Quadruped.h

/*! @file Quadruped.h
 *  @brief Data structure containing parameters for quadruped robot
 *
 *  This file contains the Quadruped class.  This stores all the parameters for
 * a quadruped robot.  There are utility functions to generate Quadruped objects
 * for Cheetah 3 (and eventually mini-cheetah). There is a buildModel() method
 * which can be used to create a floating-base dynamics model of the quadruped.
 */

#ifndef LIBBIOMIMETICS_QUADRUPED_H
#define LIBBIOMIMETICS_QUADRUPED_H

#include "Dynamics/ActuatorModel.h"
#include "Dynamics/FloatingBaseModel.h"
#include "Dynamics/SpatialInertia.h"
#include <vector>

#include <eigen3/Eigen/StdVector>

/*!
 * Basic parameters for a cheetah-shaped robot
 */
namespace cheetah
{
constexpr size_t num_act_joint = 12;
constexpr size_t num_q = 19;
constexpr size_t dim_config = 18;
constexpr size_t num_leg = 4;
constexpr size_t num_leg_joint = 3;
} // namespace cheetah

/*!
 * Link indices for cheetah-shaped robots
 */
namespace linkID
{
constexpr size_t FR = 9;  // Front Right Foot
constexpr size_t FL = 11; // Front Left Foot
constexpr size_t HR = 13; // Hind Right Foot
constexpr size_t HL = 15; // Hind Left Foot

constexpr size_t FR_abd = 2; // Front Right Abduction
constexpr size_t FL_abd = 0; // Front Left Abduction
constexpr size_t HR_abd = 3; // Hind Right Abduction
constexpr size_t HL_abd = 1; // Hind Left Abduction
} // namespace linkID

using std::vector;

/*!
 * Representation of a quadruped robot's physical properties.
 *
 * When viewed from the top, the quadruped's legs are:
 *
 * FRONT
 * 2 1   RIGHT
 * 4 3
 * BACK
 *
 */
template <typename T>
class Quadruped
{
public:
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
  RobotType _robotType;
  T _whole_mass;
  T _bodyLength, _bodyWidth, _bodyHeight, _bodyMass;
  T _abadGearRatio, _hipGearRatio, _kneeGearRatio;
  T _abadLinkLength, _hipLinkLength, _kneeLinkLength, _kneeLinkY_offset, _maxLegLength;
  T _motorKT, _motorR, _batteryV;
  T _motorTauMax;
  T _jointDamping, _jointDryFriction;
  SpatialInertia<T> _abadInertia, _hipInertia, _kneeInertia, _abadRotorInertia, _hipRotorInertia, _kneeRotorInertia, _bodyInertia;
  Vec3<T> _abadLocation, _abadRotorLocation, _hipLocation, _hipRotorLocation, _kneeLocation, _kneeRotorLocation;
  FloatingBaseModel<T> buildModel();
  bool buildModel(FloatingBaseModel<T>& model);
  std::vector<ActuatorModel<T>> buildActuatorModels();

  /*!
   * Get if the i-th leg is on the left (+) or right (-) of the robot.
   * @param leg : the leg index
   * @return The side sign (-1 for right legs, +1 for left legs)
   */
  static T getSideSign(int leg)
  {
    const T sideSigns[4] = {-1, 1, -1, 1};
    assert(leg >= 0 && leg < 4);
    return sideSigns[leg];
  }

  /*!
   * Get location of the hip for the given leg in robot frame
   * @param leg : the leg index
   */
  Vec3<T> getHipLocation(int leg)
  {
    assert(leg >= 0 && leg < 4);
    Vec3<T> pHip((leg == 0 || leg == 1) ? _abadLocation(0) : -_abadLocation(0),
                 (leg == 1 || leg == 3) ? _abadLocation(1) : -_abadLocation(1),
                 _abadLocation(2));
    return pHip;
  }
};

template <typename T, typename T2>
Vec3<T> withLegSigns(const Eigen::MatrixBase<T2>& v, int legID);

#endif // LIBBIOMIMETICS_QUADRUPED_H