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US 8,570,147 B2Granted
Debounce strategy for validating switch actuation
AssigneeLear Corporation
InventorsHilton W. Girard, III, Keith A. Christenson
Life of this patent
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Abstract
A debounce strategy is disclosed for use with a switch detection circuit to validate whether the switch is properly actuated or whether interferences, switch bounce, or other interruptions are presenting indications of switch activation. The debounce strategy may be implemented in a multi-stage process so that systems relying on debounce validation can begin processing, or other so that other time depending operations begin processing, prior to completing debounce validation.
Claims17
For use with a door handle pull-switch operable between a first position and a second position with a pulling motion, the first position corresponding with a door lock being orientated to lock a vehicle door, the second position corresponding with the door lock being orientated to unlock the vehicle door, a method comprising:
- monitoring a voltage level of a door handle detection circuit that is configured to generate electrical signals reflective of the door handle being actuated from the first position to the second position, the voltage level changing from a first level to a second level upon actuation of the door handle from the first position to the second position;
- after detecting the voltage level to be at least equal to the second level, performing a first debounce test to determine whether the second voltage is continuously detected for at least a first period of time;
- in the event the second level is continuously detected for at least the first period of time:
- (i) issuing a first message to indicate a successful completion of the first debounce test;
- and
- (ii) conducting a second debounce test to determine whether the second voltage is continuously detected for a second period of time, the second period of time beginning after completion of the first period of time;
- in the event the second voltage is continuously detected for the second period of time, issuing a second message to indicate successful completion of the second debounce test;
- and
- increasing the first period of time in the event the second voltage is not continuously detected for the second period of time, wherein increasing comprises increasing the first period of time by at least one unit, the one unit being equal to a sampling rate of a detector used to monitor the voltage level.
6 more elements
A debounce controller being operable to:
- monitor a voltage level of a detection circuit used to generate electrical signals reflective of a switch being actuated from a first position to a second position, the voltage level changing from a first level to a second level upon actuation of the switch from the first position to the second position;
- conduct a primary debounce test to determine whether the second voltage is continuously detected for at least a first period of time;
- conduct a secondary debounce test to determine whether the second voltage is continuously detected for a second period of time, the secondary debounce test being conducting only following a successful primary debounce test;
- lengthen the first period of time for a next time the primary debounce test is to be conducted following an unsuccessful secondary debounce test;
- and
- lengthen the first period of time by one unit, the one unit being equal to a sampling rate of a detection circuit used to monitor the voltage level.
3 more elements
A passive entry system for use in a vehicle comprising:
- at least one fob being operable to transmit at least one signal;
- a passive entry controller operable to facilitate executing passive entry related control of one or more vehicle systems when in a fully operational state in response to the at least one signal, the passive entry controller being operable in a partially operational state where the passive entry controller is awaken from a sleeping state but prevented from executing the passive entry related control of the one or more vehicle systems;
- and
- a debounce controller being operable to:
- (i) monitor a voltage level of a circuit connected to a switch to detect actuation of the switch from a first position to a second position:
- (ii) conduct a first debounce test to determine whether the voltage level is greater than a first threshold for at least a first period of time;
- (iii) conduct a second debounce test to determine whether the voltage level is greater than the first threshold for at least a second period of time;
- (iv) lengthen the first period of time by one unit for a next time the primary debounce test is to be conducted following an unsuccessful second debounce test, the one unit being equal to a sampling rate of a detection circuit used to monitor the voltage level;
- and
- (v) transmit a first message upon successful completion of the first debounce test and a second message upon successful completion of the second debounce test, the passive entry controller being operable to transition to the partially operational state upon receipt of the first message, and thereafter, to the fully operational state upon receipt of the second message.
7 more elements
Dependencies are inferred from the claim text.