tgBaseString.h

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/*
 * Copyright © 2012, United States Government, as represented by the
 * Administrator of the National Aeronautics and Space Administration.
 * All rights reserved.
 * 
 * The NASA Tensegrity Robotics Toolkit (NTRT) v1 platform is licensed
 * under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0.
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
*/

#ifndef TG_BASE_STRING_H
#define TG_BASE_STRING_H

// This application
#include "tgModel.h"

#include <deque> // For history
// Forward declarations
class tgWorld;

// Should always be a child Model of a tgModel
class tgBaseString : public tgModel
{
public: 
    
    struct Config
    {
    public:
        Config( double s = 1000.0,
        double d = 10.0,
        bool h = false,
        double rot = 0,
        double mf = 1000.0,
        double tVel = 100.0,
        double mxAcc = 10000.0,
        double mnAL = 0.1,
        double mnRL = 0.1);
      
      void scale (double sf);
      
      // Muscle2P Parameters
      double stiffness;
      double damping;
      
      // History Parameters
      bool hist;
      
      // Construction Parameters
      double rotation;
        
      // Motor model parameters
      double maxTens;
      
      double targetVelocity;
      
      double maxAcc;
      
      double minActualLength;
      
      double minRestLength;     
    };
    
    struct BaseStringHistory
    {
        std::deque<double> lastLengths;
        
        std::deque<double> restLengths;

        std::deque<double> dampingHistory;

        std::deque<double> lastVelocities;
        
        std::deque<double> tensionHistory;
    };

    virtual ~tgBaseString();

    virtual void setup(tgWorld& wdorld);
    
    virtual void teardown();
    
    virtual void step(double dt);
    
    // Called from controller class, it makes the restLength get closer to preferredlength.
    virtual void moveMotors(double dt) = 0;
    
    // @todo look into a base class implementation of this. Wouldn't be
    // difficult with existing get functions
    virtual void tensionMinLengthController(const double targetTension,
                                            float dt) = 0;
    
    virtual void setRestLength(double newLength, float dt);
      
    virtual const double getStartLength() const = 0;
    
    virtual const double getCurrentLength() const = 0;
    
    virtual const double getTension() const = 0;
    
    virtual const double getRestLength() const = 0;
    
    virtual const double getVelocity() const = 0;

protected: 
    
    tgBaseString(const tgTags& tags,
           tgBaseString::Config& config,
           double restLength,
           double actualLength);
    
    tgBaseString(std::string space_separated_tags,
           tgBaseString::Config& config,
           double restLength,
           double actualLength);
           
protected:
    Config m_config;
    
    BaseStringHistory * const m_pHistory;

    
    double m_restLength;
    
    double m_preferredLength;
    
    double m_startLength;
    
    double m_prevVelocity;
private:

    void constructorAux();

    bool invariant() const;


};


#endif