A new algorithm called homotopy iteration method based on the homotopy function is studied and improved. By the improved homotopy iteration method, Polynomial systems with high Order and deficient can be solved fast a...A new algorithm called homotopy iteration method based on the homotopy function is studied and improved. By the improved homotopy iteration method, Polynomial systems with high Order and deficient can be solved fast and efficiently comparing to the original homotopy iteration method. Numerical examples for the ninepoint path synthesis of four-bar linkages show the advantages and efficiency of the improved homotopy iteration method.展开更多
The design of single-degree-of-freedom spatial mechanisms tracing a given path is challenging due to the highly non-linear relationships between coupler curves and mechanism parameters.This work introduces an innovati...The design of single-degree-of-freedom spatial mechanisms tracing a given path is challenging due to the highly non-linear relationships between coupler curves and mechanism parameters.This work introduces an innovative application of deep learning to the spatial path synthesis of one-degree-of-freedom spatial revolute–spherical–cylindrical–revolute(RSCR)mechanisms,aiming to find the non-linear mapping between coupler curve and mechanism parameters and generate diverse solutions to the path synthesis problem.Several deep learning models are explored,including multi-layer perceptron(MLP),variational autoencoder(VAE)plus MLP,and a novel model using conditional-β-VAE(c-β-VAE).We found that the c-β-VAE model withβ=10 achieves superior performance by predicting multiple mechanisms capable of generating paths that closely approximate the desired input path.This study also builds a publicly available database of over 5 million paths and their corresponding RSCR mechanisms.The database provides a solid foundation for training deep learning models.An application in the design of human upper-limb rehabilitation mechanism is presented.Several RSCR mechanisms closely matching the wrist and elbow path collected from human movements are found using our deep learning models.This application underscores the potential of RSCR mechanisms and the effectiveness of our model in addressing complex,real-world spatial mechanism design problems.展开更多
It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-ind...It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-industrial production mode with minimum waste emission. A new conception of simple stoichiometric reaction is presented for reaction path synthesis problem. All simple stoichiometric reactions can be obtained by mathematical transformation for atom matrix of a reaction system. Based on the conception, a two-tier optimization method for complex reaction path synthesis problems is addressed. The first step is to determine the eco-nomic optimal overall reactions, and the second step to decompose each overall reaction into several sub-reactions and find out the best thermodynamic feasible reaction path. Further, a method of reaction path synthesis with waste closed-cycle is proposed based on simple stoichiometric reactions for achieving zero waste emission to poly-generation problem of multi-products. Case studies show that the proposed methods can efficiently solve practical re-action path synthesis problems.展开更多
The problem of synthesizing a planar four-bar linkage with two given fixed pivots such that the coupler curve passes through five given points is considered with the Groebner-Sylvester hybrid approach.First,closed-for...The problem of synthesizing a planar four-bar linkage with two given fixed pivots such that the coupler curve passes through five given points is considered with the Groebner-Sylvester hybrid approach.First,closed-form equations of a single point are constructed.The reduced Groebner basis in degree lexicographic ordering for the closed-form equations is then obtained using com-puter algebra.A 23623 Sylvester’s matrix can be con-structed by selecting 23 out of 89 Groebner bases.A 36th degree univariate equation is obtained directly from the determinate of the matrix.The same result can be obtained with a continuation method.A numerical example is given and verifies that the problem has at most 36 solutions in the complex field.展开更多
Vehicle collision avoidance system is a kind of auxiliary driving system based on vehicle active safety,which can assist the driver to take the initiative to avoid obstacles under certain conditions,so as to effective...Vehicle collision avoidance system is a kind of auxiliary driving system based on vehicle active safety,which can assist the driver to take the initiative to avoid obstacles under certain conditions,so as to effectively improve the driving safety of vehicle.This paper presents a collision avoidance system for an autonomous vehicle based on an active front steering,which mainly consists of a path planner and a robust tracking controller.A path planner is designed based on polynomial parameterization optimized by simulated annealing algorithm,which plans an evasive trajectory to bypass the obstacle and avoid crashes.The dynamic models of the AFS system,vehicle as well as the driver model are established,and based on these,a robust tracking controller is proposed,which controls the system to resist external disturbances and work in accordance with the planning trajectory.The proposed collision avoidance system is testified through CarSim and Simulink combined simulation platform.The simulation results show that it can effectively track the planning trajectory,and improve the steering stability and anti-interference performance of the vehicle.展开更多
Area and test time are two major overheads encountered duringdata path high level synthesis for BIST. This paper presents an approach to behavioral synthesis for loop-based BIST. By taking into account the requirement...Area and test time are two major overheads encountered duringdata path high level synthesis for BIST. This paper presents an approach to behavioral synthesis for loop-based BIST. By taking into account the requirements of theBIST scheme during behavioral synthesis processes, an area optimal BIST solutioncan be obtained. This approach is based on the use of test resources reusabilitythat results in a fewer number of registers being modified to be test registers. Thisis achieved by incorporating self-testability constraints during register assignmentoperations. Experimental results on benchmarks are presented to demonstrate theeffectiveness of the approach.展开更多
文摘A new algorithm called homotopy iteration method based on the homotopy function is studied and improved. By the improved homotopy iteration method, Polynomial systems with high Order and deficient can be solved fast and efficiently comparing to the original homotopy iteration method. Numerical examples for the ninepoint path synthesis of four-bar linkages show the advantages and efficiency of the improved homotopy iteration method.
基金supported by the National Science Foundation of USA(under Grant No.STTR phase II\#2126882)the co-author/co-PI Dr.Purwar,who also holds stocks in Mechanismic Inc.,USA.
文摘The design of single-degree-of-freedom spatial mechanisms tracing a given path is challenging due to the highly non-linear relationships between coupler curves and mechanism parameters.This work introduces an innovative application of deep learning to the spatial path synthesis of one-degree-of-freedom spatial revolute–spherical–cylindrical–revolute(RSCR)mechanisms,aiming to find the non-linear mapping between coupler curve and mechanism parameters and generate diverse solutions to the path synthesis problem.Several deep learning models are explored,including multi-layer perceptron(MLP),variational autoencoder(VAE)plus MLP,and a novel model using conditional-β-VAE(c-β-VAE).We found that the c-β-VAE model withβ=10 achieves superior performance by predicting multiple mechanisms capable of generating paths that closely approximate the desired input path.This study also builds a publicly available database of over 5 million paths and their corresponding RSCR mechanisms.The database provides a solid foundation for training deep learning models.An application in the design of human upper-limb rehabilitation mechanism is presented.Several RSCR mechanisms closely matching the wrist and elbow path collected from human movements are found using our deep learning models.This application underscores the potential of RSCR mechanisms and the effectiveness of our model in addressing complex,real-world spatial mechanism design problems.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29836140).
文摘It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-industrial production mode with minimum waste emission. A new conception of simple stoichiometric reaction is presented for reaction path synthesis problem. All simple stoichiometric reactions can be obtained by mathematical transformation for atom matrix of a reaction system. Based on the conception, a two-tier optimization method for complex reaction path synthesis problems is addressed. The first step is to determine the eco-nomic optimal overall reactions, and the second step to decompose each overall reaction into several sub-reactions and find out the best thermodynamic feasible reaction path. Further, a method of reaction path synthesis with waste closed-cycle is proposed based on simple stoichiometric reactions for achieving zero waste emission to poly-generation problem of multi-products. Case studies show that the proposed methods can efficiently solve practical re-action path synthesis problems.
基金supported by the National Basic Research Program of China(No.2004CB31800)the National Natural Science Foundation of China(Grant No.50475161)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China(No.2005-0013006)the National Hi-Tech Research and Development Program of China(No.2007AA04Z211).
文摘The problem of synthesizing a planar four-bar linkage with two given fixed pivots such that the coupler curve passes through five given points is considered with the Groebner-Sylvester hybrid approach.First,closed-form equations of a single point are constructed.The reduced Groebner basis in degree lexicographic ordering for the closed-form equations is then obtained using com-puter algebra.A 23623 Sylvester’s matrix can be con-structed by selecting 23 out of 89 Groebner bases.A 36th degree univariate equation is obtained directly from the determinate of the matrix.The same result can be obtained with a continuation method.A numerical example is given and verifies that the problem has at most 36 solutions in the complex field.
基金supported by the Research Project of Advanced Manufacture Technology for Automobile Parts(Chongqing University of Technology)Ministry of Education(Grant No.2015KLMT04)the National Natural Science Foundation of China(Grant No.51375007 and 51605219)
文摘Vehicle collision avoidance system is a kind of auxiliary driving system based on vehicle active safety,which can assist the driver to take the initiative to avoid obstacles under certain conditions,so as to effectively improve the driving safety of vehicle.This paper presents a collision avoidance system for an autonomous vehicle based on an active front steering,which mainly consists of a path planner and a robust tracking controller.A path planner is designed based on polynomial parameterization optimized by simulated annealing algorithm,which plans an evasive trajectory to bypass the obstacle and avoid crashes.The dynamic models of the AFS system,vehicle as well as the driver model are established,and based on these,a robust tracking controller is proposed,which controls the system to resist external disturbances and work in accordance with the planning trajectory.The proposed collision avoidance system is testified through CarSim and Simulink combined simulation platform.The simulation results show that it can effectively track the planning trajectory,and improve the steering stability and anti-interference performance of the vehicle.
文摘Area and test time are two major overheads encountered duringdata path high level synthesis for BIST. This paper presents an approach to behavioral synthesis for loop-based BIST. By taking into account the requirements of theBIST scheme during behavioral synthesis processes, an area optimal BIST solutioncan be obtained. This approach is based on the use of test resources reusabilitythat results in a fewer number of registers being modified to be test registers. Thisis achieved by incorporating self-testability constraints during register assignmentoperations. Experimental results on benchmarks are presented to demonstrate theeffectiveness of the approach.
