Assume a single-DOF motion control system whose mathematical model is given as: a(q)q¨ + b(q, q˙) + g(q) + τext = Kti_ref. For this system, the torque constant and the inertia can respectively be given as a(q) = an + Δa and Kt = Kn + ΔK. Assume that the system given in Problem-1 will be used in force control application. Further, assume also that the disturbances in the system are compensated and the system is initially positioned at the contact point of the environment. If the environment is a lossless environment for which the contact force can be given as Fe(t) = Keq(t) and the system is supposed to trace a twice differentiable continuous force reference Fref(t): Write down the tracking error for this system.