Abstract: A method and system of determining a vehicle's driving characteristics such as the vehicle mass, drag force coefficients and driving surface inclination. The vehicle's mass, drag force coefficients and inclination are determined using signals input from the vehicle's accelerometer.

Abstract: One implementation of a six-speed transmission includes a first gearset including first and second planetary gearsets each having a number of teeth. The transmission also has a second gearset including a third planetary gearset operably associated with the first and second planetary gearsets. The third planetary gearset has an equal number of teeth with respect to one of the first and second planetary gearsets. The transmission also has a first plurality of shift elements operably associated with the first and second planetary gearsets, each of the first plurality of shift elements being movable between a released state and an applied state to selectively engage at least one of the first and second planetary gearsets. The transmission also has a second plurality of shift elements operably associated with the third planetary gearset, each of the second plurality of shift elements being movable between a released state and an applied state to selectively engage the third planetary gearset.

Abstract: A method and system of determining a vehicle's driving characteristics such as the vehicle mass, drag force coefficients and driving surface inclination. The vehicle's mass, drag force coefficients and inclination are determined using signals input from the vehicle's accelerometer.

Abstract: A transmission for a vehicle includes a first gear set and a second gear set. A first plurality of elements are operable in an applied state and a released state and a second plurality of elements are operable in an applied state and a released state. A controller toggles the first and second plurality of elements between the applied state and the released state to achieve a desired gear ratio. The controller times entry of at least one of the first and second plurality of elements into the released state with entry of at least another of the first and second plurality of elements into the applied state by controlling a hold pressure applied to the at least one element entering the released state. The controller determines the hold pressure by referencing current operating conditions of the transmission in a lookup table stored in a memory of the controller.

Abstract: The present disclosure improves both the D-N and N-D garage shift by reducing torque applied to the powertrain mount system and vehicle suspension systems during garage shifts. Since less energy in stored in the mount system and suspension system, the reaction bump during garage shifts will be reduced without compromising vehicle performance. For the N-D garage shift, such as after key-on when a shift lever is positioned in drive, a vehicle shifts to second gear (or some other higher gear) which provides reduced torque applied to the powertrain mount system and vehicle suspension system. For the D-N garage shift, as a vehicle slows down to a zero speed with the brake on, the vehicle is shifted into a higher gear. As the vehicle starts to launch, the vehicle is immediately shifted back to first gear, launching the vehicle with its first gear ratio.

Abstract: A method of determining a fill volume of a clutch of an automatic transmission. A clutch fill sequence is observed from measurement of fluid pressure applied to the clutch, wherein the sequence may include a initial rise, a plateau, and a final rise. A fill end time may be identified as corresponding to an intersection of a forward extrapolated portion of the plateau and a backward extrapolated portion of the final rise.

Abstract: One implementation of a six-speed transmission includes a first gearset including first and second planetary gearsets each having a number of teeth. The transmission also has a second gearset including a third planetary gearset operably associated with the first and second planetary gearsets. The third planetary gearset has an equal number of teeth with respect to one of the first and second planetary gearsets. The transmission also has a first plurality of shift elements operably associated with the first and second planetary gearsets, each of the first plurality of shift elements being movable between a released state and an applied state to selectively engage at least one of the first and second planetary gearsets. The transmission also has a second plurality of shift elements operably associated with the third planetary gearset, each of the second plurality of shift elements being movable between a released state and an applied state to selectively engage the third planetary gearset.

Abstract: The present disclosure improves both the D-N and N-D garage shift by reducing torque applied to the powertrain mount system and vehicle suspension systems during garage shifts. Since less energy in stored in the mount system and suspension system, the reaction bump during garage shifts will be reduced without compromising vehicle performance. For the N-D garage shift, such as after key-on when a shift lever is positioned in drive, a vehicle shifts to second gear (or some other higher gear) which provides reduced torque applied to the powertrain mount system and vehicle suspension system. For the D-N garage shift, as a vehicle slows down to a zero speed with the brake on, the vehicle is shifted into a higher gear. As the vehicle starts to launch, the vehicle is immediately shifted back to first gear, launching the vehicle with its first gear ratio.

Abstract: A transmission for a vehicle includes a first gear set and a second gear set. A first plurality of elements are operable in an applied state and a released state and a second plurality of elements are operable in an applied state and a released state. A controller toggles the first and second plurality of elements between the applied state and the released state to achieve a desired gear ratio. The controller times entry of at least one of the first and second plurality of elements into: the released state with entry of at least another of the first and second plurality of elements into the applied state by controlling a hold pressure applied to the at least one element entering the released state. The controller determines the hold pressure by referencing current operating conditions of the transmission in a lookup table stored in a memory of the controller.

Abstract: A system for monitoring performance of a fuel system in a vehicle includes a plurality of sensing modules that periodically sense data from a plurality of control systems in the vehicle during a predetermined evaluation period. The system includes a control module that analyzes the data after the evaluation period, generates performance ratings for the control systems based on the data, generates a set of values for the performance of the fuel system based on the performance ratings and a plurality of predetermined fuzzy logic rules, and generates a control signal based on a numerical analysis of the set of values. The system includes an indicator module that indicates in real time whether the performance of the fuel system conforms to a designed performance of the vehicle based on the control signal.

Abstract: An automatic transmission for a vehicle includes a multi-plate clutch having an applied state and a released state and an overrunning clutch having an engaged state and an overrunning state. In addition, the transmission includes a controller that effectuates a gear shift of the transmission by applying a volume of fluid to the multi-plate clutch to toggle the multi-plate clutch from the released state to the applied state at approximately the same time the overrunning clutch is toggled into the overrunning state. The applied volume of fluid at which the multi-plate clutch is applied is substantially given by the following equation: VF=VL?(k*T) where VF is the volume, VL is the instantaneous volume at any time, k is a constant, and T is the input torque to the transmission.

Abstract: A method of determining a fill volume of a clutch of an automatic transmission. A clutch fill sequence is observed from measurement of fluid pressure applied to the clutch, wherein the sequence may include a initial rise, a plateau, and a final rise. A fill end time may be identified as corresponding to an intersection of a forward extrapolated portion of the plateau and a backward extrapolated portion of the final rise.

Abstract: A system for monitoring performance of a fuel system in a vehicle includes a plurality of sensing modules that periodically sense data from a plurality of control systems in the vehicle during a predetermined evaluation period. The system includes a control module that analyzes the data after the evaluation period, generates performance ratings for the control systems based on the data, generates a set of values for the performance of the fuel system based on the performance ratings and a plurality of predetermined fuzzy logic rules, and generates a control signal based on a numerical analysis of the set of values. The system includes an indicator module that indicates in real time whether the performance of the fuel system conforms to a designed performance of the vehicle based on the control signal.

Abstract: An automatic transmission for a vehicle includes an input shaft, an output shaft, a first and second plurality of gears, and a series of engagement elements. The series of engagement elements includes at least one overrunning engagement element in mechanical communication with the second plurality of gears. A controller is operable to disengage a first engagement element associated with a first one of the first plurality of gears and apply a second engagement element associated with a second one of the first plurality of gears to achieve a speed change of the first plurality of gears. The controller is adapted to disengage one of the overrunning engagement elements from engagement with one of the second plurality of gears within a range of 20 to 120 milliseconds after the speed change of the first plurality of gears to accomplish a gear shift of the transmission.

Abstract: A transmission includes an input shaft, an output shaft, a first plurality of gears, a second plurality of gears, and a series of engagement elements operable between an engaged position and a disengaged position. A controller is further provided to selectively toggle the series of engagement elements between the engaged position and the disengaged position to selectively couple one of the first plurality of gears or one of the second plurality of gears to the input shaft and the output shaft. The series of engagement elements sequentially couples the first plurality of gears to the input shaft and the output shaft during operation of the transmission and selectively couples one of the first plurality of gears or the second plurality of gears to the input shaft and the output shaft during a downshift operation of the transmission.

Abstract: A method of double-downshifting from a first gear ratio to a second gear ratio includes the steps of first reducing torque transfer from a first clutch to a first driven gear. Engine speed then increases. Next, torque transfer from a second clutch to a third driven gear is increased while simultaneously the first clutch is disengaged from the first driven gear. Torque transfer from the second clutch to the third driven gear is then reduced. Torque transfer from the second clutch to the third driven gear is next increased. The first clutch is engaged to the second driven gear. Then, torque transfer from the first clutch to the second driven gear is increased while simultaneously the torque transfer from the second clutch to the third driven gear is reduced. Finally, the second clutch is disengaged from the third driven gear.

Abstract: A method of double-downshifting from a first gear ratio to a second gear ratio includes the steps of first reducing torque transfer from a first clutch to a first driven gear. Engine speed then increases. Next, torque transfer from a second clutch to a third driven gear is increased while simultaneously the first clutch is disengaged from the first driven gear. Torque transfer from the second clutch to the third driven gear is then reduced. Torque transfer from the second clutch to the third driven gear is next increased. The first clutch is engaged to the second driven gear. Then, torque transfer from the first clutch to the second driven gear is increased while simultaneously the torque transfer from the second clutch to the third driven gear is reduced. Finally, the second clutch is disengaged from the third driven gear.

Abstract: The present invention provides a means to learn and accommodate the amount of air that needs to be purged from a clutch circuit after being off for a predetermined time. The scheme helps to maintain proper control timing as necessary for good shift quality and clutch durability and further helps to minimize unnecessary delays in clutch application. Once the air has been purged, then normal control timing can be resumed.

Abstract: A novel transmission is provided that has a first, second, third and fourth gear, wherein said second gear includes two alternate and selectable speed ratios. The primary speed ratio of the second gear is used during upshifts and downshifts of adjacent gears. The alternate speed ratio of the second gear is utilized exclusively during downshifts from non-adjacent gears and may also be utilized during a downshift from the third gear depending on certain conditions and parameters. The primary speed ratio is larger than the alternate speed ratio of the second gear to provide better acceleration characteristics of the transmission during upshifting. The smaller alternate speed ratio of the second gear can provide smoother downshifts because of the less abrupt speed ratio change from the higher gears. Also, a method for controlling the gear selection of an automatic transmission having a plurality of gears is provided, wherein one position includes two speed ratios.

Abstract: A sensing system for detecting the position of a manually operated shift lever in an automatic transmission. The sensing system includes a plate member movable in response to movement of a shift lever. The plate member includes a generally flat contact surface having a predetermined pattern of electrically conductive and non-conductive areas. An electrical sensor unit is mounted in the transmission and positioned to communicate with the contact surface of the plate member. At least five electrical contact members engage the conductive and non-conductive areas on the contact surface generate binary codes having combinations that are indicative of the shift lever position in each of the predetermined operating modes. The engagement between the contact members and the contact surface further generates at least four unique binary codes indicative of the transitions between the predetermined operating modes.