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Wireless capsule endoscopy (WCE) offers a non-invasive evaluation of the digestive system, eliminating the need for sedation and the risks associated with conventional endoscopic procedures. Its significance lies in diagnosing gastrointestinal tissue irregularities, especially in the small intestine. However, existing commercial WCE devices face limitations, such as the absence of autonomous lesion detection and treatment capabilities. Recent advancements in micro-electromechanical fabrication and computational methods have led to extensive research in sophisticated technology integration into commercial capsule endoscopes, intending to supersede wired endoscopes. This Review discusses the future requirements for intelligent capsule robots, providing a comparative evaluation of various methods’ merits and disadvantages, and highlighting recent developments in six technologies relevant to WCE. These include near-field wireless power transmission, magnetic field active drive, ultra-wideband/intrabody communication, hybrid localization, AI-based autonomous lesion detection, and magnetic-controlled diagnosis and treatment. Moreover, we explore the feasibility for future “capsule surgeons”. future requirements for intelligent wireless capsule endoscopy, providing a comparative evaluation of various methods’ merits and disadvantages, and highlighting recent developments in six technologies.

A thorough understanding of the effects induced by continuous curved pipe jacking on adjacent underground facilities is paramount for ensuring both safety and operational efficiency during construction. This study posits a three-stage analytical framework designed to calculate the displacement of existing objects resulting from sequential vertical curved rectangular pipe jacking. The methodology involves the following stages: first, the stresses at the object surface must be derived based on classical Mindlin’s solutions; second, the displacements at arbitrary points of the object must be determined using the Winkler foundation model, wherein soil–object interactions are modeled as elastic springs to transform displacements into normal and shear forces; and third, the rigid-body displacement and rotation of objects, caused by aggregate forces, must be calculated by kinematic analysis. The validity of the proposed method is confirmed through comparison with a reduced-scale experimental test, and a parametric study discussing the influence of key factors, including Poisson’s ratio and object geometry, is presented.

The tunnel boring machine (TBM) is widely used in tunnel construction projects. The thrust system plays a crucial role to drive the machine ahead and support gripper shoes stably while tunneling. More and more attention has been paid to the pressure and velocity regulation efficiency as the TBM advances in complex rock conditions to ensure the stabilization of the tunneling process. A thrust hydraulic control system, assembled with a proportional pressure reducing valve, is established with system operating parameters. The mathematical model of the thrust electro-hydraulic system is revealed. To improve the control characteristics of the thrust system, a self-tuning fuzzy PID controller is introduced in the pressure and velocity regulation procedures. After that, tests on a Φ2.5 m scaled TBM test rig are carried out. The test results show that the thrust system adopting the fuzzy PID controller results in less oscillation and a smoother regulation process. It takes less time to reach the target goal of pressure regulation with less vibration during the pressure regenerating periods, and both systems of conventional PID controller and fuzzy PID controller are qualified in velocity regulation movements. The proposed control methods show better benefits in reduction of vibrations and shorter time of regulation to stable conditions, which extends the machine’s life and affects the acceleration of the tunneling process.

Hydro-viscous clutch is a speed-regulating device for heavy fans and water pumps. It has important engineering significance in the fields of soft-start for rotating machinery. More and more attention has been paid to its torque and control characteristics. This paper is focused on the torque formula for hydro-viscous clutch (HVC), assuming that multi-friction plates distribute ununiformly with different oil film thickness. A mathematical model of friction plates was constructed, then the distribution formula of the oil film thickness was obtained. A new expression was presented using a modified factor. Parameters such as pressure, viscous torque, and oil film thickness were obtained. The results show that each clearance of friction plates is not the same and the distribution of oil film thickness is influenced by pressing force, groove depth, angular ratio of groove/non-groove, and static friction force. To verify the proposed expression, relevant experiments were carried out on an HVC with multi-friction plates, and the experimental results indicate that the new expression is more accurate compared to the original one.

At present, the splicing of steel arches for open-type TBM suffers from the problems of labor-intensive, time-consuming, low efficiency and greater potencial risk to workers. Rock-fall and collapse caused by untimely support is still one of the main construction accidents. In this paper, a novel steel arch splicing manipulator is developed for unmanned and automated steel arch splicing, and a backstepping method based cascade control strategy is proposed to improve the trajectory tracking control performance. Firstly, the inner-loop controller is designed to compensate the flow coupling between each joint-driven hydraulic cylinder based on dynamic analysis and feedback linearization. Secondly, the adaptive robust controller is adopted for outer-loop controller design to deal with parametric uncertainties and external disturbances. Finally, the system stability is proved by Lyapunov function, then comparative experiments are conducted to verify the effectiveness and superiority of the proposed control scheme. It can be concluded that the proposed controller has a better trajectory tracking control performance, while the control input is much smoother than that of traditional PID controller.

In order to achieve sustainable development, low-carbon economic efficiency (LCEE) is particularly important in China. Therefore, this study uses SBM-DEA model to evaluate the LCEE of 30 provinces in China from 2008 to 2017. Based on the uncoordinated coupling model, this study discusses the interaction between China’s provincial LCEE and scientific and technological development level (STDL), and uses the panel VAR model to consider the interactive response relationship between China’s provincial LCEE and STDL. The research shows that the uncoordinated coupling degree (UCCD) between the STDL and LCEE in 30 provinces showed a decreasing trend as a whole during the research period. In terms of spatial distribution, the provinces with UCCD less than 0.5 mainly concentrated in the eastern and southern provinces, gradually spread to the north, and showed positive spatial autocorrelation, with significant spatial accumulation effect. From the perspective of influencing factors, patents, urbanization level, traffic level and financial development have significant positive effects on promoting the coordinated development of STDL and LCEE. From the relationship between them, the STDL has a positive promoting effect on LCEE, but the mechanism of the two is not obvious enough. Therefore, it is necessary to emphasize the coordinated development of low-carbon economy and science and technology, and promote the development of low-carbon economy through scientific innovation.

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.

Condition-based hydraulic cylinder maintenance necessitates quantitative fault diagnostics. However, existing methods are characterized by either qualitative or limited quantitative capabilities. In this paper, a quantitative fault diagnostic method using a particle filter for hydraulic cylinders is proposed. The problem of quantitative fault diagnostics is formally formulated in a stochastic framework to assess the health/fault state, and an architecture based on joint state-parameter estimation is proposed. Through the establishment and analysis of a nonlinear dynamic model of the hydraulic cylinder, the impact of time-varying parameters on the state variables is revealed. Three fault modes of the cylinder, including friction, internal leakage, and external leakage, are theoretically identified. The proposed method allows for a simultaneous quantitative diagnosis of these three fault modes. The performance of the proposed method is evaluated using meticulously designed experiments. The results demonstrate that the mean absolute percentage errors in the parameter estimations are below 9% (accuracy exceeding 91%), thus validating its feasibility and effectiveness.

The rapid and accurate control of air chamber pressure in slurry pressure balance (SPB) shield tunneling machines is crucial for establishing the balance between slurry pressure and soil and water pressure, ensuring the stability of the support face. A novel air chamber pressure control method based on nonlinear adaptive robust control (ARC) and using a pneumatic proportional three-way pressure-reducing valve is proposed in this paper. Firstly, an electric proportional control system for the air chamber pressure is developed. Secondly, a nonlinear state space model for the air chamber pressure regulation process is established. Utilizing experimental data from the SPB shield tunneling machine test bench, nonlinear adaptive identification is conducted through the nonlinear recursive least square algorithm. The results demonstrate the model’s effectiveness and accuracy. Then, a nonlinear ARC for air chamber pressure is designed based on the backstepping method, and its Lyapunov stability is proved. Finally, the feasibility and effectiveness of the controller designed in this paper is verified through simulation and experiments. The results demonstrate that the developed control system can compensate for the nonlinearity and disturbance in the air chamber pressure regulation process. It can achieve good transient and steady-state performance and has good robustness against uncertainty.

As a rotational speed controller, a hydro-viscous clutch (HVC) is usually used in the constant pressure water supply system to maintain the needed water pressure constant. However, when the hydro-viscous clutch is working, it often suffers from the problem of output rotational speed fluctuation since the spool of proportional relief valve can easily get stuck. Consequently, water pressure will fluctuate too. A special pump control system of HVC was proposed based on the Fuzzy-PID controller for the purpose of reducing the fluctuation rate. The MATLAB simulation was carried out according to the mathematical model and the results show that the Fuzzy-PID control strategy is superior to traditional PID control. The corresponding experiment was performed and the result indicate that through applying the Fuzzy-PID controller based pump control system, the rotational output speed fluctuation of HVC can be inhibited from ±60π to ±6π rad/min, and the water pressure fluctuation is dropped from ±0.1 to ±0.002 MPa.