Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Abstract: A method is provided for measuring the phase relationship between the two shafts. The method includes: providing a first index means on the first pulse wheel; providing a second index means on the second pulse wheel; generating a first sequence of pulses based upon the characteristics of the first pulse wheel including the first index means thereon; generating a second sequence of pulses based upon the characteristics of the second pulse wheel including the second index means thereon; and determining a phase relationship between the two shafts based on part, or all pulses generated by the two pulse wheels, thereby having a measurement accuracy determined by the wheel that generates the most pulses.

Abstract: In a variable cam timing (VCT) system (10a) which has a feedback control loop wherein an error signal (36) relating to at least one sensed position signal of either a crank shaft position (24a) or at least one cam shaft position (22a) is fed back for correcting a predetermined command signal (12). The system further includes a valve (14) for controlling a relative angular relationship of a phaser (42); and includes a variable force solenoid (20) for controlling a translational movement of the valve (14). An improved control method comprising the steps of: providing a dither signal (38) sufficiently smaller than the error signal (36); as temperature varies, changing at least one parameter relating to the dither signal (38); and applying the dither signal (38) upon the variable force solenoid (20), thereby using the dither signal (38) for overcoming a system hysteresis without causing excessive movement of valve (14).

Abstract: In a VCT system having a feedback loop for controlling a phaser angular relationship, a control law disposed to receive a plurality of set point values and a plurality of feed back values is provided to include: a computation block for receiving the plurality of set point values as inputs, the computation block outputting a first output and a second output; a first summer for summing the first output and the plurality of feed back values to produce a first sum (e0); a phase integrator and a phase compensator receiving the first sum (e0) and derivatives (e1) thereof outputting a processed value (e2); a amplifier amplifying the second output by a predetermined scale (Kff); and e) a second summer for summing the processed value (e2) and the amplified second output to produce a second sum (e3).

Abstract: In a Variable Cam Timing (VCT) control system, there are conditions when the system must operate in an open-loop mode, and other situations where closed-loop operation is desired. A number of operating states is provided for VCT control system to switch between the states. A control methodology for switching between these two modes of operation, with minimal disturbances, is described. Further, during switching from open loop to closed loop, a scheme that impedes the impact upon the VCT system is provided.

Abstract: An engine with dependent intake cams requires a different method and formula to determine the phase of the intake cams. The exhaust camshaft drives the intake camshaft and so the intake cam position is dependent upon the exhaust cam position. The present invention provides a VCT cam timing system utilizing calculation of intake phase for dual dependent cams.

Abstract: In a dual dependent variable cam timing system, the desired intake global phase is reached by directly controlling the global phase of exhaust VCT phaser and controlling the local phase of intake VCT phaser. The global intake set point specified by an engine controller is converted into a local intake set point first, then passed through a set point filter, and compared with the measured local intake phase. The difference (error signal) is passed through a PI controller and a phase compensator, which have the same control structures as those of exhaust VCT phaser control, to form a control signal.

Abstract: In a variable cam timing (VCT) system (10a) which has a feedback control loop wherein an error signal (36) relating to at least one sensed position signal of either a crank shaft position (24a) or at least one cam shaft position (22a) is fed back for correcting a predetermined command signal (12). The system further includes a valve (14) for controlling a relative angular relationship of a phaser (42); and includes a variable force solenoid (20) for controlling a translational movement of the valve (14). An improved control method comprising the steps of: providing a dither signal (38) sufficiently smaller than the error signal (36); as temperature varies, changing at least one parameter relating to the dither signal (38); and applying the dither signal (38) upon the variable force solenoid (20), thereby using the dither signal (38) for overcoming a system hysteresis without causing excessive movement of valve (14).

Abstract: An engine with dependent intake cams requires a different method and formula to determine the phase of the intake cams. The exhaust camshaft drives the intake camshaft and so the intake cam position is dependent upon the exhaust cam position. The present invention provides a VCT cam timing system utilizing calculation of intake phase for dual dependent cams.

Abstract: In a dual dependent variable cam timing system, the desired intake global phase is reached by directly controlling the global phase of exhaust VCT phaser and controlling the local phase of intake VCT phaser. The global intake set point specified by an engine controller is converted into a local intake set point first, then passed through a set point filter, and compared with the measured local intake phase. The difference (error signal) is passed through a PI controller and a phase compensator, which have the same control structures as those of exhaust VCT phaser control, to form a control signal.

Abstract: In a Variable Cam Timing (VCT) control system, there are conditions when the system must operate in an open-loop mode, and other situations where closed-loop operation is desired. A number of operating states is provided for VCT control system to switch between the states. A control methodology for switching between these two modes of operation, with minimal disturbances, is described. Further, during switching from open loop to closed loop, a scheme that impedes the impact upon the VCT system is provided.

Abstract: In a VCT system having a feedback loop for controlling a phaser angular relationship, a control law disposed to receive a plurality of set point values and a plurality of feed back values is provided to include: a computation block for receiving the plurality of set point values as inputs, the computation block outputting a first output and a second output; a first summer for summing the first output and the plurality of feed back values to produce a first sum (e0); a phase integrator and a phase compensator receiving the first sum (e0) and derivatives (e1) thereof outputting a processed value (e2); a amplifier amplifying the second output by a predetermined scale (Kff); and e) a second summer for summing the processed value (e2) and the amplified second output to produce a second sum (e3).

Abstract: A camshaft (126) has a vane (160) secured to an end thereof for non-oscillating rotation therewith. The camshaft also carries a sprocket (132) which can rotate with the camshaft but which is also oscillatable with the camshaft. The vane has opposed lobes (160a, 160b) which are received in opposed recesses (132a, 132b), respectively, of the sprocket. The recesses have greater circumferential extent than the lobes to permit the vane and sprocket to oscillate with respect to one another, and thereby permit the camshaft to change in phase relative to a crankshaft whose phase relative to the sprocket is fixed by virtue of a chain drive extending therebetween.

Abstract: A camshaft (26) has a vane (60) secured to an end thereof for non-oscillag rotation therewith. The camshaft also carries a sprocket (32) which can rotate with the camshaft (26) but which is also oscillatable with the camshaft (26). The vane (60) has opposed lobes (60a, 60b) which are received in opposed recesses (32a, 32b), respectively, of the sprocket (32). The recesses have greater circumferential extent than the lobes (60a, 60b) to permit the vane (60) and sprocket (32) to oscillate with respect to one another, and thereby permit the camshaft (26) to change in phase relative to a crankshaft whose phase relative to the sprocket (32) is fixed by virtue of a chain drive (38) extending therebetween.