The degree of product design resources reuse is the key factor that influences the enterprise's response time on market demand and the costs of design. The characterization way of customized products gene was defined based on the relationship between customized products and resource reuse. Three kinds of the strategy of resources reuse which included genetic reuse, variation reuse, and mutation reuse were obtained based on genetic and the development process of customized product. For the convenience of the choice to the strategy, the availability of resources was evaluated based on the similarity analysis, the similarity between existing product gene with customized product gene was calculated by Euclidean distance, and the similarity threshold was set based on Weber's law to determine the resource reuse strategy. Finally, the strategy was verified by a design example of customized reusable small agricultural machinery.

Aiming at the stability problems of vehicles,by establishing an extended two degrees of freedom vehicle model and using simplified Magic Formula to fit the practical tire lateral force,the stable zone boundaries of phase-plane were acquired based on phase plane theory. After studying the effects of the road frictional coefficient and vehicle speed on the phase plane of boundary,the boundary functions of the sideslip angle-sideslip angle rate called β-β phase plane and the sideslip angle-yaw rate called β-r phase plane were determined and the vehicle stability control method was put forward.The control strategy was validated on the co-simulation platform based on Simulink and Carsim,when the system phase trajectory got out of the stability region,the stability controller would calculate the required yaw moment by combining β-β phase plane with β-r phase plane,to limit the system within the stability boundary,and thus pulled the unstable states to the stable zone.Finally,by comparing with the two phase plane controllers,yaw rate method and the uncontrolled case,the results showed that the integrated control method had a certain advantage and could improve vehicle stability under extreme condition obviously.

The combined rotor of gas turbine bears large centrifugal stress and high temperature in a long term, and its performance degrads easily. Turbine discs creep is one of the important factors that cause the performance degradation of the combined rotor. To research the performance degradation characteristics of combined rotor caused by turbine discs creep, firstly, the turbine discs creep calculation model of combined rotor considering contact interface stiffness was established, the creep effect and the relationship between creep quantitative data and time were researched. Then a research method for the performance degradation of the combined rotor caused by turbine discs creep was presented. By describing degradation path caused by turbine discs creep through defining degradation degree parameters, performance degradation quantitative evaluation of combined rotor was realized. Finally, the variation law of the performance degradation rate of the combined rotor was studied under the different speeds and numbers of rod. The calculation results showed that the creep rate of combined rotor decreased with the increasing of time, and the first wheel of the turbine got the fastest creep rate; the turbine discs creep caused performance degradation of combined rotor, the greater the rotating speed, the more number of the rod, the faster the degradation rate of the combined rotor. Therefore, it is necessary to consider the influence of turbine discs creep on the structural design of composite rotor, especially when the speed and the number of the rod are changed, the influence can not be ignored.

The designers' learning ability and information communication ability are important factors affecting concurrent product development. In order to research the influence of designers' learning ability and information communication ability to downstream design activity, the learning knowledge quantity function and the rework rate function were constructed, the mathematical model of start time of downstream design activity and information communication times between design activities was put forward, the influence of designers' learning ability and information communication ability to the start time of downstream design activity and the information communication times between design activities was researched, and the judging conditions of the start time of downstream design activity and the information communication times between design activities were obtained, and the judging conditions were analyzed and verified through an example. The start time of downstream design activity and the information communication times between design activities were calculated on the basis of the judging conditions and the designers' learning ability and information communication ability indexes. The study provides theoretical reference for shortening the product development time and reducing the product development cost.

Friction which reduces the tracking precision is a kind of external perturbation when the linear motor is running. The design of feed-forward compensator based on friction model is an important means to realize friction inhibition. Firstly, the characteristics of the friction was analyzed and the appropriate friction model was choosen. Secondly, speed feed-forward controller and acceleration feed-forward controller were designed to improve the tracking performance of the machine. With measured friction values of the motor under different speeds, the friction model parameters were identified through differential evolution algorithm, and the feed-forward controller was designed to achieve the friction suppression of the permanent magnet synchronous linear motor. Simulation results showed that the friction model accurately described the characteristics of the tested linear motor, and the designed feed-forward controller based on the friction model which identified by this algorithm effectively eliminated the speed stick-slip phenomenon caused by friction and reduced the location tracking error.

When the field test of rope pulled automatic catwalk was carried out, the load fluctuation of rope was obvious, and it was difficult to complete the lifting of the target weight column. Therefore, the structure and motion characteristics of rope pulled automatic catwalk were analyzed, and dynamic model based on the D'Alemebert principle was established, MATLAB software was used to analyze the influence of the distance between the block on the base and the bottom of the ramp, the hinge position of the transfer arm and the support arm, and the length of the support arm on the load of rope. The analysis results showed that adjusting the position of block on the base to the bottom of the ramp, and reducing the length of support arm could reduce the required force of rope in the process of lifting. According to the analysis results, the structure size of automatic catwalk was adjusted to carry out the field test, the test result showed that the maximum lifting oil pressure of the hydraulic which was decreased by more than 2 MPa, the lifting capacity of automatic catwalk was improved. The analysis and experimental results can guide the design and optimization of rope pulled automatic catwalk.

The frame will be subject to the test of various conditions in the actual moving conditions. So a plurality of topology results under every condition must be considered when conducting topology optimization of the frame structure. While there is a common issue during the process of multi-case topology optimization about how to determine the weight ratio of respective condition and the final topology results of the frame depend directly on this distribution. This issue was showed a further study and a feasible solution to this problem with a combination of surrogate model and genetic algorithm was gaved. At first, a comprehensive object function maximizing the static stiffness under multi-case was defined by using compromise programming approach. And then, a Radial Basis Function surrogate model was constructed by using optimal Latin Hypercube Sampling, meanwhile, optimal weight ratios of every load condition had been obtained with the method of combining surrogate model with NSGA-II. At last, the optimal weight ratios obtained in the previous process were applied into the object function and a feasible topology result of the frame structure was got which had considered multi-case loads. Moreover, the contrastive study was carried out to compare the comprehensive objective optimization approach proposed in this study with those that determined the weight ratio by analytic hierarchy process (AHP) or orthogonal experimental design (OED). Compared with the other two methods, this method had the lowest value of comprehensive objective function and the weighted compliance of all conditions was also the lowest. Results show that the method proposed in this paper is a good solution to obtain weight ratio of every condition in the process of topology optimization of a frame and is superior to reference methods.

In order to improve the braking torque of conventional hybrid magnetorheological brake(MRB) with single coil, a novel MRB with double coils placed on the side housing is proposed. The novel structure enabled it to have larger area of controllable interaction face in cylindrical surface of brake disk and a larger braking torque. The torque model and design method of magnetic circuit of the novel MRB were proposed based on Herscher-Bulkley model. And then a multi-objective optimization under the specific condition was conducted. Comparative analysis between conventional and novel MRB demonstrated that under the condition of the same volume, the novel MRB had a larger braking torque. And in order to make full advantage of the rheological properties of MRF and get a more compact structure, the width of the brake should be 80-100 mm and the reasonable range of the length-width ratio should be 0.6-1.2. After optimization, the braking torque was increased by 11% in the situation which its weight basically remained unchanged. The results can be taken as reference to the design of MRB.

The composite hydrogen storage vessel is directly subjected to both high pressure and temperature load during the hydrogen charging process, which contributes to the complicated failure mechanisms of the vessel structure. A micromechanics-based progressive failure analysis strategy was presented to study the complex failure behaviors of the composite vessel under thermo-mechanical loadings. An effective finite element model was developed based on the integration of micromechanics of failure (MMF) theory and material property degradation method (MPDM), where the MMF was used to predict the failure initiation at the constituent level and the MPDM was employed to account for the post failure behavior of the damaged materials. In addition, the micromechanics analysis of a typical unit cell model was performed in order to obtain the interaction information which bridged the micro-level and macro-level analysis. This micromechanics-based approach was implemented by a user-material subroutine (UMAT) in ABAQUS. Different failure patterns were obtained and the ultimate load-bearing ability of the vessel was predicted. The predictions of the model were also compared with experiments and reasonably good agreements were obtained. This work provides theoretical guidance for the safety and economical design as well as practical application of the composite vessel in fields of hydrogen fuel cell vehicles.

Aiming at the problems of serious vibration and noise during the operation of the crank-group driving mechanism, the mass moment substitution method and the momentum moment substitution method in the dynamic balance theory of the planar linkage mechanism were used to derive the dynamic balancing condition of crank-group driving mechanism. Then ADAMS software package was utilized to establish the dynamic models of rigid six crank-group both before and after adding counterweight and the loading curve of crank's fixed rotate pair of each model was comparatively analyzed. Based on the former simulation results of rigid virtual prototype model, the rigid-flexible coupling virtual prototype model of mechanism was obtained. The simulation results of rigid-flexible coupling dynamic balancing model showed that the unbalanced force and moment of six crank-group mechanism were well balanced. Therefore, the desired dynamic balancing effect can not be achieved by merely imposing counterweight mass so that the application of rigid-flexible coupling dynamic balancing method provide a new approach for the research of dynamic characteristics of crank-group driving mechanism.

Aiming to the status quo that the inspection robot couldn't surmount all kinds of obstacles in overhead ground wires, a kind of brand-new method for the inspection robot obstacle negotiation was put forward. The inspection robot was driven by single arm and the mission of obstacle negotiation was accomplished by other two mechanical arms. This brand-new method could surmount all kinds of fittings with simple mechanical movements and less driving force. The key link of obstacle negotiation was calculated by theoretical analysis and simulation experiments which showed the motion characteristics of the robot during surmounting obstacles. On this base, an experimental prototype was came out to experiment on the high-voltage transmission lines in laboratory. The results show that the inspection robot can perform preplanned functions. The effectiveness and feasibility of the brand-new method are verified by surmounting obstacles test.

Aiming at path planning problem of AGV accessing cars in intelligent solid garage, a hybrid algorithm is proposed by combining Dijkstra algorithm with ant colony algorithm. Firstly, Link Method was used to establish environment model of AGV, Dijkstra algorithm was applied to plan the initial path of AGV. Then, with the methods of nodes random selection mechanism and the combination of local renewal and global renewal of the pheromone, the traditional ant colony algorithm was optimized and improved. Finally, the initial path planned by Dijkstra algorithm was optimized by improved ant colony algorithm. The simulation results showed that the optimized path from starting point to ending point could be attained with Dijkstra algorithm and Dijkstra-Ant colony algorithm on the premise of effectively avoiding obstacles. Moreover, compared with Dijkstra algorithm, Dijkstra-Ant colony algorithm could effectively raise search efficiency, shorten the search path length, and improve the quality of search path. The results indicate that Dijkstra-Ant colony hybrid algorithm is correct, feasible and effective, and simultaneously exhibits stronger global search ability and better convergence performance, and can meet the requirement of AGV accessing cars in path planning.

In order to improve accuracy and quality of print moldings, high-precision feed system based on 3D printer of FDM and the implement method is improved. This system used IRF530N power tube, heating pipe and PWM as a Heating Module; Pt100 platinum thermistor, differential amplifier circuit and PID Algorithm as a Temperature Measuring and Controlling Module. It not only simplified the calculation of scale changes, but also reduced the influence of the measurement of resistance drift. Based on feeding control module of the stepping motor, some measures for reducing the phenomenon of the stepper motor which losed step were given. The realization of constant temperature control of 180-250℃ range, ±1℃ accuracy can guarantee the constant temperature and high precision feeding of 3D printer of FDM. It can also be used to control the humidity, pressure, displacement and angle and other physical quantities.

The uncertainties existed in the servo system of virtual axis machine tool that was used to process the circular arc gears will affect the performance of the system and reduce the machining accuracy of the circular arc gears,and the chattering phenomenon existed in the sliding mode control will influence the control accuracy and stability. In order to improve the machining accuracy of the virtual axis machine tool and reduce chattering phenomenon in the sliding mode control, an sliding model control scheme with improved disturbance observer was proposed to control the servo motor of the virtual axis machine tool. The disturbance observer was used to observe the uncertainties existed in the servo system of virtual axis machine tool in this algorithm and the symbolic function in the variable structure control was replaced by the saturation function to reduce the chattering phenomenon which was brought by the variable structure control system. The control law was deduced based on the improved observer of sliding mode variable structure, and the stability of the designed controller was proved. In order to verify the validity of the algorithm, the simulation was taken in MATLAB, the simulation results showed that the algorithm proposed could effectively observe the uncertainties in the system, and chattering phenomenon in the sliding model control was reduced, then the motor servo system had stronger position tracking performance and anti-interference ability.

In order to study the load characteristic of the shearer cutter at working state, the three-axis force testing scheme of shearer cutter was designed, and some related experimental studies were carried on by applying the testing scheme to the shearer of type MG400/930-WD. The curve of three-axis force on the shearer cutter tooth was obtained when the shearer cutter was cutting the laboratory simulation coal wall. And then the experimental results were compared with the theoretical calculation results. Under the influence of the error and random factors, it showed a good agreement between experiment results and theoretical analysis, and verified the feasibility of testing solution. The study can provide experimental data and theoretical basis for enhancing design related parameters of cutting tooth and shearer cutting unit.

With the rebound of the drill rod,the rigid impact between the drill rod and the body of the hydraulic rock drill is more difficult,which reduces the working efficiency and the service life of the hydraulic rock drill.So a design approach to anti-rebound buffer device and a computing method for the rebound velocity of the rod were put forward to solve this problem on the basis of an analysis of wave theory of rebound respectively.The mathematical model of the buffer piston was established based on the coupling of the accumulator and local resistance.Through the mathematical model,the non-linear equation of the buffer piston was obtained.The kinematics of the buffer piston was simulated in Simulink to analyze the influence of different precharge pressure on the dynamic characteristics of the buffer piston and the response ability of the device under different working mediums,and the simulation result was verified by comparing with the experiment result. The results showed that the rebound velocity was related to the working mediums,but not to the precharge pressure,and the rebound velocity increases as the medium coefficient increases.In additions,the working efficiency of the hydraulic rock drill was increased by 7.23%.Considering the high reliability and the good response ability of working condition,the design of the anti-rebound buffer device was finally selected to be used in the actual working conditions.