An introductory review of active compliant control.

Active compliant control enables to quickly and freely adjust the properties and dynamic behavior of interactions of mechanisms within certain limits. According to the emerging applications in many robotic fields and related areas, the number of publications has also strongly increased. This paper meets the need for a recent comprehensive review, including a profound and concise characterization and classification of compliant control approaches extending the basic concepts, hybrid and parallel force/position, impedance and admittance control, by a survey of their variants and combinations. It mainly focuses on individually operating, stiff, non-redundant systems. Unlike previous reviews, this work is based on a transparent and systematic literature search methodology, which can easily be adapted or updated by any reader, hence remaining enduringly up-to-date over time. Also, a novel selection scheme is proposed, which facilitates the choice of appropriate control approaches for given requirements, particularly for newcoming researchers to the field.