Estimation of a ride height of an axle

A system for estimating a current ride height of a first axle of a vehicle, wherein the first axle is connected to a first drive shaft, the first drive shaft being driven by a second drive shaft by the second drive shaft rotating a mechanical joint connected to both the first drive shaft and the second drive shaft, the first drive shaft having a first angle to the mechanical joint, and the second drive shaft having a second angle to the mechanical joint, and wherein the current ride height of the first axle is at least partly determined by the first angle and the second angle, the system comprising:

• one or more sensors comprising:
• a ride height sensor,
• an angle sensor,
• a drive shaft sensor;
• a processor device configured to:
• obtain an initial ride height of the first axle from the ride height sensor;
• for a predetermined time period, obtain a variation in rotational speed of the first drive shaft from the drive shaft sensor, the variation in rotational speed being caused at least partially by the first angle and the second angle, wherein at least one of the first angle or second angle are determined from the angle sensor;
• obtain a condition signal from at least one the one or more sensors, the condition signal indicating any one or more out of:
• that the second angle is fixed within an interval of a predetermined error margin, or
• a current ride height of a second axle, wherein the current ride height of the second axle at least partly determines the second angle;
• and
• estimate the current ride height of the first axle based on the variation in rotational speed of the first drive shaft, the obtained initial ride height of the first axle, and the condition signal.