【正文】 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。Semiautomatic control system for hydraulic shovel Abstract A semiautomatic control system for a hydraulic shovel has been developed. Using this system, unskilled operators can operate a hydraulic shovel easily and accurately. A mathematical control model of a hydraulic shovel with a controller was constructed and a control algorithm was developed by simulation. This algorithm was applied to a hydraulic shovel and its effectiveness was evaluated. High control accuracy and highstability performance were achieved by feedback plusfeedforward control, nonlinear pensation, state feedback and gain scheduling according to the attitude. Keywords: Construction machinery。 State feedback。 hi scylinder length。 Pi scylinder rodside pressure。 Ksbulk modulus of oil。 determines the condition of each control lever。 thus, the effects of the control algorithm described in Chap. 3 were ascertained. . Effect of nonlinear pensation Fig. 11. Effect of nonlinear pensation on boom angle. Because dead zones exist in the electrohydraulic systems, steadystate error remains when simple position feedback without pensation is applied in the figure.. Addition of nonlinear pensation in the figure. can reduce this error. . Effect of state feedback control For the arm and bucket, stable response can be obtained by position feedback only, but adding acceleration or pressure feedback can improve fastresponse capability. As regards the boom, with only the position feedback, the response bees oscillatory. Adding acceleration or pressure feedback made the response stable without impairing fastresponse capability. As an example, Fig. 12 shows the test results when pressure feedback pensation was applied during boom lowering. . Le213。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)。 關(guān)鍵詞：施工機(jī)械；液壓挖掘機(jī)；前饋；狀態(tài)反饋；操作 1．引言 液壓挖掘機(jī)，被稱為大型鉸接式機(jī)器人，是一種施工機(jī)械。 液壓挖掘機(jī)之所以要求較高的操作技能，其理由如下。在這種情況下，操作手柄的操作表明了執(zhí)行元件的動(dòng)作方向，但是這種方向與工作方向不同。 1. 自動(dòng)控制系統(tǒng)必須采用普通的控制閥。具體闡述如下。 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 。Fi是液壓缸的動(dòng)摩擦力。 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。在半自動(dòng)控制系統(tǒng)中，為了實(shí)現(xiàn)自控與手控的協(xié)調(diào)，必須使用手動(dòng)的主控閥。 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。 但是，一般很難精確的測出加速度。 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)。 實(shí)際上，用不同的 △ θ2值可確定 1。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。（在 SK16 大型液壓挖掘機(jī)進(jìn)行模擬實(shí)驗(yàn)。通過現(xiàn)場試驗(yàn)可驗(yàn)證其操作性。液壓控制系統(tǒng)控制產(chǎn)生的液壓力與電磁比例閥的電信號成比例，主控閥的滑芯的位置控制流入液壓缸液壓油的流量。 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。對動(dòng)臂操作桿的手控操作能暫時(shí)中斷自動(dòng)控制，因?yàn)槭挚夭僮鞯膬?yōu)先級高于自動(dòng)控制。 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。5186。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。例如，圖 12 表示動(dòng)臂下降時(shí)，采用壓力反饋補(bǔ)償時(shí)的測試結(jié)果。如圖示的 “開 ”。與不裝補(bǔ)償裝置的情況相比較，圖中的關(guān)表示 不裝時(shí)，開的情況具有補(bǔ)償提供穩(wěn)定響應(yīng)。 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)的影響。因而應(yīng)用這些控制技術(shù)，允許即使是不熟練的司機(jī)也能容易和精確地操控液壓