Non-obstacle design is critical to tailor physically handicapped workers in manufacturing system. Simultaneous consideration of variability in physically disabled users, machines and environment of the manufacturing s...Non-obstacle design is critical to tailor physically handicapped workers in manufacturing system. Simultaneous consideration of variability in physically disabled users, machines and environment of the manufacturing system is extremely complex and generally requires modeling of physically handicapped interaction with the system. Most current modeling either concentrates on the task results or functional disability. The integration of physical constraints with task constraints is far more complex because of functional disability and its extended influence on adjacent body parts. A framework is proposed to integrate the two constraints and thus model the specific behavior of the physical handicapped in virtual environment generated by product specifications. Within the framework a simplified model of physical disabled body is constructed, and body motion is generated based on 3 levels of constraints(effecter constraints, kinematics constraints and physical constraints). The kinematics and dynamic calculations are made and optimized based on the weighting manipulated by the kinematics constraints and dynamic constraints. With object transferring task as example, the model is validated in Jack 6.0. Modelled task motion elements except for squatting and overreaching well matched with captured motion elements. The proposed modeling method can model the complex behavior of the physically handicapped by integrating both task and physical disability constraints.展开更多
The angular position controller is system (EHSAS) to control the output of the rotary applied to electro-hydraulic servo actuator actuator. It works as a compensator based on the frequency response of the EHSAS. Its...The angular position controller is system (EHSAS) to control the output of the rotary applied to electro-hydraulic servo actuator actuator. It works as a compensator based on the frequency response of the EHSAS. Its design model is verified on the state-space model of EHSAS by using simulation program SIMULINK. Real data used to test the system. Simulation results give a good agreement for the controller and also for the state-space model.展开更多
This paper deals with control system design and implementation problems encountered in multiple robot systems. The methodology developed is depicted by a set of coordination mechanisms using hierarchical net structure...This paper deals with control system design and implementation problems encountered in multiple robot systems. The methodology developed is depicted by a set of coordination mechanisms using hierarchical net structures and their accompanying rules. With the net models, the hierarchical and distributed control system is designed for an assembly task. Synchronization commands allow coordination of the movements of the robots. The net models make concurrency of the movements of the robots transparent to users. The net based machine controller executes robot motion control through the communication with the external robot controller using the command/response concept. Sensory signals indicating the change of state of robots are used to trigger or initiate tasks. Simultaneous movement of the robots is obtained by creating different background threads running in parallel under Windows OS. The multilevel hierarchical control system can be consistently constructed using net models.展开更多
In this paper, the method based on uniform design and neural network is proposed to model the complex system. In order to express the system characteristics all round, uniform design method is used to choose the model...In this paper, the method based on uniform design and neural network is proposed to model the complex system. In order to express the system characteristics all round, uniform design method is used to choose the modeling samples and obtain the overall information of the system;for the purpose of modeling the system or its characteristics, the artificial neural network is used to construct the model. Experiment indicates that this method can model the complex system effectively.展开更多
A robust control for uncertain nonlinear systems based on T-S fuzzy model is discussed in this paper. First, a T-S fuzzy system is adopted to model the uncertain nonlinear systems. Then, for the system with input vari...A robust control for uncertain nonlinear systems based on T-S fuzzy model is discussed in this paper. First, a T-S fuzzy system is adopted to model the uncertain nonlinear systems. Then, for the system with input variables adopting standard fuzzy partitions, the efficient maximal overlapped-rules group (EMORG) is presented, and a new sufficient condition to check the stability of T-S fuzzy system with uncertainty is derived, which is expressed in terms of Linear Matrix Inequalities. The derived stability condition, which only requires a local common positive definite matrix in each EMORG, can reduce the conservatism and difficulty in existing stability conditions. Finally, a simulation example shows the proposed approach is effective.展开更多
Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety d...Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand,the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.展开更多
There are two main opposing views in the wireless industry on the feasibility of developing 5th generation(5G) cellular networks in mm-Wave bands. The optimistic view is based on the fact that the path loss in mm Wave...There are two main opposing views in the wireless industry on the feasibility of developing 5th generation(5G) cellular networks in mm-Wave bands. The optimistic view is based on the fact that the path loss in mm Wave bands is not significantly worse than that in cellular bands when beamforming gain is also considered. The cautious view points out the significant blockage issues due to the lack of diffraction and adequate penetration in mm Wave bands. The implementation of 5G mm Wave cellular networks also faces major challenges due to the high link budget needed for long- range communication and the strong dependency on beamforming technology. This paper addresses some of these fundamental technology issues, from mm Wave channel characters and channel modeling to the implications on system and network architecture design.Although we believe that mm Wave can be used for 5G networks, we show that the air interface, device and network design will be very different from existing cellular design.展开更多
The system is based on the globally shared product model conforming to VRML Standard, and uses SmarTeam (PDM) system to integrate and encapsulate CAD, CAE and other application software for product development. The ...The system is based on the globally shared product model conforming to VRML Standard, and uses SmarTeam (PDM) system to integrate and encapsulate CAD, CAE and other application software for product development. The system takes sugarcane harvester? mobile telephone design analysis and evaluation as an example, and utilizes fuzzy evaluation principle to evaluate the design and simulation analysis results for decisions making. The platform provides a collaborative intelligent environment for the design of products, aiming at integrating people, process and data in the virtual product development. The multi-layered system architecture provides capability for KBM and conception innovation design process with a single unified data and process model so as to achieve true process streamlining and data integrity throughout the entire product development lifecycle, and hence improves enterprises efficiency.展开更多
A framework was proposed for designing a system of systems(SoS) that takes account of the system' s evolution over time.Given the design space of the SoS analysis,construct a multiepoch scenario design,SoS optimiz...A framework was proposed for designing a system of systems(SoS) that takes account of the system' s evolution over time.Given the design space of the SoS analysis,construct a multiepoch scenario design,SoS optimization,and robust designs.A hybrid model based on multi-agent and system dynamic models was used to analyze the evolution of an SoS and find robust designs.The framework can help decision makers generate a robust SoS structure based on the SoS' s capabilities over multiple epochs.展开更多
Neural mass models can simulate the generation of electroencephalography(EEG) signals with different rhythms,and therefore the observation of the states of these models plays a significant role in brain research. Th...Neural mass models can simulate the generation of electroencephalography(EEG) signals with different rhythms,and therefore the observation of the states of these models plays a significant role in brain research. The structure of neural mass models is special in that they can be expressed as Lurie systems. The developed techniques in Lurie system theory are applicable to these models. We here provide a new observer design method for neural mass models by transforming these models and the corresponding error systems into nonlinear systems with Lurie form. The purpose is to establish appropriate conditions which ensure the convergence of the estimation error. The effectiveness of the proposed method is illustrated by numerical simulations.展开更多
In textile and apparel field,the CAD technology has been developed rapidly.The CAD system with the func-tions of pattern making,marking and grading has be-come substantial equipment for an apparel factory,But this app...In textile and apparel field,the CAD technology has been developed rapidly.The CAD system with the func-tions of pattern making,marking and grading has be-come substantial equipment for an apparel factory,But this apparel CAD system is only one graphic system con-centrating on the two-dimensional paper patterns,the three-dimensional apparel CAD system or virtual reali-ty apparel CAD is still not put into practical use.But it is one of the most interesting studying fields for展开更多
A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the con...A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the controller of concurrent design. With the help of the controller of concurrent design, each feature of a part can be designed and evaluated based on manufacturing knowledge and resources, and can be modified according to the results of evaluation. The machining method of design feature can be selected based on manufacturing knowledge. So real time concurrent product and process design can be implemented based on integrated product model that is established based on generalized feature. Products and its design process can be optimized with the help of this system. The information and function integration of product design process can be realized. The time to market and the cost of products can be reduced.展开更多
为在保障热防护系统可靠性的前提下减轻重量,本文建立考虑多源不确定性的烧蚀型热防护系统的概率设计和可靠性评估方法。采用有限元方法计算系统热响应,通过试验测试与数值模型对比验证方法的有效性。并构建热防护系统的不确定性输入参...为在保障热防护系统可靠性的前提下减轻重量,本文建立考虑多源不确定性的烧蚀型热防护系统的概率设计和可靠性评估方法。采用有限元方法计算系统热响应,通过试验测试与数值模型对比验证方法的有效性。并构建热防护系统的不确定性输入参数与目标输出的代理模型,基于代理模型与蒙特卡洛方法进行热防护系统目标变量的概率特性分析。采用Sobol指标对不确定性参数进行灵敏度分析,并以系统可靠性为指标进行概率设计。该方法针对来流、几何以及材料属性等多源不确定性进行热防护系统的概率设计与可靠性评估,以二维平板模型为例,计算热防护系统最高背温的概率特性以及不确定性参数的灵敏度,得到了不同涂层厚度情况下系统的可靠性。结果表明,与安全系数 n =1.5的设计相比,概率设计减重达到24%。展开更多
基金supported by National Natural Science Foundation of China(Grant No. 60975058)
文摘Non-obstacle design is critical to tailor physically handicapped workers in manufacturing system. Simultaneous consideration of variability in physically disabled users, machines and environment of the manufacturing system is extremely complex and generally requires modeling of physically handicapped interaction with the system. Most current modeling either concentrates on the task results or functional disability. The integration of physical constraints with task constraints is far more complex because of functional disability and its extended influence on adjacent body parts. A framework is proposed to integrate the two constraints and thus model the specific behavior of the physical handicapped in virtual environment generated by product specifications. Within the framework a simplified model of physical disabled body is constructed, and body motion is generated based on 3 levels of constraints(effecter constraints, kinematics constraints and physical constraints). The kinematics and dynamic calculations are made and optimized based on the weighting manipulated by the kinematics constraints and dynamic constraints. With object transferring task as example, the model is validated in Jack 6.0. Modelled task motion elements except for squatting and overreaching well matched with captured motion elements. The proposed modeling method can model the complex behavior of the physically handicapped by integrating both task and physical disability constraints.
文摘The angular position controller is system (EHSAS) to control the output of the rotary applied to electro-hydraulic servo actuator actuator. It works as a compensator based on the frequency response of the EHSAS. Its design model is verified on the state-space model of EHSAS by using simulation program SIMULINK. Real data used to test the system. Simulation results give a good agreement for the controller and also for the state-space model.
文摘This paper deals with control system design and implementation problems encountered in multiple robot systems. The methodology developed is depicted by a set of coordination mechanisms using hierarchical net structures and their accompanying rules. With the net models, the hierarchical and distributed control system is designed for an assembly task. Synchronization commands allow coordination of the movements of the robots. The net models make concurrency of the movements of the robots transparent to users. The net based machine controller executes robot motion control through the communication with the external robot controller using the command/response concept. Sensory signals indicating the change of state of robots are used to trigger or initiate tasks. Simultaneous movement of the robots is obtained by creating different background threads running in parallel under Windows OS. The multilevel hierarchical control system can be consistently constructed using net models.
文摘In this paper, the method based on uniform design and neural network is proposed to model the complex system. In order to express the system characteristics all round, uniform design method is used to choose the modeling samples and obtain the overall information of the system;for the purpose of modeling the system or its characteristics, the artificial neural network is used to construct the model. Experiment indicates that this method can model the complex system effectively.
基金supported by the National Natural Science Foundation of China (No.70471087)China Postdoctoral Science Foundation Funded Project(No.20080430929)Liaoning Province Education Bureau Foundation (No.20060106)
文摘A robust control for uncertain nonlinear systems based on T-S fuzzy model is discussed in this paper. First, a T-S fuzzy system is adopted to model the uncertain nonlinear systems. Then, for the system with input variables adopting standard fuzzy partitions, the efficient maximal overlapped-rules group (EMORG) is presented, and a new sufficient condition to check the stability of T-S fuzzy system with uncertainty is derived, which is expressed in terms of Linear Matrix Inequalities. The derived stability condition, which only requires a local common positive definite matrix in each EMORG, can reduce the conservatism and difficulty in existing stability conditions. Finally, a simulation example shows the proposed approach is effective.
基金supported by National Natural Science Foundation of China (Grant No. 51075180)Open Foundation of State Key Laboratory of Vehicle NVH and Safety Technology of China (Grant No.NVHSKL-201013)
文摘Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand,the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.
文摘There are two main opposing views in the wireless industry on the feasibility of developing 5th generation(5G) cellular networks in mm-Wave bands. The optimistic view is based on the fact that the path loss in mm Wave bands is not significantly worse than that in cellular bands when beamforming gain is also considered. The cautious view points out the significant blockage issues due to the lack of diffraction and adequate penetration in mm Wave bands. The implementation of 5G mm Wave cellular networks also faces major challenges due to the high link budget needed for long- range communication and the strong dependency on beamforming technology. This paper addresses some of these fundamental technology issues, from mm Wave channel characters and channel modeling to the implications on system and network architecture design.Although we believe that mm Wave can be used for 5G networks, we show that the air interface, device and network design will be very different from existing cellular design.
文摘The system is based on the globally shared product model conforming to VRML Standard, and uses SmarTeam (PDM) system to integrate and encapsulate CAD, CAE and other application software for product development. The system takes sugarcane harvester? mobile telephone design analysis and evaluation as an example, and utilizes fuzzy evaluation principle to evaluate the design and simulation analysis results for decisions making. The platform provides a collaborative intelligent environment for the design of products, aiming at integrating people, process and data in the virtual product development. The multi-layered system architecture provides capability for KBM and conception innovation design process with a single unified data and process model so as to achieve true process streamlining and data integrity throughout the entire product development lifecycle, and hence improves enterprises efficiency.
基金National Natural Science Foundations of China(Nos.71331008,71501182)National Social Science Foundation of China(No.15GJ003-278)
文摘A framework was proposed for designing a system of systems(SoS) that takes account of the system' s evolution over time.Given the design space of the SoS analysis,construct a multiepoch scenario design,SoS optimization,and robust designs.A hybrid model based on multi-agent and system dynamic models was used to analyze the evolution of an SoS and find robust designs.The framework can help decision makers generate a robust SoS structure based on the SoS' s capabilities over multiple epochs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61473245,61004050,and 51207144)
文摘Neural mass models can simulate the generation of electroencephalography(EEG) signals with different rhythms,and therefore the observation of the states of these models plays a significant role in brain research. The structure of neural mass models is special in that they can be expressed as Lurie systems. The developed techniques in Lurie system theory are applicable to these models. We here provide a new observer design method for neural mass models by transforming these models and the corresponding error systems into nonlinear systems with Lurie form. The purpose is to establish appropriate conditions which ensure the convergence of the estimation error. The effectiveness of the proposed method is illustrated by numerical simulations.
文摘In textile and apparel field,the CAD technology has been developed rapidly.The CAD system with the func-tions of pattern making,marking and grading has be-come substantial equipment for an apparel factory,But this apparel CAD system is only one graphic system con-centrating on the two-dimensional paper patterns,the three-dimensional apparel CAD system or virtual reali-ty apparel CAD is still not put into practical use.But it is one of the most interesting studying fields for
文摘A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the controller of concurrent design. With the help of the controller of concurrent design, each feature of a part can be designed and evaluated based on manufacturing knowledge and resources, and can be modified according to the results of evaluation. The machining method of design feature can be selected based on manufacturing knowledge. So real time concurrent product and process design can be implemented based on integrated product model that is established based on generalized feature. Products and its design process can be optimized with the help of this system. The information and function integration of product design process can be realized. The time to market and the cost of products can be reduced.
文摘为在保障热防护系统可靠性的前提下减轻重量,本文建立考虑多源不确定性的烧蚀型热防护系统的概率设计和可靠性评估方法。采用有限元方法计算系统热响应,通过试验测试与数值模型对比验证方法的有效性。并构建热防护系统的不确定性输入参数与目标输出的代理模型,基于代理模型与蒙特卡洛方法进行热防护系统目标变量的概率特性分析。采用Sobol指标对不确定性参数进行灵敏度分析,并以系统可靠性为指标进行概率设计。该方法针对来流、几何以及材料属性等多源不确定性进行热防护系统的概率设计与可靠性评估,以二维平板模型为例,计算热防护系统最高背温的概率特性以及不确定性参数的灵敏度,得到了不同涂层厚度情况下系统的可靠性。结果表明,与安全系数 n =1.5的设计相比,概率设计减重达到24%。