CN113655712A - Vascular robot coupling modeling and robust self-adaptive control method - Google Patents
Vascular robot coupling modeling and robust self-adaptive control method Download PDFInfo
- Publication number
- CN113655712A CN113655712A CN202110604422.XA CN202110604422A CN113655712A CN 113655712 A CN113655712 A CN 113655712A CN 202110604422 A CN202110604422 A CN 202110604422A CN 113655712 A CN113655712 A CN 113655712A
- Authority
- CN
- China
- Prior art keywords
- robot
- vascular
- blood
- equation
- substances
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
- G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
- G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
- G05B13/042—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Abstract
A vascular robot coupling modeling and robust self-adaptive control method belongs to the technical field of control. The invention aims to establish a vascular robot attitude and orbit integrated kinematics and dynamics coupling model based on a spiral theory and dual quaternion, design a gravity-buoyancy compensation device, fully analyze the influence of blood pulsation flow field effect, and finally design a vascular robot coupling modeling and robust self-adaptive control method with a certain control precision robust self-adaptive control scheme. The invention establishes a model of the vascular robot for integrating the attitude and orbit kinematics and dynamics; building a gravity-buoyancy compensation device; the influence of the vessel wall motion on the blood flow velocity is combined to finally analyze the resistance borne by the vessel robot; and designing a robust adaptive controller. The invention can move spirally in blood without contacting with blood vessels, thereby realizing the effect that the vascular robot has no damage to vascular tissues, and having important significance for the application of the vascular robot in the medical field.
Description
Technical Field
The invention belongs to the technical field of control.
Background
Along with the development of society, people's income is higher and higher, and people also pay more and more attention to health. Cardiovascular and cerebrovascular diseases as three killers of human health are also increasingly paid attention. At present, the most perfect and advanced method for treating cardiovascular and cerebrovascular diseases is minimally invasive vascular interventional surgery. The minimally invasive vascular interventional operation needs medical care personnel to diagnose cardiovascular and cerebrovascular diseases under X-ray, and under a guiding device, a catheter guide wire needs to be inserted and the guide wire can move in a human body by controlling the tail end of the guide wire. Medical care personnel are required to be exposed to rays for working, so that the body of the medical care personnel is inevitably injured; the guide wire catheter needs to enter the body of a patient for a long time and a long distance, so that great trauma is caused to the patient; medical personnel carry out manual operation through the terminal wire that leads, highly rely on doctor's experience, therefore a little misoperation all can produce irreversible injury to the disease, and this makes vascular intervention operation more highly require medical personnel's operation accuracy and experience.
Disclosure of Invention
The invention aims to establish a vascular robot attitude and orbit integrated kinematics and dynamics coupling model based on a spiral theory and dual quaternion, design a gravity-buoyancy compensation device, fully analyze the influence of blood pulsation flow field effect, and finally design a vascular robot coupling modeling and robust self-adaptive control method with a certain control precision robust self-adaptive control scheme.
The method comprises the following steps:
s1, establishing a model of the vascular robot for integrating the attitude and orbit kinematics and dynamics;
the error-pair quaternion is defined as:
wherein the content of the first and second substances, represents a dual quaternion multiplication;
the vascular robot needs to firstly perform attitude conversion q by a body coordinate systemBDThen is translated againAnd when the position of the target coordinate system is reached, the vessel robot posture and track coupling kinematic equation of the spiral theory and the dual quaternion:
wherein the content of the first and second substances,the angular velocity of the blood vessel robot body coordinate system relative to the inertial system is represented under the blood vessel robot body coordinate system;
the dual angular momentum can be expressed as:
according to the Euler equation:
wherein the content of the first and second substances,the dual resultant force to which the vascular robot is subjected is expressed as follows:
wherein the content of the first and second substances,is a resultant force acting on the center of mass of the vascular robot, anAs a driving force, the driving force is,is the resultant force of gravity and buoyancy,in order to be a fluid resistance, it is,in order to be subjected to the disturbing force,
formula (1036) is simplified to yield:
the vascular robot posture and track coupling kinetic equation of the spiral theory and the dual quaternion is as follows:
the coupling terms are a second term and a fourth term, so that the coupling influence of the gesture motion and the track motion is analyzed;
the second term of the dynamic posture and track coupling model of the vascular robot is as follows:
wherein the content of the first and second substances,is a cross-product factor of the velocity vector,andrespectively are cross multiplication factors of an angular velocity vector and a linear velocity vector of the vascular robot; the concrete expression is substituted into formula (1040) to obtain:
the fourth term of the kinetic model is simplified:
s2, designing a gravity-buoyancy compensation device;
the volume and magnetization of the robot, the magnetic force expression of the micro-robot is:
wherein, gx,gy,gzThree components of the magnetic flux gradient, respectively; in order to move the robot in the horizontal direction, the magnetic force components in the x-axis and the y-axis should satisfy the following equation:
wherein the values of the gradient of the magnetic induction along the x-axis and the y-axis should be equal, i.e. gx=gyBy ghTo replace gx,gy. Magnetic force F in z-axis directionmzIs divided into two parts, whereinFor counteractingRepresenting part of the vascular robot driving force, magnetic field gradient splitting at the z-axisAndtwo parts;
the magnetic force and the magnetic field gradient along the z direction should satisfy the following relations:
s3, analyzing the relationship process of the pulsating flow field effect and the blood vessel wall motion and the blood flow velocity as follows:
resistance to the vascular robotIncluding bloodResistance to the spherical head of a tube robotAnd the resistance to which the helical tail is subjectedThe specific expression is as follows:
where ρ isfExpressed as blood density, r represents the robot head radius,indicating the relative speed of the robot with respect to the blood,τ0is a dimensionless ratio related to local vessel occlusion;
pulsating fluid velocity ofBy a parabolic function vs(x) And time-varying periodic blood pulsatile flow function vt(t) composition, time-varying blood velocity vt(t)=ζ1Expressed as an N-order truncated Fourier series;
wherein, VrMean blood flow rate;
for the coupling effect between the vessel wall motion and the blood flow velocity, the following assumptions are made:
(1) the blood vessel is semi-infinitely long;
(2) the vessel wall is an isotropic Hooke elastomer;
(3) blood is a homogeneous newtonian viscous fluid and is incompressible and flows in an axisymmetric layer;
assuming that an original point is taken at the center of an inlet face, setting an x axis as an axial direction and an r axis as a longitudinal direction, and setting a cylindrical coordinate system x, r and theta;
establishing a mathematical model of blood flow:
wherein the boundary conditions are:
wherein, Vx=Vx(r,x,t),Vr=Vr(r,x,t),P=P(x,t),υ0Is the characteristic velocity, P, of blood at the vascular opening0Is the mean pressure at the vascular inlet, ak,bk,gk,hkIs a constant number of times, and is,omega is the oscillation frequency;
obtaining the average blood inlet velocity Vr(ii) a Assumption (2) for the blood vessel wall that the deformation of the blood vessel wall following the blood is slight; the thickness of the vessel wall is h, the ratio of the thickness to the radius of the vessel is kept constantAre small;
the vascular wall can receive axial, radial effort, its expression respectively is:
where H is the actual vessel wall thickness, ρωH, R and E are respectively the density, thickness, radius and elastic modulus of the vessel wall, and mu is the poisson ratio of the vessel;ζ is the vessel axial and radial displacement, respectively. p, peRespectively the internal pressure and the external pressure of the vessel wall;
irrespective of the constraints of the surrounding tissue, H ═ H, ω 00 and for the blood flow rate, the radial velocity of the blood is much greater than the axial velocity, i.e. the velocityWhen neglecting the viscous term, inertia in the equation of motionAfter the term, the axial motion equation (1056) is:
radial equation (1057) the left inertial term of the equation is much less affected than the right and therefore can be ignored, and the radial equation is written as:
combining equations (1060) and (1061) yields the radial displacement equation:
at the vascular wall R-R junction, the coupling condition is expressed as:
s4, designing a robust adaptive controller according to the steps S1, S2 and S3; the robust adaptive control algorithm design process comprises the following steps:
modeling the robot kinematics and kinetic coupling established at S1 as:
wherein the content of the first and second substances,in the form of a dual-moment matrix of inertia,in the form of a nominal matrix, the matrix,is an indeterminate portion;
firstly, set upThe attitude and orbit coupling kinetic equation is the attitude angle of the motion of the vascular robot, and can be:
wherein the content of the first and second substances,Θddesired attitude angle for robot movement, eΘ==Θ-ΘdIn order to be an attitude angle tracking error,in order to control the total force for the system,external disturbance force to the system; and is
The robust control law is designed as follows:
defining the auxiliary signal:
designing a robust control item:
wherein the content of the first and second substances,k1,k2,k3>0;representing a robust term of the system for coping with external disturbances to which the vascular robot is bounded, i.e.And β (β > 0); definition ofWhereinFor a known nominal moment of inertia, the same applies
In order to deal with the uncertain part of the moment of inertia, an adaptive operator is designed:
wherein a ═ a1,a2,a3]T;
Let I be the identity matrix, define
The adaptive robust control law is designed as follows:
wherein the content of the first and second substances,is thetaΔMAn estimated value of, andin the formula, gamma is a positive definite diagonal matrix.
The vascular robot researched by the invention consists of a magnetic spherical head and a spiral tail; the blood vessel robot can move spirally in the blood without contacting with the blood vessel, thereby realizing the effect that the blood vessel robot has no damage to the blood vessel tissue; in order to reduce the volume of the vascular robot and enable the vascular robot to flexibly move in a blood environment, a driving force needs to be provided for the vascular robot by virtue of an external three-dimensional magnetic field; in order to counteract the sinking motion under the action of gravity and buoyancy, ensure that the robot can perform expected motion in blood and reduce the contact to the vessel wall, an external three-dimensional magnetic field is needed to establish a gravity-buoyancy compensation device; in order to analyze the resistance of the vascular robot, the blood pulsation flow field effect and the influence of the vascular wall motion on the blood flow rate need to be analyzed; finally, a robust self-adaptive control scheme is determined, and trajectory tracking control simulation is carried out, so that the method has important significance for the application of the vascular robot in the medical field.
Drawings
Fig. 1 is a straight line view of PLUCKER;
FIG. 2 is a schematic representation of the rotational momentum of the rigid body velocity and the dual momentum;
FIG. 3 is a schematic diagram of a limited displacement screw principle;
FIG. 4 is a diagram of a quaternion representation coordinate transformation;
FIG. 5 is a schematic diagram of a transformation relationship between coordinate systems;
FIG. 6 is a diagram of a vascular robot gravity-buoyancy compensation analysis;
FIG. 7 is a schematic diagram of vascular robot gravity-buoyancy compensation;
FIG. 8 is a schematic diagram of the resistance experienced by the vascular robot;
FIG. 9 is a diagram showing the physical structure and parameters of each part of the vascular robot;
FIG. 10 is a schematic view of a linear irregular diameter vessel;
FIG. 11 is a graph of linear trajectory tracking of a vascular robot;
FIG. 12 is a graph showing the directional error of the linear trajectory of the vascular robot along each coordinate axis;
FIG. 13 is a graph of a linear trajectory tracking yaw angle tracking of a vascular robot;
FIG. 14 is a graph of the tracking error of the linear trajectory tracking yaw angle of the vascular robot;
FIG. 15 is a linear trajectory tracking pitch angle tracking graph of the vascular robot;
FIG. 16 is a graph of linear trajectory tracking pitch angle tracking error of a vascular robot;
FIG. 17 is a linear trajectory tracking roll rate tracking graph of a vascular robot;
FIG. 18 is a graph of the tracking error of the linear trajectory tracking roll angular velocity of the vascular robot;
FIG. 19 is a schematic view of a curvilinear vessel;
FIG. 20 is a graph of a curvilinear trajectory tracking of a vascular robot;
FIG. 21 is a graph showing the error in the direction of each coordinate axis of the curve-shaped trajectory of the vascular robot;
FIG. 22 is a graph of a vascular robot curve-type trajectory tracking yaw angle tracking;
FIG. 23 is a graph of a curve-type trajectory tracking yaw angle tracking error of a vascular robot;
FIG. 24 is a graph of a vascular robot curve-type trajectory tracking pitch angle tracking;
FIG. 25 is a graph of a curve-type trajectory tracking pitch angle tracking error of a vascular robot;
FIG. 26 is a graph of a vascular robot curve-type trajectory tracking roll rate tracking;
fig. 27 is a graph of the vascular robot curve-type trajectory tracking roll angular velocity tracking error.
Detailed Description
The invention aims at a vascular robot attitude and orbit integrated coupling model and a track tracking control method, and firstly establishes a vascular robot attitude and orbit integrated kinematics and dynamics coupling model based on a spiral theory and dual quaternion and analyzes the problem of the coupling effect between attitude motion and track motion. Aiming at the problem that the vascular robot generates sinking action under the action of gravity and buoyancy in the vertical direction in the blood movement process, the gravity-buoyancy compensation device is established to enable the vascular robot to move in the expected direction. Considering the influence of the pulsating flow field effect on the vascular robot, analyzing the coupling effect between the vascular wall motion and the blood flow velocity, and finally analyzing the resistance of the vascular robot in the blood complex environment. And finally, designing a robust adaptive controller, and performing linear and curve track tracking control simulation to prove the effectiveness of the control method.
The invention is described in detail below with reference to the attached drawing figures:
the invention comprises the following steps:
the method comprises the following steps: establishing a posture and orbit integrated kinematics and dynamics coupling model of the vascular robot based on a spiral theory and dual quaternion; step two: aiming at the sinking action of the vascular robot caused by the gravity and buoyancy in the vertical direction in the blood movement process, a gravity-buoyancy compensation device is established;
step three: analyzing the influence of the blood pulsation flow field effect according to the complexity of the blood environment, and finally analyzing the resistance borne by the vascular robot by combining the influence of the blood vessel wall motion on the blood flow rate;
step four: and designing a robust adaptive controller, and performing trajectory tracking control simulation.
Firstly, basic explanations are made on quaternion, even pair, dual quaternion and spiral theories:
quaternions, originally proposed by William Roman Hamilton, irish, in the nineteenth century, were applicable to rigid body kinematics, and are specifically defined as:
wherein the content of the first and second substances,and q is0Is a scalar quantity of a quaternion,a vector that is a quaternion;the following conditions are satisfied for the unit vectors intersected two by two:
when | | q | luminance2When 1, it is called a unit quaternion. When in useWhen q is called a scalar quaternion, when q is0When 0, it is called a vector quaternion.
For the even nineteenth century, Clifford invented the even number, which was defined as:
wherein the content of the first and second substances,respectively a real part and a dual part of a dual number, and epsilon is a dual unit and satisfies epsilon 20, epsilon ≠ 0, which, as used herein,indicating belonging to an even pair.
The dual vector is developed on the basis of a dual number, the real part and the dual part of the dual vector are vectors, and the expression is as follows:
the invention introduces the concept of 'rotation amount' when a dual vector is applied to a space, when a straight line in the space is described by the dual vector, a real part of the dual vector is called a positioning vector, a dual part is called a free vector and is expressed as a moment between a unit direction vector of the straight line in the space and the straight line relative to a coordinate origin, and the dual vector is called the 'rotation amount'.
The straight line in the space coordinate system can be expressed as:
where the dual vector may be referred to as the Plucker line, as shown in FIG. 1,is the real part of the signal,then the two-part is the dual part, andare orthogonal to each other.
The dual vectors as described above may be referred to as "spin", as dual momentum and dual force vectors, and the like. The dual quaternion is a combination of even and quaternion as the name implies. The expression includes two types, one is that the expression is expressed as a quaternion with an even number of elements, and the expression is:
the second is expressed as a pair of even numbers with elements being quaternions, and the expression is:
wherein q and q' are quaternions.
Theory of helicity
The even number is used for describing the spiral amount and the spiral theory, such as:
where ω represents angular velocity and v represents linear velocity. The following steps are repeated:
wherein f represents the resultant force received by the rigid body, and T represents the resultant moment received by the rigid body.
Momentum:
wherein, p represents the translational momentum of the rigid body, and h is the rotational momentum of the rigid body. From the above series of equations, it can be seen that the real part of the spiral quantity is a quantity independent of the selected point, while the dual part is dependent on the selected point.
The spiral amount has conversion property, and the expression is as follows:
wherein the content of the first and second substances,expressed as the Hermitian matrix moving from point b to point a, the expression for which is:
an expression of pose transformation is given by applying a finite spiral displacement theory:
wherein the content of the first and second substances,the dual angle is expressed as the displacement of the rigid body, the real part is the angle of the rigid body rotating around the spiral shaft, and the dual part is the distance of the rigid body moving along the spiral shaft;the displacement is expressed as a rotation axis of the rigid body, the real part is a unit direction vector, and the dual part is a moment of the axis relative to the origin. A schematic diagram of which is shown in fig. 3.
A quaternion is utilized to establish the vascular robot attitude kinematics, a dynamic model is defined by the quaternion, and a unit quaternion can be obtained and is used for describing the attitude in rigid motion. The rotational motion can be represented by a unit quaternion as:
wherein the vector part represents the position of the fixed shaft,the unit vector of Euler rotation axis direction is represented, and the scalar part represents the rotation angle theta
The system O-X of the vascular robot represented by quaternion can be obtained through the analysisIYIZIRelative to the inertial system O-XBYBZBThe attitude motion equation of (a) is:
the kinematic equation of the attitude of the vascular robot expectation system relative to the inertial system can be expressed as:
wherein the content of the first and second substances,respectively representing angular velocity vectors of the spiral vascular robot body system relative to an inertial system under the body and inertial coordinate systems;for the angle of the vessel robot object system relative to the inertial systemAnd representing the velocity vector in the target and inertial coordinate system.
The error quaternion is the conversion from the body coordinate system of the vascular robot to the target coordinate system and is defined as:
the error angular velocity is defined as:
in the same way, the method for preparing the composite material,
wherein the content of the first and second substances,the representation of the error angular velocity vector of the vascular robot target system relative to the system under the vascular robot system is shown.
Derivation of equation (1015) and substitution of equations (1013), (1014) into the equation of relative motion that yields the error quaternion representation:
the vascular robot dynamics equation based on unit quaternion can be expressed as:
wherein, F is the external resultant moment suffered by the vascular robot, and M is a positive definite matrix and is the rotational inertia of the vascular robot.
Substituting equation (1017) and the above equation into equation (1020) may result in the robot relative dynamics equation expressed in unit quaternion:
based on the definition of the dual quaternion and the spiral theory, the pose and orbit integrated kinematics and dynamics model of the vascular robot based on the spiral theory can be expressed as the pose coupling kinematics equation of a coordinate system X relative to Y as follows:
as can be known from the above formula, the vascular robot attitude motion equation based on dual quaternions is similar to the six-degree-of-freedom attitude motion equation represented by common quaternions, that is:
wherein the dual angular velocitiesAndthe dual angular velocities of coordinate system X relative to coordinate system Y are represented under coordinate system X and coordinate system Y, respectively. WhereinAndare respectivelyAndthe derivation of the time is carried out,andare respectivelyAndassociated rates of change in coordinate system X and coordinate system Y.
According to equation (1023), we can respectively express the kinematic equations of the vessel robot system and the vessel robot target system relative to the inertial system as:
the dual angular momentum is defined as:
according to the Euler equation:
wherein the content of the first and second substances,the dual resultant force to which the vascular robot is subjected is expressed as follows:
wherein the content of the first and second substances,is the resultant force of the action points on the centroid of the vascular robot, anAs a driving force, the driving force is,is the resultant force of gravity and buoyancy,in order to be a fluid resistance, it is,in order to be subjected to the disturbing force,is the resultant moment acting on the centroid.
Substituting equation (1007) and equation (1026) into equation (1027) yields:
when the vascular robot mass is fixed with the defined moment of inertia, the above equation is simplified:
then separating the real part and the dual part in the above equation into a kinetic equation of the trajectory motion and the attitude motion of the vascular robot:
vascular robot attitude and orbit integrated coupling mathematical model
The error-pair quaternion is defined as:
the vessel robot needs to transfer from the position of the body coordinate system to the target coordinate system, and then the vessel robot needs to perform attitude transformation q from the body coordinate systemBDThen is translated againWhen the position of the target coordinate system is reached, the correlation transformation between the coordinate systems is shown in fig. 5.
Derivation of equation (1032) in combination with equation (1022) yields the vessel robot kinematics equation represented by an error pair-even quaternion:
the dual angular momentum can also be expressed as:
Equation (1027) can be written as:
simplified by equation (1023):
this is obtained by the formula (1036):
substituting equation (1038) into equation (1036) can obtain a vascular robot posture and trajectory coupling kinetic equation based on the spiral theory and dual quaternion:
and the coupling terms are a second term and a fourth term, so that the coupling influence of the gesture motion and the track motion is analyzed.
Vascular robot mathematical model coupling effect analysis
The second term of the dynamic posture and track coupling model of the vascular robot is as follows:
wherein the content of the first and second substances,is a cross-product factor of the velocity vector,andare respectively provided withIs the cross product factor of the angular velocity vector and the linear velocity vector of the vascular robot.
The concrete expression is substituted into formula (1040) to obtain:
it can be seen that the real part appearsThe method shows that the track motion of the vascular robot has an influence on the posture motion, but the influence is small.
For the same reason, the fourth term of the kinetic model is simplified:
as can be seen from the above formula, the dual part comprisesIt can be obtained that the relative angular velocity of the vascular robot affects the track motion of the vascular robot, i.e. the gesture motion affects the track motion of the vascular robot. The analysis can show that the coupling effect exists between the posture motion and the track motion of the vascular robot when the vascular robot moves in blood, and lays a foundation for designing the posture-orbit integrated robust self-adaptive control of the vascular robot.
Gravity-buoyancy compensation device for blood vessel designing robot
through the stress analysis of the vascular robot, it can be known that the vascular robot designs a gravity-buoyancy compensation device for counteracting the sinking motion of the vascular robot under the action of gravity and buoyancy in the vertical direction, and a compensation coordinate system P is established firstly, and the schematic diagram is shown in fig. 7.
Fig. 7 shows that when the component of the external three-dimensional magnetic field in the z-axis direction is equal to the resultant force of gravity and buoyancy, the sinking effect of the vascular robot can be completely cancelled, and when the volume and magnetization of the robot are known, the magnetic expression of the micro-robot is as follows:
wherein, gx,gy,gzThree components of the magnetic flux gradient. In order to move the robot in the horizontal direction, the magnetic force components in the x-axis and the y-axis should satisfy the following equation:
wherein the values of the gradient of the magnetic induction along the x-axis and the y-axis should be equal, i.e. gx=gyBy ghTo replace gx,gyThe robot is subject to gravityBuoyancy forceActing to generate a magnetic force F in the z-axis directionmzIs divided into two parts, whereinFor counteractingFmz1Indicating vascular robot partial drivesDynamic, magnetic field gradient division at the z-axisAnd gz1Two parts.
The magnetic force and the magnetic field gradient along the z direction should satisfy the following relations:
therefore, the sinking effect of gravity and buoyancy in the vertical direction of the vascular robot can be compensated by applying the deflection angle of the external magnetic field.
Pulsating flow field effect analysis
Resistance to which the spiral vascular robot is subjectedIncluding resistance to the spherical head of the vascular robotAnd the resistance to which the helical tail is subjectedThe specific expression is as follows:
where ρ isfIs the blood density, r is the robot head radius,is the relative velocity of the robot with respect to the blood,τ0is a dimensionless ratio related to local vessel occlusion.
Considering the blood pulsation flow field effect, the vascular robot moves in the blood vessel to avoid the effect and takes a parabolic flow pattern, and the velocity of the pulsation fluid isBy a parabolic function vs(x) And time-varying periodic blood pulsatile flow function vt(t) composition, time-varying blood velocity vt(t)=ζ1Represented as an N-th truncated fourier series.
Wherein, VrMean blood flow rate.
For the average flow rate of blood studied, the following assumptions were made:
(1) first assume that the vessel is semi-infinitely long;
(2) the vessel wall is an isotropic Hooke elastomer;
(3) blood is a homogeneous newtonian viscous fluid and is incompressible and flows in an axisymmetric layer.
Assuming that the origin is taken at the center of the inlet face and the x-axis is axial and the r-axis is longitudinal, a cylindrical coordinate system x, r, θ is set. Establishing a mathematical model of blood flow by using a Navier-Stokes equation:
wherein the boundary conditions are:
wherein, Vx=Vx(r,x,t),Vr=Vr(r,x,t),P=P(x,t),υ0Is the characteristic velocity, P, of blood at the vascular opening0Is the mean pressure at the vascular inlet, ak,bk,gk,hkIs constant and ω is the oscillation frequency.
solving the blood flow velocity motion equation based on the boundary conditions to obtain the blood inlet average velocity Vr. The derivation of the equation of motion for the arterial wall is also crucial, considering the pulsatile flow effect in the artery, and the blood motion is tightly coupled to the motion of the vessel wall.
Based on the assumed conditions for the vessel wall, it is additionally assumed that the vessel wall follows the bloodIs relatively minor; the thickness of the vessel wall is h, the ratio of the thickness to the radius of the vessel is kept constantAre small.
The vascular wall can receive axial, radial effort, its expression respectively is:
where H is the actual vessel wall thickness, ρωH, R and E are respectively the density, thickness, radius and elastic modulus of the vessel wall, and mu is the poisson's ratio of the vessel.ζ is the vessel axial and radial displacement, respectively. p, peThe internal and external pressure of the vessel wall, respectively (usually considered as constants, pe=3.8kPa)。
Irrespective of the constraints of the surrounding tissue, H ═ H, ω 00 and for the blood flow rate, the radial velocity of the blood is much greater than the axial velocity, i.e. the velocityThe axial and radial equations of motion can be:
when the viscous term and the inertia term in the motion equation are ignored, the axial motion equation (1058) is:
radial equation (1059) the inertial term of the equation is much less influential than on the right and therefore negligible, and the radial equation is written as:
combining equations (1060) and (1061) yields the radial displacement equation:
the blood flow equation and the vessel wall motion equation can be solved through a boundary coupling condition, and at the juncture of the vessel wall R ═ R, the coupling condition is as follows:
robust adaptive controller for designing vascular robot
Based on the established vascular robot kinematics and dynamics mathematical model, the attitude and orbit coupling dynamics equation is simplified
Wherein the content of the first and second substances,in the form of a dual-moment matrix of inertia,in the form of a nominal matrix, the matrix,is an indeterminate portion. In accordance withAnd designing an adaptive robust controller according to the dynamics modeling of the spiral vascular robot.
Firstly, set upThe attitude and orbit coupling kinetic equation is the attitude angle of the motion of the vascular robot, and can be:
wherein the content of the first and second substances,Θddesired attitude angle for robot movement, eΘ==Θ-ΘdIn order to be an attitude angle tracking error,in order to control the total force for the system,is the external disturbance force received by the system. And is
The robust control law is designed as follows:
defining the auxiliary signal:
designing a robust control item:
wherein the content of the first and second substances,k1,k2,k3>0。representing a robust term of the system for coping with external disturbances to which the vascular robot is bounded, i.e.And beta (beta > 0). Definition ofWhereinFor a known nominal moment of inertia, the same applies
In order to deal with the uncertain part of the moment of inertia, an adaptive operator is designed:
wherein a ═ a1,a2,a3]T。
Let I be the identity matrix, define
The adaptive robust control law is designed as follows:
wherein the content of the first and second substances,is thetaΔMAn estimated value of, andin the formula, gamma is a positive definite diagonal matrix.
The robustness self-adaptive controller stability proves that:
in order to prove the stability of the controller, the method is divided into two steps, firstly, when the dynamic model of the vascular robot is considered to have bounded disturbance, the designed adaptive robust control is proved to be asymptotically stable; secondly, when the dynamic model of the vascular robot is considered to have bounded disturbance, the designed control method is proved to be applied to any eΘ(0) Are all final value bounded.
Before the controller stability certification is carried out, firstly, the assumed conditions are set:
(1) presence of a normal number λ1,λ2So that λ1I3×3≤M≤λ2I3×3;
(2)nΘBounded, i.e. nΘ||≤nΘm;
Proving that:
under the above assumptions (1), (2), (3), a positive definite function is defined:
Formula (1075) is thus arranged:wherein λ3Can be according to KcThe expression is derived, thus for ρ, β and the matrix K in the expressioncCan be obtained by limitation
Thus proving the progressive stability of the closed loop system.
And (2) proving that:
under the assumptions (1), (2), (4), a positive definite function is defined:
to V2(t,nΘ) The derivation yields:
definition ofFrom the condition 1, the dual inertia matrix M is bounded, so that a normal number λ exists1,λ2The following steps are performed:
let nΘ=[n1,n2,n3]TFrom the euclidean norm relationship we can derive:
from the above equation, for an arbitrary initial tracking error eΘ(0) In other words, when t is sufficiently large, the tracking error eΘ(t)||≤C。
Thus, the certification is completed.
The following specific examples were employed to verify the control effect of the present invention.
Example one: and (4) performing track tracking control simulation on the linear motion track of the vascular robot by using the robust adaptive controller designed in the step four, and verifying the control effect of the robust adaptive control method.
The parameters of the vascular robot are set as follows:
TABLE 1 vascular robot simulation parameters
In the process of operation, because the vascular robot enters, vasospasm is easily caused, so that blood generates ineffectiveness to the robot, the following interference couple force is added in the track tracking control simulation, and the validity and the accuracy of a control algorithm are more powerfully verified. The interference couple force is as follows:
assuming an initial velocity of 0mm/s and an average motion velocity of 1mm/s, the initial velocityTheta, psi are 0rad, 0rad/s, respectively.
First, linear trajectory tracking control simulation is performed on the spiral vascular robot, and assuming that the vascular robot performs approximate linear trajectory simulation, the robot starting point is located at (0,0,0), and the reference route shown in fig. 10 is followed.
Defining the linear trajectory equation as:
and performing tracking control simulation on the linear track through an adaptive robust control algorithm, wherein the simulation result is shown in fig. 11-18. Fig. 11 is a robot trajectory tracking curve, and it can be known that the robust adaptive controller has better control accuracy. FIG. 12 is a graph showing the three different directional errors of the vascular robot in the coordinate system, indicating the linear motion of the vascular robotIn the process, the control precision and stability of the vascular robot in the blood can be met. FIGS. 13-18 show respectivelyThe tracking curve and the error curve of theta and psi can be known from the figure, the spiral vascular robot can achieve the control precision specified by the attitude motion and the track motion in the track tracking simulation, and has certain stability.
Example two: and (4) performing track tracking control simulation on the curvilinear motion track of the vascular robot by using the robust adaptive controller designed in the step four, and verifying the control effect of the robust adaptive control method.
A schematic diagram of the reference path of the spiral vascular robot in a curved vessel is shown in fig. 19. In the simulation of the bending type track, assuming the origin (0,5,0) of the coordinate system of the starting point of the robot, the bending type track equation is defined as follows:
the curve type track simulation diagram is shown in fig. 20-27. Fig. 20 is a curve trace tracing graph, and the adaptive robust trace controller can more accurately trace the trace of the robot in the curve trace simulation. FIG. 21 is a graph of the error in X, Y and Z directions during the movement of the robot, from which it can be seen that the tracking error of the controller is small and within the controllable range. FIGS. 22-27 show the movement of the vascular robotTheta, psi tracking curves and tracking errors. Fig. 27 shows that the error of the roll angular velocity ψ is 0.8953rad/s at the maximum, which occurs at the turning of the vascular robot, that is, the roll angular velocity error is large at the initial movement and the movement at the middle turning of the vascular robot, and fluctuates somewhat at the end stage. In conclusion, the adaptive robust control has stability for the curve track tracking of the vascular robot and certain control precision.
Claims (1)
1. A vascular robot coupling modeling and robust self-adaptive control method is characterized in that:
s1, establishing a model of the vascular robot for integrating the attitude and orbit kinematics and dynamics;
the error-pair quaternion is defined as:
wherein the content of the first and second substances, represents a dual quaternion multiplication;
the vascular robot needs to firstly perform attitude conversion q by a body coordinate systemBDThen is translated againAnd when the position of the target coordinate system is reached, the vessel robot posture and track coupling kinematic equation of the spiral theory and the dual quaternion:
wherein the content of the first and second substances,the angular velocity of the blood vessel robot body coordinate system relative to the inertial system is represented under the blood vessel robot body coordinate system;
the dual angular momentum can be expressed as:
according to the Euler equation:
wherein the content of the first and second substances,the dual resultant force to which the vascular robot is subjected is expressed as follows:
wherein the content of the first and second substances,is a resultant force acting on the center of mass of the vascular robot, anAs a driving force, the driving force is,is the resultant force of gravity and buoyancy,in order to be a fluid resistance, it is,in order to be subjected to the disturbing force,
formula (1036) is simplified to yield:
the vascular robot posture and track coupling kinetic equation of the spiral theory and the dual quaternion is as follows:
the coupling terms are a second term and a fourth term, so that the coupling influence of the gesture motion and the track motion is analyzed;
the second term of the dynamic posture and track coupling model of the vascular robot is as follows:
wherein the content of the first and second substances,is a cross-product factor of the velocity vector,andrespectively are cross multiplication factors of an angular velocity vector and a linear velocity vector of the vascular robot; the concrete expression is substituted into formula (1040) to obtain:
the fourth term of the kinetic model is simplified:
s2, designing a gravity-buoyancy compensation device;
the volume and magnetization of the robot, the magnetic force expression of the micro-robot is:
wherein, gx,gy,gzThree components of the magnetic flux gradient, respectively; in order to move the robot in the horizontal direction, the magnetic force components in the x-axis and the y-axis should satisfy the following equation:
wherein the values of the gradient of the magnetic induction along the x-axis and the y-axis should be equal, i.e. gx=gyBy ghTo replace gx,gy. Magnetic force F in z-axis directionmzIs divided into two parts, whereinFor counteracting Representing part of the vascular robot driving force, magnetic field gradient splitting at the z-axisAndtwo parts;
the magnetic force and the magnetic field gradient along the z direction should satisfy the following relations:
s3, analyzing the relationship process of the pulsating flow field effect and the blood vessel wall motion and the blood flow velocity as follows:
resistance to the vascular robotIncluding resistance to the spherical head of the vascular robotAnd the resistance to which the helical tail is subjectedThe specific expression is as follows:
where ρ isfExpressed as blood density, r represents the robot head radius,indicating the relative speed of the robot with respect to the blood,τ0is a dimensionless ratio related to local vessel occlusion;
by a parabolic function vs(x) And time-varying periodic blood pulsatile flow function vt(t) composition, time-varying blood velocity vt(t)=ζ1Expressed as an N-order truncated Fourier series;
wherein, VrMean blood flow rate;
for the coupling effect between the vessel wall motion and the blood flow velocity, the following assumptions are made:
(1) the blood vessel is semi-infinitely long;
(2) the vessel wall is an isotropic Hooke elastomer;
(3) blood is a homogeneous newtonian viscous fluid and is incompressible and flows in an axisymmetric layer;
assuming that an original point is taken at the center of an inlet face, setting an x axis as an axial direction and an r axis as a longitudinal direction, and setting a cylindrical coordinate system x, r and theta;
establishing a mathematical model of blood flow:
wherein the boundary conditions are:
wherein, Vx=Vx(r,x,t),Vr=Vr(r,x,t),P=P(x,t),υ0Is the characteristic velocity, P, of blood at the vascular opening0Is the mean pressure at the vascular inlet, ak,bk,gk,hkIs constant, ω is oscillation frequency;
obtaining the average blood inlet velocity Vr(ii) a Assumption (2) for the blood vessel wall that the deformation of the blood vessel wall following the blood is slight; the thickness of the vessel wall is h, the ratio of the thickness to the radius of the vessel is kept constantAre small;
the vascular wall can receive axial, radial effort, its expression respectively is:
where H is the actual vessel wall thickness, ρωH, R and E are respectively the density, thickness, radius and elastic modulus of the vessel wall, and mu is the poisson ratio of the vessel;ζ is the vessel axial and radial displacement, respectively. p, peRespectively the internal pressure and the external pressure of the vessel wall;
irrespective of the constraints of the surrounding tissue, H ═ H, ω00 and for the blood flow rate, the radial velocity of the blood is much greater than the axial velocity, i.e. the velocityWhen the viscous term and the inertia term in the motion equation are ignored, the axial motion equation (1056) is:
radial equation (1057) the left inertial term of the equation is much less affected than the right and therefore can be ignored, and the radial equation is written as:
combining equations (1060) and (1061) yields the radial displacement equation:
at the vascular wall R-R junction, the coupling condition is expressed as:
s4, designing a robust adaptive controller according to the steps S1, S2 and S3; the robust adaptive control algorithm design process comprises the following steps:
modeling the robot kinematics and kinetic coupling established at S1 as:
wherein the content of the first and second substances,in the form of a dual-moment matrix of inertia,in the form of a nominal matrix, the matrix,is an indeterminate portion;
firstly, set upThe attitude and orbit coupling kinetic equation is the attitude angle of the motion of the vascular robot, and can be:
wherein the content of the first and second substances,Θddesired attitude angle for robot movement, eΘ==Θ-ΘdIn order to be an attitude angle tracking error,in order to control the total force for the system,external disturbance force to the system; and is
The robust control law is designed as follows:
defining the auxiliary signal:
designing a robust control item:
wherein the content of the first and second substances,representing a robust term of the system for coping with external disturbances to which the vascular robot is bounded, i.e.And β (β > 0); definition ofWhereinFor a known nominal moment of inertia, the same applies
In order to deal with the uncertain part of the moment of inertia, an adaptive operator is designed:
wherein a ═ a1,a2,a3]T;
Let I be the identity matrix, define
The adaptive robust control law is designed as follows:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110604422.XA CN113655712B (en) | 2021-05-31 | 2021-05-31 | Vascular robot coupling modeling and robust self-adaptive control method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110604422.XA CN113655712B (en) | 2021-05-31 | 2021-05-31 | Vascular robot coupling modeling and robust self-adaptive control method |
Publications (2)
Publication Number | Publication Date |
---|---|
CN113655712A true CN113655712A (en) | 2021-11-16 |
CN113655712B CN113655712B (en) | 2023-03-24 |
Family
ID=78489110
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110604422.XA Active CN113655712B (en) | 2021-05-31 | 2021-05-31 | Vascular robot coupling modeling and robust self-adaptive control method |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113655712B (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1475332A (en) * | 2003-06-24 | 2004-02-18 | 浙江大学 | Todpole imitation and spiral blood vessel robot |
CN102349827A (en) * | 2011-07-21 | 2012-02-15 | 长沙学院 | Miniature robot facing tiny pipes of inner cavity of human body and motion method of miniature robot |
CN108132604A (en) * | 2017-12-27 | 2018-06-08 | 北京航空航天大学 | Quadrotor robust attitude control method, apparatus and system based on quaternary number |
CN111904486A (en) * | 2020-05-18 | 2020-11-10 | 吉林大学 | Attitude and orbit integrated self-adaptive sliding mode tracking control method for spiral vascular robot |
CN111973279A (en) * | 2019-05-21 | 2020-11-24 | 复旦大学 | Master-slave position self-adaptive tracking control method of vascular interventional surgical robot |
-
2021
- 2021-05-31 CN CN202110604422.XA patent/CN113655712B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1475332A (en) * | 2003-06-24 | 2004-02-18 | 浙江大学 | Todpole imitation and spiral blood vessel robot |
CN102349827A (en) * | 2011-07-21 | 2012-02-15 | 长沙学院 | Miniature robot facing tiny pipes of inner cavity of human body and motion method of miniature robot |
CN108132604A (en) * | 2017-12-27 | 2018-06-08 | 北京航空航天大学 | Quadrotor robust attitude control method, apparatus and system based on quaternary number |
CN111973279A (en) * | 2019-05-21 | 2020-11-24 | 复旦大学 | Master-slave position self-adaptive tracking control method of vascular interventional surgical robot |
CN111904486A (en) * | 2020-05-18 | 2020-11-10 | 吉林大学 | Attitude and orbit integrated self-adaptive sliding mode tracking control method for spiral vascular robot |
Non-Patent Citations (6)
Title |
---|
于业伟: "磁控形状记忆合金执行器轨迹跟踪控制方法研究", 《CNKI》 * |
刘月: "螺旋形血管机器人建模及控制方法研究", 《CNKI》 * |
宇旭东: "基于对偶四元数的机器人动力学建模及轨迹规划研究", 《CNKI》 * |
张颖: "血管机器人建模及姿态轨迹跟踪控制方法研究", 《CNKI》 * |
陈文雪: "螺旋形血管机器人耦合建模及纠偏控制方法研究", 《CNKI》 * |
韩阳: "螺旋型血管机器人建模及轨迹跟踪控制方法研究", 《CNKI》 * |
Also Published As
Publication number | Publication date |
---|---|
CN113655712B (en) | 2023-03-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Hooshiar et al. | Haptic telerobotic cardiovascular intervention: a review of approaches, methods, and future perspectives | |
Jayender et al. | Autonomous image-guided robot-assisted active catheter insertion | |
Ganji et al. | Catheter kinematics for intracardiac navigation | |
Alderliesten et al. | Simulation of minimally invasive vascular interventions for training purposes | |
CN111243746B (en) | Operation simulation method and system of vascular intervention operation robot | |
WO2011137336A1 (en) | Motion compensating catheter device | |
Tercero et al. | Autonomous catheter insertion system using magnetic motion capture sensor for endovascular surgery | |
CN103961179A (en) | Surgical instrument moving simulation method | |
Shapiro et al. | Modeling a hyperflexible planar bending actuator as an inextensible Euler–Bernoulli beam for use in flexible robots | |
WO2014002805A1 (en) | Puncture control system and method therefor | |
CN111904486A (en) | Attitude and orbit integrated self-adaptive sliding mode tracking control method for spiral vascular robot | |
Tomić et al. | Human to humanoid motion conversion for dual-arm manipulation tasks | |
CN113655712B (en) | Vascular robot coupling modeling and robust self-adaptive control method | |
CN110176306B (en) | Automatic positioning method for soft tissue drifting target point based on dynamic multi-element LSTM network | |
CN111603241B (en) | Medical robot positioning device based on differential particle filtering and improvement method | |
JP7458929B2 (en) | Continuum robot control system, its operating method, and program | |
Wijayasinghe et al. | Potential and optimal target fixating control of the human head/eye complex | |
CN111310641A (en) | Motion synthesis method based on spherical nonlinear interpolation | |
Wu et al. | Kirchhoff rod-based three-dimensional dynamical model and real-time simulation for medical-magnetic guidewires | |
Loschak et al. | Predictive filtering in motion compensation with steerable cardiac catheters | |
Alderliesten et al. | Simulation of guide wire propagation for minimally invasive vascular interventions | |
Meng et al. | Evaluation of a reinforcement learning algorithm for vascular intervention surgery | |
Yang et al. | Multi-inertial sensor-based arm 3d motion tracking using elman neural network | |
Jayender et al. | Autonomous robot-assisted active catheter insertion using image guidance | |
Mahvash et al. | Bilateral teleoperation of flexible surgical robots |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |