This book is concerned with the development of design techniques for controlling motion of mechanical systems which are employed to execute certain tasks acting collaboratively. The book introduces unified control design procedure for functionally related systems. The controllers for many different tasks in motion control can be successfully designed by applying the proposed simple procedure. The book gives an overview of the control methods appearing in the motion control area and the detailed design procedures for the class of systems that are required to execute certain task together. Tasks can generally be divided in their components, denoted as functions in the book. It is shown how dynamics of those tasks can be described. Based on the presented description, several control methods were discussed. Applicability of the introduced control design approach was demonstrated in subsequent chapters for various tasks.