Abstract:
To address the high-precision stabilized pointing challenge for airborne laser weapons under multi-source disturbances, this paper presents an active-passive synergistic vibration isolation and fine-stabilized tracking control method. A three-degree-of-freedom dynamic model is first established, which incorporates the carrier base, stabilization platform, gimbal, and optical path assembly. Through dimensionless scaling based on the natural frequency of the stabilization platform, the original system with seven dimensional parameters is reduced to a canonical form. This form is characterized by only five dimensionless parameters — inertia ratios
ν and
μ, stiffness ratio
κ, and damping ratios
ζf and
ζg — thereby decoupling plant dynamics from payload configuration. A hierarchical control architecture is then designed. Specifically, an inner loop employs proportional-derivative (PD) feedback with a tuned bandpass filter to introduce virtual stiffness and virtual damping to the stabilization platform and to inject concentrated energy dissipation at the primary isolation frequency. An outer loop integrates proportional-integral (PI) feedback with feedforward compensation based on a nominal inertial model of the aerodynamic disturbance torque to enhance low-frequency disturbance rejection. Closed-loop transfer functions from base vibrations, aerodynamic torques, and optical path disturbances to beam pointing error are derived. The influence patterns of key parameters are systematically investigated from a mechanical mechanism perspective. The effect of the primary isolation damping ratio
ζf is governed by the competition between energy dissipation and phase lag: large damping introduces excessive phase lag at high frequencies, potentially causing the transmitted force to align in phase with downstream subsystem modes and amplify the response, therefore, the core principle of active-passive synergy is low structural damping combined with high active control gain. PD gains are mechanically equivalent to virtual stiffness and virtual damping; increasing either alone raises the quality factor or amplifies reaction force excitation, possibly triggering modal coupling or higher-order mode excitation. The bandpass filter provides frequency-selective concentrated damping injection, and its tuning involves a trade-off between narrowband efficiency and broadband robustness. The secondary isolation stage functions essentially as an impedance mismatch layer to block vibration energy transmission; its parameters
κ and
ζg require synergistic optimization among low-frequency support, resonance suppression, and high-frequency isolation. Among mass distribution parameters,
μ reflects a frequency-domain trade-off between primary-mode inertial decoupling and high-frequency inertial filtering, while
ν is the inertial bottleneck of servo bandwidth, embodying the mechanical balance between tracking and disturbance rejection. A mapping relationship between total pointing error variance and key design parameters is established, providing a theoretical basis for system-level error budgeting. This study provides a systematic theoretical framework and mechanically grounded design guidelines for stabilized pointing systems in airborne laser weapons.