ABSTRACT Stick–slip vibrations are widespread and hazardous phenomena in drilling practice. The objective of this paper is to develop a simple and general control strategy to minimise such vibrations together with unknown disturbances. Taking into account the transmission delay of the torsional energy from the surface to downhole, a neutral-type drill-string model is established and applied rather than a lumped-parameter model that cannot provide satisfactory modelling precision. Based on this neutral-type model, the major contribution consists of the combination of disturbance estimator and smith predictor to develop a robust vibration control scheme for drill-string systems. One conspicuous advantage of this scheme is that the effects of stick–slip vibrations and external disturbances are estimated without the need for any prior knowledge in the control input channel, and are offset correspondingly. Simulations confirm that this control scheme can achieve effective suppression of stick–slip vibrations with good tracking and disturbance rejection performance.

中文翻译：

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基于干扰估计器和史密斯预测器的钻柱系统粘滑振动主动抑制

摘要 粘滑振动是钻井实践中普遍存在的危险现象。本文的目的是开发一种简单而通用的控制策略，以最大限度地减少此类振动和未知干扰。考虑到扭转能量从地面到井下的传输延迟，建立并应用中性型钻柱模型，而不是不能提供令人满意的建模精度的集中参数模型。基于这种中性模型，主要贡献包括干扰估计器和史密斯预测器的组合，为钻柱系统开发稳健的振动控制方案。该方案的一个显着优点是在不需要控制输入通道中的任何先验知识的情况下估计粘滑振动和外部干扰的影响，并相应地抵消。仿真证实，该控制方案可以有效抑制粘滑振动，具有良好的跟踪和抗扰性能。