> The first theoretical analysis and practical application of PID was in the field of automatic steering systems for ships, developed from the early 1920s onwar

> The first theoretical analysis and practical application of PID was in the field of automatic steering systems for ships, developed from the early 1920s onwards. https://en.m.wikipedia.org/wiki/Proportional%E2%80%93integral%E2%80%93derivative_controller https://en.m.wikipedia.org/wiki/Proportional%E2%80%93integra...