Patent Publication Number: US-2021190264-A1

Title: Parallel wire device, parallel wire system, operating device for medical robot, mobile projecting device, and mobile photographing device

Description:
TECHNICAL FIELD 
     The technology disclosed in the present specification relates to a parallel wire device, a parallel wire system, an operating device for a medical robot, a mobile projecting device, and a mobile photographing device that translate and rotate a target object. 
     BACKGROUND ART 
     A parallel wires system and a parallel link system are known as driving systems with small inertia. In general, the parallel wire system has smaller inertia. These parallel mechanisms can be used to drive a controller operated by an operator on a master side and a device (end effector) at an output terminal on a slave side in a master-slave system, for example. 
     For example, a proposal has been made with regard to a tendon suspend platform robot of the parallel wire system, the robot including a platform suspended by a plurality of flexible tendons, and translating and rotating the platform by controlling the extension length of each of the flexible tendons (see PTL 1). In addition, a wearable force sense presenting device of the parallel wire system has been proposed (see PTL 2). 
     When a parallel wire mechanism with small inertia is applied to the controller operated by the operator on the master side, advantages are obtained in that a load is small and the operator does not become fatigued easily. When an application involving usage for a long period of time as in a case of a medical robot that performs endoscopic surgery or the like is considered, it is preferable that the controller have low inertia and that the load on the operator be reduced. 
     However, the parallel wire mechanism has a problem of a small rotational movable range. This is because wires interfere with each other during rotation. A wrist of a human has a movable range of approximately ±90 degrees, and the controller operated by a human preferably has a movable range corresponding to that of the wrist. Thus, it is difficult to apply the parallel wire mechanism having the small rotational movable range. In addition, another problem also occurs in that the wires and hands interfere with one another. 
     Meanwhile, a system in which equipment for photographing is supported by parallel wires in a ceiling-suspended manner and special photographing is performed in the air has already been put to practical use. In a case where a parallel wire device is used to thus drive a heavy object, the weight of the parallel wire device is preferably reduced as much as possible in preparation for a danger at a time of falling. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] 
     Japanese Translation of PCT International Application Publication No. JP-T-H09-500337 
     [PTL 2] 
     JP 2016-207005A 
     [PTL 3] 
     WO2017/130562 
     [PTL 4] 
     JP 2000-79586A 
     SUMMARY 
     Technical Problems 
     It is an object of the technology disclosed in the present specification to provide a parallel wire device, a parallel wire system, an operating device for a medical robot, a mobile projecting device, and a mobile photographing device that can translate a target object and rotate the target object in a wide movable range. 
     Solution to Problems 
     The technology disclosed in the present specification has been made in consideration of the above-described problems. According to a first aspect of the technology disclosed in the present specification, there is provided a parallel wire device including a movement unit, a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis, a first parallel wire configured to translationally drive the movement unit, and a second parallel wire configured to rotationally drive the rotational movement unit. 
     The rotational movement unit has two or more degrees of rotational freedom with respect to the movement unit, and the second parallel wire includes a parallel wire configured to rotationally drive the rotational movement unit about one axis and a parallel wire configured to rotationally drive the rotational movement unit about another axis. 
     The rotational movement unit includes a serial link, and the second parallel wire includes a parallel wire configured to drive the serial link. Alternatively, the rotational movement unit includes a parallel link, and the second parallel wire includes parallel wires configured to drive respective links constituting the parallel link. 
     In addition, according to a second aspect of the technology disclosed in the present specification, there is provided a parallel wire system including a movement unit, a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis, a first parallel wire configured to translationally drive the movement unit, a second parallel wire configured to rotationally drive the rotational movement unit, and a plurality of actuators configured to drive respective wires included in the first parallel wire and the second parallel wire. 
     However, a “system” referred to herein refers to a logical set of a plurality of devices (or functional modules implementing specific functions), and no particular distinction is made as to whether or not devices and function modules are present within a single casing. 
     In addition, according to a third aspect of the technology disclosed in the present specification, there is provided an operating device for a medical robot of a master-slave system, the operating device being for operating a medical instrument attached to a slave side from a master side, the operating device including a movement unit, a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis, an operating unit for an operator, the operating unit being attached to the rotational movable unit, a first parallel wire configured to translationally drive the movement unit, and a second parallel wire configured to rotationally drive the rotational movement unit. 
     In addition, according to a fourth aspect of the technology disclosed in the present specification, there is provided a mobile projecting device including a movement unit, a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis, a projecting device attached to the rotational movable unit, a first parallel wire configured to translationally drive the movement unit, and a second parallel wire configured to rotationally drive the rotational movement unit. 
     In addition, according to a fifth aspect of the technology disclosed in the present specification, there is provided a mobile photographing device including a movement unit, a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis, a camera attached to the rotational movable unit, a first parallel wire configured to translationally drive the movement unit, and a second parallel wire configured to rotationally drive the rotational movement unit. 
     Advantageous Effects of Invention 
     According to the technology disclosed in the present specification, it is possible to provide a parallel wire device, a parallel wire system, an operating device for a medical robot, a mobile projecting device, and a mobile photographing device that can translate a target object and rotate the target object in a wide movable range. 
     It is to be noted that the effects described in the present specification are merely illustrative, and that the effects of the present invention are not limited thereto. In addition, the present invention may further produce additional effects other than the above-described effects. 
     Still other objects, features, and advantages of the technology disclosed in the present specification will become apparent from more detailed description based on embodiments to be described later and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram depicting a configuration of a parallel wire device  100 . 
         FIG. 2  is a diagram depicting a configuration of a parallel wire device  200 . 
         FIG. 3  is a diagram depicting a configuration of a parallel wire device  300 . 
         FIG. 4  is a diagram depicting a configuration of a parallel wire device  400 . 
         FIG. 5  is a diagram depicting a configuration of a parallel wire device  500 . 
         FIG. 6  is a diagram depicting a state in which a rotational movement unit  520  of the parallel wire device  500  is viewed from above. 
         FIG. 7  is a diagram depicting a configuration example of a master device  700  to which a parallel wire system is applied. 
         FIG. 8  is a diagram depicting the configuration example of the master device  700  to which the parallel wire system is applied. 
         FIG. 9  is a diagram depicting a controller  701 . 
         FIG. 10  is a diagram depicting the controller  701 . 
         FIG. 11  is a diagram depicting a state in which an operator is using a gripping force sense presenting device  870 . 
         FIG. 12  is a diagram depicting a state in which the operator is using the gripping force sense presenting device  870 . 
         FIG. 13  is a diagram depicting a state in which the operator is using the gripping force sense presenting device  870 . 
         FIG. 14  is a diagram depicting a configuration example of a spherical parallel link device. 
         FIG. 15  is a diagram depicting the controller  701 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the following, five basic configuration examples of parallel wire devices to which the technology disclosed in the present specification is applied are illustrated as a first embodiment in  FIGS. 1 to 5  and will be described with reference to the respective drawings. In addition, an embodiment in which a parallel wire system according to the technology disclosed in the present specification is applied to a controller of a master device of a master-slave system will be described as a second embodiment with reference mainly to  FIGS. 7 to 10 . In addition, a modification of a parallel link device driven by using a parallel wire device according to the technology disclosed in the present specification will be described as a third embodiment with reference to  FIG. 14 . Moreover, a range of application of the parallel wire devices disclosed in the present specification will be mentioned as a fourth embodiment. 
     First Embodiment 
       FIG. 1  schematically illustrates a basic configuration example of a parallel wire device  100  to which the technology disclosed in the present specification is applied. A paper plane will be set as an XY plane, and a Z-axis will be set in a direction perpendicular to the paper plane. In addition, for the convenience of description, suppose that the parallel wire device  100  illustrated in  FIG. 1  has a total of three degrees of freedom including degrees of translational freedom in two X- and Y-directions and a degree of rotational freedom about one axis, that is, the Z-axis. 
     The parallel wire device  100  includes six parallel wires  101  to  106  and a movement unit  110  supported by these wires  101  to  106 . In addition, a rotational movement unit  120  is attached to an upper surface of the movement unit  110  so as to be rotatable at least about the Z-axis with respect to the movement unit  110 . Incidentally, the movement unit  110  is assumed to be supported slidably on a flat surface, for example, on a board (not illustrated) or the like. 
     The wire  101  has a distal end portion fixed to an end portion  111  of the movement unit  110 , and has a proximal portion attached to a linear actuator  131 . A length of the wire  101  can be controlled by driving of the linear actuator  131 . In the illustrated example, a driving direction of the linear actuator  131  is changed by winding the wire  101  around a direction changing pulley  141 , and the distal end portion of the wire  101  is attached to the end portion  111 . The distal end portion of the wire  101  is preferably joined to the end portion  111  by a joint that changes in angle freely, such as a universal joint or the like. 
     In addition, the wire  102  has a distal end portion fixed to an end portion  112  of the movement unit  110 , and has a proximal portion attached to a linear actuator  132 . A length of the wire  102  can be controlled by driving of the linear actuator  132 . However, a driving direction of the linear actuator  132  is changed by winding the wire  102  around a direction changing pulley  142 , and the distal end portion of the wire  102  is attached to the end portion  112 . The distal end portion of the wire  102  is preferably joined to the end portion  112  by a joint that changes in angle freely, such as a universal joint or the like. 
     In addition, the wire  103  has a distal end portion fixed to an end portion  113  of the movement unit  110 , and has a proximal portion attached to a linear actuator  133 . A length of the wire  103  can be controlled by driving of the linear actuator  133 . However, a driving direction of the linear actuator  133  is changed by winding the wire  103  around a direction changing pulley  143 , and the distal end portion of the wire  103  is attached to the end portion  113 . The distal end portion of the wire  103  is preferably joined to the end portion  113  by a joint that changes in angle freely, such as a universal joint or the like. 
     In addition, the wire  104  has a distal end portion fixed to an end portion  114  of the movement unit  110 , and has a proximal portion attached to a linear actuator  134 . A length of the wire  104  can be controlled by driving of the linear actuator  134 . However, a driving direction of the linear actuator  134  is changed by winding the wire  104  around a direction changing pulley  144 , and the distal end portion of the wire  104  is attached to the end portion  114 . The distal end portion of the wire  104  is preferably joined to the end portion  114  by a joint that changes in angle freely, such as a universal joint or the like. 
     A distal end portion of the wire  105  is wound around and fixed to a side surface portion of the rotational movement unit  120 , and a distal end portion of the wire  106  is wound around and fixed to the side surface portion of the rotational movement unit  120  in an opposite direction from the wire  105 . Then, a proximal portion of the wire  105  is attached to a linear actuator  135 , and a proximal portion of the wire  106  is attached to a linear actuator  136 . The lengths of the wires  105  and  106  can be respectively controlled by driving of the respective linear actuators  135  and  136 . However, a driving direction of the linear actuator  135  is changed by winding the wire  105  around direction changing pulleys  145  and  146 , and the wire  105  is then wound around the side surface portion of the rotational movement unit  120 . In addition, a driving direction of the linear actuator  136  is changed by winding the wire  106  around direction changing pulleys  147  and  148 , and the wire  106  is then wound around the side surface portion of the rotational movement unit  120 . 
     Suppose that each of the linear actuators  131  to  136  is collectively controlled by a control unit not illustrated. 
     The four wires  101  to  104  are parallel wires for translating the movement unit  110  in an XY plane. The control unit changes the length of each of the wires  101  to  104  by synchronously driving the linear actuators  131  to  134  at the proximal portions of the respective wires  101  to  104 . The movement unit  110  can be thereby translated in the XY plane. It is also possible to rotate the movement unit  110  about the Z-axis in a certain movable range in an XYZ coordinate system by synchronously changing the lengths of the respective wires  101  to  104 . 
     Specifically, the movement unit  110  is moved in a positive Y-direction by pulling the wires  101  and  102  by the linear actuators  131  and  132 , and extending the wires  103  and  104  by the linear actuators  133  and  134  so as to balance with the pulling of the wires  101  and  102 . The movement unit  110  is moved in a negative Y-direction by pulling the wires  103  and  104  by the linear actuators  133  and  134  and extending the wires  101  and  102  by the linear actuators  131  and  132  so as to balance with the pulling of the wires  103  and  104 . In a case where the linear actuators are of a wire winding type, the wires are pulled by being wound, and the wires are extended by being unwound (the same is true in the following). 
     Meanwhile, the movement unit  110  is moved in a negative X-direction by pulling the wires  101  and  104  by the linear actuators  131  and  134  and extending the wires  102  and  103  by the linear actuators  132  and  133  so as to balance with the pulling of the wires  101  and  104 . The movement unit  110  is moved in a positive X-direction by pulling the wires  102  and  103  by the linear actuators  132  and  133  and extending the wires  101  and  104  by the linear actuators  131  and  134  so as to balance with the pulling of the wires  102  and  103 . 
     In addition, the two wires  105  and  106  are parallel wires for rotational movement of the rotational movement unit  120  on the movement unit  110  about the Z-axis. The rotational movement unit  120  can be rotated about the Z-axis with respect to the movement unit  110  (or in the XYZ coordinate system) when the control unit shortens the length of one of the two wires  105  and  106  and extends the other by such a length that the two wires are balanced by synchronously driving the linear actuators  135  and  136 . 
     Specifically, the rotational movement unit  120  can be rotated clockwise in  FIG. 1  by pulling the wire  105  by the linear actuator  135  and extending the wire  106  by the linear actuator  136  so as to balance with the pulling of the wire  105 . Conversely, the rotational movement unit  120  can be rotated counterclockwise in  FIG. 1  by pulling the wire  106  by the linear actuator  136  and extending the wire  105  by the linear actuator  135  so as to balance with the pulling of the wire  106 . 
     Incidentally, in addition to the translation of the movement unit  110  in the XY plane, the movement unit  110  can be rotated about the Z-axis to a certain extent by changing the lengths of the respective wires  101  to  104 . Hence, a wider rotational movable range can be secured by utilizing the functions of rotating both the movement unit  110  and the rotational movement unit  120 . 
     In  FIG. 1 , the wires  101  to  104  provided in parallel to translate the movement unit  110  are depicted in black, and the wires  105  and  106  provided in parallel to rotate the rotational movement unit  120  are depicted in gray. 
     The linear actuators  131  to  136  can be, for example, formed by a ball screw, a shaft motor, a linear motor, a combination of a motor, a gear, and a rack type linear motion structure, or the like. However, the linear actuators  131  to  136  do not need to be linear actuators as long as the linear actuators  131  to  136  are capable of performing the operations of shortening and lengthening the lengths of the respective wires  101  to  106 . For example, the linear actuators can be replaced by combining a rotary motor and a mechanism that winds a wire by rotation of the motor. 
     In the parallel wire device  100  formed by attaching the four wires  101  to  104  for translation and the two wires  105  and  106  for rotation to the movement unit  110  provided with the rotational movement unit  120 , the arrangement of the wires  101  to  106  and the linear actuators  131  to  136  that drive the respective wires  101  to  106  is not limited to the configuration example illustrated in  FIG. 1 . In addition, the number and arrangement of the direction changing pulleys  141 ,  142 , . . . around which the respective wire  105  to  106  are wound are not limited to the configuration example illustrated in  FIG. 1  either. It suffices to determine the arrangement of the linear actuators  131  to  136  and the direction changing pulleys  141 ,  142 , . . . in consideration of the movable range and ease of movement of the movement unit  110  and the rotational movement unit  120 , interferences with other members not illustrated within the device  100 , and the like. 
     The wires  101  to  106  used in the parallel wire device  100  according to the present embodiment can be fabricated by using, for example, a metallic string (a wire rope including a stranded wire manufactured of stainless steel or the like) or a chemical fiber. The metallic string has an advantage of being not elongated easily. In addition, while there is a risk of the chemical fiber being elongated easily, the chemical fiber has an advantage of being conforming easily. In addition, not all of the wires to be used necessarily needs to uniformly include an identical material. 
       FIG. 2  schematically illustrates an example of a configuration of another parallel wire device  200  to which the technology disclosed in the present specification is applied. However, in  FIG. 2 , XYZ axes are set in a similar manner to  FIG. 1 , and the parallel wire device  200  has a total of three degrees of freedom including degrees of translational freedom in two X- and Y-directions and a degree of rotational freedom about one axis, that is, the Z-axis. 
     The parallel wire device  200  includes six parallel wires  201  to  206  and a movement unit  210  supported by these wires  201  to  206 . In addition, a rotational movement unit  220  rotatable about the Z-axis is attached to an upper surface of the movement unit  210 . 
     Incidentally, the movement unit  210  is assumed to be supported slidably on a flat surface, for example, on a board (not illustrated) or the like. 
     The parallel wire device  200  is similar to the parallel wire device  100  illustrated in  FIG. 1  in that the wires  201  to  206  are respectively driven by linear actuators  231  to  236 , in that the wires  201  to  206  are wound around direction changing pulleys  241  to  248 , and in that the movement unit  210  is moved by the wires  201  to  204  and the rotational movement unit  220  is rotated by the wires  205  and  206 . 
     A main difference between the parallel wire device  200  and the parallel wire device  100  is a method of attaching the wires  201  to  204  to the movement unit  210 . Then, for the convenience of attaching the wires  201  to  204  to the movement unit  210 , the arrangement of the linear actuators  231  to  234  driving the respective wires  201  to  204  and the direction changing pulleys  241  to  244  around which the respective wires  201  to  204  are wound is also changed. 
     Then, the parallel wire device  200  illustrated in  FIG. 2  is configured such that the movement unit  210  is rotated easily by driving the wires  201  to  204 , and naturally the rotational movement unit  220  is also rotated easily by driving the wires  201  to  204 . Hence, an even wider rotational movable range than that of the parallel wire device  100  illustrated in  FIG. 1  can be secured by utilizing the functions of rotating both the movement unit  210  and the rotational movement unit  220 . 
     Specifically, the movement unit  210  can be rotated clockwise in  FIG. 2  by pulling the wires  201  and  203  by the linear actuators  231  and  233  and extending the wires  202  and  204  by the linear actuators  232  and  234  so as to balance with the pulling of the wires  201  and  203 . Conversely, the movement unit  210  can be rotated counterclockwise in  FIG. 2  by pulling the wires  202  and  204  by the linear actuators  232  and  234  and extending the wires  201  and  203  by the linear actuators  231  and  233  so as to balance with the pulling of the wires  202  and  204 . 
     Incidentally, the two wires  205  and  206  are parallel wires for rotational movement of the rotational movement unit  220  on the movement unit  210  about the Z-axis. The rotational movement unit  220  can be rotated about the Z-axis with respect to the movement unit  210  (or in the XYZ coordinate system) by shortening the length of one of the two wires  205  and  206  and extending the other by such a length that the two wires are balanced by synchronously driving the linear actuators  235  and  236 . 
       FIG. 3  schematically illustrates an example of a configuration of yet another parallel wire device  200  to which the technology disclosed in the present specification is applied. However, in  FIG. 3 , XYZ axes are set in a similar manner to  FIG. 1 , and a parallel wire device  300  has a total of three degrees of freedom including degrees of translational freedom in two X- and Y-directions and a degree of rotational freedom about one axis, that is, the Z-axis. 
     The parallel wire device  300  includes six parallel wires  301  to  306 , and a movement unit  310  supported by these wires  301  to  306 . In addition, a rotational movement unit  320  rotatable about the Z-axis is attached to an upper surface of the movement unit  310 . Incidentally, the movement unit  310  is assumed to be supported slidably on a flat surface, for example, on a board (not illustrated) or the like. 
     The parallel wire device  300  is similar to the parallel wire device  100  illustrated in  FIG. 1  in that the wires  301  to  306  are driven by the respective linear actuators  331  to  336 , in that the wires  301  to  306  are wound around direction changing pulleys  341  to  348 , and in that the movement unit  310  is moved by the wires  301  to  304  and the rotational movement unit  320  is rotated by the wires  305  and  306 . 
     A main difference between the parallel wire device  300  and the parallel wire device  100  lies in that the wires  305  and  306  for rotation-driving the rotational movement unit  320  are respectively wound around direction changing pulleys  351  and  352  each disposed on the movement unit  310 , and thereafter, distal end portions of the respective wires  305  and  306  are wound around side surface portions of the rotational movement unit  320  in opposite directions from each other. 
     Even when the position or attitude of the movement unit  310  changes as a result of the movement unit  310  being translated by the driving of the wires  301  to  304  or of the rotational movement unit  320  being rotated or when the relative position of the movement unit  310  with respect to the direction changing pulleys  346  and  347  changes, the wires  305  and  306  can always be in contact with the side surface of the rotational movement unit  320  at fixed contact positions via the direction changing pulleys  351  and  352 . Hence, the rotational movement unit  320  always receives the tensions of the wires  305  and  306  from the same directions. Such a configuration can widen a movable range in which the rotational movement unit  320  is rotated about the Z-axis. 
     Needless to say, in addition to the translation of the movement unit  310  in the XY plane, the movement unit  310  can be rotated about the Z-axis to a certain extent by changing the lengths of the respective wires  301  to  304 . Hence, a wider rotational movable range can be secured by utilizing the functions of rotating both the movement unit  310  and the rotational movement unit  320 . 
       FIG. 4  schematically illustrates an example of a configuration of yet another parallel wire device  200  to which the technology disclosed in the present specification is applied. However, in  FIG. 4 , XYZ axes are set in a similar manner to  FIG. 1 , and a parallel wire device  400  has a total of three degrees of freedom including degrees of translational freedom in two X- and Y-directions and a degree of rotational freedom about one axis, that is, the Z-axis. 
     The parallel wire device  400  includes four parallel wires  401 ,  404 ,  405 , and  406  and a movement unit  410  supported by these wires  401 , . . . . In addition, a rotational movement unit  420  rotatable about the Z-axis is attached to an upper surface of the movement unit  410 . Incidentally, the movement unit  410  is assumed to be supported slidably on a flat surface, for example, on a board (not illustrated) or the like. 
     The wires  401  and  404  are parallel wires mainly for the translation of the movement unit  410 . A distal end portion of the wire  401  is fixed to an end portion  411  of the movement unit  410 , the wire  401  is wound around a direction changing pulley  441 , and thereafter, a proximal portion of the wire  401  is attached to a linear actuator  431 . In addition, a distal end portion of the wire  404  is fixed to an end portion  414  of the movement unit  410 , the wire  404  is wound around a direction changing pulley  444 , and thereafter a proximal portion of the wire  404  is attached to a linear actuator  434 . 
     The wires  405  and  406  are parallel wires that rotate the rotational movement unit  420  and are also used for the translation of the movement unit  410 . A distal end portion of the wire  405  is wound around and fixed to a side surface portion of the rotational movement unit  420 , the wire  405  is wound around direction changing pulleys  445  and  446 , and thereafter, a proximal portion of the wire  405  is attached to a linear actuator  435 . In addition, a distal end portion of the wire  406  is wound around and fixed to a side surface portion of the rotational movement unit  420 , the wire  406  is wound around direction changing pulleys  447  and  448 , and thereafter, a proximal portion of the wire  406  is attached to a linear actuator  436 . 
     The movement unit  410  is moved in a negative X-direction by pulling the wires  401  and  404  by the linear actuators  431  and  434  and extending the wires  405  and  406  by the linear actuators  435  and  436  so as to balance with the pulling of the wires  401  and  404 . Conversely, the movement unit  410  is moved in a positive X-direction by pulling the wires  405  and  406  by the linear actuators  435  and  436  and extending the wires  401  and  404  by the linear actuators  431  and  434  so as to balance with the pulling of the wires  405  and  406 . 
     In addition, the movement unit  410  is moved in a positive Y-direction by pulling the wires  401  and  405  by the linear actuators  431  and  435  and extending the wires  405  and  406  by the linear actuators  435  and  436  so as to balance with the pulling of the wires  401  and  405 . Conversely, the movement unit  410  is moved in a negative Y-direction by pulling the wires  404  and  406  by the linear actuators  434  and  436  and extending the wires  401  and  405  by the linear actuators  431  and  435  so as to balance with the pulling of the wires  404  and  406 . 
     In addition, the rotational movement unit  420  can be rotated clockwise in  FIG. 4  by pulling the wire  405  by the linear actuator  435  and extending the wire  406  by the linear actuator  436  so as to balance with the pulling of the wire  405 . On the other hand, the rotational movement unit  420  can be rotated counterclockwise in  FIG. 4  by pulling the wire  406  by the linear actuator  436  and extending the wire  405  by the linear actuator  435  so as to balance with the pulling of the wire  406 . 
     A main difference of the parallel wire device  400  illustrated in  FIG. 4  from the parallel wire devices  100 ,  200 , and  300  respectively illustrated in  FIGS. 1 to 3  lies in that the wires  405  and  406  for the rotation of the rotational movement unit  420  are also used as wires for the translation of the movement unit  410 . As described above, when one of the wires  405  and  406  for the rotation of the rotational movement unit  420  is pulled and the other is extended, the rotational movement unit  420  can be rotated, whereas the movement unit  410  can be translated by pulling or extending the wires  405  and  406  at the same time. That is, the rotational movement unit  420  is rotated by using a difference between changes in length of the wire  405  and the wire  406 , and a sum of changes in length of the wire  405  and the wire  406  is used to translate the movement unit  410 . As is understood from a comparison of  FIG. 4  with  FIGS. 1 to 3 , a total number of wires and the number of linear actuators can be reduced by using the pair of wires for both rotation and translation. However, the movable range of rotation of the movement unit  410  is decreased. 
       FIG. 5  schematically illustrates an example of a configuration of yet another parallel wire device  200  to which the technology disclosed in the present specification is applied. 
     A parallel wire device  500  includes eight parallel wires  501  to  508  and a movement unit  510  supported by these wires  501  to  508 . In order to simplify the drawing, the movement unit  510  forms a simple flat plate shape. Then, in  FIG. 5 , XY axes are set on a plane parallel with this flat plate, and a Z-axis is set in a direction perpendicular to the XY plane. Incidentally, the movement unit  510  is assumed to be supported slidably on a flat surface, for example, on a board (not illustrated) or the like. 
     The four wires  501  to  504  are parallel wires for translating the movement unit  510 . A distal end portion of the wire  501  is fixed to an end portion  511  of the movement unit  510 , the wire  501  is wound around a direction changing pulley  541 , and thereafter, a proximal portion of the wire  501  is attached to a linear actuator  531 . In addition, a distal end portion of the wire  502  is fixed to an end portion of the movement unit  510 , the wire  502  is wound around a direction changing pulley  542 , and thereafter, a proximal portion of the wire  502  is attached to a linear actuator  532 . In addition, a distal end portion of the wire  503  is fixed to an end portion of the movement unit  510 , the wire  503  is wound around a direction changing pulley  543 , and thereafter, a proximal portion of the wire  503  is attached to a linear actuator  533 . In addition, a distal end portion of the wire  504  is fixed to an end portion of the movement unit  510 , the wire  504  is wound around a direction changing pulley  544 , and thereafter, a proximal portion of the wire  504  is attached to a linear actuator  534 . A mechanism for translating the movement unit  510  by using the four parallel wires is similar to that of the parallel wire device  100  illustrated in  FIG. 1 , and therefore, detailed description thereof will be omitted in the following. 
     The parallel wire device  500  greatly differs from the parallel wire devices  100  to  400  respectively illustrated in  FIGS. 1 to 4  in that a rotational movement unit  520  having degrees of rotational freedom about at least two axes among the XYZ axes is attached to the upper surface of the movement unit  510 . In the example illustrated in  FIG. 5 , the rotational movement unit  520  is a rod-shaped structure, and a connecting portion  521  as a base portion of the rotational movement unit  520  is formed by using a ball joint or a universal joint, for example, and imparts degrees of rotational freedom about at least two axes to the rotational movement unit  520 . 
     The four wires  505  to  508  are parallel wires for rotating the rotational movement unit  520  about at least two axes with respect to the movement unit  510 . A distal end portion of the wire  505  is fixed to the side surface of the rod-shaped rotational movement unit  520 , passed through the lower surface side of the movement unit  510  via a through insertion hole drilled in the movement unit  510 , and further wound around direction changing pulleys  545  and  546 , and thereafter, a proximal portion of the wire  505  is attached to a linear actuator  535 . In addition, a distal end portion of the wire  506  is fixed to the side surface of the rod-shaped rotational movement unit  520 , passed through the lower surface side of the movement unit  510  via a through insertion hole drilled in the movement unit  510 , and further wound around direction changing pulleys  547  and  548 , and thereafter, a proximal portion of the wire  506  is attached to a linear actuator  536 . In addition, a distal end portion of the wire  507  is fixed to the side surface of the rod-shaped rotational movement unit  520 , passed through the lower surface side of the movement unit  510  via a through insertion hole drilled in the movement unit  510 , and further wound around direction changing pulleys  549  and  550 , and thereafter, a proximal portion of the wire  507  is attached to a linear actuator  537 . In addition, a distal end portion of the wire  508  is fixed to the side surface of the rod-shaped rotational movement unit  520 , passed through the lower surface side of the movement unit  510  via a through insertion hole drilled in the movement unit  510 , and further wound around direction changing pulleys  551  and  552 , and thereafter, a proximal portion of the wire  508  is attached to a linear actuator  538 . 
       FIG. 6  illustrates a state in which the rotational movement unit  520  is viewed from above. When the wires  505  and  506  are pulled by the linear actuators  535  and  536 , and the wires  507  and  508  are extended by the linear actuators  537  and  538  so as to balance with the pulling of the wires  505  and  506 , the rotational movement unit  520  rotates about the Y-axis on the connecting portion  521  with respect to the movement unit  510  (or in the XYZ coordinate system), and falls in a positive X-direction. In addition, when the wires  507  and  508  are pulled by the linear actuators  537  and  538 , and the wires  505  and  506  are extended by the linear actuators  535  and  536  so as to balance with the pulling of the wires  507  and  508 , the rotational movement unit  520  rotates about the Y-axis on the connecting portion  521  and falls in a negative X-direction. 
     Meanwhile, when the wires  505  and  507  are pulled by the linear actuators  535  and  537 , and the wires  506  and  508  are extended by the linear actuators  536  and  538  so as to balance with the pulling of the wires  505  and  507 , the rotational movement unit  520  rotates about the X-axis on the connecting portion  521  with respect to the movement unit  510  (or in the XYZ coordinate system), and falls in a negative Y-direction. In addition, when the wires  506  and  508  are pulled by the linear actuators  536  and  538 , and the wires  505  and  507  are extended by the linear actuators  535  and  537  so as to balance with the pulling of wires  5062  and  508 , the rotational movement unit  520  rotates about the X-axis on the connecting portion  521  and falls in a positive Y-direction. 
     As described above, the parallel wire devices  100  to  500  illustrated in  FIGS. 1 to 5  can translate the movement units  110 ,  210 , . . . supported by a plurality of parallel wires, and rotate the rotational movement units  120 ,  220 , . . . attached to the movement units  110 ,  210 , . . . . Then, while the plurality of wires attached to the movement units  110 ,  210 , . . . includes parallel wires for translation and parallel wires for rotation, the wires do not interfere with each other at any of a time of translation, a time of rotation, or a time of performing translation and rotation at the same time. 
     In addition, in each of the parallel wire devices  100  to  500  illustrated in  FIGS. 1 to 5 , the linear actuators for translation and for rotation are all installed at the proximal portions of the respective wires. Hence, no driving actuators are mounted at all in the movement units  110 ,  210 , . . . translated and rotated by the parallel wires, so that the movement units  110 ,  210 , . . . can be fabricated in small size and with light weight. Because of the light weight, the movement units  110 ,  210 , . . . can be translated or rotated by relatively small pulling forces of the wires. In addition, even in a case where an accident in which the movement units  110 ,  210 , . . . fall occurs, damage can be minimized because of the small size and the light weight. 
     In the embodiments of the parallel wire devices  100  to  500  illustrated in  FIGS. 1 to 5 , the movement units  110 ,  210 , . . . have two degrees of freedom for translation in the XY plane. However, degrees of translational freedom in three directions can be realized by further adding two wires for pulling in a Z-direction. In addition, in the embodiments of the parallel wire devices  100  to  400  illustrated in  FIGS. 1 to 4 , the rotational movement units  120 ,  220 , . . . that can rotate only about one axis are attached to the movement units  110 ,  210 , . . . , and each have a degree of rotational freedom about one axis. However, two or more degrees of rotational freedom can also be realized by providing the rotational movement units  120 ,  220 , . . . with degrees of rotational freedom about two axes or more, and adding two wires for rotating the rotational movement units  120 ,  220 , . . . about each axis. For example, it suffices to mount a parallel link device on a movement unit capable of translation by parallel wires, and add two wires for driving each link. 
     Meanwhile, wires can generate only tension. It is known in the art that at least seven wires are therefore necessary to operate an object having six degrees of freedom to a freely-selected position by only wires (see PTL 4, for example). That is, when there are at least seven wires, the position (angle) of the target object can be controlled. In addition, 12 wires are necessary to completely control the six degrees of freedom including both the position (angle) and force (torque). 
     Further, two wires are necessary to drive the rotational movement unit  120  attached to the movement unit  110  as in the parallel wire device  100  according to the present embodiment, and two wires are necessary for each degree of freedom in a case where the rotational movement unit  520  has two or more degrees of rotational freedom as in the parallel wire device  500 . Hence, a parallel wire device realizing the translation of a movement unit and the rotation of a rotational movement unit as in the present embodiment needs a minimum of 11 wires and a maximum of 16 wires. 
     When the number of wires is increased, the arrangement of the wires becomes complex, and the number of driving devices such as linear actuators pulling the wires is increased. Thus, a total weight is increased, and a cost is also increased. In contrast, a mechanism for reducing the number of wires may be introduced into a parallel wire device. For example, one of a minimum of seven wires for driving the parallel wire device can be used in a shared manner by using a difference between changes in the length of two wires for the rotation of a rotational movement unit and using a sum of the changes in the length for the translation of a movement unit. As described above, in the parallel wire device  400  illustrated in  FIG. 4 , the wires  405  and  406  for the rotation of the rotational movement unit  420  are also used as wires for the translation of the movement unit  410 . The rotational movement unit  420  is rotated by using a difference between changes in the length of the wire  405  and the wire  406 , and the movement unit  410  is translated by a sum of the changes in the length of the wire  405  and the wire  406 . 
     The parallel wire devices  100  to  500  illustrated in  FIGS. 1 to 5  have effects as follows. 
     (1) A wide rotational movable range can be achieved while low inertia intrinsic in the parallel wires is achieved. 
     (2) A wide translational movable range intrinsic in the parallel wires can be provided. 
     (3) The number of wires and actuators for driving the wires can be reduced by partially sharing the wires for translation and the wires for rotation. 
     (4) In a case where a universal joint is used at points of attachment of the wires, the attachment points are changed easily, a rotational center is not shifted according to the orientations of the wires, and an error from a model can be suppressed. 
     Second Embodiment 
       FIG. 7  and  FIG. 8  illustrate an example in which a parallel wire system is applied in a master device  700  of a master-slave system. However,  FIG. 7  illustrates a state in which the master device  700  operated by an operator is obliquely viewed from the front of the operator, and  FIG. 8  illustrates a state in which the master device  700  being operated by the operator is overlooked. Suppose that the master device  700  performs two-way communication with a slave device not illustrated, and that a bilateral system, for example, is used to operate a slave from a master and simultaneously feed back the state of the slave to the master. 
     A main body of the master device  700  is a box-shaped structure that opens in an upper surface thereof. A plurality of wires is extended in parallel from the side surface of the box to the inside of the box. Then, these wires support each of a controller  701 L for a left hand and a controller  701 R for a right hand in the air. In addition, a plurality of linear actuators that pulls the respective wires on proximal sides is attached to the master device  700 . 
     As illustrated in  FIG. 7  and  FIG. 8 , the operator can operate the controller  701 L for the left hand and the controller  701 R for the right hand in a state of placing the left and right hands in the box. As will be described later, the controllers  701 L and  701 R include a gripping force sense presenting device, and the operator operates the controllers  701 L and  701 R while gripping the gripping force sense presenting devices by the respective left and right hands. Neither of the controllers  701 L and  701 R includes a power source such as a linear actuator for pulling a wire or the like, and each of the controllers  701 L and  701 R can therefore be configured in small size, with light weight, and with low inertia, and provide the operator with good operability. The controller  701 L for the left hand and the controller  701 R for the right hand basically have a bilaterally symmetric shape and a bilaterally symmetric structure. In the following, description will be made mainly of the controller  701  for the right hand. 
     The controller  701  includes: a controller main body unit that is translated in a three-dimensional space by parallel wires, and a rotational movement unit that is attached so as to be rotatable about at least one axis with respect to a controller main body, and is rotated by parallel wires. In other words, the parallel wires supporting the controller  701  in the air include parallel wires for translating the controller main body and parallel wires for rotating the rotational movement unit. In addition, in  FIG. 7  and  FIG. 8 , the wires used to translate the main body unit of the controller  701  are depicted by solid lines, and the wires used to rotate the rotational movement unit within the main body are depicted by broken lines. However, details of a mechanism for translating and rotating the controller  701  will be described later. The wires are pulled by linear actuators at proximal portions of the respective wires. 
     The proximal portion of each of the wires is oriented in a translational direction of the corresponding linear actuator, while the distal end portion of each of the wires is oriented in an operating direction of a target object to be translated or rotated. Each of the wires is wound around one or two or more pulleys (not illustrated in  FIG. 7  nor  FIG. 8 ) at an intermediate point(s) and folded back or changed in direction as appropriate, and each of the wires is arranged such that the wires do not interfere with each other. 
     The wires used in the master device  700  can be fabricated by using, for example, a metallic string (a wire rope including a stranded wire manufactured of stainless steel or the like) or a chemical fiber. The metallic string has an advantage of being not elongated easily. In addition, while there is a risk of the chemical fiber being elongated easily, the chemical fiber has an advantage of being conforming easily. In addition, not all of the wires to be used necessarily needs to uniformly include an identical material. Generally, a tension up to approximately 10 kgf is expected to act on the wires. However, a maximum instantaneous tension may not be limited to this value. 
       FIG. 9 ,  FIG. 10 , and  FIG. 15  illustrate, in enlarged dimension, the controller  701  in the master device  700 . Incidentally, for the convenience of description, in  FIG. 9  and  FIG. 10 , XYZ axes are set as illustrated in the figures. The controller  701  illustrated in the figures includes: a controller main body unit that is translated in a three-dimensional space by parallel wires; and a rotational movement unit that is attached so as to be rotatable about at least one axis with respect to the controller main body, and is rotated by parallel wires. 
     The controller main body unit is formed by integrated three plates, that is, a bottom plate portion  801  having a Z-axis direction as a normal, a side wall portion  802  having a Y-axis direction as a normal, and a side wall portion  803  having an X-axis direction as a normal. 
     The bottom plate portion  801  may have four universal joints  811  to  814  for attaching a plurality of wires in parallel. When parallel wires for translation are attached (not illustrated in  FIG. 9  nor  FIG. 10 ) to the respective universal joints  811  to  814 , and the bottom plate portion  801  is pulled, the controller  701  is supported so as to float in the air within the box of the master device  700 , as illustrated in  FIG. 7  and  FIG. 8 , and the controller  701  can be translated in each of the XYZ axial directions. 
     Incidentally, the universal joints  811  to  814  are joints that change in angle freely, and are used to make a rotational center fixed at all times when the universal joints  811  to  814  are pulled by the respective wires. That is, an angle at which each wire is incident on the bottom plate portion  801  changes according to a position to which the bottom plate portion  801  is translated. However, the universal joints  811  to  814  maintain the rotational center position of the wires at all times, and thereby suppress an error from an ideal model of a parallel wire mechanism and also contribute to a reduction in damage to the wires. In addition, when the universal joints are used, attachment points can be changed by screws, and it is therefore easy to change the attachment points without damaging the wires. 
     The rotational movement unit attached to the main body unit of the controller  701  is a parallel link structure with two degrees of freedom, the parallel link structure including a first serial link  851  and a second serial link  852 . In addition, this parallel link is mounted with a gripping force sense presenting device  870  that the operator grips by hand and operates directly. Then, this parallel link is configured to be housed within a space of the controller main body unit including the bottom plate portion  801  and the two side wall portions  802  and  803 . 
     A pulley  821  rotatable about a Y-axis is attached to the inner wall surface of the side wall portion  802 . In addition, the first serial link  851  rotates about the Y-axis integrally with the pulley  821 . Then, respective distal end sides of two wires  861  and  862  are wound around the periphery of the pulley  821  so as to be in opposite directions from each other. 
     Other end sides of these wires  861  and  862  are released to the outside of the controller main body unit via two respective insertion holes  803   a  and  803   b  drilled in the side wall portion  803 , and are pulled by respective linear actuators (not illustrated in  FIG. 9  nor  FIG. 10 ). Hence, the first serial link  851  is rotated in a clockwise direction about the Y-axis integrally with the pulley  821  by pulling the wire  861  from the other end side and extending the wire  862  so as to balance with the pulling of the wire  861 . In addition, the first serial link  851  is rotated in a counterclockwise direction about the Y-axis integrally with the pulley  821  by pulling the wire  862  from the other end side and extending the wire  861  so as to balance with the pulling of the wire  862 . 
     A pulley  822  rotatable about an X-axis is attached to the inner wall surface of the side wall portion  803 . In addition, the second serial link  852  rotates about the X-axis integrally with the pulley  822 . Then, respective distal end sides of two wires  863  and  864  are wound around the periphery of the pulley  822  so as to be in opposite directions from each other. 
     Other end sides of these wires  863  and  864  are released to the outside of the controller main body unit via two respective insertion holes  802   a  and  802   b  drilled in the side wall portion  802 , and are pulled by respective linear actuators (not illustrated in  FIG. 9  nor  FIG. 10 ). Hence, the second serial link  852  is rotated in a clockwise direction about the X-axis integrally with the pulley  822  by pulling the wire  863  from the other end side and extending the wire  864  so as to balance with the pulling of the wire  863 . In addition, the second serial link  852  is rotated in a counterclockwise direction about the X-axis integrally with the pulley  822  by pulling the wire  864  from the other end side and extending the wire  863  so as to balance with the pulling of the wire  864 . 
     Here, as is also understood from  FIG. 9 , one pair of the insertion holes  802   a  and  802   b  on the side wall portion  802  side and one pair of the insertion holes  803   a  and  803   b  on the side wall portion  803  side are drilled with height differences (that is, such that the positions thereof in the Z-direction do not coincide with one another). Hence, the wires  861  and  862  inserted through the insertion holes  803   a  and  803   b  and the wires  863  and  864  inserted through the insertion holes  802   a  and  802   b  pass on different planes, and can pull the respective pulleys  821  and  822  for rotation so as not to interfere with one another. 
     The pulley  822  is disposed such that the axis of rotation of the pulley  822  is orthogonal to that of the pulley  821  that rotates about the Y-axis. In addition, a parallel link including the first serial link  851  and the second serial link  852  realizes degrees of rotational freedom about two axes orthogonal to each other. For example, the first serial link  851  and the second serial link  852  can be rotated by approximately ±80 degrees about the respective rotational axes. Hence, two degrees of rotational freedom can be imparted to the gripping force sense presenting device  870  mounted on the parallel link. Further, a flat type motor  881  may be mounted. A third degree of freedom that enables a wide rotation of ±90 degrees or more about the rotational axis of the motor  881  can be imparted to the gripping force sense presenting device  870 . The use of a flat type motor as the motor  881  can realize a simple structure that does not easily collide with surroundings at a time of rotation. 
     As is understood from  FIGS. 7 to 10 , the master device  700  drives the controller  701  by the parallel wire system. The parallel wires have low inertia. In addition, according to the parallel wire mechanism of translating the controller  701  in three directions by the wires for translation and rotating the gripping force sense presenting device  870  within the controller  701  about two axes by the wires for rotation, a force can be presented to the operator, and the state of the slave is fed back to the master at the same time as the slave is operated from the master. Thus, bilateral control can be realized suitably. 
     The gripping force sense presenting device  870  is a UI (User Interface) mounted in the controller  701 , and gripped by hand and operated by the operator.  FIG. 7  and  FIG. 8  illustrate a state in which the operator is operating the gripping force sense presenting devices respectively mounted in the left and right controllers  701 L and  701 R by a left hand and a right hand. Incidentally, a six-axis force sensor (not illustrated) may be mounted on the proximal side of the gripping force sense presenting device  870 . An order in which the six-axis force sensor and the motor  881  are arranged is optional. There is a case where it is better to dispose the force sensor closer to the proximal side than the motor  881  in consideration of cable wiring design. The technology disclosed in PTL 3, for example, can be applied to the gripping force sense presenting device  870 . A configuration of the gripping force sense presenting device  870  will be briefly described in the following. 
       FIGS. 11 to 13  illustrate a state in which the operator is using the gripping force sense presenting device  870 . The gripping force sense presenting device  870  includes a rod-shaped main body portion  1101 , a link portion  1104  supported by a bearing portion  1102  in the vicinity of a distal end of the main body portion  1101  so as to be rotatable about a rotational center  1103 , a finger contact portion  1105  on the upper surface of a distal end of the link portion  1104 , and a rail portion  1106  on the lower surface of the distal end of the link portion  1104 . 
     The operator can hold the gripping force sense presenting device  870  so as to sandwich the main body portion  1101  between a thumb and a middle finger. In addition, the link portion  1104  can be operated so as to be opened and closed with respect to the main body portion  1101  by making an index finger abut against the finger contact portion  1105  and further pushing in the index finger. In addition, the rail portion  1106  appears from the main body portion  1101  and disappears with the opening and closing operation of the link portion  1104 . 
     Though not illustrated, housed within the main body portion  1101  are an encoder that measures the rotational angle of the link portion  1104 , an actuator that applies a load to the opening and closing operation of the link portion  1104 , and a transmitting mechanism that transmits a driving force of the actuator. See PTL 3 for details. 
     In a case where the master-slave system is applied to a medical robot that performs a surgical operation (for example, a surgical operation using an endoscope, a microscope, or a catheter) or the like, the controller  701 L for the left hand and the controller  701 R for the right hand should be installed as a surgeon console for operating a medical instrument attached on the slave side from the master side. In addition, when ergonomics is taken into consideration, the controller  701 L for the left hand and the controller  701 R for the right hand are preferably attached in attitudes in which the operator easily operates the controller  701 L for the left hand and the controller  701 R for the right hand by respective left and right arms and hands. When the controller  701 L for the left hand and the controller  701 R for the right hand are each attached at an appropriate angle, the operator operates the controller  701 L for the left hand and the controller  701 R for the right hand easily, can perform work with high accuracy, and does not feel the fatigue of the arms and the hands easily. The operator can therefore endure work for a long period of time. 
     In general, a human does not become tired easily in a state in which a hand goes downward from upward. Accordingly, in the example illustrated in  FIG. 7  and  FIG. 8 , assuming a state in which the left and right hands of the operator go downward from upward, each of the controller  701 L for the left hand and the controller  701 R for the right hand is attached such that the gripping force sense presenting device  870  is oriented upward. 
     In addition, when an elbow is bent to a certain extent, the person performs operation more easily, can respond instantly, and does not hurt the elbow easily. Ergonomically, an attitude is preferable in which fingers of the left and right hands of the operator respectively go from the left and right outsides to the front of the body. Accordingly, in the example illustrated in  FIG. 7  and  FIG. 8 , the controller  701 L for the left hand and the controller  701 R for the right hand are each disposed such that the pulleys  821  and  822  supported by the side wall portions  802  and  803  are on the inside of both hands, and such that the gripping force sense presenting devices  870  are oriented to the left and right outsides. It can also be said that the rotational movement unit is disposed so as to be on the inside of the hand of the operator when the parallel wire device is installed and used in front of the operator. Then, the operator can grip the gripping force sense presenting device  870  in a state in which the elbows of the left and right arms are bent to a certain extent and in an attitude in which the left and right hands each go from the outside to the front of the body. Thus, the operator performs operation easily, can respond instantly, does not hurt the elbow easily, and can proceed with an operation procedure smoothly. 
     According to the arrangement of the controllers  701 L and  701 R as illustrated in  FIG. 7  and  FIG. 8 , the operator can operate the controllers  701 L and  701 R while using a wide movable range intrinsically possessed by the arms of the human. Conversely, when the controllers  701 L and  701 R are arranged in directions in which it is difficult to orient the hands of the human without ergonomics being taken into consideration, the operator can use only a part of the movable range possessed by the arms of the operator for the operation of the controllers  701 L and  701 R, and therefore becomes fatigued easily and hurts the elbows easily. 
     Third Embodiment 
     The rotational movement unit attached to the main body unit of the controller  701  in the embodiment illustrated in  FIGS. 7 to 10  is a two-axis parallel link structure and is not limited to this. It suffices to mount a parallel link device with three axes or more in the main body unit of the controller  701  and drive each link by two wires. 
     For example, a spherical parallel link device having three degrees of rotational freedom, the spherical parallel link device being referred to also as an “Agile eye,” can also be mounted in the main body unit of the controller  701 . The spherical parallel link device is a parallel link device in which each link is configured to move on a spherical surface having a common center. 
       FIG. 14  illustrates an example of a configuration of the spherical parallel link device. The spherical parallel link device  1400  illustrated in the figure includes a base portion  1401 , three serial links attached in parallel to the base portion  1401 , and an end effector portion  1402  supported by distal end portions of these three serial links. 
     In the spherical parallel link device  1400  illustrated in the figure, the three parallel serial links are of a substantially identical configuration. The three parallel serial links each include a proximal portion  1411  attached with a degree of rotational freedom about one axis to the base portion  1401 , a driving link  1412  that rotates integrally with the proximal portion  1411 , and a driven link  1413  that is coupled to a distal end portion of the driving link  1412  and supports the end effector portion  1402  at a distal end portion of the driven link  1413 . 
     The proximal portion  1411  of each link is formed as a pulley, for example. Two wires  1421  and  1422  are wound around the periphery of the proximal portion  1411  in opposite directions from each other. The proximal portion  1411  and the driving link  1412  can be rotation-driven by pulling one of the wires  1421  and  1422  and extending the other. Then, the three-dimensional attitude of the end effector portion  1402  with respect to the base portion  1401  can be changed by synchronously driving the three serial links. 
     The spherical parallel link device  1400  is characterized by having a wide movable range and being driven at high speed and high acceleration. When a camera is mounted on the end effector portion  1402 , for example, the camera has a wider angle of view than an eye of a human, and a line of sight can be changed at higher speed and high acceleration than an eye of a human. 
     Fourth Embodiment 
     A range of application of the parallel wire device disclosed in the present specification is not limited to a controller of a master device. For example, the parallel wire device as described above may be applied for translation and rotation of a remote operation target such as a manipulator on the slave device side or the like. 
     In addition, the range of application of the parallel wire device disclosed in the present specification is not limited to the master-slave system. 
     For example, when a moving projector is floated in the air by the parallel wire device disclosed in the present specification, the moving projector can be translated in a three-dimensional space, and further a video projecting direction can be changed in a wide movable range at each position to which the moving projector is moved. Specifically, the rotational movement unit including the parallel link structure as illustrated in  FIG. 14  is mounted on the movement unit, and the projector is attached to the parallel link. The pulling of the wire can translate the projector in the three-dimensional space, and change the projecting direction at each movement position. It is therefore possible to realize a moving projector having a wide translational movable range and a wide rotational movable range. 
     In addition, when photographing equipment such as a camera or the like is floated in the air by the parallel wire device disclosed in the present specification, the camera can be translated in the three-dimensional space to change a viewpoint position, and further the sight line direction of the camera can be changed in a wide movable range at each viewpoint position to which the camera is moved. In a case where a ceiling suspension type camera is used in a stadium in which a ball game such as soccer, athletic sports, or the like is performed, for example, a plurality of parallel wires is provided on a ceiling or in the air in the sporting venue, and the pulling of the wires can move the ceiling suspension type camera or adjust a pan or a tilt in a wide range. Specifically, the rotational movement unit including the parallel link structure as illustrated in  FIG. 14  is mounted on the movement unit, and the ceiling suspension type camera is attached to the parallel link. The pulling of the wires can translate the viewpoint position of the camera in the three-dimensional space, and change the sight line direction of the camera at each movement position. It is therefore possible to realize a moving camera having a wide translational movable range and a wide rotational movable range. 
     In a case where the equipment such as the moving projector, the camera, or the like is floated in the air by the parallel wire device disclosed in the present specification, linear actuators for driving the wires are arranged in the vicinity of the proximal portions of the respective wires. Thus, the movement unit mounted with the equipment can be fabricated in small size and with light weight. Hence, the equipment can be translated or rotated with a relatively small pulling force. In addition, even in a case where an accident in which the movement unit mounted with the equipment falls occurs, damage can be minimized because of the small size and the light weight. 
     Incidentally, it is to be understood that the parallel wire device applied to the master device  700  illustrated in  FIGS. 7 to 10  has effects similar to those of the parallel wire device described in the first embodiment. The parallel wire device has low inertia, and has a wide translational movable range and a wide rotational movable range. When the controller  701  is driven by using such a parallel wire device, a force can be presented to the operator, and the state of the slave is fed back to the master at the same time as the slave is operated from the master. Thus, bilateral control can be realized suitably. 
     INDUSTRIAL APPLICABILITY 
     The technology disclosed in the present specification has been described above in detail with reference to particular embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions in the embodiments without departing from the spirit of the technology disclosed in the present specification. 
     The parallel wire device to which the technology disclosed in the present specification is applied can be used for the translation and rotation of the controller on the master device side and for the translation and rotation of the operation target such as a manipulator on the slave device side in the master-slave system, for example. The applications of the parallel wire device to which the technology disclosed in the present specification is applied are not limited to the master-slave system. In addition, various equipment including a moving projector and a camera can be floated in the air and translated and rotated by using the parallel wire device to which the technology disclosed in the present specification is applied. 
     In short, the technology disclosed in the present specification has been described in a form of illustration, and the contents described in the present specification are not to be construed in a limited manner. In order to determine the gist of the technology disclosed in the present specification, claims are to be considered. 
     Incidentally, the technology disclosed in the present specification can also have the following configurations. 
     (1) A parallel wire device including: 
     a movement unit; 
     a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis; 
     a first parallel wire configured to translationally drive the movement unit; and 
     a second parallel wire configured to rotationally drive the rotational movement unit. 
     (2) The parallel wire device according to the above (1), in which 
     the rotational movement unit has two or more degrees of rotational freedom with respect to the movement unit, and 
     the second parallel wire includes a parallel wire configured to rotationally drive the rotational movement unit about one axis and a parallel wire configured to rotationally drive the rotational movement unit about another axis. 
     (3) The parallel wire device according to the above (1), in which 
     the rotational movement unit includes a serial link, and 
     the second parallel wire includes a parallel wire configured to drive the serial link. 
     (4) The parallel wire device according to the above (1), in which 
     the rotational movement unit includes a parallel link, and 
     the second parallel wire includes parallel wires configured to drive respective links constituting the parallel link. 
     (5) The parallel wire device according to the above (1), in which 
     the second parallel wire includes two wires configured to rotationally drive the rotational movement unit about one axis. 
     (6) The parallel wire device according to the above (1), in which 
     the second parallel wire includes a wire used for translationally driving the movement unit in a shared manner. 
     (7) The parallel wire device according to the above (6), in which 
     the second parallel wire includes two wires configured to rotationally drive the rotational movement unit by using a difference between changes in length, and translationally drive the movement unit by using a sum of changes in length. 
     (8) The parallel wire device according to the above (4), further including: 
     an actuator configured to drive a structure attached to a distal end of the parallel link. 
     (9) The parallel wire device according to the above (2), in which 
     the parallel wire configured to rotationally drive the rotational movement unit about one axis and the parallel wire configured to rotationally drive the rotational movement unit about the other axis are arranged so as to pass on different planes and so as not to interfere with each other. 
     (10) The parallel wire device according to any one of the above (1) to (9), in which 
     when the parallel wire device is provided and used in front of an operator, the rotational movement unit is disposed so as to be on an inside of a hand of the operator. 
     (11) A parallel wire system including: 
     a movement unit; 
     a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis; 
     a first parallel wire configured to translationally drive the movement unit; 
     a second parallel wire configured to rotationally drive the rotational movement unit; and 
     a plurality of actuators configured to drive respective wires included in the first parallel wire and the second parallel wire. 
     (12) An operating device for a medical robot of a master-slave system, the operating device being for operating a medical instrument attached to a slave side from a master side, the operating device including: 
     a movement unit; 
     a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis; 
     an operating unit for an operator, the operating unit being attached to the rotational movable unit; 
     a first parallel wire configured to translationally drive the movement unit; and 
     a second parallel wire configured to rotationally drive the rotational movement unit. 
     (12-1) A medical robot of a master-slave system, the medical robot including an operating device for the medical robot of the master-slave system, the operating device being on a master side that operates a medical instrument attached to a slave side, the operating device including: 
     a movement unit; 
     a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis; 
     an operating unit for an operator, the operating unit being attached to the rotational movable unit; 
     a first parallel wire configured to translationally drive the movement unit; and 
     a second parallel wire configured to rotationally drive the rotational movement unit. 
     (13) A mobile projecting device including: 
     a movement unit; 
     a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis; 
     a projecting device attached to the rotational movable unit; 
     a first parallel wire configured to translationally drive the movement unit; and 
     a second parallel wire configured to rotationally drive the rotational movement unit. 
     (14) A mobile photographing device including: 
     a movement unit; 
     a rotational movement unit attached to the movement unit so as to be rotatable about at least one axis; 
     a camera attached to the rotational movable unit; 
     a first parallel wire configured to translationally drive the movement unit; and 
     a second parallel wire configured to rotationally drive the rotational movement unit. 
     REFERENCE SIGNS LIST 
     
         
         
           
               100  . . . Parallel wire device 
               101  to  106  . . . Wire 
               110  . . . Movement unit 
               120  . . . Rotational movement unit 
               131  to  136  . . . Linear actuator 
               141  to  148  . . . Direction changing pulley 
               200  . . . Parallel wire device 
               201  to  206  . . . Wire 
               210  . . . Movement unit 
               220  . . . Rotational movement unit 
               231  to  236  . . . Linear actuator 
               241  to  248  . . . Direction changing pulley 
               300  . . . parallel wire device 
               301  to  306  . . . Wire 
               310  . . . Movement unit 
               320  . . . Rotational movement unit 
               331  to  336  . . . Linear actuator 
               341  to  348  . . . Direction changing pulley 
               351 ,  352  . . . Direction changing pulley 
               400  . . . Parallel wire device 
               401 ,  404 ,  405 ,  106  . . . Wire 
               410  . . . Movement unit 
               420  . . . Rotational movement unit 
               431 ,  434 ,  435 ,  436  . . . Linear actuator 
               441 ,  444  to  148  . . . Direction changing pulley 
               500  . . . Parallel wire device 
               101  to  106  . . . Wire 
               510  . . . Movement unit 
               520  . . . Rotational movement unit 
               521  . . . Connecting portion 
               531  to  538  . . . Linear actuator 
               541  to  552  . . . Direction changing pulley 
               700  . . . Master device 
               701  . . . Controller 
               801  . . . Bottom plate portion 
               802  . . . Side wall portion 
               802   a ,  802   b  . . . Insertion hole 
               803  . . . Side wall portion 
               803   a ,  803   b  . . . Insertion hole 
               811  to  814  . . . Universal joint 
               821 ,  822  . . . Pulley 
               851  . . . First serial link 
               852  . . . Second serial link 
               861  to  864  . . . Wire 
               870  . . . Gripping force sense presenting device 
               881  . . . Motor 
               1101  . . . Main body portion 
               1102  . . . Bearing portion 
               1103  . . . Rotational center 
               1104  . . . Link portion 
               1105  . . . Finger contact portion 
               1106  . . . Rail portion 
               1400  . . . Spherical parallel link device 
               1401  . . . Base portion 
               1402  . . . End effector portion 
               1411  . . . Proximal portion (pulley) 
               1412  . . . Driving link 
               1413  . . . Driven link 
               1421 ,  1422  . . . Wire