Single sensor misfire detection apparatus and method for an internal combustion engine

Claim 1

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: means for sensing rotation of a crankshaft; means connected to said sensing means for calculating a crankshaft velocity based on the sensed rotation of the crankshaft; means for adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the compensated crankshaft velocity is within a predetermined crankshaft velocity range having an upper limit and a lower limit and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 2

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: means for sensing rotation of a crankshaft; means connected to said sensing means for calculating a crankshaft velocity based on the sensed rotation of the crankshaft; means for adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the compensated crankshaft velocity is within a predetermined crankshaft velocity range having an upper limit and a lower limit and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 3

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: means for sensing rotation of a crankshaft; means connected to said sensing means for calculating a crankshaft velocity based on the sensed rotation of the crankshaft; means for adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the compensated crankshaft velocity is within a predetermined crankshaft velocity range having an upper limit and a lower limit and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range; and target means forming a plurality of trip points on the crankshaft for a predetermined interval of an expansion stroke.

Claim 4

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: means for sensing rotation of a crankshaft; means connected to said sensing means for calculating a crankshaft velocity based on the sensed rotation of the crankshaft; means for adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the compensated crankshaft velocity is within a predetermined crankshaft velocity range having an upper limit and a lower limit and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range; and target means forming a plurality of trip points on the crankshaft for a predetermined interval of an expansion stroke.

Claim 6

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: means for sensing rotation of a crankshaft; means connected to said sensing means for calculating a crankshaft velocity based on the sensed rotation of the crankshaft; means for adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the compensated crankshaft velocity is within a predetermined crankshaft velocity range having an upper limit and lower limit and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined range; a target connected to the crankshaft and having a plurality of teeth formed by slots as trip points on the crankshaft for a predetermined interval of an expansion stroke; and wherein said sensing means comprises a crankshaft sensor mounted at a fixed point in proximity with said target for sensing edges of said teeth.

Claim 7

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: means for sensing rotation of a crankshaft; means connected to said sensing means for calculating a crankshaft velocity based on the sensed rotation of the crankshaft; means for adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the compensated crankshaft velocity is within a predetermined crankshaft velocity range having an upper limit and lower limit and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined range; a target connected to the crankshaft and having a plurality of teeth formed by slots as trip points on the crankshaft for a predetermined interval of an expansion stroke; and wherein said sensing means comprises a crankshaft sensor mounted at a fixed point in proximity with said target for sensing edges of said teeth.

Claim 10

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: a single target connected to a crankshaft and having a plurality of teeth formed by slots to act as trip points; a single crankshaft sensor mounted at a fixed point in proximity with said single target for sensing edges of said teeth and rotation of the crankshaft; means connected to said single crankshaft sensor for calculating a crankshaft velocity based on the sensed rotation of the crankshaft and subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the difference between the calculated crankshaft velocities is within a predetermined crankshaft velocity range having an upper limit and lower limit and counting a misfire if the difference between the calculated crankshaft velocities is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 11

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: a single target connected to a crankshaft and having a plurality of teeth formed by slots to act as trip points; a single crankshaft sensor mounted at a fixed point in proximity with said single target for sensing edges of said teeth and rotation of the crankshaft; means connected to said single crankshaft sensor for calculating a crankshaft velocity based on the sensed rotation of the crankshaft and subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the difference between the calculated crankshaft velocities is within a predetermined crankshaft velocity range having an upper limit and lower limit and counting a misfire if the difference between the calculated crankshaft velocities is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 12

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: a target connected to a crankshaft and having a plurality of teeth formed by slots to act as trip points; a crankshaft sensor mounted at a fixed point in proximity with said target for sensing edges of said teeth and rotation of the crankshaft; means connected to said sensor for calculating a crankshaft velocity based on the sensed rotation of the crankshaft and determining whether the calculated crankshaft velocity is within a predetermined velocity range and counting a misfire if the calculated crankshaft velocity is within the predetermined velocity range; and wherein said target is generally circular and said teeth are spaced circumferentially at a nine degree and sixty-nine degree interval for an expansion stroke.

Claim 13

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising: a target connected to a crankshaft and having a plurality of teeth formed by slots to act as trip points; a crankshaft sensor mounted at a fixed point in proximity with said target for sensing edges of said teeth and rotation of the crankshaft; means connected to said sensor for calculating a crankshaft velocity based on the sensed rotation of the crankshaft and determining whether the calculated crankshaft velocity is within a predetermined velocity range and counting a misfire if the calculated crankshaft velocity is within the predetermined velocity range; and wherein said target is generally circular and said teeth are spaced circumferentially at a nine degree and sixty-nine degree interval for an expansion stroke.

Claim 15

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising; a single target connected to the crankshaft and having a plurality of teeth formed by slots to act as trip points; a single crankshaft sensor mounted at a fixed point in proximity with said single target for sensing edges of said teeth and rotation of the crankshaft, said single crankshaft sensor being mounted at top dead center relative to the crankshaft; means connected to said single crankshaft sensor for calculating a crankshaft velocity based on the sensed rotation of the crankshaft and subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the difference between the calculated crankshaft velocities is within a predetermined crankshaft velocity range having an upper limit and lower limit and counting a misfire if the difference between the calculated crankshaft velocities is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 16

An apparatus to detect misfire in individual cylinders of an internal combustion engine in a motor vehicle, comprising; a single target connected to the crankshaft and having a plurality of teeth formed by slots to act as trip points; a single crankshaft sensor mounted at a fixed point in proximity with said single target for sensing edges of said teeth and rotation of the crankshaft, said single crankshaft sensor being mounted at top dead center relative to the crankshaft; means connected to said single crankshaft sensor for calculating a crankshaft velocity based on the sensed rotation of the crankshaft and subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity and determining whether the difference between the calculated crankshaft velocities is within a predetermined crankshaft velocity range having an upper limit and lower limit and counting a misfire if the difference between the calculated crankshaft velocities is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 17

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: sensing rotation of a crankshaft; calculating a crankshaft velocity based on the sensed rotation of the crankshaft; adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and lower limit to determine if therein; and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 18

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: sensing rotation of a crankshaft; calculating a crankshaft velocity based on the sensed rotation of the crankshaft; adaptively compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and lower limit to determine if therein; and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 22

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: forming a target on a crankshaft with teeth spaced circumferentially to form a predetermined interval; sensing rotation of the crankshaft; starting a timer when the crankshaft sensor detects a sixty-nine degree edge of a tooth on the target; stopping the timer when the crankshaft sensor detects a nine degree edge of a tooth on the target; calculating a crankshaft velocity based on the sensed rotation of the crankshaft and the time elapsed on the timer; compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and a lower limit to determine if therein; and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 23

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: forming a target on a crankshaft with teeth spaced circumferentially to form a predetermined interval; sensing rotation of the crankshaft; starting a timer when the crankshaft sensor detects a sixty-nine degree edge of a tooth on the target; stopping the timer when the crankshaft sensor detects a nine degree edge of a tooth on the target; calculating a crankshaft velocity based on the sensed rotation of the crankshaft and the time elapsed on the timer; compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and a lower limit to determine if therein; and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 24

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: forming a target on a crankshaft with teeth spaced circumferentially to form a predetermined interval; sensing rotation of the crankshaft; starting a timer when a crankshaft sensor detects a sixty-nine degree edge of a tooth on the target; stopping the timer when the crankshaft sensor detects a nine degree edge of a tooth on the target; calculating a crankshaft velocity based on the sixty degree difference between edges of the teeth and the time elapsed on the timer; compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated. crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and a lower limit to determine if therein; and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 25

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: forming a target on a crankshaft with teeth spaced circumferentially to form a predetermined interval; sensing rotation of the crankshaft; starting a timer when a crankshaft sensor detects a sixty-nine degree edge of a tooth on the target; stopping the timer when the crankshaft sensor detects a nine degree edge of a tooth on the target; calculating a crankshaft velocity based on the sixty degree difference between edges of the teeth and the time elapsed on the timer; compensating the calculated crankshaft velocity based on a predetermined cylinder by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated. crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and a lower limit to determine if therein; and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 26

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: forming a target on a crankshaft with teeth spaced circumferentially about every sixty degrees; locating a crankshaft sensor at a top dead center position relative to the crankshaft; sensing rotation of a crankshaft by starting a timer when the crankshaft sensor detects an edge of a tooth and stopping the timer when the crankshaft sensor detects an edge of another tooth for the sixty degree interval; calculating a crankshaft velocity based on the sixty degree difference between the edges of the teeth and the time elapsed on the timer; compensating the calculated crankshaft velocity by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and a lower limit to determine if therein and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.

Claim 27

A method of detecting misfire in individual cylinders of an internal combustion engine in a motor vehicle, said method comprising the steps of: forming a target on a crankshaft with teeth spaced circumferentially about every sixty degrees; locating a crankshaft sensor at a top dead center position relative to the crankshaft; sensing rotation of a crankshaft by starting a timer when the crankshaft sensor detects an edge of a tooth and stopping the timer when the crankshaft sensor detects an edge of another tooth for the sixty degree interval; calculating a crankshaft velocity based on the sixty degree difference between the edges of the teeth and the time elapsed on the timer; compensating the calculated crankshaft velocity by subtracting the calculated crankshaft velocity from a previous calculated crankshaft velocity; comparing the compensated crankshaft velocity to a predetermined crankshaft velocity range having an upper limit and a lower limit to determine if therein and counting a misfire if the compensated crankshaft velocity is within the upper limit and lower limit of the predetermined crankshaft velocity range.