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US 9,002,602 B2Granted
Method of determining a current operating range of a transfer case
AssigneeGM Global Technology Operations LLC
InventorsPeter John Giles, Michael A. Turley
Life of this patent
Estimating the term…
Abstract
A method of determining a current operating range of a transfer case includes continuously calculating current Combined Drive Ratio (CDR), and categorizing the current CDR into one of a pre-determined number of expected CDRs. Counters are used to track when the current CDR is identified as an expected CDR. The different counters are then analyzed using simple mathematical operations to identify which gear ratio the transfer case is currently operating in.
Claims20
A method of controlling a vehicle, the method comprising:
- defining each of a pre-determined number of expected Combined Drive Ratios (CDR) as one of either an expected Verified High CDR, an expected Un-verified High CDR, an expected Verified Low CDR, or an expected Un-verified Low CDR;
- repeatedly calculating a current CDR of the vehicle by sensing an input speed with a first rotational speed sensor, sensing an output speed with a second rotational speed sensor, and dividing the sensed input speed by the sensed output speed with a processor of a vehicle controller;
- categorizing the calculated current CDR into one of the pre-determined number of expected CDRs with the vehicle controller;
- monitoring a period of time the calculated current CDR is categorized in the one of the pre-determined number of expected CDRs with the vehicle controller;
- incrementing a counter stored in a memory of the vehicle controller for the one of the pre-determined number of expected CDRs, from a value of zero to a value of one, if the monitored time the calculated current CDR is categorized in the one of the pre-determined number of expected CDRs is greater than a minimum time period;
- further incrementing the counter for the one of the pre-determined number of expected CDRs, from a value of one to a value of two, if the monitored time the calculated current CDR is categorized in the one of the pre-determined number of expected CDRs is greater than a second time period and the one of the pre-determined number of expected CDRs is defined as either an expected Verified High CDR or an expected Verified Low CDR;
- determining that a transfer case is operating in a low range, with the vehicle controller, when a total counter sum for the expected Verified Low CDRs is equal to or greater than two, or when a total product for the low range CDRs is equal to or greater than one;
- determining that the transfer case is operating in a high range, with the vehicle controller, when a total counter sum for the expected Verified High CDRs is equal to or greater than two, or when a total product for the high range CDRs is equal to or greater than one;
- and
- controlling the operation of the vehicle based on which of the low range or the high range the vehicle controller determines that the vehicle is currently operating in.
7 more elements
A vehicle comprising:
- an engine;
- a transmission coupled to the engine and including a plurality of different gear ratios;
- a transfer case coupled to the transmission and including at least two different gear ratios;
- an axle coupled to the transfer case and including an axle gear ratio;
- and
- a control module including all sensors, processors, electronic connections, and memory having computer-executable instructions saved thereon operable to determine which range the transfer case is operating in, wherein the control module is operable to:
- define each of a pre-determined number of expected Combined Drive Ratios (CDR) as one of either an expected Verified High CDR, an expected Un-verified High CDR, an expected Verified Low CDR, or an expected Un-verified Low CDR;
- continuously calculate a current CDR of the vehicle;
- categorize the calculated current CDR into one of the pre-determined number of expected CDRs;
- monitor a time period the calculated current CDR is categorized in the one of the pre-determined number of expected CDRs;
- increment a counter associated with the one of the pre-determined number of expected CDRs, from a value of zero to a value of one, when the monitored time the calculated current CDR is categorized in the one of the pre-determined number of expected CDRs is greater than a minimum time period;
- further increment the counter for the one of the pre-determined number of expected CDRs, from a value of one to a value of two, when the monitored time the calculated current CDR is categorized in the one of the pre-determined number of expected CDRs is greater than a second time period and the one of the pre-determined number of expected CDRs is defined as either an expected Verified High CDR or an expected Verified Low CDR;
- sum the values of the counters associated with each of the pre-determined number of expected CDRs defined as an expected Verified High CDR, to define a total counter sum for the expected Verified High CDRs;
- sum the values of the counters for each of the pre-determined number of expected CDRs defined as an expected Un-verified High CDR, to define a total counter sum for the expected Un-verified High CDRs;
- sum the values of the counters for each of the pre-determined number of expected CDRs defined as an expected Verified Low CDR, to define a total counter sum for the expected Verified Low CDRs;
- sum the values of the counters for each of the pre-determined number of expected CDRs defined as an expected Un-verified Low CDR, to define a total counter sum for the expected Un-verified Low CDRs;
- multiply the total counter sum for the expected Verified High CDRs by the total counter sum for the expected Un-verified High CDRs, to define a total product for the high range CDRs;
- multiply the total counter sum for the expected Verified Low CDRs by the total counter sum for the expected Un-verified Low CDRs, to define a total product for the low range CDRs;
- determine that the transfer case is operating in the low range when the total counter sum for the expected Verified Low CDRs is equal to or greater than two, or when the total product for the low range CDRs is equal to or greater than one;
- and
- determine that the transfer case is operating in the high range when the total counter sum for the expected Verified High CDRs is equal to or greater than two, or when the total product for the high range CDRs is equal to or greater than one.
18 more elements
Dependencies are inferred from the claim text.