CA3221356A1 - Kit, system and method for real-time, autonomous remote monitoring of wear in a bushing of earth-moving equipment - Google Patents

Abstract

Disclosed are a kit, system and method for the real-time, autonomous, remote monitoring of the wear of the body of a bushing, installed in earth-moving equipment, including a lug of a bucket, the kit comprising: a measurement module; an acquisition module; and an adapter that connects the two modules. The system comprises the kit, in communication with a receiving means and a wireless communication network, with a central unit located inside or outside the place of operation of the mining machine. The temporary or permanent removal of the bushing is scheduled once the bushing wear data have been received. The monitoring method comprises taking measurements of capacitance with thermal compensation, in a control specimen in the measurement module of the sleeve of the bushing, which wears jointly with same; and, complementarily, quantifying the level of electrical conducting lines spaced apart in the control specimen, which are gradually eliminated with wear.

Description

I
KIT, SYSTEM AND METHOD FOR REAL-TIME, AUTONOMOUS REMOTE MONITORING OF
WEAR IN A BUSHING OF EARTH-MOVING EQUIPMENT
FIELD OF THE INVENTION
The present invention refers to a kit, system and method for remote, autonomous, real-time monitoring of bushing wear or thickness installed in an earth moving machine, preferably, in the bucket ear of a mining machine, wherein the kit comprises: a measurement module, an acquisition module, and a one flexible and one rigid end adapter. The system comprises the aforementioned kit in communication with a wireless receiving means and a wireless communication network comprising at least one central unit which may be located in or outside the mine, which are in communication to receive and manage remotely, the collected bushing wear data and schedule stops to replace said bushing either temporarily or permanently. The monitoring method is based on the complementarity, but not limited to, of two ways of determining bushing wear; while the first way is based on capacitance measurements with thermal compensation, in at least one witness specimen of the measurement module, which is located in the bushing mantle, and which wears together with the bushing, the other one performs quantification measurements of the level of the electrical conduction lines spaced in the witness specimen, which are eliminated as the wear level progresses.
BACKGROUND
The purpose of the bushings is to protect other critical components from wear caused by friction between moving mechanisms, in this case, between the bucket ear and the pin.
They are made of a special steel alloy that allows them to operate for a certain period of time or for a certain amount of tons of displaced material. However, these elements can suffer a reduction in their useful life due to accelerated, excessive and unforeseen wear, causing damage to other components that the bushing is intended to protect, resulting in unscheduled stoppages with significant economic losses for the mine.
There are few companies that venture to monitor the bushings so that they can be replaced in time without generating economic damages due to unscheduled stops. Current solutions range from visual inspections of bushing thickness to post-analysis of photographs of the parts. These methods are imprecise, subjective, costly and impractical, because their results are not immediate, and to carry them out, it is necessary to stop the work to estimate wear. In addition, they depend on the experience and judgment of the operator who carries out the measurement,

2 and the measurement must be made from a considerable distance because, for safety reasons, personnel cannot access a mining shovel during a mining operation.
US10696337B2 or US10046815B2 (WearPro Inc.) relate to a wear train control device comprising a roller assembly including a fixed roller component and a bushing. An opening is formed within the fixed roller component. A first sensor is arranged within the opening of the fixed roller component on the bushing. The first sensor is configured to detect a first physical characteristic of the bushing. The fixed roller component is a shaft or a housing. The first sensor is a temperature sensor or a Hall effect sensor. A magnet is disposed in the roller assembly. A
second sensor is disposed within the opening of the fixed roller component on the bushing. The second sensor is configured to detect a second physical characteristic of the bushing. A data transmission device is coupled to the first sensor. Data is collected from the sensor and transmitted to a receiving device.
US6868711B2 (General Electric Technology GmbH) discloses a method for monitoring mechanical wear caused by a first component on a second component, wherein the first and second components are movable relative to each other and wherein the first and second components are at least at times, in mechanical contact with each other, at least one sensor head is arranged in a wear area for monitoring the second component. The at least one sensor head is mechanically worn by the first component upon reaching a predetermined wear limit. When the at least one sensor head is mechanically worn, a measurement signal is generated by the at least one sensor head or a change of a measurement signal, produced by the at least one sensor head before it has been mechanically worn, is detected. The measurement is the intensity of the light reflected from the metal cover.
US20150066291A1 (Caterpillar Inc) discloses a Wear Monitoring System for an undercarriage component includes an ultrasonic sensor disposed on the undercarriage component. The ultrasonic sensor is configured to emit ultrasonic waves to detect wear of the undercarriage component. The wear monitoring system further includes a wear monitoring device arranged in communication with the ultrasonic sensor. The wear monitoring device is located remote from the ultrasonic sensor. Further, the wear monitoring device is configured to generate an output indicative of the wear of the landing gear component.

3 US20160121945A1 (Caterpillar Inc) discloses a roller of an undercarriage track system for a machine, comprising a body and a sensed function. The body is a solid of revolution formed around a roller shaft. The body includes a bore surface and a roller contact surface. The bore surface defines a bore extending through the body. The bore surface is a radially interior surface of the body. The roller contact surface is located outward from the bore surface. The sensed feature is located in the body. The sensed feature is configured to rotate with the body and be detected by a sensor. The sensor is a magnetic velocity sensor, and measures the length of a tooth/protrusion or recess extending from and integral to the body.
US20160221618A1 (Caterpillar Inc) discloses a wear sensing device that may be used in conjunction with a carrier roller assembly of a track assembly and may have a wear sensor roller mounted on a shaft of the carrier roller assembly, which may be configured to contact a track pin assembly connected to one or more track links of the track assembly. The wear detection device may further have a wear sensor mounted on the wear sensor roller and configured to generate a signal indicative of a wear parameter of one or more chain links. The sensor is a Hall effect sensor, an ultrasonic sensor, a magnetic sensor, an induction sensor, or a laser sensor.
US20090223083A1 (Pacific Bearing Co) discloses a bearing including a portable section that includes a wear sensor. The bearing includes a wear sensor that provides information to the user regarding the service life of the bearing that has been used. The sensor may be in the form of a wire embedded in the portable section of the bearing, so that as the portable section wears over time, the wire may wear by breaking a circuit including the wire. An indicator module can detect cable breakage and determine the amount of bearing life that has been used. In one implementation, the bearing is used in a drying drum; and method for monitoring bearing wear including monitoring changes in electrical properties of a sensor mounted on the bearing.
DE102007063519A1 (Lein Claudius) discloses a wear and overload monitoring system has two movable elements against each other, wherein the elements are supported or coupled by means for a spring or absorption coupling. The means comprises an elastomeric component. A unit is integrated or fixed in the elastic component for an electrical wear monitoring or absorption measurement and an overload indication. The elastic component consists of two mutually moving elements which by means of a spring and/or unloading coupling are mutually supported or coupled to each other, which comprises at least one elastomeric component. The electrically conductive, conductive or semi-conductive structures in the elastomeric component are

4 introduced or vulcanized, and produce the electrical contact between the two mutually movable elements which in turn are electrically conductive or have electrically conductive contacts and have a sensor and/or open or closed circuit with different parameters, and have conductive structures with fracture or fatigue behavior or lifetime based on defined physical, thermal or chemical parameters.
US20150081166A1 (Caterpillar Inc) discloses a wear monitoring system for monitoring wear of a surface of a track roller associated with an undercarriage of a machine, comprising a sensing device positioned beneath an upper surface of the track roller, which in turn comprises a probe configured to undergo wear along with the upper surface of the track roller, a controller circuit configured to monitor the degree of wear of the upper surface of the track roller as a function of wear of the probe, an antenna, and a power source. The wear monitoring system further comprises a transceiver configured to transmit a signal indicative of the degree of wear of the tracker roller. The wear monitoring system further comprises a monitoring device configured to generate an output indicative of the degree of wear of the tracker roll.
KR101863909B1 (KRRI) discloses a controller and a method of controlling an abrasion "tester"
on an axle floor planer of a rail vehicle, a controller for receiving a detection signal detected from the plurality of sensors of the performance "tester" that simulates driving characteristics of the rail vehicle and issuing a command to control the driving device of the performance tester; an input/output board for receiving an input signal, converting the signal to a digital signal and transmitting the signal to the controller, and sending an analog signal to the performance tester in accordance with a command from the controller, and a motor controller for controlling the motor device in accordance with a command from the controller. The apparatus enables an automatic abrasion resistance test of a rail vehicle axle ground planer and a method of controlling the performance tester. An abrasion resistance test environment that simulates the environment of a real vehicle during wear testing of an axle ground brush for a rail vehicle and a sliding disk are constructed to reproduce a dynamic numerical change measured on a real rail vehicle, and to perform the test at low cost.
US20150266527A1 (Caterpillar Inc) discloses a linkage for a rail assembly for a machine, comprising: a linkage body defining an opening configured to receive a track pin therein. The link body further includes a first surface configured to contact a rotating element of the rail assembly and a second surface configured to contact a rail shoe coupled to the link body. The linkage

5 further includes a plurality of marks defined on the linkage body proximate the first surface. Each of the plurality of marks is indicative of progressive wear of the link body with respect to the first surface.
There are products on the market that, although they do not measure wear on bushings, can measure wear on SAG mill liners, such as High Service's Smart Wear System (SWS), with its SWS product, Smart Wear System, which is achieved by means of a wireless transmission device in the form of a bolt that is installed in the mills and allows online access to liner wear information.
As for wear monitoring, WearPro, whose patented product UCM
(U520130255354A1/U51004681562), monitors wear on link bushings in track-type traction devices. The sensor reports wear on roller bushings and gears remotely and uses a hall-effect sensor to measure thickness.
The present invention, instead, refers to a kit, system and method for remote, autonomous, real-time monitoring of the wear of a bushing installed in an earthmoving machine, preferably, in the bucket ear (1), where the kit is installed directly on the bushing (2), and provides information on the state of wear thereof, in a reliable manner and with low energy consumption.
The present kit comprises at least one measurement module of reduced size that can be installed in small spaces, thus adapting to spaces of various geometries, and comprises at least one witness specimen, at least one capacitive chip, at least one digital counter chip and at least one temperature measurement chip, and at one end, a female connector for connections of flexible flat circuits.
The present kit also comprises at least one printed circuit acquisition module, multilayer, with an antenna that does not present electromagnetic shielding due to the high presence of metals in its environment, which is a frequent problem in telecommunications, and instead, emits microwave/radiofrequency signals from a metallic environment where there are small gaps and spaces. The acquisition module also includes high capacity batteries, micro SD
memory for error logging and data storage, rigid connector to attach to the adapter, microcontroller, RF chips, power management chip, LED lights, among others.
Likewise, the acquisition module comprises an external protective housing (13) that protects -both the aforementioned electronic components and other passive electronic components,

6 including resistors, capacitors and inductances, among others, from an environment with high thermal and corrosive fluctuations, and from shocks/impacts and vibrations that occur as a result of the acceleration/deceleration of the mining machine, and the loading and unloading of ore, among others.
The present kit also comprises an adapter (7) with a rigid vertical connector (8) at one end, and a flexible connector (9) at the other end, which allows it to dispense with other mechanical connection elements (such as bolts, screws, nuts, among others), and thus, be able to withstand low temperatures without deterioration, wherein said flexible connector comprises a flexible flat circuit that is housed in the female connector of the measurement module, and said rigid vertical connector comprises a circuit that is attached to the acquisition module.
The present system comprises the above-described kit, a wireless receiving means and a wireless communication network with at least one central communication unit, in communication with said kit, specifically, in communication with said acquisition module of said kit.
The method is based on the complementarity, but not limited to, of two ways of determining bushing wear. The first way comprises capacitance measurement with thermal compensation, considering that the bushing wear varies proportionally with the wear length of said at least one witness specimen of said measuring module which wears solidly with the bushing, and which is located at least in a rectangular channel in the bushing mantle. The second way performs length measurements on said at least one witness specimen by detecting and quantifying the level of its spaced conducting electrical lines (21, 22), which reflects the advance/degree of wear, this means that at lower levels of conducting electrical lines or lower density of quantization of levels is higher the wear on said at least one witness specimen, while at higher levels of conducting electrical lines or higher density of quantization of levels is lower the wear on witness specimens.
The bushing comprises in its mantle, at least one rectangular, shallow channel, and further at least one through perforation in said channel wherein said at least one witness specimen of said measurement module is located, and a flared end. The bushing may have multiple channels regularly distributed in the mantle, and each channel may have multiple through perforations for receiving multiple witness specimens.

7 BRIEF DESCRIPTION OF FIGURES
FIGURE 1: Shows section of bucket ear (1), with cylindrical opening to house bushing.
FIGURES 2A-2F: Shows bushing (2) with at least one rectangular, low-profile/shallow channel (Figs. 2A and 2B), terminating at its end with a channel extension. It may have 1 or more through cylindrical bores distributed along the channel to accommodate specimens or witnesses (4). The bushing is illustrated with 3 rectangular, shallow channels and one or more through cylindrical bores distributed along the channel (Figs. 2C and 2D). Illustrated are bushings with 5 rectangular, shallow channels and one or more through cylindrical bores distributed along the channel (Figs. 2E and 2F).
FIGURES 3A and 3B: Shows bushing (2), with at least one channel installed in bucket ear (1).
FIGURE 4: Shows measurement module (3) for at least one channel containing at least 1 or more wear witness specimens (4), at least 1 or more measurement chips, which may be capacitive, digital counters or both, at least 1 or more temperature measurement chips. It also contains at one end a female connector (5) for flexible flat circuit connections.
FIGURES 5A-5C: Shows at least one measuring module (3) installed in at least one channel of the bushing (2), with one channel (Fig. 5A), three channels (Fig. 5B) and five channels (Fig. 5C).
FIGURES 6A and 6B: Bushing with measuring module (2) installed in bucket ear (1). Section of the channel (6) protruding from the side of the ear is observed, section that allows later installation of the adapter (Fig. 6A). A view of the cutout in the ear (1) is shown (Fig. 6B).
FIGURES 7A-7C: Shows Perspective View (Fig. 7A) of adapter (7). Bottom plan view (Fig. 7B).
Top elevation view (Fig. 7C). Flexible flat connector (9) and rigid connector

(8).
FIGURES 8A-8C: Shows a cutaway view in the ear (1) of measurement module (3) and adapter (7) connected and installed in the channel (6) of the bushing (2). The adapter (7) consists of two ends, the first consists of a flexible flat circuit that is housed in the connector of the measurement module, the second end consists of a rigid vertical connector.

FIGURES 9A-9C: Shows different perspectives of the system after installation of the structural washer (10). It can be seen that the vertical end of the adapter (7) is completely sealed except for the upper opening of the structural washer cavity (11), a cavity that allows the acquisition module to be subsequently installed from above.
FIGURES 10A-101: Shows different perspectives of the acquisition module (12) and assembled with housing (13).
FIGURES 11A-11D: Shows different perspectives of the system after installation of the acquisition module (12) with housing (13).
FIGURES 12A and 12B: Shows cross section of the complete system.
FIGURE 13: Shows the acquisition module (12) with connector (14), antenna (15) and batteries (16).
FIGURE 14: Shows a schematic of operation of the present system and method.
FIGURE 15: Shows Graph of specimen capacitance versus bushing wear.
FIGURE 16: Shows Digital probe level versus bushing wear graph.
FIGURE 17: Shows wireless connectivity between acquisition modules and receiver on cabin roof.
FIGURE 18: Shows wireless connectivity between acquisition modules, cabin top receivers, cloud or server, with end user devices, such as computers, Tablet, cell phones, among others.
FIGURE 19: Shows different layers of fabrication of the same witness specimen (4) , which includes wear capacitor (19), reference capacitor (20) and circuits forming the different levels of conductor lines (21, 22).

9 DESCRIPTION OF THE INVENTION
The present kit, system and method of remote, autonomous, real-time monitoring of bushing wear installed in an earth moving machine, preferably, in the bucket ear of a mining machine, allows to monitor and report periodically, wirelessly or telematically, the level of wear accumulated in one or more bushings, in one or more machines, and in response, to program their maintenance and definitive or temporary replacement in order to prolong the useful life thereof, and thus, prevent undesired damages or unforeseen stoppages in the mining machine.
The present kit allows then, to measure the bushing wear, by positioning in at least one rectangular, shallow channel in the outer mantle of the bushing, at least one measurement module, which is connected to at least one (data) acquisition module by means of an adapter, wherein the acquisition module is located in a cavity of the structural washer, and wherein said bushing wear information collected and processed by said at least one measurement module and received by said at least one acquisition module, which transmits to a wireless receiving means and from said wireless receiving means to a central unit of a communication network, which may be the cloud (Internet) or a server (connected to the Internet, or else to a local network), thus enabling the management of maintenance, replacement or removal of the monitored bushing(s).
The channel, where the measurement module is housed, does not negatively affect the performance of the bushing during operation, nor does it reduce its useful life, and instead, allows to reliably measure the wear from its own body, without the need to estimate it from the outside of the bucket ear or from a similar position of the mining machine, as it has been done so far. The measurement module, as well as the acquisition module, once connected, are autonomous and do not require external on/off, guaranteeing a low energy consumption with an autonomy of 2 years.
The bushing comprises in its mantle, at least one rectangular channel, of shallow depth, and further at least one through perforation in said channel wherein said at least one witness specimen of said measurement module is located, and wherein said at least one channel has a flared end for receiving said adapter connecting said measurement module and said acquisition module.
The bushing may thus comprise multiple rectangular channels distributed in a regular manner in the bushing mantle, as well as multiple through bores equally distributed in each channel. Multiple measurement modules with multiple witness specimens allow a complete wear profile to be achieved for the entire bushing body, whereas with a single measurement module and more than

10 one witness specimen, a localized wear profile is achieved on one line of the bushing mantle, and particularly, for only one witness specimen, a single wear point is achieved.
The measurement module has a small size that allows it to be installed in small spaces, thus adapting to spaces of various geometries, and has at its end a low-profile female connector for flat and flexible circuit connections. This type of connector withstands high vibrations and temperatures.
The measurement module comprises at least one witness specimen, at least one capacitive measurement chip, at least one digital counter chip, at least one temperature measurement chip, and a female connector for flexible flat circuit connections, at one end, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others.
The witness specimen (4) comprising at least two functional layers (bilayer), comprising at least a first outer layer comprising at least one wear capacitor (19), and a second inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location with the second inner layer, and further optionally, the witness specimen may comprise a complementary third inner layer and a fourth inner layer comprising at least one circuit each layer, and together form the different levels of conductor lines (21, 22).
These third inner layer and fourth inner layer may be located either immediately downstream or upstream of the bilayer of first outer layer and second inner layer or between said first outer layer and said second inner layer, and wherein the wear capacitor (19) allows measuring the capacitance of the witness specimen as the same wears, while from the reference capacitor (20) measurements are obtained that allow correcting the wear measurement on the witness specimen according to the effect of temperature. Meanwhile, said third inner layer and fourth inner layer forming the different levels of conductor lines (21, 22) allow complementarily to measure the wear of the witness specimen.
The witness specimen may comprise at least one additional layer to the aforementioned configuration and which increases in at least one layer the bilayer comprising a first outer layer and a second inner layer either in an additional layer comprising a wear capacitor, an additional layer comprising a reference capacitor or both or different combinations thereof. The witness specimen may also comprise at least one additional complementary layer comprising circuits complementing the conducting lines, which may be located immediately upstream or downstream of or between the aforementioned wear capacitor and reference capacitor layers.

11 The wear capacitor comprises two conductor wires or two conductor tracks facing each other in a comb-shaped interleaved manner. The reference capacitor differs from the wear capacitor only in that it is shorter in length.
The acquisition module comprises at least one antenna that does not present electromagnetic shielding due to the high presence of metals in its environment, emitting microwave/radiofrequency signals from a metallic environment where there are small gaps and spaces; it also comprises a set of light indicators with patterns and colors that allow visualizing a successful connection with said measurement module, where said light indicators can be of permanent or intermittent light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer; a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module and processes the same, including errors coming from said measurement module and other peripherals, and in general, the execution of tasks of the other components of this module; a memory card that stores the information/data of said daily periodic measurements of the measurement module and its errors or those of other peripherals, including RF chips, power managers, among others, preferably selected from a microSD card memory; an integrated circuit/chip maintaining intermittent or continuous communication with said receiving means for wirelessly sending/transmitting to said receiving means said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module and other peripherals, enabling radio frequency communication through the use of Bluetooth Low Energy and Lora protocols at 2. 4 GHz; an integrated circuit/chip that manages/controls, the power supply from a power source selected from at least 2 batteries, controlled by the microcontroller, and that supplies power to both the acquisition module and the measurement module, thus avoiding excessive consumption when the components are not being used, favoring an energy autonomy of at least two years.
The acquisition module also includes an external protective housing (13) that protects the electronic components that make up the module from an environment with high thermal and corrosive fluctuations, and from shocks/impacts and vibrations that occur as a result of the acceleration/deceleration of the mining machine, and the loading and unloading of ore, among others.

12 Fig. 1 illustrates the bucket ear of the mining shovel. While Figs. 2A-2F show in illustrative mode, at least one modified bushing to comprise in its mantle, one shallow rectangular trough, three shallow rectangular troughs, or five shallow rectangular troughs. In Figs. 3A
and 3B, the installation of the bushing in the bucket ear of the mining shovel is illustrated as an example.
The configuration of the measurement module and the witness specimens are illustrated as an example in Fig. 4 and Fig. 19, where the latter figure shows a three-layer realization on the specimen surface with an outer layer for the wear capacitor (19), an intermediate layer for the reference capacitor (20) and an inner layer for the circuits forming the different levels of conductor lines (21, 2). The installation of the measurement module in at least one bushing with one shallow rectangular channel, three shallow rectangular channels or five shallow rectangular channels are illustrated as an example in Figs. 5A-5C. While in bushing with the measurement module installed in the bucket ear, it is illustrated in Figs. 6A and 6B, showing in a cut section, the side of the ear that subsequently allows the installation of the adapter.
Figs. 7A-7C illustrate as an example, the adapter observed from different views, and highlighting the end receiving flexible connector from the measurement module and rigid vertical connector receiving rigid connector from the acquisition module, where each connector is located at opposite ends of the adapter. While Figs. 8A-8C show a cutaway view of the bushing ear with the measurement module installed and the adapter connected to the measurement module via the flexible flat connector, where the connectors correspond to circuits.
Figs.9A-9C illustrate as an example, different views of the rear structural washer installation system, shown that the vertical end of the adapter is completely sealed except for the top opening of the structural washer cavity, where the acquisition module is installed from above, connecting the rigid connector of the acquisition module to the rigid vertical module of the adapter.
Figs. 10A-10H, illustrate as an example, different views of acquisition module without housing and with assembled housing. While Figs. 11A-11D illustrate as an example, different views of the rear installation system of the acquisition module with housing. Figs. 12A and 12B illustrate as an example, a cross section of the complete system installed on the bushing and Fig. 13 illustrates as an example, the acquisition module with rigid connector, antenna and power supply which may comprise at least one battery, battery, among other power sources.

13 Fig. 14 shows the operation scheme of present system and method. While Fig. 17 shows the wireless connectivity between acquisition modules and receiver module on the cab roof of an earthmoving machine, and Fig. 18 shows the wireless connectivity between acquisition modules, receiver module on the cab roof, cloud or server, with end-user devices, such as computers, Tablet, cell phones, among others.
Fig. 15 and Fig. 16 show a graph of witness specimen capacitance versus bushing wear and digital level graph of witness specimen versus bushing wear.
The present kit for remote, autonomous, real-time monitoring of the wear or thickness of a bushing installed in an earth moving machine, preferably, in a bucket ear, wherein said bushing comprises in its outer mantle, at least one rectangular, shallow channel, and further at least one through cylindrical bore in said rectangular channel for housing at least one witness specimen and a flared end, said kit comprising:
a) at least one measurement module to be located in said at least one rectangular channel of the external mantle of said bushing, comprising:
a.1) at least three chips located on a single electronic board, which may have diverse geometry and perform daily periodic measurements of at least 2 parameters selected from: bushing wear/thickness, a capacitive chip and a digital counter chip;
and bushing temperature, a temperature measurement chip, which allows the realization of a thermal compensation to adjust the measurements coming from said capacitive chip, eliminating the temperature dependence that generates distortion in the same, and thus, increasing the degree of confidence in the measurements, a.2) at least one witness specimen projecting from said single electronic board, through a flexible conductor forming a variable angle between 0 and 1800, preferably at an angle of 900, which allow to obtain measurements of variations of bushing wear as it wears in solidarity with the bushing, and which are subjected to thermal variations in the range of -15 C to 85 C, during bushing operation, said at least one witness specimen having electrical properties/characteristics that vary as its length decreases, including capacitance; and electrical conducting lines of its own, on an electronic board that electrically connects the parts to each other, having said witness specimen on its surface at least two layers, a first outer layer comprising at least one wear capacitor (19), a second inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location

14 with the second inner layer, and optionally, the witness specimen may comprise a third inner layer and a fourth complementary inner layer which together form the different levels of conductor lines (21, 22), which may be located either immediately downstream or upstream of the bilayer of the first outer layer and the second inner layer or between said first outer layer and said second inner layer, and wherein the wear capacitor (19) allows the capacitance of the witness specimen to be measured as the same wears, while from the reference capacitor (20) measurements are obtained which allow correction of the wear measurement on the witness specimen according to the effect of temperature, and wherein said third inner layer and fourth inner layer forming the different levels of conductor lines (21, 22) allow complementarily to measure the wear of the witness specimen, and wherein the witness specimen may comprise at least one additional layer to the aforementioned configuration and which increases by at least one layer the bilayer comprising a first outer layer and a second inner layer either in an additional layer comprising a wear capacitor, an additional layer comprising a reference capacitor or both or different combinations thereof, and wherein additionally the witness specimen may also comprise at least one additional complementary layer comprising circuits complementing the lead lines, which may be located immediately upstream or downstream of or between the aforementioned wear capacitor and reference capacitor layers;
a.3) a single electronic board comprising the components a.1) and a.2 ) of essentially rectangular elongated and flat geometry, flexo-rigid and multilayer, having a first zone or bending zone, of flexible material, preferably selected from polyamide, which can be bent without generating damage to the electrical connections present on said single electronic board, while the second zone opposite to said first zone, is of semi-rigid material, preferably selected from FR4, which can be slightly bent without damaging the electrical connections present on said single electronic board, and at one end, a female connector for connection of flexible flat circuits, and wherein an electronic circuit comprises said capacitive chip which receives and processes capacitance measurements coming from said at least one witness specimen and is located immediately before the beginning of the flexible zone of said single electronic board; said counting chip which receives and processes the count of interrupted/cut electrical conductor lines connecting said counting chip with said witness specimen, and is located immediately before the beginning of the flexible zone of said at least one witness specimen,

15 wherein each electrical conductive line is a level corresponding to a wire/conductor leading from a witness specimen to the counting chip, wherein the number of levels may vary as required, and preferably, the number of levels is 32, and said levels are located on said witness specimen, and further comprises a temperature measurement chip which is located in the center of said single electronic board, and measures the temperature at the center of the outer mantle of the bushing, and whose information is used for thermal compensation of the capacitive measurement, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others, of low profile and reduced dimensions, b) at least one acquisition module which is located in a cavity in the structural washer, having a unique individual identifier code (ID) that allows the bushing to be identified and registered in a wireless local network connected to a server, which may or may not be connected to the Internet, and comprises:
b.1) a set of light indicators with patterns and colors that allows visualizing a successful connection with said measurement module, where said light indicators may be of permanent or flashing light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer;
b.2) a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module, including errors coming from said measurement module or other peripherals, and in general, the execution of tasks of the remaining components of this module, b.3) a memory card that stores the information/data of said daily periodic measurements of said measurement module, as well as any errors coming from said measurement module or other peripherals, including chips, such as RF chips, power management chips, RGB LED control chips, among others, preferably selected from a microSD card memory, b.4) an integrated circuit/chip that maintains intermittent or continuous communication with said receiving means to wirelessly send/transmit to it said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module, which allows radio frequency communication through the use of Bluetooth Low Energy and Lora protocols at 2.4 GHz, b.5) an integrated circuit/chip that manages/controls the power supply from a power source selected from at least 2 batteries, controlled by said microcontroller, and that supplies power to both the acquisition module and said measurement module, thus

16 avoiding excessive consumption when said acquisition module and said measurement module are not in use, favoring an energy autonomy of at least two years, b.6) at least one antenna allowing wireless communication with said receiving medium, and b.7) a protective casing which houses each of the components b.1) to b.6 ), protecting them from dust and water, having a parallelepiped geometry, with mainly flat and smooth faces, which allows its easy displacement through the cavity or emptying of the structural washer, and in the final installation position, it is embedded inside the structural washer, being visible only through the upper emptying end of the structural washer, protecting it from the outside, for example, from rocks that may hit the bucket ear, and connected to an adapter; and c) at least one adapter for high vibration environments withstanding temperatures up to 125 C, which is selected from a flexo-rigid plate selected from polyamide and FR4, to be located at the end of said rectangular channel of the bushing, and to be connected at the flexible end, with said measurement module, while at the other rigid end, it is connected to said acquisition module by means of a vertical connector.
The present system for remote, autonomous, real-time monitoring of bushing wear or thickness installed in an earthmoving machine, preferably, in the bucket ear, comprises:
a) at least one kit as described above, comprising:
a.1) at least one measurement module to be located in said at least one rectangular channel of the outer mantle of said bushing, comprising:
a.1.1) at least three chips located on a single electronic board, which may have diverse geometry and perform daily periodic measurements of at least 2 parameters selected from: bushing wear/thickness, a capacitive chip and a digital counter chip;
and bushing temperature, a temperature measurement chip, which allows the realization of a thermal compensation to adjust the measurements coming from said capacitive chip, eliminating the temperature dependence that generates distortion in the same, and thus, increasing the degree of confidence in the measurements, a.1.2) at least one witness specimen projecting from said single electronic board, through a flexible conductor forming a variable angle between 0 and 180 , preferably at an angle of 900, which allow obtaining measurements of variations of the bushing wear as it wears in solidarity with the bushing, and which are subjected to thermal variations in the range of -15 C to 85 C, during bushing operation, said at least one witness specimen having

17 electrical properties/characteristics that vary as its length decreases, including capacitance; and electrical conducting lines of its own, on an electronic board electrically connecting the parts together, said witness specimen comprising on its surface at least two layers, a first outer layer comprising at least one wear capacitor (19), a second inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location with the second inner layer, and optionally, the witness specimen may comprise a complementary third inner layer and fourth inner layer which together form the various levels of conductor lines (21, 22), which may be located either immediately downstream or upstream of the bilayer of the first outer layer and the second inner layer or between said first outer layer and said second inner layer, and wherein the wear capacitor (19) permits measurement of the capacitance of the witness specimen as the same wears, while from the reference capacitor (20) measurements are obtained which permit correction of the wear measurement on the witness specimen according to the effect of temperature, and wherein said third inner layer and fourth inner layer forming the different levels of conductor lines (21, 22) additionally permit measurement of the wear of the witness specimen, and wherein the witness specimen may comprise at least one additional layer to the aforementioned configuration and which increases by at least one layer the bilayer comprising a first outer layer and a second inner layer either in an additional layer comprising a wear capacitor, an additional layer comprising a reference capacitor or both or different combinations thereof, and wherein additionally the witness specimen may also comprise at least one additional complementary layer comprising circuits complementing the conducting lines, which may be located immediately upstream or downstream of or between the aforementioned layers of wear capacitors and reference capacitors, wherein the wear capacitor comprises two conductive wires or two conductive tracks facing each other in a comb-like manner, and the reference capacitor differs from the wear capacitor only in that it is shorter in length, a.1.3) a single electronic board comprising components a.1.1) and a.1.2) of essentially rectangular elongated and flat, flexo-rigid, multilayer geometry, having a first zone or bending zone, of flexible material, preferably selected from polyamide, which can be bent without generating damage to the electrical connections present on said single electronic board, while the second zone opposite to said first zone, is of semi-rigid material, preferably selected from FR4, which can be slightly bent without damaging the electrical

18 connections present on said single electronic board, and at one end, a female connector for connection of flexible flat circuits, and wherein an electronic circuit comprises said capacitive chip which receives and processes capacitance measurements coming from said at least one witness specimen and is located immediately before the beginning of the flexible zone of said single electronic board; said counting chip which receives and processes the count of interrupted/cut electrical conductor lines connecting said counting chip with said witness specimen, and is located immediately before the beginning of the flexible zone of said at least one witness specimen, wherein each electrical conductive line is a level corresponding to a wire/conductor leading from a witness specimen to the counting chip, wherein the number of levels may vary as required, and preferably, the number of levels is 32, and said levels are located on said witness specimen, and further comprises a temperature measurement chip which is located in the center of said single electronic board, and measures the temperature at the center of the outer mantle of the bushing, and whose information is used for thermal compensation of the capacitive measurement, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others, of low profile and reduced dimensions, a.2) at least one acquisition module that is located in a cavity in the structural washer, having a unique individual identifier code (ID) that allows to identify and register the bushing in a local, wireless network, connected to a server, which may or may not be connected to the Internet, and comprises:
a.2.1) a set of light indicators with patterns and colors that allows visualizing a successful connection with said measurement module, where said light indicators may be of permanent or intermittent light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer;
a.2.2) a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module, including errors coming from said measurement module or other peripherals, and in general, the execution of tasks of the remaining components of this module, a.2.3) a memory card that stores the information/data of said daily periodic measurements of said measurement module, as well as any errors coming from said measurement module or other peripherals, including chips, such as RF chips, chips for power management, chips for the control of RGB LED lights, among others, preferably selected from a microSD card memory,

19 a.2.4) an integrated circuit/chip that maintains intermittent or continuous communication with said receiving means to send/transmit to it wirelessly said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module, which allows radio frequency communication by using Bluetooth Low Energy and Lora protocols at 2.4 GHz, a.2.5) an integrated circuit/chip that manages/controls the power supply from a power source selected from at least 2 batteries, controlled by said microcontroller, and that supplies power to both the acquisition module and said measurement module, thus avoiding excessive consumption when said acquisition module and said measurement module are not in use, favoring an energy autonomy of at least two years, a.2.6) at least one antenna allowing wireless communication with said receiving medium, and a.2.7) a protective casing which houses each of the components a.2.1) to a.2 .6), protecting them from dust and water, having a parallelepiped geometry, with mainly flat and smooth faces, which allows its easy displacement through the cavity or emptying of the structural washer, and in the final installation position, it is embedded inside the structural washer, being visible only through the upper emptying end of the structural washer, protecting it from the outside, for example, from rocks that may hit the bucker ear, and connected to an adapter; and a.3) at least one adapter for high vibration environments withstanding temperatures up to 125 C, which is selected from a flexo-rigid plate selected from polyamide and FR4, to be located at the end of said rectangular channel of the bushing, and to be connected at the flexible end, with said measurement module, while at the other rigid end, it is connected to said acquisition module by means of a vertical connector;
b) at least one receiver module or Gateway located, preferably, on the roof of the mining machine cabin, in communication with said acquisition module and said network server;
c) at least one network server that processes said information/data from said daily periodic measurements that are sent/transmitted by said receiver module to estimate the wear condition and the useful life of the bushing by means of a projection according to the wear rate calculated from the daily periodic wear measurements accumulated over time, and optionally, comprises means of alarms either visual, audible, or both, that account for

20 a risk either because a risky bushing wear has been reached, i.e. the bushing has a thickness/thickness of less than 6 mm; a risky bushing temperature, i.e. the bushing has reached a temperature in excess of 85 C, among others, wherein said alarm means are selected from alarm means that send/transmit to the user, a notification email message, a visual or audible message with display on the screen of a wireless device selected from a laptop computer, cell phone, a Tablet, among others, wherein said audible message is selected from a horn/siren, an audio message, among others, and wherein said visual message is selected from a fixed or flashing light signal, among others, and wherein said alarm messages are automatically and periodically updated, Prior to its use, each control specimen is electrically characterized by means of the relationship between capacitance and length, at different temperatures, since its electrical characteristics depend on both length and temperature, and with this, a relationship between capacitance and length is determined, as a function of temperature, which allows estimating the level of wear of the bushing. See Figures 14 and 15.
As for said at least one rectangular channel of the bushing, this is obtained by machining the bushing, preserving its mechanical properties, that is, without generating significant stress or strain deformations in said rectangular channel of the bushing, which may eventually give rise to micro-fractures, which during machining may eventually propagate, shortening the useful life of the bushing. The bushing may be eccentric, i.e. the circular inner bore of the bushing is not concentric with the outer diameter of the bushing. To be installed inside the bucket ear, the said bushing with the said measurement module, or simply the sensorized bushing, is immersed in liquid nitrogen, until it reaches a radius smaller than the radius it would have at room temperature, in order to be able to enter with the necessary clearance inside the bucket ear. The measuring module has been designed to withstand immersion in liquid nitrogen without damage.
The measuring module is designed so that none of its electronic components and parts protrude beyond the contour of the bushing volume to the outside, which ensures that it is not damaged, both during transportation of the bushing and during the installation process in the bucket ear. In addition, the measuring module is resistant to vibrations and shocks transmitted to the bushing which are inherent in the work because the said single electronic board and the said at least one witness specimen are a continuous or single body. This resistance would not be achieved if the witness specimens are attached to the plate by welding or other bonding means.

21 The single electronic plate of the measurement module has holes/perforations that assist in attachment to the bushing, either by a threaded bolt type attachment means, rivet, through-hole means or bonding means. These holes also allow the alignment of the single electronic plate along the length and width of the rectangular channel of the bushing, which facilitates the subsequent installation of the adapter.
The installation of the measuring module is performed prior to the installation of the bushing in the bucket ear. Subsequently and optionally, the perforations that receive the witness specimens, as well as the rest of the channel volume, are filled with a liquid polymer resin and the curing of the polymer resin is awaited.
The electrical conductor lines or wear levels are wires/conductors that run from a witness specimen to the digital counter chip. The levels are located on the specimens and these are close to the counter chip, otherwise, if they were not close, it would require a large volume of cables/conductors that would need extra space across the width of the plate, and with that, the bushing channel would also have to be widened, which would make it fragile and reduce its useful life to enable monitoring, which is an undesirable effect.
An adapter connects the measurement module and the acquisition module. It is quick and easy to install. It is installed, once the bushing has been installed in the bucket ear and prior to the installation of the structural washer. It is placed at the end of the bushing channel where the measurement module goes. It is a plate of flexible rigid material, which allows greater comfort at the time of installation and better dampens vibrations. At one end it has a set of flat raceways that mates with the connector of the measurement module. At the other end it has a vertical connector, which mates with the acquisition module connector. All connectors, both of the measurement module, the adapter and the acquisition module, are connectors for high vibration environments that withstand temperatures up to 125 C.
The acquisition module comprises an external protective casing that allows it to be easily slid into the cavity of the structural washer. In the final installation position, the casing is embedded inside the cavity of the structural washer and is only visible at the top end of the casting, so none of the electronics or parts are exposed to the external environment, where they could be damaged by, for example, rock impact on the bucket ear.

22 The acquisition module communicates wirelessly with the outside by means of an antenna that can be tuned despite the essentially metallic environment surrounding it, at a transmission frequency between 2.4 GHz and 2.5 GHz, thus allowing the transmission of measurement information from the measurement module in the bushing to the gateway or receiving medium and from there to a network server.
The Receiver or Gateway module is located so that it has line of sight or direct line of sight with the direction of propagation of the antenna. Preferably, it could be installed on the mining machine and even more preferably on the roof of the mining machine cab, the mast that holds the bucket, as well as some other place that has line of sight.
The present system starts monitoring from the moment the kit installation is completed, i.e. when the acquisition module is connected through the cavity to the adapter, closing the electrical power circuit. The acquisition module wirelessly links/communicates with said receiver module and said network server, and then the kit registers itself by means of a unique identification code (ID) and provides information on the time it was installed. It then begins to report daily and at pre-set/pre-programmed times, the level of wear on the bushing.
On the other hand, it is known that, when a potential difference is applied to a capacitor, which is a device formed by two electrical conductors close to each other and surrounded by a dielectric medium, an electric field is generated and, consequently, a distribution of charges inside that allows energy to be stored. The conductors can be foils, thin films, metallic tracks or electrolytes.
It is also known that capacitance depends on a geometric factor such as the area A (A = width (a) x length (0) and, therefore, if a capacitor of constant width a and length I, decreases its length, its capacitance also decreases.
In accordance with the above, witness specimens were designed as capacitors or sensitive elements comprising a first outer layer comprising a wear capacitor which in turn comprises two conductors facing each other in the form of combs, which, as they wear, lose sections and decrease the capacitance of the capacitor.
The measurement of the capacitance change corresponds to a digital analog conversion of the measured physical signal, for which a capacitive microchip is used, specially dedicated to the measurement of the capacitance of the witness specimens. The microchip delivers a digital value

23 proportional to the division of the resonance frequency of the circuit that includes the witness specimen and an internal reference frequency of the chip. This chip is managed from the acquisition module by the microprocessor (MCU), which through a power management chip turns the capacitive microchip on or off, managing power efficiently and telling it when to measure.
The MCU can iterate one or several consecutive measurements, to obtain a statistically significant set of measurements, and thus eliminate noise and artifacts inherent to analog-to-digital conversion, including aliasing, quantization noise, among others. In addition, it can calculate the standard deviation of the set of measurements and establish a degree of reliability.
Additionally, the MCU transforms the digital frequency reading of the capacitive microchip into length values, using an experimentally obtained relationship from the sensor calibration (fc), which relates the digital reading of the analog-to-digital conversion (d1) with the length of the witness specimen (Li), see Eq. 1.
Li [mm] = fc ND Eq. 1 However, capacitance measurements are susceptible to temperature changes, so an additional and complementary temperature sensor reports the temperature at the bushing at the same time as the capacitance is measured. With this information, the acquisition module can compensate the digital frequency measurement and establish an effective value of the measurement, Di. The compensation consists of matching the current reading of the capacitive microchip with its temperature response. fT, experimentally obtained by relating the capacitance measurement to different temperatures. See Eq. 2 and Eq. 3.
Di = fAdi) Eq. 2 L1 [mm] = f c (DO Eq. 3 The method further comprises the incorporation of an intermediate layer comprising a reference capacitor located as a next layer to the wear capacitor, which will be used to obtain a differential measurement or correction reference measurement. This capacitor does not suffer from wear during the operation of the measurement module so that its length L2 remains constant, however,

24 the measurement is affected by the temperature difference. The capacitance of the reference capacitor CR can be modeled as follows (Eq. 4):
CR = B[t(T) .. Eq. 4 Where B corresponds to a geometrical factor and corresponds to the value of the dielectric constant as a function of temperature. Since the geometry of the capacitor is constant, B is constant, implying that variations in capacitance measurements are attributable only to temperature changes in the medium.
Analogously, the wear capacitor can be modeled as (Eq. 5):
CD = A(1) (T) Eq. 5 In this case, the geometrical factor A(1) depends on the wear, i.e. the length of the capacitor, while the dielectric constant (T) is a function of the temperature. Then if we divide both expressions we obtain (Eq. 6 and Eq. 7):
CD A(1)1t(T) = ________________________________________________ Eq. 6 CR Bi.t(T) CD A(1) Eq.7 CR B
From this last expression it follows that the geometrical factor of the wear capacitor that depends on the length can be written as a function of the capacitance values measured in each capacitor multiplied by a geometrical factor (Eq. 8).
CD
A(1) = ¨ B Eq. 8 CR
The latter expression provides an additional element and a complementary method for determining the level of wear of the witness specimen.

25 The capacitance measurement stage is complemented with an additional discrete measurement stage, that is, the measurement of a variable that can take only certain values in a given interval, which may or may not be equidistant, and where the resolution of the measurement is determined by the difference between two consecutive values.
In this case, the discrete measurement corresponds to a digital counter of states, for this purpose, a witness specimen is used, which has at least 32 circuits, and each circuit can have two states, 1 or 0, which means energized or not energized. The digital counter chip evaluates the state of each circuit and counts the positive states (1), with a first counting sensor, each circuit is spaced equidistantly along the specimen in the direction of wear, preferably at a difference of 1 mm.
Alternatively, they can be located so that there are more circuits (dense zone) in the most critical areas of wear, for example, in the area closest to the measurement module. So as the wear increases, circuits are cut and change state, in this way, it is possible to obtain the bushing thickness by counting how many circuits are on, e.g.: the counter detects 22 circuits on, which translates into a length of 22 mm.
The digital counter chip is managed from the MCU through the power manager chip. It turns the counter chips on and off whenever measurements need to be updated. The counter chips deliver a number of active circuits and send that information to the MCU, which transforms it into the current bushing thickness and reports it to the gateway or receiver, which in turn reports it to a network server. The main advantage of this type of measurement is that it is invariant or independent of temperature changes.
If both measurement methods are combined, it is possible to establish a redundant routine for verification of measured wear and error. Although the digital measurement has a low resolution, in the order of 1mm, it allows to measure efficiently and independently of thermal variations. While the capacitive method has a much higher resolution, but depends on temperature and analog-to-digital conversion. By combining both methods, it is possible to check if the capacitive measurement is correct by comparing with the current and previous digital measurement. If the current measurement is not in range it is discarded and must be remeasured until both results are consistent.

26 The present method of remote, autonomous, real-time monitoring of bushing wear installed in an earthmoving machine, preferably, in a bucket ear, using the system described above, comprises the following stages:
a) adapting a bushing to have at least one shallow rectangular channel in its outer mantle, and adapting a structural washer of a bushing to comprise a cavity, wherein said at least one measurement module is located in said rectangular channel, and wherein at least one acquisition module is located in said cavity of said structural washer of a bushing, wherein said at least one measurement module comprises at least three chips located on a single electronic board, which may have different geometry and perform daily periodic measurements of at least 2 parameters selected from: bushing wear/thickness, a capacitive chip and a digital counter chip; and bushing temperature, a temperature measurement chip, which allows the realization of a thermal compensation to adjust the measurements coming from said capacitive chip, eliminating the temperature dependence that generates distortion therein, and thus, increasing the degree of confidence in the measurements, at least one witness specimen projecting from said single electronic board, through a flexible conductor forming a variable angle between 0 and 1800, preferably at an angle of 90 , which allow measurements of variations in bushing wear to be obtained as it wears in solidarity with the bushing, and which are subjected to thermal variations in the range of -15 C to 85 C, during bushing operation, having said at least one witness specimen having electrical properties/characteristics that vary as its length decreases, including capacitance; and electrical conducting lines of its own, on an electronic board that electrically connects the parts to each other, comprising said witness specimen on its surface at least two layers, a first outer layer comprising at least one wear capacitor (19), a second inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location with the second inner layer, and optionally, the witness specimen may comprise a complementary third inner layer and a fourth inner layer which together form the different levels of conductor lines (21, 22), which may be located either immediately following or before the bilayer of first outer layer and second inner layer or between said first outer layer and said second inner layer, and where the wear capacitor (19) allows measuring the capacitance of the witness specimen as it wears, while from the reference capacitor (20) measurements are obtained that allow correcting the wear measurement on the

27 witness specimen according to the effect of temperature, and where said third inner layer and fourth inner layer forming the different levels of conductor lines (21, 22) allow additionally measuring the wear of the witness specimen, and wherein the witness specimen may comprise at least one additional layer to the aforementioned configuration and which increases in at least one layer the bilayer comprising a first outer layer and a second inner layer either in an additional layer comprising a wear capacitor, an additional layer comprising a reference capacitor or both or different combinations thereof, and wherein additionally the witness specimen may also comprise at least one additional complementary layer comprising circuits complementing the conductor lines, which may be located immediately before or after or between the aforementioned layers of wear capacitors and reference capacitors, wherein the wear capacitor comprises two conductive wires or two conductive tracks facing each other in a comb-like manner, and the reference capacitor differs from the wear capacitor only in that it is shorter in length, a single electronic board comprising the components described above, of essentially elongated and flat rectangular geometry, flexo-rigid and multilayer, having a first zone or bending zone, of flexible material, preferably selected from polyamide, which can be bent without causing damage to the electrical connections present on said single electronic board, while the second zone, opposite to said first zone, is of semi-rigid material, preferably selected from FR4, which can be slightly bent without damaging the electrical connections present on said single electronic board, and at one end, a female connector for connection of flexible flat circuits, and wherein an electronic circuit comprises said capacitive chip that receives and processes capacitance measurements coming from said at least one witness specimen and is located immediately before the beginning of the flexible zone of said single electronic board; said counting chip that receives and processes the count of interrupted/cut electrical conductor lines connecting said counting chip with said witness specimen, and is located immediately before the beginning of the flexible zone of said at least one witness specimen, wherein each electrical conductive line is a level corresponding to a wire/conductor leading from a witness specimen to the counting chip, wherein the number of levels may vary as required, and preferably, the number of levels is 32, and said levels are located on said witness specimen,

28 and further comprises a temperature measurement chip which is located in the center of said single electronic board, and measures the temperature at the center of the outer mantle of the bushing, and whose information is used for thermal compensation of the capacitive measurement, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others, of low profile and reduced dimensions, and said at least one acquisition module has a unique individual identifier code (ID) that allows to identify and register the bushing in a local, wireless network, connected to a server, which may or may not be connected to the Internet, and comprises a set of light indicators with patterns and colors that allows to visualize a successful connection with said measurement module, where said light indicators may be of permanent or intermittent light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer;
a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module, including errors coming from said measurement module or other peripherals, and in general, the execution of tasks of the remaining components of this module, a memory card that stores the information/data of said daily periodic measurements of said measurement module, as well as any errors coming from said measurement module or other peripherals, including chips, such as, RF chips, chips for power management, chips for the control of RGB LED lights, among others, preferably selected from a microSD
card memory, an integrated circuit/chip that maintains intermittent or continuous communication with said receiving means to wirelessly send/transmit to it said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module, which allows radio frequency communication through the use of Bluetooth Low Energy and Lora protocols at 2.4 GHz, an integrated circuit/chip that manages/controls the power supply from a power source selected from at least 2 batteries, controlled by said microcontroller, and that supplies power to both the acquisition module and said measurement module, thus avoiding excessive consumption when said acquisition module and said measurement module are not in use, favoring an energy autonomy of at least two years, at least one antenna allowing wireless communication with said receiving means, and

29 a protective casing that houses each of the components described above, protecting them from dust and water, having a parallelepiped geometry, with mainly flat and smooth faces, which allows its easy displacement through the cavity or emptying of the structural washer, and in the final installation position, it is embedded inside the structural washer, being visible only through the upper casting end of the structural washer, protecting it from the outside, for example, from rocks that may hit the bucket ear, and connected to an adapter;
and an adapter for high vibration environments withstanding temperatures up to 125 C, which is selected from a flexo-rigid plate selected from polyamide and FR4, which joins said measurement module and said acquisition module, connecting at the flexible end, with said measurement module, while at the other rigid end, it is connected to said acquisition module by means of a vertical connector, b) to prepare a curve of capacitance compensation values of the witness specimens as a function of the measurements of the temperature measurement chip of the measurement module;
c) determine the value of the bushing wear from the capacitance measurements of the witness specimen of the measurement module, thermally compensating according to the compensation values of the curve obtained in stage b), d) determine the temperature of the bushing from the measurements of the temperature measurement chip, e) set the level of the bushing wear value accumulated over time according to the wear values determined in c) accumulated over time, and optionally f) activate means of alarms either visually, audibly or both, either because a risky bushing wear has been reached, i.e. the bushing has a thickness/thickness of less than 6 mm; or a risky bushing temperature, i.e., the bushing has reached a temperature above 85 C, among others, and optionally, wherein said alarm means are selected from alarm means that send/transmit to the user, a notification email message, a visual or audible message with display on the screen of a wireless device selected from a laptop computer, cell phone, a tablet, among others, wherein said audible message is selected from a horn/siren, an audio message, among others, and wherein said visual message is selected from a fixed or flashing light signal, among others, and wherein said alarm messages are automatically and periodically updated.
g) optionally after step b), prepare a curve of bushing wear values as a function of the digital counter chip measurements;

30 h) determine the bushing wear value from the measurements of the digital counter chip of the measuring module according to the curve obtained in step g); and i) establish the level of the value of the bushing wear accumulated over time according to the values of the wear determined in g) accumulated over time, to complement step e).
The following examples refer to obtaining calibration curves for capacitance and digital probe level and bushing wear.
Example 1: Capacitance of witness specimen versus bushing wear In a laboratory environment, a 32 mm specimen connected to the capacitive chip was worn in a controlled manner. The wear was generated with a mechanical lathe at a 1 mm feed rate per pass, completely roughing the face of the specimen on each pass. Each time the specimen was worn the capacitance value was acquired, thus a relationship between the length of the specimen and the capacitance value at constant temperature was obtained. Figure 15 shows the length measured by the measuring module vs. the length of the specimen as the wear increased.
Example 2: Digital level of witness specimen versus bushing wear In a laboratory environment, a 35 mm specimen connected to the digital wear chip was worn in a controlled manner. The wear was generated with a mechanical lathe at 1 mm feed rate per pass, completely roughing the face of the specimen on each pass. Each time the specimen was worn, the number of interrupted or cut tracks was recorded with the digital wear sensor. As each track is equally spaced it is possible to transform the number of remaining tracks into length by multiplying that number by the track spacing. Figure 16 shows the length measured by the digital sensor vs. the length of the specimen as wear increased.

Claims (14)

31

1. A remote, autonomous, real-time monitoring kit for wear or thickness of a bushing installed in an earthmoving machine, preferably in a bucket ear of a mining machine, wherein said bushing comprises in its outer mantle, at least one rectangular, shallow channel, and further at least one through cylindrical borehole in said rectangular channel for housing at least one witness specimen and a flared end, CHARACTERIZED in that it comprises:
a) at least one measurement module to be located in said at least one rectangular channel of the outer mantle of said bushing, comprising:
a.1) at least three chips located on a single electronic board, which may have different geometry and perform daily periodic measurements of at least 2 selected parameters of:
bushing wear/thickness, a capacitive chip and a digital counter chip; and bushing temperature, a temperature measurement chip, which allows the realization of a thermal compensation to adjust the measurements coming from said capacitive chip, eliminating the temperature dependence that generates distortion in the measurements, and thus, increasing the degree of confidence in the measurements, a.2) at least one witness specimen that is projected from said single electronic board, through a flexible conductor forming a variable angle between 0 and 180 , preferably at an angle of 900, which allows obtaining measurements of variations in the wear of the bushing as it wears in solidarity with it, and which are subjected to thermal variations in the range of -15 C to 85 C, during the operation of the bushing, having said at least one witness specimen, electrical properties/characteristics that vary as its length decreases, including capacitance; and proper electrical conducting lines, on an electronic board that electrically connects the parts together, comprising said witness specimen on its surface at least two layers, an outer layer comprising at least one wear capacitor (19), and an inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location with the second inner layer, wherein the wear capacitor (19) permits measurement of the capacitance of the witness specimen as the same wears, while from the reference capacitor (20) measurements are obtained which allow correction of the wear measurement on the witness specimen according to the effect of temperature, and wherein the wear capacitor comprises two conductive wires or two conductive tracks facing each other in a comb-like manner, and the reference capacitor differs from the wear capacitor only in that it is shorter in length, a.3) a single electronic board comprising components a.1) and a.2) of essentially rectangular, elongated, flat, flexo-rigid, multilayer geometry, having a first flex zone or bending zone of flexible material, preferably selected from polyamide, which can be bent without causing damage to electrical connections present on said single electronic board, wherein the second zone opposite said first zone, is of semi-rigid material, preferably selected from FR4, which can be slightly bent without damaging the electrical connections present on said single electronic board, and at one end, a female connector for connection of flexible flat circuits, and wherein an electronic circuit comprises said capacitive chip which receives and processes the capacitance measurements coming from said at least one witness specimen and is located immediately before the beginning of the flexible zone of said single electronic board; said counter chip which receives and processes the count of the interrupted/cut electrical conductor lines connecting said counter chip with said witness specimen, and is located immediately before the beginning of the flexible zone of said at least one witness specimen, wherein each electrically conductive line is a level corresponding to a wire/conductor leading from a witness specimen to the counting chip, wherein the number of levels may vary as required, and preferably, the number of levels is 32, and said levels are located on said witness specimen, and further comprises a temperature measurement chip which is located in the center of said single electronic board, and measures the temperature at the center of the outer mantle of the bushing, and which information is used for thermal compensation of the capacitive measurement, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others, of low profile and reduced dimensions, b) at least one acquisition module that is located in a cavity in the structural washer, having a unique individual identifier code (ID) that allows the bushing to be identified and registered in a local, wireless network connected to a server, which may or may not be connected to the Internet, and comprises:
b.1) a set of light indicators with patterns and colors that allows visualizing a successful connection with said measurement module, where said light indicators may be of permanent or intermittent light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer;

b.2) a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module, including errors coming from the measurement module or other peripherals, and in general, the execution of tasks of the remaining components of this module, b.3) a memory card that stores the information/data of said daily periodic measurements of said measurement module, as well as any errors coming from said measurement module or other peripherals, including chips, such as, RF chips, chips for power management, chips for control of RGB LED lights, among others, preferably selected from a microSD card memory, b.4) an integrated circuit/chip that maintains intermittent or continuous communication with said receiving means to wirelessly send/transmit to it said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module, which allows a radio frequency communication through the use of Bluetooth Low Energy and Lora protocols at 2.4 GHz, b.5) an integrated circuit/chip that manages/controls the power supply from a power source selected from at least 2 batteries, controlled by said microcontroller, and that supplies power to both the acquisition module and said measurement module, thus avoiding excessive consumption when said acquisition module and said measurement module are not in use, favoring an energy autonomy of at least two years, b.6) at least one antenna that enables wireless communication with said receiving medium, and b.7) a protective casing that houses each of the components b.1) to b.6 ), protecting them from dust and water, having a parallelepiped geometry, with mainly flat and smooth faces, which allows its easy displacement through the cavity or emptying of the structural washer, and in the final installation position, it is embedded inside the structural washer, being visible only through the upper emptying end of the structural washer, protecting it from the outside, for example, from rocks that may hit the bucket ear, and connected in an adapter;
and c) at least one adapter for high vibration environments withstanding temperatures up to 125 C, which is selected from a flexo-rigid plate selected from polyamide and FR4, to be located at the end of said rectangular channel of the bushing, and to be connected at the flexible end, with said measurement module, while at the other rigid end, it is connected to said acquisition module by means of a vertical connector.

2. The kit of claim 1 CHARACTERIZED in that said witness specimen additionally comprises on its surface at least a third inner layer and a fourth complementary inner layer which together form the different levels of driving lines (21, 22) allowing the complementary measurement of the wear of the specimen.

3. The kit of claim 1 CHARACTERIZED in that said witness specimen additionally comprises additionally on its surface at least one additional layer, the bilayer comprising a first outer layer and a second inner layer either in an additional layer comprising a wear capacitor, an additional layer comprising a reference capacitor or both or different combinations thereof.

4. The kit of claim 1 CHARACTERIZED in that said witness specimen further comprises on its surface at least one additional complementary layer comprising circuits complementing the lead lines, and which may be located immediately upstream or downstream of the bilayer of a first outer wear capacitor layer and a second reference capacitor layer or between said first outer wear capacitor layer and said second inner reference capacitor layer.

5. A remote, autonomous, real-time, bushing wear or thickness monitoring system installed in an earthmoving machine, primarily, in a bucket ear of a mining machine, CHARACTERIZED
in that it comprises:
a) at least one kit as described above, comprising:
a.1) at least one measurement module to be located in said at least one rectangular channel of the outer mantle of said bushing, comprising:
a.1.1) at least three chips located on a single electronic board, which may have diverse geometry and perform daily periodic measurements of at least 2 parameters selected from: bushing wear/thickness, a capacitive chip and a digital counter chip;
and bushing temperature, a temperature measurement chip, which allows the realization of a thermal compensation to adjust the measurements coming from said capacitive chip, eliminating the temperature dependence that generates distortion in the same, and thus, increasing the degree of confidence in the measurements, a.1.2) at least one witness specimen projecting from said single electronic board, through a flexible conductor forming a variable angle between 0 and 1800, preferably at an angle of 900, which allow measurements of variations in bushing wear to be obtained as it wears in solidarity with the bushing, and which are subjected to thermal variations in the range of -15 C to 85 C, during bushing operation, having at least one witness specimen, electrical properties/characteristics that vary as its length decreases, including capacitance; and electrical conducting lines of its own, on an electronic board that electrically connects the parts together, comprising said witness specimen on its surface at least two layers, an outer layer comprising at least one wear capacitor (19), and an inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location with the second inner layer, wherein the wear capacitor (19) permits measurement of the capacitance of the witness specimen as the same wears, while from the reference capacitor (20) measurements are obtained which allow correction of the wear measurement on the witness specimen according to the effect of temperature, and wherein the wear capacitor comprises two conductive wires or two conductive tracks facing each other in a comb-like manner, and the reference capacitor differs from the wear capacitor only in that it is shorter in length, a.1.3) a single electronic board comprising the components a.1.1) and a.1 .2) of essentially elongated and flat rectangular geometry, flexo-rigid and multilayer, having a first zone or bending zone, of flexible material, preferably selected from polyamide, which can be bent without damaging the electrical connections present on said single electronic board, while the second zone opposite to said first zone, is of semi-rigid material, preferably selected from FR4, which can be slightly bent without damaging the electrical connections present on said single electronic board, and at one end, a female connector for connection of flexible flat circuits, and wherein an electronic circuit comprises said capacitive chip which receives and processes capacitance measurements coming from said at least one witness specimen and is located immediately before the beginning of the flexible zone of said single electronic board; said counting chip which receives and processes the count of interrupted/cut electrical conductor lines connecting said counting chip with said witness specimen, and is located immediately before the beginning of the flexible zone of said at least one witness specimen, wherein each electrically conductive line is a level corresponding to a wire/conductor leading from a witness specimen to said counting chip, wherein the number of levels may vary as required, and preferably, the number of levels is 32, and said levels are located on said witness specimen, and further comprising a temperature measurement chip which is located in the center of said single electronic board, and measures the temperature at the center of the outer mantle of the bushing, and which information is used for thermal compensation of the capacitive measurement, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others, of low profile and reduced dimensions, a.2) at least one acquisition module that is located in a cavity in the structural washer, having a unique individual identifier code (ID) that allows to identify and register the bushing in a local, wireless network, connected to a server, which may or may not be connected to the Internet, and comprises:
a.2.1) a set of light indicators with patterns and colors that allows visualizing a successful connection with said measurement module, where said light indicators may be of permanent or intermittent light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer;
a.2.2) a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module, including errors coming from the measurement module or other peripherals, and in general, the execution of tasks of the remaining components of this module, a.2.3) a memory card that stores the information/data of said daily periodic measurements of said measurement module, as well as any errors coming from said measurement module or other peripherals, including chips, such as, RF chips, chips for power management, chips for control of RGB LED lights, among others, preferably selected from a microSD card memory, a.2.4) an integrated circuit/chip that maintains intermittent or continuous communication with said receiving means to wirelessly send/transmit to it said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module, which allows radio frequency communication through the use of Bluetooth Low Energy and Lora protocols at 2.4 GHz, a.2.5) an integrated circuit/chip that manages/controls the power supply from a power source selected from at least 2 batteries, controlled by said microcontroller, and that supplies power to both the acquisition module and said measurement module, thus avoiding excessive consumption when said acquisition module and said measurement module are not in use, favoring an energy autonomy of at least two years, a.2.6) at least one antenna allowing wireless communication with said receiving medium, and a.2.7) a protective housing which houses each of the components a.2.1) to a.2 .6), protecting them from dust and water, having a parallelepiped geometry, with mainly flat and smooth faces, which allows its easy displacement through the cavity or emptying of the structural washer, and in the final installation position, it is embedded inside the structural washer, being visible only through the upper emptying end of the structural washer, protecting it from the outside, for example, from rocks that may hit the bucket ear, and connected to an adapter; and a.3) at least one adapter for high vibration environments withstanding temperatures up to 125 C, which is selected from a flexo-rigid plate selected from polyamide and FR4, to be located at the end of said rectangular channel of the bushing, and to be connected at the flexible end, with said measurement module, while at the other rigid end, it is connected to said acquisition module by means of a vertical connector;
b) at least one receiver module or Gateway located on the mining machine, preferably, on the roof of the mining machine cabin, in communication with said acquisition module and said network server;
c) at least one network server that processes said information/data from said daily periodic measurements that are sent/transmitted by said receiver module to estimate the wear condition and the useful life of the bushing by means of a projection according to the wear rate calculated from the daily periodic wear measurements accumulated over time.

6. The system of claim 5 CHARACTERIZED in that said witness specimen additionally comprises on its surface at least a third inner layer and a fourth complementary inner layer which together form the different levels of driving lines (21, 22) which allow complementary measurement of the wear of the specimen.

7. The system of claim 5 CHARACTERIZED in that said witness specimen further comprises on its surface at least one additional complementary layer comprising circuits complementing the driving lines, and which can be located immediately before or downstream of the bilayer of a first outer wear capacitor layer and a second reference capacitor layer or between said first outer wear capacitor layer and said second inner reference capacitor layer.

8. The system of claim 5 CHARACTERIZED in that it comprises means of alarms either visual, audible, or both, that account for a risk either because a risky bushing wear has been reached, wherein the bushing has a thickness/thickness of less than 6 mm; or a risky temperature in the bushing, wherein said bushing has reached a temperature in excess of 85 C.

9. The system of claim 8 CHARACTERIZED in that said alarming means are selected from alarming means that send/transmit to the user, a notification email message, a visual or audible message with display on the screen of a wireless device selected from a laptop computer, cell phone, a tablet, among others, wherein said audible message is selected from a horn/siren, an audio message, among others, and wherein said visual message is selected from a fixed or flashing light signal, among others, and wherein said alarm messages are automatically and periodically updated.

10. A method of remote, autonomous, real-time monitoring of bushing wear installed in a mining machine, preferably, in a bucket ear of a mining machine, using the above-described system, CHARACTERIZED in that it comprises the following stages:
a) adapting a bushing so that in its outer mantle it has at least one rectangular channel, of shallow depth, and adapting a structural washer of a bushing so that it comprises a cavity, wherein said at least one measurement module is located in said rectangular channel, and wherein at least one acquisition module is located in said cavity of said structural washer, wherein said at least one measurement module comprises at least three chips located on a single electronic board, which may have different geometry and perform daily periodic measurements of at least 2 parameters selected from: bushing wear/thickness, a capacitive chip and a digital counter chip; and bushing temperature, a temperature measurement chip, which allows the realization of a thermal compensation to adjust the measurements coming from said capacitive chip, by eliminating the temperature dependence, which generates distortion in the measurements, is eliminated, thus increasing the degree of confidence in the measurements, at least one witness specimen that is projected from said single electronic plate, through a flexible conductor forming a variable angle between 0 and 180 , preferably at an angle of 90 , which allows to obtain measurements of variations of the wear of the bushing as it wears in solidarity with it, and which are subjected to thermal variations in the range of -15 C to 85 C, during the operation of the bushing, having said at least one witness specimen, having electrical properties/characteristics that vary as its length decreases, including capacitance; and electrical conducting lines of its own, on an electronic board electrically connecting the parts to each other, comprising said witness specimen on its surface at least two layers, an outer layer comprising at least one wear capacitor (19), and an inner layer comprising at least one reference capacitor (20), wherein the first outer layer may optionally alternate its location with the second inner layer, wherein the wear capacitor (19) allows measurement of the capacitance of the witness specimen as the witness specimen wears, while from the reference capacitor (20) measurements are obtained which allow correction of the wear measurement on the witness specimen according to the effect of temperature, and where the wear capacitor comprises two conductive wires or two conductive tracks facing each other in a comb-like manner, and the reference capacitor differs from the wear capacitor only in that it is shorter in length, a single electronic board comprising the components described above, of essentially elongated and flat rectangular geometry, flexo-rigid and multilayer, having a first zone or bending zone, of flexible material, preferably selected from polyamide, which can be bent without generating damage to the electrical connections present on said single electronic board, while the second zone opposite to said first zone, is of semi-rigid material, preferably selected from FR4, which can be slightly bent without damaging the electrical connections present on said single electronic board, and at one end, a female connector for connection of flexible flat circuits, and wherein an electronic circuit comprises said capacitive chip which receives and processes the capacitance measurements coming from said at least one witness specimen and is located immediately before the beginning of the flexible zone of said single electronic board; said counter chip which receives and processes the count of the interrupted/cut electrical conductor lines connecting said counter chip with said witness specimen, and is located immediately before the beginning of the flexible zone of said at least one witness specimen, wherein each electrically conductive line is a level corresponding to a wire/conductor leading from a witness specimen to the counting chip, wherein the number of levels may vary as required, and preferably, the number of levels is 32, and said levels are located on said witness specimen, and further comprises a temperature measurement chip which is located in the center of said single electronic board, and measures the temperature at the center of the outer mantle of the bushing, and which information is used for thermal compensation of the capacitive measurement, and also comprises passive electronic components selected from capacitors, resistors, inductances, among others, of low profile and reduced dimensions, and said at least one acquisition module has a unique individual identifier code (ID) that allows to identify and register the bushing in a local, wireless network connected to a server, which may or may not be connected to the Internet, and comprises a set of light indicators with patterns and colors that allows to visualize a successful connection with said measurement module, where said light indicators may be of permanent or intermittent light emission, preferably a set of RGB LED lights, and are visible from the open end of the structural washer;
a microcontroller (MCU) that manages/controls the performance of said daily periodic measurements of said measurement module, including errors coming from the measurement module or other peripherals, and in general, the execution of tasks of the remaining components of this module, a memory card that stores the information/data of said daily periodic measurements of said measurement module, as well as any errors coming from said measurement module or other peripherals, including chips, such as, RF chips, chips for power management, chips for the control of RGB LED lights, among others, preferably selected from a microSD
card memory, an integrated circuit/chip that maintains intermittent or continuous communication with said receiving means to send/transmit to it wirelessly said information/data accumulated from said daily periodic measurements and said errors coming from said measurement module, which allows a radio frequency communication through the use of Bluetooth Low Energy and Lora protocols at 2.4 GHz, an integrated circuit/chip that manages/controls the power supply from a power source selected from at least 2 batteries, controlled by said microcontroller, and that supplies power to both the acquisition module and said measurement module, thus avoiding excessive consumption when said acquisition module and said measurement module are not in use, favoring an energy autonomy of at least two years, at least one antenna allowing wireless communication with said receiving means, and a protective casing that houses each of the components described above, protecting them from dust and water, having a parallelepiped geometry, with mainly flat and smooth faces, which allows its easy displacement through the cavity or casting of the structural washer, and in the final installation position, it is embedded inside the structural washer, being visible only from the upper emptying end of the structural washer, protecting it from the outside, for example, from rocks that may hit the bucket ear, and connected to an adapter;
and an adapter for high vibration environments withstanding temperatures up to 125 C, which is selected from a flexo-rigid plate selected from polyamide and FR4, which joins said measurement module and said acquisition module, connecting at the flexible end, with said measurement module, while at the other rigid end, it is connected to said acquisition module by means of a vertical connector, b) prepare a curve of capacitance compensation values of the witness specimens as a function of the measurements of the temperature measuring chip of the measuring module;
c) determine the value of the bushing wear from the capacitance measurements of the witness specimen of the measurement module, thermally compensating according to the compensation values of the curve obtained in step b), d) determine the temperature of the bushing from the measurements of the temperature measuring chip, and e) establish the level of the bushing wear value accumulated over time according to the values of the wear determined in c) accumulated over time.

11. The method of claim 10 CHARACTERIZED in that it comprises activating means of alarms either visually, audibly, or both, either because a risky bushing wear has been reached, i.e., the bushing has a thickness/thickness of less than 6 mm; or a risky bushing temperature, i.e., the bushing has reached a temperature above 85 C, among others, and optionally, wherein said alarm means are selected from alarm means that send/transmit to the user, a notification email message, a visual or audible message with display on the screen of a wireless device selected from a laptop computer, cell phone, a tablet, among others, wherein said audible message is selected from a horn/siren, an audio message, among others, and wherein said visual message is selected from a fixed or flashing light signal, among others, and wherein said alarm messages are automatically and periodically updated.

12. The method of claim 10 CHARACTERIZED in that said witness specimen additionally comprises on its surface at least a third inner layer and a fourth complementary inner layer which together form the different levels of driving lines (21, 22) which allow complementary measurement of the wear of the specimen.

13. The method of claim 10 CHARACTERIZED in that said witness specimen further comprises on its surface at least one additional complementary layer comprising circuits complementing the conductor lines, and which can be https://www.youtube.com/shorts/YukYZZKlaqMubicar immediately upstream or downstream of the bilayer of a first outer wear capacitor layer and a second reference capacitor layer or between said first outer wear capacitor layer and said second inner reference capacitor layer.

14. The method of claim 10 CHARACTERIZED in that after step b), it further comprises step f), preparing a bushing wear value curve based on the digital counter chip measurements; g) determining the bushing wear value from the digital counter chip measurements of the measurement module according to the curve obtained in step f); and h) establishing the level of the bushing wear value accumulated over time according to the wear values determined in f) accumulated over time, to supplement step e).