Abstract: A method is provided for monitoring a state of health of a vehicle system and includes measuring a plurality of parameter values for the system at different running conditions as an end of line test, storing the parameter values in a fingerprint file, measuring the same plurality of parameter values that is comprised in the fingerprint file after a predefined time interval, adding a predefined, ageing offset to the fingerprint file, where the ageing offset corresponds to a predicted wear of the system during the predefined time interval, thereby obtaining a time modified fingerprint file for the system, comparing the measured values with the time modified fingerprint file, and issuing a message if the measured values deviates from the time modified fingerprint file. The state of health can be compared with initial measurements such that the state of health of a vehicle system or component can be monitored over a longer time period.

Abstract: A method for error detection during charging of an energy storage system in a vehicle is provided, the vehicle including an electric machine which is arranged for propulsion of the vehicle. The method includes requesting a charging pattern from an external power supply, by a vehicle control unit, upon connection of the energy storage system to the external power supply; and supplying the charging pattern to the energy storage system by an external charging control unit forming part of the external power supply. The method furthermore includes providing a predetermined modulation of the requested charging pattern; evaluating whether the charging pattern supplied to the energy storage system includes the predetermined modulation; and, if this is not the case, indicating that the charging of the energy storage system is erroneous. An arrangement for error detection during charging of an energy storage system, and a vehicle including an electric machine and having such an arrangement are also provided.

Abstract: A method is provided for operating a hybrid electric vehicle including an internal combustion engine and an electrical system, which electrical system includes at least one electronic control unit, an engine-driven electric machine (operable as a motor for driving the vehicle or as a generator for supplying power to one or more electrical loads via a high voltage traction bus, and a high voltage battery pack coupled to the high voltage traction bus by at least one contactor arranged to connect the battery pack to the high voltage traction bus. If it is determined that the at least one parameter indicates a condition preventing the battery pack from being connected to the high voltage bus, the electric machine is operated in voltage control mode during operation of the vehicle until the condition is eliminated, whereafter the high voltage bus is pre-charged and the high voltage battery pack reconnected.

Abstract: A method is provided for balancing the voltage of multiple series-connected electrochemical cells of an electrical storage system of a hybrid electric vehicle. The method includes discharging the electrical storage system by operating at least one large electrical machine of the vehicle at vehicle standstill until the state of charge of the electrical storage system or the cell having the lowest state of charge has reached a predetermined level, and subsequently balancing the voltage of the cells.

Abstract: An energy management system is provided for a hybrid electric vehicle including an electrical machine for vehicle traction drive and recuperative braking, an electrical storage system ESS for storing recuperated energy, and at least one additional vehicle electrical auxiliary device different from the electrical machine. An energy management controller is arranged to, upon establishing a potential for increased amount of recuperated energy during a predicted future downhill descent, direct electrical power from the ESS to the at least one additional electrical auxiliary device for the purpose of reducing the electrical charge level of the ESS, such that an increased amount of energy may be recuperated and stored in the ESS during the predicted future downhill descent.

Abstract: A method for controlling a hybrid vehicle electrical system includes driving the vehicle in a first driving mode where the battery pack is connected to the traction voltage DC-link and the battery pack is supplying the electrical auxiliary units with power, shutting down the power electronics unit in order to cease power delivery from the electric machine to the traction voltage DC-link or to the electric machine from the traction voltage DC-link, disconnecting the battery pack from the traction voltage DC-link by opening the relay, and activating the power electronics unit and controlling output voltage of the power electronics unit to a predetermined level.

Abstract: An energy management system is provided for a hybrid electric vehicle including an electrical machine for vehicle traction drive and recuperative braking, an electrical storage system ESS for storing recuperated energy, and at least one additional vehicle electrical auxiliary device different from the electrical machine. An energy management controller is arranged to, upon establishing a potential for increased amount of recuperated energy during a predicted future downhill descent, direct electrical power from the ESS to the at least one additional electrical auxiliary device for the purpose of reducing the electrical charge level of the ESS, such that an increased amount of energy may be recuperated and stored in the ESS during the predicted future downhill descent.

Abstract: A method is provided for controlling the temperature of a traction battery in a hybrid vehicle, where the hybrid vehicle includes an internal combustion engine and an electric motor for traction power. The method includes providing a first temperature regulating circuit for the internal combustion engine, providing a second temperature regulating circuit for the traction battery, heating the traction battery by an electrical heater provided in the second temperature regulating circuit in series with a pump, a radiator and the traction battery, transferring power to the electrical heater via a DC/DC converter from the electrical motor, which electrical motor is driven by the internal combustion engine, while the battery is below a predetermined temperature interval.

Abstract: A method is provided for controlling the temperature of a traction battery in a hybrid vehicle, where the hybrid vehicle includes an internal combustion engine and an electric motor for traction power. The method includes providing a first temperature regulating circuit for the internal combustion engine, providing a second temperature regulating circuit for the traction battery, heating the traction battery by an electrical heater provided in the second temperature regulating circuit in series with a pump, a radiator and the traction battery, transferring power to the heater via a DC/DC converter in the second temperature regulating circuit from the electrical motor, which electrical motor is driven by the internal combustion engine, while the battery is below a predetermined temperature interval.

Abstract: Method for optimizing the operational efficiency of a hybrid electric vehicle is disclosed. The method comprises operating an engine of a hybrid electric vehicle preferentially on an optimized power curve of the engine for maximizing the efficiency of the engine and sensing a state-of-charge (SOC) condition of a battery of the hybrid electric vehicle being at a preferential value indicative of no additional charging being desired. The running torque of the engine is reduced below the optimized torque curve to a point that the power produced by the engine is substantially equal to the power demanded for driving the hybrid electric vehicle.

Abstract: Method for calibrating and synchronizing sensed operating torques of an engine and a generator in a planetary gear based hybrid electric vehicle is disclosed. The method includes providing a sensor that detects the operational torque of an engine of a hybrid electric vehicle at the engine's interface with a planetary gear system of the hybrid electric vehicle. A sensor is provided that detects the operational torque of a generator of a hybrid electric vehicle at the motor's interface with the planetary gear system of the hybrid electric vehicle. The planetary gear system of the hybrid electric vehicle is operated in a split mode so that the generator is directly linked to the engine and a reading of the sensor that detects the operational torque of the generator may be used to compute the operating torque of the engine. Paired values of sensed operational torques of the engine and the generator at like times are recorded.

Abstract: Method for maintaining a catalyst of an emissions system in a hybrid electric vehicle in an operative condition is disclosed. The method includes sensing that an engine of a hybrid electric vehicle has stopped operating. A time period is predicted after which a catalyst of an emissions system associated with the engine will cool to a light-off temperature below which the catalyst becomes ineffective. The predicting step is based on known qualities of the catalyst and ambient conditions in which the vehicle is being operated. The engine is restarted when the predicted time period has expired thereby maintaining the catalyst at temperatures in excess of the light-off temperature.

Abstract: Method for maintaining a catalyst of an emissions system in a hybrid electric vehicle in an operative condition is disclosed. The method includes sensing that an engine of a hybrid electric vehicle has stopped operating. A time period is predicted after which a catalyst of an emissions system associated with the engine will cool to a light-off temperature below which the catalyst becomes ineffective. The predicting step is based on known qualities of the catalyst and ambient conditions in which the vehicle is being operated. The engine is restarted when the predicted time period has expired thereby maintaining the catalyst at temperatures in excess of the light-off temperature.

Abstract: Method for optimizing the operational efficiency of a hybrid electric vehicle is disclosed. The method comprises operating an engine of a hybrid electric vehicle preferentially on an optimized power curve of the engine for maximizing the efficiency of the engine and sensing a state-of-charge (SOC) condition of a battery of the hybrid electric vehicle being at a preferential value indicative of no additional charging being desired. The running torque of the engine is reduced below the optimized torque curve to a point that the power produced by the engine is substantially equal to the power demanded for driving the hybrid electric vehicle.

Abstract: Method for calibrating and synchronizing sensed operating torques of an engine and a generator in a planetary gear based hybrid electric vehicle is disclosed. The method includes providing a sensor that detects the operational torque of an engine of a hybrid electric vehicle at the engine's interface with a planetary gear system of the hybrid electric vehicle. A sensor is provided that detects the operational torque of a generator of a hybrid electric vehicle at the motor's interface with the planetary gear system of the hybrid electric vehicle. The planetary gear system of the hybrid electric vehicle is operated in a split mode so that the generator is directly linked to the engine and a reading of the sensor that detects the operational torque of the generator may be used to compute the operating torque of the engine. Paired values of sensed operational torques of the engine and the generator at like times are recorded.

Abstract: Method for minimizing driver perceptible drive train disturbances during take-off in a hybrid electric vehicle when maximized power is often desired is disclosed. The method includes sensing an actual state-of-charge (SOC) value of a battery in a hybrid electric vehicle and a traveling velocity of the vehicle during take-off operation. The sensed actual SOC value is compared with a SOC reference value and computing a delta SOC value as a difference therebetween. A velocity-based SOC calibration factor is looked up that corresponds to the traveling velocity of the vehicle. A combination is utilized of the delta SOC value and the SOC calibration factor as a SOC feedback engine speed control instruction to an engine controller of the hybrid electric vehicle. A driver's desired vehicular acceleration is sensed based on accelerator position.