A suspension system includes a spring assembly including a gas spring and an accumulator, and a controller. The accumulator is coupled to the gas spring and includes a bladder. The accumulator has a compressed state and an uncompressed state. The controller is configured to a) determine a target amount of gas in the spring assembly and b) adjust the amount of gas in the spring assembly towards the target amount of gas based on a pressure difference across the bladder.

A method for determining a tyre normal force range (F.sub.z,min, F.sub.z,max) of a tyre force (F.sub.z) acting on a vehicle (100), the method comprising; obtaining (S1) suspension data (310) associated with a suspension system of the vehicle (100); obtaining (S2) inertial measurement unit, IMU, data (320) associated with the vehicle (100); estimating (S3), by a suspension-based estimator (330) a first tyre normal force range (F.sub.z1,min, F.sub.z1,max) based on the suspension data (310); estimating (S4), by an inertial force-based estimator (340), a second tyre normal force range (F.sub.z2,min, F.sub.z2,max)based on the IMU data (320); and determining (S5) the tyre normal force range (F.sub.z,min, F.sub.z,max) based on the first tyre normal force range (F.sub.z1,min, F.sub.z2max) and on the second tyre normal force range (F.sub.z2,min, F.sub.z2,max).

Methods and apparatus to adjust vehicle suspension damping are disclosed herein. An example apparatus includes memory and at least one processor to execute computer readable instructions to obtain wheel position information and vehicle speed information from sensors associated with wheels of a vehicle, the wheel position information including first wheel position data and second wheel position data, determine a terrain condition based on a greater of the first wheel position data and the second wheel position data, determine a compression damping command based on the terrain condition and the vehicle speed information, and adjust a damping system of the vehicle based on the compression damping command.

A system and method are provided for configuring suspension ratios in a multi-rear axle vehicle, the vehicle having a drive axle suspension and at least one tag axle suspension, each suspension having one or more air springs. The timing of the performance of an adjustment cycle series of steps for adjusting the suspension height and air spring pressure readings is optimized by monitoring the acceleration of the vehicle and conducting the adjustment cycle steps when the vehicle acceleration is below an acceleration threshold. Additionally, air spring pressure adjustments may be scaled based on a confidence factor of the air spring pressure readings. Finally, a method is provided for configuring suspension ratios in a multi-rear axle vehicle, the vehicle having a drive axle suspension and at least one tag axle suspension, and for adjusting the air suspension pressures.

Systems for estimating an axle load of a vehicle wherein axle load is estimated in response to an angle between two components of an axle. The angle may change as weight is added to or removed from the axle such that axle load may be determined as a function of the angle.

An object of the present invention is to provide a vehicle motion state estimation device and method that can estimate the vertical motion state amount with high accuracy by taking into consideration vertical force in which the frictional force acting in the front-rear direction or lateral direction of the wheel acts on the vehicle body due to the geometry of suspension. A vehicle motion state estimation device in a vehicle in which a wheel and a vehicle body are coupled via a suspension, the vehicle motion state estimation device including: a vertical motion-caused wheel speed component estimation unit that estimates a wheel speed component caused by vertical motion of the vehicle; a vertical force estimation unit that calculates vertical force in which frictional force of the wheel caused by motion of the vehicle acts on the vehicle body by geometry of the suspension; and a vertical motion estimation unit that estimates a state amount of vertical motion of a vehicle, in which the vertical motion estimation unit estimates a state amount of vertical motion of the vehicle based on a wheel speed component from the vertical motion-caused wheel speed component estimation unit and vertical force acting on the vehicle body from the vertical force estimation unit.

A road surface detection system, in one example the system includes a hydraulic unit of an anti-lock braking system, the hydraulic unit including a preload adjuster, and a plurality of pressure sensors configured to generate pressure sensor data. The system also includes a controller configured to receive the pressure sensor data from the plurality of pressure sensors, determine a target preload pressure level, compare the pressure sensor data with the target preload pressure level to calculate a pressure differential between the pressure sensor data and the target preload pressure level, determine a road surface based upon the calculated pressure differential, and regulate the preload adjuster to change the pressure within the hydraulic unit based upon the road surface.

The present invention relates to a method for determining a functional status of a vehicle shock absorber arrangement (100). The method determines a difference between force values during compression and expansion of the vehicle shock absorber arrangement (100), whereby the shock absorber arrangement (100) can be determined to be degraded if the difference is below a predetermined threshold.

A system for controlling the stability of a vehicle equipped with semi-active dampers includes: an actuator, a plurality of sensors, a low-level control unit, a high-level control unit and a mid-level control unit adapted to execute an algorithm for calculating a damping level (C.sub.ref).

Provided is a vehicle behavior device including: a variable damper, which is provided between a vehicle body side and a wheel side of a vehicle, and is configured to adjust a force to be generated; a camera device configured to measure a road surface state forward of the vehicle; a future vehicle state estimation unit configured to predict a sprung behavior of the vehicle from a road surface displacement acquired by the camera device and a vehicle speed; and a command value calculation unit configured to obtain a force to be generated by the variable damper based on a predicted value obtained by the future vehicle state estimation unit, and output a command signal.