A system and method for controlling a vehicle powertrain including an engine and a motor operable to propel the vehicle includes reducing a torque of the motor at a first torque reduction rate from a torque level above a minimum motor torque in response to a deceleration request. A torque of the engine is reduced at a second torque reduction rate less than the first torque reduction rate in response to the deceleration request.

Some embodiments of the present invention comprise a method of controlling a powertrain of a vehicle, the powertrain comprising drive torque means, a transmission and a driveline, the drive torque means comprising an internal combustion engine, the method comprising: detecting that coasting entry criteria have been met; causing the powertrain to assume a first coasting mode for a first time period in which the drive torque means delivers positive drive torque to the driveline to substantially balance powertrain losses; determining a value for at least one parameter, the or each parameter being indicative of: a probability that a demand will be made for torque to be delivered to the driveline in addition to torque delivered to substantially balance powertrain losses; or a probability that a demand will be made for braking of the vehicle; and setting the value of the first time period in dependence on the value of the or each parameter.

A vehicle includes a motor positioned between an engine and a driveline connected to a vehicle wheel, and a controller. The controller controls engine torque and maintains motor torque during wheel torque and driveline component torque reversals to limit a vehicle output torque rate of change through a lash region associated with a range of driveline torque ratios. A method of controlling a hybrid vehicle includes controlling engine torque to a specified profile and maintaining motor torque at a generally constant value during at least one of wheel torque and driveline component torque reversals to limit a vehicle output torque rate of change through a lash region associated with a range of driveline torque ratios.

A control system for a hybrid vehicle. The system comprises a controller configured to cause a net negative drive torque to be applied by an engine or an electric machine of the vehicle to the input shaft of a transmission in a direction opposing travel of the vehicle to effect braking, determine when a transmission gear shift is about to occur requiring a non-negative torque to be applied at the input shaft, and when the gear shift is about to occur, temporarily cause a net non-negative drive torque to be applied to the input shaft by causing the electric machine to apply a positive drive torque to the input shaft to compensate for negative torque applied by the engine, and cause brake force to be applied by a braking system to compensate for a reduction in negative drive torque applied to the input shaft, while the gear shift occurs.

A method and apparatus for evaluating the driving of a vehicle performing a journey on a road network is disclosed. The method comprises determining a fuel usage rate and an engine speed of a vehicle, and determining when the vehicle is coasting based upon at least one of the fuel usage rate and the engine speed of the vehicle. An acceleration of the vehicle, when the vehicle is determined to be coasting, is compared with a predetermined reference acceleration, and an application of braking during the coasting is determined based on the result of the comparison. A method and apparatus is also disclosed for determining a score indicative of the relative amount of time for which the vehicle is coasting without braking during a journey.

A vehicle coasting control system for a vehicle having a prime mover includes an accelerator pedal positional throughout an accelerator pedal position range; a vehicle controller interfacing with the accelerator pedal, the vehicle controller adapted to control operating speeds of the prime mover of the vehicle corresponding to positions, respectively, of the accelerator pedal within the accelerator pedal position range; and the vehicle controller is adapted to operate the prime mover at idle when the accelerator pedal is positioned at a coast zone within the accelerator pedal position range. A vehicle coasting control method is also disclosed.

A method and a system for controlling a cruise control and a transmission in a vehicle over the course of a road section, wherein prior to the road section, the vehicle has applied coasting and utilizes the cruise control. A reference speed v.sub.ref utilized in the cruise control during the coasting is lowered to a lowest permitted speed v.sub.min defined for the road section if the lowering is deemed applicable. A comparison of a drive force F.sub.dd requested from an engine system in the vehicle with a threshold value F.sub.lim for the drive force is also carried out. The coasting is then suspended if the requested drive force F.sub.dd exceeds the threshold value F.sub.lim for the drive force.

The invention concerns a method for automatically controlling a motor vehicle (10) for switching from a “normal” mode to a “freewheel” mode, the vehicle (10) comprising an engine (12) capable of providing engine torque to drive wheels (14) via an automatically controlled clutch device (18) that comprises a drive shaft (15) and a driven shaft (16). A transition step (E1) is interposed chronologically between the “normal” mode and the “freewheel mode” during which the engine (12) is automatically controlled in such a way that the driven shaft (16) and the drive shaft (15) turn at the same speed without transmitting torque to the drive wheels (14).

A method for controlling a drivetrain of a motor vehicle is disclosed. Either a start mode for starting the reciprocating engine is activated via the driving vehicle wheel, or a coasting mode is activated for driving the reciprocating engine via the driving vehicle wheel. At least one volume-reducing stroke is executed that follows an intake stroke for at least one cylinder of the reciprocating engine with at least intermittently open cylinder. Alternately at least one volume-enlarging stroke is executed for at least one cylinder of the reciprocating engine, which is followed by a compression stroke of this cylinder, and at least one volume-reducing stroke of this cylinder, which follows an expansion stroke that follows the compression stroke, with a cylinder that is closed, if possible, in this operating mode.

Presented are vehicle powertrains and control logic for provisioning intelligent fast-torque output, methods for making/using such systems, and electric-drive vehicles with dynamically allocated fast-torque production. A method of controlling torque output of a vehicle powertrain includes a vehicle controller receiving sensor data and determining therefrom maximum and minimum motor torque capacities of a traction motor. The controller calculates the traction motor's maximum and minimum effective motor capacities based on a previous motor torque command and the maximum and minimum torque capacities, respectively. The controller then determines if a negative of the crankshaft torque reserve is: (1) greater than the minimum effective motor capacity; and (2) less than the maximum effective motor capacity. If (1) or (2) is true, an engine spark torque command is set equal to an air torque spark value, and the controller commands an engine assembly to modulate its torque output based on the spark torque command.