TAGS

TECHNICAL FIELD

[0001] Example embodiments generally relate to power equipment and, more particularly, relate to a system configured to protect the user of a chainsaw or other power equipment such as power cutters with blade or chain.

BACKGROUND

[0002] Property maintenance tasks are commonly performed using various tools and/or machines that are configured for the performance of corresponding specific tasks. Some of those tools, like chainsaws, are designed to be effective at cutting trees in situations that could be relatively brief, or could take a long time including, in some cases, a full day of work. When operating a chainsaw for a long period of time, fatigue can play a role in safe operation of the device. However, regardless of how long the operator uses the device, it is important that the operator remain vigilant to implementing safe operating procedures in order to avoid injury to himself/herself and to others.

[0003] To help improve safety, operators are encouraged to wear protective clothing and other personal protective equipment (PPE). However, wearing PPE alone may not always be sufficient to protect the operator while operating power equipment. Accordingly, it may be desirable to define additional “intelligent” protection solutions that compliment or augment the PPE in order to protect users of chainsaws and other outdoor power equipment.

BRIEF SUMMARY OF SOME EXAMPLES

[0004] Some example embodiments may provide for a protection assembly for a power tool. The protection assembly may include a sensor array which may be disposed at the power tool and include an electronic reader, a plurality of electronic tags that may be disposed at various positions at an operator of the power tool, and a controller that may be disposed at the power tool, the controller may include processing circuitry configured to initiate a protective action with respect to a working assembly of the power tool responsive to a trigger event occurring, the trigger event may include at least one of the plurality of electronic tags intruding on a protective zone that may be defined by a predetermined distance threshold value that may extend from all sides of the working assembly.

[0005] Some example embodiments may provide for a power tool. The power tool may include a working assembly that may perform a cutting operation, and a protection assembly that may protect an operator of the power tool during the cutting operation. The protection assembly may include a sensor array which may include an electronic reader, and a controller which may include processing circuitry that may be configured to initiate a protective action with respect to a working assembly of the power tool responsive to a trigger event occurring, where the trigger event may include at least one of a plurality of electronic tags intruding on a protective zone defined by a predetermined distance threshold value that may extend from all sides of the working assembly.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) [0006] Having thus described some example embodiments in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0007] FIG. 1 illustrates a concept diagram of a system in which wearable sensors may operate in accordance with an example embodiment;

[0008] FIG. 2 illustrates a power tool with a protection assembly in accordance with an example embodiment;

[0009] FIG. 3A illustrates a control flow diagram for a scenario involving detection of a distance between a reader and an electronic tag in accordance with an example embodiment; [0010] FIG. 3B illustrates a plot of return signals from electronic tags in accordance with an example embodiment; and

[0011] FIG. 4 illustrates a block diagram of the protection assembly in accordance with an example embodiment.

DETAILED DESCRIPTION

[0012] Some example embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Furthermore, as used herein, the term “or” is to be interpreted as a logical operator that results in true whenever one or more of its operands are true. As used herein, operable coupling should be understood to relate to direct or indirect connection that, in either case, enables functional interconnection or interaction of components that are operably coupled to each other.

[0013] FIG. 1 illustrates a protection assembly of an example embodiment being applied where the power tool is a chainsaw 100 having a working assembly that may include an endless chain 102 that rotates about a guide bar to perform cutting operations. As shown in FIG. 1, an operator 110 may wear wearable sensors. In this regard, the operator 110 may wear a helmet 112, gloves 114, and boots 116 as examples of PPE. The sensors may be integrated into the PPE, or may be attached thereto. Of course, the sensors could alternatively be integrated into or attached to other clothing or gear, and at other locations as well. Thus, the specific examples of the protection assembly shown in FIG. 1 should be appreciated as being non-limiting in relation to the numbers of sensors, locations of the sensors, and methods of attaching the sensors to the operator 110 and/or the gear of the operator 110.

[0014] In this example, the wearable sensors of the protection assembly may include IMU- based sensors 120. The IMU-based sensors 120 of FIG. 1 may be disposed on the helmet 112, gloves 114 and boots 116 that the operator 110 may be wearing, but could be at other locations as well, as noted above. Thus, for example, additional IMU-based sensors 120 could be provided at the knees, elbows, chest or other desirable locations on the operator 110. The IMU- based sensors 120 may operate in cooperation with a tool position sensor 122, which may be disposed at the working assembly of the power tool (e.g., chainsaw 100). Of note, the tool position sensor 122 may itself be an IMU-based sensor and/or may include a set of such sensors. The IMU-based sensors 120 and the tool position sensor 122 may each be configured to perform motion tracking in three dimensions in order to enable relative positions between body parts at which the IMU-based sensors 120 are located and the tool to be tracked. The motion tracking may be performed in connection with the application of motion tracking algorithms on linear acceleration and angular velocity data in three dimensions. [0015] The wearable sensors of this example may also include distance sensors 130. Although the distance sensors 130 of this example are shown to be in the same locations on the operator 110 that the IMU-based sensors 120 have been placed, such correspondence is not necessary. As such, more or fewer distance sensors 130 could be provided than IMU-based sensors 120, and the distance sensors 130 could be provided at the same or different locations on the operator 110. The distance sensors 130 may be configured to operate in cooperation with a tool distance sensor 132 that may be disposed at a portion of the tool (e.g., chainsaw 100). In this example, the tool distance sensor 132 may be disposed at a guide bar of the chainsaw 100 so that distance measurements made between the tool distance sensor 132 and one or more of the distance sensors 130 are indicative of a distance between the guide bar and the body part on which the corresponding one of the distance sensors 130 is being worn. Of note, the tool distance sensor 132 may be a single sensor and/or may include a set of such sensors. For example, the tool distance sensor 132 may be embodied as an electromagnetic reader (or transponder) that is mounted on the chainsaw (e.g., on the guide bar) and the distance sensors 130 may be embodied as electronic tags. The electromagnetic reader may be configured to sense the distance sensors 130 using a back-scattering principle. A radio frequency identification (RFID) tag is an example of such a distance sensor 130, however, the distance sensor 130 could also be active in some cases.

[0016] As can be appreciated from the descriptions above, the IMU-based sensors 120 may track movement in three dimensions. Meanwhile, the distance sensors 130 may be configured to measure or track distances in either two dimensions or simply in one dimension (i.e., straight line distance). In either case, distances or proximity measurements may be performed so that the chainsaw 100 (or at least the cutting action thereof) may be disabled based on distance or proximity thresholds that can be defined (e.g., for short distances), or based on combinations of relative motion of body parts and the tool at angular velocities or linear velocities above certain thresholds (e.g., stop delay based distances for larger distances).

[0017] In an example embodiment, a controller 140 may be disposed at the power tool (e.g., chainsaw 100) and, in this case, may be provided within a housing 150 of the chainsaw 100. The controller 140 may be configured to communicate with the tool position sensor 122 and/or the IMU-based sensors 120 to perform motion tracking as described herein. In FIG. 1, the controller 140 and tool position sensor 122 are shown to be collocated. However, such collocation is not necessary. Moreover, the tool position sensor 122 could be located at any desirable location on the chainsaw 100. Thus, for example, the controller 140 may have a wired or wireless connection to the tool position sensor 122. If communications between the IMU -based sensors 120 and the controller 140 occur, such communication may be accomplished via wireless communication (e.g., short range wireless communication techniques including Bluetooth, WiFi, Zigbee, and/or the like).

[0018] While FIG. 1 illustrates a specific view of a protection assembly for the chainsaw 100 according to an example embodiment, FIG. 2 illustrates a general view of an example embodiment of a power tool 200 including a protection assembly 230. In some embodiments, sensors may be worn by the operator 110 disposed in PPE or otherwise affixed to the body of the operator 110 to assist with tracking the distance of the operator 110 relative to the power tool 200. Accordingly, FIG. 2 illustrates a power tool 200 that may include a working assembly 210 which may perform a cutting operation, a powerhead which may power the working assembly 210, a housing 220 which may be operably coupled to the working assembly 210 and may contain the powerhead, and the protection assembly 230. In some embodiments, the power tool 200 may be a chainsaw 100. In this regard, the working assembly 210 may include a cutting chain 102, and a guide bar about which the chain 102 rotates. In some other embodiments, the power tool 200 may be power cutters, and in this regard, the working assembly 210 may include a cutting blade. The protection assembly 230 may include a sensor array 240 which may be disposed at the power tool 200. The sensor array 240 may be an embodiment of the tool distance sensor 132, and may thus provide distance tracking and/or object recognition for the protection assembly 230. In some embodiments, the sensor array 240 may include an electromagnetic reader 250 that may be configured to sense a tag 260 (e.g., the distance sensor 130) using a back- scattering principle.

[0019] As shown in the example embodiment of FIG. 2, the sensor array 240 may be disposed on the working assembly 210 itself (e.g. on the guide bar), but such orientation may not be necessary. In this regard, the sensor array 240 may be disposed on the housing 220 between the working assembly 210 and a handle 205 of the power tool 200. In an example embodiment, the sensor array 240 may be split into separate portions and disposed on the housing 220 on opposing sides of the working assembly 210. In other cases, the sensor array 240 may be disposed at any location on the power tool 200 that may provide an unobstructed view of the working assembly 210, such as on a front face of the power tool 200 and proximate to the working assembly 210.

[0020] In some embodiments, the protection assembly 230 may further include a protective zone 280. The protective zone 280 may be a boundary that extends a predetermined distance (DI) around all sides of the working assembly 210. In other words, the protective zone 280 may define a minimum distance around the working assembly 210 that the tag 260 may approach, occupy or exit, to define a trigger event. In other words, the trigger event may be related to the tag 260 contacting the protective zone 280. The sensor array 240, and thus the electromagnetic reader 250 (or transponder 250), may communicate with the electronic tags 260 to generate mappings of the distance of each of the tags 260 in space relative to the transponder 250. In this regard, the controller 140 may save and process the mappings of the distance of each tag 260 from the transponder 250. By comparing consecutive saved mappings, the controller 140 may be able to track the change of the distance of each tag 260 over time and determine if the tag 260 may be entering or approaching, may be disposed within, or may be exiting the protective zone 280. Thus, responsive to determining that the tag 260 may be in some way interacting with the protective zone 280, the controller 140 may conclude that the trigger event has occurred and may accordingly initiate a protective action with respect to the power tool 200. In some cases, the protective zone 280 around the working assembly 210 may be defined by a predetermined distance threshold that the radio frequency field covers when the transponder 250 may be disposed at the working assembly 210. In other words, the transponder 250 may use the guide bar as an antenna to ensure the radio frequency signal is evenly distributed on all sides of the working assembly 210 to establish the protective zone 280 around the working assembly 210.

[0021] FIG. 2 also illustrates the tags 260 disposed within the PPE worn by the operator 110. In this regard, the location of the tags 260 relative to the protective zone 280 may directly correlate to the location of the PPE, and the operator 110, relative to the protective zone 280. Therefore, the protective action may directly protect the operator 110 and the PPE worn on the operator 110 simultaneously. In some embodiments, the tags 260 may be placed in different orientations in the PPE to reduce data collection errors caused by the different approaching angles of the power tool 200 moving toward the operator 110.

[0022] The protection assembly 230 may monitor tags 260 even when the tags 260 may not necessarily be located proximate to the protective zone 280. As such, the mappings or other data generated by the sensor array 240 may be used by the controller 140 to determine if the tag 260 is approaching the working assembly 210, and, if so, its velocity and acceleration. If the controller 140 determines that the tag 260 may be approaching the working assembly 210 at a velocity that exceeds a predetermined threshold velocity, then the controller 140 may enlarge the protective zone 280 to create a larger buffer between the tag 260 and the working assembly 210 and allow more time for the protective action to take place. In contrast, if the controller 140 determines that the tag 260 may be approaching the working assembly 210 at a velocity that is less than the predetermined threshold velocity, then the controller 140 may reduce the protective zone 280 and create a smaller buffer between the tag 260 and the working assembly 210 to allow for more precise and controlled operation of the power tool 200 in certain settings. Similarly, the controller may increase the size of the protective zone 280 responsive to detecting the tag 260 accelerating toward the protective zone 280 where the acceleration exceeds a predetermined threshold acceleration. As such, the controller 140 may dynamically alter the size of the protective zone 280 based on whether or not the tags 260 are determined to have a velocity and/or an acceleration relative to the working assembly 210. In some cases, the predetermined threshold velocity and the predetermined threshold acceleration may be functions of the current size of the protective zone 280, the distance of the tag 260 to the protective zone 280 and the velocity and acceleration of the tag 260. In this regard, the predetermined threshold velocity and the predetermined threshold acceleration may be a function that may reflect the variety of conditions that must be met rather than a static numerical value.

[0023] Referring now to FIG. 3A, one such method of determining the distance of each tag 260 may be through an adaptive transmission power algorithm. In this regard, the reader 250 may utilize power provided by the power tool 200 to execute the adaptive transmission power algorithm as part of the range determination process. The adaptive transmission power algorithm may include generating an initial detection signal 300 for transmission with a modulated code over a carrier wave by raising transmit power until a detection occurs. When the tag 260 is within a prescribed distance from the reader 250, and the power level is sufficient, the tag 260 will receive sufficient power from the initial detection signal 300 transmitted to generate a response 310 that is then detected by the reader 250. The response 310 will retransmit a code used as an identifier for the tag 260 back to the transponder 250 to identify the tag 260. Having detected the tag 260, the transponder 250 may then reduce the transmit power from the transponder 250 to transmit a power reduced signal 320 having an incrementally lower value than the initial detection signal 300. If received with sufficient power, the tag 260 will send a power reduced response 330. The reader 250 will then reduce power again (e.g., incrementally) and repeat the incremental power reductions until no response is received from the tag 260. The signal associated with the last (i.e., lowest) power transmitted, when the tag 260 is no longer detected, may be referred to as a distance marker signal 340. When the power of the distance marker signal 340 is determined, it can be seen that this power is proportional to distance in a fairly consistent and accurate way.

[0024] In this regard, detection range is generally exponentially proportional to the output power or transmit power of the reader 250. Although the specific values may change from antenna to antenna (e.g., reader to reader), the proportionality is fairly consistent. Thus, an accurate mapping of power to detection range may be achieved. Accordingly, such mappings may generally indicate the distance of each tag 260 to the transponder 250. Small calibration adjustments may be made for individual antennas, and other correction factors (e.g., for temperature) may also be applicable in some cases.

[0025] The sensor array 240 may communicate the mappings or other data to the controller 140 that may use the mappings to determine when the trigger event occurs. The controller 140 may include processing circuitry 270 which may include a data processing algorithm to translate the mappings into simpler distance data that may be compared to the protective zone 280 distance threshold to determine when the trigger event occurs. In an example embodiment, the processing circuitry 270 may include one or more instances of a processor 272 and memory 274 that may be in communication with or otherwise control other components or modules that interface with the processing circuitry 270. As such, the processing circuitry 270 may be embodied as a circuit chip (e.g., an integrated circuit chip) configured (e.g., with hardware, software or a combination of hardware and software) to perform operations described herein. In some embodiments, the processing circuitry 270 may be embodied as a portion of an onboard computer housed in the housing 220 of the power tool 200 to control operation of the system relative to interaction with other motion tracking and/or distance measurement devices.

[0026] The mappings may be stored in the memory 274, and accessible to the controller 140 for determining the distance measurement information. Accordingly, when the distance marker signal 340 is determined, the process above can be repeated (as shown by operation 350) to determine additional instances of the distance marker signal 340. Any desirable number of repeated iterations can be completed, and a convergence around a range of powers at which the tag 260 is lost may be determined. For example, an average or mean power for distance marker signals may be computed with each, or with a predetermined number of iterations of operation 350. The average or mean power for the distance marker signals may then be correlated to the mapping stored in the memory to determine a range or distance between the corresponding sensor (i.e., the tag 260) and the reader 250. This process can be repeated and cycled through rapidly for each one of the tags 260 using a time division scheme.

[0027] Referring now to FIG. 3B, one such method of determining the distance of each tag 260 may be through correlating signal strength values from each tag 260 to a distance from the transponder 250. In an example embodiment, rather than use the adaptive transmission power algorithm described above with respect to FIG. 3A, the distance to each tag 260 may be determined using the received signal strength indication 302 (RSSI). The RSSI 302 may be an estimated measure of the backscattered signal power that the transponder 250 receives from a given tag 260. In most cases, standard RFID protocol may include the RSSI 302 in the response 310 from the tag 260 to the transponder 250. RSSI 302, which is depicted as dashed vertical lines in FIG. 3B, may provide an indication of the distance between the transponder 250 and respective tags 260. In this regard, the transponder 250 may send out the initial detection signal 300 with a predetermined and constant output power, as indicated by the horizontal line in FIG. 3B. In some embodiments, the tags 260 may be fixed in place at the operator 110 or at the PPE worn by the operator 110. The distance of the tags 260 relative to each other and to the working assembly 210 may be calibrated and recorded into the controller 140 before operating the power tool 200. In some cases, the protective zone 280 may thus be defined by a predetermined distance threshold value that may accordingly be calibrated and saved into the controller. In this regard, responsive to the transponder 250 sending out the initial detection signal 300 with a predetermined and constant output power, the tags 260 may return differing RSSI’s 302 due to their respective positions on the operator 110.

[0028] Similar to the adaptive transmission power algorithm, the distance from the tag 260 to the transponder 250 may be exponentially proportional to the RSSI 302 in an ideal setting where environmental factors can be controlled. In a real world application, having a plurality of tags 260 may improve the accuracy of using RSSI 302 by reducing the error in the overall system. For instance, say for example one particular tag 260 is disposed deeper in the PPE of the operator 110 and because of that, the tag 260 may return a poor signal strength indication back to the transponder 250. If that particular tag 260 were the only tag 260 in the system, the controller 140 may think that tag 260 may be disposed far away. In using many tags 260, the controller 140 may compare the RS SI 302 from other tags 260 located nearby to determine that the tag 260 reporting the poor RSSI 302 may be an outlier and isn’t actually disposed far away. Additionally, by including a plurality of tags 260, the transponder 250 may read many tags 260 in a shorter period of time which may be advantageous for filtering out some errors such as the one described in the example above.

[0029] In some embodiments, the transponder 250 may include various predetermined output powers for the initial detection signal 300 which may correspond to different distances read by the transponder 250. In this regard, the transponder 250 may monitor more tags 260 by sending a higher output power initial detection signal 300 that may reach tags 260 that may be disposed further away on the operator 110. By comparing the RSSI 302 information returned from the tags 260 with the calibrated distances of the tags 260, the controller 140 may determine the orientation of the tags 260 relative to the working assembly 210 and the protective zone 280 to determine if the trigger event has occurred.

[0030] As can be appreciated from the descriptions above, the protection assembly 230 may be configured to measure or track distances or objects in either three dimensions, two dimensions, or simply in one dimension (i.e., straight line distance). In any case, distances or proximity measurements may be performed so that the power tool 200 (or at least the cutting action thereof) may be disabled based on distance or proximity thresholds that can be defined for the protective zone 280.

[0031] FIG. 4 shows a block diagram of the controller 140 in accordance with an example embodiment. In an example embodiment, the controller 140 may be disposed at the power tool 200 and, in such cases, may be provided within the housing 220 of the power tool 200. The controller 140 may be configured to communicate with the sensor array 240 and/or the IMU- based sensors 120 to perform object recognition and distance measuring and/or motion tracking as described herein. In this regard, object recognition may refer to the identification of the tags 260 by the transponder 250. The controller 140 may have a wired or wireless connection to the sensor array 240. If communications between the IMU-based sensors 120 and the controller 140 occur, such communication may be accomplished via wireless communication (e.g., short range wireless communication techniques including Bluetooth, WiFi, Zigbee, and/or the like).

[0032] The sensor array 240 may communicate with the controller 140 to provide the mappings either on a continuous, periodic or event-driven basis. At one end of the spectrum, continuous mappings may be provided to, and evaluated by, the controller 140 at routine and frequent intervals. At the other end of the spectrum, the mappings may only be provided when the tag 260 interacts with the protective zone 280. In any case, the controller 140 may be configured to evaluate the maps or voltages relative to initiation of warnings or other protective actions that the controller 140 may control. As an example, the protective action may include stopping any cutting operation (e.g., via activating a chain brake 170) of the chainsaw 100 in FIG. 1 responsive to the controller 140 determining that a trigger event has occurred.

Alternatively or additionally, the protective action may include providing a warning (e.g., audibly, visually, or via haptic feedback). For example, if hearing protection 180 is worn by the operator 110 as shown in FIG. 1, an audible warning could be provided via the hearing protection 180. In some cases, the protective action may include both providing the warning and stopping any cutting operations (e.g., activating the chain brake 170).

[0033] As shown in FIG. 4, the controller 140 may include processing circuitry 270 of an example embodiment as described herein. The processing circuitry 270 may be configured to provide electronic control inputs to one or more functional units of the power tool 200 (e.g., the chain brake 170) or the system (e.g., issuing a warning to the hearing protection 180) and to process data received at or generated by the one or more of the IMU-based sensors 120 or the sensor array 240 regarding various indications of movement or distance between the power tool 200 and the operator 110 or the tags 260. Thus, the processing circuitry 270 may be configured to perform data processing, control function execution and/or other processing and management services according to an example embodiment.

[0034] In some embodiments, the processing circuitry 270 may be embodied as a chip or chip set. In other words, the processing circuitry 270 may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The processing circuitry 270 may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single “system on a chip.” As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0035] Although not required, some embodiments of the controller 140 may employ or be in communication with a user interface 290. The user interface 290 may be in communication with the processing circuitry 270 to receive an indication of a user input at the user interface 290 and/or to provide an audible, visual, tactile or other output to the operator 110. As such, the user interface 290 may include, for example, a display, one or more switches, lights, buttons or keys, speaker, and/or other input/output mechanisms. In an example embodiment, the user interface 290 may include the hearing protection 180 of FIG. 1 , or one or a plurality of colored lights to indicate status or other relatively basic information. However, more complex interface mechanisms could be provided in some cases.

[0036] The controller 140 may employ or utilize components or circuitry that acts as a device interface 400. The device interface 400 may include one or more interface mechanisms for enabling communication with other devices (e.g., the sensor array 240, the chain brake 170, the hearing protection 180, and/or the IMU-based sensors 120). In some cases, the device interface 400 may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive and/or transmit data from/to components in communication with the processing circuitry 270 via internal communication systems of the power tool 200 and/or via wireless communication equipment (e.g., a one way or two way radio). As such, the device interface 400 may include an antenna and radio equipment for conducting Bluetooth, WiFi, or other short range communication, or include wired communication links for employing the communications necessary to support the functions described herein.

[0037] The processor 272 may be embodied in a number of different ways. For example, the processor 272 may be embodied as various processing means such as one or more of a microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or the like. In an example embodiment, the processor 272 may be configured to execute instructions stored in the memory 274 or otherwise accessible to the processor 272. As such, whether configured by hardware or by a combination of hardware and software, the processor 272 may represent an entity (e.g., physically embodied in circuitry - in the form of processing circuitry 270) capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor 272 is embodied as an ASIC, FPGA or the like, the processor 272 may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor 272 is embodied as an executor of software instructions, the instructions may specifically configure the processor 272 to perform the operations described herein.

[0038] In an exemplary embodiment, the memory 274 may include one or more non- transitory memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or re-movable. The memory 274 may be configured to store information, data, applications, instructions or the like for enabling the processing circuitry 270 to carry out various functions in accordance with exemplary embodiments of the present invention. For example, the memory 274 could be configured to buffer input data for processing by the processor 272. Additionally or alternatively, the memory 274 could be configured to store instructions for execution by the processor 272. As yet another alternative or additional capability, the memory 274 may include one or more databases that may store a variety of data sets. Among the contents of the memory 274, applications may be stored for execution by the processor 272 in order to carry out the functionality associated with each respective application. In some cases, the applications may include instructions for motion tracking and/or object recognition and distance measuring and distance tracking as described herein.

[0039] As stated above, the sensor array 240 may communicate the mappings or other data to the controller 140, which may use the mappings or other data to determine when a trigger event occurs. In this regard, the maps or other data may accordingly be communicated from the sensor array 240 to the memory 274 via the device interface 400 and the processor 272. In some cases, the memory 274 may save the maps in a circular buffer. In other words, a set amount of storage space may be available in the memory 274 and in order to save new data from the sensor array 240, the memory 274 may overwrite the oldest saved data with the newest saved data. The processor 272 may then access the memory 274 under the direction of an application from the memory 274 to compare numerous sets of saved data from the sensor array 240 to determine the change over time with respect to tags 260 detected near the protective zone 280. [0040] Distance measurement and determination can be embodied many ways depending on the specific sensors and methods used to implement distance measurement devices. In another example embodiment of reader based measurement, the distance sensors 130 may be embodied as ultra wide band (UWB) modules. For example, the sensor array 240 may include a UWB module that may be mounted on the power tool 200 (e.g., proximate to the working assembly 210, or on the guide bar). The UWB module on the power tool may be configured to sense a separate UWB module disposed at the operator 110 or at the PPE worn by the operator 110. As a technology, UWB, while similar to RFID, differs in that RFID requires a designated transponder 250 and designated tags 260, whereas UWB is capable of transmitting data between each UWB module via a communication pulse without such designations and with less interference than in a similarly constructed RFID based system. Similar to an RFID based system, the UWB modules may be used as distance sensors 130 with or without the additional integration of IMU-based sensors 120.

[0041] In some embodiments, multiple (i.e. 4 or more) UWB modules may be used for trilateration which may yield increased accuracy in determining 3D positioning. In this regard, three of the four or more UWB modules act as anchors and form a plane including the three anchors. A reference UWB module that may not be planar with the anchors may then have its position defined by a point of intersection of the communication pulse of each anchor relative to the plane of anchors with great precision. In an example embodiment, UWB trilateration may be used with an anchor UWB module on each of the arms of the operator 110, and a third on the helmet 112 of the operator 110. The fourth UWB module may be mounted on the power tool 200 and may be precisely tracked relative to the arms and head of the operator 110 while the power tool 200 is in use. In some cases, the anchors may be disposed at the power tool 200 instead of at the operator 110. In this regard, the reference UWB module may be any of a plurality of UWB modules that may be disposed at various positions at the operator 110. This orientation of UWB modules may provide an accurate representation of the location of the operator 110 relative to the power tool 200. In such cases, the respective location of each anchor UWB module may be fixed relative to each other since they may be disposed at different locations on the power tool 200. For example, a first anchor may disposed at a distal end of the working assembly 210, a second anchor may be disposed at the base of the working assembly 210 proximate to the housing 220, and a third anchor may be disposed at the handle 205 of the power tool, then the distances between each anchor may remain constant and may provide greater accuracy for trilateration. In other cases, a similar process of locating the reference UWB module using only two or more anchors, where the anchors may be disposed at the operator 110, at the power tool 200 or at both the operator 110 and the power tool 200.

[0042] In this regard, if the power tool 200 were to move close enough to the operator 110 for any of the UWB modules to be in contact with the protective zone 280, the controller 140 may determine that the trigger event has occurred and may initiate the protective action. The protective zone 280, in this case, may be defined by a predetermined distance threshold that extends on all sides of the working assembly 210. In another example embodiment, the anchor UWB modules may be disposed at the right and left sides of the hips of the operator 110, and at the chest of the operator 110, respectively. In this regard, the fourth UWB module on the power tool 200 may be precisely tracked with respect to the torso of the operator 110. In other cases, the anchor UWB modules may be disposed at any respective locations on the operator 110 from which the location of the power tool 200 may be desirable to track.

[0043] Some example embodiments may provide for a protection assembly for a power tool. The protection assembly may include a sensor array which may be disposed at the power tool and include an electronic reader, a plurality of electronic tags that may be disposed at various positions at an operator of the power tool, and a controller that may be disposed at the power tool, the controller may include processing circuitry configured to initiate a protective action with respect to a working assembly of the power tool responsive to a trigger event occurring, the trigger event may include at least one of the plurality of electronic tags intruding on a protective zone that may be defined by a predetermined distance threshold value that may extend from all sides of the working assembly.

[0044] The protection assembly of some embodiments may include additional, optional features, and/or the features described above may be modified or augmented. Some examples of modifications, optional features and augmentations are described below. It should be appreciated that the modifications, optional features and augmentations listed below may each be added alone, or they may be added cumulatively in any desirable combination. For example, in some embodiments, the electronic reader may emit a radio frequency signal at a constant predetermined output power to define the protective zone. In some cases, the plurality of electronic tags may be radio frequency identification (RFID) tags. In an example embodiment, the controller may determine a distance from the electronic reader to each of the plurality of electronic tags based on a received signal strength indication (RSSI) that may be communicated to the electronic reader from each of the electronic tags. In some cases, the predetermined distance threshold value and the distance of the electronic tags relative to each other may be calibrated and recorded into the controller. In an example embodiment, the controller may compare the RSSI from each of the electronic tags to the predetermined distance threshold value to determine if at least one of the electronic tags may be intruding on the protective zone, which may indicate the trigger event. In some cases, the controller may initiate the protective action responsive to determining at least one of the electronic tags may be intruding on the protective zone. In an example embodiment, the distance from the electronic reader to each of the electronic tags may be determined based on an adaptive transmission power algorithm. In some cases, the controller may initiate the protective action responsive to determining at least one of the electronic tags may be intruding on the protective zone. In an example embodiment, the electronic reader and the plurality of electronic tags may be ultra wideband (UWB) modules. In some cases, the UWB modules may use trilateration to determine a position of the operator relative to the protective zone via a communication pulse. In an example embodiment, in trilateration, three UWB modules may be operably coupled to the operator and may act as anchors that may form a plane, and a reference UWB module may be disposed at the working assembly out of the plane comprising the anchors. In some cases, the reference UWB module may be precisely located relative to the plane via an intersection of the communication pulse from each of the anchors. In an example embodiment, the protection assembly may include personal protective equipment (PPE) that may be worn by an operator. In some cases, the electronic tags may be disposed at various positions at the PPE. In an example embodiment, the power tool may be a chainsaw. In some cases, the working assembly may include a chain and a guide bar. In an example embodiment, the protective action may include activating a chain brake of the chainsaw responsive to the controller determining that the trigger event may have occurred. In some cases, the electromagnetic reader may be disposed at the working assembly and may use the guide bar as an antenna to emit the radio frequency signal. In an example embodiment, the power tool may be a chainsaw or power cutters. In some cases, the working assembly may include a chain and guide bar or a cutting blade. In an example embodiment, the protective action may include providing an audible or visual warning to an operator responsive to the controller determining that the trigger event may have occurred.

[0045] Some example embodiments may provide for a power tool. The power tool may include a working assembly that may perform a cutting operation, and a protection assembly that may protect an operator of the power tool during the cutting operation. The protection assembly may include a sensor array which may include an electronic reader, and a controller which may include processing circuitry that may be configured to initiate a protective action with respect to a working assembly of the power tool responsive to a trigger event occurring, where the trigger event may include at least one of a plurality of electronic tags intruding on a protective zone defined by a predetermined distance threshold value that may extend from all sides of the working assembly.

[0046] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.