LaserBasedProximity.h

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/**
 * This file is part of ArmarX.
 *
 * ArmarX is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * ArmarX 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 this program. If not, see <http://www.gnu.org/licenses/>.
 *
 * @author     Fabian Reister ( fabian dot reister at kit dot edu )
 * @author     Christian R. G. Dreher ( c dot dreher at kit dot edu )
 * @date       2021
 * @copyright  http://www.gnu.org/licenses/gpl-2.0.txt
 *             GNU General Public License
 */
 
#pragma once
 
#include <cstdint>
#include <optional>
 
#include <boost/circular_buffer.hpp>
 
#include <SimoxUtility/color/ColorMap.h>
 
#include <armarx/navigation/core/NavigationStackGeneralConfig.h>
#include <armarx/navigation/core/basic_types.h>
#include <armarx/navigation/core/types.h>
#include <armarx/navigation/util/geometry.h>
 
#include "SafetyGuard.h"
 
namespace armarx::viz
{
    struct Layer;
}
 
namespace armarx::navigation::safety_guard
{
 
    struct ProximityFieldParams
    {
        enum class Mode : std::uint8_t
        {
            Disabled,
            DirectionDependent,
            DirectionIndependent
        };
 
        Mode mode = Mode::DirectionDependent;
 
        float safetyDistance{500.F};
        float influenceDistance{2000.F};
 
        // if enabled, reduce the velocity between safetyDistance and influenceDistance. If false, the robot will move with maximum velocity until it has to stop at safetyDistance.
        bool reduceVelocity{true};
 
        // Parameters to reduce the velocity in proximity to an obstacle between minDistance and maxDistance.
        // It is v = v_max / (1 + lambda * d_s^lambda) with d_s = (1 - (d / maxDistance))^k
        float k{4.F};
        float lambda{6.F};
    };
 
    /// Why a laser scanner feature does not constrain the velocity.
    enum class FilterReason : std::uint8_t
    {
        /// The feature constrains, or is a candidate to constrain, the velocity.
        None,
 
        /// The feature has no points.
        NoPoints,
 
        /// The feature lies fully inside one of the ignored regions.
        IgnoredRegion,
 
        /// The feature lies fully inside the inflated OOBB of an attached object.
        AttachedObject,
 
        /// Small feature close to the robot, most likely a measuring artifact of the sensor.
        NearFieldArtifact,
 
        /// The feature is outside the influence distance.
        TooFarAway,
 
        /// The robot is moving away from the feature.
        MovingAway,
 
        /// The robot passes the feature exactly tangentially.
        Tangential
    };
 
    struct LaserBasedProximityParams : public SafetyGuardParams
    {
        float robotRadius{500.F}; //TODO(utetg): should there be a default, if yes what
 
        bool enableHumans{true};
        bool enableLaserScanners{true};
 
        ProximityFieldParams humanProximityField;
        ProximityFieldParams laserScannerProximityField;
 
        // any laser scanner feature that lies **fully** inside any of these regions will be ignored
        std::vector<Eigen::AlignedBox2f> ignoredRegions;
 
        float attachedObjectsInflation = 200; // [mm]
 
        // any laser scanner feature that lies **fully** inside the OOBB of the attached object will be ignored
        bool ignoreAttachedObjects{true};
 
        // Whether to filter out small laser scanner features close to the robot
        // These can appear due to measuring errors of the sensors
        bool enableLaserScannerFiltering{true};
        // features with <= this number of points are ignored
        int laserScannerFilteringThreshold = 3;
        // [mm]; only filter features where all points are within this distance from the robot
        float laserScannerMaxFilteringDistance = 300;
 
        Algorithms algorithm() const override;
        aron::data::DictPtr toAron() const override;
        static LaserBasedProximityParams FromAron(const aron::data::DictPtr& dict);
    };
 
    class LaserBasedProximity : virtual public SafetyGuard
    {
    public:
        using Params = LaserBasedProximityParams;
 
        LaserBasedProximity(const Params& params,
                            const core::GeneralConfig& generalConfig,
                            const core::Scene& scene,
                            const Context& ctx);
        ~LaserBasedProximity() override = default;
 
        SafetyGuardResult computeSafetyLimits(const Eigen::Vector2f& global_V_movement) override;
 
    private:
        struct DistanceAndClosestPoint
        {
            float distance;
            Eigen::Vector2f closestPoint;
 
            std::size_t clusterSize;
 
            /// Centroid of the feature in the global frame. Only used for debug visualization.
            Eigen::Vector2f centroid;
 
            /// Why this feature does not constrain the velocity.
            FilterReason filterReason;
        };
 
        std::optional<core::TwistLimits> safetyLimitsHumans(viz::Layer& layer) const;
        std::optional<core::TwistLimits>
        safetyLimitsLaserScanners(viz::Layer& layer,
                                  viz::Layer& clusterLayer,
                                  viz::Layer& filteredLayer,
                                  const Eigen::Vector2f& global_V_movement) const;
 
        DistanceAndClosestPoint
        calculateMinDistance(const util::geometry::polygon_type& convexHull,
                             const core::Pose& robot_T_global,
                             const std::vector<Eigen::Vector3f>& globalPoints) const;
 
        std::pair<core::TwistLimits, float>
        evaluateProximityField(const ProximityFieldParams& proximityField, float minDistance) const;
 
        FilterReason
        featureIgnoreReason(const std::vector<Eigen::Vector3f>& featurePoints3DGlobal,
                            const std::vector<Eigen::Vector2f>& featurePoints2DGlobal,
                            const Eigen::Vector2f& centroid) const;
 
        struct InternalVelocityLimitResult
        {
            core::TwistLimits twistLimits;
            std::optional<float> minDistance;
 
            // not necessarily the closest point according to the Euclidean distance, but the point that leads to the calculated safety limits
            std::optional<Eigen::Vector2f> closestPoint;
        };
 
        /// Annotates `minDistanceToObstacles` with the reason why each feature does (not)
        /// constrain the velocity.
        InternalVelocityLimitResult
        velocityLimitsDirectionDependent(const Eigen::Vector2f& global_V_movement,
                                         std::vector<DistanceAndClosestPoint>& minDistanceToObstacles,
                                         const Eigen::Isometry3f& global_T_robot) const;
 
        InternalVelocityLimitResult velocityLimitsDirectionIndependent(
            const std::vector<DistanceAndClosestPoint>& minDistanceToObstacles) const;
 
 
    protected:
        const Params params;
 
    private:
        core::GeneralConfig generalConfig;
 
        simox::ColorMap humanColorMap_;
        simox::ColorMap laserColorMap_;
 
        mutable boost::circular_buffer<std::vector<memory::LaserScannerFeatures>>
            laserScannerFeatureHistory_{5};
    };
} // namespace armarx::navigation::safety_guard