Electronic control system for controlling torque converter bypass clutches

Claim 2

A fluid pressure operated clutch assembly comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pressure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor means including means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring speed ratio of the speeds of said members and means for determining a desired slip of said clutch assembly for said set of values by measuring actual slip and subtract­ing a percentage of the difference between said actual slip and said target slip.

Claim 3

In a bypass clutch for a hydrokinetic torque converter for an automatic transmission and engine; a clutch member connected to said engine, a converter having a friction surface adapted to cooperate frictionally with said clutch member; a fluid pressure operated means for controlling the clutching capacity of said bypass clutch whereby clutch slip may be effected for a variety of engine and transmission conditions, electronically operated valve means for control­ling the pressure applied to said fluid pressure operated means, said valve means being connected to and being responsive to an electronic pressure having control logic that responds to changes in operating conditions of said transmission and engine; said control logic determining a desired slip for each set of values for at least two operating condi­tions of said transmission; means for determining a target slip for each set of said operating conditions; means for determining the actual slip of said bypass clutch; means for determining the desired slip for said bypass clutch for each operating condition of said trans­mission; and means for effecting a decay of the actual slip over time by calculating a value for slip that is a function of the difference between the actual slip and the target slip for each set of said operating conditions.

Claim 4

In a bypass clutch for a hydrokinetic torque converter for an automatic transmission and engine; a clutch member connected to said engine, a converter having a friction surface adapted to cooperate frictionally with said clutch member; a fluid pressure operated means for controlling the clutching capacity of said bypass clutch whereby clutch slip may be effected for a variety of engine and transmission conditions, electronically operated valve means for control­ling the pressure applied to said fluid pressure operated means, said valve means being connected to and being responsive to an electronic pressure having control logic that responds to changes in operating conditions of said transmission and engine; said control logic determining a desired slip for each set of values for at least two operating condi­tions of said transmission; means for determining a target slip for each set of said operating conditions; means for determining the actual slip of said bypass clutch; means for determining the desired slip for said bypass clutch for each operating condition of said trans­mission; and means for effecting a decay of the actual slip over time by calculating a value for slip that is a function of the difference between the actual slip and the target slip for each set of said operating conditions.

Claim 5

A torque converter bypass clutch assembly comprising a clutch plate, an impeller housing enclosing a turbine and an impeller, said clutch plate defining with said impeller housing a control pressure chamber, said plate being actuated by fluid pressure within said impeller housing with the pressure in said pressure chamber opposing the fluid pressure actuating said plate; valve means for controlling said control pres­sure in accordance with variations in impeller torque and turbine speed whereby a controlled slip of said clutch is achieved; means for determining a target slip of said clutch for each set of turbine speed and impeller torque values; means for determining a desired slip for each set of said values; and means for effecting a decay in the actual slip of said clutch toward said target slip in accordance with a percentage of the difference between said actual slip and said target slip.

Claim 6

A torque converter bypass clutch assembly comprising a clutch plate, an impeller housing enclosing a turbine and an impeller, said clutch plate defining with said impeller housing a control pressure chamber, said plate being actuated by fluid pressure within said impeller housing with the pressure in said pressure chamber opposing the fluid pressure actuating said plate; valve means for controlling said control pres­sure in accordance with variations in impeller torque and turbine speed whereby a controlled slip of said clutch is achieved; means for determining a target slip of said clutch for each set of turbine speed and impeller torque values; means for determining a desired slip for each set of said values; and means for effecting a decay in the actual slip of said clutch toward said target slip in accordance with a percentage of the difference between said actual slip and said target slip.

Claim 7

In a friction bypass clutch assembly for a hydrokinetic torque converter comprising an impeller, a turbine and an impeller shell enclosing said impeller and said turbine, an engine being connected to said impeller shell; a clutch plate within said impeller shell connected to said turbine, said clutch plate defining with said shell a control pressure chamber; control passage means communicating with said control pressure chamber for distributing a clutch capa­city determining control pressure to said chamber, bypass clutch control valve means communicating with said control pressure means, bypass clutch solenoid valve means communicating with said clutch control valve means; electronic processor means for establishing a voltage signal for said solenoid valve means including means for sensing engine torque, means for sensing turbine speed, means for establishing a desired slip of said clutch based upon the engine torque and turbine speed values, means for measuring the actual slip of said clutch, means for determining slip error, and means for establishing a control signal that is established as a function of a first constant proportional to slip error and a second constant that is determined by a derivative of said error; and means for subjecting said solenoid valve means to the control signal of said control signal estab­lishing means.

Claim 8

In a friction bypass clutch assembly for a hydrokinetic torque converter comprising an impeller, a turbine and an impeller shell enclosing said impeller and said turbine, an engine being connected to said impeller shell; a clutch plate within said impeller shell connected to said turbine, said clutch plate defining with said shell a control pressure chamber; control passage means communicating with said control pressure chamber for distributing a clutch capa­city determining control pressure to said chamber, bypass clutch control valve means communicating with said control pressure means, bypass clutch solenoid valve means communicating with said clutch control valve means; electronic processor means for establishing a voltage signal for said solenoid valve means including means for sensing engine torque, means for sensing turbine speed, means for establishing a desired slip of said clutch based upon the engine torque and turbine speed values, means for measuring the actual slip of said clutch, means for determining slip error, and means for establishing a control signal that is established as a function of a first constant proportional to slip error and a second constant that is determined by a derivative of said error; and means for subjecting said solenoid valve means to the control signal of said control signal estab­lishing means.

Claim 9

The combination as set forth in claim 4 wherein said processor includes means for determining slip values in repetitive sequence and means for calcu­lating a target slip for each control sequence, said desired slip being equal to the actual slip minus a predetermined percentage of the difference between said actual slip and said target slip.

Claim 12

The method set forth in Claim 6 wherein said desired slip equals actual slip minus a percentage of the difference between said actual slip and said target slip.

Claim 13

The invention as set forth in Claim 6 wherein the method comprises calculating a table of values for target slip as a function of said turbine speed signal and said torque signal, said table being stored for retrieval during repetitive clutch control sequences, said slip error being determined during each clutch control sequence.

Claim 14

The invention as.set forth in Claim 7 wherein the method comprises calculating a table of values for target slip as a function of said turbine speed signal and said torque signal, said table being stored for retrieval during repetitive clutch control sequences, said slip error being determined during each clutch control sequence.

Claim 15

A fluid pressure operated clutch assembly for a multiple speed ratio power transmission mechanism comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pres­sure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor means including means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring speed ratio of the speeds of said members and means for determining a desired slip of said clutch assembly for said set of values by measuring actual slip and subtract­ing the difference between said actual slip and said target slip multiplied by a slip reduction factor less than unity whereby a controlled decay of the actual over time is calculated.

Claim 16

A fluid pressure operated clutch assembly for a multiple speed ratio power transmission mechanism comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pres­sure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor means including means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring speed ratio of the speeds of said members and means for determining a desired slip of said clutch assembly for said set of values by measuring actual slip and subtract­ing the difference between said actual slip and said target slip multiplied by a slip reduction factor less than unity whereby a controlled decay of the actual over time is calculated.

Claim 17

The combination as set forth in claim 10 wherein said processor includes means for determining slip values in repetitive sequence and means for calcu­lating a target slip for each control sequence, said desired slip being equal to the actual slip minus the difference between said actual slip and said target slip multiplied by a slip reduction factor less than unity.

Claim 18

The combination as set forth in claim 10 wherein said processor means includes means for detecting the speed ratio of said transmission mechanism and means for storing a separate slip reduction factor in a memory holding register for each of said speed ratios whereby aid decay occurs at a rate that is dependent upon the existin speed ratio.

Claim 19

The combination as set forth in claim 11 wherein said processor means includes means for detecting the speed ratio of said transmission mechanism and means for storing a separate slip reduction factor in a memory holding register for each of said speed ratios whereby aid decay occurs at a rate that is dependent upon the existing speed ratio.

Claim 20

A fluid pressure operated clutch assembly comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pressure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor including means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement, means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring speed ratio of the speeds of said members and means for determining a desired slip of said clutch assembly for said set of values by measuring actual slip and subtract­ing a percentage of the difference between said actual slip and said target slip during operation in a clutch engage mode.

Claim 21

A fluid pressure operated clutch assembly comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pressure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor including means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement, means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring speed ratio of the speeds of said members and means for determining a desired slip of said clutch assembly for said set of values by measuring actual slip and subtract­ing a percentage of the difference between said actual slip and said target slip during operation in a clutch engage mode.

Claim 22

In a bypass clutch for a hydrokinetic torque converter for an automatic transmission and engine; a clutch member connected to said engine, a converter having a friction surface adapted to cooperate frictionally with said clutch member; a fluid pressure operated means for controlling the clutching capacity of said bypass clutch whereby clutch slip may be effected for a variety of engine and transmission conditions, electronically operated valve means for control­ling the pressure applied to said fluid pressure operated means and for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement, said valve means being connected to and being responsive to an electronic processor having control logic that responds to changes in operating conditions of said transmission and engine; said control logic determining a desired slip for each set of values for at least two operating condi­tions of said transmission; means for determining a target slip for each set of said operating conditions; means for determining the actual slip of said bypass clutch; means for determining the desired slip for said bypass clutch for each operating condition of said trans­mission; and means for effecting a decay of the actual slip over time by calculating a value for slip that is a function of the difference between the actual slip and the target slip for each set of said operating conditions during operation in a clutch engage mode.

Claim 23

In a bypass clutch for a hydrokinetic torque converter for an automatic transmission and engine; a clutch member connected to said engine, a converter having a friction surface adapted to cooperate frictionally with said clutch member; a fluid pressure operated means for controlling the clutching capacity of said bypass clutch whereby clutch slip may be effected for a variety of engine and transmission conditions, electronically operated valve means for control­ling the pressure applied to said fluid pressure operated means and for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement, said valve means being connected to and being responsive to an electronic processor having control logic that responds to changes in operating conditions of said transmission and engine; said control logic determining a desired slip for each set of values for at least two operating condi­tions of said transmission; means for determining a target slip for each set of said operating conditions; means for determining the actual slip of said bypass clutch; means for determining the desired slip for said bypass clutch for each operating condition of said trans­mission; and means for effecting a decay of the actual slip over time by calculating a value for slip that is a function of the difference between the actual slip and the target slip for each set of said operating conditions during operation in a clutch engage mode.

Claim 24

A torque converter bypass clutch assembly comprising a clutch plate, an impeller housing enclosing a turbine and an impeller, said clutch plate defining with said impeller housing a control pressure chamber, said plate being actuated by fluid pressure within said impeller housing with the pressure in said pressure chamber opposing the fluid pressure actuating said plate; valve means for controlling said control pres­sure in accordance with variations in impeller torque and turbine speed whereby a controlled slip of said clutch is achieved; means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement; means for determining a target slip of said clutch for each set of turbine speed and impeller torque values; means for determining a desired slip for each set of said values; and means for effecting a decay in the actual slip of said clutch toward said target slip in accordance with a percentage of the difference between said actual slip and said target slip during operation of said clutch assembly in an engage mode.

Claim 25

A torque converter bypass clutch assembly comprising a clutch plate, an impeller housing enclosing a turbine and an impeller, said clutch plate defining with said impeller housing a control pressure chamber, said plate being actuated by fluid pressure within said impeller housing with the pressure in said pressure chamber opposing the fluid pressure actuating said plate; valve means for controlling said control pres­sure in accordance with variations in impeller torque and turbine speed whereby a controlled slip of said clutch is achieved; means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement; means for determining a target slip of said clutch for each set of turbine speed and impeller torque values; means for determining a desired slip for each set of said values; and means for effecting a decay in the actual slip of said clutch toward said target slip in accordance with a percentage of the difference between said actual slip and said target slip during operation of said clutch assembly in an engage mode.

Claim 26

In a friction bypass clutch assembly for a hydrokinetic torque converter comprising an impeller, a turbine and an impeller shell enclosing said impeller and said turbine, an engine being connected to said impeller shell; a clutch plate within said impeller shell connected to said turbine, said clutch plate defining with said shell a control pressure chamber; control passage means communicating with said control pressure chamber for distributing a clutch capa­city determining control pressure to said chamber, bypass clutch control valve means communicating with said control pressure means, bypass clutch solenoid valve means communicating with said clutch control valve means; electronic processor means for establishing a voltage signal for said solenoid valve means including means for sensing engine torque, means for sensing turbine speed, means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement, means for establishing a desired slip of said clutch based upon the engine torque and turbine speed values, means for measuring the actual slip of said clutch, means for determining slip error, and means for establishing a control signal that is established as a function of a first constant proportional to slip error and a second constant that is determined by a derivative of said error during operation of said clutch assembly in an engage mode; and means for subjecting said solenoid valve means to the control signal of said control signal estab­lishing means.

Claim 27

In a friction bypass clutch assembly for a hydrokinetic torque converter comprising an impeller, a turbine and an impeller shell enclosing said impeller and said turbine, an engine being connected to said impeller shell; a clutch plate within said impeller shell connected to said turbine, said clutch plate defining with said shell a control pressure chamber; control passage means communicating with said control pressure chamber for distributing a clutch capa­city determining control pressure to said chamber, bypass clutch control valve means communicating with said control pressure means, bypass clutch solenoid valve means communicating with said clutch control valve means; electronic processor means for establishing a voltage signal for said solenoid valve means including means for sensing engine torque, means for sensing turbine speed, means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement, means for establishing a desired slip of said clutch based upon the engine torque and turbine speed values, means for measuring the actual slip of said clutch, means for determining slip error, and means for establishing a control signal that is established as a function of a first constant proportional to slip error and a second constant that is determined by a derivative of said error during operation of said clutch assembly in an engage mode; and means for subjecting said solenoid valve means to the control signal of said control signal estab­lishing means.

Claim 28

The combination as set forth in claim 17 wherein said processor includes means for determining slip values in repetitive sequence and means for calcu­lating a target slip for each control sequence, said desired slip being equal to the actual slip minus a predetermined percentage of the difference between said actual slip and said target slip.

Claim 29

A fluid pressure operated clutch assembly comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pressure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor including means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring actual slip by determining speed ratio of the speeds of said members and means for determining a calculated desired slip of said clutch assembly that is less than the actual slip at successive time intervals during clutch actuation whereby a slip decay occurs toward said target slip.

Claim 30

A fluid pressure operated clutch assembly comprising: a driving member, a driven member, each member having a friction surface thereon engagable by the other; fluid pressure operated clutch actuator means for frictionally connecting said driving and driven members; a pressure source, passage means defined in part by a clutch control valve for distributing control pressure to said actuator means; electronically operated valve means for estab­lishing a clutch control valve actuating pressure; an electronic processor means for varying said actuating pressure according to variations in operating conditions including torque delivered by said clutch assembly and speed of one of said members; said processor including means for storing a target slip for said clutch assembly for each set of values of said operating conditions, means for measuring actual slip by determining speed ratio of the speeds of said members and means for determining a calculated desired slip of said clutch assembly that is less than the actual slip at successive time intervals during clutch actuation whereby a slip decay occurs toward said target slip.

Claim 31

In a bypass clutch for a hydrokinetic torque converter for an automatic transmission and engine; a clutch member connected to said engine, a converter having a friction surface adapted to cooperate frictionally with said clutch member; a fluid pressure operated means for controlling the clutching capacity of said bypass clutch whereby clutch slip may be effected for a variety of engine and transmission conditions, electronically operated valve means for control­ling the pressure applied to said fluid pressure operated means and for establishing a stroke mode pressure to actuate said clutch to a pre engaged condition whereby further pressure increase will cause clutch engagement, said valve means being connected to and being responsive to an electronic processor having control logic that responds to changes in operating conditions of said transmission and engine; said control logic determining a desired slip for each set of values for at least two operating condi­tions of said transmission; means for determining a target slip for each set of said operating conditions; means for determining the actual slip of said bypass clutch; means for determining the desired slip for said bypass clutch for each operating condition of said trans­mission; and means for effecting a decay of the actual slip over time by calculating a value for slip that is less than the actual slip by a predetermined amount at successive time intervals during clutch actuation.

Claim 32

In a bypass clutch for a hydrokinetic torque converter for an automatic transmission and engine; a clutch member connected to said engine, a converter having a friction surface adapted to cooperate frictionally with said clutch member; a fluid pressure operated means for controlling the clutching capacity of said bypass clutch whereby clutch slip may be effected for a variety of engine and transmission conditions, electronically operated valve means for control­ling the pressure applied to said fluid pressure operated means and for establishing a stroke mode pressure to actuate said clutch to a pre engaged condition whereby further pressure increase will cause clutch engagement, said valve means being connected to and being responsive to an electronic processor having control logic that responds to changes in operating conditions of said transmission and engine; said control logic determining a desired slip for each set of values for at least two operating condi­tions of said transmission; means for determining a target slip for each set of said operating conditions; means for determining the actual slip of said bypass clutch; means for determining the desired slip for said bypass clutch for each operating condition of said trans­mission; and means for effecting a decay of the actual slip over time by calculating a value for slip that is less than the actual slip by a predetermined amount at successive time intervals during clutch actuation.

Claim 33

A torque converter bypass clutch assembly comprising a clutch plate, an impeller housing enclosing a turbine and an impeller, said clutch plate defining with said impeller housing a control pressure chamber, said plate being actuated by fluid pressure within said impeller housing with the pressure in said pressure chamber opposing the fluid pressure actuating said plate; valve means for controlling said control pres­sure in accordance with variations in impeller torque and turbine speed whereby a controlled slip of said clutch is achieved; means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement; means for determining a target slip of said clutch for each set of turbine speed and impeller torque values; means for determining a desired slip for each set of said values; and means for effecting a decay in the actual slip of said clutch toward said target slip during operation of said clutch assembly in an engage mode.

Claim 34

A torque converter bypass clutch assembly comprising a clutch plate, an impeller housing enclosing a turbine and an impeller, said clutch plate defining with said impeller housing a control pressure chamber, said plate being actuated by fluid pressure within said impeller housing with the pressure in said pressure chamber opposing the fluid pressure actuating said plate; valve means for controlling said control pres­sure in accordance with variations in impeller torque and turbine speed whereby a controlled slip of said clutch is achieved; means for establishing a stroke mode pressure to actuate said clutch to a pre-engaged condition whereby further pressure increase will cause clutch engagement; means for determining a target slip of said clutch for each set of turbine speed and impeller torque values; means for determining a desired slip for each set of said values; and means for effecting a decay in the actual slip of said clutch toward said target slip during operation of said clutch assembly in an engage mode.