RTCP(rotation tool centre point)检测方法是一种被广泛应用的五轴机床动态控制精度检测方法,目前针对RTCP检测的测量结果可视化方法对误差检测结果信息的展示完整度、误差图像特征明显程度等方面有进一步提升的空间,值得进一步研究改...RTCP(rotation tool centre point)检测方法是一种被广泛应用的五轴机床动态控制精度检测方法,目前针对RTCP检测的测量结果可视化方法对误差检测结果信息的展示完整度、误差图像特征明显程度等方面有进一步提升的空间,值得进一步研究改进。提出了一种新型误差检测结果可视化方法,将误差信息转化为极坐标形式,将误差数据进行极坐标网格化展示,能够更加充分地展示检测结果信息和图像特征,并通过应用示例论证了该方法的有效性、相对传统方法的优势、以及在误差溯源方面的应用潜力。目前,该方法已在ISO10791国际标准修订草案的会议讨论中获得应用,取得了良好的展示效果。展开更多
Two-stage directional valves usually employ proportional pilot control technology,which has the disadvantages of dead zones,leakage,and the large moving mass of the pilot valve.It is difficult,therefore,to achieve fas...Two-stage directional valves usually employ proportional pilot control technology,which has the disadvantages of dead zones,leakage,and the large moving mass of the pilot valve.It is difficult,therefore,to achieve fast-response performance of the main valve.In order to overcome this problem,a switching pilot technology that employs two independent high-speed on/off valves(HSVs)is proposed to replace the traditional pilot proportional valve.Due to the rapid switching characteristics of HSVs,the dead zone of the pilot stage is avoided,and the dynamic response performance of the main valve is improved.The experiments indicate that the switching frequency of the pilot HSVs and supply pressure of the pilot stage have a very large effect on the dynamic performance and control accuracy of the main valve.Increasing the switching frequency of the pilot HSVs is helpful for improving main-valve control accuracy.The larger supply pressure of the pilot stage can achieve a faster dynamic performance of the main valve while causing larger static errors.The results show that the switching pilot technology can clearly improve the static and dynamic performances of the main valve.With the increase of pilot supply pressure,the step rise time is reduced from 21.4 ms to 16.8 ms,and the dynamic performance of the main valve is improved by 21.5%.With the increase of pilot switching frequency,the steady-state error decreases from 24μm to 20μm,and the control accuracy of the main valve is improved by 16.7%.展开更多
An approach of simultaneous strategies with two novel techniques is proposed to improve the solution accuracy of chemical dynamic optimization problems. The first technique is to handle constraints on control vari- ab...An approach of simultaneous strategies with two novel techniques is proposed to improve the solution accuracy of chemical dynamic optimization problems. The first technique is to handle constraints on control vari- ables based on the finite-element collocation so as to control the approximation error for discrete optimal problems, where a set of control constraints at dement knots are integrated with the procedure for optimization leading to a significant gain in the accuracy of the simultaneous strategies. The second technique is to make the mesh refine- ment more feasible and reliable by introducing length constraints and guideline in designing appropriate element length boundaries, so that the proposed approach becomes more efficient in adjusting dements to track optimal control profile breakpoints and ensure accurate state and centrol profiles. Four classic benchmarks of dynamic op- timization problems are used as illustrations, and the proposed approach is compared with literature reports. The research results reveal that the proposed approach is preferz,ble in improving the solution accuracy of chemical dy- namic optimization problem.展开更多
文摘RTCP(rotation tool centre point)检测方法是一种被广泛应用的五轴机床动态控制精度检测方法,目前针对RTCP检测的测量结果可视化方法对误差检测结果信息的展示完整度、误差图像特征明显程度等方面有进一步提升的空间,值得进一步研究改进。提出了一种新型误差检测结果可视化方法,将误差信息转化为极坐标形式,将误差数据进行极坐标网格化展示,能够更加充分地展示检测结果信息和图像特征,并通过应用示例论证了该方法的有效性、相对传统方法的优势、以及在误差溯源方面的应用潜力。目前,该方法已在ISO10791国际标准修订草案的会议讨论中获得应用,取得了良好的展示效果。
基金supported by the Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-201906)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province,China(No.2022C01132)+1 种基金the Natural Science Foundation of Zhejiang Province,China(No.LQ21E050017)the China Postdoctoral Science Foundation(Nos.2021M692777 and 2021T140594)。
文摘Two-stage directional valves usually employ proportional pilot control technology,which has the disadvantages of dead zones,leakage,and the large moving mass of the pilot valve.It is difficult,therefore,to achieve fast-response performance of the main valve.In order to overcome this problem,a switching pilot technology that employs two independent high-speed on/off valves(HSVs)is proposed to replace the traditional pilot proportional valve.Due to the rapid switching characteristics of HSVs,the dead zone of the pilot stage is avoided,and the dynamic response performance of the main valve is improved.The experiments indicate that the switching frequency of the pilot HSVs and supply pressure of the pilot stage have a very large effect on the dynamic performance and control accuracy of the main valve.Increasing the switching frequency of the pilot HSVs is helpful for improving main-valve control accuracy.The larger supply pressure of the pilot stage can achieve a faster dynamic performance of the main valve while causing larger static errors.The results show that the switching pilot technology can clearly improve the static and dynamic performances of the main valve.With the increase of pilot supply pressure,the step rise time is reduced from 21.4 ms to 16.8 ms,and the dynamic performance of the main valve is improved by 21.5%.With the increase of pilot switching frequency,the steady-state error decreases from 24μm to 20μm,and the control accuracy of the main valve is improved by 16.7%.
基金Supported by the Joint Funds of NSFC-CNPC of China(U1162130)the International Cooperation and Exchange Project of Science and Technology Department of Zhejiang Province(2009C34008)+1 种基金the National High Technology Research and Development Program of China(2006AA05Z226)the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scientists(R4100133)
文摘An approach of simultaneous strategies with two novel techniques is proposed to improve the solution accuracy of chemical dynamic optimization problems. The first technique is to handle constraints on control vari- ables based on the finite-element collocation so as to control the approximation error for discrete optimal problems, where a set of control constraints at dement knots are integrated with the procedure for optimization leading to a significant gain in the accuracy of the simultaneous strategies. The second technique is to make the mesh refine- ment more feasible and reliable by introducing length constraints and guideline in designing appropriate element length boundaries, so that the proposed approach becomes more efficient in adjusting dements to track optimal control profile breakpoints and ensure accurate state and centrol profiles. Four classic benchmarks of dynamic op- timization problems are used as illustrations, and the proposed approach is compared with literature reports. The research results reveal that the proposed approach is preferz,ble in improving the solution accuracy of chemical dy- namic optimization problem.
