A suspension system and associated control methods for improving comfort by disabling passive pitch stiffness in the suspension system by holding open electromechanical comfort valves positioned in a manifold assembly of the suspension system. The manifold comfort valves are held open to disable the passive pitch stiffness of the suspension system if the vehicle is traveling down a rough road or if the vehicle is approaching a discrete road event like a pot-hole or speed bump. Deactivation of the passive pitch stiffness of the suspension system is determined based on road classification information, saved road events, and/or real-time vehicle data from on-board sensors. The suspension system therefore reduces pitch angles during pitch events induced by inertial forces caused by driver inputs and disables the pitch stiffness when the pitch event is caused by road inputs.

A suspension system and associated control methods that reduce temperature related fluctuations in the internal pressures and stiffness of the suspension system. A manifold assembly is connected in fluid communication with a plurality of dampers via hydraulic circuits and a pump assembly via a pump hydraulic line. Onboard sensors generate real-time data regarding the vehicle. A suspension control unit, arranged in electronic communication with the aforementioned components, monitors the real-time data, sets a target stiffness and a target pressure, calculates an effective stiffness based on the real-time data, determines if the effective stiffness is above or below the target stiffness and sets a new target pressure accordingly by making stepwise decreases or increases until the new target pressure is reached.

A state module selectively sets a present state to a first state in a predetermined order of states; a valve control module determines first target open and closed states for valves of a suspension system based on the present state and opens and closes the valves according to the first target open and closed states, respectively; a pump control module configured to, when the valves are in the first target open and closed states, respectively, selectively operate an electric pump of the suspension system in a first direction and pump hydraulic fluid toward the suspension system; and a diagnosis module configured to: record first and second values of pressures within the suspension system measured using pressure sensors, respectively, before and after the operation of the electric pump in the first direction, respectively; and selectively diagnose faults in a first subset of the valves based on whether pressure increases occurred.

A system for grading filling of a suspension system includes: a pump control module configured to, during first and second periods, operate an electric pump of the suspension system in first and second directions and decreasing and increasing hydraulic fluid pressure within the suspension system, respectively; a monitoring module configured to: store a first pressure of hydraulic fluid within the suspension system measured using a pressure sensor when the first pressure is less than or equal a first predetermined pressure while the pump is operated in the first direction; and store a second pressure measured using the pressure sensor when the second pressure is greater than or equal a second predetermined pressure while the pump is operated in the second direction; and a grade module configured to determine a grade value for the filling of the suspension system based on the first and second pressures.

A rinsing system includes: a pump control module configured to, when a hydraulic line is connected to a port that is fluidly connected to a hydraulic line of a suspension system, selectively operate a hydraulic fluid pump of the suspension system and pump hydraulic fluid from a hydraulic fluid tank of the suspension system through the hydraulic fluid pump toward the hydraulic line; and a valve control module configured to, when the hydraulic line is connected to the port and the hydraulic fluid pump is pumping hydraulic fluid, open valves of the suspension system and fluidly connect the hydraulic fluid pump with the hydraulic line.

A suspension system and associated control methods for improving the effectiveness of driver assistance systems is disclosed where the driver assistance systems can generate and send requests to a suspension control unit (SCU) of the suspension system to actuate (e.g., close) one or more comfort valves in the suspension system to increase the roll stiffness and/or pitch stiffness of the suspension system when the driver assistance systems are taking corrective action. As part of a two-way communication between the suspension control unit (SCU) and the driver assistance systems, the suspension control unit (SCU) communicates target stiffnesses and/or calculated effective stiffnesses to the driver assistance systems, which is used to update the vehicle stability models used by the driver assistance systems.

An air management system for a vehicle having a first pneumatic circuit and a second pneumatic circuit, in which the first and second pneumatic circuits are pneumatically connected in a neutral position via a cross-flow mechanism. The first pneumatic circuit includes a first leveling valve configured to adjust independently the height of a first side of the vehicle. The second pneumatic circuit includes a second leveling valve configured to adjust independently the height of a second side of the vehicle. The first and second leveling valves are configured to establish pneumatic communication between the first and second pneumatic circuits when the first leveling valve is not independently adjusting the height of the first side of the vehicle and the second leveling valve is not independently adjusting the height of the second side of the vehicle.

A suspension system including four dampers where each damper includes compression and rebound chambers. The suspension system has four hydraulic circuits, each including a cross-over hydraulic line that extends between dampers located at opposite corners of the vehicle (i.e., between the front left and back right dampers or between the front right and back left dampers). The suspension system further includes four electromechanical comfort valves that open and close four bridge hydraulic lines that extend between the cross-over hydraulic lines at each corner of the vehicle. Each cross-over hydraulic line is connected to a manifold assembly by a corresponding manifold hydraulic line. The manifold assembly includes four manifold valves that are connected to a pump assembly and two manifold comfort valves. All six comfort valves are electromechanical valves that can be actuated to control the roll and pitch of the vehicle during cornering, braking, and acceleration.

Systems and methods for load monitoring and/or braking control. The load monitoring may include calculating a weight on one or more axles of a vehicle or a trailer using cross-flow pressure information indicative of an air pressure within a cross-flow passage between first and second leveling valves of first and second pneumatic circuits configured to adjust independently heights on first and second sides, respectively, of the vehicle or the trailer. The braking control may include (i) using the cross-flow pressure and speed and/or acceleration information indicative of a speed and/or acceleration of the vehicle and/or the trailer to calculate first and second brake application levels and (ii) applying the calculated first and second brake application levels to first and second brakes on the first and second sides, respectively, of the vehicle or the trailer.

A bed truck having multiple axles has a hydraulic suspension including multiple hydraulic cylinders for each axle, a ride height sensor associated with each hydraulic cylinder, a high pressure hydraulic circuit connecting each of the cylinders and accumulators to a hydraulic pressure source, a low pressure hydraulic circuit connecting each of the cylinders to a fluid tank, and a plurality of valves operable to isolate operation of any one hydraulic cylinder from some or all of the other hydraulic cylinders. A control system is operable to control each of the hydraulic cylinders, either independently of all the other hydraulic cylinders, or in concert with one or more other hydraulic cylinders, such control including locking any one or more of the hydraulic cylinders at a minimum ride height position.