Public participation has become increasingly important in collaborative urban design; yet, existing processes often face challenges in achieving efficient and scalable citizen engagement. To address this gap, this study explores how large language models (LLMs) can support cooperation among community members in participatory design. We introduce CoDesignAI, a collaborative urban design tool that combines multiple users, representing residents or stakeholders, with multiple AI agents, representing domain experts who provide facilitation and professional knowledge during the conceptual stage of urban design. This paper presents the system architecture and main components of the tool, illustrating how users interact with AI agents within a collaborative and iterative design workflow. Specifically, the system integrates generative AI with spatial mapping services to support street-level visualization of design proposals. AI agents assist users by summarizing discussion content, extracting shared design intentions, and generating prompts for presenting design interventions. The system also enables users to revise and refine their ideas over multiple rounds while documenting the design process. By combining conversational AI, multi-user interaction, and image-based design grounded in real-world urban contexts, this study argues that AI-enabled design systems can help shift urban design from an expert-centered practice to a more open and participatory process. The paper contributes a new web-based platform for AI-assisted collaborative design and offers an early exploration of how AI agents may expand the capacity for public participation in urban design.

翻译：公众参与在协作式城市设计中日益重要，然而现有流程往往难以实现高效且可扩展的市民参与。为弥补这一不足，本研究探索大型语言模型如何支持社区成员在参与式设计中的协作。我们提出CoDesignAI——一种协作式城市设计工具，该系统将代表居民或利益相关者的多用户，与代表领域专家的多AI智能体相结合，在城市设计概念阶段提供协调支持与专业知识。本文阐述了该工具的系统架构与核心组件，说明用户如何在协作迭代的设计工作流中与AI智能体交互。具体而言，该系统整合生成式AI与空间地图服务，以支持街道层级的设计方案可视化。AI智能体通过总结讨论内容、提取共识性设计意图、生成用于呈现设计干预措施的提示词来协助用户。系统还支持用户在多轮迭代中修订完善设计构思，并完整记录设计过程。通过融合对话式AI、多用户交互以及基于真实城市环境的图像化设计，本研究论证了AI赋能的设计系统有助于推动城市设计从专家主导模式转向更开放、更具参与性的过程。本文贡献了一个基于网络的AI辅助协作设计平台，并对AI智能体如何拓展公众参与城市设计的能力进行了前瞻性探索。