Patent Description:
Conventionally, it is known that an industrial vehicle irradiates a notification light toward a road surface on a rear side of the vehicle in order to notify a person in the vicinity of the vehicle of the approach of the vehicle (see, for example, Patent Document <NUM>). In addition, some of industrial vehicles called picking trucks are also configured to be capable of irradiating a notification light.

<FIG> shows a picking truck <NUM> configured as described above. As shown in the figure, the picking truck <NUM> includes a vehicle body <NUM> having a travelling device, a mast <NUM> provided on a rear side of the vehicle body <NUM>, a driving cab <NUM> capable of being lifted and lowered along the mast <NUM>, a pair of left and right forks <NUM> and <NUM> that are lifted and lowered together with the driving cab <NUM>, and an illumination part <NUM> disposed at a head guard <NUM> of the driving cab <NUM> via a suitable bracket <NUM>. The illumination part <NUM> irradiates a notification light L toward a road surface F on the rear side of the vehicle and displays a mark M on the road surface F.

Patent literature <CIT>, which discloses a system comprising the features of the preamble of independent claim <NUM>, describes a method for avoiding a collision with an industrial truck, in a first step, a current dynamic parameter of the industrial truck is determined; in a further step, a light is emitted as a function of the determined current dynamic parameter with a light source arranged on the industrial truck in order to warn of a collision with the industrial truck.

However, the notification by the conventional picking truck <NUM> is insufficient for other picking trucks operating (travelling) in the same operation area. That is because the approach speed between picking trucks is higher than the approach speed between a picking truck and a person, and even if a passenger of another picking truck notices the mark M and performs an operation to avoid collision, it is likely that collision cannot be timely avoided.

If the mark M is displayed far away from the vehicle, the above problem may be solved. However, if such a measure is taken, another problem arises, that is, the mark M is also noticed by a person far away from the vehicle and may cause annoyance to this person.

The present invention has been made in view of the above circumstances, and an objective of the present invention is to provide a vehicle approach notification device capable of effectively notifying a person in the vicinity and another vehicle travelling in the vicinity of the approach of a vehicle, and a picking truck provided with the device.

To solve the above problems, a system according to independent claim <NUM> is provided wherein a vehicle approach notification device is provided in each of a plurality of vehicles travelling within a predetermined operation area, which includes an illumination part, an irradiation direction change part, and a control part. The illumination part is disposed at a driving cab of the vehicle and irradiates a notification light toward a road surface on a rear side of the vehicle, and the driving cab is capable of being lifted and lowered. The irradiation direction change part changes an irradiation direction by changing a configuration angle of the illumination part with respect to the driving cab. The control part changes a command associated with the configuration angle sent to the irradiation direction change part based on own-vehicle information associated with an own vehicle and other-vehicle information associated with another vehicle. The own-vehicle information includes a current position of the own vehicle in the operation area. The other-vehicle information includes a current position of the another vehicle in the operation area, a tire angle of the another vehicle, and a speed of the another vehicle. In a case where (<NUM>) the current position of the another vehicle is within a predetermined monitoring area set on a rear side of the own vehicle, (<NUM>) a predicted position of the another vehicle after a predetermined time predicted from the current position, the tire angle, and the speed of the another vehicle is within the monitoring area after the predetermined time, and (<NUM>) the predicted position of the another vehicle is closer to a predicted position of the own vehicle than the current position of the another vehicle, the control part changes the command sent to the irradiation direction change part.

The own-vehicle information further includes a tire angle of the own vehicle and a speed of the own vehicle. The monitoring area after the predetermined time is a monitoring area after the predetermined time predicted from the current position, the tire angle, and the speed of the own vehicle. The predicted position of the own vehicle is a position of the own vehicle after the predetermined time predicted from the current position, the tire angle, and the speed of the own vehicle.

The case where the predicted position of the another vehicle is closer to the predicted position of the own vehicle than the current position of the another vehicle includes a case where a distance between the current position of the own vehicle and the current position of the another vehicle is longer than a distance between the predicted position of the own vehicle and the predicted position of the another vehicle.

When (<NUM>), (<NUM>), and (<NUM>) above are satisfied, the control part of the vehicle approach notification device may be configured to send the irradiation direction change part the command so that a position of the road surface to be irradiated moves away from the own vehicle.

The control part of the vehicle approach notification device may be configured to acquire vehicle information associated with the another vehicle as the other-vehicle information from a management device that stores vehicle information associated with each of the plurality of vehicles.

The own-vehicle information in the vehicle approach notification device may further include a lifting position of the driving cab, and in this case, the control part may send the command to the irradiation direction change part so that a position of the road surface to be irradiated does not change even if the lifting position changes.

The monitoring area in the vehicle approach notification device may have a substantially triangular shape or a substantially fan shape of which a dimension in a vehicle width direction increases as a distance from the rear side of the own vehicle increases.

Further, to solve the above problems, the vehicles of the system are picking trucks.

According to the present invention, it is possible to provide a system comprising a plurality of vehicles, each provided with a vehicle approach notification device capable of effectively notifying a person in the vicinity and another vehicle travelling in the vicinity of the approach of a vehicle, and aplurality of picking trucks provided with such a device.

Hereinafter, embodiments of a picking truck and a vehicle approach notification device according to the present invention will be described with reference to the accompanying drawings.

<FIG> shows a picking truck 10A according to a first embodiment of the present invention. The picking truck 10A is a vehicle that operates (travels) with another picking truck 10A in a predetermined operation area, and as shown in the figure, includes a vehicle body <NUM> having travelling device, a pair of left and right legs <NUM> and <NUM> and a mast <NUM> provided on the rear side of the vehicle body <NUM>, and a driving cab <NUM> that may be lifted and lowered along the mast <NUM>. The travelling device includes a tire <NUM> that serves both as a driving wheel and a steering wheel.

The driving cab <NUM> has an operation panel <NUM> composed of various levers and the like operated by a passenger, a fall guard <NUM> for preventing the passenger from falling, a pair of left and right forks <NUM> and <NUM> extending toward the rear side, and a head guard <NUM> covering above the passenger's head. The forks <NUM> and <NUM> are provided at the floor plate of the driving cab <NUM>.

The picking truck 10A according to this embodiment further includes a control part 21A, an irradiation direction change part <NUM>, and an illumination part <NUM>, which constitute a vehicle approach notification device 20A, a main control part 30A, a vehicle speed detection part <NUM>, and a tire angle detection part <NUM>. The irradiation direction change part <NUM> includes an irradiation direction detection part <NUM> (not shown in <FIG>).

The illumination part <NUM> is composed of an LED light that irradiates a notification light L toward a road surface F on the rear side of the vehicle. An image (hereinafter referred to as a "mark") M of the notification light L shown on the road surface F may have a circular shape with a blurred outline, or may have a spot shape, a line shape, or an arrow shape with a clear outline by the effect of lenses or slits provided in the illumination part <NUM>. Further, the color of the notification light L (mark M) is preferably a color that stands out with respect to the road surface F in order to enhance the notification effect. In this embodiment, the mark M has a blue line shape extending in the vehicle width direction.

The irradiation direction change part <NUM> changes an irradiation direction (in this embodiment, a direction θ with respect to a vertical line V) by changing a configuration angle of the illumination part <NUM> with respect to the driving cab <NUM> (the head guard <NUM> in this embodiment) based on a command from the control part 21A.

The control part 21A changes the command sent to the irradiation direction change part <NUM> according to whether another vehicle that satisfies all of three conditions to be described later is present. At this time, the control part 21A refers to a detection result of the irradiation direction detection part <NUM> which directly or indirectly detects the irradiation direction θ.

As shown in <FIG>, the picking truck 10A (10A-<NUM>, 10A-<NUM>. ) according to this embodiment wirelessly communicates with a management device <NUM>.

Specifically, the main control part 30A of the picking truck 10A-<NUM> transmits and stores own-vehicle information to the management device <NUM> by wireless communication, and the own-vehicle information includes a vehicle speed detected by the vehicle speed detection part <NUM>, an angle of the tire <NUM> (hereinafter referred to as a "tire angle") detected by the tire angle detection part <NUM>, and a current position in the operation area obtained by performing a calculation therefrom. At this time, the main control part 30A also sends the own-vehicle information to the control part 21A.

Another picking truck 10A-<NUM>. also transmits and stores own-vehicle information to the management device <NUM>. As a result, the management device <NUM> collects the own-vehicle information of all the picking trucks 10A-<NUM>, 10A-<NUM>. operating in the operation area. The own-vehicle information of the picking truck 10A-<NUM> stored in the management device <NUM> is other-vehicle information for the picking truck 10A-<NUM>.

The main control part 30A of the picking truck 10A-<NUM> receives the other-vehicle information (i.e., the own-vehicle information of the picking truck 10A-<NUM>. ) stored in the management device <NUM> by wireless communication and sends it to the control part 21A. The main control part 30A of the another picking truck 10A-<NUM>. also receives the other-vehicle information from the management device <NUM> and sends it to the control part 21A.

In this manner, the control part 21A of the vehicle approach notification device 20A provided in each picking truck 10A acquires the own-vehicle information including the current position, the vehicle speed, and the tire angle of the own vehicle, and the other-vehicle information including the current position, the vehicle speed, and the tire angle of other vehicles. Then, the control part 21A changes the command sent to the irradiation direction change part <NUM> based on the acquired own-vehicle information and other-vehicle information to change the irradiation direction θ and an irradiation distance D. When the own vehicle does not move or does not move temporarily, it is also possible not to have information such as the vehicle speed and the tire angle of the own vehicle.

The change to the irradiation direction θ and the irradiation distance D made by the control part 21A will be described in detail with reference to <FIG> and <FIG>.

Upon acquiring the own-vehicle information and the other-vehicle information, based on a current position P1 of the picking truck 10A-<NUM> (hereinafter also referred to as "own vehicle") included in the own-vehicle information and a current position P2 of another picking truck 10A-<NUM> (hereinafter also referred to as "another vehicle") included in the other-vehicle information, the control part 21A of the picking truck 10A-<NUM> (own vehicle) performs a first determination of determining whether the current position P2 of the another vehicle 10A-<NUM> is within a predetermined monitoring area <NUM> set on the rear side of the own vehicle 10A-<NUM>. In the example shown in <FIG>, it is determined that the current position P2 of the another vehicle 10A-<NUM> is within the monitoring area <NUM>.

The monitoring area <NUM> has a substantially fan shape of which the dimension in the vehicle width direction increases as the distance from the rear side of the own vehicle 10A-<NUM> increases.

After the first determination, the control part 21A of the own vehicle 10A-<NUM> performs a second determination of determining whether a predicted position after a predetermined time (after <NUM> seconds in embodiment) predicted from the current position P2, the vehicle speed, and the tire angle of the another vehicle 10A-<NUM> included in the other-vehicle information is within a monitoring area 40a after the predetermined time (after <NUM> seconds in this embodiment) predicted from the current position P1, the vehicle speed, and the tire angle of the own vehicle 10A-<NUM> included in the own-vehicle information. When the predicted position is P2a, it is determined that the predicted position is within the monitoring area 40a. When the predicted position is P2b, it is also determined that the predicted position is within the monitoring area 40a. In contrast, when the predicted position is P2c, it is determined that the predicted position is not within the monitoring area 40a.

After the second determination, based on the current position P1 of the own vehicle 10A-<NUM>, the current position P2 of the another vehicle 10A-<NUM>, the predicted position P1a after the predetermined time (after <NUM> seconds in this embodiment) predicted from the current position P1, the vehicle speed, and the tire angle of the own vehicle 10A-<NUM>, and the predicted position of the another vehicle 10A-<NUM> predicted at the time of the second determination, the control part 21A of the own vehicle 10A-<NUM> performs a third determination of determining whether a distance PD between the current position P1 and the current position P2 is longer than a distance PD' between the predicted position P1a of the own vehicle 10A-<NUM> and the predicted position of the another vehicle 10A-<NUM>. In other words, in the third determination, it is determined whether the predicted position of the another vehicle 10A-<NUM> is closer to the predicted position of the own vehicle 10A-<NUM> than the current position of the another vehicle 10A-<NUM>. When the predicted position is P2b, it is determined that the distance PD is longer than the distance PD'. When the predicted position is P2c, it is also determined that the distance PD is longer than the distance PD'. In contrast, when the predicted position is P2a, it is determined that the distance PD is equal to the distance PD'. If the own vehicle 10A-<NUM> does not move or does not move temporarily, it is also possible not to have information such as the vehicle speed and the tire angle of the own vehicle 10A-<NUM>. It may be determined whether the predicted position of the another vehicle 10A-<NUM> is closer to the current position of the own vehicle 10A-<NUM> than the current position of the another vehicle 10A-<NUM>.

The control part 21A of the own vehicle 10A-<NUM> performs the same determination for all the other vehicles operating within the operation area.

An another vehicle with which the current position is determined to be within the monitoring area <NUM> in the first determination, the predicted position is determined to be within the monitoring area 40a in the second determination, and the distance PD is determined to be longer than the distance PD' in the third determination, i.e., an another vehicle that satisfies three predetermined conditions, may collide with the rear side of the own vehicle 10A-<NUM> if continuing in this manner. Therefore, when such another vehicle is present, the control part 21A of the own vehicle 10A-<NUM> changes the command sent to the irradiation direction change part <NUM> to change the irradiation direction θ from θ<NUM> to θ<NUM> (see (A) of <FIG>). As a result, the irradiation distance D changes from D1 to D2 (see (B) of <FIG>), and the position of the mark M changes from M1 to M2 (see <FIG>). In other words, the mark M moves away from the own vehicle. As a result, the passenger of the another vehicle, which may collide with the own vehicle 10A-<NUM>, can quickly notice the presence of the own vehicle 10A-<NUM>.

When the own vehicle 10A-<NUM> does not move or does not move temporarily, it is also possible not to have information such as the vehicle speed and the tire angle of the own vehicle 10A-<NUM>. At that time, <FIG> may be simplified as <FIG>. The second determination and the third determination as described above may be changed as follows.

As a modification example of the second determination, when the own vehicle 10A-<NUM> does not move or does not move temporarily, as shown in <FIG>, after the first determination, the control part 21A of the own vehicle 10A-<NUM> performs a second determination of determining whether a predicted position after a predetermined time (after <NUM> seconds in this embodiment) predicted from the current position P2, the vehicle speed, and the tire angle of the another vehicle 10A-<NUM> included in the other-vehicle information is within the monitoring area <NUM>. When the predicted position is P2a, it is determined that the predicted position is within the monitoring area <NUM>. When the predicted position is P2b, it is also determined that the predicted position is within the monitoring area <NUM>. In contrast, when the predicted position is P2c, it is determined that the predicted position is not within the monitoring area <NUM>.

As a modification example of the third determination, after the second determination, based on the current position P1 of the own vehicle 10A-<NUM>, the current position P2 of the another vehicle 10A-<NUM>, and the predicted position of the another vehicle 10A-<NUM> predicted at the time of the second determination, the control part 21A of the own vehicle 10A-<NUM> performs a third determination of determining whether the predicted position is closer to the current position P1 than the current position P2. When the predicted position is P2b, it is determined that the predicted position is closer than the current position P2. When the predicted position is P2c, it is also determined that the predicted position is closer than the current position P2. In contrast, when the predicted position is P2a, it is determined that the predicted position is farther than the current position P2.

An another vehicle of which the current position is determined to be within the monitoring area <NUM> in the first determination, the predicted position is determined to be within the monitoring area <NUM> in the second determination, and the predicted position is determined to be closer to the current position of the own vehicle than the current position in the third determination, i.e., an another vehicle that satisfies the three predetermined conditions, may collide with the rear side of the own vehicle 10A-<NUM> if continuing in this manner. Therefore, when such another vehicle is present, the control part 21A of the own vehicle 10A-<NUM> changes the command sent to the irradiation direction change part <NUM> to change the irradiation direction θ from θ<NUM> to θ<NUM> (see (A) of <FIG>). As a result, the irradiation distance D changes from D1 to D2 (see (B) of <FIG>), and the position of the mark M changes from M1 to M2 (see <FIG>). In other words, the mark M moves away from the own vehicle. As a result, the passenger of the another vehicle, which may collide with the own vehicle 10A-<NUM>, can quickly notice the presence of the own vehicle 10A-<NUM>. On the other hand, when an another vehicle that satisfies the three predetermined conditions is not present, the control part 21A of the own vehicle 10A-<NUM> maintains the irradiation direction θ at θ<NUM> without changing the command sent to the irradiation direction change part <NUM>.

In this embodiment, the irradiation direction change part <NUM> which changes the irradiation direction θ under the control of the control part 21A has the following configuration.

In other words, as shown in <FIG>, the irradiation direction change part <NUM> is composed of a power cylinder <NUM> provided on the lower surface of the head guard <NUM>, a link mechanism including three link members <NUM>, <NUM>, and <NUM>, a support member <NUM> suspended from the lower surface of the head guard <NUM>, and the irradiation direction detection part <NUM>.

The power cylinder <NUM> includes a motor that rotates according to the command from the control part 21A. When the motor rotates according to the command, the power cylinder <NUM> expands and contracts along the front-rear direction of the picking truck 10A by an amount corresponding to the rotation amount of the motor. The command includes a command associated with a rotation direction and a command associated with a rotation speed.

One end portion of the first link member <NUM> is rotatably connected to a tip portion of the power cylinder <NUM>, and the other end portion is rotatably connected to a front connecting portion 29a of the support member <NUM>. One end portion of the second link member <NUM> is rotatably connected to a middle portion of the first link member <NUM>, and the other end portion is rotatably connected to a front upper end portion of the third link member <NUM>. A front lower end portion of the third link member <NUM> is rotatably connected to a rear connecting portion 29b of the support member <NUM>. Then, the illumination part <NUM> is fixed to a rear end portion of the third link member <NUM>.

The irradiation direction detection part <NUM> is composed of a potentiometer provided at the rear connecting portion 29b of the support member <NUM>. The irradiation direction detection part <NUM> detects the position of the third link member <NUM> with respect to the rear connecting portion 29b and outputs a signal associated with the detection result to the control part 21A. This signal may be said to correspond to the irradiation direction θ.

When the power cylinder <NUM> expands and contracts according to the command from the control part 21A, the link mechanism <NUM>, <NUM>, and <NUM> operates to change the configuration angle of the illumination part <NUM> with respect to the head guard <NUM>, and as a result, the irradiation direction θ changes. (B) of <FIG> shows a state in which the power cylinder <NUM> is extended and the irradiation direction θ is smaller as compared to (A) of <FIG>.

<FIG> shows a picking truck 10B according to a second embodiment of the present invention. The picking truck 10B differs from the picking truck 10A in that it includes a vehicle approach notification device 20B in place of the vehicle approach notification device 20A, includes a main control part 30B in place of the main control part 30A, and further includes a lifting position detection part <NUM>, but is similar to the picking truck 10A in other aspects. Further, the vehicle approach notification device 20B differs from the vehicle approach notification device 20A in that it includes a control part 21B in place of the control part 21A, but is similar to the vehicle approach notification device 20A in other aspects.

As shown in <FIG>, the picking truck 10B (10B-<NUM>, 10B-<NUM>. ) according to this embodiment wirelessly communicates with the management device <NUM>.

Specifically, the main control part 30B of the picking truck 10B-<NUM> transmits and stores own-vehicle information to the management device <NUM> by wireless communication, and the own-vehicle information includes a vehicle speed detected by the vehicle speed detection part <NUM>, a tire angle detected by the tire angle detection part <NUM>, a current position in the operation area obtained by performing a calculation therefrom, and a lifting position H of the driving cab <NUM> detected by the lifting position detection part <NUM>. At this time, the main control part 30B also sends the own-vehicle information to the control part 21B.

Another picking truck 10B-<NUM>. also transmits and stores own-vehicle information to the management device <NUM>. As a result, the management device <NUM> collects the own-vehicle information of all the picking trucks 10B-<NUM>, 10B-<NUM>. operating in the operation area. The own-vehicle information of the picking truck 10B-<NUM> stored in the management device <NUM> is other-vehicle information for the picking truck 10B-<NUM>.

The main control part 30B of the picking truck 10B-<NUM> receives the other-vehicle information (i.e., the own-vehicle information of the picking truck 10B-<NUM>. ) stored in the management device <NUM> by wireless communication and sends it to the control part 21B. The main control part 30B of the another picking truck 10B-<NUM>. also receives the other-vehicle information from the management device <NUM> and sends it to the control part 21B.

In this manner, the control part 21B of the vehicle approach notification device 20B provided in each picking truck 10B acquires the own-vehicle information including the current position, the vehicle speed, the tire angle, and the lifting position H of the own vehicle, and the other-vehicle information including the current position, the vehicle speed, and the tire angle of other vehicles. Then, based on the acquired own-vehicle information and other-vehicle information, the control part 21B changes the command sent to the irradiation direction change part <NUM> to change the irradiation direction θ and the irradiation distance D. In other words, when another vehicle that satisfies the three predetermined conditions above is present, the control part 21B changes the command sent to the irradiation direction change part <NUM> to keep the mark M away from the own vehicle. When the own vehicle does not move or does not move temporarily, it is possible not to have information such as the vehicle speed and the tire angle of the own vehicle.

In parallel with this, the control part 21B also changes the command sent to the irradiation direction change part <NUM> according to the lifting position H of the driving cab <NUM> included in the acquired own-vehicle information.

For example, in the case where another vehicle that satisfies the three predetermined conditions above is not present, when the lifting position H of the driving cab <NUM> of the own vehicle changes from H1 to H3 (where H3 > H1), the control part 21B maintains the irradiation distance D at D1 by decreasing the irradiation direction θ to θ<NUM> corresponding to H3 (see (A) and (B) of <FIG>, and <FIG>). Further, in the case where another vehicle that satisfies the three predetermined conditions above is not present, when the lifting position H changes from H2 to H3 (where H2 > H3), the control part 21B maintains the irradiation distance D at D1 by increasing the irradiation direction θ to θ<NUM> (see (A) and (B) of <FIG>, and <FIG>).

Similarly, in the case where another vehicle that satisfies the three predetermined conditions above is present, when the lifting position H changes from H1 to H3 (where H3 > H1), the control part 21B maintains the irradiation distance D at D2 by decreasing the irradiation direction θ to θ<NUM>' corresponding to H3 (see (C) and (D) of <FIG>). Further, in the case where another vehicle that satisfies the three predetermined conditions above is present, when the lifting position H changes from H2 to H3 (where H2 > H3), the control part 21B maintains the irradiation distance D at D2 by increasing the irradiation direction θ to θ<NUM>' (see (C) and (D) of <FIG>).

The control part 21B constantly performs control to maintain the irradiation distance D at D1 or D2.

As described above, in the picking trucks 10A and 10B and the vehicle approach notification devices 20A and 20B according to the first embodiment and the second embodiment of the present invention, the mark M of the notification light L moves away from the vehicle only when another vehicle approaching from the rear side is present. Therefore, according to the first embodiment and the second embodiment of the present invention, while minimizing annoyance to a person far away from the vehicle, it is possible to quickly notify the passenger of another vehicle, which may collide with the own vehicle, of the presence of the own vehicle.

Further, in the picking truck 10B and the vehicle approach notification device 20B according to the second embodiment of the present invention, the irradiation distance D does not change even if the lifting position H changes. Therefore, according to the second embodiment of the present invention, it is possible to prevent the mark M from becoming thin and the visibility from being lowered at the time of high lift.

Although the first embodiment and the second embodiment of the picking truck and the vehicle approach notification device according to the present invention have been described above, the configuration of the present invention is not limited thereto.

For example, the monitoring area <NUM> may have shapes shown in (A) to (C) of <FIG>. However, to accurately find another vehicle that is approaching the own vehicle, it is preferable that the shape of the monitoring area <NUM> has a dimension in the vehicle width direction that increases as the distance from the rear side of the vehicle increases. In other words, the shape of the monitoring area <NUM> is preferably a substantially fan shape shown in <FIG> and <FIG>, a substantially triangular shape shown in (A) of <FIG>, and a shape shown in (B) of <FIG>.

Further, the irradiation direction change part <NUM> and the illumination part <NUM> constituting the vehicle approach notification devices 20A and 20B may be provided at a portion other than the head guard <NUM> of the driving cab <NUM>.

Further, the control parts 21A and 21B constituting the vehicle approach notification devices 20A and 20B may be provided on the driving cab <NUM> side instead of the vehicle body <NUM>.

Further, the control parts 21A and 21B may acquire the other-vehicle information directly from the management device <NUM> rather than from the main control parts 30A and 30B.

Further, the own-vehicle information sent by the main control part 30A to the control part 21A may include at least the current position, the vehicle speed, and the tire angle of the own vehicle, and the own-vehicle information sent by the main control part 30B to the control part 21B may include at least the current position, the vehicle speed, the tire angle, and the lifting position H of the own vehicle. When the own vehicle does not move or does not move temporarily, it is also possible not to have information such as the vehicle speed and the tire angle of the own vehicle.

Further, the own-vehicle information transmitted by the main control parts 30A and 30B to the management device <NUM> may include at least the current position, the vehicle speed, and the tire angle of the own vehicle.

Further, the other-vehicle information acquired by the control parts 21A and 21B may include at least the current position, the vehicle speed, and the tire angle of other vehicles. As described above, the control parts 21A and 21B may acquire the other-vehicle information via the main control parts 30A and 30B, or may acquire the other-vehicle information directly from the management device <NUM>.

Further, the control parts 21A and 21B may acquire the own-vehicle information from the management device <NUM> rather than from the main control parts 30A and 30B.

Further, the predetermined time "<NUM> seconds" in the first embodiment and the second embodiment is merely an example and may be changed as appropriate.

Claim 1:
A system, comprising vehicle approach notification devices (20A, 20B), and provided in each of a plurality of vehicles travelling
within a predetermined operation area, each vehicle approach notification device (20A, 20B) comprising:
an illumination part (<NUM>) that is disposed at a driving cab (<NUM>) of the vehicle and irradiates a notification light toward a road surface on a rear side of the vehicle;
an irradiation direction change part (<NUM>) that changes an irradiation direction by changing a configuration angle of the illumination part (<NUM>) with respect to the driving cab (<NUM>); and
a control part (21A, 21B) that changes a command associated with the configuration angle sent to the irradiation direction change part (<NUM>) based on own-vehicle information associated with an own vehicle and other-vehicle information associated with another vehicle,
wherein : :
the own-vehicle information comprises a current position of the own vehicle in the operation area, characterised in that:
the driving cab (<NUM>) is capable of being lifted and lowered;
the other-vehicle information comprises a current position of the another vehicle in the operation area, a tire angle of the another vehicle, and a speed of the another vehicle, and
in a case where (<NUM>) the current position of the another vehicle is within a predetermined monitoring area set on a rear side of the own vehicle, (<NUM>) a predicted position of the another vehicle after a predetermined time predicted from the current position, the tire angle, and the speed of the another vehicle is within the monitoring area after the predetermined time, and (<NUM>) the predicted position of the another vehicle is closer to a predicted position of the own vehicle than the current position of the another vehicle, the control part (21A, 21B) changes the command sent to the irradiation direction change part (<NUM>).