Adaptive feedforward broadband precision micro-amplitude force output with a LESO dynamic phase compensator

This paper develops a precise micro-amplitude force output device (PMAFOD) and its control strategy to meet the needs of precision-instrument environmental simulation and active vibration suppression. Building on adaptive inverse control (AIC) and active disturbance-rejection control (ADRC), a disturbance-compensation adaptive inverse control (DCAIC) scheme is proposed for fast time-domain force tracking. A linear extended state observer (LESO) is used to construct the disturbance-compensation loop, which explicitly targets the system’s frequency response, mitigates AIC divergence caused by PMAFOD phase lag, and preserves ADRC’s disturbance-rejection capability. Experiments on the PMAFOD show that fixed- and sweep-frequency tracking achieves an effective bandwidth of 20–500 Hz with tracking errors approaching the 1 mN measurement noise floor, while band-limited random-waveform tracking maintains errors below 10 mN. The proposed framework provides a practical solution for broadband micro-force generation and can be extended to other precision actuation platforms.