An active two-stage isolation mounting, on which servo-hydraulic system is used as the actuator (secondary vibration source) and a diesel engine is used as primary vibration source, has been built. The upper mass of t...An active two-stage isolation mounting, on which servo-hydraulic system is used as the actuator (secondary vibration source) and a diesel engine is used as primary vibration source, has been built. The upper mass of the mounting is composed of a 495diesel and an electrical eddy current dynamometer. The lower mass is divided into four small masses to which servo-hydraulic actuator and rubber isolators are attached. According to the periodical characteristics of diesel vibration signals, a multi-point adaptive strategy based on adaptive comb filtered algorithm is applied to active multi-direction coupled vibrations control for the engine. The experimental results demonstrate that a good suppression in the effective range of phase compensation in secondary path (within 100Hz) at different operation conditions is achieved, and verify that this strategy is effective. The features of the active system, the development activities carried out on the system and experimental results are discussed in the paper.展开更多
A novel active steering system with force and displacement coupled control(the novel AFS system) was introduced,which has functions of both the active steering and electric power steering.Based on the model of the nov...A novel active steering system with force and displacement coupled control(the novel AFS system) was introduced,which has functions of both the active steering and electric power steering.Based on the model of the novel AFS system and the vehicle three-degree of freedom system,the concept and quantitative formulas of the novel AFS system steering performance were proposed.The steering road feel and steering portability were set as the optimizing targets with the steering stability and steering portability as the constraint conditions.According to the features of constrained optimization of multi-variable function,a multi-variable genetic algorithm for the system parameter optimization was designed.The simulation results show that based on parametric optimization of the multi-objective genetic algorithm,the novel AFS system can improve the steering road feel,steering portability and steering stability,thus the optimization method can provide a theoretical basis for the design and optimization of the novel AFS system.展开更多
BBU(Beam breakup)instability once appeared in the early stage of 'Dragon-Ⅰ' LIA,which was excited by TM_(110)mode stimulated when the eccentric beam passed through the multi-functional cavity(MFC).The radio f...BBU(Beam breakup)instability once appeared in the early stage of 'Dragon-Ⅰ' LIA,which was excited by TM_(110)mode stimulated when the eccentric beam passed through the multi-functional cavity(MFC).The radio frequency characteristics of MFC were analyzed with three methods such as analytic calculation,numerical computation,and measurement.The frequency of the TM_(110)mode from these methods agreed with the experimental results,while the transverse coupling impedance was different from the experimental results by some times.The main BBU exciter was the big transverse coupling impedance of the MFC which could be concluded.A grid was designed to shield the gap of the MFC.The experiments show that the BBU was compressed and the high frequency oscillation disappeared.展开更多
文摘An active two-stage isolation mounting, on which servo-hydraulic system is used as the actuator (secondary vibration source) and a diesel engine is used as primary vibration source, has been built. The upper mass of the mounting is composed of a 495diesel and an electrical eddy current dynamometer. The lower mass is divided into four small masses to which servo-hydraulic actuator and rubber isolators are attached. According to the periodical characteristics of diesel vibration signals, a multi-point adaptive strategy based on adaptive comb filtered algorithm is applied to active multi-direction coupled vibrations control for the engine. The experimental results demonstrate that a good suppression in the effective range of phase compensation in secondary path (within 100Hz) at different operation conditions is achieved, and verify that this strategy is effective. The features of the active system, the development activities carried out on the system and experimental results are discussed in the paper.
基金Project(51005115) supported by the National Natural Science Foundation of ChinaProject(KF11201) supported by the Science Fund of State Key Laboratory of Automotive Safety and Energy,ChinaProject(201105) supported by the Visiting Scholar Foundation of the State Key Laboratory of Mechanical Transmission in Chongqing University,China
文摘A novel active steering system with force and displacement coupled control(the novel AFS system) was introduced,which has functions of both the active steering and electric power steering.Based on the model of the novel AFS system and the vehicle three-degree of freedom system,the concept and quantitative formulas of the novel AFS system steering performance were proposed.The steering road feel and steering portability were set as the optimizing targets with the steering stability and steering portability as the constraint conditions.According to the features of constrained optimization of multi-variable function,a multi-variable genetic algorithm for the system parameter optimization was designed.The simulation results show that based on parametric optimization of the multi-objective genetic algorithm,the novel AFS system can improve the steering road feel,steering portability and steering stability,thus the optimization method can provide a theoretical basis for the design and optimization of the novel AFS system.
文摘BBU(Beam breakup)instability once appeared in the early stage of 'Dragon-Ⅰ' LIA,which was excited by TM_(110)mode stimulated when the eccentric beam passed through the multi-functional cavity(MFC).The radio frequency characteristics of MFC were analyzed with three methods such as analytic calculation,numerical computation,and measurement.The frequency of the TM_(110)mode from these methods agreed with the experimental results,while the transverse coupling impedance was different from the experimental results by some times.The main BBU exciter was the big transverse coupling impedance of the MFC which could be concluded.A grid was designed to shield the gap of the MFC.The experiments show that the BBU was compressed and the high frequency oscillation disappeared.
