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The purpose of this paper is to investigate the effect of fluid–structure interaction in micro-scale on the performance of the hydrostatic spindle and improve the analysis precision of the dynamic performance of hydrostatic spindle.

Dynamic analysis of hydrostatic spindle before and after fluid–structure interaction is carried out according to stiffness and damping performance of the bearing, which demonstrates that the natural frequency and peak response of the spindle are increased in the micro-scale.

It is concluded from the simulation and experimental results that there is micro-scale effect in the actual operation of the spindle system and slippage exists in the oil film flow. The error between the modal detection result and the theoretical value is within 10 per cent, which also verifies the correctness of the above conclusions.

This paper analyzes the changes of the bearing performance parameters at macro- and micro-scale, which present the influence of the static and dynamic performance of the spindle in the micro-scale.

The purpose of this paper is to propose the pressure fluctuation to further evaluate and predict the dynamic and static characteristics of the aerostatic slider and improve the calculation accuracy of the aerostatic slider.

First-order velocity slip is introduced into the traditional gas-film fluid equation, and the numerical analysis method is used to solve the static performance of the aerostatic slider. The finite element analysis method is used to solve its dynamic characteristics.

It can be concluded from the simulation and experimental results that the model considering the velocity slip in the gas film flow is more accurate. The errors between the modal detection results and the vibration detection results (0.8%–5.8%) under speed slip are smaller than the traditional cases (23.7%–210%), which also verifies the correctness of the above conclusions.

In this paper, the method of simulation and experiment is used to prove that the first-order velocity slip model is more suitable to predict the dynamic response of the aerostatic slider than the condition without slip.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0059/

This paper aims to better design the resonant tank parameters for LLC resonant converter. And, it is found that under heavy load, the voltage gain is affected by junction capacitors of the primary side switching and the parasitic parameters of the secondary side diodes converted to the primary side, which will cause the voltage gain decreased when the switching frequency decreased.

This paper proposes an optimization parameters design method to solve this problem, which was based on impedance model considering the parasitic parameters of switching devices and diodes.

The effectiveness of the proposed method is verified by impedance Bode plots and experimental results.

From the perspective of impedance modeling, this paper finds the reasons for the insufficient voltage regulation capability of LLC resonant converters under heavy load and finds solutions through analysis.

Continuum robots offer unique advantages in various specialized environments, particularly in confined or hard-to-reach spaces. Inverse kinematics and real-time shape estimation constitute crucial aspects of closed-loop control for continuum robots, presenting challenging problems. This paper aims to present an inverse kinematics and shape reconstruction method, which relies solely on the knowledge of base and end positions and orientations.

Based on the constant curvature assumption, continuum robots are regarded as spatial curves composed of circular arcs. Using geometric relationships, the mathematical relationships between the arc chords, points on the bisecting plane and the coordinate axes are established. On this basis, the analytical solution of the inverse kinematics of the continuum robots is derived. Using the positions and orientations of the base and end of the continuum robots, the Levenberg–Marquardt algorithm is used to solve the positions of the cubic Bezier curves, and a new method of spatial shape reconstruction of continuum robots is proposed.

The inverse kinematics and spatial shape reconstruction simulation of the continuum robot are carried out, and the spatial shape measurement experimental platform for the continuum robot is constructed to compare the measured and reconstructed spatial shapes. The results show that the maximum relative error between the actual shape and the reconstructed shape of the continuum robot is 2.08%, which verifies the inverse kinematics and shape reconstruction model. Additionally, when the bending angle of a single bending section of the continuum robot is less than 135°, the shape reconstruction accuracy is higher.

The proposed inverse kinematics solution method avoids iterative solving, and the shape reconstruction model does not rely on mechanical models. It has the advantages of being simple to solve, highly accurate and fast in computation, making it suitable for real-time control of continuum robots.

This study aims to solve the problem that under light-load conditions, the output voltage regulation capability is lost due to the fact that the voltage gain of the LLC resonant converter does not decrease with the increase of the switching frequency.

In this paper, the impedance model considering the parasitic parameters of the primary and secondary sides is calculated under light-load conditions, the limitations of the previous method are explained and a new circuit improvement is proposed.

In this paper, an improved circuit is proposed, and the impedance Bode plot is used to verify that the circuit can effectively improve the voltage gain problem under light-load conditions. Finally, the experimental results verify the effectiveness of the proposed circuit through comparison with traditional solutions and circuits.

In this paper, the impedance model considering the parasitic parameters of the primary and secondary sides is calculated, the limitations of the previous method are explained and a new circuit improvement is proposed. When compared with the previous method, the proposed circuit improvement can suppress the voltage gain increase that occurs when the switching frequency increases to a certain level.

The purpose of this study is to present a simplified analytical method to estimate ground lateral displacement due to excavation. Excavations of foundation pit will inevitably lead to soil movements that may adversely impact surrounding facilities or structures. Thus, estimation of the ground displacement induced by excavation is essential in engineering practice.

Based on a theory of elastic mechanics, a simplified analytical method for predicting the ground lateral displacement resulting from foundation pit excavation is proposed.

As the distance from the soil to the supporting structure increases, the maximum ground lateral displacement decreases nonlinearly but at a reduced rate. Poisson’s ratio of soil has a mild influence on the ground lateral displacement, whereas the influence of the supporting structure’s deflection modes is significant.

The advantage of the proposed simplified analytical method lies in that it considers the supporting structure’s arbitrary deflections, giving it wider practical applicability than previous methods.