反馈线性化控制一台转动液压传动外文文献翻译/中英文翻译/外文翻译

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. 译文： 反馈线性化控制一台转动液压传动 控制工程实践， 15 卷， 12 期， 2007 年 12 月，页 1495 至 1507 页 Jaho Seo, Ravinder Venugopal 和 Jean-Pierre Kenn 摘要 线性反馈技术是用于设计控制器的位移 、 速度和控制液压 往复 传动 的 压差。该控制器， 应用了 平方根非线性系统的动力学， 用于 实施实验性测试平台和成果的 绩效评估测试。本研究的目的是双重的： 第一 ，以目前的一个统一的方法跟踪控制的位移，速度和压差 ；第二，通过实验解决问题的系统是否可以 以 足够的精确度模仿， 从而 有效地取消了非线性在 实际 体系 中的应用 。 关键词：非线性控制 ；反馈线性化 ；液压作动器 ；实时系统 1 导言 电液伺服液压系统（ ehss ）广泛 应用于各 个行业 ，涉及到 液压冲压 、 注塑成型机 和 航天飞行控制致动器。电液伺服液压系统作为非常有效的动力驱动系统，拥有高功率 /质量比，反应快，高刚度，高承载能力 等优点 。最大限度地 利用 液压系统，并满足日益严格的性能 要 求 ，鲁棒跟踪精度高 和 快 的 响应速度 是 高性能伺服控制器 所 需要 的 。但是，传统的线性控制器（ Anderson， 1988年 和 Merritt， 1967 年 ）的局限性 在于 非线性动力学在电液伺服液压系统 中的应用 ，具体地说，一个平方根关系压差驱动流的液压流体和流速。这些限制已在文献上 都有记载了 ，见 Ghazy（ 2001 ） ， Sun and Chiu（ 1999 ） ，例如 : 若干做法已 被 提出，以解决这方面的不足，包括使用变结构控制（ 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）和反馈线性（ Chiriboga et al.， 1995 年 和 Jovanovic， 2002 年 ） 。变结构控制在其基本形式是容易的抖振（ guglielmino Edge， 2004 年） 因为 控制算法是基于 转换的 ；但是， 提出了一些方案来解决这一问题 （ ghazy ， 2001 年 ， guglielmino and Edge， 2004 and Mihajlov et al.， 2002 年 ） 。回步 这 种技术，是基于 Lyapunov 理论，并保证渐近跟踪（ Jovanovic, 2002， ， kaddissi 等人， 2005 年 ， Kaddissi et al.， 2007 年 和 Ursu and Popescu, 2002） ，但是，寻找一 种 适当 应用函数 的 技术 具有挑战性。使用这种方法 的 控制器 具有 典型的复杂性 而且 校正控制参数瞬态响应 也 不直观。其他的 Lyapunov 为基础的技术解决了系统的非线性如摩擦，但也容易产生同样的缺点（ Liu & Alleyne, 1999 年） 。反馈线性化， 实现了 非线性系统转化为一个等价的线性 系统 有效地抵消闭环系统 中的 非线性计算， 并 提 出 了一种解决非线性系统 的方法 ，同时也允许 使用动力 线性控制设计技术 来研究 瞬态响应要求和舵机的局限性。使用反馈线性控制电液伺服液压系统已被描述在 Chiriboga et al. (1995) and Jovanovic (2002) 、 Brcker and Lemmen ( 2001 ） 的书里 ，为跟踪控制的液压柔性机器人 而进行的抗扰被认为是利用 解耦技术类似的反馈线性化方法提出了此处。但是，这种方法需要测量干扰势力及其 衍变的时间 ，在实际应用中 这是不太可能的。 与上述提到的 都是 以 全状态反馈为基础的做法 相比 ， Sun and Chiu（ 1999 ） 提出了设计 一个基于观测器的算法，专门为部队控制的一个电液伺服液压系统。一个采用迭代的方法 设计的 自适应控制器 来 更新控制参数 并解决由于较小厂房和扰动 知识 造成的 摩擦影响 在这里被提出 Tar, Rudas, Szeghegyi, and Kozlowski (2005)模型的基础上，在 Brcker and Lemmen (2001) 描述了。 大部分的 文献 就此 有着相仿的记录， 与 实际 的 试验结果 Liu and Alleyne (1999), Niksefat and Sepehri (1999), Sugiyama and Uchida (2004) 表现出的明显的例外 。本研究的 重 点是介绍一 种全面的 控制器设计方法， 也 就是涵盖位移 、 速度和压差控制 的设计 ， 它提出 非线性在电液伺服液压系统 中的弊端 并 探讨像 瞬态响应和实时实现 这样的 实际 性 问题。因此， 文中重要的部分是关于 实验方面的研究。此外，这 篇文章可以 作为一个明确的指导，帮助其制定和实施反馈线性化控制器 在 电液伺服液压系统 中的应用 。 本文的组织结构如下：第 2 节 提出 了旋转液压传动 是用来作为实验测试平台。在这一节中， 该系统的 数学 建模 ，还审查和审定 了 实验数据。第 3 节描述设计 PID控制器 通过模仿 和实验结果 对 反馈线性控制器 的基线业绩进行考核 ；