JP2015083949A - Visibility simulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable artificial snowflakes to uniformly fall down in a space around a test piece with inexpensive test equipment to achieve simple reproduction of visibility under a specific weather condition.SOLUTION: A visibility simulation device for evaluating determination performance of a sensor with artificial snowflakes 4 falling in a test space where a test piece 2 is placed at a predetermined position comprises: a suction pipe 8 which sucks the artificial snowflakes 4 together with an air flow from an artificial snowflake storage section 7 installed at a bottom of the test space; and a discharge pipe 11 which is connected to an end of the suction pipe 8 and arranged along a ceiling surface. An artificial snowflake swirling section which has a plurality of spiral fins arranged in a circumferential direction at equal intervals on an inner face thereof and a tube body made up of an equal number of tubes to the spiral fins are installed at the end of the discharge pipe 11. Each tube has an injection port at a tip thereof and a direction of each injection port is decided so as to allow the artificial snowflakes equally taken in by the artificial snowflake swirling section to uniformly fall down in a space around the test piece.

Description

  The present invention relates to a simulated visual field simulation apparatus for testing a sensor affected by visual field, such as a CCD camera, a laser radar, an infrared distance sensor, and the like.

  As a sensor affected by the field of view, for example, a life support robot is equipped with a sensor such as a CCD camera. In order for the life support robot to safely share a space with a human and perform movement and work, it is required that the surrounding environment can be recognized appropriately and reliably by a sensor or a sensor group such as a CCD camera. Therefore, the development of international standards for testing methods and procedures for evaluating whether such sensors and sensor groups can exhibit performance that satisfies safety requirements under various environments is being considered.

The International Electrotechnical Commission (IEC) has developed and issued the IEC61496 series as a safety standard for ESPE (Electro-Sensitive Protective Equipment), a non-contact human detection device.
In these standards, sensor detection capability and durability, as well as requirements and test methods for ambient temperature and humidity, electrical and mechanical interference, interference with ambient light, interference with sensor optical window contamination, etc. Have been described. Sensors that comply with the standard are required to continue normal operation or to cause no dangerous failure even when exposed to a specified environment.

However, since these standards are intended to ensure the safety of workers in factories, etc., indoors are assumed exclusively as environmental conditions, and weather conditions under natural environments such as rain and snow are considered. It has not been. Testing in the natural environment is extremely important to formulate safety standards for sensors mounted on robots, etc., but it is very difficult to reproduce the natural environment suitable for testing, Implementation of the test is difficult due to the need for large-scale facilities.
Therefore, it is realistic to use an artificial rain device, an artificial snow device, or the like that can reproduce the field of view under bad weather in the test space using a simulated snow device.

  Patent Document 1 discloses an automatic rolling mechanism that rolls down an ice block with an arbitrary rolling force, and an automatic ice breaking mechanism that cuts an ice block that is in a reduced state by cutting it with a blade that rotates relative to the ice block and makes it fall. Automatic sieving mechanism that receives ice breaks and distributes and drops them uniformly, snow falling cylinders that allow free fall of the falling ice pieces to observe them as simulated snowfall, and melting some of the ice breaks that fall inside the snow falling cylinders A simulated wet snow snowfall experiment apparatus including a heat treatment mechanism that creates simulated wet snow and a measurement mechanism that receives the simulated wet snow and measures the simulated snowfall amount is described.

Japanese Patent Laid-Open No. 10-253405

The simulated wet snow snowfall experiment apparatus of Patent Document 1 is premised on manufacturing simulated wet snow by cutting an ice block and irradiating an ice laser on an crushed ice piece. For this reason, it is not possible to cause the snow flakes to fall uniformly in a test space that requires expensive equipment and requires a certain volume.
Therefore, using simulated snowflakes, install multiple discharge pipes along the ceiling of the test space, open simulated snowflake outlets in each pipe, and eject simulated snowflakes with compressed air from the entire ceiling. Can be considered.

  However, in such a simulated snowfall device, it is very difficult to evenly distribute the simulated snowflakes to each of the plurality of discharge pipes. Therefore, it is necessary to provide a pseudo snowflake supply part and a suction part for each discharge pipe. Furthermore, since the amount of air in each simulated snowflake discharge pipe changes depending on the pressure of the compressed air from the upstream side to the downstream side, a uniform amount of simulated snowflakes is applied to each of the upstream opening and the downstream opening. It is also necessary to equalize the amount of pseudo snowflakes ejected from each opening end so as to be ejected.

Therefore, in the simulated visual field simulation device of the present invention, when feeding the simulated snowflakes together with the compressed air, a swirling flow is generated, and the simulated snowflakes are evenly distributed to the plurality of tubes provided with the ejection ports. By selecting the orientation, the simulated snowflakes descended evenly in the space around the test piece.
More specifically, the simulated field-of-view simulation apparatus of the present invention lowers a simulated snowflake in the test space and evaluates the object discrimination performance by the sensor, or simulates the reduction in visibility due to bad weather. A simulated visual field simulation device, which is connected to a suction pipe for sucking the simulated snowflake together with an air flow from a simulated snowflake storage part provided at the bottom of the test space, and connected to an end of the suction pipe, on the ceiling surface of the test space. A discharge pipe disposed along the end of the discharge pipe, and a pseudo snowflake turning with a plurality of spiral fins uniformly formed in the circumferential direction on the inner surface from the inlet end to the outlet end. And a tube body comprising the same number of tubes as the spiral fins, each of the inlet ends of the tubes being adjacent to each other in the pseudo snowflake turning portion. In order to take in the pseudo snowflake distributed evenly between the spiral fins, it is arranged so as to face the exit end of the pseudo snowflake turning section, and each of the tubes has the pseudo snowflake taken in the test space. The direction of the jet nozzle provided at the tip is selected so as to descend uniformly.

According to the present invention, since the simulated snowflake is evenly distributed to each tube by the simulated snowflake turning section, by selecting the direction of the jet outlet at the tip of each tube, the simulated snowflake is placed in the space around the test piece. The field of view in a specific weather condition can be easily reproduced by the flow velocity of air flow, the shape of a pseudo snowflake, and the like.
Moreover, it is possible to lower the cost of the test equipment because it is possible to evenly drop simulated snowflakes around the test piece with a single air compressor just by providing one discharge pipe on the ceiling of the test room. become.

FIG. 1 is a diagram showing the overall structure of a test facility equipped with a simulated snowfall device according to this embodiment. FIG. 2 is a diagram showing a basic structure of the simulated snowflake falling device according to the present embodiment. FIG. 3 is a diagram illustrating a simulated snowflake turning unit of the simulated snowflake falling apparatus according to the present embodiment. FIG. 4 is a diagram showing the structure of the nozzle portion of the simulated snowflake falling device according to the present embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall structure of a test facility equipped with a simulated snowfall device according to this embodiment.
In general, if it is possible to recognize the presence of a person at a distance of 3 m, safety is ensured. As shown in FIG. 1, this simulated snowfall device has a width of 4 m, a depth of 1 m, and a height of 1.5 m. A test piece 2 that imitates a human being is placed 1 m from the side wall in the test chamber 1 and the simulated snowflake 4 is snowed from the simulated snowflake injection unit 3, and the robot 5 is opened from the window 5 that is 3 m away. It is tested whether or not the presence of the test piece 2 can be surely recognized by the sensor 6 mounted on the sensor. The sensor 6 includes various devices such as a CCD camera, a stereo camera, a laser distance measuring device, and an infrared distance measuring device.
In this example, the test chamber 1 was manufactured by covering a ceiling surface and side walls with a vinyl sheet on a stainless frame.

  Here, in order to reproduce the influence of the reflection by the simulated snowflake around the test piece 2 in the test space, the amount of fall of the simulated snowflake 4 is set to the periphery of the test piece 2 so that the predetermined amount of snowfall is reproduced. It is necessary to distribute it evenly in the space.

FIG. 2 is a diagram for explaining the basic structure of the simulated snowflake falling device for that purpose.
On the floor surface of the test space as shown in FIG. 1, a reverse truncated cone-shaped pseudo snowflake storage part 7 is provided, and the pseudo snowflake 4 is stored. The tip of the suction pipe 8 is arranged at the central part of the pseudo snowflake storage part 7 so as to be positioned directly above the stored pseudo snowflake 4. A compressed air ejection portion 9 is provided on the outer periphery of the suction pipe 8, and the compressed air from the air compressor 10 is ejected upward in the suction pipe 8. The air compressor 10 is provided with an air volume adjustment function and a pressure adjustment function such as a ball valve, and can adjust the ejection amount of the pseudo snowflake 4 according to the visibility condition for performing the simulation.

  As the pseudo snowflake 4, a resin material such as foam beads is used, but in order to prevent static electricity from being generated due to contact with or colliding with each other and forming a lump or adhering to the side wall of the test apparatus, It is preferable to perform antistatic treatment. Further, since the pseudo snowflake 4 has a different residence time in the air and a reflection amount depending on the specific gravity and particle size, the material and shape of the resin material are selected so that the field of view at the time of actual snowfall can be reproduced. In this example, spherical resin foam beads having a particle size of about 1 mm to 3 mm were used.

  The suction pipe 8 rises to the ceiling along the side wall of the test chamber 1, and in the present embodiment, the pipe extends along the ceiling surface to the vicinity immediately above the test piece 2. In the present embodiment, the suction pipe 8 is referred to as reaching the ceiling portion, and the pseudo-snow piece injection portion 3 described later is referred to as the discharge pipe 11 along the ceiling surface from the upper end thereof.

  The simulated snowflake 4 injected from the simulated snowflake injection unit 3 is again collected in the pseudo-cone-shaped simulated snowflake storage unit 7, and the height of the simulated snowflake in the central part of the simulated snowflake storage unit 7 is made substantially constant during the test period. Can be maintained. Thereby, it is possible to prevent the amount of the pseudo snowflake 4 sucked from the suction pipe 8 from fluctuating. Of course, the outer edge of the upper end of the truncated cone-shaped pseudo snowflake storage portion 7 may be extended to the side wall of the test chamber 1 so that the entire amount of the pseudo snowflake that has been ejected can be recovered.

Next, the structure of the pseudo snowflake injection unit 3 will be described.
The pseudo snowflake injection section 3 includes a cylindrical pseudo snowflake turning section 12 that expands in a trumpet shape as shown in FIG. 3, and a fitting formed at an end of the expansion side (upward in FIG. 3). The end of the discharge pipe 11 extending to the vicinity of the center portion along the ceiling surface is coupled to the portion 13. A spiral fin 14 having a predetermined height is formed on the inner peripheral surface of the pseudo snowflake turning part 12 from the lower part of the fitting part 13 toward the base end part 20 (downward in FIG. 3). Is provided on the inner peripheral surface.

  As shown in FIG. 4, the base end portion 16 of the nozzle portion 15 is fitted on the outer periphery of the base end portion 20 of the pseudo snowflake turning portion 12. On the upper surface of the base end portion 16, a tube body 18 composed of eight tubes 17 of the same number as the fins 14 formed on the inner peripheral surface of the pseudo snowflake turning portion 12 is integrally formed. The vertical cross section of each tube 17 has a fan shape with a central angle of approximately 45 °, and a passage through which the pseudo snowflake 4 passes is formed inside.

  FIG. 4 explains the structure of the tube body 18 in an easy-to-understand manner. In this embodiment, the base end portion 16 of the nozzle portion 15 is coupled so as to be continuous with the pseudo snowflake turning portion 12 along the ceiling surface. Therefore, the length of each tube 17 and the direction of the injection port are selected so that the pseudo snowflake 4 is uniformly lowered around the test piece 2 from the injection port formed at the tip of each tube 17. .

  The lower end of each tube 17 is integrally formed so as to form eight radial ribs 19 on the upper surface of the base end portion 16, and when the rib 19 is fitted to the lower end of the pseudo snowflake turning portion 12. The shape is determined so as to be aligned with the ends of the eight fins 14. For this reason, the mark, the recessed part which fits each other, and the convex part are formed in both so that the lower end of each tube 17 and the base end part 20 of the pseudo snowflake turning part 12 may be positioned correctly.

The operation of the pseudo snowflake injection unit 3 will be described.
As shown in FIG. 2, the pseudo snowflake 4 stored in the pseudo snowflake storage unit 7 is sucked from the end of the suction pipe 8 by the air compressor 10. Then, it reaches the ceiling part of the test space, and is introduced into the pseudo snowflake turning part 12 through the discharge pipe 11.
The simulated snowflake 4 flows under the inside of the discharge pipe 11 due to its own weight, but the downstream side (the lower side in FIG. 2) is formed by a spiral fin 14 formed on the inner periphery of the simulated snowflake turning portion 12. ), A strong swirl flow is formed.
Centrifugal force acts on the pseudo snowflake 4 by this swirl flow, but since the inner peripheral surface of the pseudo snowflake turning portion 12 is gradually reduced in diameter, between the adjacent fins 14 before reaching the base end portion 20. Will be evenly distributed.
As a result, the pseudo snowflakes 4 are evenly distributed until reaching the rib 19 formed at the lower end of each tube 17, and almost the same number of pseudo snowflakes 4 are introduced into each tube 17. Thus, the same number of pseudo snowflakes 4 are ejected around the test piece in the test chamber 1 from the jet port provided in the test chamber 1.

The direction of the jet outlet at the tip of each tube 17 is set so that the pseudo snowflakes 4 ejected from the respective jet outlets descend uniformly around the test piece 2 according to the air volume of the air compressor 10. Then, the optimum one is selected according to the viewing conditions for the simulation. An adjustment mechanism may be provided so that the direction of the tip of each tube 17 can be freely adjusted, or the tube 17 itself may be formed of a flexible material. Since the same number of pseudo snowflakes is ejected from the ejection port provided at the tip of each tube 17, the adjustment can be easily performed.
The descending density in the space of the pseudo snowflake 4 can also be adjusted by the shape of the jet outlet at the tip of each tube 17.

In the embodiment, one unit of the pseudo snowflake injection unit 3 is provided in the test chamber 1, but a plurality of units may be provided depending on the volume of the test chamber 1 and the visibility condition for performing the simulation.
In addition, the experimental results are compared in advance so that the visibility conditions can be reproduced according to the weather conditions such as rain, snowfall, dense fog, etc., so that the air volume of the air compressor 10 and the simulated snowflakes to be used can be selected. It is preferable to create a correspondence map.

  As described above, according to the present invention, a pseudo-snow piece is placed around the test piece by using a low-cost facility in which one air compressor is provided and one discharge pipe is provided on the ceiling of the test room. It can be lowered uniformly, and various viewing conditions can be accurately reproduced with low-cost equipment. Therefore, it can be expected to be widely used as a simulated viewing simulation apparatus.

DESCRIPTION OF SYMBOLS 1 Test chamber 2 Test piece 3 Pseudo snowflake injection part 4 Pseudo snowflake 5 Window 6 Sensor 7 Pseudo snowflake storage part 8 Suction pipe 9 Compressed air ejection part 10 Air compressor 11 Discharge pipe 12 Pseudo snowflake turning part 13 Fitting part with discharge pipe 14 Spiral fin 15 Nozzle part 16 Base end part of nozzle part 17 Tube 18 Tube body 19 Rib 20 Base end part of pseudo snowflake turning part

Claims (4)

A simulated visual field simulation device for lowering simulated snowflakes in a test space and evaluating object discrimination performance by a sensor, or for reproducing simulated visibility reduction due to bad weather,
A suction pipe that sucks in the pseudo snowflake together with an air flow from the pseudo snowflake storage section provided at the bottom of the test space;
A discharge pipe connected to the end of the suction pipe and disposed along the ceiling surface of the test space;
Connected to the end of the discharge pipe, and from the inlet end to the outlet end, a pseudo snowflake turning part in which a plurality of spiral fins are uniformly formed in the circumferential direction on the inner surface,
A tube body comprising the same number of tubes as the spiral fins;
Each of the inlet ends of the tubes is disposed so as to face the outlet end of the pseudo snowflake turning portion so as to take in the pseudo snowflake evenly distributed between adjacent spiral fins in the pseudo snowflake turning portion. ,
Each of the tubes is a simulated visual field simulation device, wherein the direction of the jet port provided at the tip thereof is selected so that the captured pseudo snowflakes are uniformly lowered in the test space.   The simulated field of view according to claim 1, wherein the pseudo snowflake turning portion has a reverse truncated cone shape in which an inner diameter gradually decreases from a connection portion with the end of the discharge pipe toward the outlet end. Simulation device.   The said tube body is equipped with the radial rib on the upper surface of the base end part, The said tube is integrally molded so that it may extend from the said rib, The Claim 1 or Claim 2 characterized by the above-mentioned. Simulated visual field simulation device.   4. The simulated visual field simulation apparatus according to claim 3, wherein the rib is disposed so as to be aligned with an end of the helical fin.

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