Abstract: The echolocater device described herein incorporates the features of integrated sampling radar technology to create a unique device that provides, for example, the visually impaired with an excellent new tool to help navigate the world. Much like a bat using its bio-sonar, the visually impaired will be able to hear subtle differences in audio-replicated radar echoes. In one preferred embodiment of the invention, two integrated-sampling type radar receivers are spaced some convenient distance apart. A single transmitter centered between two receivers transmits pulses of an RF carrier. Audio “IF” output from each receiver is processed and sent to a small speaker worn near each ear. With practice, the user of this invention will be able to discern the range, location and motion of individual objects, and may also be able to distinguish particular echo characteristics of differing objects.

Abstract: The echolocater device described herein incorporates the features of integrated sampling radar technology to create a unique device that provides, for example, the visually impaired with an excellent new tool to help navigate the world. Much like a bat using its bio-sonar, the visually impaired will be able to hear subtle differences in audio-replicated radar echoes. In one preferred embodiment of the invention, two integrated-sampling type radar receivers are spaced some convenient distance apart. A single transmitter centered between two receivers transmits pulses of an RF carrier. Audio “IF” output from each receiver is processed and sent to a small speaker worn near each ear. With practice the user of this invention will be able to discern the range, location and motion of individual objects, and may also be able to distinguish particular echo characteristics of differing objects.

Abstract: Pulsed radar detects the presence and range of very short-range objects via small perturbations in phase and/or amplitude of relatively long duration coherently related transmit pulses. In one embodiment, echoes forming a received signal waveform from a sampling baseband radar receiver are processed at audio frequency to look for perturbations of the phase of the time-stretched received radar signal while the radar is still transmitting a long-duration pulse. In a second embodiment, the time-stretched received signal is processed to look for perturbations in the amplitude of the received radar signal. Small amplitude perturbations due to constructive and destructive interference of the transmitted and reflected signals occur in the receiver when objects are very close to the radar if the receiver is not heavily saturated. These same techniques can also be used to achieve highly accurate ranging of long-distance objects and detection of overlapping echoes from multiple objects.

Abstract: The frequency of an RF signal to be transmitted is modulated at the transmitting unit, and the modulation information is used by the receiving unit to filter out any unwanted noise. The modulation information may be used to retrieve associated filter coefficients that are used by the receiver to filter out the noise. Accordingly, for each transmit frequency, a multitude of filter coefficients stored in a memory are applied by the receiver to filter out the noise. The filtering operation may be performed after the received signal is downconverted from an RF to an audio signal.

Abstract: To modulate the frequency of a signal to be transmitted, the biasing voltage applied to a terminal of a transistor is dynamically modulated. To achieve this, the pulse width or a pulse amplitude of a control signal is modulated. Alternatively, a multi-bit control signal may be used to perform the modulation. The frequency of the transmitted signal is optionally modulated by varying the temperature of a oscillator. To vary this temperature, the current flowing through one or more resistive elements positioned in proximity of the oscillator is varied in response to the pulse width or amplitude of a second control signal. The temperature may also be changed by varying a multi-bit control signal. As the level of this current flow varies, the amount of heat emitted by the resistors vary, thereby changing the temperature of the oscillator which has a non-zero temperature coefficient.

Abstract: A directional back-up alarm deployed in a vehicle moving in an open space, in accordance with one embodiment of the present invention includes, in part, a first ultrasonic generator adapted to generate a first ultrasound signal; a second ultrasonic generator adapted to generate a second ultrasound signal; an audible sound generator adapted to generate an audible signal; a modulator adapted to modulate the first ultrasonic signal with the audible signal to generate a modulated signal; and a summing circuit adapted to receive and sum the modulated signal with the second ultrasonic signal to generate a combined signal. The combined signal is transmitted with a transmit antenna. The transmit antenna may include a Piezoelectric or silicon device.

Abstract: A safety alarm system for use on moving vehicles and heavy equipment provides an added level of safety by not only indicating motion, but by adding a distinct audible warning according to a selected sound pattern template when danger is imminent to those in the local area of potential danger. The sound pattern is selected on the basis of signals from various combinations of signals detected from an object detection sensor and an ambient noise level sensor, thereby providing enhanced safety in the work environment.

Abstract: The frequency of an RF signal to be transmitted is modulated at the transmitting unit, and the modulation information is used by the receiving unit to filter out any unwanted noise. The modulation information may be used to retrieve associated filter coefficients that are used by the receiver to filter out the noise. Accordingly, for each transmit frequency, a multitude of filter coefficients stored in a memory are applied by the receiver to filter out the noise. The filtering operation may be performed after the received signal is downconverted from an RF to an audio signal.

Abstract: A rotating beacon including a plurality of light emitting diodes and a plurality of reflectors is disclosed. The light emitting diodes are attached to one or more printed circuit boards mounted on a base. The reflectors gather light from the light emitting diodes into a plurality of beams which are directed away from the base. A motor and shaft assembly rotates a mirror element. The mirror element is arranged to reflect the beams into a horizontal plane of the rotating beacon.

Abstract: An audible alert device determines the effect of environmental factors upon the output sound pressure level of a transducer and establishes drive signal parameters adapted to the current operating environment. The drive signal parameters are based upon supply voltage, ambient temperature and/or resonant frequency. The drive signal is optionally a pulse width modulated signal for which the drive signal parameters represent the frequency and duty-cycle of the drive signal pulses. The audible alert device generates the drive signal using the drive signal parameters and delivers it to the transducer thereby controlling the output sound pressure level.

Abstract: To modulate the frequency of a signal to be transmitted, the biasing voltage applied to a terminal of a transistor is dynamically modulated. To achieve this, the pulse width or a pulse amplitude of a control signal is modulated. Alternatively, a multi-bit control signal may be used to perform the modulation. The frequency of the transmitted signal is optionally modulated by varying the temperature of a oscillator. To vary this temperature, the current flowing through one or more resistive elements positioned in proximity of the oscillator is varied in response to the pulse width or amplitude of a second control signal. The temperature may also be changed by varying a multi-bit control signal. As the level of this current flow varies, the amount of heat emitted by the resistors vary, thereby changing the temperature of the oscillator which has a non-zero temperature coefficient.

Abstract: Techniques for reducing interference among transceivers are disclosed. A transistor generates a radio frequency transmit signal in response to a generated pulse. The pulse is generated when transitions are detected in a clock signal. The clock signal is produced by an oscillator block which includes a ceramic resonator configured as a clock source. When interference is detected, the pulse applied to the transistor is varied. The frequency of the transmit signal is optionally modulated by varying the temperature of a resonator element. To vary this temperature, the current flowing through one or more resistive elements positioned in proximity of the resonator element is varied according to a control signal. As the level of this current flow varies, the amount of heat emitted by the resistive elements varies, thereby changing the temperature of the resonator element which has a relatively high temperature sensitivity.

Abstract: The present invention relates to a system for managing assets such as vehicles and/or equipment in an area such as a repair yard or parking lot. A plurality of mobile devices periodically wake-up at different times and transmit their uncorrected GPS location data to one or more fixed local devices. Each fixed local device periodically forwards its accumulated, uncorrected GPS data for each mobile device to a reference device. A reference device is precisely located and capable of differentially correcting the data and forwarding the corrected result sets either back to the local devices and/or to third parties.

Abstract: A multi-tone vehicle motion alarm is provided as an augmentation of a single-tone alarm by imbedding in the alarm sound a plurality band-limited single-tone acoustic signals of different frequencies that are emitted in pulsed synchronism so that the warning signal is emitted in a form that allows directionality of the source to be determined by those around the alarmed equipment. This functional extension preserves many of the familiar aspects of existing alarms. Further, limiting the frequency band of the alarm reduces useless noise in the worksite. The preferred embodiment emits a pulsating tone alarm consisting of two discrete and identifiable monotones. The alarm is an extension of widely recognized pulsating reverse warning sounds. Additional tones may be employed to aid in the speed with which the sound source can be located with human hearing.

Abstract: Apparatus and methods for adjusting or “hopping” the center frequency or the pulse repetition frequency of a radar system improve the co-locatability of multiple radars commonly located in a region. In a Time Domain Downconversion (TDDC) or Ultra-Wideband (UWB) radar system having a display update period between range sweeps, the preferred device comprises a frequency variable oscillator for adjusting the radar's internal timing reference frequency during a plurality of the display update periods. Radar frequency hopping methods and apparatus may result in improvements in interference immunity compared to other interference reduction techniques and may achieve cost reduction. In frequency hopping radar, if an actual target is present, the receiver waveform will repeat at the newly adjusted center frequency. Confirmation of a target is realized as an ongoing reflection and not interference.

Abstract: The present invention relates to a system for use in motorized vehicles to provide a vehicle back-up alarm system, intended for mounting on a vehicle, that also incorporates an apparatus for detecting and alarming low battery conditions. Preferably incorporated into a main housing are the electronic components that perform power regulation, system control, voltage sensing, timing, alarm tone generation, sound emitting and, optionally, light emitting. The housing serves to securely fix and retain these components and to protect them from moisture and dirt. The circuitry is connected to the vehicle upon which it is installed by preferably three connection terminals situated on the housing. Distinctive tones and/or lamp sequences alert the operator and those by-standers within proximity to the vehicle to different alarm conditions.

Abstract: A rotating beacon employs an array of LEDs mounted on a rotor assembly in a pattern for unidirectional emission wherein the LEDs are excited through noncontact inductive coupling between a load coupling on the rotor assembly and a source coupling on the stator or mount element. In a particular embodiment, a primary sender flat coil of an air gap transformer is disposed concentrically forming a disc and mounted juxtaposed to a secondary receiver flat coil so that power can be conveyed across the air gap while the rotor is in motion. The transferred power excites substantially all of the LED array in a fixed pattern on the rotating mount. In a second embodiment, the air gap transformer has a primary sender coil is mounted coaxially with a secondary receiver coil (which is typically but not necessarily inside the primary coil), so the secondary, with the array can freely rotate and draw power from the source.

Abstract: A warning device in one embodiment includes a housing which is portable, the housing containing preferably a microwave transceiver operating as a proximity-sensing device, a stroboscopic lamp and/or a horn disposed in the housing in electrical connection with the sensing device for emitting a series of flashes and/or honks in response to the sensing of an object within predetermined range of the sensing device, a battery in the housing for powering the sensing device and the lamp and/or horn, and a system for mounting the housing to a variety of supporting objects.

Abstract: A safety alarm system for use on moving vehicles and heavy equipment provides an added level of safety by not only indicating motion, but by adding a distinct audible warning according to a selected sound pattern template when danger is imminent to those in the local area of potential danger. The sound pattern is selected on the basis of signals from various combinations of signals detected from an object detection sensor and an ambient noise level sensor, thereby providing enhanced safety in the work environment.