Abstract: The present disclosure relates to a radar device and technique for detecting the presence of objects located in the near-field of a frequency modulated, continuous wave (FMCW) radar device. The technique includes transmitting and receiving a frequency modulated signal, generating an intermediate frequency signal based on the transmitted and received signals, and analyzing the frequency content of the intermediate frequency signal. The frequency content of the intermediate signal is analyzed without filtering out a carrier signal.

Abstract: A system and method for providing a fork sensor including an emitter, a receiver, and at least one lens assembly wherein the width of the effective beam does not depend upon the size of the emitter or the receiver. One aspect of the present invention is a method for detecting or counting the number of objects interrupting the effective beam of the fork sensor. Another aspect of the present invention is a method for measuring the dimensions of objects using the fork sensor.

Abstract: A light screen safety curtain system including multiple light screens cascaded together to cooperatively protect an area or machine against unwanted intrusion. Such a system includes a plurality of independently operating light screens electrically connected to each other and to a control unit. When any one light screen detects an unwanted intrusion through a guarded opening, a stop or warning signal is generated by that light screen and is transmitted to the control unit. A method of configuring a light screen safety system without the need for an external programming device is provided.

Abstract: A computer controlled system, method, and corresponding computer data product for determining a range of image decimation values for use in processing of images within a machine vision system. The system and method generates a high resolution reference image, generates a set of decimated reference images from the high resolution reference image, generates a set of interpolated reference images having a spatial image resolution identical to the high resolution reference image from the set of decimated images, cross-correlates the set of interpolated reference images with the high resolution reference image to generate a set of cross-correlation values, and selects a subset of the set of decimated reference images corresponding to interpolated references images that generated a cross correlation value greater than a predetermined threshold value.

Abstract: A retroreflective sensor apparatus which includes a light source with a collimating lens and a photoelement with a condensing lens. The light source and the photoelement are positioned adjacent to and offset from each other. A mask is placed between the light source and the collimating lens on a side away from the photoelement to block a portion of the light from the light source from reaching the collimating lens. A method of constructing a retroreflective optical sensor including providing a light source with a collimating lens and a photoelement with a condensing lens. The light source and the photoelement are positioned adjacent to and offset from each other. An opaque mask is placed between the light source and the collimating lens on a side away from the photoelement to block a portion of the light from the light source from reaching the collimating lens. A reflector is positioned to receive light from the light source and reflect it to the photoelement.

Abstract: A system and method are disclosed for shielding a capacitive sensor. The system and method drive the shield to the same potential as the sensor electrode being shielded to eliminate sensor interference due to mutual capacitance. An independently created signal is applied to the shield which matches the signal applied to the sensor electrode. Use of the independent driving signal allows the shield to maintain the same potential as the sensor electrode, especially during rapid transition of the sensor electrode's potential.

Abstract: Circuits and methods for generating signals representing the division or multiplication of two analog signals are incorporated into optical triangulation distance measurement systems. In one embodiment one of two analog voltage signals is used to generate a current signal. A capacitor is charged by the current signal. The voltage on the capacitor is compared with the other analog voltage signal and a signal is generated that has a time interval representing the division of the two analog voltage signals. In the application of the circuit and method to optical triangulation distance measurement the time interval signal is further processed to obtain distance measurement to a target.

Abstract: The present invention is directed to a method and apparatus for measuring a magnetic field and determining whether an anomaly is present based on the magnetic field measurement and a measured ambient magnetic field. The present invention is also directed to a method and apparatus for measuring the intensity of the magnetic field by implementing operations to essentially eliminate error components that arise due to factors including offsets and gains affecting the intensity signal processing.

Abstract: A system and method are disclosed for detecting the occurrence of an external event. The system eliminates the need for users to adjust amplifier offsets as well as detection thresholds by continually analyzing the signal and optimizing the offset and threshold values accordingly. Additionally, the system detects the external events in a noisy environment when the duration of the events vary by several orders of magnitude by employing cascaded difference filters.

Abstract: A distance sensing system employs an optical triangulation system and a position sensitive device (PSD). The PSD generates a pair of current signals when a target reflects light from a light source back to the surface of the PSD. An automatic power control circuit is used to keep one of the current signals a constant value. The position of the reflected light spot on the PSD is linearly proportional to the other current generated by the PSD according to the formula:Y=C.times.I2Where Y is the spot position and C is a normalization constant. The signal I2 is processed to extract distance information relative to the target.

Abstract: A detection sensor with a single switch for multi-function programming of the sensor is disclosed. The sensor has a processor operatively connected to the switch, an emitter, and a detector for controlling one or more operational parameters of the sensor in response to a program signal from the switch. In the preferred embodiment the processor compares a signal detected by the sensor in a first state and a second state and automatically establishes the sensor amplifier gain and switching thresholds based on the signal difference in the two states.

Abstract: A binary sensor has a device for detecting the presence or condition of an object. The sensor has circuitry connected to the detecting device to generate a binary output signal that represents the presence or condition of the object. The sensor also includes circuitry that generates a diagnostic signal associated with the sensor. The diagnostic signal is superimposed on the binary output signal. The binary output signal with the superimposed diagnostic signal are simultaneously transmitted to a controller such as a Programmable Logic Controller or a smart drop in a bus network. The diagnostic signal is designed so that it will not interfere with the ability of the controller to recognize the binary output. The controller may be provided with circuitry to detect and interpret the diagnostic signal.

Abstract: A modulated photoamplifier precludes false output signals and oscillations in the event of component failure. The photoamplifier converts modulated electromagnetic energy into voltage pulses. A phototransistor receives the modulated electromagnetic energy and generates corresponding current pulses. A differential amplifier with negative feedback receives the current pulses and produces the corresponding amplified voltage pulses. A capacitor within the feedback network produces optimum gain at the frequency of the modulated electromagnetic energy. A failure of any component within the photoamplifier removes its ability to generate voltage pulses. Therefore, the photoamplifier precludes false output signals and fails to a safe condition in response to the component failure.

Abstract: A photoelectric sensor interfaces and operates directly on the power available from a standard current loop without requiring an independent power supply. The sensor includes an emitter and receiver for measuring a parameter such as the distance between a target and the sensor. The intensity of light received by the receiver controls, as an inverse function, the amount of current drawn by the emitter. As the target becomes distant and the intensity of received light decreases, the sensor directs more current to the emitter, which also serves to enhance the sensor's range. As the target becomes closer to the sensor, the intensity of received light increases and the sensor directs less current to the emitter because less current is required to produce a signal of sufficient strength for the receiver to detect. With less current directed to the emitter, sufficient current from the current loop is still available to operate the remaining circuitry in the sensor.

Abstract: An improved photoelectric sensor assembly has a one-piece threaded barrel housing, preferably with focus lenses formed therein. An aperture piece fits within the barrel housing, and a printed circuit board carrying the scanner electronics fits in behind it with the optoelectronic elements aligned with the aperture piece and the lenses. A power and signal cable from the circuit board extends out the back end of the sensor housing. A foam compression ring fits against the PC board and is backed by a washer, second compression ring and second washer, all of which have apertures for the cable to pass through. An end cap threads onto the rear of the threaded barrel and compresses the washers and compression rings.

Abstract: A DC circuit for a sensor or control device is disclosed which has a primary output, and a secondary output which, at the option of the user, is either the complement of the primary output or an unrelated output signal such as an alarm signal. The user selects the mode of operation of the secondary output terminal by selecting the polarity of a supply voltage applied to the control device at two input terminals.