Constant groundspeed autoshift method and apparatus for maximizing fuel economy
AssigneeCaterpillar Inc.
InventorTimothy Alan Lorentz
Life of this patent
Estimating the term…
Abstract
A method of determining shift points in a step gear transmission system to maximize fuel economy is disclosed. In operation, the method uses fuel economy data from a first gear ratio to determine a first series of constant fuel consumption curves for the first gear ratio. The method then uses fuel economy data from a second gear ratio to determine a second series of constant fuel consumption curves for the second gear ratio. Next, the method determines points of intersection where a respective fuel consumption curve for the first gear ratio intersects its corresponding fuel consumption curve for the second gear ratio. A decision curve is generated from the points of intersection.
Claims27
A method of determining shift points in a step gear transmission system to maximize fuel economy, comprising:
- using fuel economy data from a first gear ratio to determine a first series of constant fuel consumption curves for the first gear ratio;
- using fuel economy data from a second gear ratio to determine a second series of constant fuel consumption curves for the second gear ratio;
- determining points of intersection where a respective fuel consumption curve for the first gear ratio intersects its corresponding fuel consumption curve for the second gear ratio;
- and
- generating a decision curve from the points of intersection.
A machine-readable storage medium having stored thereon machine executable instructions, the execution of said instructions adapted to implement a method of determining shift points in a step gear transmission system to maximize fuel economy, said method comprising:
- using fuel economy data from a first gear ratio to determine a first series of constant fuel consumption curves for the first gear ratio;
- using fuel economy data from a second gear ratio to determine a second series of constant fuel consumption curves for the second gear ratio;
- determining points of intersection where a respective fuel consumption curve for the first gear ratio intersects its corresponding fuel consumption curve for the second gear ratio;
- and
- generating a decision curve from the points of intersection.
A system for determining shift points in a step gear transmission system to maximize fuel economy, comprising:
- a controller and memory coupled to the controller, the controller operable to:
- use fuel economy data from a first gear ratio to determine a first series of constant fuel consumption curves for the first gear ratio;
- use fuel economy data from a second gear ratio to determine a second series of constant fuel consumption curves for the second gear ratio;
- determine points of intersection where a respective fuel consumption curve for the first gear ratio intersects its corresponding fuel consumption curve for the second gear ratio;
- and
- generate a decision curve from the points of intersection.
A method of controlling a step gear transmission to maximize fuel economy, comprising:
- receiving data regarding the operating point of an engine;
- comparing the operating point to a stored decision curve, wherein said decision curve divides a range of operating points between a first adjacent gear ratio and a second adjacent gear ratio based on the most fuel efficient gear ratios for operation;
- and
- shifting the transmission between the first adjacent gear ratio and the second adjacent gear ratio based on the comparison of the operating point to the decision curve.
A system for controlling a step gear transmission to maximize fuel economy, comprising:
- a controller and memory coupled to the controller, the controller operable to:
- receive data regarding the operating point of an engine;
- compare the operating point to a stored decision curve, wherein said decision curve divides a range of operating points between a first adjacent gear ratio and a second adjacent gear ratio based on the most fuel efficient gear ratio for operation;
- and
- shift the transmission between the first adjacent gear ratio and the second adjacent gear ratio based on the comparison of the operating point to the decision curve.
Dependencies are inferred from the claim text.