Filing activity in this dataset concentrates among a small group of established industrial control vendors, with a long tail of single-filing entrants behind them. Rather than one dominant leader, the data shows several large incumbents holding significant but declining recent-year output, alongside smaller players filing once or twice. Recent-year momentum has slowed across nearly all of the largest names, so historical filing volume is a better guide to who holds foundational claims than to who is actively expanding right now.

No — filings rose from 31 in 2017 to a peak of 81 in 2022, then declined toward the single digits by 2026. Because publication typically lags filing by around 18 months, the most recent one to two years are undercounted and the real decline is probably less steep than the raw chart implies. Even accounting for that lag, the plateau after 2022 suggests the field has moved from active growth into a maturing phase.

Core control and regulating systems (IPC class G05B) appear in 827 of the 880 families in this dataset, making it by far the dominant classification. Data processing (G06F) and digital transmission (H04L) are present in a meaningful minority of families, while AI-based computing (G06N) and business-process data handling (G06Q) are smaller still. This means most HMI, historian, alarm and redundancy claims are drafted as extensions of a control-systems architecture rather than as standalone software or networking inventions.

The lighter-populated IPC branches in this dataset — AI-based analytics overlapping with control systems, power-grid integration for redundancy, multiplex field-device communication, and business-process analytics layered on data historians — carry far fewer filed families than the dominant control-systems classification. That does not guarantee the space is commercially valuable, but it does mean the claim floor is lower there than in core control and HMI claims, which sit on a much denser prior-art base including some heavily cited foundational patents.

Patent applications typically publish about 18 months after filing, so any year within roughly the last two years in a filing trend chart will show fewer records than were actually filed. In this dataset, that means the apparent drop-off after the 2022 peak is likely overstated, particularly for the most recent partial year. Analysts should treat the last one to two data points as provisional and weight the multi-year trend more heavily than the final year when judging whether activity is truly declining.