Industrial Robotic Arm Prototype Design Using Adaptive Control for Improved Accuracy of Automated Assembly

Abstract

This study aims to design and validate an industrial robotic-arm prototype that integrates adaptive control to improve automatic assembly accuracy under time-varying uncertainties. A qualitative methodology with an embedded single-case design was adopted to capture not only performance outcomes but also implementation mechanisms and operational constraints. The research was conducted in a mechatronics and automation laboratory complemented by a manufacturing pilot assembly cell to balance controlled iteration with ecological validity. Purposive sampling yielded ten informants, including controls engineers, maintenance specialists, process/quality engineers, and line technicians, selected for direct experience with accuracy-critical assembly and robot commissioning. The prototype combined a baseline controller with a bounded adaptive layer and was evaluated in representative free-space and contact-sensitive assembly tasks under payload variation and drift conditions. Results indicated reduced steady-state offsets, narrower cycle-to-cycle error dispersion, and more stable approach-to-contact behavior compared with fixed-gain control, leading to improved assembly reliability. The study recommends phase-aware adaptation constraints, enhanced sensing and filtering, and future integration of adaptive impedance or force feedback to further strengthen contact robustness.