Robot system

A robot system is provided, which includes a robot body including, robot arm and an end effector attached to robot arm, and operating device, having operating part and configured to output, when operating part is operated, operational information according to operation, a motion controller configured to control operation of robot body according to the operational information outputted from the operating device, a velocity detector configured to detect a velocity at a tip end of the end effector, a virtual reaction-force information generating module configured to output force information containing a first force component having a positive correlation to the velocity at the tip end of the end effector, as virtual reaction-force information, and a force applying device configured to give a force to the operating part in order to make an operator perceive a force according to the virtual reaction-force information outputted from the virtual reaction-force information generating module.

TECHNICAL FIELD

The present disclosure relates to a robot system.

BACKGROUND ART

Conventionally, technologies utilizing tactile sensing information in robot systems have been known. For example, Patent Document 1 discloses a robot system in which a mobile robot is operated, while obtaining a force sensing feedback between a joy stick and the mobile robot. In recent years, the robot system is applied to various works which require high precision. Examples of application of a master-slave type robot system include a component fitting work, a surgical operation system, etc.

REFERENCE DOCUMENT OF CONVENTIONAL ART

Patent Document

DESCRIPTION OF THE DISCLOSURE

Problem to be Solved by the Disclosure

However, during the work by the conventional robot system, if a force component according to a force received by a slave arm from an object to be worked is presented to a master arm, the master arm itself moves by the force as an operator removes his/her hand from the master arm. Thus, it gives an adverse effect to operability and, as a result, work accuracy decreases. Such a problem is common to a case in which the robot system is applied to a work which requires high precision, such as the component fitting work.

Thus, one purpose of the present disclosure is to enable a highly-precise work in a robot system.

SUMMARY OF THE DISCLOSURE

A robot system includes a robot body including a robot arm and an end effector attached to the robot arm, an operating device having an operating part and configured to output, when the operating part is operated, operational information according to the operation, a motion controller configured to control operation of the robot body according to the operational information outputted from the operating device, a velocity detector configured to detect a velocity at a tip end of the end effector, a virtual reaction-force information generating module configured to output force information containing a first force component having a positive correlation to the velocity at the tip end of the end effector, as virtual reaction-force information, and a force applying device configured to give a force to the operating part in order to make an operator perceive a force according to the virtual reaction-force information outputted from the virtual reaction-force information generating module.

With this configuration, when the operating part is operated by the operator, the operating device outputs operational information according to the operation. The motion controller controls operation of the robot body according to the operational information outputted from the operating device. The velocity detector detects the velocity at the tip end of the end effector attached to the robot arm. The virtual reaction-force information generating module outputs force information containing the first force component having the positive correlation to the velocity at the tip end of the end effector, as the virtual reaction-force information. The force applying device gives the force to the operating part in order to make the operator perceive the force according to the virtual reaction-force information outputted from the virtual reaction-force information generating module. The operator is able to perceive the force according to the virtual reaction-force information given to the operating part. That is, the operator is able to operate the operating part to operate the robot so that the robot suitably performs a work to an object to be worked, while perceiving from the operating part the virtual reaction force of which viscous resistance is exaggerated. Therefore, a highly-precise work is possible.

The robot body may be a slave arm, the operating device may be a master arm, and the slave arm is remotely controlled by the master arm.

The virtual reaction-force information generating module may output force information consisting of the first force component as the virtual reaction-force information.

With this configuration, the force information consisting of the first force component is outputted as the virtual reaction-force information, and the force applying device gives the force to the operating part in order to make the operator perceive a force according to the force information consisting of the first force component. Thus, the operating part does not operate unintentionally even when the operator removes his/her hand from the operating part. Therefore, it does not have a bad influence on the operability.

The virtual reaction-force information generating module may determine whether the velocity at the tip end of the end effector is positive or negative, and output the virtual reaction-force information when the velocity at the tip end of the end effector is positive, and output a value of zero when the velocity at the tip end of the end effector is negative.

With this configuration, when the velocity at the tip end of the end effector is positive, the force applying device gives the force to the operating part according to the virtual reaction force information of which the viscous resistance is exaggerated. On the other hand, when the velocity at the tip end of the end effector is negative, the force applying device gives no force to the operating part. For example, in a case of drawing a surgical instrument out of an incising part in a surgical operation system, since the operator does not perceive the viscous resistance from the surgical instrument, a smooth operation is possible.

The robot body may include a force detecting device configured to detect a force applied to the tip end of the end effector. The virtual reaction-force information generating module may output force information that is obtained by adding a second force component according to the force detected by the force detecting device to the first force component, as the virtual reaction-force information. Here, the force detected by the force detecting device includes forces in each direction of three axis which are perpendicular to each other and moment acting about each axis.

With this configuration, when the force detecting device detects the force applied to the tip end of the end effector, the virtual reaction-force information generating module outputs the force information that is obtained by adding the second force component according to the force detected by the force detecting device to the first force component, as the virtual reaction-force information. Then, the force applying device gives the force to the operating part in order to make the operator perceive the force according to the force information which is consisting of the first and second force components. Here, the force given to the operating part is a force which falls within a range where the movement of the operating part is permitted when the operator removes his/her hand from the operating part. Thus, the operator is able to sense from the operating part the virtual reaction force of which the viscous resistance is exaggerated more.

The force detecting device may be attached to a base end of the end effector, and may be a force sensor configured to detect the force applied to the tip end of the end effector.

The first force component may be a force component proportional to the velocity at the tip end of the end effector.

The robot system may further include a mode selector configured to select, as an operating mode of the motion controller in which operation of the robot body is controlled, any one of an automatic mode in which the operation of the robot body is controlled using a given preset program without reflecting the operational information on the operation of the robot body, a correctable automatic mode in which the operation of the robot body is controlled using the given preset program in the state where the operational information is reflectable on the operation of the robot body, and a manual mode in which the operation of the robot body is controlled using the operational information without using the given program. When the operating mode is the correctable automatic mode, the motion controller may control the robot body so as to perform an operation corrected from the operation related to the given program in response to the operational information while the robot body operates using the given program.

With this configuration, since the automatic mode is selectable by the mode selector as the operation mode of the motion controller, when the operation of the robot is not necessary to be corrected, the automatic mode is selected. In this manner, it is prevented that the operating device is unnecessarily operated to correct the operation. Further, since the manual mode is selectable by the mode selector as the operation mode of the motion controller, the robot main body is operated without using the given program.

The remote control system of the robot may be applied to a surgical operation system, and the end effector may be a surgical instrument.

Effect of the Disclosure

According to the present disclosure, the highly-precise work is enabled in the robot system.

The purpose described above, other purposes, features, and advantages of the present disclosure will be made clear from the following detailed description of suitable embodiments with reference to the accompanying drawings.

MODES FOR CARRYING OUT THE DISCLOSURE

Hereinafter, embodiments according to the present disclosure will be described with reference to the accompanying drawings. Below, the same reference characters are assigned to the same or corresponding components throughout the drawings to omit redundant description.

First Embodiment

FIG. 1is a schematic view illustrating one example of a configuration of a robot system according to a first embodiment of the present disclosure. As illustrated inFIG. 1, a robot system100of this embodiment is comprised of a master-slave type robot remote control system in which a slave arm1is remotely controlled by a master arm2.

The robot remote control system100(hereinafter, simply referred to as “remote control system”) includes the slave arm1comprised of a first robot, the master arm2comprised of a second robot, a control device3, a force sensor5, an input device9, a camera11, and a monitor12. The slave arm1may be comprised of a robot of any type. The slave arm1corresponds to a “robot body” of the present disclosure. In this embodiment, the slave arm1is, for example, comprised of a well-known articulated robot, and includes a pedestal1a, an articulated or multi joint arm1bprovided to the pedestal1a, and a hand part1cprovided to a tip end of the arm1b. Each joint of the multi joint arm1bincludes a driving servo motor, an encoder which detects a rotational angular position of the servo motor, and a current sensor which detects current flowing into the servo motor (none of them is illustrated). An end effector4is attached to the hand part1c. The force sensor5is attached to the end effector4.

The master arm2may be comprised of a robot of any type. The master arm2corresponds to an “operating device” of the present disclosure. The master arm2has an operating part26, and is configured so that, when the operating part26is operated, operational information according to the operation is outputted to the control device3. Although the operating part26has a similarity structure to the multi joint arm1bof the slave arm1in this embodiment, the operating part26may be a simple device, such as a switch, an adjustment knob, a control lever, or a mobile terminal such as a tablet, or may be a joystick, as long as the operating part26is able to operate the slave arm1by an operator operating it.

The input device9is comprised of man-machine interface(s), such as a touch panel and/or a keyboard. The input device9is mainly used in order to input switching of three modes, an automatic mode, a correctable operation mode, and a manual mode of the slave arm1(described later), as well as various data. The information inputted into the input device9is transmitted to the control device3.

In the remote control system100, the operator who is located at a position distant from a workspace of the slave arm1(outside the workspace) operates the master arm2to input operational information so that the slave arm1performs an operation corresponding to the operational information to perform a specific work. Moreover, in the remote control system100, the slave arm1is also capable of automatically performing a given work without the operator operating the master arm2.

The operating mode in which the slave arm1is operated according to the operational information inputted through the master arm2is herein referred to as “the manual mode.” Note that “the manual mode” also includes a case where part of the operation of the slave arm1under operation is automatically corrected based on the operational information inputted by the operator operating the master arm2. Moreover, the operating mode in which the slave arm1is operated according to a given preset program is referred to as “the automatic mode.”

Further, the remote control system100of this embodiment is configured to be correctable of the operation of the slave arm1which is to be performed automatically, by reflecting the operation of the master arm2on the automatic operation of the slave arm1, while the slave arm1operates automatically. The operating mode in which the slave arm1is operated according to the given preset program in a state where the operational information inputted through the master arm2is reflectable is herein referred to as a “correctable automatic mode.” Note that “the automatic mode” described above is distinguished from “the correctable automatic mode” in that the operation of the master arm2is not reflected on the operation of the slave arm1when the operating mode in which the slave arm1is operated is the automatic mode.

The camera11is provided so as to be able to image the operation of the slave arm1in all or part of a movable range of the slave arm1. The image information imaged by the camera11is transmitted to the control device3, and the control device3then controls the monitor12to display an image corresponding to the image information.

FIG. 2is a schematic view illustrating one example of a configuration of a tip end of the slave arm1. As illustrated inFIG. 2, the end effector4is attached to an attachment surface1dat the tip end of the hand part1c. In this embodiment, the end effector4is a robot hand which is capable of gripping a fitting component200. The robot hand includes a hand main body attached to the attachment surface1dat the tip end of the hand part1c, and two finger parts driven by an actuator (not illustrated), for example, comprised of a motor. When the actuator operates, the two finger parts move with respect to the hand main body. That is, the two finger parts of the robot hand are movable so as to approach or separate mutually, and are capable of gripping the fitting component200. In the remote control system100of this embodiment, a shaft (200) held by the robot hand (4) is inserted into a hole (211) of a gear (210) by the operation of the slave arm1. Lubricating oil212is applied to the surface and the side surface of the hole (211) of the gear (210). Since high precision is required for this work, this work requires a skilled operator among assembly operations.

The force sensor5is attached between the attachment surface1dat the tip end of the hand part1c, and the end effector4. The force sensor5corresponds to a “force detecting device” of the present disclosure. In this embodiment, the force sensor5is attached to a base end of the end effector4, and it is configured to detect a force applied to the tip end of the end effector4. In this embodiment, the force sensor5is a 6-axis force sensor capable of detecting forces in XYZ-axes directions defined by a hand part coordinate system, and moment acting about each axis. Here, the hand part coordinate system is a coordinate system on the basis of the hand part1c. InFIG. 2, the X-axis and the Y-axis are defined in parallel with the attachment surface1dof the hand part1c, and the Z-axis is defined in a direction perpendicular to the attachment surface1d. The force sensor5transmits wirelessly or wiredly a detection signal to the control device3.

FIG. 3is a block diagram illustrating a configuration of the master arm2and the control device3. As illustrated inFIG. 3, the master arm2includes the operating part26, an operational information generating part27, and a force applying device28. The operating part26is comprised of the multi joint arm similar to the slave arm1(seeFIG. 1), and it is operated by the operator and a force (torque) is given to each joint shaft by the force applying device28. The operational information generating part27is configured so that it generates, when the operating part26is operated by the operator, the operational information according to this operation, and outputs it to a motion controller6. The force applying device28is configured to give a force (torque) to each joint shaft of the multi joint arm (the operating part26).

The control device3includes the motion controller6, a force-sensing information processor7, a monitor controller8, a memory10, and an interface part (not illustrated). The control device3is comprised of a device having arithmetic processing capabilities, such as a computer, a micro controller, and a microprocessor. The motion controller6, the force-sensing information processor7, and the monitor controller8are implemented by an operation processor (not illustrated) of the control device3executing given program(s) stored in the memory10of the control device3. The hardware configuration of the control device3may be arbitrary, and the control device3may be provided separately from other devices, such as the slave arm1, or may be provided integrally with other devices.

The motion controller6controls the operation of the slave arm1according to the operational information transmitted from the master arm2and the information inputted from the input device9. Here, a mode selector25of the input device9is for the operator to select any one of “the automatic mode,” “the correctable automatic mode,” and “the manual mode” which are described above as the operating mode in which the slave arm1is operated. The information related to the mode selected by the operator is inputted into the motion controller6from the mode selector25. The memory10is a readable and writable recording medium, which stores beforehand the given program(s) and various data for causing the slave arm1to automatically perform the given operation. The given program is, for example, instruction information which is stored by an instruction work in which the slave arm1is operated to perform the given work. In this embodiment, the instruction information may be information stored by instructing the operation of the slave arm1by operating the master arm2, or may be information stored by a direct instruction. Note that, although the memory10is provided integrally with the control device3, it may be provided separately from the control device3. Specifically, the motion controller6controls the servo motor which drives each joint shaft of the slave arm1based on at least one of the operational information from the master arm2and the prestored information. The motion controller6generates a positional instruction value of each joint shaft of the slave arm1, and generates a velocity instruction value based on a difference between the generated positional instruction value and the detection value (actual value) of the encoder. Then, the motion controller6generates a torque instruction value (current instruction value) based on the difference between the generated velocity instruction value and a present velocity value, and controls the servo motor based on a difference between the generated current instruction value and a detection value (actual value) of the current sensor.

The force-sensing information processor7includes a position calculating module21, a velocity calculating module22, and a virtual reaction-force information generating module23.

The position calculating module21is capable of acquiring the detection signal of the encoder20, and identifying the position and posture of the hand part1cof the slave arm1in a common base coordinate system based on the rotational angular position of each joint shaft of the slave arm1, and dimensions of links which constitute the slave arm1. Then, the position calculating module21calculates the position at the tip end of the end effector4on the basis of the base coordinate system by storing beforehand a vector from the position of the hand part1cto the tip end of the end effector4in the hand part coordinate system on the basis of the hand part1c, and outputs it to the velocity calculating module22. Note that the remote control system100may have a measuring device (not illustrated) capable of measuring an arbitrary point on space and generating coordinate data of the point, and the position calculating module21may convert the coordinate data of the measured point from a given coordinate system of the measuring device to the base coordinate system to calculate the position at the tip end of the end effector4on the basis of the base coordinate system.

The velocity calculating module22acquires the position at the tip end of the end effector4outputted from the position calculating module21, calculates a velocity component at the tip end of the end effector4based on an amount of movement at a given time interval, and outputs it to the virtual reaction-force information generating module23.

The virtual reaction-force information generating module23acquires the detection signal of the force sensor5, and the velocity component at the tip end of the end effector4calculated by the velocity calculating module22, generates virtual reaction-force information based on the information, and outputs it to the master arm2. Here, the virtual reaction-force information generating module23determines whether the force applied to the tip end of the end effector4increases with time based on the detection signal of the force sensor5. If the force applied to the tip end of the end effector4increases, the virtual reaction-force information generating module23outputs force information containing a first force component having a positive correlation to the velocity at the tip end of the end effector4to the force applying device28as the virtual reaction-force information. The virtual reaction-force information generating module23outputs a value of zero to the force applying device28if the force applied to the tip end of the end effector4decreases with time.

The force applying device28gives a force to the operating part26in order to make the operator perceive the force corresponding to the virtual reaction-force information outputted from the virtual reaction-force information generating module23. Here, synthetic reaction-force information is converted into a torque value to each joint shaft of the master arm2(the operating part26). For example, the converted torque value corresponds to a torque instruction to a driver circuit of the servo motor which drives each joint.

The monitor controller8controls the monitor12to display the image corresponding to the image information which is imaged by the camera11. The operator is able to operate the slave arm1as he/she intended by operating the master arm2(the operating part26) while looking at the monitor12.

Operation

Next, operation of the remote control system100is described usingFIGS. 2 to 4. In the remote control system100of this embodiment, the shaft (200) held by the robot hand (4) is inserted into the hole (211) of the gear (210) by the operation of the slave arm1(seeFIG. 2). Here, a case where the operating mode selected by the operator with the mode selector25is “the manual mode” is described. The motion controller6controls the operation of the slave arm1according to the operational information (inputted instruction) sent by operating the master arm2without using the given program, when the operating mode in which the slave arm1is operated is “the manual mode” (seeFIG. 3).

FIG. 4is a view schematically illustrating the force acting on the tip end of the robot hand (4) according to a work stage. First, as illustrated inFIG. 4(A), the operator operates the master arm2(the operating part26) while looking at the monitor12to depress the robot hand (4) which grips the shaft (200) in a direction toward the gear (210) (in this figure, the positive Z-axis direction) by the operation of the slave arm1. Here, the centerline of the shaft (200) is controlled so as to be aligned with the centerline of the hole (211) of the gear (210). In this embodiment, a contact determination of whether the tip end of the shaft (200) contacts the gear (210) is performed based on the detection signal of the force sensor5. Since no force is applied to the tip end of the robot hand (4) until the tip end of the shaft (200) contacts the gear (210), a force value detected by the force sensor5is zero. Note that, in this embodiment, since the shaft (200) is gripped by the robot hand (4), the force applied to the tip end of the shaft (200) gripped by the robot hand (4) is about the same as the force applied to the tip end of the robot hand (4).

Next, as illustrated inFIG. 4(B), when the tip end of the shaft (200) contacts the gear (210), the operator starts the work in which the shaft (200) is inserted into the gear (210) by the operation of the slave arm1, by operating the master arm2while looking at the monitor12. When the force sensor5attached to the tip end of the slave arm1detects the force F applied to the tip end of the robot hand (4), the virtual reaction-force information generating module23determines whether the force F applied to the tip end of the end effector4increases with time based on the detection signal of the force sensor5. InFIG. 4(B), when the tip end of the shaft (200) contacts the surface of the gear (210) or the side surface of the hole (211), it receives the force in the negative Z-axis direction. In this case, since the force applied to the tip end of the robot hand (4) increases with time, the virtual reaction-force information generating module23outputs force information containing the first force component having the positive correlation to the velocity at the tip end of the robot hand (4) as virtual reaction-force information P(t) to the master arm2(the force applying device28), as illustrated in Equation (1).
P(t)=(K×(dr/dt))×h(t)  (1)
Here, r represents the position at the tip end of the robot hand (4), t represents time, and K represents a factor of proportionality. h(t) represents a unit step function illustrated in Equation (2). F represents the force applied to the tip end of the robot hand (4).
h(t)=1(dF/dt≤0,h(t)=0(dF/dt<0)  (2)
According to Equation (1), the first force component having the positive correlation to the velocity at the tip end of the robot hand (4) is a force component proportional to the velocity component at the tip end of the robot hand (4). That is, the virtual reaction-force information generating module23converts the velocity component dr/dt at the tip end of the robot hand (4) into an appropriate range, and outputs it to the force applying device28of the master arm2as the virtual reaction-force information. Note that noise component of the virtual reaction-force information may be removed by a low pass filter (not illustrated).

The force applying device28gives a force to the master arm2(the operating part26) in order to make the operator perceive the force according to the virtual reaction-force information outputted from the virtual reaction-force information generating module23. The operator is able to perceive the force according to the virtual reaction-force information given to the operating part26. That is, the operator is able to operate the operating part26so that the shaft (200) is inserted by the operation of the slave arm1, into the gear (210) to which the lubricating oil (212) is applied, while perceiving from the operating part26the virtual reaction force of which viscous resistance is exaggerated. Therefore, a highly-precise work is possible.

Moreover, since the force applying device28gives the force to the operating part26in order to make the operator perceive the force according to the force information which is consisting of the first force component (see Equation (1)), the operating part26does not operate unintentionally even when the operator removes his/her hand from the operating part26. Therefore, it does not have a bad influence on the operability.

On the other hand, as illustrated inFIG. 4(C), the operator may draw out a tip-end part of the once-inserted shaft (200) from the hole (211) during the work. Since the lubricating oil (212) is applied to the inside of the hole (211), the tip end of the shaft (200) receives a force in the minus Z-axis direction. In this case, the force F applied to the tip end of the shaft (200) (the negative Z-axis direction) decreases, compared with the case ofFIG. 4(B). As a result, since the force applied to the tip end of the robot hand (4) decreases with time, the virtual reaction-force information generating module23outputs the value of zero to the force applying device28of the master arm2. As a result, the force applying device28gives no force to the operating part26. Since the operator does not perceive the viscous resistance from the operating part26, a smooth operation is possible.

Note that, in this embodiment, although the virtual reaction-force information generating module23outputs the force information containing the first force component having the positive correlation to the velocity at the tip end of the robot hand (4) as the virtual reaction-force information (see Equation (1)), the present disclosure is not limited to this configuration. As illustrated in Equation (3), the virtual reaction-force information generating module23may output force information which is obtained by adding a second force component according to the force detected by the force sensor5to the first force component as the virtual reaction-force information P(t).
P(t)=(K×(dr/dt))×h(t)+f(t)  (3)
Here, f(t) represents the second force component according to the force detected by the force sensor5. Thus, the operator is able to sense from the operating part26the virtual reaction force of which the viscous resistance is exaggerated.

Note that, upon generating the second force component f(t), the virtual reaction-force information generating module23converts the force applied to the tip end of the robot hand (4) detected by the force sensor5into the appropriate range to set the force given to the operating part26as a force which falls within a range where the movement of the operating part26is permitted when the operator removes his/her hand from the operating part26.

Note that, in this embodiment, although the virtual reaction-force information generating module23outputs the value of zero when the force applied to the tip end of the robot hand (4) decreases (see Equation (1)), it may output the value of zero when an absolute value of the force is smaller than a given value.

FIG. 5is a block diagram illustrating a configuration of a control device3A of a remote control system of a robot according to a modification of this embodiment. As illustrated inFIG. 5, the remote control system of this modification differs from this embodiment in that it is not provided with the force sensor5(seeFIG. 3). A force-sensing information processor7A is further provided with a force calculating module24. Although the force calculating module24acquires from the current sensor30a value of current flowing into the servo motor which drives each joint shaft of the slave arm1, and calculates the force acting on the tip end of the end effector4of the slave arm1based on a rate of change in a difference between the current instruction value and the detection value of the current sensor30, it may calculate the force acting on the tip end of the end effector4of the slave arm1based on a rate of change in a positional deviation or velocity deviation of each joint shaft. In this modification, a virtual reaction-force information generating module23A determines whether the tip end of the shaft (200) contacts the gear (210) based on an output signal of the force calculating module24. Moreover, the virtual reaction-force information generating module23A generates virtual reaction-force information only based on the velocity at the tip end of the robot hand (4). The virtual reaction-force information generating module23A determines whether the velocity at the tip end of the robot hand (4) is positive or negative, and according to Equations (1) illustrated above and (4), outputs the virtual reaction-force information P(t) when the velocity at the tip end of the robot hand (4) is positive, and outputs the value of zero when the velocity at the tip end of the robot hand (4) is negative.
P(t)=(K×(dr/dt))×h(t)  (1)
h(t)=1(dr/dt≤0),h(t)=0(dr/dt)<0  (4)
In the remote control system of this modification, since the force sensor5is unnecessary, a similar effect to this embodiment can be attained with a simple configuration.

Moreover, also in this modification, the virtual reaction-force information generating module23A may output the virtual reaction-force information P(t) illustrated in Equation (3).

Note that, although in this embodiment the case where the operating mode selected in the mode selector25is “the manual mode” is described, the operating mode selected in the mode selector25may be “the automatic mode.” The motion controller6controls the operation of the slave arm1according to the given preset program without using the operational information sent from the master arm2, when the operating mode in which the slave arm1is operated is “the automatic mode.”

Moreover, the operating mode selected in the mode selector25may be “the correctable automatic mode.” When the operating mode is “the correctable automatic mode,” the motion controller6uses both the given program and the operational information. Note that, when the operating mode is “the correctable automatic mode,” the motion controller6uses only the given program if the operational information has not been sent to the motion controller6. In more detail, when the operating mode in which the slave arm1is operated is “the correctable automatic mode,” the motion controller6controls the operation of the slave arm1using both the given program and the operational information, if the operational information is received while the slave arm1operates automatically using the given program. Thus, the slave arm1performs an operation corrected from the operation related to the given program, i.e., the operation which is to be performed automatically.

Note that, in this embodiment, although the motion controller6is configured so that the slave arm1is operated according to any one of operating modes, “the automatic mode,” “the correctable automatic mode” and “the manual mode,” which is selected by the operator using the mode selector25of the input device9, the present disclosure is not limited to such a configuration. For example, the motion controller6may have an output controlling module (not illustrated) which outputs an inquiry about a permission to continue the automatic operation of the slave arm1to the operator when the motion controller6controls the slave arm1so that the slave arm1is operated in “the automatic mode” up to a given step, and a continuation determining module (not illustrated) which determines whether a continuation of the automatic operation is permitted based on an inputted signal received by a receiving module (not illustrated) after the output of the inquiry by the output controlling module (not illustrated). Thus, in a scene where the skilled operator is required, the operator is able to perform the work after switching the mode from “the automatic mode” to “the manual mode.”

Note that, in this embodiment, although the remote control system100is applied to the work in which the component which has already been applied the lubricating oil (212) is mounted by another component, the present disclosure is not limited to this configuration. The remote control system100may be applied to, for example, a work to an object to be worked which is in liquid, or a stirring work of high-viscosity liquid, as long as the work requires high precision. It becomes easier to distinguish whether the object to be worked is in liquid by adding a viscous resistance to the force presented to an operating device.

Second Embodiment

Next, a second embodiment is described. A fundamental configuration of the remote control system of this embodiment is similar to that of the embodiment described above. Below, description of configurations common to those of the first embodiment is omitted, but different configurations are mainly described. The remote control system of this embodiment is applied to a surgical operation system, and the end effector is a surgical instrument. The surgical operation system is a master-slave type operation support robot. Here, it is a system in which an operator, such as a surgeon, performs an endoscope surgical operation to a patient.

Note that, since the surgical operation system of this embodiment is for operation support, the slave arm1is configured so as to operate only in “the manual mode.” Thus, the input device9is not provided with the mode selector25for selecting the operating mode by the operator (seeFIG. 3). The operator operates the operating part26of the master arm2while looking at the monitor12to operate the slave arm1as he/she intended. The operating part26may have a well-known configuration, as long as the operator is able to operate the operating part26to operate the slave arm1. The slave arm1may also have a well-known configuration, as long as it is controllable according to the operational information outputted from the master arm2. For example, the slave arm1has a configuration in which the tip-end part is movable in a three-dimensional space with respect to the base-end part.

FIG. 6is a schematic view illustrating a configuration of the remote control system of the robot according to the second embodiment. As illustrated inFIG. 6, a holder36(instrument holder) which holds an instrument (surgical instrument)42is formed in the hand part1cat the tip end of the slave arm1. The force sensor5is attached between the attachment surface1d(a back surface of the holder36) of the hand part1cat the tip end of the slave arm1, and the instrument42. The instrument42is held attachably and detachably by the holder36. A shaft43of the instrument42held by the holder36is configured so as to extend parallel with reference directions D. Note that an endoscope assembly may be held attachably and detachably by the holder36. In this embodiment, the operator operates the instrument42of the slave arm1by the operation of the slave arm1.

The instrument42is comprised of a drive unit45provided to a base-end part thereof, the end effector (surgical tool)4provided to a tip-end part thereof, and a long and narrow shaft43which connects between the drive unit45and the end effector4. The reference directions D are defined in the instrument42, and the drive unit45, the shaft43, and the end effector4are aligned in parallel with the reference directions D. The end effector4of the instrument42is selected from the group comprised of surgical instruments having operable joint(s) (e.g., forceps, scissors, and a grasper, a needle holder, a microdissector, a staple applier, a tucker, a siphonage tool, a snare wire, and a clip applier), and instruments without a joint (e.g., a cutting blade, a cauterize probe, a syringe, a washer, a suction orifice).

In the surgical operation system (100), various operations are performed to a patient214by the surgical instrument (4) at the tip end of the slave arm1. Not only a general operation but the operation using the surgical operation system (100) also requires the skilled operator.

FIG. 7is a view schematically illustrating a force acting on the tip end of the surgical instrument (4) according to an operating stage. First, as illustrated inFIG. 7(A), the operator operates the master arm2(the operating part26) while looking at the monitor12to depress the tip end of the surgical instrument (4) attached to the shaft43in a direction toward the patient214(in this figure, the positive Z-axis direction) by the operation of the slave arm1. Here, for example, the tip end of the surgical instrument (4) is controlled so that it is located at an incising part Q of the patient214. In this embodiment, a contact determination of whether the tip end of the surgical instrument (4) contacts the patient214is performed based on the detection signal of the force sensor5. Since no force is applied to the tip end of the surgical instrument (4) until the tip end contacts the incising part Q, a force value detected by the force sensor5is zero.

Next, as illustrated inFIG. 7(B), when the tip end of the surgical instrument (4) contacts the incising part Q, the operator starts the operation with the surgical instrument (4) by the operation of the slave arm1by operating the master arm2while looking at the monitor12. When the force sensor5attached to the tip end of the slave arm1detects the force applied to the tip end of the surgical instrument (4), the virtual reaction-force information generating module23determines whether the force F applied to the tip end of the surgical instrument (4) increases with time based on the detection signal of the force sensor5. InFIG. 7(B), when the tip end of the surgical instrument (4) contacts the incising part Q of the patient214, it receives a force in the negative Z-axis direction. In this case, since the force applied to the tip end of the surgical instrument (4) increases with time, the virtual reaction-force information generating module23outputs, as above Equation (1), the force information containing the first force component having the positive correlation to the velocity at the tip end of the surgical instrument (4), to the master arm2(the force applying device28) as the virtual reaction-force information P(t). According to Equation (1), the first force component having the positive correlation to the velocity at the tip end of the robot hand (4) is a force component proportional to the velocity component at the tip end of the robot hand (4).

The force applying device28gives a force to the master arm2(the operating part26) in order to make the operator perceive the force according to the virtual reaction-force information outputted from the virtual reaction-force information generating module23. The operator is able to perceive the force according to the virtual reaction-force information given to the operating part26. That is, the operator is able to operate the operating part26so as to cut the incising part Q of the patient214by the surgical instrument (4), while perceiving from the operating part26the virtual reaction force of which the viscous resistance is exaggerated. Therefore, a highly-precise work is possible.

Moreover, since the force applying device28gives the force to the operating part26in order to make the operator perceive the force according to the force information consisting of the first force component (see Equation (1)), the operating part26does not have a bad influence on its operability even if the operator removes his/her hand from the operating part26because the operating part26does not operate unintentionally.

On the other hand, as illustrated inFIG. 7(C), the operator may take out the once-inserted surgical instrument (4) from in vivo of the patient214during or after the operation. In this case, the tip end of the surgical instrument (4) receives a force in the minus Z-axis direction. The power F applied to the tip end of the surgical instrument (4) (in the negative Z-axis direction) decreases compared with the case ofFIG. 7(B). As a result, since the force applied to the tip end of the surgical instrument (4) decreases with time, the virtual reaction-force information generating module23outputs the value of zero to the force applying device28of the master arm2. As a result, the force applying device28does not give any force to the operating part26. Since the operator does not perceive the viscous resistance from the operating part26, a smooth operation is possible.

Note that, in this embodiment, although the virtual reaction-force information generating module23outputs the force information containing the first force component having positive correlation to the velocity at the tip end of the surgical instrument (4) as the virtual reaction-force information (see Equation (1)), the present disclosure is not limited to this configuration. The virtual reaction-force information generating module23may output the virtual reaction-force information P(t) illustrated in Equation (3) described above.

Note that, upon generating the second force component f(t) of Equation (3), the virtual reaction-force information generating module23converts the force applied to the tip end of the surgical instrument (4), which is detected by the force sensor5, into an appropriate range, to set the force given to the operating part26as a force which falls within a range where the movement of the operating part26is permitted, when the operator removes his/her hand from the operating part26.

Note that, in this embodiment, although the virtual reaction-force information generating module23outputs the value of zero when the force applied to the tip end of the surgical instrument (4) decreases (see Equation (1)), it may output the value of zero when an absolute value of the force is smaller than a given value.

Note that, as a modification of this embodiment, it may not be provided with the force sensor5, similar to the configuration of the modification of the first embodiment (seeFIG. 5). In this case, the virtual reaction-force information is generated only based on the velocity at the tip end of the surgical instrument (4). Since the force sensor5is unnecessary, similar effects to this embodiment can be obtained with a simple configuration.

Note that, in each of the embodiments, although the first force component having the positive correlation to the velocity at the tip end of the end effector4is the force component proportional to the velocity component at the tip end of the end effector4(see Equation (1)), it may be a force component, for example, proportional to a square of the velocity component, as long as it is a force component which increases according to the increase in the velocity component.

Other Embodiments

Note that, although the robot system100of each of the embodiments described above is comprised of the master-slave type remote control system, the present disclosure is not limited to this configuration. For example, it may be configured in other robot systems so that, when a work is performed by the end effector attached to the robot arm, surrounding persons or administrator(s) of the system perceive the virtual reaction force.

It is apparent for a person skilled in the art that many improvements and other embodiments of the present disclosure are possible from the description. Therefore, the above description is to be interpreted only as illustration, and it is provided in order to teach a person skilled in the art the best mode that implements the present disclosure. Details of one or both the structure and function can substantially be changed, without departing from the spirit of the present disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure is useful when applying the robot system to the work which requires high precision.

DESCRIPTION OF REFERENCE CHARACTERS