Abstract: A method of distributing a torque demand in a hybrid electric vehicle having an internal combustion engine 200 and an electric motor 202 is provided. In hybrid operation, the motor 202 initially starts the vehicle. When the vehicle desired power demand reaches a first vehicle operational parameter, a controller 214 switches the torque demand to the engine 200. An accelerator pedal 220 has a position sensor 222 which determines a non-fixed pedal 220 first position during transition between the motor 202 and engine 200. The accelerator pedal 220 also has a preset second position wherein a maximum of engine 200 torque is requested. The controller 214, cognizant of the accelerator pedal 220 first and second positions, linearly scales the accelerator pedal 220 to provide a uniform torque-responsive accelerator pedal.

Abstract: A vehicle system controller for a vehicle having an engine, a motor/generator, and subsystem controllers is provided. The vehicle system controller includes a state machine having a number of predefined states which represent vehicle operating modes. The predefined states include a motor drive state, which represents a vehicle operating mode wherein the motor/generator provides all driveline torques. The vehicle system controller further includes a set of rules which define logical relationships between each of the predefined states. A set of commands, unique to each state, are supplied to the subsystem controllers. The commands are provided to the subsystem controllers to achieve desired vehicle functionality within the states, and to transition between different states.

Abstract: A method of distributing a torque demand in a hybrid electric vehicle having an internal combustion engine 200 and an electric motor 202 is provided. In hybrid operation, the motor 202 initially starts the vehicle. When the vehicle desired power demand reaches a first vehicle 27. A method as described in claim 26, wherein said third predefined percentage of accelerator pedal travel position is 0%.operational parameter, a controller 214 switches the torque demand to the engine 200. An accelerator pedal 220 has a position sensor 222 which determines a non-fixed pedal 220 first position during transition between the motor 202 and engine 200. The accelerator pedal 220 also has a preset second position wherein a maximum of engine 200 torque is requested. The controller 214, cognizant of the accelerator pedal 220 first and second positions, linearly scales the accelerator pedal 220 to provide a uniform torque-responsive accelerator pedal.

Abstract: A regenerative braking system for use with a hybrid electric vehicle 10 including an internal combustion engine 14, an electric motor/generator or transaxle assembly 16, and a transmission assembly 18 which selectively receives torque from the engine 14 and transaxle 16 and delivers the received torque to vehicle's wheels 26, 28. The engine 14 is connected to the transmission assembly 16 by use of a clutch 20. During regenerative braking events, the system automatically disengages clutch 20, thereby allowing a maximum amount of energy to be recovered by the transaxle assembly 16, as engine “drag” is eliminated. Furthermore, the system disengages clutch 20 during idling conditions, and utilizes transaxle 16 to provide a negative torque to the driveline, effective to recover energy and to simulate engine drag forces due to compression braking effects, thereby providing a driver of the vehicle 10 with consistent feel during all operating modes.

Abstract: A starter/alternator system (24) for hybrid electric vehicle (10) having an internal combustion engine (12) and an energy storage device (34) has a controller (30) coupled to the starter/alternator (26). The controller (30) has a state of charge manager (40) that monitors the state of charge of the energy storage device. The controller has eight battery state-of-charge threshold values that determine the hybrid operating mode of the hybrid electric vehicle. The value of the battery state-of-charge relative to the threshold values is a factor in the determination of the hybrid mode, for example; regenerative braking, charging, battery bleed, boost. The starter/alternator may be operated as a generator or a motor, depending upon the mode.

Abstract: The present invention provides a control strategy for a parallel hybrid electric vehicle (HEV) configuration where power from the engine and the motor can each independently provide torque to the vehicle powertrain. The invention has a logical structure defining main system operating modes (states) and the transition between the different states. In addition to the predefined states, the present invention provides a set of rules defining logical relationships between each of the plurality of predefined states and a set of commands unique to each state. These commands are supplied to subsystem controllers to achieve desired vehicle functionality. The predefined states can be prioritized according to operator demands, energy management requirements, and system fault occurrences. The present invention can also be configured to have at least one of a plurality of transition flags.

Abstract: An energy control strategy (10) for a hybrid electric vehicle that controls an electric motor during bleed and charge modes of operation. The control strategy (10) establishes (12) a value of the power level at which the battery is to be charged. The power level is used to calculate (14) the torque to be commanded to the electric motor. The strategy (10) of the present invention identifies a transition region (22) for the electric motor's operation that is bounded by upper and lower speed limits. According to the present invention, the desired torque is calculated by applying equations to the regions before, during and after the transition region (22), the equations being a function of the power level and the predetermined limits and boundaries.

Abstract: An energy control strategy (10) for a hybrid electric vehicle that controls an electric motor during bleed and charge modes of operation. The control strategy (10) establishes (12) a value of the power level at which the battery is to be charged. The power level is used to calculate (14) the torque to be commanded to the electric motor. The strategy (10) of the present invention identifies a transition region (22) for the electric motor's operation that is bounded by upper and lower speed limits. According to the present invention, the desired torque is calculated by applying equations to the regions before, during and after the transition region (22), the equations being a function of the power level and the predetermined limits and boundaries.

Abstract: A vehicle system controller (20) is presented for a LSR parallel hybrid electric vehicle having an engine (10), a motor (12), wheels (14), a transmission (16) and a battery (18). The vehicle system controller (20) has a state machine having a plurality of predefined states (22-32) that represent operating modes for the vehicle. A set of rules is defined for controlling the transition between any two states in the state machine. The states (22-32) are prioritized according to driver demands, energy management concerns and system fault occurrences. The vehicle system controller (20) controls the transitions from a lower priority state to a higher priority state based on the set of rules. In addition, the vehicle system controller (20) will control a transition to a lower state from a higher state when the conditions no longer warrant staying in the current state. A unique set of output commands is defined for each state for the purpose of controlling lower level subsystem controllers.