An output feedback dynamic control scheme is proposed for efficient velocity trajectory tracking tasks for direct current (DC) electric motors. An asymptotic differentiation approach of signals is also introduced and applied for real-time angular acceleration estimation. The novel feature of this differentiator of signals is that it does not require any system mathematical model. Hence the presented differentiation approach admits a wide variety of practical applications in diverse electric power systems that require signal differentiation for their control and identification. The synthesis of the differentiation scheme considers the possible practical scenario of contaminated output signals with reasonably small noise. Some computer simulations results are included to show controller robustness to reject completely unknown chaotic load torque disturbances and parametric uncertainty, as well as effectiveness of the differentiation scheme of signals. (C) 2015 Elsevier B.V. All rights reserved.