The necessity of new approaches for structural synthesis of mechanical systems, which directly identify a limited number of structures that carry a potential for solving the technical problems and meet the specific requirements for the design of mechanical systems, mainly for specialised robots, is specified. The identified five types of kinematic chains (primary, parallel, secondary, additional and subsidiary), with different functionality, allow the synthesis of manipulators structures according to the defined goal tasks and specific functional requirements for hybrid systems, in particular specialised industrial robots. Two mechatronic approaches for functional structural synthesis of mechanical systems of industrial robots, where the main manipulation mechanism is a path generator, were introduced. A limited number of structures that meets the set of objectives and technical requirements to design mechanisms, is directly determined. Emphasis is placed on the tasks of passive (mechanical) control of manipulation systems associated with specialized robotics. Two mechatronic approaches for functional structural synthesis of mechanical systems of industrial robots, where the main manipulation mechanism is a motion generator, are introduced. A limited number of structures is directly defined that meets the set of technical objectives and requirements for the designed mechanisms. Emphasis is placed on the tasks of passive control of the manipulation systems associated with the specialized robotics.