Apparatus and method for controlling the end of fill of a fluid actuated clutch

Abstract

The present invention discloses a system and a method for controlling the timing of the filling of a fluid actuate. The system includes, a fluid actuated clutch 83, an electronic controller adapted to detect an end-of-fill point for the fluid actuated clutch 83, compare the end-of-fill point with a desired end-of-fill point and adjust at least one of a plurality of clutch fill parameters in response to the comparison in order to control the timing of the filling of the clutch 83, and a control valve that is activated by the electronic controller.

What is claimed is:  
     
       1. A system for controlling the timing of the filling of a fluid actuated clutch comprising: 
       a fluid actuated clutch;  
       an electronic controller adapted to detect an end-of-fill point for said fluid actuated clutch, compare said end-of-fill point with a desired end-of-fill point and dynamically adjust at least one of a plurality of clutch fill parameters in response to said comparison in order to control the timing of the filling of the clutch; and  
       a control valve that is activated by said electronic controller and said control valve is operatively connected to said fluid actuated clutch.  
     
     
       2. A system, as set forth in  claim 1 , further comprising: 
       an input mechanism that generates a signal, including a value for an input speed of said fluid actuated clutch and a value of output speed for said fluid actuated clutch; and  
       wherein said controller is further adapted to detect an instantaneous clutch slip, which is a difference between said input speed of said fluid actuated clutch and said output speed of said fluid actuated clutch and detect when said instantaneous clutch slip is less than a dynamically determined reference clutch slip value, where this condition represents said end-of-fill point for said fluid actuated clutch.  
     
     
       3. A system, as set forth in  claim 2 , wherein said electronic controller is further adapted to responsively compare said end-of-fill point with a desired end-of-fill region, and adjust said at least one of a plurality of clutch fill parameters in response to said end-of-fill point being outside said desired end-of-fill region, said parameters including a fill ramp command and a hold command, said fill ramp and hold commands having a current level and a time duration. 
     
     
       4. The system of  claim 3 , wherein said electronic controller is further adapted to determine which of said plurality of clutch fill parameters to adjust in response to said comparison. 
     
     
       5. The system of  claim 4 , wherein said electronic controller selects a predetermined adjustment value for said parameter and responsively adjust said parameter. 
     
     
       6. The system of  claim 4 , wherein said electronic controller is adapted to dynamically determine an adjustment value for said parameter. 
     
     
       7. The system, as set forth in  claim 1 , wherein said controller is further adapted to compare said end-of-fill point with a previous end-of-fill point and adjust said at least one of a plurality of clutch fill parameters in response to said end-of-fill point being outside said desired end-of-fill region, and said end-of-fill point being within a predetermined threshold of said previous end-of-fill point. 
     
     
       8. The system, as set forth in  claim 7 , wherein said previous end-of-fill point is a filtered end-of-fill point. 
     
     
       9. The system, as set forth in  claim 8 , wherein said controller is adapted to adjust said hold command when said end-of-fill point occurs later than said desired end-of-fill region, and adjust said ramp command and said hold command when said end-of-fill point occurs a threshold value later than said desired end-of-fill region. 
     
     
       10. The system, as set forth in  claim 9 , wherein said controller is adapted to adjust said hold command when said end-of-fill point occurred earlier than said desired end-of-fill region, and adjust said hold command and said ramp command when said end-of-fill point occurred a threshold value earlier than said desired end-of-fill region. 
     
     
       11. A method for controlling the timing of the filling of a fluid actuated clutch, which is operatively connected to a control valve that is activated by an electronic controller the method comprising the steps of: 
       determining an end-of-fill point;  
       comparing said end-of-fill point with a desired end-of-fill point; and  
       dynamically adjusting at least one of a plurality of clutch fill parameters in response to said comparison in order to control the timing of the filling of said fluid actuated clutch.  
     
     
       12. A method, as set forth in  claim 11 , wherein the step of determining an end-of-fill point further comprises the steps of: 
       receiving a signal from an input mechanism, including a value for an input speed of said fluid actuated clutch and a value of output speed for said fluid actuated clutch;  
       detecting an instantaneous clutch slip, which is a difference between said input speed of said fluid actuated clutch and said output speed of said fluid actuated clutch; and  
       detecting when said instantaneous clutch slip is less than a dynamically determined reference clutch slip value, where this condition represents the end-of-fill point for said fluid actuated clutch.  
     
     
       13. A method, as set forth in  claim 12 , further comprising the steps of: 
       comparing the end-of-fill point with a desired end-of-fill region; and  
       adjusting said at least one of a plurality of clutch fill parameters in response to said comparison, said parameters including a fill ramp command and a hold command, said fill ramp and hold commands having a current level and a time duration.  
     
     
       14. The method of  claim 13 , wherein the step of adjusting said at least one parameter further comprises the step of said adjusting at least one parameter when said end-of-fill point occurs outside said desired end-of-fill region. 
     
     
       15. A method as set forth in  claim 14 , wherein the step of adjusting said clutch parameters includes the step of adjusting said parameters by a predetermined amount. 
     
     
       16. A method, as set forth in  claim 14 , wherein the step of adjusting said clutch parameters includes the step of adjusting said parameters by a dynamically determined amount. 
     
     
       17. A method, as set forth in  claim 16 , further comprising the steps of: 
       comparing said end-of-fill point with a previous end-of-fill point and adjusting said at least one of a plurality of clutch fill parameters in response to said end-of-fill point being outside said desired end-of-fill region and said end-of-fill point being within a predetermined threshold of said previous end-of-fill point.  
     
     
       18. The system, as set forth in  claim 17 , wherein said previous end-of-fill point is a filtered end-of-fill point. 
     
     
       19. The system, as set forth in  claim 18 , wherein the step of adjusting said at least one of said parameters further comprises the steps of: 
       adjusting said hold command when said end-of-fill point is occurs later than said desired end-of-fill region; and  
       adjusting said ramp command and said hold command when said end-of-fill point occurs a threshold value later than said desired end-of-fill region.  
     
     
       20. The system, as set forth in  claim 19 , wherein the step of adjusting at least one of said parameters further comprises the steps of: 
       adjusting said hold command when said end-of-fill point occurs earlier than said desired end-of-fill region; and  
       adjusting said hold command and said ramp command when said end-of-fill point occurs a threshold value earlier than said desired end-of-fill region.