Working vehicle and attachment usage system

Abstract

A working vehicle includes a machine body, a position changer on the machine body, a linkage on the position changer to attach/detach an attachment thereto/therefrom, a receiver in/on the machine body to receive wireless signal(s) transmitted periodically from transmitter(s) in/on the attachment(s), including piece(s) of identification information of the attachment(s), and compliant with a near field communication standard, and a controller configured/programmed to, based on received signal strength(s) of the wireless signal(s) received by the receiver, select identification information of the attachment attached to the linkage and perform a predetermined process based on the selected identification information. The position changer is operable to be driven to change a position of the linkage relative to the machine body. The controller is configured/programmed to select, based on a selection condition varying depending on the relative position, identification information included in a wireless signal with a received signal strength satisfying the selection condition.

What is claimed is: 
     
         1 . A working vehicle comprising:
 a machine body;   a position changer provided on the machine body;   a linkage provided on the position changer to attach and detach an attachment thereto and therefrom;   a receiver provided in or on the machine body to receive one or more wireless signals which are transmitted periodically from one or more transmitters in or on one or more of the attachments, which include respective one or more pieces of identification information of the one or more attachments, and which are compliant with a near field communication standard; and   a controller configured or programmed to, based on one or more received signal strengths of the one or more wireless signals received by the receiver, select a piece of identification information of the attachment attached to the linkage and perform a predetermined process based on the selected piece of identification information; wherein   the position changer is operable to be driven to change a relative position of the linkage relative to the machine body; and   the controller is configured or programmed to select, based on a selection condition varying depending on the relative position, a piece of identification information included in a wireless signal with a received signal strength which satisfies the selection condition.   
     
     
         2 . The working vehicle according to  claim 1 , wherein
 the controller is configured or programmed to acquire a first threshold having a value that varies depending on the relative position; and   the selection condition includes a condition in which the piece of identification information to be selected by the controller is a piece of identification information included in a wireless signal with a received signal strength greater than the first threshold.   
     
     
         3 . The working vehicle according to  claim 2 , wherein the controller is configured or programmed to, when a relative distance between the machine body or the receiver and the linkage is a first distance, acquire the first threshold having a value less than when the relative distance is a second distance which is shorter than the first distance. 
     
     
         4 . The working vehicle according to  claim 3 , wherein
 the position changer includes:
 a boom supported on the machine body such that the boom is swingable up and down; and 
 an arm swingably connected to a distal portion of the boom; wherein 
   the linkage is swingably connected to a distal portion of the arm.   
     
     
         5 . The working vehicle according to  claim 4 , further comprising a posture detector to detect a posture of the boom relative to the machine body and a posture of the arm relative to the boom; wherein
 the controller is configured or programmed to acquire the first threshold based on the posture of the boom and the posture of the arm detected by the posture detector.   
     
     
         6 . The working vehicle according to  claim 5 , wherein the controller is configured or programmed to acquire the first threshold by correcting a first reference value based on the posture of the boom and the posture of the arm. 
     
     
         7 . The working vehicle according to  claim 1 , wherein
 the controller is configured or programmed to acquire a first threshold having a value that varies depending on the relative position and a second threshold having a value that varies depending on the relative position, the second threshold being greater than the first threshold; and   the selection condition includes a condition in which the piece of identification information to be selected by the controller is a piece of identification information included in a wireless signal with a received signal strength greater than the first threshold and less than or equal to the second threshold.   
     
     
         8 . The working vehicle according to  claim 7 , wherein the controller is configured or programmed to, when a relative distance between the machine body or the receiver and the linkage is a first distance, acquire the first threshold and the second threshold which have respective values less than when the relative distance is a second distance which is shorter than the first distance. 
     
     
         9 . The working vehicle according to  claim 8 , wherein
 the position changer includes:
 a boom supported on the machine body such that the boom is swingable up and down; and 
 an arm swingably connected to a distal portion of the boom; and 
   the linkage is swingably connected to a distal portion of the arm.   
     
     
         10 . The working vehicle according to  claim 9 , further comprising a posture detector to detect a posture of the boom relative to the machine body and a posture of the arm relative to the boom; wherein
 the controller is configured or programmed to acquire the first threshold and the second threshold based on the posture of the boom and the posture of the arm detected by the posture detector.   
     
     
         11 . The working vehicle according to  claim 10 , wherein the controller is configured or programmed to:
 acquire the first threshold by correcting a first reference value based on the posture of the boom and the posture of the arm; and   acquire the second threshold by correcting a second reference value based on the posture of the boom and the posture of the arm, the second reference value being greater than the first reference value.   
     
     
         12 . The working vehicle according to  claim 1 , wherein
 the controller is configured or programmed to acquire a second threshold having a value that varies depending on the relative position; and   the selection condition includes a condition in which the piece of identification information to be selected by the controller is a piece of identification information included in a wireless signal with a received signal strength less than or equal to the second threshold.   
     
     
         13 . The working vehicle according to  claim 12 , wherein the controller is configured or programmed to, when a relative distance between the machine body or the receiver and the linkage is a first distance, acquire the second threshold having a value less than when the relative distance is a second distance which is shorter than the first distance. 
     
     
         14 . The working vehicle according to  claim 13 , wherein
 the position changer includes:
 a boom supported on the machine body such that the boom is swingable up and down; and 
 an arm swingably connected to a distal portion of the boom; and 
   the linkage is swingably connected to a distal portion of the arm.   
     
     
         15 . The working vehicle according to  claim 14 , further comprising a posture detector to detect a posture of the boom relative to the machine body and a posture of the arm relative to the boom; wherein
 the controller is configured or programmed to acquire the second threshold based on the posture of the boom and the posture of the arm detected by the posture detector.   
     
     
         16 . The working vehicle according to  claim 15 , wherein the controller is configured or programmed to acquire the second threshold by correcting a second reference value based on the posture of the boom and the posture of the arm. 
     
     
         17 . The working vehicle according to  claim 1 , wherein
 the controller is configured or programmed to correct the received signal strength based on a relative distance between the machine body or the receiver and the linkage; and   the selection condition includes a condition in which the piece of identification information is to be selected by the controller based on a value of the corrected received signal strength relative to a reference value.   
     
     
         18 . The working vehicle according to  claim 17 , wherein the controller is configured or programmed to correct the received signal strength such that the corrected received signal strength is greater when the relative distance is a first distance than when the relative distance is a second distance which is shorter than the first distance. 
     
     
         19 . The working vehicle according to  claim 18 , wherein
 the position changer includes:
 a boom supported on the machine body such that the boom is swingable up and down; and 
 an arm swingably connected to a distal portion of the boom; and 
   the linkage is swingably connected to a distal portion of the arm.   
     
     
         20 . The working vehicle according to  claim 19 , further comprising a posture detector to detect a posture of the boom relative to the machine body and a posture of the arm relative to the boom; wherein
 the controller is configured or programmed to correct the received signal strength based on the posture of the boom and the posture of the arm detected by the posture detector.   
     
     
         21 . The working vehicle according to  claim 20 , wherein the controller is configured or programmed to acquire a first threshold as the reference value, and select a piece of identification information included in a wireless signal with a corrected received signal strength greater than the first threshold. 
     
     
         22 . The working vehicle according to  claim 20 , wherein the controller is configured or programmed to acquire, as a plurality of the reference values, a first threshold and a second threshold greater than the first threshold, and select a piece of identification information included in a wireless signal with a corrected received signal strength greater than the first threshold and less than or equal to the second threshold. 
     
     
         23 . The working vehicle according to  claim 20 , wherein the controller is configured or programmed to acquire a second threshold as the reference value, and select a piece of identification information included in a wireless signal with a corrected received signal strength less than or equal to the second threshold. 
     
     
         24 . An attachment usage system comprising:
 a position changer provided on a machine body of a working vehicle;   a linkage provided on the position changer to attach and detach an attachment thereto and therefrom;   one or more transmitters provided in or on one or more of the attachments to periodically transmit one or more wireless signals which include respective one or more pieces of identification information of the one or more attachments and which are compliant with a near field communication standard;   a receiver provided in or on the machine body to receive the one or more wireless signals which are transmitted from the one or more transmitters; and   a controller configured or programmed to, based on one or more received signal strengths of the one or more wireless signals received by the receiver, select a piece of identification information of the attachment attached to the linkage and perform a predetermined process based on the selected piece of identification information; wherein   the position changer is operable to be driven to change a relative position of the linkage relative to the machine body; and   the controller is configured or programmed to select, based on a selection condition varying depending on the relative position, a piece of identification information included in a wireless signal with a received signal strength which satisfies the selection condition.