Fluid clutch fill detection system and method

A control system for a transmission including a source of pressurized fluid, at least one clutch having a chamber, at least one control valve, and a fluid supply line connecting the source of pressurized fluid with the at least one control valve, comprising:

• a pressure sensor disposed in the fluid supply line between the source of pressurized fluid and the at least one control valve to sense the pressure of the fluid in the fluid supply line;
• and
• a control configured to selectively open the at least one control valve to allow pressurized fluid to enter the chamber of the at least one clutch, to monitor the pressure of the fluid in the fluid supply line, to determine a rate of change in the volume of fluid entering the clutch chamber based on the pressure of the fluid in the fluid supply line;
• and to determine when the chamber of the at least one clutch is filled with fluid based on the rate of change in the volume of fluid entering the clutch chamber.

A transmission system, comprising:

• at least one clutch having a chamber;
• a source of pressurized fluid configured to provide pressurized fluid to the at least one clutch;
• at least one control valve configured to control the flow rate of pressurized fluid to the at least one clutch;
• a pressure sensor disposed between the source of pressurized fluid and the at least one control valve;
• and
• a control configured to selectively open the at least one control valve to allow pressurized fluid to enter the chamber of the at least one clutch, to monitor the pressure of the fluid between the source of pressurized fluid and the at least one control valve, to determine a rate of change in the volume of fluid entering the clutch chamber based on the pressure of the fluid between the source of pressurized fluid and the at least one control valve, and to determine when the clutch chamber is filled with fluid based on the rate of change in the volume of fluid entering the clutch chamber.