Powered wheeled vehicle capable of travelling on level ground, over uneven surfaces and on stairs

A powered wheeled vehicle, capable of travelling both on level ground and over uneven surfaces, comprising two driving treads supported by two rollers located at the front of the vehicle and two rollers located at the rear of the vehicle as well as two pairs of front and rear wheels, one of which is a drive, each of these wheels with the driving torque being mounted on a rocker arm which may pivot around an axis parallel to the axis of the wheel and perpendicular to the longitudinal axis of the tread, each of the rocker arms of the rear wheels of the aforesaid driving torque being securely attached to an actuator designed so as to position said wheels in a first low position wherein the supporting area of the wheels is located below the supporting area of the treads so that the wheels by themselves provide the driveability of said wheeled vehicle, wherein said actuator is designed so as to position the wheels in a second high position wherein the supporting area of the wheels remains in contact with the ground so that the driveability of the vehicle results from the combination of the effects of the tread and said driving wheels, said vehicle comprising a controller taking into account information from position, proximity, and tilt sensors, and acting on the gear motors actuating the rear wheels, on the gear motors, actuating the treads, on the electric actuator actuating the arms, on the gear motor actuating the translational movement of the front wheels, and on the electric actuator actuating the seat so as to allow a transition to be carried out in reverse gear, between horizontal ground and the first step of the staircase, upon moving up a staircase, including the following steps:

• positioning the vehicle in abutment against the first step,
• upward motion of the front and rear wheels,
• having the tread rest on the ground,
• having the rear wheel rest against the horizontal plane of the first step,
• simultaneous starting of the tread surface and of the rear wheel,
• the bearing surface of the rear wheel in the high position, being tangent to the bearing surface defined by the tread, so as to cooperate with the movement for crossing the first step of the staircase.