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The process of service composition and optimal selection in cloud manufacturing (CMfg-SCOS) involves three types of users: service demanders, resource providers, and cloud platform operators. The interests of all users are a research focus of CMfg-SCOS, as their participation in the CMfg system directly affects the efficiency and long-term development of CMfg. However, the current research on CMfg-SCOS rarely considers the interests of all three types of users simultaneously, and the interest of resource providers is not clearly defined, which lags behind the reality of CMfg. Therefore, this study first proposes a three-tier programming model of CMfg-SCOS that considers the interests of service demanders, cloud platform operators, and resource providers. At the lower level of the model, service demanders are the decision makers, aiming to minimize time and cost and maximize service quality. At the middle level of the model, cloud platform operators are the decision makers, aiming to maximize resource use and flexibility in the face of uncertain environments. At the upper level, resource providers are the decision makers, aiming to maximize enterprise surplus. Then, this study develops an improved fast nondominated sorting genetic algorithm with advancement and inheritance (namely, a-i-NSGA-II) to solve the three-tier model efficiently. Numerical experiments conducted in this study found that in comparison to the art of state algorithms, including original nondominated sorting genetic algorithm II (NSGA-II), multiobjective particle swarm optimization (MOPSO), and multiobjective spotted hyena optimizer (MOSHO), the proposed a-i-NSGA-II has better diversity and comprehensive performance at the middle level of the model and better solution quality at the upper level. Furthermore, a case study of the actual production of an automobile fuel tank assembly enterprise verifies the effectiveness of the proposed model and algorithm.

Supplemental material, sj-docx-1-pib-10.1177_09544054221100873 for An effective multi-part dedicatedflow-line reconfiguration model considering the optimal selection of machining process path and machines by Hao Yu, Bo Yang, Shilong Wang, Yankai Wang, Sibao Wang, Zehua Wang and Zhongning Wang in Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture

Supplemental material, sj-docx-1-pib-10.1177_09544054221100873 for An effective multi-part dedicatedflow-line reconfiguration model considering the optimal selection of machining process path and machines by Hao Yu, Bo Yang, Shilong Wang, Yankai Wang, Sibao Wang, Zehua Wang and Zhongning Wang in Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture

The gas outburst potential is typically high when roadways uncover the gassy coal seams associated with outburst hazards. This paper describes the complex stress and displacement evolution that occurs in roadway tunnelling through coal seams under different original stress conditions, which is helpful for better understanding how the stress leads to an outburst accident, and proposing some relevant control measures. The stress concentration is primarily resulted from the strength difference between coal and rock, and the abutment stress increases gradually as the forward residual rock thickness decreases when the roadway excavation enters a coal seam from rock stratum. When the abutment stress is sufficiently high, the forward residual rock will suddenly be broken after the next cycle, and the stress will decrease rapidly to release elastic energy and generate new fractures. Meanwhile, the coal and rock in front of the heading face will move rapidly towards the free space. Therefore, an outburst accident may occur immediately when the gas pressure in front of the heading face is high enough. Once the outburst accident is triggered, the gas expansion energy and elastic energy distant from the heading face will contribute to developing the accident. The stress perpendicular to the roadway is the primary factor causing such outbursts. The abutment stress concentration will be higher when the maximum original stress is perpendicular to the roadway, which will increase the outburst potential. Therefore, it is suggested that arranging roadways parallel to the maximum original stress, if possible, can also reduce the outburst threat. Outbursts are triggered by the elastic energy near the heading face and developed by the gas expansion energy and elastic energy distant from the heading face. In this study, the method of “strong-weak” coupling circle-layers was proposed to reduce the outburst hazard when roadways excavated through gassy coal seams. This method was proven to be valid by the comparative experiment. The weak circle can be realized by boreholes and hydraulic cutting. It could not only reduce the elastic energy near the heading face but also prevent the distant energy from contributing to the outburst accident. In addition, the strong circle can be made by injecting water slurry and applying anchors. It could help to reduce the strength difference between coal and rock, thereby decreasing the local stress concentration, resisting the residual outburst energy near the heading face, and preventing the outburst from being triggered. The “strong-weak” coupling structure was successfully applied in Bailongshan coal mine when uncovering the #7,8 coal seam. This structure can effectively promote gas drainage, reduce the coal and gas outburst risk. As a result, the mining efficiency improves a lot, and the uncovering time greatly decreases from the expected 2 years to 5 months.

Manufacturing industries frequently encounter production scheduling problems containing device dynamic reconfiguration processes (DRP). DRP refers to dynamic device adjustments (such as replacement of tools), leading to changes in the devices’ actual processing time. It has a severe impact on the production schedule. Nevertheless, there is scarcely research upon hybrid flow shop scheduling problem (HFSP) with DRP. Besides, it is necessary to consider multiple conflict objectives in the HFSP. Thus, the multi-objective HFSP with DRP (MOHFSP-DRP) is significant in both theoretical research and application. This paper first proposes a multi-objective mathematical model (MOHFSP-DRP) that simultaneously considers the DRP and devices’ adjustable processing modes. The bi-objective of this model is to minimize both the makespan and the whole device’s energy consumption. This study then proposes an improved multi-objective whale optimization algorithm (IMOWOA) to solve the MOHFSP-DRP and obtain the Pareto-based optimal solution set. After that, to verify the proposed method’s effectiveness, numerical experiments are implemented based on the real-world cases in a Chinese company’s digital hot-rolling workshop. Results denote that the presented IMOWOA is superior to SPEA2 and NSGA-II. Finally, the MOHFSP-DRP model and IMOWOA are applied to a real-world hot-rolling shop successfully. The real-world cases verify the proposed IMOWOA can tackle the presented MOHFSP-DRP very well.

Guaiacol produced by O-methylation of catechol with methanol over solid catalysts is a green environmental synthesis route. In order to achieve high catalytic efficiency, it is quite necessary to employ low-cost catalysts with high activity and stability. Herein, series of aluminophosphate catalysts were synthesized by a simple precipitation route modified by Zr. The characterization results indicated that the prepared Al-P-Zr catalysts possessed appropriate weak acid and weak base sites, which were beneficial for the O-methylation of catechol with methanol. Different Zr amount and calcined temperature exerted a significant influence on physicochemical properties of the catalysts and catalytic performance. The Al-P-Zr catalysts containing Zr/Al molar ratio of 0.012 calcined under 400 °C showed the optimal catalytic activity and long-term stability for vapor-phase selective O-methylation of catechol with methanol.

Fault protection measures and interval positioning isolation methods are proposed for open-circuit faults of the constant current remote supply system, in order to realize the efficient and reliable operation of cabled underwater information network. Achieving the protection of the power conversion module in the trunk node by researching the protection circuit, and based on the controllable electrical switching type switch in the main node of the trunk, the system fault isolation circuit was designed and a new method of open-circuit fault location isolation was proposed. The research content has reference significance for the design and construction of cabled network underwater information network in the future.

Service composition optimization is one of the core issues of cloud manufacturing research. At present, relevant researches mostly focus on single-task service composition, and there are few reports on the problem of multi-task service composition considering resource competition. However, in the real cloud manufacturing environment, multi-task service composition is common, so how to formulate a robust multi-task service composition model is a meaningful research direction. This paper first proposes a multi-task service composition optimization model considering resource competition constraints (MTSCOM-RCC) in the cloud manufacturing environment to fill the above-mentioned gap. The MTSCOM-RCC model considers the conflicts of interest and time between parallel subtasks and proposes an important service evaluation indicator. Secondly, a two-layer coding method, including task layer and subtask, is proposed based on studying the MTSCOM-RCC’s competition mechanism and characteristics. An improved hybrid genetic artificial bee colony algorithm model is proposed to solve the multi-task model. The model is combined with the global optimization method and task queue optimization method. Experimental results prove that the two-layer task optimization method model is more feasible and effective than the other two solution models.

Surmounting obstacles during continuously climbing in a complex environment is an important issue for pole-climbing robots. An obstacle-surmounting strategy is presented for a pole-climbing robot. The force and moment applied on the pole-climbing robot in static status were analyzed, and the analysis of pole-climbing robot’s upward vertical climbing was conducted. The climbing execution has four steps: loosening the lower gripper, curling up, striding forward, and clamping the upper gripper. To obtain the information of obstacle crossing accurately, the obstacle-surmounting conditions were analyzed in detail. We modeled the striding linkage with thickness and obtained the Denavit–Hartenberg coordinates of each vertex. The model of the grippers with thickness was proposed and the Denavit–Hartenberg coordinates of each vertex of the grippers were obtained. Then single-step negotiating an obstacle and multistep negotiating an obstacle were proposed. Experiments were conducted to verify the effectiveness of the obstacle-surmounting strategy.

The low permeability of coal seams is the primary difficulty for gas production. Hydraulic cutting is one of the most effective technologies for increasing permeability and stimulating gas production. This paper investigates the hydraulic cutting styles in boreholes and the optimal equivalent borehole diameter after discharging the pulverized coal particles. This paper introduces the hydraulic cutting equipment and cutting styles and determines that the cutting cylinder is the most suitable style for a soft coal seam that is prone to gas outburst. The numerical simulation suggests that the radius of the stress-relaxed range increases quickly when the equivalent borehole radius is small, and the rate slows when the borehole radius becomes large. Then the result was verified by a field experiment in Pingmei coalfield. The gas drainage flowrate and stress-relaxed range greatly increased after initially outputting 2 tons of coal from the borehole, whereas the second outputting 2 tons of coal did not appreciably increase the stress-relaxed range and the flowrate. Too much or too little coal discharge is not optimal, and the borehole radius is recommend to be between 0.3 m and 0.4 m after the hydraulic cutting considering the pros and cons in Pingmei coalfield. The results are helpful for the engineering application of the hydraulic cutting technology, for increasing coal seam permeability, and for stimulating gas production. The method for finding the optimal coal discharge in this paper is also helpful for other coal mines.

1.1 Background of the research 1.1.1 Brief classification of motor[1][2][3][4] Motor is a kind of electrical machine which converts electrical energy into mechanical one. With recent development and improvement, the structure of motor is usually made up of rotor part and stator part. By classification of driving strategy. There are two kinds of motor, DC motor and AC motor. (1). DC motor: The driving current of DC motor is directcurrent. The motor has a commutator. It causes sparks when DC motor runs with large current. To avoid this problem, brushless DC motor[1] has been invented. But both of them(DC motor and brushless DC motor) require a complicated DC power supply system, which causes power losses when electricity power is alternated. (2). AC motor: The driving signal of AC motor is sinusoidal current. This kind of motor usually has three-phase currents. Each phase current is apart from each other by 120 degrees in space. In AC motors, there are two popular ones, induction motor and synchronous motor. In induction motor, rotor speed lags behind stator speed. This is named slip, and slip is the reason why induction motor cannot achieve high efficiency. Synchronous can be divided by rotor structure as wound rotor synchronous motor and PMSM(permanent magnet synchronous motor). The paper targets PMSM as the controlled plant. The structure of PMSM is introduced in detail within Chapter 2. The mentioned motor classification is shown in Fig.1.1 1.1.2 PMSM speed control strategy PMSM speed control system is complicated. Compared with brush DC motor speed control system, it is more difficult for PMSM to achieve high accuracy, stability and fast response. Nowadays, researchers and engineers are focusing on improving these characteristics for PMSM speed control system. There are mainly three achievements.There are mainly three achievements. There are mainly three achievements.There are mainly three achievements. (1). VVVF (Variable voltage frequency) Control[5] VVVF control strategy is an early speed control method for AC motors, including PMSM.It was firstly proposed to achieve AC motor speed control because it is a constant when supply voltage divided by motor frequency, if the flux is not altered. (2). DTC(Direct Torque Control)[6] DTC control strategy is a loop control method for AC motors. It was first proposed by Dr. Depenbrock in 1985. This kind of control strategy get electrical driving torque by calculating stator flux. (3). FOC (Field Oriented Control) [7][8] FOC control strategy was proposed by Siemens engineer in 1970s. From that time, vector control for AC motor has been applied into motor speed control field. With Park and Clerk transformation, this control strategy has been greatly imporved. In this paper, this control strategy has been applied. And will be introduced in Chapter 2. 1.1.3 PMSM position sensorless speed control strategy Position sensorless speed control strategy for PMSM reduces the whole system cost and makes the system be possible to work in high dust environment. There are a lot of methods to achieve sensorless control.The methods are classified according to the motor speed. (1). High-speed position sensorless method [9][10][11] High-speed position sensorless control method usually uses voltage and current which contain Back-EMF signals to estimate the position and speed information. By these estimationmations, position sensorless control is achieved in high-speed region. (2). Low-speed position sensorless method [12][13] Low-speed position sensorless control method usually injects small amplitude high frequency signal in d-axis. If the motor has salient pole, a large induced voltage happens. With this saliency of PMSM,it can achieve low-speed position sensorless control. 1.2 Aims of the study This study aims at IPMSM position sensorless control in low speed range with EKF(Extended Kalman Filter) As our former method cannot achieve low-speed range position sensorless control. EKF can solve the problem above to some extend. To achieve better system characteristics,a d-axis current random signal injection method with EKF is proposed, which makes EKF be able to achieve better IPMSM position sensorless control in low speed -range. 1.3 Comparison with former study The former method is EEMF Observer. This method can achieve IPMSM position sensorless control above 300rpm. 300rpm is defined as the boundary between high and low-speed region. By using d-axis current random signal injection method with EKF, IPMSM can achieve low-speed range position sensorless control.The lowest controlled speed is 0 rpm. To improve robustness to load torque, noise balanced matrix Q of EKF is compensated. 1.4 Composition of the paper This paper is made up of the following 7 parts. Chapter 1 is the abstract. It includes background and aims of the study and comparison with former one. Chapter 2 introduces about basic characteristics of PMSM, which includes PMSM construction, mathematics dynamics and FOC strategy. Chapter 3 discusses about EEMF Observer for PMSM position sensorless control, which is the former study method. After analyzing, the weakness of EEMF Observer is pointed out. Chapter 4 introduces EKF(Extended Kalman Filter) for IPMSM. Addtionally, d-axis current random signal injection method with EKF will be discussed in this part. Chapter 5 shows simulation results to prove the aims of this study. Chapter 6 is the conclusions according to the discussion and simulation results. Then,the future plan is given., 三重大学大学院 工学研究科 博士前期課程 電気電子工学専攻 電気システム工学講座, 82p

In this paper, the approach and application of semi-blind source separation (SBSS) in aero-engine vibration signal is studied. Firstly, the features of aero-engine vibration signal and difficulties for blind source separation (BSS) are summarized, and the SBSS incorporated the available prior knowledge is match to the goal of signal processing. Then, the ICA with reference (ICA-R) algorithm based on classical FastICA is introduced, with Newton iteration and gradient descent iteration approach to obtain optimal solution. The unique parameters in ICA-R for aero-engine vibration signal are also provided. Finally, the efficacy and the accuracy of the ICA-R algorithm are verified by numerical simulations and real engine vibration signals. The approach of SBSS in this paper perfectly suited to handle aero-engine vibration source separation and it lead to efficient implementation in fault diagnosis.

In the case of compressors, frame vibrations cause significant noise problems. In former research, several solutions are presented based on additional sensors, such as accelerometers. However, since the use of sensors includes negative aspects such as high cost and more space, the research on additional sensorless skill is a hot point. In this paper, a novel sensorless anti-vibration system for PMSM-drive applications called Specific Component Reduction System (SCRS) is proposed. This system uses a novel controller called SCRC instead of repetitive controller. The stability of SCRS is analyzed. Experimental results show the effectiveness of the proposed system.

Regarding to the relative attitude and orbit of spacecraft formation flying, a nonlinear dynamic model of six degree of freedom coupled with attitude and orbits established, with the help of characteristic model, this paper mainly analyzes the factors of the spatial perturbation and multiple disturbance torques, a kind of intelligent adaptive controller is designed based on the combination of RBF neural network and the golden section adaptive control. Later, the simulation platform Jade is used to simulate and analyze the Multi-Agent system of spacecraft formation. The results show that the spacecraft formation can run along in the ideal orbit, the effect of the control system has good robustness, fault tolerance and intelligence.