Continuously adaptive moisture sensor system for wiper control
First Claim
1. A wiper control for use with the window of a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control comprising:
- moisture sensing means responsive to the presence of moisture for producing a moisture signal representative of the amount of moisture present;
reference signal generating means for generating a reference signal;
comparison means responsive to said moisture signal and said reference signal for producing an output to the vehicle wiper means indicative of the relationship between said moisture signal and said reference signal; and
wherein the improvement comprises said reference signal generating means being responsive to said moisture signal and including signal processing means for substantially continuously adapting said reference signal to said moisture signal at a faster rate during periods of decreasing sensed moisture than during periods of increasing sensed moisture.
1 Assignment
0 Petitions
Accused Products
Abstract
An adaptive moisture sensor system includes a moisture sensor unit having a moisture sensor, which produces a moisture signal, a reference signal generating circuit and a comparator circuit for comparing the moisture signal with the reference signal and for producing an indication to the vehicle'"'"'s wiper control of the relationship between the signals. The reference signal generating circuit indicates a fast positive signal processing circuit for rapidly processing changes in the moisture signal representing decreasing moisture and a slow signal processing circuit to process changes of the moisture signal in both directions at a slow rate. The fast positive signal processing circuit is only enabled during rain conditions due to a contaminant film on the sensed window. The reference signal generating circuit further includes a fast negative signal processing circuit which responds to a stable moisture signal occuring during rain conditions by rapidly offsetting the reference signal to discontinue wiper operation. Multiple sensing assemblies, each including a sensor, a reference signal generating circuit and a comparator, are combined with a master control unit, which responds to any sensing assembly indicating a rain condition, in order to switch all sensing assemblies to a rain mode.
-
Citations
30 Claims
-
1. A wiper control for use with the window of a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control comprising:
-
moisture sensing means responsive to the presence of moisture for producing a moisture signal representative of the amount of moisture present; reference signal generating means for generating a reference signal; comparison means responsive to said moisture signal and said reference signal for producing an output to the vehicle wiper means indicative of the relationship between said moisture signal and said reference signal; and wherein the improvement comprises said reference signal generating means being responsive to said moisture signal and including signal processing means for substantially continuously adapting said reference signal to said moisture signal at a faster rate during periods of decreasing sensed moisture than during periods of increasing sensed moisture. - View Dependent Claims (2, 3, 4)
-
-
5. A wiper control for use with the window of a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control comprising:
-
moisture sensing means responsive to the presence of moisture for producing a moisture signal representative of the amount of moisture present; reference signal generating means for generating a reference signal; comparison means responsive to said moisture signal and said reference signal for producing an output to the vehicle wiper means indicative of the relationship between said moisture signal and said reference signal; and wherein the improvement comprises said reference signal generating means being responsive to said moisture signal for substantially continuously adapting said reference signal to said moisture signal and including first signal processing means for adapting said reference signal toward said moisture signal at a first predetermined rate and second signal processing means for adapting said reference signal toward said moisture signal at a second predetermined rate that is faster than said first predetermined rate, said second signal processing means responsive only to a relationship of said moisture signal to said reference signal indicative of decreasing sensed moisture. - View Dependent Claims (6, 7, 8)
-
-
9. A wiper control for use with the window of a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control comprising:
-
moisture sensing means responsive to the presence of moisture for producing a moisture signal representative of the amount of moisture present; reference signal generating means for generating a reference signal; comparison means responsive to said moisture signal and said reference signal for producing an output to the vehicle wiper means indicative of the relationship between said moisture signal and said reference signal; mode means responsive to said output indicating a predetermined relationship between said moisture signal and said reference signal for producing an indication of the presence of moisture; and said reference signal generating means being responsive to said moisture signal generating means being responsive to said moisture signal and said mode means and including means for determining that said moisture signal is stable and said mode means is producing an indication of the presence of moisture and for offsetting the reference signal in response to a stable moisture signal and an indication of the presence of moisture in order to cause said mode means to change said predetermined relationship between said moisture signal and said reference signal. - View Dependent Claims (10)
-
-
11. A wiper control for use with the window of a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control comprising:
-
moisture sensing means responsive to the presence of moisture for producing a moisture signal representative of the amount present; reference generating means responsive to said moisture signal for generating a reference signal; comparison means responsive to said moisture signal and said reference signal for producing an output signal adapted to operate the vehicle wiper means when said moisture signal has a predetermined relationship to said reference signal; and said reference generating means including moisture signal processing means for continually processing said moisture signal in a manner to maintain a predetermined relationship between said moisture signal and a processed moisutre signal, including first means for integrating differentials between said moisture signal and said processed moisture signal of one polarity and second means for integrating said differentials of both said one polarity and another polarity opposite to said one polarity, wherein said first means causes said reference generating means to integrate said differentials at a different rate than the rate at which said second means integrates said differentials and wherein said reference signal is a function of the value of said processed moisture signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. A wiper control for use with a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control comprising:
-
moisture sensing means responsive to the presence of moisture on the vehicle window for producing a moisture signal representative of the amount of moisture present on said window; reference generating means responsive to said moisture signal for generating a reference signal; comparison means responsive to said moisture signal and said reference signal for producing an output signal adapted to operate the vehicle wiper means when said moisture signal has a predetermined relationship to said reference signal; said reference generating means including a capacitor, said reference signal being proportional to the voltage across said capacitor; a bidirectional conductance path between said moisture sensing means and said capacitor including a first predetermined series impedance; a unidirectional conductance path between said moisture sensing means and said capacitor including a second predetermined series impedance and a series unidirectional switch; and said second impedance has a value lower than said first impedance and said unidirectional switch oriented to conduct changes in said moisture signal representing a decrease in the amount of moisture on said windshield, such that said reference signal will respond more rapidly to decreases in the amount of moisture on said windshield than to increases in the amount of moisture on said windshield. - View Dependent Claims (22, 23, 24, 25)
-
-
26. A wiper control system for use with a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control system comprising:
-
a plurality of moisture sensing units, each of said moisture sensing units including moisture sensing means responsive to the presence of moisture on the vehicle window for producing a moisture signal representative of the amount of moisture present at said sensing unit, reference generating means responsive to said moisture signal for generating a reference signal and comparison means responsive to said moisture signal and said reference signal for producing an output to the vehicle wipe control system indicative of the relationship between said moisture signal and said reference signal; and a master control interconnected with said plurality of moisture sensing units and including modifying means actuatable for modifying the manner in which said reference generating means on said plurality of moisture sensing units respond to their respective moisture signals, said modifying means being actuated in response to any one of said moisture sensing units producing an output indicative of a predetermined relationship between its moisture and reference signals that indicates the presence of moisture. - View Dependent Claims (27)
-
-
28. A wiper control system for use with a vehicle having a window and wiper control system for use with a vehicle having a window and wiper means operative to remove moisture from a portion of said window, said wiper control system comprising:
-
a plurality of moisture sensing units, each of said moisture sensing units including moisture sensing means responsive to the presence of moisture on the vehicle window for producing a moisture signal representative of the amount of moisture present at said sensing unit, reference generating means responsive to said moisture signal for generating a reference signal and comparison means responsive to said moisture signal and said reference signal for producing an output to the vehicle wipe control system indicative of the relationship between said moisture signal and said reference signal; a master control interconnected with said plurality of moisture sensing units and including modifying means actuatable for modifying the manner in which said reference generating means on said plurality of moisture sensing units respond to their respective moisture signals, said modifying means being actuated in response to any one of said moisture sensing units producing an output indicative of a predetermined relationship between its moisture and reference signals that indicates the presence of moisture; and wherein said reference generating means when not modified by said modifying means responds at a first predetermined rate to incremental changes in said moisture signal of both first and second opposite polarities, said first polarity being indicative of a decrease in the presence of moisture and said second polarity being indicative of an increase in the presence of moisture, and in which said reference generating means when modified by said modifying means responds to incremental changes in said moisture signal of said first polarity at a second predetermined rate which is substantially faster than said first predetermined rate, and to incremental changes in said moisture signal of said second polarity at said first predetermined rate. - View Dependent Claims (29, 30)
-
Specification