With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization tech...With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.展开更多
Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturi...Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing process.This paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged robots.The LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion capabilities.This innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged robots.Furthermore,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality components.Using the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully developed.This robot boasts low mass and inertia,high strength,and a simplified component structure.To assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)model.Experimental jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.展开更多
A novel stability computation approach for tactical missile autopilots is detailed. The limi- tations of traditional stability margins are exhibited. Then the vector margin is introduced and com- pared with sensitivit...A novel stability computation approach for tactical missile autopilots is detailed. The limi- tations of traditional stability margins are exhibited. Then the vector margin is introduced and com- pared with sensitivity function to show their essential relationship. The longitudinal three-loop auto- pilot for tactical missiles is presented and used as the baseline for all the available linear autopilots. Ten linear autopilot topologies using all the measurable feedback components are given with the iden- tical closed-loop characteristic equation and time-domain step response. However, the stability of the ten autopilots differs when considering the actuator dynamics, which limits their application. Then vector margin method is adopted to compute and evaluate the stability of all available autopi- lots. The analysis and computation results show that the vector margin method could better evaluate autopilot stability.展开更多
A multi-objective optimal control model for nonlinear multilevel dynamical system is built in this paper. The existence of the solutions to this system and the controllability and the polykeys of the control are discu...A multi-objective optimal control model for nonlinear multilevel dynamical system is built in this paper. The existence of the solutions to this system and the controllability and the polykeys of the control are discussed. In order to obtain the global optimal solution, Uniform Design method is introduced to select initial feasible points, then an improved Hooke-Jeeves algorithm is proposed. The new algorithm and its corresponding software we developed has validated in more than 12 horizontal wells, which show their advantages such as less length of trajectory designed, more accuracy of target hitting and less time-consuming comparison with present conventional method.展开更多
The smart grid with flexible topologies receives intensive attention recently.Transmission switching(TS)alters the power system topology during operation,and has been demonstrated for the advantage of economic and sec...The smart grid with flexible topologies receives intensive attention recently.Transmission switching(TS)alters the power system topology during operation,and has been demonstrated for the advantage of economic and secure operation of power systems.TS includes a chain of sequential switching actions which bring disturbances to the system if the switching actions are not properly designed.Unfortunately,it is not considered or well-studied in existing works.In this paper,a new multi-period TS model that considers the transition security and a two-stage iterative method are proposed.In the TS model,we take into account the fact that only one line is permitted to switch up or down at a time and the security of each switching action is considered.The proposed iterative solution makes the TS model more tractable in ACframework.Case studies on a 6-bus system and the IEEE 57-bus test system have verified the effectiveness of theproposed model.Numerical results show that:àthe consideration of transition security of TS is essential;`the transition path is directly related to secure and fast the transmission switching;′the proposed model and solution method give an effective way to determine the switching sequence and switching timing under transition security criteria.展开更多
文摘With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.
基金Heilongjiang Provincial Youth Science and Technology Talent Support Project(No.2023QNTJ008)Self-Planned Task of State Key Laboratory of Robotics and System from Harbin Institute of Technology(HIT)(No.SKLRS 202301A03)Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-202203),China.
文摘Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing process.This paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged robots.The LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion capabilities.This innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged robots.Furthermore,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality components.Using the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully developed.This robot boasts low mass and inertia,high strength,and a simplified component structure.To assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)model.Experimental jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.
基金Supported by the National Natural Science Foundation of China(61172182)
文摘A novel stability computation approach for tactical missile autopilots is detailed. The limi- tations of traditional stability margins are exhibited. Then the vector margin is introduced and com- pared with sensitivity function to show their essential relationship. The longitudinal three-loop auto- pilot for tactical missiles is presented and used as the baseline for all the available linear autopilots. Ten linear autopilot topologies using all the measurable feedback components are given with the iden- tical closed-loop characteristic equation and time-domain step response. However, the stability of the ten autopilots differs when considering the actuator dynamics, which limits their application. Then vector margin method is adopted to compute and evaluate the stability of all available autopi- lots. The analysis and computation results show that the vector margin method could better evaluate autopilot stability.
文摘A multi-objective optimal control model for nonlinear multilevel dynamical system is built in this paper. The existence of the solutions to this system and the controllability and the polykeys of the control are discussed. In order to obtain the global optimal solution, Uniform Design method is introduced to select initial feasible points, then an improved Hooke-Jeeves algorithm is proposed. The new algorithm and its corresponding software we developed has validated in more than 12 horizontal wells, which show their advantages such as less length of trajectory designed, more accuracy of target hitting and less time-consuming comparison with present conventional method.
基金supported by National Natural Science Foundation of China(No.U1766205)Science and Technology Foundation of SGCC "Research on Efficient Integration of Large Scale Long Distance Offshore Wind Farm and Its Key Technologies in Operation and Control".
文摘The smart grid with flexible topologies receives intensive attention recently.Transmission switching(TS)alters the power system topology during operation,and has been demonstrated for the advantage of economic and secure operation of power systems.TS includes a chain of sequential switching actions which bring disturbances to the system if the switching actions are not properly designed.Unfortunately,it is not considered or well-studied in existing works.In this paper,a new multi-period TS model that considers the transition security and a two-stage iterative method are proposed.In the TS model,we take into account the fact that only one line is permitted to switch up or down at a time and the security of each switching action is considered.The proposed iterative solution makes the TS model more tractable in ACframework.Case studies on a 6-bus system and the IEEE 57-bus test system have verified the effectiveness of theproposed model.Numerical results show that:àthe consideration of transition security of TS is essential;`the transition path is directly related to secure and fast the transmission switching;′the proposed model and solution method give an effective way to determine the switching sequence and switching timing under transition security criteria.
