JP5636239B2 - Medical manipulator - Google Patents

Description

  The present invention relates to a medical manipulator including a distal end working unit having an end effector capable of posture changing operation.

  In endoscopic surgery (also called laparoscopic surgery), a plurality of holes are opened in the patient's abdomen, etc., trocars (tubular instruments) are inserted into these holes, and then through each trocar, A laparoscope (camera) and a plurality of forceps are inserted into the body cavity. A gripper, a scissors, an electric knife blade, and the like are attached to the distal end portion of the forceps as an end effector for gripping a living tissue. After the laparoscope and forceps are inserted into the body cavity, the operation is performed by operating the forceps while observing the inside of the abdominal cavity reflected on a monitor connected to the laparoscope. Since such an operation method does not require laparotomy, the burden on the patient is small, and the number of days until recovery and discharge from the operation is greatly reduced. For this reason, such an operation method is expected to expand the application field.

  As forceps inserted from trocars, in addition to general forceps that do not have joints at the tip, forceps that have multiple joints at the tip and can change the posture of the tip, so-called medical manipulators have been developed. (For example, refer to Patent Document 1). According to such a medical manipulator, an operation with a high degree of freedom is possible in the body cavity, the procedure becomes easy, and the number of applicable cases increases.

  In the medical manipulator proposed in Patent Document 1, a shaft extends forward from an operation unit having a grip handle, and a tip operating unit having an end effector is provided at the tip of the shaft. Yes. The posture changing mechanism in the distal end working unit includes a main shaft member that rotates about the yaw axis, and a gear body that is rotatably supported by the main shaft member and rotates about the roll shaft. The main shaft member and the gear body are driven to rotate by the driving force of the motor being transmitted by the power transmission mechanism. The main shaft member is driven to rotate, so that the tip operating portion performs yaw operation, and the gear body is driven to rotate. The tip operating unit rolls.

JP 2009-107087 A

  The power transmission mechanism that transmits the driving force of the motor to the main shaft member usually has mechanical backlash (hereinafter referred to as backlash). Therefore, even if the motor operates within the backlash range, the main shaft member operates. I will not. Therefore, there is a concern that the trajectory accuracy and positioning accuracy of the distal end working unit may be lowered.

  Further, when the gear body is rotated in order to perform the roll operation, the main shaft member that supports the gear body receives a force from the gear body. At this time, there is a concern that the locus accuracy and the positioning accuracy of the tip working portion may be lowered due to the backlash existing in the power transmission mechanism of the yaw axis drive system or due to elastic deformation when the rigidity of the power transmission mechanism is low. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a medical manipulator that can improve the trajectory accuracy and positioning accuracy of the distal end working portion.

In order to achieve the above object, a medical manipulator according to the present invention performs a first posture changing operation by mechanically transmitting a driving force of a first driving source, an end effector, and the first driving source. A first operating unit having a first operating unit configured to perform the operation of the first operating unit by mechanically transmitting a driving force of the first drive source via a meshing unit or an engaging unit . A first power transmission mechanism and a controller for controlling the first drive source, the first power transmission mechanism including the meshing part or the engagement part has a mechanical backlash; The controller, when receiving a first operation command related to the first posture change operation, generates a first target trajectory based on the first operation command as the first compensation control, and the first target trajectory Is a target value of the first drive source based on And generating a regular uniaxial target value of 1, and generating a first correction value to eliminate the influence of the backlash present in the first power transmission mechanism based on the first target trajectory, the first normal Generating a first corrected one-axis target value that is a target value for controlling the first drive source based on the one-axis target value and the first correction value, and performing the first correction 1 The first drive source is controlled using an axis target value .

According to said structure, the backlash which exists in a 1st power transmission mechanism is compensated by 1st compensation control. For this reason, the attitude control of the first operation unit can be performed with high accuracy, and the operability is improved. Further, since the first corrected one-axis target value is generated by correcting the first normal one-axis target value with the first correction value that eliminates the influence of the play existing in the first power transmission mechanism, Trajectory accuracy and positioning accuracy can be improved effectively.

The medical manipulator includes a shaft having the distal end working portion provided at the distal end, a second driving source, and a second power that mechanically transmits the driving force of the second driving source to operate the second working portion. A transmission mechanism, and the tip motion section is based on a yaw motion as the first posture changing motion that tilts with respect to a yaw axis that is non-parallel to the axis of the shaft, and a roll shaft that points to the tip. A roll operation as a second posture changing operation that rotates in the first direction, the first operating unit is a member that can rotate about the yaw axis, and the second operating unit is a second posture changing unit. by the so capable of performing the operation first operation portion is rotatably supported about the roll axis, wherein the controller, when receiving the second operation command according to the rolling operation, the second operation command Based on the second drive source With Gosuru, as the second compensation control, so as to prevent or suppress the occurrence of the yaw behavior caused by the rolling operation, it controls the first driving source, the controller, in the second compensation control , Processing for generating a second target trajectory based on the second operation command, processing for generating a second normal uniaxial target value that is a target value of the first drive source based on the second target trajectory, A process of generating a second correction value that eliminates backlash in a direction opposite to the direction of the force received by the first operating unit from the second operating unit due to a roll operation; and the second normal uniaxial target value; Generating a second corrected one-axis target value that is a target value for controlling the first drive source based on the second correction value, and using the second corrected one-axis target value. And controlling the first drive source .

According to said structure, generation | occurrence | production of the 1st attitude | position change operation | movement resulting from 2nd attitude | position change operation | movement is prevented or suppressed by 2nd compensation control. That is, it is possible to effectively improve the trajectory accuracy and positioning accuracy of the distal end working unit when performing the second posture changing operation. Further, since the second corrected uniaxial target value is corrected by the second correction value that eliminates the influence of the play existing in the first power transmission mechanism, the second corrected uniaxial target value is generated. It is possible to effectively improve the trajectory accuracy and positioning accuracy of the distal end working unit when the second posture changing operation is performed. In addition, when the second operation unit is caused to perform the second posture changing operation, the first operation unit is operated in a direction opposite to the direction of the force received by the first operation unit from the second operation unit, thereby causing an influence of backlash. Therefore, it is possible to effectively prevent the occurrence of the operation of the first operation unit due to the backlash.

The shaft further includes a shaft provided with the tip operating portion at the tip, a second driving source, and a second power transmission mechanism that mechanically transmits the driving force of the second driving source to operate the second operating portion. The tip motion unit is configured to tilt with respect to a yaw axis that is not parallel to the axis of the shaft as a reference for the yaw motion as the first posture change motion, and to rotate with respect to the roll shaft that is directed toward the tip. A roll operation as a change operation is possible, the first operation unit is a member that can rotate around the yaw axis, and the second operation unit can perform a second posture change operation. When the controller receives the second operation command related to the roll operation, the second operation command based on the second operation command is supported by the first operation unit so as to be rotatable about the roll axis. Control drive source and second compensation As control, so as to prevent or suppress the occurrence of the yaw behavior caused by the rolling operation, the controls the first driving source, the controller, in the second compensation control, based on the second operation command Processing for generating a second target trajectory, processing for generating a second normal uniaxial target value that is a target value of the first drive source based on the second target trajectory, and elastic deformation of the first power transmission mechanism Based on the process of generating the second correction value that prevents or suppresses the occurrence of the operation of the first operation unit due to the first normal axis value and the second correction value, the first correction value performs a process of generating a second correction uniaxial target value is a target value for control of the driving source, may it controls the first driving source using the second correction uniaxial target value.

  According to the above configuration, the corrected one-axis target value is corrected by correcting the normal one-axis target value with the correction value that prevents or reduces the occurrence of the operation of the first operation unit due to the elastic deformation of the first power transmission mechanism. Since it produces | generates, generation | occurrence | production of the operation | movement of the 1st action part resulting from the elastic deformation of the 1st power transmission mechanism at the time of making the 2nd action part perform the 2nd posture change operation can be prevented effectively.

The second correction value in the second compensation control is caused by elastic deformation of the first power transmission mechanism in a high torque state in which interference torque to the first operation unit by the second operation unit is relatively high. More than the correction value for preventing occurrence of the operation of the first operating unit, and the first operating unit is caused by elastic deformation of the first power transmission mechanism in a low torque state where the interference torque is relatively low. It is preferable that the value is equal to or less than a correction value for preventing the occurrence of an operation.

According to the above configuration, the state of the end effector is obtained by using a value that is greater than or equal to the correction value corresponding to the low torque state and less than or equal to the correction value corresponding to the high torque state as the second correction value in the second compensation control. Or, without measuring or estimating the operating resistance of the second operating unit, it is possible to effectively improve the trajectory accuracy and positioning accuracy of the distal end operating unit when the second operating unit is caused to perform the second posture changing operation.

  The controller performs the second compensation control with a correction value corresponding to the low torque state when in the low torque state, and corresponds to the high torque state when the end effector is in the high torque state. The second compensation control may be performed with a correction value.

  According to the above configuration, since the second compensation control is performed with the correction values corresponding to the low torque state and the high torque state, the operation of the first operation unit due to the elastic deformation of the first power transmission mechanism is performed. Generation | occurrence | production can be prevented effectively.

  The controller may perform the second compensation control with a correction value corresponding to the measured or estimated operating resistance of the second operating unit.

  According to the above configuration, since the second compensation control is performed with the correction value corresponding to the measured or estimated operation resistance of the second operation unit, the operation of the first operation unit due to the elastic deformation of the first power transmission mechanism. Can be effectively prevented.

  The medical manipulator according to the present invention can improve the trajectory accuracy and positioning accuracy of the distal end working unit.

It is a perspective view of the medical manipulator concerning one embodiment of the present invention. It is a perspective view of a front-end | tip operation | movement part. It is a partial cross section side view of the manipulator main body in the state which isolate | separated the working part and the operation part. It is a partially omitted cross-sectional plan view of a working part. FIG. 5 is a schematic structural diagram of a mechanism for transmitting a driving force of a driving unit to a posture changing mechanism. It is a partially omitted side view showing a medical manipulator provided with a detection mechanism according to a first configuration example in a state where a working unit is mounted on an operation unit. It is a partially omitted side view of a medical manipulator provided with a detection mechanism according to a second configuration example. It is a functional block diagram of a medical manipulator. FIG. 9A is a first schematic explanatory view for explaining a corrected uniaxial target value when the tip operating unit performs a yaw operation, and FIG. 9B is a corrected uniaxial target value when the tip operating unit performs a yaw operation. FIG. 9C is a third schematic explanatory view illustrating a corrected one-axis target value when the yaw operation is performed by the distal end operating portion. FIG. 10A is a diagram illustrating a temporal change in the normal speed command value of the first motor when the tip operating unit performs the yaw operation, and FIG. 10B is a speed of the first motor when the tip operating unit performs the yaw operation. FIG. 10C is a diagram illustrating a change over time of the correction command value, and FIG. 10C is a diagram illustrating a change over time in the speed command value of the first motor when the tip operating unit performs a yaw operation. FIG. 11A is a first schematic explanatory view for explaining the influence on the yaw motion when the tip action portion performs the roll action, and FIG. 11B explains the influence on the yaw action when the tip action portion performs the roll action. FIG. 11C is a third schematic explanatory diagram for explaining the influence on the yaw motion when the tip motion section performs a roll motion. FIG. 12A is a first schematic explanatory diagram for explaining a uniaxial correction value when the tip operation unit performs a roll operation, and FIG. 12B explains a uniaxial correction value when the tip operation unit performs a roll operation. FIG. 12C is a third schematic explanatory view for explaining a uniaxial correction value when the tip operating portion performs a roll operation. FIG. 13A is a diagram illustrating a change over time in the normal speed command value of the second motor when the tip operation unit performs a roll operation, and FIG. 13B illustrates the speed of the first motor when the tip operation unit performs a roll operation. It is a figure which shows the time change of command value (speed correction value).

  DESCRIPTION OF EXEMPLARY EMBODIMENTS A medical manipulator (hereinafter referred to as a manipulator) according to the present invention will be described below with reference to preferred embodiments and with reference to the accompanying drawings.

  First, an overall configuration of a medical manipulator 10 according to an embodiment of the present invention will be described with reference to FIG. The manipulator 10 is a medical instrument for performing a predetermined treatment by grasping or touching a part of a living body with a distal end working unit 12 provided at the distal end. Usually, the manipulator 10 is a grasping forceps or a needle driver (holding tool). It is also called a needle).

  The manipulator 10 includes a manipulator main body 11 constituting a medical instrument, and a controller 29 connected to the manipulator main body 11 via a cable 28. The manipulator body 11 includes a body 21, a shaft 18 extending from the body 21, and a distal end working unit 12 provided at the distal end of the shaft.

  In the following description, the extending direction of the shaft 18 is defined as the Z direction, and the front (tip side) of the shaft 18 is defined as the Z1 direction and the rear (root side) is defined as the Z2 direction. Further, the right-and-left direction with respect to the manipulator body 11 when the manipulator body 11 is in the posture shown in FIG. 1 is the X direction, and in particular, the left side direction of the manipulator body 11 is the X1 direction, The right direction is defined as the X2 direction. Further, the vertical direction of the manipulator body 11 when the manipulator body 11 is in the posture shown in FIG. 1 is defined as the Y direction, and in particular, the upper direction is defined as the Y1 direction and the lower direction is defined as the Y2 direction. To do.

  Unless otherwise specified, the description of these directions is based on the case where the manipulator body 11 is in the reference posture (neutral posture). These directions are for convenience of explanation, and it is needless to say that the manipulator body 11 can be used in any direction (for example, upside down).

  The manipulator main body 11 includes an operation unit 14 that is gripped and operated by a hand and a work unit 16 that is detachable from the operation unit 14. The operation unit 14 constitutes a part of the body 21 described above, constitutes a housing, and a pair of left and right upper covers 25a and 25b extending in a substantially L shape in the Z1 direction and the Y2 direction, and the upper covers 25a and 25b. It has the drive part 30 accommodated in the inside, and the composite input part 24 operated manually.

  The drive unit 30 includes a first motor (first drive source) 50 a and a second motor (second drive source) 50 b as drive sources 50 for changing the posture of the distal end working unit 12. The force is mechanically transmitted to the distal end working unit 12 so that the posture of the distal end working unit 12 can be changed.

  The first motor and the second motor are provided with encoders 51a and 51b, respectively, and the operation angles (rotation angles) of the first motor 50a and the second motor 50b are detected by the encoders 51a and 51b, The first motor 50a and the second motor 50b are feedback controlled by the controller 29 using the detected angle as a feedback signal.

  A portion extending in the Y2 direction on the proximal end side of the operation unit 14 is configured as a grip handle 26 that is gripped by a hand. The composite input unit 24 provided on the upper portion of the grip handle 26 includes a rotation operation unit 90 and a tilt operation unit 92. By performing a rotation operation in the left-right direction with respect to the rotation operation unit 90 and a tilting operation with respect to the tilting operation unit 92 singly or in combination, a signal corresponding to the operation is transmitted to the controller 29, and the controller 29 receives the first motor and By controlling the driving of the second motor, the posture of the distal end working unit 12 is changed.

  The working unit 16 includes a pair of lower covers 37a and 37b divided substantially symmetrically in the Z direction as a housing. The distal end working unit 12 and the long and hollow provided with the distal end working unit 12 at the distal end are provided. The shaft 18, the base end side of the shaft 18 is fixed, the pulley box 32 accommodated in the lower covers 37a and 37b, the rear of the pulley box 32, and the axis in the X direction with the trigger shaft 39 as a fulcrum. And a trigger lever 36 pivotally supported at the center. The lower covers 37a and 37b, the pulley box 32, and the trigger lever 36 constitute a part of the body 21 described above.

  The working unit 16 is connected and fixed to the operation unit 14 by a pair of left and right attachment / detachment levers 40, 40 provided on the operation unit 14, and can be separated from the operation unit 14 by an opening operation of the attachment / detachment lever 40. It is possible to easily perform replacement work or the like at the operation site without using a simple instrument.

  The trigger lever 36 includes a trigger operator 36b configured to be hooked by an operator's finger, and an arm portion 36a provided on an upper portion of the trigger operator 36b. A trigger shaft 39 is provided at the arm portion 36a. By being pivotally supported by the shaft, the shaft is disposed so as to be swingable in the front-rear direction (Z direction) about the axis in the X direction.

  FIG. 2 is a perspective view of the distal end working unit 12. The distal end working unit 12 includes an end effector 19 that opens and closes, and a posture changing mechanism 13 that changes the posture of the end effector 19. The end effector 19 is configured to be openable and closable on the basis of a predetermined opening / closing operation axis, for example, as a gripper for gripping a part of the living body or a suture needle, or a scissor for cutting a part of the living body. The illustrated end effector 19 is configured as a gripper 19A.

  The end effector 19 opens and closes when a force based on a manual operation (push / pull operation) of the trigger lever 36 is mechanically transmitted. Specifically, the working unit 16 includes rods 83a and 83b (see FIGS. 3 and 4), wires 82a and 82b (see FIGS. 3 and 4) as power transmission members, pulleys, and the like. A transmission mechanism is provided, and a push / pull operation of the trigger lever 36 is converted into an opening / closing operation of the end effector 19 by the transmission mechanism.

  As a mechanism for converting the operation of the trigger lever 36 into the opening / closing operation of the end effector 19, for example, a configuration similar to the configuration described in Japanese Patent Application Laid-Open No. 2008-104855 and Japanese Patent Application Laid-Open No. 2009-106606 is adopted. It's okay.

  The posture changing mechanism 13 includes a yaw operation (first posture changing operation) that tilts with respect to the Y-direction yaw axis Oy, and a roll operation that rotates based on the roll axis Or (or Z axis in the neutral posture) that points toward the tip. Second posture changing operation). Since the yaw operation moves in a direction inclined with respect to the axis of the shaft 18, it can also be called a tilting operation. The posture changing mechanism 13 can perform a roll operation and a yaw operation selectively or in combination.

  In the case of the present embodiment, the posture change operation (yaw operation and roll operation) of the end effector 19 is driven by the drive source 50 based on the operation of the composite input unit 24, and the driving force of the drive source 50 is the tip operation unit. This is done by being mechanically transmitted to 12.

  The distal end working unit 12 and the shaft 18 are configured to have a small diameter and can be inserted into the body cavity 22 through a cylindrical trocar 20 attached to the patient's abdomen or the like, and by operation of the composite input unit 24 and the trigger lever 36. Various procedures such as excision of the affected area, grasping, suturing and ligation can be performed in the body cavity 22.

  The controller 29 shown in FIG. 1 is a control unit that comprehensively controls the manipulator body 11 and is connected to a cable 28 that extends from the lower end of the grip handle 26. A part or all of the functions of the controller 29 can be integrally mounted on the operation unit 14, for example. The controller 29 includes a plurality (three in the illustrated example) of connection ports 27a to 27c, and can control the three manipulator bodies 11 independently and simultaneously.

  Next, a mechanism for mechanically transmitting the driving force of the driving source 50 to the distal end working unit 12 will be described. Here, FIG. 3 is a partially sectional side view of the manipulator main body 11 in a state where the working unit 16 and the operation unit 14 are separated, and FIG. 4 is a partially omitted sectional plan view of the working unit 16. In the working unit 16, two rods 83a and 83b that are components of a mechanism that transmits the operation force input to the trigger lever 36 to the end effector 19 are arranged in the Y direction and extend in the Z direction. The rods 83a and 83b have their distal ends (ends on the Z1 direction side) reaching the cavity 66 constituting the pulley box 32.

  Further, wires 82a and 82b (cord) that are inserted through the shaft 18 and extend to the distal end working unit 12 (see FIG. 1) are connected to the distal ends of the rods 83a and 83b, respectively. The ends of the wires 82a, 82b on the Z1 direction side are engaged with an opening / closing mechanism (not shown) for driving the end effector 19 of the distal end working unit 12, and the wire 82a, The opening / closing mechanism is driven by the forward / backward movement of 82b, and the end effector 19 is opened / closed.

  As shown in FIGS. 3 and 4, a pair of pin holes 84 and 84 that are symmetrical with respect to the Z direction are formed on the Z2 side of the pulley box 32. A pair of guide pins 86, 86 projecting from the bottom surface of the bracket 52 in the Y1 direction are inserted into the pin holes 84, 84 when the working unit 16 and the operating unit 14 are mounted. The part 16 is positioned and mounted with high rigidity.

  The drive unit 30 converts the rotation directions of the first and second motors 50a and 50b, the bracket 52 that supports the first and second motors 50a and 50b, and the first and second motors 50a and 50b. And a gear mechanism 54 that transmits to the working unit 16 side. The gear mechanism 54 includes drive bevel gears 58a and 58b fixed to the output shafts 56a and 56b of the first motor 50a and the second motor 50b, and driven bevel gears 62a and 62b that mesh with the drive bevel gears 58a and 58b, respectively. Have.

  Drive shafts 60a and 60b are fixed to the driven bevel gears 62a and 62b, respectively. The drive shafts 60a and 60b are spaced apart in the X direction and arranged in parallel to each other, and are rotatably supported by the bracket 52 by a bearing (not shown). Engagement projections 64a and 64b are provided at the lower ends of the drive shafts 60a and 60b, respectively. The engaging protrusions 64a and 64b can be formed in, for example, a tapered shape with a corrugated cross-sectional hexagonal shape.

  The pulley box 32 provided in the working unit 16 includes a hollow portion 66 that is open on both sides in the X direction, and driving pulleys (driven shafts) 70a and 70b and guide members 72a and 72b housed in the hollow portion 66. The shaft 18 is fixed and supported by a hole that penetrates the cavity 66 on the Z1 side.

  The drive pulleys 70a and 70b are spaced apart from each other in the X direction and are arranged in parallel to each other, and an engagement recess 74a that can be engaged with the engagement protrusions 64a and 64b on the drive shafts 60a and 60b side at the upper end thereof. 74b. The engaging recesses 74a and 74b can be engaged (fitted) with the engaging protrusions 64a and 64b. For example, the engaging recesses 74a and 74b have recesses having a tapered corrugated shape with a corrugated cross section.

  In a state where the working unit 16 is mounted on the operation unit 14, the engaging convex portions 64a and 64b and the engaging concave portions 74a and 74b are engaged. Thereby, the rotational driving force of the drive shafts 60a and 60b is transmitted to the drive pulleys 70a and 70b via the engaging convex portions 64a and 64b and the engaging concave portions 74a and 74b. The engagement structure of the engagement convex part 64a and the engagement concave part 74a may be another structure.

  As shown in FIG. 4, the guide members 72a and 72b are disposed on the Z1 side of the drive pulleys 70a and 70b, and the interval between the outer peripheral surfaces of the guide members 72a and 72b is larger than the interval between the outer peripheral surfaces of the drive pulleys 70a and 70b. It is set narrowly. The wires (corresponding bodies) 80 a and 80 b are wound around the drive pulleys 70 a and 70 b, guided by the guide members 72 a and 72 b, and inserted into the shaft 18.

  FIG. 5 is a schematic structural diagram of the posture changing mechanism 13, the first power transmission mechanism, and the second power transmission mechanism. The posture changing mechanism 13 includes a main shaft member (first operation unit) 100 that can rotate around a yaw axis (tilting axis) Oy that is not parallel to the axis of the shaft 18, and a roll axis Or that matches the axis of the main shaft member. A gear body 102 (first operating portion) supported by the main shaft member so as to be rotatable about the center, and a gear body 104 which meshes with the gear body 102 and is supported rotatably about the yaw axis Oy.

  The main shaft member 100 can be rotated around the yaw axis Oy by a shaft 106 provided at the tip of the shaft 18. A front portion of the main shaft member 100 is configured as a cylindrical tube portion 100a, and a driven pulley 100b around which a wire 80a is wound is integrally provided at the base end portion of the main shaft member 100. Part of the wire 80a is fixed to the driven pulley 100b by a predetermined fixing means, thereby preventing slippage between the wire 80a and the driven pulley 100b.

  Since the main shaft member 100 can rotate around the yaw axis Oy, the driven pulley 100b is rotationally driven by the wire 80a, so that the main shaft member 100 integrally provided with the driven pulley 100b is It rotates about the axis Oy.

  The gear body 102 is fixed to the tip cover 108 and is supported on the outer periphery of the cylindrical portion 100a of the main shaft member 100 in a state where the gear body 102 is rotatable about the roll axis Or and restricted in the direction of the roll axis Or. . A face gear 110 that meshes with the gear 104b is provided on the end surface of the gear body 102 in the Z2 direction.

  The gear body 104 has a driven pulley 104a around which a wire 80b is wound, and a gear 104b provided concentrically on the driven pulley 104a, and is rotatably supported by a shaft 106. A part of the wire 80b wound around the driven pulley 104a is fixed to the driven pulley 104a by a predetermined fixing means, thereby preventing slippage between the driven pulley 104a and the driven pulley 104a.

  In the posture changing mechanism 13 configured as described above, when the driven pulley 100b is rotated, the main shaft member 100 integrally provided with the driven pulley 100b rotates about the yaw axis Oy, and the gear body 102, The tip cover 108 and the end effector 19 are tilted integrally with the main shaft member 100 about the yaw axis Oy. That is, the yaw operation of the posture changing mechanism 13 is performed.

  On the other hand, when the gear body 104 is rotated, the gear body 102 is rotated about the roll axis Or by the gear body 104, and the tip cover 108 and the end effector 19 are rotated about the roll axis Or integrally with the gear body 102. To do. That is, the roll operation of the posture changing mechanism 13 is performed.

  The first power transmission mechanism 112 a is a mechanism that mechanically transmits the driving force of the first motor 50 a to the main shaft member 100 so as to operate the main shaft member 100. Therefore, the driving bevel gear 58a, the driven bevel gear 62a, the engaging convex portion 64a, the engaging concave portion 74a, the driving pulley 70a, and the wire 80a described above are components of the first power transmission mechanism 112a. There is a backlash on the power transmission path in the first power transmission mechanism 112a. In the case of the first power transmission mechanism 112a of the illustrated example, a reduction gear (not shown), a meshing portion of the driving bevel gear 58a and the driven bevel gear 62a constituting the gear mechanism portion 54, and an engaging convex portion 64a and an engaging concave portion 74a. Since there is a slight backlash in each of the engaging portions, the sum of these backlashes is the backlash present in the first power transmission mechanism 112a.

  The second power transmission mechanism 112b is a mechanism that mechanically transmits the driving force of the second motor 50b to the gear body 102 so as to rotate the gear body 102. Therefore, the driving bevel gear 58b, the driven bevel gear 62b, the engaging convex portion 64b, the engaging concave portion 74b, the driving pulley 70b, and the wire 80b described above are components of the second power transmission mechanism 112b. Note that the backlash exists on the power transmission path of the second power transmission mechanism 112b as in the first power transmission mechanism 112a.

  As shown in FIG. 6, the manipulator body 11 further includes a detection mechanism 120 according to a first configuration example that detects an operation state of the trigger lever 36. The detection mechanism 120 shown in FIG. 6 is configured to detect that the trigger lever 36 has reached the pulling position. In other words, the detection mechanism 120 detects that the trigger lever 36 has reached the operating position corresponding to the state where the gripper 19A as the end effector 19 is closed or almost closed.

  With respect to the trigger lever 36, the “pushing position” means a position where the trigger lever 36 is sufficiently pushed out (a position where the trigger lever 36 is most rotated in the Z1 direction) or a position in the vicinity thereof. Further, regarding the trigger lever 36, the “pull position” means a position where the trigger lever 36 is sufficiently pulled (a position where the trigger lever 36 is most rotated in the Z2 direction) or a position near the position. In FIG. 6, the trigger lever 36 when in the pushing position is drawn with a solid line, and the trigger lever 36 when in the pulling position is drawn with a two-dot chain line.

  The detection mechanism 120 includes a cam body (detection protruding piece) 122 provided on the trigger lever 36 and a detection unit 124 provided on the operation unit 14. The cam body 122 is fixed (provided) to the arm portion 36a of the trigger lever 36, and is provided so as to protrude in the Z2 direction in the illustrated example, and operates integrally with the trigger lever 36. That is, when the trigger lever 36 swings in the front-rear direction (Z direction), the cam body 122 also swings about the trigger shaft 39 as a rotation fulcrum.

  The detection unit 124 is provided at a position facing the cam body 122 in the operation unit 14 in a state where the work unit 16 is mounted on the operation unit 14, and the detection unit 124 cams in a state where the work unit 16 is mounted on the operation unit 14. By detecting the body 122, it is detected that the trigger lever 36 has reached the pulling position.

  The detecting unit 124 in the illustrated example includes a working rod 126 that is pressed by the cam body 122 and moves in the Z direction, and a cylindrical guide member 128 through which the working rod 126 is inserted to guide the movement of the working body. The tact switch 130 is pressed by the actuating rod 126. The end of the actuating rod 126 on the Z1 side protrudes toward the cam body 122, and is biased in the Z1 direction by a spring (not shown), and is prevented from coming out toward the cam body 122 by a locking member (not shown). The tact switch 130 is fixed to a switch board 132 provided inside the operation unit 14, and the switch board 132 is electrically connected to the controller 29 via the cable 28, and a signal output from the switch board 132. Is transmitted to the controller 29.

  In the detection mechanism 120 configured as described above, when the trigger lever 36 is in the push-out position, the cam body 122 does not push the operating rod 126 in the Z2 direction, so that the tact switch 130 is not pressed by the operating rod 126. On the other hand, when the trigger lever 36 is rotated in the Z2 direction in FIG. 6 and reaches the pulling position, the cam body 122 presses and moves the operating rod 126 in the Z2 direction, and the tact switch 130 is pressed by the operating rod 126. The Then, a signal corresponding to the depression is output from the tact switch 130, and this signal is transmitted to the controller 29, whereby the controller 29 recognizes (detects) that the trigger lever 36 has reached the pulling position. The

  The detection mechanism 120 in the illustrated example is configured to detect that the trigger lever 36 has reached the pulling position, but instead, is configured to detect that the trigger lever 36 has reached the push-out position. May be. The detection mechanism 120 may be configured to detect both when the trigger lever 36 reaches the pulling position and when the trigger lever 36 reaches the pushing position. In the detection mechanism 120, the cam body 122 may be provided in the trigger operator 36b, and the detection unit 124 may be provided in the grip handle 26.

  Thus, in the manipulator 10, since the detection mechanism 120 detects that the trigger lever 36 has reached the pulling position or the pushing position, it is possible to grasp the usage state of the trigger lever 36. For example, when it is detected that the trigger lever 36 is in the pulling position, the controller 29 is in a “gripping state” in which the end effector 19 grips a gripping target (for example, a part of a living tissue, a curved needle, etc.). You may recognize it. If it is not detected that the trigger lever 36 is in the pulling position, the controller 29 may recognize that the end effector 19 is in a “non-gripping state” in which the object is not gripped.

  Note that the detection unit 124 of the detection mechanism 120 may be provided with a photosensor including a projector and a light receiver instead of the tact switch 130. When such a photosensor is provided, the projector and the light receiver are arranged so that when the trigger lever 36 comes to the pulling position, the operating rod 126 enters between the light projector and the light receiver and blocks light from the light projector. Thus, it can be detected that the trigger lever 36 has reached the pulling position. Further, a magnetic sensor, a proximity sensor, or the like may be used as other sensing means instead of the tact switch 130.

  Next, a detection mechanism 140 according to a second configuration example will be described with reference to FIG. The detection mechanism 140 is configured to detect the operation direction of the trigger lever 36, that is, the position in the rotation direction. As shown in FIG. 7, the trigger lever 36 has a movable range of an angle θ from the most advanced position P1 rotated to the most Z1 side to the last retracted position P2 rotated to the most Z2 side.

  The detection mechanism 140 includes a drive element 142 that operates integrally with the trigger lever 36, a driven element 144 that is provided in the operation unit 14 and that is linked to the drive element 142 in a state where the work unit 16 is mounted on the operation unit 14, and a driven And a detection unit 146 that detects the position of the element 144 in the operation direction. In the illustrated example, the drive element 142 is a first gear portion 142A having teeth extending in the circumferential direction around the rotation axis of the trigger lever 36, and the driven element 144 is rotatably provided on the operation portion 14. The second gear unit 144A meshes with the first gear unit 142A in a state where the working unit 16 is mounted on the operation unit 14, and the detection unit 146 is a rotation detector 146A that detects the rotation angle of the second gear unit 144A. is there.

  The first gear portion 142A is provided to rotate integrally with the trigger lever 36. That is, the first gear portion 142A is fixed to a trigger shaft 39 that rotates integrally with the trigger lever 36, and when the trigger lever 36 rotates in the front-rear direction (Z direction), the first gear portion 142A is also triggered. The shaft 39 is rotated about the rotation fulcrum. In the illustrated first gear portion 142A, teeth are formed on the entire circumference. However, if the first gear portion 142A can mesh with the second gear portion 144A in the entire movable range of the trigger lever 36, it is only on a part of the outer periphery. Teeth may be formed.

  The second gear portion 144A is provided on the side surface of the upper cover 25b. The rotation detector 146A is provided inside the upper covers 25a and 25b. The second gear portion 144A and the rotation detector 146A are connected via a shaft 148 that passes through the upper covers 25a and 25b. A seal member (not shown) (for example, an O-ring) is disposed between the upper covers 25a and 25b and the shaft, and the seal member prevents liquid and dust from entering the inside 23 of the upper covers 25a and 25b from the outside. Is done.

  As the rotation detector 146A, for example, a rotary encoder, a potentiometer, a resolver, or the like can be used. As the rotary encoder, there are an incremental encoder and an absolute encoder, either of which may be used. The rotation detector 146A is electrically connected to the controller 29 via the cable 28, and a signal output from the rotation detector 146A is transmitted to the controller 29.

  In the detection mechanism 140 configured as described above, when the trigger lever 36 is rotated, the first gear portion 142A provided in the trigger lever 36 rotates about the trigger shaft 39 integrally with the trigger lever 36. To do. As the first gear portion 142A rotates, the second gear portion 144A that meshes with the first gear portion 142A rotates, and the rotation angle of the second gear portion 144A is detected by the rotation detector 146A, and the operation of the trigger lever 36 is performed. An angle is detected. That is, a signal corresponding to the rotation angle is output from the rotation detector 146A, and this signal is transmitted to the controller 29. The controller 29 calculates the operating angle of the trigger lever 36 based on the signal from the rotation detector 146A. .

  When the rotation detector 146A is an incremental encoder, only pulses are output from the incremental encoder according to the change in the rotation angle, and the absolute angle of the trigger lever 36 cannot be directly detected. On the other hand, since the movable range (maximum rotation angle) θ of the trigger lever 36 is known, the absolute angle of the trigger lever 36 can be estimated from the rotation angle range in use. Therefore, when rotation detector 146A is an incremental encoder, controller 29 uses trigger lever 36 based on the movable range θ of trigger lever 36 and the rotation angle range detected by rotation detector 146A when manipulator body 11 is used. 36 absolute angles are estimated (calculated). Thus, by estimating the absolute angle of the trigger lever 36 from the detection signal of the incremental encoder, the operation angle of the trigger lever 36 can be detected with a simple configuration.

  In the manipulator 10 equipped with the detection mechanism 140, the operating angle of the trigger lever 36 is detected at every predetermined sampling time while the manipulator body 11 is used. Therefore, it can be detected that the trigger lever 36 is in the pushing position (P1 or its vicinity), the pulling position (P2 or its vicinity), or a position between the pushing position and the pulling position. When the controller 29 detects that the trigger lever 36 is in the pulling position, the controller 29 recognizes that the end effector 19 is in the “gripping state”, and detects that the trigger lever 36 is in a position other than the pulling position. May recognize that the end effector 19 is in the “non-gripping state”.

  A magnetic coupling may be adopted as a mechanism for transmitting the rotation of the trigger lever 36 to the rotation detector 146A. That is, at least one of the drive element 142 provided on the trigger lever 36 and the driven element 144 provided on the operation unit 14 is configured as a disk on which a permanent magnet is disposed, and the other is a disk on which a permanent magnet is disposed or A magnetic coupling may be configured by the driving element 142 and the driven element 144 configured as described above as a disk made of a ferromagnetic material.

  Incidentally, as described above, the first power transmission mechanism 112a (see FIG. 5) that transmits the driving force of the first motor 50a to the main shaft member 100 normally has backlash. Even if the motor 50a operates, the main shaft member 100 does not rotate around the yaw axis Oy, and eventually the tip operation unit 12 is not rolled. For this reason, the roll operation may be delayed with respect to the input operation to the rotation operation unit 90, and there is a concern that the trajectory accuracy and positioning accuracy of the distal end operation unit 12 may be lowered.

  In order to cope with this, in the manipulator 10 according to the present embodiment, when the controller 29 receives the yaw axis operation command (the first operation command related to the first posture changing operation) from the tilt operation unit 92, the first As compensation control, the first motor 50a is controlled so as to compensate for the backlash present in the first power transmission mechanism 112a. That is, the controller 29 performs control to compensate for the backlash by feedforward control or the like in order to perform more precise yaw motion attitude control.

  The first compensation control will be described with reference to FIG. FIG. 8 is a functional block diagram of the manipulator 10. When the tilt operation unit 92 is operated to perform the yaw operation, a yaw axis operation command c1 corresponding to the operation amount is output, and the output yaw axis operation command c1 is generated by the yaw axis target trajectory generation provided in the controller 29. Input to means 150. The yaw axis target trajectory generating means 150 generates a target value (hereinafter referred to as a yaw axis target value v1) of the yaw axis (spindle member 100) according to the yaw axis operation command c1, and the generated yaw axis target value v1 is The first correction value generation unit 156 and the normal 1-axis / bi-axis target trajectory generation unit 154 are input.

  The normal one-axis / two-axis target trajectory generating means 154 solves the interference matrix based on the yaw axis target value v1 and the target value of the roll axis (gear body 102) (hereinafter referred to as roll axis target value v2). This is means for generating target values for control of the first motor 50a and the first motor 50b (hereinafter referred to as a normal 1-axis target value v3 and a normal 2-axis target value v4, respectively). In the posture changing mechanism 13, since there is a mechanical interference between the mechanism for performing the yaw axis operation and the mechanism for performing the roll operation, the first motor 50a and the first motor 50a and the first motor are prevented so as not to cause operation interference with each other. It is necessary to control the motor 50b.

  For example, in order to rotate the main shaft member 100 about the yaw axis Oy without rotating the gear body 102 about the roll axis Or, not only the first motor 50a is driven and the main shaft member 100 is rotated, It is necessary to drive the second motor 50b to rotate the gear body 104 in the same direction and at the same angle as the main shaft member 100. Further, when performing the roll operation and the yaw operation in combination, in order to perform the roll operation in the rotation direction and the rotation amount instructed by the input operation to the rotation operation unit 90, the second motor is expected in consideration of the interference due to the yaw operation. It is necessary to rotate 50b.

  The first correction value generation unit 156 generates a correction value (hereinafter, referred to as a first correction value v5) that eliminates the influence of backlash existing in the first power transmission mechanism 112a when performing the yaw operation. The generated first correction value v5 and the normal uniaxial target value v3 are input to the corrected uniaxial target trajectory generating means 160. The corrected uniaxial target trajectory generating means 160 calculates a corrected uniaxial target value v7 (target value obtained by correcting the normal uniaxial target value v3 with the first correction value v5) from the first corrected value v5 and the normal uniaxial target value v3. Generate.

  The generated corrected one-axis target value v7 is input to the first motor control means 162. On the other hand, the normal two-axis target value v4 generated by the normal one-axis / two-axis target trajectory generating means 154 is input to the second motor control means 164. The first motor control means 162 and the second motor control means 164 are motor drivers that drive and control the first motor 50a and the second motor 50b, respectively.

  The first motor 50a and the second motor 50b provided in the operation unit 14 have their operating angles corrected by the first motor control means 162 and the second motor control means 164, respectively, as corrected one-axis target value v7 and regular two-axis target value v4. Feedback control is performed so that In this case, output signals from encoders 51a and 51b (see FIG. 1) attached to the first motor 50a and the second motor 50b, respectively, become feedback signals in feedback control. As the first motor 50a and the second motor 50b are driven and controlled in this way, the main shaft member 100 is rotationally driven via the first power transmission mechanism 112a (see FIG. 5) based on the driving of the first motor 50a. At the same time, the gear body 104 is rotationally driven via the second power transmission mechanism 112b based on the driving of the second motor 50b. In this case, the corrected one-axis target value v7 of the first motor 50a is a target value compensated so as to eliminate the influence of the play existing in the first power transmission mechanism 112a. A yaw operation with attitude control is performed.

  In the following description, only when referring to FIG. 8, the above-described yaw axis target value, roll axis target value, normal 1 axis target value, normal 2 axis target value, first correction value, second correction value, and correction 1 Assume that reference numerals v1 to v7 are respectively attached to the axis target values.

  Next, with reference to FIG. 9A to FIG. 9C, a method for generating the first correction standard value when the tip operating unit 12 performs the yaw motion will be described. As shown in FIG. 9A, it is assumed that there is a backlash of the same size in the positive direction and the negative direction of the normal uniaxial target value.

  In this case, when the operating angle of the first motor 50a is moved in the positive direction in FIG. 9A (when there is a speed command in the positive direction), the corrected one-axis target value (that is, in the control of the first motor 50a) (Target value) is obtained by adding the final value of the first correction value to the normal uniaxial target value. Here, the final value of the first correction value corresponds to the size of the play existing in the first power transmission mechanism 112a (size of play in the positive direction and the negative direction with respect to the normal uniaxial target value). On the other hand, the corrected uniaxial target value when the operating angle of the first motor 50a is moved in the negative direction (when the negative speed command is issued) is obtained by subtracting the first corrected value final value from the normal uniaxial target value. It will be a thing.

  As described above, the normal uniaxial target value is corrected in the positive direction or the negative direction by an amount corresponding to the backlash according to the operation direction of the first motor 50a, so that the yaw operation in which the backlash is compensated is performed. Done. .

  The example shown in FIG. 9A explains the basic concept of the first compensation control. However, in actual control, the control target value changes every predetermined sampling time, and the first correction value is also set. Generated (calculated) at every sampling time. For this reason, in terms of control, a correction uniaxial target value is obtained by adding or subtracting the correction amount of the first correction value to be corrected to the current first correction value.

  For example, as shown in FIG. 9B, the corrected one-axis target value when the operating angle of the first motor 50a is moved in the positive direction is the first correction value to be corrected to the current first correction value (negative correction value). This is the sum of the correction amounts of the correction values (= normal uniaxial target value + first correction value final value). As shown in FIG. 9C, the corrected one-axis target value when the operating angle of the first motor 50a is moved in the negative direction is the first correction value to be corrected from the current first correction value (negative correction value). Is obtained by subtracting the correction amount (= normal uniaxial target value−first correction value final value).

  Normally, the current first correction value is a positive or negative first correction value final value. When a speed command in the positive direction is issued when the current first correction value is the positive first correction value final value, the first correction value does not change with the positive first correction value final value. On the other hand, when a speed command in the negative direction is issued when the current first correction value is the positive first correction value final value, the change amount of the first correction value is −2 × first correction value final value, Eventually, the first correction value becomes the negative first correction value final value.

  As described above, according to the manipulator 10 according to this embodiment, the controller 29 performs the first compensation control, so that the main shaft member 100 is in a state similar to that in which the backlash present in the first power transmission mechanism 112a is eliminated. Can be operated. For this reason, the positional accuracy of the main shaft member 100 is improved, and the operability is improved. In the first compensation control, the corrected uniaxial target value is generated by correcting the normal uniaxial target value with the first correction value that eliminates the influence of the play existing in the first power transmission mechanism 112a. The locus accuracy and positioning accuracy of the portion 12 can be effectively improved.

  Next, a method for generating a speed command value for the first motor 50a when performing a yaw operation will be described with reference to FIGS. 10A to 10C.

  FIG. 10A shows the change over time of the normal speed command value of the first motor 50a. The normal speed command value of the first motor 50a is a command value corresponding to the normal uniaxial target value, and is generated based on the yaw axis operation command from the tilt operation unit 92 (see FIG. 1). When the command from the tilt operation unit 92 is stepped such as on / off of a switch, it is preferable that a smooth speed command signal as shown in FIG.

  FIG. 10B shows the time change of the speed correction command value of the first motor 50a. The speed correction command value of the first motor 50a is a speed command value corresponding to the first correction value, and is generated by a function having the normal speed command value shown in FIG. 10A as a variable. For example, this function may calculate a speed correction command value proportional to the normal speed command value of the first motor 50a. By using such a function, the acceleration based on the speed correction command value is performed in synchronization with the acceleration based on the normal speed command value, so that the correction for eliminating the backlash of the first power transmission mechanism 112a can be performed without difficulty. .

  When the integral value of the speed correction command value (the area of the portion indicated by S1 in FIG. 10B) reaches the final value of the first correction value, the speed command is set to zero. As shown in FIG. 10C, the uniaxial speed command value that is the speed command value (corrected speed command value) of the first motor 50a is obtained by adding the speed correction command value to the normal speed command value.

  In the above description, there has been a concern about a decrease in the trajectory accuracy and positioning accuracy of the distal end working unit 12 due to backlash existing in the first power transmission mechanism 112a. However, there is a concern that the following yaw operation may occur during the roll operation. . That is, when the gear body 102 (see FIG. 5) is rotated to perform the roll operation, the main shaft member 100 that supports the gear body 102 receives a force from the gear body 102, and at this time, the first power transmission mechanism 112a. The tip action unit 12 may perform a yaw action due to the backlash. Such a yaw operation can also occur when the rigidity of the first power transmission mechanism 112a is not sufficient for the following reason.

  For example, in a state where the trigger lever 36 is pulled to the pulling position, the gear body 102 is pressed against the main shaft member 100 in the axial direction (Z2 direction), so that the rotational resistance (operation resistance) of the gear body 102 increases. In a state where the trigger lever 36 is pushed out to the pushing position, the gear body 102 is pressed against the main shaft member 100 in the axial direction (Z1 direction), so that the rotational resistance of the gear body 102 increases.

  When the end effector 19 is to be rolled by rotating the gear body 104 (see FIG. 5) and rotating the gear body 102 meshing with the gear body 104, the gear body 102 tries to rotate about the roll axis Or. In addition to this, it also acts as torque (hereinafter referred to as interference torque) for rotating the main shaft member 100 about the yaw axis Oy. Then, the first power transmission mechanism 112a receives the torque for rotating the main shaft member 100 around the yaw axis Oy. For this reason, when the rigidity of the first power transmission mechanism 112a is not sufficient, a component (wire or the like) of the first power transmission mechanism 112a may be elastically deformed to generate a yaw operation.

  In order to cope with this, in the manipulator 10 according to the present embodiment, when the controller 29 receives a roll operation command (second operation command related to the second posture changing operation) from the rotation operation unit 90, the second compensation is performed. As the control, the first motor 50a is controlled so as to prevent or suppress the occurrence of the yaw motion due to the roll motion. In other words, the controller 29 performs control to compensate for the effects of backlash existing in the first power transmission mechanism 112a and elastic deformation of the first power transmission mechanism 112a by feedforward control or the like in order to perform more precise posture control.

  The outline of the second compensation control will be described first with reference to FIG. When the rotation operation unit 90 is operated to perform a roll operation, a roll axis operation command c2 corresponding to the operation amount is output. The output roll axis operation command c2 is generated by a roll axis target trajectory generation provided in the controller 29. Input to means 152. The roll axis target trajectory generating means 152 generates a target trajectory (target value) of the roll axis (gear body 102) according to the roll axis operation command c2, and the generated target trajectories are normal 1-axis and 2-axis target trajectories. The data is input to the generation unit 154 and the second correction value generation unit 158. The normal one-axis / two-axis target trajectory generating means 154 generates a normal one-axis target value v3 and a normal two-axis target value v4.

  When the controller 29 receives the roll axis operation command c2, the second correction value generation unit 158 is able to reduce the backlash present in the first power transmission mechanism 112a and the influence of the elastic deformation of the first power transmission mechanism 112a due to the interference torque. A correction value to be lost (hereinafter referred to as a second correction value v6) is generated. The generated second correction value v6 and the normal uniaxial target value v3 are input to the corrected uniaxial target trajectory generating means 160. The corrected one-axis target trajectory generating means 160 calculates a corrected one-axis target value v7 (in this case, a target obtained by correcting the normal one-axis target value v3 with the second correction value v6) from the first correction value v5 and the normal one-axis target value v3. Value).

  The generated corrected one-axis target value v7 is input to the first motor control means 162. On the other hand, the normal two-axis target value v4 generated by the normal one-axis / two-axis target trajectory generating means 154 is input to the second motor control means 164.

  The first motor 50a and the second motor 50b provided in the operation unit 14 have their operating angles corrected by the first motor control means 162 and the second motor control means 164, respectively, as corrected one-axis target value v7 and regular two-axis target value v4. Feedback control is performed so that By controlling the driving of the second motor 50b in this way, the gear body 104 is rotationally driven via the second power transmission mechanism 112b based on the driving of the second motor 50b and the driving of the first motor 50a. Based on this, the main shaft member 100 is rotationally driven via the first power transmission mechanism 112a.

  In this case, the corrected one-axis target value v7 of the first motor 50a is a target value that has been compensated so as to eliminate the effects of backlash and elastic deformation of the first power transmission mechanism 112a. The yaw motion resulting from the motion does not occur, and the roll motion is performed under the action of highly accurate posture control.

  Next, with reference to FIGS. 11A to 11C, the influence on the yaw operation when the tip operation unit 12 performs the roll operation will be described. Here, only the influence of the play existing in the first power transmission mechanism 112a is focused, and the influence of the elastic deformation of the first power transmission mechanism 112a due to the interference torque is not considered. Compensation in consideration of the influence of elastic deformation of the first power transmission mechanism 112a will be described later.

  When causing the distal end working unit 12 to roll in the forward direction (when rotating the gear body 102 in the forward direction), the main shaft member 100 also receives the interference torque in the forward direction. As a result, regardless of the magnitude of the interference torque, as shown in the lower side of FIG. That is, the yaw motion resulting from the roll motion occurs in the positive direction.

  When the direction of the roll operation is the positive direction, as shown in FIG. 11B, the uniaxial target value, which is the target value of the first motor 50a, is corrected in the negative direction by the backlash (the backlash is erased). Since the main shaft member 100 is not moved in the forward direction and the yaw motion due to the roll motion does not occur.

  When the direction of the roll operation is the positive direction, as shown in FIG. 11C, if the uniaxial target value is corrected by the backlash in the forward direction (when the backlash is erased to the opposite side). The main shaft member 100 is moved in the positive direction by two backlashes in the positive direction and the negative direction. That is, the yaw motion resulting from the roll motion occurs in the positive direction.

  Next, with reference to FIGS. 12A to 12C, a method for generating the second correction value when the tip operating unit 12 performs a roll operation will be described. In FIGS. 12A to 12C, it is assumed that the direction of the roll operation is the positive direction.

  FIG. 12A shows a correction method corresponding to the case of FIG. 11A. When the current second correction value is 0, the corrected second correction value becomes the negative second correction value final value. In this case, the amount of change in correction is the same as the final value of the second correction value. Here, the final value of the second correction value corresponds to the amount of play existing in the first power transmission mechanism 112a (the amount of play in the positive and negative directions with respect to the normal uniaxial target value). As described above, the second correction value is a correction value for correcting the target value of the main shaft member 100 in the direction opposite to the direction of the force that the main shaft member 100 receives from the gear body 102.

  FIG. 12B shows a correction method corresponding to the case of FIG. 11B. When the current second correction value is a negative second correction value final value, the corrected second correction value is a positive second correction value final value. The value remains unchanged. In this case, the amount of change in correction is zero.

  FIG. 12C shows a correction method corresponding to the case of FIG. 11C. When the current second correction value is a positive second correction value final value, the corrected second correction value is the negative second correction value final value. Value. In this case, the amount of change in correction is twice the final value of the second correction value.

  As described above, according to the manipulator 10 according to the present embodiment, the controller 29 performs the second compensation control, thereby eliminating the influence of the backlash of the first power transmission mechanism 112a when performing the roll operation. Occurrence of yaw motion due to roll motion can be prevented or suppressed, and operability can be improved. In the second compensation control, the normal uniaxial target value is corrected with a correction value that eliminates the influence of the first power transmission mechanism 112a to generate the corrected uniaxial target value. It is possible to effectively prevent the yaw movement caused by the play and the elastic deformation during the operation. Further, in the second compensation control, the main shaft member 100 is operated in the direction opposite to the direction of the force received by the main shaft member 100 from the gear body 102, thereby eliminating the influence of play. Can be more effectively prevented.

  Next, a method for generating speed command values for the first motor 50a and the first motor 50b when performing the second compensation control will be described with reference to FIGS. 13A and 13B.

  FIG. 13A shows a change over time of a command value (biaxial speed command value) corresponding to a normal biaxial target value that is a target value for control of the second motor 50b. When the command from the rotation operation unit 90 is stepped such as on / off of a switch, it is preferable to perform a filtering process or the like to obtain a smooth speed command signal as shown in FIG. 13A.

  FIG. 13B shows the speed command value of the first motor 50 a when there is no yaw operation command from the tilt operation unit 92 and only the roll operation command from the rotation operation unit 90. In this case, the speed command value is only the speed correction command value corresponding to the second correction value. As shown in FIG. 13B, the speed correction command value of the first motor 50a is generated by a function having the speed command value of the second motor 50b as a variable.

  For example, this function may calculate a speed correction command value proportional to the speed command value of the first motor 50a. By using such a function, the correction that eliminates the backlash of the first power transmission mechanism 112a is performed in synchronization with the start of the roll operation, so that the correction can be performed at an appropriate timing.

  When the integral value of the speed correction command value (the area of the portion indicated by symbol S2 in FIG. 13B) reaches the final value of the second correction value, the speed command is set to zero. Thereby, the main shaft member 100 can be moved by the second correction value final value.

  When there is a yaw operation command from the tilt operation unit 92 in parallel with the roll operation command from the rotation operation unit 90, the speed command value of the first motor 50a is the normal speed command value shown in FIG. 10A. The command value is obtained by adding the speed correction command value shown in FIG. 13B.

  In the above description, the second correction value is described as correcting the backlash of the first power transmission mechanism 112a. However, the backlash is equivalent to being zero within a certain range of rigidity of the first power transmission mechanism 112a. Can think. In other words, the elastic deformation of the first power transmission mechanism 112a due to the interference torque can be considered equivalent to a certain amount of play. Therefore, the second correction value can be similarly applied as an interference torque compensation when the rigidity of the first power transmission mechanism 112a is low, that is, a correction value that eliminates the influence of the elastic deformation of the first power transmission mechanism 112a due to the interference torque. .

  Therefore, the second correction value generation unit 158 prevents the yaw operation of the main shaft member 100 from occurring due to the elastic deformation of the first power transmission mechanism 112a to the correction value considering the backlash of the first power transmission mechanism 112a. Or what added the correction value to reduce may be produced | generated as a 2nd correction value. As a result, not only the yaw motion caused by the play but also the yaw motion caused by the elastic deformation of the first power transmission mechanism 112a can be prevented or suppressed, and the posture control of the distal end working unit 12 can be performed with higher accuracy. It can be carried out.

  In a state in which the end effector 19 is closed (“pulling state” in which the trigger lever 36 is pulled to the pulling position), a state in which the object to be grasped (for example, a part of a living tissue, a curved needle, etc.) is strongly grasped (gripping state) The rotation resistance of the gear body 102 is large, and the interference torque is large. Further, in a state in which the end effector 19 is largely opened (“extruded state” in which the trigger lever 36 is pushed out to the pushing position), it is considered that some object is being spread (expanded state), and the interference torque is large. In such a high torque state, the influence of the yaw operation becomes large. On the other hand, when the end effector 19 is neither in the pulling position nor in the pushing position, the interference torque is small. In such a low torque state, the influence of the yaw operation is small.

  As described above, when the interference torque varies depending on the state of the end effector 19, a second correction value that takes into account the elastic deformation of the first power transmission mechanism 112a is generated according to the magnitude of the interference torque in each state. Good. As described above, in the case of the manipulator 10 according to the present embodiment, the detection mechanism 120, 140 can detect that the trigger lever 36 is in the pulling position (high torque state). Therefore, the optimal second correction value in the high torque state is set as “second correction value C1”, and the optimal second correction value in the low torque state is set as “second correction value C2”. The second correction value generation means 158 may be configured to generate a correction value. However, the second correction value C2 ≦ the second correction value C1.

  Thus, the normal uniaxial target value is corrected by the second correction value C1 in the high torque state, and the normal uniaxial target value is corrected by the second correction value C2 in the low torque state. It becomes possible. Therefore, correction corresponding to the interference torque that changes in accordance with the state of the end effector 19 can be performed, and the posture control of the distal end working unit 12 can be performed with higher accuracy. Although the detection mechanism 120, 140 can detect that the trigger lever 36 is in the pulling position, but cannot detect that the trigger lever 36 is in the push-out position, the state where the trigger lever 36 is not in the pulling position is referred to as “low torque state”. Therefore, the above correction is performed.

In the manipulator 10, when the above-described detection mechanisms 120 and 140 are not provided, a second correction value C1 suitable for the high torque state and a second correction value C2 suitable for the low torque state are obtained, and the intermediate The value may be generated by the second correction value generation unit 158 as the second correction value. The second correction value in this case only needs to satisfy the following expression (1) or (2).
Second correction value C2 ≦ second correction value ≦ second correction value C1 (1)
Second correction value = (second correction value C1 + second correction value C2) / 2 (2)

  By controlling the first motor 50a using the second correction value generated according to the above equation (1) or (2), the yaw operation by the interference torque can be performed even when the detection mechanisms 120 and 140 are not provided. Occurrence can be suppressed.

Further, when the interference torque is different between the pulled state of the trigger lever 36 and the pushed-out state (both high torque states), they are distinguished as the second correction value C1 (a) and the second correction value C1 (b), respectively. Also good. In the manipulator 10 in which the detection mechanisms 120 and 140 are not provided, when the interference torque is different as described above, the second correction value generated by the second correction value generation unit 158 is expressed by the following equations (3) to (3). 5) Any one satisfying any one of the formulas may be used. However, the expression (3) is a case where the second correction value C1 (a)> the second correction value C1 (b), and the expression (4) is the second correction value C1 (a) <the second correction value C1. This is the case in (b).
Second correction value C2 ≦ second correction value v6 ≦ second correction value C1 (a) (3)
Second correction value C2 ≦ second correction value v6 ≦ second correction value C1 (b) (4)
Second correction value = (second correction value C1 (a) + second correction value C1 (b) + second correction value C2) / 3 (5)

  By controlling the first motor 50a using the second correction value generated according to any one of the above formulas (3) to (5), interference can be achieved even when the detection mechanisms 120 and 140 are not provided. Generation of yaw motion due to torque can be suppressed.

  In the case where the manipulator 10 is provided with a mechanism capable of detecting or estimating the interference torque during the roll operation (torque around the yaw axis Oy acting on the main shaft member 100), the manipulator 10 is provided with the first one corresponding to the interference torque that varies depending on the use situation. The normal one-axis target value of the first motor 50a may be corrected using the two correction values. By performing such correction, the posture control of the distal end working unit 12 can be performed with higher accuracy.

  In the above, since the first correction value and the second correction value generating means are different, the uniaxial correction value (correction value for the normal target value of the first motor 50a) when performing the yaw operation is used as the first correction value and the roll operation. The one-axis correction value in the case of performing is described as the second correction value. However, at the time of control, it may be handled as one correction value as a uniaxial correction value. That is, the uniaxial correction value = first correction value + second correction value may be handled. However, uniaxial correction value ≦ first correction value final value = second correction value final value.

  In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

DESCRIPTION OF SYMBOLS 10 ... Medical manipulator 12 ... End operation | movement part 13 ... Posture change mechanism 14 ... Operation part 16 ... Working part 19 ... End effector 29 ... Controller 50 ... Drive source 50a ... 1st motor 50b ... 2nd motor 100 ... Main shaft member 102 ... Gear body

Claims (6)

A first drive source;
A tip operating unit having an end effector and a first operating unit configured to perform a first posture changing operation by mechanically transmitting a driving force of the first driving source;
A first power transmission mechanism that mechanically transmits the driving force of the first driving source via a meshing part or an engaging part to operate the first operating part;
A controller for controlling the first drive source,
In the first power transmission mechanism including the meshing part or the engaging part, mechanical play exists,
The controller, when receiving a first operation command related to the first posture change operation, generates a first target trajectory based on the first operation command as the first compensation control, and the first target trajectory the elimination and generating a first normal uniaxial target value is a target value of the first drive source based on the effect of the backlash present in the first power transmission mechanism based on the first target trajectory 1 Based on a process for generating a correction value, the first normal uniaxial target value and the first correction value, a first correction uniaxial target value which is a target value for controlling the first drive source is generated. And controlling the first drive source using the first corrected one-axis target value .
A medical manipulator characterized by that. The medical manipulator according to claim 1, wherein
The shaft further includes a shaft provided with the tip operating portion at the tip, a second driving source, and a second power transmission mechanism that mechanically transmits the driving force of the second driving source to operate the second operating portion. ,
The tip motion section is a yaw motion as the first posture change operation that tilts with respect to a yaw axis that is not parallel to the axis of the shaft, and a second posture change that rotates with reference to a roll axis that points to the tip. Roll operation as an operation is possible,
The first operation unit is a member that can rotate around the yaw axis,
The second operation unit is supported by the first operation unit so as to be rotatable around the roll axis so that a second posture changing operation can be performed.
When the controller receives a second operation command related to the roll operation, the controller controls the second drive source based on the second operation command, and the second compensation control results from the roll operation. so as to prevent or suppress the occurrence of yawing operation, it controls the first driving source,
In the second compensation control, the controller generates a second target trajectory based on the second operation command, and a second normal value that is a target value of the first drive source based on the second target trajectory. A process of generating a uniaxial target value, and a process of generating a second correction value that eliminates backlash in the direction opposite to the direction of the force that the first operating unit receives from the second operating unit due to the roll operation. Performing a process of generating a second corrected one-axis target value that is a target value for controlling the first drive source based on the second normal one-axis target value and the second correction value; Controlling the first drive source using the second corrected one-axis target value;
A medical manipulator characterized by that. The medical manipulator according to claim 1 , wherein
The shaft further includes a shaft provided with the tip operating portion at the tip, a second driving source, and a second power transmission mechanism that mechanically transmits the driving force of the second driving source to operate the second operating portion. ,
The tip motion section is a yaw motion as the first posture change operation that tilts with respect to a yaw axis that is not parallel to the axis of the shaft, and a second posture change that rotates with reference to a roll axis that points to the tip. Roll operation as an operation is possible,
The first operation unit is a member that can rotate around the yaw axis,
The second operation unit is supported by the first operation unit so as to be rotatable around the roll axis so that a second posture changing operation can be performed.
When the controller receives a second operation command related to the roll operation, the controller controls the second drive source based on the second operation command, and the second compensation control results from the roll operation. Controlling the first drive source to prevent or suppress the occurrence of yaw motion;
In the second compensation control , the controller generates a second target trajectory based on the second operation command, and a second normal value that is a target value of the first drive source based on the second target trajectory. A process for generating a uniaxial target value , a process for generating a second correction value for preventing or suppressing the occurrence of an operation of the first operation unit due to an elastic deformation of the first power transmission mechanism, and the second based on regular uniaxial target value and the second correction value, it performs a process of generating a second correction uniaxial target value is a target value for control of the first driving source, the second Controlling the first drive source using the corrected one-axis target value;
A medical manipulator characterized by that. The medical manipulator according to claim 3 , wherein
The second correction value in the second compensation control is caused by elastic deformation of the first power transmission mechanism in a high torque state in which interference torque to the first operation unit by the second operation unit is relatively high. More than the correction value for preventing occurrence of the operation of the first operating unit, and the first operating unit is caused by elastic deformation of the first power transmission mechanism in a low torque state where the interference torque is relatively low. It is a value below the correction value to prevent the occurrence of movement,
A medical manipulator characterized by that. The medical manipulator according to claim 4 , wherein
The controller performs the second compensation control with a correction value corresponding to the low torque state when in the low torque state, and corresponds to the high torque state when the end effector is in the high torque state. Performing the second compensation control with a correction value;
A medical manipulator characterized by that. The medical manipulator according to claim 3 , wherein
The controller performs the second compensation control with a correction value according to the measured or estimated operating resistance of the second operating unit;
A medical manipulator characterized by that.

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