METHOD OF CONTROLLING A PICKUP MANOEUVRE OF A HYBRID VEHICLE

A method of controlling a pickup manoeuvre of a vehicle is described. The vehicle comprises a hybrid propulsion system (10) including an in-series arrangement comprising an internal combustion engine (E), a first clutch (KO), an electric motor (M), a second clutch (K1) and a gearbox (G) having an input shaft and an output shaft. The first clutch is arranged between the internal combustion engine and the electric motor, and the second clutch is arranged between the electric motor and the input shaft of the gearbox. The method is characterized in that the pickup manoeuvre is actuated with the internal combustion engine (E) off, the electric motor (M) active and said first clutch (K0) in an open condition. In a first phase of the pickup manoeuvre, advancement of the vehicle is obtained by progressively closing the second clutch (K1) so that the input shaft of the gearbox is set in rotation with an increasing rotational speed, while the electric motor also rotates at an increasing speed which is higher than the rotational speed of the input shaft of the gearbox at any instant, with the second clutch which is in a slip condition. Upon a request for a start of the internal combustion engine (E), the first clutch (K0) is progressively closed so that the internal combustion engine starts to be driven by the electric motor (M), while the second clutch (K1) is kept in a slip condition. The slip condition of the second clutch is maintained until the internal combustion engine and the electric motor rotate substantially at a same speed, higher than the rotational speed of the input shaft of the gearbox, and once this condition is reached a closing manoeuvre of the second clutch is started.