Transmission control fault detection
AssigneeCaterpillar Inc.
InventorsRandall M. Mitchell, Ashok Kajjam, Alan L. Stahl
Life of this patent
Estimating the term…
Abstract
A diagnostic system is provided for detecting a fault condition in a transmission having a plurality of rotating components, a plurality of clutches, and a transmission control. The diagnostic system includes speed sensors producing speed and direction signals representative of the rotational velocity of the rotating components, a processor for calculating the relative rotational speed between two or more clutches and for indicating a fault condition in response to the relative rotational speed and a period of time.
Claims29
An apparatus for detecting a fault condition in a transmission having a plurality of rotating components, a plurality of clutches, and a transmission control having a means for modulating the engagement of the clutches, comprising:
- a plurality of speed sensors producing speed and direction signals in response to the rotational speed of a plurality of the rotating components;
- means for calculating the relative rotational speed between two or more clutches in response to said speed and direction signals;
- and
- diagnostic means for indicating a fault condition in response to the relative rotational speed and the duration of a period of time.
An apparatus for detecting a fault condition in a transmission having a plurality of rotating components, and a plurality of clutches, comprising:
- a plurality of speed sensors producing speed and direction signals in response to the rotational speed of a plurality of the rotating components;
- means for calculating a relative rotational speed between two or more clutches in response to said speed and direction signals;
- means for determining a first clutch engagement status in response to said relative rotational speed;
- and
- means for reversing the direction signal of at least one of said plurality of speed sensors and determining a second clutch engagement status using the reversed direction signal.
An apparatus for detecting a fault condition in a transmission having a plurality of rotating components, and a plurality of clutches, comprising:
- a plurality of speed sensors producing speed and direction signals in response to the rotational speed of a plurality of the rotating components, said plurality of speed sensors including a torque converter output speed sensor;
- means for calculating a relative rotational velocity between two or more clutches in response to said speed and direction signals;
- means for calculating a torque converter ratio and comparing said torque converter ratio to a predetermined constant;
- and
- means for determining whether a direction clutch is slipping or the torque converter output sensor signal is incorrect in response to the direction of said relative rotational velocity and the comparison of said torque converter ratio to said predetermined constant.
A method for detecting a fault condition in a transmission having a plurality of rotating components, a plurality of clutches, and a transmission control having a means for modulating the engagement of said plurality of clutches, comprising the steps of:
- producing speed and direction signals in response to the rotational speed of a plurality of the rotating components;
- calculating the relative rotational speed between two or more clutches in response to said speed and direction signals;
- and
- indicating a fault condition in response to the relative rotational speed and the duration of a period of time.
A method for detecting a fault condition in a transmission having a plurality of rotating components, and a plurality of clutches, comprising the steps of:
- producing speed and direction signals in response to the rotational speed of a plurality of the rotating components;
- calculating a relative rotational speed between two or more clutches in response to the speed and direction signals;
- determining a first clutch engagement status in response to the relative rotational speed;
- reversing one of the direction signals and determining a second clutch engagement status using the reversed direction signal.
Dependencies are inferred from the claim text.