Patent Publication Number: US-2019176677-A1

Title: Accommodation Device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2017-237638 filed Dec. 12, 2017, the disclosure of which is hereby incorporated in its entirety by reference. 
     TECHNICAL FIELD 
     This invention relates to an accommodation device for accommodating a plurality of work vehicles which carry out a work while traveling autonomously. 
     BACKGROUND DISCUSSION 
     Conventionally, there has been used a technique for causing a vehicle to travel autonomously. As an example of such vehicle which travels autonomously, there is known a work vehicle which effects unmanned traveling while carrying out a predetermined work (e.g. grass cutting/mowing work) in a vast field. 
     An unmanned traveling work vehicle disclosed in Patent Document 1 includes an electric motor mounted on a vehicle body and receiving power from a battery and an engine mounted on the vehicle body. In operation, as the vehicle travels in a work area with driving its wheels by the engine, an implement mounted on the vehicle body is driven by the electric motor for carrying out a work. 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-164741 
     SUMMARY 
     Problem to be Solved by Invention 
     Here, the work carried out by the unmanned work vehicle disclosed in Patent Document 1 can be carried out with using not only an unmanned traveling work vehicle owned by an individual, but by an unmanned traveling work vehicle owned by a contractor firm. And, such contractor firm can sometimes carry out a plurality of contracted works with using a plurality of unmanned traveling work vehicles. The technique disclosed in Patent Document 1 does not contemplate or expect transportation of a work vehicle(s) to a work site where the contracted work is to be carried out. So smooth transportation of the work vehicle(s) may not be possible. 
     Then, there is a need for an accommodation device capable of transporting a work vehicle(s) smoothly. 
     Solution 
     According to a characterizing feature of an accommodation device relating to the present invention, an accommodation device configured to accommodate a plurality of work vehicles that carry out a work while traveling autonomously, comprises: 
     a plurality of accommodation cases mounted on a load carrying bed of a transporter vehicle and capable of accommodating the plurality of work vehicles individually; 
     a supporting section for supporting the plurality of accommodation cases respectively with allowing movement thereof along a preset path; 
     an actuator for driving the supporting section for causing the accommodation cases to move along the path; and 
     an electric generator for supplying electric power to the actuator. 
     With the above-described characterizing feature, it becomes possible to transport a plurality of work vehicles smoothly. Therefore, even when a contractor firm owning a plurality of work vehicles is to travel to a plurality of work sites different from each other, the assignment can be accomplished by a smaller number of attendants. 
     Further, preferably, the accommodation device further comprises: 
     a detection section for detecting a stored power amount of the battery mounted on the work vehicle as the work vehicle is accommodated in the accommodation case; and 
     a power storage section for charging electric power to the battery to be stored therein with using electric power from the electric generator in case the stored power amount of the battery falls short of a preset power storage amount. 
     With the above-described arrangement, it becomes possible to charge a battery of the work vehicle during transportation thereof by a transporter vehicle. Therefore, it becomes possible to carry out the work by the work vehicle speedily at the destination of the transporter vehicle. 
     Further, preferably, the accommodation device further comprises: 
     a temperature sensor mounted on the work vehicle for detecting an ambient temperature; 
     a gas cylinder mounted on the work vehicle and charged with fire extinguishing gas; and 
     a valve control section configured to open a valve of the gas cylinder when the ambient temperature becomes equal to or higher than a preset temperature. 
     With the above-described arrangement, even if a fire should occur in the vicinity of the work vehicle, such fire can be extinguished automatically. Thus, as catching fire by the work vehicle can be prevented, even when a user is not present nearby, damage or deterioration of the work vehicle can be prevented. Further, if the fire extinguishing gas was used, only its cylinder can be replaced. So, increase of component cost can be suppressed advantageously. 
     Moreover, preferably: 
     the work to be carried out by the work vehicles is a grass cutting work for cutting grass growing in the work site; and 
     the work vehicle includes an air blowing section for blowing air onto a dropped object in the work site. 
     With the above-described arrangement, it becomes possible to collect dropped objects in a work site automatically at time of the work by the work vehicle. Therefore, collection of dropped objects in a work site is possible without giving trouble to the user. 
     Further, preferably: 
     the work to be carried out by the work vehicles is a grass cutting work for cutting grass growing in the work site; and 
     the work vehicle includes an arm portion that extends from a vehicle body along a work surface of the work site in a direction intersecting an advancing direction of the work vehicle. 
     With the above arrangement too, collection of dropped objects in a work site is possible without giving trouble to the user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a work vehicle, 
         FIG. 2  is a plan view of the work vehicle, 
         FIG. 3  is a view showing a mode of collecting grass leaves by air blowing, 
         FIG. 4  is a view showing a mode of collecting grass leaves by arm portions, 
         FIG. 5  is a view schematically showing a configuration of an accommodation device, and 
         FIG. 6  is a view illustrating charging of a battery. 
     
    
    
     EMBODIMENT 
     An accommodation device relating to the present invention is configured to be able to transport a work vehicle(s) smoothly. This accommodation device is a device for accommodating a plurality of work vehicles that carry out a work while traveling autonomously. In the following discussion, there will be explained an exemplary case of carrying out a grass (lawn) cutting (mowing) work for cutting grass (lawn) grown or planted in a work site. Here, the language “autonomous traveling” relating to the instant embodiment refers to traveling along a traveling route set based on an output of a device mounted on the work vehicle (e.g. an output of a sensor, a captured image captured by a camera, etc.), while avoiding objects (e.g. obstacles, etc.). Such work vehicle corresponds to a so-called autonomous robot. 
       FIG. 1  shows a side view of a work vehicle  1  to be accommodated in an accommodation device  100  (see  FIG. 5 ) relating to the instant embodiment.  FIG. 2  shows a plan view of the work vehicle  1 . As shown in  FIG. 1  and  FIG. 2 , the work vehicle  1  includes wheels  2  and a vehicle body  3 . The wheels  2  consist of first wheels  2 A on one end side in a vehicle longitudinal direction of the vehicle body and second wheels  2 B on the other end side in the vehicle longitudinal direction. The first wheels  2 A and the second wheels  2 B are provided respectively one left and right pair along a width direction of the vehicle body. In the instant embodiment, the first wheels  2 A are configured as driving/steerable wheels provided on the rear side in the advancing direction of the work vehicle  1  and driven by a traveling control device  10  to be described later. The second wheels  2 B are configured as so-called caster wheels provided on the front side in the advancing direction of the work vehicle  1 . Accordingly, when the left and right wheels of the first wheels  2 A are rotated at an equal speed and in a same direction, straight traveling is effected. When the left and right wheels of the first wheels  2 A are rotated at different speeds and in a same direction, steering is effected to the side of the slower speed one of the left and right wheels of the first wheels  2 A. Further, when the left and right wheels of the first wheels  2 A are rotated at an equal speed and in different directions, the work vehicle  1  can spin at its present position. Incidentally, although it was explained in the above that the first wheels  2 A and the second wheels  2 B are provided respectively one left and right pair along the width direction of the vehicle body, this is just one example. Alternatively, it is also possible to configure such that the respective numbers of the first wheels  2 A and the second wheels  2 B differ from each other depending on e.g. the size of the vehicle body or they are comprised of either one or three or more wheels. 
     The vehicle body  3  mounts a pair of motors  4  as power source for the first wheels  2 A, a battery  5  for storing an amount of electric power to be supplied to the motors  4  and other electric devices included in the work vehicle  1 , the traveling control device  10  for controlling traveling of the work vehicle  1 , and a motor  6  driven by power supplied from the battery  5  for driving a grass cutter device  53  (an example of “implement unit”) having a cutter blade  54  used in cutting grass. 
     Further, the vehicle body  3  mounts a GPS module  99  constituted as a GNSS module. This GPS module  99  has a GPS antenna for receiving GPS signals or GNSS signals (“GPS signals” in the instant embodiment). Incidentally, for complementing the GPS navigation, the GPS module  99  may include an inertial navigation module incorporating a gyro acceleration sensor a magnetic field sensor. Needless to say, such inertial navigation module may be provided at a site different from the GPS module  99 . The GPS signals acquired by the GPS module  99  will be utilized in autonomous traveling of the work vehicle  1  described above. 
     The work vehicle carries out a grass cutting work on grass grown or planted in a work site. In such work site, there can be leaves which have fallen from trees in its surrounding. Further, there may be fallen wastepaper, bodies of insects, etc. there. Then, the work vehicle  1  is provided with an air blowing section  51  for blowing air to such fallen objects present in the work site. The “fallen objects” in the work site correspond to leaves, wastepaper, insect bodies, etc. described above. In the instant embodiment, the following explanation will be made with citing leaves as fallen objects in the work site. The work vehicle  1  is configured to blow air from the air blowing section  51  in the direction toward a designated place. With this, as shown in  FIG. 3 , leaves receiving the air from the air blowing section  51  of the work vehicle  1  can be collated at the designated place. Incidentally, the air from the air blowing section  51  may be discharged constantly while the work vehicle  1  is carrying out a grass cutting work or may be discharged if presence of fallen leaves in the work site is detected by using a captured image captured by an unillustrated camera or a sonar. 
     Further, in the instant embodiment, the work vehicle  1  is provided with arm portions  52  which extend from the vehicle body in directions intersecting the advancing direction of the work vehicle  1  and along the work surface of the work site. In the instant embodiment, as shown in  FIG. 2 , these arm portions  52  are stored at lateral face portions of the work vehicle  1  and can be spread out when needed in the directions intersecting the advancing direction of the work vehicle  1  to be capable of collecting the fallen objects in the work site (e.g. leaves, wastepaper, insect bodies, etc.). With this, as illustrated in  FIG. 4 , the fallen objects can be collected by the arm portions  52 . Further, the arm portions  52  can be arranged to be spread out constantly while the work vehicle  1  is carrying out a grass cutting work or may be arranged to be spread out when presence of fallen leaves in the work site is detected by using a captured image captured by the unillustrated camera or the sonar. Incidentally, for the fallen objects in the work site, both of the air blowing section  51  and the arm portions  52  may be employed or either one of them may be employed. 
     In the above, although the work vehicle  1  carries out a grass cutting work, the cut grass clippings will be discharged onto the work site for the so-called mulching purpose. Then, if such discharged grass clippings catch fire which then extends to the work vehicle  1 , the work vehicle  1  may not be used continuously. Then, this work vehicle  1  is configured to prevent such catching fire. In the instant embodiment, as shown in  FIG. 2 , the work vehicle  1  mounts a temperature sensor  41  for detecting an ambient temperature. Here, “ambient temperature” refers to the temperature at the position where the temperature sensor  41  is disposed. In  FIG. 2 , the temperature sensor  41  is accommodated within the vehicle body  3 , but may be provided on the outer face of the vehicle body  3  instead. The temperature sensor  41  detects the temperature (ambient temperature) its disposed location and transmits detection result to a valve control section  43  to be described later. 
     The work vehicle  1  further mounts a gas cylinder  42  charged with an amount of fire extinguishing gas. This fire extinguishing gas is gas that extinguishes fire or suppress catching fire by its suffocation effect of covering up combustible objects. 
     Specifically, carbon dioxide gas can be cited as an example thereof. The gas cylinder  42  is charged/filled with such carbon dioxide gas. Needles to say, the gas cylinder  42  may be charged/filled with nitrogen gas, so that fire may be extinguished or catching fire may be suppressed by increasing the nitrogen gas concentration to reduce the oxygen concentration inside the vehicle body  3 . 
     The valve control section  43  is configured to open a valve of the gas cylinder  42  when the ambient temperature becomes equal to or higher than a preset temperature. The ambient temperature will be transmitted as detection result from the temperature sensor  41 . Here, the “preset temperature” may be set as a temperature at which fire can be detected or a temperature at which catching of fire by an object will hardly occur. Then, the valve control section  43  automatically opens the valve of the gas cylinder  42  if the detection result of the temperature sensor  41  is equal to or higher than the preset temperature. With this, the fire extinguishing gas charged in the gas cylinder  42  will be jetted, whereby fire if occurred will be extinguished or nearly catching fire condition may be suppressed for preventing catching fire. 
       FIG. 5  is a block diagram schematically showing a configuration of the accommodation device  100  of the instant embodiment. Further,  FIG. 6  is a view illustrating charging of the battery  5  of the work vehicle  1 . As shown in  FIG. 5  and  FIG. 6 , the accommodation device  100  includes, as functional sections thereof, accommodation cases  21 , a supporting section  22 , an actuator  23 , an electric generator  24 , a detection section  25  and a power storage section  26 . These respective functional sections can be constituted of hardware and/or software including a CPU as a core component thereof in order to carry out various operations relating to accommodation of the work vehicle  1 . 
       FIG. 5  shows that the accommodation cases  21  are spaced from the supporting section  22 , the actuator  23  and the electric generator  24 . In actuality, however, the accommodation cases  21  are mounted as being joined to the supporting section  22  and the accommodation cases  21 , the supporting section  22 , the actuator  23  and the electric generator  24  will mounted altogether on a load carrying bed of a transporter vehicle (e.g. a truck)  300 . 
     The accommodation cases  21  are provided in plurality so as to be able to accommodate a plurality of work vehicles  1  individually therein. In  FIG. 5 , there is shown an example in which the work vehicles  1  are accommodated in six accommodation cases  21  respectively. Each accommodation case  21  is moved along the supporting section  22  as will be described later. In this, in order to prevent accidental exiting or dropping of the work vehicle  1  from the accommodation case  21 , a shutter may be attached to the opening portion of the accommodation case  21 . 
     The supporting section  22  is arranged to support the plurality of accommodation cases  21  with allowing movements thereof along a preset path. In the instant embodiment, the supporting section  22  is formed like a “rail” of a preset path (track) (vertically disposed in the example shown in  FIG. 5 ) and supports the accommodation cases  21  from the lateral sides thereof. Though not shown, in a side face of the accommodation case  21 , a joint portion connectable to the supporting section  22  may be provided, so that this joint portion and the supporting section  22  may be joined to each other. The supporting section  22  is arranged to be rotatable along an arrow A shown in  FIG. 5 . With this arrangement, it becomes possible to provide an instruction for causing each accommodation case  21  to move along the preset path. 
     The actuator  23  drives the supporting section  22  for causing the accommodation cases  21  to move along the path. As described above, the supporting section  22  is provided along the preset path and supports the accommodation cases  21 . And, the actuator  23  is arranged to render the supporting section  22  to be rotatable as indicated by the arrow A. With this, the accommodation cases  21  as accommodating the work vehicles  1  therein will be moved along the path. This movement can be done by an operation of a switch by the user. 
     The electric generator  24  supplies electric power to the actuator  23 . The actuator  23 , as configured as an electrically driven type, is driven by the power supplied from the electric generator  24 . With the above-described configuration of the accommodation device  100 , it is possible to transport the plurality of work vehicles  1  smoothly by the transporter vehicle  300 , thus allowing use of a required number of work vehicles  1  according to the work site and/or contents of the work. 
       FIG. 6  shows a mode of charging of the battery  5  of the work vehicle  1 . As shown in  FIG. 6 , each accommodation case  21  includes the detection section  25  and the power storage section  26 . The detection section  25  detects a stored power amount of the battery  5  mounted on the work vehicle  1  as this work vehicle  1  is accommodated within the accommodation case  21 . To this end, in an inner wall portion of the accommodation case  21 , there is provided a connection terminal  201  connectable to a charging terminal  7  provided at the front end portion of the work vehicle  1 . As the work vehicle  1  is accommodated in the accommodation case  21  from the front side in the advancing direction, it is arranged such that the charging terminal  7  and the connection terminal  201  are connected to each other. Via this connection terminal  201 , the stored power amount of the battery  5  is detected. It is not easy to detect this stored power amount directly. Thus, preferably, an arrangement may be made such that the detection section  25  detects an output voltage of the battery  5  via the connection terminal  201  and then detects the stored power amount on a difference between this output voltage and an output voltage at time of fully charged state of the battery  5 . As such detection is known, explanation thereof will be omitted herein. The detection result of the detection section  25  will be transmitted to the power storage section  26  to be described later. 
     The power storage section  26  charges the battery  5  with using the electric power from the electric generator  24  if the stored power amount of the battery  5  is equal to or smaller than a preset stored power amount. Such preset stored power amount can be set to be 50% of the fully charged stored power amount (100%) of the battery  5 . Needless to say, it may also be set as any other value (i.e. a value greater than 50% or a value smaller than 50%). The power storage section  26  allows power storage in the battery  5  by the power from the electric generator  24  if the detection result of the detection section  25  is equal to or smaller than the preset stored power amount (e.g. 50% of the fully charged stored power amount). 
     With the above arrangement, if the stored power amount of the battery  5  of the work vehicle  1  accommodated in the accommodation case  21  falls short of the predetermined stored power amount, charging can be done automatically even during transportation by the transporter vehicle  300 . Therefore, as there is no need to provide a charger device for each work site, installment cost can be reduced. Further, in case such grass cutting work is to be carried out by a contractor, the contractor will deliver the work vehicles  1  to the work site to cause them to carry out the work and will collect the work vehicles  1  after completion of the work, thus, eliminating need to install a charging stand. On the side of the client of the contracted work too, no charging stand needs to be installed. So, capital investment can be eliminated. 
     Other Embodiments 
     In the foregoing embodiment, it was explained that the accommodation device  100  includes the detection section  25  and the power storage section  26 . However, the accommodation device  100  can be configured with omission of the detection section  25  and the power storage section  26 . In such case, it will be advantageous to arrange for instance such that charging will be done irrespectively of the stored power amount of the battery  5  when the work vehicle  1  is accommodated in the accommodation case  21 . 
     In the foregoing embodiment, it was explained that the work vehicle  1  includes the temperature sensor  41 , the gas cylinder  42  and the valve control section  43 . However, the work vehicle  1  can be configured with omission of the temperature sensor  41 , the gas cylinder  42  and the valve control section  43 . 
     In the foregoing embodiment, it was explained that the work vehicle  1  includes the air blowing section  51  and the arm portions  52 . However, the work vehicle  1  can be configured with omission of the air blowing section  51  and the arm portions  52 . 
     In the foregoing embodiment, it was explained that the work is a grass cutting work. However, it may be any other work. 
     INDUSTRIAL APPLICABILITY 
     The present invention is applicable to an accommodation device for accommodating a plurality of work vehicles which carry out a work while traveling autonomously. 
     REFERENCE SIGN LIST 
       1 : work vehicle 
       5 : battery 
       21 : accommodation case 
       22 : supporting section 
       23 : actuator 
       24 : electric generator 
       25 : detection section 
       26 : power storage section 
       41 : temperature sensor 
       42 : gas cylinder 
       43 : valve control section 
       51 : air blowing section 
       52 : arm portion 
       100 : accommodation device 
       300 : transporter vehicle