A method to control a hybrid vehicle with a parallel architecture and with an unknown speed profile, wherein the hybrid vehicle is provided with an internal combustion engine and with a reversible electrical machine connected to a storage system designed to store electrical energy; the method comprises the steps of recognizing the operating mode of the hybrid vehicle; determining a function of the specific fuel consumption of the drive system of the hybrid vehicle as a function of the operating mode of the hybrid vehicle; determining the optimal value of the power of the storage system and the optimal value of the power of the internal combustion engine, which correspond to the values that permit a minimization of said function.

An apparatus for controlling a hybrid vehicle may include an engine that generates driving torque by combustion of fuel; an integrated starter-generator that starts the engine and generates electrical energy by selectively operating as a power generator; a drive motor that supports the power of the engine and generates electrical energy by selectively operating as a power generator; a battery that charges with the electrical energy generated by the integrated starter-generator and the drive motor; a nitrogen oxide purification device (LNT) that purifies nitrogen oxide included in exhaust gas exhausted from the engine; and a controller that controls engine torque by calculating a target engine torque for regenerating the nitrogen oxide purification device, supports the engine torque through the integrated starter-generator or the drive motor when a driving torque necessary for driving is greater than the target engine torque at a regeneration mode of the nitrogen oxide purification device, and performs regenerative braking the driving torque through the integrated starter-generator or the drive motor when the driving torque is less than the target engine torque.

A vehicle clutch control device is provided for switching from a two-wheel drive traveling to a four-wheel drive traveling. The vehicle clutch control device includes a dog clutch that separates a rear wheel drive from a front wheel drive by releasing the dog clutch, an electronically controlled coupling that distributes a driving force of a transverse engine to left and right rear wheels in accordance with a clutch connection capacity, and a four-wheel drive control unit. The four-wheel drive control unit switches the drive mode to one of a disconnect two-wheel drive mode in which the dog clutch and the electronically controlled coupling are released, a connect four-wheel drive mode in which the dog clutch and the electronically controlled coupling are engaged, and a stand-by two-wheel drive mode in which the dog clutch is engaged while the electronically controlled coupling is released.

A through-the-road (TTR) hybridization strategy is proposed to facilitate introducing hybrid electric vehicle technology in a significant portion of current and expected trucking fleets. In some cases, the technologies can be retrofitted onto an existing vehicle (e.g., a trailer, a tractor-trailer configuration, etc.). In some cases, the technologies can be built into new vehicles. In some cases, one vehicle may be built or retrofitted to operate in tandem with another and provide the hybridization benefits contemplated herein. By supplementing motive forces delivered through a primary drivetrain and fuel-fed engine with supplemental torque delivered at one or more electrically-powered drive axles, improvements in overall fuel efficiency and performance may be delivered, typically without significant redesign of existing components and systems that have been proven in the trucking industry.