Double and Type (3,0) Minkowski Pythagorean Hodograph Curves

In present paper, Double Minkowski Pythagorean Hodograph (DMPH) curves and type (3,0) Minkowski Pythagorean Hodograph (MPH) curves are studied. Firstly, the conditions for a MPH curve to be a DMPH curve are obtained. Then, these conditions are examined in split quaternion form. Finally, a special class of seventh degree MPH curves is characterized and illustrative examples are given.