【作者】 郑洪波；

【导师】 孙友松；

【作者基本信息】 广东工业大学 ， 材料加工工程， 2012， 博士

【摘要】 伺服直驱泵控液压技术是一种新型传动技术,具有节能、高效、宽调速范围、高可靠性、低噪音、易实现计算机数字控制等诸多优点,在成形加工装备领域有着广泛的潜在的应用。但伺服直驱泵控液压系统属于容积调速,且包含了驱动器和电机环节,使得整个系统存在响应慢、控制特性差等难点问题,本文围绕这些难点问题进行了深入系统的研究,并对伺服直驱泵控液压技术的节能机理进行了深入探讨。建立了伺服直驱泵控液压系统的数学模型,对主要参数对于伺服直驱泵控液压系统的性能影响进行了仿真分析和开环阶跃响应实验研究；对伺服直驱泵控液压系统和进口节流阀调速系统进行了能耗分析和对比实验研究；研究了可拓控制、神经网络模型预测控制等智能控制策略在伺服直驱泵控液压系统中的应用；研究了伺服直驱泵控液压系统的节能机理,设计了一种伺服直驱泵控液压机并对其动态性能和能耗进行了仿真和实验研究；研究了伺服直驱泵控液压驱动技术在传统压铸机节能改造中的应用并通过仿真和实验进行了节能机理研究。本文的主要贡献包括以下几个部分：(1)针对电液伺服系统快速性、稳定性和精确性存在矛盾的问题,提出了一种多模态可拓控制方法,根据提取的系统特征信息,建立特征状态可拓关联函数,由关联度来划分测度模式选择不同的控制模态,在不同控制论域内分别采用不同的控制策略,通过多模态可拓控制切换器实现分段控制,使每一种控制策略在其能够有效控制的范围内达到理想的控制效果,从而兼顾系统快速性、稳定性和精确性的要求。该系统具有较快的响应速度和对参数变化的鲁棒性,并能实现高精度控制,为电液伺服系统的智能控制提供了新的途径。(2)针对传统控制策略的滞后性和液压系统强非线性、参数时变等特点,将神经网络模型预测控制应用于伺服直驱泵控液压系统中,提出了伺服直驱泵控液压系统神经网络预测控制。设计了控制系统结构并进行了仿真研究,该系统能实现在线自学习,比常规PID控制和模糊控制等控制策略具有更好的自适应能力和控制性能。(3)建立了伺服直驱泵控液压系统的数学模型和能耗分析仿真方法,对该系统的响应速度、精度和稳定性进行了理论分析,提出了提高其动态性能的措施；研究了伺服直驱泵控液压系统的节能机理。与切削加工不同,成形加工呈现出周期尖峰的负载特性,为适应这一特性,普通液压驱动系统无论是容积调速还是节流调速,均不可避免地存在能量损失；而伺服直驱泵控液压系统依靠伺服电机的速度、扭矩控制,主动适应变化的负载特性,可实现最大限度节能。(4)设计了2000kN多功能伺服直驱泵控液压机液压系统,开发了首台样机。结合一种具体的金属板材拉深工艺,对伺服直驱泵控液压机的工作性能和节能机理进行了理论分析、数值仿真和实验研究。其主要节能环节在于保压减少溢流和待机时电机停转。研究表明,该液压机可实现位移(速度)或压力的双闭环控制,可优化工艺程序；较同型号普通液压机节能20%以上,数值模拟与实验结论较好地吻合。(5)设计了8000kN压铸机伺服直驱泵控改造方案并付诸实施。对该系统的节能机理进行了仿真和实验研究。实验表明,改造后的压铸机节能达46.3%,提高生产效率5%,数值模拟与实验结论较好地吻合。其节能的主要环节在于伺服直驱泵控液压驱动技术解决了动力源和变负载的匹配问题,减少了节流损耗和溢流损耗；而生产率的提高的主要原因在于蓄能器补液阶段和空行程阶段电机加速。鉴于国内目前尚无商品化伺服直驱泵控液压机和压铸机产品,本文的研究为该类新产品的开发提供了理论基础和技术指导,具有重要的理论和实用价值。更多还原

【Abstract】 Direct drive pump-controlled servo hydraulic technology is a new transmission technology with advantages such as energy-saving, high efficiency, wide timing range, high reliability, low noise and being easy to realize digital control, and it has broad and potential application in forming equipment field. But direct drive pump-controlled servo hydraulic system is a kind of volume velocity governing, along with including the part of driver and motor, it has main key problems of long response time and imperfect control performance. Deep and systematic researches have been done centered on the difficult problems, and the applications of direct drive pump-controlled servo hydraulic technology in forming equipment and its energy-saving mechanism have been thoroughly exploredThe mathematical model of direct drive pump-controlled servo hydraulic system was built, simulations and open-loop step experiments were held to analyze and research the affect that main parameters exert on the performance of direct drive pump-controlled servo hydraulic system. The energy consumption analysis and experiment of the two systems, which are pump-controlled speed governing system and hydraulic speed governing system with inlet throttle, are given. The applications of intelligent control strategies, including extension control and neural network predictive control, were studied. The application of direct drive pump-controlled servo hydraulic technology in hydraulic press was researched, a pump-controlled servo hydraulic press was designed and its dynamic performance and energy consumption simulation and experiment was made. The application of direct drive pump-controlled servo hydraulic technology in retrofitting traditional die casting machines are given, and the simulation and experiment were made. Concretely, the dissertation’s main contributions are as follows:(1) Aiming at the contradiction between rapid response, stability and accuracy in position control of pump-controlled electro-hydraulic servo system, a multi-mode extension control electro-hydraulic servo system was proposed. According to the characteristic information of the system, correlation function was established by multi-mode extension control switch. The movement process was divided into three parts according to correlative degree, different control mode is used in different domain to realize subsection control. Every control mode could get ideal result in its effective control domain. Multiple requirements of control system are considered and the goals of rapid, smooth and accurate positioning could be got. The system had rapid response and strong robustness, and can realize high precision control. It provides a new way for the intelligent control of electro-hydraulic system.(2) Aiming at the hysteresis of traditional control strategy and the strong nonlinearity and time-varying parameters of hydraulic systems, neural network model predictive control was applied to direct drive pump-controlled servo hydraulic system, the structure of control system was designed and the simulation research was carried out. The system can realize on-line self-learning, compared with traditional PID control and fuzzy control, it has better self-adaptive ability and control precision.(3) Mathematical model and energy consumption simulation method for direct drive pump-controlled servo hydraulic system have been built, and the measures to improve its dynamic performance have been proposed on the basis of analyzing its response speed and precision stability theoretically; the energy-saving mechanism of direct drive pump-controlled servo hydraulic system have been researched. Unlike cutting, load of forming process presents periodical peak-like feature, to fit it, the traditional hydraulic drive system exists energy loss inevitably no matter volume speed governing or cutting speed governing are adopted; however, relying on controlling speed and torque to fit actively the varying load, direct drive pump-controlled servo hydraulic system can save energy to the full.(4) The hydraulic system of the2000kN multi function direct drive pump-controlled servo hydraulic press was designed and the first prototype was developed. Taking a specific metal sheet deep-drawing process as an example, the working principle and energy-saving mechanism were analyzed theoretically and simulated numerically and researched by experiment. The main energy-saving links lies in reducing the overflow in keeping pressure stage and stopping the motor in standby stage. The study shows the hydraulic press can realize position (speed) and pressure double closed-loop control, and can optimize the process program. Compared to same type of traditional hydraulic press, over20%energy can be saved, the simulations were in agreement with the experiments.(5) The direct drive pump-controlled servo retrofitting scheme for8000kN die casting machine was given and carried out. The energy-saving mechanism was researched by simulation and experiment. The experiment shows that the retrofitted die casting machine can save46.3%energy and improve production efficiency by5%. The simulation was identical with the experiment. The main energy-saving links lays that direct drive pump-controlled servo hydraulic technology solved the problem of the match between the power source and the varying load, lowering the throttling loss and the overflow loss; the main reason for improving the production was speeding up the motor during the accumulator adding oil.Given at present there are not commercial direct drive pump-controlled servo hydraulic presses and die casting machines in China, the research of the paper provides theoretical basis and technological guidance for the development of such new products and possesses important theory and application value.更多还原