Showing papers on "Process variable published in 1983"

Pattern-recognizing self-tuning controller

Abstract: A pattern-recognizing, self-tuning controller is provided for controlling a process wherein measured characteristics including at least one peak of an error signal, derived from the differences occurring over time between the values of a process controlled variable and a desired set-point level for that variable, are used for identifying the behavior pattern of the error signal so that an operating parameter of the controller can be changed as required to minimize process recovery time whenever the process is subsequently disturbed or an abrupt change is made to the set-point level at some later time. The preferred embodiment of the device is in the form of a proportional-integral-derivative (PID) controller in which the PID coefficients are calculated in accordance with prescribed relationships that are based on damping, overshoot and time period characteristics of the error signal. Provisions are also made for including a user-specified noise threshold in order to reduce substantially the possibility of detecting a noise peak as a true peak of the error signal. A pre-adapt mode is also included, in which the controller automatically determines the initial values of the PID coefficients, the noise threshold, and the approximate time scale of the process, before on-line adaptive control of the process is given to the controller.

Generation of a set point for process control

Abstract: In a process in which a first process variable is manipulated so as to maintain a second process variable substantially equal to a desired value for the second process variable, a set point for the first process variable is generated based on the difference between the actual value of the second process variable and the set point for the second process variable. The magnitude of the set point is determined by the probability that the second process variable may reach an undesirable value and thus control using the set point takes into the consideration the fact that large control actions may be required under some circumstances and minimal control actions may be required under other circumstances in a process.

Control system for fluid flow distribution

Abstract: Process control is disclosed, applicable in particular to fluid flow distribution, by which decoupling of the individual process variable changes, by set point setting changes, is effected through anticipation of the interaction through the process, using Gauss-Jordan elimination to find the solutions to simultaneous equations, whereby all set point settings are simultaneously adjusted by adding such anticipations.

Controlling method for process

Abstract: PURPOSE:To attain quick control without overshooting by increasing a manipulated variable up to its maximum value and calculates a point of time for switching the manipulated variable from an individual condition of a controlled system at time of control operation and feeding back the manipulated variable from its maximum value in accordance with the calculated result to control the manipulated variable CONSTITUTION:The maximum value of a square wave pulse is supplied as a manipulated variable at the control operation of a controlled system Power supply 7 is inputted to a buffer amplifier 21 through an inverter 1 and through a buffer amplifier 22 from an input terminal 8 and then inverted and amplified by an inversional amplifier 3 A variable resistor for feedback sets up a parameter and a comparator 4 discriminates whether a set point is S or P to detect a point of time for switching the manipulated variable A variable resistor 13 is adjusted so that the output of an amplifier 14 is turned to zero to automatically set up differential time An integrator is connected to the post-stage of the amplifier 14 Thus it is possible to control the process variable of the controlled system to its set point within a short time without generating overshooting

Process for the production of optical fiber preforms

Abstract: An improved process for the production of optical fiber porous preforms (4) of predetermined refractive index distribution by the vapor-phase deposition method is disclosed wherein a glass material and a dopant material are subjected to flame oxidation by the use of an oxyhdrogen burner (2) to form fine glass particles which are deposited on one end of a supporting rod (3) adapted to move apart from the oxyhydrogen burner (2) while rotating to allow a rod-like porous preform (4) to grow thereon. The improved process is characterized in that the correlation between the shape of the deposition face and the refractive index distribution is previously determined mathematically, and on a basis of the correlation therebetween, a process variable such as the distance between the porous preform (4) and the burner (2) is adjusted to produce the desired shape of the deposition face (7) whereby there can be obtained an optimum refractive index distribution.

Display method for process variable

Abstract: PURPOSE:To offer the information of fluctuation of a process variable required for the operator quickly and accurately, by displaying a predetermined process control pattern and a present process variable on the same screen of a display device at any time periodically. CONSTITUTION:Various process information from an atomic power generating plant 1 is inputted from an input device 21 via an input device 10 at any time or periodically and process information (a) is stored in an information storage section 25. After target value information (b) from a target value calculation section 22 is stored in the information storage section 25, a display information forming section 23 receives process information and target value information (c) from the section 25, forms the display information of the target value and the process information and gives the information to a display output section 24 as display information (d). A display device 30 displays the output information from the section 24.

Adaptive control arrangement

Abstract: An adaptive control arrangement (8) for a process (10) utilises a process parameter calculator (14) made up of simple function blocks which generates a plurality of process parameters (P), and a tuning parameter calculator (16), also made up of simple function blocks, for calculating tuning parameters (m) for a controller (12) for the process (10) from the process parameters (P). The process parameter calculator (16) is provided with values for various disturbances (d), a set point (c), a control output (u) from the process controller (12) and process structure data including process sensitivity and nominal operating data. From these values, the process parameters (P) are determined. The tuning parameter calculator (16) is provided, in addition to the process parameters (P), with performance parameters and design function data for generating the tuning parameters (m) that are applied to the controller (12) for modifying the control output (u) in response thereto.

Digital display device

Abstract: PURPOSE:To use the digital display device of an electric power plant by displaying a process value on the dedicated display device when it is important for plant conditions, and selectively displaying the process variable when it is not important. CONSTITUTION:Process variables detected by detectors 1'-1'n are inputted to an electronic computer 5. An important process variable detected by a detector 1, on the other hand, is inputted to a detection part 2, where it is converted into a binary code. The obtained code data is inputted to a display control part 3 by being selected by a gate part 6. This gate part 6 performs switching between process data of a computer 5 and the process data from the detection part 2 in accordance with a switching signal 7 from the computer 5. When a turbine is started, its rotational frequency is an important process variable, which is read in the detection part 2 through the detector 1 and displayed on a display part 4, but when the turbine starting is completed, it is used as a rated speed, so that the gate part 6 is changed over to the side of the computer 5 by the signal 7.