Patent Publication Number: US-2023144236-A1

Title: Position/force control system, position/force control apparatus, position/force control method, and storage medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority under 35 USC 119 of Japanese Patent Application No. 2021-182220 filed on Nov. 8, 2021 the entire disclosure of which, including the description, claims, drawings, and abstract, is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a position/force control system, a position/force control apparatus, a position/force control method, and a storage medium. 
     Description of the Related Art 
     A massage chair on which the body of a user is massaged is known. 
     For example, the massage chair has a function of massaging the back, shoulders, or another part of the user while moving a pressing member that is contained in a backrest and is improved in various ways so as to provide a massage similar to treatment that is provided by a practitioner such as a masseur. 
     Japanese Unexamined Patent Application Publication No. 2005-118126 discloses a technique regarding a massage machine that presumes the sense of a user about a massage operation and that controls and changes the massage operation in a direction that the user wishes, based on the presumed sense. 
     The technique disclosed in Japanese Unexamined Patent Application Publication No. 2005-118126 is used to provide an effective massage depending on the sense of the user that varies as the massage progresses and to improve the reliability of the presumed sense. 
     BRIEF SUMMARY OF THE INVENTION 
     A position/force control system according to an aspect of the present invention comprising:
     one or multiple master apparatuses that receive an input of a treatment operation;   one or multiple slave apparatuses that output a treatment operation; and   a controller that controls the one or multiple master apparatuses and the one or multiple slave apparatuses,   wherein the controller transmits a control parameter for causing the one or multiple slave apparatuses to output force tactile sensation that corresponds to the treatment operation that is inputted into the one or multiple master apparatuses to the one or multiple slave apparatuses and transmits a control parameter for causing the one or multiple master apparatuses to output reaction force against the treatment operation that is outputted by the one or multiple slave apparatuses to the one or multiple master apparatuses.   

    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       [ FIG.  1   ]  FIG.  1    schematically illustrates the system configuration of a position/force control system 1 according to an embodiment of the present invention. 
       [ FIG.  2   ]  FIG.  2    schematically illustrates the structure of each of the master apparatuses 10. 
       [ FIG.  3   ]  FIG.  3    schematically illustrates the structure of each of the slave apparatuses 20. 
       [ FIG.  4   ]  FIG.  4    illustrates the hardware configuration of an information processing apparatus 800 that includes the functional unit for control in the position/force control system 1. 
       [ FIG.  5   ]  FIG.  5    is a block diagram illustrating the functional configuration of each master apparatus 10. 
       [ FIG.  6   ]  FIG.  6    is a block diagram illustrating an algorithm for control over the transmission of the force tactile sensation that is used according to the present embodiment. 
       [ FIG.  7   ]  FIG.  7    is a block diagram illustrating the functional configuration of each slave apparatus 20. 
       [ FIG.  8   ]  FIG.  8    is a block diagram illustrating the functional configuration of the control device 30. 
       [ FIG.  9   ]  FIG.  9    schematically illustrates the concept of the individual-treatment mode in the position/force control system 1. 
       [ FIG.  10   ]  FIG.  10    schematically illustrates the concept of the multiple-treatment mode in the position/force control system 1. 
       [ FIG.  11   ]  FIG.  11    is a flowchart illustrating the flow of the remote treatment process that is performed by the position/force control system 1. 
       [ FIG.  12   ]  FIG.  12    is a flowchart illustrating the flow of the individual-treatment process. 
       [ FIG.  13   ]  FIG.  13    is a flowchart illustrating the flow of the multiple-treatment process. 
       [ FIG.  14   ]  FIG.  14    schematically illustrates the structure of the slave apparatus 20 that has a function of rubbing the back of the user. 
       [ FIG.  15   ]  FIG.  15    is a front view of the slave apparatus 20 illustrated in  FIG.  14   . 
       [ FIG.  16   ]  FIG.  16    is a sectional view of the slave apparatus 20 taken along line A-A′ in  FIG.  15   . 
       [ FIG.  17   ]  FIG.  17    is a sectional view of the slave apparatus 20 taken along line B-B′ in  FIG.  15   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of the present invention will hereinafter be described with reference to the drawings. 
     Structure 
       FIG.  1    schematically illustrates the system configuration of a position/force control system 1 according to an embodiment of the present invention. 
     As for the position/force control system  1  according to the present embodiment, multiple master apparatuses  10  that are used by practitioners and multiple slave apparatuses  20  that are used by users are remotely located, and a communication link can be established between a combination of a freely selected one of the master apparatuses  10  and a freely selected one of the slave apparatuses  20 . The master apparatuses  10  receive treatment operations that are performed by the practitioners. The slave apparatuses  20  enable the users (people to be treated) to receive the treatment operations that are performed by the practitioners. Transmission of force tactile sensation between the master apparatuses  10  and the slave apparatuses  20  is controlled, the treatment operations that are performed by the practitioners by using the master apparatuses  10  are consequently inputted into the users by using the slave apparatuses  20 , and reaction force that is inputted from the users into the slave apparatuses  20  is provided to the practitioners by using the master apparatuses  10 . 
     Accordingly, a massage device can provide tactility similar to that in the case where the practitioners directly massage the users. 
     As illustrated in  FIG.  1   , the position/force control system  1  according to the present embodiment includes the master apparatuses  10  that receive the treatment (such as massages) operations that are inputted by the practitioners, the slave apparatuses  20  that output the treatment operations to the users (people to be treated), a control device  30  that controls the transmission of the force tactile sensation between the master apparatuses  10  and the slave apparatuses  20 , imaging apparatuses C that image the users to be treated by the slave apparatuses  20 , and display devices D that display the images of the users that are captured by the imaging apparatus C. The master apparatuses  10 , the slave apparatuses  20 , the control device  30 , the imaging apparatus C, and the display devices D can communicate with each other via a network 40 such as the internet. According to the present embodiment, the position/force control system  1  includes the multiple master apparatuses  10 , the multiple slave apparatuses  20 , the multiple imaging apparatuses C, and the multiple display devices D. 
     The master apparatuses  10  include mechanisms that receive the treatment operations that are inputted by the practitioners, and members (right-hand pressure-receiving members  106 R and left-hand pressure-receiving member  106 L described later) that receive the pressing operations of the practitioners are movable in an up-down direction (the spine direction of each user), in a left-right direction (the shoulder width direction of each user), and in a front-rear direction (a direction in which the body of each user is pressed). According to the present embodiment, the master apparatuses  10  have a structure following the shape of a human being near the shoulders and the neck and can receive movement when the practitioners actually treat people to be treated. 
       FIG.  2    schematically illustrates the structure of each of the master apparatuses  10 . 
     In  FIG.  2   , the upper body of a person to be treated by using the master apparatus  10  is also schematically illustrated, and enclosed numbers and arrows represent corresponding movement at the upper body of the person to be treated and the master apparatus  10 . 
     As illustrated in  FIG.  2   , the master apparatus  10  includes a base portion  101  that serves as the base of the entire master apparatus  10 , a pressure-receiving unit  102  that is movable in the up-down direction with respect to the base portion  101 , a front-rear arm  103  that extends in the front-rear direction in the pressure-receiving unit  102 , a right-hand arm portion  104 R and a left-hand arm portion  104 L that are installed at ends of the front-rear arm  103  and that extend in the left-right direction, a right-hand operation portion  105 R that is movable in the left-right direction at the right-hand arm portion  104 R, and a left-hand operation portion  105 L that is movable in the left-right direction at the left-hand arm portion  104 L. The right-hand operation portion  105 R includes the right-hand pressure-receiving member  106 R that receives the pressing operation of the practitioner and a right-hand support member  107 R that supports the right-hand pressure-receiving member  106 R such that the right-hand pressure-receiving member  106 R is movable in the front-rear direction. The left-hand operation portion  105 L includes the left-hand pressure-receiving member  106 L that receive the pressing operation of the practitioner and a left-hand support member  107 L that supports the left-hand pressure-receiving member  106 L such that the left-hand pressure-receiving member  106 L is movable in the front-rear direction. 
     An actuator  108  can control the movement of the pressure-receiving unit  102  in the up-down direction. As for the movement of the right-hand operation portion  105 R and the left-hand operation portion  105 L in the left-right direction and the movement of the right-hand pressure-receiving member  106 R and the left-hand pressure-receiving member  106 L in the front-rear direction, actuators  109  to  112  can apply reaction force. 
     The master apparatus  10  also includes a master control unit  113  that controls the master apparatus  10  in accordance with the control of the control device  30 . 
     The base portion  101  is a support member that serves as the base of the entire master apparatus  10  and supports the pressure-receiving unit  102  such that the pressure-receiving unit  102  is movable in the up-down direction. The actuator  108  changes the position of the pressure-receiving unit  102  in the up-down direction and enables the pressure-receiving unit  102  to be fixed at a target position. 
     The pressure-receiving unit  102  is movable in the up-down direction with respect to the base portion  101 , and the front-rear arm  103 , the right-hand arm portion  104 R, the left-hand arm portion  104 L, the right-hand operation portion  105 R, and the left-hand operation portion  105 L are installed. That is, the pressure-receiving unit  102  moves in the up-down direction, and the positions of the front-rear arm  103 , the right-hand arm portion  104 R, the left-hand arm portion  104 L, the right-hand operation portion  105 R, and the left-hand operation portion  105 L in the up-down direction consequently change. 
     The front-rear arm  103  is a member that extends in the front-rear direction and is installed in the pressure-receiving unit  102 , and the right-hand arm portion  104 R and the left-hand arm portion  104 L are fixed at the ends. The inclination of the right-hand arm portion  104 R and the left-hand arm portion  104 L with respect to the horizontal direction may be adjustable. 
     The right-hand arm portion  104 R is installed at one of the ends of the front-rear arm  103  and extends in the right-hand direction from the front-rear arm  103 . The right-hand arm portion  104 R supports the right-hand operation portion  105 R such that the right-hand operation portion  105 R is movable in the left-right direction. The position of the right-hand operation portion  105 R in the left-right direction changes due to the treatment operation of the practitioner. 
     The left-hand arm portion  104 L is installed at the other end of the front-rear arm  103  and extends in the left-hand direction from the front-rear arm  103 . The left-hand arm portion  104 L supports the left-hand operation portion  105 L such that the left-hand operation portion  105 L is movable in the left-right direction. The position of the left-hand operation portion  105 L in the left-right direction changes due to the treatment operation of the practitioner. 
     The right-hand operation portion  105 R is movable in the left-right direction with respect to the right-hand arm portion  104 R and includes the right-hand support member  107 R that supports the right-hand pressure-receiving member  106 R such that the right-hand pressure-receiving member  106 R is movable in the front-rear direction. The right-hand pressure-receiving member  106 R receives the pressing operation of the practitioner who treats the user and moves in the front-rear direction with respect to the right-hand support member  107 R. The position of the right-hand pressure-receiving member  106 R in the front-rear direction changes due to the pressing operation of the practitioner. 
     The left-hand operation portion  105 L is movable in the left-right direction with respect to the left-hand arm portion  104 L and includes the left-hand support member  107 L that supports the left-hand pressure-receiving member  106 L such that the left-hand pressure-receiving member  106 L is movable in the front-rear direction. The left-hand pressure-receiving member  106 L receives the pressing operation of the practitioner who treats the user and moves in the front-rear direction with respect to the left-hand support member  107 L. The position of the left-hand pressure-receiving member  106 L in the front-rear direction changes due to the pressing operation of the practitioner. 
     The actuator  108  moves the pressure-receiving unit  102  in the up-down direction with respect to the base portion  101  in response to an operation of the practitioner or an instruction from the master control unit  113 . The actuator  108  includes a rotary encoder  108   a  that detects the rotation angle of the rotor of the actuator  108 . The rotation angle that is detected by the rotary encoder  108   a  is transmitted to the master control unit  113 . 
     The actuator  109  applies the reaction force against the movement of the right-hand operation portion  105 R when the right-hand operation portion  105 R moves in the left-right direction due to the treatment operation of the practitioner. The actuator  109  includes a rotary encoder  109   a  that detects the rotation angle of the rotor of the actuator  109 . The rotation angle that is detected by the rotary encoder  109   a  is transmitted to the master control unit  113 . 
     The actuator  110  applies the reaction force against the movement of the left-hand operation portion  105 L when the left-hand operation portion  105 L moves in the left-right direction due to the treatment operation of the practitioner. The actuator  110  includes a rotary encoder  110   a  that detects the rotation angle of the rotor of the actuator  110 . The rotation angle that is detected by the rotary encoder  110   a  is transmitted to the master control unit  113 . 
     The actuator  111  applies the reaction force against the movement of the right-hand pressure-receiving members  106 R when the right-hand pressure-receiving members  106 R moves in the front-rear direction due to the treatment operation of the practitioner. The actuator  111  includes a rotary encoder  111   a  that detects the rotation angle of the rotor of the actuator  111 . The rotation angle that is detected by the rotary encoder  111   a  is transmitted to the master control unit  113 . 
     The actuator  112  applies the reaction force against the movement of the left-hand pressure-receiving member  106 L when the left-hand pressure-receiving member  106 L moves in the front-rear direction due to the treatment operation of the practitioner. The actuator  112  includes a rotary encoder  112   a  that detects the rotation angle of the rotor of the actuator  112 . The rotation angle that is detected by the rotary encoder  112   a  is transmitted to the master control unit  113 . 
     The master control unit  113  controls the actuators  108  to  112  of the master apparatus  10  in accordance with the control of the control device  30  and transmits the rotation angles of the actuators  108  to  112  that are detected by the rotary encoders  108   a  to  112   a  to the control device  30 . 
     The slave apparatuses  20  include mechanisms that output the treatment operations to the users (people to be treated), and members (right-hand pressing members  206 R and left-hand pressing members  206 L described later) that output the pressing operations for the treatment to the users are movable in the up-down direction (the spine direction of each user), in the left-right direction (the shoulder width direction of each user), and in the front-rear direction (the direction in which the body of each user is pressed). 
     The slave apparatuses  20  include the mechanisms that output the treatment operations to the users (people to be treated), and the members (the right-hand pressing members  206 R and the left-hand pressing members  206 L described later) that output the pressing operations to the users are movable in the up-down direction (the spine direction of each user), in the left-right direction (the shoulder width direction of each user), and in the front-rear direction (the direction in which the body of each user is pressed). The slave apparatuses  20  can be installed for various kinds of equipment that can provide massages to the users such as a chair, a sofa, a bed, and a seat of an automobile. 
       FIG.  3    schematically illustrates the structure of each of the slave apparatuses  20 . 
     In  FIG.  3   , the appearance of a part of a backrest in which the mechanical structure of the slave apparatus  20  is mounted inside is also illustrated, and enclosed numbers and arrows represent movement similar to the movement of the master apparatus  10  illustrated in  FIG.  2   . 
     As illustrated in  FIG.  3   , the slave apparatus  20  includes a support portion  201  that supports the entire slave apparatus  20 , a treatment unit  202  that is movable in the up-down direction with respect to the support portion  201 , a base portion  203  that serves as a base member that supports the treatment unit  202 , a right-hand arm portion  204 R and a left-hand arm portion  204 L that are installed in the base portion  203  and that extend in the left-right direction, a right-hand action portion  205 R that is movable in the left-right direction at the right-hand arm portion  204 R, and a left-hand action portion  205 L that is movable in the left-right direction at the left-hand arm portion  204 L. The right-hand action portion  205 R includes the right-hand pressing member  206 R that presses the user, and a right-hand support member  207 R that supports the right-hand pressing member  206 R such that the right-hand pressing member  206 R is movable in the front-rear direction. The left-hand action portion  205 L includes the left-hand pressing member  206 L that presses the user and a left-hand support member  207 L that supports the left-hand pressing member  206 L such that the left-hand pressing member  206 L is movable in the front-rear direction. 
     An actuator  208  can control the movement of the treatment unit  202  in the up-down direction. Actuators  209  to  212  can control the movement of the right-hand action portion  205 R and the left-hand action portion  205 L in the left-right direction and the movement of the right-hand pressing member  206 R and the left-hand pressing member  206 L in the front-rear direction. 
     The slave apparatus  20  also includes a slave control unit  213  that controls the slave apparatus  20  in accordance with the control of the control device  30 . 
     The support portion  201  is a support member that supports the entire slave apparatus  20  and supports the treatment unit  202  such that the treatment unit  202  is movable in the up-down direction. The actuator  208  changes the position of the treatment unit  202  in the up-down direction and enables the treatment unit  202  to be fixed at a target position. 
     The treatment unit  202  is movable in the up-down direction with respect to the support portion  201 , and the base portion  203 , the right-hand arm portion  204 R, the left-hand arm portion  204 L, the right-hand action portion  205 R, and the left-hand action portion  205 L are installed. That is, the treatment unit  202  moves in the up-down direction, and the positions of the right-hand arm portion  204 R, the left-hand arm portion  204 L, the right-hand action portion  205 R, and the left-hand action portion  205 L in the up-down direction consequently change. 
     The base portion  203  is a base member that supports the treatment unit  202  and supports the treatment unit  202  such that the treatment unit  202  is movable in the up-down direction. The actuator  208  changes the position of the treatment unit  202  in the up-down direction and enables the treatment unit  202  to be fixed at a target position. 
     The right-hand arm portion  204 R is installed in the base portion  203  and extends in the right-hand direction (more specifically, a lower right-hand direction parallel to typical shoulder inclination) from the base portion  203 . The right-hand arm portion  204 R supports the right-hand action portion  205 R such that the right-hand action portion  205 R is movable in the left-right direction. The position of the right-hand action portion  205 R in the left-right direction changes in accordance with reference values of position and force that are transmitted from the control device  30  depending on the treatment operation of the practitioner. 
     The left-hand arm portion  204 L is installed in the base portion  203  and extends in the left-hand direction (more specifically, a lower left-hand direction parallel to the typical shoulder inclination) from the base portion  203 . The left-hand arm portion  204 L supports the left-hand action portion  205 L such that the left-hand action portion  205 L is movable in the left-right direction. The position of the left-hand action portion  205 L in the left-right direction changes in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the treatment operation of the practitioner. 
     The right-hand action portion  205 R is movable in the left-right direction with respect to the right-hand arm portion  204 R and includes the right-hand support member  207 R that supports the right-hand pressing member  206 R such that the right-hand pressing member  206 R is movable in the front-rear direction. The right-hand pressing member  206 R presses the user in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the pressing operation of the practitioner and moves in the front-rear direction with respect to the right-hand support member  207 R. That is, the position of the right-hand pressing members  206 R in the front-rear direction changes due to the pressing operation of the practitioner. 
     The left-hand action portion  205 L is movable in the left-right direction with respect to the left-hand arm portion  204 L and includes the left-hand support member  207 L that supports the left-hand pressing member  206 L such that the left-hand pressing member  206 L is movable in the front-rear direction. The left-hand pressing members  206 L presses the user in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the pressing operation of the practitioner and moves in the front-rear direction with respect to the left-hand support member  207 L. That is, the position of the left-hand pressing members  206 L in the front-rear direction changes due to the pressing operation of the practitioner. 
     The actuator  208  moves the treatment unit  202  in the up-down direction with respect to the support portion  201  in response to an operation of the user or an instruction from the slave control unit  213 . In the case where the treatment unit  202  moves in the up-down direction in response to the instruction from the slave control unit  213 , the reaction force that is inputted into the right-hand action portion  205 R and the left-hand action portion  205 L, for example, is detected, and the position at which the treatment unit  202  is fixed can be automatically adjusted so as to be suitable for the positions of the shoulders of the user. The actuator  208  includes a rotary encoder  208   a  that detects the rotation angle of the rotor of the actuator  208 . The rotation angle that is detected by the rotary encoder  208   a  is transmitted to the slave control unit  213 . 
     The actuator  209  moves the right-hand action portion  205 R in the left-right direction in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the treatment operation of the practitioner. The actuator  209  includes a rotary encoder  209   a  that detects the rotation angle of the rotor of the actuator  209 . The rotation angle that is detected by the rotary encoder  209   a  is transmitted to the slave control unit  213 . 
     The actuator  210  moves the left-hand action portion  205 L in the left-right direction in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the treatment operation of the practitioner. The actuator  210  includes a rotary encoder  210   a  that detects the rotation angle of the rotor of the actuator  210 . The rotation angle that is detected by the rotary encoder  210   a  is transmitted to the slave control unit  213 . 
     The actuator  211  moves the right-hand pressing member  206 R in the front-rear direction in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the treatment operation of the practitioner. Consequently, the right-hand pressing member  206 R presses the user at and by the position and the force that correspond to those of the treatment operation of the practitioner. The actuator  211  includes a rotary encoder  211   a  that detects the rotation angle of the rotor of the actuator  211 . The rotation angle that is detected by the rotary encoder  211   a  is transmitted to the slave control unit  213 . 
     The actuator  212  moves the left-hand pressing member  206 L in the front-rear direction in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the treatment operation of the practitioner. Consequently, the left-hand pressing members  206 L presses the user at and by the position and the force that correspond to those of the treatment operation of the practitioner. The actuator  212  includes a rotary encoder  212   a  that detects the rotation angle of the rotor of the actuator  212 . The rotation angle that is detected by the rotary encoder  212   a  is transmitted to the slave control unit  213 . 
     The slave control unit  213  controls the actuators  208  to  212  of the slave apparatus  20  in accordance with the control of the control device  30  and transmits the rotation angles of the actuators  208  to  212  that are detected by the rotary encoders  208   a  to  212   a  to the control device  30 . 
     The control device  30  controls the transmission of the force tactile sensation between the master apparatuses  10  and the slave apparatuses  20 . According to the present embodiment, the control device  30  associates a freely selected one of the master apparatuses  10  and a freely selected one of the slave apparatuses  20  with each other among the multiple master apparatuses  10  and the multiple slave apparatuses  20 , and this enables a master-slave system to be dynamically provided. The control device  30  stores control parameters for transmitting the force tactile sensation when the practitioners treat the users by using the master apparatuses  10  and the slave apparatuses  20 . The control device  30  transmits the stored control parameters to the slave apparatuses  20 , and the treatment of the practitioners on the users can consequently be reproduced. At this time, the control device  30  can transmit the stored control parameters that are not edited to the slave apparatuses  20  (that is, the stored treatment is reproduced) and can transmit the stored+- control parameters that are edited, for example, the control parameters that are partly deleted, the control parameters that are partly repeated, or the control parameters in which the force is changed, to the slave apparatuses  20 . Editing the control parameters enables the content of the treatment to be changed into one that the users prefer and enables the content of the treatment provided to a different user to be changed into one that is suitable for the body shapes or preference of the users to be treated. 
     The imaging apparatuses C image the users to be treated by using the slave apparatuses  20  and transmit the data of the captured images to the control device  30 . 
     The display devices D receive the images of the users that are captured by the imaging apparatus C from the control device  30  and display the images of the users (people to be treated) for the practitioners that provide the treatment by using the master apparatuses  10 . 
     Hardware Configuration 
     The hardware configuration of a functional unit for control in the position/force control system  1  will now be described. 
     As for the position/force control system  1 , the control device  30 , the master control units  113 , and the slave control units  213  are included in an information processing apparatus such as a personal computer (a PC), a server computer, or a tablet terminal and have the same basic structure. 
       FIG.  4    illustrates the hardware configuration of an information processing apparatus  800  that includes the functional unit for control in the position/force control system  1 . 
     As illustrated in  FIG.  4   , the information processing apparatus  800  includes a CPU (Central Processing Unit)  811 , a ROM (Read Only Memory)  812 , a RAM (Random Access Memory)  813 , a bus  814 , an input unit  815 , an output unit  816 , a storage unit  817 , a communication unit  818 , a drive  819 , and an image capture unit  820 . 
     The CPU  811  executes various processing according to programs that are recorded in the ROM  812 , or programs that are loaded from the storage unit  820  to the RAM  813 . 
     The RAM  813  also stores data and the like necessary for the CPU  811  to execute the various processing, as appropriate. 
     The CPU  811 , the ROM  812  and the RAM  813  are connected to one another via the bus  814 . The input unit  815 , the output unit  816 , the storage unit  817 , the communication unit  818 , the drive  819  and the image capture unit  820  are connected to the bus  814 . 
     The input unit  815  is configured by various buttons and the like, and inputs a variety of information in accordance with instruction operations by the user. 
     The output unit  816  is configured by the display unit, a speaker, and the like, and outputs images and sound. 
     Note that in the case where the information processing apparatus  800  is configured as a smart phone or a tablet terminal, a configuration provided with a touch panel is also possible by overlapping the input unit  815  with a display of the output unit  816 . 
     The storage unit  817  is configured by DRAM (Dynamic Random Access Memory) or the like, and stores various data managed by each server. 
     The communication unit  818  controls communication with other devices via networks. 
     A removable medium  831  composed of a magnetic disk, an optical disk, a magneto-optical disk, semiconductor memory or the like is installed in the drive  819 , as appropriate. Programs that are read via the drive  819  from the removable medium  831  are installed in the storage unit  817 , as necessary. 
     The image capture unit  820 , which is configured by using an imaging apparatus including a lens and an image sensor, captures digital images of subjects. 
     When the information processing apparatus  800  is configured as a server, the image capture unit  820  may be omitted. When the information processing apparatus  800  is configured as a tablet terminal, the input unit  815  may be configured by using a touch sensor which overlies the display of the output unit  816 . Thus, the information processing apparatus  800  may have a configuration including a touch panel. 
     Functional Configuration of Control System 
     The functional configuration of a control system of each apparatus of the position/force control system  1  will now be described. 
     Functional Configuration of Master Apparatus  10   
       FIG.  5    is a block diagram illustrating the functional configuration of each master apparatus  10 . 
     As for a CPU  811  of the master apparatus  10  (the master control unit  113 ), as illustrated in  FIG.  5   , a user interface control unit (a UI control unit)  151 , a mode-setting unit  152 , a sensor-information-acquiring unit  153 , a force-tactile-sensation control unit  154 , and a treatment-data-managing unit  155  function. A treatment-data storage unit  171  is formed in a storage unit  817  of the master apparatus  10 . 
     The treatment-data storage unit  171  stores the control parameters in the treatment and information about the user who is treated by the practitioner by using the master apparatus  10 . The information about the user who is treated by the practitioner includes attribution information such as the preference of the content of the treatment, the contact address, the gender, the age, and the name of the user. The control parameters in time series regarding the transmission of the force tactile sensation during the treatment of the practitioner are stored as the control parameters in the treatment. 
     The UI control unit  151  controls the display of various input and output screens in the process (a remote treatment process described later) for the practitioner who treats the user by using the position/force control system  1 . For example, the UI control unit  151  receives a setting that represents whether an individual-treatment mode in which the practitioner treats the user in a one-to-one manner is activated, or a multiple-treatment mode in which the single practitioner treats multiple users is activated in the remote treatment process. The UI control unit  151  displays the images of the users that are transmitted from the control device  30  on, for example, the display devices D or a display of the output unit  816  that is included in the master apparatus  10 . 
     The mode-setting unit  152  sets the mode that is activated in the remote treatment process. According to the present embodiment, the individual-treatment mode in which the practitioner treats the user in a one-to-one manner can be set, or the multiple-treatment mode in which the single practitioner treats the multiple users can be set, and the mode-setting unit  152  sets one of the modes in accordance with an input from the practitioner or an instruction from the control device  30 . 
     The sensor-information-acquiring unit  153  acquires information about positions (the rotation angles of rotors) that are detected by the rotary encoders  108   a  to  112   a  of the actuators  108  to  112 . According to the present embodiment, the actuators  109  to  112  of the master apparatus  10  involve in the transmission of the force tactile sensation, and accordingly, the sensor-information-acquiring unit  153  acquires the information about the positions (the rotation angles of the rotors) from the rotary encoders  109   a  to  112   a  at a rate that enables the treatment operation in the remote treatment process to be continuous and smooth, for example, in every  100  [ms]. The information about the positions (the rotation angles of the rotors) that is acquired from the rotary encoders  109   a  to  112   a  changes depending on the output (that is, an input from the body of the user into each slave apparatus  20 ) of each actuator and the treatment operation that is inputted by the practitioner. 
     The force-tactile-sensation control unit  154  controls the transmission of the force tactile sensation, based on the information about the positions (the rotation angles of the rotors) that is acquired by the sensor-information-acquiring unit  153  and the information about the positions (the rotation angles of the rotors) in the actuators of the slave apparatus  20  that is transmitted from the control device  30 . That is, the force-tactile-sensation control unit  154  uses the information about the positions (the rotation angles of the rotors) in the actuators of the slave apparatus  20  as the reference values and uses the reference values and the information about the positions (the rotation angles of the rotors) that is acquired by the sensor-information-acquiring unit  153  as input data, and causes a target actuator in the master apparatus  10  to follow the operation (output of the position and the force) of the corresponding actuator in the slave apparatus  20 . 
       FIG.  6    is a block diagram illustrating an algorithm for control over the transmission of the force tactile sensation that is used according to the present embodiment. 
     As illustrated in  FIG.  6   , the algorithm for the control over the transmission of the force tactile sensation is expressed as a control rule that includes a reverse conversion block  440 , an ideal force origin block  420  or an ideal velocity (position) origin block  430 , a force/velocity distribution conversion block  410 , and the actuators  109  to  112  (a system to be controlled) . According to the present embodiment, the actuators  109  to  112  of the master apparatuses  10  and the actuators  209  to  212  of the slave apparatuses  20  are associated with each other in a one-to-one manner in the case where the remote treatment process is performed. For this reason, the algorithm described below relates to the control over the transmission of the force tactile sensation between a single actuator in the master apparatuses  10  and the corresponding actuator in the slave apparatuses  20 . 
     A position and velocity (or acceleration) or an angle and angular velocity (or angular acceleration) are parameters that can be replaced by calculus. Accordingly, in the case where processing regarding the position or the angle is performed, these can be appropriately replaced with, for example, the velocity or the angular velocity. According to the present embodiment, the rotation angles of the rotors are used as information about the positions of the actuators, but another information may be used provided that the information represents physical quantities related to each other such as the position of a member that operates in conjunction with a rotor of an actuator. 
     The force/velocity distribution conversion block  410  defines coordinate transformation where a value (a reference value) on which the operations of the actuators  109  to  112  are based and the current positions of the rotation axes of the actuators  109  to  112  are inputted. The coordinate transformation includes conversion of an input vector, elements of which are the reference value and current velocity (or position) into an output vector that includes velocity (or position) for calculating a target control value for the velocity (or position) and conversion of an input vector, elements of which are the reference value and current force into an output vector that includes force for calculating a target control value for the force. Specifically, the coordinate transformation of the force/velocity distribution conversion block  410  is expressed as the following expressions (1) and (2). 
     
       
         
           
             dx2 
               
             = 
               
             
               H 
             
             ⋅ 
             dx1 
           
         
       
     
     
       
         
           
             F2 
               
             = 
               
             
               H 
             
             ⋅ 
             F1 
           
         
       
     
     In the expression (1), d is an operator that represents first derivative, dX2 is a velocity vector for deriving the state value of the velocity, dX1 is a vector, an element of which is the velocity (the velocity of the rotation axis of each of the actuators  109  to  112 , or the velocity of a portion that operates in conjunction with the rotation axis of each of the actuators  109  to  112 ) based on the reference value and the actions of the actuators  109  to  112 , and H is a conversion matrix that represents a bilateral function. In the expression (2), d 2 F2 (d 2  is an operator that represents second derivative) is a force vector for deriving the state value of the force, and d 2 F1 is a vector, an element of which is the force (the rotational torque of the rotation axis of each of the actuators  109  to  112 , or the force of a portion that operates in conjunction with the rotation axis of each of the actuators  109  to  112 ) based on the reference value and the actions of the actuators  109  to  112 . 
     As for the force/velocity distribution conversion block  410 , coordinate transformation (that is, conversion from an oblique coordinate system into a rectangular coordinate system) of input data, elements of which are a position (velocity) and force related to each other in the real space into that in a virtual space in which the position (velocity) and the force are independent from each other is carried out, and calculation regarding the position (velocity) and calculation regarding the force can be independently made. 
     The ideal force origin block  420  makes calculation in a force domain in accordance with the coordinate transformation that is defined by the force/velocity distribution conversion block  410 . As for the ideal force origin block  420 , a target value regarding the force when calculation based on the coordinate transformation that is defined by the force/velocity distribution conversion block  410  is made is set. The target value is set as a fixed value or a variable value so as to correspond to a function (bilateral function) of transmitting the force tactile sensation that is performed by the master apparatuses  10  and the slave apparatuses  20 . In the case where the force is scaled up or down, a coefficient in force scaling can be used for the coordinate transformation of the force/velocity distribution conversion block  410 , conversion in the same scale can be maintained as for the force in the coordinate transformation of the force/velocity distribution conversion block  410 , and the ideal force origin block  420  can set the target value of the scaled force. 
     The ideal velocity (position) origin block  430  makes calculation in a velocity (position) domain in accordance with the coordinate transformation that is defined by the force/velocity distribution conversion block  410 . As for the ideal velocity (position) origin block  430 , a target value regarding the velocity (position) when the calculation based on the coordinate transformation that is defined by the force/velocity distribution conversion block  410  is made is set. The target value is set as a fixed value or a variable value so as to correspond to the function (the bilateral function) of transmitting the force tactile sensation that is performed by the master apparatuses  10  and the slave apparatuses  20 . In the case where the position is scaled up or down, a coefficient in position scaling can be used for the coordinate transformation of the force/velocity distribution conversion block  410 , conversion in the same scale can be maintained as for the position in the coordinate transformation of the force/velocity distribution conversion block  410 , and the ideal velocity (position) origin block  430  can set the target value of the scaled position. 
     The reverse conversion block  440  converts the values in the velocity (position) and force domains into values (for example, the value of voltage or the value of electric current) in a domain of an input into each actuator. 
     Consequently, when the information about the positions (the rotation angles of the rotors) of the actuators is inputted into the force/velocity distribution conversion block  410 , information about the velocity (position) and the force that is acquired based on the information about the positions is used, and the force/velocity distribution conversion block  410  uses the control rule in the velocity (position) and force domains depending on the function (the bilateral function) of transmitting the force tactile sensation. The ideal force origin block  420  calculates the force depending on the function of transmitting the force tactile sensation, the ideal velocity (position) origin block  430  calculates the velocity (position) depending on the function of transmitting the force tactile sensation, and control energy is distributed to the force and the velocity (position). 
     The results of the calculation of the ideal force origin block  420  and the ideal velocity (position) origin block  430  correspond to information that represents a control target for each actuator, and the results of the calculation are used as input values into the actuator as for the reverse conversion block  440 . 
     Consequently, each actuator operates in accordance with the function (the bilateral function) of transmitting the force tactile sensation that is defined by the force/velocity distribution conversion block  410 , and the treatment operation is performed such that the force tactile sensation is transmitted between the master apparatuses  10  and the slave apparatuses  20 . 
     Return to  FIG.  5   , the treatment-data-managing unit  155  acquires the control parameters in the treatment and the information about the user who is treated by the practitioner by using the master apparatus  10  and stores these in the treatment-data storage unit  171 . The practitioner reads the information about the user that is stored in the treatment-data storage unit  171  and can consequently treat the user more appropriately when the same user is treated for the second time or later. In the case where the practitioner provides the treatment, the control parameters that are stored in the treatment-data storage unit  171  are partly or entirely transmitted to the control device  30 , and the treatment operation that is performed by the practitioner can consequently be automatically repeated. For example, in the case where the pressing operation is performed on the left-hand shoulder after the pressing operation is performed on the right-hand shoulder, and the right-hand shoulder and the left-hand shoulder are treated again in the same manner, the control parameters that are stored in the treatment-data storage unit  171  are transmitted to the control device  30 , and workload when the practitioner performs the same treatment operation can consequently be reduced. 
     Functional Configuration of Slave Apparatus  20   
       FIG.  7    is a block diagram illustrating the functional configuration of each slave apparatus  20 . 
     As for a CPU  811  of the slave apparatus  20  (the slave control unit  213 ), as illustrated in  FIG.  7   , a user interface control unit (a UI control unit)  251 , a mode-setting unit  252 , a sensor-information-acquiring unit  253 , a force-tactile-sensation control unit  254 , and a treatment-data-managing unit  255  function. A treatment-data storage unit  271  is formed in a storage unit  817  of the slave apparatus  20 . 
     The treatment-data storage unit  271  stores the control parameters in the treatment and information about the practitioner who treats the user by using the slave apparatus  20 . The information about the practitioner who treats the user includes attribution information such as the evaluation of the treatment technique, the contact address, the gender, the age, and the name of the practitioner. The control parameters in time series regarding the transmission of the force tactile sensation during the treatment of the practitioner are stored as the control parameters in the treatment. 
     The UI control unit  251  controls the display of various input and output screens in the process (the remote treatment process) for the practitioner who treats the user by using the position/force control system  1 . For example, the UI control unit  251  receives the setting that represents whether the individual-treatment mode in which the practitioner treats the user in a one-to-one manner is activated, or the multiple-treatment mode in which the single practitioner treats multiple users is activated in the remote treatment process. In the case where the user sets the individual-treatment mode, the UI control unit  251  receives the selection of the practitioner whom the user wishes. The UI control unit  251  also receives an instruction for repeating the treatment operation from the user. The UI control unit  251  may cause a display of the output unit  816  to display the image (such as the image of the face that is captured in advance or an image that is captured in real time) of the practitioner who treats the user. 
     The mode-setting unit  252  sets the mode (the individual-treatment mode or the multiple-treatment mode) that is activated in the remote treatment process. The mode-setting unit  252  sets the individual-treatment mode or the multiple-treatment mode in accordance with an instruction from the user. 
     The sensor-information-acquiring unit  253  acquires information about positions (the rotation angles of rotors) that are detected by the rotary encoders  208   a  to  212   a  of the actuators  208  to  212 . According to the present embodiment, the actuators  209  to  212  of the slave apparatus  20  involve in the transmission of the force tactile sensation, and accordingly, the sensor-information-acquiring unit  253  acquires the information about the positions (the rotation angles of the rotors) from the rotary encoders  209   a  to  212   a  at a rate that enables the treatment operation in the remote treatment process to be continuous and smooth, for example, in every  100  [ms]. The information about the positions (the rotation angles of the rotors) that is acquired from the rotary encoders  209   a  to  212   a  changes depending on the output (that is, an input from the practitioner into the master apparatus  10 ) of each actuator and a reaction when the right-hand pressing member  206 R and the left-hand pressing member  206 L act on the body of the user. 
     The force-tactile-sensation control unit  254  controls the transmission of the force tactile sensation, based on the information about the positions (the rotation angles of the rotors) that is acquired by the sensor-information-acquiring unit  253  and the information about the positions (the rotation angles of the rotors) in the actuators of the master apparatus  10  that is transmitted from the control device  30 . That is, the force-tactile-sensation control unit  254  uses the information about the positions (the rotation angles of the rotors) in the actuators of the master apparatus  10  as the reference values and uses the reference values and the information about the positions (the rotation angles of the rotors) that is acquired by the sensor-information-acquiring unit  253  as input data, and causes a target actuator in the slave apparatus  20  to follow the operation (output of the position and the force) of the corresponding actuator in the master apparatus  10 . As for the force-tactile-sensation control unit  254 , an algorithm for the control over the transmission of the force tactile sensation is the same as the algorithm illustrated in  FIG.  6   . 
     The force-tactile-sensation control unit  254  has a fail-safe function for the slave apparatus  20 . In the case where the control parameters for the force tactile sensation that exceed the upper limit values of various physical quantities (for example, the upper limit value of the force, the upper limit value of the velocity, and the upper limit value of displacement) are detected, the control over the transmission of the force tactile sensation to the master apparatus  10  is canceled, and control (control for inhibiting the action on the user) for urgently stopping the treatment unit  202  is autonomously implemented. The content of the control for urgently stopping the treatment unit  202  can be determined in advance. For example, while control for immediately stopping the treatment unit  202  or compliance control for the operation of the treatment unit  202  is used, control for movement to a predetermined retracted position (for example, a neutral position) at a low velocity, for example, can be implemented. 
     The treatment-data-managing unit  255  acquires the control parameters in the treatment and the information about the practitioner who treats the user by using the slave apparatus  20  and stores these in the treatment-data storage unit  271 . The user reads the information about the practitioner that is stored in the treatment-data storage unit  271 , selects the practitioner who provided the treatment in the past again, and can consequently be treated. In the case where the user is treated, the control parameters that are stored in the treatment-data storage unit  271  are partly or entirely read for execution, and the treatment operation that is performed by the practitioner can consequently be reproduced. 
     Functional Configuration of Control Device  30   
       FIG.  8    is a block diagram illustrating the functional configuration of the control device  30 . 
     As for a CPU  811  of the control device  30 , as illustrated in  FIG.  8   , a request-receiving unit  351 , a link-establishing unit  352 , a force-tactile-sensation-transmission-managing unit  353 , and a history-data-managing unit  354  function. A history database (a history DB)  371  is produced in a storage unit  817  of the control device  30 . 
     The history DB  371  contains various kinds of data regarding the control over the transmission of the force tactile sensation that is implemented in the position/force control system  1 . For example, the history DB  371  contains the information about the user who is treated by using the position/force control system  1 , the information about the practitioner who provides the treatment, the control parameters that are set in the remote treatment process, information (such as a history in which the control parameters are reproduced and a history in which the force is adjusted) that is inputted into the slave apparatus  20  by the user, and information (such as a history in which the treatment operation is automatically repeated and a history in which the characteristics (such as the tendency of fatigue and precautions for the treatment) of the user who is treated are memorized) that is inputted into the master apparatus  10  by the practitioner. 
     The request-receiving unit  351  receives a request from the user who wishes to be treated in the remote treatment process. The request-receiving unit  351  selects the practitioner who can provide the treatment in the remote treatment process, in response to the request from the user or based on a predetermined selection standard. Examples of the predetermined selection standard include a standard (such as the gender or matching between the content of the treatment that the user wishes and the content of the treatment that the practitioner is good at) based on the attributes of the user and the attributes of the practitioner, a standard (such as equalization of the total treatment time of the practitioner) based on levelling of the workload of the practitioner, and a standard (such as a priority over a combination of the user and the practitioner who provided the treatment in the past) based on the history of the treatment. 
     The link-establishing unit  352  establishes a communication link between the slave apparatus  20  and the master apparatus  10  that performs the remote treatment process depending on the mode that is set by the user of the slave apparatus  20 . That is, the link-establishing unit  352  establishes a link between the single slave apparatus  20  in the individual-treatment mode and the single master apparatus  10  in a one-to-one manner. Alternatively, the link-establishing unit  352  establishes links between multiple slave apparatuses  20  in the multiple-treatment mode and the single master apparatus  10  in a one-to-n manner (n is a natural number of  2  or more). 
     In the case where the remote treatment process is performed in the individual-treatment mode, the force-tactile-sensation-transmission-managing unit  353  controls (the bilateral control) the transmission of the force tactile sensation between the single slave apparatus  20  in the individual-treatment mode and the single master apparatus  10 . At this time, the force-tactile-sensation-transmission-managing unit  353  can scale up or down the force that is outputted from the slave apparatus  20  in response to the request from the user of the slave apparatus  20 . 
     In the case where the remote treatment process is performed in the multiple-treatment mode, the force-tactile-sensation-transmission-managing unit  353  normalizes the control parameters that are transmitted from the master apparatus  10  and transmits these to the slave apparatuses  20  of the users who are treated. For example, the force-tactile-sensation-transmission-managing unit  353  converts (normalizes) the control parameters that are transmitted from the master apparatus  10  into those for the treatment operation that is performed in the case where an imaginary user who has a standard body shape is treated and transmits these to the slave apparatuses  20  of the users who are treated. This enables the control parameters that can be shared and used by the multiple users to be transmitted to the slave apparatuses  20 . The slave apparatuses  20  correct the normalized control parameters such that the control parameters are suitable for the users who are treated, and the force-tactile-sensation control unit  254  can control the transmission of the force tactile sensation. For example, the shoulder width and the thickness of muscle of each user are set in the slave apparatuses  20  in advance, the amount of correction based on a difference between the standard body shape and the body shape of the user is added into the control parameters, and the pressing operation can be outputted. The force-tactile-sensation-transmission-managing unit  353  may add the amount of correction based on the difference between the standard body shape and the body shape of the user into the control parameters and may transmit the corrected control parameters to the slave apparatuses  20 . The normalized control parameters may not be corrected. Instead, as for the output of the force tactile sensation from the slave apparatuses  20 , the weight of control over the force against control over the position may be increased, or only the control over the force may be implemented. The force tactile sensation similar to the adjusted force in the normalized control parameters is outputted with the result that the weight of the control over the force is increased. Accordingly, the treatment can be provided to a user who has a different body shape with the adjusted force that is the same as in the case where the standard body shape is treated by using the normalized control parameters. 
     The history-data-managing unit  354  stores various kinds of data regarding the control over the transmission of the force tactile sensation that is implemented in the position/force control system  1  in the history DB  371 . The history-data-managing unit  354  can transmit history data that is stored in the history DB  371  to the master apparatuses  10  or the slave apparatuses  20 , can identify the preference of each user by analyzing the data, and can evaluate the technique of each practitioner. 
     Treatment Mode 
     The mode of the remote treatment process that is activated in the position/force control system  1  will now be described. 
     Individual-Treatment Mode 
       FIG.  9    schematically illustrates the concept of the individual-treatment mode in the position/force control system  1 . 
     The position/force control system  1  includes the multiple master apparatuses  10  and the multiple slave apparatuses  20 . As illustrated in  FIG.  9   , the user of each slave apparatus  20  can set the individual-treatment mode in which the practitioner treats the user in a one-to-one manner. 
     In the individual-treatment mode, a communication link can be established between a freely selected one of the slave apparatuses  20  and a freely selected one of the master apparatuses  10 , and the remote treatment process can be performed. For example, the user of the slave apparatus  20  selects a specific practitioner, or the control device  30  selects a practitioner from practitioners who can currently provide the treatment. This enables the transmission of the force tactile sensation between the master apparatus  10  and the slave apparatus  20  in a one-to-one manner to be controlled. 
     The individual-treatment mode enables detailed treatment to be provided while the practitioner checks the condition of the user by using an image that is displayed on, for example, the display device D. In the case where the remote treatment process is performed in the individual-treatment mode, the treatment can be provided while the user and the practitioner have a conversation by using microphones and speakers of the master apparatus  10  and the slave apparatus  20 . 
     Multiple-Treatment Mode 
       FIG.  10    schematically illustrates the concept of the multiple-treatment mode in the position/force control system  1 . 
     The position/force control system  1  includes the multiple master apparatuses  10  and the multiple slave apparatuses  20 . As illustrated in  FIG.  10   , the users of the slave apparatuses  20  can set the multiple-treatment mode in which the single practitioner treats the multiple users. 
     In the multiple-treatment mode, communication links can be established between the multiple slave apparatuses  20  and a specific one of the master apparatuses  10 , and the remote treatment process can be performed. For example, when the practitioner who is evaluated as one who has a high treatment technique provides the treatment, the multiple users who wish to be treated by the practitioner participate in the treatment in the multiple-treatment mode, or the users participate in the treatment of the practitioner in the multiple-treatment mode in the case where there are no idle practitioners due to, for example, congestion, the transmission of the force tactile sensation between the specific single master apparatus  10  and the multiple slave apparatuses  20  is controlled. 
     The multiple-treatment mode enables the treatment of a popular practitioner to be provided to many users at the same time and enables a user who prioritizes the time zone of the treatment to be treated without an influence of the situation of congestion. 
     In the case where the remote treatment process is performed in the multiple-treatment mode, the control parameters that are transmitted from the master apparatus  10  are normalized and transmitted to the slave apparatuses  20  of the users to be treated, the slave apparatuses  20  correct the normalized control parameters such that the control parameters are suitable for the users to be treated, and the force-tactile-sensation control unit  254  can control the transmission of the force tactile sensation. 
     For this reason, the treatment appropriate for the body shape of each user can be provided also in the multiple-treatment mode. 
     Operation 
     The operation of the position/force control system  1  will now be described. 
       FIG.  11    is a flowchart illustrating the flow of the remote treatment process that is performed by the position/force control system  1 . 
     The control device  30  starts the remote treatment process in response to the input of an instruction for performing the remote treatment process. 
     After the remote treatment process starts, at a step S 1 , the request-receiving unit  351  of the control device  30  checks the practitioners who can currently provide the treatment. For example, the request-receiving unit  351  polls the master apparatuses  10  that are registered in the position/force control system  1  to check whether the master apparatuses  10  are running, the practitioners of the master apparatuses  10  that are running can be set as the practitioners who can currently provide the treatment. The practitioners who can currently provide the treatment can be checked in a manner in which the practitioners transmit, for example, a message that represents that the practitioners can provide the treatment from the master apparatuses  10  to the control device  30 . 
     At a step S 2 , the request-receiving unit  351  receives the requests from the users who wish to be treated in the remote treatment process. At this time, the request-receiving unit  351  may transmit, for example, a list of the practitioners who can currently provide the treatment to the slave apparatuses  20 , the users may refer the list, and the transmitted requests may be received. 
     At a step S 3 , the request-receiving unit  351  determines the mode in the requests from the slave apparatuses  20 . 
     In the case where the individual-treatment mode is requested, the process proceeds to a step S 4 . 
     In the case where the multiple-treatment mode is requested, the process proceeds to a step S 5 . 
     In the case where both of the individual-treatment mode and the multiple-treatment mode are requested from the multiple slave apparatuses  20 , the processes at the step S 4  and the step S 5  are performed in parallel. 
     At the step S 4 , the request-receiving unit  351  performs an individual-treatment process (see  FIG.  12   ). 
     After the step S 4 , the remote treatment process is repeated. 
     At the step S 5 , the request-receiving unit  351  performs a multiple-treatment process (see  FIG.  13   ). 
     After the step S 5 , the remote treatment process is repeated. 
     Individual-Treatment Process 
     The individual-treatment process that is performed at the step S 4  in the remote treatment process will now be described. 
       FIG.  12    is a flowchart illustrating the flow of the individual-treatment process. 
     The individual-treatment process is performed as a sub-flow at the step S 4  in the remote treatment process. 
     After the individual-treatment process starts, at a step S 11 , the request-receiving unit  351  checks the practitioner who is selected by the user, based on the request that is received from the slave apparatus  20 . Specifically, whether the data of the request contains information for the user to select the specific practitioner or contains information to freely select a practitioner (that is, whether information for selecting no practitioner is contained), for example, is determined. 
     At a step S 12 , the request-receiving unit  351  determines the practitioner who treats the user from the practitioners who can currently provide the treatment. 
     At a step S 13 , the link-establishing unit  352  establishes a communication link between the master apparatus  10  and the slave apparatus  20 . Consequently, the transmission of the force tactile sensation between the master apparatus  10  of the practitioner who is determined at the step S 12  and the slave apparatus  20  of the user can be controlled. 
     At a step S 14 , the force-tactile-sensation-transmission-managing unit  353  starts moving the master apparatus  10  and the slave apparatus  20  from the neutral positions to standard positions (initial positions depending on the body shape of the user). That is, the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  start descending from the neutral positions (for example, the positions of upper ends in the up-down direction). 
     At a step S 15 , the force-tactile-sensation-transmission-managing unit  353  determines whether the treatment unit  202  comes into contact with the body of the user. That is, the slave control unit  213  of the slave apparatus  20  determines whether it is detected that predetermined reaction force acts on the treatment unit  202 . 
     If the treatment unit  202  does not come into contact with the body of the user, the result of determination at the step S 15  is NO, and the process at the step S 15  is repeated. 
     If the treatment unit  202  comes into contact with the body of the user, the result of determination at the step S 15  is YES, and the process proceeds to a step S 16 . 
     At the step S 16 , the force-tactile-sensation-transmission-managing unit  353  stops moving the master apparatus  10  and the slave apparatus  20  from the neutral positions. That is, the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  stop moving. Positions at which these stop at the step S 16  are set as the initial positions of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20 . 
     The processes at the step S 14  to the step S 16  may be performed by only the slave apparatus  20 . The transmission of the force tactile sensation between the actuator  108  of the master apparatus  10  and the actuator  208  of the slave apparatus  20  may be controlled, the practitioner may manually move the pressure-receiving unit  102  of the master apparatus  10  and may stop these when the practitioner feels contact between the treatment unit  202  of the slave apparatus  20  and the user. 
     At a step S 17 , the force-tactile-sensation-transmission-managing unit  353  determines whether the practitioner imposes a restriction (for example, a pressing distance is restricted to a set value or less) on the movement of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  in the up-down direction in the master apparatuses  10 . That is, when the practitioner provides the treatment, whether a restriction is imposed on the movement of the right-hand pressure-receiving member  106 R and the left-hand pressure-receiving member  106 L of the pressure-receiving unit  102  and the right-hand pressing member  206 R and the left-hand pressing members  206 L of the treatment unit  202  in the up-down direction is determined. The movement of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  in the up-down direction is thus restricted. Consequently, for example, the practitioner can avoid pressing the user too strongly with certainty. 
     If the practitioner does not impose the restriction on the movement of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  in the up-down direction, the result of determination at the step S 17  is NO, and the process proceeds to a step S 18 . 
     If the practitioner imposes the restriction on the movement of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  in the up-down direction, the result of determination at the step S 17  is YES, and the process proceeds to a step S 19 . 
     At the step S 18 , the force-tactile-sensation-transmission-managing unit  353  does not impose the restriction on the movement of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  in the up-down direction. 
     At the step S 19 , the force-tactile-sensation-transmission-managing unit  353  imposes the restriction on the movement of the pressure-receiving unit  102  of the master apparatus  10  and the treatment unit  202  of the slave apparatus  20  in the up-down direction. 
     At a step S 20 , the force-tactile-sensation-transmission-managing unit  353  starts controlling the transmission of the force tactile sensation (the bilateral control). Together with this, the history-data-managing unit  354  starts recording the control parameters regarding the control over the transmission of the force tactile sensation (sequentially stores the control parameters in the history DB  371 ). The control parameters regarding the control over the transmission of the force tactile sensation may be stored in the treatment-data storage unit  271  of the slave apparatus  20 . An expiration date (for example, the current day only) may be set, and it may be permitted that the control parameters regarding the control over the transmission of the force tactile sensation are stored in the treatment-data storage unit  271  of the slave apparatus  20 . 
     At a step S 21 , the force-tactile-sensation-transmission-managing unit  353  transmits the treatment operation that is inputted into the master apparatus  10  by the practitioner to the slave apparatus  20  and controls the transmission of the reaction force that is inputted from the body of the user in the slave apparatus  20  (controls the transmission of the force tactile sensation). In the case where the user is treated by using the slave apparatus  20 , according to the present embodiment, the practitioner provides the first treatment on the current day by using the master apparatus  10 , and the second or later treatment on the current day can be provided by reproducing the stored control parameters. 
     In the case where the process at the step S 21  is performed, the force-tactile-sensation control unit  254  of the slave apparatus  20  monitors the control parameters that are transmitted from the control device  30  and the control parameters that are set in the slave apparatus  20 . In the case where the control parameters for the force tactile sensation that exceed values (for example, the upper limit value of the force, the upper limit value of the velocity, and the upper limit value of the displacement) that are set as the upper limit of various physical quantities are detected, the force-tactile-sensation control unit  254  cancels the control over the transmission of the force tactile sensation to the master apparatus  10 , and the control (the control for inhibiting the action on the user) for urgently stopping the treatment unit  202  is autonomously implemented. 
     At a step S 22 , the force-tactile-sensation-transmission-managing unit  353  receives notification (notification of the end of the treatment operation) that the input of the treatment operation from the master apparatus  10  ends. The notification of the end of the treatment operation is transmitted, for example, in a manner in which the practitioner operates the master apparatus  10  to end the treatment. 
     At a step S 23 , the UI control unit  251  of the slave apparatus  20  determines whether an instruction for repeating the treatment operation is inputted from the user. 
     If the instruction for repeating the treatment operation is not inputted from the user, the result of determination at the step S 23  is NO, the individual-treatment process ends, and the process returns to the remote treatment process. 
     If the instruction for repeating the treatment operation is inputted from the user, the result of determination at the step S 23  is YES, and the process proceeds to a step S 24 . 
     At the step S 24 , the treatment-data-managing unit  255  of the slave apparatus  20  saves the control parameters for the treatment operation that is repeated as a predetermined file in the treatment-data storage unit  271 . The predetermined file that is saved at this time contains the control parameters for the treatment that the user wishes to repeat. For example, the control parameters for the entire treatment operation that is provided by the practitioner can be contained, or some control parameters that are selected by the user among those of the treatment operation that is provided by the practitioner can be contained. 
     At a step S 25 , the force-tactile-sensation-transmission-managing unit  353  reproduces the control parameters that are contained in the file that is saved at the step S 24 . Consequently, the treatment operation that the user wishes to repeat is reproduced, and the user can be treated without the treatment operation of the practitioner. 
     After the step S 25 , the slave apparatus  20  finishes reproducing the treatment operation (that is, an individual control process ends), and the process returns to the remote treatment process. 
     Multiple-Treatment Process 
     The multiple-treatment process that is performed at the step S 5  in the remote treatment process will now be described. 
       FIG.  13    is a flowchart illustrating the flow of the multiple-treatment process. 
     The multiple-treatment process is performed as a sub-flow at the step S 5  in the remote treatment process. 
     After the multiple-treatment process starts, at a step S 31 , the request-receiving unit  351  checks the practitioner who is selected by the users, based on the requests that are received from the slave apparatuses  20 . Specifically, whether the data of the request contains information for the users to select the specific practitioner or contains information to freely select a practitioner (that is, whether information for selecting no practitioner is contained), for example, is determined. 
     At a step S 32 , the request-receiving unit  351  determines the practitioner who treats the multiple users from the practitioners who can currently provide the treatment. That is, in the case where the specific practitioner who is selected by the users can currently provide the treatment, it is determined that the specific practitioner treats the multiple users. As for a user who freely selects the practitioner, the practitioner who is selected by the request-receiving unit  351 , based on the predetermined selection standard among the practitioners who can currently provide the treatment is determined as the practitioner who provides the treatment. 
     At a step S 33 , the link-establishing unit  352  establishes communication links between the master apparatus  10  and the multiple slave apparatuses  20 . Consequently, the transmission of the force tactile sensation between the master apparatus  10  of the practitioner who is determined at the step S 32  and the slave apparatuses  20  of the multiple users can be controlled. 
     At a step S 34 , the force-tactile-sensation-transmission-managing unit  353  starts moving the master apparatus  10  and the multiple slave apparatuses  20  from the neutral positions to the standard positions (the initial positions depending on the body shapes of the users). That is, the pressure-receiving unit  102  of the master apparatus  10  and the treatment units  202  of the multiple slave apparatuses  20  start descending from the neutral positions (for example, the positions of the upper ends in the up-down direction). 
     At a step S 35 , the force-tactile-sensation-transmission-managing unit  353  determines whether the treatment unit  202  of each slave apparatus  20  comes into contact with the body of the user. That is, the slave control unit  213  of the slave apparatus  20  determines whether it is detected that the predetermined reaction force acts on the treatment unit  202 . 
     If the treatment unit  202  does not come into contact with the body of the user, the result of determination at the step S 35  is NO, and the process at the step S 35  is repeated. 
     If the treatment unit  202  comes into contact with the body of the user, the result of determination at the step S 35  is YES, and the process proceeds to a step S 36 . 
     At the step S 36 , the force-tactile-sensation-transmission-managing unit  353  stops moving the master apparatus  10  and the slave apparatuses  20  from the neutral positions. That is, the pressure-receiving unit  102  of the master apparatus  10  and the treatment units  202  of the slave apparatuses  20  stop moving. Positions at which these stop at the step S 36  are set as the initial positions of the pressure-receiving unit  102  of the master apparatus  10  and the treatment units  202  of the slave apparatuses  20 . 
     The processes at the step S 34  to the step S 36  can be performed in parallel by the slave apparatuses  20  to which the communication links are established. The processes at the step S 34  to the step S 36  may be performed by only the slave apparatuses  20 . 
     At a step S 37 , the force-tactile-sensation-transmission-managing unit  353  starts controlling the transmission of the force tactile sensation (controlling the transmission of the force tactile sensation from the master apparatus  10  to the slave apparatuses  20 ). Together with this, the history-data-managing unit  354  starts recording the control parameters regarding the control over the transmission of the force tactile sensation (sequentially stores the control parameters in the history DB  371 ). The control parameters regarding the control over the transmission of the force tactile sensation may be stored in the treatment-data storage units  271  of the slave apparatuses  20 . The expiration date (for example, the current day only) may be set, and it may be permitted that the control parameters regarding the control over the transmission of the force tactile sensation are stored in the treatment-data storage units  271  of the slave apparatuses  20 . 
     At a step S 38 , the force-tactile-sensation-transmission-managing unit  353  controls the transmission of the force tactile sensation such that the treatment operation that is inputted by the practitioner into the master apparatus  10  is transmitted to the slave apparatuses  20 . At this time, the force-tactile-sensation-transmission-managing unit  353  normalizes the control parameters that are transmitted from the master apparatus  10  and transmits the control parameters to the slave apparatuses  20  of the users to be treated. The slave apparatuses  20  correct the normalized control parameters such that the control parameters are suitable for the users to be treated, and the force-tactile-sensation control unit  254  can control the transmission of the force tactile sensation. 
     At a step S 39 , the force-tactile-sensation-transmission-managing unit  353  receives notification of the end of the treatment operation that represents the input of the treatment operation from the master apparatus  10  ends. The notification of the end of the treatment operation is transmitted, for example, in a manner in which the practitioner operates the master apparatus  10  to end the treatment. 
     At a step S 40 , the UI control units  251  of the slave apparatuses  20  determine whether the instruction for repeating the treatment operation is inputted from the users. 
     If the instruction for repeating the treatment operation is not inputted from the users, the result of determination at the step S 40  is NO, the multiple-treatment process of the slave apparatuses  20  ends, and the process returns to the remote treatment process. 
     If the instruction for repeating the treatment operation is inputted from the users, the result of determination at the step S 40  is YES, and the process proceeds to a step S 41 . 
     At the step S 41 , the treatment-data-managing units  255  of the slave apparatuses  20  save the control parameters for the treatment operation that is repeated as predetermined files in the treatment-data storage units  271 . The predetermined files that are saved at this time contain the control parameters for the treatment that the users wish to repeat. For example, the control parameters for the entire treatment operation that is provided by the practitioner can be contained, or some control parameters that are selected by the users among those of the treatment operation that is provided by the practitioner can be contained. The control parameters that are saved at this time can be normalized control parameters that are transmitted from the master apparatus  10 , or the slave apparatuses  20  can correct the normalized control parameters such that the control parameters are suitable for the users to be treated. 
     At a step S 42 , the force-tactile-sensation-transmission-managing unit  353  reproduces the control parameters that are contained in the files that are saved at the step S 41 . Consequently, the treatment operation that the users wish to repeat is reproduced, and the users can be treated without the treatment operation of the practitioner. 
     After the step S 42 , the slave apparatuses  20  finish reproducing the treatment operation (that is, a multiple-control process ends), and the process returns to the remote treatment process. 
     As for the position/force control system  1  according to the present embodiment, the multiple master apparatuses  10  and the multiple slave apparatuses  20  are remotely located, and a communication link can be established between a combination of a freely selected one of the master apparatuses  10  and a freely selected one of the slave apparatuses  20  as described above. The transmission of the force tactile sensation between the master apparatuses  10  and the slave apparatuses  20  is controlled, the treatment operations that are performed by the practitioners by using the master apparatuses  10  are consequently inputted into the users by using the slave apparatuses  20 , and the reaction force that is inputted from the users into the slave apparatuses  20  is provided to the practitioners by using the master apparatuses  10 . 
     Accordingly, a massage device can provide tactility similar to that in the case where the practitioners directly massage the users. 
     The treatment enables the autonomic nerve of the users to be steady and enables a relaxation effect to be expected for working, driving, learning, or an activity such as a hobby. 
     As for the position/force control system  1  according to the present embodiment, the control parameters for the treatment operations that are performed by the practitioners on the users by using the position/force control system  1  are stored, and the treatment operations can be partly or entirely reproduced automatically. 
     For this reason, it is easy for the users to repeatedly acquire the desired treatment operations, and the workload of the practitioners can be reduced because it is not necessary to repeat the same treatment operation. 
     As for the position/force control system  1 , the remote treatment process can be performed in the individual-treatment mode in which the practitioner treats the user in a one-to-one manner and in the multiple-treatment mode in which the single practitioner treats the multiple users. 
     For this reason, the specific practitioner who is selected by the user or the practitioner who is selected by the position/force control system  1  can treats the user in a one-to-one manner in the individual-treatment mode, and accordingly, the detailed treatment can be provided while the condition of the user is checked. 
     The specific practitioner who is selected by the users or the practitioner who is selected by the position/force control system  1  can treat the multiple users at the same time in the multiple-treatment mode, and this enables the treatment of the popular practitioner to be provided to many users at the same time and enables the user who prioritizes the time zone of the treatment to be treated without the influence of the situation of congestion. 
     First Modification 
     According to the embodiment described above, the mechanical structures of the master apparatuses  10  and the slave apparatuses  20  can be changed in various ways depending on the content of the treatment that is provided by the position/force control system  1 . 
       FIG.  14    schematically illustrates the structure of the slave apparatus  20  that has a function of rubbing the back of the user.  FIG.  15    is a front view of the slave apparatus  20  illustrated in  FIG.  14   .  FIG.  16    is a sectional view of the slave apparatus  20  taken along line A-A′ in  FIG.  15   .  FIG.  17    is a sectional view of the slave apparatus  20  taken along line B-B′ in  FIG.  15   . 
     The structure of the slave apparatus  20  illustrated in  FIG.  14    to  FIG.  17    differs from the structure of the slave apparatus  20  illustrated in  FIG.  3    in including a right-hand rubbing portion  214 R and a left-hand rubbing portion  214 L that are movable in the front-rear direction and in the left-right direction. 
     The right-hand rubbing portion  214 R is movable in the left-right direction with respect to the right-hand arm portion  204 R and includes a right-hand support member  216 R that supports a right-hand rubbing member  215 R such that the right-hand rubbing member  215 R is movable in the front-rear direction. The right-hand rubbing portion  214 R is a member that performs a rubbing action on the user in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the rubbing operation of the practitioner and moves in the front-rear direction with respect to the right-hand support member  216 R. That is, the position of the right-hand rubbing portion  214 R in the front-rear direction changes due to the rubbing operation of the practitioner. 
     The movement of the right-hand rubbing portion  214 R in the left-right direction can be controlled by an actuator  217 . The movement of the right-hand rubbing portion  214 R in the front-rear direction can be controlled by an actuator  218 . The actuators  217  and  218  include respective rotary encoders  217   a  and  218   a  that detect the rotation angles of rotors. 
     The left-hand rubbing portion  214 L is movable in the left-right direction with respect to the left-hand arm portion  204 L and includes a left-hand support member  216 L that supports a left-hand rubbing member  215 L such that the left-hand rubbing member  215 L is movable in the front-rear direction. The left-hand rubbing portion  214 L is a member that performs the rubbing action on the user in accordance with the reference values of position and force that are transmitted from the control device  30  depending on the rubbing operation of the practitioner and moves in the front-rear direction with respect to the left-hand support member  216 L. That is, the position of the left-hand rubbing portion  214 L in the front-rear direction changes due to the rubbing operation of the practitioner. 
     The movement of the left-hand rubbing portion  214 L in the left-right direction can be controlled by an actuator  219 . The movement of the left-hand rubbing portion  214 L in the front-rear direction can be controlled by an actuator  220 . The actuators  219  and  220  include respective rotary encoders  219   a  and  220   a  that detect the rotation angles of rotors. 
     Each master apparatus  10  has a structure for the rubbing action that corresponds to the right-hand rubbing portion  214 R and the left-hand rubbing portion  214 L as in the right-hand operation portion  105 R and the left-hand operation portion  105 L of the right-hand action portion  205 R and the left-hand action portion  205 L. The rubbing operation that the practitioner inputs by using the structure for the rubbing action can be transmitted to the user by using the right-hand rubbing portion  214 R and the left-hand rubbing portion  214 L of each slave apparatus  20  under the control over the transmission of the force tactile sensation. The master apparatus  10  may also include an operation portion (such as a controller that causes the right-hand rubbing portion  214 R and the left-hand rubbing portion  214 L to move in the up-down direction and in the left-right direction by using a lever) for enabling the right-hand operation portion  105 R and the left-hand operation portion  105 L to function as the structure for the rubbing action by changing settings or for remotely performing the rubbing operation of the right-hand rubbing portion  214 R and the left-hand rubbing portion  214 L. 
     With this structure, the rubbing operation of the right-hand rubbing portion  214 R and the left-hand rubbing portion  214 L can be performed as the treatment operation on the user in addition to the pressing operation of the right-hand pressing member  206 R and the left-hand pressing member  206 L. 
     In an example of the structure of the slave apparatus  20  illustrated in  FIG.  14    to  FIG.  17   , the single right-hand rubbing portion  214 R and the single left-hand rubbing portion  214 L are included. However, multiple right-hand rubbing portions  214 R and multiple left-hand rubbing portions  214 L may be included. 
     The position/force control system  1  according to the present embodiment includes one or multiple master apparatuses  10  that receive the input of the treatment operations, one or multiple slave apparatuses  20  that output the treatment operations, and the control device  30  that controls the one or multiple master apparatuses  10  and the one or multiple slave apparatuses  20  as described above. 
     The control device  30  transmits the control parameters for causing the one or multiple slave apparatuses  20  to output the force tactile sensation that corresponds to the treatment operations that are inputted into the one or multiple master apparatuses  10  to the one or multiple slave apparatuses  20  and transmits the control parameters for causing the one or multiple master apparatuses  10  to output the reaction force against the treatment operations that are outputted by the one or multiple slave apparatuses  20  to the one or multiple master apparatuses  10 . 
     Consequently, the treatment operations that are performed by the practitioners by using the one or multiple master apparatuses are inputted into the users by using the one or multiple slave apparatuses, and the reaction force that is inputted from the users into the one or multiple slave apparatuses is provided to the practitioners by using the one or multiple master apparatuses. 
     Accordingly, a massage device can provide tactility similar to that of massages in the cases where the practitioners directly treat the users. 
     The control device  30  establishes a communication link between one of the master apparatuses  10  and the slave apparatus  20  that makes a request in response to the request from the slave apparatus  20  and causes the force tactile sensation that corresponds to the treatment operation that is inputted into the master apparatus  10  to be outputted to the slave apparatus  20 . 
     Consequently, the practitioner can provide the treatment in a one-to-one manner while the condition of the user is checked, and accordingly, the detailed treatment can be provided. 
     The control device  30  receives the requests from the multiple slave apparatuses  20  and establishes communication links between any one of the master apparatuses  10  and the multiple slave apparatuses  20  that make the requests. 
     Consequently, the treatment of the specific practitioner can be provided to many users at the same time, and the users can be treated without the influence of the situation of congestion about the practitioner. 
     The control device  30  establishes communication links between the single master apparatus  10  that is specified by the requests from the slave apparatuses  20  and the multiple slave apparatuses  20  that make the requests. 
     Consequently, the treatment of the practitioner that the users wish can be provided to the multiple users. 
     The control device  30  transmits the control parameters acquired by normalizing the treatment operation that is inputted into the master apparatus  10  to the multiple slave apparatuses  20 . 
     Consequently, the control parameters that can be shared and used by the multiple users can be transmitted to the slave apparatuses  20 . 
     The slave apparatuses  20  correct the normalized control parameters that are transmitted from the control device  30  depending on the users of the slave apparatuses  20  and output the force tactile sensation, based on the corrected control parameters. 
     Consequently, the treatment appropriate for the body shapes of the users can be provided also in the case where the single practitioner treats the multiple users. 
     In the case where a physical quantity that is represented by the control parameters that are transmitted from the control device  30  exceeds a predetermined upper limit, or in the case where a communication state in which the control parameters are received from the control device  30  becomes worse than a predetermined state, the slave apparatuses  20  implement predetermined control for inhibiting the action on the users. 
     Consequently, in the case where there is a possibility that the appropriate force tactile sensation is not provided to the users, inappropriate action can be inhibited from being inputted into the users. 
     The slave apparatuses  20  reproduce the stored control parameters and consequently output the force tactile sensation that corresponds to the treatment operation. 
     Consequently, the slave apparatuses  20  can reproduce the treatment operation that was performed in the past. 
     Each slave apparatus  20  includes the pressing members (the right-hand pressing member  206 R and the left-hand pressing member  206 L) that press the user who is treated and outputs the force tactile sensation of the pressing operation that is inputted into the master apparatus  10  by using the pressing members. 
     Consequently, the position/force control system  1  enables the treatment in which the user is pressed to be provided while the force tactile sensation is transmitted. 
     Each slave apparatus  20  includes the rubbing members (the right-hand rubbing portion  214 R and the left-hand rubbing portion  214 L) that rub the user who is treated and outputs the rubbing operation by using the rubbing members in response to an operation for the rubbing operation that is inputted into the master apparatus  10 . 
     Consequently, the position/force control system  1  enables the treatment in which the user is rubbed to be provided while the force tactile sensation is transmitted. 
     Each slave apparatus  20  (a position/force control apparatus) according to the present embodiment is a position/force control apparatus that serves as a slave apparatus  20  of the position/force control system  1  that includes the one or multiple master apparatuses  10  that receive the input of the treatment operations, the one or multiple slave apparatuses  20  that output the treatment operations, and the control device  30  that controls the one or multiple master apparatuses  10  and the one or multiple slave apparatuses  20 . 
     The slave apparatus  20  outputs the force tactile sensation that corresponds to the treatment operation, based on the control parameters that represent the force tactile sensation that corresponds to the treatment operation that is inputted into the master apparatus  10  that receives the input of the treatment operation. 
     Consequently, the slave apparatus  20  can output the treatment operation that is inputted into the master apparatus  10  in real time or the treatment operation that was performed in the past. 
     In an example described according to the embodiment, the control device  30  is separated from the master apparatuses  10  and the slave apparatuses  20  but is not limited thereto. That is, the master control unit  113  or the slave control unit  213  may have a part or the whole of the function of the control device  30 , provided that the functional configurations of the control device  30 , the master control unit  113 , and the slave control unit  213  are included in the position/force control system  1 . The control device  30  may have the functions of the master control unit  113  and the slave control unit  213 , and the structures of the master apparatuses  10  and the slave apparatuses  20  may be simplified. 
     According to the embodiment described above, in the case where the slave apparatuses  20  detect the control parameters for the force tactile sensation that exceed the values (for example, the upper limit value of the force, the upper limit value of the velocity, and the upper limit value of the displacement) that are set as the upper limit of various physical quantities, fail-safe control is implemented, but this is not a limitation. That is, in the case where the communication state becomes worse than the predetermined state (such as disruption, reduction in velocity, and great variation in velocity), the slave apparatuses  20  may implement the fail-safe control. 
     The modification and the embodiment described above can be appropriately combined to carry out the present invention. 
     The process for control in the embodiment and the like may be performed through hardware or software. 
     That is, any configuration may be employed as long as a function for performing the process described above is provided for the position/force control system  1 . The functional configuration and the hardware configuration for realizing the function are not limited to the examples described above. 
     When the process described above is performed through software, programs constituting the software are installed from a network or a storage medium to a computer. 
     The storage medium that stores the program is constituted by, for example, a removable medium that is distributed separately from the device body, or a storage medium that is previously built in the device body. The removable medium is constituted by, for example, a USB (Universal Serial Bus) flash drive, an SD card, a magnetic disk, an optical disc, or a magneto-optical disk. The optical disc is constituted by, for example, a CD-ROM (Compact Disk-Read Only Memory), a DVD (Digital Versatile Disk), or a Blu-ray Disc (trademark). The magneto-optical disk is constituted by, for example, a MD (Mini-Disk). The storage medium that is previously built in the device body is constituted by, for example, ROM or a hard disk in which the program is stored.