【正文】
ms. 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。NZER Aalborg University Institute of Energy Technology, Pontoppidanstr230。Jansson,Palmberg, 1990。 Feigel 1990). This is not a new idea but has not been implemented mercially because of the high cost of pressure transducers and micro controllers. However, with the current drop in cost of micro controllers and pressure transducers this idea is now mercially feasible. The concept is very simple, spool position is calculated from the Bernoulli equation using the pressure drop across the spool and a reference flow. Even though this is a simple equation, it is not easy to implement. The accuracy of the flow control is dependent on the precision of the position sensors and of the pressure on the pressure or the position signals can cause stability problems. Filtering the noise,introduces delays in the control which can also affect stability. In addition the Bernoulli equation is not followed exactly over the entire operating range of the valve, so it may be necessary to store the valve characteristics as a data table or develop a more plex equation. Cylinder Control Strategy To control a hydraulic cylinder, the strategy has to be able to handle four different situations depending on the directions of the load and the velocity of the cylinder. Refer to Figure 3 The control strategies that have appeared in the literature are usually quite plex and depend on measurements of the cylinder position and velocity (Elfving,Palmberg 1997。 Ayres, J. L. (1997). Load Sensing Directional Valves, Current Technology and Future Development, The Fifth Scandinavian International Conference on Fluid Power Back233。lhydraulik und Pneumatik 34 Elfving, M.。NZER 奧爾堡大學(xué) 能源技術(shù)研究所 Pontoppidanstr230。 關(guān)鍵詞: 移動(dòng)液壓起重機(jī) ; 控制策略 ;單獨(dú)的輸入輸出儀表; 1 導(dǎo) 言 在這篇論文中論題描述的目的是改進(jìn) 控制移動(dòng)液壓起重機(jī)。 該控制系統(tǒng)作動(dòng) 是 移動(dòng)的機(jī)械結(jié)構(gòu),一 種控制 傳動(dòng)裝置的方法 ,一種給 傳動(dòng)裝置 供電 的方法 , 和接受操作者的輸入的方法。 :不同類型的傳動(dòng)裝置,不同類型的控制策略和不同方式的組織構(gòu)成。這將會(huì)減少商業(yè)適用但是將是更多研究的一個(gè)起點(diǎn)。 行業(yè)法規(guī)是第一要求,必須加以解決。穩(wěn)定性的確認(rèn),樹(shù)立了控制系統(tǒng)的執(zhí)行要求。人類工作者也施加影響控制系統(tǒng)的限制。 目前控制系統(tǒng)主要是水壓和遭受的三個(gè)主要的問(wèn)題: 性 不穩(wěn)定性 不穩(wěn)定是一個(gè)嚴(yán)重的問(wèn)題,因?yàn)樗梢栽斐蓚θ祟惖?操作者 或損壞的設(shè)備。但是由于起重機(jī)安全系統(tǒng)的要求,標(biāo)準(zhǔn)速度的控制是不穩(wěn)定的。為了確保完整系統(tǒng) 范圍對(duì)穩(wěn)定性,性能可能在某個(gè)參數(shù)范圍的目標(biāo)中犧牲掉。 這使構(gòu)成的成本上升。因此,出口方將制定一 個(gè)回壓力的行為,在反方向 行進(jìn) ,從而增加 維持運(yùn)動(dòng)進(jìn)口邊的要求壓力 。這額外的電力是浪費(fèi)。這些系統(tǒng)都有優(yōu)點(diǎn)和缺點(diǎn),需要加以分析,如果最優(yōu)化的解決辦法是選擇。 Jansson, Palmberg, 1990。 這消除了需要制造數(shù)百種不同的 變值 。如果證明即泵基于控制是要方式,未來(lái)舉例來(lái)說(shuō),分析,然后將表現(xiàn)在這方面的工作。第一,一個(gè)簡(jiǎn)單的自由度,起重機(jī),目的是作為一個(gè)實(shí)驗(yàn)平臺(tái)??刂崎y 的 控制算法,將程序是一種數(shù)字信號(hào)處理器( DSP ) /奔騰雙處理器系統(tǒng)。 壓力補(bǔ)償器保持恒定的壓力下降,全國(guó)主要閥芯的閥,不斷流不斷。 這不是一個(gè)新的構(gòu)思,但一直沒(méi)有得到實(shí)施,因?yàn)樵谏虡I(yè)上的成本高昂,壓力傳感器和微控制 器。精確的流量控制是依賴于高精度的位置傳感器和壓力傳感器。 閥門 的全部運(yùn)行 范圍,因此它可能是必要的儲(chǔ)存閥的特點(diǎn)作為一個(gè)數(shù)據(jù)表或開(kāi)發(fā)一個(gè)更復(fù)雜的方程 。 Virvalo 1997)他們 基于同樣的 基礎(chǔ)上,而不是復(fù)雜的控制算法。移動(dòng)液壓閥的需求,低漏電,并由于大多數(shù)流動(dòng)閥閥芯閥門,他們通常有大的重疊。 其中一個(gè)例子 是 一項(xiàng)新戰(zhàn)略,這是簡(jiǎn)單的和穩(wěn)健的描述如下。 要解決大的重疊和緩慢的驅(qū)動(dòng)階段,壓力控制器不僅 是儀表輸出 控制。在這種情況下,壓力范圍,壓力控制器,在出口增加的一個(gè)值,其中反對(duì)負(fù)荷的力量。 穩(wěn)定是沒(méi)有達(dá)到,因?yàn)槠鹬貦C(jī)是配備了負(fù)荷控股閥。 5 結(jié)論 即使沒(méi)有太大的試點(diǎn)工作已經(jīng)完成,一個(gè)好的開(kāi)始,已取得初步測(cè)試已大有希望的。 6 鳴謝 這個(gè)項(xiàng)目 由 丹佛斯流體動(dòng)力 A/S 提供部分資金