MX2010007634A - Personnel safety system utilizing time variable frequencies. - Google Patents

Abstract

A system to improve safety of workers who are in proximity to mobile machines includes a machine mountable radio-frequency identification reader that wirelessly monitors radio-frequency identification tags worn by workers moving relative to and in proximity to a mobile machine when the reader is mounted on the machine. The reader includes a processor and an antenna front-end which is switchable between an omni¬ directional antenna or at least one directional antenna. The omni-directional antenna is mountable so as to monitor a machine circumference completely around the mobile machine. Each directional antenna is mountable so as to monitor only either a front or a back of the mobile machine relative to the machine's direction of motion.

Description

radio frequency "passive, low cost, which can be integrated in or fixed to articles, products, and the like to transmit information about a product via a scanner. Identification labels] by radiofrequency can be generally small or similar labels with an integrated miniature antenna. Labels can be passive or active, active labels requiring an internal energy supply. A reader or scanner interrogates the radio-frequency identification tag with an electronic "activation" signal. The label! in turn generates an electromagnetic pulse response that is readable by the scanner, the response containing the product information.

Several commercial applications have been suggested, for radio frequency identification tags, particularly in the area i of retail marketing and sales. For example, RFID technology can be used to collect information related to consumer trends, purchasing habits, consumption assessments, etc. It has also been suggested that RFID technology is promising in the areas of inventory control, manufacturing processes and control, counting of the product and tracking systems, etc. Manufacturers, shippers, and retailers may be able to track a given product through their respective systems from their initial production through the point of sale.

I Chen et al. teaches the use of identification tags by radiofrequency for identification with protective articles, such as clothing, goggles, vests, balaclava, breathing devices assisted and similar, and personnel exploration using such items for ensure that the staff is properly equipped with the equipment of necessary security.

As discussed by Eckstein et al. in the U.S. Patent.

No. 6,894,614 which was published on May 17, 2005, for Radio Frequency Detection and Identification System, some RFID systems operate with resonant labels for identification of items to which the resonant tag is set or the destination to which the articles they should be directed. It is taught that the use of circuit labeling resonance for item identification is advantageous compared to I optical bar coding because this is not subject to the problems such as dirt darkening and may not require exact alignment of: I the label with the label detection system, and that generally, the systems using multiple tuned circuit detection interrogate sequentially each resonant circuit with a signal having a resonant circuit frequency and then wait for radiated energy from new from each of the circuits tuned to be detected. i In the prior art the applicants are also aware I of the U.S. Patent No. 6,703,930 which was published on March 9, ? 2004, for Skinner for Personal Alerting Apparatus and Methods, in where Skinner teaches the detection of an occurrence of an event and notifies a user of the event as well as the nature of the event. Skinner? discusses that a sensor can be configured to probe the presence of an RFID tag to determine the presence, absence, or proximity of an object carrying the label, providing the example of detection of a domestic pet that has been lost outside of a detectable scope for the label. Skinner also discusses that a receiver can be configured to activate an automatic response to a given event, providing the example that the receiver is configured to initiate or control the operation of an actuator that is connected to the a valve or the like, or an electric switch or the like to start er response the operation of the respective valve or switch providing the examples of automatically closing a valve water supply in response to a flood message, or shutting down a i power switch in response to a fire message Skinner also discusses that a message can be presented to the user in at least one of several modes, including audible, visual mechanical, or sensorial based electrical. 1 In the prior art, the applicants are also aware of the U.S. Patent No. 6,861, 959 which was published on March 1 I 2005, for Torres Sabate et al. where it is described to provide beacons I of radio signals, both fixed and portable, and receiver units' including those carried by pedestrians, or transceivers of combination for pedestrians, being described that a user carry a receiver with these to be notified of different danger zones when it crosses areas with beacon coverage of radio signals. Is provided the example that in the case of warning messages, these are produced sufficiently in advance to allow the user to take evasive action free of surprise, suggesting the user to reduce the speed or take the vehicle to a full stop, depending on the case. It is also j taught to provide mobile warnings to alert of the proximity and situation of a danger in movement. It is also taught to incorporate a I mobile transceiver in moving vehicles or install an element i transceiver in the case of pedestrians or cyclists, the example being given by Jo the types of warning including the transport of dangerous loads' such as flammable or corrosive materials as well as the proximity of I cyclists, slow racers, horse racers or motorcyclists In the prior art, the applicants are also aware of the U.S. Patent No .: 5,198,800 which was published on 30 March, 1993, for Tozawa et al for Alarm System for Constructional Machine which describes the use of a plurality of transceivers of radiofrequency in an excavator and in excavation workers inside of the reach of the excavator. A control unit reduces or stops the movement of the excavator components when moving for ' i approach the workers.

As stated above, previous attempts for; use ? RFID tags to improve the safety of personnel working around moving equipment have proven to be unsatisfactory. The systems Previous ones using RFID tags have not been sufficiently linked! in the operation system of the piece of equipment and therefore have only provided an audible warning to the operator of the equipment or to the individual bearer of the RFID tag when the worker is too close to the equipment. Due to the high noise levels at such work sites, these types of audible signals may be insufficient to ensure that the piece of equipment does not continue to hit the worker. In addition, there has been resistance to implement the immobilization of such equipment in response to the proximity of RFID tags due to the adverse impact of such immobilization that will have i on the productivity of the work site. In particular, stopping the movement of a machine results in at least a period of time during which the machine is not performing its intended function and therefore the overall efficiency of the industrial process is reduced. An additional difficulty with previous users of RFID tags for security devices has been the location of only a single RFID tag at a point of origin localizable to the user. Such an RFID tag origin point may be liable to be hidden or blocked from being read by a I antenna in a vehicle depending on the orientation of the body of the worker using such a tag and therefore can potentially result I in a false negative reading for the presence of an RFID tag. Such a false negative reading can in turn lead to the piece of equipment hitting or injuring the worker. , In particular, what is lacking in the prior art, and which is an object of the various objects of the present invention to provide, is an RFID based personnel security system employing 360 degree coverage antennas mounted on garments worn by the workers in combination with for example the use of spectrum communications! widening of continuous waves modulated in standard frequency 'IEEE Í 802. 15.4a for accurate location with data scope for use in substantially industrial observation line configurations where, within the workplace environment, light and heavy articulated and / or mobile work machinery is routinely used in the vicinity of personnel, in addition of the operator of the machinery, who are required by the nature of their work to pass in the vicinity of such mobile or articulated machinery, and to stop or slow down the movement of such machinery or elements thereof when the proximity of personnel within the Defined damage zones arise in situations that increase the probability of physical collision between machinery and personnel detected.

I I BRIEF DESCRIPTION OF THE INVENTION An RFID-based personnel security system in accordance with the present invention includes a transponder tag (RF) radio frequency to be used by workers, the transponder in discontinuous radiofrequency communication with an RF transponder detection system mounted on the machine to detect transponders in workers. The RF transponder detection system mounted on the machine may include an RF transponder interrogator connected to at least one antenna and a processor and / or programmable logic controller (PLC), which in turn cooperates with electromechanical controls at the machine. The transponder tags used by user workers can be passive RFID transponders that do not require batteries.

In accordance with a first embodiment of the present invention, a method is described for immobilizing equipment selectively para- ensure the safety of a nearby worker in the vicinity of the equipment, the method comprising: provide an article of clothing usable by the next worker, the item of clothing having an RFID tag having an antenna, I and preferably at least two antennas, distributed around the article of clothing to provide RF coverage substantially surrounding the worker, for example coverage in the form of a bull, when using the article of clothing; detect the proximity of the RFID tag to a portion of the equipment; Y ! stop or slow down the movement of the portion of the equipment in response to detection.

The method may comprise providing a visual indicator of the article of clothing. Detection may include stopping the movement of i the portion of the equipment when the RFID tag is less than a first distance from the equipment portion. The method may comprise decreasing the speed of movement and / or providing an audible signal when the RFID tag is less than a second distance from the portion of said equipment, wherein the second distance is greater than the first distance.

In accordance with a further embodiment of the present invention, a system is provided for selectively immobilizing equipment to ensure the safety of a nearby worker, the system comprising: an article of clothing usable by the next worker, the item of clothing having an RFID tag having an antenna and preferably at least two antennas, distributed around the article of clothing providing RF coverage substantially around the worker when using the article of clothing; . { a sensor detecting the proximity of the RFID tag to a portion of the equipment; and i means of stopping or reducing speed to stop or slow down the movement of the portion of the equipment in response to detection. [ The sensor may comprise at least one detection antenna defining a zone for sending and receiving signals to and from the RFID tag within the area, a transceiver for receiving signals generated from at least one antenna and a processor for comparing the signals received by the antenna against values representing distance from the RFID tag to the antenna. The system may comprise a plurality of detection antennas, all cooperating with the transceiver, wherein the I plurality of antennas is mounted adjacent to the corresponding damage zones in the equipment. The detection antennas can be directional antennas by directionally detecting the RFID tags within the pre-selected damage zones around the equipment.

The stopping means for stopping may comprise ur switch adapted to interrupt the movement of the portion of the equipment The switch may comprise an electrical disconnect switch. The switch can comprise an electromechanical valve actuator.

The system may also comprise a visual indicator in the article of clothing. The visual indicator may comprise a reflector wherein the article of clothing comprises a safety vest.

The stopping means may be adapted to stop the movement of the portion of the equipment when the RFID tag is less than a first distance from the portion of the equipment. The system may further comprise speed reduction means adapted to reduce the movement of the portion of the equipment and / or an audible signal generator to generate an audible signal when the RFID tag is less than a second distance from the portion of the equipment, where the second distance is greater than the first distance. 1 In accordance with a first embodiment of the present invention, a method is described for selectively immobilizing equipped to ensure the safety of a nearby worker in the vicinity of the equipment. The method comprises transmitting a first signal from the equipment and detecting the first signal on a label usable by the worker. The label transmits a second signal under reception of the first signal. The method also includes detecting the second signal in the equipment and stopping the movement of a portion of the equipment in response to the detection of the second signal). The first and second signals have a variable frequency in time. The method can also include defining a first distance from the equipment and calculating the distance between the equipment and the base label. i in a delay between the transmission of the first signal and the detection of second signals in the equipment. The equipment can be stopped when the distance between the equipment and the next worker is less than the threshold distance. i The first and second signals may vary continuously over time. The first and second signals can be spread spectrum signals of frequency-modulated continuous waves, for example in accordance with the IEEE standard 802.15.14a. Frequency modulated continuous wave signals can have a waveform of continuous waves modulated in linear frequency. The wave signals! Frequency modulated continuums can have a waveform of continuous waves modulated at exponential frequency. Frequency modulated continuous wave signals can increase in frequency over time. Frequency modulated continuous wave signals may decrease in frequency over time.

In accordance with a further embodiment of the invention, a system for selectively immobilizing equipment to ensure the safety of a nearby worker is described. The system comprises a first transceiver associated with the equipment and a second transceiver having a collaborating antenna being usable by the worker. The first second transceivers are adapted to transmit and receive signals having a variable frequency in time. The system further includes stop means for stopping the movement of the portion of the equipment in response to receiving a signal transmitted by the second transceiver on the first transceiver.

The first transceiver can periodically transmit a first signal having a variable frequency with time. The second The reader is adapted to disable at least partially the movement of the mobile machine under detection of at least one of the labels within a reaction zone within the detection zones and under the processor thus determining a probability of collision between the mobile machine on which the reader is mounted and at least one of the labels.

In a mode switching to an input from the antennas is done by a radio frequency switch controlled by a 'processor control unit. In a preferred embodiment the reader is a single radio device, and is adapted to measure the distance of the i labels, and to provide a feedback alarm to a machine operator of the mobile machine. In addition, the reader can be i adapted to perform distance measurements from point to point and point to multi-point, whereby a multiplicity of labels is located by I reader around the reader. Each of the labels can provide unique identity information to the reader. Wherein the reader further comprises a cabin antenna mountable in a capsule of the machine. i mobile to detect one of the labels when it is used by an operator of machine in the cabin of the mobile machine. The reader in that case is switchable to receive input from the car antenna.

A seat sensor can be provided in the cab to detect the operator where the reader turns on the cabin antenna when the seat sensor is activated by the operator. Under activation of the sensor These antennas can be configured for use with broadband with frequency division such as frequency modulated continuous waves multiplexed by OFDM orthogonal frequency division. : The improved antenna system according to an aspect i of the present invention provides the ability to send and receive signals accurately and consistently regardless of the proximity of other users, and thus provide a means to identify the identity and location of each individual user. even with a multitude of users.

The present invention can provide the following useful advantages: precise distance measurement, reliable operation in very severe and highly reflective radio environments, being able to measure i the distance at high speed, which makes the system reliable for monitoring | moving objects, platforms or mobile equipment, or machines. Signal very robust, minim holes and resists fading in areas saturated with radio waves, high. The system can detect people from virtually every aspect: frontal, posterior, lateral, abdominal decubitus. The system has a limited ability to "see around the corners" even in highly reflective enclosures, and this is not strictly a line system of í | vision so "line of sight" as used in this document was intended to include limited vision around the corners. The system has the ability to identify people and objects, and to differentiate between i | these even when groups of people are present, and it is resistant to interference from the human body. The presence of the operator of the machine i can be detected using an operator-sensing characteristic present when he / she is at the controls of the machine, our system then it will ignore the operator until such time as he / she leaves the operation compartment of the machine, once the operator leaves the cabin or control area, our system will respond to the label once plus. The machines can be equipped with object labels machine, so that the machines recogneach other in areas where Multiple machines are in use, especially when machines operate with limited fields of vision. The operator-present characteristic can be adapted to implement secure pedestrian areas within the ' confines of the buildings of the workplace. This is, object labels dJ operator-present can be mounted to guardrails, or placed in another way to create an area in which the system will ignore the presence of body tags used by workers, except within an area of danger or internal reaction where the collision is imminent, in which case the movement of the machine is altered, for example stopped automatically. ! BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagrammatic view of a label of 'I RFID transponder and transponder detection system; RFID I correspondent. ! backward and forward coverage mounted on a piece of mobile machinery, and the overlap of the coverage of a monopole antenna also mounted on the mobile machine.

Figure 11 is an illustration of a test worker during the test to establish the baseline reading of a vest containing a patch antenna.

Figure 12a is the test worker of figure 1 during the test with the worker carrying a box so as not to completely cover the patch antenna.

Figure 12b is the test worker of figure 12a carrying the box to completely cover the patch antenna.

Figure 13a is the test worker of figure 11 during a left-sided angled frontal detection test.

Figure 13b is the test worker of figure 1 during a front-right angled detection test.

Figure 14a is the test worker of figure 1 1 standing away from the reader during the rear angled detection test.

Figure 14b is the test worker of figure 11 standing to left side on the reader during the rear angled detection test.

Figure 14c is the test worker of figure 11 from right to right on the reader during the rear angled detection test.

Figure 15a is the test worker of Figure 1 1 standing during baseline reading using dual rear and front patch antennas on the workers' vest.

Figure 15b is the test worker of figure 15a facing the reader and stopped to pick up a box during the detection test. '; Figure 15c is the test worker of Figure 15b alloyed right on the reader during the test to detect the worker. ' Figure 15d is the test worker of the figure; 15c lying down, with the right side on the reader during the test i detection. i Figure 15e is the test worker of Figure 15d inclined to pick up a box while facing away from the reader during the detection test.

Figure 16 is a graph showing the input impedance measured for both an antenna which is on the worker's body. i test and which is in the free space. | Figure 17a is a magnitude (decibels) against radial degrees around an antenna used by a test worker and measured in the vertical E plane.

Figure 17b is a graph of a magnitude against degrees I radials of the test of figure 17a measured in the horizontal plane H.

Figure 17c is a graph of a magnitude versus radial degrees of a co-polar double antenna arrangement, measured in the vertical E plane when double antennas are used by a test worker.

Figure 17d is a graph of a magnitude versus radial degrees of the antenna-double, co-polar arrangement, when measured in the horizontal H plane and the double antenna is used by a test worker.

Figure 17e is a graph of one magnitude versus radial degrees of a single front patch antenna (free space), co-polar, measured in the E plane.

Figure 18 is a diagrammatic view of a further application of labels and readers in accordance with a further aspect of the present invention showing the interaction between moving machines moving near congested pedestrian walkways.

Figure 19a is, in a front elevation view, a further use of the object mounted labels such as those used in the application of Figure 18, mounted towards the front of a cargo bay garage door.

Figure 19b is, in plan view, the door of figure 19a showing coverage by the object labels mounted on the door which provide a wave pattern coverage area through the front of the door which acts to reduce inconvenient trips from mobile machines passing there. i I Directionals can improve the operator's ability to detect the proximity of personnel hidden from the view of the operator of the machine.

The transceiver 12 generates an interrogation signal that is transmitted via at least one antenna 22 in the travel direction of the machine or the direction of the part in motion or otherwise articulated to the machine. The signal activates the transponder 10a, and is therefore of appropriate frequency and energy to activate a transponder within the desired detection ranges.

A warning signal coming from the RFID tag of the worker 10 is received by the antenna 22 on the machine, routed to the transceiver 12, and then transmitted to the processor 30. In the processor 30, the signal is received by a microprocessor ( not shown) quej processes the signal and generates the appropriate output to a user interface ta as an alarm or status display, and to a controller for example ' I a PLC and actuator to stop the machine or disable the movement of the machine or any part of it. Thus the outputs generated can include a sensory alarm to alert the operator to the presence of the worker within detectable range or scope of the system. Sensory alarms can be visual, auditory, or any other appropriate sensory alarm, and combinations thereof.

For example, in situations where there is a high level of background noise, an audible alarm alone may be insufficient to ensure alerting the operator, and therefore other alarms, such as a strobe light or flashing red, can be installed on the machine such as in the user interface. The outputs may also include RFID encoded data read from the worker's label 10, such as a unique identifier which can be recorded by the processor 30 in its associated memory for subsequent repetition to display, for example, worker identity, speed of the trip of the machine, location information (if the system is equipped with GPS) of the worker in relation to the machine, etc. These outputs may be generated by information transmitted from the RFID tag of worker 10, or may be information that is stored in the processor 30 and its memory or in a related server computer cooperating wirelessly with the processor, and whose information is correlated with the unique identifier transmitted to the transponder detection system.

Additionally, the processor 30 may be designed to allow simultaneous detection of multiple labels or multiple workers. In systems using multiple antennas 22, the direction of movement of the label 10 relative to the machine transponder detection system can be determined more precisely. For example, it is known in the prior art that multiple diverging yagi antennas can be arranged to allow the differentiation of the alert signal within the sectors; for example, within three sectors such as I just faced, proximal left side, and right proximal side. 1 The transponder detection system 20 is mounted i on an articulated or mobile machine 24 which may include, without limitation, a forklift truck as seen in Figure 2, a battery charger drag end front hub such as a Bobcat ™ loader I as seen in Figure 3, or a crawler excavator such as the view in I Figure 4. The crawler excavator is an example of a machine which It is both mobile and articulated. By way of example, a zone of damage i indicated generally by the reference number B, where the worker 14 may be hidden from the view of an operator (not shown) of the machine 24, can include a zone towards the back of a forklift, Loader, excavator or other mobile machine. Then advantageously, an antenna 22 is mounted towards the rear of the machine 24 for probing towards the rear area of machine damage by the presence of a label RFID 10 to determine the proximity of a worker 14 carrying a label 10 and in particular during backward translation of the machine 24 in Address C.

I Optionally, the system may include an ultrasound sensor 70 mounted on the machine. The ultrasound sensor 70 can be activated in response to the detection of an RFID tag 10 by the antenna 22. The Ultrasound sensor 70 will emit and measure reflected ultrasound frequencies outside of the person using the RFID tag 10 to determine the distance of the person using the RFID tag from the machine 24. Where the processor 30 determines, based on the input from the sensor ultrasound 70, that the worker using the RFID tag is moving away from the machine, this allows the machine to continue moving. However, where the processor 30 determines based on the measurements of the ultrasound sensor 70 that the worker is moving towards the machine, this can stop the movements of the machine before safe distances are otherwise reached.

Where the machine 24 is articulated, for example to oscillate a machine component such as the arm of the digger 26 and its associated hub 28 in the direction D around the axis of rotation E, the damage zone is within the sweep area by the arm arch 26 and the hub 28 when it is rotated, restricted by the freedom of movement of the arm and the hub.

I So the damage zone associated with an articulated machine component it can be completely independent of the translation direction of the machine, if it is mobile. Thus advantageously a separate antenna 22 is; provided in cooperation with the transponder detection system 20, for example mounted on the distal end of the arm 26. Thus, still; if the machine 24 is moving away from the worker 14 in such a way that no alarm needs to be generated by a first mounted antenna 22 on the back of the machine 24 detecting the worker in the area of I rear damage, the simultaneous articulation of a machine component ta as the arm 26 in a direction towards the worker 14 can cause a i proximity warning when the transpondedoij detection system 20 detects the proximity of the label of the worker 10 by the processing of the proximity detection information by the processor 30.

In one embodiment of the present invention, a range of single read detection and its corresponding detection zone, indicated in the Figures, diagrammatically as spheres or sectors of sphere F which are not intended to be limiting, correspond to an area of internal damage where physical contact or blow of the worker by the machine is imminent and consequently the processor 30 is programmed to I immediately cause the controls 32 such as, for example electrical, mechanical or electrochemical controls, in the machine to turn off the machine or at least stop its movement or the movement of the articulated machine component in the direction of the worker. In one embodiment a switch 36 can be used to interrupt the power supply to at least a part of the machine.

The transponder detection system may also include an emergency shutdown switch to shut down the machine through controls 32 when activated by a user. In a preferred mode i, in addition to the internal read range corresponding to internal damage area F, the transponder detection system 20 also simultaneously monitors an outside reading range corresponding to an outer damage zone G, again indicated diagrammatically in the Í | Figures as a sphere or spherical sector which again is not i | intended to be limiting. The area of internal damage can, for example, be I use in this document, the internal damage zone F is alternatively referred to as the reaction zone, and the external damage zone G is alternatively referred to as the warning zone.

Returning now to Figure 5, a security vest 50 is illustrated incorporating an RFID tag for cooperative use in the transponder detection system 20. The security vest 50 includes an RFID tag 10 having an RFID transponder 10a and an antenna 52 distributed around the vest 50 or more alternately, and as described below more advantageously placed as a pair of small parts, this is miniaturized flat antennas 52a (shown in dotted contours) on opposite sides of the vest or other garment. As illustrated in Figure 5, the antenna 52 can be oriented along a circumferential portion of the security vest 54 to substantially encircle the wearer of the security vest. However, it will be i appreciated that the antenna 52 can also be oriented along other elements of the safety vest to provide a plurality of surfaces projecting towards the outside of the safety vest having a portion of the antenna, and that the antenna can be mounted on; other articles or outer garments which could be worn by a worker, for example hats, jackets, gloves, raincoats for rain, etc., reflective. Collectively when used herein the term "safety vest" is intended for include all of such outfits. The use of a plurality of surfaces projecting I I As can be understood due to the nature of the directional nature of the hazard discussed herein, it will be appreciated that it is advantageous that the antennas 22 and sensors 70 are directional antennas as discussed above. This is because in many applications of the present invention, for example in mobile equipment, especially in congested industrial areas such as warehouses in the forklift example, it is important that the mobile equipment be able to function through out-of-phase work without need to stop, or without unnecessary alarms (also referred to herein as uncomfortable travel) being activated because workers who are passing or working perch of the machine but who are not within the area of limited damage i spatially current within which the probability of physical collision is greatly increased. These various spatially limited damage zones will depend on the type of machinery and the application. The examples provided herein are not intended to be limiting but merely illustrative of the principles in such a way that a zone of spatially limited damage can be focused so that, when the proximity of a worker, male or female, is within such an area activates an alarm causing the machine or movement of the machine to be temporarily stopped or disabled in another way, this will only happen when there is a significant probability that the worker is in fact in imminent danger or that the relative approach speed is ta a very short period of time the worker is in danger imminent. As described below, the system of the present invention can determine when a label is merely on the side or on one side of a machine moving towards the back and towards the front and toward the back and thus is not in imminent danger by the use of both ominidirectional and directional antennas on the machine in combination with spread-spectrum communications of continuous waves modulated in RFID frequency as described below.

It is also advantageous to use a progressive proximity or multiple list or two-list warning and detection system as described above. In one embodiment, for the two or several different ranges required for example for the internal reading range and the external reading range, different radio frequencies may be employed. The processor can monitor the speed of the vehicle, and determine the relative approach distance for example using the ultrasound sensor 70 up to a factor where, for example, the response time required for a piece of machinery to slow down or stop It will generally increase with the increased speed of the machine approaching the worker. The processor will thus adjust or the system will adjust otherwise, for example, the internal reading range as appropriate to provide increased reaction time to allow the delay between detection and implementation of an automatic machine shutdown and stop the machine. The processor may also optionally include a user input, such as, for example, a disk I selector, or a computer interface in such a way that a user may be able to adjust the dimensions of the internal and external reaches F and G, respectively for any desired zone.

Optionally, multiple frequency signals can be transmitted by the antenna 22 which can activate the RFID tag 10 to reduce holes and propagation errors. For example, the antenna 22 can transmit, and the RFID tag 10 is operable to receive, multi-band frequencies or an ultra high frequency band when these are known. In addition, the transceiver 12 and the antenna 22 can be adapted.

I to produce a signal in pulses from the antenna 22 for use in locations where a continuous radio frequency signal could result in reflection and propagation errors.

It is not intended that the present invention be limited to mobile equipment described in the figures. The principle in accordance with the present invention is intended to be applicable to mobile equipment, stationary articulated equipment, and other industrial and commercial processes and related machinery to protect personnel including workers pedestrians, or others, or animals such as livestock, to be in accidental contact or impact with such mobile or articulated equipment. ! As part of the method of use of the present invention, the transponder labels 10 can be tested periodically! or for example before each delay by the worker having to pass the corresponding worker's label through an interrogating station (not intermittent or discontinuous. The first signal 108 may be transmitted in accordance with a predefined interval or at other times as required as described further below. The first signal shown). The second transceiver may optionally include a threshold adjustment input 134 to adjust the threshold input. The threshold adjustment input 134 may include a computer interface where the operating software for the first and second transceivers can be adapted to adjust the threshold. Optionally, the threshold adjustment input 134 may include an input selector disk, or other appropriate adjustment means as is known in the art. In addition, the first transceiver 102 can optionally transmit an additional signal to the second! 106 transceiver to activate an alarm on the second transceiver for | alert the person who carries it of the presence of a dangerous condition. In some embodiments of the present invention, the second transceiver 106 nc I it will be activated until it is in reception of the first signal 108 from the first transceiver.

It will be appreciated that the first and second transceivers 102 and 106 can be used to determine approach speeds between the piece of mobile equipment 100 and the nearby worker 104 by recording a plurality of distance measurements 140 with a time indicator. associated. It will be appreciated that the approach speeds of the 100 team towards the worker 104 can in turn directly affect the different actions that the equipment can be instructed or allowed to perform by the processor 128. Different second transceivers 106 or labels can each have their own identification code transmitted on the carrier signal of frequency modulated continuous waves to identify the ? individual workers. As a result, more than one worker 104 can be identified in the area of imminent impact.

As discussed above, the personnel security system in accordance with the present invention is aimed at improving the safety of workers in hazardous workplaces and is an example of how i the aspects of the present invention can be employed. The personnel safety system prevents an accident from happening between a worker and a mobile machine such as a forklift. In a typical industrial workplace, there are a number of forklifts or other mobile machinery that circulate in close proximity to a group of workers, naturally increasing the chances of an accident happening.) : I Furthermore, in such a crowded environment, the noise of the engine of the machine becomes a background noise for many of the workers and therefore, they may be less alert to the warning signals of the machine, leading to a place potentially unsafe The security system in accordance with the presented I invention is well suited to improve the safety of such environments This improves the safety of workers at all times and in real time without any intervention by the worker or the operator of the machine. The system : i is an independent wireless monitoring sensor that records the distance between the forklift and the worker, and then controls the machine's motor when this distance becomes less than a predefined damage zone.

This security system acts as a wireless real-time radiofrequency (RF) range system. Since this is intended to include indoor use, a conventional narrow-band technique is excluded due to its vulnerability to signals with loss of quality and multiple trajectories. In addition, a narrow-band technique suffers from low accuracy in short range range applications. In ! Contradiction spread spectrum systems use techniques that are specifically suited for communication in harsh multi-trajectory environments. The accuracy of distance measurement in such systems is greatly improved due to the broadband nature of the signal. The Expanded Spectrum Modulation Frequency Modulated Continuous Waves (CSS) is one type of these techniques and presents additional advantages when it reaches short distance ranges, such as removing the "near-far" problem frequently faced in short distance range with other systems.

The security system according to the present invention consists of two components: an RF interrogator mounted on the machine and an RF sensor integrated in the worker's clothing, for example and advantageously in a safety vest such as the so-called vest-vision.

The worker's RF sensor includes an antenna connected to a transceiver and a processor that communicates with the sensor mounted on the machine via the transceiver and antenna. The sensor mounted on the machiné I are OFF) then one of the following scenarios could be possible: 1 1- If ID1 is detected, then the worker (carrier ID1) is located on the front (or back) of the forklift. The forklift was warned of this presence during the ON step of the directional antenna in the preceding cycle. I 2- If ID2 is detected, then this ID carrier must be located on one of the sides of the forklift since ID2 was not detected during the ON step of the directional antenna in the cycle I preceding. The operator of the machine is then notified accordingly. 3- If no ID is detected by the monopole antenna, then no one is present near the sides, and the ID1 located by the antennas i directional is located a distance ahead of the front (or back) that the distance covered by the coverage area of the monopole antenna. Without However, the directional antenna can still continue to track the position of ID1.; The monopole radio can use different types of modulation in different frequency bands different from those of the directional antenna. Using a narrow band signal may be sufficient and therefore alternate mode may not be required.

The data available on the sensor mounted on the machine I can be sent to a door in connection network communications Topology chosen for this application has an antenna on the front and the other behind the upper parts of the opposite shoulders of the vest. Other configurations are also possible, such as placing the antenna on opposite sides of the vest or even antennas integrated under the respective straps of the vest.

In a preferred embodiment, the antenna integrated in the security vest is a microstrip patch antenna constructed on a hard substrate. The use of a hard substrate is mainly to eliminate any bending and wrapping effects that could affect the performance of the antenna. The size of the total antenna is approximately 60 x 60 mm (2 6/16 x 2¡ 6/16 j inches), and is fed through a feed insert. The I Patch dimensions are optimized to cover the entire ISM frequency band 2-4 - 2.485 GHz.

The patch antenna has proven to have great immunity against the effect of the human body. In fact, its input impedance seems to see almost no effect if the antenna is in free space or placed in any part against the body. The coupling level generated by the insert feed is good enough to keep the impedance of the antenna tuned regardless of how the antenna is used.

I The antenna gain has been measured at 3.5 dB and 3.2 dB in free space and in the body, respectively, which is sufficient for this application. Planes E and H were measured in free space and on the body. In free space, the beam opening from 3 dB to 2.45 GHz was 76o 'and 97 ° | It should be pointed out that a fully integrated solution j is possible using cloth antennas sewn directly onto the fabric of i security. A simple cloth antenna can be manufactured from a sheet of conductive fabric that lies on a nonwoven fabric material such as fleece or polyester. This will eliminate the need to use coaxial cables to connect the PCB to traditional antennas made on rigid substrates.

In the test to establish baseline readings for use of antennas 52a on opposite shoulders of a safety vest, a worker wearing the vest was measured as observed standing, in figure 11 with 17 meters of separation between the worker and the reader mounted on top of a forklift. The output power of the reader and the i worker was minus 20 dBm. The reader used a monopole antenna. AND I worker remained stationary facing the reader with an antenna j front patch on the right shoulder of the vest. No obstructions were used between the reader antenna and the workers' tag antenna. ! The baseline test resulted in zero percent errors with the distance between the reader and the label set in a first-range attempt 100 percent of the time. The minimum measured distance was 1 18.41 meters, the maximum distance measured was 19.57 meters, with an average distance measured of 18.98 meters. I I The second set of tests was using a worker - i carrying a box as an obstacle. A worker was tested with uni reader. The separation of the worker and the reader was 17 meters. The energy of worker output and the reader was minus 20 dBm. The reader had a monopole antenna, and the worker used a front patch antenna on the right shoulder of the vest. During the test the worker kept a box in a i normal position, this is lower carry position as can I Observe in Figure 12a and in a position where the antenna was covered with the box as seen in Figure 12b. In a second part of this test, the box was covered in thin aluminum foil. The worker remained i stationary Again, there were zero percent errors and the distance was established in a first attempt to reach 100 percent of the time. Although 0.05 percent of the maximum broadcast was lost. The minimum distance measurement was 18.08 meters, the maximum distance measured was 19.23 meters, with the average distance measured being 18.7 meters. The data were not recorded for the second part of the test where the box was covered with aluminum foil although the visual evaluation of the data in the test time did not show significant problems. The distance measured during this second portion of the tests was the same as during the first portion.

The third set of tests measured the angle detection frontal, with the test worker oriented as observed in the figure I 13a and 13b. Again, a single worker was used with a single reader. The separation between the worker and the reader was 17 meters. The label of I Worker and the output power of the reader were varied by minus 10 minus 20 dBm. The reader used a monopole antenna and the worker used a j j I front patch antenna on the right shoulder. During the test the worker turned to find a maximum angle where the reader was able to consistently get a reach towards the workers label.

This was done first with output power of minus 10 dBm, and it was repeated at least 20 dBm. i The results of the test showed that the angle of rotation I the worker's label and the worker's label rotated in relation to the reader It was achieved with the highest energy. In particular the right angle of rotation Larger was 85 degrees and the largest left turn angle was 90 degrees. The same maximum turning angles were achieved with the levels of lower energy when the distance from the reader to the worker It was reduced.

Another set of tests were conducted to determine the Detection of the back angle with the conio-oriented test worker is observed in Figures 14a-14c. Again, only a single worker and unique reader were employees. The separation between the label of the workers and the reader was 17 meters. The worker's label and energy of the reader's output were varied between minus 10 and minus 20 dBm. The jector It had a monopole antenna. The worker used a rear patch antenna over the left shoulder of the vest. During the test the worker was rotated to find the maximum angle where the reader was able to dispose l Consistently the rear patch antenna of the workers; The Figures 15a-15c. Again a single worker was employed with a unique reader. The separation of the worker and the reader was 17 meters. Energy The output of the reader and the label of the workers was less than 20 dBm. The reader had a monopole antenna. The workers' vest had antennas Front rear patch on the opposite shoulders. Figure 15a illustrates the worker in the baseline position. Figure 15b illustrates the worker flexed to raise a box while standing in front of the reader.

Figure 15c illustrates the worker flexed to pick up a box while is standing on the side towards the reader. Figure 15d illustrates the worker lying or tilting simulating the worker doing work while lying down or sleeping. Figure 15e illustrates the worker raising a box while facing away from the reader.

In the test of using the worker in the pose of Figure 15b, the front antenna in the vest was detected and the rear antenna provided Reflected trajectory data. In the posture of figure 15c, the front antenna, which is on the shoulder of the vest closest to the reader, was detected. ! In the pose of figure 15d, the front antenna of the workers' vest was detected. In the pose of figure 15e the rear antenna of the vest of the workers was detected and the front antenna provided reflected data. Erj this set of tests the worker was detected in all positions ! of posture Reflected trajectory measurements were present. For the minus one sensor reported correct range distance. The speeds of j error were similar to the baseline tested although the rate of loss of broadcasting was slightly greater than that of the baseline test.

The conclusions were thus drafted that the carrier of a box in front of an antenna of workers in the vest of workers had little impact on the worker's detection by the reader and that the various carry and carry-up scenarios substantially did not show differences based on the positions of the cashier. It was further concluded) that the dual antenna provided 360 full degrees of coverage for the worker wearing the vest, not supporting the results of individual rotation tests suggesting an angle of 5 degrees on each side where the measurements may not have been reliable.

Thus the double antenna was an improvement and not merely the sum of the individual antennas since the double antenna provided very good results i during the 360 degree turn tests at the 5 degree angle positions where the measurements were not so. reliable when testing individual antennas. It was determined that vertical current polarization I Linear antenna was sufficient to provide detection when the test worker was inclined. | Figure 16 illustrates the impedance output measured with a patch antenna constructed on an FR4 substrate when used in the I body on the test worker and when measured in free space. As can be seen from Figure 16, the measured input impedance for both the body test and the free space test are close Figures 17a-17e illustrate the results of testing a patch antenna mounted on a vest when worn by the test worker in a sitting position. Both vertical planes E and horizontal H were measured. The measurements were both co-polar and cross polar. These measurements were also repeated with the patch antenna ran an independent. Thus figure 17a illustrates the measurements in the vertical plane E a 2. 45 GHz when the patch antenna was used by the test person Diagrammatically illustrated as sitting in the middle of the plane graph I E. The plan graphs E and H of figures 17 illustrate the magnitude in I decibels of the various antenna configurations as they are distributed around the antenna in the E or H planes. Co-polar and polar cross graphs are shown. : Figure 17b is a graph in the horizontal H plane of a i antenna at 2.45 GHz when it is used by a test worker. The figure Í | 17c is a graph of the dual antenna configuration, co-polar, in the E plane i vertical when the double antenna was used by the test worker. Figure 17d is the measurement of the double-antenna co-polar arrangement, of the figure 17c in the horizontal plane H when used by the worker of proof. Figure 17e shows the measurement of a frontal patch antenna as an independent measure in free space, co-planar, measured ^ in e plane E. ' The present invention also addresses a further deficiency in the current industry. Contact incidents commonly occur where I of reaction zone of the security system, once the high traffic area has been completed by the machine the system returns back to normal operations. Many different machine control options are possible with this system, the one above is just an example.

Antennas can be mounted on walls, posts, guardrails, etc., these can be even integrated into concrete floors, depending on the desired coverage. : Thus the aisle object label will cause the reader in a piece of mobile equipment to enter the aisle area to ignore the warning zone (this is the outside detection zones around the machine) in nearby marked areas and protected aisles, but they will allow the coverage of the reaction zone (the interior detection zone) to remain working, but without alarm if only the warning zone is passed on. This can almost eliminate annoying trips for areas with sheltered corridors. Object tags can also cause the speed limitation of all machines that pass through this protected area.

Thus, in an area of general higher pedestrian traffic 200 within for example an airport warehouse or operation, it is conventional for defined walking footpaths 202 to be defined for example by lines or patterns painted on, the floor or ground. Pedestrians including workers are instructed by training, signs, announcements to walk only along defined corridors and, even then, í always be careful of mobile machinery such as forklifts, tender, luggage trolleys, etc., whose operators can not for some reason see the defined corridors or pedestrians in these, which are operating or traveling through machine travel areas adjacent 204 in machine travel directions M. Machine travel areas 204 are often restricted between pedestrian walkways 202 and rigid immobile obstacles 205 such as walls or drive units. Í shelving.

In the labels of the present invention, they interact in a manner similar to the operator labels present in the cabins of the mobile machine to, first, disable activation or trip detection system when body tags used by pedestrians. in their garments they are detected within the outside warning zone of the machine reader, and second, to cause the machine to slow down as it travels through a slow-moving zone of the machine 204a. ! The coverage of the tag antenna can be formed c used in multiple ways to provide formed protection areas where circular zones may be undesirable or overlapping areas if these are required. For example, in a wide garage door, three c four separate antennas can also be mounted, to provide an area of overlap for accurate measurement as seen in Figure 19. I As will be apparent to those skilled in the art in light of the foregoing description, many alterations and modifications! they are possible in the practice of this invention without deviating from the spirit or scope thereof. Accordingly, the scope of this invention is to be defined in accordance with the subject matter defined by the following claims.

Claims (10)

1. NOVELTY OF THE INVENTION CLAIMS 1. - A system to improve worker safety being in the vicinity of mobile machines comprising: a machine with mountable radiofrequency identification reader that monitors wirelessly radio frequency identification tags used by workers moving in relation to and in the proximity of a mobile machine when said reader is mounted on the machine where said reader includes a processor and an antenna interface which is switchable between an omni-directional antenna and at least one antenna directional, and wherein said omin-directional antenna is mountable! to monitor a machine circumference completely around the mobile machine, and wherein said at least one directional antenna is mountable to monitor only one front or one: part of the moving machine in relation to the direction of movement of the machines, and wherein said processor determines the location of said labels which are not in said front or back side comparing s the detected tags are detected by only that antenna omni- directional and not said at least one directional antenna, where said reader is programmable to monitor multiple variable detection zones or fixed and where said labels include alarms and are adapted to I activating said alarms to alert workers using said labels when said labels are detected by said reader within said detection zones, and wherein said label is integrated with a corresponding upper body garment usable by a worker and each label includes a first discrete garment antenna and a second discrete garment antenna mounted to said garment at substantially the shoulder level of said garment, wherein the first and second garment antennas are oppositely disposed on said garment to provide 360 line of sight monitoring degrees of said label in a full 360 degree circumference around said label by said reader when a worker using said garment moves in a line of sight position within said detection zones, and wherein said wireless monitoring of said labels by said said reader uses a spread spectrum technique of continuous waves modulated in frequency to provide resistance to multiple trajectories and high noise, and wherein said reader is adapted to at least partially disable the movement, of the mobile machine under detection of at least one of said labels within a reaction zone within of said detection zones and under said processor thus determining a probability of collision between the mobile machine on which said reader is mounted and at least one of said labels. 2 - . 2 - The system according to claim 1), further characterized by the switching to a remote input any of said antennas is made by a radio frequency switch) i controlled by the control unit of said processor. i 3. - The system according to claim 2 further characterized in that said reader is a single radio device. 4. - The system according to claim 3, further characterized in that said reader is adapted to reach said labels, and to provide a feedback alarm to a machine operator of the mobile machine. j 5. - The system according to claim 4j j further characterized in that said reader is adapted to perform operaciones point-to-multi-point and point-to-point distance measurement operations, whereby a multiplicity of said tags is located by measuring the distances by said reader around said reader. j 6. - The system according to claim 4 further characterized in that said labels each provide unique identity information to said reader and wherein said reader further comprises a cabin antenna mountable in a cabin j of the mobile machine to detect one of said labels when it is used by a machine operator in the cabin of the mobile machine, and where; said reader is switchable to receive input from said car antenna. j 7. - The system according to claim 6 ', i further characterized in that it additionally comprises a seat sensor in the cabin for detecting the operator and wherein said reader turn on said cabin antenna when said seat sensor is activated i by the operator. 8. - The system according to claim. 7, further characterized in that under activation of said seat sensor by the operator of the machine said reader disables a transmitter of said operator label to save energy and reduce signal interference, and where when said seat sensor is deactivated to indicate to the operator that the operator has left the seat, said reader re-activates said operator label and has an alance to it. ' 9. - The system according to claim 1, further characterized in that said reader is adapted in such a way that the i location by said reader is done without using any reference nodes. í 10. - The system according to claim 1, further characterized in that said garment antennas are antennas miniaturized flat and where the overlapping patterns of radiation of said garment antennas provide 360 degree coverage around that garment. i 1 - The system according to claim 10 further characterized in that said garment antennas have planes of basis to eliminate the effect of radiation performance of said antennae garment of a worker's body when the worker is wearing, said garment. i 12. - The system according to claim 1 1, further characterized in that each of said label is adapted to establish communication with any said reader located within a reading range of each said label. 13. - The system according to claim 12, i further characterized in that each said label includes a motion sensor cooperating with a corresponding label processor in each said label to cut off the energy of the label after a pre-programmed time of inactivity. | 14. - The system according to claim 1, further characterized in that said processor monitors any of said tags more frequently within a zone of close proximity damage by measuring the distance of said tags more frequently to update their locations after said distance measurement. of other more distant labels outside said danger zone. 15. - The system according to claim 1 further characterized in that it additionally comprises a wall-mountable active label wherein said active tag mountable d is adapted to measure the distance of only said reader or a plurality of said readers, wherein said tag active is mountable to walls or poles. 16. - The system according to claim 15, further characterized in that said active label covers a running area slow down of machine and detects said readers within the slow travel zone, and wherein said active tag cooperates with said readers within said i) slow-motion zone so that said readers ignore said tags within said detection zones, but not within said reaction zones and so within said slow-moving zone said readers reduce, without stopping, the speed of said corresponding readers to mobile machines, and where, within the slow-moving zones, said readers stop their corresponding mobile machines under detection of said labels within said reaction zones. i I