A novel graphical joint-joint adjacent matrix method for the automatic sketching of kinematic chains with multiple joints

Abstract The automatic sketching of kinematic chains (KCs) is an important part of the conceptual design of mechanisms, which is useful for the creative design of mechanisms. In this paper, a novel algorithm for automatic sketching of planar KCs with multiple joints was proposed based on joint-joint adjacent matrix (JJAM). Firstly, the standardization rules of JJAM were introduced, and the loops of planar KCs were extracted from the JJAM using breadth-first search algorithm (BFS). Further, the breadth-first spanning tree of the planar KCs was drawn by minimum crossing rules. Meanwhile, the rules of drawing structure diagram of a single link in JJAM were presented. Moreover, graphical joint-joint adjacent matrix (GJJAM) implying structure diagram between joints was expressed. This matrix was transformed into a graphical joint-joint adjacent matrix of planar KCs by matching structure diagram of the single link. This method has several advantageous features resulting in lower complexity relative to the methods presented in literatures. Finally, the examples demonstrate that the method is novel, efficient and convenient.