Abstract:
A system for collecting and analyzing vibration data is provided. The system includes: at least one sensor for sensing vibrations and producing an electrical signal corresponding to the sensed vibrations; a Universal Serial Bus (USB) communication device for receiving the electrical signal corresponding to the sensed vibrations from the at least one sensor and conditioning and sampling the electrical signal to produce a conditioned signal; and a data collector for receiving the conditioned signal and storing the conditioned signal in a data storage device.

Description:
BACKGROUND OF THE INVENTION 
     The subject matter disclosed herein relates to a portable data collector and analyzer for diagnosing machinery and, more particularly, to a portable data collector and analyzer with a Universal Serial Bus (USB) interface for transferring data at a high-rate. 
     Traditionally, rotating machinery diagnostics has required large and bulky test equipment along with a large amount of data to properly diagnose machine vibration problems. The bulky test equipment must be operated close to a power source and in a harsh environment. A device must be designed to have the same technical capabilities as the large and bulky test equipment, but must be compact in size and have the ability to be operated with a battery for at least 6 to 8 hours. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, a system for collecting and analyzing vibration data is provided. The system includes at least one sensor for sensing vibrations and producing an electrical signal corresponding to the sensed vibrations; a Universal Serial Bus (USB) communication device for receiving the electrical signal corresponding to the sensed vibrations from the at least one sensor and conditioning and sampling the electrical signal to produce a conditioned signal; and a data collector for receiving the conditioned signal and storing the conditioned signal in a data storage device. 
     In another embodiment, a vibration data acquisition system is provided. The portable system includes at least one sensor for sensing vibrations and producing an electrical signal corresponding to the sensed vibrations; a Universal Serial Bus (USB) communication device for receiving the electrical signal corresponding to the sensed vibrations from the at least one sensor and conditioning and sampling the electrical signal to produce a conditioned signal; and a data collector for receiving the conditioned signal and storing the conditioned signal in a data storage device, the data collector including a power supply configured to supply power to the USB communication device. 
     In yet another embodiment, a portable vibration data acquisition system is provided. The portable system includes at least one sensor for sensing vibrations and producing an electrical signal corresponding to the sensed vibrations; a Universal Serial Bus (USB) communication device for receiving the electrical signal corresponding to the sensed vibrations from the at least one sensor and conditioning and sampling the electrical signal to produce a conditioned signal; a data collector for receiving the conditioned signal and storing the conditioned signal in a data storage device, the data collector includes a power supply configured to supply power to the USB communication device; and at least one set of buffers for temporarily storing the conditioned signal before being stored in the data storage device. 
     These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a schematic of a vibration data acquisition system having a USB communications device that consumes low amounts of power and enables high data throughput in accordance with an exemplary embodiment of the present invention; 
         FIG. 2  is a schematic of a vibration data acquisition system having a set of buffers for temporarily storing vibration data before being stored in a data storage device in accordance with an exemplary embodiment of the present invention; and 
         FIG. 3  is a flow chart of a method for transferring raw analog vibration signals from multiple sensors and converting the signals into self describing data objects for storage onto a data storage device in accordance with an exemplary embodiment of the present invention. 
     
    
    
     The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Exemplary embodiments are directed to a system for collecting and analyzing vibration data that includes a USB interface as the primary communication link between sensors and a computer interface of the system in accordance with one embodiment. Further, in these embodiments, the system continuously takes raw analog vibration signals from multiple sensors and converts the signals into self describing data objects (e.g., digital data) for storage onto a data storage device (e.g., non-volatile solid state device) while maintaining a high rate of data transfer in accordance with one exemplary embodiment. The USB interface consumes low amounts of power and still effectively provides a high rate of data throughput. 
     For a better understanding of the invention and its operation, turning now to the drawings,  FIG. 1  illustrates a portable vibration data acquisition system  10  in accordance with one exemplary embodiment of the present invention. The system includes one or more sensors  12 , a USB communications device  14 , and a data collector device  16 . For simplistic purposes, the one or more sensors  12  will be described herein as a plurality of sensors  12 . However, it should be understood that a single sensor can be used in exemplary embodiments of the present invention. 
     The plurality of sensors  12  is configured to continuously sense vibrations or raw analog vibration signals, which are depicted as lines  18 , produced by an operating machine (not shown). The plurality of sensors  12  produce electrical signals corresponding to the raw analog vibration signals or sensed vibrations. One end of each of the plurality of sensors  12  is placed against the machine to sense vibrations, which are often indicative of the condition of the machine, while another end of each of the plurality of sensors  12  is correspondingly coupled to the USB communications device  14  via signal lines  20 . While signal lines  20  are depicted as single lines, it should be understood that each of these single lines may also represent twisted wire pairs or wireless communication. Of course, other suitable communication means for transmitting the sensed vibration signals can be used in other exemplary embodiments and should not be limited to the configurations illustrated herein. 
     In accordance with one non-limiting exemplary embodiment, each of the plurality of sensors  12  includes a vibration transducer. Each of the plurality of sensors  12  may also include a proximity sensor, velocimeter, accelerometer, or any other sensing device that is capable of sensing vibrations in other exemplary embodiments.  FIG. 1  illustrates four sensors for sensing vibrations. However, it should be understood that less or more than four sensors can be used to sense vibrations depending on the application and should not be limited to the configuration as shown. 
     In accordance with one embodiment, the USB communication device  14  includes a USB interface  22  and a digital signal processor (DSP)  24  or a field-programmable gate array (FPGA). One end of the USB communication device  14  is coupled to the plurality of sensors  12  while the other end of the USB communication device  14  is coupled to the data collector  16  via a USB connector  26 . The USB communication device  14  operably receives the electrical signals from the sensors and is configured to transfer vibration data to the data collector  16  via the USB connector  26 . In particular, the DSP  24  receives the electrical signals from the sensors  12  for conditioning and sampling the electrical signals to produce a conditioned signal and the USB interface  22  transfers the conditioned signal to the data collector  16  through the USB connector  26 . The DSP  24  is configured to sample the raw analog vibration signals at different sampling rates in accordance with one exemplary embodiment. 
     The USB interface  22  can be any conventional USB interface  22  suitable for transferring data to the data collector  16  at a high-rate while having the power consumption equivalent to more traditional interfaces (i.e. Ethernet, RS-232). However, the USB interface  22  has the ability to be suspended to the data collector  16  when not in use and does not require a separate power source to operate or internet service, which can be difficult to obtain at times. Thus, a continuous digital vibration data flow, which is depicted by arrow  28 , can be formed between the USB interface  22  and the data collector  16 . 
     The DSP  24  includes one or more analog to digital converters (not shown) for converting the analog vibration data to self-describing data objects or digital vibration data. In accordance with one embodiment, the DSP  24  is configured to construct vibration data packets out of the digital vibration data as conditioned signals, which are sent to the data collector  16  by the USB interface  22  for storage and/or further processing. 
     The data collector  16  can be any conventional data collecting device suitable for collecting vibration data. In one embodiment, the data collector  16  includes a housing  30  and a data storage device  32  for storing vibration data. In accordance with one non-limiting exemplary embodiment, the data collector  16  is portable. Of course, the data collector  16  can be a stationary device in other exemplary embodiments. In accordance with one non-limiting embodiment, the data storage device  32  is a solid-state device disposed within the housing  30 . Of course, any suitable data storage type can be used in accordance with exemplary embodiments of the present invention. The data collector  16  includes a central processing unit (CPU)  34  for controlling the operations of the data collector  16 . In one example, the CPU  34  parses the vibration data packets and archives the vibration data to the appropriate directory in the data storage device  32  of the data collector  16 . In another example, the CPU  34  performs various measurements (e.g., decimation on conditioned signal, digital filtering, etc.) and stores the output in the data storage device  32 . The CPU  34  can be any conventional processing unit configured for carrying out the methods and/or functions described herein. In one exemplary embodiment, the CPU  34  comprises a combination of hardware and/or software/firmware with a computer program that, when loaded and executed, permits the CPU  34  to operate such that it carries out the methods described herein. 
     The data collector  16  further includes a power supply  36  for providing electrical power to the components in the system  10 . In one embodiment, the power supply  36  is a rechargeable battery that can hold enough power to allow the user to complete a test without the need to recharge the power supply  36  while still being compact in size. For example, the power supply  36  can be a rechargeable battery with a battery life of approximately 6 to 8 hours. In another example, the power supply  36  can be a non-rechargeable battery with a battery life of approximately 6 to 8 hours. It should be understood that the power supply  36  can be any size and hold up to any amounts of electrical power depending on the application and should not be limited to the examples set forth above. 
     In accordance with one embodiment, the power supply  36  of the data collector  16  provides electrical power to the USB communication device  14  and the components thereof via the USB connector  26 . As such, when the USB communication device  14  is coupled to the housing  30  of the data collector  16 , the USB communication device  14  can be powered up when the data collector  16  is powered up. When the data collector  16  is powered down or in hibernation, the USB communication device  14  is placed in the same state, thereby further minimizing the consumption of power from the power supply  36 . The power supply  36  may also effectively power the plurality of sensors  12  in accordance with one embodiment. In an alternate embodiment, the sensors  12  are powered by a separate power source. 
     In one exemplary embodiment, the data collector  16  further includes a first set of buffers  38  for temporarily storing the vibration data packets and a second set of buffers  40  for temporarily storing the parsed vibration data packets before being stored in the data storage device  32  as shown in  FIG. 2 . In this embodiment, each conditioned signal from the USB interface  22  is stored in one of the buffers in the first set of buffers  38  in a sequential fashion. For example, one conditioned signal is stored in the first buffer; the next conditioned signal is stored in the second buffer; and so forth. As the buffers in the first set of buffers  38  are being filled or once the first set of buffers  38  are full, the CPU  34  takes the conditioned signals from the first set of buffers  38  one at a time and parses the signals and temporarily stores the parsed signals in the second set of buffers  40  in an orderly fashion. As the buffers in the second set of buffers  40  are being filled or once the second set of buffers  40  are full, the CPU  34  takes the parsed signals from the second set of buffers  40  and archives the parsed signals into the data storage device  32  in an orderly fashion. This process is continuous until all data is saved onto the data storage device  32 . It is contemplated that only a single set of buffers is used to temporarily store parsed signals. Of course, the number of buffer sets may vary depending on the application and should not be limited to the configurations herein. It should be understood that the conditioned signals from the USB interface  14  may also be saved directly onto the data storage device  32  without being parsed in accordance with other exemplary embodiments. 
     Now referring to  FIG. 3 , a method for transferring raw analog vibration signals from multiple sensors and converting the signals into self describing data objects for storage onto a data storage device in accordance with one exemplary embodiment will now be discussed. 
     At step  100 , the plurality of sensors  12  senses vibrations produced by the operating machine. The plurality of sensors  12  produce electrical signals corresponding to the raw analog vibration signals. 
     At step  102 , the DSP  24  receives the raw analog vibrations and conditions and samples the signals to produce digital vibration data. The DSP  24  converts the analog vibration data to digital vibration data utilizing analog to digital converters. 
     At step  104 , the DSP  24  constructs vibration data packets out of the digital vibration data as conditioned signals. 
     At step  106 , the USB interface  22  sends the conditioned signals (vibration data packets) to the data collector  16 . 
     At step  108 , the data collector  16  parses the vibration data packets and stores the parsed vibration data packets in the data storage device  32 . 
     While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.