JP2009001388A - Travel safety device of industrial vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a travel safety device capable of reliably detecting the approach of an industrial vehicle to an object with a simple constitution. <P>SOLUTION: A forklift is advanced, a control device 12 transmits the command of connection to an antenna 18 for direct advance to a direct advance-turn changing switch 19 based on a signal from a steering angle detection device 13. An RFID reader 9 is thus connected to the antenna 18 for direct advance to start the communication in a front communication area and in a rear communication area. During the turning mode, the control device 12 transmits the connection command to an antenna 8 for turn to the direct advance-turn changing switch 19 based on the signal from the steering angle detection device 13, and the communication in the entire communication area around the forklift is started. Thus, since the communication is performed only in the specified communication area according to the kind of the travel of the forklift, any mistaken detection is not generated, and an object can be reliably detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a travel safety device for industrial vehicles such as forklifts and towing vehicles that travel on or off the premises of factories or warehouses.

  Conventionally, a forklift is equipped with a wireless communication device to detect an object or to detect the approach of a forklift in order to prevent an accident from coming into contact with an object such as an operator or another industrial vehicle while the forklift is traveling. A method of informing them is being implemented.

  For example, in the prior art shown in FIG. 1 and FIG. 2 of Patent Document 1, a radio receiver 5 that receives signals transmitted in all directions from a radio transmitter 2 mounted on a forklift 1 is received. The operator is informed that the forklift 1 is approaching by sounding the buzzer 9 built in the wireless receiver 5.

In Patent Document 2, as shown in FIG. 3, at least seven antennas 22 connected to the reader / writer 25 are arranged around the forklift 30 so as to communicate with each of the antennas 22, and the RFID (abbreviation of Radio Frequency Identification. The area around the forklift 30 is covered without omission by the sum of the areas 23. The object 26 such as a person or an article is provided with an RFID tag 26a. Therefore, when the object 26 exists in the communication area 23 around the forklift 30, the RFID reader / writer 25 detects the object 26 by mutual communication between the antenna 22 and the RFID tag 26 a, and sends a detection signal to the control unit 11. input. The control unit 11 determines whether or not the object 26 is present in the dangerous area by a method such as measuring the distance to the detected object 26, and displays the situation.
JP 2003-317163 A JP 2006-188353 A

  As is well known, forklifts frequently carry forward, reverse, and turn to carry a load. In general, the vehicle travels at a relatively high speed during forward and reverse travel, and travels at a low speed during turning. For this reason, in the method disclosed in Patent Document 1 for transmitting signals in all directions, a detailed description is not given. However, in order to prevent contact with an operator, the communication area of the wireless transmitter 2 is advanced and It is necessary to set so that the radio receiver 5 of the worker in a relatively distant position can receive the signal so as to adapt to the high speed at the time of reverse travel. However, when the forklift travels straight, such as forward and backward, the danger area of the worker on the side of the forklift is limited to a relatively narrow range. Therefore, an operator at the side of the path where the forklift goes straight receives a signal from the wireless transmitter 2 even though there is no danger with the forklift, and the buzzer 9 sounds every time. In addition to feeling this, there is a risk of affecting work.

  The method disclosed in Patent Document 2 performs bidirectional communication between the RFID reader / writer 25 and the RFID tag 26a and measures the distance to the object 26 to determine whether it is dangerous. Since the communication area 23 is formed so as to cover the entire periphery of the forklift 30, the forklift 30 has a problem similar to that of Patent Document 1 when the forklift 30 goes straight. That is, the danger area of the object 26 on the side of the forklift 30 is limited to a very narrow range, and is greatly different from the danger area when going straight ahead. Such a determination criterion must be set for all antennas, and the configuration for the control must be extremely complicated. Further, if such a setting is not severely performed, there is a problem that when the forklift 30 goes straight ahead, the object 26 outside the originally dangerous area is erroneously detected as being in the dangerous area.

  An object of the present invention is to provide a travel safety device that can reliably detect the approach between an industrial vehicle and an object with a simple configuration.

  The present invention according to claim 1 is an industrial vehicle in which an RFID reader having an antenna capable of communicating with an RFID tag held by an object is disposed in a part of a vehicle body, and the industry is used as an antenna of the RFID reader. A directional antenna for straight traveling of the vehicle and an antenna for turning, and the RFID reader is switched between the directional antenna for straight traveling and the antenna for turning when the industrial vehicle is traveling straight or turning. A switching device for connection is provided.

  According to the first aspect of the present invention, it is possible to reliably detect the approach of an object regardless of where the industrial vehicle is in any driving state.

  According to a second aspect of the present invention, the switching device turns from the directivity directional antenna when a detection signal of a predetermined steering angle or more is transmitted from a steering angle detection device of the industrial vehicle. Since it is characterized by switching to an antenna for time, switching between a directional antenna for straight traveling and an antenna for turning can be reliably performed with a simple configuration.

  The invention of claim 3 is characterized in that the antenna for turning is constituted by an omnidirectional antenna, so that it can reliably cover a communication area required when turning an industrial vehicle.

  The invention according to claim 4 is characterized in that the antenna for turning is composed of two directional antennas directed to the sides of the industrial vehicle. Can be substantially covered.

  The present invention according to claim 5 is characterized in that the directional antenna for straight travel is configured by separate directional antennas for forward travel and reverse travel, and the switching device is used when the industrial vehicle travels forward or backward. It is characterized by switching the directional antenna and connecting to the RFID reader, so there is no communication to the communication area in the unnecessary direction when going straight, that is, the rear area when moving forward and the front area when moving backward. Can be surely eliminated and useless communication can be eliminated.

  In the present invention of claim 6, the RFID reader is connected to a control device, and the control device transmits an alarm signal to an alarm device provided in an industrial vehicle based on an RFID tag detection signal from the RFID reader. Therefore, it is possible to accurately notify the driver of the industrial vehicle of the approach to the object.

  The present invention can reliably detect the approach between an industrial vehicle and an object when the industrial vehicle is traveling with a simple configuration.

(First embodiment)
Hereinafter, a first embodiment implemented in a reach forklift will be described with reference to FIGS.
In FIG. 1, a reach-type forklift 1 (hereinafter simply referred to as a forklift 1) shows an overview of a general structure including a fork 2, a handle 3, a head guard 4, and the like. An RFID unit 5 is installed on the upper surface of the head guard 4.

  As shown in FIG. 2, the RFID unit 5 includes a flat-type directional straight-ahead antenna 18 and a non-directional bar-shaped turning antenna 8 that are formed for straight travel including forward and backward movement of the forklift 1. It is composed of The RFID unit 5 incorporates an RFID reader 9 shown in FIG. The rectilinear antenna 18 has a communication area 18a that covers a front area corresponding to the forward speed of the forklift 1 and a communication area 18b that covers a rear area that corresponds to the reverse speed. Communication is possible. The communication areas 18a and 18b cover a relatively far area. Further, the turning antenna 8 has a communication area 8 a that covers all directions of the forklift 1 in a relatively narrow area corresponding to the turning speed of the forklift 1.

  The relationship between the devices shown in the block diagram in FIG. 3 will be described. The straight traveling antenna 18 is connected to the terminal 19a of the straight traveling / turning switch 19 and the turning antenna 8 is connected to the terminal 19b. Further, the terminal 19 c of the straight / turning switch 19 is connected to the RFID reader 9. A control device 12 mounted on the forklift 1 is connected to a straight travel / turning switch 19 and an RFID reader 9. The control device 12 includes a steering angle detection device 13 including an encoder disposed on a steering (not shown) connected to the handle 3, a forward / backward detection device 14 for detecting the position of a forward / reverse lever (not shown), and the like. An alarm 15 arranged near the driver's seat of the forklift 1 is connected.

  The steering angle detection device 13 can output a steering angle signal corresponding to the rotation amount to the control device 12 when the handle 3 is rotated leftward or rightward. In the control device 12, the steering angle is set in advance so that it is determined that the forklift 1 is traveling straight up to a certain steering angle, and that the forklift 1 is determined to turn when the steering angle exceeds a certain steering angle. Note that the worker 16 corresponding to the object always carries the RFID tag 17 capable of bidirectional communication with both the straight traveling antenna 18 and the turning antenna 8. The antenna built in the RFID tag 17 is preferably omnidirectional, but may be directional. In the present embodiment, the RFID reader 9 can detect the radio field intensity of a signal transmitted from the RFID tag 17 and recognize the presence of the RFID tag 17.

The operation of the first embodiment having the above configuration will be described below.
When the driver of the forklift 1 moves an operation lever (not shown) to the forward position so that the driver moves straight forward, the driver does not rotate the handle 3, and therefore the steering angle detection device 13 starts to move straight ahead. The corresponding steering angle signal is transmitted to the control device 12. The control device 12 transmits a connection command with the terminal 19a to the straight travel / turning switch 19 based on the steering angle signal during straight travel. Accordingly, as indicated by the solid line, the straight travel / swivel changeover switch 19 connects the terminal 19a and the terminal 19c, so the RFID reader 9 is connected to the antenna 18 for straight travel, and the communication areas 18a on the front and rear of the forklift 1, Communication covering 18b is started.

  For example, if the worker 16 enters the communication area 18a while the forklift 1 is moving forward, the RFID tag 17 receives the communication of the RFID reader 9 and confirms the worker such as an appropriate signal or ID signal indicating its presence. Send a signal. Since this signal is received by the antenna 18 for traveling straight and is input to the RFID reader 9, the RFID reader 9 outputs an operator confirmation signal to the control device 12. The control device 12 immediately inputs an alarm signal to the alarm device 15 based on the input worker confirmation signal. The alarm device 15 sounds a buzzer, for example, and notifies the operator of the forklift 1 of the confirmation of the operator 16. Note that there are various methods for alarming, and besides the buzzer, lighting or blinking of a lamp, display on a monitor, use of these methods in appropriate combination, and the like can be mentioned. When the driver of the forklift 1 is informed of the presence of the worker 16 by the alarm device 15, the driver 16 can confirm the worker 16 while decelerating and can take the safest action in advance. On the other hand, a region other than the traveling direction of the forklift 1, that is, a region that is not dangerous on the side, is outside the communication area 18a of the straight traveling antenna 18, so that no erroneous detection occurs. Accordingly, it is possible to reliably detect the front area that requires safety confirmation.

  Further, when the driver once stops the forklift 1 and moves straight back, the steering wheel 3 is not rotated as in the forward movement, so that the steering angle signal is transmitted from the steering angle detector 13. The control device 12 transmits a connection signal to the terminal 19a to the straight travel / turning switch 19. Since the rectilinear / swivel changeover switch 19 is connected to the terminal 19a and the terminal 19c, the RFID reader 9 is kept connected to the rectilinear antenna 18 and communication areas 18a, 18b covering the front area and the rear area of the forklift 1. Communication with is continued. The treatment when the worker 16 is present in the communication area 18b is exactly the same as that at the time of advancement. Since there is no communication to the side that does not become a dangerous area when the forklift 1 moves backward, there is no waste such as erroneous detection as in the case of moving forward, and the rear safety can be ensured.

  When the forklift 1 is turned for work at the loading position or the unloading position, the driver rotates the handle 3 greatly, so that a steering angle signal equal to or higher than the steering angle set in advance from the steering angle detection device 13 is generated. It is transmitted to the control device 12. If the input steering angle signal is equal to or greater than a preset steering angle, the control device 12 determines that the vehicle is turning and outputs a connection signal to the terminal 19b to the straight travel / turning switch 19. Accordingly, since the straight travel / turning switch 19 is connected to the terminal 19b and the terminal 19c as shown by the phantom line, the RFID reader 9 is connected to the turning antenna 8, and the forklift 1 shown by the phantom line in FIG. Communication within the communication area 8a covering the entire surrounding area of the mobile phone is started. When the worker 16 is present in the communication area 8a, the same treatment as in the case of the straight traveling is performed. In addition, since communication is not performed in the front and rear communication areas 18a and 18b that cover a distant area, there is no waste of erroneous detection and the safety of the turning position can be ensured.

  In the first embodiment, the front and rear communication areas 18a and 18b of the forklift 1 can be secured with one antenna, so that the configuration can be simplified and the safety in the front-rear direction can be ensured when going straight. it can.

(Second Embodiment)
The second embodiment shown in FIGS. 4 and 5 is a modification of the straight traveling antenna 18 in the first embodiment. The same reference numerals are given to the same components as those in the first embodiment, and the details are as follows. The detailed explanation is omitted.

  As shown in FIG. 4, the RFID unit 5 is a non-directional flat antenna having a flat directivity formed as an antenna for straight travel of the forklift 1, a reverse antenna 7, and an antenna 6, 7. It is comprised from the antenna 8 for turning. The forward antenna 6 has a communication area 6a that covers a relatively far front area corresponding to the forward speed of the forklift 1 when traveling straight, and the reverse antenna 7 covers a relatively far rear area that matches the reverse speed. Communication area 7a. Further, the turning antenna 8 has a communication area 8 a that covers all directions of the forklift 1 in a relatively narrow area corresponding to the turning speed of the forklift 1.

The relationship between the devices shown in the block diagram in FIG. 5 will be described. The forward antenna 6 and the reverse antenna 7 are connected to the terminals 10 a and 10 b of the forward / reverse selector switch 10, respectively. The terminal 10c of the forward / reverse selector switch 10 is further connected to the terminal 11a of the straight / reverse selector switch 11. On the other hand, the turning antenna 8 is connected to a terminal 11 b of the straight / turning switch 11. Further, the terminal 11 c of the straight / turning switch 11 is connected to the RFID reader 9. A control device 12 mounted on the forklift 1 is connected to a forward / reverse switching switch 10, a straight / revolution switching switch 11, and an RFID reader 9.
The worker 16 corresponding to the object always carries an RFID tag 17 that can communicate with any of the forward antenna 6, the reverse antenna 7, and the turning antenna 8.

The operation of the second embodiment having the above configuration will be described below.
When the driver of the forklift 1 moves an operation lever (not shown) to the forward position so as to go straight forward, the forward / backward detection device 14 detects the forward position and transmits a forward position signal to the control device 12. Further, since the driver does not rotate the steering wheel 3, a steering angle signal corresponding to the straight traveling is transmitted from the steering angle detection device 13 to the control device 12. The control device 12 transmits a connection command with the terminal 10a to the forward / reverse selector switch 10 and transmits a connection command with the terminal 11a to the rectilinear / turn switch 11 based on the forward position signal and the steering angle signal during straight travel. . Therefore, the forward / reverse selector switch 10 and the straight / swivel selector switch 11 are connected to the terminal 10a and the terminal 10c, and the terminal 11a and the terminal 11c, respectively, as indicated by solid lines. Then, communication covering the communication area 6a in front of the forklift 1 is started.

  If the worker 16 enters the communication area 6a while the forklift 1 is moving forward, the RFID tag 17 receives the communication of the RFID reader 9, and receives an operator confirmation signal such as an appropriate signal indicating the presence or an ID signal. send. Since this signal is received by the forward antenna 6 and input to the RFID reader 9, the RFID reader 9 outputs an operator confirmation signal to the control device 12. The control device 12 immediately inputs an alarm signal to the alarm device 15 based on the input worker confirmation signal. The alarm device 15 sounds a buzzer, for example, and notifies the operator of the forklift 1 of the confirmation of the operator 16. When the driver of the forklift 1 is informed of the presence of the worker 16 by the alarm device 15, the driver 16 can confirm the worker 16 while decelerating and can take the safest action in advance. On the other hand, an area other than the traveling direction of the forklift 1, that is, a non-hazardous area such as a side or a rear side is outside the communication area 6 a of the forward antenna 6, so that no erroneous detection occurs. Accordingly, it is possible to reliably detect the front area that requires safety confirmation.

  Next, when the driver once stops the forklift 1 and moves straight forward, when the driver operates a forward / reverse lever (not shown) to the reverse position, the forward / reverse detection device 14 controls the reverse position signal. 12 to send. In this case, since the steering wheel 3 is not rotated as in the forward movement, the steering angle signal is transmitted from the steering angle detection device 13, and the control device 12 sends a connection signal to the terminal 10 b to the forward / reverse selector switch 10. Send. Since the forward / reverse selector switch 10 is connected to the terminals 10b and 10c as indicated by the phantom line, the RFID reader 9 is connected to the reverse antenna 7 and communicates with the communication area 7a covering the rear area of the forklift 1. Is started. The treatment when the worker 16 is present in the communication area 7a is exactly the same as that at the time of forward movement. Since there is no communication to the front or side that does not become a dangerous area when the forklift 1 moves backward, there is no waste such as erroneous detection as in the case of moving forward, and the safety of the rear can be ensured.

In the second embodiment, since the forward antenna 6 and the reverse antenna 7 are individually arranged during straight traveling, for example, when the forklift 1 moves forward, the rear region is a normal safety region, so unnecessary communication is not performed. Can contribute to energy saving.

  When the forklift 1 is turned for work at the loading position or the unloading position, the driver rotates the handle 3 greatly, so that a large angle is detected from the steering angle detection device 13 as in the first embodiment. A steering angle signal is transmitted to the control device 12. The control device 12 determines that the vehicle is turning because the input steering angle signal is greater than a preset steering angle, and outputs a connection signal to the terminal 11b to the straight travel / turning switch 11. Accordingly, as indicated by the phantom line, the straight travel / turning switch 11 is connected to the terminal 19b and the terminal 19c, and the RFID reader 9 is connected to the turning antenna 8 to cover the entire area around the forklift 1. Communication within 8a is started.

(Third embodiment)
The third embodiment shown in FIG. 6 is obtained by changing the turning antenna 8 in the second embodiment. The same reference numerals are given to the same components as those in the first embodiment, and a detailed description is given. Omitted.

  The RFID unit 5 disposed on the upper surface of the head guard 4 includes the forward antenna 6 and the reverse antenna 7 which are the same as those of the first embodiment, and has a directional left antenna 20 formed in a planar shape as a turning antenna. And the right antenna 21 are provided as individual antennas. As shown in the drawing, the left and right antennas 20 and 21 are set to form communication areas 20a and 21a in which the lateral distance of the forklift 1 is narrow and the distance in the front-rear direction is widened. Therefore, even when the turning antenna has a configuration in which a plurality of directional antennas are arranged on both sides of the forklift 1, it is possible to obtain substantially the same operational effects as those of the first and second embodiments. .

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications are possible within the scope of the gist of the present invention, and can be implemented as follows.

(1) In the above embodiments, the worker 16 is described as an example of the object of the present invention, but the object may include other forklifts.
(2) Although the RFID reader 9 in each of the above embodiments has been described with the method of detecting the radio wave intensity of the signal transmitted from the RFID tag 17 as the object, the RFID tag 17 and the antennas 6, 7, 18 for straight traveling or turning This can be implemented by a method of measuring the distance between the hour antennas 8, 20, and 21.
(3) In each of the above embodiments, the communication method in the RFID reader 9 and the RFID tag 17 has been described as a configuration capable of bidirectional communication. However, the RFID tag 17 is configured to be capable of one-way communication, and only the RFID reader 9 is received. Even if communication is performed as a possible configuration, the present invention can be implemented.
(4) Although the steering angle signal of the steering angle detection device 13 is used as a detection signal for switching the straight travel / turning changeover switches 11 and 19, the turning radius is calculated based on the steering angle of the forklift 1 and the wheel interval. Based signal may be used.
(5) The straight travel / turning switch 19 shown in FIG. 3 and the forward / backward changeover switch 10 and the straight travel / turning switch 11 shown in FIG. 4 are configured to operate in response to a command from the control device 12. You may comprise so that it may operate | move by the command from the reader | leader 9. FIG.
(6) The RFID reader 9, the forward antenna 6 and the reverse antenna 7, which are antennas for straight traveling, the antenna 8 for turning, and the antenna 18 for straight traveling are unitized by the RFID unit 5. May be arranged individually at appropriate positions.
(7) The straight antennas 6, 7, 18 and the turning antenna 8 are all disposed on the upper surface of the head guard 4. However, some antennas or all antennas are appropriately positioned other than the head guard 4. It can be set as the structure arrange | positioned.
(8) The present invention can be implemented in industrial vehicles such as forklifts such as reach-type forklifts and counter-type forklifts and towing vehicles.

It is the schematic of a reach type forklift. It is a top view of the reach type forklift which shows the communication area in a 1st embodiment. It is a control block diagram which shows 1st Embodiment. It is a top view of the reach type forklift which shows the communication area in a 2nd embodiment. It is a control block diagram which shows 2nd Embodiment. It is a top view of the reach type forklift which shows the communication area in a 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Forklift 3 Handle 4 Head guard 5 RFID unit 6 Forward antenna 6a, 7a, 8a, 18a, 18b, 20a, 21a Communication area 7 Reverse antenna 8 Turning antenna 9 RFID reader 10 Forward / reverse selector switch 11, 19 Straight ahead Rotation switch 12 Control device 13 Steering angle detection device 14 Forward / backward detection device 15 Alarm 16 Worker 17 RFID tag 18 Straight-forwarding antenna 20 Left antenna 21 Right antenna

Claims (6)

In an industrial vehicle in which an RFID reader provided with an antenna capable of communicating with an RFID tag held by an object is arranged on a part of a vehicle body
The RFID reader includes a directional antenna for straight traveling of the industrial vehicle and an antenna for turning, and the directional antenna for straight traveling and the antenna for turning when the industrial vehicle is traveling straight or turning. A traveling safety device for an industrial vehicle, characterized in that a switching device is provided for switching between and connected to the RFID reader.   The switching device switches from the directivity directional antenna to the turning antenna when a detection signal of a predetermined steering angle or more is transmitted from a steering angle detection device of the industrial vehicle. The travel safety device for an industrial vehicle according to claim 1.   The traveling safety device for an industrial vehicle according to claim 1 or 2, wherein the turning antenna is configured by an omnidirectional antenna.   3. The traveling safety device for an industrial vehicle according to claim 1, wherein the antenna for turning is composed of two directional antennas directed to the sides of the industrial vehicle.   The directional antenna for straight travel is composed of separate directional antennas for forward travel and reverse travel, and the switching device switches the directional antenna to connect to the RFID reader during forward or reverse travel of the industrial vehicle. The travel safety device for an industrial vehicle according to any one of claims 1 to 4, wherein the travel safety device is an industrial vehicle.   The RFID reader is connected to a control device, and the control device transmits an alarm signal to an alarm device provided in an industrial vehicle based on an RFID tag detection signal from the RFID reader. The traveling safety device for an industrial vehicle according to any one of the above.

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