US 7,548,171 B2Granted

Wireless sensors for system monitoring and diagnostics

AssigneeXerox Corporation

InventorsXenofon Koutsoukos, Patrick C. P. Cheung

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Abstract

A plurality of wireless sensors can be placed within a large system in various locations to monitor critical elements of that system. Each wireless sensor can include sensor elements usable to monitor one or more parameters of an element of the system and a wireless signal transmitter, such as, for example, a speaker or an antenna. Each sensor can transmit one or more unique identifying signals to a signal-receiving device, which can be processed by a signal processor. The signal processor can determine each received signal, the sensor corresponding to that identified signal, and the time the wireless signal was generated. Based on this information, the wireless signals can be diagnostically compared against expected values for the system being monitored and evaluated. If a discrepancy is detected, then the components and/or subsystems within the system that are implicated in the discrepant wireless signals can be evaluated for possible errors.

Claims20

Dependent claims

A printing device including a wireless sensor system usable to sense a position of paper having a predetermined bands printed thereon by a sensed system using predetermined timing data and to transmit a sound signal utilizing audio phrase data to transmit information when the bands are detected, the information being used for reconstructing the position and speed of paper, the wireless sensor system comprising:

a plurality of sensor subsystems provided on the printing device, each sensor subsystem including a sensor positioned along a paper path of the printing device and wirelessly transmitting information by transmitting the sound signal on at least one audio frequency that is unique to that sensor subsystem, the at least one audio frequency being generated based on a frequency defined in a frequency look-up table;
and
a signal processor subsystem that receives the wirelessly transmitted sound signal from the plurality of sensor subsystems and that determines, from time for transmission of the sound signal, a transmission time of the wirelessly transmitted information, wherein the signal processor subsystem determines which of the plurality of sensor subsystems transmitted the information based on the unique audio frequency used to transmit the information and the transmission time of the information, and
the signal processor subsystem determines the position and speed of paper based on the timing data and the transmission time of the information for reconstructing the timing data.

1 more element

A method for wirelessly sensing a position of paper having a predetermined bands printed thereon by a sensed system using predetermined timing data and transmitting a sound signal utilizing audio phrase data to transmit information when the bands are detected for reconstructing the position and speed of paper, in a printing device, comprising:

sensing the position of paper using a plurality of wireless sensor devices, each wireless sensor device positioned along a paper path of the printing device and capable of sensing a condition of the position and speed of paper;
outputting a wireless sensor signal by transmitting the sound signal based on the sensed condition from each wireless sensor device at least one audio frequency that is unique to that wireless sensor device, the at least one audio frequency being generated based on a frequency defined in a frequency look-up table;
receiving a plurality of the wireless sound signals from at least some of the plurality of wireless sensor devices;
determining a unique audio frequency of each of the received wireless sensor signals;
determining a transmission time of the received wireless sound signal from time for transmission of the sound signal;
determining which of the plurality of wireless sensor devices output the received wireless sensor signals based on the determined unique audio frequencies for the received wireless sound signal and the transmission time of the received wireless sound signal;
and
determining the position and speed of paper based on the timing data and the transmission time of the received wireless sound signal for reconstructing the timing data.

5 more elements

Dependencies are inferred from the claim text.