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Bearings are one of the most important components in rotating machineries. Their failures will lead to great production loss and increase the maintenance cost. So, condition monitoring work of bearings can save and avoid the potential loss caused by bearing fault. Lucy-Richardson deconvolution (LRD) algorithm, as an image processing technique, started to be used in bearing fault diagnosis. However, only data of bearings working in electric motor are used to validate the method. In engineering cases, most bearings are working in gearbox. Therefore, the bearing fault signals are very weak compared to the gear vibration signal. It is usually difficult to detect the bearing fault in this case. LRD algorithm is used to enhance the bearing fault diagnosis and some characteristics in this case are discussed. Experiment data analysis demonstrates that LRD can enhance the periodic impulse signal effectively. Otherwise, if the desired fault signal is weak compared to non-desired signal, then, the desired fault signal will be continued weaken by LRD which is not benefit to bearing’s incipient fault detection.

This paper studies the global stabilization problem for a class of high-order nonlinear systems with low-order and high-order nonlinearities, and multiple time-varying delays. Systems become more general due to both low-order and high-order in nonlinearities taking values in certain intervals. By introducing a novel Lyapunov–Krasovskii functional, a state feedback controller based on the Lyapunov–Krasviskii theorem together with the adding a power integrator and sign function methods is designed to guarantee the globally uniformly asymptotic stability of the closed-loop system. [ABSTRACT FROM AUTHOR]

This paper, using the finite element software ABAQUS, establishes the model of laser shock peening (LSP) of TC4 titanium alloy, and analyzes the influence of different parameters on the residual stress of TC4 titanium alloy and plastic deformation. The results show that LSP can make the surface of TC4 titanium alloy have large compressive stress and plastic deformation, hardness and prolong the fatigue life of materials. Laser energy and the impact frequency are the main factor of surface residual stress effects. The multi-point LSP can perform processing enhanced in surface area, and form residual compressive stress on the surface of the material and in a certain depth.

Construction machinery hydraulic cylinder is usually discarded after service cycle. The residual value of discarded products can be recycled greatly by remanufacturing. Disassembly and assembly is the key process in hydraulic cylinder remanufacturing. The construction machinery hydraulic cylinder disassembly and assembly equipment is developed. Hydraulic power is adopted in this equipment. The clamping, positioning of cylinder tube is realized by hydraulic clamping mechanism automatically. The piston component pulling out or into cylinder tube is realized by hydraulic working mechanism automatically. This equipment has been applied successfully in the project of "key technology and equipment for construction machinery parts remanufacturing" in a research institute. The results indicate that the application of this equipment will not only increase the automaticity and efficiency remarkably, but also reduce the damage to hydraulic cylinder key part greatly.

Communication module design is one of the key technologies in offshore drilling platform cleaning robot, through overall design and analysis of communication systems, the communication module is selected and technology roadmap is analyzed. thus communication module hardware architecture (PC, PLC and multi-sensor ) is designed, multi-sensor (Sonar, infrared, camera, SINS, pressure sensors and fiber optic gyrocompass) underwater monitor is designed and selected, the system software is programmed (PC configuration software, PLC software and communication protocol software); Finally, control structure and running track is designed. The research ensures the operation accurately and improves the cleaning efficiency.

Wind power becomes one of the most important cleaner energy in the world. The maintenance problem becomes the main factor preventing the appropriate power price which can be accepted by people. So, many researches contribute to improve the availability of wind farms. Traditionally, most researchers paid attention to the fault diagnosis, prognosis and maintenance strategies optimization to short the down time and the maintenance cost. But they all neglect the condition monitoring work of repaired gearbox of wind turbine before it is delivered to the customer from maintenance center to the wind farm. The life of repaired gearbox is also a very critical factor which influences the availability of wind farm. Good checking methods and good standard can provide a good support of good performance after the gearbox installed on the up tower. So, this paper proposed how to address these issues.

Many research papers implemented fault diagnosis and prognosis when there are many history data. However, for some capital and high reliability equipment, it is very difficult to acquire some run-to-failure data. In this case, the fault diagnosis and prognosis become very hard. In order to address this issue, continuous hidden Markov model (CHMM) is used to track the degradation process in this paper. With the degradation, the log-likelihood which is the output of CHMM will decrease gradually. Therefore, this indicator can be used to evaluate the health condition of monitored equipment. Finally, bearing run-to-failure data sets are used to validate the model’s effectiveness

Aiming at the inherent deficiencies of large-scale wireless sensor network for positioning technology, the DV-hop algorithm is mainly studied and improved, and two kinds of improved algorithms DV-hop and DV-hop+Lastdist DV-hop-MinMax are proposed, and can select the appropriate algorithm according to actual application environment. Finally, the paper gives the method to realize OMNeT + + in the simulation environment, and carries out the simulation analysis.

Adopting the control idea of configuration, based on the PROFIBUS field bus, and combined with the advantages of PLC and DCS, this paper puts forward a set of new design scheme of field bus control system. With the development of fieldbus technology and intelligent equipment, after simple modification, the system on-site can be realized all real distributed control system (FCS). The system is easy to expend, and has good portability and strong practical value.

The micro inertial sensor parts (gyroscope and accelerometer) measurement error is the main factors to influence the accuracy of the inertial navigation system, in order to improve the navigation precision of SINS (strap-down inertial navigation system), we must reduce inertial sensor measurement error. Based on the error analysis of the inertial measurement device, with accelerometer attitude computation information as gyro attitude computation information reference quantity, established the algorithm of the attitude angle. In the sensor output signal pretreatment technology, this paper mainly introduced the use of surface fitting technology, to establish the error compensation surface equation, and gives the mathematical derivation of calculation error model parameter, the experiment got a good compensation effect.

For the inherent deficiencies of fieldbus control system, the thesis is designed and implemented a kind of embedded network controller with AT91RM9200 which is a 32bits microprocessor, multiple Ethernet interfaces and field bus interface for embedded network controller, the establishment of a Windows CE-based embedded software development platform. Embedded Network Controller to the CNC system, CAN bus and DSP by matching the system to improve timeliness and reliability, a remote distributed measurement and control and communication purposes.

ALOHA algorithm can’t prevent collision much effectively, the process of anti-collision is longer while the amount of tags plunged collision is numerous, and sometimes the problem about estimating mistakenly arises. Binary search algorithm, which identification efficiency is higher, the problem about estimating mistakenly can’t arise, but its delay tima is more longer, security is short. The amelioration algorithm, return binary search algorithm can identify tag more effectively and rapidly, identifying time and the amount of tags is the relation of line form. The significance is very momentous that vast goods are identified, traced and managed by this amelioration algorithm.

800x600 Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} A new quadrilateral arrangements for landmark Multi Dimensional Scaling (LMDS) is proposed in this paper. The proposed strategy for choosing the landmark points improved the accuracy which was the main flaw of LMDS. After employing this arrangement, the improved quadrilateral landmarks MDS (QLMDS) preserves the computational efficiency of LMDS and uses quadrilateral arrangement of landmark points to obtain a higher accuracy. To compare the accuracy and computational efficiency of QLMDS with classical Multi Dimensional Scaling (CMDS) and then the accuracy of QLMDS with LMDS, several simulations are presented. The results, apparently, show that QLMDS is as fast as LMDS, but with a higher accuracy which makes it a better choice than CMDS and LMDS.