Patent Publication Number: US-2023150392-A1

Title: Battery swapping station and control method therefor

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation Application of U.S. patent application Ser. No. 16/768,084 filed on Jul. 23, 2020, which is a national-phase application of PCT Application No. PCT/CN2018/118558 filed on Nov. 30, 2018, which requests the priority of the Chinese patent application with the application date of Nov. 30, 2017 and the application number of CN201711240305.X. This application refers to the full text of the above-mentioned Chinese patent application. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a battery swapping station and a control method therefor. 
     BACKGROUND 
     Nowadays, vehicle exhaust emission still presents as an important factor of environmental pollution. To govern the vehicle emissions, the human kind has developed natural gas cars, hydrogen cars, solar cars and electric cars to take the place of oil-fueled cars. Electric cars are the most prospecting one. 
     Direct-charge electric cars are mostly small cars, for example, taxis and family cars. Direct-charge electric cars are currently charged by the charging piles built on the ground. However, the charging piles are difficult to manage, especially with the increasing popularity of electric cars, centralized management of charging to the electric cars becomes more difficult. 
     Quick-change is currently used for bus system. At the quick-change station, the on-board power battery of electric buses can be quickly changed to ensure the continuous operation of those electric buses. But, at present, the problems of long time for battery change and low efficiency in change operation exist in the quick-change station. 
     DISCLOSURE OF THE INVENTION 
     Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. 
     It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. 
     The present invention provides a high-efficient battery swapping station and a control method therefor, to overcome the deficiencies of the battery swapping station in the prior art that the battery change time is long and the change efficiency is low. 
     The present invention solves the above technical problems by the following technical solutions: 
     A battery swapping station, comprising:
         a first charging compartment and a second charging compartment, both the first charging compartment and the second charging compartment being used to store a battery of a vehicle and charge the battery of the vehicle;   a first battery swapping platform, the first battery swapping platform being arranged between the first charging compartment and the second charging compartment; and the first battery swapping platform being used to swap the batteries of the vehicle;   a first shuttle and a second shuttle, the first shuttle travels between the first battery charging compartment and the first battery swapping platform, the second shuttle travels between the second battery charging compartment and the first battery swapping platform, and the first shuttle and the second shuttle are both used for executing the operations of battery unmounting and battery mounting for the vehicle on the first battery swapping platform; and   a control unit, the control unit is electrically connected to the first shuttle and to the second shuttle, the control unit is used for controlling the first shuttle and the second shuttle to perform the following operations: when operating a same vehicle on the first battery swapping platform, if the first shuttle is executing either operation of battery unmounting or battery mounting, the second shuttle execute the other operation of battery unmounting or battery mounting.       

     Preferably, the battery swapping station further comprises a second battery swapping platform and a third shuttle;
         the second battery swapping platform is arranged at the opposite side of the first battery charging compartment relative to the first battery swapping platform;   the third shuttle travels between the first battery charging compartment and the second battery swapping platform and is electrically connected to the control unit, and the third shuttle is used to execute operations of battery unmounting and battery mounting for a vehicle on the second battery swapping platform.       

     A plurality of battery swapping channels (the second battery swapping platform) are arranged in the battery swapping station, which allows battery swapping for multiple vehicles at the same time, thus reducing the waiting time. 
     Preferably, a first stacker and a second stacker are arranged respectively in the first battery charging compartment and the second battery charging compartment, wherein both of the first stacker and the second stacker are electrically connected to the control unit;
         a first front compartment and a first rear compartment which are mutually communicated are formed in the first battery charging compartment, the first stacker travels between the first front compartment and the first rear compartment, the first shuttle swaps batteries with the first stacker in the first front compartment, the first rear compartment is used to store a first battery rack, and the first stacker is used to pick and place batteries on the first battery rack;   a second front compartment and a second rear compartment which are mutually communicated are formed in the second battery charging compartment, the second stacker travels between the second front compartment and the second rear compartment, the second shuttle swaps batteries with the second stacker in the second front compartment, the second rear compartment is used to store a second battery rack, and the second stacker is used to pick and place batteries on the second battery rack;       

     Preferably, the first battery swapping platform is respectively connected to an uphill ramp and to a downhill ramp at upstream and the downstream of a travelling direction of the vehicle. 
     Preferably, the battery swapping station further comprises a first monitoring compartment;
         in the direction of a vehicle travelling to the first battery swapping platform, the first monitoring compartment is arranged at the upstream of the first battery charging compartment; and the control unit is arranged in the first monitoring compartment.       

     Preferably, the battery swapping station further comprises a first monitoring compartment and a second monitoring compartment;
         the control unit comprises a first monitoring device and a second monitoring device, the first monitoring device and the second monitoring device are respectively arranged in the first monitoring compartment and the second monitoring compartment;   the first monitoring device is used for controlling the first shuttle to alternately execute the operations of battery unmounting and battery mounting for the vehicle on the first battery swapping platform.   the second monitoring device is used for controlling the second shuttle to alternately execute the operations of battery unmounting and battery mounting for the vehicle on the first battery swapping platform.       

     Preferably, the first shuttle comprises a chassis, a lifting frame and a jacking mechanism;
         the jacking mechanism is connected to the chassis and the lifting frame and used to lift the lifting frame relative to the chassis; the jacking mechanism comprises a connecting rod, a first end of the connecting rod connected to the lifting frame in a rotary way, and a second end of the connecting rod connected to the chassis in a rotary way;   the lifting frame is used for unmounting and mounting the battery of the vehicle.       

     Preferably, the connecting rod is a cam. 
     A control method applied to the battery swapping station as described above, the control method comprises following steps:
         S 1 : when a vehicle does not travel into the first battery swapping platform, the control unit controls the first shuttle to pick up a fully-charged battery from the first battery charging compartment and stand by in the first battery charging compartment;   S 2 : after the vehicle travels into the first battery swapping platform, the control unit controls the second shuttle to travel to the first battery swapping platform and unmount the battery of the vehicle.   S 3 : the control unit controls the first shuttle to mount the fully-charged battery on the vehicle which is on the first battery swapping platform;       

     Preferably, in the step S 2 , after the second shuttle unmounts the battery of the vehicle, the control unit controls the second shuttle to transfer the battery of the vehicle to the second battery charging compartment for charging and pick up a fully-charged battery from the second battery charging compartment and stand by in the second battery charging compartment;
         in the step S 3 , after the first shuttle mounts the fully-charged battery on the vehicle which is on the first battery swapping platform, the control unit controls the first shuttle to return to the first battery charging compartment to stand by;   the control method further comprises following steps:   S 4 : after a next vehicle travels to the first battery swapping platform, the control unit controls the first shuttle to travel to the first battery swapping platform and unmount the battery of the vehicle, after the first shuttle unmounts the battery of the vehicle, the control unit controls the first shuttle to transfer the battery of the vehicle to the first battery charging compartment for charging and pick up the fully-charged battery in the first battery charging compartment and stand by in the first battery charging compartment;   S 5 : the control unit controls the second shuttle to mount the fully-charged battery on the vehicle which is on the first battery swapping platform; after the second shuttle mounts the fully-charged battery on the vehicle, the control unit controls the second shuttle to return the second battery charging compartment to stand by;   S 6 : return to the step S 2 .       

     The positive progress effect of the present invention lies in that: the battery swapping station and the control method therefor, by means of alternating operations of the first shuttle and the second shuttle, reduce the waiting time for vehicles when swapping batteries, thus increasing the battery swapping efficiency of the battery swapping station. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic planar structure diagram of a battery swapping station according to a preferred embodiment of the present invention.  FIG.  2    is a schematic flow diagram of a control method of a battery swapping station according to a preferred embodiment of the present invention.  FIG.  3    is a schematic perspective diagram of a shuttle battery pack replacing device according to a preferred embodiment of the present invention.  FIG.  4    is a schematic perspective diagram of a chassis according to a preferred embodiment of the present invention.  FIG.  5    is a schematic perspective diagram of a lifting frame according to a preferred embodiment of the present invention.  FIG.  6    is a partial schematic structure diagram of a shuttle battery pack replacing device according to a preferred embodiment of the present invention, wherein, the battery lifting portion and the vehicle fixing portion are removed.  FIG.  7    is a schematic perspective diagram of a cam according to a preferred embodiment provided by the present invention.  FIG.  8    is a schematic structure diagram of assembly of a cam and a lifting frame according to a preferred embodiment of the present invention.  FIG.  9    is a schematic perspective diagram of a vehicle fixing portion according to a preferred embodiment of the present invention.  FIG.  10    is a schematic perspective diagram of a battery lifting portion according to a preferred embodiment of the present invention.  FIG.  11    is another schematic perspective diagram of a battery lifting portion according to a preferred embodiment of the present invention.  FIG.  12    is a schematic perspective diagram of a second moving frame according to a preferred embodiment of the present invention.  FIG.  13    is a schematic perspective diagram of a tray according to a preferred embodiment of the present invention.  FIG.  14    is a schematic structure diagram of another part of a shuttle battery pack replacing device according to a preferred embodiment of the present invention, wherein, the battery lifting portion is removed.  FIG.  15    is a schematic structure diagram of a battery swapping platform according to a preferred embodiment of the present invention. 
     
    
    
     Description of symbols in the Figures: chassis  101 ; first side wall  102 ; second side wall  103 ; guide portion  104 ; rotating shaft  105 ; lifting frame  106 ; guide groove  107 ; vehicle fixing portion  120 ; first moving frame  121 ; first fork  122 ; unlocking mechanism  123 ; connecting plate  124 ; guide opening  125 ; battery lifting portion  130 ; second moving frame  131 ; insertion slot  132 ; tray  133 ; second fork  134 ; spring  135 ; insertion piece  136 ; guide block  140 ; guide rail  150 ; first driving portion  160 ; second driving portion  170 ; cam  181 ; insertion axis  182 ; bearing  183 ; jacking drive unit  184 ; pulley  185 ; first end  186 ; second end  187 ; battery swapping platform  190 ; lifting mechanism  191 ; vehicle  200 ; battery  210 ; battery swapping station  300 ; first battery swapping platform  301 ; second battery swapping platform  302 ; third shuttle  303 ; uphill ramp  304 ; downhill ramp  305 ; first full-function container  310 ; first battery charging compartment  311 ; first front compartment  312 ; first rear compartment  313 ; first monitoring compartment  314 ; first operating compartment  315 ; first monitoring device  316 ; first stacker  317 ; first shuttle  318 ; first battery rack  319 ; second full-function container  330 ; second battery charging compartment  331 ; second front compartment  332 ; second rear compartment  333 ; second monitoring compartment  334 ; second operating compartment  335 ; second monitoring device  336 ; second stacker  337 ; second shuttle  338 ; second battery rack  339 . 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Combining the drawings, the present invention is further described below with embodiments, but the present invention is not hence limited within the range of the embodiments. 
     As shown in  FIG.  1   , a battery swapping station  300  comprises a first full-function container  310  and a second full-function container  330 , and the first full-function container  310  and the second full-function container  330  are arranged side by side. A first battery swapping platform  301  is arranged between the first full-function container  310  and the second full-function container  330 , while a second battery swapping platform  302  is arranged at the opposite side of the first full-function container  310  and the second full-function container  330  relative to the first battery swapping platform  301 . A battery of a vehicle  200  can be replaced on the first battery swapping platform  301  and the second battery swapping platform  302 . The first battery swapping platform  301  is respectively connected to an uphill ramp  304  and to a downhill ramp  305  at upstream and the downstream of a travelling direction of the vehicle  200 , and the second battery swapping platform  302  is respectively connected to an uphill ramp  304  and to a downhill ramp  305  at upstream and the downstream of a travelling direction of the vehicle  200 . 
     A first battery charging compartment  311  and a first monitoring compartment  314  are arranged in the first full-function container  310 . 
     The first battery charging compartment  311  is used to store and charge the battery of the vehicle  200 . A first stacker  317  and a first shuttle  318  are also arranged in the first battery charging compartment  311 . The first shuttle  318  travels between the first battery charging compartment  311  and the first battery swapping platform  301 . The first shuttle  318  is used for executing the operations of battery unmounting and battery mounting for the vehicle  200  on the first battery swapping platform  301 . A first front compartment  312  and a first rear compartment  313  are mutually communicated and formed in the first battery charging compartment  311 , the first stacker  317  travels between the first front compartment  312  and the first rear compartment  313 , the first shuttle  318  swaps batteries with the first stacker  317  in the first front compartment  312 , the first rear compartment  313  is used to store a first battery rack  319 , and the first stacker  317  is used to pick and place batteries on the first battery rack  319 . 
     In the direction in which the vehicle  200  travels to the first battery swapping platform  301 , a first monitoring compartment  314  is arranged at upstream of the first battery charging compartment  311 , and a first monitoring device  316  is arranged in the first monitoring compartment  314 . In addition to a first monitoring device  316 , a first operating compartment  315  for an operator&#39;s access is further arranged in the first monitoring compartment  314 . The first monitoring device  316  is electrically connected to the first shuttle  318 , the first stacker  317  and the battery rack for controlling the action of the first shuttle  318  and the first stacker  317 , and monitoring the charging condition of the first battery rack  319 . 
     A second battery charging compartment  331  and a second monitoring compartment  334  are arranged in the second full-function container  330 . 
     The second battery charging compartment  331  is used to store the battery of the vehicle  200  and charge the battery of the vehicle  200 . A second stacker  337  and a second shuttle  338  are further arranged in the second battery charging compartment  331 . The second shuttle  338  travels between the second battery charging compartment  331  and the second battery swapping platform  302 . The second shuttle  338  is used for executing operations of battery unmounting and battery mounting for the vehicle  200  on the first battery swapping platform  301 . A second front compartment  332  and a second rear compartment  333  are mutually connected and formed in the second battery charging compartment  331 , the second stacker  337  travels between the second front compartment  332  and the second rear compartment  333 , the second shuttle  338  swaps batteries with the second stacker  337  in the second front compartment  332 , the second rear compartment  333  is used to store a second battery rack  339 , and the second stacker  337  is used to pick and place batteries on the second battery rack  339 . 
     In the direction in which the vehicle  200  travels to the first battery swapping platform  301 , a second monitoring compartment  334  is arranged at upstream of the second battery charging compartment  331 , and a second monitoring device  336  is arranged in the second monitoring compartment  334 . In addition to a second monitoring device  336 , a second operating compartment  335  for an operator&#39;s access is further arranged in the second monitoring compartment  334 . The second monitoring device  336  is electrically connected to the second shuttle  338 , the second stacker  337  and the battery rack for controlling the action of the second shuttle  338  and the second stacker  337  and monitoring the charging condition of the second battery rack  339 . 
     A third shuttle  303  is arranged at the opposite side of the first stacker  317  relative to the first shuttle  318  and at the opposite of the second stacker  337  relative to the second shuttle  338 . The third shuttle  303  travels between the first battery charging compartment  311  and the second battery swapping platform  302 , and the third shuttle  303  is electrically connected respectively to the first monitoring device  316  and the second monitoring device  336 , the third shuttle  303  is used for executing operations of battery unmounting and battery mounting for the vehicle  200  on the second battery swapping platform  302 . 
     When operating a same vehicle  200  on the first battery swapping platform  301 , if the first shuttle  318  is executing either operation of battery unmounting or battery mounting, the second shuttle  338  executes the other operation of battery unmounting or battery mounting, and the first shuttle  318  and the second shuttle  338  alternatively execute the operations of battery unmounting and battery mounting, so that the batteries of the vehicle  200  can be swapped quickly. While, the second battery swapping platform  302  follows the normal battery swapping process. 
     The process of battery swapping on the first battery swapping platform  301  is described below according to  FIG.  2   . 
     Step S 1 : when the vehicle  200  does not travel into the first battery swapping platform  301 , the first monitoring device  316  controls the first shuttle  318  to pick up a fully-charged battery from the first battery charging compartment  311  and stand by in the first battery charging compartment  311 . 
     Step S 2 : after the vehicle  200  travels into the first battery swapping platform  301 , the second monitoring device  336  controls the second shuttle  338  to travel to the first battery swapping platform  301  and unmount the battery of the vehicle  200 ; after the second shuttle  338  unmounts the battery of the vehicle  200 , the second monitoring device  336  controls the second shuttle  338  to transfer the battery of the vehicle  200  to the second battery charging compartment  331  for charging and pick up a fully-charged battery from the second battery charging compartment  331  and stand by in the second battery charging compartment  331 . When the second shuttle  338  unmounts the battery of the vehicle  200 , the first shuttle  318  can travel to one side of the vehicle  200  to stand by, so that when the second shuttle  338  travels out of the bottom of the vehicle  200  from the other side of the vehicle  200 , the first shuttle  318  can travel into the bottom of the vehicle  200  from one side of the vehicle  200  to install battery for the vehicle  200 . This can further save the time for swapping batteries. 
     Step S 3 : the first monitoring device  316  controls the first shuttle  318  to mount the fully-charged battery on the vehicle  200  which is on the first battery swapping platform  301 ; after the first shuttle  318  mounts the fully-charged battery on the vehicle  200  on the first battery swapping platform  301 , the first monitoring device  316  controls the first shuttle  318  to return to the first battery charging compartment  311  to stand by. 
     Step S 4 : when a next vehicle  200  travels into the first battery swapping platform  301 , the first monitoring device  316  controls the first shuttle  318  to travel to the first battery swapping platform  301  and unmount the battery of the vehicle  200 ; after the first shuttle  318  unmounts battery of the vehicle  200 , the first monitoring device  316  controls the first shuttle  318  to transfer the battery of the vehicle  200  to the first battery charging compartment  311  for charging and pick up a fully-charged battery from the first battery charging compartment  311  and stand by in the first battery charging compartment  311 . When the first shuttle  318  unmounts the battery of the vehicle  200 , the second shuttle  338  can travel to one side of the vehicle  200  to stand by, so that when the first shuttle  318  travels out of the bottom of the vehicle  200  from the other side the vehicle  200 , the second shuttle  338  can travel into the bottom of the vehicle  200  from one side of the vehicle  200  to install battery for the vehicle  200 . 
     Step S 5 : the second monitoring device  336  controls the second shuttle  338  to mount the fully-charged battery on the vehicle  200  on the first battery swapping platform  301 ; after the second shuttle  338  mounts the fully-charged battery on the vehicle  200 , the second monitoring device  336  controls the second shuttle  338  to return the second battery charging compartment  331  to stand by. 
     Step S 6 : return to the step S 2 . 
     In the above process, although the first monitoring device  316  and the second monitoring device  336  respectively control the device in the first full-function container  310  and the second full-function container  330 , the first monitoring device  316  is also electrically connected to the second monitoring device  336  by means of wireless and wired communication to mutually coordinate and give instructions. 
     In the present embodiment, the first shuttle  318 , the second shuttle  338 , and the third shuttle  303  all adopt a cam structure, other than a traditional shear structure so that the initial height of the shuttles is low, thus to avoid setting deep pits on the battery swapping platforms resulting in reducing the overall height of the battery swapping platforms and decreasing the construction cost of the battery swapping station  300 . 
     The structure of the first shuttle  318  is described below according to  FIGS.  3 - 14   . The structure of the second shuttle  338  and the structure of the third shuttle  303  are basically the same as that of the first shuttle  318  and will not be described again. 
     As shown in  FIG.  3   , the first shuttle  318  comprises a chassis  101 , a lifting frame  106 , a battery lifting portion  130 , a vehicle fixing portion  120  and a jacking mechanism. 
     As shown in  FIG.  4   , the chassis  101  presents a four-frame structure, and the lifting frame  106  is arranged in the four-frame structure. A cam  181  is connected to the inner side of the two opposing first side walls  102  of the chassis  101 , and a guide portion  104  is arranged at the inner side of a second side wall  103  of the chassis  101  which is adjacent to the first side wall  102 . 
     As shown in  FIG.  5   , the lifting frame  106  presents a plate type structure, a guide groove  107  is arranged at the side of the lifting frame  106  and the guide groove  107  extends in the horizontal direction. 
     As shown in  FIGS.  6 - 8   , the jacking mechanism is connected to the chassis  101  and the lifting frame  106 , and lifts the lifting frame  106  relative to the chassis  101 . As shown in  FIG.  6   , the cam  181  located on top of the drawing is not engaged with the lifting frame  106 . 
     The jacking mechanism comprises four cams  181  which can be rotatably arranged on the chassis  101  via a rotating shaft  105 ; and a jacking drive unit  184 . A first end  186  of the cam  181  is rotatably connected to the lifting frame  106 , and a second end  187  of the cam  181  is rotatably connected to the chassis  101 . The rotating shaft  105  is connected to the jacking drive unit  184 . The jacking drive unit  184  is a rotary motor which is arranged on the chassis  101 . The jacking drive unit  184  drives the rotating shaft  105  to rotate through a pulley structure arranged at the outer side of the chassis  101 .  FIG.  6    only illustrates the belt pulley  185 , but the belt which is connecting to the pulley  185  is not illustrated. 
     An insertion axis  182  is arranged at the first end  186  of the cam  181 , and the insertion axis  182  is inserted into the guide groove  107  and can slide in the guide groove  107 . A bearing  183  sleeves on the insertion axis  182  to reduce the friction force when the insertion axis  182  slides in the guide groove  107 . A guide portion  104  that extends vertically is arranged on the second side wall  103  of the chassis  101 , and the guide portion  104  is used to guide the lifting frame  106  to move linearly in the up and down directions. In the present embodiment, the guide portion  104  is a vertically extending guide rail, the guide rail fits with a sliding block arranged on the lifting frame  106  to guide the lifting frame  106  to slide in the vertical direction. Alternatively, the guide portion may also be in other forms, for example, a vertically extending groove, a protrusion that fits with the groove arranged on the lifting frame, or when a guide portion is a sliding block, a guide rail is arranged on the lifting frame to fit with the sliding block. 
       FIG.  8    illustrates the fitting structure of the cam  181  with the guide groove  107  of the lifting frame  106  in the present embodiment. Under the combined action of the guide portion  104  and the guide groove  107 , when the cam  181  is rotating, the lifting frame  106  can move linearly in the vertical direction without displacement in the horizontal direction. 
     In other embodiments, the cam  181  can also be replaced by other link mechanisms. Alternatively, the cam  181  is replaced by a rod piece. Preferably, the cam  181  may be replaced by an eccentric wheel. When an eccentric wheel is used, it can avoid the eccentric wheel from being jammed when it rotates to the top dead center or the bottom dead center. 
     Both the battery lifting portion  130  and the vehicle  200  fixing portion  120  can be arranged on the lifting frame  106  in a sliding way in the lateral direction (the direction indicated by the double-headed arrow X in  FIG.  3   ). The battery lifting portion  130  and the vehicle  200  fixing portion  120  can cooperate with each other to execute battery mounting and unmounting for the vehicle  200 . 
     As shown in  FIG.  9   , the vehicle fixing portion  120  comprises a first moving frame  121  and an unlocking mechanism  123 , the unlocking mechanism  123  is provided on the first moving frame  121 . A first fork  122  is arranged on both sides of the first moving frame  121 , and the first fork  122  is used to fork the vehicle  200  to be fixed relative to the vehicle  200 . The unlocking mechanism  123  may unlock or lock the batteries on the vehicle  200 . 
     As shown in  FIGS.  10 - 11   , the battery lifting portion  130  includes a second moving frame  131  and a tray  133 , the tray  133  is arranged above the second moving frame  131  and used to hold the battery, and the tray  133  and the second moving frame  131  are elastically connected with each other. 
     A spring  135  is arranged between the tray  133  and the second moving frame  131 , the spring  135  sleeves on a pin (not shown), one end of the pin is fixed to either the tray  133  or the second moving frame  131 , the length of the pin is shorter than the length of a undeformed spring  135  but longer than the minimum contracted length of the spring  135 , so that the second moving frame  131  can elastically support the tray  133 . 
     As shown in  FIGS.  12 - 13   , a second fork  134  is arranged at the side of the tray  133 , and the second fork  134  is used to fork the battery of the vehicle  200  to be fixed relative to the battery of the vehicle  200 . An insertion piece  136  is arranged below the tray  133 , and a “V” shaped insertion slot  132  is arranged above the second moving frame  131 ; the tray  133  is fixed relative to the second moving frame  131  through the insertion piece  136  which is inserted into the insertion slot  132 , so that when the second moving frame  131  moves laterally, the tray  133  can be driven to move. 
     In the present embodiment, a schematic presentation is provided for a structure of the battery lifting portion that is a double-layer structure. Alternatively, the battery lifting portion may also be a single-layer plate type structure which can move laterally relative to the lifting frame and hold the battery, and the second fork is directly arranged on the single-layer plate type structure. 
     The shuttle battery pack replacing device  100  further comprises a horizontal travelling mechanism (not indicated in the figures), and the chassis  101  is arranged on the horizontal travelling mechanism. The chassis  101  may be fixedly connected to the horizontal travelling mechanism or just placed on the horizontal travelling mechanism. The horizontal travelling mechanism is used to drive the chassis to move horizontally on the pre-laid track. Optionally, the horizontal travelling mechanism may also be one that moves arbitrarily on a flat ground or a ramp according to an external remote control command. 
     According to  FIGS.  6  and  14   , the movement manners of the first moving frame  121  and the second moving frame  131  relative to the lifting frame  106  are briefly described as follows. 
     As shown in  FIG.  6   , a guide rail  150  is laterally arranged on the lifting frame  106 , a guide block  140  is arranged on the lower surface of the first moving frame  121  and the second moving frame  131 , and the guide block  140  can slide on the guide rail  150 . The first moving frame  121  and the second moving frame  131  share the same guide rail  150 . The lifting frame  106  is also provided with a first driving portion  160  and a second driving portion  170 , the first driving portion  160  is used to drive the first moving frame  121  to move laterally, and the second driving portion  170  is used to drive the second moving frame  131  to move laterally. 
     As shown in  FIG.  14   , the first moving frame  121  is arranged below the second moving frame  131 , and the first moving frame  121  is connected to the first driving portion  160  through a connecting plate  124  so that it can be driven by the first driving portion  160 . A guide opening  125  is arranged on the first moving frame  121  to expose the guide block  140  which is connected to the second moving frame  131 . The second moving frame  131  is arranged above the first moving frame  121  but is not in contact with the first moving frame  121 , and the lower surface of the second moving frame  131  is connected to the second driving portion  170  so that it can be driven by the second driving portion  170 . The first driving portion  160  and the second driving portion  170  both comprise a screw-nut transmission mechanism and a rotary motor that drives the screw of the screw-nut transmission mechanism to rotate, thus to achieve the linear motion of the first moving frame  121  and the second moving frame  131 . The screw-nut transmission mechanism and the rotary have been widely used in the prior art, so no more detailed description will be provided herein. Those skilled in the art may also use other devices, such as a linear motor, as the first driving portion  160  and the second driving portion  170 . 
     The first driving portion  160 , the second driving portion  170  and the jacking drive unit  184  are under the common control of a control unit, the control unit may be a control device arranged on the first shuttle car  318 , or may be a master control unit in the battery swapping station  300  in which using the first shuttle  318 . 
     When it is required to unmount the battery of the vehicle  200 , the first shuttle  318  moves to the bottom of the vehicle  200 . The first driving portion  160  and the second driving portion  170  receive a command and allow the first moving frame  121  and the second moving frame  131  to move laterally to a preset position firstly, and then the jacking drive unit  184  receives the command and causes the lifting frame  106  to rise to the preset position; at this time, the first fork  122  forks the lock base for locking the battery pack on the vehicle  200 , the second fork  134  forks the batteries of the vehicle  200 , and the unlocking mechanism  123  unlocks the battery to make the battery unlocked from the vehicle  200 , then the first moving frame  121  remains stationary, while the second moving frame  131  moves away from the first moving frame  121 , so that the battery is removed from the vehicle  200 ; the battery falls on the tray  133  after being removed from the vehicle  200 , the lifting frame  106  moves downward together with the battery, and then the first shuttle  318  drives away from the bottom of the vehicle  200  with bringing the removed battery. 
     When it is required to mount the battery of the vehicle  200 , the first shuttle  318  moves to the bottom of the vehicle  200  with bringing a fully-charged battery, the first driving portion  160  and the second driving portion  170  receive a command and allow the first moving frame  121  and the second moving frame  131  to move laterally to a preset position, and then the jacking drive unit  184  receives the command and causes the lifting frame  106  to rise to the preset position; at this time, the first fork  122  forks the lock base for locking the battery pack on the vehicle  200 , the second fork  134  forks the fully-charged battery; then the first moving frame  121  remains stationary, while the second moving frame  131  moves toward the first moving frame  121 , so that battery are fixed onto the vehicle  200  and the unlocking mechanism  123  locks the battery on the vehicle  200 . 
     As shown in  FIG.  15   , the battery swapping station  300  comprises a battery charging compartment (not shown), a battery swapping platform  190 , a lifting mechanism  191  and a first shuttle  318 . 
     The lifting mechanism  191  is arranged on the battery swapping platform  190  and is used to lift the vehicle  200  on the battery swapping platform  190 . The lifting mechanism  191  is generally a pier for supporting four wheels of the vehicle  200 . In  FIG.  15   , the lifting mechanism  191  is lifted. 
     The first shuttle  318  can travel between the battery swapping platform  190  and the charging compartment, and is used to transfer the fully-charged battery  210  in the charging compartment to the vehicle  200  or transfer the battery  210  unmounted from the vehicle  200  to the charging compartment for charging. 
     When the first shuttle  318  is loaded with the battery  210  (whether it is the battery unmounted from the vehicle  200  or the fully-charged battery) and needs to enter and exit from the bottom of the vehicle  200 , the lifting mechanism  191  lifts the vehicle  200  up to allow the first shuttle  318  to enter and exit smoothly from the bottom of the vehicle  200 . 
     As the first shuttle  318  adopts a cam mechanism, its own height is low (the total height of the equipment is 175 mm), the synchronous lifting height of four cams  181  is 80 mm, while the height of the floor of the vehicle  200  from the ground is generally 190 mm. After the vehicle  200  enters the battery swapping platform  190 , the first shuttle  318  can directly enter the bottom of the vehicle  200 , and the first shuttle  318  is lifted by 80 mm, thus to lock or unlock the battery. After unmounting the battery, the lifting mechanism  191  lift the vehicle  200  up by 200 mm, to allow the first shuttle  318  to move out of the bottom of the vehicle  200  with the battery loaded. 
     Because the overall height of the first shuttle  318  is reduced, it is not necessary to arrange a deep pit in the battery swapping platform  190  of the battery swapping station  300  to allow the first shuttle  318  to enter the bottom of the vehicle  200 . Hence, the overall height of the battery swapping platform  190  is reduced, the height of the uphill ramp  304  and the downhill ramp  305  for entering the battery swapping platform  190  can be reduced to 230 mm (the original height is 480 mm), which further reduces the difficulty to drive towards the vehicle  200 . The lengths of the uphill ramp  304  and the downhill ramp  305  are also reduced accordingly, from the original 7345 mm and 4545 mm to 4500 mm and 3000 mm, thereby reducing the construction cost of the battery swapping station  300 . 
     Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example, and the protection scope of the present invention is defined by the enclosed Claims. Those skilled in the art can make various changes or modifications to these embodiments as long as not departing from the principle and essence of the present invention, but these changes and modifications will fall within the protection scope of the present invention.