Abstract: A new approach to automated conceptual design of mechanical system is presented by means of a state-space. At first, a state equation is set up according to the function of a basic mechanical unit transformed a motion between input and output terminal. Then, the input and output characteristic vectors and the state space matrices are defined by means of a state equation, which are corresponding to a certain basic mechanical unit, even composite one. The conceptual design can be extracted from the dimension design by the way. Secondly, the state space is established in terms of the set of all characteristic vectors for transformation units and whose properties are discussed, such as vectors plus, constant multiplying, reversible driving, zero vector as well as a state space matrices decomposable. However, the mathematic model is presented and the groundwork is laid for the onceptual design in the state space. Finally, an example is given to show the process of conceptual design in state space.

Key words: Conceptual design Kinematic scheme design, State-space CAD