vpAdaptiveGain.h

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2025 by Inria. All rights reserved.
 *
 * This software 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 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Adaptive gain.
 */

 
#ifndef _vpAdaptiveGain_h_
#define _vpAdaptiveGain_h_
 
#include <iostream>
#include <visp3/core/vpConfig.h>
 
BEGIN_VISP_NAMESPACE
class vpColVector;

 
class VISP_EXPORT vpAdaptiveGain
{
public:
  static const double DEFAULT_LAMBDA_ZERO;
  static const double DEFAULT_LAMBDA_INFINITY;
  static const double DEFAULT_LAMBDA_SLOPE;
 
private:
  // Coefficient such as lambda (x) = a * exp (-b*x) + c
  double coeff_a; // \f$ a = \lambda(0) - \lambda(\infty) \f$
  double coeff_b; // \f$ b = {\dot \lambda}(0) / a \f$
  double coeff_c; // \f$ c = \lambda(\infty) \f$
 
  // Last computed value
  mutable double lambda;
 
public:
  vpAdaptiveGain();

  VP_EXPLICIT vpAdaptiveGain(double c);

  vpAdaptiveGain(double gain_at_zero, double gain_at_infinity, double slope_at_zero);

  void initFromConstant(double c);

  void initFromVoid(void);

  void initStandard(double gain_at_zero, double gain_at_infinity, double slope_at_zero);

  double setConstant(void);

  double value_const(double x) const;

  double value(double x) const;

  double limitValue_const(void) const;

  double limitValue(void) const;

  inline double getLastValue(void) const { return this->lambda; }

  double operator()(double x) const;

  double operator()(const vpColVector &x) const;

  double operator()(void) const;

  friend VISP_EXPORT std::ostream &operator<<(std::ostream &os, const vpAdaptiveGain &lambda);
};
END_VISP_NAMESPACE
#endif