WO2008013515A2 - Elevator system including an ultra wideband device - Google Patents

Abstract

An elevator system incorporates ultra wideband (UWB) technology to monitor and control characteristics and features of an elevator system, sense elevator occupants, and elevator user input. UWB sensors are disposed in communication with an elevator car for purposes of communicating data and commands from the sensor to a local or remote processor for purposes of analysis. Alternatively, UWB sensors are used to communicate commands to an elevator car, car driving mechanism, car control system, or other destination. In one embodiment, UWB sensors may be disposed in close proximity with elevator car doors to detect the presence of people and objects therebetween. Occupancy sensors may be positioned in the floor, ceiling or walls of the elevator car to sense car occupancy. UWB sensors may also be implemented in close proximity with elevator call buttons to track passengers approaching an elevator call button or bank of elevators. UWB sensors in another embodiment may be used to detect and track the location of an elevator car within the hoistway.

Description

ELEVATOR SYSTEM INCLUDING AN ULTRA WIDEBAND DEVICE

Randolph W. Huff

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent

Application Serial No. 60/681,100, entitled ELEVATOR SYSTEM INCLUDING AN ULTRA WIDEBAND DEVICE, filed on May 13, 2005, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The term "ultra wideband" (UWB) is a relatively new term often used to describe a technology which has been known as "carrier-free," "baseband," or "impulse" technology. The basic concept is to develop, transmit and receive an short duration burst of radio frequency (RF) energy - such as a few tens of picoseconds (trillionths of a second) to a few nanoseconds (billionths of a second) in duration. These bursts represent from one to a few cycles of an RF carrier wave. The resultant waveforms may be broadband, so much so that it may be difficult to determine an actual RF center frequency - thus, the term "carrier-free." Some early methods of signal generation utilized "baseband" (e.g., non-RF), fast rise-time pulse excitation of a wideband microwave antenna to generate and radiate the antenna's effective "impulse" or "step" response. Some UWB systems no longer utilize direct impulse excitation of an antenna because such an approach may present an inability to adequately control emission bandwidths and apparent center frequencies.

[0003] Since UWB waveforms are typically of such relatively short time duration, they may provide some rather unique properties. hi communications, for example, UWB pulses may be used to provide high data rate performance in multi-user network applications. For radar applications, these same pulses may provide very fine range resolution and precision distance and/or positioning measurement capabilities. For instance, multifunction architectures encompassing communications, radar and positioning applications have been developed.

[0004] These short duration waveforms may be relatively immune to multipath cancellation effects as observed in mobile and in-building environments. Multipath cancellation occurs when a strong reflected wave - e.g., off of a wall, ceiling, vehicle, building, etc. - arrives partially or totally out of phase with the direct path signal, causing a reduced amplitude response in the receiver. With very short pulses, the direct path may have come and gone before the reflected path arrives, such that no cancellation occurs. As a consequence, UWB systems may be particularly well suited for high-speed, mobile wireless applications. In addition, because of the short duration waveforms, packet burst and time division multiple access (TDMA) protocols for multi-user communications may be readily implemented.

[0005] As bandwidth is inversely related to pulse duration, the spectral extent of these waveforms may be made quite large. The resultant energy densities (i.e., transmitted Watts of power per unit Hertz of bandwidth) may be quite low. This low energy density may translate into a low probability of detection (LPD) RF signature. An LPD signature may be of particular interest for military applications (e.g., for covert communications and radar) or other applications; however, an LPD signature may also produce minimal interference to proximity systems and minimal RF health hazards, which may be significant for military, commercial, and other applications. [0006] Other advantages of UWB technology may include low system complexity and low cost. UWB systems may be made nearly "all- digital," with minimal RP or microwave electronics. Because of the typical RF simplicity of UWB designs, these systems may be highly frequency adaptive, enabling them to be positioned anywhere within the RF spectrum. This feature may avoid interference to existing services, while fully utilizing the available spectrum.

[0007] UWB receiver technology may permit the ability to detect single pulses of UWB energy with high sensitivity and in the presence of high interference and in-band interferers. A single-pulse detection capability may be advantageous for high-speed (multiple Mb/s), mobile wireless applications. Single-pulse detection may also allow for a significant reduction in transmitted power, with resultant reduction in interference potential to other systems. UWB detectors may also provide the ability to respond to the leading edge of a UWB pulse, enabling applications for precision positioning and geolocation for in-building, high multipath environments.

[0008] UWB transmitter design may provide for frequency adaptive, bandwidth adaptive architectures. These architectures may enable the development of UWB systems which can coexist with existing spectral users without mutual interference, and which minimize the peak and average power levels required for reliable communications. However, some designs may utilize direct impulse excitation of an antenna, which may result in the generation of large amounts of unwanted, out- of-band radiation that may result in harmful interference.

[0009] The following is a listing of but a few exemplary applications of UWB technology:

Tactical Handheld & Network LPI/D Radios Non-LOS LPI/D Groundwave Communications LPI/D Altimeter/Obstacle Avoidance Radar

Military Tags (Facility and personnel security, logistics)

Military Intrusion Detection Radars

Military Precision Geolocation Systems

Unmanned Aerial Vehicle (UAV) and Unmanned Ground Vehicle

(UGV) Datalinks

Proximity Fuses

LPI/D Wireless Intercom Systems

High Speed (20+ Mb/s) LAN/WANs

Altimeter/Obstacle Avoidance Radars (e.g., commercial aviation)

Collision Avoidance Sensors

Commercial Tags (e.g., Intelligent Transportation Systems, Electronic

Signs, Smart Appliances) Commercial Intrusion Detection Radars Commercial Precision Geolocation Systems Industrial RF Monitoring Systems Exemplary radar applications for UWB technology include, but are not limited to, the following:

Ultra-Low Power Short Range Miniature Radar on a single Chip

(ASIC) for <$ 10

Radar Imaging of People and Objects "Through the Wall" Collision Avoidance Radar for Automobiles, Space Vehicle Docking

& Aircraft Ground Traffic Proximity Sensors - Advantages over Ultrasonic, Infrared, and Doppler such as less susceptible to interference, ability to pass through materials such as concrete, etc. Motion Sensors Altimeters Fluid Level Sensors [0011] Exemplary smart tag tracking device applications for UWB technology include, but are not limited to, the following:

Inventory Tracking RFID Applications Indoor 3D Positioning Systems Personnel Tracking/Locators Sensor Networks

[0012] Exemplary communications applications for UWB technology include, but are not limited to, the following:

Ad Hoc Mesh Networking Wireless Communications through building walls Low Probability of Intercept/Detection Radio Communications Dual Use Systems for Radar and Communications High Bandwidth - Low Cost Data Communications PAN - Personal Area Networks to replace USB & Bluetooth with High Bandwidth short range digital communications.

[0013] As will become apparent from the discussion below, UWB may provide the following properties:

Relatively difficult to detect

Non-interfering with other systems

High multipath immunity in building interior environments

Material Penetration Properties - Concrete, Drywall, etc.

Material Identification Properties - UWB radar does not use Doppler

Effect, Wave Form is altered by object position and density Frequency and bandwidth adaptive Common architecture for communications Radar & positioning (software re-definable) Low Power Consumption, can run a 2 AA batteries for a year Low cost & nearly "all-digital" architectures with minimal RF Components [0014] It should be noted that UWB is an RF technology and has the potential, as does any RF technology, to interfere with existing systems in certain situations. Furthermore, there are several ways in which UWB emissions can be generated. Some of these techniques may be more prone to generate harmful interference effects than are others. For example, UWB systems that utilize direct impulse excitation of an antenna may produce energy that is spread over a spectral extent significantly greater than the design bandwidth of the antenna. (For design bandwidth, one may select a VSWR bandwidth — e.g., frequency extent for which the voltage standing wave ratio is less than some number, such as 2:1; or a radiation bandwidth which represents the frequency extent over which the main lobe of the antenna pattern remains within certain bounds, such as -3 dB from its peak value.)

[0015] Some techniques create a UWB waveform through pulse shaping prior to transmission from an antenna. These techniques may provide an advantage of being controllable, both in frequency and bandwidth; and may be made to operate outside of restricted bands such as those reserved for GPS and safety of life systems.

[0016] Other aspects of UWB design that may impact interference potential include pulse duty cycle and modulation strategy. Typically, the higher the pulse duty cycle, the greater the average amount of energy is transmitted. In some UWB schemes, multiple pulses may be transmitted per single bit of information. This may produce effect of further increasing the total amount of energy transmitted, or forcing the designer to accept a much lower data rate for a given average energy. hi addition, a high pulse repetition frequency (PRF) with minimal interpulse dithering may have the effect of further concentrating this energy into a set of spectral lines. When a spectral line falls into the passband of a sensitive receiver (e.g., GPS), interference may result, even though the "bandwidth" of the waveform may extend over hundreds of megahertz.

[0017] In "baseband" architectures (i.e., those relying upon direct impulse excitation of an antenna), the corresponding receiver front end is typically left wide open, with RF filtering performed only by the receive antenna itself. The antenna by itself may provide little or no filtering of "out-of-band" signals and noise. For this reason, some of these systems may incorporate additional lowpass or bandpass filtering prior to the receiver amplifier/detector stages. However, while helping to remove interference, this additional receive filtering may also remove energy from the desired signal. Such "baseband" systems may also be prone to generate interference with other receivers.

[0018] "Correlating" receivers, in which the received waveform is essentially template-matched with a local replica of the transmitted waveform, may also have little immunity to broadband noise or impulsive interference. This may be due to the fact that any impulse or white Gaussian noise excitation of the wideband receiver front end may produce a received waveform having characteristics very similar to those of the transmitted waveform. A strong in-band continuous wave (CW) interferer may similarly create havoc with such receiver architectures by simply overloading the detector.

[0019] Time-gated correlating receivers, in which the correlation operation may be gated to the pulse duration and synchronized to the incoming bit stream, may be quite effective in reducing the effects of in-band interference in UWB receiver architectures. A UWB detector and receiver processor may utilize this process or a variant thereof in which additional immunity to strong in-band CW interferers may be achieved through a modified constant false alarm rate (CFAR) algorithm. In some detectors, matched filter processing may be achieved directly at RF through the use of the integration properties of a gated quantum tunneling device. A tunnel diode is known as a relatively sensitive device for the detection of weak energy, such as subnanosecond signals.

[0020] Unlike some spread spectrum waveforms (whether direct sequence

DSSS or frequency hopping FHSS), the spread bandwidth for some UWB waveforms is generated directly, i.e., without individual bit modulation by a separate spreading sequence such as a PN code or hopping (chipping) pattern. Thus, UWB may be essentially a time- domain concept in which a short RF pulse directly generates a wide instantaneous bandwidth signal because of the time-scaling properties of the Fourier transform relationship between time/and frequency F:

/(at) ^ M-I

[0021] In addition, DSSS or FHSS waveforms are typically constant envelope in nature. That is, their instantaneous amplitude may not change with time. For a DSSS waveform, individual transmission bits may be further subdivided into biphase-modulated chipping intervals; while for FHSS, individual transmission bits may be further subdivided into distinct frequency changes. As a consequence, spread spectrum waveforms may have unity (100%) duty cycle - i.e., peak and average power levels are equal. With UWB, on the other hand, pulse durations may be quite short relative to pulse interarrival times. Thus, waveform duty cycles may be typically small fractions of a percent, and peak-to- average ratios may be quite large.

[0022] From a communications perspective, the performances of both types of systems (whether spread spectrum or UWB) may be determined by the effective energy per bit to noise spectral density ratio Eb/No. As No = kTeB, where k is Boltzmann's constant, Te is the effective system noise temperature and B is the instantaneous bandwidth, it is apparent that the wider the bandwidth, the more energy is needed for communications. For a UWB system, Eb = PT with P the peak pulse power and T the effective pulse duration. Thus, the shorter the pulse, the higher the necessary peak power for a given bit error rate (BER) performance. For a spread spectrum waveform, Eb is also given by PT; where T represents the bit duration (i.e., NTc where N is the so- called processing gain and Tc is the chip duration.) It may be shown that for equivalent average power levels, both spread spectrum and UWB have equivalent BER performance.

[0023] However, there are some very important advantages of UWB over spread spectrum. These may include, but are not limited to, (a) significantly lower implementation complexity and cost for relatively high bandwidths - and, thus, high data throughputs; (b) independence of BER performance with change in data rates — for a constant envelope waveform, a doubling of the data rate requires a doubling of the peak and average power; and (c) practically realizable designs for mobile multipath immunity and dual use (e.g., radar & communications) applications.

[0024] In the context of radar, it will be appreciated that some conventional radar systems typically use beamed and reflected single-frequency (narrowband) electromagnetic energy in the microwave frequency range to detect, locate, and track objects. Such conventional systems may send out continuous waves in bursts. Some conventional radar systems may step through multiple (wideband) frequencies to obtain more information about a scene. A UWB radar system (also known as micropower impulse radar) or other UWB sensor system may use relatively short electromagnetic pulses that contain energy over a relatively wide band of frequencies, and may detect objects at a shorter range than some conventional radar systems, thereby providing greater resolution, hi some UWB radar systems, as the pulse is shortened, the band is wider, thereby providing more information about reflected objects. A UWB device may thus provide precise, vector-based information about an object's location and/or structural features or other features.

[0025] In addition, by using a short pulse (e.g., on the order of a subnanosecond), a signal may be generated using relatively little power. That is, the system may be configured such that current is drawn only during the short time the system is pulsed, such that power requirements are on the order of microamperes. By way of example only, a UWB radar system may be provided that operates for several years on the same pair of AA batteries.

[0026] The components of a UWB radar system may comprise a transmitter with a pulse generator, a receiver with a pulse detector, timing circuitry, a signal processor, and antennas. By way of example only, a UWB transmitter may emit rapid, wideband radar pulses at a nominal rate of 2 million per second. This rate may be intentionally randomized by a noise circuit. The components comprising a transmitter may send out shortened and sharpened electrical pulses with rise times as short as 50 trillionths of a second (50 picoseconds). A receiver, which may use a pulse-detector circuit, may be configured such that it only accepts echoes from objects within a preset distance (round-trip delay time) - such as from a few centimeters to many tens of meters.

[0027] UWB radar systems may provide a range on the order of 50 meters, by way of example only. With an omnidirectional antenna, a UWB radar system may look for echoes in an invisible radar bubble of adjustable radius surrounding the unit. Directional antennas may be used to aim pulses in a specific direction and add gain to the signals. Transmitter and receiver antennas may be separated to establish an electronic "trip- line," such that targets, intruders, or other people or objects crossing the line may trigger an event, such as an alarm or other signal.

[0028] To the extent that using short, low-power pulses results in less energy being measured on UWB radar returns, many pulses may be transmitted rapidly, and all returns may be averaged. As stated above, using short pulses across a wide band of frequencies may provide relatively high resolution and accuracy. A UWB radar system may also be less susceptible to interference from other radars. In addition, microwave power associated with pulsed transmission of UWB radar may be relatively low (e.g., averaging tens of microwatts), such that a UWB radar is medically safe. Indeed, a UWB radar may be made such that it emits less than one-millionth the power of a cellular telephone.

[0029] UWB motion sensors may employ a range gating technique in capturing return signals. Under this technique, the UWB device may sample only those signals occurring in a narrow time window after each transmitted pulse, providing a range gate. If a delay time is chosen after each transmitted pulse corresponding to a range in space, a receiver "gate" may be opened after that delay and closed an instant later. Such gating may reduce the likelihood of receiving unwanted signals. A UWB receiver may be configured such that it measures only one delay time or range gate per transmitted pulse. Sensors may operate by starting at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A system may be configured such that only return pulses within a small range gate - corresponding to a fixed distance from device to target — are measured. A system may also be configured such that the gate width (the sampling time) is fixed based on the length of the pulse, while the delay time (the range) is adjustable, as is the detection sensitivity. Averaging thousands of pulses may improve the signal-to-noise ratio for a single measurement, whereby noise is reduced and sensitivity increased. A selected threshold on an averaged signal may sense motion and trigger a switch or event, such as an alarm or signal. Changes in an averaged sampling gate output may represent changes in the radar reflectivity at a particular range, and thus motion. Of course, motion may also be tracked with a UWB system.

[0030] As previously discussed, a noise source may be intentionally added to the timing circuitry of a UWB radar system such that the amount of time between pulses varies around 2 MHz. Such ramdomization of the pulse repetition rate, and averaging thousands of samples at those random times, may be desirable for several reasons. First, interference from radio and/or TV station harmonics may otherwise trigger false alarms. With randomizing, interference may be effectively averaged to zero. Second, multiple UWB units may be activated in one vicinity without interfering with each other if the operation of each unit is randomly coded and unique. In other words, each unit may create a pattern that is recognizable only by the originating unit. Interference among an array of UWB sensors may also be reduced or prevented through time division multiplexing. Third, randomizing may spread the sensor's emission spectrum such that the UWB signals resemble background noise, which may be difficult for other sensors to detect. Emissions from UWB sensor may be virtually undetectable with a conventional RF receiver and antenna only 3 m away. Other advantages of randomized pulse repetition will be apparent to those of ordinary skill in the art.

[0031] A UWB sensor device may cycle through several range gates. The delay time may be swept, or varied, slowly with each pulse (e.g., about 40 sweeps per second) to effectively fill in a detection bubble with a continuous trace of radar information. In other words, samples may be taken at different times or different distances away from the device. The result may be an "equivalent-time" record of all return pulses that may be correlated to object distance. An equivalent-time echo pattern may be displayed on an oscilloscope or read into a computer.

[0032] Equivalent-time sampling may also be used to form images by moving a rangefinder in front of a target area or by using a stationary array of rangefmders. A vertical trace may be provided as a return signal from a different position along a target area. Many individual vertical views into the target area may be stacked side-by-side, permitting reconstruction of a cross section of the target area in a model. An image-reconstruction algorithm may be used to resolve the locations of objects in a target area. Using such techniques, a full 3-D view or model of the target area may be rendered. By way of example only, these techniques may be used to inspect a concrete floor, by providing a view of rebar, conduit, etc. buried within the concrete.

[0033] UWB systems may also be capable of penetrating or "seeing through" a variety of materials, including but not limited to rubber, glass, water, ice, mud, concrete, plastics, wood, walls, concrete, human tissue, etc. Such an ability to penetrate may permit a UWB device to be easily concealed. Penetrability of UWB signals through a given material may be a function of the material's electrical conductivity. For instance, a UWB device may have greater difficulty penetrating thick metal than it will penetrating concrete.

[0034] Additional advantages of UWB technology may include a sharply defined and adjustable range of operation and/or adjustable sensitivity, which may reduce false reads or alarms. Several units may be operated simultaneously without interference among the units. With randomized emissions, a UWB device may be difficult to detect. A UWB device may also be configured to not produce interference effects on other devices, including other UWB devices and non-UWB devices. As a sensor technology, UWB may provide motion detection or proximity, distance measurement, microwave image formation, communications, or a variety of other applications. A UWB sensor may be less susceptible to adverse effects produced by temperature, light, weather, electromagnetic interference, or other environmental conditions when compared to other sensor technologies.

[0035] UWB signals may also be sent along a wire or other solid conduit. For instance, an "electronic dipstick" may be provided by sending a UWB signal along a metal wire to measure transit time of reflected electromagnetic pulses from the top of the dipstick down to a liquid surface.

[0036] An exemplary use for UWB devices (a touch-less switch for turning a faucet on and off) is disclosed in U.S. Patent Application Publication No. 2002/0171056, the disclosure of which is incorporated by reference herein.

[0037] An exemplary UWB device is the XSIlO, provided by Freescale

Semiconductor, Inc. of Austin, Texas. Freescale's XSI lO Ultra- Wideband (UWB) solution may provide full wireless connectivity implementing direct sequence ultra- wideband (DS-UWB) and the IEEE® 802.15.3 media access control (MAC) protocol. The chipset may deliver more than 110 Mbps data transfer rate supporting applications such as streaming video, streaming audio, and high-rate data transfer at relatively low levels of power consumption. In addition to high data rates, the XSl 10 may support peer-to-peer as well as ad hoc networking for mobile wireless connectivity. The XSIlO includes an RF front-end and transceiver chip integrating a low noise amplifier (LNA) having both high gain (20 dB) and low gain (0 dB) settings and a high gain noise figure of 5.6 dB, with an RF transceiver that creates a UWB signal through a transistor-based pulse, forming a network operating at baseband speed. The XSI lO also includes a baseband processor chip integrating UWB baseband and analog to digital converter (ADC) functions with multiple Forward Error Correction (FEC) options, fast acquisition and agile tracking. The XSIlO also includes a single-chip medium access controller supporting streaming media applications based on the emerging TDMA-based IEEE 802.15.3 protocol. In addition, the XSIlO has an antenna that is a 1" x 1" flat planar design etched on a single metal layer of common FR4 circuit board material. Other features of the XSIlO include the following: data rates of 29, 57, 86 and 114 Mbps; support for IEEE 802.15.3 streaming media protocol; enables wire-like high definition video applications; 750 mW ~ 3.3V power consumption; co-exists with IEEE 802.1 lb/a/g, Bluetooth™ technology, global positioning system (GPS) and all United States-based wireless systems; built using low- cost 0.18 μm CMOS and SiGe technology.

Another exemplary use for UWB technology includes UWB

Localizers. Localizers may be strategically placed make a wireless network of signposts. Localizers may also be used to find people in a variety of situations, including: fire fighters in a burning building, police officers in distress, injured skier on a ski slope, hikers injured in a remote area, or children lost in the mall or amusement park, etc.. Combining Localizers with home appliances such as TV's, ovens, lamps, etc. may make possible smart homes that activate the correct appliance by knowing both the location of the various residents and the location of various home times with respect to those residents. Ordinary household control functions may be automated such as keyless locks that open when the owner reaches for the handle, or rooms that adjust the light, temperature, and music sound level per an individual's profile as that individual approaches the room. Localizers may also be used to find personal items, such as one's pets, car purse, luggage, etc. Localizers may give real-time inventory tracking, such as by being placed on or in retail items. Localizers linking with a system may give updated information on purchase patterns and stocking levels. Unlike some RFED inventory systems, Localizers may create a virtual boundary so that the contents of one container can be differentiated from that of a nearby one.

[0039] Localizers are enabling technology for wireless "finest grained" networking of ubiquitous mobile Internet devices. The Next Generation Internet may fill consumers' homes and businesses with cybernetic servants in the guise of everyday things. Their job may be to interpret and respond to consumers' needs, and to do so in the least intrusive way. They may mediate human interaction with the Internet in a direct and intuitive manner using sensors and effectors distributed throughout the environment. To be ubiquitous and mobile, these "smart things" may be wireless and capable of determining precise relative position location.

ULTRA WIDEBAND DEVICES IN ELEVATOR SYSTEMS

[0040] UWB technology presents several opportunities for innovation in the field of elevator systems. In particular, and by way of example only, UWB technology may be used in the following elevator system applications: door edge detection systems; occupancy sensor systems; hall sensor or people tracking systems; touch-less fixtures or buttons; and car location systems. It will be appreciated, however, that in any or all of the following examples, a Doppler-based device may be used as an alternative to, supplement to, and/or variation of a UWB device.

[0041] General Use of UWB Devices in Elevator Systems

[0042] While several of the examples below relate to the use of UWB devices in elevator systems for purposes of detecting characteristics and features of an elevator system, elevator occupants, and elevator user input, it will be appreciated that UWB devices may be used to serve a variety of other purposes and functions within an elevator system. By way of example only, an elevator system may employ UWB for purposes of communicating data, commands, and the like. For instance, UWB may be used to communicate data from a sensor to a local or remote processor for purposes of analysis and/or logging. UWB may be used to communicate commands from a user input device to a local or remote processor for purposes of responding to the command and/or logging. UWB may also be used to communicate commands from a local or remote system to an elevator car, car driving mechanism, car control system, or other destination. The source of a transmission through UWB and/or the recipient of a transmission through UWB may be in an elevator car, on an elevator car, outside an elevator car, or at any other location, hi addition, the source and/or recipient may be a UWB device, a non-UWB device, or any other type of device, including combinations thereof. If desired, an elevator system may comprise a plurality of UWB relays to create a communications network. Such relays may be dedicated relays or may be part of devices that serve other purposes. In one embodiment, a plurality of UWB relays are positioned within an elevator shaft. Still other ways in which UWB may be used for communication purposes in the context of elevator systems will be apparent to those of ordinary skill in the art.

It will be appreciated that a UWB device, including a UWB communications device or network, may encounter difficulty with respect to signal penetration of materials possessing a relatively high electrical conductivity. By way of example only, where a UWB sensor is placed on the outside of a metal wall of an elevator car, and the sensor is configured to detect or measure something inside the elevator car, signals sent from or back to the sensor may be adversely affected by the metal wall. Where such effects need to be addressed or are otherwise undesired, the effects may be addressed by providing a "window" in the material that is adversely affecting passage of the UWB signal. For instance, and without limitation, an opening may be formed in the elevator car wall adjacent the sensor. The opening may be left open or filled with a material such as plastic or another material. Of course, in this example, such an opening need not extend completely through to the inside of the elevator car. If the interior wall of the car near the sensor comprises wood, the signal may pass through the wood without encountering significant adverse effects. The sensor may thus remain hidden from the view of occupants of the car. Still other ways in which "windows" may be incorporated to address any adverse effects encountered with materials having relatively high electrical conductivity will be apparent to those of ordinary skill in the art.

[0044] In some elevator system applications of UWB devices, it may be desirable to monitor an area that is larger than that which a single UWB device is configured to monitor or is capable of monitoring satisfactorily. In such a situation, the UWB device may be moveable, such as by a mounting the device to a track or other means for moving the UWB device. Alternatively, an array of UWB devices may be provided. Where an array of UWB devices are used, range-gating may reduce the likelihood of the devices of the array interfering with each other. As another alternative, the UWB device may be tuned or reconfigured to monitor the full area. It will be appreciated that such tuning may be dynamic, such as on a periodic, random, or manual basis. Still other ways to control the monitoring area of a UWB device or plurality of UWB devices will be apparent to those of ordinary skill in the art.

[0045] It will also be appreciated that, in any of the following examples discussing the use of a single UWB device or sensor, more than one UWB device or sensor may be used. Accordingly, as used herein, terms such as "UWB sensor," "UWB device," and variations thereof shall be read to include plurals. In addition, terms such as "UWB sensor," "UWB device," "UWB radar," and the like shall be read interchangeably. These same terms shall be read to include devices, processors, systems, and other structures that are coupled or in communication with a UWB device.

[0046] Door EdRe Detector

[0047] In one embodiment, a UWB sensor is used as a door edge detector for one or more elevator doors.

[0048] Some conventional elevator cars employ actuator mechanisms to detect the presence of people and objects between elevator doors when the doors are closing. Such actuators may provide an undesired result for . persons standing between the elevator doors of having components of the actuation mechanism come into contact with the person. Accordingly, it may be desirable to provide a detector that is operable to detect the presence of persons or objects between the doors of an elevator without the need for physical contact with the thing detected.

[0049] hi the present example, a UWB sensor is used to detect the presence of people and objects between the elevator doors, or people and objects near the edges of elevator doors, or people and objects traveling on a direction vector towards the door opening. In this embodiment, the UWB sensor communicates a signal (e.g., a "red light" signal) indicating the presence of such people and objects to a logic that is configured to prevent the doors from being closed in response to the signal. When persons or objects are no longer positioned between the doors, the UWB device ceases to send the signal, and the logic permits the doors to fully close. In yet another embodiment, the UWB sensor communicates a certain signal (e.g., a "green light" signal) only when no persons or objects are positioned between the doors or near the edges of the doors. In this embodiment, the UWB sensor is in communication with a logic that is configured to close the doors only when it is receiving this signal. This embodiment may distinguish between, for example, persons walking by an elevator door opening versus persons walking toward an elevator opening. Detection of object size and material, or any other consideration, may aid the decision whether to reopen a closing door or wait in an open state for a longer period of time. Such considerations may alternatively or additionally influence other decisions. Still other variations for employing a UWB device for door edge detection will be apparent to those of ordinary skill in the art.

[0050] Occupancy Sensor

[0051] In one embodiment, an occupancy sensor comprises a UWB device using volumetric load weighting. Some conventional load weighing devices measure the difference in weight of an empty car versus the weight of a car with passengers and objects loaded inside the car. It has been seen that, in some systems using such devices, a car may be loaded fully by volume before the maximum load weight has been reached. For example, a person carrying several large boxes may fill the space of a car without reaching the maximum carrying weight of the elevator car. A UWB radar may be used to gather 3-D information for use by a Volumetric Load Weighing processor in building a map or model of the internal space of the elevator car. The use of UWB radar may overcome some disadvantages of using cameras and machine vision processing to determine the volume capacity. Some conventional machine vision systems employ many techniques to attempt to overcome changing environmental issues which affect the image seen on cameras. UWB may not be susceptible to some variables such as changing reflectance, low light, soft light, hard light, debris on the floor, changing reflectance from moisture or waxing of floors, obstruction of a lens from moisture or dirt, or other variables.

[0052] In another embodiment, a UWB device is used to detect the number of occupants in an elevator car. The UWB device and/or a device in communication with the UWB device may be used to count and/or track the number of occupants in an elevator car. hi the case of an elevator being requested by a hall call to service a secured floor, a UWB device may ensure that an empty car is delivered to the secured floor, thereby avoiding sending persons without a security clearance on to a secured floor.

[0053] In one embodiment, one or more UWB sensors are positioned under the floor of an elevator car. The sensors are configured to detect the presence of occupants by detecting, e.g., feet, wheelchair wheels, or other indicia of occupant presence through the floor. The sensors, or a device in communication with the sensors, may include a logic or algorithm configured to differentiate between indicia of occupant presence and non-occupant objects (e.g., bags, boxes, etc.) on any suitable basis or bases. Such bases may include, but need not be limited to, size, shape, type of material, density, electrical conductivity, or any other property or feature of the detected object, including combinations thereof.

[0054] hi yet another embodiment, one or more UWB sensors are positioned in or above the ceiling of an elevator car. In this embodiment, the sensors are configured to detect the presence of occupants by detecting, e.g., heads of occupants, hi addition, or as an alternative, UWB sensors may be placed on, in, or outside the walls of the elevator car to detect occupant presence. Of course, UWB sensors may be positioned in any suitable location or plurality of locations on, in, or around an elevator car to detect occupant presence.

[0055] hi still another embodiment, one or more UWB sensors are configured to detect occupant presence by detecting or measuring biometrics of occupants. For instance, a UWB sensor may be configured to detect human heartbeats. The sensor may be configured to translate sensed heartbeat data into a number of occupants. As another example, a UWB sensor may be configured to detect respiration. The sensor may be configured to translate sensed respiration data into a number of occupants. Other biometric features and phenomena which a UWB sensor may be configured to detect for purposes of detecting, measuring, and/or monitoring occupant presence will be apparent to those of ordinary skill in the art.

[0056] In another embodiment, an occupancy sensor comprises a UWB device positioned in, on, or adjacent to the doors of an elevator car. In this embodiment, the UWB device detects people entering and leaving the car. By way of example only, such a device may comprise a UWB transmitter positioned at one side of the door, and a UWB receiver positioned at the other side of the door. The UWB device may thus comprise a "trip-line" type of configuration. Other ways in which a UWB device may be used or configured to measure occupancy as a function of persons entering and leaving the car will be apparent to those of ordinary skill in the art.

[0057] It will be appreciated that any of the foregoing occupancy sensor embodiments, including variations thereof, may be used in conjunction with other sensors. For instance a UWB-based occupancy sensor may be used in conjunction with a conventional weight sensors. Still other combinations may be used.

[0058] If desired, UWB sensors could provide a 2-D map or 3-D model of the contents of a car. Of course, where such modeling or rendering is desired, data obtained from the UWB sensors may be processed through an imaging program to produce a meaningful image. Suitable ways of obtaining and/or using occupancy data obtained at least n part with a UWB sensor will be apparent to those of ordinary skill in the art. [0059] Hall Sensor or People Tracking

[0060] In one embodiment, a hall sensor or people tracking device comprises a UWB device comprising a proximity sensor. The hall sensor or people tracking device is configured to count people along with direction vectors.

[0061] By way of example only, a UWB device or system may be configured such that the elevator system "knows" who is approaching an elevator. The system may command an elevator car to retrieve the person, and the car may know which floor the person wants to get to before the person boards the car. The person may thus be taken to their destination without having to touch any buttons or otherwise issue any commands. For instance, the system may reference a database, based on data identifying the person, indicating the floor that the approaching person works on, and issue a command to the elevator car to take the person to that floor. The system may recognize the person (i.e., detect the person's identity) based on the presence of a UWB Localizer or other device that is associated with the person (e.g., on a card carried by the person, etc.). Alternatively, the system may recognize the person on any other basis, or through any other means. The system may detect the presence of the person outside the elevator by detecting the Localizer. Alternatively, the system may detect the presence of the person outside the elevator by using a UWB motion sensor. Still other ways in which a person's presence and/or identity may be detected outside of the elevator or elsewhere will be apparent to those of ordinary skill in the art, as will ways in which data obtained through such detection may be used.

[0062] Of course, where an elevator system comprising a UWB device is configured to automatically take passengers to presumed destinations, each car may still have buttons or other means to permit the overriding of presumed destination commands, such as when an occupant desires to go to a floor they typically do not go to.

[0063] To the extent that Localizers are used in an elevator system, such

Localizers may be used to prevent or permit occupants to exit the elevator at certain floors. For instance, where certain floors have restricted access, Localizers may include data indicative of a given occupant's authorization to access that floor. Other ways in which Localizers or other manifestations of UWB technology may be used as security devices in the context of elevator systems will be apparent to those of ordinary skill in the art.

[0064] In another embodiment, a UWB sensor detects the presence of a person in a hallway or a person approaching an elevator. In response to such detection, the elevator system sends a car to retrieve the person at the corresponding floor. To the extent that a car is already positioned at the floor, the elevator system may open the doors for the person to enter the car. Of course, these embodiments are subject to numerous variations.

[0065] In another embodiment, a UWB sensor may be used to help dispatching by detecting the number of people behind a pressed or otherwise actuated/activated hall button. The dispatcher may assign the call to car(s) differently if one person is waiting versus a crowd of people waiting for one actuated/activated hall button.

[0066] In another embodiment, many elevators contain secure hall calls such as VIP service. A secure hall call entered by a primary person may be aided by a UWB sensor which may help prevent "Piggybacking" of the secured call by secondary persons. The hall sensor may see if one person is waiting for the secure call, and then may watch as the car is loaded for the secure call. If a secondary person follows the primary person onto the call, the UWB sensor may send a signal to deactivate the secured call.

[0067] Of course, these embodiments are subject to numerous variations.

[0068] Touch-less Fixtures or Buttons

[0069] Those of ordinary skill in the art will appreciate that it may be desirable to provide a fixture or button that may be operated by a user without the need for the user to physically touch the fixture or button. By way of example only, such touching may be undesirable where the acquisition of a virus or bacteria from the button is of concern. In one embodiment, a touch-less fixture or button comprises a UWB device configured to detect direction vector and size of objects.

[0070] A UWB radar may detect direction vector and size of objects, and may be useful in hospitals and public spaces where virus transmission is a concern or elsewhere. Material identification or other techniques may reduce false object detections. A miniature all digital UWB radar may be embedded inside an elevator push button. Multiple buttons such as up/down buttons may be operated with separate UWB radars in close proximity. By altering the beam characteristics, the button's radar can be narrowly focused to a cone directly in front of its button. The low cost and low power requirements may make this technology particularly suited to elevator applications. Some traditional touch-less switches and buttons have used technologies that struggle with inference from light, heat, water droplets, dirt, and other sources. UWB may be impervious to these types of interference. The addition of UWB communications may also serve as the buttons' communications device to a wireless transceiver inside the hoistway or located elsewhere. Some prior wireless transmitters were unable to penetrate building wall materials and required wiring to reach inside the elevator hoistway. The dual use of UWB as a radar and a communications device may reduce the button device to a combination proximity sensor and wireless communications device on the same silicon. A UWB localizer may be used in conjunction with UWB radar buttons to identify a person as the person's hand nears a button and unlock floor buttons on locked secured floors where the person should have access rights. Other ways in which UWB technology may be implemented in a touch-less fixture or button application will be apparent to those of ordinary skill in the art.

[0071] A UWB device utilizing a separate transmitter and receiver may be used to detect an object, such as a finger, by transmitting and receiving a pulse simultaneously and looking for a reflection. Reflection patterns from objects such as a finger may be stored and quickly compared to the incoming signal.

[0072] In another embodiment, four UWB devices are positioned at the four corners of a panel of buttons and a processor is used to coordinate the four signals and build an image map or model of objects in front of the panel. Multiple images may be used to determine direction vectors and selection of a button to activate.

[0073] Still other embodiments of touch-less fixtures or buttons using UWB technology are shown in the drawings included herewith.

[0074] Other ways in which UWB technology may be implemented in a touch-less fixture or button application will be apparent to those of ordinary skill in the art.

[0075] Car Location

[0076] It may be desirable to detect and/or track the location of an elevator cars. By way of example only, such location detection may be useful in leveling the car with a landing at a stop, or for a variety of other purposes. Some techniques for detecting the location of elevator cars are disclosed in U.S. Patent No. 6,651,028, the disclosure of which is incorporated by reference herein. There are various ways in which UWB technology may be employed to provide such detection and/or tracking. Such UWB-based systems may provide several advantages over the system disclosed in U.S. Patent No. 6,651,028.

[0077] In one embodiment, one or more UWB sensors may be provided on or in a car to detect car location. In this embodiment, the car location may be determined by the sensor referencing the position of one or more reference points or devices on or in the walls, ceiling, and/or floor of the elevator shaft. In another embodiment, the UWB device comprises an altimeter, and detects the car location as a function of altitude, hi yet another embodiment, the UWB device detects car location with reference to the bottom of the elevator shaft. In still another embodiment, the UWB device detects car location with reference to the top of the elevator shaft. In addition to or as an alternative to having a UWB device in or on the car to detect car location, a UWB device may be provided in the elevator shaft to detect car location. Such a device or devices may be positioned at the top of the shaft, at the bottom, and/or on a wall of the shaft. Suitable variations will be apparent to those of ordinary skill in the art.

[0078] It will also be appreciated that any UWB device that is configured to detect car location may also be used to detect car velocity and other properties.

[0079] Conclusion

[0080] Having shown and described various embodiments and concepts of the invention, further adaptations of the methods and systems described herein can be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the invention. Several of such potential alternatives, modifications, and

Claims

- 29 -What is claimed is:

1. An occupancy sensor system for an elevator comprising:

an elevator car; and

one or more UWB sensors positioned in communication with the interior of said elevator car, at least one of said one or more UWB sensors being adapted to detect occupant presence by sensing and measuring biometrics of occupants within said elevator car.

- 28 -

variations have been mentioned, and others will be apparent to those skilled in the art in light of the foregoing teachings.