Suspension system for a heavy vehicle

A vehicle comprising a chassis, a pair of left and right wheels and a suspension system for connecting the wheels and the chassis, wherein the suspension system comprises:

• a wheel axle that extends transversely across the vehicle and that is connected at the end portions thereof to the left and right wheels;
• a pair of left and right leaf springs connected to the wheel axle in association with a corresponding wheel, wherein each leaf spring is connected also to the chassis so as to, while deflecting, allow relative vertical movement between the chassis and the wheel axle and thereby also between the chassis and the wheels;
• an inertial measurement unit arranged at the wheel axle, wherein the inertial measurement unit is adapted to provide a signal indicative of a current angular velocity of the wheel axle about a longitudinal roll axis of the vehicle and thus to provide information on whether one of the wheels passes a significant bump on a road surface while driving the vehicle;
• and
• left and right level sensors arranged to provide a signal indicative of a current vertical position of a corresponding leaf spring in relation to the chassis and thus to provide information on a degree of deflection of each of the left and right leaf springs when functioning as intended;
• wherein the vehicle further comprises:
• a control circuitry configured to control the suspension system, wherein the control circuitry is configured to:
• compare the signals on current vertical position obtained from the left and right level sensors and determine whether a current difference in vertical position between the left and right leaf springs is greater than a first threshold value;
• when the determined difference is greater than the first threshold value:
• determine, based on timing information related to the signals provided by the inertial measurement unit and the left and right level sensors, whether the determined difference in vertical position between the left and right leaf springs is related in time with a signal from the inertial measurement unit indicating that the angular velocity of the wheel axle is greater than a second threshold;
• and
• when the determined difference in vertical position is not related in time with the signal indicating that the angular velocity of the wheel axle is greater than the second threshold:
• generate an alarm signal indicative of a detected or possibly detected leaf spring failure.