CN-122005093-A - Multi-mode motion and path tracking control method for magnetic control micro-robot

CN122005093ACN 122005093 ACN122005093 ACN 122005093ACN-122005093-A

Abstract

The invention discloses a multi-mode motion and path tracking control method and system for a magnetic control micro-robot, and relates to the technical field of magnetic control micro-robots and intelligent control systems. Aiming at the technical pain points that the existing magnetic control micro-robot has single motion mode, low path tracking precision and difficulty in reaching focus accurately in the intestinal environment, the invention realizes stable triggering and flexible switching of the overturning and rolling dual-mode motion by regulating and controlling the relative angle between an external magnetic field plane and the length direction of the robot, respectively builds dynamic models of the two motions, adopts a model prediction control algorithm adapting to overturning characteristics, and combines visual real-time feedback to realize path tracking closed-loop control. The invention effectively improves the obstacle surmounting capability of the complex intestinal environment of the robot, obviously improves the path tracking precision and the control stability, can ensure that the robot accurately reaches the intestinal focus, and provides reliable technical support for accurate diagnosis and treatment of intestinal diseases.

Inventors

LI GONGXIN
XIE HUITING
FANG LU
DU YIJIE
MAO YUTING

Assignees

江南大学

Dates

Publication Date: 20260512
Application Date: 20260327

Claims (10)

1. The multi-mode motion and path tracking control method of the magnetic control micro robot is characterized by comprising the following steps of: S1, constructing an external magnetic control driving system, and realizing stable triggering and flexible switching of two modes of overturning motion of the robot along the width direction and rolling motion along the length direction by regulating and controlling the relative angle between an external magnetic field rotating plane and the length direction of the magnetic control micro-robot; S2, based on the structural characteristics and the magnetic field action principle of the magnetic control micro-robot, respectively constructing a corresponding dynamic model aiming at the overturning motion and the rolling motion, and quantifying the corresponding relation between the magnetic moment, the motion gesture and the motion parameter of the robot; and S3, aiming at the problem that the overturning motion trail is easy to deviate, a model prediction control algorithm adapting to overturning motion characteristics is adopted, and a path tracking closed-loop control strategy is constructed by combining with robot motion parameters fed back in real time by vision, so that the motion trail of the robot is corrected in real time, and the accurate tracking of a preset path is completed.
2. The method for multi-modal movement and path-following control of a magnetically controlled micro-robot according to claim 1, wherein in step S1, the specific implementation method of the overturning movement is: The method comprises the steps of placing the length direction of a magnetic control micro-robot along a y axis, firstly applying a bias magnetic field along the positive direction of a z axis to enable the robot to form a V-shaped configuration, then applying a rotating magnetic field in an xz plane to enable the rotating plane of the externally applied magnetic field to be perpendicular to the length direction of the robot, and driving the robot to finish stable overturning motion along the width direction of the robot through magnetic moment, wherein the vector expression of the rotating magnetic field is as follows: ; In the formula, In order to rotate the strength of the magnetic field, 、、 The rotating magnetic field intensity in the directions of the x axis, the y axis and the z axis respectively, For the rotation of the magnetic field frequency, Is time.
3. The method for multi-modal movement and path-tracking control of a magnetically controlled micro-robot according to claim 1, wherein in step S1, the specific implementation method of the rolling movement is: The length direction of the magnetic control micro robot is placed along the x axis, a bias magnetic field along the positive direction of the z axis is firstly applied to enable the robot to form a V-shaped configuration, then a rotating magnetic field in an xz plane with the same parameters as the overturning motion is applied to enable the rotating plane of the applied magnetic field to be parallel to the length direction of the robot, and the magnetic moment drives the robot to finish stable rolling motion along the length direction of the robot.
4. The method for multi-modal motion and path-tracking control of a magnetically controlled micro-robot according to claim 1, wherein in step S2, the specific method for constructing the overturning motion dynamics model is as follows: The method comprises the steps of simplifying a bilateral symmetry magnetic control micro-robot into a cuboid model, dividing the overturning motion into two working conditions of rotation around a V-shaped vertex A and rotation around a connecting line P of two endpoints of the V-shaped according to the switching characteristic of a rotating shaft in the overturning motion, respectively calculating the moment of inertia under the two working conditions based on a parallel shaft principle, respectively constructing dynamics equations corresponding to the two working conditions by combining magnetic moment and gravity moment, and quantifying the corresponding relation of overturning angle, angular acceleration and magnetic moment.
5. The method for multi-modal motion and path-tracking control of a magnetically controlled micro-robot according to claim 1, wherein in step S2, the specific method for constructing the rolling motion dynamics model is as follows: The method comprises the steps of dividing a rolling process into two stages of sliding contact points on an arc and rotating the contact points around the arc end points, calculating corresponding moment of inertia according to the working condition of the robot rolling around any contact point, and constructing a kinetic equation corresponding to rolling motion by combining the mechanical analysis of gravitational moment and magnetic moment to accurately describe the motion state change of the robot in the rolling process.
6. The method for multi-modal motion and path-tracking control of a magnetically controlled micro-robot according to claim 1, wherein in step S3, the process of visual real-time feedback includes: The method comprises the steps of acquiring motion parameters of a magnetic control micro-robot in real time through an external integrated visual detection module, including a centroid position and a yaw angle, calculating a deviation value of an actual motion track of the robot and a preset reference path based on the acquired motion parameters, dynamically adjusting external magnetic control signal parameters based on the deviation value, and correcting the motion track of the robot in real time.
7. The method for multi-modal motion and path-tracking control of a magnetically controlled micro-robot according to claim 1, wherein in step S3, a prediction model construction process of a model prediction control algorithm adapted to a roll-over motion characteristic is as follows: converting a kinetic model of robot overturning motion into a state vector The control input is Wherein And Representing the barycenter position coordinates of the magnetically controlled micro robot in a motion plane; Indicating the yaw angle of the robot, The transpose is represented by the number, The method comprises the steps of representing the angular speed of a robot as an adjusting variable of a control system to the motion gesture of the robot, carrying out Taylor series expansion and discretization on a nonlinear system at a reference point of a reference track, constructing an augmented state variable, and converting a discrete state space equation into a prediction model, wherein the expression of the prediction model is as follows: ; ; In the formula, Is that The state variable of the augmentation of the moment in time, 、、 Is a matrix of state space coefficients that is, Is that The control input increment of the moment in time, Is the output of the system.
8. The method for multi-modal motion and path tracking control of a magnetically controlled micro-robot according to claim 7, wherein in the model predictive control algorithm, a quadratic objective function is designed based on a predicted time domain and a control time domain, and the expression of the objective function is: ; In the formula, To at the same time At the moment, the system comprehensively evaluates the control performance of a future period of time, In order to predict the time domain of the signal, In order to control the time domain of the signal, Is that The trajectory of the moment of time tracks the deviation, Is that The control increment of the moment of time, In the form of a state weight matrix, In order to control the incremental weight matrix, In order to relax the weight of the factor, Is a relaxation factor.
9. The method for multi-modal motion and path-tracking control of a magnetically controlled micro-robot according to claim 8, wherein when solving the objective function, a constraint is applied to the control input quantity and the control increment, and the constraint condition is: ; ; In the formula, Is that The control input quantity of the moment in time, 、 Respectively the upper limit value and the lower limit value of the control input quantity, 、 Respectively controlling the upper limit value and the lower limit value of the increment; and converting the track tracking optimal control problem into a quadratic programming problem to solve by combining an objective function and constraint conditions to obtain an optimal control increment sequence: ; In the formula, Is that A sequence of control increments of time of day, 、、 Respectively is 、、 The control input increment of the moment.
10. A multi-modal motion and path tracking control system for a magnetically controlled micro-robot, wherein the system is configured to implement the multi-modal motion and path tracking control method for a magnetically controlled micro-robot according to any one of claims 1 to 9, and specifically comprises: The multi-mode motion triggering and switching module is used for constructing an external magnetic control driving system, and realizing stable triggering and flexible switching of two modes of overturning motion of the robot along the width direction and rolling motion along the length direction by regulating and controlling the relative angle between the rotation plane of an external magnetic field and the length direction of the magnetic control micro-robot; The multi-mode dynamics model construction module is used for constructing a corresponding dynamics model aiming at overturning motion and rolling motion respectively based on the structural characteristics and the magnetic field action principle of the magnetic control micro-robot, and quantifying the corresponding relation between magnetic moment, the motion gesture of the robot and the motion parameters; The overturning motion path tracking closed-loop control module is used for constructing a path tracking closed-loop control strategy by adopting a model prediction control algorithm adapting to overturning motion characteristics and combining with robot motion parameters fed back in real time by vision to correct the motion path of the robot in real time so as to finish the accurate tracking of a preset path.

Description

Multi-mode motion and path tracking control method for magnetic control micro-robot Technical Field The invention relates to the technical field of magnetic control micro robots and intelligent control systems, in particular to a multi-mode motion and path tracking control method of a magnetic control micro robot. Background In the field of medical accurate diagnosis and treatment, the magnetic control micro-robot has the advantages of wireless remote control, good biocompatibility, adaptability to narrow physiological space and the like, and becomes an important research direction of targeted diagnosis and treatment of intestinal diseases, and the motion control performance directly determines the diagnosis and treatment precision and the feasibility of clinical application, wherein the accurate control of multi-mode motion realization and overturning motion is a key point of core technology. The invention is closest to the prior art, mainly focuses on the motion control research of the magnetic control micro-robot, but has two major core problems in practical application, and particularly comprises the following steps that firstly, the existing magnetic control micro-robot is single in motion mode, most of the existing magnetic control micro-robot can only realize single motion mode, stable triggering and flexible switching mechanisms of rolling and overturning modes are not formed, the passing requirements of complex unstructured environments such as intestinal mucosa folds and narrow sections cannot be adapted, the clinical application scene of the robot is limited, secondly, the control precision of overturning motion is insufficient, the prior art does not construct a dynamics model which is attached to the practical scene according to the characteristic of overturning motion, the special condition of rotating shaft switching in overturning motion is not considered, and a path tracking control strategy which is adapted to overturning motion is not designed, so that the gesture is unstable in the overturning motion process, the track is easy to deviate, the control precision is difficult to meet the requirements of accurate arrival of intestinal lesions, and the clinical application of accurate diagnosis and treatment of intestinal diseases cannot be supported. Disclosure of Invention Therefore, the embodiment of the invention provides a multi-mode motion and path tracking control method for a magnetic control micro-robot, which is used for solving the problems that the magnetic control micro-robot in the prior art has a single motion mode, cannot adapt to the traffic demand of complex unstructured environments of intestinal tracts, has insufficient overturning motion control precision, poor path tracking robustness and stability and is difficult to accurately reach intestinal lesions. In order to solve the technical problems, an embodiment of the present invention provides a multi-mode motion and path tracking control method for a magnetically controlled micro-robot, the method comprising the following steps: S1, constructing an external magnetic control driving system, and realizing stable triggering and flexible switching of two modes of overturning motion of the robot along the width direction and rolling motion along the length direction by regulating and controlling the relative angle between an external magnetic field rotating plane and the length direction of the magnetic control micro-robot; S2, based on the structural characteristics and the magnetic field action principle of the magnetic control micro-robot, respectively constructing a corresponding dynamic model aiming at the overturning motion and the rolling motion, and quantifying the corresponding relation between the magnetic moment, the motion gesture and the motion parameter of the robot; and S3, aiming at the problem that the overturning motion trail is easy to deviate, a model prediction control algorithm adapting to overturning motion characteristics is adopted, and a path tracking closed-loop control strategy is constructed by combining with robot motion parameters fed back in real time by vision, so that the motion trail of the robot is corrected in real time, and the accurate tracking of a preset path is completed. Preferably, in step S1, the specific implementation method of the overturning motion is as follows: The method comprises the steps of placing the length direction of a magnetic control micro-robot along a y axis, firstly applying a bias magnetic field along the positive direction of a z axis to enable the robot to form a V-shaped configuration, then applying a rotating magnetic field in an xz plane to enable the rotating plane of the externally applied magnetic field to be perpendicular to the length direction of the robot, and driving the robot to finish stable overturning motion along the width direction of the robot through magnetic moment, wherein the vector expression of the rotating magnetic field is as follows