# US 10,118,802 B2 · Structural health monitoring of an escalator drive system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,118,802 B2 - Document ID: US10118802B2 - Status: Granted - Kind: B2 - Application number: 15/516,708 - Filed: 2015-10-28 - Published: 2017-10-19 - Granted: 2018-11-06 - Earliest claimed: 2014-10-31 - Assignees: Otis Elevator Company - Applicants: Otis Elevator Company - Inventors: Soumitra Borthakur; Randall Keith Roberts - Web page: https://patentgrep.com/patent/US10118802B2 ## CPC - B66B 25/006: {Monitoring for maintenance or repair (for security reasons B66B29/005)} - B66B 23/02: Driving gear - F16H 7/00: Gearings for conveying rotary motion by endless flexible members (specific for conveying rotary motion with variable gear ratio or for reversing rotary motion F16H9/00) - F16H 57/01: Monitoring wear or stress of gearing elements, e.g. for triggering maintenance - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) - F16H: GEARING ## Abstract A structural health monitoring system is provided. The system includes a drive system having a first drive member a second drive member 38 operationally connected to the first drive member, and a tension member 39 operationally connecting the first drive member to the second drive member. At least one sensor 50 is configured to monitor a characteristic of at least one of the first drive member and the second drive member. A processor 54, in communication with the at least one sensor, is configured to determine if the structural health of the tension member is compromised based on the monitored characteristic. The processor is further configured to perform a safety response action when the structural health of the tension member is determined to be compromised. ## Claims ### Claim 1 A structural health monitoring system comprising: a drive system of an escalator or moving walkway comprising: a first drive member; a second drive member operationally connected to the first drive member; and a tension member operationally connecting the first drive member to the second drive member; at least one first sensor configured to monitor a characteristic of the first drive member; a processor in communication with the at least one sensor and configured to determine if the structural health of the tension member is compromised based on the monitored characteristic, the processor further configured to perform a safety response action when the structural health of the tension member is determined to be compromised, and at least one second sensor configured to monitor a characteristic of the second drive member, wherein the processor is configured to monitor a transfer function between the first and second drive members to determine if the structural health of the tension member is compromised, wherein the transfer function comprises signal averaging of signals received from the at least one first sensor and the at least one second sensor and wherein frequency domain curve fitting is employed to compensate for noise in the system. ### Claim 2 (depends on 1) The structural health monitoring system of claim 1, wherein the at least one first sensor is disposed on or located proximal to the first drive member. ### Claim 3 (depends on 1) The structural health monitoring system of claim 1, further comprising a motor operationally connected to at least one of the first drive member and the second drive member. ### Claim 4 (depends on 1) The structural health monitoring system of claim 1, wherein the first drive member and the second drive member each comprise a sheave, a pulley, a gear, a wheel, a sprocket, a cog, or a pinion. ### Claim 5 (depends on 1) The structural health monitoring system of any of claim 1, wherein the tension member comprises a chain, a belt, a cable, a ribbon, a band, or a strip. ### Claim 6 (depends on 1) The structural health monitoring system of claim 1, wherein the at least one first sensor and the at least one second sensor each comprise an accelerometer, a resistance temperature detector, a thermocouple, a non-contact eddy current probe displacement sensor, a contact linear variable displacement transducer, a velocity sensor, a strain sensor, a load sensor, a pressure sensor, a microphone, or a non-contact chain vibration measurement device. ### Claim 7 (depends on 1) The structural health monitoring system of claim 1, wherein the safety response action comprises at least one of powering off the drive system, providing a displayed notification on a display screen, transmitting a notice to an external device, and providing an indicator light and/or sound indicating that the structural health of the drive system is compromised. ### Claim 8 (depends on 1) The structural health monitoring system of claim 1, wherein the processor and the at least one sensor form a single device. ### Claim 9 A structural health monitoring system comprising: a drive system of an escalator or moving walkway comprising: a first drive member; a second drive member operationally connected to the first drive member; and a tension member operationally connecting the first drive member to the second drive member; at least one first sensor configured to monitor a characteristic of the first drive member; at least one second sensor configured to monitor a characteristic of the second drive member; and a processor in communication with the first and second sensors and configured to measure and monitor a transfer function between the first and second drive members to determine if the structural health of the drive system is compromised, wherein the processor is configured to monitor a transfer function between the first and second drive members to determine if the structural health of the tension member is compromised, wherein the transfer function comprises signal averaging of signals received from the at least one first sensor and the at least one second sensor and wherein frequency domain curve fitting is employed to compensate for noise in the system. ### Claim 10 (depends on 9) The structural health monitoring system of claim 9, wherein the processor is configured to perform a safety response action when the structural health of the drive system is determined to be compromised. ### Claim 11 A method of monitoring the structural health of an escalator or moving walkway drive system, the drive system includes a first drive member, a second drive member, and a tension member operationally connecting the first and second drive members, the method comprising: measuring a characteristic of at least one of the first and second drive members; determining if the structural health of the tension member is compromised based on the measured characteristic; and performing a safety response action when it is determined that the structural health of the tension member is compromised, wherein the measuring step comprises measuring a transfer function between the first drive member and the second drive member based on the measured characteristic, wherein the transfer function comprises signal averaging of signals received from the at least one first sensor and the at least one second sensor and wherein frequency domain curve fitting is employed to compensate for noise in the system. ### Claim 12 (depends on 11) The method of claim 11, wherein the determining step comprises comparing the measured characteristic to a known quantity. ### Claim 13 (depends on 12) The method of claim 12, wherein the known quantity is analytically determined. ### Claim 14 (depends on 12) The method of claim 12, wherein the known quantity is a measured characteristic of the structural health of the tension member when the tension member is known to be healthy.