【正文】 ynamic model of excavator, Journal of Aerospace Engineering 6 2 1990 April. [7] H. Hanafusa, Design of electrohydraulic servo system for articulated robot, Journal of the Japan Hydraulics and Pneumatics Society 13 7 1982 1–8. [8] . Kuntze et al., On the modelbased control of a hydraulic large range robot, IFAC Robot Control 1991 207–212. 。在控制精度方面沒有發(fā)現(xiàn)與不加載荷時(shí)有很大的不同。 位置的補(bǔ)償作用 當(dāng)反鏟處在上升位置或者反鏟動(dòng)作完成時(shí)，反鏟水平動(dòng)作趨于不穩(wěn)定。 狀態(tài)反饋控制的作用 對(duì)于斗柄和鏟斗，只需位置反饋就可獲得穩(wěn)定響應(yīng)，但是增加加速度或壓力反饋能提高響應(yīng)速度 。 7 現(xiàn)場(chǎng)試驗(yàn)結(jié)果與分析 通過對(duì)系統(tǒng)進(jìn)行現(xiàn)場(chǎng)試驗(yàn)，證實(shí)該系統(tǒng)能準(zhǔn)確工作。其具體功能如下。這一節(jié)將討論該控制系統(tǒng)的結(jié)構(gòu)與功能。為了解決這個(gè)難題，根據(jù)位置的自適應(yīng)增益調(diào)度并入反饋環(huán)中（圖 6）。例如，如圖 6 所示，在反鏟水 平動(dòng)作控制中，動(dòng)臂的控制是通過保持斗柄底部 Z（由 θ1與 θ2計(jì)算所得）與 Zr 的高度。例如，大型液壓挖掘機(jī) SK16 中。為了獲得更精確的控制，非線性補(bǔ)償和 狀態(tài)反饋均加入位置反饋中。Xi是滑芯的位置； Psi是供給壓力 。依次表示動(dòng)臂，斗柄，鏟斗 )。 2. 液壓挖掘機(jī)必須補(bǔ)償其動(dòng)態(tài)特性以提高其控制精度。 ，至少有兩個(gè)操作手柄必須同時(shí)操作并且要協(xié)調(diào)好。采用該系統(tǒng)，即使是不 熟練的操作者也能容易和精確地操控液壓挖掘機(jī)。 selects control modes andcalculates actuating variables。 Vi soil volume in the cylinder and piping。 Operation 1. Introduction A hydraulic shovel is a construction machinery that can be regarded as a large articulated robot. Digging and loading operations using this machine require a high level of skill, and cause considerable fatigue even in skilled operators. On the other hand, operators grow older, and the number of skilled operators has thus decreased. The situation calls forhydraulic shovels, which can be operated easily by any person w1–5x. The reasons why hydraulic shovel requires a high level of skill are as follows. 1. More than two levers must be operated simultaneously and adjusted well in such operations. 2. The direction of lever operations is different from that of a shovel’s attachment movement. For example, in level crowding by a hydraulicshovel, we must operate three levers ?arm, boom, bucket. simultaneously to move the top of a bucketalong a level surface ?Fig. 1.. In this case, the lever operation indicates the direction of the actuator, but this direction differs from the working direction. If an operator use only one lever and other freedoms are operated automatically, the operation bees very easily. We call this system a semiautomatic control we develop this semiautomatic control system, these two technical problems must be solved. 1. We must use ordinary control valves for automatic control. 2. We must pensate dynamic characteristics of a hydraulic shovel to improve the precision of control. Fig. 1. Level crowding of an excavator and frame model of anexcavator. We have developed a control algorithm to solve these technical problems and confirm the effect of this control algorithm by experiments with actual hydraulic shovels. Using this control algorithm, we have pleted a semiautomatic control system for hydraulic shovels. We then report these items. 2. Hydraulic shovel model To study control algorithms, we have to analyzenumerical models of a hydraulic shovel. The hydraulic shovel, whose boom, arm, and bucket joints are hydraulically driven, is modeled as shown in . The details of the model are described in thefollowing. Fig. 2. Model of hydraulic shovel. . Dynamic model [6] Supposing that each attachment is a solid body, from Lagrange’s equations of motion, the following expressions are obtained: 其中 K sm 1 g。 State feedback。 Pi scylinder rodside pressure。 determines the condition of each control lever。D Kobe Steel Engineering Reports 37 2 1987 74–78. [6] . Vaha, . Skibniewski, Dynamic model of excavator, Journal of Aerospace Engineering 6 2 1990 April. [7] H. Hanafusa, Design of electrohydraulic servo system for articulated robot, Journal of the Japan Hydraulics and Pneumatics Society 13 7 1982 1–8. [8] . Kuntze et al., On the modelbased control of a hydraulic large range robot, IFAC Robot Control 1991 207–212. 液壓挖掘機(jī)的半自動(dòng)控制系統(tǒng) 摘要 :開發(fā)出了一種應(yīng)用于液壓挖掘機(jī)的半自動(dòng)控制系統(tǒng)。 液壓挖掘機(jī)之所以要求較高的操作技能，其理由如下。 1. 自動(dòng)控制系統(tǒng)必須采用普通的控制閥。 動(dòng)態(tài)模型 [6] 假定每一臂桿組件都是剛體，由拉格朗日運(yùn)動(dòng)方程可得以下表達(dá)式： 其中 g 是重力加速度； θi鉸接點(diǎn)角度； τi是提供的扭矩； li 組件的長度； lgi轉(zhuǎn)軸中心到重心之距； mi組件的質(zhì)量； Ii是重心處的轉(zhuǎn)動(dòng)慣量 (下標(biāo) i=13。hi是液壓缸的長度 。 3 角度控制系統(tǒng) 如圖 4 所示， θ角基本上由隨動(dòng)參考輸入角 θγ 通過位置反饋來控制。 狀態(tài)反饋 建立在第 2 節(jié)所討論的模型的基礎(chǔ)上，若動(dòng)臂角度控制動(dòng)態(tài)特性以一定的標(biāo)準(zhǔn)位置逼近而線性化（滑芯位移 X 10，液壓缸壓力差 P 110，動(dòng)臂夾角 θ10），則該閉環(huán)傳遞函數(shù)為 其中， Kp 是位置反饋增益系數(shù)； 由于系統(tǒng)有較小的系數(shù) a1,所以反應(yīng)是不穩(wěn)定的。 4 伺服控制系統(tǒng) 當(dāng)一聯(lián)軸器是手動(dòng)操控，而其它的聯(lián)軸器是因此而被隨動(dòng)作控制時(shí)，這必須使用伺服控制系統(tǒng)。因此，要在所有位置以恒定的增益穩(wěn)定的控制機(jī)器是困難的。通過現(xiàn)場(chǎng)試驗(yàn)可驗(yàn)證其操作性。 控制功能 控制系統(tǒng)有三種控制模式，能根據(jù)操作桿 和選擇開關(guān)自動(dòng)切換。 系統(tǒng)主要采用 C 語言編程來實(shí)現(xiàn)這些功能，以構(gòu)建穩(wěn)定模組提高系統(tǒng)的運(yùn)行穩(wěn)定性。加入非線性補(bǔ)償后（圖 11 中的開）能減少這種錯(cuò)誤的產(chǎn)生。如圖示的 “開 ”。 受載作用 利用控制系統(tǒng)，使液壓挖掘機(jī)執(zhí)行實(shí)際挖掘動(dòng)作，以研究其受載時(shí)