Abstract:
Disclosed is an actuation system for adjusting the rigidity of elastic elements by using two sets of transmission modules together with a link gear and two sets of nonlinear elastic elements. The actuation system actuates an external arm by controlling the two sets of transmission modules to rotate in different directions and adjusts the rigidity of the elastic elements by controlling the two sets of transmission modules to rotate in the same direction, so as to achieve the effects of reducing the number of actuation modules used, minimizing the volume of the actuation system, and reducing production cost.

Description:
[0001]    This application claims the benefit of Taiwan Application Patent No. 101120028, filed on Jun. 4, 2012, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to an actuation system, and more particularly to the actuation system that uses two transmission modules in conjunction with a nonlinear elastic. element to achieve the effects of improving the output kinetic energy and adjusting the rigidity of the elastic element. 
       BACKGROUND OF THE INVENTION 
       [0003]    Mechanical arm is an automated machine with the abilities including the planning ability, motion ability and coordination ability similar to those of human beings and living organisms, and thus the mechanical arm is a highly elastic automated machine. At present, the technology of mechanical arms is developed rapidly and applied extensively in different areas, and the structure of the mechanical arms is experiencing a big change. Basically, the mechanical arm can be divided into two main types, respectively: an industrial mechanical arm used in manufacturing environments, and a mechanical arm used in non-manufacturing environments. The so-called industrial mechanical arm used in the manufacturing environments refers to a multi-joint mechanical arm or a multiple degree-of-freedom mechanical arm. The mechanical arm used in the non-manufacturing environments refers to any mechanical arm other than the industrial mechanical arm and it includes a service mechanical arm, an underwater mechanical arm, an entertaining mechanical arm, a military mechanical arm, an agricultural mechanical arm, a cleaning mechanical arm, etc. 
         [0004]    Most of the present simulating robotic arms come with an elasticity adjusting function and a drive controlling function. The robotic arms can use the elasticity adjusting function to adjust the elastic resilience of the mechanical arm for its interactions with human beings and improve the user&#39;s safety during the use of the mechanical arm. When it is necessary to use the mechanical arm for a positioning operation, the elastic resilience can be adjusted again to achieve a precise positioning operation of the mechanical arm. However, most of the present simulating mechanical arms adjust the elasticity and drive the operation of the arms by using a plurality of actuation units. When the arm is driven to move, some of the actuation units are used, but the remaining actuation units are idle, thus failing to utilize the actuation units effectively and causing unnecessary waste of cost. 
         [0005]    In view of the aforementioned problems of the conventional actuation system, the inventor of the present invention developed an actuation system that combines two transmission modules with two nonlinear elastic elements to overcome the problems of the prior art and improve the industrial application. 
       SUMMARY OF THE INVENTION 
       [0006]    It is a primary objective of the present invention to provide an actuation system to overcome the problems of the conventional actuation system that fails to utilize an actuation unit effectively. 
         [0007]    To achieve the aforementioned objective, the present invention provides an actuation system, comprising: a first transmission module, a second transmission module and a linking module. The first transmission module comprises a first transmission shaft, a first transmission part, a first actuation part and a first elastic element, The first transmission shaft comes with a rod structure. The first transmission part is sheathed on the first transmission shaft, and an external surface of the first transmission part has a threaded structure. The first actuation part is sheathed on a first adjusting element, and the first adjusting element is sheathed on the first transmission shaft. The first elastic element is sheathed on the first transmission shaft and disposed between the first transmission part and the first actuation part. The second transmission module comprises a second transmission shaft, a second transmission part, a second actuation part and a second elastic element. The second transmission shaft comes with a rod structure. The second transmission part is sheathed on the second transmission shaft, and an external surface of the second transmission part has a threaded structure. The second actuation part is sheathed on a second adjusting element, and the second adjusting element is sheathed on the second transmission shaft. The second elastic element is sheathed on the second transmission shaft and disposed between the second transmission part and the second actuation part. The linking module comprises a linking element and an external arm. The linking element comes with a disc structure. The linking element is mounted onto a frame and disposed between the first transmission part and the second transmission part, and an external periphery of the linking element has a serrated structure corresponding to the threaded structure, and the serrated structure is embedded with the threaded structures of the first transmission part and the second transmission part. The external arm is sheathed on a linking shaft for coupling the linking element. 
         [0008]    Preferably, the first actuation part is driven to rotate in a first direction while the second actuation part is being driven to rotate in a second direction to drive the first transmission shaft and the second transmission shaft to rotate in the first direction and the second direction respectively, so that the first transmission part and the second transmission part are rotated in the first direction and the second direction respectively, and the linking element is rotated to drive and rotate the external arm synchronously. 
         [0009]    Preferably, the first actuation part and the second actuation part are driven to rotate in a first direction or a second direction simultaneously to drive the first transmission shaft and the second transmission shaft to rotate in the first direction or the second direction, so that the first transmission part and the second transmission part are rotated in the first direction or the second direction simultaneously, and the linking element is not rotated. 
         [0010]    Preferably, when the first actuation part and the second actuation part are driven to rotate in the first direction or the second direction simultaneously, so that the linking element, the first transmission part, the second transmission part, the first transmission shaft and the second transmission shaft are not rotated, and when the first actuation part and the second actuation part are driven to rotate continuously, the first actuation part and the second actuation part are displaced in an axial direction through the first adjusting element and the second adjusting element to compress or stretch the first elastic element and the second elastic element respectively. 
         [0011]    Preferably, the first elastic element and the second elastic element are conical springs. 
         [0012]    Preferably, when the external arm is pushed by an external force, the linking element is linked to rotate, so that the first transmission part and the second transmission part are displaced in an axial direction along the first transmission shaft and the second transmission shaft respectively. 
         [0013]    To achieve the aforementioned objective, the present invention provides an actuation system, comprising: a transmission module and an actuation module. The transmission module comprises a first transmission shaft, a first transmission part, a first actuation part, a first elastic element, a second transmission shaft, a second transmission part, a second actuation part, a second elastic element and a linking element. The first transmission shaft comes with a rod structure. The first transmission part is sheathed on the first transmission shaft, and an external surface of the first transmission part has a threaded structure. The first actuation part is sheathed on a first adjusting element, and the first adjusting element is sheathed on the first transmission shaft. The first elastic element is sheathed on the first transmission shaft and disposed between the first transmission part and the first actuation part. The second transmission shaft comes with a rod structure. The second transmission part is sheathed on the second transmission shaft, and an external surface of the second transmission part has a threaded structure. The second actuation part is sheathed on a second adjusting element, and the second adjusting element is sheathed on the second transmission shaft. The second elastic element is sheathed on the second transmission shaft and disposed between the second transmission part and the second actuation part. The linking element is a disc structure mounted onto a frame, coupled to an external arm, and disposed between the first transmission part and the second transmission part, and an external periphery of the linking element is embedded with the threaded structure. The actuation module comprises a first actuation unit and a second actuation unit. The first actuation unit is coupled to a first actuation gear set, and the first actuation gear set is embedded with the first actuation part. The second actuation unit is coupled to a second actuation gear set, and the second actuation gear set is embedded with the second actuation part. 
         [0014]    Preferably, the first actuation part is driven to rotate in a first direction or a second direction, and the second actuation part is driven to rotate in the second direction or the first direction to drive the first transmission shaft and the second transmission shaft to rotate in the first direction and the second direction respectively, so that the first transmission part and the second transmission part are rotated in the first direction or the second direction respectively, and the linking element is rotated to drive the external arm to rotate synchronously. 
         [0015]    Preferably, the first actuation part and the second actuation part are driven to rotate in a first direction or a second direction simultaneously to drive the first transmission shaft and the second transmission shaft to rotate in the first direction or the second direction, so that the first transmission part and the second transmission part are rotated in the first direction or the second direction simultaneously, and the linking element is not rotated. 
         [0016]    Preferably, when the first actuation part and the second actuation part are driven to rotate in the first direction or the second direction, so that the linking element, the first transmission part, the second transmission part, the first transmission shaft and the second transmission shaft are not rotated, and when the first actuation part and the second actuation part are driven to rotate continuously, the first actuation part and the second actuation part are displaced in an axial direction through the first adjusting element and the second adjusting element to compress or stretch the first elastic element and the second elastic element respectively. 
         [0017]    Preferably, the first elastic element and the second elastic element are conical springs. 
         [0018]    Preferably, when the external arm is pushed by an external force, the linking element is linked to rotate, so that the first transmission part and the second transmission part are displaced in an axial direction along the first transmission shaft and the second transmission shaft respectively. 
         [0019]    In summation, the actuation system of the present invention has one or more of the following advantages: 
         [0020]    (1) In this actuation system, two sets of transmission modules are combined with two sets of nonlinear elastic elements to achieve the effect of adjusting the rigidity of the elastic element actively. When the system has a high rigidity, the system can provide a better positioning control; and when the system has a low rigidity, the system provides a better elasticity between the input mechanism and the output mechanism of the system. Therefore, this actuation system allows users to achieve better operation effects, 
         [0021]    (2) This actuation system can adjust the rigidity of the elastic elements effectively, so that the actuation system can be applied in simulating mechanical equipments. The elasticity of each elastic element of the actuation system allows external forces to be applied onto the actuation system directly during the motion of the output shaft, so as to achieve a man-machine interaction effect safely, 
         [0022]    (3) This actuation system drives the two actuation parts and rotates the output shafts in different directions simultaneously to obtain a greater output torque. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a first schematic view of an actuation system of a first preferred embodiment of the present invention; 
           [0024]      FIG. 2  is a second schematic view of an actuation system of the first preferred embodiment of the present invention; 
           [0025]      FIG. 3  is a third schematic view of an actuation system of the first preferred embodiment of the present invention; 
           [0026]      FIG. 4  is a fourth schematic view of an actuation system of the first preferred embodiment of the present invention; 
           [0027]      FIG. 5  is a fifth schematic view of an actuation system of the first preferred embodiment of the present invention; 
           [0028]      FIG. 6  is a sixth schematic view of an actuation system of the sixth preferred embodiment of the present invention; 
           [0029]      FIG. 7  is a seventh schematic view of an actuation system of the first preferred embodiment of the present invention; 
           [0030]      FIG. 8  is a first schematic view of an actuation system of a second preferred embodiment of the present invention; 
           [0031]      FIG. 9  is a second schematic view of an actuation system of the second preferred embodiment of the present invention; 
           [0032]      FIG. 10  is a third schematic view of an actuation system of the second preferred embodiment of the present invention; 
           [0033]      FIG. 11  is a fourth schematic view of an actuation system of the second preferred embodiment of the present invention; 
           [0034]      FIG. 12  is a fifth schematic view of an actuation system of the second preferred embodiment of the present invention; and 
           [0035]      FIG. 13  is a sixth schematic view of an actuation system of the second preferred embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    The technical characteristics, contents, advantages and effects of the present invention will be apparent with the detailed description of a preferred embodiment accompanied with related drawings as follows. The drawings are provided for the illustration, and same numerals are used to represent respective elements in the preferred embodiments. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive. 
         [0037]    With reference to  FIGS. 1 to 3  for the first to third schematic views of an actuation system of the first preferred embodiment of the present invention respectively, the actuation system  1  comprises a first transmission module  10 , a second transmission module  20  and a linking module  30 . The first transmission module  10  comprises a first transmission shaft  101 , a first transmission part  102 , a first actuation part  103 , a first adjusting element  104 , and a first elastic element  105 . The second transmission module  20  comprises a second transmission shaft  201 , a second transmission part  202 , a second actuation part  203 , a second adjusting element  204  and a second elastic element  205 . The linking module  30  comprises a linking element  301 , a frame  302 , a linking shaft  303  and an external arm  304 . The first transmission shaft  101  comes with a rod structure. The first transmission part  102  is sheathed on the first transmission shaft  101 , and an external surface of the first transmission part  102  has a threaded structure. The first actuation part  103  is sheathed on a first adjusting element  104 , and the first adjusting element  104  is sheathed on the first transmission shaft  101 . The first elastic element  105  is sheathed on the first transmission shaft  101  and disposed between the first transmission part  102  and the first actuation part  103 . The second transmission shaft  201  comes with a rod structure. The second transmission part  202  is sheathed on the second transmission shaft  201 , and an external surface of the second transmission part  202  has a threaded structure. The second actuation part  203  is sheathed on a second adjusting element  204 , and the second adjusting element  204  is sheathed on the second transmission shaft  201 . The second elastic element  205  is sheathed on the second transmission shaft  201  and disposed between the second transmission part  202  and the second actuation part  203 . The linking module  30  comprises a linking element  301 , a frame  302 , a linking shaft  303  and an external arm  304 . The linking element  301  is mounted onto the frame  302  and disposed between the first transmission part  102  and the second transmission part  202 , and an external periphery of linking element  301  has a serrated structure corresponding to the threaded structure, and the serrated structure is embedded with the threaded structures of the first transmission part  102  and the second transmission part  202 . Wherein, the first transmission part  102  and the second transmission part  202  are ball worm gears; the first actuation part  103  and the second actuation part  203  are worm gears; and the linking element  301  is an umbrella gear. The external arm  304  is sheathed on the linking shaft  303  and coupled to the linking element  301 . The first elastic element  105  and the second elastic element  205  are conical springs (or nonlinear springs). 
         [0038]    In short, the first transmission module  10  and the second transmission module  20  are disposed on both sides of the frame  302  respectively, and the linking module  30  is disposed between the first transmission module  10  and the second transmission module  20 , and the external periphery of the first transmission part  102  or the second transmission part  202  has a threaded structure each, and the linking element  301  has a serrated structure corresponding to the threaded structure, and the serrated structure is embedded with the threaded structure. 
         [0039]    With reference to  FIGS. 4 and 5  for the fourth and fifth schematic views of an actuation system of the first preferred embodiment of the present invention respectively, when the first actuation part  103  is driven to rotate in a first direction  401 , while the second actuation part  203  is being driven to rotate in a second direction  402 , the first transmission shaft  101  is linked to rotate in the first direction  401 , and the second transmission shaft  201  is linked to rotate in the second direction  402 . In addition, the linking element  301  is embedded with the threaded structures of the first transmission part  102  and the second transmission part  202  by the serrated structure, so that when the first transmission part  102  rotates in the first direction  401 , the linking element  301  is linked to rotate. Since the linking element  301  is fixed to the frame  302 , the first transmission part  102  is displaced in a first axial direction  501  along the first transmission shaft  101 . When the second transmission part  202  rotates in the second direction  402 , the linking element  301  is linked to rotate, so that the second transmission part  202  is displaced in a second axial direction  502  along the second transmission shaft  201 . When the linking element  301  is driven to rotate, the linking shaft  303  is linked and rotated with the external arm  304 . 
         [0040]    Similarly, when the first actuation part  103  is driven to rotate in the second direction  402 , and the second actuation part  203  is driven to rotate in the first direction  401 , the first transmission part  102  and the second transmission part  202  are linked to rotate in the second direction  402  and the first direction  401  respectively and interacted with the linking element  301 , so that the first transmission part  102  is displaced in the second axial direction  502 , and the second transmission part  202  is displaced in the first axial direction  501 . 
         [0041]    In short, when the first actuation part  103  and the second actuation part  203  are driven to rotate in different directions, the first transmission part  102  and the second transmission part  202  are interacted with the linking element  301  to rotate in different directions and displace in an axial direction, so that the external arm  304  is driven to rotate. 
         [0042]    It is noteworthy that the first transmission part  102  and the second transmission part  202  can be sheathed on a spline structure, and the first transmission shaft  101  and the second transmission shaft  201  are spline shafts. In other words, the first transmission part  102  and the second transmission part  202  can slide on the first transmission shaft  101  and the second transmission shaft  201  respectively (for the displacement in the axial direction). When the first transmission shaft  101  and the second transmission shaft  201  are driven to rotate, the first transmission part  102  and the second transmission part  202  are also driven to rotate. 
         [0043]    With reference to  FIGS. 6 and 7  for the sixth and seventh schematic views of an actuation system of the first preferred embodiment of the present invention respectively, the relation of components of the actuation system  1  is the same as that described above, and thus will not be repeated. It is noteworthy that when the first actuation part  103  and the second actuation part  203  are driven to rotate in the first direction  401  (or the second direction  402 ) simultaneously, the first transmission part  102  and the second transmission part  202  are linked synchronously to rotate in the first direction  401  (or the second direction  402 ). Since the linking element  301  is fixed to the frame  302 , therefore the first transmission part  102 , the second transmission part  202  and the linking element  301  are latched with one another and cannot be rotated. As a result, the first transmission shaft  101  and the second transmission shaft  201  cannot be rotated. Now, if the first actuation part  103  and the second actuation part  203  are driven continuously, then the first actuation part  103  and the second actuation part  203  will interact with the first adjusting element  104  and the second adjusting element  204  respectively, so that the first actuation part  103  and the second actuation part  203  are displaced in the second axial direction  502  (or the first axial direction  501 ) along the first adjusting element  104  and the second adjusting element  204  respectively. 
         [0044]    Further, when the first actuation part  103  and the second actuation part  203  are driven to rotate in different directions (such as both rotating in the first direction  401  or both rotating in the second direction  402 ), the first transmission part  102  rotates the linking element  301  clockwise (or counterclockwise), and the second transmission part  202  rotates the linking element  301  counterclockwise (or clockwise), so that the linking element  301  interacts with the first transmission part  102  and the second transmission part  202 , and the first transmission shaft  101  and the second transmission shaft  201  cannot be rotated. On the other hand, the first adjusting element  104  and the second adjusting element  204  cannot be rotated. Wherein, the external peripheries of the first adjusting element  104  and the second adjusting element  204  have a threaded structure each, so that internal walls of the first actuation part  103  and the second actuation part  203  have corresponding threaded structures, and the first actuation part  103  and the second actuation part  203  can be displaced along the first adjusting element  104  and the second adjusting element  204  by the threaded structures. When the first actuation part  103  and the second actuation part  203  are driven to rotate in the first direction  401  (or the second direction  402 ) and the first actuation part  103  and the second actuation part  203  are driven to rotate continuously, the first actuation part  103  and the second actuation part  203  are displaced in the first axial direction  501  (or the second axial direction  502 ) respectively to push or stretch the first elastic element  105  and the second elastic element  205  to adjust the rigidity of the first elastic element  105  and the second elastic element  205 . In practical applications, the first adjusting element  104  and the second adjusting element  204  can be ball bearings. 
         [0045]    In short, when the first actuation part  103  and the second actuation part  203  are driven to rotate in different directions, the first transmission part  102 , the linking element  301  and the second transmission part  202  are latched with one another, so that the first elastic element  105  and the second elastic element  205  can be compressed or stretched to adjust the rigidity of the first elastic element  105  and the second elastic element  205 . 
         [0046]    With reference to  FIGS. 8 and 9  for the first and second schematic views of an actuation system of the second preferred embodiment of the present invention respectively, the actuation system  1  comprises a transmission module and an actuation module. The transmission module  40  comprises a first transmission shaft  101 , a first transmission part  102 , a first actuation part  103 , a first adjusting element  104 , a first elastic element  105 , a second transmission shaft  201 , a second transmission part  202 , a second actuation part  203 , a second adjusting element  204 , a second elastic element  205 , a linking element  301 , a frame  302 , a linking shaft  303  and an external arm  304 . The actuation module comprises a first actuation unit  61 , a first actuation gear set  62 , a second actuation unit  71  and a second actuation gear set  72 . The first actuation unit  61  is coupled to the first actuation gear set  62 , and the first actuation gear set  62  is embedded with the first actuation part  103 . The second actuation unit  71  is coupled to the second actuation gear set  72 , and the second actuation gear set  72  is embedded with the second actuation part  203 . Wherein, the first actuation gear set  62  and the second actuation gear set  72  are formed by a plurality of gears. 
         [0047]    When the first actuation unit  61  drives the first actuation gear set  62  to operate, the first actuation part  103  is linked to rotate, so that the first transmission shaft  101  and the first transmission part  102  are rotated, and the linking element  301  is rotated. Similarly, the second actuation unit  71  drives the second actuation part  203 , so that the linking element  301  can be rotated by the second transmission part  202 , and the operation of the external arm  304  can be controlled or the rigidity of the first elastic element  105  or the second elastic element  205  can be adjusted. 
         [0048]    With reference to  FIGS. 10 and 11  for the third and fourth schematic views of an actuation system of the second preferred embodiment of the present invention respectively, the configuration and relation of the components of the actuation system  1  are the same as those described above, and thus will not be repeated. It is noteworthy that when the first actuation unit  61  and the second actuation unit  71  are controlled to rotate in different directions respectively (such as setting the first actuation unit  61  to rotate clockwise and the second actuation unit  71  to rotate counterclockwise), the rotation of the external arm  304  can be controlled. When the first actuation unit  61  and the second actuation unit  71  are rotated in the same direction (such as both in clockwise direction or both in counterclockwise direction), the first transmission part  102 , the linking element  301  and the second transmission part  202  are latched with one another, so that the first adjusting element  104  and the second adjusting element  204  can adjust the rigidity by compressing or stretching the first elastic element  105  and the second elastic element  205  by the first actuation part  103  and the second actuation part  203 . 
         [0049]    With reference to  FIGS. 12 and 13  for the fifth and sixth schematic views of an actuation system of the second preferred embodiment of the present invention respectively, the actuation system  1  can be applied in a mechanical arm. In the figures, a user can control the actuation module for the operation of the robotic arm, wherein the configuration and operation of related components have been described above and thus will not be repeated. When the mechanical arm is pushed by an external force, the external arm  304  drives the linking element  301  to rotate and further drives the first transmission part  102  and the second transmission part  202  to displace in an axial direction along the first transmission shaft  101  and the second transmission shaft  201 . When the first transmission shaft  101  and the second transmission shaft  201  are displaced in the axial direction, the first elastic element  105  and the second elastic element  205  are stretched or compressed, so that the elastic resilience can be used to return the external arm  304  to its original position. More specifically, the first elastic element  105  and the second elastic element  205  are configured to provide elasticity similar to that of human arms to the mechanical arm. 
         [0050]    In addition, this actuation system  1  can be applied in rehabilitation appliances, and rehabilitators can wear the actuation system  1  at their arm or leg. At an early stage of rehabilitation, the rehabilitators can use the actuation system  1  to drive an external arm  304  to assist them to lift their arm. At a later stage of rehabilitation, the rehabilitators can pull the external arm  304  or adjust the rigidity of each elastic element of the actuation system  1  by applying their own force according to the conditions of individual rehabilitators, so as to achieve the assisted rehabilitation effect. 
         [0051]    While the means of specific embodiments in present invention has been described by reference drawings, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims. The modifications and variations should in a range limited by the specification of the present invention,