Abstract: A system for determining the position of each of a plurality of objects in a specified environment by determining the transit times of slowly propagating measurement energy transmitted from a measurement energy transmitter on each object to a plurality of fixed measurement energy receivers in the specified environment, the transmission of the measurement energy being triggered by a burst of high speed propagating trigger energy into the specified environment from a trigger energy transmitter, the measurement energy transmitter on each object being triggered by an object-mounted trigger energy receiver, each burst of trigger energy being encoded so as to trigger one only of the measurement energy transmitters, wherein a coordinating control system determines the order in which the measurement energy transmitters are triggered, in response to updatable information relating to service demands of the trigger energy transmitter and/or objects.

Abstract: An ultrasonic sonar has a transceiver equipped with an ultrasonic oscillator. An ultrasonic wave is transmitted from the transceiver. The ultrasonic wave reflected from an obstacle is received by the ultrasonic oscillator to detect the obstacle. The transmission frequency of the ultrasonic wave is set to be different from the reverberation frequency. When the obstacle is detected, a microcomputer converts the analog signal received by the ultrasonic oscillator into a digital signal, performs a frequency transform of this signal by Fourier transform to extract only the transmission frequency component, and performs an inverse transform.

Abstract: An ultrasonic sensor is located in the bottom of a lift cylinder of a forklift and emits ultrasonic waves toward a piston in the cylinder. A controller controls the ultrasonic sensor to consecutively emit ultrasonic waves that have different amplitudes at predetermined intervals. The ultrasonic waves are emitted in order of smallness of amplitude. The controller computes the distance between the ultrasonic sensor and the piston based on a period from when the ultrasonic sensor emits one of the ultrasonic waves to when the ultrasonic sensor receives the ultrasonic wave that is reflected by the piston. As a result, the range of the detectable distances is extended.

Abstract: An apparatus and method for detecting utilities buried in the ground wherein an array of sonic receivers are arranged in rows and ranks against the ground and a corresponding array of sonic transmitters are arranged relative to the array of sonic receivers so that a distance between each sonic transmitter and each adjacent sonic receiver is the same. Echoes generated by the apparatus may then be normalized, averaged and compared to the original echoes to develop a profile of the buried utility.

Abstract: Ultrasound is used to determine, by echo ranging, the distance of objects in front of a user for allowing a visually impaired pedestrian to walk safely. A double circuit allows two simultaneous measurements. Distances measured are converted into human paces or steps. Then each ear of the human receives measurement information. The user can calibrate the apparatus for his or her own stride.

Abstract: A system is disclosed that provides. a sonar operator with the most likely range to a target of interest. The system generates and displays a contour based on ship's parameters, target parameters, environmental data, and operator parameters. The sonar operator can vary many of the parameters in “what if” scenarios so as to generate groups of contours for preselected probabilities of detection. Contours can be used to show the actions that should be taken to ensure a favorable outcome.

Abstract: A sonar system that includes a new comb-like waveform constructed by modulating the tines of a comb spectrum according to a set of Hermite functions defining a Hermite Function Space (HFS), and a processing method that reduces the sidelobes of the ambiguity function associated with the normally-processed HFS comb waveform. Noise-limited performance remains high, because the waveform is designed to be power-efficient; range ambiguity is superior to the highly-rated sinusoidal frequency-modulation (SFM) waveform; and reverberation-limited performance is equal to or better than that offered by any other waveform designed for this purpose. The full Doppler sensitivity normally associated with pulsed CW can be realized by the application to HFS signals of the constrained, regularized deconvolution method of this invention.

Abstract: A sonar depth sounder device and method for processing echo signals, reflected from objects within a body of water, utilizes a processor, a memory, a display, and a keypad connected to the processor. The receiver receives sonar signals indicative of ambient noise in an underwater environment. The processor receives an electrical signal representative of the ambient noise, and calculates a detection threshold. The detection threshold is calculated by multiplying a scaling factor times the variance of the signal indicative of the ambient noise, and adding that product to the mean of the signal indicative of the ambient noise in the underwater environment. A transmitter then excites a transducer which emits sonar pulses into a body of water, and a receiver receives reflected sonar echo signals. When the intensity of the reflected sonar echo signals is less than the detection threshold, the reflected echo signals are eliminated from processing.

Abstract: A dither oscillator randomly modulates the instantaneous phase of a precision radar PRF oscillator. Radar spectral emission lines occurring at multiples of a transmit PRF oscillator are spread by the phase modulation, resulting in a continuous noise-like spectrum for reduced interference. The dither oscillator is based on a CMOS logic inverter and has adjustable coherence. The transition times of the PRF clock are decreased to 100 ps using negative resistance in an emitter follower to help injection-lock an RF oscillator to the PRF clock. Applications include spread-spectrum radar sensors operating in the crowded ISM bands, such as robotic and automotive pulse-echo rangefinders.

Abstract: In a position detecting device which detects a piston rod based on the time elapsed from a point at which an ultrasonic wave is emitted from an ultrasonic wave sensor toward a lower end surface of the piston rod reciprocatingly moved linearly by supply and discharge of a working oil with respect to a hydraulic cylinder to a point at which the ultrasonic wave reflected by the lower end surface of the piston rod is received by the ultrasonic wave sensor, if the working oil's temperature is detected by a temperature sensor, then a microcomputer sets the strength of the ultrasonic wave emitted from the ultrasonic wave sensor in accordance with the temperature of the working oil so as to accurately detect the position of the piston.

Abstract: An apparatus (20) determines a target (e.g., a vehicle occupant 22) beyond a predetermined distance. In an exemplary embodiment, the apparatus (20) determines a distant target for use in control of air bag deployment. The apparatus (20) includes a sensor (44) for emitting and receiving first (52, 56) and second (54, 58) signals in an interspersed predetermined emission sequence toward the target. A controller (60) successively determines a time interval between the emission of a current signal and the reception of an echo. The controller (60) successively compares at least two time intervals to determine whether a sufficient difference exists to indicate that the target is beyond the predetermined distance and outputs a signal to the air bag actuation system (62).

Abstract: Methods for controlling deployment of an occupant restraint device in a vehicle and determining whether an object is a child seat in which one ultrasonic transducer is arranged on a ceiling of the vehicle and another ultrasonic transducer is arranged at a different location in the vehicle, ultrasonic waves are transmitted from each transducer into the passenger compartment and received thereby, and the distance from each transducer to the object is calculated based on the time difference between the transmitted waves when transmitted from the transducer and the reflected waves when received at the transducer. Deployment of the occupant restraint device is controlled based on the calculated distances and/or a determination is made whether the object is a child seat based on the calculated distances.

Abstract: Safety apparatus and method for sensing the presence of an object in a safety zone including at least one ultrasonic transducer having an asymmetrical transmission field and received signal processing circuitry operative to receive signals reflected from objects within the asymmetrical transmission field and to discard signals lying outside an asymmetrical detection field lying within the asymmetrical transmission field and defining the safety zone.

Abstract: A distance measuring system is described which may be used as an altimeter for a helicopter or for a load carried by its winch. The system comprises: a transmitting transducer for converting a first modulated electrical signal into a corresponding acoustic signal to be directed towards and reflected by a surface; a receiving transducer for converting the received reflected acoustic signal into a corresponding second electrical signal; and a correlation processor for receiving the second electrical signal, or the first and second electrical signals, and correlating the modulations thereof to produce an indication of a time delay thereof from which the distance travelled by the acoustic signal can be determined.

Abstract: The present invention discloses a buried object detection system. The detection system has an acoustic emitter capable of generating a non-linear acoustic impulse or a continuous acoustic signal of variable amplitude and frequency. Sensors are deployed on an appropriate surface or surfaces of a granular medium, which are capable of detecting the backscattered and, if possible, forward scattered signals of the original impulse or wave from a buried inclusion or inclusions. The information received by the sensors may be transmitted to a computer for further manipulation and analysis.

Abstract: An underwater detection apparatus comprises a transducer, a transmitter capable of generating transmitting signals of a plurality of respective frequencies and for generating a transmitting signal, a broadband trap circuit for transferring the transmitting signal fed from the transmitter to the transducer and for passing an echo signal fed from the transducer, a preamplifier for amplifying the echo signal fed from the broadband trap circuit, a mixer for converting an output of the preamplifier into a signal of a specific frequency, a filter for selectively passing the signal of only the specific frequency-band output from the mixer, a main amplifier for amplifying an output of the filter, an A/D converter for converting an output of the main amplifier into a digital form, and a display circuit for displaying the digitized output of the A/D converter on a monitor, wherein the preamplifier is of a low-gain type.

Abstract: An apparatus for determining the relative height between two targets is disclosed. The present invention also discloses a method for determining the relative height between two targets; the method is substantially similar to the operational aspects of the device of the present invention. The method requires no angular measurements in order to determine the different height between the two targets, but rather only distance measurements that can be performed simply and accurately. The apparatus for determining the relative height between two targets a disclosed.

Abstract: The signal echo monitoring device includes a transmitting unit (5) for broadcasting a transmitted signal (s(t)) which is a group of randomly generated pulses, a receiving unit (6) for receiving an echo signal (e(t)), reflected by an object (12), of the transmitted signal and a combined control and evaluation unit (2) including a device (10) for jointly evaluating the transmitted signal (s(t)) and the echo signal (e(t)) with an integrated adaptive filter (14). The adaptive filter (14) automatically calibrates its impulse response b(t) and may be a digital filter.

Abstract: A sonic water level measuring method and system for mounting a wave-guide tube for measuring a water level in a reservoir, a river, etc. generating sonic pulses at the upper of the wave-guide tube, measuring transit times that it takes for the sonic pulses to transit them through air medium and transit back to an original point after being reflected on the water surface, and multiplying the transit times by a sound velocity to compute a water level comprises steps of measuring the sound velocity using the times that it takes for the sonic pulse to transit in two intervals in order to exactly measure the sound velocity that is changed according to the changing of an air temperature, pressure and component in the wave-guide tube; and measuring the water level considering an arithmetical average value of the sound velocities measured as a sound velocity in the wave-guide tube.

Abstract: A spoken word-producing detector identifies objects by comparing signatures of detected objects with stored signatures of known objects. When the signatures compare, the detector produces stored word sounds associated with the detected object identifications. An annunciator produces the words from pre-digitized human voice sounds. A screen displays the words.

Abstract: A distance measurement apparatus includes a transmitting device for transmitting a forward electromagnetic wave. A receiving device operates for receiving an echo wave caused by reflection of the forward electromagnetic wave at an object, and converting the received echo wave into a first received signal. A scattered-wave detecting device operates for detecting a scattered wave reaching the receiving device and caused by reflection of the forward electromagnetic wave at an obstacle which occurs prior to the reflection of the forward electromagnetic wave at the object. A cancel-signal generating device operates for generating a cancel signal to cancel a scattered-wave-corresponding component of the first received signal generated by the receiving device in response to the scattered wave detected by the scattered-wave detecting device.

Abstract: The present invention pertains to a method for range measurement by means of a signal transmitted in the direction of an object to be measured, wherein an echo signal, on which is superimposed a first reference pulse, is received by a receive device, wherein the echo signal is compared with a second reference signal that features a second reference pulse for determining a signal travel time, and wherein a first comparison value of the echo signal and a second comparison value of the second reference signal are compared with each other for determining an amplitude offset between the echo signal and the second reference signal, and these values, in regards to time, are before the first and second reference pulses in a region of the echo signal curve and of the second reference signal curve, respectively, and in these regions, these curves feature a slope that is at least approximately zero.

Abstract: A level sensing apparatus for attachment to a sounding tube in order to measure levels of contents in a tank. This level sensing apparatus includes a housing for enclosing the various components of the level sensing apparatus. The level sensing apparatus of the present invention also includes a sounding tube adapter operatively connected to the housing and is further adapted for attachment to a sounding tube. Additionally, the sounding tube adapter includes an orifice disposed through its sidewall. The sounding tube adapter also includes a cover which can seal off the orifice, or may be opened to allow manual liquid level measurement.

Abstract: A radar device for use in backing up a vehicle is disclosed herein. A plurality of wave sensors is installed on a rear portion of a vehicle for detecting an obstacle therebehind. A master controller has a plurality of transceiver circuits and a microprocessor connected to the plurality of transceiver circuits. Each transceiver circuit corresponds to one of the plurality of wave sensors. The microprocessor activates the plurality of transceiver circuits to drive the plurality of wave sensors for transmitting and receiving ultrasound wave signals thereby determining the location of the obstacle. A location display device is connected to the master controller for receiving and decoding data related to the location of the obstacle thereby indicating the direction of the obstacle and displaying in numerical form the distance between the obstacle and the vehicle.

Abstract: An ultrasonic distance measuring system for monitoring railroad car loads. The system includes an ultrasonic transducer, a pulse generation and detection circuit and a measurement circuit. The transducer produces a transmitted ultrasonic pulse beam to be directed at a load in a railroad car and receives a return pulse beam from the load. The pulse generation and detection circuit is coupled to the transducer and causes the transducer to produce the transmitted pulse beam. A return pulse beam is detected by the pulse generation and detection circuit. The measurement circuit is coupled to the pulse generation and detection circuit and generates a measurement signal representative of the load as a function of the time delay between the transmitted and return pulse beams.

Abstract: An occupant position measuring system (10) comprising: a transmitter for generating a pulse modulated transmitter signal; a receiver for receiving a reflection of the transmitter signal, the receiver being characterized as having a relatively low Q factor; a controller, responsive to the receipt of the reflected signal and for generating an indication of the distance between an occupant the transmitter.

Abstract: A method of measuring the position of a target feature in a pulse-echo ranging system including transmitting at least one pulse of high frequency energy from a transducer towards the target feature, receiving energy reflected back from the direction of the target feature to the transducer to provide at least one return signal, repeatedly sampling the amplitude of the return signal(s) at intervals to form a digital database relating signal amplitude to elapsed time, and searching the database for at least one target zone in which a greater than background rate of fall of the return signal amplitude is sustained.

Abstract: An apparatus and method for weighing and non-contact measuring of dimensions of a stationary object wherein the platen on which the object is placed for weighing and measuring is isolated from the support assembly for the dimension measuring sensors for greater sensitivity and accuracy in weight determination. A method of determining object speed of linearly in-motion object, useful for determining object dimensions, is also disclosed.

Abstract: A transmission wave is applied to a predetermined angular range in a width-wise direction of a vehicle. Object-unit data pieces containing at least data pieces representing distances to objects in correspondence with vehicle-width-wise direction angles are generated on the basis of a reflected wave. A determination is made as to whether each object is moving or stationary on the basis of a speed of the vehicle and a relative speed of the object. From the object-unit data pieces, ones are extracted which are effective for road shape recognition on the basis of a result of determining whether each object is moving or stationary. Ones of the extracted object-unit data pieces which represent monotonically increasing distances as viewed along one of clockwise and counterclockwise angle directions are grouped to generate data representing a road-side-object group. A road edge is recognized on the basis of the data representing the road-side-object group.

Abstract: An ultrasonic sensor is located in the bottom of a lift cylinder of a forklift and emits ultrasonic waves toward a piston in the cylinder. A controller controls the ultrasonic sensor to consecutively emit ultrasonic waves that have different amplitudes at predetermined intervals. The ultrasonic waves are emitted in order of smallness of amplitude. The controller computes the distance between the ultrasonic sensor and the piston based on a period from when the ultrasonic sensor emits one of the ultrasonic waves to when the ultrasonic sensor receives the ultrasonic wave that is reflected by the piston. As a result, the range of the detectable distances is extended.

Abstract: A level sensing apparatus for attachment to a sounding tube in order to measure levels of contents in a tank and for determining the purity of contents in a tank. This level sensing apparatus includes a housing for enclosing the various components of the level sensing apparatus. The level sensing apparatus of the present invention also includes a sounding tube adapter operatively connected to the housing and is further adapted for attachment to a sounding tube. Additionally, the level sensing apparatus includes a lock operatively connected to the sounding tube adapter and capable of receiving the housing. Finally, the level sensing apparatus includes a swivel connector operatively connected to the housing, whereby the housing is capable of moving cooperatively with the swivel connector.

Abstract: A radio frequency (RF) sync pulse is transmitted throughout a building having a plurality of rooms to be traversed by a plurality of players during, for example, an assault training exercise. Ultra-sound pulses are transmitted from fixed piezoelectric transducers mounted at each corner of each room. The ultra-sound pulses with encoded room identity information are generated in a predetermined timed sequence by different ultra-sound transducers after each RF sync pulse. Each player carries an RF receiver for receiving the RF sync pulses. Each player also carries multiple microphones for receiving the ultra-sound pulses transmitted in a room in which the player is currently located. Timing circuitry carried by each player generates signals representative of the delays between each RF sync pulse and the receipt of each of the ultra-sound pulses sequentially received thereafter.

Abstract: A transmission wave is applied to a predetermined angular range in a width-wise direction of a vehicle. A position of each object and a relative speed of the object are detected on the basis of the reflected wave. A determination is made as to whether each object is moving or stationary on the basis of the detected relative speed of the object and a speed of the vehicle. For at least one of right-hand and left-hand sides of the vehicle, calculation is given of a vehicle width-wise direction position where each stationary object effective for road shape recognition passes through the related side of the vehicle. The calculated vehicle width-wise direction position is memorized. A line connecting the memorized vehicle width-wise direction position and the detected position of the currently handled object corresponding to the effective stationary object is recognized as a road edge.

Abstract: A peak detecting section 121 detects the maximum values (peaks) of frequency distributions, at intervals of unit times, from the wavelet intensity signal output from an intensity computing section 113. More specifically, giving attention to frequency distributions of the wavelet intensity signal as the transform result obtained by a signal converting section 110 at predetermined time intervals, the peak detecting section 121 detects the peaks (maximum values) of the frequency intensity distributions at intervals of unit times (predetermined time intervals). Changes in various frequency features over time which are contained in the time-series signal obtained by a wavelet transform of the time-series signal can be quantitatively grasped more accurately.

Abstract: An ultrasonic sonar has a transceiver equipped with an ultrasonic oscillator. An ultrasonic wave is transmitted from the transceiver. The ultrasonic wave reflected from an obstacle is received by the ultrasonic oscillator to detect the obstacle. The transmission frequency of the ultrasonic wave is set to be different from the reverberation frequency. When the obstacle is detected, a microcomputer converts the analog signal received by the ultrasonic oscillator into a digital signal, performs a frequency transform of this signal by Fourier transform to extract only the transmission frequency component, and performs an inverse transform.

Abstract: A collision avoidance system including a control module, a first transmitting device connected to the control module, wherein the first transmitting device transmits a signal, a first receiving device connected to the control module, wherein the first receiving device receives a return of the signal transmitted from the first transmitting device and transmits a first return signal representative of the return to the control device, a second transmitting device connected to the control module, wherein the second transmitting device transmits a signal, and a second receiving device connected to the control module device, wherein the second receiving device receives a return of the signal transmitted from the second transmitting device and transmits a second return signal representative of the return to the control device, wherein the control module includes measurement circuitry used to measure the first and second return signals and display means for displaying a transverse location of an object as a function

Abstract: A method and apparatus for measuring the depth of fluid in a well and for controlling the speed of a pump which pumps fluid out of the well according to the measured depth is disclosed. The depth of fluid in a well is measured by sending an acoustic pulse into an annulus between the well casing and the production tubing and sensing reflections of the acoustic pulse from collars on the tubing and a reflection from the fluid surface. Since the collar spacing on the production tubing is known, the distance from the top of the well to the surface of the fluid can be obtained by accumulating the distance associated with the collars detected in the reflection signal. The collar reflections are sensed by converting the reflected acoustic wave into electrical signals and then amplitude demodulating the broadband electrical signals.

Abstract: A sludge blanket level is determined in a waste water treatment clarifier using sonic pulse reflections. Additionally, using similar techniques, the clarity of the waste water is determined. A sonic pulse is directed into the waste water. Echos are generated as the pulse encounters the impedance mismatches indicative of changes in the density of the water. The echos are compensated for attenuation as a function of travel time through the water, energy lost due to prior peak reflections, and are processed to remove random signals using correlation techniques. A sludge blanket is selected from the compensated echo signal as a function of the size and location of echo peaks. Additionally, the clarity is determined as a function of the area under the echo signal between two points corresponding to predefined levels in the clarifier tank.

Abstract: Condition detecting system has a detecting device (1) including a plurality of pieces of distance sensors arranged at one corner of an observing sector such as a toilet, a judging device for judging the condition of a staying person in the observing sector on the basis of the information from the detecting device (1), a signal transmitting section for transmitting the results of judgment, and a warning device for issuing a warning on the basis of the signal from the signal transmitting section, and the plurality of pieces of distance sensors are set to perform detection in a plurality of different directions by using infrared ray beams.

Abstract: A chair monitoring system is used in a nursing home, hospital, healthcare facility or home or in a vehicle application, to detect an individual's attempted departure from a seat before the individual leaves the seat, or as an individual starts to slide out of a seated position. The purpose of this invention is to help prevent falls and provide an early alarm to enable caregivers, nursing staff, or another responsible individual to respond quickly and appropriately to reduce injuries. This alarm can be audible and visual at the chair and/or can trigger a nurse call system. A new technology is used to continually, invisibly, and remotely monitor a person's presence in a chair. There are no pads, strings, clips or attachments to the monitored person. The safe area can be easily adjusted to fit the specific needs of the situation and enable a caregiver to be alerted when a person slides down, leans forward or starts to leave the chair before he or she has physically left the chair.

Abstract: An ultrasonic ranging system and method for detecting the presence of and distance to a target using ultrasonic sound waves generated by an ultrasonic transducer with reduced audible noise. Electrical ultrasonic signal pulses are modulated according to a smooth modulation envelope and a transducer drive signal is generated from the modulated signal pulses. The transducer drive signal drives an ultrasonic transducer which generates ultrasonic sound waves for transmission in a desired path, and further receives ultrasonic sound waves reflected from targets in the transmission path. The received ultrasonic sound waves are converted to an electrical signal that is processed by a processor to provide time and distance information to the target. The distance information is computed by using a middle time value for the transmitted and received signals.

Abstract: A method for processing an echo amplitude profile generated by an echo ranging system with reference to a temporal axis to identify return echoes comprised by the profile by identifying amplitude peaks in the profile above with respect to an amplitude axis, a threshold curve on the same temporal axis, wherein the threshold curve is generated by identifying rising edges of echoes in the profile, and generating curve segments extending on the temporal axis from points at or above said leading edges to intersections with descending edges of echoes in the profile, whereby to trace echo base lines delimiting access of the echoes. The invention also extends to a method for processing an echo amplitude profile.

Abstract: The apparatus for measuring a distance to an object with ultrasound includes a number of ultrasonic transducers (1 to 10) arranged in a motor vehicle for propagation of ultrasonic pulses and a controller (13) including a device for controlling the ultrasonic transducers to sequentially propagate ultrasonic pulses from the respective ultrasonic transducers (1 to 10) and a device to simultaneously propagate ultrasonic pulses from each ultrasonic transducer so that the ultrasonic pulses from respective ultrasonic transducers are superimposed on each other when no obstacle is detected during sequentially propagating ultrasonic pulses, or according to a vehicle speed. Reflected ultrasonic pulses from an object near the vehicle are received by at least one of the ultrasonic transducers (1 to 10) after propagation of the ultrasonic pulses. An evaluation device evaluates the reflected ultrasonic pulses from the object and preferably activates warning devices for the driver as needed.

Abstract: An ultrasonic distance measuring device for use, for instance, in the building trades, conventionally measures distance by projecting a sonic beam towards the target and detecting the reflection from the target. Also provided is an associated co-axial laser pointer which provides a visual indication of where the sonic beam is pointed. This laser pointer provides a laser beam which illuminates the target. However, the laser beam is not a typical laser beam, but instead is diffracted so that it covers an area at the target approximately the same size and shape as the area covered by the sonic beam. This provides a clear indication to the user that the sonic beam is not a single point beam but instead is possibly reflecting from any one of a number of points on the target.

Abstract: A radar device for detecting distances and relative speeds of obstructions such as preceding vehicles has a stationary object identifier for identifying stationary objects such as roadside guard rails and the like and a stationary object eliminator for eliminating data identified as pertaining to such stationary objects. The stationary object identifier detects peak densities in a beat spectrum detected as a difference between transmitted and received frequencies of a radar beam modulated to rise and fall in frequency periodically and identifies peak groups having peak densities above a predetermined value as stationary objects. Therefore, it is possible to detect a stationary roadside object on the basis of peak densities. The stationary object eliminator eliminates data of peak groups identified as stationary objects by the stationary object identifier and thereby removes them as objects of combination processing for pairing rise side beat frequencies with fall side beat frequencies.

Abstract: A distance measuring device having a housing, a transmitting and receiving unit for measuring signal arranged in the housing, an evaluated element for determining a distance to an object by a travel time measurement, at least one reference point fixed on the housing to which a measured distance is referred, the at least one reference point being a part of a reference plane, such that an abutment surface which faces an object and an abutment surface which faces away from the object are arranged in the reference plane and fixed to the housing.

Abstract: An equivalent time pulse-echo radar or other pulse-echo system employs a transmit reference sampler collocated with the transmitter to provide a transmit reference pulse, which initiates a pulse width modulated (PWM) pulse. A receive sampler connected to a receive antenna provides an echo-detection pulse that terminates the PWM pulse, such that the width of the PWM pulse indicates target range. The transmit reference sampler and the receive sampler are driven from a common clock such that transmit-receive timing offset drift precisely cancels on a picosecond scale, thereby enabling sub-mm range accuracy with common, low-cost circuit elements. The radar further includes automatically referenced pulse detectors that are responsive to either the magnitude or the phase of the sampler outputs. The radar can be used for precision tank level measurements, robotics, or automotive ranging applications.

Abstract: For electromagnetic wave distance measurement by the pulse transit time method, short electromagnetic transmission pulses are emitted at periodic transmission instants. The signals received in selected transmission cycles after the respective transmission instants are sampled for obtaining in each of these transmission cycles a sample at a sampling instant in a respective sampling time interval, each sampling instant having a delay dictated by a sampling function relative to the respective transmission instant. The sampling instants exhibit differing delays relative to the respective transmission instant so that the samples in sequence produce an image of the sampled received signal extended in time. The sampling function dictating the delays is generated by a computing circuit, preferably a microcomputer, thus making it possible to make use of any sampling function and to modify sampling of the received signals in any way.

Abstract: An apparatus and method for measuring the true distance and relative velocity between first and second objects. The apparatus comprises a transceiver located at the first object which measures a first transit time for the transmission of a first signal from a first object to a second object and for the reflection of the first signal from the second object back to the first object. The transceiver further measures a second transit time for the transmission and reflection of a second signal, the second signal being transmitted immediately upon the reflection of the first signal back to the first object. First and second transit times can be used to calculate first and second apparent distances between the first and second objects, respectively. The apparatus also includes calculating means for determining the relative velocity between the first and second objects using the first transit time and the second transit time.

Abstract: A method for determining the location of an object in a passenger compartment of a vehicle in which ultrasonic waves are transmitted from a first transducer into the passenger compartment, waves reflected off an object in the passenger compartment are received by the first transducer and a first distance from the first transducer to the object is calculated based on the time difference between the transmitted waves and reflected waves when received by the first transducer. Further, different ultrasonic waves are transmitted from a second transducer into the passenger compartment which then receives reflected waves off the object and a second distance from the second transducer to the object is calculated based on the time difference between the transmitted waves and reflected waves when received by the second transducer. The approximate location of the object in the passenger compartment is determined based on the first distance and the second distance.