【正文】 泵基于控制策略。因?yàn)檫@個環(huán)節(jié)，這是不可能 設(shè)置 的壓力水平在氣缸獨(dú)立 的兩邊 。一個系統(tǒng)調(diào)整參數(shù)的穩(wěn)定可能對另一個參數(shù)不穩(wěn)定。 當(dāng)前控制系統(tǒng)的分析 在新的控制系統(tǒng)設(shè)計(jì)之前最好分析當(dāng)前的控制系統(tǒng)來發(fā)現(xiàn)它們的問題。沒有穩(wěn)定性，不能使用控制系統(tǒng)。 ， 如更高的性能，提高效率，更靈活的控制等。 控制系統(tǒng)的定義是故意留下模糊，目的是不加任何約束在它的設(shè)計(jì)上。Virvalo, T. (1997). Computed Force Control of Hydraulic Manipulators, 5th Scandinavian International Conference On Fluid Power 中文譯文 控制移動液壓起重機(jī) Marc E. M220。jbjerg Maskinfabrik (HMF) A/S for the donation of the test crane. 7 REFERENCES Andersen, B. R.。t affect the action of the cylinder. For example, the action of the cylinder for 0psi/600 psi would be the same as 1000psi/1600psi. However, in the second case, the power supply would have to supply much more power. This extra power is wasted. Options for Control Systems Current control systems use hydraulic actuators with directional/proportional valves to control the movement. However there are many different options for controlling a cylinder. Options range from new high performance electrohydraulic valves, to separate meter in / separate meter out (SMISMO) valves, to hydraulic bus systems, to intelligent actuators with built in power supplies, to pump based control strategies. These systems all have advantages and disadvantages which need to be analyzed if the most optimum solution is to be chosen. Near Future Solution It is expected that even if it is proven that a pletely new system topology is the optimum configuration, the crane manufacturers and ponent manufacturers will not accept the new technology overnight. This will most likely take time, so an interim solution will be developed. This solution will be made up of micro puter controlled Separate Meter In / Separate Meter Out (SMISMO) valves (Elfving,Palmberg 1997。 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 current control systems to find out what their problems are. Current control systems are mainly hydraulic and can suffer from three main problems: cost Instability is a serious problem as it can cause injury to human operators or damage to equipment. When a system bees unstable it usually starts to oscillate violently. To avoid instability in current systems, the designers either sacrifice certain functions which are desirable,or add plexity and cost. For example, in the crane shown in Figure 1, it would be desirable to have control over the speed. But due to the safety system that cranes are required to have, standard speed control is not stable. To add speed control requires a more plex and more expensive mechanical system. The parameters of a hydraulic system, such as temperature or load force, also affect system that is stable with one set of parameters might be unstable with another set. To ensure stability over the entire operating range of the system, performance must sometimes be sacrificed at one end of the parameter range. cost Current systems are purely hydraulicmechanical, so if the user wants a certain function, the user buys a certain hydraulicmechanical ponent. Because most users have different requirements, there are many different variations of the same basic ponent. This means that many specialized ponents must be manufactured rather than one standard drives up the cost of ponents. One form of inefficie