摘要:
Method for controlling a position and drive for moving an object, wherein a control error between the desired position and the actual position is determined, wherein the control value is determined from the control error by means of linear operations as long as the control error is below an upper critical value and above a lower critical value, and the control value is determined from the control error according to a non-linear function as long as the control error is above the upper critical value and below the lower critical value.
摘要:
A PID controlling apparatus and method for providing a control value to a control object according to the difference between an output value of the control object and a target value are provided, in which an error calculator outputs an error value between the target value and the output value of the control object, a PID operator calculates a proportional value, an integral value, and a derivative value of the error value, calculates the control value using the proportional value, the integral value, and the derivative value, and outputs the control value to the control object, a first sampler samples the output value of the control object a plurality of times with respect to the target value and outputs a sampled output value, and a controller controls the PID operator to repeat a PID operation and output the control value according to a sampling period of the first sampler.
摘要:
A servo control apparatus and method controls systems at least partially on the basis of an observable variable that has an absolute value functional relationship with the controlled variable and does not change sign for positive and negative variations from a nominal value. When applied to the positional control of an object, the control system observes a value of a position error signal and maps (148) that signal to two different potentially correct displacement values. Two estimators (150, 152) within the control system are initiated, one using the positive displacement and the other using the negative displacement, and the two estimators each predict the future position of the object and the corresponding position error signal for each estimated position. A new position error signal is detected and compared to the two estimated position error signals. After sufficient system evolution, the control system can select one or the other of the estimators as being correct and the associated displacement is identified as correct and is used for future positioning applications, preferably until the sign of the displacement of the head again becomes ambiguous. The control system can be used in combination with other control mechanisms including those using complimentary control information that provides more complete positioning information. The control method, system and apparatus find particularly advantageous application in magnetic storage hard disk drive systems.
摘要:
A control system for a plant is disclosed. The control system includes a controller which controls the plant based on a controlled object model which is obtained by modeling the plant. The controlled object model is modeled using an input and an output of the plant which are sampled at intervals of a period which is longer than a control period of the controller. The controller carries out a control process of the plant at intervals of the control period.
摘要:
A plant controller controls a plant modeled in a discrete-time system. The controller uses a frequency-shaping response-designating control algorithm having a filtering function to cause a difference between output of the plant and a target value to converge. Thus, the plant is robustly controlled without causing undesired frequency components. When the plant is an engine, the engine is modeled using a ignition timing corrective quantity as input and a rotational speed as output. The controller performs the frequency-shaping response-designating control algorithm to determine the ignition timing corrective quantity. The frequency-shaping response-designating control may be frequency-shaping sliding-mode control. In one embodiment, the control input into the plant may includes a corrective term for stabilizing an internal variable of the filter, a corrective term for stabilizing the difference between the output of the plant and the target value and a corrective term that varies depending on a switching function.
摘要:
A discrete type repetition control apparatus is capable of stably controlling the repetition even when the status variables of the object to be controlled are not observable, and is provided with time delay elements (Z-1) of a number greater than a value that is obtained by dividing the period of a period target input by a sampling period of deviation between the period target input and the ouput of the object being controlled. To each time delay element is periodically applied the sum of a product of the deviation and a first gain (h1, ---, hn) related to each of the elements, a product of an input (u(k)) to the object being controlled and a second gain (m1, ---, mn) related to each of the time delay elements, and outputs (Wn(k+n), ---, W1(k+1)) of elements of the preceding stage. The control apparatus periodically applies to the object being controlled the sum (u(k)) of a product of the deviation and a third gain (h0) and the output (W1(k)) of a time delay element of the side of the object being controlled, in order to stably operate the object being controlled maintaining flexibility for a change in the period of the target input without inviting follow-up delay for the target input that periodically changes in a single pattern of change.
摘要:
In a manufacturing process using multivariate analysis for statistical process control, data representing a plurality of process and/or product variables is collected during operation of the process. A surrogate variable, representing the overall state of the process is evaluated. The surrogate variable is a function of a plurality of intermediate variables, which in turn are a function of the process and/or product variables. When the value of the surrogate variable is outside of a predetermined limit, the contributions to the surrogate variable by the intermediate variables are calculated. The intermediate variable with the largest contribution is identified and the contributions to the identified intermediate variable by the process variables is calculated. The process variables with the largest contribution to the identified intermediate variable are identified, and used to diagnose and correct the problem with the process.
摘要:
Statistical process control system for an air-separation plant using off-line and on-line computer means to define control chart limits, trend thresholds and dynamic models for use with on-line process variable data for determination of statistical process control.