CPTG_DiffDrive_alpha.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */
#pragma once
 
#include <mrpt/nav/tpspace/CPTG_DiffDrive_CollisionGridBased.h>
 
namespace mrpt
{
namespace nav
{
/** The "a(symptotic)-alpha PTG", as named in PTG papers.
 * - **Compatible kinematics**: differential-driven / Ackermann steering
 * - **Compatible robot shape**: Arbitrary 2D polygon
 * - **PTG parameters**: Use the app `ptg-configurator`
 *
 * This PT generator functions are:
 *
 * \f[ v(\alpha) = V_{MAX} e^{ -\left( \dfrac{\alpha-\phi}{cte_{a0v}} \right)^2}
 * \f]
 * \f[ \omega(\alpha) = W_{MAX} \left( -\dfrac{1}{2} +\dfrac{1}{1+ e^{ -
 * \dfrac{\alpha-\phi}{cte_{a0w}} } } \right) \f]
 *
 * So, the radius of curvature of each trajectory is NOT constant for each
 * "alpha" value in this PTG:
 *
 *  ![C-PTG path examples](PTG2_paths.png)
 *
 * \note [Before MRPT 1.5.0 this was named CPTG2]
 *  \ingroup nav_tpspace
 */
class CPTG_DiffDrive_alpha : public CPTG_DiffDrive_CollisionGridBased
{
        DEFINE_SERIALIZABLE(CPTG_DiffDrive_alpha)
   public:
        CPTG_DiffDrive_alpha() : cte_a0v(0), cte_a0w(0) {}
        CPTG_DiffDrive_alpha(
                const mrpt::config::CConfigFileBase& cfg, const std::string& sSection)
        {
                loadFromConfigFile(cfg, sSection);
        }
        virtual void loadFromConfigFile(
                const mrpt::config::CConfigFileBase& cfg,
                const std::string& sSection) override;
        virtual void saveToConfigFile(
                mrpt::config::CConfigFileBase& cfg,
                const std::string& sSection) const override;
 
        std::string getDescription() const override;
        void ptgDiffDriveSteeringFunction(
                float alpha, float t, float x, float y, float phi, float& v,
                float& w) const override;
        void loadDefaultParams() override;
 
   protected:
        double cte_a0v, cte_a0w;
};
}
}