【作者】 许明；

【导师】 李伟； 金波；

【作者基本信息】 浙江大学 ， 机械电子工程， 2009， 博士

【摘要】 电液变转速是通过改变电动机转速来改变液压泵输出流量的液压驱动技术,近年来研究和发展迅速,并逐步应用到液压电梯、注塑机、风机等领域。电液变转速驱动技术获得广泛应用的主要原因是节能效果显著,但同时也存在着响应速度慢、低速性能差等缺点。其中,响应速度慢是其主要缺点,致使其目前仅用于对响应速度及控制精度要求不高的场合。在普通变转速驱动的基础上加上阀控,组成变转速一节流复合驱动,有利于提高控制精度和减速时的响应速度,但不能提高加速时的响应速度。基于能量调节的电液变转速驱动技术是解决这个问题的一个很好途径。在系统中加装能量调节器,当系统需要能量,而液压泵由于加速响应慢而不能快速加速时,能量调节器释放能量,加快执行对象的加速响应;而在系统能量过剩时,同样由于液压泵的减速响应慢而不能快速减速时,能量调节器吸收能量,减少系统节流及溢流损耗。其余情况下,能量调节器关闭。基于能量调节的电液变转速驱动技术已就执行对象为液压缸时进行了仿真和试验研究,结果表明,此技术在保持传统变转速驱动高效率的基础上,能够大大提高执行对象液压缸的加速响应,获得了良好的效果,但所有的试验都是在空载情况下进行,并没有进行带载试验。本论文研究的是基于能量调节的电液变转速驱动技术在液压马达速度控制上的应用。在建模分析能量调节器及整个系统之后,提出基于分层控制的系统控制策略,并从能量调节思想出发,实现对被控对象的协调控制。进行了大量的仿真和试验研究,除空载外,还进行了马达的带载仿真和试验。结果表明,基于能量调节的电液变转速驱动技术在液压马达的速度控制上也收到了很好的成效,在保持传统变转速驱动高效率的基础上,提高了马达的响应速度,而且抗负载干扰能力较好。与此同时,能量调节器结构简单,应用到实际中系统改造小,具有良好的应用前景。第1章首先简要说明了液压领域里两种最基本的调速方式,即节流调速和容积调速的各自特点。然后从变频技术的发展出发,详细阐述了电液变转速驱动的发展背景及研究现状。蓄能器是能量调节器的重要构件,所以也对蓄能器的主要功能及典型应用作了说明。控制策略也是至关重要的,尤其是对于本系统的多输入多输出控制对象而言,在第1章中也对液压领域常用的控制策略进行简要说明。第2章对能量调节器进行了详尽分析。首先从功能特点出发,将能量调节器在系统中的作用分为两方面,即辅助动力源和吸收压力脉动。并详细说明了能量调节器在系统中的应用,即开式回路或闭式回路形式的系统结构。能量调节器作为辅助动力源使用是其在系统中的主要作用,作为吸收压力脉动使用时,分析了其能够吸收压力脉动的原因。第3章首先说明了基于能量调节的电液变转速阀控马达的原理,试验台构造。着重分析了基于ARM的系统控制器设计。然后推导出了整个系统的数学模型,并对其线性化,分析了系统的控制性能。此外,还定性分析了能量调节器的加入对阎控马达调速性能的影响。第4章从能量调节思想出发,提出了系统的分层控制结构,并分别对能量层、控制层、反馈层进行了详细说明以及给出了各自实现。本章还对三种对比研究系统的控制策略进行了说明。第5章为仿真研究。首先是定负载仿真,然后是变负载仿真。设计了阶跃、正弦、方波等多种指令转速形式,并进行了扰动仿真,目的是全面分析本系统的特点和性能。除此之外,本章还对蓄能器的主要参数对系统的影响进行了仿真分析,得出了能量调节器的设计原则和依据。第6章是试验研究。同仿真研究一致,也进行了定负载试验和变负载试验,指令转速的形式也有多种。仿真和试验结果表明,本系统在保持传统变转速驱动高效率的基础上,提高了马达的响应速度,而且抗负载干扰能力也很好。第7章为结论和展望。总结得出了本论文研究的主要结论,以及今后研究的方向。更多还原

【Abstract】 Variable-speed electrohydraulic drive is the technique that changing the pump’s output flowrate via changing the motor’s speed. It has been greatly studied and improved these years. And it has been used in hydraulic elevator, injection machine and fan drive et al. Variable-speed electrohydraulic drive is very popular because of its high efficiency. But it also has some disadvantages such as slow response, poor low-speed performance due to the big inertia of motor-pump. The main disadvantage is slow-response, which makes it only be used in the situations of low response and low control precision. To solve these problems, a flow control valve is added to realize the compound control drive composing of variable-speed control and valve control. The compound control drive can improve control precision, low-speed performance, and the deceleration response. But it is helpless to improving the acceleration response.Energy regulation based variable-speed electrohydraulic drive technique through adding an energy regulation device (ERD) into the compound drive system, is a good solution to this problem. If the system is accelerating while the pump can’t accelerate quickly due to its big interia, the ERD releases energy in order to improve response. If the system is decelerating while the pump can’t decelerate quickly, the ERD is open to absorb system redundant hydraulic oil. It decreases restriction loss and overflow loss. In other cases, the ERD is closed. Energy regulation based variable-speed electrohydraulic drive technique has been applied in cylinder control. The simulations and experiments results have shown that it can improve the acceleration response greatly and gain a good energy-saving effect. But all experiments were implemented under no-load condition. Load experiments have not accomplished yet.This dissertation discusses the application of energy regulation based variable-speed electrohydraulic drive technique to the hydraulic motor’s speed control. After modeling and analyzing the ERD and the total system, the hierarchical control strategy is proposed, which realizes the coordinate control together with the erergy regulation idea. A large number of simulations and experiments, which include no-load and load conditions, have been carried out. The results show that the energy regulation based variable-speed electrohydraulic valve-controlled motor drive can improve the hydraulic motor’s acceleration response on the base of high efficiency as the conventional variable-speed electrohydraulic drive and it has a good anti-load-interference ability. At the same time, the modification works will be small due to the ERD’s simple structure. And the energy regulation based variable-speed electrohydraulic drive has a very good application prospect.The Chapter 1 introduces the two basic speed-regulation modes, the valve resistance technique and the pump displacement control technique, in hydraulic drive firstly. Then, from the development of frequency control technique, the background and the present state of the variable-speed electrohydraulic drive are discussed in detail. The accumulator is an important component of the ERD. So the accumulator’s main functions and some typical application examples were given. The control strategy is very important too, sepecially to the MIMO system. The frequent control strategies are also discussed in the Chapter 1.The Chapter 2 discusses the ERD thoroughly. The ERD can display two aspects of effect, which are the auxiliary power sourse and the role of absorbing pulse ripple. And this chapter gives a detailed description about the ERD’s use in the open-loop or close-loop hydraulic systems. The main effect of the ERD to this system is its purpose of auxiliary power sourse. Also, the Chapter 2 discusses the reason why the ERD can absorb pulse ripple.The Chapter 3 firstly introduces the principles of energy regulation based variable-speed electrohydraulic valve-controlled motor drive, the structure of the testrig. It introduces emphatically the design of the controller based on ARM. Then the mathematical model of the whole system was deduced. After linearization, the system’s control performance was discussed. The Chapter 3 also discussed qualitatively the influence of adding ERD to the valve-controlled motor drive system.The Chapter 4 proposed the hierarchical control structure on the base of energy regulation idea. It also discussed the principles and implementations of the energy layer, the control layer and the feedback layer. The control strategies of the other three contrast system were also discussed in this chapter.The Chapter 5 is the simulation discussiones, which not only includes the constant-load simulations, but also the varying-load simulations. To analyzing the system’s performances generally, various input speed forms, like as step, sinusoldai, rectangle et al, are designed. The disturbed simulations are also implemented. The simulations of ERD’s main parameters are also carried out in this chapter for the purpose of the design rule of the ERD.The Chapter 6 is the experiment discussiones, which also include the constant-load and the varying-load experiments. It also has various input speed forms as the Chapter 5. The simulations and experiments results show that the discussed system in this paper can improve the hydraulic motor’s acceleration response on the base of high efficiency like as conventional variable-speed electrohydraulic drive. And the energy regulation based vairvble-speed drive has a good anti-load-interference ability.The Chapter 7 is the conclusions. It also gives the suggestions for the further research.更多还原