PEA-Based Active Stiffness Scheduling for Resonance-Margin Control of Aircraft Control Surface Transmission Chains

Aircraft control surface systems are prone to resonance when the modal frequency of the transmission chain approaches the excitation frequency under varying load and operating conditions. To address this problem, this paper introduces a PEA-based preload regulation branch into the load bearing path of the transmission chain and develops a schedulable cross-layer mapping model from input voltage to modal frequency. The model follows the path of voltage, additional preload, axial equivalent stiffness, output side equivalent torsional stiffness, and modal frequency, and is used to judge whether the PEA branch has enough frequency shifting authority at a given working point. Based on this map, a resonance margin-constrained active stiffness scheduling method is established. Instead of applying a fixed or maximum voltage, the method calculates the minimum input voltage required to move the target modal frequency outside the dangerous resonance region. The numerical results show that increasing the voltage from 0 V to 150 V shifts the target modal frequency from approximately 56.4 Hz to 66.3 Hz, which indicates the available frequency regulation range of the added branch. For the studied excitation condition, the scheduler selects 64 V as the first feasible input and achieves a resonance margin of 1.003. The corresponding target mode RMS response is reduced by about 58.6%. Although the maximum voltage case gives stronger RMS attenuation, it requires larger preload and higher relative electrical energy demand. The proposed method is therefore not intended to maximize vibration attenuation under all conditions. It provides a resonance margin-based voltage selection rule that converts local PEA-based stiffness regulation into a system-level target modal frequency-scheduling mechanism for the studied transmission chain.