Abstract: A system for controlling a fan in a vehicle having a heat exchanger may include defining first and second geographic areas and determining a geographic location of the vehicle. A processor may be programmed to send a signal to operate the fan in a first rotational direction to move air through the heat exchanger in a first direction, and to send a signal to the fan to operate it in a second rotational direction opposite the first rotational direction to move air through the heat exchanger in a second direction opposite the first direction when a plurality of conditions are met.

Abstract: A thermal management system and method for a vehicle includes a cooling system having a variable cooling capacity and which is connectable to a heat-producing system of the vehicle. A control system is configured to increase the cooling capacity of the cooling system to a first predetermined level in response to the at least one input indicating an increase in the future heat load of the heat-producing system when a temperature of the cooling system is at least a predetermined temperature and the cooling system is operating below the first predetermined level. The control system is also configured to inhibit increasing the cooling capacity of the cooling system to the first predetermined level in response to the at least one input indicating an increase in the future heat load of the heat-producing system when the temperature of the cooling system is less than the predetermined temperature.

Abstract: A system for controlling a fan in a vehicle having a heat exchanger may include defining first and second geographic areas and determining a geographic location of the vehicle. A processor may be programmed to send a signal to operate the fan in a first rotational direction to move air through the heat exchanger in a first direction, and to send a signal to the fan to operate it in a second rotational direction opposite the first rotational direction to move air through the heat exchanger in a second direction opposite the first direction when a plurality of conditions are met.

Abstract: A plurality of fans is connectable to a heat exchanger arrangement having a plurality of separated cooling loops. At least one of the fans is operable to move air through at least two of the cooling loops, and at least one other fan is operable to move air through at least one of the cooling loops. A control system includes at least one controller and is operable to control each of the at least one fan using a respective control strategy correlating temperature values with fan outputs, and to control each of the at least one other fan using a respective control strategy that is different from each control strategy used to control the at least one fan.

Abstract: A thermal management system and method for a vehicle includes a cooling system having a variable cooling capacity and which is connectable to a heat-producing system of the vehicle. A control system is configured to increase the cooling capacity of the cooling system to a first predetermined level in response to the at least one input indicating an increase in the future heat load of the heat-producing system when a temperature of the cooling system is at least a predetermined temperature and the cooling system is operating below the first predetermined level. The control system is also configured to inhibit increasing the cooling capacity of the cooling system to the first predetermined level in response to the at least one input indicating an increase in the future heat load of the heat-producing system when the temperature of the cooling system is less than the predetermined temperature.

Abstract: A plurality of fans is connectable to a heat exchanger arrangement having a plurality of separated cooling loops. At least one of the fans is operable to move air through at least two of the cooling loops, and at least one other fan is operable to move air through at least one of the cooling loops. A control system includes at least one controller and is operable to control each of the at least one fan using a respective control strategy correlating temperature values with fan outputs, and to control each of the at least one other fan using a respective control strategy that is different from each control strategy used to control the at least one fan.

Abstract: Synchronous shift control in a multi-mode, hybrid transmission utilizes motor torques to control clutch synchronizations and torque conditions thereacross for substantially torque disturbance free shifting from one mode to another.

Abstract: A shift control for an electrically variable transmission shifts between modes through a neutral mode wherein the output is decoupled from the transmission. Normally, shifts between modes are accomplished synchronously through a duration of fixed-ratio operation. Extreme driving conditions may invoke shifts through neutral mode. Ratio violations characterized by one mode being active in a preferred input/output ratio range for another mode are handled by a shift through neutral. Similarly, rapid acceleration and deceleration conditions likely to result in undesirable engine speeds if synchronous shifting is employed are handled by a shift through neutral.

Abstract: A method and apparatus to control acceleration of a vehicle equipped with an electrically variable transmission and including a regenerative braking system, each are operably connected to a vehicle driveline. The method and apparatus include determining which one of a preselected shift selector position for the transmission is commanded, and determining operator demand for acceleration, using inputs from throttle pedal and brake pedal. Vehicle acceleration is measured, and magnitude of commanded torque transferred from the electrically variable transmission and the regenerative braking system to the vehicle driveline is controlled based upon the commanded preselected shift selector position, the operator demand for acceleration, and the measured vehicle acceleration.

Abstract: A vehicular powertrain has output torque established in accordance with various torque contributions in including throttle and brake torques. Throttle torque contribution is reduced proportionally to the amount of brake torque requested. Furthermore, such torque reductions are less aggressively applied with increasing throttle torques requested.

Abstract: A method for providing traction control in vehicle powertrain systems is particularly adapted for traction control in a powertrain system of a hybrid electric vehicle comprising an internal combustion engine, an electric machine and a transmission that is operatively coupled to the electric machine and the engine and adapted to provide a transmission torque output in response to a transmission torque input received as a torque output from either or both of the engine and the electric machine. The method is adapted to utilize conventional traction control and engine control hardware, software and communication standards to implement traction control. In one embodiment of the invention, a conventional traction controller is used to detect a wheel spin condition and provide a plurality of first output torque command messages in response thereto.

Abstract: A multi-mode hybrid transmission has speed control provided via an open loop model derived as a function of preselected transmission accelerations and controlled and uncontrolled transmission torques. Motor torques are selected as the controlled torques and other preselected transmission torques are selected as the uncontrolled torques. The control also employs a closed loop control effort responsive to at least one preselected transmission speed error.

Abstract: A method for providing an active engine stop of the engine of a hybrid electric vehicle. The method utilizes the electric machine to oppose and rapidly stop the rotation of the engine at a controlled rate. The method includes the calculation of an input speed reduction trajectory using the engine speed when the active engine stop request is made and a predetermined speed reduction interval. The speed reduction interval is less than a time from the active stop request to the shutoff command to the electric machine The method provides rapid deceleration of the engine, particularly through the powertrain resonance speed, reducing the amount of vibration energy dissipated through the powertrain and chassis. The method removes the electric machine torques from the engine prior to achieving zero engine speed in order to avoid imparting a negative engine speed or counter-rotation of the engine.

Abstract: A vehicular powertrain includes operatively coupled engine, electrically variable transmission and driveline. During normal operation when all motors are operating as expected, the engine is operated in a torque control mode in accordance with a torque command provided by a system controller to an engine controller and engine speed is controlled by the motors. During operation when all motors are not operating as expected, the engine is operated in a speed control mode in accordance with a speed command provided by the system controller to the engine controller and engine load torque is controlled by the operative motors.

Abstract: An electrically variable transmission has a pair of clutches and a first mode when the first clutch is applied and the second clutch released, a second mode when the second clutch is applied and the first clutch released, and a fixed-ratio mode when both clutches are applied. Upshifts and downshifts out of fixed-ratio are accomplished in accordance with a control based upon shift confidence factors determined in accordance with proportional and derivative input speed error quantities. Additional authority limits are placed upon the shift confidence factors in accordance with output speed derivative quantities. Additional override downshift control is provided in accordance with additional input speed condition determinations.

Abstract: Clutch engagement is preferably determined in accordance with monitored pressure conditions within a clutch control chamber. Clutch slip is monitored and information respecting clutch engagement inferred therefrom is stored for subsequent retrieval and use in a redundant slip based clutch engagement determination. Clutch slip is also monitored for information respecting clutch disengagement for use in a redundant slip based clutch disengagement determination.

Abstract: A powertrain includes a diesel compression engine and an electric machine operatively coupled thereto and effective to rotate the engine during engine cranking. Cold engine cranking is accomplished in a staged manner including a first stage wherein the engine is cranked to a first speed below the resonant speed of the coupled engine and electric machine combination for a first duration and thereafter cranked to a second speed above the resonant speed for a second duration. Transition out of cranking at the first and second speeds is accomplished when relative combustion stability is demonstrated. Cranking at the first or second speed is aborted when excessive crank times or if low battery voltages are observed. A third stage is included wherein the engine is cranked to a third speed below the engine idle speed. Transition out of cranking at the third speed is accomplished when relative combustion stability is demonstrated, whereafter normal engine control takes over.

Abstract: An electrically variable transmission has a pair of clutches and a first mode when the first clutch is applied and the second clutch released, a second mode when the second clutch is applied and the first clutch released, and a fixed-ratio mode when both clutches are applied. Upshifts and downshifts out of fixed-ratio are accomplished in accordance with a control based upon shift confidence factors determined in accordance with proportional and derivative input speed error quantities. Shift cycling is avoided by applying a variety of conditional tests intended to inhibit return to fixed-ratio operation.

Abstract: A condition of impaired speed and torque control of a parallel electrically variable transmission due to factors beyond nominal modeling and estimation errors is diagnosed under low speed operation. The transmission includes at least one electric machine and a motor torque controller for regulating the transmission input speed and output torque. The motor torque controller includes an open-loop control path based on predetermined torques and accelerations and a closed loop control path based on input speed error. The presence of a larger than expected closed-loop correction magnitude, combined with low output speed and one or more other conditions is used to diagnose a condition of potential torque error, in which case the transmission control is altered to prevent unwanted operation.

Abstract: Hydraulic fill and drain of a clutch chamber is controlled with a blocking valve and a trim valve. The blocking valve selectively provides pressurized fluid to the trim valve which in turn selectively provides the pressurized fluid to the clutch chamber. Exhausting of the clutch chamber is effected through one of two alternate paths utilizing deactivation of one of the trim and blocking valves. Back up exhausting of the clutch chamber is effected through the other of the alternative paths. Such system allows for determination of valve failures and continued operation until such failures can be rectified.