Abstract: Industry 5.0 emphasizes the central role of human beings, and the concept of human-centric is receiving increasing attention in all stages of product design, manufacturing, operation, and service. Conceptual design is the earliest stage of the product life cycle, the core of which is to generate the conceptual solutions that can meet the personalized requirements through the creative activities of the design subject, which greatly determines the level of innovation and the quality of implementation of the subsequent stages. The concept of human-centric puts forward new challenges for conceptual design, and the traditional designer-oriented conceptual design model needs to be transformed into a multi-design subject model in which the designer, user, and machine are in communion. Therefore, this stundy closely integrates the reasoning and decision-making ability of the designer with the deep participation of the user and the computational generation ability of the machine, and proposes a product conceptual design model and framework of user-designer-machine multi-design subject communion under the human-centric perspective, which is aimed to better serve human-centric intelligent manufacturing under Industry 5.0. First, the connotation of human-centric conceptual design is elaborated in terms of influencing factors, forms of expression, and main characteristics. Then, by integrating the human interaction mechanism, human-machine synergy mechanism and design process operation mechanism in conceptual design, a human-centric conceptual design model ‘H（Human）-M（Machine）-D（Design） model’ is proposed, and its basic logic and operation principle are analyzed from the dimensions of users and designers, smart machine, and design process. Finally, an overall implementation framework for human-centric conceptual design is established, and four types of key technologies including cognitive understanding of design thinking, collaborative interaction of design subjects, personalized knowledge services, and conceptual design reasoning and decision-making, are elaborated to provide support for the realization of human-human collaboration, human-object collaboration, and human-machine collaboration in the conceptual design with the communion of multiple design subjects. The human-centered conceptual design process of an elevator is used as a case to validate the proposed model and framework.

Key words: Industry 5.0, conceptual design, human-centric, multiple design subjects, collaborative interaction