Movement accuracy is the key factor to be considered in designing precision instrument linkage and mini-linkage mechanisms. Although manufacturing errors, elastic deformation, kinematic pair clearance and friction fac...Movement accuracy is the key factor to be considered in designing precision instrument linkage and mini-linkage mechanisms. Although manufacturing errors, elastic deformation, kinematic pair clearance and friction factors all will have synthesis effect on the position accuracy of the mechanical system, the essential factor to guarantee the movement precision remains the kinematic dimensions. Combining the classical theory of mechanical synthesis with the modern error theory and the numerical method, the authors put forward a systematic and complete process and method of computer aided design for the instrument crank-coupler mechanism in which the follower takes the linear displacement approximately within a certain limited domain, with the design result of least transmission ratio error.展开更多
Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, wh...Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.展开更多
Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condi...Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 for- ward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.展开更多
Presents the new concept of ″Desired to be small″ based on the basic function of vehicle flight control system for an optimal design of flying vehicle control system, and the definition of S/N ratio and calculation ...Presents the new concept of ″Desired to be small″ based on the basic function of vehicle flight control system for an optimal design of flying vehicle control system, and the definition of S/N ratio and calculation formula for ″Desired to be small″ dynamic characteristics, and the S/N ratio method established for design of velicle flight control systems, by which, an orthogrnal table is used to arrange test schemes, and error facters are used to simulate various interferences, and the use of S/N ratio as a design criterion to synthesise the design of dynamic and static characteristics for definition of an optimal scheme, the application of S/N ratio method to the design of a type of vehicle control system and the single run success abtained in design of control system, technical evaluation test and design finalization flight test.展开更多
文摘Movement accuracy is the key factor to be considered in designing precision instrument linkage and mini-linkage mechanisms. Although manufacturing errors, elastic deformation, kinematic pair clearance and friction factors all will have synthesis effect on the position accuracy of the mechanical system, the essential factor to guarantee the movement precision remains the kinematic dimensions. Combining the classical theory of mechanical synthesis with the modern error theory and the numerical method, the authors put forward a systematic and complete process and method of computer aided design for the instrument crank-coupler mechanism in which the follower takes the linear displacement approximately within a certain limited domain, with the design result of least transmission ratio error.
文摘Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.
文摘Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 for- ward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.
文摘Presents the new concept of ″Desired to be small″ based on the basic function of vehicle flight control system for an optimal design of flying vehicle control system, and the definition of S/N ratio and calculation formula for ″Desired to be small″ dynamic characteristics, and the S/N ratio method established for design of velicle flight control systems, by which, an orthogrnal table is used to arrange test schemes, and error facters are used to simulate various interferences, and the use of S/N ratio as a design criterion to synthesise the design of dynamic and static characteristics for definition of an optimal scheme, the application of S/N ratio method to the design of a type of vehicle control system and the single run success abtained in design of control system, technical evaluation test and design finalization flight test.
