Present Status and Prospect of High-Frequency Electro-hydraulic Vibration Control Technology

Electro-hydraulic vibration equipment(EHVE)is widely used in vibration environment simulation tests,such as vehicles,weapons,ships,aerospace,nuclear industries and seismic waves replication,etc.,due to its large output power,displacement and thrust,as well as good workload adaptation and multi-controllable parameters.Based on the domestic and overseas development of high-frequency EHVE,dividing them into servo-valve controlled vibration equipment and rotary-valve controlled vibration equipment.The research status and progress of high-frequency electro-hydraulic vibration control technology(EHVCT)are discussed,from the perspective of vibration waveform control and vibration controller.The problems of current electro-hydraulic vibration system bandwidth and waveform distortion control,stability control,offset control and complex vibration waveform generation in high-frequency vibration conditions are pointed out.Combining the existing rotary-valve controlled high-frequency electro-hydraulic vibration method,a new twin-valve independently controlled high-frequency electro-hydraulic vibration method is proposed to break through the limitations of current electro-hydraulic vibration technology in terms of system frequency bandwidth and waveform distortion.The new method can realize independent adjustment and control of vibration waveform frequency,amplitude and offset under high-frequency vibration conditions,and provide a new idea for accurate simulation of high-frequency vibration waveform.

From tunnel boring machine to tunnel boring robot: perspectives on intelligent shield machine and its smart operation

Advances in intelligent shield machines reflect an evolving trend from traditional tunnel boring machines(TBMs)to tunnel boring robots(TBRs).This shift aims to address the challenges encountered by the conventional shield machine industry arising from construction environment and manual operations.This study presents a systematic review of intelligent shield machine technology,with a particular emphasis on its smart operation.Firstly,the definition,meaning,contents,and development modes of intelligent shield machines are proposed.The development status of the intelligent shield machine and its smart operation are then presented.After analyzing the operation process of the shield machine,an autonomous operation framework considering both stand-alone and fleet levels is proposed.Challenges and recommendations are given for achieving autonomous operation.This study offers insights into the essence and developmental framework of intelligent shield machines to propel the advancement of this technology.