WO2014030363A1 - Dispositif d'estimation de force externe et système de forceps - Google Patents

Dispositif d'estimation de force externe et système de forceps Download PDF

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Publication number
WO2014030363A1
WO2014030363A1 PCT/JP2013/053771 JP2013053771W WO2014030363A1 WO 2014030363 A1 WO2014030363 A1 WO 2014030363A1 JP 2013053771 W JP2013053771 W JP 2013053771W WO 2014030363 A1 WO2014030363 A1 WO 2014030363A1
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WO
WIPO (PCT)
Prior art keywords
external force
forceps
joint
force estimation
estimation device
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Application number
PCT/JP2013/053771
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English (en)
Japanese (ja)
Inventor
耕太郎 只野
健嗣 川嶋
大輔 原口
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国立大学法人東京工業大学
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Application filed by 国立大学法人東京工業大学 filed Critical 国立大学法人東京工業大学
Publication of WO2014030363A1 publication Critical patent/WO2014030363A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/04—Measuring force or stress, in general by measuring elastic deformation of gauges, e.g. of springs
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/06—Measuring instruments not otherwise provided for
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/16—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring several components of force
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/06—Measuring instruments not otherwise provided for
    • A61B2090/064—Measuring instruments not otherwise provided for for measuring force, pressure or mechanical tension
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
    • A61B34/30—Surgical robots

Definitions

  • the present invention relates to a novel external force estimation device.
  • the present invention also relates to a novel forceps system having this external force estimation device.
  • a multi-degree-of-freedom forceps used in a conventional surgical robot system has a 2-degree-of-freedom arm inside the body (3 degrees-of-freedom when grasping is included) and a 4-degree-of-freedom arm outside the body. This is because it is difficult to realize multiple degrees of freedom at the tip of the small-diameter forceps.
  • Non-Patent Document 1 the arm outside the body moves up and down, left and right, etc. during work, which interferes with the assistant, and when using a plurality of forceps, the arms interfere with each other. There is a point.
  • Non-Patent Document 2 is an endoscope bending mechanism. Ring-shaped leaf springs are laminated together by welding to form a single spring structure. Bends close to 180 ° are possible.
  • Non-Patent Document 3 realizes bending in an arbitrary direction by connecting four leaf springs to a rigid rod.
  • the inventor has developed a laparoscopic forceps manipulator having a simple flexible bending mechanism suitable for miniaturization (see Non-Patent Document 4).
  • the joint structure consists only of a single-work cutting spring. By bending and pushing the superelastic alloy wire that passes through the pneumatic cylinder, a bending operation with higher rigidity than the conventional antagonistic drive using wire tension. Made possible.
  • the joint can bend in two degrees of freedom.
  • the present inventor performs external force estimation using a simple theoretical model that approximates a flexible joint to a rigid link mechanism with two degrees of freedom (see Non-Patent Document 5).
  • Non-Patent Document 2 cannot bend isotropically in all directions due to structural limitations.
  • Non-Patent Document 3 there is a concern that a small part such as a shaft is required for connection, and that it is weak against torsion.
  • Non-Patent Document 2 and Non-Patent Document 3 have problems such as a large number of parts and time-consuming assembly.
  • Non-Patent Document 4 In the joint structure of Non-Patent Document 4, the external force estimation method is not described.
  • the external force estimation based on the theoretical model of Non-Patent Document 5 is effective when the joint is in a straight posture, but the error increases as the bending angle increases. In addition, there is no description about force estimation with 3 degrees of freedom.
  • This invention is made
  • an object of this invention is to provide the novel forceps system which has this external force estimation apparatus.
  • an external force estimation device of the present invention includes a detection unit that detects a change amount of the length of the elastic member, and a change amount of the elastic member that is deformed by an external force. And a calculation unit for calculating external force.
  • the calculation unit calculates the three-axis component of the external force.
  • a wire for detecting the amount of change.
  • a detection part consists of a position sensor.
  • the forceps system of the present invention has the external force estimation device.
  • the present invention has the following effects.
  • the external force estimation device of the present invention has a detection unit that detects a change amount of the length of the elastic member and a calculation unit that calculates the external force using the change amount for the elastic member that is deformed by the external force.
  • An estimation device can be provided.
  • the forceps system of the present invention has the external force estimation device, a novel forceps system can be provided.
  • tip part of a forceps manipulator. It is a figure which shows the drive part of a forceps manipulator. It is a figure which shows the pipe internal structure of a forceps manipulator. It is a figure which shows the cross section of the pipe part of a forceps manipulator. It is a block diagram of external force estimation. It is a figure which shows the definition of a position coordinate. It is a figure which shows an experimental apparatus. It is the figure which compared the external force estimated value when it always calculated as l 0, and the measured value of a force sensor. It is the figure which compared the 3 DOF external force estimated value and the measured value of a force sensor.
  • the external force estimation apparatus of the present invention is an apparatus having a detection unit that detects a change amount of the length of the elastic member and a calculation unit that calculates an external force using the change amount for an elastic member that is deformed by an external force.
  • the forceps system of the present invention is a system having the external force estimation device.
  • (English character symbol) hat refers to an English character symbol with a hat symbol
  • (English character symbol) over dot refers to an English character symbol with an over dot. It describes.
  • This is a system that takes the cylinder position signal from a position sensor (potentiometer, encoder, etc.) and the pressure signal at the output port of the servo valve into a control computer having a calculation unit, and calculates and outputs the input voltage to the servo valve. .
  • a position sensor potentiometer, encoder, etc.
  • the driving force can be estimated without mounting a force sensor on the manipulator side.
  • FIG. Bending in one direction is realized by two cylinders.
  • a schematic diagram of one-way bending is shown, but a total of four cylinders are used for bending in two directions.
  • Each cylinder is driven by one 5-port servo valve.
  • Symbol suffixes 1 and 3 of each drive channel correspond to the wire arrangement numbers in FIG.
  • a pressure sensor is attached to the output port of the servo valve, and the driving force of the cylinder can be estimated from the pressure measured here.
  • a potentiometer is attached to the cylinder rod as a position sensor.
  • FIG. 3 shows the appearance of the forceps manipulator.
  • FIG. 4 shows the tip of the forceps manipulator.
  • the distal end portion is composed of a bent portion (joint) and a grip portion.
  • the joint part employs a precision spring manufactured by cutting, and the attachment part with the gripping part and the guide hole of the drive wire can be integrally processed.
  • the gripping part is a mechanism that opens and closes by air pressure. For this reason, an air pipe is passed through the joint. Since the grip portion is not wire-driven, there is an advantage that the opening / closing operation does not interfere with the bending operation of the joint.
  • FIG. 5 shows the drive unit of the forceps manipulator.
  • Four superelastic alloy wires that drive the joint are connected in a straight line to the rod of the pneumatic cylinder through the connector. Since the wire is not bent during the connection process, that is, the wire is always in a straight line except for the bending joint, the sliding frictional force of the mechanism during driving can be minimized, contributing to improvements in controllability and external force estimation accuracy. To do.
  • the cylinder rod position is measured with a potentiometer. By controlling the rod position of the pneumatic cylinder, the superelastic alloy wire is pushed and pulled to cause the tip joint to perform a desired motion.
  • FIG. 6 shows the internal structure of the body pipe part of the forceps manipulator.
  • FIG. 7 shows a cross-sectional view of the pipe portion.
  • the superelastic alloy wire passes through the guide pipe and is connected to the bending joint to prevent buckling.
  • the guide pipe itself is also passed through the support member at regular intervals to prevent buckling.
  • FIG. 8 is a block diagram of external force estimation in the forceps system.
  • F Driving force vector of the pneumatic actuator, specifically, a force vector for pushing and pulling the cylinder rod.
  • X The displacement of the cylinder rod, calculated from the value of the potentiometer.
  • X overdot The speed of the cylinder rod.
  • s is a Laplace differential operator, it is actually obtained by computer numerical differentiation (pseudo-differentiation). Note that the above three variables relate to the pneumatic cylinder and are four-dimensional vectors.
  • q A position variable vector of the flexion joint, which is a three-dimensional vector represented by Expression (2). The specific meaning of each component of q is shown in FIG.
  • the change amount l of the joint length is the change amount of the length of the center line of the joint, that is, the portion indicated by the broken line in FIG.
  • ⁇ and ⁇ are expressed in the following ranges. ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 0 P is the position coordinate of the forceps tip, Ls is the natural length of the flexion joint, Lg is the length of the gripping part, r is the arrangement radius of the drive wire, and numerals 1 to 4 are the drive wires. Number.
  • the position P of the forceps tip can be expressed as follows.
  • Z hat Inverse dynamic model of joints, which is a cylinder driving force vector for realizing a desired joint position and velocity, and is a four-dimensional vector.
  • the Z hat is calculated as follows.
  • the first term is the cylinder viscosity, and C is the viscosity matrix.
  • the second term is the Coulomb friction of the whole mechanism, and D is a matrix of Coulomb friction force.
  • ⁇ is a dynamic friction coefficient. Since this frictional force increases when the joint is bent, it is a nonlinear function of the bending angle ⁇ .
  • the nonlinear part e 2 ⁇ in the second term is not limited to the above. An approximate polynomial of ⁇ identified experimentally can also be applied.
  • Non-Patent Document 5 there is no nonlinear part related to ⁇ , but the above two terms are a more accurate friction model according to the bending state of the joint. If the second term is used, the frictional force can be estimated more accurately than the equation described in Non-Patent Document 5. As a specific effect of this, accuracy in manipulator position control and external force estimation is improved.
  • the third term is the elastic force applied to the bending of the joint, and K b is its stiffness matrix.
  • the third term is a model that linearly approximates the elastic force for bending.
  • a similar expression is described in Non-Patent Document 5, but there is a difference in the joint structure applied in this application and Non-Patent Document 5.
  • a superelastic alloy spine is provided at the center of a flexible joint, and a stainless steel wire having almost no elastic force is used as a drive wire.
  • there is no spine at the center of the joint and a superelastic alloy having elasticity is used for the drive wire.
  • K a is the stiffness matrix.
  • a variable l representing expansion and contraction is introduced as a variable of the third degree of freedom, so that three independent degrees of freedom (3 Axis) external force can be estimated. It should be noted that the influence of inertia including gravity is assumed to be sufficiently smaller than the above components and can be ignored.
  • F ext , F ext hat vectors of external force components of cylinder driving force, which are four-dimensional vectors. This occurs when the cylinder is back-driven by receiving external force at the tip of the forceps.
  • a symbol with a hat means an estimated value by calculation. The same applies to symbols to be described later.
  • ⁇ ext hat an external force component of torque and translational force with respect to joint position coordinates q ( ⁇ , ⁇ , l).
  • f ext hat An external force vector applied to the forceps tip, which is a three-dimensional vector in the x, y, and z directions.
  • J a T is a conversion matrix from F ext to ⁇ ext .
  • J a is a Jacobian from the joint speed q overdot to the cylinder speed X overdot, and can be calculated by differentiating the equation (1) with respect to time.
  • J T ) + A conversion matrix from ⁇ ext to f ext .
  • J is a Jacobian from the joint speed q overdot to the forceps tip speed p overdot, and can be calculated by differentiating the equation (3) with time.
  • Equation (6) there is a component related to the joint length variable l, so that independent three-axis translational forces can be estimated.
  • C, D, ⁇ , Kb, Ka were obtained experimentally. That is, automatic control was performed by giving an appropriate trajectory to the flexion joint, and the above parameters were adjusted by trial and error so that the target trajectory and the actual trajectory were in good agreement.
  • the following values were used for C, D, ⁇ , Kb, and Ka.
  • C 0.3 [N ⁇ s / mm]
  • D 0.6 [N]
  • ⁇ 0.9
  • Kb 2.8 [N / mm]
  • Ka 2.0 [N / mm]
  • the tip of the forceps is bent about 30 degrees, and the gripping part and the force sensor are connected with a wire.
  • the wire was pulled by moving the entire forceps in the direction of the arrow in the figure.
  • the effectiveness of the external force estimation described above was verified by comparing the estimated value of the external force by the forceps manipulator and the measured value of the force sensor.
  • Equation (6) the external force was finally calculated using Equation (6).
  • the matrix and vector components in Equation (6) were calculated using the previous equations.
  • the external force was finally calculated using the equation (6).
  • the equations (1) to (4) in the calculation process were calculated by setting all l to 0.
  • the external force estimation device and forceps system of the present invention have the following effects.
  • manufacturing force can be reduced, and it becomes easy to manufacture a small forceps having an outer diameter of 5 mm or less.
  • the combination of cutting spring and superelastic alloy wire can increase the rigidity required for work while being a flexible body.
  • translational external force with 3 independent degrees of freedom (3 axes) can be estimated using only the joint at the tip.
  • the ability to estimate an independent triaxial translational force (xyz) means that the force can be felt in any translational direction.
  • An advantage of using the joint at the tip for estimating the external force is that it is not affected by the restraint of the movement from the trocar and the frictional force that pass when inserting into the abdominal cavity. That is, the external force estimation accuracy is unlikely to deteriorate due to factors such as differences in the forceps insertion state in each operation.
  • the elastic member is not limited to this.
  • the elastic member it is possible to employ a member that is formed by processing a slit in a hollow object so that it can be flexibly bent.
  • a superelastic alloy wire has been described as a member that transmits the change amount of the length of the elastic member, the member that transmits the change amount is not limited to this.
  • a flexible wire made of another material such as a stainless steel wire can be employed as a member for transmitting the amount of change.
  • the detection unit is not limited to this.
  • an encoder or the like can be employed as the detection unit.
  • the driving force generator is not limited to this.
  • an electric motor, a hydraulic cylinder, a hydraulic cylinder, or the like can be employed as the driving force generator.
  • a pressure sensor has been described as a driving force measuring device
  • the driving force measuring device is not limited to this.
  • a method of directly mounting a force sensor on a manipulator can be employed as a driving force measuring device.
  • the application of the external force estimation device is not limited to this.
  • Other applications of the external force estimation device include application to a manipulator that cannot be equipped with a force sensor because it is used in an electromagnetic environment.

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  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Surgery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Medical Informatics (AREA)
  • Pathology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Manipulator (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)
  • Surgical Instruments (AREA)

Abstract

La présente invention concerne un nouveau dispositif d'estimation de force externe et un nouveau système de forceps. Ce dispositif d'estimation de force externe possède une unité de détection pour détecter la quantité de changement de longueur d'un élément élastique déformé par une force externe, et une unité de calcul pour utiliser la quantité de changement de façon à calculer la force externe. Dans la présente invention, de préférence, l'unité de calcul calcule un composant à trois axes de la force externe. De préférence, un fil est utilisé pour détecter la quantité de changement. De préférence, l'unité de détection comprend un capteur de position. De préférence, la quantité de changement dans une articulation élastique est détectée. De plus, ce système de forceps comporte le dispositif d'estimation de force externe.
PCT/JP2013/053771 2012-08-20 2013-02-16 Dispositif d'estimation de force externe et système de forceps WO2014030363A1 (fr)

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JP2012181863A JP2014038075A (ja) 2012-08-20 2012-08-20 外力推定装置及び鉗子システム
JP2012-181863 2012-08-20

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115844544A (zh) * 2023-02-16 2023-03-28 极限人工智能有限公司 介入机器人导管弯曲控制方法、系统、设备及存储介质

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JP6736201B2 (ja) * 2015-02-04 2020-08-05 株式会社不二越 配管割断治具および配管割断装置
GB2540930B (en) * 2015-07-13 2020-10-28 Cmr Surgical Ltd Flexible robotic surgical instrument
CN106493710B (zh) * 2015-09-06 2020-08-18 杭州华臻环保科技有限公司 多骨骼联动系统
WO2019073860A1 (fr) * 2017-10-12 2019-04-18 日本発條株式会社 Tube souple de manipulateur à usage médical, et structure flexible
JP7055767B2 (ja) 2019-04-11 2022-04-18 日本発條株式会社 可撓部材
JP7217825B2 (ja) * 2019-04-11 2023-02-03 日本発條株式会社 可撓部材
JP7055766B2 (ja) 2019-04-11 2022-04-18 日本発條株式会社 可撓部材
JP7116004B2 (ja) 2019-04-11 2022-08-09 日本発條株式会社 可撓部材

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Publication number Priority date Publication date Assignee Title
JPH01267429A (ja) * 1988-04-19 1989-10-25 Chinkou Higashijima 多分力の計測方法
JP2002264048A (ja) * 2001-03-08 2002-09-18 Hitachi Ltd 被牽引機構の位置決め制御装置
JP2004205432A (ja) * 2002-12-26 2004-07-22 Matsushita Electric Ind Co Ltd コード状感圧センサ入力装置
WO2011036750A1 (fr) * 2009-09-24 2011-03-31 株式会社 東芝 Unité de commande de robot

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Publication number Priority date Publication date Assignee Title
JPH01267429A (ja) * 1988-04-19 1989-10-25 Chinkou Higashijima 多分力の計測方法
JP2002264048A (ja) * 2001-03-08 2002-09-18 Hitachi Ltd 被牽引機構の位置決め制御装置
JP2004205432A (ja) * 2002-12-26 2004-07-22 Matsushita Electric Ind Co Ltd コード状感圧センサ入力装置
WO2011036750A1 (fr) * 2009-09-24 2011-03-31 株式会社 東芝 Unité de commande de robot

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Title
DAISUKE HARAGUCHI: "A Prototype of Pneumatically-Driven Forceps Manipulator with Force Sensing Capability Using a Simple Flexible Joint", IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, September 2011 (2011-09-01), pages 931 - 936 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115844544A (zh) * 2023-02-16 2023-03-28 极限人工智能有限公司 介入机器人导管弯曲控制方法、系统、设备及存储介质
CN115844544B (zh) * 2023-02-16 2023-08-04 极限人工智能有限公司 介入机器人导管弯曲控制方法、系统、设备及存储介质

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