Slotted waveguide array antenna has the advantages of compact structure,light weight, good performance and so on,and it is often used in airborne radar or missile borne radar.The ran-dom vibration is the main load form of radar and causes the antenna distorted,which affects the radiation gain.At present,the traditional process for calculating the effect of random vibration on the antenna gain is very complicated and consumes more computation time and memory.An e-quivalent method for calculating the effect of random vibration on the antenna gain was proposed by using the root mean square values of the distorted displacement response.It was assumed that the random vibration load was a stationary process of a normal distribution,and the average value of the load was zero.Multiple samples were generated based on the complete correlation between each node.Firstly,the root mean square values of the gains were obtained by the traditional method and the equivalent method.Then,the applicable condition of the equivalent method was deduced by Taylor expansion.Lastly,taking the broad-wall longitudinal slotted arrays in rectan-gular waveguides as an example,the validation of the presented approach was confirmed by using simulation and experiment,and the maximal calculation error was less than 0.1 dB.The study showed that the effect of random vibration on the gain of the antenna could be calculated quickly under certain conditions.This equivalent method greatly improves the computational efficiency and saves computation time.The result has great significance of engineering,and provides a ref-erence to antenna designers.

At present,effective methods to solve hydraulic support's linkage relationship among four connecting rod mechanism,top beam and column are still defected in the process of virtual simulation.In view of this,a seamless linkage method among hydraulic support components based on analytic method and virtual reality technology was put forward.Firstly,according to a certain type of hydraulic support,a 3D model had been established and repaired in the software of UG and key dimensions of attitude were calculated by using analytic method.Then in the virtual environment of Unity3d,a parent-child relationship was set up and a cooperative program was written by using C # language.Then motion state task and relationship based on finite state ma-chine and two interaction ways including GUI interface and virtual operation using virtual hand were established.Finally,the feasibility and effectiveness of the seamless linkage method are ver-ified by practical application and test,which provides theoretical support and application practice for the linkage simulation and 3D virtual reality monitoring and control of hydraulic support.

The numerical simulation analysis for the hydraulic performance of the conventional PDC bit bottom hole flow field has the disadvantages of high threshold,long time consuming and repeated workload.To solve the problems mentioned above,the bottom hole flow field analysis platform of PDC bit based on Web service was proposed.From top to bottom,the frame of the a-nalysis platform was divided into software interface layer,analysis service layer and result output layer.The analysis process of the bottom hole flow field of the drill bit achieving automation,pa-rameterization and integration was realized through the knowledge encapsulation technology on server side.Then the parametric flow field analysis template was packaged and managed by using the Web packaging technology,which realized the analysis of the bottom hole flow field of PDC bit based on Web Service on client-side.The example shows that analyzing the hydraulic perform-ance of PDC bit by the analysis platform can effectively reduce the using threshold of CFD soft -ware,improve the analysis efficiency of bottom flow field,save the manpower and material resources, and a standardized technical support for petroleum equipment enterprises can be provided.

Autonomous underwater vehicle (AUV), especially the revolving AUV, is an important tool in the sea floor exploration,ocean landform observation and marine military ocea-nography research,but the endurance has been a key issue to limit its completion of long distance and long hours.At present,the underwater docking device only can dock with AUV with the par-ticular size and has poor versatility.In order to solve the problem of providing energy supplement and data uploading/downloading for different sizes of revolving AUVs,the different underwater docking forms were introduced and a universal underwater docking device was designed on this basis.The device used the underwater lighting guidance to guide the positioning of AUV, through the shroud to guide the AUV navigation when AUV entered the docking device,and used the screw slide to clamp and fix AUV finally.The device could provide energy supplement and upload/download tasks for different sizes of revolving AUVs,and improve its endurance,da-ta collection capabilities and cruising range. The light guide and clamping device of the underwater docking device were tested in the pool,and the reliability and feasibility of the under-water docking device were verified.The device is simple,versatile,stable and reliable,in addi-tion,it has a certain reference for the overall design of the underwater docking device.

In order to improve the NVH (noise,vibration and harshness) performance and sound quality of fuel pumps,the pressure fluctuation control of the regenerative pumps for the fuel sys -tem is carried out.The pressure fluctuation characteristics of a regenerative pump were studied by the CFD numerical simulation and theoretical analyses.Two impellers with different degree of uneven blades were designed by the method of random blade distribution.An improved design method of the uneven blade distribution impeller was developed based on the CFD numerical sim -ulation and theoretical analyses.The noise test for the fuel pump of the pressure fluctuation con-trol scheme was conducted to verify the feasibility of the scheme.Results showed that the high-pitched noise disappeared in the high frequency and the NVH performance was improved for the fuel pump with uneven blade distribution impeller compared with even blade distribution impeller.Random uneven blade distribution impeller could significantly disperse the peak value of the blade passing frequency.With the degree of the uneven distribution blades increasing,the amplitudes of blade passing frequencies decreased more.Therefore,the use of random uneven blade distribution method helps to improve pressure fluctuation characteristics of the regenerative pump and to provide an important engineering value for the fuel pump NVH performance improvement.

In view of vibroseis vibrator's key problems of big disturbance and low signal-to-noise ratio in the engineering application and combined with reaction mass movement path tests,the dynamic behavior law of the reaction mass-piston rod was studied through theoretical calculation and numerical simulation.On this basis,vibrator disturbance control was studied and the vertical passageway vibrator was put forward.Then the simulation results were compared with the results of horizontal passageway,and the vertical passageway vibrator disturbance test verification was carried out.The results showed that the reaction mass was driven by the rotation torque around z axis and the piston rod was deformed,which resulted in a point movement path of the reaction mass being a space curve and increased the vibrator disturbance.Therefore,the key reason of large vibrator disturbance was the horizontal passageway.In addition,the rotation torque did not influence the reaction mass and the piston rod deformation was improved greatly in the vertical passageway, which could reduce the vibrator disturbance effectively. Consequently, it is suggested that adopting the vertical passageway in the design of vibrator,which is good for im-proving output signal quality and enhancing output signal resolution.

In order to study the feedback efficiency of driving motor for electric vehicle and test the feedback efficiency expediently,the PMSM (permanent magnet synchronous motor) energy feed-back system based on sliding mode control algorithm is proposed.It can control the input voltage and current to drive another motor with the same features to generate.Based on the theory of en-ergy feedback,the energy feedback simulation model for PMSM driving system was established, which consisted of the sliding mode and variable structure control block,the space vector block and the PMSM numerical simulation model.And then,the energy feedback simulation model for PMSM system was simulated and analyzed.The simulation results showed that the proposed en-ergy feedback method could obtain about 70% feedback efficiency.That's meant that the pro-posed energy feedback method was feasible.Then,the hardware-in-the-loop (HIL) test system with dSPACE controller for PMSM energy feedback was built.The proposed energy feedback method was verified by the hardware-in-the-loop (HIL) test system.The test results showed that the obtained feedback efficiency was 60% 80%.The test value was very close to the offline simu-lation value.Obviously, the test results not only verify the accuracy of energy feedback simulation model for PMSM,but also prove the feasibility of the energy feedback for the driving motor of electric vehicle.In addition,the proposed energy feedback method can provide more choices for current energy feedback mode.And,the hardware-in-the-loop test system also can provide some technology support for PMSM platform test and real-vehicle test research.

It is inevitable that there is clearance between the bolt and the hole of bolted joint plate on account of the need of assemble and manufacture errors.And the changes of clearance have some influence on the modal frequencies of the bolted joint plate.The influence mechanisms of bolt-hole clearance on the modal frequencies of a single lapped and single bolted joint plate system were investigated,and subsequently a dynamical design method for bolted joint plate system by changing the diameter of through-hole was proposed.Firstly,the finite element modeling method was proposed by using ABAQUS package and Python language.Thereafter,a dynamic finite ele-ment model of the bolted joint plate system with variable diameter of through-hole was set up. Then the relation of the bolt-hole clearance and the modal frequencies of bolted joint plate was analyzed in two kinds of boundary conditions,including one end fixed and both ends fixed.Under a typical vibrating frequency band,the dynamic design method of the bolted joint plate system by changing the diameter of through-hole was discussed in the end.Results indicated that when the diameter of the through-hole was 1.02-1.20 times of the bolt diameter,the influences of bolt-hole clearance on the modal frequencies of bolted joint plate could be negligible.However,when the diameter of through-hole was larger than 1.21 times of bolt diameter,the effects of bolt-hole clearance on the vibration modal frequencies were obvious and the modal frequencies were mutation.The research shows that the modal frequency of system can be changed by changing the bolt-hole clearance in the specific incentive environment,so as to avoid the structure resonance. The proposed method provides some reference for analyzing the influence of bolt-hole clearance on natural frequency of complex bolted joint system,and also provides an idea of anti-vibration fatigue design method for the bolted joint system.

The prediction of ultimate bearing capacity (UBC) on submarine layered foundations is a key point for the installation of offshore jack-up drilling platform.At present,the estimation of UBC of a layered foundation is mainly based on the empirical formulas for which the application scopes and limiting conditions are not clear.In order to evaluate the UBC of spudcan of jack-up on hard-soft clay foundations,the instalation of spudcan was modeled as a quasi-static process of gradully penetrating on a half-infinate elastic-plastic foundation.The soil was considered as an isotropic,elastic-plastic,Mohr-Coloumb material.The spudcan-soil interface was defined as a master-slave interface obeying Coloumb friction law.Non-linear numerical analysis on UBC of spudcan of jack-up platform on hard-soft clay foundations was carried out with finite element method (FEM) by using ABAQUS.The impacts of the strength ratio of overlying to underlying strata and the relative thickness of overlying clay on the UBC were analysed.The UBC data from FEM and the results calculated from the empirical formulas were compared.The results showed that when the relative thickness of overlying clay was fixed,the lower the strength ratio of over-lying to underlying strata S ut/Sub was,the larger the UBC of double-layered foundations would be.When H/B=1.0,the Brown and Meyerhof formula could be used to calculate the UBC only when S_ut/S_ub > 3 0..The scope of application of the method of projection area was 4.0 < S_ut/S_ub < 6.0.If the strength ratio was fixed,the larger the relative thickness of overlying clay was,the smaller influence of underlying soft soil on the UBC of double-layered foundations would be. When S_ut/S_ub > 3.0.,the Brown and Meyerhof formula and the method of projection area could be utilized to predict the UBC of double-layered foundations only when H/B < 1.0.The higher the strength ratio for overlying to underlying strata and the smaller the relative thickness of overlying stratum were,the greater the possibility for punch-through would be.These conclusions have certain instructional significance to engineering design of installation of spudcan.

Taking into account the problems of large error and poor stability because of the com-plicated force calculation of four-bar mechanism of coal hydraulic support,a method of particle swarm optimization is proposed to optimize the four-bar mechanism combined with the space force of the four-bar mechanism and movement trajectories.Firstly,the four-bar mechanism opti-mization model was established.Then,the parameters having greater impact on results were se-lected as the optimization variables in the optimization model, and the sum of trajectory deviation,connecting rod length and connecting rod force was taken as the objective function,and the constraints could be determined according to design specification of the hydraulic support. Lastly,the particle swarm optimization algorithm was used to solve the objective function and the penalty function method was used to solve the problems of inequality constraints in the optimization model.The purposes of lightweight,less force,high stability after the optimization of the four-bar mechanism were achieved by the comparison of rod length,stress and stability data be-fore and after optimization.The results indicate that the method has practical reference value for the design of the four-bar mechanism.

To solve path planning problems of accessing cars by AGV (automated guided vehicle) in the intelligent lift parking garage,the strategies of time-sharing use were utilized,and a path planning method of parking system based on dynamic time window was proposed through effec-tively combining Dijkstra algorithm and time window.First of all,the AGV having task was as-signed the priorities by the introduction of priority strategy.Then,according to the task priority order,Dijkstra algorithm was used to plan the shortest feasible path for the AGV having task. Finally,on the basis of feasible AGV's path,multiple AGV collision-free path planning was a-chieved by the method which contained time window initialization,time window real-time update and real-time arrangement.To test and verify the feasibility and effectiveness of path planning al-gorithm of parking system based on dynamic time window,the intelligent lift parking garage with four AGVs working at the same time was tested in the simulation experiment.The experi-mental results showed that the proposed method could solve some problems in the multiple AGV path planning,which included poor flexibility,easily arising deadlock conflict and collision con-flict,etc.Furthermore,the proposed method also could plan out a minimum-time optimal path for the AGV having task under the premise of effectively solving path conflicts.The results indi-cate that the method is correct,feasible and effective,and has a better robustness and flexible. Besides,it can effectively improve the overall operating efficiency of the intelligent parking system and reduce waiting time for accessing cars.

Aiming at some problems of high subjective dependence and long time consuming in the process of high speed dry hobbing process parameters decision, a low carbon optimization decision method for high speed dry hobbing process parameters based on case-based reasoning (CBR) and optimization algorithms was proposed.At the same time,it was a method to achieve the low carbon of the hobbing processing.At the beginning,a back propagation (BP) neural net-works model was established based on the cases of high speed hobbing process,which could pre-dict the machining effect evaluation of hobbing processing.In addition,an improved K-means al-gorithm was used to obtain the similarity example extraction set for target process problem,and several process solutions were obtained to construct process parameter constraints.Moreover,the flower pollination algorithm (FPA) was applied to search the optimal process parameters for tar -get process problems,which took the minimum carbon consumption of the hobbing processing as the optimization objective.A high speed dry hobbing machine in an enterprise was used as an in -stance to verify the feasibility and effectiveness of proposed method.The experimental results in-dicate that the proposed optimization method is a very useful tool for achieving lower energy consumption and better processing effect.The method can also effectively avoid relying on process manuals,personal experience or cutting experiments so as to improve decision efficiency.Moreo-ver,the results also show that it is conducive to achieve high performance and low carbon operation of high speed dry cutting hobbing machine,which can provide important reference value for ma-chinery manufacturing enterprises to achieve low carbon manufacturing.

In order to test and analyze shearer drum's load force in the process of cutting coal and rock,the equal proportion shearer experimental platform which was used to analyze mechanical properties was established,the change of shearer drum's load was monitored online by the test method of equivalent structure idler shaft sensor in the process of cutting coal and rock,and the transmission of the test data in real time was realized by using wireless signal transmitting device. The cutting experiment results showed that,in the process of cutting coal and rock for shearer, the peak value differences of load for drum in the three directions of x,y,z were 29.941,17.459 and 7.371 kN,and the load changed significantly.The test results conform to the actual field con-ditions and provide the important theoretical and numerical basis for realizing shearer's coal-rock dynamic identification and automatic height adjustment control.

A pulse recurrence system is designed to achieve tele pulse diagnosis.Aiming at slow re-sponse and complex control of the current pulse recurrence devices,a new type pulse recurrence device combined mechanical and hydraulic circuit was designed.Furthermore, this system included an intelligent pressure feedback module considering different pulse collection pressure and used adaptive inverse control algorithm to calibrate the recurrence error.Experiments were designed to compare the collected pulse and the recurrence pulse,then the correlation coefficient was calculated and t-test was did to obtain the mean value and variance of the two signal's charac-teristic parameters.The results showed that there was no significant difference between the pulse characteristic parameters of the replayed and the collected waveform,and the correlation coeffi-cient of two waveforms was greater than 0.91,which indicated they had a prominent correlation. Further more,three veteran Traditional Chinese Medicine doctors were invited to make blind tests on the system,and the accuracy was above 93%.The system can remotely replay the testees' pulse and can be applied in Traditional Chinese Medicine tele pulse diagnosis and education field.

In order to solve the problems of traditional soil limit moisture content detection,such as artificial site operation mode,long time consuming,data collection difficulties and poorly in data transport on real-time,an automatic detection device for soil limit moisture content was de-signed.The device adopted SIEMENS S7-200PLC as the control core, and the hardware comprised conveyor belt,cube container,stirring device,electronic scales,smooth system,cone penetrometer and heating box,and real time data was monitored by using MCGS configuration software on the host computer,and it used the sampling drying method to measure moisture content and took liquid-plastic limit combined measurement to measure liquid-plastic index.In practical applica-tion,the system could complete automatic mixing,simultaneous determination of multiple sets of data and real-time data transfer.The classification of soil and estimation of bearing capacity of foundation soil were achieved by using moisture content and liquid-plastic index.The device has advantages of high degree of automation,simple and easy operation and low cost,which can be widely applied to determination of limit moisture content for various soils and has a certain reference value for the design and implementation of agricultural engineering.

In order to improve the interrupting capacity of MCCB (molded case circuit breaker), the arc chamber of MCCB is optimized.Based on the theoretical study of the arc breaking process,three methods were used to improve the arc voltage.Firstly,the structures of arc plates were optimized,the pattern of the first piece's guide,the last piece's obstruction and the middle pieces' normal arrangement was used to achieve a good effect of arc cutting.Secondly,the mag-netic flux structure of slot motor was added,the speed of arc could be increased by increasing the intensity of magnetic field,the results of ANSYS simulation showed that the new structure in-creased 97 N magnetic blow force.Thirdly,air blowing structure was added,the voltage drop of arc column was increased by reducing the temperature of arc column,and PA66 was used as the gassing insert which had the fast recovery rate of medium.The methods were combined to get the optimized design scheme and to make the prototype sample to do short circuit interrupting test under the condition of 25℃ & 415 V AC voltage.Originally,it could only pass 50 kA,after op-timization it could pass 70 kA and the arcing time was shortened from 5 ms to 3 ms at the same time.It could be found that some of the products appeared arc chamber shell cracked issue after disassembling these samples,so the wall thickness of the crack position was increased 2 mm,the static analysis module of ANSYS was used to compare the equivalent stress of the shell before and after the change.The results showed that the new structure improved the strength of 40.2%, and it passed the engineering test after the new prototype samples were assembled again.The re-searching achievement has a certain significance for the follow -up new development and design improve-ment of MCCB products.