| CPC A61B 34/30 (2016.02) [A61B 90/96 (2016.02); G16H 40/63 (2018.01); A61B 2034/107 (2016.02); A61B 2034/2057 (2016.02); A61B 2034/2065 (2016.02); A61B 2090/3945 (2016.02)] | 4 Claims |
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1. A measurement viewing angle multi-objective optimization method for a surgical robot navigation and positioning system, wherein the method obtains a number, a serial number and a position of required positioning tools of each link in a surgical process through a surgical operation planning system, and establishes a multi-objective minimization problem based on a decision variable x:
x=[q1,q2,q3, . . . ,qN] (Formula 1)
where q1, q2, q3, . . . , qN are joint variables; N is the number of the joint variables; the decision variable x denotes a vector consisted of N joint variables of a robot, and the value range is the joint value range Q achievable by each joint of the robot, that is, x∈Q;
the method comprises the following steps:
Step 1, establishing a three-dimensional Cartesian coordinate system for each positioning tool;
Step 2, defining at least two objective functions f1 and f2 of minimization optimization;
Step 3, setting constraint conditions to minimize the at least two objective functions f1 and f2 at the same time;
wherein Step 1 comprises the following steps:
Step 1.1, designing a center of each positioning tool with a specific shape feature, and taking an intersection point between a feature axis and a plane where a centroid of a positioning part is located as a coordinate origin, wherein a shape feature is at least a round hole, a hemisphere, a boss and a cone; taking the coordinate origin as the center of a sphere, and constructing a minimum circumscribed ball enveloping K positioning parts on the positioning tool for each positioning tool, wherein the radius of the minimum circumscribed ball is li;
Step 1.2, taking a normal direction of the plane where the centroids of K positioning parts are located as a z axis direction, wherein the direction towards the side where the K positioning parts are attached is a positive direction of the z axis; establishing the three-dimensional Cartesian coordinate system by taking a direction perpendicular to the z axis and pointing to the positioning part farthest from the coordinate origin as the positive direction of the x axis;
Step 1.3, denoting a set of all positioning tools as S, in which the center of the coordinate system of the i-th positioning tool is Mi, that is, Mi∈S;
in which at least two objective functions f1 and f2 of minimization optimization in Step 2 are defined as follows:
f1=maxm∥NMm∥ (Formula 2)
f2=minj,k∈S−Omin(j,k) (Formula 3)
where ∥NMm∥ denotes a distance between the coordinate origin of the m-th positioning tool and the coordinate origin of a positioning sensor; f1 denotes a maximum distance between the coordinate origin of all positioning tools and the coordinate origin of the positioning sensor; Omin(j, k) denotes a smaller non-interference margin function in a camera coordinates of the positioning sensor for a given pair of positioning tools j and k; minj,k∈SOmin (j, k) denotes a minimum non-interference margin function value among the binary combinations of all the positioning tools measured in all the cameras of the positioning sensor under the pose of the robot determined by q;
calculating the smaller non-interference margin function Omin (j, k) by the following formula:
 where G is the coordinate origin of the left or right camera in the positioning sensor; L and R are a coordinate origins of the left and right cameras in the positioning sensor, respectively; Mj and Mk are the centers of a minimum circumscribed ball whose radii are lj and lk for any two positioning tools j and k, respectively, that is, the coordinate origin of the positioning tools j and k; rj and rk are an extension radii of the positioning tools j and k, respectively; margin coefficient ω is a constant greater than 1; the vector lengths ∥GMj∥ and ∥GMk∥ are measured by the positioning sensor; · denotes vector point multiplication.
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