Abstract: Control of shield tunneling attitude is challenging due to its hysteresis and lack of theoretical support. The authors address this issue by developing an optimal correction curve model for the shield by leveraging manual expertise and expert knowledge. An attitude fuzzy controller is established to propose an automatic attitude control method. This method effectively addresses the problem of traditional fuzzy control systems exceeding the basic theory domain in terms of input parameters. When the attitude deviation and trend values fall within the allowable range, the fuzzy controller can immediately initiate the output of cylinder pressure differences to regulate the attitude. However, if these values exceed the acceptable deviation range, an optimal deviation curve model is employed. The input parameters for the fuzzy controller are then determined based on the shield′s attitude deviation and trend relative to the optimal deviation curve, allowing for correction through adjustments in cylinder pressure differences. Furthermore, to validate this approach, an automatic control system for shield attitude is designed and tested at a shield construction site. The results demonstrate the successful implementation of automatic shield attitude control, leveraging fuzzy theory and the optimal correction curve.

Key words: shield attitude, automatic control, fuzzy control, correction curve