43 results about "Roll moment" patented technology

The present application relates to a kind of vehicle steering body posture and control method of handling stability, comprising the following steps: the signal input required for control is collected, vehicle total anti-lateral moment is calculated by body posture feedforward-feedback controller, front and rear axle anti-roll moment distribution ratio is calculated by handling stability feedforward-feedback controller, total anti-roll moment and its front and rear axle distribution ratio are calculated, revised by control comprehensive module, finally output each suspension angle vertical force control instruction of vehicle.The present application has the following advantages:1) vehicle body posture control and handling stability control are comprehensively considered, and both are simultaneously optimized;2) vehicle body posture control and handling stability control both use feedback-feedforward, avoid the problem of pure feedforward control or feedback control, so that the overall performance of vehicle is more "natural";3) steering input and road input are decoupled, and four high sensors are saved.

A control method, control apparatus and control system for an active stabilizer bar of a vehicle, and an electronic device, a vehicle and a computer-readable storage medium. The control method for an active stabilizer bar of a vehicle comprises: acquiring a sensor signal and a vehicle CAN signal of a vehicle; on the basis of the acquired sensor signal and vehicle CAN signal of the vehicle, estimating vehicle kinematic-state parameters, so as to obtain physical parameters that reflect a vehicle kinematic state; on the basis of the physical parameters that reflect the vehicle kinematic state, performing anti-roll moment decision-making, so as to obtain a desired anti-roll moment for the vehicle in the current state; and on the basis of the desired anti-roll moment for the vehicle in the current state, generating a torque control instruction corresponding to an active stabilizer bar configured for the vehicle, such that the active stabilizer bar outputs, on the basis of the torque control instruction, a reverse torque for preventing the vehicle from rolling. The requirement for anti-roll control of an active stabilizer bar can be met, thereby improving the vehicle operation stability and safety.

The invention relates to a stabilization self-adaptive control method and device based on double gyroscopes, and the self-adaptive control method comprises the steps: constructing a real-time updated'sea wave-ship-double gyroscope 'coupling dynamic model, and introducing the online identification of ship rolling parameters; physical limit, damping, maximum torque and other constraints of the double-gyroscope executing mechanism are explicitly written into a control law; the two gyroscopes are symmetrically arranged and opposite in precession direction, so that yawing torques are mutually counteracted and rolling torques are superposed, and the stabilization efficiency is improved; adaptively selecting PID according to the rolling amplitude, the sea condition uncertainty and the working state of the actuator, and adaptively switching the fuzzy adaptive PID and the model prediction control strategy; calculating a control instruction based on the selected strategy and the updating model, and performing physical constraint processing such as torque saturation and angle amplitude limiting; and outputting a safety instruction to drive the gyroscope to generate stabilization torque. The method can adapt to different working conditions, and the efficient and stable active stabilization performance and stabilization effect are kept under the multiple working conditions.

The invention relates to the technical field of vehicle active suspension control systems, in particular to a vehicle roll-forward control method for an active suspension, which comprises the following steps of: constructing a roll state prediction unit, deducing a roll moment for causing roll of a vehicle body during steering of the vehicle, and predicting the roll degree of the vehicle body; constructing a control moment calculation unit, calculating the deformation resistance moment of the vehicle suspension, and determining the moment generated by the ground friction force on the vehicle chassis; a torque distribution calculation unit is constructed, and the total torque borne by the chassis during vehicle steering and the distribution proportion of the total torque between the front chassis and the rear chassis are determined; constructing a control force calculation unit, calculating active suspension target acting forces at four wheels required for realizing the front and rear suspension control moment, converting the target control moment into a target control force, and providing a specific control instruction for rear-end execution; according to the method, the roll degree of the vehicle body can be quickly predicted, the control target can be calculated in time, the control instruction is sent out before the vehicle body actually has large roll, and the stable control effect is achieved.

The invention relates to the technical field of automobile control, in particular to an anti-skid control method and device for a four-wheel-drive electric automobile and the automobile, and the method comprises the steps that the driving torque, the four-wheel positive pressure and the resultant pressure after rolling torque distribution of the four-wheel-drive electric automobile during wheel speed slipping are obtained, and the friction coefficient of the automobile is estimated according to the three parameters; and judging the friction working condition of the four-wheel-drive electric vehicle based on the friction coefficient. Under the friction working condition, four-wheel gravity is calculated, and four-wheel driving force, a driver control signal and a vehicle body posture signal are obtained; and determining a front wheel resultant moment and a rear wheel resultant moment based on the four-wheel gravity, the four-wheel driving force, the driver control signal and the vehicle body posture signal. And under the slipping working condition of the four-wheel-drive electric automobile, anti-slip control is conducted on the automobile according to the front wheel resultant moment and the rear wheel resultant moment. Therefore, the problems of difficulty in timely and active inhibition of vehicle slipping and drifting under high torque on the ice and snow covered pavement, insufficient safety and the like in related technologies are solved.

The present application relates to the field of vehicle dynamics control, and discloses a kind of diagonal module configuration vehicle diagonal steering switching control method: the three-degree-of-freedom model of vehicle translation, yaw and roll of vehicle is established, and then the system state space equation is established;Vehicle desired state, vehicle output and the control index of controller are defined according to the front and rear wheel rotation angle of vehicle, the state feedback control law of controller is obtained;LPV system model is established in combination with system state space equation and time-varying vehicle speed, and LPV system model is used to describe the change of system state space equation caused by vehicle speed change;Gain scheduling is carried out based on LPV system model, and the state feedback control law under different vehicle speeds is obtained according to the state feedback control law of controller, the expected additional yaw moment and the expected roll moment are output, and then the expected wheel end torque of four wheels and the expected active suspension force are output.The present application solves the control problem of diagonal module configuration vehicle in mode switching process.

The application is a kind of estimation method for main dynamic parameters of vehicle, comprising the following steps: step one: establishing vehicle longitudinal dynamics model and wheel dynamics model, jointly estimating vehicle state and parameters through unscented Kalman filtering algorithm, obtaining vehicle mass center height, mass center to vehicle front axle distance and vehicle mass; step two: establishing vehicle single-track yaw dynamics model, jointly estimating vehicle state and parameters through unscented Kalman filtering algorithm combined with the estimation results of vehicle mass center height, mass center to vehicle front axle distance and vehicle mass obtained by vehicle longitudinal dynamics model, obtaining vehicle yaw axis moment of inertia; step three: obtaining longitudinal velocity, longitudinal acceleration, lateral acceleration, yaw angular velocity and roll angular velocity, and training and testing the identification of roll moment of inertia through multi-layer feedforward neural network; step four: estimating vehicle roll moment of inertia through the trained neural network observer.

The invention discloses a yaw-roll stability control method for a distributed driving automobile, which comprises the following steps: acquiring a target corrected yaw moment according to first data of a target vehicle, a preset linear two-degree-of-freedom vehicle ideal state model and a preset yaw moment control state equation; according to second data of the target vehicle, obtaining a target corrected roll-over moment including the first target corrected roll-over moment and a second target corrected roll-over moment; according to the target corrected yaw moment and the first target corrected roll moment, obtaining a target adjustment driving moment of each wheel; according to the second target correction roll moment, obtaining a target adjustment control moment of each suspension; the yaw-roll stability of the target vehicle is controlled by additionally applying the target adjustment driving torque to each wheel and additionally applying the target adjustment control torque to each suspension. The yaw stability and the roll stability of the distributed driving automobile can be controlled at the same time, and the driving safety of the automobile is improved.

This invention discloses an active suspension roll control method, system, vehicle, and computer-readable storage medium, belonging to the field of vehicle suspension technology. The active suspension roll control method is applied to a vehicle's active suspension system. The control method includes: acquiring the vehicle's total mass, lateral acceleration, and center of gravity height; calculating the total roll moment using the following formula: M_roll_total = M * Ay * Hei_CoG; where M_roll_total is the total roll moment, M is the vehicle's total mass, Ay is the lateral acceleration, and Hei_CoG is the center of gravity height; and controlling the active suspension system based on the total roll moment. By controlling the active suspension system based on the total roll moment calculated from the lateral acceleration, rather than feedback control based on the error between the target roll angle and the actual roll angle, the problem of robustness being affected by large noise at the actual roll angle is eliminated, making the roll control of the vehicle's active suspension system more stable and reliable.

The application belongs to the technical field of aircraft flight load design, and particularly relates to a correction method of an aircraft aerodynamic roll moment, initialization of a calculation parameter, calculation of an aircraft true airspeed, equivalent speed and aircraft speed pressure based on the calculation parameter, calculation of a motion parameter based on a dynamic response of a maneuver simulation, calculation of a full-aircraft target aerodynamic roll moment based on the motion parameter, given of an unbalanced moment tolerance, solving of the unbalanced moment based on the full-aircraft target roll moment, comparison and analysis of a difference value between the unbalanced moment and the unbalanced moment tolerance, and end of the calculation if an absolute value of the unbalanced moment is less than the unbalanced moment tolerance. By adjusting a local angle of attack of each profile of a wing component in a span direction, a wing spanwise pressure distribution characteristic is reconstructed, an unbalanced aerodynamic roll moment of the aircraft caused by the pressure distribution characteristic is eliminated, a load balance purpose is achieved, and a design requirement in engineering is met.

The invention relates to the technical field of lithium battery copper foil manufacturing, and discloses a crude foil engine control method and device, a crude foil engine, a storage medium and a program product, and the crude foil engine comprises a cathode roller used for electrolyzing crude foil and a winding roller used for drawing and collecting copper foil; the measuring roller is used for measuring the linear speed and the winding tension of the crude foil; the method comprises the steps that the actual winding speed and the actual winding tension in the copper foil winding process of a winding roller and the measuring linear speed of a measuring roller are monitored; based on the actual winding speed and the measurement linear speed, the actual winding diameter is calculated; based on the actual winding tension and the actual winding diameter, the initial winding moment is calculated; determining a tension compensation torque based on the magnitude relationship between the actual winding tension and the preset winding tension; and the target winding torque is determined on the basis of the sum of the initial winding torque and the tension compensation torque, the winding roller is controlled to execute winding operation at the target winding torque, and speed and tension matching between cathode roller electrolytic foil generation and winding of the winding roller is achieved.

In one mode, with a vehicle control apparatus, a vehicle control method, and a vehicle control system according to the present invention, a control command is output for operating an actuator unit mounted in a vehicle, so as to obtain a control moment including at least one of a roll moment, a pitch moment, and a yaw moment that are generated for the vehicle before a curve on a traveling road on which the vehicle runs, based on a physical quantity about a curvature ahead on the traveling road and a physical quantity about a speed of the vehicle. In this way, the passenger's sense of security when the vehicle runs on the curve may be improved.

This invention proposes a lightweight loading device and its design method suitable for low-altitude propeller balances, belonging to the technical field of low-altitude aircraft test balances. The aim is to solve the problem that existing loading devices cannot meet the requirements of low-altitude propeller six-component balances with diameters less than 200mm for simulating real-world installation methods, high rigidity, and lightweight calibration. In this invention, the low-altitude propeller balance is horizontally mounted on a raised base via a lower balance connector, and the upper surface of the low-altitude propeller balance is connected to the upper balance connecting plate. The central body is mounted on the outside of the low-altitude propeller balance; the front and rear, and left and right cantilever arms are all mounted on the central body; drag lugs are installed on both sides of the left and right cantilever arms, and normal force and roll moment lugs are installed on the left and right cantilever arms; pitch moment lugs are installed on the front and rear cantilever arms. This invention solves the problem that existing loading devices cannot meet the requirements of low-altitude propeller six-component balances with diameters less than 200mm for simulating real-world installation methods, high rigidity, and lightweight calibration.

The application relates to the technical field of vehicles and provides an automobile, which comprises a vehicle body and a side-tilt-preventing roof pressing device, at least one of the top of the vehicle body and the bottom of the vehicle body is provided with the side-tilt-preventing roof pressing device, and the side-tilt-preventing roof pressing device is used for increasing the height of the automobile in the up-down direction. The height of the automobile in the up-down direction is increased through the side-tilt-preventing roof pressing device, the highest point of the automobile is raised, the contact point with a large vehicle is raised, on one hand, when the large vehicle approaches and tilts to a small extent, the highest point of the automobile contacts the vehicle body of the large vehicle, the gravity arm of the large vehicle is reduced, and the downward pressure load of the side tilt of the large vehicle is reduced; on the other hand, the position where the automobile contacts the large vehicle is closer to the top of the large vehicle, the support arm of the automobile is increased, the support force required by the automobile for balancing the side-tilt torque of the large vehicle is correspondingly reduced, and the danger caused by the side tilt of the large vehicle to the automobile is reduced to a certain extent.

The invention discloses a forklift active anti-rollover control system and method based on multi-source sensing and dynamic detection. The defects that in the prior art, sensing is single, and control is extensive are overcome. The system comprises a sensing module (a forward binocular camera and an inertia / acceleration / steering angle sensor), a data processing module (a YOLOv8 algorithm and a dynamic model), a hierarchical control module and an execution module. According to the method, cargo images and forklift operation data are collected, cargo inclination parameters are fused and recognized, the gravity center and the roll moment of the forklift are calculated, five risk grades are divided, and progressive control over sound-light alarm, reverse compensation moment, forced deceleration, emergency braking and power cut-off is correspondingly achieved. The system realizes synchronous monitoring of cargo and forklift states, is accurate in control, adapts to various forklifts, effectively improves the anti-rollover early warning accuracy and operation safety, and is suitable for warehouse logistics and other complex working conditions.

The application discloses a kind of vehicle control methods for limit cornering operating mode, belong to vehicle dynamics control technical field.The method first obtains target longitudinal resultant force, target additional yaw moment and target total anti-roll moment;Establish the mapping relationship between vehicle control target and actuator layer control quantity;Introduce control target slack variable, rewrite each target into soft constraint form containing slack variable;Joint optimization cost function containing control target priority trade-off cost is constructed;Under the condition of satisfying tire adhesion constraint, the optimal distribution of each wheel longitudinal force and front, rear axle active stabilizer bar output torque is obtained.The application realizes the adaptive trade-off of control target under limit operating mode by slack variable mechanism, avoids distribution rigidity and degree of freedom lock, and optimizes stabilizer bar interaxle distribution based on adhesion margin, inhibits single axle tire premature saturation, significantly improves the yaw stability and steering controllability of vehicle in high-speed sharp turn, emergency obstacle avoidance and other limit operating mode.

Method for influencing the driving position of a motor vehicle by means of at least one active component (3, 4) for compensating roll moments, wherein the component (3, 4) can be deactivated automatically or manually, wherein the motor vehicle has an off-road mode, wherein the off-road mode can be set automatically or manually, wherein in the off-road mode the active component (3, 4) is deactivated, and wherein in the deactivated state of the active component (3, 4) the active component (3, 4) is manually activated and set.

The invention provides an underwater vehicle target strength calculation method considering ocean current influence, which comprises the following steps: determining vehicle types including a cylindrical vehicle and a flat vehicle; aiming at different aircrafts, respectively constructing aircraft disturbance torque models, and acquiring rolling torques and pitching torques of a cylindrical aircraft and a flat aircraft; based on the obtained rolling torque and pitching torque of the cylindrical vehicle and the flat vehicle, attitude response models of the cylindrical vehicle and the flat vehicle are constructed respectively, the attitude response models of the vehicles are solved, and rolling angles and pitching angles of the cylindrical vehicle and the flat vehicle are obtained; calculating the static target strength of the aircraft, and correcting the target strength by considering the real-time change of the rolling angle and the pitching angle of the aircraft to obtain a time-varying curve of the target strength of the aircraft; according to the method, the influence of rolling and pitching on the target strength of the underwater vehicle is considered, and the calculation precision of the target strength is improved.

A rotor control device for performing attitude control of a fuselage of an aircraft includes a VTOL rotor control unit for controlling each rotor based on a roll moment command value, a pitch moment command value, and a yaw moment command value. When the magnitude of the roll moment command value or the magnitude of the pitch moment command value is equal to or greater than a threshold, the VTOL rotor control unit controls each rotor without using the yaw moment command value.

The invention discloses a multi-stage electro-hydraulic steering system and an active anti-rollover control method thereof. The method comprises the steps that a vehicle rollover dynamic model is established; collecting vehicle sensor data, and calculating a vehicle transverse load transfer rate; according to the vehicle transverse load transfer rate and the sprung mass roll angle, a comprehensive risk index is obtained through calculation, and a comprehensive risk index threshold value is set; judging a comprehensive risk index of the vehicle, and generating an additional anti-side-tipping moment according to a judgment result; the roll angle of the vehicle is reduced, and active rollover prevention is achieved. By means of a multi-stage hydraulic rod coupling mode and in combination with the power-assisted motor, the power-assisted steering device has the power-assisted steering function and the active steering function under the condition that mechanical steering is reserved; active steering intervention is achieved through sliding mode control, and the rollover risk under the working conditions of cross country and the like is effectively restrained in combination with an active transverse stabilizer bar.

The invention discloses a vehicle anti-roll cooperative control method and device based on multi-source signal fusion, electronic equipment and a storage medium. The method comprises the steps that multi-source signals including vehicle three-axis acceleration, three-axis angular velocity, front road curvature information, vehicle speed and front wheel steering angles are obtained; after fusing the multi-source signals, estimating through an extended Kalman filter to obtain a vehicle roll state; based on the vehicle roll state and a multi-source signal, outputting a vehicle control quantity through a sliding mode controller of an enhanced sliding mode surface; a QP optimization algorithm is adopted to decompose the vehicle control quantity into suspension roll moment and active front wheel steering correction; and the suspension rigidity and damping are adjusted according to the suspension roll moment, the front wheel steering angle is controlled according to the active front wheel steering correction, and cooperative control is completed. According to the invention, based on multi-source data fusion driving cooperative control, an information island problem of a traditional independent closed-loop control architecture is solved.

This invention proposes a control method, control device, and vehicle for an active stabilizer bar. The control method includes the following steps: obtaining vehicle attitude information, vehicle steering preview information, and road surface information; determining the operating mode of the active stabilizer bar based on the vehicle steering preview information; and, in the corresponding operating mode, controlling the active stabilizer bar to output a corresponding anti-roll torque based on at least one of the vehicle attitude information and the road surface information. The active stabilizer bar control method of this invention is applicable to various driving conditions, improves the vehicle's anti-roll capability, reduces the time lag in controlling the output anti-roll torque of the active stabilizer bar, and improves control response.

The application discloses a method for controlling in-bank leaning of an active suspension vehicle, a vehicle and a computer program product, and relates to the technical field of vehicle control, in particular to a method for controlling in-bank leaning of an active suspension vehicle, which comprises the following steps: setting an in-bank leaning function activation condition in advance, obtaining a target roll angle according to real-time collected vehicle speed and lateral acceleration signals when the condition is met; after the target roll angle is determined, calculating a passive roll moment and a total roll moment to obtain an active roll moment, and distributing the active roll moment to front and rear axle active suspensions according to a preset distribution coefficient; converting the distributed roll moment into an active force of an active suspension actuator, driving the suspension to act so as to make the vehicle body lean to the in-bank side, realizing in-bank leaning and reaching the target roll angle. The method can eliminate the influence of centrifugal force from the source, greatly improve the lateral stability and control safety of the vehicle driving on a curve, effectively reduce the centrifugal feeling of passengers, optimize the riding comfort, and has clear control logic and accurate execution, and is suitable for different types of active suspension systems and meets higher demands for driving comfort and driving safety.

The application provides a roll torque measuring device and method for a high-speed underwater vehicle, comprising a head slip ring fixing structure, a bearing cabin section structure and a pool cover plate, the head slip ring fixing structure is arranged on the head of a measured prototype, the bearing cabin section structure is arranged between adjacent cabin sections of the measured prototype, and the head slip ring fixing structure and the bearing cabin section structure are fixedly connected with the pool cover plate; the head slip ring fixing structure comprises an optical slip ring, a rotor of the optical slip ring is fixedly connected with the measured prototype, and a stator of the optical slip ring is fixedly connected with the pool cover plate; the bearing cabin section structure is internally provided with a bearing, an inner ring of the bearing is sleeved on the outside of the measured prototype, and an outer ring of the bearing is fixedly connected with the bearing cabin section structure body. The application can simulate the high-speed self-propelled motion process of the vehicle in water, simulate the roll motion response in the high-speed navigation process at a low cost and risk, and accurately measure the roll torque generated by the vehicle body and different differential rudder angles at different navigation speeds.

The invention relates to a vehicle operation control method and a vehicle, and is applied to the technical field of vehicle control. The vehicle operation control method comprises the steps that under the condition that it is determined that a vehicle is in a target working condition, vehicle information is obtained, and the vehicle information comprises basic information and operation state information of the vehicle; determining a required roll angle corresponding to the vehicle based on the vehicle information; determining a target roll active force allocated to each wheel based on the demand roll angle and the vehicle information; and the damping force of each wheel shock absorber is adjusted based on the target roll main power so as to perform rollover prevention control on the vehicle, according to the embodiment of the invention, the damping force of each wheel shock absorber can be adjusted through the roll main power, the roll trend is actively intervened in advance, and the rollover prevention control on the vehicle is realized. The anti-roll moment generated by the main power and the centrifugal moment are balanced in real time, so that the roll angle is prevented from being further increased, and the risk of rollover of the vehicle is reduced.

This invention belongs to the field of tiltrotor aircraft drive mechanism design, and discloses a tilt mechanism, a tiltrotor aircraft, and a method. This method determines key design input parameters of the rotor system, such as weight, moment of inertia, and tilt angular velocity. A rotary crank-guide rod mechanism is selected as the core transmission mechanism. A geometrical mathematical model of the tilt angle and linear servo travel is established to solve for the mechanism link length, theoretical travel, and minimum effective lever arm. Based on the input parameters, the total driving torque is obtained by superimposing inertial torque, gravitational eccentric torque, gyroscopic torque, and roll torque. Finally, the thrust requirement of the linear servo is calculated by combining the minimum effective lever arm and safety factor to complete the selection. This method achieves smooth and precise control, eliminating transmission jamming and uneven force distribution; it comprehensively considers the dynamic load during flight mode transitions, preventing flight control failure risks and increased structural redundancy and weight; and it improves design efficiency, matching accuracy, and overall mechanism reliability.

The invention relates to the field of vehicle dynamics control, and discloses a diagonal steering switching control method for a vehicle with an angle module configuration, which comprises the following steps of: establishing a vehicle three-degree-of-freedom model of translation, yaw and roll of the vehicle, and further establishing a system state space equation; defining a vehicle expected state, vehicle adjusted output and a control index of a controller according to front and rear wheel turning angles of the vehicle, and obtaining a state feedback control law of the controller; establishing an LPV system model in combination with the system state-space equation and the time-varying vehicle speed, wherein the LPV system model is used for describing the change of the system state-space equation caused by the change of the vehicle speed; gain scheduling is conducted on the basis of an LPV system model, state feedback control laws under different vehicle speeds are obtained according to the state feedback control laws of a controller, expected additional yaw moment and expected roll moment are output, and then expected wheel end torque and expected active suspension force of four wheels are output. According to the invention, the control problem of the angle module configuration vehicle in the mode switching process is solved.

The invention provides a high-aspect-ratio model supporting device and a support interference correction method. The high-aspect-ratio model supporting device comprises an attack angle mechanism, a first supporting rod part, a first balance, at least two groups of second supporting rod parts and at least two groups of second balances, the attack angle mechanism is connected with the first balance through the first supporting rod part, the first balance is connected with the first side wing of the model through the first group of second supporting rod parts and the second balance, and the first balance is connected with the second side wing of the model through the second group of second supporting rod parts and the second balance. The splayed supporting rod is formed by the two sets of second supporting rod parts, the three-component second balance is installed at the tail end of the splayed supporting rod to measure resistance, lift force and pitching moment, the other three components of aerodynamic force (lateral force, rolling moment and yawing moment) are measured through the six-component first balance, and therefore the aerodynamic force of the splayed supporting rod is prevented from being measured, higher measurement precision is obtained, and the measurement precision is improved. The support interference variable of each aerodynamic component is deducted more accurately, and support interference is corrected.

The invention provides a control method of an electric vehicle, a controller and the electric vehicle. When the roll angle of a vehicle body of the electric vehicle is increased to be larger than a first preset value, the steering angles of front wheels and rear wheels of the electric vehicle are controlled to increase the included angle between the direction of a vehicle head of the vehicle and the centroid speed direction; the stable force arm of the electric vehicle is increased. After the stabilizing moment arm is increased, the stabilizing moment of the electric vehicle can be further increased, so that the capability of the electric vehicle for resisting the roll-over moment is enhanced, the roll-over risk of the vehicle is reduced, and the life safety of passengers is guaranteed.

A suspension system includes four dampers each having a compression chamber and a rebound chamber. First and second hydraulic circuits connect the compression and rebound chambers of the front damper, while third and fourth hydraulic circuits connect the compression and rebound chambers of the rear damper. A first bidirectional pump is connected in series to a first longitudinal hydraulic line extending between the first and third hydraulic circuits, and a second bidirectional pump is connected in series to a second longitudinal hydraulic line extending between the second and fourth hydraulic circuits. The first and second two-way pumps may operate independently of each other, simultaneously in the same direction, or simultaneously in opposite directions. The pitch and roll stiffness levels can be adjusted by operating the first and second bidirectional pumps to vary the pressure in particular hydraulic circuits of the system.