Granted Patent B2

US 7,097,587 · App. 10/916,893 · Granted Aug 29, 2006

Abstract

Claims (25)

1. A gear ratio selection method for a transmission in a motor vehicle comprising:

determining a vehicle operator power request;

detecting a vehicle speed of the motor vehicle;

detecting an engine speed of the motor vehicle;

providing a plurality of variograms relating vehicle speed to requested power for determining corresponding engine speed;

selecting a first variogram and a second variogram from the plurality of variograms;

calculating a first desired engine speed from the first variogram using the power request and the vehicle speed;

calculating a second desired engine speed from the second variogram using the power request and the vehicle speed;

determining a blend factor from the power request, the vehicle speed, and the engine speed wherein the blend factor represents a ratio of the vehicle operator's desire for performance reflected by the first desired engine speed versus performance reflected by the second desired engine speed;

calculating a blended desired engine speed from the first desired engine speed, the second desired engine speed, and the blend factor; and

using the blended desired engine speed to determine a gear ratio for the transmission.

2. The method of claim 1 wherein the first and second variogram are selected by accessing a look-up table based on the power request, vehicle speed and engine speed.

3. A gear ratio selection method for a transmission in a motor vehicle comprising:

determining a vehicle operator power request;

detecting a vehicle speed of the motor vehicle;

detecting an engine speed of the motor vehicle;

calculating a desired economy engine speed from an economy variogram using the power request and the vehicle speed;

calculating a desired sport engine speed from a sport variogram using the power request and the vehicle speed;

determining a blend factor from the power request, the vehicle speed, and the engine speed wherein the blend factor represents a ratio of the vehicle operator's desire for sport performance versus economy performance;

calculating a blended desired engine speed from the desired economy engine speed, the desired sport engine speed, and the blend factor; and

using the blended desired engine speed to determine a gear ratio for the transmission.

4. The gear ratio selection method of claim 3 , wherein the economy variogram includes a graph of engine speed versus power request tailored to provide optimized fuel economy.

5. The gear ratio selection method of claim 3 , wherein the sport variogram includes a graph of engine speed versus power request tailored to provide optimized sport performance.

6. The gear ratio selection method of claim 3 , wherein the blend factor is a number between 0 and 1 corresponding to the ratio of desired economy performance versus desired sport performance.

7. The gear ratio selection method of claim 3 , wherein the transmission is a continuously variable transmission.

Assignments (19)