Patent Grant
10571367
The described embodiments relate to monitoring of power tool usage for performance evaluation and maintenance oversight.
Many types of power tools are subject to periodic maintenance and calibration to ensure proper performance. The reliable operation of power tools in an organized manufacturing setting is important to ensure consistent manufacturing workflow. Furthermore, the accuracy of power tool operation is often critical to ensure the reliability of the final manufactured good.
Typically, power tools are subject to maintenance and calibration procedures at fixed, scheduled time intervals. However, the need for maintenance and calibration is most often driven by actual tool usage. For operational scenarios with predictable tool usage, the simple passing of time may be a reasonable approximation of actual tool usage. However, for tools subject to intermittent and irregular use, fixed, scheduled maintenance intervals are likely to be an inaccurate measure of actual tool use, and may lead to either inadequate or excessive maintenance.
Improvements to systems for estimating actual usage of a power tool and communicating an indication of the actual tool usage without interfering with the operation of the tool are desired.
Methods and systems for characterizing actual tool usage based on a measurement of sound emitted from the tool are presented herein. Furthermore, methods and systems for communicating an indication of actual tool usage to a user or another computing system without interfering with the operation of the tool are also presented.
In one aspect, a power tool usage auditor (PTUA) senses activity on the part of a power tool and communicates an indication of that activity to a user or an external computing system.
In one embodiment, a (PTUA) includes a sound measuring device offset from the surface of a power tool. The sound measuring device senses sound waves emitted from the surface of power tool and generates an electrical signal indicative of the sound emitted from the surface of the power tool.
In another embodiment, a power tool usage auditor (PTUA) includes a magnetic field measuring device offset from a surface of a power tool. The magnetic field measuring device senses changes in magnetic field induced by motion generated by the power tool. The magnetic field measuring device generates an electrical signal indicative of the motion generated by the power tool.
A processor is configured to receive the electrical signals indicative of tool activity and generate a signal indicative of actual tool usage. In some examples, the processor is configured to determine the transition between an off cycle and an on cycle of the power tool by identifying when the magnitude of the electrical signal exceeds a predetermined threshold value. Similarly, the processor is configured to determine the transition between an on cycle and an off cycle by identifying when the magnitude of the electrical signal is less than the predetermined threshold value. In addition, the processor is configured to determine the periods of time when the tool is in use.
In a further aspect, the processor is configured to determine whether a successful tool operation has taken place based on the measured electrical signal. In one example, the processor is configured to compare the duration of each period of tool use with a predetermined time window indicative of a successful tool operation to determine whether a successful tool operation has taken place. In another example, the processor is configured to compares the amplitude of the electrical signal during each tool usage cycle to a predetermined threshold value to determine degradation or failure of a particular power tool.
In another further aspect, the PTUA includes one or more communication interfaces to transmit signals indicative of actual tool usage from the power tool to an external computing system and receive signals indicative of operational parameters (e.g., threshold values used by the PTUA for signal analysis.
In yet another further aspect, the PTUA is configured to record the sound emitted from the surface of a power tool during one or more desirable tool operations. The PTUA is further configured to analyze the recorded signal to determine one or more threshold values used for subsequent signal analysis.
In some embodiments, the PTUA includes a display device suitable for communicating indications of actual tool usage to a user directly without interfering with tool usage.
In another further aspect, the PTUA includes a passive vibration measurement device, such as a piezoelectric vibration sensor, to detect vibration of the power tool. The detected vibration is employed as a trigger signal to “wake-up” electronic circuits of PTUA. In this manner, the PTUA can operate in a “sleep” mode with a minimum of power consumption, until triggered to “wake-up” and begin monitoring actual tool usage.
In yet another further aspect, data communicated from the PTUA is presented on a display of an external computing system. An external computing system may be a personal computer, mobile computer, or other electronic device configured to receive actual tool usage data from the PTUA, process the data, and present useful indications (e.g., performance metrics, maintenance logs, estimations of remaining tool life, etc.) to a user.
In yet another further aspect, the PTUA is configured to perform a frequency analysis of sound signals to determine frequency components of the measured signals. These frequency components are employed to determine indications actual tool usage such as tool degradation or failure or success or failure of tool operation.
The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not limiting in any way. Other aspects, inventive features, and advantages of the devices and/or processes described herein will become apparent in the non-limiting detailed description set forth herein.
Reference will now be made in detail to background examples and some embodiments of the invention, examples of which are illustrated in the accompanying drawings.
System 100 includes a power tool usage auditor (PTUA) 101 including a housing 105 that is mechanically coupled to a power tool 102 over a mechanical interface area 103. Housing 105 is not mechanically coupled to power tool 102 over a portion 106 of the surface of power tool 102. PTUA 101 includes a sound measuring device 110, a passive vibration measurement device 112, a memory 130, a processor 120, a wireless communication transceiver 150, a Radio Frequency Identification (RFID) module 195 and a wired communication interface 190. Each of these elements is communicatively coupled over bus 140.
Sound measuring device 110 is coupled to housing 105 and offset from the portion 106 of the surface of power tool 102 not mechanically coupled to housing 105 by offset distance, D, depicted in
System 400 includes a power tool usage auditor (PTUA) 401 including a housing 105 that is mechanically coupled to a power tool 402 over a mechanical interface area 103. PTUA 401 includes a magnetic field measuring device 410 (e.g., a Hall-effect sensor), a passive vibration measurement device 112, a memory 130, a processor 120, a wireless communication transceiver 150, a Radio Frequency Identification (RFID) module 195, and a wired communication interface 190. Each of these elements is communicatively coupled over bus 140.
Magnetic field measuring device 410 is coupled to housing 105 and offset from the surface of power tool 402. Sound measuring device 410 includes a magnetic field probe that senses the changes in magnetic field induced by the motion of a shaft 411 of power tool 402. Magnetic field measuring device 410 is configured to generate an electrical signal 413 indicative of the motion generated by power tool 402. As depicted in
Processor 120 is configured to receive signal 113 and generate a signal indicative of actual tool usage based on signal 113. For example,
In one example, processor 120 generates a signal indicative of the cumulative amount of time the tool has been used (e.g., Ton1+Ton2+Ton3) as an indication of actual tool usage.
In another example, processor 120 compares the duration of each period of tool use with a predetermined time window indicative of a successful tool operation, and determines an indication of actual tool usage based on the comparison. For repetitive assembly tasks, the duration of time of power tool use is indicative of whether or not the task was successfully performed. For example, based on experience it is known that it takes a given power tool two seconds with a tolerance of ten percent (e.g., 1.8 second to 2.2 seconds) of actual use to properly secure two particular plastic parts together with a particular screw. In this example, processor 120 compares the duration of each period of tool use (e.g., Ton1, Tone, and Ton3) with the known range of time duration for successful tool operation and determines whether each tool cycle has successfully performed the task. In this example, processor 120 is configured to generate a signal indicative of whether or not a successful tool operation has occurred.
In yet another example, processor 120 compares the amplitude achieved during each tool usage cycle to a second predetermined threshold value to determine degradation or failure of a particular power tool. For example, if the peak amplitude achieved during each tool cycle slowly decreases, this may be indicative of a degradation of the tool itself, or its power supply. In another example, if the peak amplitude achieved during each tool cycle suddenly decreases, this may be indicative of a sudden failure of the power tool.
PTUA 101 includes one or more communication interfaces (e.g., wireless communication transceiver 150 and a wired communication interface 190) to transmit signals indicative of actual tool usage from power tool 102 to an external computing system (not shown). In one example, wireless communication transceiver 150 is configured to transmit signals 152 indicative of actual tool usage. In another example, wired communication interface 190 is configured to transmit signals 192 indicative of actual tool usage.
In some embodiments, a PTUA 101 includes a near field communication (NFC) device such as radio frequency identification (RFID) module 195. In one example, RFID module 195 is configured to transmit signals 197 indicative of a unique identity of PTUA 101 (e.g., a unique identification code such as a serial number). It may be desirable to employ an RFID device as a low power data storage device that can be read by an external computing system without using power on-board PTUA 101. This is particularly useful when long battery life (e.g., greater than six months) of PTUA 101 is desired. In one example, RFID module 195 is configured to transmit signals 197 that are also indicative of actual tool usage.
As discussed hereinbefore, in some examples, predetermined threshold values provide a basis for analysis of signals indicative of the sound emitted from the surface of power tool 102.
In some examples, one or more predetermined threshold values are received by PTUA 101 from an external computing system over a communication interface. For example, PTUA 101 may receive a signal 153 indicative of one or more predetermined threshold values over wireless communication transceiver 150. In another example, PTUA 101 may receive a signal 191 indicative of one or more predetermined threshold values over wired communication interface 190. In another example, PTUA 101 may receive a signal 198 indicative of one or more predetermined threshold values over RFID module 195.
In some other examples, one or more predetermined threshold values are determined based on an analysis of a “master” signal indicative of a desirable sound emitted from the surface of power tool 102.
In some examples, the “master” signal is received by PTUA 101 from an external computing system over a communication interface as described hereinbefore.
In some other examples, the “master” signal is a recording of sound emitted from the surface of power tool 102 during one or more desirable tool operations. In one example, PTUA 102 includes an input device 160 (e.g., a push button momentary switch, etc.). When input device 160 receives a mechanical input (e.g., button press) from a user, a signal 161 is generated. In response, processor 120 initiates a recording of the sound emitted from the surface of power tool 102. The duration of the recording may, for example, be for a fixed period of time, or in another example, for as long as the user continues to interact with input device 160. The recorded sound emitted from the surface of power tool 102 is stored in memory 131 as a “master” signal.
In some examples the stored “master” signal is analyzed to determine predetermined threshold values used in subsequent analyses of measured signals. In some examples, one or more predetermined threshold values are determined as a percentage of the maximum voltage of a master profile.
In some embodiments, PTUA 101 includes a display device 170. Display device 170 is configured to receive signal 171 and communicate an indication of the actual tool usage to a user of the power tool. In one embodiment, display device 170 is an LCD screen that renders a symbol to a user indicating whether or not a successful tool operation has occurred. In another example, the LCD screen renders a symbol to a user indicating that the power tool is due for maintenance, calibration, or repair. In another embodiment, display device 170 is an LED or array of LEDs. In general any number of different combinations of light emitting devices may be employed to indicate actual tool usage.
In another embodiment, display device 170 could be a head up display (HUD). Such a display allows users to keep their eyes on the interaction between the tool and the work piece while receiving indications of tool usage from PTUA 101. In this manner, a user does not have to shift attention from the interaction between the tool and the work piece to read the visual cues offered by display device 170. Examples of suitable HUD devices include head mounted display devices such as Google Glass™, manufactured by Google Inc., Mountain View, Calif. (USA).
In general, display device 170 could be any device suitable for communicating indications of actual tool usage. In some alternative embodiments, an audio device may be employed, alternatively, or in combination with display device 170. By way of non-limiting example, a sequence of audible tones may be generated by the audio device to indicate actual tool usage.
In another further aspect, PTUA 101 includes a passive vibration measurement device 112, such as a piezoelectric vibration sensor to detect vibration of power tool 102. The passive vibration measurement device 112 is able to generate a signal 114 indicative of the presence of vibration of power tool 102 without electrical power consumption. In turn, signal 114 can be employed as a trigger signal to “wake-up” electronic circuits of PTUA 101. In this manner, PTUA 101 can operate in a “sleep” mode with a minimum of power consumption, until triggered by vibration signal 114 to “wake-up” and begin monitoring actual tool usage. This may be particularly advantageous with long battery life of PTUA 101 is desired.
In another further aspect, actual tool usage, tool degradation or failure, or success or failure of tool operation may be based on measurements of vibration emitted from the tool, alone, or in combination with sound measurements.
In yet another further aspect, data communicated from the PTUA 101 is presented on a display of an external computing system.
In yet another further aspect, PTUA 101 may be configured to perform a frequency analysis of signals 113 to determine frequency components of the measured signals. These frequency components may be employed to determine indications actual tool usage such as tool degradation or failure or success or failure of tool operation.
Although power tool 302 is illustrated as a hand-held powered screwdriver, in general, any powered tool may be contemplated within the scope of this patent document.
It should be recognized that the various steps described throughout the present disclosure may be carried out by a single computer system or, alternatively, a multiple computer system. Moreover, different subsystems of the system, such as the sound measurement sensor, may include a computer system suitable for carrying out at least a portion of the steps described herein. Therefore, the aforementioned description should not be interpreted as a limitation on the present invention but merely an illustration.
In addition, the computer system described herein may be communicatively coupled to any other subsystem (e.g., a display device, an sound measurement sensor, an input device, etc.) in any manner known in the art. For example, the one or more computing systems may be coupled to computing systems associated with the display device and sound measurement sensor. In another example, any of the input device, sound measurement sensor, and display device may be controlled directly by a single computer system.
The computer system may be configured to receive and/or acquire data or information from the subsystems of the system (e.g., input device, sound measurement sensor, and the like) by a transmission medium that may include wireline and/or wireless portions. In this manner, the transmission medium may serve as a data link between the computer system and other subsystems of the system.
By way of non-limiting example, the computing system of PTUA 101 may include, but is not limited to, a microcontroller, microcomputer, or any other device known in the art. In general, the term “computing system” may be broadly defined to encompass any device having one or more processors, which execute instructions from a memory medium.
Program instructions 132 implementing methods such as those described herein may be transmitted over a transmission medium such as a wire, cable, or wireless transmission link. For example, as illustrated in
In block 201, a computing system of PTUA 101 receives an electrical signal indicative of a sound emitted from a surface of a power tool from a sound measuring device mounted to a housing that is mechanically coupled to the power tool, wherein the sound measuring device is offset from the surface of the power tool.
In block 202, the computing system determines a signal indicative of actual tool usage based on the electrical signal.
In block 203, the signal indicative of actual tool usage is transmitted to an external computing system.
Hereinbefore, many aspects of PTUA 101 are described in detail with reference to system 100 depicted in
In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media, and communication media, including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
Although certain specific embodiments are described above for instructional purposes, the teachings of this patent document have general applicability and are not limited to the specific embodiments described above. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.
The present application for patent claims priority under 35 U.S.C. § 119 from U.S. provisional patent application Ser. No. 61/988,545, entitled “Power Tool Usage Monitor,” filed May 5, 2014, the subject matter of which is incorporated herein by reference in its entirety.
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