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High-flow hydraulic servo systems are extensively employed in contemporary industrial applications due to their considerable flow capacity and cost-effectiveness. Nonetheless, hydraulic servo systems frequently encounter unpredictable internal and external disturbances, and high-flow proportional directional valves always have unsatisfactory hydraulic characteristics, compromising the precision and robustness of high-flow hydraulic servo systems. This study proposes a novel control strategy integrating the Soft Actor-Critic (SAC) reinforcement learning algorithm with Adaptive Robust Control (ARC) to enhance system performance. This approach features a two-tiered controller: the upper controller utilizes the SAC algorithm to learn and adapt to the dynamics of the hydraulic servo system, iteratively refining the lower controller’s hyperparameters. Meanwhile, grounded in the ARC strategy, the lower controller executes real-time control of the hydraulic servo system. The simulation and experimental results demonstrate that the proposed control strategy can effectively adjust the control hyperparameters according to the learned system dynamic and tracking errors. Consequently, this approach enhances control precision amidst varying external and internal disturbances. Moreover, this control strategy is anticipated to realize high-flow, high-precision, and high-robust hydraulic servo systems, which can be used in various fields such as marine and offshore engineering.

The widely use of covered conductor increases the reliability of distribution network. However, a new problem of partial discharge caused by covered conductor at the position of tower head is generated at the same time. This kind of partial discharge will damage the insulation layer or accelerate the deterioration of insulation, which may cause the single-phase grounding fault and affect the power supply reliability. At present, there is few systematic studies on the characteristics of this partial discharge. This paper mainly analyzes the electric field distribution near the covered conductor around tower head, builds the partial discharge experiment platform, and obtains the pulse current characteristics of partial discharge under different working conditions. The results show that the maximum electric field intensity is located at the interface between covered conductor, binding wire and air. The main causes of partial discharge are the wet and dirty of the surface of porcelain insulator and conductor insulation. The minor cause is the breakage of covered conductor insulation. Under different conditions, the initial partial discharge pulse current wave front time is 8ns ~ 45ns, the tail time is 30ns ~ 150ns. The discharge time interval can be as low as $30~\mu \text{s}$ . In addition, it is found that there are two types of partial discharge through spectral analysis. One occurs when the covered conductor insulation is damaged under binding wire; the other is the covered conductor insulation is intact.

At present, solenoid (helical) coils are widely used in various researches, especially electromagnetic forming (EMF), due to their advantages of simple manufacture and high magnetic field strength. However, in the study of EMF, there are still some defects in the high precision calculation of solenoid coils in the magnetic field the main reason is that the solenoid coil is of non-axisymmetric structure, which is generally equivalent to the 2-D or 3-D axisymmetric structure in practical research. Not only can it ignore the effect of the pitch effect of the solenoid coil, but also causes a certain deviation in the calculation of the magnetic field. Hence, this paper establishes 5 helical coils and 3-D axisymmetric finite element coils models with different layers for comparative analysis. The simulation results show that the magnetic flux density distribution deviation of helical coil and the 3-D axisymmetric coil is small and can be ignored when the coil layers are 1 or 2 layers. However, the number of linear circles increasing, the deviation between the two increases obviously. Therefore, in the study of EMF, the effect of solenoid coil pitch effect on magnetic field calculation can be ignored when the layers, radius and pitch of helical coils are used less whereas the effect of solenoid coil pitch effect on magnetic field calculation must be considered when the layers, radius and pitch of helical coils are used more.

Though end-to-end siamese networks have achieved great performance on object tracking owing to offline pre-training with large datasets. They are still liable to fail to track fast moving object and their accuracy suffers from the cosine window for mitigating background interference. The cosine window will aggravate the boundary effect and have a negative impact on track. In this paper, we propose an accurate positioning siamese network (FPSiam) for real-time object tracking. This approach can better estimate the search candidate area of the object in the current frame from the previous tracking position and can keep tracking well for the fast moving object. The unbalanced penalty mechanism of the cosine window in the tracking process is avoided. Furthermore, the features of the low-level layers are high-resolution, which is suitable for positioning the object. High-level layers are full of rich semantic features which are suitable for classifying the objects. In order to utilize the advantages of high-level features and low-level features, we introduce a densely connected tracking network. A number of experiments were conducted on five challenging tracking datasets: OTB50, OTB2013, OTB2015, VOT2015, and VOT2016, and the proposed method achieved excellent results on these benchmarks.

This paper proposes an approach to design the length, width, and bundlewidth dimensions of rectangular ironless coils for magnetically levitated planar motors. Firstly, a model for the propulsion and levitation forces generated from a single coil in Halbach permanent magnetic field by using Lorenz force volume integral method is developed. Then, a dimensionless factor named coil width dependent factor, Kc, which can define the amplitudes of propulsion and levitation forces, is formulated. In order to maximize the value of Kc, the optimal coils number, n, of a square forcer is derived to be m/2 + 1, where m is the multiples of coil length Lc to magnetic pole pitch τ. Thereafter, the coil width Wc and bundlewidth Bc are determined considering the given magnetic pole pitch τ. The comparison between the proposed approach and other formulations verifies that if such designed coils is utilized in a forcer, the average amplitude and the quadratic sum of all coil currents are both minimal when the forcer is desired to generate the identical driving forces. The proposed approach can be used to design the dimensions of a single coil and also to configure the high power density forcers or coil arrays for magnetically levitated planar motors.

Oil-immersed insulation paper (OIP) bushing is one of the most important equipment in power transmission and distribution systems. Moisture is one of the most serious factors that affect the insulation status of OIP bushing. In this paper, the OIP bushing was assumed to be in a stable and simplicity condition, and then the transient moisture distribution of capacitor core and its effects on the electric field were studied. First, by dissecting a 110 kV OIP bushing, the specific sizes for modelling were obtained. Afterwards, a moisture diffusion model for OIP bushing was established based on COMSOL Multiphysics software, and it was also verified by moisture diffusion experiment. Then, the moisture distribution for different conditions were obtained and analyzed. Finally, a model for the electric field of OIP bushing was established, and then the effects of moisture on the electric field were studied.

Studying the moisture diffusion in non-oil-immersed insulation paper is helpful to optimize the drying process and improve the drying efficiency of oil-immersed equipment. Moisture diffusion factor (MDF) is the key parameter to describe the moisture diffusion in non-oil-immersed insulation paper. Thermal aging affects the moisture absorption capacity of insulation paper obviously, thus, this paper intends to modify the empirical expression of MDF by considering the effects of thermal aging. The transient moisture contents of non-oil-immersed insulation paper with different thicknesses were measured at 40 °C and 60 °C, respectively. Then, the experimental values of MDF were extracted, and the empirical expression of MDF was modified by considering the effects of thermal aging. Finally, the modified expression of MDF was verified. The following conclusion can be obtained: 1) the equilibrium time constant of non-oil-immersed insulation paper increases with thermal aging; 2) the moisture absorption rate of non-oil-immersed insulation paper decreases with thermal aging, and; 3) the modified expression of MDF is reasonable and effective.

Cyber-physical manufacturing systems (CPMSs) are a new paradigm of manufacturing systems that integrate cyber systems and physical systems to aid smart manufacturing. CPMSs can improve the system's flexibility and productivity and adapt to new market demands. However, CPMSs are susceptible to cyber-attacks, which can modify manufacturing intents to produce parts incorrectly and cause hazards to equipment, employees, and consumers. Therefore, the trustworthiness of CPMSs is critical to the entire systems. In order to describe and analyze the trustworthiness of CPMSs, generalized stochastic Petri nets are adopted to model CPMSs and the trustworthiness is measured from three metrics, i.e., the reliability, availability and security. To study the trustworthiness evolution of CPMSs, a malicious software spreading dynamics model is presented, and its dynamic behaviors are analyzed. Finally, the CPMS trustworthiness evolution model is constructed depending on the proposed dynamics model. The simulation results demonstrate that the proposed approach is effective to model and analyze the CPMS trustworthiness.