StiffnessSolver.h

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/*
* ==========================================================================
*               This file is part of the implementation of
*
*               <FrameFab: Robotic Fabrication of Frame Shapes>
*               Yijiang Huang, Juyong Zhang, Xin Hu, Guoxian Song, Zhongyuan Liu, Lei Yu, Ligang Liu
*               In ACM Transactions on Graphics (Proc. SIGGRAPH Asia 2016)
----------------------------------------------------------------------------
*               class:  StiffnessSolver
*
*               Description:
*
*               Version:  1.0
*               Created:  Mar/23/2016
*               Updated:  Aug/24/2016
*
*               Author:  Xin Hu, Yijiang Huang, Guoxian Song
*               Company:  GCL@USTC
*               Citation:       this module utilize solver and data structure from
*                       Title:                  Eigen
*                                                       C++ template library for linear algebra: matrices, vectors, numerical 
*                                                       solvers, and related algorithms.
*                       Code Version:   3.2.9
*                       Availability:   http://eigen.tuxfamily.org/index.php?title=Main_Page
----------------------------------------------------------------------------
*               Copyright (C) 2016  Yijiang Huang, Xin Hu, Guoxian Song, Juyong Zhang
*               and Ligang Liu.
*
*               FrameFab is free software: you can redistribute it and/or modify
*               it under the terms of the GNU General Public License as published by
*               the Free Software Foundation, either version 3 of the License, or
*               (at your option) any later version.
*
*               FrameFab is distributed in the hope that it will be useful,
*               but WITHOUT ANY WARRANTY; without even the implied warranty of
*               MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*               GNU General Public License for more details.
*
*               You should have received a copy of the GNU General Public License
*               along with FrameFab.  If not, see <http://www.gnu.org/licenses/>.
* ==========================================================================
*/

#ifndef STIFFNESS_SOLVER_H
#define STIFFNESS_SOLVER_H

#include <iostream>
#include <Eigen/Dense>
#include <Eigen/Sparse>
#include <Eigen/SparseCholesky>
#include <Eigen/LU>

#include "choreo_task_sequence_planner/utils/Timer.h"

#define sind(x) (sin(fmod((x),360) * M_PI / 180))
#define cosd(x) (cos(fmod((x),360) * M_PI / 180))

using namespace std;

class StiffnessSolver
{
public:
        typedef Eigen::SparseMatrix<double> SpMat;
        typedef Eigen::MatrixXd                         MX;
        typedef Eigen::Matrix3d                         M3;
        typedef Eigen::VectorXd                         VX;
        typedef Eigen::Vector3d                         V3;
        typedef Eigen::VectorXi                         VXi;
        typedef Eigen::MatrixXi                         MXi;
        
public:
        StiffnessSolver();
        ~StiffnessSolver(){};

public:
        /* solver I/O*/

    /*
    * SolveSystem  -  solve {F} =   [K]{D} via L D L' decomposition        2/Dec/2015
    *                 This override function is implemented for sovling Kqq * d_q = F_q,
    *                 where no partitioned LDLt is needed.
    * @param K   : stiffness matrix for the restrained frame
    * @param D   : displacement vector to be solved
    * @param F   : mechenical force(external load vector)
    * @param verbose    :  =1 for copious screenplay
    * @param info: <0 : not stiffness matrix positive definite
    * Note: This function use eigen library SimplicialLDLt module to solve the linear system.
    */
    bool SolveSystem(
        SpMat &K,
                VX &D, 
                VX &F, 
                int verbose, 
                int &info  
        );


        /*
        * SolveSystem  -  solve {F} =   [K]{D} via conjugate gradient with guess       30/Mar/2016
        *                 This override function is implemented for sovling Kqq * d_q = F_q,
        *                 where no partitioned LDLt is needed.
        * @param K   : stiffness matrix for the restrained frame
        * @param D   : displacement vector to be solved
        * @param F   : mechenical force(external load vector)
        * @param verbose        :  =1 for copious screenplay
        * @param info: <0 : not stiffness matrix positive definite
        * Note: This function use eigen library :ConjugateGradient module to solve the linear system.
        */
        bool SolveSystem(
                SpMat &K, 
                VX &D, 
                VX &F, 
                VX &D0, 
                int verbose, 
                int &info
                );

        void Debug();

public:
        /*
        * This LUDecomp module use Eigen library to solve the linear system
        */
        bool LUDecomp(
                MX &A,
                VX &x,
                VX &b
                );

public:
        Timer   compute_k_;
        Timer   solve_d_;

        /* Timing Stat */
        bool            detailed_timing_;
};

#endif