Abstract: A positioning system for an elevator cab (37) includes transponder modules (10) having a unique ID for receiving a signal (39) and emitting an ultrasonic signal when the signal is equivalent to the unique ID with a determination of position based on the time duration of the signals.

Abstract: A system for automatically determining video quality receives video input from one or more surveillance cameras (16a, 16b . . . 16N), and based on the received input calculates a number of video quality metrics (40). The video quality metrics are fused together (42), and provided to decision logic (44), which determines, based on the fused video quality metrics, the video quality provided by the one or more surveillance cameras (16a, 16b . . . 16N). The determination is provided to a monitoring station (24).

Abstract: An alarm filter (22) for use in a security system (14) to reduce the occurrence of nuisance alarms receives sensor signals (S1-Sn, Sv) from a plurality of sensors (18, 20) included in the security system (14). The alarm filter (22) produces an opinion output as a function of the sensor signals and selectively modifies the sensor signals as a function of the opinion output to produce verified sensor signals (S1?-Sn?).

Abstract: A positioning system comprising a plurality of transponder modules each located at a known location for receiving an electromagnetic signal and emitting a light signal, at least one transceiver module for emitting an electromagnetic signal and receiving the light signal, and apparatus processing the received light signal to determine a position of the at least one transceiver module.

Abstract: A refrigerant system is provided with a method and a control programmed to perform the method, in which a low charge of refrigerant is identified. The mass flow of refrigerant through the system is calculated utilizing at least two different methods. The two calculated mass flow rates are compared, and if they differ by more than predetermined amount, a determination is made that there is a low charge of refrigerant within the system.

Abstract: A method and system for detecting and predicting air filter condition for an air handling system operates by determining a system resistance to air flow. The system resistance is utilized to determine a detection statistic indicative of current filter condition and to predict remaining life of the air filter. The system resistance is determined using models that approximate the expected operation of the air handling system. The approximation is then compared to actual values to obtain a difference. Once the difference between the approximated value exceeds a threshold value, an alarm is initiated that is indicative of system resistance. The remaining air filter life is then determined by using historically gathered data, or by using a known degradation rate of the air filter. Once the remaining life of the air filter is estimated, replacement can be scheduled that would coincide with other maintenance.

Abstract: A noise or vibration control system reduces a sampling rate and reduces a control rate to improve computation efficiency. The present invention permits the use of a sample frequency (fs) that is less than twice the frequency of interest (fd). The sensed signals are filtered to extract a particular frequency range with a lower bound given by (2n?1)*fs/2 and an upper bound given by (2n+1)*fs/2, where n is an integer chosen so that the frequency of interest (fd) is within the extracted frequency range. The control commands are also calculated at a reduced rate, which is dependent upon the bandwidth of the tone, rather than the absolute frequency of the tone. Rather than updating the control signals directly on the sampled sensor data yk as it enters the computer, the control computations are done on the harmonic components ak and bk, or equivalently on the magnitude and phase.

Abstract: A method of diagnosing sensor faults for a heating, ventilation and air conditioning system includes the steps of creating a component model for a specific component within the system. The component model is created through the use of commonly available manufacturing data. Data within the system is input into the component model and compared to calculated and predicted values that are also calculated using the identical component models. Differences between the calculated and actual values is determined and compared to a threshold difference value. If the difference exceeds the threshold value, then a fault is detected. The specific type of sensor fault is determined using probability distribution analysis. Each type of sensor fault produces a different type of statistical deviation from normal distribution.

Abstract: A cabin communication system for improving clarity of a voice spoken within an interior cabin having ambient noise includes an adaptive speech enhancement filter for receiving an audio signal that includes a first component indicative of the spoken voice, a second component indicative of a feedback echo of the spoken voice and a third component indicative of the ambient noise, the speech enhancement filter filtering the audio signal by removing the third component to provide a filtered audio signal, the speech enhancement filter adapting to the audio signal at a first adaptation rate, and an adaptive acoustic echo cancellation system for receiving the filtered audio signal and removing the second component in the filtered audio signal to provide an echo-cancelled audio signal, the echo cancellation signal adapting to the filtered audio signal at a second adaption rate, wherein the first adaptation rate and the second adaptation rate are different from each other so that the speech enhancement filter does not

Abstract: A method for detecting and predicting refrigerant level includes the steps of determining an estimated value for a parameter indicative of refrigerant level and comparing that estimated value to an actual value. The difference between the actual and estimated value provides a refrigerant charge indicator value. The charge indicator value is indicative of the amount of refrigerant contained within the system. A change value is combined with the charge indicator value to provide a prediction for the future value of the charge indicator value. This future value is determined based on a rate of change and charge indicator value over a selected period of time.

Abstract: A cabin communication system for improving clarity of a voice spoken within an interior cabin having ambient noise includes a microphone for receiving the spoken voice and the ambient noise and for converting the spoken voice and the ambient noise into an audio signal, the audio signal having a first component corresponding to the spoken voice and a second component corresponding to the ambient noise, a speech enhancement filter for removing the second component from the audio signal to provide a filtered audio signal, the speech enhancement filter removing the second component by processing the audio signal by a method taking into account elements of psycho-acoustics of a human ear, and a loudspeaker for outputting a clarified voice in response to the filtered audio signal.

Abstract: An elevator system (20) includes wireless communicating portions (40, 42) that communicate with each other to provide elevator cab (22) position information within a hoistway (24). In one example, a first communicating portion (40) is supported on the elevator cab (22) that generates a radio frequency trigger signal (58) that is received by a second communicating portion (42) at a selected position along the hoistway (24). The second communicating portion (42) responsively generates an ultrasound signal (64) that is received by the first communicating portion (40). A characteristic of the received locating signal, such as the timing between the trigger signal and the receipt of the locating signal, provides position information regarding the cab within the hoistway.

Abstract: An improved user interface is installed in the cabin of a vehicle incorporating a cabin communication system using acoustic echo cancellation for improving the ease and flexibility of the cabin communication. Separate controls at each seat location enable the person occupying that seat to selectively converse with other occupants in the vehicle, create a recorded message and/or place a telephone call.

Abstract: A cabin communication system for improving clarity of a voice spoken within an interior cabin uses a microphone array including a first microphone, positioned at a first location within the cabin, for receiving the spoken voice primarily in a first direction and for converting the spoken voice into a first audio signal, and a second microphone, positioned at a second location within the cabin, for receiving the spoken voice primarily in the first direction and for converting the spoken voice into a second audio signal. A sound source, such as the speaker of an entertainment system, inputs sound into the cabin such that the input sound approaches the microphone array primarily in a second direction different from the first direction.

Abstract: An automatic gain control for a cabin communication system for improving clarity of a voice spoken within a movable interior cabin having ambient noise includes a microphone for receiving the spoken voice and the ambient noise and for converting the spoken voice and the ambient noise into a first audio signal having a first component corresponding to the spoken voice and a second component corresponding to the ambient noise, a filter for removing the second component from the first audio signal to provide a filtered audio signal, an acoustic echo canceller for receiving the filtered audio signal in accordance with a supplied dither signal and providing an echo-canceled audio signal, a control signal generating circuit for generating a first automatic gain control signal in response to a noise signal that corresponds to a current speed of the cabin, the first automatic gain control signal controlling a first gain of the dither signal supplied to the filter, the control signal generating circuit also for genera

Abstract: The present invention teaches a system for improving the clarity of a voice spoken within an enclosed space. The system comprises a first microphone, positioned at a first location, for receiving the audible communication and for converting the audible communication at the first location into a first audio signal. The system also comprises a loudspeaker for receiving the first audio signal, and for converting the first audio signal into a first reproduced audible communication, the reproduced audible communication also being fed back and received by the first microphone and converted with the audible communication into the first audio signal.

Abstract: A noise or vibration control system reduces a sampling rate and reduces a control rate to improve computation efficiency. The present invention permits the use of a sample frequency (fs) that is less than twice the frequency of interest (fd). The sensed signals are filtered to extract a particular frequency range with a lower bound given by (2n−1)*fs/2 and an upper bound given by (2n+1)*fs/2, where n is an integer chosen so that the frequency of interest (fd) is within the extracted frequency range. The control commands are also calculated at a reduced rate, which is dependent upon the bandwidth of the tone, rather than the absolute frequency of the tone. Rather than updating the control signals directly on the sampled sensor data yk as it enters the computer, the control computations are done on the harmonic components ak and bk, or equivalently on the magnitude and phase.

Abstract: A method of reducing undesired components from a signal that includes a desired component and undesirable components utilizes an autoregressive model technique. An autoregressive module determines a power spectral density approximation of the signal. An error component of the power spectral density approximation includes the desired component. Portions of the error component having frequencies outside of the expected range of the desired component preferably are filtered so that the result is the desired component with the undesired component removed. The invention is useful, for example, for reducing undesirable noise components from sound signals.

Abstract: A security system that is useful for protecting vehicles from theft and buildings from unauthorized entry, for example, includes utilizing random numbers within remotely transmitted signals. A remote signaling device transmits a signal to a system controller with instructions for a desired operation of the system. The invention prevents a potential thief from capturing one or more transmitted signals and later mimicking or predicting a subsequent signal by including or utilizing a random number when generating the transmitted signal. The random number is incorporated into the transmitted signal in one of several ways according to this invention. Single-use or limited re-use of random numbers enhances the security and integrity of the system.

Abstract: An automobile door receiver module (30) and a plurality of keychain fob transmitter units (16) contain identification numbers, secret initial values, and secret feedback masks so as to authenticate encrypted messages from any of the assigned fobs, indicative of commands registered by closing switches on the fob. Each fob is synchronized with the receiving module by means of a truly random number concatenated with a secret initial value and encrypted, through a linear feedback shift register or other operations. A second secret initial value is encrypted and command bits are exclusive ORed into the low order bit positions; the two encrypted numbers are concatenated and encrypted to form a key word which is transmitted with the fob ID. Synchronization includes decrypting to recover the truly random number and the secret initial value concatenated therewith; the truly random number is compared with previously received random numbers in order to avoid copying of recently transmitted synchronization commands.