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parallel_flexure_guide_transfer

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parallel_flexure_guide_transfer [2018/05/16 13:43]
marijn.nijenhuis 		parallel_flexure_guide_transfer [2020/06/04 12:23]
marijn.nijenhuis
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 {{::parallel flexure guide.png?direct|}} {{::parallel flexure guide.png?direct|}}
  
-The state-space equations (from which the transfer function follows) can be computed by specifying the input and output for the transfer function. For this example, actuation force in x-direction on node 3 (a node on the end-effector) is used for input, and displacement in x-direction of node 3 is used for the output. This can be specified with the ''nprops(i).transfer_in'' and ''nprops(i).transfer_out'' arguments. Furthermore, to enable the computation of the state-space equations, the optional field ''opt.transfer'' has to be set to ''true''. For details, see the [[full_syntax|SPACAR Light full syntax]]. For this case, the MATLAB file that defines the flexure mechanism is supplemented with+The state-space equations (from which the transfer function follows) can be computed by specifying the input and output for the transfer function. For this example, actuation force in x-direction on node 3 (a node on the end-effector) is used for input. Two desired outputs are specified: the first is the displacement in x-direction of node 3; the second is the velocity in x-direction of node 5. These can be specified with the ''nprops(i).transfer_in'' and ''nprops(i).transfer_out'' arguments. Furthermore, to enable the computation of the state-space equations, the optional field ''opt.transfer'' has to be set to ''true''. For details, see the [[full_syntax|SPACAR Light full syntax]]. For this case, the MATLAB file that defines the flexure mechanism is supplemented with
 <code matlab> <code matlab>
-nprops(3).transfer_in  = {'force_x'};       %Input for state-space equations +nprops(3).transfer_in  = {'force_x'};       %Input 1 for state-space equations 
-nprops(3).transfer_out = {'displ_x'};       %Output for state-space equations+nprops(3).transfer_out = {'displ_x'};       %Output 1 for state-space equations 
 +nprops(5).transfer_out = {'veloc_x'};       %Output 2 for state-space equations
 ... ...
 opt.transfer = {true 0.01};       %Calculation of state-space equations (with relative damping 0.01) opt.transfer = {true 0.01};       %Calculation of state-space equations (with relative damping 0.01)
 </code> </code>
-It has to be noted that the state-space equations can only be computed for an undeformed flexure mechanism. Therefore, no external loads (actuation force) or input displacements are allowed when computing state-space equations. (An error message will appear.) 
  
-The resulting transfer function is plotted in the figure below, with the first eiqenfrequency at approximately 10 rad/s and the first disturbing frequency at 360 rad/s.+Note that 
 +  * the state-space equations can only be computed for an undeformed flexure mechanism. Therefore, no external loads (actuation force) or input displacements are allowed when computing state-space equations. (An error message will appear.) 
 +  * velocity outputs are supported as well; 
 +  * relative damping for all modes of the system can be specified optionally by means of the ''opt.transfer'' field. 
 +For details, see the [[full_syntax|SPACAR Light full syntax]]. 
 + 
 +The resulting transfer function is plotted in the figure below. The first eigenfrequency is approximately 10 rad/s;  the first parasitic eigenfrequency appears at 360 rad/s.
  
 {{::transfer pfg.png?direct|}} {{::transfer pfg.png?direct|}}
- 
  
 An example file for providing the input for SPACAR Light and plotting the transfer function is provided below. An example file for providing the input for SPACAR Light and plotting the transfer function is provided below.
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 %node 3 %node 3
 nprops(3).transfer_in  = {'force_x'};       %Input for state-space equations nprops(3).transfer_in  = {'force_x'};       %Input for state-space equations
-nprops(3).transfer_out = {'displ_x'};       %Output for state-space equations+nprops(3).transfer_out = {'displ_x'};       %Output nr 1 (displ. in x-direction on node 3) for state-space equations 
 +nprops(5).transfer_out = {'veloc_x'};       %Output nr 2 (veloc. in x-direction on node 5) for state-space equations
  
 %node 4 %node 4
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 eprops(1).dim      = [50e-3 0.2e-3];   %Width: 50 mm, thickness: 0.2 mm eprops(1).dim      = [50e-3 0.2e-3];   %Width: 50 mm, thickness: 0.2 mm
 eprops(1).orien    = [0 0 1];          %Orientation of the cross-section as a vector pointing along "width-direction" eprops(1).orien    = [0 0 1];          %Orientation of the cross-section as a vector pointing along "width-direction"
-eprops(1).nbeams   = 2;                %2 beam elements for simulating these elements +eprops(1).nbeams   = 2;                %2 beam elements for simulating these flexures 
-eprops(1).flex     = 1:6;            %Full flexible beam +eprops(1).flex     = 1:6;              %Fully flexible beam 
-eprops(1).color    = 'grey'; +eprops(1).color    = 'grey';           %Color of elements 
-eprops(1).opacity  = 0.7; +eprops(1).opacity  = 0.7;              %Opacity of elements 
-eprops(1).cw       = true;+eprops(1).cw       = true;             %Enable (approximate) torsional stiffening due to constraint warping 
 %Property set 2 %Property set 2
 eprops(2).elems    = [2 4];            %Add this set of properties to element 2 and 4 eprops(2).elems    = [2 4];            %Add this set of properties to element 2 and 4
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 eprops(2).dim      = [50e-3 25e-3];    %Width: 50 mm, thickness: 25 mm eprops(2).dim      = [50e-3 25e-3];    %Width: 50 mm, thickness: 25 mm
 eprops(2).orien    = [0 0 1];          %Orientation of the cross-section as a vector pointing along "width-direction" eprops(2).orien    = [0 0 1];          %Orientation of the cross-section as a vector pointing along "width-direction"
-eprops(2).nbeams   = 1;                %1 beam element for simulating this element +eprops(2).nbeams   = 1;                %1 beam element for simulating this component 
-eprops(2).color    = 'darkblue';+eprops(2).color    = 'darkblue';       %Color of elements
  
  
 %% OPTIONAL ARGUMENTS %% OPTIONAL ARGUMENTS
 opt.transfer = {true 0.01};       %Calculation of state-space equations (with relative damping 0.01) opt.transfer = {true 0.01};       %Calculation of state-space equations (with relative damping 0.01)
 +opt.filename = 'file';
  
 %% CALL SPACAR_LIGHT %% CALL SPACAR_LIGHT
parallel_flexure_guide_transfer.txt · Last modified: 2021/05/05 14:17 by marijn.nijenhuis

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