# Active Hydraulic Oil Pressure Measurement System as a Source of Information About the Technical Condition of the Aircraft Hydrostatic Drive

## TL;DR

This paper introduces a new method to assess aircraft hydraulic systems using active pressure measurements, avoiding costly disassembly.

## Contribution

A novel active pressure measurement system using a corrective hydraulic accumulator for diagnosing hydrostatic drive conditions.

## Key findings

- Changes in the corrector's operation signal indicate wear in hydraulic components.
- Pressure step response studies confirmed the system's effectiveness in diagnosing hydrostatic drives.
- The method allows non-invasive and cost-effective evaluation of hydraulic system health.

## Abstract

Current methods for assessing the technical condition of aircraft hydrostatic drives require disassembly of the hydraulic components and their testing on test stands. These methods are expensive and do not provide a quick assessment of their technical condition. The aim of this work is to present the possibility of using an active hydraulic fluid pressure measurement system using a corrective hydraulic accumulator to assess the technical condition of a hydrostatic drive. In the proposed method, the diagnostic information carrier is a change in the corrector’s operation (changes in the course or shape of the output signal), resulting, for example, from wear of the hydraulic pairs of precision hydraulic devices that complete the hydrostatic drive. The output signal from the active pressure measurement system is a control signal that, together with the input interference signal and the output pressure signal, allows for the analysis of changes occurring in the hydrostatic drive. Therefore, based solely on the examination of changes in the corrector’s operation, it is possible to assess various changes occurring in the hydrostatic drive and its hydraulic systems. Studies of pressure step responses in the hydrostatic drive confirmed that hydrostatic drives and their hydraulic systems can be tested using an active hydraulic fluid pressure measurement system with a properly selected corrective hydraulic accumulator.