function [stewart] = generateCubicConfiguration(stewart, args) % generateCubicConfiguration - Generate a Cubic Configuration % % Syntax: [stewart] = generateCubicConfiguration(stewart, args) % % Inputs: % - stewart - A structure with the following fields % - geometry.H [1x1] - Total height of the platform [m] % - args - Can have the following fields: % - Hc [1x1] - Height of the "useful" part of the cube [m] % - FOc [1x1] - Height of the center of the cube with respect to {F} [m] % - FHa [1x1] - Height of the plane joining the points ai with respect to the frame {F} [m] % - MHb [1x1] - Height of the plane joining the points bi with respect to the frame {M} [m] % % Outputs: % - stewart - updated Stewart structure with the added fields: % - platform_F.Fa [3x6] - Its i'th column is the position vector of joint ai with respect to {F} % - platform_M.Mb [3x6] - Its i'th column is the position vector of joint bi with respect to {M} arguments stewart args.Hc (1,1) double {mustBeNumeric, mustBePositive} = 60e-3 args.FOc (1,1) double {mustBeNumeric} = 50e-3 args.FHa (1,1) double {mustBeNumeric, mustBeNonnegative} = 15e-3 args.MHb (1,1) double {mustBeNumeric, mustBeNonnegative} = 15e-3 end assert(isfield(stewart.geometry, 'H'), 'stewart.geometry should have attribute H') H = stewart.geometry.H; sx = [ 2; -1; -1]; sy = [ 0; 1; -1]; sz = [ 1; 1; 1]; R = [sx, sy, sz]./vecnorm([sx, sy, sz]); L = args.Hc*sqrt(3); Cc = R'*[[0;0;L],[L;0;L],[L;0;0],[L;L;0],[0;L;0],[0;L;L]] - [0;0;1.5*args.Hc]; CCf = [Cc(:,1), Cc(:,3), Cc(:,3), Cc(:,5), Cc(:,5), Cc(:,1)]; % CCf(:,i) corresponds to the bottom cube's vertice corresponding to the i'th leg CCm = [Cc(:,2), Cc(:,2), Cc(:,4), Cc(:,4), Cc(:,6), Cc(:,6)]; % CCm(:,i) corresponds to the top cube's vertice corresponding to the i'th leg CSi = (CCm - CCf)./vecnorm(CCm - CCf); Fa = CCf + [0; 0; args.FOc] + ((args.FHa-(args.FOc-args.Hc/2))./CSi(3,:)).*CSi; Mb = CCf + [0; 0; args.FOc-H] + ((H-args.MHb-(args.FOc-args.Hc/2))./CSi(3,:)).*CSi; stewart.platform_F.Fa = Fa; stewart.platform_M.Mb = Mb;