KR101787265B1 - A positioning arm - Google Patents

Abstract

According to one embodiment, the positioning arm comprises: a base; A rolling body rotatable relative to the base about a first rotational axis; A pitching link rotatable relative to the rolling body about a second axis of rotation that is disposed long in a direction intersecting the first axis of rotation; A slider slidable relative to the rolling body in a direction intersecting the first rotation axis and the second rotation axis; A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And an elastic module connected between the slider and the pitch link, the elastic module at least partially formed of a material having elasticity.

Description

Positioning Arm {A POSITIONING ARM}

The following description relates to the positioning arm.

Robots have been used in various fields such as medical field and industrial field. For example, in the medical field, a positioning arm, which is part of a slave system of a surgical robot system and can position a surgical instrument and a robot arm freely and stably, Is used.

Positioning arms with two degrees of freedom are commonly used, and are widely used in surgical robots such as laparoscopic surgery robots and da Vinci systems. The weight of the position adjusting arm or the weight of the instrument loaded in the position adjusting arm acts on the joint of the position adjusting arm to generate a gravity torque. Since the gravity torque can change the posture of the position adjusting arm, it is necessary to constantly operate a constant force in order to keep the posture of the position adjusting arm constant. For example, the user can provide a force to hold the position adjusting arm, use an actuator such as a motor to provide a constant torque, or can be fixed using a brake.

However, due to the weight of the position adjustment arm, it is very difficult for the user to perform the surgical operation while continuously providing such force, and there is a limit to the weight that can support the position adjustment arm. In addition, even if an actuator such as a motor is used, there is a problem that an excessive load is applied. In order to overcome this problem, there has been a problem that the price is high, the volume is large, and it is inefficient compared with the volume. In the case of using a brake, it is necessary to unfasten and tighten the brake to reduce the usability. Also, when the brake is loosened to adjust the position of the position adjusting arm, There was a problem. Therefore, a gravity compensating means for compensating the self weight of the position adjusting arm has been required.

It is an object of the embodiments to provide a position adjustment arm that has a rotational degree of freedom in at least two directions and which can also be operated with a small force using a gravity compensation mechanism.

According to one embodiment, the positioning arm comprises: a base; A rolling body rotatable relative to the base about a first rotational axis; A pitching link rotatable relative to the rolling body about a second axis of rotation that is disposed long in a direction intersecting the first axis of rotation; A slider slidable relative to the rolling body in a direction intersecting the first rotation axis and the second rotation axis; A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And an elastic module connected between the slider and the pitch link, the elastic module at least partially formed of a material having elasticity.

The motion converting module may include a scotch youke mechanism for converting the rotational motion into a linear motion.

The motion converting module may include: a protrusion-shaped first guide fixed to the base; And a cam-shaped second guide fixed to the slider and having the first guide inserted therein.

The first guide may be spaced apart from the base in a direction perpendicular to the first axis of rotation.

The cam shape of the second guide may have a straight shape or may have a curved shape having a radius of curvature larger than a radius of curvature of an imaginary circle having a radius from the first rotation axis to the first guide have.

The elastic module includes: a wire connected to the slider; And an elastic member having one end connected to the wire and the other end connected to the pitch link.

The pitch link may further include a pair of guide idlers that support the wire on both sides and allow the wire to extend to the slider via a particular point on the pitch link.

Wherein a distance from the first rotation axis to the second guide becomes a maximum at a position where the rolling angle is 0 degrees when the pitch angle of the pitch link is 0 degrees when the pitch link is disposed on a plane perpendicular to the paper surface, As the absolute value of the rolling angle becomes larger, it can be reduced.

The distance from the first rotation axis to the second guide can be minimized in the attitude in which the rolling angle is 90 degrees.

The elastic potential energy of the elastic module may be minimized at the point where the pitch angle is 0 degrees when the pitch angle of the pitch link is 0 degree in a vertical posture with respect to the rolling body.

And the rolling angle of the pitch link is 0 degree when the pitch link is disposed on a plane perpendicular to the paper surface, the variation width of the elasticity position energy of the elasticity module in accordance with the rotation angle change of the pitch link, When it can be maximum.

As the rolling angle increases, the variation width of the elastic position energy of the elastic module in accordance with the rotation angle change of the pitch link can be reduced.

When the rolling angle is 90 degrees, the variation width of the elastic position energy of the elastic module according to the rotation angle change of the pitch link may be zero.

The slider may be installed such that an end of the elastic module is fixed and rotatable with respect to the main body of the slider.

The fixed idler may be located on the second rotation axis when the rolling angle is 90 degrees when the pitch angle when the pitch link is disposed on a plane perpendicular to the paper is 0 degree.

The pitch link comprising: a first pitch link rotatably connected to the rolling body; And a second pitch link that is parallel to the first pitch link and is rotatably connected to the rolling body, the position adjustment arm being connected to the first pitch link and the second pitch link, And a connection link parallel to the virtual line connecting the rotation axis of the pitch link and the rotation axis of the second pitch link.

The connecting link includes: a first connecting link rotatably connected to the pitch link; And a second connection link parallel to the first connection link and rotatably connected to the pitch link.

The first rotation axis and the second rotation axis may intersect on the same plane.

According to one embodiment, the positioning arm comprises: a base; A rolling body rotatable about the base; A pitching link capable of pitch rotation relative to the rolling body; A slider vertically slidable with respect to the rolling body; And an elasticity module having one end connected to the slider and the other end connected to the pitch link to provide an elastic force for compensating for the gravity torque applied to the rotational axis of the pitch link.

According to one embodiment, the positioning arm comprises: a base; A rolling body rotatable about the base; A pitching link capable of pitch rotation relative to the rolling body; A slider slidable in a vertical direction with respect to the rolling body, corresponding to a rolling rotation angle of the rolling body; And an elastic module having one end connected to the slider and the other end connected to the pitch link.

The position adjusting arm according to the embodiment has a rotational freedom of at least two directions and can be operated with a small force using a gravity compensation mechanism for a load torque applied to the position adjusting arm.

Specifically, the position adjustment arm can operate in the pitch and roll directions, that is, at least two rotation degrees of freedom. The elasticity module connected to the pitch link is expanded and contracted according to the pitch angle of the position adjustment arm to change the elastic position energy so that the magnitude of the compensation torque for the load torque in the pitch direction can be adjusted. In addition, since the elastic range of the elastic module is adjusted in accordance with the rolling angle of the position adjusting arm, and consequently the rate of change of the elastic position energy according to the pitch angle change is changed, the compensation torque for the load torque in the pitch direction, Lt; / RTI > In other words, the position adjustment arm can provide an appropriate compensation torque in conjunction with both the pitch angle change and the rolling angle change.

On the other hand, even if some difference occurs between the load torque and the compensating torque, by the frictional force generated between the parts, or by the torque provided by the user or the actuator, only the torque corresponding to the difference is provided, So that the load on the user or the actuator can be minimized. As a result, it is possible to downsize the entire system and has advantages in terms of cost.

When the positioning arm using the above gravity compensation mechanism is used for surgery, even if a sudden power failure occurs during operation, the patient can be kept stationary without harming the patient. In order to catch, the doctor can move the robot comfortably.

1 is a perspective view of a position adjusting arm according to an embodiment.
2 is a right side view of Fig.
3 is a view illustrating a position control arm according to an exemplary embodiment of the present invention.
4 is a front view of Fig.
5 is an enlarged view of a slider according to an embodiment.
6 is a view of a portion of a position adjustment arm according to one embodiment.
FIG. 7 is a view showing a state in which the first pitch link is rotated by 45 degrees in FIG.
8 is a block diagram of a motion transformation module according to an embodiment.
FIG. 9 is a view showing a state in which the rolling body is rotated by 45 degrees in FIG.
FIG. 10 is a view showing a state in which the rolling body is rotated 90 degrees in FIG.
11 is a view showing a state when the rolling angle of the position adjusting arm according to the embodiment is 0 degrees and the pitch angle is 45 degrees.
12 is a view showing a state where the rolling angle of the position adjusting arm according to an embodiment is 45 degrees and the pitch angle is 45 degrees.
13 is a view showing a state where the rolling angle of the position adjusting arm according to the embodiment is 90 degrees and the pitch angle is 45 degrees.
14 is a view showing a state in which the rolling angle of the position adjusting arm according to the embodiment is 90 degrees and the pitch angle is 0 degrees.
15 is a graph showing the value of the gravity torque applied to the rotation axis of the pitch link in the position adjusting arm according to the embodiment, according to the change of the pitch angle and the rolling angle.
16 is a graph showing the value of the compensation torque acting on the rotation axis of the pitch link in the position adjusting arm according to the embodiment, according to the change of the pitch angle and the rolling angle.
17 is a graph showing the difference between the gravity torque and the compensation torque shown in Figs. 15 and 16, respectively, in accordance with the change of the pitch angle and the rolling angle.
FIGS. 18 and 19 are views for explaining remote center of motion (RCM) points of a position adjusting arm according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of each of the drawings, the same constituent elements are denoted by the same reference numerals even though they are shown in different drawings. In the following description of the embodiments, detailed description of known functions and configurations incorporated herein will be omitted when it may make the best of an understanding clear.

In describing the components of the embodiment, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

The components included in any one embodiment and the components including common functions will be described using the same names in other embodiments. Unless otherwise stated, the description of any one embodiment may be applied to other embodiments, and a detailed description thereof will be omitted in the overlapping scope.

FIG. 1 is a perspective view of a position adjusting arm according to one embodiment, and FIG. 2 is a right side view of FIG. 1. FIG.

1 and 2, the position adjusting arm 1 according to an embodiment is for adjusting the position of various necessary tools such as the surgical instrument I and the like. The position adjusting arm 1 can perform a pitching operation based on the rolling operation that is rotated with respect to the first rotation axis Axis 1 and the second rotation axis Axis2. In other words, the position adjusting arm 1 can have at least two rotational degrees of freedom. The angle of rotation of the rolling body 11 in the counterclockwise direction of the first rotation axis Axis is referred to as a rolling angle? R and the angle of rotation of the second rotation axis Axis 2 in the counterclockwise direction, The angle at which the pitch link 12 is rotated in the direction of the pitch angle? P is defined as the pitch angle? P.

The position adjusting arm 1 includes a base 10, a rolling body 11, a rolling motor M, a pitch link 12, a slider 13, a motion converting module 14, a resilient module 15, Link 16, as shown in FIG.

The base 10 is connected to a target object such as a surgical table and can be a reference for the operation of the position adjusting arm 1. [ The base 10 may be fixed, slidably connected, or rotatably connected to the object, for example. For example, the base 10 may be connected to the object so as to be rotatable about a rotation axis in a direction intersecting the first rotation axis Axis 1 and the second rotation axis Axis 2. In this case, the positioning arm 1 may have three degrees of freedom of rotation.

The rolling body 11 can be rolled with respect to the base 10. The rolling body 11 may be rotatably connected to the base 10 with respect to the first rotation axis Axis 1. The first axis of rotation Axis 1 may be parallel to the base 10, for example.

The rolling motor M can rotate the rolling body 11 about the first rotation axis Axis 1. The rolling motor M may provide power to compensate for the gravity torque applied to the rotational axis Axis 1 of the rolling body 11.

The pitch link 12 can be pitch-rotated with respect to the rolling body 11. The pitch link 12 may be rotatably connected to the rolling body 11 on the basis of a second rotation axis Axis 2 which is long in a direction intersecting the first rotation axis Axis 1. For example, the second rotation axis Axis 2 may be arranged in a direction perpendicular to the first rotation axis Axis 1. The second rotation axis Axis 2 may be arranged on the same plane as the first rotation axis Axis 1. It should be noted, however, that the second rotation axis Axis 2 is not necessarily located on the same plane as the first rotation axis Axis 1.

The slider 13 can move in accordance with the rolling rotation angle of the rolling body 11. For example, the slider 13 can be slidably installed in the direction intersecting the first rotation axis Axis 1 and the second rotation axis Axis 2 with respect to the rolling body 11. For example, the slider 13 can be slid in the vertical direction with respect to the rolling body 11.

The motion converting module 14 is connected between the base 10 and the slider 13 and allows the slider 13 to slide with respect to the rolling body 11 in accordance with the rotational motion of the rolling body 11 . In other words, the motion converting module 14 can convert the rotational motion of the rolling body 11 into a linear motion of the slider 13. [ For example, motion conversion module 14 may be a scotch youkke mechanism for converting rotational motion to linear motion, as described in the Figures herein. As another example, the motion converting module 14 may have a rack and pinion structure. In the present invention, the motion conversion module 14 can be any structure that converts rotational motion into linear motion, and it is not limited to the kind of the motion conversion module 14. Hereinafter, the case where the motion converting module 14 is a scotch yoke mechanism will be exemplarily described.

The motion converting module 14 includes a first guide 141 in the form of a projection fixed to the base 10 and a second guide 141 fixed to the slider 13 and having a cam shape in which the first guide 141 is inserted. And may include a guide 142. The first guide 141 may be spaced apart from the base 10 in a direction perpendicular to the first axis of rotation Axis 1. In other words, when the projecting direction of the first guide 141 is referred to as a third axis Axis 3, the third axis Axis 3 has a constant eccentric distance e from the first axis of rotation Axis 1 . The third axis (Axis 3) may be parallel to the first axis of rotation (Axis 1). The first guide 141 and the second guide 142 may be fixed to the slider 13 and the base 10, respectively, and a detailed description thereof will be omitted.

The elasticity module 15 can provide an elastic force for compensating for the gravity torque applied to the rotation axis Axis2 of the pitch link 12, corresponding to the pitch angle and the rolling angle of the position adjustment arm 1. [ One end of the elastic module 15 may be connected to the slider 13 and the other end may be connected to the pitch link 12. In other words, the elastic module 15 may be formed of a material that is connected between the slider 13 and the pitch link 12, and at least a part of which is elastic. The elastic module 15 will be described in more detail with reference to Fig.

The connecting link 16 may be rotatably connected to the pitch link 12. [

FIG. 3 is a view illustrating a position control arm according to an embodiment of the present invention; FIG. 4 is a front view of FIG. 3; FIGS. 3 and 4 are views for facilitating understanding of the elasticity module 15 according to one embodiment.

3 and 4, the elastic module 15 according to an embodiment may include an elastic member 151, a wire 152, a connection portion 153, and a fixing portion 154. [

One end of the elastic member 151 may be connected to the wire 152 through the connecting portion 153 and the other end may be connected to the pitch link 12 through the fixing portion 154.

One end of the wire 152 may be connected to the slider 13 and the other end may be connected to the elastic member 151 through the connection part 153. [ The wire 152 may be formed of, for example, steel or the like rigid against the tension.

The connecting portion 153 can be slidably connected to the pitch link 12. [ The fixing portion 154 can be fixed to the pitch link 12. The connecting portion 153 can be disposed at a position farther from the fixed portion 154 than the fixed portion 154 with respect to the rotation axis of the pitch link 12. [

The connecting portion 153 is slid with respect to the pitch link 12 by the tension applied to the wire 152 and the length of the elastic member 151 is increased by the sliding movement of the connecting portion 153 Can be changed. The elastic restoring force of the elastic member 151 generated in the above process can provide a force for compensating the gravity torque applied to the rotation axis of the pitch link 12, as described later.

On the other hand, the above-described elastic module 15 is only one example, and it is to be noted that the structure of the elastic module 15 is not necessarily limited to the above. The wire 152 may be directly connected to the elastic member 151 without the connecting portion 153 and the elastic member 151 may be connected directly to the pitch link 12 without the fixing portion 154. [ In addition, the elastic module 15 may be composed of one elastic body such as, for example, an elastic string.

The pitch link 12 may include a guide idler 1211 that is rotatably installed. The guide idler 1211 supports the wire 152 and allows the wire 152 to extend to the slider 13 via a specific point on the pitch link 12. [ A pair of idlers 1211 can be disposed on both sides of the wire 152, respectively.

According to the above structure, when the pitch link 12 is rotated, the wire 152 can be smoothly moved along the guide idler 1211, and excessive fatigue can be prevented at the point where the wire 152 is bent .

5 is an enlarged view of a slider according to an embodiment.

Referring to FIG. 5, the slider 13 according to an embodiment may include a fixed idler 131 that is rotatable relative to the body of the slider 13. The end of the elastic module 15, for example, the end of the wire 152, may be fixed to the fixed idler 131.

According to the above structure, when the pitch link 12 is rotated, the fixed idler 131 can be rotated in response to the direction of the tension acting on the wire 152.

FIG. 6 is a view of a portion of a position adjusting arm according to an embodiment, and FIG. 7 is a view illustrating a state in which the first pitch link is rotated by 45 degrees in FIG. Figs. 6 and 7 show the case where the pitch angle? _P is 0 degree and 45 degrees, respectively, when the rolling angle? R is 0 degree.

First, as shown in Fig. 6, the pitch angle? P in a posture in which the pitch link 12 is perpendicular to the rolling body 11 may be 0 degree. In this case, since the center of gravity of the pitch link 12 is located in a direction perpendicular to the rotation axis Axis2 of the pitch link 12, the pitch link 12 is positioned on the rotation axis Axis of the pitch link 12, 2 are balanced with respect to the pitch direction. Therefore, the pitch link 12 can maintain a vertical posture with respect to the rolling body 11 even if no compensation torque acts. In this state, the distance between the fixed idler 131 and the guide idler 1211 is minimized, so that the elastic potential energy of the elastic module 15 can be minimized.

7, when the pitch angle? P is 45 degrees, the center of gravity of the pitch link 12 is located on the left side (reference to Fig. 7) with respect to the rotation axis Axis2 of the pitch link 12, A counterclockwise gravity torque acts. As the pitch angle (θ_p) increases between 0 and 90 degrees, the magnitude of the gravity torque increases.

On the other hand, as the pitch angle? _P increases as long as the distance d from the rotation axis Axis 2 of the pitch link 12 to the fixed idler 131 exists, the end of the elastic module 15 The distance from the fixed idler 131 to the guide idler 1211 is increased. Therefore, as the length variation of the elastic module 15 gradually increases, the tension T applied to the wire 151 increases due to the elastic restoring force of the elastic module 15. The tension T can be decomposed into a component T_1 acting in a direction perpendicular to the pitch link 12 and a component T_2 acting in the longitudinal direction of the pitch link 12, It can act as a compensating torque acting in a clockwise direction with respect to the axis of rotation Axis2.

In other words, the elastic restoring force of the elastic modulus 15 increases as the pitch angle? P increases, and the elastic restoring force becomes larger as the compensating torque acts in the opposite direction of the gravity torque direction . ≪ / RTI > Also, the elastic restoring force can be increased as the separation distance d becomes larger.

On the other hand, the separation distance d is maintained irrespective of the pitch angle? _P and can be changed according to the rolling angle? _R as described later.

8 is a view showing a motion converting module according to an embodiment, FIG. 9 is a view showing a state where the rolling body is rotated by 45 degrees in FIG. 8, FIG. 10 is a view showing a state in which the rolling body is rotated by 90 degrees in FIG. Fig.

Referring to FIGS. 8 to 10, the first guide 141 of the motion converting module 14 according to one embodiment can be relatively slidably moved on a cam formed on the second guide 142. It can be understood that the second guide 142 is slidingly moved relative to the projection of the first guide 141 when the first guide 141 and the base 10 connected thereto are fixed.

The distance from the first rotation axis Axis 1 to the cam formed in the second guide 142 is larger than the eccentric distance e from the first rotation axis Axis 1 to the first guide 141 Can be the same. As shown in Fig. 8, the distance from the center of the cam may be the shortest.

For example, as shown in Figs. 8 to 10, the cam shape of the second guide 142 may have a straight shape. However, the shape of the cam is not necessarily limited to the above, and the eccentric distance e from the first rotation axis Axis 1 to the first guide 141 is set to be larger than the radius of curvature of the imaginary circle And may have a curved shape having a large radius of curvature. The cam shape can be designed according to the shape of the desired compensation torque.

According to the above structure, when the pitch link 12 is disposed on a plane perpendicular to the paper surface, that is, at a point where the rolling angle? R is 0 degrees, the separation distance d can be maximized have.

9, the second guide 142 and the slider 13 connected thereto are slid with respect to the rolling body 11, and as a result, the separation distance d decreases as the rolling angle? R increases, .

10, when the rolling angle? R is 90 degrees, the separation distance d becomes 0. Therefore, the rotation axis Axis 2 of the pitch link 12 and the rotation axis of the fixed idler 131 coincide with each other do. In other words, the fixed idler 131 can be located on the second rotation axis Axis2.

The above operation is also true when the rolling angle? R is increased in the opposite direction. In other words, the distance from the first rotation axis Axis 1 to the second guide 142 becomes maximum at the posture in which the rolling angle? R is 0 degrees, decreases as the absolute value of the rolling angle? R increases, Can be minimized in the attitude in which the rolling angle [theta] _r is 90 degrees.

According to the above operation, the compensation torque can be adjusted in accordance with the change of the rolling angle? _R as well as the change of the pitch angle? _P. Hereinafter, a detailed description will be given with reference to Figs. 11 to 13. Fig.

FIG. 11 is a view showing a state where the rolling angle of the position adjusting arm according to an embodiment is 0 degrees and the pitch angle is 45 degrees, FIG. 12 is a view showing a state where the rolling angle of the position adjusting arm according to an embodiment is 45 degrees And FIG. 13 is a view showing a state when the rolling angle of the position adjusting arm according to the embodiment is 90 degrees and the pitch angle is 45 degrees. 11 is a view similar to Fig.

Referring to Figs. 11 to 13, when the pitch angle? _P exceeds 0, for example, even when the angle is the same as 45 degrees, the compensation torque can be changed as the rolling angle? R changes Able to know.

11, when the rolling angle? R is 0 degree, the height of the slider 13 with respect to the rolling body 11 becomes maximum, and the separation distance d becomes the maximum. As shown in Fig. 12, when the rolling angle? R is increased, the height of the slider 13 with respect to the rolling body 11 is reduced, so that the separation distance d can be reduced. As shown in Fig. 13, when the rolling angle? R is 90 degrees, the separation distance d can be zero.

The first portion of the wire 151 extending from the fixed idler 131 to the guide idler 1211 and the second portion of the wire 151 extending from the guide idler 1211 to the connection portion 153 And the angle formed between them gradually decreases. Therefore, the component force T_1 acting in the direction perpendicular to the longitudinal direction of the pitch link 12 among the tensile forces T applied to the wire 151 is reduced, and can eventually become zero. In other words, the compensation torque becomes maximum when the rolling angle? R is 0 degrees, and the compensation torque becomes 0 when the rolling angle? R is 90 degrees.

For reference, when the rolling angle? R is 90 degrees, the pitch link 12 pivots on a horizontal plane to the ground, so that the gravity torque acting on the rotation axis Axis 2 of the pitch link 12 is substantially 0. Therefore, when the rolling angle [theta] _r is 90 degrees, the compensation torque is made to be zero, so that the attitude of the position adjustment arm 1 can be maintained.

In short, the larger the distance d is from the non-zero pitch angle? P, the greater the angle formed by the first and second portions of the wire 151 becomes. Therefore, the separation distance d or the rolling angle? _R can determine the variation width of the elastic position energy of the elasticity module 15 in accordance with the rotation angle change of the pitch link 12.

Therefore, the variation width of the elastic position energy of the elastic module 15 with the rotation angle change of the pitch link 12 becomes maximum when the rolling angle? _R is 0 degree, and decreases as the rolling angle? R increases , And becomes 0 when the rolling angle [theta] _r is 90 degrees.

14 is a view showing a state in which the rolling angle of the position adjusting arm according to the embodiment is 90 degrees and the pitch angle is 0 degrees. Fig. 14 can be understood as a state in which the pitch angle is changed in the state of Fig.

14, when the rolling angle? R is 90 degrees, even if the pitch angle? _P is changed, the elastic potential energy of the elastic module 15 does not change, and the tension on the wire 151 is transmitted to the pitch link 12 do not act on the axis of rotation Axis 2.

FIG. 15 is a graph showing the value of gravity torque applied to the rotation axis of the pitch link in a position adjusting arm according to an embodiment, according to a change in the pitch angle and the rolling angle, and FIG. 17 is a graph showing the value of the compensation torque acting on the rotation axis of the pitch link according to the change of the pitch angle and the rolling angle, and Fig. 17 is a graph showing the difference between the gravity torque and the compensation torque A pitch angle and a rolling angle.

Referring to FIGS. 15 and 16, it can be seen that the variation of the gravity torque and the variation of the compensation torque are similar. Therefore, it can be seen that the gravity torque can be compensated by using the position adjusting arm 1 according to the embodiment as shown in Fig.

For example, by appropriately changing the shape of the cam of the second guide 142, the compensating torque may accurately follow and cancel the gravity torque.

On the other hand, even if some difference occurs between the load torque and the compensating torque as shown in Fig. 17, by the frictional force generated between the parts, or by the torque provided by the user or the actuator, The attitude of the adjustment arm can be maintained, so that the load on the user or the actuator can be minimized.

As described above, according to the embodiment, the compensation torque for the gravity torque applied to the rotation axis Axis 2 of the pitch link 12 can be adjusted corresponding to both of the rolling angle? R and the pitch angle? , It becomes possible to provide an appropriate compensation torque for both rotational angles in two directions. Therefore, it is possible to maintain a static equilibrium state in all the postures of the position adjusting arm 10 without using a counter inertia, a brake, or the like.

FIGS. 18 and 19 are views for explaining remote center of motion (RCM) points of a position adjusting arm according to an embodiment.

18 and 19, the pitch link 12 includes a first pitch link 121 rotatably connected to the rolling body 11, a second pitch link 121 parallel to the first pitch link 121, And a second pitch link 122 rotatably connected to the second pitch link 122. [

The position adjustment arm 1 is connected to the first pitch link 121 and the second pitch link 122 and connects the rotation axis of the first pitch link 121 and the rotation axis of the second pitch link 122 And a connection link 16 parallel to the imaginary line.

The connecting link 16 includes a first connecting link 161 rotatably connected to the pitch link 12 and a second connecting link 161 parallel to the first connecting link 161 and rotatably connected to the pitch link 12. [ And may include a connection link 162.

According to the above structure, the pitch link 12 and the connecting link 16 can perform a movement in a form similar to a 4-bar linkage in a parallelogram shape. Therefore, as shown in Figs. 18 and 19, regardless of the pitch angle? _P of the position adjusting arm 1, a remote center of motion (RCM) is determined based on one point (RCM point) can do.

Further, when the first rotation axis Axis 1 and the second rotation axis Axis 2 intersect on the same plane, the position of the one point (RCM point), regardless of the rolling angle? R of the positioning arm 1, ) Can be used.

The position adjusting arm according to the embodiment has a rotational freedom of at least two directions and can be operated with a small force using a gravity compensation mechanism for a load torque applied to the position adjusting arm. Specifically, the position adjustment arm can operate in the pitch and roll directions, that is, at least two rotation degrees of freedom. The elasticity module connected to the pitch link is expanded and contracted according to the pitch angle of the position adjustment arm to change the elastic position energy so that the magnitude of the compensation torque for the load torque in the pitch direction can be adjusted. In addition, since the elastic range of the elastic module is adjusted in accordance with the rolling angle of the position adjusting arm, and consequently the rate of change of the elastic position energy according to the pitch angle change is changed, the compensation torque for the load torque in the pitch direction, Lt; / RTI > In other words, the position adjustment arm can provide an appropriate compensation torque in conjunction with both the pitch angle change and the rolling angle change. On the other hand, even if some difference occurs between the load torque and the compensating torque, by the frictional force generated between the parts, or by the torque provided by the user or the actuator, only the torque corresponding to the difference is provided, So that the load on the user or the actuator can be minimized. As a result, it is possible to downsize the entire system and has advantages in terms of cost. When the positioning arm using the above gravity compensation mechanism is used for surgery, even if a sudden power failure occurs during operation, the patient can be kept stationary without harming the patient. In order to catch, the doctor can move the robot comfortably.

Although the embodiments have been described with reference to the drawings, various technical modifications and variations may be applied to those skilled in the art. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Claims (20)

Base;
A rolling body rotatable relative to the base about a first rotational axis;
A pitching link rotatable relative to the rolling body about a second axis of rotation that is disposed long in a direction intersecting the first axis of rotation;
A slider slidable relative to the rolling body in a direction intersecting the first rotation axis and the second rotation axis;
A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And
And an elastic module connected between the slider and the pitch link, the elastic module at least partially formed of a material having elasticity,
Wherein the motion conversion module comprises:
A first guide in the form of a projection fixed to the base; And
And a second guide fixed to the slider and having a cam shape into which the first guide is inserted.
The method according to claim 1,
Wherein the motion conversion module comprises:
A locating arm comprising a scotch youke mechanism for converting rotational motion into linear motion.
delete The method according to claim 1,
Wherein the first guide is spaced apart from the base in a direction perpendicular to the first axis of rotation.
5. The method of claim 4,
The cam shape of the second guide may be a linear shape or a curved shape having a curvature radius larger than a radius of curvature of an imaginary circle having a radius from the first rotation axis to the first guide Adjustable arm.
Base;
A rolling body rotatable relative to the base about a first rotational axis;
A pitching link rotatable relative to the rolling body about a second axis of rotation that is disposed long in a direction intersecting the first axis of rotation;
A slider slidable relative to the rolling body in a direction intersecting the first rotation axis and the second rotation axis;
A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And
And an elastic module connected between the slider and the pitch link, the elastic module at least partially formed of a material having elasticity,
The elastic module includes:
A wire connected to the slider; And
And a resilient member having one end connected to the wire and the other end connected to the pitch link.
The method according to claim 6,
The pitch link includes:
Further comprising a pair of guide idlers that support the wire from both sides and allow the wire to extend to the slider via a particular point on the pitch link.
6. The method of claim 5,
And when the pitch angle when the pitch link is disposed on a plane perpendicular to the paper is 0 degree,
Wherein the distance from the first rotation axis to the second guide
The maximum value is attained in the posture in which the rolling angle is 0 degree,
Wherein the positioning arm is reduced as the absolute value of the rolling angle increases.
9. The method of claim 8,
Wherein the distance from the first rotation axis to the second guide
Wherein the positioning arm is minimized at the rolling angle of 90 degrees.
The method according to claim 1,
And when the pitch angle of the pitch link in a posture perpendicular to the rolling body is 0 degrees,
Wherein the elastic potential energy of the elastic module is minimized at a point at which the pitch angle is zero degrees.
The method according to claim 1,
And when the pitch angle when the pitch link is disposed on a plane perpendicular to the paper is 0 degree,
Wherein the change width of the elastic position energy of the elastic module with the rotation angle change of the pitch link is maximized when the rolling angle is 0 degree.
12. The method of claim 11,
Wherein as the rolling angle increases, the variation width of the elastic position energy of the elastic module with the rotation angle change of the pitch link decreases.
12. The method of claim 11,
Wherein when the rolling angle is 90 degrees, the change width of the elasticity position energy of the elasticity module in accordance with the rotation angle change of the pitch link is zero.
Base;
A rolling body rotatable relative to the base about a first rotational axis;
A pitching link rotatable relative to the rolling body about a second axis of rotation that is disposed long in a direction intersecting the first axis of rotation;
A slider slidable relative to the rolling body in a direction intersecting the first rotation axis and the second rotation axis;
A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And
And an elastic module connected between the slider and the pitch link, the elastic module at least partially formed of a material having elasticity,
The slider
And a fixed idler fixed to an end of the elastic module and rotatably mounted to the main body of the slider.
15. The method of claim 14,
And when the pitch angle when the pitch link is disposed on a plane perpendicular to the paper is 0 degree,
And when the rolling angle is 90 degrees, the fixed idler is positioned on the second rotation axis.
The method according to claim 1,
The pitch link includes:
A first pitch link rotatably connected to the rolling body; And
A second pitch link parallel to the first pitch link and rotatably connected to the rolling body,
Further comprising a connection link connected to the first pitch link and the second pitch link and parallel to an imaginary line connecting the rotation axis of the first pitch link and the rotation axis of the second pitch link.
17. The method of claim 16,
The connection link
A first connecting link rotatably connected to the pitch link; And
And a second connection link parallel to the first connection link and rotatably connected to the pitch link.
18. The method of claim 17,
Wherein the first rotation axis and the second rotation axis intersect on the same plane.
Base;
A rolling body rotatable about the base;
A pitching link capable of pitch rotation relative to the rolling body;
A slider vertically slidable with respect to the rolling body;
A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And
And an elastic module connected at one end to the slider and at the other end to the pitch link to provide an elastic force for compensating for gravity torque applied to the rotational axis of the pitch link,
Wherein the motion conversion module comprises:
A first guide in the form of a projection fixed to the base; And
And a second guide fixed to the slider and having a cam shape into which the first guide is inserted.
Base;
A rolling body rotatable about the base;
A pitching link capable of pitch rotation relative to the rolling body;
A slider slidable in a vertical direction with respect to the rolling body, corresponding to a rolling rotation angle of the rolling body;
A motion converting module coupled between the base and the slider and adapted to cause the slider to slide with respect to the rolling body in accordance with rotational motion of the rolling body; And
An elastic module having one end connected to the slider and the other end connected to the pitch link,
Wherein the motion conversion module comprises:
A first guide in the form of a projection fixed to the base; And
And a second guide fixed to the slider and having a cam-like shape into which the first guide is inserted.

Images