共查询到18条相似文献,搜索用时 62 毫秒
1.
2.
基于LuGre模型的自适应摩擦补偿 总被引:9,自引:0,他引:9
为提高开放式伺服系统的动态性能,使其具有良好的适应能力,提出一种基于LuGre模型的自适应摩擦补偿方法.建立开放式伺服系统的动力学模型,并通过LuGre模型来描述系统的摩擦特性.考虑到摩擦模型的参数会随系统变化而发生改变,采用Backstepping方法设计自适应摩擦补偿控制器,并采用Lyapunov定理证明系统的全局渐进稳定性.通过可编程多轴控制器(Programmable multi-axis controller,PMAC)编写伺服算法实现该自适应摩擦补偿方案,并通过试验验证该方案的有效性.试验结果表明:与传统的速度加速前馈补偿相比,该自适应摩擦补偿方案在正弦运动作为输入信号时,其跟踪误差由±40 μn降低到±7 μm.采用该补偿方案能有效地抑制摩擦干扰对伺服系统的不利影响,为提高伺服系统的动态跟踪性能奠定基础. 相似文献
3.
文中提出了一个基于分解的控制设计框架并合成了摩擦补偿方案,以最合适的控制方法来补偿每个类型的摩擦.具有未知但恒定的参数的未建模摩擦由自适应来进行补偿,而模型参数变化的摩擦及非参数未建模摩擦由鲁棒补偿器来进行补偿.两种补偿器综合起来,构成了总的补偿方案,仿真结果证明了该摩擦补偿方案的有效性. 相似文献
4.
5.
6.
论文提出了一种利用扩展两层神经网络和模糊整定PD控制相结合,对机械手伺服系统进行控制器设计的自适应跟踪控制设计方法,利用扩展两层神经网络的精确逼近特性来逼近机械手伺服系统中的未知动态摩擦。利用Lyapunov理论证明引入的一鲁棒控制律保证了机械手闭环系统的稳定性,仿真结果验证了基于扩展两层神经网络控制方法的有效性。 相似文献
7.
基于预滑—动态摩擦力矩估计模型的自适应前馈补偿方法 总被引:1,自引:2,他引:1
根据数控交流伺服工作台进给系统从静止到宏观运动的过渡时间,和零速度时刻的指令加速度大小呈反比关系,区分摩擦力矩的预滑动区和滑动区,由此提出基于力矩值估计的摩擦补偿方法;在设定指令加速度后,基于命令力矩值的摩擦力矩模型,不需要测量速度就可以补偿工作台进给系统中的摩擦。同时,考虑到参数的不确定性,设计非线性摩擦自适应控制方案,对其稳定性进行理论证明。在交流伺服工作台进给系统上对基于摩擦力矩值估计的自适应前馈补偿方法进行验证。试验结果表明,基于预滑—动态摩擦力矩估计模型的自适应前馈补偿方法能实现在不同指令加速度下对期望轨迹的跟踪,并能大大提高系统的跟踪精度。 相似文献
8.
9.
10.
11.
This paper presents a robust adaptive integral backstepping control strategy with friction compensation for realizing accurate and stable control of opto-electronic tracking system in the presence of nonlinear friction and external disturbance. With the help of integral control term to decrease the steady-state error of the system and combining robust adaptive control approach with the backstepping design method, a novel control method is constructed. Nonlinear modified LuGre observer is designed to estimate friction behavior. Robust adaptive integral backstepping control strategy is developed to compensate the changes in friction behavior and external disturbance of the servo system. The stability of the opto-electronic tracking system is proved by Lyapunov criterion. The performance of robust adaptive integral backstepping controller is verified by the opto-electronic tracking system with modified LuGre model in simulation and practical experiments. Compared to the adaptive integral backstepping sliding mode control method, the root mean square of angle error is reduced by 26.6% when the proposed control method is used. The experiment results demonstrate the effectiveness and robustness of the proposed strategy. 相似文献
12.
本文采用新型Stribeck模型和区间辨识方法对伺服系统中的摩擦补偿进行了研究。首先,针对Stribeck摩擦模型存在非线性、控制计算量大和不利于控制器设计等缺点,本文对其进行了线性化,并提出一种线性化的Stribeck模型;然后介绍了区间理论的参数辨识方法,并对方法的有效性进行了仿真验证研究;利用所提出的新模型进行了摩擦实验,结果显示该模型可以辨识出摩擦参数,接着设计了前馈摩擦补偿控制器。最后,分别采用阶跃和正弦输入信号进行实验,结果显示采用所设计摩擦补偿器补偿后,两种信号的稳态精度分别提高了26.8%和83.63%,验证了新模型和方法的有效性。本文提出的新型Stribeck模型易于工程应用,所用区间分析理论适用于参数辨识。 相似文献
13.
Modeling and control compensation of nonlinear friction using adaptive fuzzy systems 总被引:2,自引:0,他引:2
System performance in terms of control accuracy and stability is usually negatively affected by friction occurrences in mechanical systems. Thus, it is important to model the friction properly so that it can be used in controller design. This paper employs adaptive fuzzy systems to approximate unknown nonlinear friction functions, and applies the estimation of friction in proportional-derivative (PD) control law to enhance the control performance. On the basis of Lyapunov stability theory, a bound of tracking errors of the closed-loop control system is derived. Techniques proposed in this paper have been applied to a typical motion control system for simulation studies. The results obtained demonstrate that our proposed method in this paper has good potential in controlling many mechanical systems with unknown nonlinear friction. 相似文献
14.
提出了一种应用于WDM系统中的自适应偏振模色散(PMD)补偿方法,用粒子群优化(PSO)算法来实现DOP的搜索和跟踪,并经D/A转换,将对应的电压施加在偏振控制器上,调制电压范围为0~10V,调节信号的基本偏振态,从而形成闭环反馈控制模块,通过多次迭代,得到DOP的最佳值,实现对PMD的自适应补偿. 相似文献
15.
对等步距多工位工作的纳米工作台,采用灰色模型能够同时对定位误差中的系统误差和随机误差进行动态补偿。讨论了提高灰色模型精度的方法,建立了改进背景值的等维新息GM(1,1)灰色预测模型。用5 μm步距定位误差进行了一步预测分析,结果表明该模型具有较高的预测精度;5 μm和3 μm步距的定位误差预测补偿实验表明,工作台的定位误差可以控制在40 nm以内。实验证明了灰色预测模型用于纳米定位系统动态补偿的有效性,且需要的建模数据很少、计算量小,适用于具有时变特征的精密定位系统。 相似文献
16.
为了克服基于"当前"统计模型的交互式多模型算法难以恰当地确定当前模型的概率,以及系统参数amax和a-max在跟踪过程中不能自适应调整的缺点,提出了一种基于自适应模糊逻辑的多模犁跟踪算法.介绍了基于"当前"统计模型的交互式多模型算法,给出了算法的基本步骤.在"当前"统计模型算法基础上,提出了一种基于自适应模糊逻辑的多模型跟踪改进算法,采用模糊推理给出了模型的选择概率,以提高跟踪的速度;同时,采用蚁群算法对设计参数进行优化,以提高跟踪的精度.最后,将所设计的基于"当前"统计模型的多模型改进算法用于机动目标的跟踪仿真.实验结果表明:改进的算法使得跟踪精度提高了20%左右,机动目标跟踪一次仿真时间为0.047 s,基本满足高速、高精度跟踪目标的要求. 相似文献
17.
Friction is often ignored when designing a controller for the ball and plate system, which can lead to steady-error and stick-slip phenomena, especially for the small amplitude command. It is difficult to achieve high-precision control performance for the ball and plate system because of its friction. A novel reference compensation strategy is presented to attenuate the aftereffects caused by the friction. To realize this strategy, a linear control law is proposed based on a reduced-order observer. Neither the accurate friction model nor the estimation of specific characteristic parameters is needed in this design. Moreover, the describing function method illustrates that the limit cycle can be avoided. Finally, the comparative mathematical simulations and the practical experiments are used to validate the effectiveness of the proposed method. 相似文献
18.
A compound scheme is proposed to compensate the effect of nonlinear friction disturbance on the control precision of a three-axis inertially stabilized platform (ISP) for aerial remote sensing applications. The scheme consists of friction parameters identification and adaptive compensation. A LuGre model-based ISP friction model is first developed. Then, a comprehensive experimental scheme is proposed to obtain the static friction parameters. Further, the dynamic parameters are identified by experiments and dynamic optimization. On the basis of identified parameters and Lyapunov stability theory, a backstepping integral adaptive compensator is designed to compensate the nonlinear friction disturbance. Simulations and experiments are carried out to validate the scheme. The results show that the compound scheme can accurately obtain the friction parameters and improve the control precision and stability of ISP. 相似文献