Abstract: In recent years, robot-based intelligent garage (RIG) has shown its effectiveness in alleviating the problem of "difficult parking" in cities with its high capacity, high efficiency, and high safety. The core component of a RIG is an automated guided vehicle (AGV), and the control of AGV operation relies on critical RIG technologies. Based on the analysis of RIG-related literature, the existing RIG technologies are firstly reviewed in terms of "layout scheme", "scheduling strategy" and "path planning", based on the operational characteristics of RIGs. The critical component technologies are reviewed. Then, the theoretical basis, research methods, application status, advantages and disadvantages of RIG critical technologies are systematically reviewed, and the important role played by RIG critical technologies in the operation process is thoroughly discussed. Finally, in view of the problems existing in the operation of RIG, the development trend of RIG critical technologies is still foreseen from the above three aspects. It is important to emphasize that ① Big data processing technology is used to tap into the parking demand at different time periods and guide the automatic optimization of RIG layout to balance the parking capacity and access efficiency demands; ② Cloud robotics is gradually being widely applied in RIG scheduling strategies, which are combined with the mobility-as-a-service technology RIG to develop RIG scheduling strategies that meet user satisfaction; ③ As RIG layout schemes, scheduling strategies and the complexity of the actual environmental obstacles, the use of deep reinforcement learning framework to solve the path planning problem of AGVs has become the current development trend. The systematization of the research results of critical RIG technologies is an important guide for future RIG technology development and engineering applications.

Key words: intelligent garage, AGV, layout scheme, scheduling strategy, path planning