反饋線性化控制一臺轉(zhuǎn)動液壓傳動外文文獻(xiàn)翻譯/中英文翻譯/外文翻譯

外文原文： Feedback linearization based control of a rotational hydraulic drive Control Engineering Practice, Volume 15, Issue 12, December 2007, Pages 1495-1507 Jaho Seo, Ravinder Venugopal and Jean-Pierre Kenn Abstract The technique of feedback linearization is used to design controllers for displacement, velocity and differential pressure control of a rotational hydraulic drive. The controllers, which take into account the square-root nonlinearity in the systems dynamics, are implemented on an experimental test bench and results of performance evaluation tests are presented. The objective of this research is twofold: firstly, to present a unified method for tracking control of displacement, velocity and differential pressure； and secondly, to experimentally address the issue of whether the system can be modeled with sufficient accuracy to effectively cancel out the nonlinearities in a real-world system. Keywords: Nonlinear control； Feedback linearization； Hydraulic actuators； Real-time systems 1. Introduction Electro-hydraulic hydraulic servo-systems (EHSS) are extensively used in several industries for applications ranging from hydraulic stamping and injection molding presses to aerospace flight-control actuators. EHSS serve as very efficient drive systems because they posses a high power/mass ratio, fast response, high stiffness and high load capability. To maximize the advantages of hydraulic systems and to meet increasingly exacting performance specifications in terms of robust tracking with high accuracy and fast response, high performance servo-controllers are required. However, traditional linear controllers (Anderson, 1988 and Merritt, 1967) have performance limitations due to the presence of nonlinear dynamics in EHSS, specifically, a square-root relationship between the differential pressure that drives the flow of the hydraulic fluid, and the flow rate. These limitations have been well documented in the literature； see Ghazy (2001), Sun and Chiu (1999), for example. Several approaches have been proposed to address these limitations, including the use of variable structure control (Ghazy, 2001； Mihajlov, Nikolic, & Antic, 2002), back-stepping (Jovanovic, 2002； Kaddissi et al., 2005 and Kaddissi et al., 2007； Ursu & Popescu, 2002) and feedback linearization (Chiriboga et al., 1995 and Jovanovic, 2002). Variable structure control in its basic form is prone to chattering (Guglielmino & Edge, 2004) since the control algorithm is based on switching； however, several modifications have been proposed to address this problem (Ghazy, 2001, Guglielmino and Edge, 2004 and Mihajlov et al., 2002). Back-stepping is a technique that is based on Lyapunov theory and guarantees asymptotic tracking (Jovanovic, 2002, Kaddissi et al., 2005, Kaddissi et al., 2007 and Ursu and Popescu, 2002), but finding an appropriate candidate Lyapunov function can be challenging. The controllers obtained using this method are typically complicated and tuning control parameters for transient response is non-intuitive. Other Lyapunov based techniques address additional system nonlinearities such as friction, but are also prone to the same drawbacks as those listed for back-stepping (Liu & Alleyne, 1999). Feedback linearization, in which the nonlinear system is transformed into an equivalent linear system by effectively canceling out the nonlinear terms in the closed-loop, provides a way of addressing the nonlinearities in the system while allowing one to use the power of linear control design techniques to address transient response requirements and actuator limitations. The use of feedback linearization for control of EHSS has been described in Chiriboga et al. (1995) and Jovanovic (2002). In Brcker and Lemmen (2001) disturbance rejection for tracking control of a hydraulic flexible robot is considered, using a decoupling technique similar to the feedback linearization approach proposed herein. However, this approach requires measurements of the disturbance forces and their time derivatives, which are unlikely to be readily available in a practical application. In contrast to the above mentioned techniques, which are all full-state feedback based approaches, Sun and Chiu (1999) describe the design of an observer-based algorithm specifically for force control of an EHSS. An adaptive controller which uses an iterative approach to update control parameters and addresses frictional effects with minimal plant and disturbance knowledge is proposed in Tar, Rudas, Szeghegyi, and Kozlowski (2005) based on the model described in Brcker and Lemmen (2001). Most of the literature on the subject shows simulation results； notable exceptions with actual experimental results are Liu and Alleyne (1999), Niksefat and Sepehri (1999), Sugiyama and Uchida (2004), and Sun and Chiu (1999). The focus of this study is on presenting a controller design approach that is comprehensive, that is, one that covers displacement, velocity and differential pressure control, addresses the nonlinearities present in EHSS and considers practical issues such as transient response and real-time implementation. Thus, a significant portion of the paper is dedicated to the experimental aspects of the study. In addition, this paper is intended to serve as a clear guide for the development and implementation of feedback linearization based controllers for EHSS. The paper is organized as follows: Section 2 describes the rotational hydraulic drive that is used as an experimental test bench. In this section, the mathematical model of the system is also reviewed and validated using experimental data. Section 3 describes the design of PID controllers for this system with simulation and experimental results that serve as a baseline for evaluating the performance of the feedback linearization controllers； Section 4 describes the design and implementation of the feedback linearization controllers and finally, concluding remarks are provided in Section 5. 2. Modeling System description The electro-hydraulic system for this study is a rotational hydraulic drive at the LITP (Laboratoire dintgration des technologies de production) of the University of Qubec cole de technologie suprieure (TS). The set-up is generic and allows for simple extension of the results herewith to other electro-hydraulic systems, for example, double-acting cylinders. Referring to the functional diagram in Fig. 1, a DC electric motor drives a pump, which delivers oil at a constant supply pressure from the oil tank to each component of the system. The oil is used for the operation of the hydraulic actuator and is returned through the servo-valve to the oil tank at atmospheric pressure. An accumulator and a relief valve are used to maintain a constant supply pressure from the output of the pump. The electro-hydraulic system includes two Moog Series 73 servo-valves which control the movement of the rotary actuator and the load torque of the system. These servo-valves are operated by voltage signals generated by an Opal-RT real-time digital control system. Fig. 1. Functional diagram of electro-hydraulic system. The actuator and load are both hydraulic motors connected by a common shaft. One servo-valve regulates the flow of hydraulic fluid to the actuator and the other regulates the flow to the load. The actuator operates in a closed-loop while the load operates open-loop, with the load torque being proportional to the command voltage to the load servo-valve. While the actuator and load chosen for this study are rotary drives, the exact same set-up could be used with a linear actuator and load, and thus, they are represented as generic components in Fig. 1. The test set-up includes three sensors, two Noshok Series 200 pressure sensors with a 0 10 V output corresponding to a range of 20.7 MPa (3000 PSI) that measure the pressure in the two chambers of the rotational drive, as well as a tachometer to measure the angular velocity of the drive. In order to reduce the number of sensors used (a common preference for commercial application), angular displacement is obtained by numerically integrating the angular velocity measurement. Fig. 2 shows the layout of the system and the Opal-RT RT-LAB digital control system. Fig. 2. Layout of LITP test bench. The RT-LAB system consists of a real-time target and a host PC. The real-time target runs a dedicated commercial real-time operating system (QNX), reads sensor signals using an analog-to-digital (A/D) conversion board and generates output voltage signals for the servo-valves using a digital-to-analog (D/A) conversion board. The host PC is used to generate code for the target using MATLAB/Simulink and Opal-RTs RT-LAB software and also to monitor the system. Controller parameters can also be adjusted on-the-fly from the host in RT-LAB. 3. Conclusions The goal of this research is to review the nonlinear dynamics of a rotational hydraulic drive, study how these dynamics lead to limitations in PID controller performance, and to design and implement servo-controllers appropriate for displacement, velocity and pressure control. Feedback linearization theory is introduced as a nonlinear control technique to accomplish this goal in this study, and the controllers designed using this method are validated using experimental tests. From these tests, it can be seen that for hydraulic systems that have nonlinear characteristics, feedback linearization theory provides a powerful control strategy that clearly improves on PID control in terms of tracking precision and transient response. The results show that the system can be modeled with sufficient accuracy to effectively implement the controllers. This study is limited to the control of a rotational hydraulic drive. The application of feedback linearization theory to the control of more complex integrated rotational and linear drives, as well as other effects such as friction, may be considered as future extensions of this work. 譯文： 反饋線性化控制一臺轉(zhuǎn)動液壓傳動 控制工程實(shí)踐， 15 卷， 12 期， 2007 年 12 月，頁 1495 至 1507 頁 Jaho Seo, Ravinder Venugopal 和 Jean-Pierre Kenn 摘要 線性反饋技術(shù)是用于設(shè)計控制器的位移 、 速度和控制液壓 往復(fù) 傳動 的 壓差。該控制器， 應(yīng)用了 平方根非線性系統(tǒng)的動力學(xué)， 用于 實(shí)施實(shí)驗(yàn)性測試平臺和成果的 績效評估測試。本研究的目的是雙重的： 第一 ，以目前的一個統(tǒng)一的方法跟蹤控制的位移，速度和壓差 ；第二，通過實(shí)驗(yàn)解決問題的系統(tǒng)是否可以 以 足夠的精確度模仿， 從而 有效地取消了非線性在 實(shí)際 體系 中的應(yīng)用 。 關(guān)鍵詞：非線性控制 ；反饋線性化 ；液壓作動器 ；實(shí)時系統(tǒng) 1 導(dǎo)言 電液伺服液壓系統(tǒng)（ ehss ）廣泛 應(yīng)用于各 個行業(yè) ，涉及到 液壓沖壓 、 注塑成型機(jī) 和 航天飛行控制致動器。電液伺服液壓系統(tǒng)作為非常有效的動力驅(qū)動系統(tǒng)，擁有高功率 /質(zhì)量比，反應(yīng)快，高剛度，高承載能力 等優(yōu)點(diǎn) 。最大限度地 利用 液壓系統(tǒng)，并滿足日益嚴(yán)格的性能 要 求 ，魯棒跟蹤精度高 和 快 的 響應(yīng)速度 是 高性能伺服控制器 所 需要 的 。但是，傳統(tǒng)的線性控制器（ Anderson， 1988年 和 Merritt， 1967 年 ）的局限性 在于 非線性動力學(xué)在電液伺服液壓系統(tǒng) 中的應(yīng)用 ，具體地說，一個平方根關(guān)系壓差驅(qū)動流的液壓流體和流速。這些限制已在文獻(xiàn)上 都有記載了 ，見 Ghazy（ 2001 ） ， Sun and Chiu（ 1999 ） ，例如 : 若干做法已 被 提出，以解決這方面的不足，包括使用變結(jié)構(gòu)控制（ Ghazy ， 2001 年 ； Mihajlov, Nikolic, & Antic ， 2002 年） ，回步（ Jovanovic， 2002年 ； kaddissi等人， 2005年 和 kaddissi等人， 2007年 ； ursu Popescu, 2002 年）和反饋線性（ Chiriboga et al.， 1995 年 和 Jovanovic， 2002 年 ） 。變結(jié)構(gòu)控制在其基本形式是容易的抖振（ guglielmino Edge， 2004 年） 因?yàn)?控制算法是基于 轉(zhuǎn)換的 ；但是， 提出了一些方案來解決這一問題 （ ghazy ， 2001 年 ， guglielmino and Edge， 2004 and Mihajlov et al.， 2002 年 ） ?；夭?這 種技術(shù)，是基于 Lyapunov 理論，并保證漸近跟蹤（ Jovanovic, 2002， ， kaddissi 等人， 2005 年 ， Kaddissi et al.， 2007 年 和 Ursu and Popescu, 2002） ，但是，尋找一 種 適當(dāng) 應(yīng)用函數(shù) 的 技術(shù) 具有挑戰(zhàn)性。使用這種方法 的 控制器 具有 典型的復(fù)雜性 而且 校正控制參數(shù)瞬態(tài)響應(yīng) 也 不直觀。其他的 Lyapunov 為基礎(chǔ)的技術(shù)解決了系統(tǒng)的非線性如摩擦，但也容易產(chǎn)生同樣的缺點(diǎn)（ Liu & Alleyne, 1999 年） 。反饋線性化， 實(shí)現(xiàn)了 非線性系統(tǒng)轉(zhuǎn)化為一個等價的線性 系統(tǒng) 有效地抵消閉環(huán)系統(tǒng) 中的 非線性計算， 并 提 出 了一種解決非線性系統(tǒng) 的方法 ，同時也允許 使用動力 線性控制設(shè)計技術(shù) 來研究 瞬態(tài)響應(yīng)要求和舵機(jī)的局限性。使用反饋線性控制電液伺服液壓系統(tǒng)已被描述在 Chiriboga et al. (1995) and Jovanovic (2002) 、 Brcker and Lemmen ( 2001 ） 的書里 ，為跟蹤控制的液壓柔性機(jī)器人 而進(jìn)行的抗擾被認(rèn)為是利用 解耦技術(shù)類似的反饋線性化方法提出了此處。但是，這種方法需要測量干擾勢力及其 衍變的時間 ，在實(shí)際應(yīng)用中 這是不太可能的。 與上述提到的 都是 以 全狀態(tài)反饋為基礎(chǔ)的做法 相比 ， Sun and Chiu（ 1999 ） 提出了設(shè)計 一個基于觀測器的算法，專門為部隊控制的一個電液伺服液壓系統(tǒng)。一個采用迭代的方法 設(shè)計的 自適應(yīng)控制器 來 更新控制參數(shù) 并解決由于較小廠房和擾動 知識 造成的 摩擦影響 在這里被提出 Tar, Rudas, Szeghegyi, and Kozlowski (2005)模型的基礎(chǔ)上，在 Brcker and Lemmen (2001) 描述了。 大部分的 文獻(xiàn) 就此 有著相仿的記錄， 與 實(shí)際 的 試驗(yàn)結(jié)果 Liu and Alleyne (1999), Niksefat and Sepehri (1999), Sugiyama and Uchida (2004) 表現(xiàn)出的明顯的例外 。本研究的 重 點(diǎn)是介紹一 種全面的 控制器設(shè)計方法， 也 就是涵蓋位移 、 速度和壓差控制 的設(shè)計 ， 它提出 非線性在電液伺服液壓系統(tǒng) 中的弊端 并 探討像 瞬態(tài)響應(yīng)和實(shí)時實(shí)現(xiàn) 這樣的 實(shí)際 性 問題。因此， 文中重要的部分是關(guān)于 實(shí)驗(yàn)方面的研究。此外，這 篇文章可以 作為一個明確的指導(dǎo)，幫助其制定和實(shí)施反饋線性化控制器 在 電液伺服液壓系統(tǒng) 中的應(yīng)用 。 本文的組織結(jié)構(gòu)如下：第 2 節(jié) 提出 了旋轉(zhuǎn)液壓傳動 是用來作為實(shí)驗(yàn)測試平臺。在這一節(jié)中， 該系統(tǒng)的 數(shù)學(xué) 建模 ，還審查和審定 了 實(shí)驗(yàn)數(shù)據(jù)。第 3 節(jié)描述設(shè)計 PID控制器 通過模仿 和實(shí)驗(yàn)結(jié)果 對 反饋線性控制器 的基線業(yè)績進(jìn)行考核 ；