chain_coupling.hpp

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// Copyright  (C)  2007  Ruben Smits <ruben dot smits at mech dot kuleuven dot be>

// Version: 1.0
// Author: Ruben Smits <ruben dot smits at mech dot kuleuven dot be>
// Maintainer: Ruben Smits <ruben dot smits at mech dot kuleuven dot be>
// URL: http://www.orocos.org/kdl

// Modified by Juan A. Corrales (ISIR, UPMC) in order to include coupling

// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.

// This library 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
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

#ifndef KDL_CHAIN_COUPLING_HPP
#define KDL_CHAIN_COUPLING_HPP

#include <kdl/segment.hpp>
#include <string>
#include <Eigen/Core>
#include <kdl/jntarray.hpp>
#include <kdl/chain.hpp>

namespace KDL
{
typedef Eigen::MatrixXd (*updateFuncPtr)(const JntArray &q);  // Pointer to update function of coupling matrix
/*
* \brief This class encapsulates a <strong>serial</strong> kinematic
* interconnection structure. It is build out of segments.
*
* @ingroup KinematicFamily
*/
class Chain_coupling :
        public KDL::Chain
{
private:
  unsigned int nrOfIndJoints;
  updateFuncPtr updateFunction;
public:
  /*
   * The constructor of a Chain_coupling, a new Chain_coupling is always empty.
   *
   */
  Chain_coupling();

  Chain_coupling(const Chain_coupling &in);

  explicit Chain_coupling(const Chain &in);

  Chain_coupling &operator=(const Chain_coupling &in);

  Chain_coupling &operator=(const Chain &in);

  /*
   * Determines if there is coupling between the joints of a Chain_coupling.
   * @return true or false if there is or not coupling.
   */
  bool isCoupled() const;

  /*
   * Gets the function which updates the value of the coupling matrix depending
   * on the current joint values.
   * @return pointer to update function.
*/
  updateFuncPtr getUpdateCouplingFunction() const;

  /*
   * Sets the function which updates the value of the coupling matrix depending
   * on the current joint values.
   * @param updateFunc pointer to the function which implements the coupling update.
* @return true if the fucntion generates correct coupling matrices and false otherwise
*/
  bool setUpdateCouplingFunction(updateFuncPtr updateFunc);

  /*
   * Calls the update function which changes the coupling matrix according to the
   * joint values passed as parameter.
   * @param q array of current joint values.
   */
  void updateCoupling(const JntArray &q);

  /*
* Request the total number of independent joints in the Chain_coupling.
* It's the Coupling matrix rank.
* @return total nr of independ joints
*/
  unsigned int getNrOfIndJoints() const
  {
    return nrOfIndJoints;
  };

  ~Chain_coupling();

  // Matrix with coupling coefficients between joints
  Eigen::MatrixXd cm;
};
}  // namespace KDL

#endif