gait2d_osim.h

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// gait2d_osim.h
// This file defines the data structure that holds model parameters for the gait2d_osim model
 
#define MAXMUSDOF 4                             // maximum number of DOFs spanned by one muscle
#define MAXPOLTERMS 40          // maximum number of polynomial terms in a muscle path model
#define NAMELENGTH 40           // number of characters in muscle name
 
#include "gait2d_osim_multibody.h"
#include "../contact/gait2d_osim_contact.h"
 
// M_PI is known in gcc but not in Visual C++ 2008
#ifndef M_PI
#define M_PI 3.1415926535897932384626433832795
#endif
 
// structure that holds muscle properties for one muscle
typedef struct {
    char name[NAMELENGTH];                                                      // Name of muscle 
                double Lceopt;                                                                                                  // Optimal length of CE (m)
    double pennopt;                                                             // Pennation angle at optimal length of CE, in radians
                double width;                                                                                                   // Width of CE force-length relationship relative to Lceopt
                double Fmax;                                                                                                    // Maximal isometric force of CE (N)
                double Vmax;                                                                                                    // Max. contraction velocity in Lceopt/s
                double Tact, Tdeact;                                                                            // Activation and deactivation time constants
                double gmax;                                                                                                    // Maximum eccentric force
                double SEEslack;                                                                                                // Slack length of the SEE (m)
                double PEEslack;                                                                                                // Slack length of the PEE, relative to Lceopt
                double umax;                                                                                                    // Strain of SEE at Fmax load
                double krel;                            // Stiffness of PEE, force/Fmax at elongation of Width*Lceopt
                double HillA;                                                                                                   // Normalized Hill parameter a/Fmax for F-v relationship (usually 0.25)
                int    nmusdof;                                                 // Number of DOFs between origin and insertion 
    int    musdof[MAXMUSDOF];                                                   // List of DOFs between origin and insertion 
    int    npolterms;                                                           // Number of terms in polynomial 
    double  polcoeff[MAXPOLTERMS];              // Polynomial coefficients 
    int    expon[MAXPOLTERMS][MAXMUSDOF];   // Polynomial exponents 
                int spans[NDOF];                                                                                                // true/false flags for all DOFs to indicate if the muscle spans it
                
                // the following parameters are derived from other parameters during initialization
                double c3;                                                                                                                      // Continuity parameter for eccentric force-velocity relationship
                double kPEE;                                                                                                    // Stiffness parameter of PEE, relative to Fmax/Lceopt^2
                double kSEE;                                                                                                    // Stiffness parameter of SEE, in Fmax/m^2      
} muscleprop;
 
// structure that holds parameters for one joint
typedef struct {
                double K1;                                                                                      // linear stiffness (small), in N/rad
                double K2;                                                                                      // quadratic stiffness, outside range of motion, in N/rad^2
                double B;                                                                                       // damping, in Ns/rad
                double qneutral;                                        // neutral position to compute passive joint moments
    double qmin_muscleMoment, qmax_muscleMoment;   // range of dof for computation of muscle moments
    double qmin_passiveMoment, qmax_passiveMoment; // range of dof for computation of passive moments
                
} jointprop;