Dana Corporation

Steven P Thomas

Peter T Szymanski

Craig W Bladow

An integrated system for automatically controlling the operation of both an automated manual transmission and a multiple speed axle assembly in a vehicle drive train assembly includes a transmission actuator for operating the transmission in any one of a plurality of transmission gear ratios. The system further includes an axle actuator for operating the axle assembly in any one of a plurality of axle gear ratios. An electronic controller is provided for operating the transmission in a desired one of the plurality of transmission gear ratios and for operating the axle assembly in a desired one of the plurality of axle gear ratios to provide a desired overall gear ratio for the vehicle. To accomplish this, the electronic controller is responsive to one or more input signals that represent operating parameters of the vehicle. When it is determined that a change in the overall gear ratio of the vehicle is necessary, the electronic controller initially causes the amount of torque that is being generated by the engine to be reduced to a relatively low level. When it is determined that the actual torque generated by the engine has been reduced to this relatively low level, the electronic controller generates a signal to the axle actuator to pre-select a shift to an appropriate speed reduction gear ratio in the axle assembly. Next, the clutch is operated to disengage the engine from the transmission. The rotational speed of the engine is then caused to be synchronized with a calculated anticipated rotational speed of the output shaft of the transmission after the shifting process within the axle assembly has been completed. When these rotational speeds are synchronized, the clutch is operated to re-engage the engine with the transmission. Lastly, the amount of torque that is being generated by the engine is increased to a normal level.

Method for controlling a multiple speed axle shifting apparatus

An electronic controller is operated according to a method which efficiently generates output signals to a relatively large number of output devices, yet which utilizes only a relatively small amount of programming code to accomplish this. The electronic controller is responsive to various input signals for generating output signals on a bus line to a plurality of latches, each of which contains a plurality of output lines which are connected to operate the output devices. The electronic controller initially inputs the number of output lines per latch contained in the electronic control system as a variable B. Then, the number of a selected output device (designated as a variable A) is divided by the number of output lines per latch B. The result of this division is expressed in the form of an integer C plus a remainder D. The integer C designates the latch which controls the operation of the selected output device, while the remainder D designates the specific selected output device within that latch. Thus, the electronic controller generates the appropriate output signal on the bus line to the latches.

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Temperance, MI, United States of America

Steven P Thomas