Multidisciplinary Design Optimization (MDO) is the lastest and most active field of complex system design at present, which draws more and more attention from industry and research institutes. After explaining the definition of MDO, the research content of MDO technology is analyzed and the status abroad is summarized. And then comparison between the research situations domestic and abroad is carried out. Finally, the existing problems and the developing trend in the future in MDO are proposed.

Aiming at many coupled problems in product design based on axiomatic design, both axiomatic design and TRIZ are synthetically applied. A general decoupling method in axiomatic design by using the contradiction matrix of TRIZ is proposed and the process of the decoupling design was illustrated by the decoupling problem of the pile driving machine.

Taking process requirements into account, all design variables are considered as discrete ones including general discrete variables and dummy discrete variables. Further research of the design principle to generate functions in these two situations is carried out, which solves the key technical problem to apply SA algorithm in discrete variable function optimization. Then a new method of discrete variables function optimization based on SA algorithm is proposed.  in planetary gear transmission, the number of gear teeth is constrained by transmission by transmission ratio, matching requirements and coaxial requirements. The module of gear can also select some discrete values due to the limits of national standard. The above leads to bad results through classical constraint optimization method based on mathematics planning theory. However, discrete variable optimization design method of SA can easily obtain optimum scheme which satisfiesall requirements.

About 80%-90% failure of submersible pump is caused by failure of mechanical seals and bearings. Besides，other faults of submersible pump will usually increase electrical current of motor. According to this actual situation andprinciple, the authors figure out a detection method to judge the failure of submersible pump through detection of failure in mechanical seal and bearing, and whether fluctuation of electrical current is beyond standard. Because the leakage of mechanical seals are mainly due to excessive wear of the end face, and poor lubrication of bearings will lead to a early wear and then causes vibration on the pump,the authors developed the method on judging the failure of mechanical seals andbearingsby detecting water percentage of mechanical seals and acceleration of the pump’s vibration. The authors developed a failure detecting system of submersible pump, identified and verified the corresponding failure criterion through test.

The overall design idea of fault prognostics system for hydraulic components in missile launcher was presented. The monitoring target is determined, and then fault characteristic signal was selected, and finally fault characteristic parameter was abstracted from fault characteristic signal. The system hardware and software platform are respectively DAQ system and LabVIEW 8.0. Fault prognostics for hydraulic components in launcher were carried out by adopting support vector machine.

A new method using piezoelectric material (PZT) and artificial neural network control was put forward to repair in time by online monitoring the health state of cable suspension bridge. This method conducted online analysis and intelligent diagnosis on stress and stain of the mentioned bridge, which adopted the principle that when PZT had distortion, the voltage and intensity of electric field would change, to collect information and the improved ANN control. A great deal of data was obtained from experiments, and then the parameters of BP ANN were optimized, which demonstrated the feasibility and advancement of this method.

By combining graphic method with computing method, CAD method for design of profile of formed grinding wheel was presented based on mesh principle and the idea of reverse engineering. By making a series of cross-section perpendicular to the axial line of the formed grinding wheel, contact points between the grinding wheel and the helical flute of the milling cutter were obtained. After connecting those points, the contact line was gained and then after rotating this line by 360° around the axis of the grinding wheel, the profile shape is formed. This CAD method is simple and direct with accurate result. Finally, this method was illustrated in details in the forming grinding of helical flute of a rose cutter. This method can be applied to design of the profile of tools with any form manufactured by generating principle.

By taking micro-feed mechanism of high-speed roller grinding machine as the object, the overall finite element model was established. In the above model, the finite element model of components was established in HYPERMESH, and spring-damper element COMBIN14 in ANSYS was adopted to build the dynamic models of each joint. Furthermore, modal analysis and harmonic response analysis were carried out and the first ten frequencies and mode shapes were obtained. The weak points of micro-feed mechanism were identified, which provided evidence for theoptimization design of this structure.

By adopting elastic mechanics finite element method, the performance of surpassing clutch with multiple roll bodies contacting type is proposed. The performance of self-locking and contact strength in the roll body and races of the surpassing clutch are analyzed. Then the mathematical model to analyze friction and strength performance of this clutch is set up. Through computational analysis of illustration, this method is proved to be valid. Numerical analysis discloses the internal relationship between clutch structure, contact state and load, load-bearing performance and strength. Furthermore, a new method to compute friction self-locking condition and friction interval is put forward, which provides theoretic foundation for design and application of surpassing clutch with roll bodies.

The adjustable damp oil-air shock absorber is crucial for the ride comfort of pit motorcycle. The 5 DOF (degree of freedom) dynamic model of vehicle and the mathematic model of road spectrum were established, based on which simulation of the ride comfort of pit motorcycle was carried out. The results show that parameters of suspension stiffness and damping matching the running characteristics can improve the ride comfort by making the energy peak value away from passengers’ sensitive frequency and keeping the vibration acceleration at a low level on sensitive frequency. This simulation program provides references for selection of shock absorber and speed up the development of vehicle.

According to the situation that control and management of flood has many influential factors, wide range, great difficulty in engineering, complex landform and incomplete information in Taizhou-Wenzhou-Huangyan Plain, a new method based on fuzzy classification of data mining is proposed. It solved the control problem by maximally using finite historical data to abstract the input and output and establish its model with the records of the river levels and rain falls. The proposed algorithm has effective performance on real-time control of the main flood gates in Taizhou-Wenzhou-Huangyan Plain. The practicality and feasibility of the project have also been proved.

The fuel pressure control system for diesel engine should have high accuracy and quick response, but the traditional method is insufficient to fulfill its increasing requirement. So an improved fuzzy control method with Heterogeneous Distribution Membership Function was adopted to control the fuel systemquickly and accurately. Moreover, simulation of the control of fluctuation in fuel pressure of diesel engine was done to demonstrate its validity and feasibility. The simulation result indicates that this method can reduced the pressure amplitude from 1 MPa to 0.7 MPa and shorten the fluctuation time from 8 ms to 5 ms. Therefore, this method can improve both the pressure amplitude and fluctuationand is an intelligent method with wide application prospect.

In practical situation, self-adaptive control is hard to realize, andtherefore accurate adaptive control is few. Taking electric heating stove as the experimental object, during the process of implementing PID control of the temperature of electrical heating stove and ultimately reaching a stable state, a closed-loop recognition strategy for real-time recognizing the model parameterswas adopted, and then the PID parameters based on the recognition results were adjusted simultaneously to realize self-adaptive control. The running result indicates that effect of this strategy is better than that of other normal PID control. For practical self-adaptive control, the strategy proposed has a certain practical reference value.

According to the systematic process, characteristics and control requirements of water treatment process were analyzed. The configuration of softwareand hardware of the control system were properly conducted by adopting SiemensS7-200 PLC. With the powerful logical control ability and numerous inner timers, the application of PLC realized time control of water filtering, forward-washing and back-washing, and complicated chain control of pumps, motors and valves, by which the control system is guaranteed to perform safely and smoothly and a good effect is achieved in practice.

The detection of cells edges is the base of cells conformation analysis whose result has a direct effect on the analysis of illness state and diagnostic result. Traditional edge-detection factors were badly influenced by noises and cannot detect the edges of cells reliably. Therefore, the traditional ones isnot suitable for confirmation analysis. A new accurate edge detection method obtaining the best threshold of image segmentation based on iterative arithmetic and abstracting edge by eroded arithmetic of math morphologic is proposed and simulation illustration is provided. By comparing this edge detection factor with Gauss-Laplace-arithmetic factor, and Sobel arithmetic factor, this algorithm has high accuracy and strong ability to resist interference.

To systematically study the effect of appearance factors of machine tool panel on operation efficiency, design principle related to operation efficiency has been put forward based on theory of cognitive psychics and ergonomics. The principle has been applied to reformative design of the panel in DK series electricity spark numerical control incision machine. Reformative scheme is obtained with the reformation from single factors such as color, the position, shape, size and sign of button and synthesis of all the factors. Different degree of influence generated by every factor has been analyzed by forecasting and experimental method qualitatively and quantitatively, which has proved that the reformative design from the 5 factors above improved the efficiency; moreover, reformative design from synthesis of all the factors has achieved the best result and appearance. So it can be concluded as: “good looking is easy to use!”

Architecture design is the key phase for developer investing. According to domestic specifications of architecture design and requirement of law, in virtue of Game theory, optimization of architecture scheme design quality under designers' different attitudes is analyzed. By adopting diagram method, the process of the Game between sponsor and designer is illustrated and then strategy tooptimize the architecture design scheme is proposed to achieve the optimal design scheme.

Aircraft and aerospace industry as well as medical and automotive engineering continuously require to develop smaller and lighter system components. Therefore it is not only important to be able to produce micro parts but also toprovide properties for dimension and design. However, the properties known fromthe macro range can not be assigned offhand to the micro range. The miniaturization in geometry causes deviant production conditions of injection moulding process and consequently changes inner characteristics, which in turn induces different mechanical properties.