【正文】 翻譯部分 英文原文 CONTROL OF MOBILE HYDRAULIC CRANES Marc E. M220。NZER Aalborg University Institute of Energy Technology, Pontoppidanstr230。de 101 DK9220 Aalborg, Denmark The goal of the thesis described in this paper is to improve the control of mobile hydraulic cranes. The thesis is split into five parts: a requirements analysis, an analysis of the current systems and their problems, an analysis of different possibilities for system topologies, development of a new control system for the near future based on electrohydraulic separate meter in / separate meter out valves, and finally an analysis of more advanced and plex solutions which can be applied in the more distant future. The work of the thesis will be done in cooperation with industry so the thesis will have more of an industrial focus than a purely theoretical focus. Key words: Mobile Hydraulic Cranes, Control Strategies, Separate Meterin/Separate Meterout. 1 INTRODUCTION The goal of the thesis described in this paper is to improve the control of mobile hydraulic cranes. A mobile hydraulic crane can be thought of as a large flexible mechanical structure which is moved by some sort of control system. The control system takes its input from a human operator and translates this mand into the motion of actuators which move the mechanical structure. The definition of this control system is purposely left vague in order not to impose any constraints on its design. The control system consists of actuators which move the mechanical structure, a means of controlling the actuators, a means of supplying power to the actuators,and a way of accepting inputs from the operator. It is this control system which is the target of this thesis. The goal is to analyze the requirements made on the control system and present guidelines for the design of new control systems. The thesis will be split into five parts: of the requirements of the control system, from the perspective of the operator, the mechanical system, efficiency, stability, and safety requirements. of current control systems and what their problems are. of the different options for the control system: different types of actuators,different types of control strategies, and different ways of organizing ponents. of a new type of control system, which is mercially implementable. A system that will meet the needs of industry in the near future. of more optimized systems, with higher performance, better efficiency, more flexible control, etc. This will be less mercially applicable but will be a starting point for more research. 2 SECTIONS OF THE THESIS Analysis of the Control System Before starting detailed work on developing new control systems, it is important to analyze what the exact demands are on the control system. The control system is influenced by many factors. For example: the mechanical structure it is controlling, the human operator, effi ciency, stability, and industry regulations. Industry regulations are the first requirements that have to be addressed. Things like hose rupture protection and runaway load protection make a lot of demands on the control regulations, stability is the next most important requirement。 without stability the control system can’t be used. Once stability has been assured, the performance requirements of the control system have to be set. They are determined by the mechanical structure of the crane and the human operator. The mechanical structure of a mobile hydraulic crane is a very large flexible structure which has very low natural frequencies. To prevent oscillations it is necessary to keep the speed of the control system below this natural frequency or to develop a control system which can increase this frequency. The human operator also imposes limits on the control system. If the control system is too slow or too fast then it is impossible for a human operator to give it proper inputs. And finally, once the regulations have been met, stability is assured, and the performance is at the right level, the power efficiency of the control system has to be optimized. of Current Control Systems Before designing a new control system it is good to analyze the cur