JP4992397B2 - Object detection method for mobile device - Google Patents

Description

  The present invention relates to a method for detecting an object existing around a mobile device such as a robot.

  As a conventional object detection device, there is a device that detects an object on a course using a sensor mounted on an autonomous mobile device typified by an automatic cart or an autonomous vehicle. Examples of the sensor used here include an ultrasonic sensor, an optical sensor, and an infrared sensor.

  Since each of these sensors has advantages and disadvantages, there is a technology that attempts to solve the problem by combining them (see, for example, Patent Document 1).

  FIG. 8A is a schematic explanatory diagram of the traveling device in Patent Document 1, and FIG. 8B is a schematic explanatory diagram of the problem of the traveling device in Patent Document 1. Hereinafter, the same elements are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 8A, the autonomous traveling device 1 is equipped with an ultrasonic sensor 2 and an infrared sensor 3. By using the ultrasonic sensor 2 and the infrared sensor 3 together, the object 4 is detected while compensating for the respective disadvantages.

  Here, the problem in Patent Document 1 will be described with reference to FIG. As disclosed in Patent Document 1, when performing object detection by infrared rays, the infrared sensor 3 is used to receive the reflected light 5 reflected by the object 4. However, as shown in FIG. 8B, in the autonomous traveling device 1 in Patent Document 1, natural light 7 from a natural light source 6 or the like also enters the infrared sensor 3. Patent Document 1 discloses means for switching sensing between the ultrasonic sensor 2 and the infrared sensor 3 in order to reduce the influence of the natural light 7 as much as possible, and reducing the sensing by the infrared sensor 3. ing.

  Further, there is a technique for detecting an object with high accuracy using a temperature difference from the surroundings of the object in the detection of an object using an infrared sensor (see, for example, Patent Document 2).

  FIG. 9 is a schematic explanatory diagram of a traveling device in Patent Document 2.

In FIG. 9, the traveling vehicle 8 has a first infrared sensor 9 and a second infrared sensor 10. The traveling device in Patent Document 2 detects the object 11 using these two infrared sensors, and uses the data of the infrared sensor with higher detection accuracy to detect the object with high accuracy.
JP 2006-11594 A Japanese Patent Laid-Open No. 2003-04860

  However, the object detection method disclosed in Patent Document 1 may cause halation (irregular reflection) or the like due to the influence of environmental changes. Also, with the object detection method disclosed in Patent Document 2, it is difficult to detect an object when the temperature difference from the surroundings is small. In order to solve them, there is a technique of providing a plurality of sensors in combination, but for objects such as glass that have transparency and a small temperature difference from the surroundings, even if infrared sensors and optical sensors are used, Is difficult to detect.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide an object detection method for a moving apparatus that can reliably detect the presence and position of an object.

In order to achieve the above object, an object detection method for a moving apparatus according to claim 1 of the present invention includes a first step of measuring an infrared amount in a predetermined area from the moving apparatus, and the predetermined area from the moving apparatus. the heat, after releasing the electromagnetic wave or heat rays, again, the presence of the object based a second step of measuring the amount of infrared rays in the predetermined region, on the amount of infrared radiation of the first step in amount of infrared rays and the second step And a fourth step of detecting a relative positional relationship of the object with respect to the moving device based on a comparison result of the third step.

  The object detection method for a mobile device according to claim 2 of the present invention is the method according to claim 1, wherein the object exists when the relative positional relationship of the object is detected in the third step. It is characterized by releasing heat outside the region.

  The object detection method for a mobile device according to claim 3 of the present invention is the method according to claim 1 or 2, wherein the object identification result in the third step and the object measured using an optical sensor are used. The detection result is compared, and an object that exists in the object identification result in the third step and does not exist in the object detection result using the optical sensor is recognized as a transparent object.

  As described above, according to the object detection method of the mobile device of the present invention, it is possible to reliably detect the presence and position of an object without being affected by interference between sensors or changes in the surrounding environment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the present invention, the same components are denoted by the same reference numerals and description thereof is omitted.

(Embodiment 1)
FIG. 1 is a block configuration diagram of a mobile robot control system according to Embodiment 1 of the present invention.

  In FIG. 1, the mobile robot includes an object detection mechanism 13, a heat medium discharge mechanism 14, a control mechanism 15, and a drive mechanism 16.

  The object detection mechanism 13 includes an infrared amount detection unit 17 that detects the amount of infrared energy, and the heat medium discharge mechanism 14 includes a heat medium discharge unit 18.

  In the present embodiment, infrared thermography is used as the infrared amount detection unit 17. The infrared thermography has a function of converting the received infrared energy amount (wavelength) into a heat amount and outputting the heat information as a sensor signal. Furthermore, by providing a plurality of infrared thermographs and using them as stereo vision, it is possible to acquire relative position information such as the relative direction and relative distance of the heat source with respect to the mobile robot 12. In addition, a heat gun is used as the heat medium discharge unit 18. In addition to this, as the heat medium discharge section 18, it is possible to use electromagnetic wave such as microwaves, heat ray irradiation means such as an infrared heater, and air blowing means for sending temperature-controlled air such as hot and cold air.

  In addition, the control mechanism 15 adjusts the analysis unit 19 that analyzes the sensor signal of the thermal information acquired by the infrared ray amount detection unit 17, and the heat medium emission amount and emission range (emission region) in the heat medium emission unit 18. The release setting unit 20 includes a determination unit 21 that determines the presence or absence of an object around the mobile robot 12 based on the analysis result of the analysis unit 19, and a storage unit 22 that stores necessary information. ing.

  In the present embodiment, the analysis unit 19, the release setting unit 20, and the determination unit 21 are configured by a CPU or the like, and the storage unit 22 is configured by a RAM or the like. These are not limited to completely independent hardware, and may share hardware with other processing units. That is, the same hardware can be configured with different blocks by a plurality of software.

  Further, the drive mechanism 16 controls the movement of the mobile robot 12 based on the determination result of the position detection unit 23 and the determination unit 21 that detect the position (absolute position) of the mobile robot 12 in a space such as a room. The movement control unit 24 and a drive unit 25 that is driven in accordance with a movement command from the movement control unit 24 are configured.

  In the present embodiment, a wheel is used as the drive unit 25, and a mechanism that detects a position by odometry obtained from a value of an encoder attached to the wheel shaft is used as the position detection unit 23. In the present embodiment, a wheel is used as the drive unit 25. However, it is also possible to implement walking movement using at least one leg instead of the wheel.

  FIG. 2 is a diagram illustrating a processing flow of the object detection method according to the first embodiment. The outline of the object detection method in the present embodiment will be described with reference to FIG.

  In FIG. 2, first, the heat medium 27 is discharged from the heat medium discharge unit 18 to a predetermined area around the mobile robot 12. The heat medium 27 released in this way is irradiated onto an object around the mobile robot 12, and the temperature of the object rises by the heat medium 27. Thereafter, the detection result of the infrared ray 26 when the heat medium 27 is not emitted is compared with the detection result of the infrared ray 26 after the heat medium 27 is emitted, thereby detecting an object whose temperature is increased by the heat medium 27. (Step S1).

  Next, the amount of energy of the infrared ray 26 received by the infrared ray amount detection unit 17 is detected. When an object exists and the infrared ray 26 is emitted from the object, the amount of energy of the infrared ray 26 from the object can be detected by the infrared ray amount detection unit 17 (step S2).

  Next, the position information Ho of the object (heat source) is analyzed based on the received infrared rays 26, and the position information Ho is stored in the storage unit 22 as relative position information Po with respect to the mobile robot. At the same time, the position information Ro of the mobile robot 12 is detected from the position detection unit 23 and stored in the storage unit 22. Based on the relative position information Po and the position information Ro, the absolute position information Ao of the object with respect to the mobile robot 12 is determined (step S3).

  The avoidance movement is controlled by the movement control unit 24 of the mobile robot 12 based on the position information of the object obtained by the series of processing flows.

  FIG. 3 is a diagram illustrating an arrangement example of the infrared ray amount detecting unit 17 and the heat medium emitting unit 18 according to the first embodiment.

  In FIG. 3, after releasing the heat medium 27 from the heat medium emitting unit 18 around the mobile robot 12, the object 29 is detected by examining the heat distribution 30 of the object 29 in the detection range 28 with the infrared ray amount detecting unit 17. To do.

  Here, the infrared amount detection unit 17 and the heat medium discharge unit 18 are configured as a pair, and each of them is at least in order to detect an object in the moving direction of the mobile robot 12 (on the path of the mobile robot 12). One needs to be arranged in front of the moving direction of the mobile robot 12.

  In the present embodiment, in order to cover 360 degrees around the mobile robot 12 in the horizontal direction, six infrared ray detection units 17 and heat medium discharge units 18 are arranged every 60 degrees. Here, the infrared ray amount detection unit 17 can accurately detect the amount of infrared rays within the fan-shaped detection range 28 (60-degree fan shape), and the heat medium discharge unit 18 has a fan-shaped heat medium discharge range. . Here, when the six heat-medium discharge | release parts 18 are arrange | positioned every 60 degree | times like this Embodiment, it is preferable that the heat-medium discharge | release range of the heat medium discharge | release part 18 becomes larger than 60 degree | times ( For example, 90 degrees). That is, it is preferable that the total range of the heat medium discharge range by the plurality of heat medium discharge portions 18 is 360 degrees or more around the mobile robot 12. This is to cope with the case where the heat medium in a specific direction is stopped as will be described later.

  If the object 29 exists within the range in which the heat medium 27 from the heat medium discharge unit 18 acts, a heat distribution 30 is generated by the heat medium 27 discharged to the object 29. Thus, the object 29 is detected by heating the object 29 with the heat medium 27 from the mobile robot 12 to the periphery of the mobile robot 12 and obtaining the heat distribution 30 generated thereby.

  FIG. 4A is a diagram showing a temperature distribution before releasing the heat medium, and FIG. 4B is a diagram showing a temperature distribution after releasing the heat medium body.

  As shown in FIG. 4A, if the temperature difference between the object 29 and the surroundings does not occur, the object 29 cannot be detected using the infrared light amount detection unit 17 of the mobile robot 12.

Here, a heat gun having a wind speed of 1250 m / min, an air volume of 0.2 m ³ / min, and a temperature 10 mm away from the nozzle opening at a maximum temperature of about 500 degrees was used as the heat medium discharge section 18 at an environmental temperature of 30 degrees. Consider the case. As shown in FIG. 4B, a heat distribution 30 that can be detected by the infrared ray amount detection unit 17 is generated after the heat medium 27 is discharged from the heat medium discharge unit 18. The object 29 can be detected by setting the space in which the heat distribution 30 is generated as a space in which the object 29 exists.

  The principle of detecting the object 29 will be described. It is assumed that the heat medium 27 is discharged for 1 second to concrete having a side of 10 cm located 1 m away using the heat gun described above, and the concrete surface temperature is increased to 31 degrees. In this case, an infrared energy amount of about 0.055 W is emitted from the concrete. Here, when an infrared thermography having a resolution of about 0.001 W is used as the infrared amount detection unit 17, the concrete heat distribution 30 can be detected, and the object 29 can be detected based on the heat distribution 30.

  FIG. 5 is a diagram showing the position of the robot in the first embodiment.

A method for measuring the absolute position of the object 29 will be described with reference to FIG. For example, in a limited space such as a room, the position (X ₁ , Y ₁ ) of the mobile robot 12 is obtained by calculating odometry by the position detection unit 23. Thereafter, if the relative positional relationship between the mobile robot 12 and the object 29 is known, the position (X ₃ , Y ₃ ) of the object 29 can be obtained based on the position (X ₁ , Y ₁ ) of the mobile robot 12. Thereby, since the absolute position (X ₃ , Y ₃ ) of the object 29 can be grasped, for example, a map including the position information of the object can be created. Here, when the object 29 exists on the path of the mobile robot 12, the avoidance movement to the position (X ₂ , Y ₂ ) or the like is performed.

  FIG. 6 is a schematic explanatory diagram of object detection in the first embodiment.

  In FIG. 6, the heat medium 27 released from the heat medium discharge unit 18 of the mobile robot 12 is absorbed as heat energy by an object 29 present around the mobile robot 12. The absorbed energy generates a heat distribution 30 in the object 29 and radiates infrared rays 26. By detecting the emitted infrared ray 26 by the infrared ray amount detection unit 17, the object 29 is detected.

  When releasing a heat medium to an object that is greatly affected by heat, such as an object having a low flammable temperature, or when trying to save energy of the mobile robot 12, the heat medium 27 is not always released, and heat is generated as necessary. By adopting a configuration in which the medium 27 is discharged, more efficient object avoidance can be performed. The flow of the object detection method including this processing flow will be described.

  FIG. 7 is a diagram showing a flow processing flow of the object detection method in the first embodiment.

  In FIG. 7, first, the infrared ray detection unit 17 detects the infrared ray 26 around the mobile robot 12. Thereafter, it is determined whether or not infrared rays generated by heat are present, and if present, the process proceeds to step S5, and if not, the process proceeds to step S9 (step S4).

Subsequently, based on the heat detection information analyzed by the analysis unit 19 and the position information of the mobile robot 12 detected by the position detection unit 23 ((X ₁ , Y ₁ ) in FIG. 5), the heat source emitting the infrared ray 26 is detected. Position information ((X ₂ , Y ₂ ) in FIG. 5 is measured (step S5).

  Subsequently, the position information of the heat source is stored in the storage unit 22 (step S6).

  Subsequently, based on the position information of the heat source stored in the storage unit 22, it is determined whether it is necessary to set the release of the heat medium 27 from the heat medium discharge unit 18 (step S7).

  If it is determined in step S7 that the setting of the heat medium 27 discharge is necessary, the discharge setting unit 20 sets at least one of the temperature, the discharge amount, and the discharge range (release region) of the heat medium 27 (step S8).

  Subsequently, the heat medium 27 set as necessary is discharged from the heat medium discharge unit 18 (step S9).

  Subsequently, the number of discharges of the heat medium 27 is counted, and it is determined whether or not the number of heat medium discharges is the first time or less. Here, when the number of heat medium discharges is equal to or less than the first time, the process returns to step S4 and the same steps are repeated again (step S10).

  Subsequently, the object 29 is detected based on the heat source detected by the mobile robot 12 (step S11).

  The mobile robot 12 detects the object 29 by repeating the steps S4 to S11. When the mobile robot 12 avoids an obstacle using the present embodiment, the avoidance is performed by regarding the heat source (object 29) in the forward direction (on the path) of the mobile robot 12 as an obstacle.

  In the present embodiment, the absolute position of the heat source (object 29) is detected using the position information of the mobile robot 12 detected by the position detection unit 23, but only the relative position to the heat source (object 29) is detected. If it is sufficient, step S5 can be omitted.

  Further, when there are a plurality of mobile robots 12, the amount of infrared energy radiated increases, so that detection becomes easier.

  In addition, by using this embodiment, it is possible to detect an object even in a space where an ultrasonic wave is not transmitted in a vacuum and the influence of disturbance from sunlight is intense.

  According to the object detection method of the mobile device of the present invention, it is possible to reliably detect an object without being affected by the number of mobile robots or changes in the environment. Therefore, it is suitable not only for automatic carts and transport robots in living environments such as homes, hotels, golf courses, factories, airports, etc., but also in space where ultrasonic waves are not transmitted and sunlight is severely affected. It can also be applied.

Block configuration diagram of mobile robot control system in Embodiment 1 The figure which shows the processing flow of the object detection method in Embodiment 1. The figure which shows the example of arrangement | positioning of the infrared-quantity detection part 17 in Embodiment 1, and the thermal-medium discharge | release part 18 (A) The figure which shows the temperature distribution before heat carrier discharge, (b) The figure which shows the temperature distribution after heat medium body discharge | release The figure which shows the position of the robot in Embodiment 1 Schematic explanatory diagram of object detection in the first embodiment The figure which shows the processing flow of the object detection method in Embodiment 1. (A) Schematic explanatory diagram of the traveling device in Patent Document 1, (b) Schematic explanatory diagram of the problem of the traveling device in Patent Document 1. Schematic explanatory diagram of a traveling device in Patent Document 2

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 Object detection mechanism 14 Heat medium discharge | release mechanism 15 Control mechanism 16 Drive mechanism 17 Infrared ray amount detection part 18 Heat medium discharge | release part 19 Analysis part 20 Release setting part 21 Judgment part 22 Memory | storage part 23 Position detection part 24 Movement control part 25 Drive part 26 Infrared 27 Heat medium

Claims (3)

A first step of measuring the amount of infrared radiation in a predetermined area from the mobile device;
A second step of measuring the amount of infrared rays in the predetermined area again after releasing heat , electromagnetic waves or heat rays from the moving device to the predetermined area;
A third step of identifying the presence of an object based on the infrared amount of the first step and the infrared amount of the second step;
And a fourth step of detecting a relative positional relationship of the object with respect to the moving device based on a comparison result of the third step. The object detection method for a moving device according to claim 1, wherein when the relative positional relationship of the object is detected in the third step, heat is released to a region other than the region where the object exists. Compare the object identification result in the third step with the object detection result measured using the optical sensor,
3. The object that is present in the object identification result in the third step and that is not present in the object detection result using the optical sensor is recognized as a transparent object. Object detection method for mobile device.

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