Control process and apparatus, in particular lambda control
First Claim
1. A method for precontrolling and controlling a controlled variable of a controlled system, in which at least one influencing variable is measured and, depending on the measuring result, a value of a precontrolled variable is supplied for precontrolling a manipulated variable, which was determined i advance in a calibration process under given conditions such that the effect of the influencing variable was compensated to a given extent, that is a given control-manipulated value occurred, preferably the control-manipulated value associated wit the system deviation 0, the method comprising the steps of:
- subdividing the influencing variable according to value into influencing variable classes;
subdividing a variable dependent on the control-manipulated variable according to value into control-manipulated variable classes;
repeatedly determining in which control-manipulated variable class the control-manipulated value happens to lie and in which influencing variable class the value of the influencing variable happens to lie;
incrementing a counter in a cell which is part of a counter array, the cells of which can be addressed by numbers of the two classes;
after occurrence of an evaluation condition, evaluating the counter array to the effect that the distribution over the control-manipulated variable classes is established for each influencing variable class;
whenever the distribution concentrations for different influencing variable classes lie in different control-manipulated variable classes, computing a correction value for the particular influencing variable class; and
,during operation of the controlled system, influencing the manipulated variables by the associated correction value, account being taken of the relevant influencing variable class, the correction values being determined by the evaluation such that the distribution concentrations should lie in the same control-manipulated variable class for all the influencing variable classes.
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Accused Products
Abstract
A method for the adaptation of a precontrolled value for a feedback control is based on the realization that, whenever the operating conditions coincide with the calibration conditions for the initial determining of precontrolled values, no control-manipulated variable deviations may occur in all the operating ranges, and that accordingly deviations which are nevertheless observed are a sign that the calibration conditions no longer exist. This may be caused by aging effects or by uncompensated disturbances. The method establishes the differences in control-manipulated variable deviations over different classes of an influencing variable. For each influencing variable class, a correction value is then determined such that, by means of the correction value, the error previously observed for the respective range is compensated during operation of the controlled system. The method makes possible an accurate adaptation range by range in an off-line method and is therefore suitable in particular for the precontrolling feedback control of the lambda value of an internal combustion engine. An apparatus for carrying out the method is also disclosed.
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Citations
14 Claims
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1. A method for precontrolling and controlling a controlled variable of a controlled system, in which at least one influencing variable is measured and, depending on the measuring result, a value of a precontrolled variable is supplied for precontrolling a manipulated variable, which was determined i advance in a calibration process under given conditions such that the effect of the influencing variable was compensated to a given extent, that is a given control-manipulated value occurred, preferably the control-manipulated value associated wit the system deviation 0, the method comprising the steps of:
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subdividing the influencing variable according to value into influencing variable classes; subdividing a variable dependent on the control-manipulated variable according to value into control-manipulated variable classes; repeatedly determining in which control-manipulated variable class the control-manipulated value happens to lie and in which influencing variable class the value of the influencing variable happens to lie; incrementing a counter in a cell which is part of a counter array, the cells of which can be addressed by numbers of the two classes; after occurrence of an evaluation condition, evaluating the counter array to the effect that the distribution over the control-manipulated variable classes is established for each influencing variable class; whenever the distribution concentrations for different influencing variable classes lie in different control-manipulated variable classes, computing a correction value for the particular influencing variable class; and
,during operation of the controlled system, influencing the manipulated variables by the associated correction value, account being taken of the relevant influencing variable class, the correction values being determined by the evaluation such that the distribution concentrations should lie in the same control-manipulated variable class for all the influencing variable classes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. Apparatus for carrying out a method for precontrolling and controlling a controlled variable, in which at least one influencing variable is measured and, depending on the measurement result, a value of a precontrolled variable is supplied for precontrolling a manipulated variable, which was determined in advance in a calibration process under given conditions such that the effect of the influencing variable on the controlled system was compensated to a given extent, that is a given control-manipulated value occurred, preferably the control-manipulated value associated with the system deviation 0, the apparatus comprising:
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a counter array which is subdivided into influencing variable classes and control-manipulated variable classes orthogonal thereto, whereby a number of cells are produced, which can be addressed by numbers of the two classes; means for repeatedly determining, during the operation of the controlled system, in which control-manipulated variable class the control-manipulated value happens to lie and in which influencing variable class the value of the influencing variable happens to lie and for incrementing a counter in the associated cell; and
,evaluating means for evaluating said counter array after arrival of an evaluation condition, said evaluating means determining the distribution over the control-manipulated variable class for each influencing variable class and, whenever the distribution concentrations for different influencing variable classes lie in different control-manipulated variable classes, computing a correction value for the respective influencing variable class and, during the operation of the controlled system, influencing the manipulated values by the particular correction value, taking into account the relevant influencing variable class, the correction values being determined by said evaluating means such that the distribution concentrations should lie in the same control-manipulated variable class for all the influencing variable classes. - View Dependent Claims (14)
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Specification