Engine CVT control system

Claim 2

In a CVT control system, for a vehicle drivetrain with an engine having various engine speeds, including ratio control means having an input element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT and controller means developing the control signal for positioning the input element in response to operator demand, the improvement wherein the controller means (1) develops a command indicative of a desired engine speed in response to operator power demand, (2) compares the command to a measure of the actual engine speed, (3) develops the control signal in a manner determined as a function of the comparison, and (4) applies the control signal to the input element, affecting a direct control of the ratio rate and hence engine speed, in response to the operator demand.

Claim 3

In a powertrain control system including an engine having engine speed and a positionable throttle, a CVT including a ratio control means having an input element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratios rates of the CVT, and controller means developing the control signal for positioning the CVT input element and the throttle in response to operator demand, the improvement wherein: the controller generates desired engine speed and throttle position commands in response to operator power demand; the controller positions the throttle to said desired throttle position, thereby controlling engine torque; the controller compares the desired engine speed to a measure of the actual engine speed; the controller develops the control signal in a manner determined as a function of the comparison; and the controller applies the control signal to the input element to affect a direct control of the ratio rate, and hence engine speed, in response to the operator demand.

Claim 4

In a powertrain control system including an engine having engine speed and a positionable throttle, a CVT including a ratio control means having an input element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratios rates of the CVT, and controller means developing the control signal for positioning the CVT input element and the throttle in response to operator demand, the improvement wherein: the controller generates desired engine speed and throttle position commands in response to operator power demand; the controller positions the throttle to said desired throttle position, thereby controlling engine torque; the controller compares the desired engine speed to a measure of the actual engine speed; the controller develops the control signal in a manner determined as a function of the comparison; and the controller applies the control signal to the input element to affect a direct control of the ratio rate, and hence engine speed, in response to the operator demand.

Claim 5

A control method for a vehicle drivetrain including a variable speed engine and a CVT including a ratio control element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT, the control method comprising the steps of: developing a command indicative of a desired engine speed in response to operator power demand; comparing the command to a measure of the actual engine speed; developing a control signal in a manner determined as a function of the comparison; and applying the control signal to the ratio control element to affect a direct control of the ratio rate and hence engine speed, in response to operator demand.

Claim 6

A control method for a vehicle drivetrain including a variable speed engine and a CVT including a ratio control element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT, the control method comprising the steps of: developing a command indicative of a desired engine speed in response to operator power demand; comparing the command to a measure of the actual engine speed; developing a control signal in a manner determined as a function of the comparison; and applying the control signal to the ratio control element to affect a direct control of the ratio rate and hence engine speed, in response to operator demand.

Claim 7

A control method for a vehicle drivetrain including a variable speed engine having a positionable throttle and a CVT having a ratio control element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT, the control method comprising the steps of: developing a command indicative of a desired engine speed in response to operator power demand; comparing the command to a measure of the actual engine speed; developing a control signal in a manner determined as a function of the comparison; and applying the control signal to the ratio control element to affect a direct control of the ratio rate and, in conjunction with throttle position, a direct control of engine speed, in response to operator demand.

Claim 8

A control method for a vehicle drivetrain including a variable speed engine having a positionable throttle and a CVT having a ratio control element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT, the control method comprising the steps of: developing a command indicative of a desired engine speed in response to operator power demand; comparing the command to a measure of the actual engine speed; developing a control signal in a manner determined as a function of the comparison; and applying the control signal to the ratio control element to affect a direct control of the ratio rate and, in conjunction with throttle position, a direct control of engine speed, in response to operator demand.

Claim 9

A control method for a vehicle drivetrain including a variable speed engine having a positionable throttle and a CVT having a ratio control element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT, the control method comprising the steps of: developing desired engine speed and throttle position commands in response to operator power demand; positioning the throttle to said desired throttle position, thereby controlling engine torque and affecting engine speed; comparing the desired engine speed to a measure of the actual engine speed; developing a control signal in a manner determined as a function of the comparison; and applying the control signal to the ratio control element to affect a direct control of the ratio rate and, in conjunction with throttle position, a direct control over engine speed, in response to the operator demand.

Claim 10

A control method for a vehicle drivetrain including a variable speed engine having a positionable throttle and a CVT having a ratio control element positionable in response to a control signal to establish various speed ratios between input and output shafts of the CVT and various ratio rates of the CVT, the control method comprising the steps of: developing desired engine speed and throttle position commands in response to operator power demand; positioning the throttle to said desired throttle position, thereby controlling engine torque and affecting engine speed; comparing the desired engine speed to a measure of the actual engine speed; developing a control signal in a manner determined as a function of the comparison; and applying the control signal to the ratio control element to affect a direct control of the ratio rate and, in conjunction with throttle position, a direct control over engine speed, in response to the operator demand.