Realized is a technique for estimating a state quantity of a vehicle, which technique is applicable to estimation of a vehicle weight and allows an increase in accuracy and speed of the estimation. A state quantity estimating device includes a data storing section (101), a predictive quantity computing section (102), an obtaining section (107), a Kalman gain computing section (103), an estimated quantity computing section (104) which calculates an estimated state quantity and estimated covariance, and a process noise covariance correcting section (106) which corrects process noise covariance. The estimated state quantity, the estimated covariance, and the process noise covariance, each of which has been calculated or corrected, are written in the data storing section (101) as a state quantity, state covariance, and process noise covariance, respectively, and are used in a next computation for estimating a state quantity.

A control system for a vehicle is provided, the control system comprising one or more controllers, the control system configured to receive an acceleration or deceleration demand signal from an automatic cruise control system, and request modification of one or more parameters of the vehicle suspension system in response to the received acceleration or deceleration demand signal. In this way, the vehicle suspension system may be modified in preparation for an acceleration or deceleration of the vehicle, to inhibit or at least reduce the occupants of the vehicle experiencing an undesirable pitching movement of the vehicle during the course of the change in speed of the vehicle.

A method for controlling a suspension system for a vehicle to obtain optimal parameters for the damping coefficients of the vehicle suspension that minimize acceleration along a heave axis, angular acceleration around a roll axis and angular acceleration around a pitch axis is provided. These parameters may be recorded during the tuning phase or may also be continuously obtained during use of the vehicle by an end user. Also disclosed is a suspension system for a vehicle configured to advantageously operate according to the method.

The present invention achieves a technique that not only makes it possible to reduce sensor-related cost but also makes it possible to estimate a ground contact load of a vehicle with sufficiently high accuracy. A ground contact load estimation device (100) causes an acquisition section to acquire a physical quantity related to a vehicle, causes a reference inertia load calculation section (111) to calculate a reference inertia load with use of the physical quantity, uses the physical quantity to cause a correction value calculation section (112) to calculate an inertia load correction value, and causes an inertia load estimation section (110) to estimate an inertia load by adding the inertia load correction value to the reference inertia load.

A damping control system for a vehicle having a suspension located between a plurality of ground engaging members and a vehicle frame are disclosed. The vehicle including at least one adjustable shock absorber having an adjustable damping characteristic.

A method for monitoring a vehicle, the vehicle comprising a control unit and an air suspension system, the air suspension system comprising pressure sensors configured to provide data representative of operating pressures of the air suspension system. To improve the monitoring of the vehicle, the method comprises determining a centre of mass of the vehicle by the control unit on the basis of data provided by the pressure sensors at least once during operation of the vehicle.

A vehicle rollover mitigation system may include at least one first sensor to output rollover symptom signals indicating potential rollover of a vehicle, at least one second sensor to output vehicle environment signals indicating a surrounding environment of the vehicle and a controller to output rollover mitigation control signals for mitigating potential rollover of the vehicle based upon the rollover symptom signals and the vehicle environment signals. The vehicle rollover mitigation system may automatically respond to potential rollover by altering a state of an implement coupled to the vehicle.

Aspects relate to control systems for an air spring of a suspension system of a vehicle. The control system is configured to, when the air spring is operating in a high stiffness state during vehicle motion, receive a signal indicative of a rate of change of acceleration of the vehicle. The control system is configured to determine if a spring state hold condition is satisfied in dependence on the rate of change of acceleration. If the spring state hold condition is determined to be satisfied, the control system is configured to output a hold control signal to cause the air spring to remain operating in the high stiffness state.

A control system for a vehicle is provided, the control system comprising one or more controllers, the control system configured to identify an upcoming speed limit change, and in dependence on the identified speed limit change, requesting modification of one or more parameters of the vehicle suspension system. This prepares the vehicle suspension to reduce pitch forwards/backwards at a time when an acceleration/deceleration can be expected, while allowing more composed vehicle suspension settings to be used at other times.

A suspension control apparatus includes a slip state detection apparatus configured to detect a slip state of a wheel. The slip state detection apparatus includes a tire characteristic-considered slip ratio determination portion configured to determine a tire characteristic-considered slip ratio, which is a coefficient for correcting a slip ratio of the wheel determined based on a rotational velocity signal of the wheel, based on a longitudinal acceleration of a vehicle detected by a longitudinal acceleration detection portion and a tire characteristic; and a corrected slip ratio determination portion configured to determine a corrected slip ratio of the wheel by correcting the slip ratio of the wheel according to the tire characteristic-considered slip ratio.