joint_velocity_backward_difference.cpp

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#include <exotica_core_task_maps/joint_velocity_backward_difference.h>

REGISTER_TASKMAP_TYPE("JointVelocityBackwardDifference", exotica::JointVelocityBackwardDifference);

namespace exotica
{
void JointVelocityBackwardDifference::AssignScene(ScenePtr scene)
{
    scene_ = scene;

    // Get ndof
    N_ = scene_->GetKinematicTree().GetNumControlledJoints();

    // Set binomial coefficient parameters
    backward_difference_params_ = -1.0;

    // Init each col of q_ with start state
    q_.resize(N_);
    if (parameters_.StartState.rows() == 0)
        q_.setZero();
    else if (parameters_.StartState.rows() == N_)
        q_ = parameters_.StartState;
    else
        ThrowPretty("Wrong size for StartState!");

    // Init qbd_
    qbd_.noalias() = q_ * backward_difference_params_;

    // Init identity matrix
    I_ = Eigen::MatrixXd::Identity(N_, N_);
}

void JointVelocityBackwardDifference::SetPreviousJointState(Eigen::VectorXdRefConst joint_state)
{
    // Input check
    if (joint_state.rows() != N_) ThrowNamed("Wrong size for joint_state!");

    // Push back previous joint states
    q_ = joint_state;

    // Compute new qbd_
    qbd_ = q_ * backward_difference_params_;
}

void JointVelocityBackwardDifference::Update(Eigen::VectorXdRefConst q, Eigen::VectorXdRef phi)
{
    // Input check
    if (phi.rows() != N_) ThrowNamed("Wrong size of phi!");
    if (q.rows() != N_) ThrowNamed("Wrong size of q");

    // Estimate third time derivative
    phi = q + qbd_;
}

void JointVelocityBackwardDifference::Update(Eigen::VectorXdRefConst q, Eigen::VectorXdRef phi, Eigen::MatrixXdRef jacobian)
{
    // Input check
    if (jacobian.rows() != N_ || jacobian.cols() != N_) ThrowNamed("Wrong size of jacobian! " << N_);

    // Estimate third time derivative and set Jacobian to identity matrix
    Update(q, phi);
    jacobian = I_;
}

int JointVelocityBackwardDifference::TaskSpaceDim()
{
    return N_;
}
}  // namespace exotica