Apparatus for notifying the possibility of a malfunction of an automatic transmission and method therefor
First Claim
1. In a powertrain comprising an engine having a throttle valve, and an automatic transmission connected to the engine and having two shift valves for changing a speed ratio of the transmission, an apparatus for identifying a possible malfunction in the automatic transmission, the apparatus comprising:
- a throttle valve sensor constructed and arranged to detect a degree of opening of the throttle valve, and to generate a throttle valve signal corresponding to said detected degree of opening;
a rotation counter constructed and arranged to evaluate a number of rotations of both a transmission input and a transmission output, and to generate a speed ratio of said transmission input to said transmission output;
a control circuit constructed and arranged to;
obtain a first distribution of shifting times of shifts during a normal operation of said transmission, wherein shifting time corresponds to a change in said speed ratio relative to an elapsed time and said throttle valve signal indicating said detected degree of valve opening;
obtain a second distribution of shifting times of shifts during a predetermined time period;
obtain a standard deviation of said first distribution;
compare said second distribution with said standard deviation; and
determine that a malfunction possibly exists in the transmission based on a comparison of said second distribution and said standard deviation; and
warning means for indicating said possible malfunction.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed is an apparatus for notifying the possibility of a malfunction of an automatic transmission, which includes a throttle valve sensor for detecting the degree of the throttle valve'"'"'s opening to generate a throttle valve signal, a shift valve sensor for detecting the on/off state of the two shift valves to generate a .shift valve signal, a rotation number evaluation device for evaluating the number of the rotations of the transmission input and the transmission output shaft to generate a rotation number evaluation signal, a control circuit for first obtaining the standard distribution of the shifting time of all the shifts in the normal operation of the transmission to establish a plurality of error levels, second obtaining the distribution of the shifting time of the present shifts, and comparing the second obtained distribution with the error levels so as to generate a warning signal in abnormal operation of said transmission, and a warning means for displaying the possibility of the malfunction together with a possible malfunction code indicating a particular shifting mode according to the warning signal.
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Citations
14 Claims
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1. In a powertrain comprising an engine having a throttle valve, and an automatic transmission connected to the engine and having two shift valves for changing a speed ratio of the transmission, an apparatus for identifying a possible malfunction in the automatic transmission, the apparatus comprising:
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a throttle valve sensor constructed and arranged to detect a degree of opening of the throttle valve, and to generate a throttle valve signal corresponding to said detected degree of opening; a rotation counter constructed and arranged to evaluate a number of rotations of both a transmission input and a transmission output, and to generate a speed ratio of said transmission input to said transmission output; a control circuit constructed and arranged to; obtain a first distribution of shifting times of shifts during a normal operation of said transmission, wherein shifting time corresponds to a change in said speed ratio relative to an elapsed time and said throttle valve signal indicating said detected degree of valve opening; obtain a second distribution of shifting times of shifts during a predetermined time period; obtain a standard deviation of said first distribution; compare said second distribution with said standard deviation; and determine that a malfunction possibly exists in the transmission based on a comparison of said second distribution and said standard deviation; and warning means for indicating said possible malfunction. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In a powertrain comprising an engine having a throttle valve, and an automatic transmission connected to the engine and having two shift valves for changing a speed ratio of the transmission, a method for identifying a possible malfunction in the automatic transmission, comprising the steps of:
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deciding if the transmission is operating in a normal operating condition; obtaining a first distribution of shifting times of shifts in the normal operating condition obtaining a standard deviation of said first distribution; obtaining a second distribution of shifting times of shifts during a predetermined time period; comparing the second distribution with the standard deviation; identifying an abnormal operating condition of the automatic transmission in accordance with the comparison of the second distribution and the standard deviation; and indicating that a malfunction possibly exists, according to the identification of an abnormal operating condition. - View Dependent Claims (8, 9, 10)
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11. In a powertrain comprising an engine having a throttle valve, and an automatic transmission connected to the engine and having two shift valves for changing a speed ratio of the transmission, an apparatus for identifying a possible malfunction in the automatic transmission, the apparatus comprising:
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means for sensing normal operation of the automatic transmission; a control circuit constructed and arranged to; obtain a first distribution of shifting times of shifts during said normal operation of said transmission; establish a plurality of error levels according to said first distribution of shifting times; obtain a second distribution of shifting times of shifts during a predetermined period of time; and compare said second distribution with said error levels and generate a warning signal during an abnormal operation of said transmission, wherein said control circuit is constructed and arranged to calculate a standard deviation of said first distribution, and compare said second obtained distribution with said standard deviation to determine if a malfunction possibly exists; and warning means for indicating that a malfunction possibly exists. - View Dependent Claims (12, 13, 14)
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Specification