http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Pal Andre Nordhammer,Morten Kollerup Bak,Michael Rygaard Hansen 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
This paper is concerned with the robust handling of negative loads using counterbalance valves in hydraulically actuated equipment. Emphasis is on pressure compensated velocity control of a double acting cylinder. A linearized stability analysis of such a hydraulic circuit with hard quantities; cylinder volumes, cylinder area ratio and counterbalance valve pilot area ratio, is used prove to that without extra measures such a system will be unstable in a substantial part of the cylinder stroke. An alternative approach that guarantees stability while maintaining the counterbalance valve is put forward. The approach transfers the task of throttling the return flow from the counterbalance valve to the directional control valve. Thereby the remaining functionality of the multifunctional counterbalance valve is maintained. The practical implementation and limitation of the approach is discussed as well as the influence on overall performance.
P°al Andre Nordhammer,Morten Kollerup Bak,Michael Rygaard Hansen 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
This paper is concerned with the controlled motion of hydraulically actuated transmissions characterized by large inertias, backlash and several parallel coupled gearmotors. A method for controlled start and braking of such a transmission is put forward that utilizes sequential activation of the counterbalance valves of the hydraulic circuit. The method, which has been implemented into numerous high end offshore applications, is demonstrated by means of time domain simulations of a knuckle boom crane used for pipe handling in offshore drilling. The suggested activation method may yield higher load levels in the transmission but has the ability to reduce or eliminate the occurence of impact and loss of contact in the transmission.