mpc_model.cpp

      fg[1 + x_start + t]    = x1    - (x0 + v0 * CppAD::cos(psi0) * dt);
      fg[1 + y_start + t]    = y1    - (y0 + v0 * CppAD::sin(psi0) * dt);
      fg[1 + psi_start + t]  = psi1  - (psi0 + v0 * delta0 / Lf * dt);
      fg[1 + v_start + t]    = v1    - (v0 + a0 * dt);
      fg[1 + cte_start + t]  = cte1  - ((f0 - y0) + (v0 * CppAD::sin(epsi0) * dt));
      fg[1 + epsi_start + t] = epsi1 - ((psi0 - psides0) + v0 * delta0 / Lf * dt);