WO2017094843A1

WO2017094843A1 - Operation system

Info

Publication number: WO2017094843A1
Application number: PCT/JP2016/085750
Authority: WO
Inventors: 大輔原口; 慧見上; 陽一平田
Original assignee: リバーフィールド株式会社
Priority date: 2015-12-04
Filing date: 2016-12-01
Publication date: 2017-06-08
Also published as: JP2017099819A

Abstract

Provided is an operation system having an improved operational feeling. The operation system is provided with: an actuator (22); an action detection unit (11) that detects input from at least two shafts and outputs a plurality of input commands; a reference input generation unit (32) that generates a plurality of reference input commands from the input commands; and an actuator control unit (33) that controls the actuator (22) on the basis of the reference input commands. The reference input generation unit (32) carries out weighting while maintaining the directions of the input commands, and generates the reference input commands.

Description

Operation system

The present invention relates to an operation system, and more particularly to an operation system for remotely operating a shaft-like body such as a forceps or a rigid endoscope held by a holding device.

Research and development of minimally invasive medical technologies such as laparoscopic surgery from an engineering point of view, and a movement to make use in the medical field is spreading. In particular, research and development related to surgical support using robots is actively conducted.

For example, Patent Document 1 discloses a multi-joint slave arm, a master arm having a joint structure similar to the slave arm, and the slave arm operated based on an operation performed on the master arm. A control unit for controlling the arm, and the control unit is configured to control each joint of the slave arm based on the rotation amount of each joint of the master arm so that the slave arm has a similar shape to the master arm. A first control mode for controlling the rotation operation, and a predetermined portion of the tip portion of the master arm so that the predetermined portion of the tip portion of the slave arm follows the movement of the predetermined portion of the tip portion of the master arm. Disclosed is a medical system that can be switched between a second control mode for controlling the rotational motion of each joint of the slave arm based on the amount of movement of the slave arm. That (see claim 1).

Japanese Patent Laying-Open No. 2015-24036

In such a master-slave type operation system capable of remote operation, it is possible to improve the operational feeling by weighting the degree to which the input intended by the operator is reflected in the endoscope operation. However, an operation system that drives a plurality of axes at the same time may operate in a direction different from the originally intended input depending on the weighting of each axis.

Therefore, an object of the present invention is to provide an operation system with improved operational feeling.

In order to solve such a problem, an operation system according to the present invention includes an actuator, an operation detection unit that detects a plurality of inputs of two or more axes and outputs a plurality of input commands, and the plurality of input commands. A reference input generation unit that generates a plurality of reference input commands; and an actuator control unit that controls the actuator based on the plurality of reference input commands, wherein the reference input generation unit includes directions of the plurality of input commands. The plurality of reference input commands are generated by performing weighting while maintaining.

According to the present invention, an operation system with improved operational feeling can be provided.

It is the schematic which shows the structure of the operation system which concerns on 1st Embodiment. It is a block diagram which shows the structure of the operation system which concerns on 1st Embodiment. It is a block diagram which shows the signal processing of the operation system which concerns on 1st Embodiment. It is a graph which shows the relationship between the input vector and the reference input vector which weighted, (a) is a reference example, (b) shows 1st Embodiment. It is the schematic which shows the structure of the operation system which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the operation system which concerns on 2nd Embodiment. It is a figure which shows the relationship between the input vector in 3 degrees of freedom, and the reference input vector which weighted.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

<< First Embodiment >>
<Operation system S>
A configuration of the operation system S according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram illustrating a configuration of an operation system S according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration of the operation system S according to the first embodiment. In the following description, the operation system S according to the first embodiment will be described as a system that detects the operation of the operator OP and operates the visual field of the endoscope (rigid endoscope, laparoscope).

As shown in FIG. 1, the operation system S according to the first embodiment includes an operation detection unit 1 that detects the operation of the operator OP, a holding arm unit 2 that holds an endoscope (shaft-like body) 100, And a control unit 3 that controls the holding arm unit 2 based on the operation of the operator OP detected by the operation detection unit 1.

The motion detection unit 1 is mounted on the head of the operator OP and can detect the movement of the head of the operator OP. The method for fixing the motion detection unit 1 to the head of the operator OP includes, for example, a method in which a pocket is provided in a surgical cap and the motion detection unit 1 is stored in the pocket. It is not a thing.

As illustrated in FIG. 2, the motion detection unit 1 includes a motion detection unit 11 configured by, for example, a gyro sensor. The motion detection unit 11 includes an input speed ω _G ^Y around the yaw (Yaw) axis that is the rotation of the operator OP in the left-right direction and an input speed ω around the pitch (Pitch) axis that is the rotation of the operator OP in the vertical direction. and it is capable of detecting and a _G ^P. The detection signal of the motion detection unit 11 is transmitted to the control unit 3.

Returning to FIG. 1, the holding arm unit 2 includes an RCM (Remote Center Motion) mechanism that holds the endoscope 100 and realizes a pivot (fixed point) motion, with the fixed point PP as a rotation center, This is a two-degree-of-freedom holding device capable of rotating the endoscope 100 about the yaw axis and rotating about the pitch axis. The yaw axis of the endoscope 100 is a vertical axis that passes through the fixed point PP. The pitch axis of the endoscope 100 is an axis that passes through the fixed point PP and is orthogonal to the yaw axis of the endoscope 100 and the central axis of the endoscope 100.

As shown in FIG. 2, the holding arm unit 2 includes a holding arm portion 21 and a power control device 24. The holding arm unit 21 includes an actuator 22 and a state quantity detection unit 23.

The actuator 22 includes a yaw axis actuator that rotates the held endoscope 100 about the yaw axis, and a pitch axis actuator that rotates the held endoscope 100 about the pitch axis. In addition, as an actuator, a pneumatic actuator can be used, for example.

The state quantity detection unit 23 detects the state of the holding arm unit 21 (the state of the actuator 22) and transmits a detection signal to the control unit 3. Specifically, the current position q _res ^Y around the yaw axis, the current position q _res ^P around the pitch axis, the driving force f _res ^Y of the yaw axis actuator, and the driving force f _res ^P of the pitch axis actuator are detected. An encoder can be used to detect the current positions q _res ^Y and q _res ^P , and a value obtained by multiplying the pressure sensor value by the pressure receiving area can be used to detect the driving forces f _res ^Y and f _res ^P. it can.

The power control device 24 operates the actuator 22 based on a control signal from the control unit 3. When a pneumatic actuator is used as the actuator 22, the power control device 24 can use a direction controller that controls the air flow direction of the pneumatic actuator, and the control unit 3 sends a control signal to the direction controller valve. the applied voltage u ^Y, u ^P is input.

The control unit 3 includes a control unit 31 and an input / output unit 34. The control unit 31 includes a reference input generation unit 32 and a feedback control unit 33.

The control unit 31 receives the detection signals (input speeds ω _G ^Y , ω _G ^P ) from the motion detection unit 11 of the motion detection unit 1 and the state quantity detection unit 23 of the holding arm unit 2 via the input / output unit 34. Detection signals (current positions q _res ^Y and q _res ^P , driving forces f _res ^Y and f _res ^P ) are input, and control signals (applied voltages u ^Y and u ^P ) to the power control device 24 are output.

The control unit 31 of the control unit 3 will be further described with reference to FIG. FIG. 3 is a block diagram showing signal processing of the operation system S according to the first embodiment.

The reference input generation unit 32 weights the detection signals (input velocities ω _G ^Y , ω _G ^P ) from the motion detection unit 11 of the motion detection unit 1 and the endoscope 100 of the endoscope 100 held by the holding arm unit 2. A reference input speed q _dref ^Y that is a target value of the rotational speed around the yaw axis and a reference input speed q _dref ^P that is a rotational speed around the pitch axis of the endoscope 100 are generated. The generation (weighting) of the reference input speeds q _dref ^Y and q _dref ^P in the reference input generation unit 32 will be described later.

The feedback control unit 33 includes reference input velocities q _dref ^Y and q _dref ^P from the reference input generation unit 32, and detection signals (current positions q _res ^Y and q _res ^P , driving from the state quantity detection unit 23 of the holding arm unit 2. Based on the force f _res ^Y , f _res ^P ), a control signal (applied voltage u ^Y , u ^P ) to the power control device 24 is generated. Specifically, the feedback control unit 33 includes a position controller 331, a subtracter 332, and a driving force controller 333.

The position controller 331 integrates the reference input speed q _dref ^Y of the reference input generation unit 32 to generate the target position q _ref ^Y. Further, the rotational speed q _dres ^Y around the yaw axis of the endoscope 100 is generated from the difference between the current value and the previous value of the current position q _res ^Y of the state quantity detection unit 23. Then, the driving force reference value f _ref ^Y is generated so that the rotational speed q _dres ^Y approaches the reference input speed q _dref ^Y so that the current position q _res ^Y approaches the target position q _ref ^Y. Here, assuming that the gain related to the position deviation is K _p and the gain related to the speed deviation is K _d , the driving force reference value f _ref ^Y can be expressed by the following equation.
f _ref ^Y = K _p (q _dref ^Y −q _dres ^Y ) + K _d (q _ref ^Y −q _res ^Y )
Further, the position controller 331 generates the target position q _ref ^P by integrating the reference input speed q _dref ^P of the reference input generation unit 32. Further, the rotational speed q _dres ^P around the pitch axis of the endoscope 100 is generated from the difference between the current value and the previous value of the current position q _res ^P of the state quantity detector 23. Then, the driving force reference value f _ref ^P is generated so that the rotational speed q _dres ^P approaches the reference input speed q _dref ^P so that the current position q _res ^P approaches the target position q _ref ^P. Here, assuming that the gain related to the position deviation is K _p and the gain related to the speed deviation is K _d , the driving force reference value f _ref ^P can be expressed by the following equation.
f _ref ^P = K _p (q _dref ^P −q _dres ^P ) + K _d (q _ref ^P −q _res ^P )
The gains K _p and K _d may be different on the yaw axis and the pitch axis, or may be the same.

The subtractor 332 receives the driving force reference value f _ref ^Y of the position controller 331 and the driving force f _res ^Y of the state quantity detection unit 23, and the driving force reference value f _ref ^Y and the driving force f _res ^Y are input. (F _ref ^Y −f _res ^Y ) is generated and output to the driving force controller 333. Further, the subtractor 332 receives the driving force reference value f _ref ^P of the position controller 331 and the driving force f _res ^P of the state quantity detection unit 23, and the driving force reference value f _ref ^P and the driving force f _res. A difference from ^P (f _ref ^P −f _res ^P ) is generated and output to the driving force controller 333.

The driving force controller 333 sends the difference between the driving force reference value f _ref ^Y of the subtractor 332 and the driving force f _res ^Y (f _ref ^Y −f _res ^Y ) to the power control device 24 (valve of the direction controller). Control signal (applied voltage u _Y ) is generated. Further, the driving force controller 333 determines the power control device 24 (the valve of the direction controller) from the difference (f _ref ^P −f _res ^P ) between the driving force reference value f _ref ^P of the subtractor 332 and the driving force f _res ^P. ) Is generated (applied voltage u ^P ).

As described above, the control unit 3 weights the operation (input speeds ω _G ^Y , ω _G ^P ) of the operator OP detected by the motion detection unit 1 (motion detection unit 11) with a reference input speed q _dref ^Y that will be described later. , Q _dref ^P can pivot the endoscope 100 held by the holding arm unit 2 (see FIG. 1).

<Reference input generation unit 32>
Next, generation of the reference input velocities q _dref ^Y and q _dref ^P in the reference input generation unit 32 of the control unit 3 will be further described.

Here, in the operation system S as shown in FIG. 1, when the motion detection unit 1 is mounted on the head of the operator OP, the vertical direction (pitch axis rotation direction) is compared with the left-right direction (yaw axis rotation direction). Therefore, weighting is performed differently in the vertical direction and in the horizontal direction. Specifically, the weighting is performed so as to amplify the operation signal in the vertical direction. With such a configuration, the visual field of the endoscope 100 can be manipulated with a smaller movement in the vertical direction than in the horizontal direction.

(Weighting process in the reference example)
Here, FIG. 4A shows a reference example in which different weights are simply applied to the yaw axis and the pitch axis. FIG. 4A is a graph showing the relationship between the input vector in the reference example and the weighted reference input vector. As shown in FIG. 4A, the pitch axis (vertical axis in FIG. 4A) is weighted β (β> 1), and the yaw axis (horizontal axis in FIG. 4A) is not weighted (α = 1).

With such a configuration, when the head of the operator OP is shaken in the vertical direction, it moves greatly compared to before the weighting, so the endoscope can be easily operated even in the vertical movement of the head with a narrow range of motion. 100 fields of view can be rotated around the pitch axis. When the operator OP's head is shaken in the left-right direction, the field of view of the endoscope 100 can be rotated around the yaw axis in the same manner as when weighting is not performed.

However, as shown in FIG. 4A, when two-axis operations are performed simultaneously, the direction in the original input vector r (ω _G ^Y , ω _G ^P ) is an angle θ with respect to the horizontal. On the other hand, the direction in the weighted vector R (αω _G ^Y , βω _G ^P ) is the angle θ1, and the directions are different.

For this reason, the direction (angle θ) input by the operator OP is different from the direction (angle θ1) in which the endoscope 100 actually moves, which may cause the operator OP to feel uncomfortable.

(Weighting process according to the first embodiment)
Next, FIG. 4B illustrates an example in which weighting is performed in the reference input generation unit 32 of the operation system S according to the first embodiment. FIG. 4B is a graph showing the relationship between the input vector and the weighted reference input vector in the first embodiment.

Here, the horizontal axis is yaw and the vertical axis is pitch. Here, the magnitude of the input vector r can be expressed by the following formula (1), and the angle θ with respect to the horizontal indicating the direction of the input vector r can be expressed by the formula (2).

Note that the arctan2 () function in equation (2) has the following relationship.

Here, the weight in the left-right direction (yaw axis rotation direction) is α _max , the weight in the vertical direction (pitch axis rotation direction) is β _max , r · α _max is the radius of the first axis, and r · β _max is An elliptic arc E is defined as the radius of the second axis. Note that β _max is “β _max > 1” and α _max is “α _max = 1” in order to perform weighting that amplifies the operation signal in the vertical direction. Incidentally, the arc indicated by the symbol C is an arc whose radius is r.

The reference input vector R (q _dref ^Y , q _dref ^P ) has the same direction (angle θ) as the input vector r, and (q _dref ^Y , q _dref ^P ) is on the elliptical arc E. From the ellipse equation, the magnitude of the input vector R can be expressed by the following equation (3).

The reference input speeds q _dref ^Y and q _dref ^P can be expressed by the following equations (4) and (5).

As described above, the reference input generation unit 32 of the operation system S according to the first embodiment uses the reference input speed q from the input speeds ω _G ^Y and ω _G ^{P using} the expressions (1) to (5). _By generating _dref ^Y and q _dref ^P , as shown in FIG. 4B, the reference input velocities q _dref ^Y and q _dref ^P are weighted differently in the vertical direction and the horizontal direction, while the input vector r And the direction (angle θ) of the reference input vector R can be made equal. As a result, the direction input by the operator OP (angle θ of the input vector r) and the direction in which the endoscope 100 actually moves (angle θ of the reference input vector R) become equal, making the operator OP feel uncomfortable. It is not generated, and the operational feeling of the operator OP can be improved.

Here, making the direction (angle θ) of the input vector r and the reference input vector R equal indicates that the ratio of each axis component is equal between the input vector r and the reference input vector R. That is, “ω _G ^Y : ω _G ^P = q _dref ^Y : q _dref ^P ”.

Incidentally, when the head of the operator OP is swung only in the left-right direction (the yaw axis rotation direction) (that is, when ω _G ^P = 0, ω _G ^Y ≠ 0), the reference input speed q _dref ^Y is “ q _dref ^Y = α _max · ω _G ^Y ”. When the head of the operator OP is swung only in the vertical direction (pitch axis rotation direction) (that is, when ω _G ^Y = 0, ω _G ^P ≠ 0), the reference input speed q _dref ^P is “ q _dref ^P = β _max · ω _G ^P ”.

<< Second Embodiment >>
<Operation system SA>
A configuration of the operation system SA according to the second embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 is a schematic diagram illustrating a configuration of the operation system SA according to the second embodiment. FIG. 6 is a block diagram showing the configuration of the operation system SA according to the second embodiment. In the following description, the operation system S according to the second embodiment is a system that operates the robot forceps (shaft-shaped body) 150 by detecting the movement of the operator OP by operating the master robot 1A. It will be explained as being.

As shown in FIG. 5, the operation system SA according to the second embodiment includes a master robot 1A that detects the movement of the operator OP, a slave robot 2A that holds the robot forceps 150, and an operator that is detected by the master robot 1A. And a control unit 3A that controls the slave robot 2A based on the operation of the OP.

As shown in FIG. 6, the master robot 1 </ b> A includes an operation detection unit 11 and an actuator 12. Operation detecting unit 11, the position theta _M in the vertical direction (direction plugging Z-axis direction, the shaft-like body) and the position theta _M ^X of (X-axis direction, the axial direction perpendicular to the direction of insertion of the shaft-like body), the front-rear direction ^Z can be detected. The detection signal of the motion detection unit 11 is transmitted to the control unit 3.

Returning to FIG. 5, the slave robot 2 </ b> A holds the robot forceps 150 and moves the grip 151 provided at the tip of the robot forceps 150 in the vertical direction (X-axis direction) and the front-back direction (Z-axis direction, the direction in which the forceps are inserted). This is a two-degree-of-freedom holding device that can be moved. Note that the slave robot 2A pivots the robot forceps 150 around the fixed point PP as a rotation center.

As shown in FIG. 6, the control unit 3 </ b> A includes a control unit 31 having a reference input generation unit 32 and a feedback control unit 33, and an input / output unit 34. Reference input generator 32, input position theta _M ^X, by weighting the theta _M ^Z, the reference input position q _sref ^X, generates a q _sref ^Z.

The other configuration is the first implementation except that the control of “the rotational speed around the yaw axis and the rotational speed around the pitch axis” is changed to the control of “the position in the X-axis direction and the position in the Z-axis direction”. This is the same as the operation system S according to the embodiment, and a duplicate description is omitted.

The robot forceps 150 has a gripping portion 151 at the tip. The robot forceps 150 grips the grip 151 in two directions (an axial direction perpendicular to the direction in which the shaft-like body is inserted and another axial direction perpendicular to the direction in which the shaft-like body is inserted), and the gripping force. It has 3 degrees of freedom that combines 1 degree of freedom to open and close the portion 151. Although detailed description is omitted here, the bending and opening / closing of the gripping portion 151 of the robot forceps 150 can be controlled by operating the master robot 1A. In addition, the actuator 12 of the master robot 1A is operated by the power control device that operates the actuator that controls the opening / closing of the gripping portion 151 of the robot forceps 150 held by the slave robot 2A, and force feedback is performed. .

<Reference input generation unit 32>
Next, generation of reference input positions q _sref ^X and q _sref ^Z in the reference input generation unit 32 of the control unit 3A will be further described.

Here, in the operation system S as shown in FIG. 5, in order to improve the safety of the operation of the operator OP detected by the master robot 1A, the movement (z-axis direction) of the robot forceps 150 on the axis is changed. Is weighted so as to be slower than the movement of the axis, in other words, different weights are applied in the vertical direction (x-axis direction) and the front-rear direction (z-axis direction). A weighting that attenuates is performed. That is, in equations (1) to (5), ω _G ^Y , ω _G ^P , q _dref ^Y , and q _dref ^P are _read as θ _M ^X , θ _M ^Z , q _sref ^X , and q _sref ^Z , respectively. The direction weighting is α _max , the front-rear direction weighting is β _max , β _max is “β _max <1”, and α _max is “α _max = 1”.

As described above, the operation system SA according to the second embodiment sets the directions of the input vector r and the reference input vector R (angle θ in FIG. 4B) while performing different weighting in the vertical direction and the front-back direction. Can be equal. As a result, the direction input by the operator OP (angle θ of the input vector r) and the direction in which the robot forceps 150 actually move (angle θ of the reference input vector R) become equal, causing the operator OP to feel uncomfortable. This makes it possible to improve the operational feeling of the operator OP.

≪Modification≫
The operation systems S and SA according to the present embodiment (first and second embodiments) are not limited to the configuration of the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. It is.

Although the operation systems S and SA according to the present embodiment (first and second embodiments) have been described with two degrees of freedom, the present invention is not limited to this. FIG. 7 is a diagram showing the relationship between the input vector r and the weighted reference input vector R in three degrees of freedom. For example, in the left-right direction (axis perpendicular to the direction in which the shaft-shaped body is inserted), the vertical direction (the other axis orthogonal to the direction in which the shaft-shaped body is inserted), and the front-rear direction (axis in which the shaft-shaped body is inserted) An ellipsoid having axial radii of α _max · r, β _max · r, and γ _max · r, with the weighting factor in the direction being α _max , the weighting factor in the vertical direction being β _max, and the weighting factor in the front and rear direction being γ _max think of.

When the left and right direction input signals, the up and down direction input signals, and the front and back direction input signals detected by the motion detection unit 11 are respectively represented as ω _G ^x , ω _G ^y , and ω _G ^z , the magnitude of the input vector is expressed by the equation (6 The angle θ and the angle φ can be expressed by Expression (7) and Expression (8).

The size of the reference input vector R can be expressed by Equation (9).

The weighted reference input signals q _dref ^x , q _dref ^y , and q _dref ^z can be expressed by the following equations (10) to (12).

As described above, the operation systems S and SA according to the present embodiment (first and second embodiments) can be applied to a case of three degrees of freedom, and similarly, can be applied to a multi-degree of freedom operation system. can do. Note that the input signals ω _G ^x , ω _G ^y , ω _G ^z and the reference input signals q _dref ^x , q _dref ^y , q _dref ^z may indicate speed as in the first embodiment. The position may be indicated as in the second embodiment.

Moreover, although 1st Embodiment demonstrated the operating system S of the endoscope 100 and 2nd Embodiment demonstrated as operating system SA of the robot forceps 150, it is not restricted to this, Master-slave type operating system Can be widely applied in general.

Although the actuator 22 of the holding arm unit 2 has been described as using a pneumatic actuator, for example, it is not limited to this. An electric actuator may be used.

S Operation System 1 Motion Detection Unit 11 Motion Detection Unit 2 Holding Arm Unit 21 Holding Arm Unit 22 Actuator 23 State Quantity Detection Unit 24 Power Control Device 3 Control Unit 31 Control Unit 32 Reference Input Generation Unit 33 Feedback Control Unit (Actuator Control Unit)
331 Position controller 332 Subtractor 333 Driving force controller 34 Input / output unit OP Operator PP Fixed point 100 Endoscope 150 Robot forceps ω _G , θ _M Input speed (input command)
q _dref , q _sref reference input speed (reference input command)

Claims

An actuator,
An operation detector that detects a plurality of inputs of two or more axes and outputs a plurality of input commands;
A reference input generation unit for generating a plurality of reference input commands from the plurality of input commands;
An actuator controller that controls the actuator based on the plurality of reference input commands,
The reference input generation unit
An operation system that performs weighting while maintaining the directions of the plurality of input commands, and generates the plurality of reference input commands.
The reference input generation unit
2. The plurality of reference input commands are generated so that a ratio of each axis component of the plurality of reference input commands is equal to a ratio of each axis component of the plurality of input commands. Operation system.
2. The operation system according to claim 1, wherein when the plurality of input commands are ω 1 and ω 2 and the plurality of reference input commands are q 1 and q 2 , the following relationship is satisfied.
The relation of the following expressions is satisfied when the plurality of input commands are ω 1 , ω 2 , ω 3 and the plurality of reference input commands are q 1 , q 2 , q 3. The operation system described in.