Device for operating a windshield wiper
First Claim
1. An apparatus for operating a windshield wiper, comprising:
- a sensor device (10) for detecting the state of wetness of a windshield and generating a sensor signal (S);
an evaluating device (20) that receives the sensor signal, evaluating device including a first adjusting stage (21, 22,
23) for receiving measured values (MW) of the sensor signal at intervals of a fraction of a second and generating a first reference value RW1), and a second adjusting stage (24,
25) for generating a second reference value (RW2) which follows the first reference value; and
an actuator unit (30) for the windshield wiper that is actuated by the evaluating device (20) for initiating a wiping process if the difference between the second reference value (RW2) and a current measured value (MW) exceeds a threshold value,wherein the second reference value (RW2) generated by the second adjusting stage (24,
25) follows the first reference value (RW1) step-wise with consideration of recent measured values (MW) and wherein the second adjusting stage (24,
25) has a time constant on the order of magnitude of one second to a few seconds.
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Accused Products
Abstract
The invention relates to an apparatus for operating a windshield wiper, having a sensor device for detecting the state of wetness of the windshield, an evaluating device that receives the sensor signal and in which an adjusting device is provided for updating a reference value, and an actuator unit for the windshield wiper that is actuated by the evaluating device for initiating a wiping process if the difference between the reference value and a current measured value exceeds a predetermined threshold value. The evaluation and analysis of an event that influences the sensor signal, such as a slow buildup on the windshield under drizzly or foggy conditions, are facilitated by the fact that the adjusting device includes at least one adjusting stage whose time constant is in an order of magnitude of one second to a few seconds, and that the reference value can be followed step-wise, taking into consideration all current measured values received at intervals of fractions of a second.
5 Citations
11 Claims
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1. An apparatus for operating a windshield wiper, comprising:
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a sensor device (10) for detecting the state of wetness of a windshield and generating a sensor signal (S); an evaluating device (20) that receives the sensor signal, evaluating device including a first adjusting stage (21, 22,
23) for receiving measured values (MW) of the sensor signal at intervals of a fraction of a second and generating a first reference value RW1), and a second adjusting stage (24,
25) for generating a second reference value (RW2) which follows the first reference value; andan actuator unit (30) for the windshield wiper that is actuated by the evaluating device (20) for initiating a wiping process if the difference between the second reference value (RW2) and a current measured value (MW) exceeds a threshold value, wherein the second reference value (RW2) generated by the second adjusting stage (24,
25) follows the first reference value (RW1) step-wise with consideration of recent measured values (MW) and wherein the second adjusting stage (24,
25) has a time constant on the order of magnitude of one second to a few seconds. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification