se3_ransac_unittest.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

// ------------------------------------------------------
// This test file is a subset of a complete example. See:
//   [MRPT]/samples/ransac-data-association/
// ------------------------------------------------------

#include <mrpt/maps/CSimplePointsMap.h>
#include <mrpt/math/geometry.h>
#include <mrpt/poses/CPose2D.h>
#include <mrpt/poses/CPosePDFGaussian.h>
#include <mrpt/poses/CPosePDFSOG.h>
#include <mrpt/random.h>
#include <mrpt/tfest/se2.h>

#include <gtest/gtest.h>

using namespace mrpt;
using namespace mrpt::math;
using namespace mrpt::random;
using namespace mrpt::maps;
using namespace mrpt::tfest;
using namespace mrpt::poses;
using namespace std;

// ============= PARAMETERS ===================
const size_t NUM_OBSERVATIONS_TO_SIMUL = 15;
const size_t RANSAC_MINIMUM_INLIERS = 9;  // Min. # of inliers to accept

const float normalizationStd = 0.10f;  // 1 sigma noise (meters)
const float ransac_mahalanobisDistanceThreshold = 5.0f;
const size_t MINIMUM_RANSAC_ITERS = 100000;

const size_t NUM_MAP_FEATS = 50;
const double MAP_SIZE_X = 30;
const double MAP_SIZE_Y = 15;
// ==============================================

struct TObs
{
    size_t ID;  // Ground truth ID
    double x, y;
};

// Return true if test succeds.
// Due to RANSAC being non-deterministic, there exists a small chance of failed
// tests even if the algorithm is ok.
bool ransac_data_assoc_run()
{
    getRandomGenerator().randomize();  // randomize with time
    // --------------------------------
    // Load feature map:
    // --------------------------------
    CSimplePointsMap the_map;
    // Generate random MAP:
    the_map.resize(NUM_MAP_FEATS);
    for (size_t i = 0; i < NUM_MAP_FEATS; i++)
    {
        the_map.setPoint(
            i, getRandomGenerator().drawUniform(0, MAP_SIZE_X),
            getRandomGenerator().drawUniform(0, MAP_SIZE_Y));
    }
    const size_t nMapPts = the_map.size();
    const size_t nObs = NUM_OBSERVATIONS_TO_SIMUL;

    // Read the observations themselves:
    vector<TObs> observations;
    observations.resize(nObs);

    const mrpt::poses::CPose2D GT_pose(
        mrpt::random::getRandomGenerator().drawUniform(-10, 10 + MAP_SIZE_X),
        mrpt::random::getRandomGenerator().drawUniform(-10, 10 + MAP_SIZE_Y),
        mrpt::random::getRandomGenerator().drawUniform(-M_PI, M_PI));

    const mrpt::poses::CPose2D GT_pose_inv = -GT_pose;

    std::vector<std::pair<size_t, float>> idxs;
    the_map.kdTreeRadiusSearch2D(GT_pose.x(), GT_pose.y(), 1000, idxs);
    ASSERT_(idxs.size() >= nObs);

    for (size_t i = 0; i < nObs; i++)
    {
        double gx, gy;
        the_map.getPoint(idxs[i].first, gx, gy);

        double lx, ly;
        GT_pose_inv.composePoint(gx, gy, lx, ly);

        observations[i].ID = idxs[i].first;
        observations[i].x =
            lx + mrpt::random::getRandomGenerator().drawGaussian1D(
                     0, normalizationStd);
        observations[i].y =
            ly + mrpt::random::getRandomGenerator().drawGaussian1D(
                     0, normalizationStd);
    }

    // ----------------------------------------------------
    // Generate list of individual-compatible pairings
    // ----------------------------------------------------
    TMatchingPairList all_correspondences;

    all_correspondences.reserve(nMapPts * nObs);

    // ALL possibilities:
    for (size_t j = 0; j < nObs; j++)
    {
        TMatchingPair match;
        match.other_idx = j;
        match.other_x = observations[j].x;
        match.other_y = observations[j].y;

        for (size_t i = 0; i < nMapPts; i++)
        {
            match.this_idx = i;
            the_map.getPoint(i, match.this_x, match.this_y);
            all_correspondences.push_back(match);
        }
    }

    // ----------------------------------------------------
    //  Run RANSAC-based D-A
    // ----------------------------------------------------
    mrpt::tfest::TSE2RobustParams params;
    mrpt::tfest::TSE2RobustResult results;

    params.ransac_minSetSize = RANSAC_MINIMUM_INLIERS;  // ransac_minSetSize (to
    // add the solution to
    // the SOG)
    params.ransac_maxSetSize =
        all_correspondences
            .size();  // ransac_maxSetSize: Test with all data points
    params.ransac_mahalanobisDistanceThreshold =
        ransac_mahalanobisDistanceThreshold;
    params.ransac_nSimulations = 0;  // 0=auto
    params.ransac_fuseByCorrsMatch = true;
    params.ransac_fuseMaxDiffXY = 0.01f;
    params.ransac_fuseMaxDiffPhi = 0.1_deg;
    params.ransac_algorithmForLandmarks = true;
    params.probability_find_good_model = 0.999999;
    params.ransac_min_nSimulations =
        MINIMUM_RANSAC_ITERS;  // (a lower limit to the auto-detected value of
    // ransac_nSimulations)
    params.verbose = false;

    // Run ransac data-association:
    mrpt::tfest::se2_l2_robust(
        all_correspondences, normalizationStd, params, results);

    // mrpt::poses::CPosePDFSOG  & best_poses  = results.transformation;
    TMatchingPairList& out_best_pairings = results.largestSubSet;

    // Reconstruct the SE(2) transformation for these pairings:
    mrpt::poses::CPosePDFGaussian solution_pose;
    mrpt::tfest::se2_l2(out_best_pairings, solution_pose);

    // Normalized covariance: scale!
    solution_pose.cov *= square(normalizationStd);

    if (!(solution_pose.mean.distanceTo(GT_pose) < 0.9 &&
          std::abs(solution_pose.mean.phi() - GT_pose.phi()) < 10.0_deg))
    {
        std::cerr << "Solution pose: " << solution_pose.mean << endl
                  << "Ground truth pose: " << GT_pose << endl;
        return false;
    }
    return true;
}

TEST(tfest, ransac_data_assoc)
{
    // Run randomized experiments:
    bool any_ok = false;
    for (int i = 0; i < 3; i++)
        if (ransac_data_assoc_run()) any_ok = true;

    EXPECT_TRUE(any_ok);
}