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This paper aims to propose a robotic automation system for processing special-shaped thin-walled workpieces, which includes a measurement part and a processing part.

In the measurement part, to efficiently and accurately realize the three-dimensional camera hand-eye calibration based on a large amount of measurement data, this paper improves the traditional probabilistic method. To solve the problem of time-consuming in the extraction of point cloud features, this paper proposes a point cloud feature extraction method based on seed points. In the processing part, the authors design a new type of chamfering tool. During the process, the robot adopts admittance control to perform compensation according to the feedback of four sensors mounted on the tool.

Experiments show that the proposed system can make the tool smoothly fit the chamfered edge during processing and the machined chamfer meets the processing requirements of 0.5 × 0.5 to 0.9 × 0.9 mm².

The proposed design and approach can be applied on many types of special-shaped thin-walled parts. This will give a new solution for the automation integration problem in aerospace manufacturing.

A novel robotic automation system for processing special-shaped thin-walled workpieces is proposed and a new type of chamfering tool is designed. Furthermore, a more accurate probabilistic hand-eye calibration method and a more efficient point cloud extraction method are proposed, which are suitable for this system when comparing with the traditional methods.

The purpose of this paper is to explore a novel measurement approach for wheel-terrain contact angle using laser scanning sensors based on near-terrain perception. Laser scanning sensors have rarely been applied to the measurement of wheel-terrain contact angle for wheeled mobile robots (WMRs) in previous studies; however, it is an effective way to measure wheel-terrain contact angle directly with the advantages of simple, fast and high accuracy.

First, kinematics model for a WMR moving on rough terrain was developed, taking into consideration wheel slip and wheel-terrain contact angle. Second, the measurement principles of wheel-terrain contact angle using laser scanning sensors was presented, including “rigid wheel - rigid terrain” model and “rigid wheel - deformable terrain” model.

In the proposed approach, the measurement of wheel-terrain contact angle using laser scanning sensors was successfully demonstrated. The rationality of the approach was verified by experiments on rigid and sandy terrains with satisfactory results.

This paper proposes a novel, fast and effective wheel-terrain contact angle measurement approach for WMRs moving on both rigid and deformable terrains, using laser scanning sensors.

The construction industry is widely recognized as one of the most hazardous sectors in the world. Despite extensive research on safety management, a critical issue remains that insufficient attention is devoted to safety practices in rural areas. Notably, accidents frequently occur during the construction of rural self-built houses (RSH) in China. Safety management tends to be overlooked due to the perceived simplicity of the construction process. Furthermore, it is essential to acknowledge that China currently lacks comprehensive laws and regulations governing safety management in RSH construction. This paper aims to analyze the behavior of key stakeholders (including households, workmen, rural village committee and the government) and propose recommendations to mitigate safety risks associated with RSH construction.

This paper applies evolutionary game theory to analyze the symbiotic evolution among households, workmen and rural village committee, in situations with or without government participation. Additionally, numerical simulation is utilized to examine the outcomes of various strategies implemented by the government.

Without government participation, households, workmen, and rural village committee tend to prioritize maximizing apparent benefits, often overlooking the potential safety risks. Numerical simulations reveal that while government involvement can guide these parties towards safer decisions, achieving the desired outcomes necessitates the adoption of reasonable and effective strategies. Thus, the government needs to offer targeted subsidies to these stakeholders.

Considering that during the construction phase, stakeholders are the main administrators accountable for safety management. However, there exists insufficient research examining the impact of stakeholder behavior on RSH construction safety. This study aims to analyze the behavior of stakeholders about how to reduce the safety risks in building RSH. Thus, the authors intend to contribute to knowledge in this area by establishing evolutionary game model. Firstly, this study carried out a theoretical by using tripartite evolutionary game to reveal the reasons for the high safety risk during building RSH. Practically, this research points out the important role of households, workmen and rural village committee in improving safety management in rural areas. Besides, some suggestions are proposed to the government about how to reduce construction safety risks in rural areas.

The purpose of this paper is to look at the problem of fault tolerant control (FTC) for discrete time nonlinear system described by Interval Type-2 Takagi–Sugeno (IT2 TS) fuzzy model subjected to stochastic noise and actuator faults.

An IT2 fuzzy augmented state observer is first developed to estimate simultaneously the system states and the actuator faults since this estimation is required for the design of the FTC control law. Furthermore, based on the information of the states and the faults estimate, an IT2 fuzzy state feedback controller is conceived to compensate for the faults effect and to ensure a good tracking performance between the healthy system and the faulty one. Sufficient conditions for the existence of the IT2 fuzzy controller and the IT2 fuzzy observer are given in terms of linear matrix inequalities which can be solved using a two-step computing procedure.

The paper opted for simulation results which are applied to the three-tank system. These results are presented to illustrate the effectiveness of the proposed FTC strategy.

In this paper, the problem of active FTC design for noisy and faulty nonlinear system represented by IT2 TS fuzzy model is treated. The developed IT2 fuzzy fault tolerant controller is designed such that it can guarantee the stability of the closed-loop system. Moreover, the proposed controller allows to accommodate for faults, presents a satisfactory state tracking performance and outperforms the traditional type-1 fuzzy fault tolerant controller.

Shear stresses have a considerable influence on the characteristics of lubricants and become significant at high rotating speeds. This study aims to investigate the influences of shear cavitation (SC) on loading capacity of journal bearings.

A principal normal stress cavitation criterion based on the stress applied to flowing lubricant in journal bearings is developed and used to investigate SC in journal bearings. A computational fluid dynamic (CFD) model for calculating the loading capacity is established using this criterion. After validation with experimental results, the loading capacity is calculated under different conditions.

The calculation results indicate that SC intensifies when viscosity, speed and eccentricity increase. Angle of loading capacity with SC is larger than that without SC. The magnitude of loading capacity with SC is smaller than that without SC due to the decrease in the ultimate pressure. In addition, the magnitude difference between the loading capacity with and without SC increases when viscosity, speed and eccentricity increases.

Present research can provide some guidance for calculating the loading capacity when a journal bearing is operating at high speed or with a high viscosity lubricant.

This paper aims to consider numerical simulation for radionuclide transport calculations in geological radioactive waste repository.

The nonlinear two-point flux approximation is used to discretize the diffusion flux and has a fixed stencil. The cell-vertex unknowns are applied to define the auxiliary unknowns and can be interpolated by the cell-centered unknowns. The approximation of convection flux is based on the second-order upwind method with a slope limiter.

Numerical results illustrate that the positivity-preserving is satisfied in solving this convection-diffusion system and has a second-order convergence rate on the distorted meshes.

A new positivity-preserving nonlinear finite volume scheme is proposed to simulate the far-field model used in the geological radioactive waste repository. Numerical results illustrate that the positivity-preserving is satisfied in solving this convection-diffusion system and has a second-order convergence rate on the distorted meshes.

This paper aims to propose a method for automatic design of additive manufacturing (AM) flow channel paths driven by path length and pressure loss. The research focuses on the automatic design of channel paths, intending to achieve the shortest flow channel length or minimum pressure loss and improve the design efficiency of AM parts.

The initial layout of the flow channels is redesigned to consider the channels print supports. Boundary conditions and constraints are defined according to the redesigned channels layout, and the equation consisting of channel length and pressure loss is used as the objective function. Then the path planning simulation is performed based on particle swarm algorithm. The proposed method describes the path of flow channels using spline cures. The spline curve is controlled by particle (one particle represents a path), and the particle is randomly generated within the design space. After the path planning simulation is completed, the generated paths are used to create 3D parts.

Case study 1 demonstrates the automatic design of hydraulic spool valve. Compared to conventional spool valve, the pressure loss was reduced by 86% and the mass was reduced by 83%. The design results of case study 2 indicate that this approach is able to find the shortest channel path with lower computational cost.

The automatic design method of flow channel paths driven by path length and pressure loss presented in this paper provides a novel solution for the creation of AM flow components.

To solve the above problems and ensure the stability of the ad hoc network node topology in the process of wireless signal transmission, this paper aims to design a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system.

This paper designs a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system.

The simulation results show that the amorphous flat wireless self-organizing network system has good nonlinear distortion fault-tolerant correction ability under the feedback control of the designed controller, and the system has the asymptotically stable convergence ability; the test results show: the node topology of the self-organizing network structural stability is significantly improved, which provides a foundation for the subsequent realization of long-distance transmission of ad hoc network nodes.

Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further.

The controller can extract the fault information caused by nonlinear distortion in the wireless signal transmission process, and at the same time, its feedback matrix K can gradually converge the generated wireless signal error to zero, to realize the stable transmission of the wireless signal.

The purpose of this paper is to know airflow field and its distribution of pneumatic compact spinning systems. Complete compact spinning (CCS) and four-line rollers compact spinning (FRCS) are both two kinds of pneumatic compact spinning systems, which utilizes airflow in condensing equipment to condense fiber bundle and improve yarn properties.

The paper opted for an exploratory study using finite element method, the airflow field in the condensing area of CCS and FRCS were simulated. First, a periodic movement of the fibers in bundle in condensing area was detected, and the yarn tracks were described veritably under the high-speed-video-camera and AutoCAD Software. Then the physical models of the condensing zone were constructed according to the physical parameters of the practical system. The simulation of airflow velocities were extracted along the yarn tracks using ANSYS Software. Finally, the numerical results were verified by spinning experiments.

The results show that the negative velocity component along the Y-axis helps keeping beneficial hairiness. CCS has higher negative velocity value and more abundant beneficial hairiness than FRCS. The velocity component in the X-axis direction has a direct effect on yarn evenness. For the same liner density of CCS and FRCS, the larger the value of the velocity component on X-axis is, the better the yarn evenness is. For 9.7tex, CCS has larger velocity component in the X-axis direction and better yarn evenness than FRCS, showing that CCS is more suitable for spinning fine count yarn. The velocity component in the Z-axis direction has a direct effect on breaking strength. CCS has little velocity component in the Z-axis direction and little breaking strength than FRCS.

To know airflow field and its distribution by finite element method is helpful to investigate the condensing principles of the fiber bundle and improve yarn properties.

Wheel‐terrain interaction has hardly been taken into consideration in the process of conventional mobile robot design, but its importance has been reflected increasingly towards these categories of mobile robots in rough sandy terrain or obstacle‐dense ground, as the first performance index in this situation is the trafficability of robot whose propulsion is uniquely generated by wheel‐terrain interaction. Consequently, it is valuable to find an optimized design method when the terrain and robot itself are regarded simultaneously. The purpose of this paper is to present a novel and reasonable design approach to mobile robot in sandy terrain.

Leading to some conflicted performance indices of robot, terramechanics describes the non‐linear characteristics in wheel‐terrain interaction mathematically, therefore, trade‐offs must be implemented to get a proper solution by multi‐objective optimization (MOO). In this paper, a five‐wheeled drive and five‐wheeled steering (5WD5WS) reconfigurable mobile robot is taken as demonstration with taxonomy of total‐symmetrical, partial‐symmetrical and asymmetrical prototypes. After function modeling, the MOO is carried out via iSIGHT‐FD using NCGA (Neighborhood Cultivation Genetic Algorithm) to minimize the mass, wheel resistance and maximize the static stability simultaneously.

After MOO, a compact and light weighted asymmetrical prototype is obtained with better trafficability, and other prototypes can produce diversified configurations to meet specific requirements. Significantly reduced masses (about 17 kg) enhance the grade‐ability when robot is in rough terrain. Performed real‐world experiments have also verified these prototypes.

The paper presents a new design approach for a mobile robot which focuses on both robot and terrain simultaneously with respect to conflicted factors. To unveil the insight relation of these factors, MOO is an effective tool to get a trade‐offs prototype.