JP2014125201A - Underwater vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underwater vehicle capable of avoiding obstacles at low cost.SOLUTION: The underwater vehicle comprises: a left side distance sensor for measuring left side distance between the vehicle and obstacles on a left side; a right side distance sensor for measuring right side distance between the vehicle and obstacles on a right side; and a control part for controlling navigation of the vehicle based on the left side distance and the right side distance. When at least one of the left side distance and the right side distance reaches to equal to or less than a first reference value, the control part performs avoiding control for the vehicle to avoid the obstacles.

Description

  The present invention relates to an underwater machine. In particular, the present invention relates to a technique for an underwater machine to avoid an obstacle.

  “Underwater aircraft” such as submarines and unmanned submarines are known. As an unmanned submersible, an autonomous underwater vehicle (AUV) used for underwater investigation work in a relatively deep sea area or lake is known.

  Patent Document 1 discloses an underwater machine monitor and a remote control method. The underwater machine has means for docking and releasing the floating platform. The floating platform detects the coordinates of the current position via radio signals received from the satellite. In addition, the floating platform detects the distance from the underwater machine through the dating of the acoustic signal received from the underwater machine. The underwater aircraft can be self-sided by signals transmitted to and received from a single floating platform.

Japanese Patent No. 3319759

  The inventor of the present application paid attention to the following points. In general underwater aircraft, a submarine topographic map is often used to avoid obstacles. However, it is very expensive to create a submarine topographic map. In addition, in order to perform processing with reference to the seafloor topographic map, it is necessary to mount a high-performance processing device in the underwater aircraft, which also causes an increase in cost.

  One object of the present invention is to provide an underwater machine capable of avoiding obstacles at low cost.

  [Means for Solving the Problems] will be described below using the numbers and symbols used in [Best Mode for Carrying Out the Invention]. These numbers and symbols are added in parentheses in order to clarify the correspondence between the description of [Claims] and [Best Mode for Carrying Out the Invention]. However, these numbers and symbols should not be used for the interpretation of the technical scope of the invention described in [Claims].

  In one aspect of the present invention, an underwater machine (1) is provided. The underwater aircraft (1) includes a left distance sensor (10L) that measures a left distance (LL) between the aircraft and the left obstacle on the left side, and a right distance between the aircraft and the right obstacle on the right side. A right distance sensor (10R) that measures (LR), and a control unit (20) that controls navigation of the aircraft based on the left distance (LL) and the right distance (LR). When at least one of the left distance (LL) and the right distance (LR) is equal to or less than the first reference value (L1), the control unit (20) performs avoidance control for avoiding the aircraft from the obstacle.

  For example, when only one of the left distance (LL) and the right distance (LR) is equal to or less than the first reference value (L1), the control unit (20) performs the first avoidance control as the avoidance control. In the first avoidance control, the control unit (20) controls the navigation of the aircraft so that the one distance that is equal to or less than the first reference value (L1) increases. When the one distance becomes equal to or greater than the second reference value (L2) that is equal to or greater than the first reference value (L1), the control unit (20) ends the first avoidance control.

  For example, when both the left distance (LL) and the right distance (LR) are equal to or smaller than the first reference value (L1), the control unit (20) performs the second avoidance control as the avoidance control. In the second avoidance control, the control unit (20) controls the navigation of the aircraft so that the left distance (LL) and the right distance (LR) are equal. When both the left distance (LL) and the right distance (LR) are equal to or greater than the second reference value (L2) that is equal to or greater than the first reference value (L1), the control unit (20) ends the second avoidance control. To do.

  The second reference value (L2) is preferably larger than the first reference value (L1).

  For example, when at least one of the left distance (LL) and the right distance (LR) is equal to or smaller than the third reference value (L3) smaller than the first reference value (L1), the control unit (20) Stop navigation.

  While the avoidance control is not performed, the control unit (20) may control the aircraft to navigate along the predetermined route (WL).

  ADVANTAGE OF THE INVENTION According to this invention, the underwater machine which can avoid an obstruction at low cost is implement | achieved.

FIG. 1 is a conceptual diagram showing an underwater machine according to an embodiment of the present invention. FIG. 2 is a block diagram showing a functional configuration of the underwater machine according to the embodiment of the present invention. FIG. 3 is a conceptual diagram showing an example of avoidance control of the underwater machine according to the embodiment of the present invention. FIG. 4 is a conceptual diagram showing another example of the underwater aircraft avoidance control according to the embodiment of the present invention. FIG. 5 is a flowchart schematically showing underwater aircraft avoidance control according to the embodiment of the present invention.

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

  FIG. 1 conceptually shows an underwater machine 1 according to an embodiment of the present invention. The underwater machine 1 includes a left distance sensor 10L and a right distance sensor 10R. Each of the left distance sensor 10L and the right distance sensor 10R is typically an acoustic sensor (sonar), and measures the distance to the obstacle based on the reflected wave from the obstacle (eg, seabed landform).

  More specifically, the left distance sensor 10L measures the distance between the left obstacle on the left side and the aircraft. The distance measured by the left distance sensor 10L is hereinafter referred to as “left distance LL”. On the other hand, the right distance sensor 10R measures the distance between the right obstacle on the right side and the aircraft. The distance measured by the right distance sensor 10R is hereinafter referred to as “right distance LR”.

  The underwater aircraft 1 according to the present embodiment refers to the measured left distance LL and right distance LR, and performs avoidance control for avoiding the aircraft from an obstacle as necessary. In order to perform the avoidance control, the following three distances (reference values) are introduced.

  The first is the control start distance L1 (first reference value). This control start distance L1 is used as an index indicating that an obstacle is approaching to the extent that avoidance control is necessary. More specifically, when at least one of the left distance LL and the right distance LR is equal to or longer than the predetermined period T1 and equal to or less than the control start distance L1, the underwater machine 1 starts avoidance control.

  The second is the control release distance L2 (second reference value). The control release distance L2 is used as an index indicating that the obstacle has been separated to the extent that the avoidance control may be released. More specifically, when the distance that is equal to or less than the control start distance L1 is equal to or longer than the control release distance L2 as a result of the avoidance control, the underwater machine 1 ends the avoidance control. Let The control release distance L2 is set to be equal to or greater than the above-described control start distance L1 (L2 ≧ L1). From the viewpoint of control stability, the control release distance L2 is preferably larger than the control start distance L1 (L2> L1).

  The third is the alarm distance L3 (third reference value). This alarm distance L3 is used as an index indicating that an obstacle is close enough that the avoidance control is no longer in time. Therefore, the alarm distance L3 is set to be smaller than the above-described control start distance L1 (L1> L3). When at least one of the left distance LL and the right distance LR is equal to or longer than the alarm distance L3 for a predetermined period T3 or more, the underwater aircraft 1 stops the navigation of the aircraft. Here, the stop of navigation includes not only stopping the aircraft on the spot but also raising the aircraft on the spot.

  FIG. 2 is a block diagram showing a functional configuration of the underwater machine 1 according to the present embodiment. The underwater machine 1 includes the left distance sensor 10L, the right distance sensor 10 and the control unit 20 described above.

  The control unit 20 is a functional block that performs various data processing, and is typically realized by a microcomputer and a control program. The control unit 20 controls navigation of the aircraft based on measurement data obtained by various sensors. In particular, the control unit 20 controls the navigation of the aircraft based on the left distance LL and the right distance LR obtained by the left distance sensor 10L and the right distance sensor 10, respectively.

  An example of avoidance control in the present embodiment will be described with reference to FIG. Initially, the underwater aircraft 1 is performing general target route following travel. In the case of target route following travel, when a target point is set, a predetermined course (target route) is set from the start point to the target point. While the avoidance control according to the present embodiment is not performed, the control unit 20 controls the aircraft to navigate along the predetermined course. When the aircraft is off the predetermined course, the control unit 20 performs control to return the aircraft to the predetermined course. These are general target route tracking controls. On the other hand, when the approach of the obstacle is detected, the avoidance control of the present embodiment is activated as the interrupt control.

  Specifically, when one of the left distance LL and the right distance LR is equal to or longer than the predetermined period T1 and equal to or less than the control start distance L1, the control unit 20 performs “one side avoidance control (first avoidance control)”. To do. In the one-side avoidance control, the control unit 20 controls the navigation of the aircraft so that the distance that has become the control start distance L1 or less increases again. In the example shown in FIG. 3, the right distance LR is equal to or less than the control start distance L1, and the control unit 20 starts the one-side avoidance control. In the one-side avoidance control, the control unit 20 steers the aircraft in the left direction so that the right-side distance LR increases. Thereby, it is avoidable from the right side obstacle on the right side. However, as a result of this avoidance control, the aircraft deviates from the predetermined course.

  Thereafter, the right obstacle moves away from the aircraft, and the right distance LR increases. When the right distance LR is equal to or longer than the control release distance L2 for a predetermined period T2, the control unit 20 ends the one-side avoidance control. Then, the aircraft returns to a predetermined course by the target route tracking control.

  Next, another example of avoidance control in the present embodiment will be described with reference to FIG. FIG. 4 shows a case where both the left distance LL and the right distance LR are equal to or longer than the predetermined period T1 and equal to or less than the control start distance L1. In this case, the control unit 20 performs “both sides avoidance control (second avoidance control)”. In the both-side avoidance control, the control unit 20 sets the target position of the aircraft to the center position between the left obstacle and the right obstacle. That is, the control unit 20 controls the navigation of the aircraft so that the left distance LL and the right distance LR are equal.

  After that, the left and right obstacles move away from the aircraft. When the left distance LL and the right distance LR are equal to or longer than the control release distance L2 for a predetermined period T2, the control unit 20 ends the both-side avoidance control. Then, the aircraft returns to a predetermined course by the target route tracking control.

  FIG. 5 is a flowchart schematically showing avoidance control according to the present embodiment.

Step S10:
The left distance sensor 10L measures the left distance LL between the left obstacle on the left side and the aircraft. The right distance sensor 10R measures the right distance LR between the right obstacle on the right side and the aircraft. Data of the measured left distance LL and right distance LR is sent to the control unit 20.

Step S20:
The control unit 20 compares each of the left distance LL and the right distance LR with the control start distance L1. If at least one of the left distance LL and the right distance LR is equal to or longer than the predetermined period T1 and equal to or less than the control start distance L1 (step S20; Yes), the process proceeds to step S30. In other cases (step S20; No), the process returns to step S10.

Step S30:
The control unit 20 compares each of the left distance LL and the right distance LR with the alarm distance L3. When at least one of the left distance LL and the right distance LR is equal to or longer than the predetermined period T3 and equal to or shorter than the alarm distance L3 (step S30; Yes), the process proceeds to step S40. In other cases (step S30; No), the process proceeds to step S50.

Step S40:
The control unit 20 stops the navigation of the aircraft. Here, the stop of navigation includes not only stopping the aircraft on the spot but also raising the aircraft on the spot.

Step S50:
When both the left distance LL and the right distance LR are equal to or less than the control start distance L1 (step S50; Yes), the process proceeds to step S60. On the other hand, when only one of the left distance LL and the right distance LR is equal to or less than the control start distance L1 (step S50; No), the process proceeds to step S70.

Step S60:
The control unit 20 performs both-side avoidance control (see FIG. 4). Specifically, the control unit 20 sets the target position of the aircraft to the center position between the left obstacle and the right obstacle. That is, the control unit 20 controls the navigation of the aircraft so that the left distance LL and the right distance LR are equal. The process returns to Step S10 while performing the both-side avoidance control.

Step S70:
The control unit 20 performs one-sided avoidance control (see FIG. 3). Specifically, the control unit 20 controls the navigation of the aircraft so that the distance that is equal to or less than the control start distance L1 increases again. The process returns to step S10 while performing the one-side avoidance control.

Step S100:
The control unit 20 determines whether or not the avoidance control end condition is satisfied. The end condition in the case of the one-side avoidance control is that the distance that is equal to or less than the control start distance L1 is equal to or greater than the predetermined period T2 and equal to or greater than the control release distance L2. The end condition in the case of the both-side avoidance control is that the left distance LL and the right distance LR are equal to or longer than the control release distance L2 for a predetermined period T2 or more. If these end conditions for avoidance control are satisfied (step S100; Yes), the process proceeds to step S110.

Step S110:
The control unit 20 ends the avoidance control.

  Even when a forward obstacle is detected by a forward distance sensor (not shown), the control unit 20 temporarily stops the avoidance control process according to the present embodiment.

  As described above, according to the present embodiment, the obstacle avoidance control is performed based on the left distance LL and the right distance LR obtained by the left distance sensor 10L and the right distance sensor 10, respectively. For obstacle avoidance control, a seafloor topographic map is not required. Therefore, the cost is reduced. That is, according to this Embodiment, the underwater machine 1 which can avoid an obstruction at low cost is implement | achieved.

  Also, the seafloor topography changes over time. Therefore, it is not known how accurate the seafloor topographic map is. In the present embodiment, since the obstacle is detected in real time, the avoidance accuracy is improved as compared with the case of using the seafloor topographic map.

  The present invention is applicable to, for example, a small unmanned submersible or an autonomous underwater vehicle.

  The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and can be appropriately changed by those skilled in the art without departing from the scope of the invention.

1 Submersible 10L Left distance sensor 10R Right distance sensor LL Left distance LR Right distance L1 Control start distance L2 Control release distance L3 Alarm distance

Claims (8)

A left distance sensor that measures the left distance between the aircraft and the left obstacle on the left,
A right distance sensor for measuring a right distance between the aircraft and a right obstacle on the right side;
A control unit that controls navigation of the aircraft based on the left distance and the right distance; and
When at least one of the left distance and the right distance is equal to or less than a first reference value, the control unit performs avoidance control for avoiding the airframe from an obstacle. The underwater machine according to claim 1,
When only one of the left distance and the right distance is less than or equal to the first reference value, the control unit performs first avoidance control as the avoidance control,
In the first avoidance control, the control unit controls navigation of the airframe so that the one distance that is equal to or less than the first reference value increases. The underwater machine according to claim 2,
When the one distance is equal to or greater than a second reference value that is equal to or greater than the first reference value, the control unit ends the first avoidance control. The underwater machine according to any one of claims 1 to 3,
When both the left distance and the right distance are equal to or less than the first reference value, the control unit performs second avoidance control as the avoidance control,
In the second avoidance control, the control unit controls navigation of the airframe so that the left distance and the right distance are equal. The underwater machine according to claim 4,
When both the left distance and the right distance are equal to or greater than a second reference value that is equal to or greater than the first reference value, the control unit ends the second avoidance control. The underwater machine according to claim 3 or 5,
The second reference value is greater than the first reference value. It is an underwater machine as described in any one of Claims 1 thru | or 6, Comprising:
When at least one of the left distance and the right distance is equal to or smaller than a third reference value smaller than the first reference value, the control unit stops the navigation of the aircraft. It is an underwater machine as described in any one of Claims 1 thru | or 6, Comprising:
While the avoidance control is not performed, the control unit controls the aircraft to sail along a predetermined course.

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