Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G21/00—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces
  • B60G21/02—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected
  • B60G21/04—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected mechanically
  • B60G21/05—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected mechanically between wheels on the same axle but on different sides of the vehicle, i.e. the left and right wheel suspensions being interconnected
  • B60G21/055—Stabiliser bars
  • B60G21/0551—Mounting means therefor
  • B60G21/0553—Mounting means therefor adjustable
  • B60G21/0555—Mounting means therefor adjustable including an actuator inducing vehicle roll
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
  • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
  • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
  • B60G17/0195—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the regulation being combined with other vehicle control systems
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/05—Attitude
  • B60G2400/051—Angle
  • B60G2400/0511—Roll angle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/10—Acceleration; Deceleration
  • B60G2400/104—Acceleration; Deceleration lateral or transversal with regard to vehicle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/20—Speed
  • B60G2400/204—Vehicle speed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/40—Steering conditions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
  • B60G2800/90—System Controller type
  • B60G2800/91—Suspension Control
  • B60G2800/912—Attitude Control; levelling control
  • B60G2800/9123—Active Body Control [ABC]

Definitions

• the invention relates to a method and a device for controlling an active anti-roll system of a vehicle, intended to reduce the risks of detachment of one of the wheels inside the turn and overturning of the vehicle, for the purpose of improve the behavior of the vehicle, thus the safety of the driver and the comfort of driving.
• a motor vehicle is designed to exhibit the most stable behavior possible regardless of the driver's request, particularly in terms of turning the steering wheel, or the state of adhesion of the road.
• certain driving situations may cause one or both inner wheels to detach during cornering, sometimes until the vehicle overturns. Such situations are all the more likely that the center of gravity of the vehicle is high and that its path, which is the space between the two wheels of the same axle, is small.
• An anti-roll system makes it possible, among other things, to improve the behavior of vehicles in these delicate situations, for example when cornering.
• it generally comprises a central control unit receiving a sensor information on the lateral acceleration ⁇ ⁇ of the vehicle, and another sensor information on the speed of the wheels to determine the speed V of the vehicle.
• It also comprises actuators capable of acting on the stiffness of the suspension disposed between the chassis and each of the four wheels respectively, or on that of anti-roll bars at the front and rear axles. These actuators may comprise hydraulic or electric cylinders that can modify the stiffness of the suspension or activated suspension elements with controlled stiffness.
• a first object of the invention is a control method of an active anti-roll system for a motor vehicle, equipped with actuators acting on the stiffness of anti-roll bars at the front and rear axles and driven by an electronic central unit, in particular as a function of the lateral acceleration of the vehicle, characterized in that it determines the total anti-roll torque to be applied to the front and rear axles, resulting from the optimum stiffness distribution between the two trains calculated so that one of the two wheels inside the turn has a minimum load which prevents its detachment and corresponding to the desired setpoint established according to the transverse acceleration, the speed and the static gain of the vehicle during a steering wheel stroke.
• the method calculates the maximum value of the stiffness distribution on the front and rear axle respectively, as a function of the lateral and longitudinal accelerations. of the vehicle, which provides a minimum load on said front wheel, respectively rear.
• the determined total anti-roll torque is distributed between the two front and rear trains according to the optimal stiffness distribution corresponding to one of the two front inner wheels or rear considered and obtained by saturating the setpoint of the distribution of the stiffness, established according to the transverse acceleration, the speed and the static gain of the vehicle, by the maximum value of the distribution preventing the detachment of said wheel.
• the determined total anti-roll torque is applied to the rear axle according to the optimal rear stiffness distribution, corresponding to the one of the two front or rear inner wheels considered and obtained by saturation of the stiffness distribution setpoint, established as a function of the transverse acceleration, the speed and the static gain of the vehicle, by the maximum value preventing the detachment of said wheel.
• the determined total anti-roll torque is applied to the front axle according to the optimum rear stiffness distribution corresponding to the one of the two inner wheels front or rear considered and obtained from the instruction distribution of the stiffness at the front saturated by the maximum value of distribution of the stiffness preventing the detachment of said wheel.
• a second object of the invention is a device for controlling an active anti-roll system for a vehicle, comprising an electronic central unit driving actuators acting on the stiffness of the anti-roll bars, characterized in that it comprises:
• the means for calculating the anti-roll total torque setpoint to be applied to the anti-roll system actuators also calculate the distribution setpoint of the anti-roll system. the stiffness applied to the front and rear axles of the vehicle.
• the means for avoiding the detachment of an inner wheel fulfill the following different functions:
• the means of avoiding the separation of a inner wheel, receiving as input, on the one hand the maximum distribution to prevent detachment of the inner rear wheel from the calculation means, and on the other hand the total anti-roll torque setpoint perform the following different functions a function for calculating the absolute value of this total torque setpoint,
• the saturation function takes into account the maximum value of the stiffness at the front, deduces the value of the stiffness at the rear, to compare it with the desired distribution setpoint obtained from the total torque setpoint.
• Figure 1 a block diagram of a control system of a two-train anti-roll device of a vehicle
• Figures 2 and 3 the operating areas of a vehicle, defined by its lateral accelerations ⁇ ⁇ , longitudinal ⁇ L and its stiffness distribution k ar on the rear axle, respectively before
• Figure 4 the functional detail of the means of avoiding the detachment of the front or rear inner wheel in the case of a two-train anti-roll system
• Figure 5 a block diagram of a control system of a single-train anti-roll device
• FIGS. 6 and 7 show the functional detail of the means of avoiding the detachment of the front or rear inner wheel in the case of a single-train front or rear anti-roll system.
• the invention consists in calculating the optimal total anti-roll torque to be applied to each of the two sets of wheels according to a defined distribution in the case of a two-train anti-roll system, or on one of the two trains in the case of a single-train system to prevent the detachment of one of the wheels of the vehicle, inside the turn.
• the longitudinal acceleration ⁇ L is expressed by the quotient of the force F f by the maximum mass of the vehicle M max :
• M is the total mass of the vehicle, V its speed, ⁇ its yaw rate, l z its inertia around a vertical axis passing through its center of gravity, L 1 and L 2 the distance from the center of gravity at the front and rear axles respectively, ⁇ the average steering angle of the nose gear, D 1 and D 2 the drift rigidity of the front and rear trains respectively and ⁇ the drift angle.
• the control system also receives the signals used in the anti-roll control laws, such as the steering angle ⁇ , the yaw rate ⁇ , the longitudinal speed V of the vehicle among others.
• the system comprises means 3 for calculating the maximum distribution of the stiffness applied to the two trains of the vehicle, so that the inner wheel considered has a minimum load preventing it from taking off from the ground, the load being the vertical force Fz applied to the tires.
• Fz, j is the vertical force applied to the wheel i of the axle j, i and j being integers equal to 1 or 2.
• the load is expressed as a function of the lateral acceleration ⁇ ⁇ , the longitudinal acceleration ⁇ L and the weight of the vehicle, by the following expressions:
• the method according to the invention determines the distribution of stiffness between the front and rear wheels, depending on the lateral and longitudinal accelerations of the vehicle, which ensures a minimum load on one of the wheels inside the turn.
• FIG. 3 shows the operating range of a vehicle, defined by its lateral accelerations ⁇ ⁇ , longitudinal ⁇ L and its stiffness distribution k av on the front axle.
• k arMax 1 - k avMax
• the method calculates, in means 4, the total anti-roll torque set point C ARCO ⁇ S to be applied to the actuators of the anti-roll system.
• the method also calculates the stiffness distribution set point k ar c O ns, to apply between the two trains to have the desired static response of the vehicle according to the driving situation, defined in particular by the lateral acceleration ⁇ ⁇ and the speed V of the vehicle according to an anti-roll control law.
• the method delivers the total anti-roll torque C ARCO ⁇ S and anti-roll load distribution desired k arC o n s- In 5 means for avoiding the detachment of the inner wheel considered , front or rear, the method calculates the saturated torque distributed on the front or rear active anti-roll bar. This saturation of the anti-roll torque is necessary for the calculated values of the torque to be really applicable. Indeed, the distribution of the torque being made from active anti-roll bars, suspension springs also contribute to the stiffness of the roll of the vehicle and its distribution.
• the means 5 for avoiding the detachment of an inner wheel fulfill the following different functions, illustrated in FIG. 4.
• a function 6 of saturation of the distribution of the anti-roll stiffness receives as input, on the one hand, the maximum distribution k arM a x to avoid detachment of the rear inner wheel, calculated by the means 3, or k avMa ⁇ to avoid detachment of the inner front wheel, and secondly the stiffness distribution instruction k ar cons between the front and rear trains, calculated by the means 4, to output a saturated value between two lower and upper terminals of the load distribution k arSat .
• the method calculates the saturated torque to be sent to the actuator of the active anti-roll train, front or rear, for the same reasons.
• the means 5 for avoiding the separation of the inner front or rear wheel perform functions illustrated by the diagram of Figure 6 or Figure 7 according to the anti-roll single-front train or single-rear train.
• the means 5 of avoidance of the detachment of the wheel receive input, on the one hand the maximum distribution k arMax to avoid detachment of the rear inner wheel from the calculation means 3, and secondly the set of total anti-roll torque C ARCO ⁇ S from the means 4.
• To the absolute value 7 of this desired total torque setpoint is associated with a value of the stiffness distribution setpoint k arC ⁇ n between the front and rear trains, which is characteristic of the vehicle and established by mapping 8 when it is in focus.
• the value k arM a x of the maximum distribution and that of the setpoint k ar c ons , obtained by mapping, are compared in a function 6 of saturation of the distribution setpoint. If the distribution setpoint is lower than the maximum distribution, it is taken into account for calculating the total torque setpoint to be applied to the rear axle. On the other hand, if the setpoint k arC ⁇ n s is greater than the maximum distribution, it is replaced by the latter to obtain the total torque.
• the calculation of the total torque to be sent on the actuator of the rear axle is obtained by inverting the preceding curve of the load distribution as a function of the torque and multiplying by ⁇ 1 according to the sign of the total torque setpoint t- ⁇ RCons -
• Figure 7 corresponds to an anti-roll system on the front axle of the vehicle.
• the mapping 8 connecting the total torque setpoint to be applied to the load distribution setpoint at the rear has an inverse characteristic of that of the rear single-axle case.
• the desired stiffness distribution set point k arC ⁇ n s obtained from the total torque setpoint C A RCO ⁇ S, is compared to the maximum distribution k ar Ma x and replaced by this value if it is greater than .
• This control method thus makes it possible to delay or avoid the detachment of the wheels inside the turn by acting on the active anti-roll system, and has the advantage of operating continuously. It can be likened to a saturation of torque or stiffness distribution, depending on the technology, which varies depending on the driving situation.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Automation & Control Theory (AREA)
• Vehicle Body Suspensions (AREA)
• Arrangement And Driving Of Transmission Devices (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36889015

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (9)

• 2005
  • 2005-12-23 FR FR0513229A patent/FR2895314B1/fr not_active Expired - Fee Related
• 2006
  • 2006-12-08 EP EP06842127A patent/EP1963115A1/de not_active Withdrawn
  • 2006-12-08 JP JP2008546542A patent/JP2009520635A/ja active Pending
  • 2006-12-08 WO PCT/FR2006/051316 patent/WO2007074258A1/fr not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events