JP2021139692A - Obstacle detector for moving body - Google Patents

Abstract

To provide an obstacle detector for moving body, with which it is possible to estimate the presence of an obstacle by as few sensors as possible.SOLUTION: A first detection range where an obstacle is detectable by a first ultrasonic sensor 29 alone includes a first receivable region where reflected waves of the first ultrasonic sensor 29 are receivable by a second ultrasonic sensor 30 and a first unreceivable region where reflected waves of the first ultrasonic sensor 29 are not receivable by a second ultrasonic sensor 30. A second detection range where an obstacle is detectable by the second ultrasonic sensor 30 alone includes a second receivable region where reflected waves of the first ultrasonic sensor 29 are receivable by the first ultrasonic sensor 29 and a second unreceivable region where reflected waves of the second ultrasonic sensor 30 are not receivable by the first ultrasonic sensor 29. A detection unit recognizes the reception of reflected waves of the first ultrasonic sensor 29, and when reflected waves of the first ultrasonic sensor 29 are not received by the first ultrasonic sensor 29, determines that no obstacle exists in the first unreceivable region.SELECTED DRAWING: Figure 4

Description

The present invention relates to an obstacle detection device for a moving body.

As a prior art of an obstacle detection device for a moving body, for example, an object detection device disclosed in Patent Document 1 is known. The object detection device disclosed in Patent Document 1 is applied to a moving body including a plurality of object detection sensors that transmit a search wave and receive a reflected wave of the search wave as object detection information, and exists around the moving body. Detect an object. The object detection device includes a first detection means, a second detection means, and a position calculation means. The first detection means detects an object by a direct wave which is a reflected wave received by the same sensor as the sensor that transmitted the exploration wave among the plurality of object detection sensors. The second detection means detects an object by an indirect wave which is a reflected wave received by a sensor different from the sensor that transmitted the exploration wave among the plurality of object detection sensors. The position calculation means calculates the position information of the object by the principle of triangulation based on the detection results of the first detection means and the second detection means.

Japanese Unexamined Patent Publication No. 2016-80642

However, in the object detection device disclosed in Patent Document 1, it is necessary to superimpose the detection range of the object detection sensor of the first detection means and the detection range of the object detection sensor of the second detection means. There is a problem that the number of object detection sensors increases according to the number.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a moving obstacle detection device capable of estimating the presence or absence of an obstacle with as few sensors as possible.

In order to solve the above problems, the present invention comprises a plurality of ultrasonic sensors mounted on a moving body and having a transmitting function for transmitting ultrasonic waves and a receiving function for receiving reflected waves reflected by obstacles. In an obstacle detection device for a moving body, which comprises a transmission command unit that controls transmission of ultrasonic waves by the plurality of the ultrasonic sensors and a detection unit that detects an obstacle from the reception result of reflected waves by the ultrasonic sensors. The ultrasonic sensor comprises a first ultrasonic sensor having a first direction as a directing direction and a second ultrasonic sensor having a second direction different from the first direction as a directing direction. The first detection range in which the ultrasonic sensor can detect an obstacle by itself is the first receivable range in which the reflected wave of the first ultrasonic sensor can be received by the second ultrasonic sensor and the second super-ultrasonic range. The second detection range, which includes the first unreceivable region in which the reflected wave of the first ultrasonic sensor cannot be received by the ultrasonic sensor, and enables the second ultrasonic sensor to detect an obstacle by itself, is the first. 1 The second receivable area where the reflected wave of the second ultrasonic sensor can be received by the ultrasonic sensor, and the second unreceivable area where the reflected wave of the second ultrasonic sensor cannot be received by the first ultrasonic sensor. The detection unit detects obstacles based on the reception results of the reflected waves of the first ultrasonic sensor and the second ultrasonic sensor, and receives the reflected waves of the first ultrasonic sensor. When the first ultrasonic sensor does not receive the reflected wave of the first ultrasonic sensor, it is determined that there is no obstacle in the first unreceivable area, and the reflected wave of the second ultrasonic sensor is received. It is characterized in that when the second ultrasonic sensor does not receive the reflected wave of the second ultrasonic sensor, it determines that there is no obstacle in the second unreceivable region.

In the present invention, the detection unit detects an obstacle based on the reception result of the reflected wave of the first ultrasonic sensor and the second ultrasonic sensor, recognizes the reception of the reflected wave of the first ultrasonic sensor, and recognizes the reception of the reflected wave of the first ultrasonic sensor. When the ultrasonic sensor does not receive the reflected wave of the first ultrasonic sensor, it is determined that there is no obstacle in the first unreceivable area. Further, the detection unit recognizes the reception of the reflected wave of the second ultrasonic sensor, and when the second ultrasonic sensor does not receive the reflected wave of the second ultrasonic sensor, there is no obstacle in the second unreceivable area. judge. That is, based on the reception results of the reflected waves of the first ultrasonic sensor and the second ultrasonic sensor, it is possible to determine a region without obstacles in the first detection range and the second detection range with a small number of ultrasonic sensors.

Further, in the above-mentioned moving object obstacle detection device, when the second ultrasonic sensor receives the reflected wave of the first ultrasonic sensor, the detection unit has an obstacle in the first receivable area. When the first ultrasonic sensor receives the reflected wave of the second ultrasonic sensor, it may be determined that there is an obstacle in the second receivable area.
In this case, when the second ultrasonic sensor receives the reflected wave of the first ultrasonic sensor, it can be determined that there is an obstacle in the first receivable area, and the first ultrasonic sensor is the second ultrasonic sensor. When receiving the reflected wave of, it is determined that there is an obstacle in the second receivable area. Therefore, based on the reception results of the reflected waves of the first ultrasonic sensor and the second ultrasonic sensor, it is possible to determine an area with an obstacle in the first detection range and the second detection range with a small number of ultrasonic sensors.

Further, in the obstacle detection device for the mobile body, the first shield forming the first unreceivable area and the second shield forming the second unreceivable area may be provided. ..
In this case, by providing the first shield, the first receivable area and the first unreceivable area can be reliably formed in the first detection range. Further, by providing the second shield, it is possible to surely form the second receivable area and the second unreceivable area in the second detection range.

Further, the obstacle detection device for a moving body may be configured to be provided with an integrated member that integrates the first ultrasonic sensor and the second ultrasonic sensor.
In this case, the first ultrasonic sensor and the second ultrasonic sensor can be integrated by the integrated member. As a result, as compared with the case where the first ultrasonic sensor and the second ultrasonic sensor are not integrated, the work of attaching the first ultrasonic sensor and the second ultrasonic sensor to the moving body becomes easier.

Further, in the above-mentioned obstacle detection device for a moving body, the first direction is the moving direction of the moving body, the second direction is a direction that does not match the moving direction, and the moving body travels. A control unit for controlling is provided, and when the first ultrasonic sensor receives a reflected wave of the first ultrasonic sensor, the detection unit estimates that there is an obstacle in the first unreceivable area, and controls the control. The unit may be configured to perform control to warn when the moving body moves in the first direction.
In this case, when the first ultrasonic sensor receives the reflected wave of the first ultrasonic sensor, the detection unit estimates that there is an obstacle in the first unreceivable area, and the control unit brakes or brakes the moving moving body. Control to stop. As a result, the moving body is braked or stopped so that the moving body does not interfere with obstacles in the first unreceivable area.

According to the present invention, it is possible to provide an obstacle detection device for a moving body that can estimate the presence or absence of an obstacle with as few sensors as possible.

It is a side view of the forklift which concerns on 1st Embodiment of this invention. It is a rear view of the forklift which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure of a forklift. (A) is a perspective view of an ultrasonic sensor unit of an obstacle detection device, and (b) is a plan view of the ultrasonic sensor unit. It is a top view which shows typically the detection range of an obstacle. It is a flow chart which shows the procedure of detecting an obstacle by an obstacle detection apparatus. (A) is an explanatory diagram for presuming that the obstacle is in the first unreceivable area, (b) is an explanatory diagram for determining that the obstacle is in the first receivable area, and (c) is an explanatory diagram for determining that the obstacle is in the first receivable area. Is an explanatory diagram for presuming that is in the second unreceivable area, and (d) is an explanatory diagram for determining that the obstacle is in the second receivable area. It is a flow chart which shows the procedure of detecting an obstacle by the obstacle detection apparatus of 2nd Embodiment.

(First Embodiment)
Hereinafter, the moving object obstacle detection device according to the first embodiment will be described with reference to the drawings. The moving body of the present embodiment is a forklift that is an industrial vehicle, and more specifically, a counter-type battery forklift. Therefore, in the present embodiment, the obstacle detection device of the forklift (hereinafter, simply referred to as “obstacle detection device”) will be described.

As shown in FIG. 1, the battery forklift (hereinafter, simply referred to as “forklift”) 10 is provided with a cargo handling device 12 at the front portion of the vehicle body 11. A driver's seat 13 is provided near the center of the vehicle body 11. A drive wheel 14 as a front wheel is provided on the front portion of the vehicle body 11, and a steering wheel 15 as a rear wheel is provided on the rear portion of the vehicle body 11. A counterweight 16 is provided at the rear of the vehicle body 11. The counterweight 16 is for adjusting the weight of the vehicle and balancing the weight of the vehicle body 11.

The vehicle body 11 is provided with a head guard 17 that covers the upper part of the driver's seat 13. The head guard 17 is supported by a pair of left and right front pillars 18 and a pair of left and right rear pillars 19. A pair of left and right front pillars 18 are erected on the front portion of the vehicle body 11. As shown in FIG. 2, a pair of left and right rear pillars 19 are erected at the rear of the vehicle body 11.

As shown in FIG. 3, the forklift 10 includes a main controller 20 and a cargo handling device 12.
It is provided with a cargo handling mechanism 21 for operating the forklift 10, a drive mechanism 22 for traveling the forklift 10, and a key switch 23 for switching between an activated state and a stopped state of the forklift 10. Further, the forklift 10 is equipped with an obstacle detection device 24 that detects obstacles by ultrasonic waves.

The main controller 20 corresponds to a control unit and includes a calculation unit (CPU) 25 and a storage unit (memory) 26. The storage unit 26 stores a program or the like for operating the forklift 10. The calculation unit 25 performs a calculation using information input to the main controller 20, information such as a program stored in the storage unit 26, and the like. When the forklift 10 is activated by the key switch 23, the main controller 20 controls the drive mechanism 22 and the cargo handling mechanism 21 to cause the forklift 10 to perform cargo handling operations and traveling operations. On the other hand, when the forklift 10 is stopped by the key switch 23, the main controller 20 does not allow the forklift 10 to perform a cargo handling operation or a traveling operation.

As shown in FIG. 3, the obstacle detection device 24 includes an ultrasonic sensor unit 27 and a control ECU 28. As shown in FIG. 3, the ultrasonic sensor unit 27 of the present embodiment has two ultrasonic sensors, a first ultrasonic sensor 29 and a second ultrasonic sensor 30. That is, the ultrasonic sensor unit 27 is composed of a plurality of ultrasonic sensors.

The first ultrasonic sensor 29 and the second ultrasonic sensor 30 include a piezoelectric vibrator (not shown). The piezoelectric vibrator can convert an electric signal into a vibration and can also convert a vibration into an electric signal. When a transmission signal is input to the piezoelectric vibrator, the piezoelectric vibrator vibrates. When the piezoelectric vibrator vibrates, ultrasonic waves are transmitted from the first ultrasonic sensor 29 and the second ultrasonic sensor 30. The frequency of the ultrasonic wave transmitted from the first ultrasonic sensor 29 and the frequency of the ultrasonic wave transmitted from the second ultrasonic sensor 30 are the same.

When there is an obstacle ahead of the ultrasonic wave transmission direction, the transmitted ultrasonic wave hits the obstacle and is reflected to become a reflected wave. The piezoelectric vibrator vibrates when it receives a reflected wave and outputs a received signal. That is, the first ultrasonic sensor 29 and the second ultrasonic sensor 30 have a transmission function for transmitting ultrasonic waves and a reception function for receiving reflected waves. Since the piezoelectric vibrator is a transmission / reception type, it cannot receive reflected waves while the first ultrasonic sensor 29 and the second ultrasonic sensor 30 transmit ultrasonic waves. Further, the first ultrasonic sensor 29 and the second ultrasonic sensor 30 can receive not only the reflected wave of the ultrasonic wave transmitted by themselves but also the reflected wave of the ultrasonic wave transmitted by another ultrasonic sensor. Therefore, when the first ultrasonic sensor 29 and the second ultrasonic sensor 30 that transmit the ultrasonic waves and the first ultrasonic sensor 29 and the second ultrasonic sensor 30 that receive the reflected waves of the transmitted ultrasonic waves are the same. Some may be different.

In this embodiment, as shown in FIG. 2, the ultrasonic sensor units 27 are attached to a pair of left and right rear pillars 19, respectively. The left ultrasonic sensor unit 27 (27L) and the right ultrasonic sensor unit 27 (27R) have symmetrical shapes. Regarding the ultrasonic sensor unit 27, the left ultrasonic sensor unit 27 (27L) will be described, and for the right ultrasonic sensor unit 27 (27R), the description of the left ultrasonic sensor unit 27 (27L) will be incorporated. The explanation will be omitted.

As shown in FIG. 4A, the ultrasonic sensor unit 27 has a box-shaped support member 31 that supports the first ultrasonic sensor 29 and the second ultrasonic sensor 30. The first ultrasonic sensor 29 and the second ultrasonic sensor 30 are integrated by being supported by a support member 31. That is, the first ultrasonic sensor 29 and the second ultrasonic sensor 30 are integrated as an ultrasonic sensor unit 27. The support member 31 corresponds to an integrated member.

As shown in FIG. 4B, the support member 31 included in the ultrasonic sensor unit 27 includes a first side surface portion 32, a second side surface portion 33, a third side surface portion 34, and a fourth side surface portion 35. It has a flat surface portion 36, a bottom surface portion (not shown), and a mounting portion 37. The first side surface portion 32 supports the first ultrasonic sensor 29. The second side surface portion 33 has a surface orthogonal to the first side surface portion 32 and supports the second ultrasonic sensor 30. The third side surface portion 34 has a surface parallel to the first side surface portion 32, and the fourth side surface portion 35 has a surface parallel to the second side surface portion 33. The attachment portion 37 is a portion for attaching the ultrasonic sensor unit 27 to the pillar.

When the ultrasonic sensor unit 27 is attached to the rear pillar 19, the first side surface portion 32 to the fourth side surface portion 35 are vertical surfaces, and the flat surface portion 36 is a horizontal surface. Further, the ultrasonic sensor unit 27 is arranged so as to be as close as possible to the corner portion of the rear portion of the vehicle body 11. The pointing direction of the first ultrasonic sensor 29 is a direction orthogonal to the surface of the first side surface portion 32, and the pointing direction of the second ultrasonic sensor 30 is a direction orthogonal to the surface of the second side surface portion 33. Therefore, when the ultrasonic sensor unit 27 is attached to the rear pillar 19, the pointing direction of the first ultrasonic sensor 29 is the backward direction of the forklift 10, and the pointing direction of the second ultrasonic sensor 30 is orthogonal to the backward direction. To the left.

The first ultrasonic sensor 29 of the ultrasonic sensor unit 27 (27L) transmits ultrasonic waves to the rear of the vehicle body 11, and the second ultrasonic sensor 30 transmits ultrasonic waves to the left of the vehicle body 11. Incidentally, the first ultrasonic sensor 29 of the ultrasonic sensor unit 27 (27R) transmits ultrasonic waves to the rear of the vehicle body 11, and the second ultrasonic sensor 30 transmits ultrasonic waves to the right of the vehicle body 11. Therefore, the obstacles detected by the obstacle detection device 24 are obstacles existing behind the forklift 10 and on the left and right sides.

As shown in FIG. 5, behind the forklift 10, there is a first detection range A capable of detecting an obstacle by the first ultrasonic sensor 29 of the ultrasonic sensor unit 27 (27L) alone. The first detection range A of the first ultrasonic sensor 29 exists on the left side behind the forklift 10. The second detection range B of the second ultrasonic sensor 30 exists on the left side of the forklift 10. In the present embodiment, the first detection range A of the first ultrasonic sensor 29 is set within a range within 0.6 m behind the forklift 10 from the first ultrasonic sensor 29. The second detection range B of the second ultrasonic sensor 30 is set within 0.6 m to the left of the forklift 10 from the second ultrasonic sensor 30. That is, the ultrasonic waves transmitted from the first ultrasonic sensor 29 and the second ultrasonic sensor 30 can reach up to 0.6 m on the left side of the forklift 10. In the present embodiment, the first detection range A of the first ultrasonic sensor 29 and the second detection range B of the second ultrasonic sensor 30 are arranged so as to slightly overlap each other.

By the way, since the support member 31 includes the first side surface portion 32, the first detection range A is defined by the virtual line M1 that extends the second side surface portion 33 of the support member 31 of the ultrasonic sensor unit 27 to the rear. It can be divided into two. The right side of the virtual line M1 in the first detection range A is the first unreceivable area A1, and the left side of the virtual line M1 is the first receivable area A2. That is, the first detection range A includes the first unreceivable area A1 and the first receivable area A2. The first unreceivable area A1 is an area in which the second ultrasonic sensor 30 cannot receive the reflected wave of the first ultrasonic sensor 29 even if an obstacle exists in the first unreceivable area A1. That is, the first unreceivable region A1 is a region in which the reflected wave of the first ultrasonic sensor 29 cannot be received by the second ultrasonic sensor 30. As shown in FIG. 4B, the first side surface portion 32 of the support member 31 corresponds to the first shield forming the first unreceivable region A1.

The first receivable area A2 is an area in which the second ultrasonic sensor 30 can receive the reflected wave of the first ultrasonic sensor 29 when an obstacle exists in the first receivable area A2. When an obstacle exists in the first receivable area A2, the second ultrasonic sensor 30 can receive the reflected wave of the first ultrasonic sensor 29.

Since the support member 31 includes the second side surface portion 33, the second detection range B is bisected with the virtual line M2 extending the first side surface portion 32 of the support member 31 of the ultrasonic sensor unit 27 to the left as a boundary. can. The front side of the virtual line M2 in the second detection range B is the second unreceivable area B1, and the rear side of the virtual line M2 is the second receivable area B2. That is, the second detection range B includes the second unreceivable area B1 and the second receivable area B2. The second unreceivable area B1 is an area in which the first ultrasonic sensor 29 cannot receive the reflected wave of the second ultrasonic sensor 30 even if an obstacle exists in the second unreceivable area B1. That is, the second unreceivable region B1 is a region in which the reflected wave of the second ultrasonic sensor 30 cannot be received by the first ultrasonic sensor 29. As shown in FIG. 4B, the second side surface portion 33 of the support member 31 corresponds to the second shield forming the second unreceivable region B1.

The second receivable area B2 is an area in which the first ultrasonic sensor 29 can receive the reflected wave of the second ultrasonic sensor 30 when an obstacle exists in the second receivable area B2. When an obstacle exists in the second receivable area B2, the first ultrasonic sensor 29 can receive the reflected wave of the second ultrasonic sensor 30.

As shown in FIG. 5, the ultrasonic sensor unit 27 (27R) on the right side has a first detection range C of the first ultrasonic sensor 29 and a second detection range D of the first ultrasonic sensor 29. The detection range C exists on the right side of the first detection range A, and can be divided into a first unreceivable area C1 and a first receivable area C2 by a virtual line M3. The second detection range D is divided into a second unreceivable area D1 and a second receivable area D2 by the virtual line M4. The first unreceivable area C1 and the first receivable area C2 of the first detection range C are symmetrical with the first unreceivable area A1 and the first receivable area A2 of the first detection range A. The second unreceivable area D1 and the second receivable area D2 of the second detection range D are symmetrical with the second unreceivable area B1 and the second receivable area B2 of the second detection range B.

The control ECU 28 is an electronic control unit including a CPU and a memory including a RAM and a ROM. Various programs for controlling the obstacle detection device 24 are stored in the memory. The control ECU 28 may include dedicated hardware that executes at least a part of the various processes, for example, an integrated circuit (ASIC) for a specific application. The control ECU 28 may be configured as one or more processors operating according to a computer program, one or more dedicated hardware circuits such as an ASIC, or a circuit including a combination thereof. The processor includes a CPU and a memory such as RAM and ROM. The memory stores a program code or a command configured to cause the CPU to execute the process. Memory, or computer-readable medium, includes anything that can be accessed by a general purpose or dedicated computer. The control ECU 28 is connected to the main controller 20 so as to be able to communicate with each other. In this embodiment, the control ECU 28 is separate from the main controller 20.

As shown in FIG. 3, the control ECU 28 includes a transmission command unit 38 and a detection unit 39 connected to the transmission command unit 38. The transmission command unit 38 and the detection unit 39 are connected to the first ultrasonic sensor 29 and the second ultrasonic sensor 30, respectively.

The transmission command unit 38 controls the transmission of ultrasonic waves by the first ultrasonic sensor 29 and the second ultrasonic sensor 30. Specifically, the transmission command unit 38 outputs a transmission signal to the first ultrasonic sensor 29 to cause the first ultrasonic sensor 29 to transmit ultrasonic waves. Similarly, the transmission command unit 38 outputs a transmission signal to the second ultrasonic sensor 30 to cause the second ultrasonic sensor 30 to transmit ultrasonic waves.

While the forklift 10 is activated by the key switch 23, the transmission command unit 38 alternately repeatedly outputs transmission signals to the first ultrasonic sensor 29 and the second ultrasonic sensor 30 at predetermined intervals. The first ultrasonic sensor 29 and the second ultrasonic sensor 30 transmit ultrasonic waves each time a transmission signal is input from the transmission command unit 38. Therefore, the output interval of the transmission signal by the transmission command unit 38 is the same as the transmission interval of the ultrasonic waves by at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30. As for the ultrasonic transmission interval of the present embodiment, when an obstacle exists within the first detection range A, at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30 transmits ultrasonic waves. Then, the reflected wave is set to be received until at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30 transmits the ultrasonic wave.

When there is an obstacle within the first detection range A of the first ultrasonic sensor 29, the ultrasonic wave transmitted from the first ultrasonic sensor 29 hits the obstacle and is reflected. Similarly, when there is an obstacle within the second detection range B of the second ultrasonic sensor 30, the ultrasonic wave transmitted from the second ultrasonic sensor 30 hits the obstacle and is reflected. When the first ultrasonic sensor 29 receives at least one of the reflected wave of the ultrasonic wave transmitted by the first ultrasonic sensor 29 and the reflected wave of the ultrasonic wave transmitted by the second ultrasonic sensor 30, the first ultrasonic sensor 29 sends a received signal to the detection unit 39. Send. Similarly, when the second ultrasonic sensor 30 receives at least one of the reflected wave of the ultrasonic wave transmitted by the first ultrasonic sensor 29 and the reflected wave of the ultrasonic wave transmitted by the second ultrasonic sensor 30, the detection unit 39 receives the reflected wave. Send a received signal.

The detection unit 39 detects an obstacle from the reception result of the reflected wave by the first ultrasonic sensor 29 and the second ultrasonic sensor 30. The detection unit 39 has a discriminating unit 40 that determines the presence or absence of obstacles behind and to the side of the forklift 10, and an obstacle when the discriminating unit 40 determines that there is an obstacle behind or to the side of the forklift 10. It has an estimation unit 41 for determining or estimating a direction and for determining or estimating an area where no obstacle exists in the detection range. In the present embodiment, "judgment" is a case where there is a high possibility that an obstacle exists (does not exist) in the area, and "estimation" means that there is a possibility that an obstacle exists (does not exist) in the area than "judgment". It is assumed that it is low.

By identifying an ultrasonic sensor that is a source of reflected waves, the estimation unit 41 determines or estimates an obstacle region with respect to the obstacle detection device 24 from the detection range of the identified ultrasonic sensor. Further, the estimation unit 41 determines or estimates a region where no obstacle exists from the detection range of the identified ultrasonic sensor. The procedure for estimating a specific area with an obstacle and determining or estimating an area without an obstacle by the estimation unit 41 will be described later. The estimation unit 41 outputs the determined or estimated direction to the main controller 20. The main controller 20 does not allow the forklift 10 to perform a running operation to the area determined to have an obstacle (running prohibited). The main controller 20 warns against the traveling operation of the forklift 10 to the area estimated to have an obstacle (travel warning). Further, the estimation unit 41 allows the forklift 10 to travel to an area determined to be an area without obstacles (travel permission).

The traveling operation of the forklift 10 to be controlled for determining or estimating an area with an obstacle is straight backward, turning backward, and diagonal backward. The straight-ahead retreat is a traveling operation in which the forklift 10 travels linearly backward with the steering angle of the steering wheels 15 being 0 ° or the steering angle being substantially 0 °. Specifically, the forklift 10 is in a state of traveling toward the first unreceivable region A1 (C1). The turning retreat is a traveling operation in which the forklift 10 turns and moves backward while the steering angle of the steering wheel 15 is maximized or close to the maximum. Specifically, the forklift 10 is in a state of traveling toward the second unreceivable region B1 (D1). The oblique retreat is a traveling operation in which the forklift 10 travels diagonally backward at a steering angle excluding the steering angle for straight retreat and the steering angle for turning retreat. Specifically, the forklift 10 is in a state of traveling toward the first receivable area A2 (C2) or the second receivable area B2 (D2). In addition, the traveling operation of retreating by steering including turning retreat and oblique retreat is referred to as steering retreat.

Next, the procedure for detecting obstacles will be described. When the forklift 10 is activated, the obstacle detection device 24 starts detecting obstacles. The obstacle detection device 24 first determines the presence or absence of obstacles behind and to the side of the forklift 10. Here, the detection of obstacles by the ultrasonic sensor unit 27 (27L) on the left will be described.

As shown in FIG. 6, the transmission command unit 38 transmits ultrasonic waves from the first ultrasonic sensor 29 (step S01). The ultrasonic wave transmitted from the first ultrasonic sensor 29 is referred to as the first ultrasonic wave Us1. The ultrasonic wave transmitted from the second ultrasonic sensor 30 is referred to as the second ultrasonic wave Us2.

When the first ultrasonic wave Us1 is transmitted from the first ultrasonic sensor 29, the detection unit 39 determines whether or not the reflected wave has been received (step S02). When there is an obstacle in the first detection range A, the first ultrasonic wave Us1 hits the obstacle and is reflected. Therefore, at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30 is the first ultrasonic wave Us1. Receives the reflected wave Ur1. When there is no obstacle in the first detection range A of the first ultrasonic sensor 29, the first ultrasonic wave Us1 is attenuated without hitting the obstacle, so that the first ultrasonic sensor 29 and the second ultrasonic sensor 30 reflect. Does not receive wave Ur1. When the discriminating unit 40 determines that the reflected wave has been received in step S02, at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30 has received the reflected wave Ur1, and the obstacle is within the first detection range A. It can be estimated that there is something.

When the determination unit 40 determines that the reflected wave has been received in step S02, the process proceeds to determine whether the first ultrasonic sensor 29 has received the reflected wave Ur1 (step S03). After step S03, it is determined whether or not the first ultrasonic sensor 29 has received the reflected wave Ur1 (step S04). When the discriminating unit 40 determines in step S04 that the first ultrasonic sensor 29 has received the reflected wave Ur1, the estimating unit 41 estimates that the obstacle is in the first unreceivable region A1 (step S05). That is, the estimation unit 41 estimates the direction of the obstacle from the reception result of the reflected wave Ur1 of the ultrasonic wave transmitted from the first ultrasonic sensor 29. In this case, since the first ultrasonic sensor 29 receives the reflected wave Ur1, it is presumed that the obstacle is in the first unreceivable region A1, but the second ultrasonic sensor 30 receives the reflected wave Ur1. Since it is unknown whether or not they are present, there is a possibility that there is an obstacle in the first receivable area A2.

For example, as shown in FIG. 7A, when there is an obstacle G1 in the first unreceivable area A1 in the first detection range A of the first ultrasonic sensor 29, the first ultrasonic wave Us1 hits the obstacle G1. Since it is reflected, the first ultrasonic sensor 29 receives the reflected wave Ur1 of the first ultrasonic wave Us1. As shown in FIG. 7A, when the obstacle G1 is in the first unreceivable region A1, the ultrasonic sensor unit 27 blocks the reflected wave Ur1 and the second ultrasonic sensor 30 reflects the first ultrasonic wave Us1. No wave Ur1 is received.

Next, the process proceeds to determine whether or not the second ultrasonic sensor 30 has received the reflected wave Ur1 (step S06). After step S06, it is determined whether or not the second ultrasonic sensor 30 has received the reflected wave Ur1 (step S07). When the discriminating unit 40 determines in step S07 that the second ultrasonic sensor 30 has received the reflected wave Ur1, the estimating unit 41 determines that the obstacle is in the first receivable area A2 (step S08). In this case, since both the first ultrasonic sensor 29 and the second ultrasonic sensor 30 are receiving the reflected wave Ur1, it is determined that the obstacle is in the first receivable area A2. In this case, since it is determined that there is an obstacle, the probability that the obstacle is in the first receivable area A2 is higher than when it is estimated that there is an obstacle.

For example, as shown in FIG. 7B, when there is an obstacle G2 in the first receivable area A2 in the first detection range A of the first ultrasonic sensor 29, the first ultrasonic wave Us1 hits the obstacle G2. Since it is reflected, the second ultrasonic sensor 30 receives the reflected wave Ur1 of the first ultrasonic wave Us1. As shown in FIG. 7B, when the obstacle G2 is in the first receivable area A2, the ultrasonic sensor unit 27 does not block the reflected wave Ur1, and the second ultrasonic sensor 30 is the first ultrasonic wave. The reflected wave Ur1 of Us1 can be received. Further, the first ultrasonic sensor 29 can also receive the reflected wave (not shown) of the first ultrasonic wave Us1.

On the other hand, if the discriminating unit 40 determines in step S07 that the second ultrasonic sensor 30 has not received the reflected wave Ur1, the estimating unit 41 estimates that the obstacle is not in the first receivable area A2 (step S09). ). In this case, since the first ultrasonic sensor 29 receives the reflected wave Ur1 and the second ultrasonic sensor 30 does not receive the reflected wave Ur1, it is estimated that the obstacle is not in the first receivable area A2. Therefore, it can be determined that the obstacle is likely to be in the first unreceivable area A1.

Further, in step S02, when the first ultrasonic sensor 29 and the second ultrasonic sensor 30 do not receive the reflected wave Ur1 (NO in step S02), the estimation unit 41 has an obstacle in the first unreceivable area A1. It is determined that there is no obstacle, and it is estimated that there is no obstacle in the first receivable area A2 (step S10). If the first ultrasonic sensor 29 does not receive the reflected wave Ur1 in step S04 (NO in step S04), the estimation unit 41 determines that there is no obstacle in the first unreceivable area A1 and receives the first reception. It is estimated that there are no obstacles in the possible area A2 (step S10).

Next, the transmission command unit 38 transmits ultrasonic waves from the second ultrasonic sensor 30 (step S11). The ultrasonic wave transmitted from the second ultrasonic sensor 30 is referred to as the second ultrasonic wave Us2.

When the second ultrasonic wave Us2 is transmitted from the second ultrasonic sensor 30, the detection unit 39 determines whether or not the reflected wave has been received (step S12). When there is an obstacle in the second detection range B, the second ultrasonic wave Us2 hits the obstacle and is reflected. Therefore, at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30 is the second ultrasonic wave Us2. Receives the reflected wave Ur2. When there is no obstacle in the second detection range B of the second ultrasonic sensor 30, the second ultrasonic Us2 is attenuated without hitting the obstacle, so that the first ultrasonic sensor 29 and the second ultrasonic sensor 30 reflect. Does not receive wave Ur2. When the discriminating unit 40 determines that the reflected wave has been received in step S12, at least one of the first ultrasonic sensor 29 and the second ultrasonic sensor 30 has received the reflected wave Ur2, and the obstacle is within the second detection range B. It can be estimated that there is something.

When the discriminating unit 40 determines that the reflected wave has been received in step S12, the process proceeds to determine whether the second ultrasonic sensor 30 has received the reflected wave Ur2 (step S13). After step S13, it is determined whether or not the second ultrasonic sensor 30 has received the reflected wave Ur2 (step S14). When the discriminating unit 40 determines in step S14 that the second ultrasonic sensor 30 has received the reflected wave Ur2, the estimating unit 41 estimates that the obstacle is in the second unreceivable region B1 (step S15). That is, the estimation unit 41 estimates the direction of the obstacle from the reception result of the reflected wave Ur2 of the ultrasonic wave transmitted from the second ultrasonic sensor 30. In this case, since the second ultrasonic sensor 30 receives the reflected wave Ur2, it is presumed that the obstacle is in the second unreceivable region B1, but the first ultrasonic sensor 29 receives the reflected wave Ur2. Since it is unknown whether or not they are present, there remains a possibility that there is an obstacle in the second receivable area B2.

For example, as shown in FIG. 7C, when there is an obstacle G3 in the second unreceivable region B1 in the second detection range B of the second ultrasonic sensor 30, the second ultrasonic wave Us2 hits the obstacle G3. Since it is reflected, the second ultrasonic sensor 30 receives the reflected wave Ur2 of the second ultrasonic wave Us2. As shown in FIG. 7C, when the obstacle G3 is in the second unreceivable region B1, the ultrasonic sensor unit 27 blocks the reflected wave Ur2, and the first ultrasonic sensor 29 reflects the second ultrasonic wave Us2. It does not receive waves Ur2.

Next, the process proceeds to determine whether or not the first ultrasonic sensor 29 has received the reflected wave Ur2 (step S16). After step S06, it is determined whether or not the second ultrasonic sensor 30 has received the reflected wave Ur1 (step S17). When the discriminating unit 40 determines in step S17 that the first ultrasonic sensor 29 has received the reflected wave Ur2, the estimating unit 41 determines that the obstacle is in the second receivable area B2 (step S18). In this case, since both the first ultrasonic sensor 29 and the second ultrasonic sensor 30 are receiving the reflected wave Ur2, it is determined that the obstacle is in the second receivable area B2. In this case, since it is determined that there is an obstacle, the probability that the obstacle is in the second receivable area B2 is higher than when it is estimated that there is an obstacle.

For example, as shown in FIG. 7D, when there is an obstacle G4 in the second receivable area B2 in the second detection range B of the second ultrasonic sensor 30, the second ultrasonic wave Us2 hits the obstacle G4. Since it is reflected, the first ultrasonic sensor 29 receives the reflected wave Ur2 of the second ultrasonic wave Us2. As shown in FIG. 7D, when the obstacle G4 is in the second receivable area B2, the ultrasonic sensor unit 27 does not block the reflected wave Ur2, and the first ultrasonic sensor 29 is the second ultrasonic wave. The reflected wave Ur2 of Us2 can be received. Further, the second ultrasonic sensor 30 can also receive the reflected wave (not shown) of the second ultrasonic wave Us2.

On the other hand, when the discriminating unit 40 determines in step S17 that the first ultrasonic sensor 29 has not received the reflected wave Ur2, the estimating unit 41 estimates that the obstacle is not in the second receivable area B2 (step S19). ). In this case, since the second ultrasonic sensor 30 receives the reflected wave Ur2 and the first ultrasonic sensor 29 does not receive the reflected wave Ur2, it is determined that the obstacle is not in the second receivable area B2. Therefore, it can be determined that the obstacle is likely to be in the second unreceivable area B1.

Further, in step S12, when the first ultrasonic sensor 29 and the second ultrasonic sensor 30 do not receive the reflected wave Ur2 (NO in step S12), the estimation unit 41 has an obstacle in the second unreceivable region B1. It is determined that there is no obstacle, and it is estimated that there is no obstacle in the second receivable area B2 (step S20). If the second ultrasonic sensor 30 does not receive the reflected wave Ur2 in step S14 (NO in step S14), the estimation unit 41 determines that there is no obstacle in the second unreceivable region B1 and receives the second reception. It is estimated that there are no obstacles in the possible area B2 (step S20).

In FIGS. 7 (a) to 7 (d), the detection of obstacles by the left ultrasonic sensor unit 27L has been described, but the detection of obstacles by the right ultrasonic sensor unit 27R is also carried out by the left ultrasonic sensor. It is the same except that the left and right sides are different from the detection of obstacles by the unit 27L.

Next, the operation of the obstacle detection device 24 according to the present embodiment will be described. Hereinafter, a case where there are no obstacles in the first detection range C and the second detection range D and the obstacle detection device 24 determines or estimates the presence or absence of obstacles in the first detection range A and the second detection range B will be described. .. When the obstacle detection device 24 determines or estimates the presence or absence of obstacles in the first detection range A and the second detection range B, the transmission command unit 38 alternates from the first ultrasonic sensor 29L and the second ultrasonic sensor 30L. To transmit ultrasonic waves.

When the discriminating unit 40 determines that the reflected wave of the ultrasonic sensor has been received, the estimating unit 41 determines from the ultrasonic sensor that transmitted the ultrasonic wave and the ultrasonic sensor that received the reflection of the transmitted ultrasonic wave. In addition to determining or estimating an area (position) with obstacles, an area without obstacles is determined or estimated.

For example, if the estimation unit 41 estimates that the obstacle is in the first unreceivable area A1 of the first detection range A (see step S05), the main controller 20 warns against the straight backward movement of the forklift 10. I do. In this case, if the forklift 10 is moving straight and backward, the main controller 20 performs a warning control.

For example, when the estimation unit 41 determines that the obstacle is in the first receivable area A2 of the first detection range A (see step S08), the main controller 20 controls to prohibit the left oblique retreat. .. In this case, when the forklift 10 tilts backward to the left, the main controller 20 controls to brake or stop the forklift 10.

For example, if the estimation unit 41 estimates that there is no obstacle in the first receivable area A2 of the first detection range A (see step S09), the main controller 20 warns against the left oblique retreat. I do. In this case, when the forklift 10 tilts backward to the left, the main controller 20 controls to warn. Further, in this case, since it is determined that there is a high possibility that the obstacle is in the first unreceivable area A1, if the forklift 10 is moving backward and backward, the main controller 20 controls to prohibit the straight backward movement.

For example, if the estimation unit 41 determines that there is no obstacle in the first unreceivable area A1 and estimates that there is no obstacle in the first receivable area A2 (see step S10), the main controller 20 goes straight. Controls to allow retreat and controls to warn against left backward skew. In this case, even if the forklift 10 retreats straight, the main controller 20 controls to allow the forklift 10 to retreat straight, and when the forklift 10 recedes diagonally to the left, the main controller 20 controls to warn.

For example, if the estimation unit 41 estimates that the obstacle is in the second unreceivable area B1 of the second detection range B (see step S15), the main controller 20 warns against the left turning retreat of the forklift 10. Control to do. In this case, when the forklift 10 turns to the left and retracts, the main controller 20 controls to warn.

For example, if the estimation unit 41 estimates that the obstacle is in the second receivable area B2 of the second detection range B (see step S18), the main controller 20 controls to prohibit the left oblique retreat. .. In this case, when the forklift 10 tilts backward to the left, the main controller 20 controls to brake or stop the forklift 10 in order to avoid interference with obstacles.

For example, if the estimation unit 41 estimates that the obstacle is not in the second receivable area B2 of the second detection range B (see step S19), the main controller 20 warns against the left oblique retreat. I do. In this case, when the forklift 10 tilts backward to the left, the main controller 20 controls to warn. Further, in this case, since it is determined that there is a high possibility that the obstacle is in the first unreceivable area A1, if the forklift 10 is turning backward, the main controller 20 controls to prohibit turning backward.

For example, if the estimation unit 41 determines that there is no obstacle in the second unreceivable area B1 and estimates that there is no obstacle in the second receivable area B2 (see step S20), the main controller 20 is on the left. Control is performed to allow the turning retreat of the vehicle, and control is performed to warn against the diagonal retreat on the left. In this case, even if the forklift 10 turns to the left, the main controller 20 controls to allow the forklift 10 to turn left and straight forward, and when the forklift 10 turns to the left diagonally, the main controller 20 controls to warn.

When there are no obstacles in the first detection range A and the second detection range B and the obstacle areas in the first detection range C and the second detection range D are estimated, the first is the case except that the left and right are different. It is the same as the case of estimating the area of the obstacle in the detection range A and the second detection range B. Then, the left ultrasonic sensor unit 27 (27L) and the right ultrasonic sensor unit 27 (27R) are operated at the same time to detect obstacle regions in the first detection ranges A and C and the second detection ranges B and D. It may be judged or estimated.

The obstacle detection device 24 according to the present embodiment has the following effects.
(1) The detection unit 39 detects an obstacle based on the reception results of the reflected waves of the first ultrasonic sensor 29 and the second ultrasonic sensor 30, recognizes the reception of the reflected waves of the first ultrasonic sensor 29, and recognizes the reception of the reflected waves of the first ultrasonic sensor 29. When the first ultrasonic sensor 29 does not receive the reflected wave of the first ultrasonic sensor 29, it is determined that there is no obstacle in the first unreceivable region A1. Further, the detection unit 39 recognizes the reception of the reflected wave of the second ultrasonic sensor 30, and when the second ultrasonic sensor 30 does not receive the reflected wave of the second ultrasonic sensor 30, the detection unit 39 enters the second unreceivable region B1. Determine that there are no obstacles. That is, based on the reception results of the reflected waves of the first ultrasonic sensor 29 and the second ultrasonic sensor 30, it is possible to determine a region without obstacles in the first detection range A and the second detection range B. By adopting a configuration in which the obstacle detection device 24 does not easily interfere with the reflected waves of the first ultrasonic sensor 29 and the second ultrasonic sensor 30, an unobstructed region can be determined by a small number of ultrasonic sensors. Further, since the area where the first ultrasonic sensor 29 and the second ultrasonic sensor 30 overlap is small, the number of ultrasonic sensors can be reduced, and the obstacle detection device 24 can be miniaturized.

(2) When the second ultrasonic sensor 30 receives the reflected wave Ur1 of the first ultrasonic sensor 29, it can be determined that there is an obstacle in the first receivable area A2, and the first ultrasonic sensor 29 is the second. 2 When receiving the reflected wave Ur2 of the ultrasonic sensor 30, it is determined that there is an obstacle in the second receivable area B2. Therefore, based on the reception results of the reflected waves of the first ultrasonic sensor 29 and the second ultrasonic sensor 30, the area where there is an obstacle in the first detection range A and the second detection range B is determined by a few ultrasonic sensors. Can be done.

(3) By providing the obstacle detection device 24 with the first side surface portion 32 as the first shield, the first receivable area A2 and the first unreceivable area A1 are surely formed in the first detection range A. be able to. Further, by providing the obstacle detection device 24 with the second side surface portion 33 as the second shield, the second receivable area B2 and the second unreceivable area B1 are surely formed in the second detection range B. Can be done.

(4) A support member 31 is provided as an integrated member that integrates the first ultrasonic sensor 29 and the second ultrasonic sensor 30. Therefore, the first ultrasonic sensor 29 and the second ultrasonic sensor 30 can be integrated by the support member 31. As a result, it is easier to attach the first ultrasonic sensor 29 and the second ultrasonic sensor 30 to the forklift 10 as compared with the case where the first ultrasonic sensor 29 and the second ultrasonic sensor 30 are not integrated. Become.

(5) The first direction is the reverse direction, which is one of the moving directions of the forklift 10, and the second direction is the left-right direction, which is a direction that does not match the reverse direction. Further, a main controller 20 is provided as a control unit for controlling the traveling of the forklift 10. When the first ultrasonic sensor 29 receives the reflected wave of the first ultrasonic sensor 29, the detection unit 39 determines that there is an obstacle in the first unreceivable area A1, and the main controller 20 lifts the moving forklift 10. Controls braking or stopping. As a result, since the forklift 10 is braked or stopped, it does not interfere with the obstacle in the first unreceivable area A1.

(6) The forklift 10 as a moving body has a large maximum steering angle and a small turning radius as compared with an automobile. The obstacle detection device 24 can estimate the presence or absence of obstacles on the side of the vehicle body 11, and thus has an effect suitable for the actual usage of the forklift 10.

(Second Embodiment)
Next, the obstacle detection device according to the second embodiment will be described. In the present embodiment, a step of determining whether or not the reflected wave of the first ultrasonic wave is received by the second ultrasonic sensor and whether or not the first ultrasonic sensor has received the reflected wave of the second ultrasonic wave are determined. It differs from the first embodiment in that the step of determining and the step are omitted. The configuration of the obstacle detection device is the same as that of the first embodiment, and the description of the first embodiment is incorporated and a common reference numeral is used.

The procedure for detecting an obstacle by the obstacle detection device 24 according to the second embodiment follows the flow chart of FIG. Steps S101 to S105 in FIG. 8 are the same as S01 to S05 of the first embodiment. In the present embodiment, it is determined whether or not the reflected wave Ur1 of the first ultrasonic sensor 29 is received, and whether or not the first ultrasonic sensor 29 has received the reflected wave Ur1 of the first ultrasonic sensor 29. .. In the present embodiment, it is not determined whether or not the second ultrasonic sensor 30 has received the reflected wave Ur1 of the first ultrasonic sensor 29.

When the determination unit 40 determines in step S104 that the first ultrasonic sensor 29 has received the reflected wave Ur1 of the first ultrasonic sensor 29, the estimation unit 41 estimates that the obstacle is in the first unreceivable region A1. (Step S105). That is, the estimation unit 41 estimates the direction of the obstacle from the reception result of the reflected wave Ur1 of the ultrasonic wave transmitted from the first ultrasonic sensor 29. In this case, since the first ultrasonic sensor 29 receives the reflected wave Ur1, it is presumed that the obstacle is in the first unreceivable region A1, but the second ultrasonic sensor 30 receives the reflected wave Ur1. Since it is unknown whether or not they are present, there is a possibility that there is an obstacle in the first receivable area A2.

Further, in step S102, when the reflected wave Ur1 of the first ultrasonic sensor 29 is not received (NO in step S102), the estimation unit 41 determines that there is no obstacle in the first unreceivable region A1 (step S106). ). If the first ultrasonic sensor 29 does not receive the reflected wave Ur1 in step S104 (NO in step S104), the estimation unit 41 determines that there is no obstacle in the first unreceivable region A1 (step S106). ..

Further, steps S107 to S111 in FIG. 8 are the same as S11 to S15 of the first embodiment. In the present embodiment, it is determined whether or not the reflected wave Ur2 of the second ultrasonic sensor 30 is received, and whether or not the second ultrasonic sensor 30 has received the reflected wave Ur2 of the second ultrasonic sensor 30. .. In the present embodiment, it is not determined whether or not the first ultrasonic sensor 29 has received the reflected wave Ur2 of the second ultrasonic sensor 30.

When the discriminating unit 40 determines in step S110 that the second ultrasonic sensor 30 has received the reflected wave Ur2 of the second ultrasonic sensor 30, the estimating unit 41 estimates that the obstacle is in the second unreceivable region B1. (Step S111). That is, the estimation unit 41 estimates the direction of the obstacle from the reception result of the reflected wave Ur2 of the ultrasonic wave transmitted from the second ultrasonic sensor 30. In this case, since the second ultrasonic sensor 30 receives the reflected wave Ur2, it is presumed that the obstacle is in the second unreceivable region B1, but the first ultrasonic sensor 29 receives the reflected wave Ur2. Since it is unknown whether or not they are present, there remains a possibility that there is an obstacle in the second receivable area B2.

Further, in step S108, when the reflected wave Ur2 of the second ultrasonic sensor 30 is not received (NO in step S108), the estimation unit 41 determines that there is no obstacle in the second unreceivable region B1 (step S112). ). If the second ultrasonic sensor 30 does not receive the reflected wave Ur2 in step S110 (NO in step S110), the estimation unit 41 determines that there is no obstacle in the second unreceivable region B1 (step S112). ..

For example, if the estimation unit 41 estimates that the obstacle is in the first unreceivable area A1 of the first detection range A (see step S105), the main controller 20 warns against the straight backward movement of the forklift 10. I do. In this case, if the forklift 10 is moving straight and backward, the main controller 20 performs a warning control.

For example, when the estimation unit 41 determines that there is no obstacle in the first unreceivable area A1 (see step S106), the main controller 20 controls to allow straight-ahead retreat. In this case, even if the forklift 10 goes straight and retreats, the main controller 20 controls to allow the forklift 10 to go straight and retreat.

For example, if the estimation unit 41 estimates that the obstacle is in the second unreceivable area B1 of the second detection range B (see step S111), the main controller 20 warns against the left steering retreat of the forklift 10. Control to do. In this case, when the forklift 10 steers backward to the left, the main controller 20 controls to warn.

For example, if the estimation unit 41 estimates that the obstacle is not in the second unreceivable area B1 of the second detection range B (see step S112), the main controller 20 controls to allow the left steering retreat. In this case, even if the forklift 10 steers backward to the left, the main controller 20 controls to allow the left steering backward.

When there are no obstacles in the first detection range A and the second detection range B and the obstacle areas in the first detection range C and the second detection range D are estimated, the first is the case except that the left and right are different. It is the same as the case of estimating the area of the obstacle in the detection range A and the second detection range B. Then, the left ultrasonic sensor unit 27 (27L) and the right ultrasonic sensor unit 27 (27R) are operated at the same time to detect obstacle regions in the first detection ranges A and C and the second detection ranges B and D. It may be judged or estimated.

According to the present embodiment, as in the first embodiment, the presence or absence of an obstacle can be estimated by using as few sensors as possible. When the obstacle is in the first unreceivable area A1 by determining whether or not the reflected wave Ur1 of the first ultrasonic sensor 29 is received and whether or not the first ultrasonic sensor 29 has received the reflected wave Ur1. It can be estimated, and it can be determined that there is no obstacle in the first unreceivable area A1. Further, by determining whether or not the reflected wave Ur2 of the second ultrasonic sensor 30 is received and whether or not the second ultrasonic sensor 30 has received the reflected wave Ur2, the obstacle is placed in the second unreceivable area B1. It can be estimated that there is, and it can be determined that there is no obstacle in the second unreceivable area B1.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the invention. For example, the present invention may be modified as follows.

○ In the above embodiment, the first ultrasonic sensor and the second ultrasonic sensor are integrated by the support member, but the present invention is not limited to this. A first ultrasonic sensor and a second ultrasonic sensor may be provided separately.
○ In the above embodiment, an ultrasonic sensor unit having a first ultrasonic sensor and a second ultrasonic sensor is provided on the rear pillar of the forklift, but this is not the case. An ultrasonic sensor unit may be provided on a counterweight or a vehicle body. Alternatively, the first ultrasonic sensor and the second ultrasonic sensor may be directly attached to any of the pillar, the vehicle body, and the counterweight.
○ In the above embodiment, the first direction is the reverse direction of the forklift and the second direction is the left-right direction, but the present invention is not limited to this. For example, the first direction may be the front of the moving body and the second direction may be the upward direction, and the first and second directions are in specific directions if the second direction does not match the first direction. Not limited.
○ In the above embodiment, the first shield forming the first unreceivable area and the second shield forming the second unreceivable area are provided, but the first shield and the second shield are indispensable. Is not a requirement. A first unreceivable area and a first receivable area can be set in the first detection range of the first ultrasonic sensor, and a second unreceivable area and a second receivable area can be set in the second detection range of the second ultrasonic sensor. If the above can be set, it is not necessary to provide the first shield and the second shield. When the first shield and the second shield are provided, the structures of the first shield and the second shield are not particularly limited.
○ In the above embodiment, the box-shaped support member is exemplified as the integrated member, but the integrated member is not limited to this. The integrated member may be, for example, a rod-shaped member or a plate-shaped member, and is free as long as it is a member capable of integrating the first ultrasonic sensor and the second ultrasonic sensor.
○ In the above embodiment, the forklift of an industrial vehicle is illustrated as a moving body, but the moving body is not limited to the forklift. The moving body may be, for example, a towing tractor or an automatic guided vehicle, and the present invention can be applied to a vehicle having a relatively large steering angle of the steering wheels.
○ In the above embodiment, an example is shown in which a warning for a running motion and a running motion of a forklift are allowed or prohibited depending on the result of determination or estimation, but the processing method thereof may be appropriately changed as necessary. ..

10 Battery forklift 11 Body 12 Cargo handling device 20 Main controller 24 Obstacle detection device 27 (27L) Ultrasonic sensor unit (left)
27 (27R) Ultrasonic sensor unit (right)
28 Control ECU
29 First ultrasonic sensor 30 Second ultrasonic sensor 31 Support member 32 First side surface (first shield)
33 Second side surface (second shield)
38 Transmission command unit 39 Detection unit 40 Discrimination unit 41 Estimating unit A, C 1st detection range A1, C1 1st unreceivable area A2, C2 1st receivable area B, D 2nd detection range B1, D1 2nd unreceivable Area B2, D2 Second receivable area G1, G2, G3, G4 Obstacles M1, M2, M3, M4 Virtual line

Claims (5)

A plurality of ultrasonic sensors mounted on a moving body and having a transmitting function for transmitting ultrasonic waves and a receiving function for receiving reflected waves reflected by obstacles.
A transmission command unit that controls the transmission of ultrasonic waves by the plurality of ultrasonic sensors, and
In an obstacle detection device for a moving body, which comprises a detection unit that detects an obstacle from the reception result of a reflected wave by the ultrasonic sensor.
The ultrasonic sensor is
A first ultrasonic sensor whose directivity is the first direction,
It consists of a second ultrasonic sensor whose directivity is a second direction different from the first direction.
The first detection range in which the first ultrasonic sensor can detect an obstacle by itself is
A first receivable range that enables the second ultrasonic sensor to receive the reflected wave of the first ultrasonic sensor, and
The second ultrasonic sensor includes a first unreceivable region in which the reflected wave of the first ultrasonic sensor cannot be received.
The second detection range in which the second ultrasonic sensor can detect an obstacle by itself is
A second receivable range in which the reflected wave of the second ultrasonic sensor can be received by the first ultrasonic sensor, and
A second unreceivable region in which the reflected wave of the second ultrasonic sensor cannot be received by the first ultrasonic sensor is included.
The detection unit detects an obstacle based on the reception results of the reflected waves of the first ultrasonic sensor and the second ultrasonic sensor.
When the reception of the reflected wave of the first ultrasonic sensor is recognized and the first ultrasonic sensor does not receive the reflected wave of the first ultrasonic sensor, it is determined that there is no obstacle in the first unreceivable area.
Recognizing the reception of the reflected wave of the second ultrasonic sensor, when the second ultrasonic sensor does not receive the reflected wave of the second ultrasonic sensor, it is determined that there is no obstacle in the second unreceivable area. An obstacle detection device for moving objects. The detection unit
When the second ultrasonic sensor receives the reflected wave of the first ultrasonic sensor, it is determined that there is an obstacle in the first receivable area.
The moving object according to claim 1, wherein when the first ultrasonic sensor receives the reflected wave of the second ultrasonic sensor, it is determined that there is an obstacle in the second receivable area. Detection device. The first shield forming the first unreceivable area and
The obstacle detection device for a mobile body according to claim 1 or 2, wherein a second shield forming the second unreceivable area is provided. The obstacle detection device for a moving body according to any one of claims 1 to 3, wherein an integrated member for integrating the first ultrasonic sensor and the second ultrasonic sensor is provided. The first direction is the moving direction of the moving body, and is
The second direction is a direction that does not match the moving direction.
A control unit for controlling the traveling of the moving body is provided.
When the first ultrasonic sensor receives the reflected wave of the first ultrasonic sensor, the detection unit estimates that there is an obstacle in the first unreceivable area.
The obstacle detection device for a moving body according to any one of claims 1 to 4, wherein the control unit controls to warn when the moving body moves in the first direction.

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