A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine and configured to start the engine from an inactive state. A controller is programmed to execute a first control algorithm while output speed of the second electric machine is less than a first speed threshold. The controller is also programmed to execute a second control algorithm while output speed of the second electric machine is greater than the first speed threshold and less than a second speed threshold.

An electronic control unit is configured to calculate an amount of divergence of an actual MG rotational speed with respect to a reference rotational speed at the start-up of an internal combustion engine, and correct a generation timing of a compensation torque at the next start-up of the internal combustion engine based on the amount of divergence.

The invention relates to a method for starting an internal combustion engine of a hybrid vehicle, where an electric motor of the hybrid vehicle is accelerated to a predetermined engine speed and a hybrid disconnect clutch, which is arranged between the internal combustion engine and the electric motor, is moved in the closing direction depending on the set-point clutch torque. In a method which safeguards a high reproducibility of the restart operation, the set-point clutch torque for restarting the internal combustion engine is determined depending on an engine switch-off position of the internal combustion engine in a first phase in which the internal combustion engine is not running.

A vehicle includes an engine including a crank shaft; a battery; a belt-integrated starter generator (BISG) mechanically coupled to the crank shaft and configured to generate electric power from motion of the engine to charge the battery; and a controller configured to operate the BISG to apply a load to the crank shaft to slow the engine and capture electric power for storage in the battery, wherein an initial magnitude of the load is proportional to a temperature of the engine, responsive to a speed of the BISG or engine achieving a predetermined non-zero threshold, remove the load from the crank shaft, and bring the engine to a stop.

The purpose of the present invention is to swiftly start up an engine in a range in which electrical equipment having electric power supplied thereto by a battery is not reset, even in cases when the battery is insufficiently charged and the battery is deteriorated. An engine start-up device according to the present invention starts up an engine by transmitting, to the engine, the rotary force of a direct-current motor driven by a battery. The engine start-up device is provided with: a battery-voltage acquisition unit for acquiring the battery voltage of the battery; a target-current-value calculation unit which calculates, on the basis of the battery voltage acquired by the battery-voltage acquisition unit, a target current value for a motor current to be supplied from the battery to the direct-current motor; and a motor-current control unit for controlling a switching element which is connected to the direct-current motor, and through which the motor current flows, such that the motor-current value of the motor current approaches the target current value.

A method of starting an integrated starter generator drives a starter generator without using a rotor position sensor to start an engine. The method includes the following steps of: (a) applying a first drive current with a first frequency and a first amplitude to drive the starter generator to reversely rotate in a speed open-loop control mode, and acquiring a first load information according to a drive voltage and the first drive current of the starter generator, (b) confirming whether the first load information meets a heavy load condition, (c) stopping reversely rotating the starter generator when the first load information meets the heavy load condition, and (d) forwardly rotating the starter generator to drive the engine to start.

A method of controlling charging of a battery may include making, by a controller, the battery that supplies power to a drive motor start to be charged with a boosted voltage higher than a voltage of a fast charger by controlling a switch connecting the drive motor and the fast charger of a vehicle and a switch of an inverter driving the drive motor, for fast charging of the battery; determining, by the controller, whether a motor position sensor has failure according to an output signal of the motor position sensor which detects a position of the drive motor; engaging, by the controller, an engine clutch that is configured to connect or disconnect the engine of the vehicle and the drive motor, when the controller determines that the motor position sensor has the failure; and maintaining, by the controller, the fast charging for the battery when a rotation of the drive motor stops after the engine clutch is engaged.

A method for producing an active short circuit condition in an electric motor of a hybrid electric vehicle including a traction battery, an inverter having switches in communication with the electric motor and the traction battery, and an inverter controller in communication with the inverter and configured to generate driver signals to operate the switches to produce three-phase alternating current for the electric motor to drive a vehicle propulsion system or to produce direct current for charging the traction battery. The method includes determining an electric motor speed threshold, wherein the electric motor speed threshold is continuously variable, comparing a monitored speed to the speed threshold, and generating, in response to the monitored speed exceeding the speed threshold, driver signals to operate the switches to produce an active short circuit condition in the electric motor to prevent overcharging of the traction battery.

A control device for a hybrid electric vehicle includes an electronic control unit. The electronic control unit is configured to perform a start-up control of shifting the connection and disconnection clutch to a coupled state at the time of starting the internal combustion engine to rotate the internal combustion engine by the driving torque of the electric motor, and starting the first fuel injection mode using the direct injection injector. The electronic control unit is configured to switch from the first fuel injection mode to a second fuel injection mode for using the port injector prior to an end of the start-up control when the number of times of combustion cycles of the internal combustion engine with the first fuel injection mode reaches a predetermined first target number of times.

A method and system for operating a vehicle that includes feedback of operating status of an engine starting system is described. In one example, the method inhibits automatic engine pull-down in response to feedback from an engine starting system that does not meet expectations. The system and method may provide diagnostics for the engine starting system.