Showing papers on "Offset (computer science) published in 1985"

Self-tuning control of offset: a unified approach

Abstract: The CARMA model generally assumed in self-tuning control frequently leads to an offset between the measurement and the desired value when regulating a plant subjected to constant load disturbances about a nonzero set point. The normal ad hoc insertion of an integrator solves the problem but can introduce others (such as convergence difficulties). The solution explored in this paper is to use a CARIMA plant model in which the noise term is nonstationary, and it is shown that good adaptive behaviour is then possible both with generalised minimum-variance and pole-placement self-tuning controllers. The approach produces integral control terms in a natural way, and, for simplified plant models, leads directly to a general PID algorithm.

A Micropower CMOS-Instrumentation Amplifier

Abstract: A CMOS switched capacitor instrumentation amplifier is presented. Offset is reduced by an auto-zero technique and effects due to charge injection are attenuated by a special amplifier configuration. The circuit which is realized in a 4-/spl mu/m double poly process has an offset (/spl tau/) of 370 /spl mu/V, an rms input referred integrated noise (0.5 -f/sub c//2) of 79 /spl mu/V, and consumes only 21 /spl mu/W (f/sub c/ = 8 kHz, V/sub DD/ = 3 V).

Method and system for automatically determining the position and attitude of an object

Abstract: A method and system are provided for automatically determining the position and attitude of a three-dimensional body at a work station by utilizing three cameras each of which generates a non-overlapping plane of image data, including a single target point of the body without the use of structured light. The locations of the target points are determined and processed within a programmed computer together with calibration data relating to the expected position of the body in the work station to provide data relating to the position and attitude of the body with respect to the work station. The resultant data relating to the position and attitude of the body are subsequently transformed into a first set of offset data relating to the difference between the actual and expected positions of the body. The first set of offset data is then transformed into a second set of offset data in the coordinate system of a peripheral device such as a robot, programmable controller, numerically controlled machine, etc. Finally, the programmed computer transfers the second set of offset data to the peripheral device which utilizes the data to modify its pre-programmed path.

Offset curves in the plane

Abstract: For applications such as the generation of ornamental patterns for the numerical control of sewing machines in the textile industry or in the shoe industry or the numerical control of milling machines in the car body industry, offset curves must be generated from curves Di given by a designer. During the generation process further problems arise, for example finding the intersection points of neighbouring branches of the offset curves or deleting undesirable portions of the offset curves with cusps or with self-intersection points. In this paper methods are developed for attacking this problems.

Collector‐emitter offset voltage in AlGaAs/GaAs heterojunction bipolar transistors

Abstract: Factors affecting the collector‐emitter offset voltage in AlGaAs/GaAs heterojunction bipolar transistors have been examined both experimentally and theoretically. In the offset region the collector current, instead of being zero as reported in the literature, is negative and is equal to or less than the base current. The majority of our double heterojunction transistors have negligible offset voltage (50 mV). The prime reason of unusually large offset voltages as observed in some of our devices is found to be the poor quality of the base‐collector (b‐c) junction which is affected by the growth and fabrication processes. The effect of the conduction‐band spike on the offset voltage depends on the compositional grading and in properly graded devices is negligible. For zero offset voltage, high quality of the b‐c junction is important such that its turn‐on voltage is either equal to or higher than that of the emitter‐base junction.

Digital scaling circuitry with truncation offset compensation

Abstract: A scaling circuit for scaling PCM signals by factors less than one includes a bit-shift and truncating circuit. Roundoff error compensating circuitry adds an offset value to the samples to be scaled by the bit-shift circuitry to compensate for errors produced by truncation without rounding. The offset values are dithered to increase the apparent resolution of the system.

Disc brake with sliding caliper

Abstract: Disc brake of the type incorporating a caliper (10) sliding on a fixed support by way of at least one axial pin (14) lying parallel to the axis of the disc (16), a brake actuator (22) acting directly upon an inner friction component (28), and, by reaction through the caliper (10), upon an outer friction component (30), the friction components (28, 30) being tangentially offset each side of a radial plane (Pr) passing through the axis of the brake actuator (22), the inner friction component (28) being anchored on the fixed support, the outer friction component (30) being anchored on the caliper (10), the tangential offset of the friction components (28, 30) being such that during forward braking (B) the caliper is subjected to a tangential force (Ft) generated by the outer friction component (30). The caliper (10) incorporates a device for positioning (32) the caliper relative to the fixed support, the positioning device (32) being progressive and dependent upon the tangential force (Ft) over a predetermined range of the force (Ft).

Data transfer control equipment

Abstract: A Direct Memory Access Controller includes first and second registers respectively to which first and the second offset data are supplied, as well as a register to which source address data is supplied and a register to which destination address data is supplied. Every time one data item is transferred from one memory to the other, the source address data and the destination address data are updated respectively by values designated by the first offset data and the second offset data. Address data can be updated both increasingly and decreasingly. According to the Direcet Memory Access Controller of this construction, the transfer of data such as a rotational operation of graphic data stored within the image memory can be achieved without increasing the burden imposed upon the microprocessor.

Device for attaching a detectable shoplifting prevention body

Abstract: A plastic hollow body contains a resilient spring plate. The spring plate is attached to the body at one end and, at another end, has an iron core. A hole in the body is slightly offset from a hole in the spring plate such that a pin extending through the hole in the body cannot pass through the hole in the spring plate until the spring plate is bent by a force from the spring. The pin then extends through the hole in the spring plate and the spring plate is locked onto a reduced diameter portion of the pin. The release of the pin is possible only by applying a magnet adjacent the iron core so as to move the spring plate from the locked position.

Apparatus and method for removing an offset signal

Abstract: An offset compensator is disclosed. The offset compensator is suitable for use with any antipodal information signal distorted by an offset voltage. The offset compensator measures the positive and negative peak amplitudes, compares the magnitudes thereof, and produces a correction voltage based on that comparison. The correction voltage has a positive sign when the magnitude of the negative peak amplitude exceeds the magnitude of the positive peak amplitude, and the correction voltage has a negative sign when the magnitude of the positive peak amplitude exceeds the magnitude of the negative peak amplitude. The magnitude of the correction voltage represents the difference between the magnitudes of the positive and negative peak amplitudes, and is added to the antipodal information signal to remove the offset voltage.

Scanning method and apparatus

Abstract: A document scanner compensates for mechanical misalignment between a document and a photosensitive array by storing pixel information from the array and timing the output of such information in accordance with stored offset values which represent the mechanical misalignment for successive relative positions of the document and of the array.

Device and method for flow-turning

Abstract: At at least one of the metal-spinning rollers, the device has a measuring arrangement for determining the radial, axial and tangential force components acting on the metal-spinning roller. These force components or preferably their ratios to one another can serve as a criterion for the initial setting and/or continuous adjustment of the parameters to be maintained during flow-turning, in particular feed, speed of rotation, in-feed of the rollers, offset of the rollers.

Time-offset-frequency-amplitude panels for seismic identification of hydrocarbons

Abstract: A method for preparing a display of seismic data obtained from multiple-point coverage of a subterranean earth formation using an array of seismic sources and acoustic receivers. A set of seismic traces is obtained in such a manner that each trace is associated with a source-receiver pair separated by a particular offset distance, and all the traces are associated with a common subsurface reflection point. Each of the traces is filtered through a bank of band-pass filters to produce a set of filtered traces, each having a different frequency content, for each offset value. The filtered traces associated with a particular offset value are displayed in order of progressively changing frequency content, and the filtered traces associated with a particular frequency band are displayed in order of progressively changing offset value. The seismic traces are preferably processed prior to the band-pass filtering step to reduce source-generated noise, to compensate for non-geologic factors such as geometric divergence and source strength variation, and to flatten hyperbolic (or pseudo-hyperbolic) primary reflections. In one preferred embodiment, groups of filtered traces having offset values in a selected range and representing the output of one of the band-pass filters are stacked together, and the stacked traces are displayed in order to progressively changing frequency content or progressively changing ranges of offset values.

Operational amplifier offset trim that does not change the offset potential temperature drift

Abstract: A JFET operational amplifier input stage is disclosed along with am offset potential trimming circuit. The trimming circuit includes a scaled down compensation stage that is modeled after the input stage and provided with a constant temperature independent bias. This generates a trimming current that varies with temperature inversely with the transconductance of the input stage. A control circuit applies a digitally controlled portion of the trimming current to the input stage so as to compensate the offset potential. The input offset potential is therefore compensated without changing the offset potential temperature drift. Desirably the compensation is achieved after device assembly.

Mobil pre-etched data carrier

Abstract: A mobile pre-etched data carrier is provided in which the pre-etching is formed by a succession of discrete non continuous elements materializing the mean axis of the tracks. The spatial distribution of these discrete elements may be uniform or not. In a first embodiment, each discrete element is formed by a smooth track section. In a second embodiment, each discrete element comprises several sections defining a particular code. In other preferred variations of the invention, each element comprises, besides a portion centered on the mean axis of the tracks, one or more portions offset with respect to the axis. Finally, each of the pre-etchings may itself be preceded by an additional pre-etching element used for the purpose of synchronization. The tracking device comprises photodetector means, measuring circuits comprising sampler-inhibitors or storage integrator circuits and sampling circuits. A radial tracking error is formed from the evolution of the signals detected during successive passages.

Rotating planar array antenna

Abstract: A planar array antenna is contructed of two sets of slotted rectangular waveguides positioned to have the slots of adjacent waveguides offset by half the slot spacing. A bidirectional feed is used with phase switching between inputs to produce four distinct output beams from the array.

Direct-voltage measuring device with offset voltage compensation

Abstract: The direct-voltage measuring device is equipped with a hybrid chip (36) which very rapidly compensates for offset voltages within a predeterminable level by zero calibration and at the same time provides for a check of the point from which the level is exceeded or a zero calibration is no longer possible. Purely electrically activatable zero calibration elements such as a comparator (12), a successive approximation register (SAR) (14) and a D/A converter (20), externally triggered, determine to this end any offset of the transmitter before each measurement is started, hold this offset digitally stored and, by means of an analog mathematical chip (subtracter or adder) (3), superimpose it, after regeneration into an analog signal, continuously at the same level onto the measurement value of the transmitter (1) during the actual measurement.

Variable tracking word recognizer for detecting the occurrence of a dynamic-variable address

Abstract: A variable tracking word recognizer generates an indicating signal when a microprocessor has accessed a memory stack location storing a dynamically addressed variable, the address of the variable being the sum of a dynamically assigned base address of the memory stack and a known address offset where the variable is stored on the stack in relation to the base address. The variable tracking word recognizer stores the dynamically assigned base address, when determined by a space allocation subroutine of a program running on the microprocessor, and then monitors the addresses subsequently appearing on the microprocessor address bus, generating the indicating signal when the current address matches the combination of stored base address and known address offset. The variable tracking word recognizer comprises circuitry to generate a storage control signal when the base address appears on the data bus of the microprocessor, a base register for storing the base address on occurrence of the storage control signal, an arithmetic logic unit for determining the difference between the number stored in the base register and each address appearing on the microprocessor address bus, and a conventional word recognizer to generate the indicating signal when the difference so generated equals the known offset.

Solid state apparatus for imaging with improved resolution

Abstract: A solid state apparatus for imaging with improved resolution, wherein there can be present at least two solid state sets of detector elements each set of which is sensitive to a different wave length of electromagnetic energy from the other. Each detector is situated such that it may record a picture element which is systematically offset from and partially overlaps the picture elements recorded by the analogous detectors of the other sets. There are existing computer programs for changing the data obtained into a form suitable for an image of better resolution than is possible when the analogous detectors record the same picture element of the scene without offset.

Compact machine for pressing and applying fluids to webs of material

Abstract: In a compact machine for pressing and applying fluids to webs of material, a hot roller is provided in whose interior a plurality of mutually independent, offset magnet bars are provided, opposite which there are application devices with elements made of magnetisable material.

Finite prism analysis of plates and shells

Abstract: The finite prism technique introduced by Zienkiewicz and Too4 is extended to include 12-node prism elements and, more importantly, a novel offset beam element. The use of 12-node prism elements enables parabolic strain distributions to be simulated, this being useful for structures which have strongly tapered cross-sections. The offset beam element is used to simulate flexure and torsion of a beam whose centroid is offset from the main structure. The element is specified completely at the nodes of adjacent prism elements and so is not really an ‘element’ in the usual sense. The analysis is applied to thin and thick plates and to shells, with and without edge beams. It is shown to be more versatile than the finite strip method and it requires smaller computer resources than the finite element method. Experimental verification of the analysis is obtained by comparison with measurements for a double-T bridge deck tested by Loo14.

Process and device for uniting two flows of overlapping articles

Abstract: 1. A method for combining two adjacently moving streams of overlapped products, more especially folded ones, to form a common stream of products characterized in that the two streams (4 and 5) of overlapped products have an offset of their products (13) in the direction of travel by half the product pitch, are moved together in a common plane of conveyance at an acute angle till they completely overlap and at the point of confluence of the respective products (13) are diverted alternately out of the common plane of conveyance.

A Precision Baseline Offset and Drift Corrector for Low-Frequency Applications

Abstract: An analog technique for correcting baseline offset and drift in low-frequency systems is analyzed. The described method applies to periodic and nearly periodic signals, characterized by a time interval in which they may be considered at rest (electrocardiogram (ECG) signals, for instance), and is limited to linear drifts. Two different circuits have been developed and are discussed here. Signal conditioning performed on suitable input waveforms is presented. Noise effects have been theoretically considered and experimentally evaluated.

Method and circuit arrangement for reducing the torque ripple of a converter motor in the low speed range

Abstract: In the case of reducing the torque ripple of a converter motor (3) having two DC-isolated three-phase stator winding systems (U1, V1, W1; U2, V2, W2) which are offset by 30 DEG with respect to one another and are supplied from two converters, which each consist of a mains converter (NSR 1, NSR 2), and intermediate-circuit inductor (Ld1, Ld2) and a machine converter (MSR 1, MSR 2), with intermediate-circuit currents (Id1, Id2) whose amplitude can be influenced separately by driving the valves of the mains converter (NSR 1, NSR 2), it is intended, in the low speed range, both to suppress oscillating forks and to overcome discontinuities during the further switching of the electric loading (ratio of the total current per slot divided by the tooth pitch) of the converter motor (3). For this purpose, the valves (11... 16; 21... 26) of the mains converters (NSR 1, NSR 2) are driven in such a manner that two intermediate-circuit currents (Id1, Id2) flow, offset through 90 DEG with respect to one another, as sinusoidal half cycles which continuously follow one another in time. The valves (1A, 1F, 1C, 1D; 2A, 2B, 2D, 2E) of the machine converters (MSR 1, MSR 2) are driven in such a manner that each of the two intermediate-circuit currents (Id1, Id2) are switched on alternately in the positive and negative direction per sinusoidal half cycle via exclusively two (u1, v1 and u2, w2 respectively) of the three phase connections through windings of the two stator winding systems (U1, V1, W1; U2, V2, W2) whose electrical effect is mutually orthogonal.

A general approach to relative offset settings of traffic signals

Abstract: An generalised approach for simulating relative offset of traffic signals in an urban traffic network is presented. It is shown that is is possible to optimize relative offset settings of signals for various criteria. A general criterion is proposed by which either delays, stops, fuel consumption, or carbon monoxide can be selected by a proper choice of constants. When these criteria are minimized, it was found that the best criterion to be selected for offset setting is the minimization of fuel consumption, since this in turn nearly minimizes the delays, stops, and carbon monoxide emission, and it has the effect of minimizing stops at low saturation and minimizing delays as the degree of saturation increases. Further analysis of the criterion function has shown that the functions minimized are uneven around their optimum offset value and in each case an early switching is favored. The expression to determine optimum offset is updated to calculated optimum offsets that minimizes fuel consumption or carbon monoxide emission.