CONTROL METHOD OF THE POSITION OF A SOLENOID VALVE USING DITHERING
First Claim
1. Control method to control a position of a solenoid valve using dithering, the control method comprising:
- determining a target current (IOBJ), through the solenoid valve, that is expressed in digital form with a given minimum quantization interval (Δ
min);
adding to the target current (IOBJ) a dithering square wave (IDITH) that has a high frequency of oscillation;
controlling a voltage (V) applied to the solenoid valve to urge a current (I) through the solenoid follow the target current (IOBJ) added to the dithering square wave (IDITH); and
jiggling the dithering square wave (IDITH) with a frequency that is a sub-multiple of a frequency of variation of the current (I) through the solenoid valve.
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Accused Products
Abstract
Control method of the position of a solenoid valve using dithering; the control method provides the steps of: determining a target current across the solenoid valve which is expressed in digital form with a given minimum quantization interval; adding a dithering square wave to the target current; controlling the voltage applied to the solenoid valve to cause the current across the solenoid valve to track the target current added to the dithering square wave; jiggling the dithering square wave with a frequency which is a sub-multiple with respect to the maximum variation frequency of the current across the solenoid valve; and varying the amplitude of the dithering square wave for a fraction of the period of the dithering square wave itself and by an amount equal to the minimum quantization interval for temporarily determining a deviation of the mean value of the dithering square wave with respect to zero and therefore obtaining a corresponding variation of the mean value of the target current.
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Citations
20 Claims
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1. Control method to control a position of a solenoid valve using dithering, the control method comprising:
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determining a target current (IOBJ), through the solenoid valve, that is expressed in digital form with a given minimum quantization interval (Δ
min);adding to the target current (IOBJ) a dithering square wave (IDITH) that has a high frequency of oscillation; controlling a voltage (V) applied to the solenoid valve to urge a current (I) through the solenoid follow the target current (IOBJ) added to the dithering square wave (IDITH); and jiggling the dithering square wave (IDITH) with a frequency that is a sub-multiple of a frequency of variation of the current (I) through the solenoid valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Apparatus, comprising an automatic manual transmission for a vehicle, comprising:
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a driving hydraulic circuit having at least one solenoid valve; and a control unit of the transmission configured to control the position of the solenoid valve, the control unit comprising; a target current circuit configured to determine a target current (IOBJ), through the solenoid valve, expressed in digital form with a given minimum quantization interval (Δ
min);an adding circuit configured to add to the target current (IOBJ) a dithering square wave (IDITH) that has a high frequency of oscillation; a voltage control circuit configured to control a voltage (V) applied to the solenoid valve to make a current (I) through the solenoid follow the target current (IOBJ) added to the dithering square wave (IDITH); a jiggling circuit configured to jiggle the dithering square wave (IDITH) with a frequency that is a sub-multiple of the maximum frequency of variation of the current (I) through the solenoid valve; and an amplitude varying circuit configured to vary the amplitude of the dithering square wave (IDITH) for a fraction of the period (TDITH) of the dithering square wave (IDITH) and by an amount equal to the minimum quantization interval (Δ
min) of the target current (IOBJ) to temporarily determine a deviation of a mean value of dithering square wave (IDITH) compared to zero and to provide a corresponding variation of the mean value of the target current (IOBJ) by an amount equal to a fraction of the minimum quantization interval (Δ
min). - View Dependent Claims (16, 18)
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17. Control method to control a position of a solenoid valve using dithering, the control method comprising:
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determining a target current (IOBJ) through the solenoid valve that is expressed in digital form with a given minimum quantization interval (Δ
min);adding to the target current (IOBJ) a dithering square wave (IDITH) which has a high frequency of oscillation; and controlling the voltage (V) applied to the solenoid valve to make the current (I) through the solenoid follow the target current (IOBJ) added to the dithering square wave (IDITH); jiggling the dithering square wave (IDITH) with a frequency that is a sub-multiple of the maximum frequency of variation of the current (I) through the solenoid valve; and varying the amplitude of the dithering square wave (IDITH) for a fraction of the period (TDITH) of the dithering square wave (IDITH) and by an amount equal to the minimum quantization interval (Δ
min) of the target current (IOBJ) to temporarily determine a deviation of the mean value of dithering square wave (IDITH) compared to zero and therefore get a corresponding variation of the mean value of the target current (IOBJ) by an amount equal to a fraction of the minimum quantization interval (Δ
min). - View Dependent Claims (19, 20)
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Specification