PlanarManipulator.h

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/* Author: Ryan Luna */
 
#ifndef PLANAR_MANIPULATOR_H_
#define PLANAR_MANIPULATOR_H_
 
#include <vector>
#include <Eigen/Dense>
 
class PlanarManipulator
{
public:
    // A numLinks manipulator with equal length links.
    PlanarManipulator(unsigned int numLinks, double linkLength, const std::pair<double, double> &origin = {0.0, 0.0});
 
    // A numLinks manipulator with variable link lengths.
    PlanarManipulator(unsigned int numLinks, const std::vector<double> &linkLengths,
                      const std::pair<double, double> &origin = {0.0, 0.0});
 
    virtual ~PlanarManipulator();
 
    // Return the number of links
    unsigned int getNumLinks() const;
 
    // Return the base frame of the manipulator
    const Eigen::Affine2d &getBaseFrame() const;
 
    // Set the base frame of the manipulator
    void setBaseFrame(const Eigen::Affine2d &frame);
 
    // Return the length of each link
    const std::vector<double> &getLinkLengths() const;
 
    // Set the bounds for link # link
    void setBounds(unsigned int link, double low, double high);
    // Set the bounds for ALL links
    void setBounds(const std::vector<double> &low, const std::vector<double> &high);
 
    // Return true if the given link has bounds set
    bool hasBounds(unsigned int link) const;
    // Get the lower and upper joint angle bounds for this link
    void getBounds(unsigned int link, double &low, double &high) const;
    // Get all lower bound joint limits
    const std::vector<double> &lowerBounds() const;
    // Get all upper bound joint limits
    const std::vector<double> &upperBounds() const;
 
    // Forward kinematics for the given joint configuration.  The frames for links
    // 1 through the end-effector are returned.
    void FK(const double *joints, std::vector<Eigen::Affine2d> &frames) const;
    void FK(const std::vector<double> &joints, std::vector<Eigen::Affine2d> &frames) const;
    void FK(const Eigen::VectorXd &joints, std::vector<Eigen::Affine2d> &frames) const;
    void FK(const double *joints, Eigen::Affine2d &eeFrame) const;
    void FK(const std::vector<double> &joints, Eigen::Affine2d &eeFrame) const;
    void FK(const Eigen::VectorXd &joints, Eigen::Affine2d &eeFrame) const;
 
    // Inverse kinematics for the given end effector frame.  Jacobian pseudo-inverse method
    // Returns false if no solution is found to the given pose.
    // NOTE: Joint limits are not respected in this IK solver.
    bool IK(std::vector<double> &solution, const Eigen::Affine2d &eeFrame) const;
    bool IK(std::vector<double> &solution, const std::vector<double> &seed, const Eigen::Affine2d &desiredFrame) const;
 
    // Forward and backward reaching inverse kinematics (FABRIK)
    //   Aristidou and Lasenby, FABRIK: A fast, iterative solver for the inverse kinematics problem.
    //   Graphical Models 73(5): 243–260.
    bool FABRIK(std::vector<double> &solution, const Eigen::Affine2d &eeFrame, double xyTol = 1e-5,
                double thetaTol = 1e-3) const;
    bool FABRIK(std::vector<double> &solution, const std::vector<double> &seed, const Eigen::Affine2d &desiredFrame,
                double xyTol = 1e-5, double thetaTol = 1e-3) const;
 
    // Return the Jacobian for the manipulator at the given joint state.
    void Jacobian(const std::vector<double> &joints, Eigen::MatrixXd &jac) const;
    void Jacobian(const Eigen::VectorXd &joints, Eigen::MatrixXd &jac) const;
    void Jacobian(const double *joints, Eigen::MatrixXd &jac) const;
 
    // Convert the given frame to x,y,theta vector
    static void frameToPose(const Eigen::Affine2d &frame, Eigen::VectorXd &pose);
 
protected:
    bool infeasible(const Eigen::Affine2d &frame) const;
 
    // The number of links in the chain
    unsigned int numLinks_;
    // The length of each link
    std::vector<double> linkLengths_;
    // Optional bounds on the joint angles.  MUST be a subset of [-pi,pi]
    std::vector<bool> hasBounds_;
    std::vector<double> lowerBounds_;
    std::vector<double> upperBounds_;
 
    // The base frame of the kinematic chain
    Eigen::Affine2d baseFrame_;
};
 
#endif