Generation of maintainability design requirements is an important maintainability work. However there is no logical process supporting this work at present. According to product design & development process, the paper put forward an integrative generating process for maintainability design requirements based on system engineering process. The process was composed of three tasks, namely generating maintenance concept, definition and allocation for maintainability indexes and generating maintainability design requirements. Each task process was described in details．

So far, the problem of processing plan decisions still cannot be completely solved in CAPP. Firstly, based on proposing the definitions of Petri net systems and T_ invariants, a fuzzy rulebased Petri net model for part surface processing was presented according to the principle of Petri net and production rules. Then, a new selective processing plan was proposed in light of Petri net T_ invariants under manufacturing constraints. Finally, a real case was utilized to demonstrate the validity of the proposed method. The result shows that the best/hypo-best processing plans for part surface processing can be achieved．

The process of product collaborative development (PCD) is hierarchical, distributed, discrete and dynamic and how to build an effective PCD process model by a reasonable means has become a fundamental condition for PCD process management and optimization. Colored Petri net (CPN) technology was introduced into the process modeling of PCD, and the descriptive definition of CPN model about PCD's process was proposed firstly. Aiming at the characteristics of PCD, the basic CPN model structure to support the description of the basic process logics based on the workflow primitives was defined. And then in order to describe the complex collaborative relations, the modeling method for extendable CPN model structures based on the modular approach and the features of “place” & “transition” was presented. The mapping between the PCD process relations and the corresponding CPN from basic to complex was realized. Finally, its validity was demonstrated by an instance．

To resolve the conflicts in sewing equipment development, and based on rough set, the conflict resolution algorithm was presented, and attribute importance was used as evaluating information to calculate the similarity in conflict resolution process. And then concrete implementation steps for the algorithm were described in detail. Finally, the conflict resolution system was developed, and the intelligent process of conflict resolution of sewing equipment product development can be carried out based on knowledge. With the platform, rapid design of sewing equipment is maintained efficiently．

In order to facilitate the design of control system and mechanical weightmatching, research on the non-equilibrium load feature of imaging scanning systems was carried out. Beginning with the design of the cam, the operating modes of the camera was briefly introduced, and the conclusion that when the camera operated in the position-angle-extension mode, the gravitation of the cam and follower would be projected on the plane of cam scanning was drawn. Academic analysis was done to the non-equilibrium load feature of image scanning systems. Based on the analysis of the motor model, one method to test the load torque through the open-response was induced, and the root of the error was analyzed. The academic analysis shows that when camera positionangle equals to zero, the inertial force of the follower causes the non-equilibrium of motor load torque and the load torque is directionally proportional to the motor rotating speed. Otherwise, the projected part of the gravitation of the cam and follower on the cam scanning plane would affect the load torque. The load torque is also directionally proportional to the position-angle. The research would provide academic reference for the design of the control system and mechanical weight-matching．

Vehicle vibration influences human riding comfort directly. In order to evaluate human riding comfort (HRC) of human-vehicle systems in vibration environment efficiently, a biomechanical simulation model of human-vehicle systems was constructed in the ADAMS/View and LifeMOD. By simulating road roughness and inputting the road surfaces as a vibration excitation to human-vehicle systems, the simulation research on HRC was carried out on different roads and at various speeds. Then the human vibration experiments were done on the SA30-S802/ST random vibration table to verify the results of the simulations. Through comparison, it was concluded that the simulation result agreed with the experimental data generally, which verifies the correctness of the biomechanical simulation model of human-vehicle systems and reliability of simulation on HRC to some degree. The research has certain reference value for rapidly evaluating HRC of human-vehicle systems and provides efficient methods to forecast and evaluate HRC at the stage of vehicle design．

In hard disk drive systems, the thickness of air films between the rear of magnetic heads and the disk is the thinnest. So the air film pressure acted on local structures is very large, whose magnitude and distribution have an important effect on the flying stability of magnetic heads. The load-carrying performance of air films is greatly improved by optimizing the local structure of the rear of magnetic heads. Finally, a negative pressure magnetic head was designed by the proposed method. The numerical and experimental results show that the flying height of the proposed magnetic head is improved significantly.

The bad working condition and complexity of workload of shearer lead to the big risk and cost for the experiment based on prototypes. While the adoption of virtual prototyping technology for modeling and simulating can achieve a comprehensive assessment before the physical prototype is available, and gain a system-level optimized product. The rigid-flexible coupled virtual prototype model of shearer cutting units was established, and analysis on the steps including modeling with Pro/E, simulating load with MATLAB, producing modal neutral file with ANSYS and setting simulation parameter in ADAMS was carried out. It greatly enhanced the operational skills of multi-domains modeling and simulation based on Pro/E, ANSYS, ADAMS and MATLAB, and it has great reference value for the research on the multi-body system working reliability．

Aiming at the problems that the number of single-mode fault of components is too large, the work of circuit fault simulation is huge and it is hard to implement in engineering, the FEMA analysis technology was adopted in circuit fault analysis. This method can obtain the fault mode which may happen with the biggest probability and may destroy the system most heavily. Moreover, the component that influences this fault mode most can be obtained too. Through this, purposeful simulations can be carried out to reduce the times of setting faults and the workload of simulations. The proposed method is applied to a certain frequency selecting circuit, and numerical result demonstrates its validity and correctness.

Internet is of positive significance for blind people. Recently, research on haptic technology drew great attraction as an assistant means to access internet. The principle of haptic technology was presented and then by comparing to screen readers, its advantages and developing necessity were proposed. According to category of haptic feedback, the current situation and characteristics of assistant haptic technology were summarized combining with its limits and prospect.

A product design rendering is a fast, visualized and effective expression and an important link to transform an intangible originality into a visualized image. Research on the information expressed by product design renderings can help to change people's unilateral understanding, and embody their artistic value and applied value. The unique visualized thinking method of design renderings can completely transfer designer's intent and product information to help establish a feasible new product solution．

The high speed solenoid design method by combining finite element computation with empirical formula was proposed to improve its magnetic force and dynamic characteristics. The mathematical model of high speed solenoids was established and the impact of structure parameters, which could not be obtained by empirical formula, to the solenoid's static-dynamic characteristics, such as taper angle, length of armatures and non-magnetic length, was analyzed by Ansoft software. On the basis of this a high speed solenoid was designed and its static-dynamic performance was tested. The agreement between the experimental results and the simulation results proved that the design accuracy of solenoids can efficiently be improved by this method and the static-dynamic characteristics of high speed solenoids can be improved greatly by optimizing the taper angle, the length of armatures and the non-magnetic length．

Combined with the characteristics of hydraulic coke cutting in domestic delayed coking units, adopting the monitoring technology in hydraulic coke cutting, an automatic monitoring system in hydraulic coke cutting which can be commonly used in existing devices was developed. In order to reach the purpose of monitoring hydraulic coke cutting, the entire monitoring system was tested on the two following aspects: coke tower vibration signal and a high degree signal of coke device, through the acquiring and processing the two kinds of signals to monitor the position of coke cut states; In the actual test, analysis on the changes of the signals of hydraulic coke cutting processes was carried out, to ensure the reliability and security of the entire system. The monitoring system will eventually be applied to Shanghai Petrochemical delay coking process to monitor the hydraulic conditions, and thus achieve the automatic condition monitoring of hydraulic coke cutting. Moreover, this system can avoid operator experience discrimination and environmentalimpact disadvantage, and have good economic and practical significance．

In the view of water resource protection, the performance of cost and its economy, a full-automatic toilet for waste-water utilization was presented, the working principle and inner structure of which were emphatically elaborated. The performance index of washing function, water-saving efficiency, environmental protection, reliability and service life have exceeded the existing water-saving ones. Besides, the degree of its automation and convenient application has reached the international top level. The characteristics of its automation are as follows: choose waste-water preferentially when washing toilet; use the minimum volume of tap water when the waste-water is not enough; the waste-water recovery unit can keep the maximum volume of water; automatically identify the quantity of waste-water, and consequently automatically choose the right drainage tank and collect waste-water; collect waste-water automatically. The application results show that this toilet is superior in automation, performance-price ratio, reliability and flexibility and convenience, and therefore the design has a broad application prospects．

In order to improve the performance of automotive air conditioners, the best method is to escalate the heat efficiency of heat exchangers. Due to the constraints of automotive interior space, it is impossible to merely rely on increasing the volume of heat exchanger to advance the thermal efficiency, and so it is of practical significance in structural optimization and design of heat exchangers. The structure optimization design of heat exchangers can be completed by Fluent simulation and orthogonal experiment. Fluent software can simulate the heat flowing and exchanging process, and the orthogonal experiment can build regression equation. So a mathematic model can be built which can quantitatively describe the outlet temperature and exchange heating efficiency with fin pitch, fin height, tube space. In the end, experiment is done to validate the optimization design. The result shows that the optimal structure parameters of heat exchanger is 1.1 mm fit pitch, 6.9 mm fin height, and 5.2 mm tube space, and the regression equation of outlet temperature is Y=307.308+2.333X₁ +0.677X₂+0,561X₃-2.501X₁²according to Fluent simulation, and the influence factors of outlet temperature is fin spacing, fin height and pitch pipes in turn. Combining the Fluent simulation with orthogonal experimental design is an optimal method in product structure analysis and optimization．