Obstacle detection system and obstacle detection method

Abstract

To provide an obstacle detection system and an obstacle detection method with improved obstacle detection accuracy.SOLUTION: An obstacle detection method comprises: a detection region setting step for preliminarily setting, as a detection region, an area corresponding to reflection points where laser light is reflected in the absence of obstacles; and a determination step for determining the presence or absence of an obstacle based on reflected light occurring within the detection region. The detection region setting step includes: setting a forward detection region Ra formed on the forward side in a traveling direction y of a moving body; a first peripheral detection region Rb formed so as to surround the forward detection region Ra; and a second peripheral detection region Rc formed so as to surround the first peripheral detection region Rb.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an obstacle detection system and an obstacle detection method that are installed on a moving body, such as a vehicle traveling on a road, to detect the presence or absence of obstacles around the moving body, and more particularly to an obstacle detection system and an obstacle detection method that improve the accuracy of obstacle detection. [Background technology]

[0002] Various obstacle detection systems have been proposed for detecting obstacles while a crane is traveling (see, for example, Patent Document 1). The obstacle detection system described in Patent Document 1 can detect obstacles by scanning a laser beam along the direction in which the crane is traveling.

[0003] One way to improve the safety of crane travel is to expand the detection area for detecting obstacles. For example, devices such as LiDAR (Light Detection and Ranging) or 3D laser scanners can be used to expand the detection area in the lateral direction of the crane. In addition, by installing LiDAR or similar devices at a relatively high position on the crane, the detection area can be expanded in both the travel and lateral directions.

[0004] However, when LiDAR or other devices are installed high up on a crane, blind spots where the laser light does not reach can occur near the crane and close to the travel path, which can reduce the accuracy of obstacle detection. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-105822 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide an obstacle detection system and an obstacle detection method that improve the accuracy of obstacle detection. [Means for solving the problem]

[0007] An obstacle detection system for achieving the above object includes a transmitter that is installed on a moving body and emits laser light while changing the irradiation angle in the horizontal and vertical directions, a receiver that receives reflected light of the laser light, a detection area setting mechanism that presets a detection area in an area of ​​a reflection point where the laser light is reflected when there is no obstacle, and a determination mechanism that determines the presence or absence of an obstacle based on the reflected light that is reflected inside the detection area, wherein the detection area setting mechanism has a configuration that sets a forward detection area formed on the forward side in the traveling direction of the moving body, a first peripheral detection area formed in a state surrounding the periphery of this forward detection area, and a second peripheral detection area formed in a state surrounding the periphery of the first peripheral detection area. The forward detection area is in a state where the entire periphery is completely surrounded by the moving object and the first periphery detection area in a plan view, and the first periphery detection area is in a state where the entire periphery is completely surrounded by the moving object and the second periphery detection area in a plan view. It is characterized by:

[0008] An obstacle detection method for achieving the above object is an obstacle detection method in which a laser beam is emitted from a transmitter installed on a moving body while changing the emission angle in the horizontal and vertical directions, and the reflected light of this laser beam is received by a receiver to detect the presence or absence of an obstacle, the obstacle detection method comprising a detection area setting step of setting in advance, as a detection area, an area of ​​a reflection point where the laser beam is reflected when there is no obstacle, and a determination step of determining the presence or absence of an obstacle based on the reflected light reflected inside the detection area, wherein the detection area setting step has a configuration in which a forward detection area formed on the forward side in the traveling direction of the moving body, a first peripheral detection area formed in a state surrounding the periphery of this forward detection area, and a second peripheral detection area formed in a state surrounding the periphery of this first peripheral detection area are set in advance. The forward detection area is in a state where the entire periphery is completely surrounded by the moving object and the first periphery detection area in a plan view, and the first periphery detection area is in a state where the entire periphery is completely surrounded by the moving object and the second periphery detection area in a plan view. It is characterized by: [Effects of the Invention]

[0009] According to the present invention, it is possible to estimate whether an obstacle has entered a blind spot formed in the forward area from the states of the first peripheral detection area and the second peripheral detection area formed around the blind spot, which is advantageous in improving the accuracy of obstacle detection. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of an outline of an obstacle detection system. [Figure 2] FIG. 2 is an explanatory diagram illustrating a detection region in a plan view. [Figure 3] FIG. 10 is an explanatory diagram illustrating a detection region as viewed from the side. [Figure 4] FIG. 10 is an explanatory diagram illustrating an example of a detection area separated in the vertical direction. [Figure 5] FIG. 2 is an explanatory diagram illustrating a control flow of the obstacle detection system. [Figure 6] 1 is a table illustrating data held by an obstacle detection system. [Figure 7] 4 is a table illustrating data held by an obstacle detection system. [Figure 8] FIG. 10 is an explanatory diagram illustrating the relationship between a detection area and a reflection point Pmn. [Figure 9] 10A and 10B are explanatory diagrams illustrating combinations of determination results in detection areas. [Figure 10] FIG. 9 is an explanatory diagram illustrating a state in which the worker in FIG. 8 has moved. [Figure 11] 11 is an explanatory diagram illustrating a state in which the worker in FIG. 10 has moved. FIG. [Figure 12] FIG. 10 is an explanatory diagram illustrating an example of a transition pattern of a situation Qn. [Figure 13] FIG. 5 is an explanatory diagram illustrating a modified example of FIG. 4. [Figure 14] 10A and 10B are explanatory diagrams illustrating combinations of determination results in detection areas. [Figure 15] FIG. 11 is an explanatory diagram illustrating a modified example of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The obstacle detection system and obstacle detection method will be described below based on the embodiment shown in the drawings. In the drawings, the traveling direction of a mobile object such as a crane is indicated by arrow y, the lateral direction that crosses the traveling direction y at a right angle is indicated by arrow x, and the up and down direction is indicated by arrow z.

[0012] 1, an obstacle detection system 1 is installed on a mobile body 2, such as a gantry crane. The gantry crane includes a traveling device 3 that travels in a traveling direction y, four leg members 4 that are disposed above the traveling device 3 and extend in a vertical direction z, two beam members 5 that extend in a lateral direction x and connect the upper ends of the leg members 4 that face each other in the lateral direction x, a trolley 6 that is configured to be movable in the lateral direction x along the beam members 5, and a hoisting device 7 that is suspended from the trolley 6 by a wire rope. The gantry crane that constitutes the mobile body 2 loads and unloads containers using the hoisting device 7 while traveling on a traveling surface 8 in the traveling direction y.

[0013] The obstacle detection system 1 has a transmitter 9a that emits laser light toward the traveling surface 8, and a receiver 9b that receives the light reflected by the traveling surface 8. The receiver 9b is located near the transmitter 9a. In this embodiment, the transmitter 9a and the receiver 9b (hereinafter sometimes collectively referred to as the sensor 9) are installed on the four traveling devices 3. The location where the sensor 9 is installed is not limited to the above, and the sensor 9 can be installed in another location as appropriate, such as on the side of the leg member 4.

[0014] The sensor 9 is configured with, for example, a LiDAR or a 3D laser scanner. The transmitter 9a of the sensor 9 is configured to emit laser light. The transmitter 9a emits the laser light while changing the irradiation angle in the horizontal directions x and y and the vertical direction z. For the sake of explanation, in FIG. 1, the range R0 on the travel surface 8 where the laser light is irradiated is shown by a dashed line.

[0015] The obstacle detection system 1 may be configured to irradiate laser light only from the sensor 9 on the front side in the traveling direction y of the moving object 2, or may be configured to irradiate laser light from sensors 9 on both the front and rear sides.

[0016] The sensor 9 acquires data on the irradiation angle of the laser light irradiated toward the traveling surface 8 and the time from when the laser light is irradiated until reflected light is obtained. The sensor 9 may be configured to acquire data on the distance from the sensor 9 to the point where the laser light is reflected, instead of the time until reflected light is obtained. The sensor 9 is not limited to LiDAR or the like, and may be configured with other devices as long as they have a configuration that can obtain the distance to the traveling surface 8 by emitting laser light.

[0017] The obstacle detection system 1 includes a detection area setting mechanism 10 that presets a detection area in the area of ​​the reflection point where the laser light is reflected when there is no obstacle, and a determination mechanism 11 that determines the presence or absence of an obstacle based on the reflected light that is reflected inside the detection area. The detection area setting mechanism 10 and the determination mechanism 11 can be configured with various known computers. The detection area setting mechanism 10 and the like include a central processing unit (CPU), a main storage unit (memory), and an auxiliary storage unit (e.g., HDD). The detection area setting mechanism 10 and the like may also include an input unit (keyboard, mouse) and an output unit (display, printer).

[0018] The detection area setting mechanism 10 and the like are installed, for example, in the driver's cab, machine room, or electrical room of the gantry crane. The installation location of the detection area setting mechanism 10 and the like is not limited to the above. If the gantry crane is remotely operated, the detection area setting mechanism 10 and the like may be placed near the operator's console used for remote operation. The detection area setting mechanism 10 and the like are connected to the sensor 9 by wire or wirelessly.

[0019] As illustrated in FIGS. 2 and 3, the detection area setting mechanism 10 can set multiple detection areas in advance. The detection area setting mechanism 10 sets a forward detection area Ra formed ahead of the moving object 2 in the traveling direction y, a first peripheral detection area Rb formed surrounding the forward detection area Ra, and a second peripheral detection area Rc formed surrounding the first peripheral detection area Rb. For ease of explanation, in FIGS. 2 and 3, the forward detection area Ra, the first peripheral detection area Rb, and the second peripheral detection area Rc are indicated by dashed lines, and the direction of laser light irradiation is indicated by a broken line. The laser light irradiation angle θ [deg] in the horizontal direction x, y is indicated with 0° in front of the moving object 2, with the left side (upper side in FIG. 2) of the moving object 2's traveling direction indicated as a positive value and the right side (lower side in FIG. 2) as a negative value. As illustrated in FIG. 3, the laser light irradiation angle φ [deg] in the vertical direction z is indicated with 0° in the horizontal direction indicated as a negative value.

[0020] The forward detection area Ra is formed along the travel surface 8 with which the wheels of the gantry crane come into contact. In the lateral direction x, the forward detection area Ra is set to include the area through which the travel unit 3 passes. If there is no obstacle in the forward detection area Ra, the travel unit 3 can continue traveling without coming into contact with an obstacle. The forward detection area Ra is set, for example, as a rectangular parallelepiped space. As shown in FIG. 3, the forward detection area Ra has a slight size in the vertical direction z, so that reflected light from inside the detection area can be obtained even if the travel surface 8 is uneven. This prevents the problem of incorrectly detecting unevenness in the travel surface 8 as an obstacle. Furthermore, in the forward detection area Ra, a blind spot R1 occurs in the area near the travel unit 3 where the laser light is not irradiated, creating a blind spot for the sensor 9. For ease of explanation, the blind spot R1 is shaded in FIG. 3.

[0021] The first peripheral detection area Rb is set to surround the forward detection area Ra. In this specification, a surrounding state refers to a state in which an obstacle that reaches the forward detection area Ra necessarily passes through the first peripheral detection area Rb. For example, as in the embodiment illustrated in FIG. 2, a state in which the forward detection area Ra is covered by the first peripheral detection area Rb except for the portion adjacent to the moving object 2 can be said to be a surrounding state. In this embodiment, in the plan view shown in FIG. 2, one side of the rear side (left side in FIG. 2) of the rectangle that constitutes the forward detection area Ra overlaps one side of the rear side (left side in FIG. 2) of the rectangle that constitutes the first peripheral detection area Rb. Because the traveling device 3 is present on the rear side of the rectangle of the forward detection area Ra, an obstacle cannot enter the forward detection area Ra from the rear side of the moving object 2. It can also be said that the first peripheral detection area Rb does not need to be formed only in the portion of the forward detection area Ra that an obstacle cannot enter. In addition, a state in which the periphery including the rear side (left side in FIG. 2) of the forward detection region Ra in a plan view is completely covered by the first peripheral detection region Rb can be said to be a surrounding state.

[0022] The range outside the forward detection area Ra and inside the first peripheral detection area Rb is a range that does not directly affect the traveling of the moving object 2. Even if there is an obstacle in this range, the moving object 2 can continue traveling without coming into contact with the obstacle.

[0023] Similarly, the second peripheral detection area Rc is set to surround the first peripheral detection area Rb, and any obstacle that reaches the first peripheral detection area Rb will necessarily pass through the second peripheral detection area Rc.

[0024] For the sake of explanation, FIG. 4 shows the ranges of the forward detection area Ra and the like broken down in the vertical direction z. As illustrated in FIG. 4, the first peripheral detection area Rb may be set to a range that overlaps with the entire forward detection area Ra. Therefore, the range included in the forward detection area Ra is also included in the first peripheral detection area Rb. Similarly, the second peripheral detection area Rc may be set to a range that overlaps with the entire first peripheral detection area Rb. The entire forward detection area Ra and the entire first peripheral detection area Rb are included inside the second peripheral detection area Rc.

[0025] If there is no obstacle, the reflected light reflected by the travel surface 8 returns to the sensor 9. If there is an obstacle, the reflected light reflected outside the detection area returns to the sensor 9, or no reflected light returns at all. The determination mechanism 11 is configured to calculate a fulfillment rate, which is the ratio of the number of reflected lights reflected inside the forward detection area Ra to the total number of laser lights irradiated toward the forward detection area Ra, and determine that there is no obstacle if this fulfillment rate is equal to or greater than a predetermined threshold, and determine that there is an obstacle if it is less than the threshold. In other words, the determination mechanism 11 determines that there is no obstacle if the forward detection area Ra is clearly visible from the sensor 9.

[0026] The determination mechanism 11 calculates the filling rate for each of the first peripheral detection area Rb and the second peripheral detection area Rc in addition to the forward detection area Ra to determine the presence or absence of an obstacle. The presence or absence of an obstacle is determined by the determination mechanism 11 for each detection area, such as the forward detection area Ra.

[0027] The method by which the determination mechanism 11 determines whether or not an obstacle exists is not limited to the above. For example, the determination mechanism 11 may determine whether or not an obstacle exists by comparing the number of reflected light beams that are reflected inside the forward detection area Ra with the number of reflected light beams that are reflected outside the forward detection area Ra, among the laser light beams that are irradiated toward the forward detection area Ra.

[0028] The obstacle detection system 1 may include a command mechanism 12 that transmits commands to the moving object 2 in accordance with the determination result of the determination mechanism 11. The command mechanism 12, like the detection area setting mechanism 10 and the determination mechanism 11, may be configured using various known computers. For example, the detection area setting mechanism 10, the determination mechanism 11, and the command mechanism 12 may be incorporated into a single computer. The command mechanism 12 is not an essential component of the obstacle detection system 1.

[0029] The command mechanism 12 can be configured to transmit a command to the moving body 2 when the determination mechanism 11 determines that there is an obstacle in the blind spot area R1 or the forward detection area Ra, for example. Here, the command may be a deceleration command, a stop command, an emergency stop command, or the like. The deceleration command is a command to decelerate the moving body 2 within a predetermined range. The deceleration command decelerates the traveling speed of the moving body 2, for example, to 50% of the current speed, or to a preset speed such as 8 km / h. The stop command is a command to stop the moving body 2 after decelerating within a predetermined range. The emergency stop command is a command to stop the moving body 2 after decelerating at the maximum possible rate.

[0030] For example, when the determination mechanism 11 determines that there is an obstacle in the first peripheral detection area Rb or the second peripheral detection area Rc, the command mechanism 12 can be configured not to send a command to the moving body 2. In this case, even if there is an obstacle in the first peripheral detection area Rb or the second peripheral detection area Rc, the traveling of the moving body 2 is not affected.

[0031] The command mechanism 12 may be configured to notify the driver of the moving body 2 that an obstacle is present. The driver can operate the moving body 2 by referring to commands from the command mechanism 12. In this case, the command mechanism 12 is configured to send a notification to the driver without sending a control signal such as a deceleration command to the moving body 2.

[0032] As illustrated in FIG. 5, the obstacle detection system 1 first sets a detection area (hereinafter, sometimes referred to as detection area setting step S1). In the detection area setting step S1, a forward detection area Ra, a first peripheral detection area Rb, and a second peripheral detection area Rc are set. The detection areas set in the detection area setting step S1 are not limited to those described above. A detection area may be added to a position further forward of the forward detection area Ra in the traveling direction y of the moving object 2, or a detection area may be set outside the second peripheral detection area Rc. Furthermore, the first peripheral detection area Rb, etc. may be divided into multiple areas. The detection area only needs to be set once.

[0033] 6 and 7 show examples of data acquired from the sensor 9 and stored in the obstacle detection system 1. The resolution of the irradiation angle θ of the laser light in the horizontal directions x, y and the irradiation angle φ of the laser light in the vertical direction z is predetermined as part of the performance of the sensor 9. Here, an example will be described in which the resolution is 5° when the angle φ in the vertical direction z is in the range of -10° to -20°, and the resolution is 5° when the angle θ in the horizontal directions x, y is in the range of -135° to +135°. In practice, a sensor with a resolution in the range of 0.125° to 1.000° and a scan frequency of 5 to 100 Hz can be used.

[0034] As shown in Figures 6 and 7, reflection points Pmn corresponding to the angle φ in the vertical direction z and the angle θ in the horizontal directions x and y are determined in advance. Figure 8 shows the distribution of reflection points Pmn on the travel surface 8. In this embodiment, the sensor 9 first fixes the angle φ in the vertical direction z to -10° and scans the laser light with the angle θ in the horizontal directions x and y from -135° to 135°. The reflection points Pmn corresponding to this laser light are P1-1 to P1-55. Next, the sensor 9 fixes the angle φ in the vertical direction z to -15° and scans the laser light while changing the angle θ in the horizontal directions x and y. The reflection points Pmn corresponding to this laser light are P2-1 to P2-55.

[0035] In the detection area setting step S1, a detection area corresponding to each reflection point Pmn is set. Using FIG. 8 as an example, for example, since reflection point P1-1 is not included in any detection area, the detection area is set to "none." Since reflection points P1-19 and P1-28 are included in the second peripheral detection area Rc, the detection area is set to "Rc" (see FIG. 6). Since reflection points P2-19 and P3-19 shown in FIG. 8 are included in the first peripheral detection area Rb, the detection area is set to "Rb." Since reflection point P2-29 is included in the forward detection area Ra, the detection area is set to "Ra" (see FIG. 7). As described above, in the detection area setting step S1, a detection area corresponding to each reflection point Pmn is set as shown in FIGS. 6 and 7. By changing the detection area set for each reflection point Pmn, the range of each detection area in the horizontal directions x and y can be changed.

[0036] 6 and 7, the time from when the laser light is emitted until the reflected light is obtained when there is no obstacle (measurement time tmn) is predetermined for each reflection point Pmn. The measurement time tmn is automatically determined once the angle φ in the vertical direction z and the height at which the sensor 9 is installed on the moving object 2 are determined.

[0037] In the detection area setting step S1, an allowable time tn having a predetermined range centered on the measurement time tmn is set. The range of this allowable time tn is determined by the size of the detection area in the vertical direction z. By changing the range of the allowable time tn, the range of the detection area in the vertical direction z can be changed.

[0038] For example, when a gantry crane constituting the mobile body 2 travels or performs a loading / unloading operation, a laser beam is emitted from the sensor 9, and the time until reflected light is obtained is measured (hereinafter, this may be referred to as measurement step S2). In measurement step S2, a measurement time tmn is acquired for each reflection point Pmn.

[0039] First, for each reflection point Pmn, a comparison is made to see if the measurement time tmn is within the range of the allowable time tn. The comparison result is stored in the obstacle detection system 1. Next, the presence or absence of an obstacle is determined for each detection area, such as the forward detection area Ra (hereinafter, this may be referred to as determination step S3).

[0040] In the determination step S3, for example, if the measurement time tmn is within the allowable time tn at, for example, 90% or more of the 1,000 reflection points Pmn in the forward detection area Ra, the determination mechanism 11 determines that there is no obstacle in the forward detection area Ra. The threshold for determining that there is no obstacle is not limited to the above-mentioned 90%. The threshold can be determined appropriately depending on the size of the obstacle to be detected. The threshold may also be configured to change depending on the weather, etc.

[0041] Depending on the result obtained in the determination step S3, the command mechanism 12 transmits a command to the moving body 2 (hereinafter, sometimes referred to as command step S4). For example, if there is an obstacle in the forward detection area Ra, the command mechanism 12 transmits a stop command to the moving body 2. For example, if there is an obstacle in the first peripheral detection area Rb or the second peripheral detection area Rc, the command mechanism 12 may be configured not to transmit a command to the moving body 2.

[0042] In the above example, if an obstacle is detected in the forward detection area Ra, the moving object 2 is stopped by a stop command. If an obstacle is detected in the first peripheral detection area Rb or the second peripheral detection area Rc, the moving object 2 continues traveling.

[0043] The obstacle detection system 1 repeats the measurement step S2, the determination step S3, and the command step S4 to repeatedly confirm that the moving object 2 is in a state where it can travel safely.

[0044] After the moving body 2 is stopped by an obstacle, a safety check is performed by an operator or the like. After safety is confirmed, the moving body 2 resumes traveling. As the moving body 2 resumes traveling, detection by the obstacle detection system 1 resumes. At this time, the detection area setting step S1 may not be performed, or the detection area may be set anew in the detection area setting step S1, or an already set value may be read. If the detection area setting step S1 is not performed, control starts from the measurement step S2.

[0045] Command step S4 is not an essential component of the obstacle detection method. For example, if the driver of the moving body 2 sees the result of determination step S3 and slows down or stops the moving body 2, command step S4 is unnecessary.

[0046] Since a first peripheral detection area Rb and a second peripheral detection area Rc are formed in distinction from the forward detection area Ra, the control of the moving object 2 when an obstacle is detected can be set differently for the forward detection area Ra and the first peripheral detection area Rb, etc. For example, if an obstacle is detected in the forward detection area Ra, the moving object 2 can be stopped, and if an obstacle is detected in the first peripheral detection area Rb, etc., the moving object 2 can continue traveling. Near the gantry crane that is the moving object 2, the first peripheral detection area Rb, etc. can be set in the range where the chassis travels and the range where the container is placed.

[0047] Because the first peripheral detection area Rb, etc. are set around the forward detection area Ra, it is possible to estimate whether an obstacle has entered the blind spot area R1 formed in part of the forward detection area Ra from the state of the first peripheral detection area Rb, etc. In order for a worker or other obstacle that is an obstacle to the moving object 2 to move into the blind spot area R1, he or she must pass through the first peripheral detection area Rb and the second peripheral detection area Rc. Therefore, the obstacle detection system 1 can detect the presence or absence of an obstacle moving into the blind spot area R1. Specifically, if a worker or other obstacle enters the blind spot area R1 from the second peripheral detection area Rc via the first peripheral detection area Rb, the obstacle will not be detected in either area after passing through the first peripheral detection area Rb, and the obstacle detection system 1 can detect the presence of an obstacle.

[0048] The operation of the obstacle detection system 1 will be described using as an example a case where a worker 13 moves toward a blind spot R1 from a direction where the angle θ between the horizontal directions x and y is -45° as shown in Fig. 8. For the sake of explanation, in Fig. 8, the worker 13 is represented by a circle with a diagonal line inside. FIG. 9 shows a situation Qn, which is a combination of the determination results in the respective detection areas Ra, Rb, and Rc, and a command corresponding to this situation Qn.

[0049] 8, when the worker 13 is in the position indicated by the dashed line, it is determined that there are no obstacles in all the detection areas Ra, Rb, and Rc. This situation is called a third preliminary situation Q3.

[0050] When the worker 13 is located at the position indicated by the solid line in Figure 8, no reflected light from within the second peripheral detection area Rc is detected around the reflection point P1-19. As a result, it is determined that there is an obstacle in the second peripheral detection area Rc. This situation is called the second preliminary situation Q2.

[0051] When the worker 13 is located at the position indicated by the dashed line in Figure 10, no reflected light from inside the first peripheral detection area Rb is obtained around reflection points P2-19 and P3-19. As a result, it is determined that there is an obstacle in the first peripheral detection area Rb. This situation is called a first preliminary situation Q1. At this time, the worker 13 is also located inside the second peripheral detection area Rc, so it is also determined that there is an obstacle in the second peripheral detection area Rc.

[0052] In FIG. 10, when the worker 13 is located at the position indicated by the solid line, the worker 13 is in the blind spot area R1, which is the blind spot of the sensor 9. At this time, it is determined that there is no obstacle in all detection areas Ra, Rb, and Rc. This situation is called emergency situation Q5. The worker 13, who is approaching from the direction of the horizontal x-y angle θ = -45°, is not visible to the sensor 9. This emergency situation Q5 is the same as the third preliminary situation Q3 in that it is determined that there is no obstacle in all detection areas Ra, Rb, and Rc. If it is determined that there is no obstacle in all detection areas Ra, Rb, and Rc from the first preliminary situation Q1, it is determined to be emergency situation Q5, not third preliminary situation Q3. Emergency situation Q5 is a situation in which there is an obstacle in the blind spot area R1. At this time, the command mechanism 12 transmits, for example, an emergency stop command to the mobile object 2.

[0053] When the worker 13 is located at the position indicated by the solid line in FIG. 11, no reflected light from inside the forward detection area Ra is obtained around reflection point P3-27. As a result, it is determined that there is an obstacle in the forward detection area Ra. This situation is called emergency situation Q4. At this time, the worker 13 is also located inside the first peripheral detection area Rb and the second peripheral detection area Rc, so it is also determined that there is an obstacle in the first peripheral detection area Rb and the second peripheral detection area Rc. At this time, the command mechanism 12 transmits, for example, an emergency stop command to the moving object 2.

[0054] 11, when the worker 13 moves from the position indicated by the dashed line through the second peripheral detection area Rc and outside of it, the situation changes from the first preliminary situation Q1 to the second preliminary situation Q2 to the third preliminary situation Q3. If it is determined that there are no obstacles in all the detection areas Ra, Rb, and Rc after passing through the first preliminary situation Q1 to the second preliminary situation Q2, the situation is determined to be the third preliminary situation Q3, not the emergency situation Q5.

[0055] In the first preliminary situation Q1, the second preliminary situation Q2, and the third preliminary situation Q3, even if an obstacle is present, it is not close enough to impede the movement of the moving body 2, so it can be said that there is no need to immediately stop the moving body 2. The emergency situation Q4-5 can be said to be a situation where it is necessary to immediately stop the moving body 2.

[0056] As illustrated in FIG. 12, there are limited patterns for transitioning from situation Qn. Understanding the transitions from preparatory situations Q1-3 makes it possible to prepare for a transition to emergency situations Q4-5. This is advantageous for improving the accuracy of obstacle detection by the obstacle detection system 1. As illustrated in FIG. 12, there is no direct transition from the first preparatory situation Q1 to the third preparatory situation Q3, so the obstacle detection system 1 can distinguish between the third preparatory situation Q3 and the emergency situation Q5.

[0057] When the first preliminary situation Q1 occurs, there is a possibility that the situation may shift to an emergency situation Q4-5. Therefore, for example, when the first preliminary situation Q1 occurs, a speed limit command may be issued to limit the upper limit speed of the moving object 2.

[0058] As illustrated in Fig. 13, the first peripheral detection area Rb may be set to a range that does not overlap with the forward detection area Ra. In this case, the range included in the forward detection area Ra is not included in the first peripheral detection area Rb. Similarly, the second peripheral detection area Rc may be set to a range that does not overlap with the first peripheral detection area Rb. In this case, the range included in the forward detection area Ra and the first peripheral detection area Rb is not included in the second peripheral detection area Rc.

[0059] Figure 14 shows a situation Qn, which is a combination of the determination results in the detection areas Ra, Rb, and Rc, and the command corresponding to this situation Qn. As shown in Figure 14, when an obstacle is in the first peripheral detection area Rb, unlike the embodiment shown in Figure 9, the obstacle is not detected in the second peripheral detection area Rc (first preliminary situation Q1'). Similarly, when an obstacle is in the forward detection area Ra, the obstacle is not detected in the first peripheral detection area Rb or the second peripheral detection area Rc. The other parts are the same as those of the embodiment shown in Figure 9.

[0060] Measurement by the obstacle detection system 1 may be continued while the gantry crane that constitutes the mobile body 2 is at rest. When the mobile body 2 is restarted, the presence or absence of an obstacle in the blind spot area R1 can be detected. Continuing measurement while the gantry crane is at rest is not a necessary configuration requirement. Accidents caused by obstacles in the blind spot area R1 may be prevented by installing a bumper switch on the traveling device 3. The bumper switch is configured to send an emergency stop command to the gantry crane when it comes into contact with an obstacle. This occurs when the gantry crane starts to travel, and because the speed is extremely slow, the gantry crane can be stopped immediately.

[0061] 15, the first periphery detection area Rb and the second periphery detection area Rc may be divided into left and right halves in the traveling direction y. This is advantageous for improving the accuracy of obstacle detection by the obstacle detection system 1. Specifically, along the traveling direction y of the mobile object 2, the first periphery detection area Rb is formed by a first periphery detection area Rb1 on the left side of the traveling direction of the mobile object 2 and a first periphery detection area Rb2 on the right side. Furthermore, the second periphery detection area Rc is formed by a second periphery detection area Rc1 on the left side and a second periphery detection area Rc2 on the right side.

[0062] As shown in Figure 15, an example will be described in which a container 14 is present in the second peripheral detection area Rc, and a worker 13 is present in the first peripheral detection area Rb, as indicated by the dashed line. If the peripheral detection areas Rb and Rc are not divided, the obstacle detection system 1 determines that the situation is a first preliminary situation Q1. If the worker 13 moves from this situation into the blind spot area R1, the obstacle detection system 1 may recognize the situation as a second preliminary situation Q2. In other words, there is a possibility that the worker 13 in the blind spot area R1 will not be detected.

[0063] In contrast to the above, if the peripheral detection areas Rb and Rc are divided, a change from the first preliminary situation Q1 to the emergency situation Q5 is detected on the right side of the moving body 2. The worker 13 in the blind spot area R1 can be detected. The second preliminary situation Q2 is maintained on the left side of the moving body 2. The container 14 does not affect the movement of the moving body 2.

[0064] This configuration allows the presence or absence of an obstacle to be detected for each of the divided peripheral detection areas Rb and Rc, making it possible to accurately grasp the situation in which the obstacle is moving. In particular, when there are multiple obstacles, each obstacle can be detected individually. This is advantageous for improving the accuracy of obstacle detection.

[0065] The method of dividing the peripheral detection areas Rb and Rc is not limited to the above, and it is sufficient that at least one of the first peripheral detection area Rb and the second peripheral detection area Rc is divided into multiple areas. The number of divisions is not limited to two. The peripheral detection areas Rb and Rc may be divided into four areas, for example, front and rear and left and right. The number of divisions may be more than four. The first peripheral detection area Rb and the second peripheral detection area Rc may have different numbers of divisions. For example, the first peripheral detection area Rb may be divided into four areas, front and rear, left and right, and the second peripheral detection area Rc may be divided into two areas, left and right.

[0066] The obstacle detection system 1 may be configured to distinguish between individual obstacles. Obstacles that simultaneously cover reflection points Pmn that are close to each other in a planar view can be considered a single obstacle. The presence or absence of an obstacle can be detected individually by making a determination for each reflection point Pmn, rather than by determining the presence or absence of an obstacle on an area-by-area basis. In other words, when there are multiple obstacles, it is possible to identify the movement of each obstacle individually. It is possible to determine for each obstacle whether it has entered the blind spot area R1.

[0067] The amount of calculation in the determination mechanism 11 increases compared to when detecting the presence or absence of an obstacle for each of the peripheral detection regions Rb and Rc. When the number of obstacles anticipated in advance is small, it is desirable to determine the presence or absence of an obstacle for each region. This is because the amount of calculation in the determination mechanism 11 can be reduced and the determination result can be obtained in a relatively short time.

[0068] When a large number of obstacles are anticipated, it is desirable to distinguish between each obstacle. Although this increases the amount of calculation required by the determination mechanism 11, it is advantageous in improving safety because it allows for accurate detection of obstacles. The moving object 2 is not limited to a crane. The obstacle detection system 1 can also be applied to a chassis traveling in a container terminal, a car traveling on a public road, or the like. [Explanation of symbols]

[0069] 1. Obstacle Detection System 2. Mobile 3 Running gear 4 Leg members 5 Beam members 6 Trolley 7 Hanging equipment 8 Running surface 9 Sensors 9a Transmission Section 9b Receiving section 10. Detection area setting mechanism 11 Judgment mechanism 12 Command mechanism 13 Workers 14 containers x transverse direction y Travel direction z Vertical direction R0 Laser beam irradiation range R1 blind spot area Ra forward detection area Rb First peripheral detection area Rc Second peripheral detection area θ Horizontal irradiation angle φ Irradiation angle in the vertical direction Q1 First preliminary situation Q2 Second preliminary situation Q3 Third preliminary situation Q4 Emergency Situation Q5 Emergency situations

Claims

1. An obstacle detection system comprising: a transmitter that is installed on a moving body and emits laser light while changing the irradiation angle in the horizontal and vertical directions; a receiver that receives reflected light of the laser light; a detection area setting mechanism that pre-sets a detection area in an area of ​​a reflection point where the laser light is reflected when there is no obstacle; and a determination mechanism that determines the presence or absence of an obstacle based on the reflected light reflected inside the detection area, the detection area setting mechanism has a configuration for setting a forward detection area formed on the forward side in the traveling direction of the moving body, a first peripheral detection area formed in a state surrounding the periphery of the forward detection area, and a second peripheral detection area formed in a state surrounding the periphery of the first peripheral detection area, the forward detection area is completely surrounded by the moving object and the first peripheral detection area in a plan view, An obstacle detection system, characterized in that the first peripheral detection area is completely surrounded by the moving object and the second peripheral detection area in a plan view.

2. An obstacle detection system comprising: a transmitter that is installed on a moving body and emits laser light while changing the irradiation angle in the horizontal and vertical directions; a receiver that receives reflected light of the laser light; a detection area setting mechanism that pre-sets a detection area in an area of ​​a reflection point where the laser light is reflected when there is no obstacle; and a determination mechanism that determines the presence or absence of an obstacle based on the reflected light reflected inside the detection area, the detection area setting mechanism has a configuration for setting a forward detection area formed on the forward side in the traveling direction of the moving body, a first peripheral detection area formed in a state surrounding the periphery of the forward detection area, and a second peripheral detection area formed in a state surrounding the periphery of the first peripheral detection area, the forward detection area is completely surrounded by the first peripheral detection area in a plan view, An obstacle detection system, characterized in that the first peripheral detection area is completely surrounded by the second peripheral detection area in a plan view.

3. 3. The obstacle detection system according to claim 1, wherein the determination mechanism is configured to determine that an obstacle is present in a blind spot area that is a blind spot of the forward detection area based on a situation that is a combination of the determination results in the forward detection area, the first peripheral detection area, and the second peripheral detection area, when, after it has been determined that an obstacle is present in the first peripheral detection area based on the reflected light, it has been determined that no obstacle is present in the first peripheral detection area based on the reflected light and, without passing through a state in which it is determined that no obstacle is present in the first peripheral detection area based on the reflected light and, at the same time, it is determined that an obstacle is present in the second peripheral detection area based on the reflected light, in all of the forward detection area, the first peripheral detection area, and the second peripheral detection area.

4. a command mechanism that sends a command to the moving body in response to a determination result of the determination mechanism, The obstacle detection system according to claim 3 , wherein the command mechanism is configured to send a command to the moving body when the determination mechanism determines that an obstacle is present in the blind spot area or the forward detection area.

5. At least one of the first peripheral detection area and the second peripheral detection area is divided into two or more detection areas, 3. The obstacle detection system according to claim 1, wherein the determination mechanism is configured to determine the presence or absence of an obstacle for each of the plurality of detection areas.

6. An obstacle detection method for detecting the presence or absence of an obstacle by irradiating a laser beam from a transmitter installed on a moving body while changing the irradiation angle in the horizontal and vertical directions and receiving the reflected light of the laser beam with a receiver, the method comprising: a detection area setting step for setting in advance, as a detection area, an area of ​​a reflection point where the laser beam is reflected when there is no obstacle; and a determination step for determining the presence or absence of an obstacle based on the reflected light reflected inside the detection area, the detection area setting step has a configuration of setting in advance a forward detection area formed on the forward side in a traveling direction of the moving body, a first peripheral detection area formed in a state surrounding the periphery of the forward detection area, and a second peripheral detection area formed in a state surrounding the periphery of the first peripheral detection area, the forward detection area is completely surrounded by the moving object and the first peripheral detection area in a plan view, An obstacle detection method, characterized in that the first peripheral detection area is completely surrounded by the moving object and the second peripheral detection area in a plan view.

7. An obstacle detection method for detecting the presence or absence of an obstacle by irradiating a laser beam from a transmitter installed on a moving body while changing the irradiation angle in the horizontal and vertical directions and receiving the reflected light of the laser beam with a receiver, the method comprising: a detection area setting step for setting in advance, as a detection area, an area of ​​a reflection point where the laser beam is reflected when there is no obstacle; and a determination step for determining the presence or absence of an obstacle based on the reflected light reflected inside the detection area, the detection area setting step has a configuration of setting in advance a forward detection area formed on the forward side in a traveling direction of the moving body, a first peripheral detection area formed in a state surrounding the periphery of the forward detection area, and a second peripheral detection area formed in a state surrounding the periphery of the first peripheral detection area, the forward detection area is completely surrounded by the first peripheral detection area in a plan view, An obstacle detection method, characterized in that the first peripheral detection area is completely surrounded by the second peripheral detection area in a plan view.

8. 8. The obstacle detection method according to claim 6 or 7, wherein the determination step is configured to determine that an obstacle is present in a blind spot area that is a blind spot of the forward detection area based on a situation that is a combination of determination results in the forward detection area, the first peripheral detection area, and the second peripheral detection area, when it is determined that there is no obstacle in the first peripheral detection area in accordance with the reflected light, without passing through a state in which it is determined that there is no obstacle in the first peripheral detection area in accordance with the reflected light and that there is an obstacle in the second peripheral detection area in accordance with the reflected light.

9. a command step of transmitting a command to the moving body in accordance with a determination result of the determination step, 9. The obstacle detection method according to claim 8, wherein the command step includes transmitting a command to the moving body when it is determined that an obstacle is present in the blind spot area or the forward detection area.

10. At least one of the first peripheral detection area and the second peripheral detection area is divided into two or more detection areas, 8. The obstacle detection method according to claim 6, wherein the determining step determines the presence or absence of an obstacle for each of the plurality of detection areas.

Images