In order to improve the performance of the active vibration isolation system (AVIS) with electromagnetic actuator, several problems of vibration control are studied. Position control is a critical component in suspension systems, and the position sensor noise can extremely affect the stability of the system, so a tracking differentiator (TD) is proposed to obtain effective differential signal from relative position sensor. In vibration control, the feedback of acceleration combined with PD position feedback is presented to suppress transmission of periodic vibrations. Then, taking the acceleration transmission as the evaluation index, the acceleration transmission under the presented control method is derived, and the influence of control parameters on vibration isolation performance is discussed in detail. The vibration isolation performance is improved from 24.47 dB to 2.4 dB at resonance frequency, and −34 dB attenuation is achieved at 100 Hz with respect to vibration isolation mount system tested on the ground. The experimental results demonstrate that the performance of active vibration isolation system are improved by the proposed acceleration feedback control.

The electromagnet module, as a fundamental component providing levitation force for maglev trains, plays a crucial role in ensuring the stability of train operation. However, vibrations can easily occur due to the mechanical coupling between the two suspension points of the electromagnet module. To reveal the inherent instability of the system and the coupling relationship between the state variables, a state-space equation that considers the mechanical coupling between the two suspension points is established. Furthermore, a differential control algorithm based on geometric feature transformation is proposed to mitigate the structural coupling vibration. Simulation experiments are conducted to compare the dynamic characteristics of the system before and after implementing the improvement algorithm under complex conditions. At the same time, the influence of control parameters on electromagnetic vibration was analyzed, focusing particularly on vibrations resulting from parameter mismatch, offering crucial insights for enhancing system stability. Additionally, suspension tests are carried out on the high-speed double bogie test platform in the Key Laboratory of Hunan Province to further validate the effectiveness of the proposed algorithm. The proposed control framework is both effective and concise, making it easy to implement in engineering applications. This research holds significant practical value in improving the stability of maglev trains.

This paper addresses the stringent requirements of high-precision equipment for broadband, contactless active vibration isolation by tackling three key research gaps: the lack of an integrated design deeply coupling vertical and lateral subsystems, the absence of explicit characterization of the base-to-load vibration transmission chain in dynamic models, and the disconnect between theory and application due to spatial sensor–actuator mismatch. To bridge these gaps, a novel five-degree-of-freedom active magnetic levitation vibration isolation system is proposed. Its core contributions are threefold. First, an electromagnetic-structure co-design method based on the equal magnetic reluctance principle is introduced, enabling a globally optimized, integrated actuator layout that maximizes force density within spatial constraints. Second, a dynamic model incorporating explicit base kinematic excitation is established, clearly revealing the complete physical mechanism of vibration transmission through the suspension gap and providing an accurate foundation for model-based control. Third, a coordinate reconstruction control model is constructed, which transforms the ideal center-of-mass-based dynamics into a design model using only measurable gap signals via systematic coordinate transformations, thereby fundamentally eliminating control deviations from physical spatial mismatch. This work provides a comprehensive theoretical framework and solution for next-generation high-performance active vibration isolation platforms, encompassing integrated design, precise modeling, and engineering implementation.

In metal-dense indoor environments (such as maglev maintenance workshops), multipath reflections generate coherent signals that cause rank deficiency in the array covariance matrix, leading to severe angle-of-arrival (AOA) estimation bias and false peaks in the conventional MUSIC algorithm. To address this issue, this paper proposes an enhanced MUSIC Spatial Smoothing Technique (MSST) for high-precision Bluetooth Low Energy (BLE) AOA positioning. The proposed method integrates three core mechanisms: (1) overlapping subarray division and covariance matrix averaging to restore signal rank characteristics; (2) dynamic noise subspace separation based on an eigenvalue distribution threshold to suppress residual coherent interference; and (3) an optimization-driven aperture configuration to balance angular resolution with computational complexity. The algorithm was experimentally evaluated using an nRF52833-driven single-anchor receiver equipped with a 12-element uniform linear patch array in a real metal-dense scenario, benchmarked against high-precision laser tracker ground truth. Experimental results show that, compared with conventional MUSIC, MSST reduces the −3 dB–3 dB mainlobe width from 22° to 0.82° (a 96.3% compression), enhances the sidelobe suppression by 12.56 dB (reaching −34.54 dB), and reduces off-diagonal covariance energy by 62%. The eigenvalue separation ratio λ₁/λ₂ increases from 1.8 to 5.3, and the overall positioning root-mean-square error (RMSE) improves from 1.20 m to 0.28 m. These results validate MSST as an effective and high-precision solution for indoor positioning under severe multipath conditions.