Unified serve-spin low-level controller

Determine whether a single low-level controller can robustly handle the broad range of serve spin types (including topspin and underspin) in the ABB IRB 1100 robot table tennis system, and construct such a unified LLC if feasible to reduce reliance on separate spin classification and spin-specific serving policies.

Background

Serving presents higher spin magnitudes than rallying, and the system currently relies on a separate spin classifier plus distinct topspin and underspin serving LLCs. The classifier demonstrated high precision but low recall for underspin in testing, and motion capture instability during the user paper further degraded classification reliability.

The authors explicitly state they were not able to train a single LLC to handle a broad spin range for serves. Establishing a unified serve-spin policy would simplify the high-level decision process, reduce spin-classification dependency, and potentially improve serve return performance in competitive matches.