【正文】 液壓流體在環(huán)境上的優(yōu)勢。當(dāng)設(shè)計(jì)師們獲悉，一加侖 聚合物可以制造出二十加侖的流體時(shí)，即使是最昂貴的水添加劑都更有吸引力。 水基液壓系統(tǒng) 傳統(tǒng)上水基液壓系統(tǒng)已 經(jīng)應(yīng)用在鋼鐵廠煉鐵領(lǐng)域。 表 1 液壓支架的參數(shù) 表 2 四連桿 AEDA 的參數(shù) 四連桿 AEDA 的優(yōu)化 四連桿的數(shù)學(xué)模型 AEDA 的相關(guān)數(shù)據(jù)在方程 (22) (28)中都有表述。看這些偏離到底合時(shí)與否關(guān)鍵在于這個(gè)偏差是否在參數(shù) a1， a2， a4 容許的公差范圍內(nèi)。 點(diǎn) B 和 D 的坐標(biāo)分別是 ?cos5axxB ?? (1) ?sin5ayyB ?? (2) ? ??? ??? c o s6axx D (3) ? ??? ??? sin6ayy D (4) 參數(shù) a1， a2， 它能決定去怎樣尋找最主要的四連桿機(jī)構(gòu)數(shù)學(xué)模型 AEDB 的最有問題的參數(shù)a1， a2， a4，否則的話這將有必要在最小的機(jī)構(gòu)AEDB 改變這種設(shè)計(jì)方案。 中文譯文 液壓支架的最優(yōu)化設(shè)計(jì) 摘要 本文介紹了從兩組不同參數(shù)的采礦工程所使用的液壓支架中選優(yōu)的流程。如果允許的話，這會(huì)減少支架的承受能力。 a6一起被打印出來。然而端點(diǎn) C 的計(jì)算軌跡 L 可能有些偏離，因?yàn)樵谶\(yùn)動(dòng)中存在一些干擾因數(shù)。 [a1+a2+a3+a4]T= [674， 1360， 382， 1310]T (mm) (32) 在方程 (31)中 ，參數(shù) d 是液壓支架的移動(dòng)步距，為 925mm．四連桿 AEDA的桿系的有關(guān)參數(shù)列于表 2 中。 圖 4 用圖表示了端點(diǎn) C 開始的雙紐線軌跡 L（虛線）和垂直的理想軌跡 K（實(shí)線）。水基流體再次變成“熱門話題” 在 20世紀(jì) 70年代石油禁運(yùn)引發(fā)了較低成本的水基液壓流體替代高昂的液壓油的興趣。 不過，給水基流體加入防凍液可以使其凝固溫度遠(yuǎn)低于 32 華氏度。所以，系統(tǒng)流體的量在發(fā)生變化，但濃度沒有變化。 a6 are related to each other by 2222 ayx BB ?? (5) ? ? 24221 ayax DD ??? (6) By substituting (1)－ (4) into (5)－ (6) the response equations of the support are obtained as ? ? ? ? 0s i nc o s 222525 ????? aayax ?? (7) ? ?? ? ? ?? ? 0s i nc os 2426216 ???????? aayaax ???? (8) This equation represents the base of the mathematical model for calculating the optimal values of parameters a1， a2， a4. Mathematical model The mathematical model of the system will be formulated in the form proposed by Haug and Arora (1979) : min f(u， v)， (9) subject to constraints ? ? 0?vugi ， i=1， 2，?， l (10) and response equations ? ? 0?vuhj ， j=l， 2，?， m (11) The vector u=[u1? un]T is called the vector of design variables， v=[v1? vm]T is the vector of response variables and f in (9) is the objective function. To perform the optimal design of the leading fourbar mechanism AEDB， the vector of design variables is defined as u=[ a1 a2 a4]T， (12) and the vector of response variables as v=[x y]T． (13) The dimensions a3， a5， a6 of the corresponding links are kept fixed. The objective function is defined as some “measure of difference” between the trajectory L and the desired trajectory K as f(u， v) =max[g0(y) － f0(y)]2 (14) where x= g0(y) is the equation of the curve K and x= f0(y) is the equation of the curve L. Suitable limitations for our system will be chosen. The system must satisfy the wellknown Grasshoff conditions ? ? ? ? 02143 ???? aaaa (15) ? ? ? ? 04132 ???? aaaa (16) Inequalities (15) and (16) express the property of a fourbar mechanism， where the links a2， a4 may only oscillate. The condition uuu ?? (17) prescribes the lower and upper bounds of the design variables. The problems (9)(11) is not be directly solvable with the usual gradientbased optimizations methods. This could be circumvented by introducing an artificial design variable un+1 as proposed by Hsieh and Arora (1984). The new formulation exhibiting a more convenient form may be written as min un+1 (18) subject to ? ? 0v ?，ugi ， i=1， 2?， 1 (19) ? ? 0v 1 ?? ?nuuf ， ， (20) and response equations ? ? 0v ?，uhj j=l， 2，? m (21) where u=[u1… un un+1]T and v=[v1… vm]T . A nonlinear programming problem of the leading fourbar mechanism AEDB can therefore be defined as min 7a ， (22) subject to constraints ? ? ? ? 02143 ???? aaaa (23) ? ? ? ? 04132 ???? aaaa (24) 111 aaa ??，222 aaa ??，444 aaa ?? (25) ? ? ? ?? ? ? ?yy07200 ， yayfyg ???? (26) and response equations ? ? ? ? 0s i nc o s 222525 ????? aayax ?? (27) ? ?? ? ? ?? ? 0s i nc os 2426216 ???????? aayaax ???? (28) The formulation enables the minimization of the different between the transversal displacement of the point C and the prescribed trajectory K. The result is the optimal values of the parameters a1， a2， a4. stochastic model of the hydraulic support The mathematical model (22) (28) may be used to calculate such values of the parameters a1， a2， a4， that the “difference between trajectories L and K” is minimal. However， the real trajectory L of the point C could deviate from the calculated values because of different influe