Automatic transmission control system with shift lever position sensor
First Claim
1. An automatic transmission shift lever position sensing apparatus comprising:
- a lever position sensor including a plurality of sensing elements each of which produces a binary signal, each of the binary signals selectively having one of two binary values in response to a shifting motion of a gear shift lever of an automatic transmission, the sensing elements being broken down into a first and a second sensing element group, the first and second sensing element groups working to produce a first and a second binary code made up of the binary values, respectively, each of the first and second binary code carrying information about one of lever positions in which the gear shift lever is placed;
a position determining circuit which determines in which of the lever positions the gear shift lever is placed and/or determines whether the lever position sensor is failing or not based on the first and second binary codes produced by the first and second sensing element groups of the lever position sensor.
1 Assignment
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Accused Products
Abstract
An automatic transmission control system equipped with a shift lever position sensor which includes a plurality of switches which output binary signals following a shifting motion of a gear shift lever. Patterns of combinations of the switch outputs are preselected so as to represent positions to which the gear shift lever is manually shiftable. The switches are broken down into two groups each of which produces a binary code carrying information about the position of the gear shift lever to monitor a failure in operation of the shift lever position sensor. The control system also works to perform a deemed D-position hydraulic transmission control to ensure the running of the vehicle even if the shift lever position sensor is failing.
33 Citations
34 Claims
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1. An automatic transmission shift lever position sensing apparatus comprising:
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a lever position sensor including a plurality of sensing elements each of which produces a binary signal, each of the binary signals selectively having one of two binary values in response to a shifting motion of a gear shift lever of an automatic transmission, the sensing elements being broken down into a first and a second sensing element group, the first and second sensing element groups working to produce a first and a second binary code made up of the binary values, respectively, each of the first and second binary code carrying information about one of lever positions in which the gear shift lever is placed;
a position determining circuit which determines in which of the lever positions the gear shift lever is placed and/or determines whether the lever position sensor is failing or not based on the first and second binary codes produced by the first and second sensing element groups of the lever position sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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- 10. A computer executable control program for controlling an automatic transmission shift lever position sensing apparatus equipped with a lever position sensor including a plurality of sensing elements each of which produces a binary signal, each of the binary signals selectively having one of two binary values in response to a shifting motion of a gear shift lever of an automatic transmission, the sensing elements being broken down into a first and a second sensing element group, said control program including a first task to be executed to sample the binary signals produced by the first and second sensing element groups to read therefrom a first and a second binary code carrying information about one of lever positions in which the gear shift lever is placed and a second task to be executed to determine in which of the lever positions the gear shift lever is placed and/or determine whether said lever position sensor is failing or not based on a combination of the first and second binary codes made of the binary signals produced by the first and second sensing element groups.
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14. An automatic transmission shift lever sensor comprising:
a plurality of sensing elements each of which produces a binary signal, each of the binary signals selectively having one of two binary values in response to a shifting motion of a gear shift lever of an automatic transmission, the sensing elements being broken down into a first and a second sensing element group, the first and second sensing element groups working to produce a first and a second binary code made up of the binary values, respectively, each of the first and second binary code carrying information about one of lever positions in which the gear shift lever is placed. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. An automatic transmission control system comprising:
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a lever position sensor designed to produce signals each of which represents one of a parking position, a reverse position, a neutral position, and a drive position to which a gear shift lever is shifted manually by an operator;
a plurality of hydraulic control valves working to control hydraulic pressures to be supplied to frictional elements of an automatic transmission;
a manual selector valve which selectively establishes hydraulic supply circuits leading to said hydraulic control valves following a shifting motion of the gear shift lever, said manual selector valve working to establish predetermined ones of the hydraulic supply circuit to achieve a selected one of forward gears of the automatic transmission only when the gear shift lever is placed in the drive position; and
a gear change controller which monitors a position of the gear shift lever using the signal produced by said lever position sensor and operates said hydraulic control valves to hydraulically control engagement of the frictional elements of the automatic transmission to establish a selected one of gears of the automatic transmission, when the signal from said lever position sensor represents the position of the gear shift lever other than the drive position, and a predetermined condition is encountered, said gear change controller deeming the gear shift lever to be placed in the drive position and performing a deemed D-position hydraulic transmission control to establish a given one of the forward gears of the automatic transmission. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification