Vehicle provided with a suspension and an electromechanical rotary device for controlling the suspension, and method for controlling motion of a vehicle suspension

A method for adjusting motion of a vehicle suspension, the method comprising the steps of:

• a) providing a vehicle comprising:
• a vehicle body;
• at least one hub, adapted to support a wheel, whereby the wheel is rotatable about the hub;
• and
• a suspension connecting the hub to the vehicle body, so that the hub is pivotable vertically with respect to the vehicle body, said suspension comprising:
• a suspension arm hinged to the vehicle body and to the hub;
• a spring adapted to bias said suspension arm toward a predetermined neutral position of equilibrium of static forces with respect to the vehicle body;
• an electromechanical rotary actuator, integrally connected to the vehicle body and comprising an electric machine coupled to a reduction gear, said reduction gear including at least one reduction stage comprising an output shaft having a rotation axis parallel to a hinge axis of the suspension arm to the vehicle body;
• a leverage adapted to transfer motion from the at least one reduction stage to said suspension arm by said output shaft of said at least one reduction stage, said leverage and output shaft of the at least one reduction stage comprising or being formed by components configured substantially as rigid bodies;
• one or more sensors adapted to detect parameters indicative of motion of the suspension arm;
• an electronic control unit adapted to control torque and the angular position of the electric machine of the electromechanical rotary actuator, based on signals transmitted by the one or more sensors;
• and
• a battery adapted to power the electromechanical rotary actuator and receive electricity from the electromechanical rotary actuator;
• the electromechanical rotary actuator being operable between an active adjustment condition, wherein said electromechanical rotary actuator is configured to be electrically powered by the battery and to transmit to said suspension arm, via the leverage, a force causing a relative motion of said suspension arm with respect to the vehicle body, performing a positive work on the suspension, and a damping condition, wherein said electromechanical rotary actuator is configured to electrically power the battery and transmit to said suspension arm, via the leverage, a force opposing the relative motion of said suspension arm with respect to the vehicle body, performing a negative work on the suspension;
• said electromechanical rotary actuator being operable between said active adjustment condition and said damping condition on command of the electronic control unit, to respectively give motion to said suspension arm with a maximum frequency higher than 5 Hz or dampen the motion of said suspension arm with a maximum frequency greater than 5 Hz;
• b) detecting, through the one or more sensors, relative position and relative velocity between the vehicle body and the hub;
• c) when a mutual movement is detected between the vehicle body and the hub by the electronic control unit controlling the electromechanical rotary actuator so that:
• c1) if motion of the hub is such that a distance between said hub and the vehicle body tends to decrease with respect to an absolute distance that said hub would have from said vehicle body in a neutral condition of equilibrium of static forces of the suspension, powering the electromechanical rotary actuator with electric current from the battery so as to generate a torque which, transmitted to the suspension arm by the leverage, generates on said suspension arm an action with a maximum frequency F>5 Hz tending to further reduce the distance between the hub and the vehicle body as long as the relative velocity between the hub and the vehicle body does not change sign, in which case cutting off power supply from the battery to the electromechanical rotary actuator, and making said electromechanical rotary actuator work as a generator, transmitting the electric current produced to the battery;
• and
• c2) if motion of the hub is such that the distance between said hub and the vehicle body tends to increase with respect to the absolute distance that the hub would have from said vehicle body in the neutral condition of equilibrium of static forces of the suspension, powering the electromechanical rotary actuator with electric current from the battery so as to generate a torque which, transmitted to the suspension arm by the leverage, generates an action with a maximum frequency F>5 Hz on said suspension arm tending to further increase the distance between the hub and the vehicle body as long as the relative velocity between the hub and the vehicle body does not change sign, in which case cutting off power supply from the battery to the electromechanical rotary actuator and making said electromechanical rotary actuator work as a generator, transmitting the electric current produced to the battery.