In order to overcome the shortage of describing the fault states of system and components with existing membership functions, a membership function with fuzzy support radius variable is constructed to describe the fault states and a failure probability calculation method of multistate system based on Bayesian network with variable fuzzy support radius is proposed. The variable was introduced to describe fuzzy support radius of membership function and used to construct the membership function. Introducing the established membership function with variable into Bayesian network, the leaf node failure probability curve was obtained by analyzing the failure probability of leaf nodes on the multistate system using bucket elimination method. The proposed method was compared with Bayesian network method based on membership function with constant fuzzy support radius to verify the validity and generality of the method. Finally, the method was applied to analyze the CNC machine tool spindle system, and calculated the leaf node failure probability. The results show that the method can solve the subjectivity of fault states membership function selection in multistate system effectively.

If belt guide digital printing machine faults, the production schedule will be slowed down and the grey cloth will failure to print which result in the enterprise property losses. In order to reduce the machine fault rate and the property losses，aimed at all kinds of possible faults of the highspeed belt guide digital inkjet printing machine，the fault mode，effect and criticality analysis method was applied to analyze the machine’s reliability. The weak links were found out including the conduction band transmission device，inkjet printer，nozzle cleaning device. The list of the fault modes，effects and criticality of the machine(the list of FMECA) was established. The routine maintenance and repairing suggestions for the highspeed belt guide digital inkjet printing machine was proposed based on the FMECA list and to the more critical fault modes. The work can be used as a reference in enterprise to make repair and maintenance strategy of the machine and can provide basis for the reliability design of the machine.

To improve the adaptability and response speed of the underwater friction stitch welding machine for repairing pipe like ocean structures, the adaptable design method is introduced into the design process of friction stitch welding machine. According to the characteristics of function changes on mechanical products, the function structure diagram was extended to show the adaptability of the adaptable product based on the requirement analysis and function analysis. The basic platform, function modules and interfaces were defined combining with the idea of openarchitecture design, so that users could configure modules according to their requirements. A setbased method of adaptability evaluation was developed to evaluate design quality. The underwater friction stitch welding machine was studied which indicated that this method performs well in practicability and operability and could be used in the practice of product design and development.

The relationship between the resonance frequency and the size of the structure is multiparameter and nonlinear, which makes it difficult to establish accurate model when design of a rectangular microstrip antenna. To solve this problem, a new way of RBF (radial basis function) neural network algorithm was proposed by combination the methods of dynamic adaptive clustering and the pseudo inverse weighting, which possessed several advantages of unfixed neuron number on hidden layer, by means of adaptive adjustment, good approximation effect, and small amount of calculation, fast learning. Then combined with the better approximation properties of RBF neural network for multivariable and nonlinear functions , it was used for modeling the resonance frequency of the rectangular micro-strip antenna. Experiment results showed that the established neural network model was obviously superior to the result of literature in both accuracy and speed. Thus a new effective method to improve the design efficiency is provided for the developer of antenna design.

In order to accurately describe the mechanical properties of a flexure hinge, a general mechanical model based on finite element method is proposed, and the static and dynamic performance analysis is carried out according to the propose model. Euler-Bernoulli beam was adopted to simulate the mechanical behavior of the flexure hinge, and it was divided into three nodes with three degrees of freedom and two elements with variable crosssection. A closed stiffness matrix related to the structural parameters of the flexure hinge was established by using the principle of minimizing potential energy, and the mass matrix and dynamics equations were built by employing Lagrange equation. In order to validate the precision of the proposed mechanical model, the analysis results by ANSYS was compared and got the difference range from 1.1% to 5.6%, which showed that the theoretical model was close to ANSYS and the proposed model could accurately illustrate the static and dynamic properties. The finite element model of the flexure hinge can be applied accurately to analyze the relationship between its accuracy and natural frequency and structural parameters, stress distributions and frequency response. Therefore, a precise mechanical model of the circular flexure hinge is provided for the design of compliant mechanisms.

In order to explore mechanical characteristics of roadheader working mechanism for impacting and crushing rock under typical conditions, then to find the weak link and to provide the basis for improvement, a three-dimensional solid model of the working mechanism was established by means of Pro/E and a mechanical model of crushing rock of the impact hammer was exported, a penetrable force of crushing rock was obtained according to the stress wave theory and assembly language of Matlab. The process of two drill rods crushing from nonsynchronous to synchronous was analyzed by using ANSYS when the working mechanism impacted on the top right corner of a tunnel. The research showed that the stress difference of two drill rods, the torque and torsional deformation of working mechanism decreased gradually to the same during the process. The stress concentration appeared on the hinge of swing bearing, boom and liftingswinging cylinder, also on the hinge spot of the rocker arm, boom and boomcylinder. The swing bearing was the weakness of the working mechanism, and the maximum deformation happened on the head of hammer. The offset loads leaded to the obvious deformation of drill bit, and the dangerous zone of boom stress located on the offset load side, which had a great influence on the mechanical properties of the mechanism.

The neutral layer offset was discussed in order to improve the precision of straightening force. After analyzing the 3-D elastic-plastic deformation of straightening piece, the neutral layer offset theory was presented. The dynamic change rule of neutral layer offset was obtained by numerical simulation and experiment which illustrated that neutral layer offset was an important factor to influence the straightening precise and provided the theory base and data to establish more precise straightening force model.

The boom structure is a key component of boom cranes, and the stability-ensured topology optimization is critical to its lightweight design. The sensitivity-based methods are not applicable for topology optimization of large-scale structures since they are labor-intensive and time-consuming. The quantitative indices of global stability and compression member stability for boom structures were defined. The anti-buckling mechanism of boom structures was analyzed to get the freezing order of associated web members. A novel SSKO (stability-ensured soft kill option) method was proposed, which was a topology optimization method for boom structures on the basis of the SKO (soft kill option) method for bars structures. This method was applied to topology optimization of a frame and a ring crane boom to demonstrate that it could achieve stable topologies with high efficiency.

Same zeroes and poles located at different locations of the root locus plane will exhibit different dynamic performance, which shows that the system performance has nothing to do with the zeroes or poles themselves and is completely determined by their location. The relationship between root locus coordinates and dynamic performance indices were established beginning with the root locus plane in classical control theory and then with the aid of the “field theory” concept in mathematical analysis, which took the positioning accuracy and stability as the descriptive quantities of the system's dynamic performance. Through drawing the equioscillation and equiprecision curves in the root locus plane, the system dynamic performance space was built up. The real pole, complex conjugate zero, and complex conjugate pole of the sixthorder linear tracking system were globally optimized by using this dynamic performance space. Sensitivity, complementary sensitivity, and dynamic response results showed that the optimal control method can solve the discrepancy between system accuracy and positioning time delay, and meet the exact track requirements with an effect much better than that of a PID controller.

In order to meet the different controllable requirements of a new type of series-parallel hybrid transmission on the working states of its hydraulic system under different driving modes, a control strategy of hydraulic system working states and valve working states was designed based on the structures of this new type of series-parallel hybrid transmission and its hydraulic system. Through the establishment of Simulink control model in combined with rapid control prototyping technology and vehicle drum test, the correctness and reliability of the control strategy was verified. The test results showed that the control strategy could match various vehicle driving modes well and meet the control requirements of the transmission on its hydraulic system.

Based on the mechatronics technology, a kind of remotely controlled three-dimensional combination lock has been designed, which has mechanical and electronic double security password. Firstly, the structure and working principle of the combination lock was introduced focusing on the principle about threedimensional motion of the mechanical structure and the electronic control system of remote control. Then, based on the theory of structural mechanics, examination on the major motion mechanism of the mechanical structure in terms of strength was performed. Finally, the rotation accuracy of disks, password replacement and remote control reliability and other aspects of the three locks had been repeatedly verified. The verification proved the safety, reliability and practicality of the structure. The combination lock adopts remote controlled mechanical transmission mechanism with three-dimensional motion, which not only achieves the combination of mechanical and electronic usage to improve their security, but also eliminates the possibility of cracking passwords through the sound or feeling. The lock enjoys advantages of easy operation, safety and reliability and can satisfy the needs of future market.

Different scale effects on shear strength of rock mass discontinuity need to be tested by a special direct-shear apparatus to get stable mechanical shear strength parameters. To ensure the reliability of test data, the precision of apparatus should reach 1% when the load is range from 2 kN to 1 000 kN. Due to the limitations of existing technical for testing system,  the loads can not all be tested in a same apparatus. For this reason, a new integrative direct-shear apparatus was developed by three level direct-shear devices based on load classification method. Each level of device had  overlapped load zones to ensure the continuity of test results. The precision and load range of this integrative direct-shear apparatus had been tested and met the testing requirement of the multi-scale specimen. The integrative direct-shear apparatus has provided a platform to research shear strength of multi-scale rock masses.

Aiming at the locking equipment in the MW-level wind turbine and focusing on the shrink disk, an improved design method was carried out to overcome the shortage of traditional design method on the purpose of mechanical reliability and economy. Meanwhile, the effects of parameters include frictional coefficient, fit clearance and environmental temperature were analyzed. It was showed that the improved method got higher accurate data which was more close to the results of FEM simulation. The frictional coefficient of contact surface was critical whose value was recommended to range from 0.085 to 0.091. The equivalence of elasticity modulus was adopted to calculate the interference in the design process. The pressure wastage of contact surface for different fit clearance was quite large which could reach 50 MPa. The contact pressure declined as the environmental temperature rose.

Network control system is a key role for mechanical and electrical integration manufacture. Pre-calculation of the transmission delay between slaves is the basis to realize the clock synchronization of slaves in network control system. There are two types of physical layer interface on EtherCAT slave, MII (media independent interface) and EBUS. According to the type and the transmission direction of data frame, the transmission delay between slaves was analyzed. Aimed at the experiment system, the transmission delay between slaves was calculated and measured. By comparing the theoretical calculation value and the experimental test value, the correctness of the theoretical analysis was verified. Theoretical basis was provided in building actual system for matching the slaves according to the actual need, reducing the transmission delay between slaves and enhancing the real time ability of control system.

Traffic sign detection is a key factor affecting the speed and accuracy of traffic sign automatic recognition. Fixed threshold segmentation result was easily influenced by external factors such as change of light, so an adaptive threshold segmentation method based on HSI color space was firstly used to overcome the drawback. Then regions except some nonsign regions was labeled, regions with multiple connected signs was segmented and candidate regions were extracted. Lastly, the prohibition signs regions were determined through the analysis of the circle similarity parameter of external edges in the candidate regions. High robustness is demonstrated by simulation experiment under complex road environment.