Abstract: A method for accurately calculating the movement of a vertex in a three-dimensional (3-D) topography simulator. The method is particularly suited for calculating vertex movement for cases in which etch/deposition rate depends on the angle between the surface normal and the vertical direction. A workpiece is represented as a collection of material solids. Each of the material solids has a boundary model representation. The method of the present invention is comprised primarily of the steps of: advancing edges and surface planes adjacent to the vertex, creating a set of 2-D solutions by clipping with pairs of adjacent surface planes; creating a set of combined 2-D solutions by clipping invalid sections of combined 2-D solutions; construct an arbitrary vertical plane that intersects the surface at the vertex point; constructing vertex trajectories for the vertex to be moved; and clipping constructed vertex trajectories at intersections of created surface and the constructed vertical plane.

Abstract: The conditions of casting with a permeable mold having a cavity and a runner can be optimized by a computer simulation method of (1) dividing the mold and a cavity thereof into a plurality of elements; (2) providing mold properties, a pressure and a velocity of a melt flowing into the runner as initial data with respect to each element; (3) performing computations in a step-wise manner to determine the movement of a free surface of the melt and a rate of gas flowing through the mold until the cavity is filled with the melt; (4) calculating a total volume of voids generated in the melt; (5) examining whether or not the total volume of voids is substantially zero; and (6) if the total volume of voids is not substantially zero, repeating the computations with at least one of the initial data modified until the total volume of voids becomes substantially zero.

Abstract: A fault tolerant clock system that includes voting of power-on and other reset signals to ensure tight synchronization. A fault tolerant clock system (10) includes four channels, providing tolerance to a catastrophic failure in one of the channels and a second fault in another channel. Each clock channel comprises a crystal oscillator (12), an RC circuit (14), and a gain circuit (16) that are connected in a feedback loop with a first voter module (18). The first voter module produces a voted time base output signal corresponding to a majority vote of the timing signals provided by each of the four clock channels. This voted time base signal is fed back to the crystal oscillator through the RC circuit.

Abstract: A method of producing a multi-apertured workpiece such as a fuel injector comprising forming an aperture in a workpiece by EDM machining (10), supplying a calibrating fluid such as deionized water through the aperture from a reservoir (17) via a pump (18), measuring the flow and pressure through the aperture by transducers (19, 20) and comparing the results with a predetermined ideal, adjusting the EDM machine (10) in accordance with such comparison so as to compensate for the difference between the measured values and the predetermined ideal, forming a further aperture using the adjusted EDM machine (10) and repeating the preceding steps until the appropriate number of apertures has been formed. The apparatus may include CNC operation (14) and the comparison may be made by computer (15) linked to the CNC (14) for adjusting the EDM machine (10).

Abstract: A feedback control system compensator of the PID type is provided, wherein the proportional component of the compensator is replaced with a tilted component having a transfer function s to the power of -1/n. The resulting transfer function of the entire compensator more closely approximates an optimal transfer function, thereby achieving improved feedback controller. Further, as compared to conventional PID compensators, the TID compensator allows for simpler tuning, better disturbance rejection ratio, and smaller effects of plant parameter variations on closed loop response.

Abstract: A furnace 1 runs while repeating a cycle in which the furnace inside temperature varies along a preset pattern of temperature change with time under the control of a primary controller 12, and adjustment input r being applied to an enlarged system including the furnace 1 and the controller 12 is renewed at the end of each cycle of operation, based partly on output from a dual system with respect to the enlarged system, so as to reduce error between the preset temperature and the furnace inside temperature in the next cycle. The temperatures of heaters 2 of the furnace 1 are controlled by a secondary controller 35, and the set values at the input of the secondary controller 35 are given by output signals (.tau.) from the primary controller 12 which responds to the furnace inside temperatures (y). The order of the dual system is reduced, and the renewal of the adjustment input r is quickened.

Abstract: An artificial intelligence system which utilizes a unique technique for storing data, analyzing data, and reducing the complexity of data is disclosed. The technique involves identifying "world" states that have a unique exclusive relationship. The identification of these unique states considerably reduces the complexity of the world under study. Furthermore, the identified unique states are useful in combination with any way the system has to affect the world under study. These identified unique states, when placed in a hierarchical scheme, further reduces the complexity of the world under study.

Abstract: An adaptive control includes a digital error correction system (DECS) to reduce control system error to near zero by anticipating a problem and feeding forward in time a correction to deal with the problem before it happens. The adaptive control is used in a controlled system of the kind which is cyclical in operation and which operates in response to repetitive cycle commands so that the operation of the system is substantially predictable for a significant number of cycles of operation. The adaptive control is incorporated in a spatial chopping or scanning telescope system of the kind in which a telescope mirror is moved in repetitive cycle motions and in a rigidly prescribed pattern between varied orientations and wherein the mirror is held for a prescribed, relatively long period of time in each orientation and is moved rapidly in a relatively short period of time from one orientation to another.

Abstract: A method of estimating the properties of a steel product, comprising completing a computation for determining metallurgical phenomena based on information concerning steel ingredients and production conditions in steps from casting to heat treatment to successively determine the state of a metallic structure and estimating the properties of a steel product from the final state of the metallic structure.

Abstract: For each of a plurality of frame patterns, pattern data of the frame pattern, position data of character patterns and data of a maximum number of character patterns are stored in a memory. When an arbitrary one of the frame patterns and a plurality of arbitrary character patterns are selected, data composition is performed such that the selected character patterns are combined with the frame pattern at a predetermined position on the condition that the number of such character patterns is limited to the maximum number for the selected frame pattern.

Abstract: A pattern recognition adaptive controller configured to dynamically adjust proportional gain and integral time control parameters to minimize integrated absolute errors between a setpoint and a monitored controlled variable. The pattern recognition adaptive controller receives a sampled signal representative of the controlled variable, and determines a smoothed signal based on the sampled signal. The controller characterizes a disturbance in the smoothed signal by a damping factor and a closed loop response time. When a significant load disturbance or setpoint change occurs, the controller estimates an optimal gain based on the damping factor, and an optimal integral time based on the response time. The estimated optimal gain and estimated optimal integral time are used to determining a new gain and a new integral time values, to which the control parameters of the controller are then set.

Abstract: In a control system, especially a hydraulic screw-down control system for a roll stand, the controller output is acted upon by a pilot control value (v.sub.1.sup.*). At the same time, a reference value (x.sub.M ') is delivered to the controller via a subtractor as a setpoint value. The reference value (x.sub.m ') is determined in a model control loop based on the pilot controller. Parasitic response characteristics of the overall system are largely accounted for in the model control loop, so that on a time-averaged basis the controller is not activated.

Abstract: The present invention relates to processes for the automatic generation of numerical control (NC) tool paths in a CAD/CAM environment. The present invention operates on mechanical parts described as solid models. The process employs well-defined solid models of the part to be machined and the raw stock from which it will be machined. The volumetric difference between the stock and the part defines the material (delta volumes) that must be cut away during the actual machining process. Delta volumes are solid models, and users (or an expert system) can subdivide delta volumes into smaller volumes that are consistent with a manufacturing process plan. A delta volume and a user-defined strategy for machining the delta volume are then input to NC algorithms. The algorithms generate NC tool paths that remove as much delta volume material as possible. Tool volumes are automatically generated from NC tool paths to represent the volume traversed by the cutting tool.

Abstract: In order to enable the determination of a center precisely and automatically, a reference mark on a printed circuit board is image-recognized to determine tone transition points, thereby to determine an interim center and diameter of the mark by a four-points searching method. Next, a preset minute value .alpha. is added to the interim mark diameter to determine a standard circle diameter, thereby to set a standard circle having the interim center as its center. Then, image processing is performed in that standard circle and the mark is separated into a plurality of sections. The center of the mark is detected by determining the center of the section of the tone indicating the mark. Machining operations such as the perforations are carried out on the basis of the detected center.

Abstract: A method and system is provided for eliminating malfunctions in textile machines, in particular spinning machines. Malfunction signals are transmitted from the machine to a process control computer that controls the elimination of the malfunctions. The process control computer activates an alarm call transmitter that calls a desired specialist for removing the malfunction in a certain machine.

Abstract: An interactive system and method for creating and modifying embroidery designs is disclosed. The system provides a user with numerous functions for interactively creating and modifying embroidery designs, and generating the necessary stitch commands for recreating the embroidery design on an embroidery stitching machine. The system is preferably operative on an IBM PC. The system is menu-based, and may be used for modifying embroidery designs in either outline-format or stitch-format. Once a design has been entered, the user may utilize predetermined functions to quickly alter a design and visualize the resulting design. The system further provides a method for modifying embroidery designs in an outline format into bridge type lettering.

Abstract: The purpose of the invention is to carry out the most appropriate attitude control of non-contact distance detectors (5a, b) onto the tracer model (6) surface and provide a digitizing control unit with high accuracy. A non-contact distance detecting device (105) samples coordinates of a plurality of points from the model surface, and the coordinates are stored in a memory (101). A point selecting device (102) selects 3 points on the tracer model surface composing a triangle most similar to a regular triangle after selecting 3 arbitrary points of the stored coordinates. A vector determining device (103) determines the normal vector with reference to the coordinates of the 3 selected points. The attitude of the non-contact distance detecting device (105) is controlled by the attitude control device (104) using the normal vector.

Abstract: The present invention provides a method and apparatus for adaptive control which does not require a predetermined model of the process to be controlled. The method comprises the steps of 1) setting an initial state vector; 2) setting an initial parameter vector; 3) setting an initial prediction parameter gain; 4) set the initial covariance matrix; 5) performing a state update 6) estimating the model error; 7) updating the parameter vector, 8) updating the co-variance matrix, and 9) updating the controller output.

Abstract: An adaptive PID.tau..sub.d controller has a proportional derivative section that generates an error signal representing an error in the control signal, particularly, as a function of (i) a time rate of change of the controlled variable signal and (ii) a difference between the controlled variable signal and a predetermined setpoint. A summation element sums that error signal with a time-delayed integral signal to generate a summation signal. That summation signal, in turn, is filtered by the aforementioned adaptive noise filter to generate a manipulated variable signal, which is selectively applied to the process by an output section. A feedback element processes the manipulated variable signal to generate the time-delayed integral signal, referred to above. That processing includes time-delaying the manipulated variable signal an mount substantially equal to the deadtime of the process, .tau..sub.

Abstract: A PID control device identifies rise characteristics of a controlled system by a step response method on changing a reference, moves to PID control when idle time and slope successively obtained at the rise reach a predetermined condition, and computes PID control parameters based on the idle time and slope obtained up to that point. If the identification is fully executed, the computed PID control parameters are immediately set. If it is not fully executed, the PID control device 1 further watches the state to compare a proportional gain of the newly computed PID control parameters with the proportional gain of previously set PID control parameters, and the currently computed PID control parameters are set when the parameters are on a safe side.