Method and apparatus for regulating the transmission ratio of a continuously variable transmission

• US 20040054458A1
• Filed: 07/23/2003
• Published: 03/18/2004
• Est. Priority Date: 08/02/1999
• Status: Active Grant

• Current Assignee: Michael Reuschel, Thomas Endler, Thomas Pfund
• Original Assignee: Michael Reuschel, Thomas Endler, Thomas Pfund
• Inventors: Endler, Thomas, Reuschel, Michael, Pfund, Thomas
• Granted Patent: US 7,047,118 B2
• Time in Patent Office: Days
• US Class Current: 701/51
• CPC Class Codes: F16H 61/66254 controlling of shifting being influenced by a signal derived from the engine and the main coupling

Abstract

A method and apparatus for regulating the transmission ratio of a continuously variable transmission. A set point value for adjusting the transmission ratio can be changed as a function of the operating parameters of a power train that includes the transmission. The set point value is composed of an initial control value and a regulating value. The initial control value depends on at least two operating parameters of the transmission. The set point value is updated to take into account changes that occur during operation of the transmission.

Claims

1. A method for regulating the transmission ratio of a continuously variable transmission, in particular for motor vehicles, said method comprising the steps of:

a. providing a preliminary transmission ratio control value is a function of at least two transmission operating parameters;

b. providing a set point value for the transmission ratio of said transmission as a function of operating parameters of a power train, wherein the set point value is composed of the preliminary control value and a correction value;

c. deriving the correction value by comparing a measured transmission ratio with the set point transmission ratio of said transmission; and

d. updating the relationship between the transmission operating parameters and the transmission'"'"'s set point correction value based upon changes that occur during transmission operation.

2. A method in accordance with claim 1, wherein the at least two transmission operating parameters include the drive torque and the transmission ratio of the transmission.

3. A method in accordance with claim 1, wherein the preliminary control value is a function of a transmission rotational speed.

4. A method in accordance with claim 1, including the step of detecting the rate of change of the set point value.

5. A method in accordance with claim 1, including the step of generating a display when a change in the preliminary control value exceeds a predetermined limit value.

6. A method in accordance with claim 1, including the steps of:

a. providing a preliminary control data field;

b. changing control algorithms of the transmission as a function of changes in the preliminary control data field.

7. A method in accordance with claim 1, including the step of detecting changes in transmission behavior when there are changes in the set point value.

8. Apparatus for regulating the transmission ratio of a continuously variable transmission, in particular for motor vehicles, said apparatus comprising:

a. sensors for detecting operational transmission parameters;

b. an electronic control unit including a microprocessor and at least one memory in which operating parameters associated with reference transmission ratios are stored, wherein the electronic control unit further includes a preliminary control device in which a preliminary control value is determined as a function of at least one of the transmission operating parameters;

c. a regulator for comparing a measured transmission ratio of the transmission with a reference transmission ratio and for deriving therefrom a control value;

d. an adjusting device that receives the preliminary control value and the regulation value as the set point value in order to adjust the transmission;

e. wherein the preliminary control value is stored in the preliminary control device as a function of at least two transmission operating parameters and in that an adjustment system is provided which changes the preliminary control value so that the measured transmission ratio coincides with the reference transmission ratio when the control variable is at least approximately zero.

9. Apparatus in accordance with claim 8, including a monitor for generating predetermined functions based upon changes in the preliminary control value.

10. Apparatus in accordance with claim 9, wherein the monitor detects changes in the transmission ratio of the transmission as a function of changes in the controlled variable, and wherein it triggers predetermined functions in relation to changes in said changes.