A Systematic Approach for the Structural Synthesis of Differential-Type South Pointing Chariots

Abstract

South Pointing Chariot is one of the important mechanical inventions in ancient China. It achieves the purpose of fixing direction by applying mechanical devices. All existing designs can be classified into two types: "fixed-axis type" and "differential type". In this study, firstly, the existing designs are analyzed and decomposed into four parts: two inputs, a transmission part, a passive feedback mechanism, and one output. Secondly, because some existing designs have the same topological structures, new representations are used to identify different axial directions of joints and characteristics of members. Thirdly, a design methodology is proposed to systematically synthesize all feasible design concepts of differential-type South Pointing Chariots. Finally, three examples are provided.

An Orientation Sensor for Mobile Robots Using Differentials

“…The orientation sensor we proposed consists of an optical encoder and three differentials. There are many different designs of differentials that can achieve the same function [10], but we selected the model proposed in [11] as shown in Figure 1 because it can provide a lower profile. In this design, each differential includes three bevel gears so there are nine bevel gears in total.…”

On the Number of Specialized Mechanisms

“…In 1992, Yan [18] summarized such an approach as the creative mechanism design methodology for synthesizing all possible topological structures of mechanisms subject to design requirements and constraints. Yan's methodology has been widely applied to the conceptual design of mechanisms, such as step-climbing wheelchair linkages [19][20][21], anti-dive front suspension mechanisms for bicycles [22], and reconstruction design of the ancient Chinese machinery including walking machines [23][24][25][26][27][28], escapement regulators [29,30], and south pointing chariots [31,32]. In 2002, Wang et al [33,34] developed a software for automating this methodology.…”

“…The identified ordinary gear train is shown in Figure 5.10. Consider the differential-type south pointing chariot [32] shown in Figure 5.11(a). The corresponding (5, 6) kinematic chain is shown in Figure 5.11(b).…”

“…Yan et al [12,13] proposed a methodology, based on the ideas of generalization and specialization, for the systematic generation of the topological structures of mechanism that satisfy the design requirements and constraints. Yan's methodology has been widely applied to the conceptual design of mechanisms, such as suspension mechanisms [18] and reconstruction design of ancient Chinese machinery [29][30][31][32]. Freudenstein and Maki [35] developed an approach for the conceptual design of mechanisms.…”

“…variable-stroke engine mechanism[37] Differential-type south pointing chariot Yan and Chen[32] presented a design methodology to systematically synthesize all feasible design concepts of differential-type south pointing chariots. A differential-type south pointing chariot mechanism is shown inFigure 2.10.…”