Method of in-gear tolerance control

Claim 2

In a vehicle having a transmission including an input member, an output member, a gear assembly for changing the ratio of torque between the input member and output member, a plurality of input sensors for providing signals indicative of measurement data for predetermined conditions, and a controller having memory for processing and storing the signals and predetermined values and providing output signals, a method of determining and controlling the in-gear tolerance (IGT) of the transmission, said method comprising the steps of: sensing the speed of the input member and output member by the input sensors; calculating by the controller the speed of the input member and output member based on the sensed speeds; determining whether the transmission is operating in one of a plurality of in-gear condition; exiting if the transmission is not operating in one of a plurality of in-gear conditions; calculating by the controller the magnitude of IGT to be used during a shift based on the calculated speeds if the transmission is operating in one of a plurality of in-gear conditions; and controlling the transmission using the calculated magnitude of IGT.

Claim 3

A method as set forth in claim 1 wherein said step of calculating the magnitude of IGT comprises: calculating the current slip by the speed of the input member minus the product of the current in-gear ratio multiplied by the speed of the output member; determining whether the value of the calculated slip is greater than the current value of IGT; and if the value of the calculated slip is greater than the current value of IGT, setting IGT equal to the calculated slip for use as the IGT when a shift is initiated by the controller.

Claim 4

A method as set forth in claim 2 including the step of initializing the value of IGT on the first pass of the method with the transmission in one of a plurality of in-gear conditions.

Claim 5

A method as set forth in claim 3 including the step of determining whether the value of calculated slip is greater than a maximum value of slip; and if the value of calculates slip is greater than the maximum value of slip, setting the maximum value of slip equal to the calculated slip.

Claim 6

A method as set forth in claim 4 including the step of initializing the value for a maximum value of slip and an IGT timer on the first pass of the method.

Claim 7

A method as set forth in claim 5 including the step of determining whether the value of IGT timer is greater than a predetermined value.

Claim 8

A method as set forth in claim 6 including the steps of: limiting the value of IGT between first and second predetermined values if the value of the IGT timer is not greater than the predetermined value; and calculating the value of IGT based on previous IGT values if the value of the IGT timer is greater than the predetermined value.

Claim 9

In a vehicle having a transmission including an input member, an output member a gear assembly for changing the ratio of torque between the input member and output member, a plurality of input sensors for providing signals indicative of measurement data for predetermined conditions, and a controller having memory for processing and storing the signals and predetermined values and providing output signals, a method of determining and controlling the in-gear tolerance (IGT) of the transmission, said method comprising the steps of: sensing the speed of the input member and output member by the input sensors; calculating by the controller the speed of the input member and output member based on the sensed speeds; determining whether the transmission is operating in one of a plurality of in-gear conditions; exiting if the transmission is not operating in one of a plurality of in-gear conditions; if the transmission is operating in one of a plurality of in-gear conditions, initializing the value of IGT, a maximum value of slip, and an IGT timers by the controller on the first pass of the method; calculating by the controller the current slip by the calculated speed of the input member minus the product of the current in-gear ratio multiplied by the calculated speed of the output member; determining whether the value of the calculated slip is greater than the current value of IGT; if the value of the calculated slip is greater than the current value of IGT, setting IGT equal to the calculated slip by the controller; and controlling the transmission using the IGT value when a shift is initiated.

Claim 10

In a vehicle having a transmission including an input member, an output member a gear assembly for changing the ratio of torque between the input member and output member, a plurality of input sensors for providing signals indicative of measurement data for predetermined conditions, and a controller having memory for processing and storing the signals and predetermined values and providing output signals, a method of determining and controlling the in-gear tolerance (IGT) of the transmission, said method comprising the steps of: sensing the speed of the input member and output member by the input sensors; calculating by the controller the speed of the input member and output member based on the sensed speeds; determining whether the transmission is operating in one of a plurality of in-gear conditions; exiting if the transmission is not operating in one of a plurality of in-gear conditions; if the transmission is operating in one of a plurality of in-gear conditions, initializing the value of IGT, a maximum value of slip, and an IGT timers by the controller on the first pass of the method; calculating by the controller the current slip by the calculated speed of the input member minus the product of the current in-gear ratio multiplied by the calculated speed of the output member; determining whether the value of the calculated slip is greater than the current value of IGT; if the value of the calculated slip is greater than the current value of IGT, setting IGT equal to the calculated slip by the controller; and controlling the transmission using the IGT value when a shift is initiated.

Claim 11

In a vehicle having a transmission including an input member, an output member, a gear assembly for changing the ratio of torque between the input member and output member, a plurality of input sensors for providing signals indicative of measurement data for predetermined conditions, and a controller having memory for processing an storing the signals and predetermined values and providing output signals, a method of determining and controlling the in-gear tolerance (IGT) of the transmission, said method comprising the steps of: sensing the speed of the input member and output member by the input sensors; calculating by the controller the speed of the input member and output member based on the sensed speeds; determining whether the transmission is operating in one of a plurality of in-gear conditions; exiting if the transmission is not operating in one of a plurality of in-gear conditions; if the transmission is operating in one of a plurality of in-gear conditions, initializing the value of IGT, a maximum value of slip and an IGT timer by the controller on the first pass of the method; calculating by the controller the current slip by the calculated speed of the input member minus the product of the current in-gear ratio multiplied by the calculated speed of the output member; determining whether the value of calculated slip is greater than a maximum value of slip; if the value of calculated slip is greater than the maximum value of slip, setting the maximum value of slip equal to the calculated slip; determining whether the value of IGT timer is greater than a predetermined value; limiting the value of IGT between first and second predetermined values if the value of the IGT timer is not greater than the predetermined value; calculating by the controller the value of IGT based on previous IGT values if the value of the IGT timer is greater than the predetermined value; and controlling the transmission using the calculated value of IGT.

Claim 12

In a vehicle having a transmission including an input member, an output member, a gear assembly for changing the ratio of torque between the input member and output member, a plurality of input sensors for providing signals indicative of measurement data for predetermined conditions, and a controller having memory for processing an storing the signals and predetermined values and providing output signals, a method of determining and controlling the in-gear tolerance (IGT) of the transmission, said method comprising the steps of: sensing the speed of the input member and output member by the input sensors; calculating by the controller the speed of the input member and output member based on the sensed speeds; determining whether the transmission is operating in one of a plurality of in-gear conditions; exiting if the transmission is not operating in one of a plurality of in-gear conditions; if the transmission is operating in one of a plurality of in-gear conditions, initializing the value of IGT, a maximum value of slip and an IGT timer by the controller on the first pass of the method; calculating by the controller the current slip by the calculated speed of the input member minus the product of the current in-gear ratio multiplied by the calculated speed of the output member; determining whether the value of calculated slip is greater than a maximum value of slip; if the value of calculated slip is greater than the maximum value of slip, setting the maximum value of slip equal to the calculated slip; determining whether the value of IGT timer is greater than a predetermined value; limiting the value of IGT between first and second predetermined values if the value of the IGT timer is not greater than the predetermined value; calculating by the controller the value of IGT based on previous IGT values if the value of the IGT timer is greater than the predetermined value; and controlling the transmission using the calculated value of IGT.