Ultra-low heavy-duty active suspension, suspension vehicle and leveling control method

A heavy-duty active suspension, comprising:

• a suspension frame;
• a lifting unit;
• a pin axle;
• a through axle;
• two wheel-driving units;
• an encoder;
• and
• a displacement sensor;
• wherein the lifting unit is arranged on an upper side of the suspension frame, and is configured for driving a heavy-duty support platform of a vehicle to rise and descend;
• the pin axle is configured to run through the suspension frame along a longitudinal direction;
• the through axle shaft is rotatably arranged on the pin axle through a first bearing, and is configured to run through the suspension frame along a transverse direction;
• the two wheel-driving units are respectively arranged on both ends of the through axle through a second bearing;
• the encoder is arranged on the through axle, and is configured for measuring a transverse swing angle of the through axle;
• and the displacement sensor is arranged between an output end of the lifting unit and the suspension frame;
• the lifting unit comprises a hydraulic cylinder, an inner guide sleeve, an outer guide sleeve, a proportional servo valve, and a slewing bearing;
• the hydraulic cylinder is arranged on the suspension frame;
• the inner guide sleeve is sleevedly provided outside the hydraulic cylinder, and is fixedly connected to a base of the hydraulic cylinder;
• the outer guide sleeve is slidingly connected outside the inner guide sleeve;
• the proportional servo valve is configured for controlling a flow rate of the hydraulic cylinder;
• and the slewing bearing is configured for connection with the heavy-duty support platform of the vehicle;
• and
• a top end of a piston rod of the hydraulic cylinder is fixedly connected to an inner ring of the slewing bearing;
• an upper end of the outer guide sleeve is fixedly connected to the inner ring of the slewing bearing;
• and an outer ring of the slewing bearing is fixedly connected to the heavy-duty support platform of the vehicle;
• and an oil return port of the proportional servo valve is connected to an oil chamber of the hydraulic cylinder through a pipeline.