision means 6, 10 which decide distances from the sensor means 3, 9 to the obstacle; a map storage means 7 which stores the sensor output quantity information for every position in a room to run; a sensor output quantity decision means 8 which decides the sensor output quantity of the first sensor means 3 from the distance information to the obstacle 2 by the sensor distance decision means 6, 10 and the sensor output quantity information of the map storage means 7, outputs to the map memory means 7. Thereby, the sensor output quantity of the first sensor means 3 is adjusted by the second sensor means 9 and the distance to the obstacle can be measured correctly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an autonomous traveling device that travels while measuring a distance to an obstacle, a program, and a recording medium.

Conventionally, this type of autonomous traveling device moves to an arbitrary location while avoiding an obstacle based on distance information obtained by measuring the distance to the obstacle with an ultrasonic sensor (see, for example, Patent Document 1).
Japanese Patent No. 3184467

  However, in the conventional configuration, since the distance to the obstacle is measured by the time difference between the transmission time of the ultrasonic wave and the reception time of the reflected wave, when the energy amount of the ultrasonic sensor is small, the reflected wave due to the obstacle is generated. The reception time cannot be determined and the distance to the obstacle cannot be measured, and conversely, if the amount of ultrasonic energy is large, interference will occur due to multiple reflections of the obstacle, and the exact reception time will not be known. There was a problem that the distance to the obstacle could not be measured.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an autonomous traveling device, a program, and a recording medium that can accurately measure the distance to an obstacle regardless of sensor means.

  In order to solve the above-described conventional problems, the autonomous traveling device of the present invention includes first sensor means for sequentially measuring the distance to an obstacle as the traveling device body travels, and only a certain distance to the obstacle. Second sensor means for measuring, and first and second sensor distance determining means for determining the distance from the sensor output of the first and second sensor means to the obstacle and outputting the distance as the first and second distances And map storage means for storing sensor output amount information for each position of the room where the traveling device body travels, and first and second distance information to the obstacle by the first and second sensor distance determination means, The sensor output amount information stored in the map storage means is determined from the sensor output amount information of the first sensor means, and is output to the map storage means as sensor output amount information.

  Thereby, the sensor output amount of the first sensor means for sequentially measuring the distance to the obstacle is adjusted by the second sensor means for measuring only a certain distance to the obstacle. The distance can be measured accurately.

  In addition, since the program of the autonomous traveling device can be realized on a computer, means can be easily provided to the user.

  In addition, a readable recording medium on which the program is recorded can easily distribute / update the program and install the program.

  The autonomous traveling device, the program, and the recording medium of the present invention can accurately measure the distance to the obstacle regardless of the sensor means.

  The first invention includes first sensor means for sequentially measuring the distance to the obstacle as the traveling apparatus body travels, second sensor means for measuring only a certain distance to the obstacle, The first and second sensor distance determining means for determining the distance from the sensor output of the second sensor means to the obstacle and outputting the distance as the first and second distances, and the position of the room where the traveling device body travels Map storage means for storing sensor output amount information for each, first and second distance information to the obstacle by the first and second sensor distance determination means, sensor output amount information stored by the map storage means, Thus, the autonomous traveling device is provided with sensor output amount determining means for determining the sensor output amount of the first sensor means and outputting the sensor output amount information to the map storage means as sensor output amount information. Thereby, the sensor output amount of the first sensor means for sequentially measuring the distance to the obstacle is adjusted by the second sensor means for measuring only a certain distance to the obstacle. The distance can be measured accurately.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first sensor means is the first sensor output means for outputting the sensor output, and the first sensor input the reflected wave reflected by the obstacle. The distance to the obstacle can be accurately measured by measuring the distance to the obstacle from the transmission / reception time between the first sensor output means and the first sensor input means. Is.

  In the third invention, in particular, in the first or second invention, the second sensor means is constituted by a contact sensor, so that an obstacle can be detected reliably. The sensor output amount by the sensor means can be determined.

  According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects, the first distance by the first sensor distance determining unit is shorter than the second distance by the second sensor distance determining unit. By increasing the output amount of the first sensor means, the more accurate output amount of the first sensor means can be determined. In other words, the fact that there is an obstacle in the second sensor means without the obstacle being recognized by the first sensor means that the obstacle cannot be detected because the output amount of the first sensor means is small. Therefore, the obstacle detection capability is improved by increasing the output amount of the first sensor means.

  In a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the first sensor distance determining means determines that the reflected wave from the obstacle is interfering with the first sensor input means. Then, by reducing the output amount of the first sensor means, interference can be reduced and more stable obstacle detection can be performed.

  In the sixth invention, in particular, in any one of the first to fifth inventions, the map storage means displays the stored map information to the user by the map display means. Since the situation of the room can be visually taught and corrected and corrected easily, more accurate obstacle detection can be performed.

  In the seventh aspect of the invention, in particular, the program can be realized on the computer by making the computer execute at least a part of the functions of the autonomous mobile device according to any one of the first to sixth aspects of the invention. Therefore, a means can be easily provided to the user.

  In the eighth aspect of the invention, in particular, by using a readable recording medium that records the program in the seventh aspect of the invention, the program can be easily distributed / updated and installed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment)
FIG. 1 shows an autonomous traveling device according to an embodiment of the present invention.

  As shown in the figure, the autonomous traveling device in the present embodiment includes a first sensor means 3 that sequentially measures the distance to the obstacle 2 as the traveling device body 1 travels, and a constant distance to the obstacle 2. Second sensor means 9 for measuring only the first and second sensor means 3, 9 determines the distance from the sensor output of the first sensor means 3, 9 to the obstacle 2, and outputs the first and second distances as the first, Second sensor distance determining means 6, 10, map storage means 7 for storing sensor output amount information for each position of the room where the traveling apparatus body 1 travels, first and second sensor distance determining means 6, 10 determines the sensor output amount of the first sensor means 3 from the first and second distance information to the obstacle 2 and the sensor output amount information stored in the map storage means 7, and sends the sensor to the map storage means 7. Sensor output amount determining means to output as output amount information And a 8.

  The first sensor means 3 is composed of an ultrasonic sensor in the present embodiment, and first sensor output means for outputting an ultrasonic wave to the obstacle 2 with the output amount of the sensor output amount determining means 5. 3a and a first sensor input means 3b for inputting a reflected wave whose sensor output is reflected by the obstacle 2, and the obstacle is determined from the transmission and reception time between the first sensor output means 3a and the first sensor input means 3b. The distance to the object 2 is measured. The first sensor means 3 is installed in the traveling apparatus main body 1 and measures the distance between the traveling apparatus main body 1 and the obstacle 2 while moving by the motor 11 and the wheels 14.

  The first sensor distance determining means 6 calculates the distance between the obstacle 2 and the traveling apparatus body 1 by using the transmission time by the first sensor output means 3a and the reception time by the first sensor input means 3b as inputs. Is output as a distance.

  In the present embodiment, the second sensor means 9 is composed of a contact sensor provided on the bumper of the traveling apparatus main body 1, and measures the distance to the obstacle 2 by contacting the obstacle 2, and as a result. Is output to the second sensor distance determining means 10 as the second distance. The second sensor distance determining means 10 calculates the distance between the obstacle 2 and the traveling apparatus body 1 based on the result of the second sensor means 9 and outputs it as the second distance.

  The map storage means 7 stores the sensor output amount of the first sensor output means 3a according to the map position of the traveling room. The map storage means 7 outputs the sensor output amount corresponding to the travel position to the sensor output amount determination means 5 when the travel position of the traveling room is input by the travel position detection means 13.

  The sensor output amount determining means 8 receives the first distance from the first sensor distance determining means 6, the second distance from the second sensor distance determining means 10, and the sensor output amount from the map storage means 7 as inputs, and is more optimal. The output amount of the first sensor output means 3 a is determined and output to the map storage means 7. When the map storage means 7 compares the sensor output amount from the sensor output amount determination means 8 with the currently stored sensor output amount and determines that it has been updated, it corresponds to the current position of the traveling apparatus body 1. Update the map sensor output.

  The travel position detection means 13 measures the position of the travel device main body 1 from the wheel 14, the motor 11, and the motor control means 12 and outputs it to the sensor output amount determination means 8 as the travel position.

  Further, it has a map display means 15 and displays the map information stored in the map storage means 7 to the user so that the user can be visually informed of the situation of the room and can be easily corrected and corrected. It is possible to detect obstacles more accurately.

  In addition, at least a part of the functions of each means in the above-described autonomous traveling device is a program that is executed by a computer, and the program is recorded on a computer-readable recording medium.

  Next, the operation of the autonomous traveling device in the present embodiment will be described.

  First, based on FIG. 2, operation | movement of the 1st sensor distance determination means 6 is demonstrated. However, the case where an ultrasonic sensor is used as the first sensor means 3 is shown.

The ultrasonic transmission wave by the transmission sensor which is the first sensor output means 3a and the reflected wave reflected from the obstacle by the reception sensor which is the first sensor input means 3b are shown with time. As is generally known, x = (t2−t1) / (2 · v) between the transmission time t1, the reception time t2 of receiving the reflected wave, and the distance x of the obstacle.
There is a relationship. Where v is the velocity of the ultrasonic wave.

  Further, as shown in the figure, as other waves, there is a direct wave generated by propagating or wrapping around from the transmission sensor to the reception sensor in the casing.

  Generally, in order to detect the reception time t2 of the reflected wave, a threshold indicated by a dotted line in the figure is provided, and the time exceeding the value is set as the reception time t2, thereby preventing erroneous detection due to direct waves and reflection. The reception time t2 by the wave is determined.

  Next, the energy relationship between the transmitted wave and the reflected wave will be described below. However, here, the magnitude of the transmitted wave and the reflected wave, that is, the amplitude is used as an index indicating energy.

  The magnitude of the reflected wave is proportional to the magnitude of the transmitted wave. In addition, the magnitude of the reflected wave varies depending on the type of obstacle to be reflected, and cloth sofas, round bars with a small diameter, etc. have a smaller reflected wave size even at the same distance and transmitted wave size. Become. Therefore, if the reflected wave is small, it becomes smaller than the threshold value, which causes a problem that the distance to the obstacle cannot be measured.

  On the other hand, when the obstacle is a wall, the reflected wave becomes large even at the same distance and the magnitude of the transmitted wave. Therefore, when the transmission wave is large, as shown in FIG. 3, the ultrasonic wave causes multiple reflections not only between the target obstacle but also other obstacles or between the traveling apparatus main body 1 and the obstacle 2. As a result, there is a possibility of causing an interference phenomenon in which reflected waves also appear multiple times at the receiving sensor. In the worst case, there arises a problem that the distance cannot be accurately measured between the obstacle 2 and the traveling device body 1.

  Therefore, in this embodiment, the magnitude of the transmission wave is selected according to the situation. When the reflected wave is small and the obstacle 2 cannot be detected, the reflected wave is increased by increasing the energy of the transmission wave, and the detection probability of the obstacle 2 is increased. Conversely, when the interference phenomenon of reflected waves occurs, the probability of erroneous detection due to interference is reduced by reducing the energy of the transmission wave.

  This is specifically realized by the first sensor distance determining means 6, the second sensor distance determining means 10 and the sensor output determining means 8.

  Here, a system in which the first sensor means 3 performs distance measurement by an ultrasonic sensor in a non-contact manner and a system in which the second sensor means 9 performs distance measurement by a contact sensor are employed. Since the second sensor means 9 measures the distance by a contact type, the obstacle 2 can be reliably measured. Therefore, when the obstacle 2 cannot be measured by the ultrasonic sensor as the first sensor means 3 and the obstacle 2 is detected by the second sensor means 9 (the first distance by the first sensor distance determining means 6 is the first distance). When the distance is shorter than the second distance by the second sensor distance determining means 10), the energy of the transmission wave at that point is increased in order to reliably detect the obstacle. Therefore, the probability of obstacle detection by the ultrasonic sensor can be increased.

  If it is determined that the reflected wave of the ultrasonic wave is in an interference state, the energy of the transmission wave at that point is reduced in order to reduce the probability of erroneous detection of the obstacle 2 in the next run. By doing so, the probability of erroneous detection by the ultrasonic sensor can be reduced.

  According to the above operation, whether or not the magnitude of the ultrasonic transmission wave is appropriate is determined based on the data of the second sensor means 9 that is reliably detected, and the first sensor means 3 is set to an appropriate value. Changes can be made.

  In order to realize the above operation, the first sensor distance determining means 6 is used to determine the first distance between the obstacle 2 and the traveling apparatus body 1 in a non-contact manner using the ultrasonic sensor as the first sensor means 3. Do it. Similarly, the second sensor distance determining means 10 calculates the second distance using the contact sensor of the second sensor means 9.

  The sensor output amount determining means 8 compares the first distance using the ultrasonic sensor and the second distance using the contact sensor. When the first distance is not input but the second distance is input, the energy of the transmission wave of the ultrasonic sensor is assumed to be small, and the energy amount of the transmission wave at that point stored in the map storage means 7 is increased. Update to become.

  Further, if it is determined that the first sensor distance by the first sensor distance determining means 6 is in the interference state shown in FIG. 3, that is, a state in which many reflected waves exist and the distance cannot be determined, the energy of the transmission wave of the ultrasonic sensor Is larger, the energy amount of the transmitted wave at that point stored in the map storage means 7 is updated to a smaller value.

  When the travel device body 1 travels in the next travel, the sensor output amount determination means 5 adjusts the first sensor output means 3a so that the transmission wave energy at that point stored in the map storage means 7 is obtained. Therefore, since the energy of the transmission wave of the ultrasonic sensor is determined from the past obstacle detection state and obstacle state, it is possible to perform more stable distance measurement of the obstacle.

  FIG. 4 illustrates the history of the energy of the transmission wave, with the number of travels at a certain point as the horizontal axis and the energy of the transmission wave as the vertical axis. As shown in this figure, when the number of times of travel is small, it is understood that the energy of the transmitted wave is increased because the energy of the transmitted wave is small, and the energy of the transmitted wave becomes a constant value after a certain number of times of travel. . The constant energy of the transmitted wave indicates that a stable obstacle can be measured.

  FIG. 5 illustrates the energy of the transmission wave, with the number of pulses of the transmission wave as the horizontal axis and the pulse number of the transmission wave as the vertical axis. As a method of changing the energy of the transmission wave, there is a method of changing the amplitude of the transmission wave. As a simpler method, a method of using the number of pulses of the transmission wave will be described.

  An ultrasonic sensor that generates a transmission wave is a system that generates a sound wave by mechanically vibrating a piezoelectric element. Accordingly, as shown in FIG. 5, it is generally known that the number of pulses and the energy of the transmission wave are not irrelevant, and that the energy of the transmission wave increases as the number of pulses increases up to a certain pulse. Thus, it can be seen that in order to increase the energy of the transmission wave, it is better to increase the number of pulses of the transmission wave.

  The sensor output amount determination unit 5 determines the number of transmission wave pulses so that the energy of the transmission wave stored in the map storage unit 7 is obtained, and oscillates ultrasonic waves from the ultrasonic sensor by the number of pulses.

  Next, the operation of the map storage means 7 will be described with reference to FIG.

  FIG. 6A is a view of a traveling room as viewed from above. However, the sofa, chiffon and chair are also shown. FIG. 6B shows the amount of energy of the transmission wave when the room in FIG. 6A is determined by traveling a predetermined number of times or more. However, the value for each cell obtained by dividing the room into unit distances is shown.

  As shown in FIG. 6, near the surrounding wall of the room, interference due to reflected waves occurs, so that the amount of energy of the transmitted waves is reduced, and obstacles are detected in the vicinity of the ultrasonic wave having a low reflectance such as a sofa. Therefore, it can be seen that the energy of the transmission wave increases.

  The map storage means 7 stores the energy amount of the transmission wave for each cell shown in the example, and the sensor output amount determination means 5, Output to the output amount determination means 8. Further, the map storage means 7 writes the energy amount of the transmission wave determined by the sensor output amount determination means 8 in a cell corresponding to the travel position by the travel position detection means 13.

  As described above, the autonomous traveling device of the present embodiment is configured so that the sensor output amount of the first sensor means that sequentially measures the distance to the obstacle is the second sensor that measures only a certain distance to the obstacle. The distance to the obstacle can be accurately measured.

  The first sensor means includes first sensor output means for outputting a sensor output, and first sensor input means for inputting a reflected wave reflected from the obstacle by the sensor output. By measuring the distance to the obstacle from the transmission / reception time between the output means and the first sensor input means, the distance to the obstacle can be measured accurately.

  Further, since the second sensor means is constituted by a contact sensor, it is possible to reliably detect an obstacle, so that the sensor output amount by the first sensor means can be determined more accurately.

  Further, if the first distance by the first sensor distance determining means is shorter than the second distance by the second sensor distance determining means, the output amount of the first sensor means is increased, so that the more accurate first The output amount of one sensor means can be determined. In other words, the fact that there is an obstacle in the second sensor means without the obstacle being recognized by the first sensor means that the obstacle cannot be detected because the output amount of the first sensor means is small. Therefore, the obstacle detection capability is improved by increasing the output amount of the first sensor means.

  Further, when the first sensor distance determining means determines that the reflected wave from the obstacle is interfered by the first sensor input means, the interference is reduced by reducing the output amount of the first sensor means. And more stable obstacle detection can be performed.

  Further, the map storage means can display the stored map information to the user by the map display means, so that the user can visually teach the room situation and can easily make corrections and corrections. Therefore, more accurate obstacle detection can be performed.

  Moreover, since a program for executing at least a part of the functions of the autonomous mobile device by a computer can be realized on the computer, means can be easily provided to the user.

  In addition, by using a readable recording medium in which the program is recorded, the program can be easily distributed / updated and installed.

  As described above, since the autonomous traveling device, the program, and the recording medium according to the present invention can accurately measure the distance to the obstacle regardless of the sensor means, a cleaning robot, a camera-mounted robot, a lawn mowing robot, etc. It can be adapted to other uses.

The block diagram which shows the structure of the autonomous traveling apparatus in embodiment of this invention The figure which shows operation | movement of the 1st sensor distance determination means in the autonomous vehicle The figure which shows the interference state of the reflected wave in the autonomous traveling device The figure which shows the relationship between the frequency | count of driving | running | working and the energy of a transmission wave in the autonomous traveling apparatus The figure which shows the relationship between the pulse frequency of the transmission wave and the energy of the transmission wave in the autonomous traveling device (A) View of the room where the autonomous traveling device travels from above (b) Diagram showing the energy amount of the transmitted wave when the autonomous traveling device travels and determines the room more than a certain number of times

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling device main body 2 Obstacle 3 First sensor means 3a First sensor output means 3b First sensor input means 5 Sensor output amount determination means 6 First sensor distance determination means 7 Map storage means 8 Sensor output amount determination Means 9 Second sensor means 10 Second sensor distance determination means 13 Traveling position detection means 15 Map display means

Claims (8)

A first sensor means for sequentially measuring a distance to an obstacle as the traveling apparatus body travels; a second sensor means for measuring only a certain distance to the obstacle; and a first sensor means and a second sensor means. First and second sensor distance determining means for determining the distance from the sensor output to the obstacle and outputting the first and second distances, and sensor output amount information for each position of the room where the traveling device body travels The first sensor means from the map storage means for storing, the first and second distance information to the obstacle by the first and second sensor distance determination means, and the sensor output amount information stored in the map storage means An autonomous traveling apparatus comprising: a sensor output amount determining unit that determines a sensor output amount of the output and outputs the sensor output amount information to the map storage unit as sensor output amount information. The first sensor means includes first sensor output means for outputting a sensor output, and first sensor input means for inputting a reflected wave reflected by the obstacle from the sensor output. The autonomous traveling device according to claim 1, wherein the distance to the obstacle is measured from a transmission / reception time between the first sensor input means and the first sensor input means. The autonomous traveling device according to claim 1, wherein the second sensor means is a contact sensor. The output amount of the first sensor means is increased when the first distance by the first sensor distance determination means is shorter than the second distance by the second sensor distance determination means. The autonomous traveling device according to item. The first sensor distance determining means reduces the output amount of the first sensor means when the first sensor input means determines that the reflected wave from the obstacle is interfering. 2. The autonomous traveling device according to item 1. The autonomous traveling device according to any one of claims 1 to 5, wherein the map storage means displays the stored map information to the user by the map display means. The program for performing at least one part of the function in the autonomous running apparatus of any one of Claims 1-6 by a computer. A readable recording medium on which the program according to claim 7 is recorded.