INDIRECT ROTATION ANGLES MEASUREMENT METHOD IN OPERATOR'S JOINTS Russian patent published in 2019 - IPC A61B5/103 

FIELD: control systems.

SUBSTANCE: invention relates to control systems and can be used in creation of setting devices for copying control systems implemented in form of exoskeleton with non-stiff attachments to operator's body. Disclosed is a method for indirect measurement of rotation angles in operator's joints, based on use for measurement of exoskeleton with kinematic scheme, similar to kinematic scheme of human hand, links of which are located along operator's hands, fixed on operator's body with the help of rigid and non-rigid fixtures, rotation angles measurement θ in exoskeleton kinematic pairs. Additionally measuring l_B1-B2 is operator shoulder length, lB_2-B3 is the length of the forearm of the operator, calculating the Cartesian coordinates vectors of the shoulder joint B₁; wrist joint B₃, operator's hand center B₄, elbow articulation of exoskeleton C₂ by solving the kinematics direct problem, values of projections of vector B₁B₃ are calculated, connecting the shoulder and wrist joints of the operator, calculating the distance between the shoulder and wrist joints of the operator l_B1-B3, calculating semi -perimeter p of triangle formed by shoulder, elbow and wrist joints of operator, calculating distance l_K2-B2 from center of circle K₂, formed by virtual rotation of elbow joint operator around axis passing through shoulder and wrist joints, and elbow joint operator by formula:

calculating distance l_B1-K2 between shoulder joint and center of circle K₂ by formula: calculating coordinates of point K₂ by formula: where λ is ratio, in which point K₂ divides section B₁B₃, calculating two versions of B⁽ⁿ⁾_2a and B⁽ⁿ⁾_2b vectors of values of Cartesian coordinates of elbow joint by solving system of equations: where x_K2, y_K2, z_K2 – Cartesian coordinates of point K₂; A_n, B_n, C_n, D_n are coefficients of plane perpendicular to section B₁B₃ and passing through point K₂; x_B1B3, y_B1B3, z_B1B3 are values of projections of vector B₁B₃ on Cartesian coordinate system axis; x_C2, y_C2, z_C2 – Cartesian coordinates of joint C₂; l_B2-C2 – effective length of non-rigid attachment, the value of which is selected from the condition of minimizing the error of indirect measurement of turning angles in operator's joints, selecting one of calculated versions B⁽ⁿ⁾_2a and B⁽ⁿ⁾_2b Cartesian coordinates vector of the elbow joint from the condition of the shortest distance to the previous known position of the elbow joint B^(n-1)_2, where n is number of current iteration of indirect measurement of turning angles of operator's joints, rotation angle vector is formed in the operator's joints by solving the inverse kinematics problem for the known Cartesian coordinates of the operator's joints.

EFFECT: invention provides higher accuracy of measurement of turning angles in operator's joints.

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