Patent Description:
<CIT> relates to a photoelectric barrier (e.g., a light curtain) for monitoring a surveillance area. Said barrier comprises at least one first optical unit and at least one second optical unit or a reflective unit, each optical unit comprising a plurality of transceiver elements. Each transceiver element comprises at least one optical sender, at least one optical receiver and a control element operable to control the optical sender of one optical unit to emit radiation towards a corresponding optical receiver of the other one of the first and second optical units. Said control element comprises a driver unit for driving said at least one optical sender to emit radiation and at least one receiver unit for sensing and evaluating electrical signals generated by said optical receiver. Said driver unit is further operable to adjust an emission intensity of said optical sender in response to a first setting signal. Further, a warning means is provided for being actuated, if the measured radiation intensity is below a predefined threshold value.

<CIT> relates to a method for aligning a sensor system. Said sensor system has a transmitter unit having at least one light beam emit-ting transmitter and a receiver unit having at least one receiver as-signed to the transmitter, which receiver receives the light beams from the transmitter when the sensor system is in operation. In order to align the transmitter unit, an alignment receiver is positioned on the receiver unit in front of the receiver, said alignment receiver having a larger aperture angle than the receiver. The light beams emitted by the transmitter are received by the alignment receiver. Depending on the quantity of light of the light beams received by the alignment receiver, data are displayed on a display unit.

<CIT> relates generally to industrial light curtains, and, more particularly, to techniques for tuning a light curtain's operating margins individually for each channel to facilitate optimal object detection in a range of variable operating conditions.

<CIT> relates to a method of operating an automatic door installation comprising door sensor equipment including a door sensor. The automatic door installation is operable in at least a standard mode, in which the door sensor equipment conducts an obstacle check to determine whether an obstacle is present according to a first obstacle check procedure, and a contingency mode, in which the door sensor equipment conducts the obstacle check according to a different second obstacle check procedure. The method includes the steps of evaluating an operating condition of the automatic door installation; determining whether the operating condition lies within a standard operating range; and operating the automatic door installation in the contingency mode when the operating condition lies outside a respective standard operating range.

It is the object of the present invention to provide an improved method and system for using a light curtain.

A component for light curtain alignment is disclosed. A method also performs the functions of the component. The component includes a light intensity receiver configured to receive a plurality of light intensity signals from a plurality of beam receivers of a receiver unit of a light curtain. The light curtain includes a transmitter unit with a plurality of beam transmitters arranged linearly on the transmitter unit. Each beam transmitter is configured to transmit a narrow beam of light. The light curtain includes the receiver unit with the plurality of beam receivers arranged linearly. Each beam receiver is configured to receive light from a corresponding beam transmitter of the plurality of beam transmitters. The component includes a light intensity transmitter configured to transmit, from the light curtain, the plurality of light intensity signals received by the light intensity receiver. Each light intensity signal is from one or more beam receivers of the plurality of beam receivers. The component includes, in some embodiments, a trip transmitter configured to transmit a trip signal in response to determining that a light intensity signal from a beam receiver of the plurality of beam receivers is below a trip threshold.

Another component for alignment of a light curtain includes a light intensity receiver configured to receive a plurality of light intensity signals from a plurality of beam receivers of a receiver unit of a light curtain. The light curtain includes a transmitter unit with a plurality of beam transmitters arranged linearly on the transmitter unit where each beam transmitter is configured to transmit a narrow beam of light. The light curtain includes the receiver unit with the plurality of beam receivers arranged linearly. Each beam receiver is configured to receive light from a corresponding beam transmitter of the plurality of beam transmitters. The light curtain includes one or more vibration sensors.

A more particular description of the embodiments briefly described above will be rendered by reference to the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the scope of the present invention is defined only by the appended claims. The embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:.

The terms "including," "comprising," "having," and variations thereof mean "including but not limited to" unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The term "and/or" indicates embodiments of one or more of the listed elements, with "A and/or B" indicating embodiments of element A alone, element B alone, or elements A and B taken together.

Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments.

These features and advantages of the embodiments will become more fully apparent from the following description and appended claims or may be learned by the practice of embodiments as set forth hereinafter. As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method, and/or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," "module," or "system. " Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having program code embodied thereon.

Many of the functional units described in this specification have been labeled as modules, circuits, transmitters, etc. in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. For example, some embodiments might be implemented with hardware circuits to transport light intensity signals from one or more beam receivers of a light curtain. A module, circuit, transmitter and the like may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

Modules may also be implemented in software for execution by various types of processors. An identified module of program code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

Indeed, a module of program code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. Where a module or portions of a module are implemented in software, the program code may be stored and/or propagated on in one or more computer readable medium(s).

The computer readable medium may be a tangible computer readable storage medium storing the program code. The computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

More specific examples of the computer readable storage medium may include but are not limited to a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), an optical storage device, a magnetic storage device, a holographic storage medium, a micromechanical storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, and/or store program code for use by and/or in connection with an instruction execution system, apparatus, or device.

The computer readable medium may also be a computer readable signal medium. A computer readable signal medium may include a propagated data signal with program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electrical, electro-magnetic, magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport program code for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable signal medium may be transmitted using any appropriate medium, including but not limited to wire-line, optical fiber, Radio Frequency (RF), or the like, or any suitable combination of the foregoing.

In one embodiment, the computer readable medium may comprise a combination of one or more computer readable storage mediums and one or more computer readable signal mediums. For example, program code may be both propagated as an electro-magnetic signal through a fiber optic cable for execution by a processor and stored on RAM storage device for execution by the processor. As used herein, a computer readable storage medium or computer readable storage media are non-transitory.

Program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Python, Ruby, R, Java, Java Script, Smalltalk, C++, C sharp, Lisp, Clojure, PHP or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer program product may be shared, simultaneously serving multiple customers in a flexible, automated fashion.

The computer program product may be integrated into a safety relay, a controller, a client, server, a network environment and the like by providing for the computer program product to coexist with applications, operating systems and network operating systems software and then installing the computer program product on the safety relay, controller, clients, servers, etc. in the environment where the computer program product will function. In one embodiment software is identified on the safety relay, controller, clients and servers including the network operating system where the computer program product will be deployed that are required by the computer program product or that work in conjunction with the computer program product. This includes the network operating system that is software that enhances a basic operating system by adding networking features.

The embodiments may transmit data between electronic devices. The embodiments may further convert the data from a first format to a second format, including converting the data from a non-standard format to a standard format and/or converting the data from the standard format to a non-standard format. The embodiments may modify, update, and/or process the data. The embodiments may store the received, converted, modified, updated, and/or processed data. The embodiments may provide remote access to the data including the updated data. The embodiments may make the data and/or updated data available in real time. The embodiments may generate and transmit a message based on the data and/or updated data in real time. The embodiments may securely communicate encrypted data. The embodiments may organize data for efficient validation. In addition, the embodiments may validate the data in response to an action and/or a lack of an action.

Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and computer program products according to embodiments of the invention. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by program code. The program code may be provided to a processor of a general purpose computer, special purpose computer, sequencer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

The program code may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

The program code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the program code which executed on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions of the program code for implementing the specified logical function(s).

In one embodiment, the component includes a light intensity receiver module configured to receive the plurality of light intensity signals and a light intensity display module configured to display a light intensity indicator for each light intensity signal and a relative position of the one or more beam receivers associated with each light intensity signal. The light intensity indicators for each light intensity signal and corresponding positions of the one or more beam receivers provide an indication of beam alignment. In a further embodiment, the light intensity receiver module and the light intensity display module are on a portable electronic device. In other embodiments, the plurality of light intensity signals are transmitted to the portable electronic device wirelessly.

In some embodiments, the component includes a safe module configured to prevent the trip transmitter from transmitting the trip signal during a safe mode. In other embodiments, the safe module is configured to activate the light intensity transmitter to transmit the plurality of light intensity signals during the safe mode. In other embodiments, the light intensity transmitter and the trip transmitter operate simultaneously during an operation mode. In other embodiments, the light intensity transmitter transmits the plurality of light intensity signals while the trip transmitter monitors the plurality of light intensity signals to determine if a light intensity signal from a beam receiver of the plurality of beam receivers drops below the trip threshold which triggers the trip transmitter to transmit the trip signal.

In some embodiments, the component includes a threshold module configured to notify a user adjusting positioning of the transmitter unit and/or the receiver unit of a target threshold for each of the plurality of beam receivers. The target threshold includes the trip threshold adjusted by an amount of light intensity degradation due to an expected amount of vibration at the transmitter unit and/or the receiver unit. In a further embodiment, the component includes an attenuation calculator configured to determine the amount of light intensity degradation for each of the plurality of beam receivers due to vibration of the light curtain. In other embodiments, the attenuation calculator is configured to determine the amount of light intensity degradation based on light intensity signals from the light intensity receiver and operational data of equipment near the light curtain causing vibrations to the light curtain.

In other embodiments, the component includes a vibration sensor in the transmitter unit and/or a vibration sensor in the receiver unit of the light curtain. The attenuation calculator is configured to use sensed vibration in the transmitter unit and/or in the receiver unit to determine the amount of light intensity degradation for each of the plurality of beam receivers due to vibration of the light curtain. In other embodiments, the component includes a vibration learning module configured to use vibration data and light intensity signal data for transmitter units and receiver units of a plurality of light curtains to determine a relationship between vibration and light intensity degradation. The attenuation calculator is configured to use the relationship determined by the vibration learning module to determine the amount of light intensity degradation based on the vibration of the light curtain.

Another component for alignment of a light curtain includes a light intensity receiver configured to receive a plurality of light intensity signals from a plurality of beam receivers of a receiver unit of a light curtain. The light curtain includes a transmitter unit with a plurality of beam transmitters arranged linearly on the transmitter unit where each beam transmitter is configured to transmit a narrow beam of light. The light curtain includes the receiver unit with the plurality of beam receivers arranged linearly. Each beam receiver is configured to receive light from a corresponding beam transmitter of the plurality of beam transmitters. The light curtain includes one or more vibration sensors. The component includes a light intensity transmitter configured to transmit from the light curtain a plurality of light intensity signals. Each light intensity signal is from one or more beam receivers. In some embodiments, the component includes a trip transmitter that transmits a trip signal in response to determining that a light intensity signal from a beam receiver of the plurality of beam receivers is below a trip threshold.

In some embodiments, the one or more vibration sensors include a vibration sensor in the transmitter unit and/or a vibration sensor in the receiver unit. In other embodiments, the component includes an attenuation calculator configured to determine an amount of light intensity degradation for each of the plurality of beam receivers due to vibration of the light curtain sensed by the one or more vibration sensors. In other embodiments, the component includes a threshold module that notifies a user adjusting positioning of the transmitter unit and/or the receiver unit of a target threshold for each of the plurality of beam receivers. The target threshold includes the trip threshold adjusted by an amount of light intensity degradation determined by the attenuation calculator.

A method for alignment of a light curtain includes receiving a plurality of light intensity signals. Each light intensity signal is from one or more beam receivers of a plurality of beam receivers of a light curtain. The light curtain includes a transmitter unit with a plurality of beam transmitters arranged linearly on the transmitter unit. Each beam transmitter is configured to transmit a narrow beam of light. The light curtain includes a receiver unit with the plurality of beam receivers arranged linearly. Each beam receiver is configured to receive light from a corresponding beam transmitter of the plurality of beam transmitters. The method includes transmitting from the light curtain the plurality of light intensity signals, and transmitting a trip signal in response to determining that a light intensity signal from a beam receiver of the plurality of beam receivers is below a trip threshold.

In some embodiments, the method includes receiving, at a portable electronic device, the plurality of light intensity signals, and displaying a light intensity indicator for each light intensity signal and a relative position of the one or more beam receivers associated with each light intensity signal. The light intensity indicators for each light intensity signal and corresponding positions of the one or more beam receivers provide an indication of beam alignment. In another embodiment, the method includes determining the amount of light intensity degradation for each of the plurality of beam receivers due to vibration of the light curtain, and notifying a user adjusting positioning of the transmitter unit and/or the receiver unit of a target threshold for each of the plurality of beam receivers. The target threshold includes the trip threshold adjusted by the amount of light intensity degradation due to an expected amount of vibration at the transmitter unit and/or the receiver unit.

<FIG> is a schematic block diagram of a system <NUM> for light curtain beam alignment according to an embodiment. The system <NUM> includes an intensity apparatus <NUM>, a controller <NUM>, a human interface <NUM>, a graphical user interface and input/output devices <NUM>, a computer network <NUM>, a server <NUM>, a safety relay <NUM>, a network interface <NUM>, connection taps <NUM>, trunk line conductors <NUM>, tap conductors <NUM>, safety devices <NUM>, a terminator <NUM>, a light curtain <NUM>, a transmitter unit <NUM>, beam transmitters <NUM>, a receiver unit <NUM>, beam receivers, <NUM>, light beams <NUM>, transmitter/receiver connecting cable <NUM>, vibration sensors <NUM>, posts <NUM>, industrial equipment <NUM>, and a portable electronic device <NUM>, which are described below.

Aligning the transmitter unit and the receiver unit of a conventional light curtain may be difficult where typically the light curtain includes only a binary output where a trip signal is displayed if each beam receiver does not receive a light intensity from a corresponding beam transmitter above a threshold. Having a display of light intensity for each beam receiver <NUM> or for a group of beam receivers <NUM> of the light curtain <NUM> facilitates easier alignment.

The intensity apparatus <NUM> provides a way to align beam transmitters <NUM> of the transmitter unit <NUM> and beam receivers <NUM> of the receiver unit <NUM> using light intensity information of the beam receivers <NUM>. While the intensity apparatus <NUM> is depicted in the receiver unit <NUM>, the intensity apparatus <NUM>, in some embodiments, may include portions in other locations, such as the transmitter unit <NUM>, the safety relay <NUM>, the controller <NUM>, etc. In some embodiments, the receiver unit <NUM> is customized to include the intensity apparatus <NUM> configured to transmit light intensity signals from the beam receivers <NUM> where the light intensity signals from each beam receiver <NUM> or from a group of beam receivers <NUM> are displayed to aid in alignment of the transmitter unit <NUM> and/or the receiver unit <NUM> so that the light curtain <NUM> functions properly. In some embodiments, the intensity apparatus <NUM> transmits the light intensity signals and/or light intensity information to a portable electronic device ("PED") <NUM> for display where the PED <NUM> may be used at the light curtain <NUM> for beam alignment. In some embodiments, the intensity apparatus <NUM> uses expected vibration of the light curtain <NUM> to further align the transmitter unit <NUM> and the receiver unit <NUM>. The intensity apparatus <NUM> is described in more detail below.

The controller <NUM>, the human interface <NUM>, the safety relay <NUM>, the network interface <NUM>, the connection taps <NUM>, the trunk line conductors <NUM>, the tap conductors <NUM>, the safety devices <NUM>, the terminator <NUM> and the light curtain <NUM>, in some embodiments, are part of a machine safety system, which may also be called a condition monitoring system. The machine safety system includes safety devices that are installed based on a risk assessment of conditions of an industrial operation or other system with physical devices, such as the industrial equipment <NUM>, to prevent injury and to minimize down time of the industrial operation. The machine safety system may be used to prevent injury from various types of equipment, such as manufacturing equipment, electrical equipment, motors, gears, sprayers, chemical process equipment, and the like. The machine safety system, in some embodiments, is a GuardLink® system by Rockwell Automation® or similar machine safety system by another vendor. In some embodiments, a GuardLink system has an ability to daisy chain between connection taps <NUM> without having to loop the trunk line conductor <NUM> in a loop while meeting applicable safety standards, such being EN/ISO <NUM>-<NUM> performance level "e" ("PLe") certified by TÜVRheinland® or other applicable certification.

The system <NUM>, in some embodiments, includes a human-machine interface ("HMI") <NUM>, such a control panel, at or near industrial equipment <NUM> of the industrial operation to allow a user to control and interact with the controller <NUM> to control the machine safety system. The HMI <NUM> may include a display screen and a means to receive user input.

The industrial equipment <NUM> is merely representative of a system that may be monitored by a machine safety system that includes the intensity apparatus <NUM>. The industrial equipment <NUM> depicted in <FIG> includes assembly/processing equipment that interact with parts being manufactured. In other embodiments, the industrial operation may include a boiler, a gas turbine, electrical equipment, chemical processing equipment or any other system that can benefit from a machine safety system such as the machine safety system depicted in the system <NUM> of <FIG>.

The industrial equipment <NUM>, as with most industrial operations or other system with physical devices, has inherent dangers as well as equipment that may fail. The machine safety system includes components that enable monitoring of hazardous conditions, equipment health, environmental conditions, etc. to increase safety for personnel and to predict and/or detect equipment failure. In some embodiments, the components of the machine safety system help to improve performance of the industrial equipment <NUM> or other industrial operation. In some embodiments, the machine safety system includes safety devices, sensors and other components that are external to equipment within the industrial equipment <NUM>. In other embodiments, the machine safety system receives input from equipment within the industrial equipment <NUM>/industrial operation.

In some embodiments, the machine safety system includes a network interface <NUM> connected to a safety relay <NUM>. The network interface <NUM> provides a network connection to the controller <NUM>. For example, the machine safety system may include one internet protocol ("IP") address and may be able to provide information from safety devices through the single IP address to the controller <NUM>. Such an arrangement beneficially reduces the number of IP addresses for a plant that includes the industrial equipment <NUM>. Other networking interfaces <NUM> may include more than one IP address, for example, for multiple safety relays <NUM> or multiple lines from a safety relay <NUM>. A safety device may include a non-contact switch, the light curtain <NUM>, a locking switch, an emergency stop, an actuator, a cable pull switch, a key interlock switch, and the like. In other embodiments, one or more safety devices include an IP address. In other embodiments, the safety devices run on a proprietary network different than an IP network.

In the embodiment depicted in <FIG>, the machine safety system includes trunk line conductors <NUM> running between connection taps <NUM>. At each connection tap <NUM>, a tap conductor <NUM> runs to a safety device, such as a non-contact switch, a light curtain <NUM>, a locking switch, an emergency stop, a cable pull switch, etc..

The light curtain <NUM> is configured to send a trip signal when beams of light <NUM> between a transmitter unit <NUM> and receiver unit <NUM> are interrupted. The trip signal may be used to shut down equipment or take other action to prevent injury, and may also be used to prevent damage to equipment. Light curtains <NUM> are often used in industrial operations to prevent injury upon intrusion of personnel or body parts of personnel into an area with running and/or dangerous industrial equipment <NUM>. Often, the transmitter unit <NUM> and receiver unit <NUM> are connected with a transmitter/receiver connecting cable <NUM>. In other embodiments, the transmitter unit <NUM> and receiver unit <NUM> are connected wirelessly.

Transmitter units <NUM> and receiver units <NUM> are mounted on opposite sides of an opening and are arranged to transmit beams of light across the opening. The opening may be a doorway, an area between posts <NUM>, or the like. Light curtains <NUM>, in some embodiments, are set up around a perimeter of industrial equipment <NUM> in an open area of an industrial operation. The transmitter unit <NUM> and receiver unit <NUM> are typically mounted on rigid structures, such as walls, door frames, posts <NUM>, bollards, etc. Precise alignment is required to avoid nuisance tripping. Alignment can often be difficult. An example of a light curtain <NUM> is model <NUM> GuardShield™ POC safety light curtains by Allen-Bradley®, which is one of several light curtains <NUM> available by Allen-Bradley. Other manufacturers sell other light curtains <NUM>.

The light curtain <NUM> includes a transmitter unit <NUM> with a plurality of beam transmitters <NUM> arranged linearly on the transmitter unit <NUM>. Each beam transmitter <NUM> is configured to transmit a narrow beam of light <NUM> to a corresponding beam receiver <NUM> on a receiver unit <NUM>. In some embodiments, each beam transmitter <NUM> is a light emitting diode ("LED"). The beam transmitters <NUM>, in some embodiments, include optics to focus a narrow beam of light <NUM>. In other embodiments, the beam transmitters <NUM> are lasers. Typically, the beam transmitters <NUM> transmit light in a range that is not visible to humans. In some embodiments, the beam transmitters <NUM> transmit an infrared beam. In other embodiments, for safety each beam of light <NUM>, the angle of divergence or the angle the beam of light <NUM> expands is no more than <NUM> degrees at the receiver unit <NUM>.

The beam receivers <NUM> are configured to receive a beam of light <NUM> from a beam transmitter <NUM> and to measure an intensity of the received beam of light <NUM>. In some embodiments, the beam receivers <NUM> are photo transistors or photoelectric cells that generate an electric signal in response to being exposed to light. In some embodiments, the beam receivers <NUM> produce a signal that indicates intensity of the received beam of light <NUM>. The beam transmitters <NUM> and beam receivers <NUM> are depicted in <FIG> as surface mounted, but are typically mounted internally to a frame of the transmitter unit <NUM> and receiver unit <NUM>. For example, the transmitter unit <NUM> and the receiver unit <NUM> may each include a metal frame, such as an aluminum frame and the beam transmitters <NUM> and beam receivers <NUM> are mounted internal to the metal frame, which includes openings for the beams of light <NUM>, optics, etc. Typically, the beam receivers <NUM> are configured with the receiver unit <NUM> to exclude light other than from a corresponding beam transmitter <NUM>.

In some embodiments, the beam transmitters <NUM> emit pulses of invisible infrared light. The light pulses, in some embodiments, are sequenced - one beam transmitter <NUM> after another. In other embodiments, the light pulses are modulated at a specific frequency and/or pattern, which may be used by a beam receiver <NUM> to distinguish light from a beam transmitter <NUM> from other sources.

Spacing of the beam transmitters <NUM> and corresponding beam receivers <NUM> depends on the application. Some standards define finger, hand and body spacing requirements where finger spacing is set up to not allow a human finger from penetrating the beam of light <NUM> without tripping the light curtain <NUM>. Hand spacing is set up to not allow a human hand from penetrating the beam of light <NUM> without tripping the light curtain <NUM> and may be used where finger spacing requirements are not necessary. Body spacing is set up to not allow a human body part, such as an arm, a foot, etc. from penetrating the beam of light <NUM> without tripping the light curtain <NUM> and may be used where hand spacing requirements are not necessary. Typically, a light curtain <NUM> with body spacing is placed further from industrial equipment <NUM> than a light curtain <NUM> with hand spacing or finger spacing. Likewise, a light curtain <NUM> with hand spacing is typically placed further from industrial equipment <NUM> than a light curtain <NUM> with finger spacing.

Light curtains <NUM> are set up to transmit a trip signal in response to determining that a light intensity signal from any one of the beam receivers <NUM> of a receiver unit <NUM> is below a trip threshold. Typically, light intensity information of received light at a beam receiver of a light curtain is not available external to the light curtain. The light curtain <NUM> includes a light intensity transmitter that is configured to transmit, from the light curtain <NUM>, a plurality of light intensity signals. Each light intensity signal from one or more beam receivers <NUM>. In some embodiments, the light intensity transmitter is configured to transmit a light intensity signal from each beam receiver <NUM> of the receiver unit <NUM>.

In other embodiments, the beam receivers <NUM> are grouped and the light intensity transmitter is configured to transmit a light intensity signal from each group of beam receiver <NUM>. For example, a receiver unit <NUM> may include <NUM> beam receivers <NUM>, which may be divided into groups of <NUM> consecutive beam receivers <NUM>. The light intensity transmitter may then transmit a light intensity signal for each of the six groups of beam receivers <NUM> of the receiver unit <NUM>. In some embodiments, the beam receivers <NUM> are split into groups that are sized with enough granularity to allow alignment while minimizing the number of light intensity signals transmitted by the light intensity transmitter.

In some embodiments, the light intensity transmitter transmits light intensity signals for processing by the intensity apparatus <NUM> to be displayed on an electronic display. For example, the light intensity transmitter may be located in the receiver unit <NUM> and may transmit the light intensity signals over the machine safety system to another portion of the intensity apparatus <NUM> in the controller <NUM>, the safety relay <NUM> or other location for processing. The intensity apparatus <NUM> then displays or transmits for display a representation of the light intensities of the beam receivers <NUM> or groups of beam receivers <NUM>. In some embodiments, the intensity apparatus <NUM> displays a representation of the light intensities of the beam receivers <NUM> or groups of beam receivers <NUM> on the HMI <NUM> or graphical user interface <NUM>. In other embodiments, the intensity apparatus <NUM> displays a representation of the light intensities of the beam receivers <NUM> or groups of beam receivers <NUM> on the PED <NUM>, which may be located close to the light curtain <NUM>, which better facilitates alignment of the transmitter unit <NUM> and receiver unit <NUM>.

In some embodiments, the light curtain <NUM> includes vibration sensors <NUM>. The vibration sensors <NUM>, in some embodiments, provide vibration information where vibration of the transmitter unit <NUM> and/or receiver unit <NUM> cause a degradation of the intensity of the beam of light <NUM> or a measured light intensity at the beam receivers <NUM>. A small amount of vibration may cause a little degradation while increased vibration may cause a degradation of the light intensity signals at the beam receivers <NUM> to a degree that a trip transmitter transmits a trip signal. A known or expected amount of vibration may cause a known amount of degradation which may be accounted for during alignment. For example, where a light intensity signal has a range of <NUM> to <NUM> and expected vibration may cause a degradation value of <NUM> and a trip threshold is <NUM>, the intensity apparatus <NUM> may be used so that each beam receiver <NUM> has a light intensity signal of <NUM> or greater.

In some embodiments, the vibration sensors <NUM> are an accelerometer-type vibration sensor, a pin and spring vibration sensor, a piezoelectric vibration sensor, a magnetic vibration sensor, or the like. In some embodiments, the vibration sensors <NUM> are mounted internal to the transmitter unit <NUM> and/or receiver unit <NUM>. In other embodiments, the vibration sensors <NUM> are mounted on an exterior of the transmitter unit <NUM> and/or receiver unit <NUM>. In some embodiments, vibration information from the vibration sensors <NUM> is processed, transmitted, etc. by the light curtain <NUM>. In other embodiments, the vibration information from the vibration sensors <NUM> is transmitted separately from data of the light curtain <NUM>. For example, the vibration sensors <NUM> may be connected to a connection tap <NUM> and vibration information may be transmitted to the safety relay <NUM> separately from data from the light curtain <NUM>. One of skill in the art will recognize other ways for the intensity apparatus <NUM> to receive vibration information from the vibration sensors <NUM>.

The system <NUM> includes a portable electronic device ("PED") <NUM> configured to receive the plurality of light intensity signals and to display a light intensity display indicator for each light intensity signal along with a relative position of the one or more beam receivers <NUM> associated with each light intensity signal. The light intensity indicators for each light intensity signal and the corresponding positions of the one or more beam receivers provide an indication of beam alignment.

In some embodiments, the PED <NUM> is a cellular phone, a personal digital assistant ("PDA"), a tablet computer or the like. In some embodiments, the PED <NUM> is a consumer electronic device used for other purposes and includes program code and hardware circuits to receive the plurality of light intensity signals and to display the light intensity signals. In other embodiments, the PED <NUM> is a custom device designed for light curtain alignment. In some embodiments, the PED <NUM> receives the light intensity signals wirelessly. In other embodiments, the PED <NUM> is connected to the light curtain <NUM> with a wire. For example, the PED <NUM> may connect to the light curtain <NUM> with a cord with a connector on between the PED <NUM> and cord and between the light curtain <NUM> and cord.

<FIG> is a schematic block diagram for a PED <NUM> for light curtain beam alignment according to an embodiment. The PED <NUM> in <FIG> is depicted as a cellular phone with an electronic display <NUM>, but may be another device with an electronic display <NUM>. The electronic display <NUM> includes controls <NUM> at the bottom and status indicators <NUM> at the top of the electronic display. The PED <NUM> includes circles <NUM> that represent beam receivers <NUM> and rectangle <NUM> that represents the receiver unit <NUM>. Each circle <NUM> includes a dot <NUM> where the size of the dots <NUM> relative to the circles <NUM> represent an intensity of a light intensity signal. Numbers <NUM> next to the circles <NUM> indicate an intensity value so that the top circle <NUM> has an intensity value of <NUM> percent of a maximum intensity and the bottom circle <NUM> has an intensity value of <NUM> percent of the maximum intensity.

In the example of <FIG>, the beam receiver <NUM> and corresponding beam transmitter <NUM> at the top of the receiver unit <NUM> and transmitter unit <NUM> have a much lower alignment than the beam receiver <NUM> and corresponding beam transmitter <NUM> at the bottom of the receiver unit <NUM> and transmitter unit <NUM>. As the top of the receiver unit <NUM> and transmitter unit <NUM> are brought more into alignment, the beam intensities at the top of the beam intensity would increase. The representation of beam intensities in <FIG> depict one embodiment and one of skill in the art will recognize other ways to represent intensities of light intensity signals from the plurality of beam receivers <NUM> on a receiver unit <NUM>.

The PED <NUM> is depicted with various ways to receive light intensity signals. In one embodiment, the PED <NUM> receives the light intensity signals wirelessly over a wireless network, such as WiFi. In another embodiment, the PED <NUM> receives the light intensity signals wirelessly over a short range wireless network, such as Bluetooth®. In another embodiment, the receiver unit <NUM> or transmitter unit <NUM> include an infrared transmitter <NUM> and the PED <NUM> includes camera or other device capable of communicating with the infrared transmitter <NUM> using infrared signals. In another embodiment, the PED <NUM> includes a cord <NUM> with a jack that connects to the light curtain <NUM> to receive the light intensity signals. Having a wireless or tethered PED <NUM> provides a convenient way for a user aligning the transmitter unit <NUM> and receiver unit <NUM> of a light curtain <NUM> while the user is close enough to physically adjust the transmitter unit <NUM> and receiver unit <NUM>.

<FIG> is a schematic block diagram of an apparatus <NUM> for light curtain beam alignment according to an embodiment. The apparatus <NUM> includes an embodiment of the intensity apparatus <NUM> that includes a light intensity receiver <NUM>, a light intensity transmitter <NUM>, a grouping circuit <NUM> and a trip transmitter <NUM>, which are described below.

The apparatus <NUM> includes light intensity receiver <NUM> configured to receive a plurality of light intensity signals from the plurality of beam receivers <NUM> on the receiver unit <NUM> of the light curtain <NUM>. In one embodiment, the light intensity receiver <NUM> receives the light intensity signals from each beam receiver <NUM>. In one embodiment, the light intensity receiver <NUM> is electrically connected to each beam receiver <NUM>. In another embodiment, the light intensity receiver <NUM> is connected to a group of beam receivers <NUM> where the receiver unit <NUM> includes a plurality of groups of beam receivers <NUM>. In some embodiments, the intensity apparatus <NUM> is used for determining if the light curtain <NUM> has tripped based on a blocked beam of light <NUM> in addition to transmission of several light intensity signals. In other embodiments, the light intensity receiver <NUM> and light intensity transmitter <NUM> are independent of a trip function of the light curtain <NUM>.

The apparatus <NUM> includes a light intensity transmitter <NUM> configured to transmit, from the light curtain <NUM>, the plurality of light intensity signals received by the light intensity receiver <NUM>. Each light intensity signal is from one or more beam receivers <NUM> of the plurality of beam receivers <NUM> of the receiver unit <NUM>. For example, received light intensity signals may be grouped. In one embodiment, the light intensity transmitter <NUM> transmits the light intensity signals over a tap conductor <NUM> to the safety relay <NUM>. In another embodiment, the light intensity transmitter <NUM> transmits the light intensity signals to the PED <NUM> or other display, such as in the HMI <NUM> or graphical user interface <NUM>. In other embodiments, the safety relay <NUM> transmits the light intensity signals to the controller <NUM> through the network interface <NUM>. The controller <NUM> or other device may use the light intensity signals to monitor long-term degradation of the light intensity signals.

In other embodiments, the controller <NUM> or other device transmits the light intensity signals to the PED <NUM> using a standard transmission protocol, such as transmission control protocol/internet protocol ("TCP/IP"), ethernet, etc. For example, the controller <NUM> may transmit the light intensity signals over the computer network <NUM>, which may include a LAN, the Internet, a cellular network, etc. to the PED <NUM>. In other embodiments, the light intensity transmitter <NUM> transmits the light intensity signals in a more direct path using Bluetooth®, near field communication ("NFC"), infrared transmission, etc. One of skill in the art will recognize other ways for the light intensity transmitter <NUM> to transmit the light intensity signals.

In some embodiments, the light intensity transmitter <NUM> transmits a light intensity signal for each beam receiver <NUM>. In another embodiment, the light intensity transmitter <NUM> transmits an intensity signal for each group of beam receivers <NUM> where the beam receivers <NUM> are divided into several groups. In one embodiment, the intensity apparatus <NUM> includes a grouping circuit <NUM> configured to receive a light intensity signal from two or more beam receivers <NUM> of a group of beam receivers <NUM> of the receiver unit <NUM>. For example, where the receiver unit <NUM> has <NUM> beam receivers <NUM>, the beam receivers <NUM> may be divided into eight groups of five beam receivers <NUM> so that the grouping circuit <NUM> receives, for each group, light intensity signals from five beam receivers <NUM> and outputs a single light intensity signal for the group.

In one embodiment, the grouping circuit <NUM> averages the light intensity signals from the five beam receivers <NUM> in the group and outputs for to the light intensity transmitter <NUM> an averaged light intensity signal. In another embodiment, the grouping circuit <NUM> receives five light intensity signals from five beam receivers <NUM> of a group and transmits a light intensity signal that is the lowest of the group. For example, if the grouping circuit <NUM> receives light intensity signals of <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, the grouping circuit <NUM> outputs to the light intensity transmitter <NUM> a light intensity signal with a value of <NUM>. One of skill in the art will recognize other ways for the grouping circuit <NUM> to combine light intensity signals from a group of beam receivers <NUM>.

The apparatus <NUM> includes, in some embodiments, a trip transmitter <NUM> configured to transmit a trip signal in response to determining that a light intensity signal from a beam receiver <NUM> of the plurality of beam receivers <NUM> is below a trip threshold. Typically, the trip transmitter <NUM> transmits the trip signal if a light intensity signal for any of the beam receivers <NUM> of the receiver unit <NUM> is below the trip threshold, which indicates that the beam of light <NUM> transmitted from a corresponding beam transmitter <NUM> is fully or partially blocked. Depending on what is blocking the beams of light <NUM>, multiple beams of light <NUM> may be blocked causing the light intensity signal from several beam receivers <NUM> to fall below a trip threshold.

The trip threshold, in some embodiments, is dependent on a maximum expected beam intensity from a beam receiver <NUM>. For example, the trip threshold may be set to a percentage of the maximum beam intensity for the beam receiver <NUM>. In some embodiments, the trip threshold is set according to a safety standard. In other embodiments, the trip threshold may be adjusted within a range where there is a minimum allowable trip threshold. One of skill in the art will recognize other ways to set a trip threshold. In some embodiments, the intensity apparatus <NUM> includes the trip transmitter <NUM>. In other embodiments, determining if a light intensity signal is below a trip threshold and transmitting a trip signal is external to the intensity apparatus <NUM>.

<FIG> is a schematic block diagram of an apparatus <NUM> and portable electronic device for light curtain beam alignment according to another embodiment. The apparatus <NUM> includes another embodiment of an intensity apparatus <NUM> and/or an embodiment of the PED <NUM>. The embodiment of the intensity apparatus <NUM> includes a light intensity receiver <NUM>, a light intensity transmitter <NUM>, a grouping circuit <NUM>, and/or a trip transmitter <NUM>, which are substantially similar to those described above with regard to the apparatus <NUM> of <FIG>. The PED <NUM> includes a light intensity receiver module <NUM> and a light intensity display module <NUM> and the intensity apparatus <NUM> includes one or more of a safe module <NUM>, a threshold module <NUM>, an attenuation calculator <NUM> and a vibration learning module <NUM>, which are described below.

The PED <NUM> includes a light intensity receiver module <NUM> configured to receive the plurality of light intensity signals and a light intensity display module <NUM> configured to display a light intensity indicator for each light intensity signal and a relative position of the one or more beam receivers <NUM> associated with each light intensity signal. The light intensity indicators for each light intensity signal and corresponding positions of the one or more beam receivers <NUM> provide an indication of beam alignment. In some embodiments, the light intensity receiver module <NUM> and the light intensity display module <NUM> are program code stored in computer readable storage media on the PED <NUM>. In other embodiments, the light intensity receiver module <NUM> and the light intensity display module <NUM> are implemented in the PED <NUM> in another way, such with a programmable hardware device, for example, where the PED <NUM> is a custom device for use with the light curtain <NUM>.

In some embodiments, the light intensity signals received by the light intensity receiver module <NUM> are in a different form than the light intensity signals received by the light intensity receiver <NUM> in the intensity apparatus <NUM>. For example, the light intensity signals received by the light intensity receiver <NUM> may be analog signals or digital signal where the light intensity signals received by the light intensity receiver module <NUM> may be data packets that represent the analog signals received by the light intensity receiver <NUM>. In other embodiments, the light intensity signals received by the light intensity receiver module <NUM> may be conditioned, proportioned, transformed or varied in some way to be compatible with the PED <NUM>.

The light intensity display module <NUM> displays the light intensity signals of the beam receivers or of groups of beam receivers in such a way that a user is able to ascertain which portion of the transmitter unit <NUM> and receiver unit <NUM> of the light curtain <NUM> are out of alignment, and in some embodiments, by how much the transmitter unit <NUM> and the receiver unit <NUM> are out of alignment. In some embodiments, the light intensity display module <NUM> changes the display of the light intensity signals fast enough to provide real time display of intensities of the light intensity signals.

In some embodiments, the light intensity display module <NUM> displays the light intensity indicators for each light intensity signal as indicated in <FIG>. The light intensity display module <NUM>, in various embodiments, displays the light intensity indicators for each light intensity signal using a graph, a list of light intensities, a bar chart, a representation of the receiver unit <NUM>, or other display capable of conveying an indication of beam alignment of the receiver unit <NUM> and the transmitter unit <NUM> of the light curtain <NUM>.

The apparatus <NUM> includes a safe module <NUM> configured to prevent the trip transmitter <NUM> of the light curtain <NUM> from transmitting the trip signal during a safe mode. In some examples, the safe module <NUM> sets the safe mode in response to a user instruction. For example, a user may set the safe mode while the transmitter unit <NUM> and the receiver unit <NUM> are being aligned, serviced, or the like. The safe module <NUM> is further configured to activate the light intensity transmitter <NUM> to transmit the plurality of light intensity signals during the safe mode. In one embodiment, the light intensity transmitter <NUM> does not transmit the plurality of light intensity signals when not in safe mode, for example, during an operation mode so that the light intensity transmitter <NUM> and the trip transmitter <NUM> operate simultaneously during the operation mode. In other embodiments, the light intensity transmitter <NUM> transmits the plurality light intensity signals in safe mode and when not in safe mode and the safe module <NUM> merely controls transmitting of the trip signal. In some embodiments, the light intensity transmitter <NUM> periodically transmits the plurality light intensity signals.

The intensity apparatus <NUM>, in some embodiments, includes a threshold module <NUM> configured to notify a user adjusting positioning of the transmitter unit <NUM> and/or the receiver unit <NUM> of a target threshold for each of the plurality of beam receivers <NUM> of the receiver unit <NUM>. The target threshold includes the trip threshold adjusted by an amount of light intensity degradation due to an expected amount of vibration at the transmitter unit <NUM> and/or the receiver unit <NUM>. The light intensity signals are affected to some degree by vibrations in the transmitter unit <NUM> and the receiver unit <NUM>. For example, vibration of the transmitter unit <NUM> causes movement of the beam transmitters <NUM>, which affects the beams of light <NUM> transmitted by the beam transmitters <NUM>.

In some cases, the vibrations may be severe enough so that the beam of light <NUM> transmitted by a beam transmitter <NUM> moves from an aligned position to a position where no light of the beam of light <NUM> is received by the corresponded beam receiver <NUM>. The frequency of the vibration may then cause the beam of light <NUM> to shine on the corresponding beam receiver <NUM> only a percentage of the time, which will affect light intensity sensed by the beam receiver <NUM>. In less extreme situations, the vibrations may only partially misalign the beam of light <NUM> with the beam receiver <NUM>, which would cause less light intensity degradation. If the vibration frequency is low enough, a temporary misalignment of the beam of light <NUM> may cause the light intensity signal from the beam receiver <NUM> to drop below the trip threshold.

In other situations, vibration at the receiver unit <NUM> causes movement of the beam receivers <NUM>, which may also cause some degradation of the light intensity signal from the beam receivers <NUM>. The threshold module <NUM> accounts for the degradation of the light intensity signals of the beam receivers <NUM> during alignment. For example, on a light intensity scale from <NUM> to <NUM>, the trip threshold may be set to <NUM> and an expected amount of light intensity degradation may be <NUM> so that alignment of the transmitter unit <NUM> and the receiver unit <NUM> should be such that the plurality of light intensity signals should be above <NUM>. Typically, alignment should include a safety margin of light intensity above the trip threshold. Where the safety margin is <NUM> and the threshold module <NUM> setting the target threshold at <NUM>, a user would continue to align the light curtain <NUM> until the light intensity signals are above <NUM>. Over time, the beam transmitters <NUM> and the beam receivers <NUM> may degrade due to age, use, etc. Having a safety margin allows for the degradation.

In some embodiments, light intensity signals transmitted by the light intensity transmitter <NUM> of the intensity apparatus <NUM> may be used to track degradation of the beam transmitters <NUM> and the beam receivers <NUM>. In some embodiments, the threshold module <NUM> may indicate that the light intensity degradation is too high for alignment so the user may need to take steps to dampen vibrations at the light curtain <NUM>. In some embodiments, the threshold module <NUM> receives an amount of light intensity degradation from a user. For example, a user may measure vibration at the light curtain <NUM> and may calculate and amount of expected light intensity degradation.

In some embodiments, the intensity apparatus <NUM> includes an attenuation calculator <NUM> configured to determine the amount of light intensity degradation for each of the plurality of beam receivers <NUM> due to vibration of the light curtain <NUM>. In some embodiments, the attenuation calculator <NUM> correlates vibration amplitude and/or vibration frequency with light intensity degradation and determines the amount of light intensity degradation from an expected amount of vibration and/or measured vibration at the light curtain <NUM>. In some embodiments, the attenuation calculator <NUM> is configured to determine the amount of light intensity degradation based on light intensity signals from the light intensity receiver <NUM> and operational data of equipment near the light curtain <NUM> causing vibrations to the light curtain <NUM>.

In other embodiments, the light curtain <NUM> includes one or more vibration sensors <NUM>. In some examples, the light curtain <NUM> includes a vibration sensor <NUM> in or at the transmitter unit <NUM>. In other embodiments, the light curtain <NUM> includes a vibration sensor <NUM> in or at the receiver unit <NUM>. In some embodiments, the attenuation calculator <NUM> is configured to use sensed vibration in the transmitter unit <NUM> and/or in the receiver unit <NUM> to determine the amount of light intensity degradation for each of the plurality of beam receivers <NUM> due to vibration of the light curtain <NUM>. For example, the sensed vibration may be from the vibration sensor(s) <NUM>. In some embodiments, the attenuation calculator <NUM> uses light intensity signal strength during periods of little or no vibration, maybe during shutdown of equipment around the light curtain <NUM>, and light intensity signal strength during periods of measured vibration to determine the light intensity degradation.

In some embodiments, the intensity apparatus <NUM> includes a vibration learning module <NUM> configured to use vibration data and light intensity signal data for transmitter units <NUM> and receiver units <NUM> of a plurality of light curtains <NUM> to determine a relationship between vibration and light intensity degradation. In some embodiments, the attenuation calculator is configured to use the relationship determined by the vibration learning module <NUM> to determine the amount of light intensity degradation based on the vibration of the light curtain <NUM>. In some examples, the vibration learning module <NUM> uses machine learning to derive relationships between vibration data and light intensity degradation.

For instance, the vibration learning module <NUM> may use measured light intensity during periods where vibration is low or non-existent, perhaps during a period where the industrial operation and/or the industrial equipment <NUM> is shut down, and may use measured light intensity during periods of vibration, maybe when equipment around the light curtain <NUM> is operating, to determine an amount of light intensity degradation. The vibration learning module <NUM>, in some examples, correlates various vibration intensities and/or vibrational frequencies with corresponding measured light intensity degradation to derive a correlation between vibration information and light intensity degradation. One of skill in the art will recognize other ways for the vibration learning module <NUM> to use vibration data and light intensity signal data to determine a relationship between vibration and light intensity degradation.

<FIG> is a flowchart diagram of a method <NUM> for light curtain beam alignment according to an embodiment. The method <NUM> begins and receives <NUM> a plurality of light intensity signals where each light intensity signal is from one or more beam receivers <NUM> of a plurality of beam receivers <NUM> of a light curtain <NUM>. The light curtain <NUM> includes a transmitter unit <NUM> that includes a plurality of beam transmitters <NUM> arranged linearly on the transmitter unit <NUM>. Each beam transmitter <NUM> is configured to transmit a narrow beam of light <NUM>. The light curtain <NUM> includes a receiver unit <NUM> that includes the plurality of beam receivers <NUM> arranged linearly. Each beam receiver <NUM> is configured to receive light from a corresponding beam transmitter <NUM> of the plurality of beam transmitters <NUM>. The method <NUM> transmits <NUM> from the light curtain <NUM> the plurality of light intensity signals.

In some embodiments, the method <NUM> determines <NUM> if a light intensity signal from a beam receiver <NUM> is below a trip threshold. If the method <NUM> determines <NUM> that no light intensity signal from a beam receiver <NUM> is below the trip threshold, the method <NUM> returns and receives <NUM> the plurality of light intensity signals. If the method <NUM> determines <NUM> that any one of the light intensity signals from a beam receiver <NUM> is below the trip threshold, the method <NUM> transmits <NUM> a trip signal, and the method <NUM> ends. In various embodiments, the method <NUM> is implemented using one or more of the light intensity receiver <NUM>, the light intensity transmitter <NUM>, the grouping circuit <NUM> and the trip transmitter <NUM>.

<FIG> is a flowchart diagram of a method <NUM> for light curtain beam alignment using a portable electronic device according to an embodiment. The method <NUM> begins and receives <NUM>, at a PED <NUM>, the plurality of light intensity signals and displays <NUM> a light intensity indicator for each light intensity signal and a relative position of the one or more beam receivers <NUM> associated with each light intensity signal. The light intensity indicators for each light intensity signal and corresponding positions of the one or more beam receivers provide an indication of beam alignment.

The method <NUM>, in some embodiments, determines <NUM> if the transmitter unit <NUM> and the receiver unit <NUM> are aligned. If the method <NUM> determines <NUM> that the transmitter unit <NUM> and the receiver unit <NUM> are not aligned, the method <NUM> directs a user to adjust <NUM> the transmitter unit <NUM> and/or the receiver unit <NUM>. For example, the method <NUM> directs a user to adjust <NUM> the transmitter unit <NUM> and/or the receiver unit <NUM> by displaying that some of the light intensity signals are below a desired amount. If the method <NUM> determines <NUM> that the transmitter unit <NUM> and the receiver unit <NUM> are aligned, the method <NUM> ends. In various embodiments, the method <NUM> is implemented using one or both of the light intensity receiver module <NUM> and the light intensity display module <NUM>.

<FIG> is a flowchart diagram of a method <NUM> for light curtain beam alignment with vibration data according to an embodiment. The method <NUM> begins and receives <NUM> a plurality of light intensity signals where each light intensity signal is from one or more beam receivers <NUM> of a plurality of beam receivers <NUM> of a light curtain <NUM>. The light curtain <NUM> includes a transmitter unit <NUM> that includes a plurality of beam transmitters <NUM> arranged linearly on the transmitter unit <NUM>. Each beam transmitter <NUM> is configured to transmit a narrow beam of light <NUM>. The light curtain <NUM> includes a receiver unit <NUM> that includes the plurality of beam receivers <NUM> arranged linearly. Each beam receiver <NUM> is configured to receive light from a corresponding beam transmitter <NUM> of the plurality of beam transmitters <NUM>. The method <NUM> transmits <NUM> from the light curtain <NUM> the plurality of light intensity signals.

The method <NUM> determines <NUM> if the light curtain <NUM> is in a safe mode. If the method <NUM> determines <NUM> that the light curtain <NUM> is not in a safe mode, the method <NUM> returns and receives <NUM> a plurality of light intensity signals. If the method <NUM> determines <NUM> that the light curtain <NUM> is in a safe mode, the method <NUM> determines <NUM> if a light intensity signal from a beam receiver <NUM> is below a trip threshold. If the method <NUM> determines <NUM> that no light intensity signal from a beam receiver <NUM> is below the trip threshold, the method <NUM> returns and receives <NUM> the plurality of light intensity signals. If the method <NUM> determines <NUM> that any one of the light intensity signals from a beam receiver <NUM> is below the trip threshold, the method <NUM> transmits <NUM> a trip signal, and the method <NUM> ends.

The method <NUM> measures <NUM> vibration at the light curtain <NUM>, for example, using the vibration sensors <NUM>, and determines <NUM> an amount of light intensity degradation due to the measured vibration. In some embodiments, the method <NUM> uses information from the vibration learning module <NUM> to determine <NUM> the amount of light intensity degradation. The method <NUM> determines <NUM> if an light intensity from the plurality of light intensity signals from the beam receivers <NUM> minus the amount of light intensity degradation is below a trip threshold. In some embodiments, the method <NUM> includes an additional safety margin with the light intensity degradation.

If the method <NUM> determines <NUM> that an light intensity from the plurality of light intensity signals from the beam receivers <NUM> minus the amount of light intensity degradation is below a trip threshold, the method <NUM> signals <NUM> a user to adjust alignment of the transmitter unit <NUM> and/or receiver unit <NUM>, for example, by displaying light intensity information, light intensity degradation, a safety margin, a trip threshold, etc. on the PED <NUM>. If the method <NUM> determines <NUM> that an light intensity from the plurality of light intensity signals from the beam receivers <NUM> minus the amount of light intensity degradation is not below a trip threshold, the method <NUM> ends. In various embodiments, the method <NUM> is implemented using one or more of the light intensity receiver <NUM>, the light intensity transmitter <NUM>, the grouping circuit <NUM>, the trip transmitter <NUM>, the light intensity receiver module <NUM>, the light intensity display module <NUM>, the safe module <NUM>, the threshold module <NUM>, the attenuation calculator <NUM> and the vibration learning module <NUM>.

<FIG> is a flowchart diagram of a method <NUM> for correlating light intensity data for a plurality of light curtains <NUM> with vibration data from the light curtains <NUM> for use in beam alignment of a light curtain <NUM> according to an embodiment. The method <NUM> begins and receives <NUM> a plurality of light intensity signal data from beam receivers <NUM> of light curtains <NUM> and receives <NUM> corresponding vibration information from the light curtains <NUM>. The method <NUM> correlates <NUM> vibration levels with light intensity levels from the beam receivers <NUM> and uses <NUM> the correlation for light curtain alignment. The method <NUM> returns and continues to receive <NUM> additional light intensity signal data from beam receivers <NUM> of the same or additional light curtains <NUM> and receives <NUM> corresponding vibration information from the light curtains <NUM>. In various embodiments, the method <NUM> is implemented using one or more of light intensity receivers <NUM>, light intensity transmitters <NUM>, grouping circuits <NUM>, and the attenuation calculators <NUM> from various light curtains <NUM> and the vibration learning module <NUM>.

Claim 1:
A component comprising:
a light intensity receiver (<NUM>) configured to receive a plurality of light intensity signals from a plurality of beam receivers (<NUM>) of a receiver unit (<NUM>) of a light curtain (<NUM>), the light curtain comprising:
a transmitter unit (<NUM>) comprising a plurality of beam transmitters (<NUM>) arranged linearly on the transmitter unit, each beam transmitter configured to transmit a narrow beam of light; and
the receiver unit comprising the plurality of beam receivers arranged linearly, each beam receiver configured to receive light from a corresponding beam transmitter of the plurality of beam transmitters;
a light intensity transmitter (<NUM>) configured to transmit, from the light curtain, the plurality of light intensity signals received by the light intensity receiver, each light intensity signal from one or more beam receivers of the plurality of beam receivers;
a trip transmitter (<NUM>) configured to transmit a trip signal in response to determining that a light intensity signal from a beam receiver of the plurality of beam receivers is below a trip threshold; and
characterized that the component further comprises:
a safe module (<NUM>) configured to activate the light intensity transmitter to transmit the plurality of light intensity signals during a safe mode and to prevent the trip transmitter from transmitting the trip signal during the safe mode.