# US 2013/0239653 A1 · System for detecting defects on an aircraft engine impeller wheel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0239653 A1 - Document ID: US20130239653A1 - Status: Published application - Kind: A1 - Application number: 13/792,537 - Filed: 2013-03-11 - Published: 2013-09-19 - Earliest claimed: 2012-03-13 - Assignees: Snecma - Applicants: Snecma - Inventors: Geoffroy NICQ; Valerio GEREZ - Web page: https://patentgrep.com/patent/US20130239653A1 ## CPC - G01N 3/30: by applying a single impulsive force, e.g. by falling weight - F01D 21/003: {Arrangements for testing or measuring (for measuring vibrations G01H)} - F01D 21/14: responsive to other specific conditions - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) ## Abstract A method and an on-board system for detecting impact on an impeller wheel of an aircraft engine. Deflection signals representative of the deflections on the blades of the impeller wheel are acquired. Each of the deflection signals is correlated with a pulse signal typical of an impact on a sound blade at the rotation frequency of the engine, in order to identify impacts on the impeller wheel. The impact signals are extracted from among the deflection signals. The impact signals are transmitted to the ground in order that the signals are analysed to detect defects on the blades of the impeller wheel. ## Claims ### Claim 1 A method for detecting defects on an impeller wheel of an engine for an aircraft, said method comprising: acquiring deflection signals representative of deflections on blades of said impeller wheel, identifying impact by correlating each of said deflection signals with a detection pulse signal typical of an impact on a sound blade at a rotation frequency of the engine, extracting impact signals from among said deflection signals, applying a modal analysis to each of said impact signals to identify modal parameters relative to each impacted blade, and monitoring an evolution of said modal parameters in order to detect defects on said blades. ### Claim 2 (depends on 1) The method according to claim 1, wherein said acquiring, said identifying and said extracting are carried out on-board the aircraft whereas applying said modal analysis and said monitoring of the modal parameters are carried out on the ground. ### Claim 3 (depends on 1) The method according to claim 1, wherein said impact signals are transmitted to the ground and/or saved in a storage device. ### Claim 4 (depends on 1) The method according to claim 1, wherein said identifying comprises a first correlation carried out in an independent manner on each blade to identify the blade impacted first and a second correlation to identify successive blade impacts. ### Claim 5 (depends on 1) The method according to claim 1, further comprising validating the modal parameters identified for each impacted blade by reconstituting for said blade a reconstitution pulse signal and by correlating said reconstitution pulse signal with the impact signal relative to said impacted blade. ### Claim 6 (depends on 5) The method according to claim 5, further comprising comparing said modal parameters validated with modal parameters of sound blades in order to measure drifts of said parameters. ### Claim 7 (depends on 6) The method according to claim 6, wherein comparing is carried out from impact to impact to analyse the evolution of the modal parameters and the number of impacts. ### Claim 8 (depends on 5) The method according to claim 5, further comprising storing said validated modal parameters in a database specific to the impeller wheel. ### Claim 9 An on-board system for detecting impact on an impeller wheel of an engine for an aircraft, said system comprising: an acquisition device for acquiring deflection signals representative of deflections on blades of said impeller wheel, a correlation device for correlating each of said deflection signals with a pulse signal typical of an impact on a sound blade at the rotation frequency of the engine, in order to identify impacts on the impeller wheel, a calculation device for extracting impact signals from among said deflection signals, and a transmission device for transmitting said impact signals to the ground in order that said signals are analysed to detect defects on the blades of the impeller wheel. ### Claim 10 (depends on 9) An aircraft engine comprising an on-board detection system according to claim 9. ### Claim 11 (depends on 9) An analysis system for the detection of defects on an impeller wheel of an engine for an aircraft, said system comprising: a reception device for receiving impact signals from an on-board detection system according to claim 9, and a processor configured to apply a modal analysis to each of said impact signals in order to identify the modal parameters relative to each impacted blade, wherein said processor is further configured to monitor an evolution of said modal parameters in order to detect irregularities in their evolution revealing defects on the blades of the impeller wheel.