共查询到18条相似文献,搜索用时 203 毫秒
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针对高速轻型并联机器人残余振动抑制问题,基于输入整形法,对其残余振动抑制进行实验研究。首先分析了并联机构运动学,建立了机构动力学模型。然后对每个输入轴分别设计一个比例-微分(PD)控制器,建立包含PD控制器的系统动力学模型。最后分别设计了单模态零振动(ZV)、零振动微分(ZVD)整形器和双模态零振动-零振动微分(ZV-ZVD)整形器,建立了并联机器人实验系统。实验结果表明,输入整形器可以抑制并联机器人的残余振动,而双模态整形器振动抑制效果更好。 相似文献
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为实现骨科手术自动化,研制了用于获取断骨位置和姿态信息的全自动C形臂X光机,但其结构形式决定了它是一种典型的大惯量、高柔性机构,易于产生残余振动.残余振动的存在不利于图像的连续拍摄,且影响拍摄质量.采用输入指令整形技术,针对系统的一、二阶模态,设计输入指令整形器,对系统的输入指令进行整形滤波后,有效地消除了残余振动,提高了系统的响应速度.输入指令整形方法本质上是设计一种滤波器,采用该方法抑制残余振动不需要对原有系统的结构和硬件作任何改动.实验证明,这种方法对于抑制大惯量、高柔性系统中存在的残余振动问题是有效的. 相似文献
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改进型负输入整形与最优控制结合的振动抑制方法 总被引:2,自引:1,他引:1
针对诸如柔性机械臂这类柔性系统的主动振动控制问题,提出了基于改进型负输入整形和最优控制结合的振动抑制方法。以柔性机械臂为研究对象,设计最优状态反馈控制实现其旋转机动任务及柔性振动抑制。为增强柔性振动抑制效果和改善系统的运动时间,根据引入线性二次型调节器(LQR)反馈后整个闭环系统的振动频率和阻尼比设计改进型负输入整形器作为前馈控制器。将前馈控制与反馈控制相结合能发挥其各自的优点,提高系统的性能。仿真分析结果表明,所设计的混合控制策略可以有效地抑制柔性振动,且可以减少系统响应时间的延迟和加快系统响应速度。 相似文献
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《振动工程学报》2019,(6)
针对利用输入整形技术对机器人进行抑振时引入的延时问题,提出一种误差补偿法实现对斜坡信号的无延时跟踪。以6自由度机器人为对象,研究在斜坡输入信号作用下机器人末端的振动特性,设计了误差补偿方法以应对固定任务时长的运动;同时,采用基于傅立叶频谱分析和时域分析的综合方法来估计机器人系统的模态参数进而设计合理的整形器,并定量分析输入整形法对机器人末端残余振动幅值的影响。最后,搭建了6自由度机器人振动抑制测试的实验平台,进行点到点(point-to-point)实验。结果显示,机器人末端残余振动的最大幅值从15.14m/s~2降低到7.047m/s~2,且整形前后运动轨迹时长保持一致,表明该方法在固定任务时长的情况下有效地抑制了机器人末端的残余振动。 相似文献
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摘要: 针对压电俘能系统悬臂梁结构集中参数模型的局限性,引入Euler Bernoulli梁振动模型。通过分析两模型在振动时相对位移传递率发现,集中参数模型在基础激励情况下,传递率峰值存在较大偏差。理论分析了Euler Bernoulli及集中参数模型在一阶模态附近位移传递率函数,对集中参数模型进行了修正。仿真结果表明修正后的集中参数模型相对位移传递率峰值与Euler Bernoulli模型在低阶模态吻合良好。 相似文献
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航天器外伸的太阳帆板会引起驱动扰动和残余振动两类振动问题,且两者发生在不同的振动方向(扭转和弯曲),并属于不同的振动类型(强迫与自由振动)。提出一种多自由度减振装置实施方案,通过调整驱动系统动态特性降低两类振动干扰。基于虚功原理建立了太阳帆板驱动系统动力学模型,分析了减振装置刚度和阻尼参数对驱动系统动态特性的影响规律,研制了减振装置原理样机,并通过试验验证其减振效果。结果表明,减振装置刚度特性对驱动系统的固有频率至关重要,需要谨慎考虑以避免共振;减振装置等效阻尼与驱动系统模态阻尼呈正相关,应采用高损耗系数的阻尼材料;减振装置能使驱动扰动降低40%以上,99%残余振动幅值衰减时间缩短56%以上。 相似文献
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Various input-shaping schemes such as the “zero-vibration” (ZV), “zero-vibration-and-derivative” (ZVD), “negative ZV” (NZV),
and “negative ZVD” (NZVD) schemes have previously been proposed to suppress motion-induced residual vibration of lightly damped
structures. In such schemes, the input command of the dynamical system in question is properly administered (i.e., shaped), so that the dominant induced vibration modes are annihilated through destructive interference. Here we are concerned with
the effects of system payload on the vibration reduction capabilities of the aforementioned input-shaping schemes, especially
when they are applied to continuous systems. By use of the simple structure of a linearly elastic rod as a specific example,
it is demonstrated that both the minimum achievable residual vibration amplitude and the tolerance of detuning parameter errors
of the input-shaping schemes are sensitive to the amount of payload on the system. It is therefore imperative to take the
factor of system payload into account in the design of practical input shapers. 相似文献
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AbstractIt is essential to suppress vibrations of the feed drive system in order to achieve high speed and high precision machining. To analyze the dynamic response of the feed drive system, a more complete model is derived in this paper which considers the bed, longitudinal and torsional modes. The dynamic model is represented by the block diagram and is incorporated with servo controls to form a closed-loop system. To alleviate vibrations of the servo-feed drive system, a full order modified input shaping with zero vibration (FMISZV) algorithm integrated into the CNC interpolator is developed. The performance of vibration suppression using the FMISZV is compared to those of conventional input shapers, such as zero vibration with derivation (ZVD) and conventional linear acceleration/deceleration (Acc/Dec) interpolator (CLAI). It is shown that the FMISZV not only has the notch filter effect, but also exhibits low-pass filter behavior for high frequency modes. Simulation and experimental results demonstrate that the FMISZV can outperform the ZVD and CLAI. 相似文献
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A single-degree-of-freedom nonlinear spring–mass system, subjected to a particular shaped input force whose magnitude varies with time in a piecewise-constant manner is considered. The goal is to bring the point mass in the
model system from initial rest to a prescribed new equilibrium position without exciting any residual vibration. If, ideally,
the potential energy associated with the elastic spring is known as a function of its elongation, the magnitude and execution
time of each force step that serve the abovesaid purpose can be calculated by analyzing the mechanical energy flow. However,
in practice the potential function almost inevitably contains a small estimation error, and residual vibration would be excited
by the input force so calculated. By use of asymptotic techniques, the residual vibration excited by a two-step input force
with slightly incorrect task time and force magnitudes is calculated. It is also demonstrated that, by comparing the closed-form
results of the asymptotic analysis with online measurements of the excited residual vibration, the shape of the two-step input
force (characterized by the task time and force magnitudes) can be corrected iteratively, thereby suppressing the residual
vibration. 相似文献