ikfast_wrapper.cpp

/*
 * THIS IS A MODIFIED VERSION OF THE FOLLOWING:
 * 
 * IKFast Demo
 * 
 * Shows how to calculate FK from joint angles.
 * Calculates IK from rotation-translation matrix, or translation-quaternion pose.
 * Performance timing tests.
 *
 * Run the program to view command line parameters.
 * 
 * 
 * To compile, run:
 * g++ -lstdc++ -llapack -o compute ikfastdemo.cpp -lrt
 * (need to link with 'rt' for gettime(), it must come after the source file name)
 *
 * 
 * Tested with Ubuntu 11.10 (Oneiric)
 * IKFast54 from OpenRAVE 0.6.0
 * IKFast56/61 from OpenRave 0.8.2
 *
 * Author: David Butterworth, KAIST
 *         Based on code by Rosen Diankov
 * Date: November 2012
 */

/*
 * Copyright (c) 2012, David Butterworth, KAIST
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Willow Garage, Inc. nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#define IKFAST_HAS_LIBRARY // Build IKFast with API functions
#define IKFAST_NO_MAIN // Don't include main() from IKFast

/*
Set which IKFast version you are using
The API calls are slightly different for versions > 54
*/

#define IK_VERSION 61
#include "ur5e_ikfast61.cpp"

//#define IK_VERSION 56
//#include "ikfast56.Transform6D.0_1_2_3_4_5.cpp"

//#define IK_VERSION 54
//#include "output_ikfast54.cpp"


//----------------------------------------------------------------------------//

#include <stdio.h>
#include <stdlib.h>
#include <time.h> // for clock_gettime()
#include <vector>

float SIGN(float x);
float NORM(float a, float b, float c, float d);

#if IK_VERSION > 54
#define IKREAL_TYPE IkReal // for IKFast 56,61
#else
#define IKREAL_TYPE IKReal // for IKFast 54
#endif

namespace robots { 
    class Kinematics { 
        public: int num_of_joints, num_free_parameters; 
        Kinematics(); 
        ~Kinematics(); 
        std::vector<float> forward(std::vector<float> joint_config);
        std::vector<float> inverse(std::vector<float> ee_pose);
    }; 
    Kinematics::Kinematics() { 
        #if IK_VERSION > 54
            // for IKFast 56,61
            num_of_joints = GetNumJoints();
            num_free_parameters = GetNumFreeParameters();
        #else
            // for IKFast 54
            num_of_joints = getNumJoints();
            num_free_parameters = getNumFreeParameters();
        #endif
    } 
    Kinematics::~Kinematics() { } 
    std::vector<float> Kinematics::forward(std::vector<float> joint_config) {
        IKREAL_TYPE eerot[9],eetrans[3];
        std::vector<float> ee_pose;

        if( joint_config.size() != num_of_joints ) {
            printf("\nError: (forward kinematics) expects vector of %d values describing joint angles (in radians).\n\n", num_of_joints);
            return ee_pose;
        }

        // Put input joint values into array
        IKREAL_TYPE joints[num_of_joints];
        for (unsigned int i=0; i<num_of_joints; i++)
        {
            joints[i] = joint_config[i];
        }

#if IK_VERSION > 54
        // for IKFast 56,61
        ComputeFk(joints, eetrans, eerot); // void return
#else
        // for IKFast 54
        fk(joints, eetrans, eerot); // void return
#endif
        for (unsigned int i=0; i<3; i++) {
            ee_pose.push_back(eerot[i*3+0]);
            ee_pose.push_back(eerot[i*3+1]);
            ee_pose.push_back(eerot[i*3+2]);
            ee_pose.push_back(eetrans[i]);
        }

        return ee_pose;
    }
    std::vector<float> Kinematics::inverse(std::vector<float> ee_pose) {
        IKREAL_TYPE eerot[9],eetrans[3];
        std::vector<float> joint_configs;

        if( ee_pose.size() == 7 )  // ik, given translation vector and quaternion pose
        {
#if IK_VERSION > 54
            // for IKFast 56,61
            IkSolutionList<IKREAL_TYPE> solutions;
#else
            // for IKFast 54
            std::vector<IKSolution> vsolutions;
#endif
            std::vector<IKREAL_TYPE> vfree(num_free_parameters);

            eetrans[0] = ee_pose[0];
            eetrans[1] = ee_pose[1];
            eetrans[2] = ee_pose[2];

            // Convert input effector pose, in w x y z quaternion notation, to rotation matrix. 
            // Must use doubles, else lose precision compared to directly inputting the rotation matrix.
            double qw = ee_pose[3];
            double qx = ee_pose[4];
            double qy = ee_pose[5];
            double qz = ee_pose[6];
            const double n = 1.0f/sqrt(qx*qx+qy*qy+qz*qz+qw*qw);
            qw *= n;
            qx *= n;
            qy *= n;
            qz *= n;
            eerot[0] = 1.0f - 2.0f*qy*qy - 2.0f*qz*qz;  eerot[1] = 2.0f*qx*qy - 2.0f*qz*qw;         eerot[2] = 2.0f*qx*qz + 2.0f*qy*qw;
            eerot[3] = 2.0f*qx*qy + 2.0f*qz*qw;         eerot[4] = 1.0f - 2.0f*qx*qx - 2.0f*qz*qz;  eerot[5] = 2.0f*qy*qz - 2.0f*qx*qw;
            eerot[6] = 2.0f*qx*qz - 2.0f*qy*qw;         eerot[7] = 2.0f*qy*qz + 2.0f*qx*qw;         eerot[8] = 1.0f - 2.0f*qx*qx - 2.0f*qy*qy;

            // For debugging, output the matrix
            /*
            for (unsigned char i=0; i<=8; i++)
            {   // detect -0.0 and replace with 0.0
                if ( ((int&)(eerot[i]) & 0xFFFFFFFF) == 0) eerot[i] = 0.0;
            }
            printf("     Rotation     %f   %f   %f  \n", eerot[0], eerot[1], eerot[2] );
            printf("                  %f   %f   %f  \n", eerot[3], eerot[4], eerot[5] );
            printf("                  %f   %f   %f  \n", eerot[6], eerot[7], eerot[8] );
            printf("\n");
            */

            // for(std::size_t i = 0; i < vfree.size(); ++i)
            //     vfree[i] = atof(argv[13+i]);

#if IK_VERSION > 54
            // for IKFast 56,61
            bool bSuccess = ComputeIk(eetrans, eerot, vfree.size() > 0 ? &vfree[0] : NULL, solutions);
#else
            // for IKFast 54
            bool bSuccess = ik(eetrans, eerot, vfree.size() > 0 ? &vfree[0] : NULL, vsolutions);
#endif
            if( !bSuccess ) {
                // fprintf(stderr,"Error: (inverse kinematics) failed to get ik solution\n");
                return joint_configs;
            }

#if IK_VERSION > 54
            // for IKFast 56,61
            unsigned int num_of_solutions = (int)solutions.GetNumSolutions();
#else
            // for IKFast 54
            unsigned int num_of_solutions = (int)vsolutions.size();
#endif
            // printf("Found %d ik solutions:\n", num_of_solutions ); 

            std::vector<IKREAL_TYPE> solvalues(num_of_joints);
            for(std::size_t i = 0; i < num_of_solutions; ++i) {
#if IK_VERSION > 54
                // for IKFast 56,61
                const IkSolutionBase<IKREAL_TYPE>& sol = solutions.GetSolution(i);
                int this_sol_free_params = (int)sol.GetFree().size(); 
#else
                // for IKFast 54
                int this_sol_free_params = (int)vsolutions[i].GetFree().size();
#endif
                // printf("sol%d (free=%d): ", (int)i, this_sol_free_params );
                std::vector<IKREAL_TYPE> vsolfree(this_sol_free_params);

#if IK_VERSION > 54
                // for IKFast 56,61
                sol.GetSolution(&solvalues[0],vsolfree.size()>0?&vsolfree[0]:NULL);
#else
                // for IKFast 54
                vsolutions[i].GetSolution(&solvalues[0],vsolfree.size()>0?&vsolfree[0]:NULL);
#endif

                for( std::size_t j = 0; j < solvalues.size(); ++j)
                    joint_configs.push_back(solvalues[j]);
                    // printf("%.15f, ", solvalues[j]);
                // printf("\n");
            }

        } 
        else if( ee_pose.size() == 12 )  // ik, given rotation-translation matrix
        {
#if IK_VERSION > 54
            // for IKFast 56,61
            IkSolutionList<IKREAL_TYPE> solutions;
#else
            // for IKFast 54
            std::vector<IKSolution> vsolutions;
#endif
            std::vector<IKREAL_TYPE> vfree(num_free_parameters);

            eerot[0] = ee_pose[0]; eerot[1] = ee_pose[1]; eerot[2] = ee_pose[2];  eetrans[0] = ee_pose[3];
            eerot[3] = ee_pose[4]; eerot[4] = ee_pose[5]; eerot[5] = ee_pose[6];  eetrans[1] = ee_pose[7];
            eerot[6] = ee_pose[8]; eerot[7] = ee_pose[9]; eerot[8] = ee_pose[10]; eetrans[2] = ee_pose[11];
            // for(std::size_t i = 0; i < vfree.size(); ++i)
            //     vfree[i] = atof(argv[13+i]);

#if IK_VERSION > 54
            // for IKFast 56,61
            bool bSuccess = ComputeIk(eetrans, eerot, vfree.size() > 0 ? &vfree[0] : NULL, solutions);
#else
            // for IKFast 54
            bool bSuccess = ik(eetrans, eerot, vfree.size() > 0 ? &vfree[0] : NULL, vsolutions);
#endif
            if( !bSuccess ) {
                // fprintf(stderr,"Error: (inverse kinematics) failed to get ik solution\n");
                return joint_configs;
            }

#if IK_VERSION > 54
            // for IKFast 56,61
            unsigned int num_of_solutions = (int)solutions.GetNumSolutions();
#else
            // for IKFast 54
            unsigned int num_of_solutions = (int)vsolutions.size();
#endif
            // printf("Found %d ik solutions:\n", num_of_solutions ); 

            std::vector<IKREAL_TYPE> solvalues(num_of_joints);
            for(std::size_t i = 0; i < num_of_solutions; ++i) {
#if IK_VERSION > 54
                // for IKFast 56,61
                const IkSolutionBase<IKREAL_TYPE>& sol = solutions.GetSolution(i);
                int this_sol_free_params = (int)sol.GetFree().size(); 
#else
                // for IKFast 54
                int this_sol_free_params = (int)vsolutions[i].GetFree().size();
#endif
                // printf("sol%d (free=%d): ", (int)i, this_sol_free_params );
                std::vector<IKREAL_TYPE> vsolfree(this_sol_free_params);

#if IK_VERSION > 54
                // for IKFast 56,61
                sol.GetSolution(&solvalues[0],vsolfree.size()>0?&vsolfree[0]:NULL);
#else
                // for IKFast 54
                vsolutions[i].GetSolution(&solvalues[0],vsolfree.size()>0?&vsolfree[0]:NULL);
#endif
                for( std::size_t j = 0; j < solvalues.size(); ++j)
                    joint_configs.push_back(solvalues[j]);
                //     printf("%.15f, ", solvalues[j]);
                // printf("\n");
            }

        }
        else {
            printf("\nError: (inverse kinematics) please specify transformation of end effector with one of the following formats:\n"
                   "    1) A vector of 7 values: a 3x1 translation (tX), and a 1x4 quaternion (w + i + j + k)\n"
                   "    2) A (row-major) vector of 12 values: a 3x4 rigid transformation matrix with a 3x3 rotation R (rXX), and a 3x1 translation (tX)\n\n");
            return joint_configs;

        }

        return joint_configs;
    }
}

float SIGN(float x) {
    return (x >= 0.0f) ? +1.0f : -1.0f;
}

float NORM(float a, float b, float c, float d) {
    return sqrt(a * a + b * b + c * c + d * d);
}