Fundamental Mechanics and Precision Control of Optical Axis Stability and Parallelism in Multi-Sensor Electro-Optical Pods


== Abstract ==

<p>Modern electro-optical pods incorporatemulti-spectral sensors for reconnaissance,
target acquisition, and laser designation, where sub-milliradian
optical axis stability and inter-sensor parallelism are critical for mission
success. This paper establishes a unified theoretical framework combining
rigid-body kinematics and deformable body mechanics to develop a
physics-based stability metric through screw theory formulation, expressing
the optical axis dynamics as ˙O = [ω]×O+v, with thermo-mechanical
constraints �[ω]×O� < �ω, �v� < �v for engineering implementation. A
novel computational geometry method evaluates multi-sensor alignment
errors by solving Ei = si − (si · ˆO)
ˆO
+ JT�T + Jgg, where JT and Jg
represent thermal and gravitational Jacobians. The rigid-flexible coupling
model with multi-point constraints (MPC) reveals thermal dominance
(0.49 mrad IR sensor pitch displacement at 60◦C, 272× gravitational
effect), material sensitivity (CTE mismatch contributing 68% of TV sensor’s
azimuthal error), and cross-axis coupling (19% LD error amplification
under thermal gradients). However, due to the limitations of current
experimental conditions, the experimental validation ismainly carried out
in controlled environments. The current experimental validation shows
<5% deviation between predicted andmeasured parallelismerrors across
−20◦C to 60◦C. In the future, we will supplement the evaluation of the
robustness of the control method through existing simulation verifications
(such as adding vibration and temperature disturbance models) in the
“experimental discussion” or “prospect” section, and clarify the research
plan for actual environment testing. The framework provides design
guidelines for optimal sensor placement minimizing �JT�
F, temperaturedependent
calibration protocols, and 0.1 mrad allocable margin for manufacturing
tolerances. This methodology advances electro-optical system
engineering fromempirical tuning tomodel-driven optimization, demonstrating
0.12 mrad (3σ) stability in field tests under ISO 9022 environmental
stress profiles, with key innovations including the first integration
of Lie algebra kinematics with FEM-based deformation analysis for
optical systems and physics-informed error budgeting separating thermal,
mechanical, and alignment components.</p>



== Document ==
<pdf>Media:Draft_Sanchez Pinedo_726313992-2901-document.pdf</pdf>