Method of preparing fluid-structure interactive numerical model and method of manufacturing fluttering robot using the same

Abstract

A numerical model related to fluttering of an insect, when an equivalent model of actual structure of a wing of the insect is moved in the air in accordance with a model of fluttering motion of the wing of the insect is calculated by fluid-structure interactive analysis, in which behavior of the wing and behavior of the air are given as numerical values, including interaction therebetween. Thereafter, a method of controlling a fluttering robot, wing shape and the like are determined by modifying numerical models of fluttering of an insect prepared by fluid-structure interactive analysis, in accordance with sensitivity analysis. Accordingly, a method of preparing numerical models of wing and air considering the behavior of the wing of the insect in the air is provided and, in addition, a method of manufacturing a fluttering robot utilizing the numerical model prepared by this method of preparing numerical model can be provided.

What is claimed is:  
     
         1 . A method of preparing a fluid-structure interactive numerical model, for preparing, when an actual structure as a living organism performs a prescribed motion in a fluid, a numerical model related to said fluid and a numerical model related to said structure, comprising: 
 actual structure measuring step of measuring physical values related to an actual structure of said structure;    the step of preparing equivalent numerical model of actual structure that can be regarded as equivalent to said actual structure, in which the physical values related to said actual structure measured in said actual structure measuring step are given as numerical values;    manner of motion measuring step causing said actual structure make a prescribed motion and measuring physical values related to a manner of said prescribed motion;    motion model preparing step of preparing a motion model in which the physical values related to said manner of prescribed motion are given as numerical values; and    fluid-structure interactive analysis step of calculating, when said equivalent numerical model of actual structure performs said prescribed motion represented by said motion model in a pre-set virtual fluid for analysis, a numerical model related to the fluid of said virtual fluid (numerical fluid model) and a numerical model related to the structure of said equivalent numerical model of actual structure, by performing fluid-structure interactive analysis in which behavior of said fluid and behavior of said structure are given as numerical models including interaction therebetween.    
     
     
         2 . The method of preparing fluid-structure interactive numerical model according to  claim 1 , wherein 
 said structure includes a first structure and a second structure different from but of the same type as said first structure;    said actual structure measuring step includes 
 the first measuring step of measuring physical values related to the actual structure of said first structure, and  
 the second measuring step of measuring physical values related to actual structure of a featured portion of second structure;  
   said step of preparing equivalent numerical model of actual structure includes 
 the step of preparing a numerical model of detailed figure in which physical values related to the actual structure of said first structure measured in said first measuring step are given as numerical values, and  
 converting step of preparing said equivalent model of actual structure, by performing a prescribed conversion on said numerical model of detailed figure, using the physical values related to the actual structure of featured portion of said second structure measured in said second step; and  
 in said manner of motion measuring step, physical values related to the manner of prescribed motion of said actual second structure are measured.  
   
     
     
         3 . The method of preparing fluid-structure interactive numerical model according to  claim 2 , wherein 
 in said first measuring step, shape, mass and rigidity are measured as physical values related to the structure of said first structure; and    in said second measuring step, shape and rigidity are measured as physical values related to the structure of a featured portion of said second structure.    
     
     
         4 . The method of preparing fluid-structure interactive numerical model according to  claim 1 , wherein 
 measurement of said prescribed motion is performed only for a featured portion that enables identification of an attitude of the actual said structure.    
     
     
         5 . The method of preparing fluid-structure interactive numerical model according to  claim 1 , wherein said virtual fluid represents a space in which unsteady flow is generated when said actual structure performs said prescribed motion.  
     
     
         6 . The method of preparing fluid-structure interactive numerical model according to  claim 1 , wherein 
 said structure is a wing of an insect;    said fluid is air; and    said prescribed motion is a fluttering motion.    
     
     
         7 . The method of preparing fluid-structure interactive numerical model according to  claim 6 , wherein 
 in said actual structure measuring step, physical values related to the actual structure of the wing of an insect are measured, assuming that the actual structure of said wing of the insect consists of a collection of shell structures.    
     
     
         8 . The method of preparing fluid-structure interactive numerical model according to  claim 6 , wherein 
 in said the motion model preparing step, said motion model is prepared by using values obtained by smoothing time-differentiated values of the physical values related to said manner of motion of said wing actually measured.    
     
     
         9 . The method of preparing fluid-structure interactive numerical model according to  claim 8 , wherein 
 said smoothing is performed separately on translational motion and rotational motion of said wing.    
     
     
         10 . The method of preparing fluid-structure interactive numerical model according to  claim 6 , wherein 
 said motion model consists of time-sequential position data of prescribed three points among actual portions of said wing of the insect, when the prescribed three point change during said prescribed motion.    
     
     
         11 . The method of preparing fluid-structure interactive numerical model according to  claim 10 , wherein 
 said prescribed three points are selected from a portion among actual portions of the wing of said insect which is not deformed by the motion based on said motion model.    
     
     
         12 . The method of preparing fluid-structure interactive numerical model according to  claim 11 , wherein 
 said prescribed three points are selected from a potion near a root of the actual wing of said insect.    
     
     
         13 . The method of preparing fluid-structure interactive numerical model according to  claim 11 , wherein 
 a triangle formed by said prescribed three points is a right triangle.    
     
     
         14 . The method of preparing fluid-structure interactive numerical model according to  claim 6 , wherein 
 said actual structure measuring step includes a bending rigidity measuring step of measuring bending rigidity of the actual wing of said insect; and    said numerical model of detailed figure of the actual wing of the insect has its thickness determined to have bending rigidity equivalent to the bending rigidity of said actual wing of the insect measured in said bending rigidity measuring step.    
     
     
         15 . A method of manufacturing a fluttering robot, including 
 a wing for a fluttering motion,    a wing driving apparatus for driving said wing in accordance with a numerical model of driving force, and    a wing drive control apparatus controlling said wing driving apparatus by applying said numerical model of driving force to said wing driving apparatus, comprising the step of 
 determining said numerical model of driving force by a numerical model of driving force prepared in accordance with the method of preparing fluid-structure interactive numerical model according to  claim 6 .  
   
     
     
         16 . A method of manufacturing a fluttering robot including 
 a wing for a fluttering motion,    a wing driving apparatus driving said wing, and    a wing drive control apparatus controlling the wing driving apparatus, comprising the step of 
 determining a numerical model of a structure of said wing by modifying said equivalent numerical model of actual structure used in the method of preparing fluid-structure interactive numerical model according to  claim 6 , in accordance with sensitivity analysis.  
   
     
     
         17 . The method of manufacturing a fluttering robot according to  claim 16 , wherein 
 change in numerical model of lift force with respect to change in a prescribed numerical model is used as the sensitivity in said sensitivity analysis.    
     
     
         18 . A method of manufacturing a fluttering robot including 
 a wing for a fluttering motion,    a wing driving apparatus driving the wing, and    a wing drive control apparatus for controlling the wing driving apparatus, comprising the step of 
 determining manner of fluttering motion of said wing by modifying said motion model used in the method of preparing fluid-structure interactive numerical model according to  claim 6 , in accordance with sensitivity analysis.  
   
     
     
         19 . The method of manufacturing a fluttering robot according to  claim 18 , wherein 
 change in numerical model of lift force with respect to change in a prescribed numerical model is used as the sensitivity in said sensitivity analysis.    
     
     
         20 . A method of manufacturing a fluttering robot, comprising: 
 the step of preparing numerical model of artificial wing, preparing a numerical model related to a structure of an artificial wing;    the step of preparing numerical model of detailed figure, which will be a reference of interpolation;    the step of preparing detailed numerical motion model, preparing detailed numerical motion model corresponding to the manner of motion of said numerical model of detailed figure;    the step of detailed fluid-structure interactive analysis, calculating a numerical model related to the structure of said numerical model of detailed figure and a numerical model related to fluid of said numerical model of detailed figure, by performing fluid-structure interactive analysis, using said numerical model of detailed figure and said detailed numerical motion model;    the step of preparing first numerical model of interpolated structure, for preparing a first numerical model of interpolated structure by interpolating the numerical model related to the structure of said artificial wing and said numerical model of detailed figure with a prescribed interpolation ratio;    the step of preparing a first numerical motion model of the interpolated structure corresponding to said first numerical model of the interpolated structure, by changing said detailed numerical motion model such that change in a specific numerical model is smaller than change in the specific numerical model of the numerical model related to the structure and the numerical model related to fluid resulting from fluid-structure interactive analysis using said first numerical model of the interpolated structure and said detailed numerical motion model;    the step of first fluid-structure interactive analysis calculating a numerical model related to a structure of said first numerical model of interpolated structure and a numerical model related to fluid of said first numerical model of interpolated structure, by performing fluid-structure interactive analysis, using said first numerical model of interpolated structure and said first numerical motion model of the interpolated structure;    the step of preparing a second numerical model of interpolated structure by interpolating the numerical model related to the structure of said artificial wing and said first numerical model of interpolated structure with a prescribed interpolation ratio;    the step of preparing a second numerical motion model of interpolated structure corresponding to said second numerical model of interpolated structure, by changing said first numerical motion model of the interpolated structure, such that change in a specific numerical model is smaller than change in the specific numerical model of the numerical model related to the structure and the numerical model related to fluid resulting from fluid-structure interactive analysis using said second numerical model of interpolated structure and said first numerical motion model of the interpolated structure; and    the step of second fluid-structure interactive analysis calculating a numerical model related to a structure of said second numerical model of interpolated structure and a numerical model related to fluid of said second numerical model of interpolated structure, by performing fluid-structure interactive analysis, using said second numerical model of interpolated structure and said second numerical motion model of the interpolated structure; wherein 
 while successively updating respective said models until the numerical model of interpolated structure is matched or approximated with the numerical model related to the structure of said artificial wing, accumulatively repeating steps similar to said step of preparing second numerical model of interpolated structure, said step of preparing the second numerical motion model of the interpolated structure and said second fluid-structure interactive analysis step and thereafter, using the numerical motion model of the interpolated structure corresponding to the numerical model of interpolated structure that matches or is approximated with the numerical model related to the structure of said artificial wing, the method of controlling a wing driving apparatus driving the artificial wing is determined.  
   
     
     
         21 . The method of manufacturing a fluttering robot according to  claim 20 , wherein 
 in said step of preparing the second numerical motion model of the interpolated structure, said first numerical motion model of the interpolated structure is changed such that change in a specific numerical model of the numerical model related to the structure and the numerical model related to fluid is made zero.    
     
     
         22 . The method of manufacturing a fluttering robot according to  claim 20 , wherein said specific numerical model is a numerical model of lift force.  
     
     
         23 . The method of manufacturing a fluttering robot according to  claim 20 , wherein 
 said numerical model of detailed figure is said equivalent numerical model of actual structure used in the method of preparing fluid-structure interactive numerical model according to  claim 6.