FR2669381A1 - STABILIZED SUSPENSION SYSTEM WITH LOAD CONTROLLED STRENGTH FOR SUSPENDED VEHICLE AND OBJECT. - Google Patents

Abstract

A suspension system is disclosed which enables handling and/or stabilized suspension operations on a load F. It comprises: a tilting means (100) capable of pivoting about a shaft (101) mounted on a base, with one end fitted with a fixed or rotating body mounting (102) for receiving or transmitting a load (F); support means, specifically hydropneumatic (105, 109, 112, 113), to maintain the tilting means in an average angular position; hydropneumatic compensation means (120-124, 125, 130, 160, 180) separate from the support means and comprising a co-operating portion (107) with respect to the support means to create negative stiffness; control means (125, 130, 160, 180) providing a functional link between the support means and the compensation means to obtain a suspension stiffness which is substantially invariable or controlable as a function of the load (F) on the end of the tilting means and/or an external specific suspension stiffness command; control electronics (180) implementing the method. The system may be used in suspended object handling, active stabilized suspension for motor vehicles, handling and stabilized suspension of submersed objects towed by a surface vessel, winch for an application of this type.

Description

The present invention relates to a stabilized suspension system with controlled stiffness according to the load, for a suspended vehicle and object, - It is known, on the one hand, that vehicle suspensions in particular of the hydropneumatic type such as those of the brand "CITROEN "present, under variable load, a variable flexibility detrimental to the road behavior and the comfort of the vehicle. If one wants to modify the road behavior or the comfort, it is necessary to add to the known suspension system, a device of control of flexibility, called also stiffness control, which notably consists in introducing an additional gas capacity by electro-hydraulic switching means controlled by microprocessor which make it possible to automatically modify the behavior of the vehicle to obtain the so-called optimum suspension from information delivered by sensors placed on: the steering wheel; the accelerator pedal, the braking circuit, the body and the comfort mode selector, or driving behavior.

The stiffness and damping of the suspension are modified while making it possible to observe a predetermined constant average attitude of the body with respect to the ground. Such a device known as active suspension does not, however, make it possible to keep a substantially constant stiffness and damping under variable load: the more the vehicle is loaded the harder the suspension becomes, the frequency of the oscillations also being modified. . This drawback could be eliminated by an almost continuous adaptation of the gas volume of the spheres of the hydro-pneumatic suspension according to the load supported, impossible to implement practically because requiring complex switching means on the hydraulic suspension circuit.

- It is known, on the other hand, that systems for suspending objects such as those allowing suspension at a substantially constant attitude, independently of the movement of the support base, such as, in particular, systems intended for handling objects and towing a submerged object of the "SONAR" type, to compensate for changes in attitude of the boat due to swell, mainly in vertical movement, with hitting phenomenon and to a lesser extent in roll and yaw, use means of control active, slaved to - constant effort by means of winching unrolling or permanently winding the tractor cable of the object, which considerably reduces the life of this, a major drawback because it is a transmission cable complex therefore expensive to replace often, - constant attitude of the holding end of the towing cable by compensation for movement: the cable and / or its winch are then almost gyro-stabilized.

The disadvantages of such systems are - complexity, since they require closed-loop control means and force or acceleration and, or position sensors and associated processing and calculation means.

- energy consumption, even if these systems include a device for balancing the average static load and have been subject to extensive optimization.

The object of the invention is to propose a new stabilized suspension system which avoids the aforementioned drawbacks by allowing - to balance an average load F created by a suspended vehicle or object in order to allow their handling, with almost zero effort on most of the angular displacement of a suspension lever of the so-called passive suspension system with quasi-invariant stiffness, - adapting the stiffness of the suspension device in dependence on the variation in average load F supported by at least one wheel a vehicle in order to obtain a so-called active suspension with quasi-invariant stiffness or which can be controlled in order to obtain an optimum vehicle suspension, - to adapt the stiffness of the suspension device in dependence on the variation in average load F supported and , or the stiffness of the support means for balancing the average load and, or a suspension stiffness control in order to obtain a so-called suspension active at almost invariant stiffness or which can be controlled in order to obtain an optimum stabilized suspension of a submerged object towed by a surface building subjected in particular to swell, to allow good insonification and detection by the "SONAR" placed in the submerged object.

The basic system proposed according to the first four embodiments does not require - neither complex closed loop control, - nor switching system with additional hydropneumatic accumulator placed on the circuit of the support means which balance the load, - while having a capacity reduced energy storage of the load support means.

 I1 is characterized by stiffness control means distinct from the support means making it possible to obtain a minimum energy consumption without common measure with the known active suspension systems.

The present invention discloses a stabilized suspension system with controlled stiffness according to the load for a vehicle and suspended object comprising - a tilting means, which can be called a pulled arm, which can pivot on an axis resting on a base, which can be called a chassis, having one end provided with a fixed or rotating member support intended to support and / or transmit a load F, - support means for holding the lever means around an average angular position allowing handling operations and, or of stabilized load suspension, in particular of suspension of at least one vehicle wheel or of suspension of an object, in particular of a submerged object, towed by a surface vessel, characterized in that it also comprises compensation means to make the suspension stiffness substantially invariant or controllable depending on the variation: of the load F on the end of said tilting means and, or the stiffness of said support means and, or an external control of determined stiffness in order to obtain a stabilized suspension of the suspended base or object.

The invention and its features will be better understood with the aid of the description which follows, given solely by way of example and made with reference to the appended plates 1 to 12.

The same reference number always identifies a homologous element whatever the embodiment.

The embodiments or variants of the invention, although described in particular forms, may be subject to modifications within the reach of the skilled person without departing from the scope and spirit of the invention. .

 - Figure 1 shows a curve 1 connecting the pressure P1 in a hydro-pneumatic device 105,106,110, shown in Figure la, to the volume of gas V1 in the hydro-pneumatic accumulation means 110.

- Figure 2 shows - a first curve 2 connecting the change in stiffness dP / dV to the first pressure P1 of the hydropneumatic device, shown in Figure 1A, - a second curve 3 of approximation of curve 2 connecting a second pressure P2 to the first press
P1, P2 being an image of dP / dV, - Figure 3 shows a first embodiment of the invention.

- Figure 4 shows a variant 130 of the control means 125 in the form: in Figure 4a of functional block and in Figure 4b of a corresponding embodiment, hydraulic valve, or electrohydraulic.

- Figure 5 shows a second embodiment of the invention.

- Figure 6 shows a third embodiment of the invention, application made to a motor vehicle suspension, showing two adjacent wheels, Figure 6a being a variant of the damping means 114, compensation means.

- Figure 7 shows the means 105,110 of the stabilized suspension cooperating with the lever 100 to support a rotating member 102 located at the end (O) of the lever pivoting around (C) which supports the load F at an angle Q; application made to suspension of submerged object, towed by cable 92.

- Figure 8 shows two curves set according to V connecting the first pressure P1 prevailing in the actuating means 105 to a variable lcd, defined below
V: speed of the towing boat up to 10 m / s, lcd: length of the towing cable unwound up to 100 m - Figure 9 represents - a first curve 1 connecting the second pressure P2 prevailing in the actuating means 120 to the first pressure P1, - a second curve 2 connecting the second pressure P2 to the first pressure P1, as a function of a variable V, for a constant parameter lcd for example equal to 50 m.

- Figure 10 represents curves connecting the couple
CC exerted on the lever 100 by the load F at the angular position e of said lever, for 3 different values of external parameters V; Lcd; e0: being a predetermined average angular position of said lever, which can vary up to: + 300.

- Figure 11 shows curves connecting the couple
CV1 exerted by the cylinder 105 of the support means 105, 110 at the angular position e for 3 different values of the first pressure P1 prevailing in the cylinder 105. The curve CVE shows the relationship obtained by the retraction of the pivot point (E) of the cylinder by variation of the dimension (e) of figure 7.

- Ld FIG. 12 represents curves connecting the differential torque CD obtained by the algebraic addition of the couples CC and CV1, which are exerted on the lever 100 pivoting around (c), at the angular position 9 of said lever for parameters V ; lcd already defined.

- Figure 13 schematically shows the load suspension device F and load balancing support means 100,105,110, or
T: is the substantially horizontal component of the load exerted,
P: is the gravity component corresponding substantially to the supported loads such as the apparent weight of the towed submerged object, towing cable, etc., m: is the mass equivalent to the masses attached or connected to said lever pivoting around (c ),
X: is the stroke of the piston of section S1 of the cylinder 105, - Figure 14 represents a functional diagram of the device represents in figure 13 or - Kf is a term of viscous damping, - Kt is a term of stiffness due to the component Load T F, - Ka is a term of stiffness of the support means 100,105,110, - Figure 15 represents two curves called "BODE" of frequency response of the device according to Figures 13,14 - curve 1 for a speed V = om / s, - curve 2 for a speed V = 10 m / s, - Figure 16 represents the time response of the device modeled in Figure 15 or - A is the amplitude + 1 m of the typical swell h, s' working on the towing boat for a period of 6.3 s, - O is the response of the end of the lever for 2 speeds V of the boat obtained with optimum damping.

- Figure 17 shows the same type of response as Figure 16 but where the swell period is double or 12.6 s.

- Figure 18 shows a fourth embodiment of the invention seen in elevation, Figure 18 a showing a top view of the stabilized suspension device for suspended object, application made to the suspension of submerged object, towed by a surface boat and winched by a winch 90 winding the faired cable 92 for towing said object, the pivoting jib 100 being mounted on a base resting on the boat, this base being able to be itself mobile, for example around a Z axis The cylinder of the support means can be a double cylinder 105, 105 ′, each cylinder having one end linked by pivot 103 to the lever 100 and the opposite end linked by pivot 104 to said base 99.

The cable 92 is wound on a pivoting pulley 91 transmitting the load exerted F at the end O of said lever.

The jack 120 cooperates with the lever 100 by the end 107 opposite the end 102, and by the opposite end 122 located on said base 99. The two jack ends 120 are pivotally mounted at (A) and (B) .

FIG. 19 represents - FIG. 19 a, a series of curves connecting the differential torque Cd to the angle of the lever e - eo, similarly to FIG. 12 but where the curves in solid line marked Vo, V1, V2, show: a torque Cd substantially zero at e, obtained by the control means 109,113, adjusting the pressure P1 of the hydropneumatic means 105,110 of the support means 105,109,110,113, adapted to the average load F exerted on the lever 100, ie respectively a first pressure P10 = 160 bar, P11 = 150 bar; P12 = 143 bar given as an example for a suspension system shown in Figure 18.

- Figure 19b, a series of curves connecting the torque CV2 exerted by the jack 120 on said lever 100 pivoting around the center (C), at the angular position e - e0 of the lever 100 for different angular positions A of the pivot A of the means d actuation 120, called actuator.

FIG. 20 represents a curve connecting the residual torque Cr obtained by the algebraic addition of the couple Cd with CV2, at the angular position e - 6 ,, Crm being a maximum limit value for obtaining a suspension stiffness Kr of a value determined limit allowing stabilization at a very long oscillation period.

- Figure 21a is a first variant of the fourth embodiment of the invention, application made to a stabilized suspension of a suspended object.

- Figure 21b is a second variant which shows the cylinder 105 split into two cylinders 105,105 'mounted in parallel, one of the two cylinders 105', is only powered by a 4-way proportional valve control means 188 'associated with a suitable means of switching by valve 189 '. The associated control electronics 200 ′ is a variant of the associated electronics 200, comprising an additional correction term 208 introduced into the loop by a summing means 205 ′.

- Figure 22 shows a variant of the actuator 120 relating to the fourth embodiment of the suspension device shown in Figure 18, Figure 22a is an elevational view.

 The operation of the suspension system object of the present invention is explained below, taking into account the comments already made during the presentation of the figures.

Curve 1 in FIG. 1 connects a force F exerted on a transmitting element 106 via the surface S1 of an actuating means: called a jack subjected to a first pressure P1 prevailing in the hydro-pneumatic accumulator 110 and the chamber of the jack 105. This well known device, in equilibrium for a hydraulic pressure value P10 and a volume of compressed gas V10 has a stiffness dP / dV represented by the tangent at the equilibrium point O to the curve 1.

If a greater force is exerted on the transmitting element 106, the operating point moves to another hydrostatic equilibrium point o ': the stiffness materialized by the tangent to the curve at this point is different. FIG. 2 shows, according to curve 2, this change in stiffness dP / dV as a function of the first pressure P1 exerted on the transmitting element 106 is written in a manner well known to the skilled person.

pour un point de fonctionnement O prédéterminé déjà appelé point d'équilibre, autour duquel se déplace le moyen transmetteur 106 soumis à une charge :: FO + F ou FO est la charge supportée telle que
FO = P10.S1
Donc, la première pression P1 est l'image de la charge F exercée, c'est-à-dire
(2) P1 = f (F) appelée par la suite première relation fonctionnelle.An approximate functional relationship which is one of the characteristics of the invention can be deduced, represented according to curve 3

for a predetermined operating point O already called equilibrium point, around which the transmitting means 106 subjected to a load moves: FO + F or FO is the supported load such that
FO = P10.S1
Therefore, the first pressure P1 is the image of the load F exerted, that is to say
(2) P1 = f (F) subsequently called the first functional relationship.

We can also consider a second pressure
P2 subsequently called compensation pressure, as an image of the stiffness, for example around the equilibrium point O, that is to say
(3) P2 = f (P1) ~ K. [P1 -PT) called thereafter second functional relationship.

FIG. 7 represents said support means 105,110,113 for maintaining a said lever 100 around an equilibrium position GO allowing handling and load suspension operations F the support devices comprising in particular a hydropneumatic device 105,106,110 already described and a means additional depreciation 111. The actuation means, in particular a cylinder means 105, of the lever 100 pivoting around the center C of the base, is mounted by one end E on the base by a pivoting means 104 and by the other end D on the lever by another pivoting means 103. Complementary means for supplying the suspension device with fluid are provided 108, for maintaining the variable load F at predetermined average attitude 6O which can be modified by the control means 80,180, and of adjustment control 109,113 pressure. The operation of the means for controlling and adjusting the mean angular position e0 of said lever subjected to a variable load F is shown in FIG. 3 which represents a first embodiment of the invention.

This embodiment comprises a hydraulic valve 109 for correcting attitude known per se which delivers a first pressure P1 according to a first functional relationship P1 = f (F) in the following manner - A position feedback device known per se 80, adjustable , connects the end 107 of said lever 100 by means of springs to the control lever of the valve. Any variation in load + h F on the lever leads to a displacement + 5 of the control means 80 which causes a correlative variation in pressure P1 to balance the variation in load F. The valve 109 is designed to avoid being sensitive rapid angular movements of the lever 100, encountered in a motor vehicle suspension device.

According to the invention, compensation means 120,124,125,130,160,170 are also provided to make the stiffness of the suspension substantially invariant or controllable depending on the variation - of the load F exerted on the end 102 of the tilting means 100 and , or - the stiffness of said support means 105,109,112,113, and, or - an external control of determined suspension stiffness, in order to obtain a stabilized suspension of said base or of the suspended object.

As shown in FIG. 7, the actuating means 105, kinematically associated with the lever 100 by the pivot 103 and at the base by the pivot 104, creates a torque CVî around the pivot point C.

- The load F which is exerted at the end of the lever 100, for example at an angle T with respect to the horizontal can create a torque CC around the pivot point C of the lever 100 on the base, of the shape
CC = (P2 + T2) * R. Sin 8 + C + e Figure 10 represents this relation.

The actuating means which can be a jack means whose surface S1 of piston 106 is subjected to pressure
P1. The couple created is of the form CVî = Sl.P20.f (+, X). Sin e
X: is the stroke of cylinder 105
:: is a kinematic shape parameter of the jack 105 associated with the lever 100 and the base.

Figure 11 shows this relationship.

The algebraic addition of the couples Cd = CC + CVî is represented in FIG. 12, for different values of parameters V, lcd, already defined for the application of a suspension of submerged object towed by boat.

In the case of a vehicle suspension since the load component F is mainly a weight component P, this representation of the differential torque Cd is unique. Figure 19a shows this for the parameter Vo.

The stiffness K1 of the suspension device constituted by the support means 100,105,112 is the tangent to the curve at the equilibrium point O of angle eO. .

According to a characteristic of the invention shown in Figure 3, as a first embodiment, a compensation means 120-124 comprising at least one cylinder 120,120 'which is pivotally mounted by its ends, one on the base 122 and l other on the cooperation part 107 of the lever means 100.

The surface piston S2 is subjected to a second pressure P2, called compensation. The couple creates CV2, around the pivot point C is of the form
CV2 = S2.P10. f (> yY). sin e
Y = cylinder stroke 120
= = is a shape parameter
FIG. 19b represents this relation parameterized as a function of the angle A formed by the longitudinal axis of the jack 120 relative to the median of the angular movement of the lever 100. The stiffness K2 of the compensation means 120-124 at the point of equilibrium is a negative stiffness, the means 120-124 tending to move the lever 100 from its predetermined equilibrium position by the support means, taking into account the described operation.

 According to a characteristic of the invention, the compensation means 120-124,125,130,160,170 are distinct from the support means 105,109,112,113, and they have a part of cooperation 107 with the tilting means 100 and, in addition, in that the compensation means comprise at least one actuation means 120, 120 ′ and at least one means for accumulating energy 124 to create a negative stiffness which opposes, in whole or in part: the stiffness of the means and, or the stiffness created by the load F in order to obtain a predetermined stiffness of stabilized suspension which can be invariant and, or substantially zero over the greater part of the angular movement e of the lever, and consuming substantially no energy.

permet d'apprécier l'avantage apporté par l'invention.The characteristic of the invention of being able to reduce the suspension stiffness of said support means Ka and, or the stiffness created by the load Kt, the resulting stiffness being K1, makes it possible to obtain a suspension stiffness
Kr = K1 + K2 shown in FIG. 20 less than a predetermined value which can be substantially zero. This characteristic makes it possible to very significantly reduce the capacity V10 of the energy accumulation means 110 of said support devices avoiding a suspension arrangement which is unacceptable. Taking the example of application of the invention to the suspension of a towed submerged object, FIG. 13 shows the diagram of said support means, FIG. 14 the functional diagram of these, FIG. 15 the dynamic response which is changes due to the stiffness created by the load Kt varying considerably with the parameter V. It follows that the stabilization device becomes ineffective: the suspension "hardening". The theory teaches us according to formula (O) that we should increase the capacity
V10, for example from 20 1 to 200 1 to obtain a predetermined stiffness of the means sufficiently low, substantially equal to or less than Kr to obtain the simulated temporal responses shown in 16 and 17 by the curves O (V = 0) in order to obtain optimum stabilized suspension of the submerged, towed object, that is to say: the movement of the lever end 100 compensating for the substantially vertical movement of the boat due to swell. The well-known relation defining the period of oscillation Z of an oscillating system as modeled in figure 14,

allows to appreciate the advantage provided by the invention.

According to a characteristic of the invention, the actuating means 120 is in particular at least one hydraulic cylinder 120, 120 ′ associated with at least one hydro-pneumatic means of energy accumulation 124 in order to obtain a stabilized suspension device whose capacity V10 energy accumulation of the support means can be reduced, while obtaining a very long suspension oscillation period.

The particular characteristic of the invention requires to optimize jointly the characteristics - kinematics and hydro-pneumatic - f (> 1, X) of the so-called support means 105, 110, - f () 2, Y) of the compensation means 120-124 , to obtain a predetermined stiffness Kr which allows a suitable oscillation period, which can be very long, necessary for the stabilized suspension system, object of the invention, to operate as a low frequency filter.

According to a characteristic of the invention, the cylinder 120, 120 ′ is pivotally mounted at its ends, one 122 on the base and the other on the cooperation part 107 of the tilting means (100) which can be a lever for creating a negative stiffness K2 in relation to the hydro-pneumatic and kinematic characteristics of the compensation means 120-124 associated with those of the support means 105-112 in order to obtain a predetermined stiffness Kr of the stabilized suspension device and, in addition, to at least one end of the angular movement, an elastic end-of-travel stop means allowing suspension of optimum performance.

According to a first embodiment shown in FIG. 3, it is provided that the pivot point 122 of the cylinder 120, 120 ′ on the base, can be moved by a removable fixing means 123 to allow the angular position (or attitude) to be modified mean e0 of the lever 100, the angle thus created: Â, according to a variant of FIG. 5 further influencing the shape parameter) 2 allowing in particular a stiffness Kr of the stabilized suspension device ion better adapted.

According to a characteristic of the invention, the cylinder 120, 120 ′ is mounted, by one end on the base by a pivoting means 122 which can be moved in a direction substantially parallel to the direction of mobility of the lever in order to obtain an average angular position. variable e0, adapted to allow greater angular movement @ e -e0 of the leverage in a preferential determined direction.

According to the first embodiment of the invention shown in Figure 3, there is further provided a so-called control means 125,130,160, the role of which is explained below - A negative stiffness K2 must be created to compensate for variations in stiffness K1 created by the load F due to the substantially vertical component of weight P acting on the device constituted by the support means 105,112,113 and, or, due to the substantially horizontal component T, of the load.

- A first pressure is: P1 = f (F) - A so-called compensation pressure is: P2 = f (P1), which is the image of the stiffness K1 which varies as already explained. The invariance of the stiffness of the suspension device comprising said support means 105,112,113 and the compensation means 120-124 is then achieved by the control means 125,130, controlled by the pressure P1 transmitted by the link 81,184, adjusting the pressure P2 of compensation which acts on the jack 120 to balance any variation in stiffness of the support means, according to the second function relationship, for example
P2 = K. [P1 - PT] shown in Figure 2.This "hydraulic equation" can be achieved by means of a hydraulic valve, the functional diagram of which is shown by 125 in Figure 3 on which an adjustment means R is provided for adjusting the initial PT pressure point.

According to a characteristic of the invention: to the compensation means 120-124 is added a control means 125,130,160 associated functionally with a detection means 81,191 of a said first pressure P1 in order to obtain a stabilized semi-active suspension capable of adapt to variations in load F and, or in stiffness of the support means 105, 109, 112, 113, and, or in an external stiffness control V.

According to a characteristic of the invention, the control means 125,130,160 is a proportional hydraulic or electro-hydraulic valve means 125, 130,160 controlled in dependence on a first pressure P1 prevailing in the circuit of the support means 105,112 to create a pressure called compensation P2 which is in proportion to the first pressure P1 to act on the means 120-124 in order to compensate for the variation in stiffness of the support means 105,109,112,113.

 The hydraulic valve 125 incorporates damping means, to prevent the so-called compensation pressure P2 from varying when the first pressure P1 varies too rapidly, that is to say that P2 is controlled in dependence on the average pressure. P10. The damping means, known per se, symbolically represented on the functional diagram 125,130 will not be described, as being within the reach of the skilled person.

According to a characteristic of the invention, the valve means 125,130,160 creates the so-called compensation pressure P2 according to a functional relationship with the first pressure P1, the first pressure P1 being in particular the average pressure which corresponds substantially to the average angular position e0 which can vary , so that the compensation pressure P2 is not dependent on rapid variations of the first pressure P1.

According to a variant of the control means called a hydraulic valve, an additional characteristic is provided, to compensate for the stiffness Kt due to the component of the load which is not detected by the pressure P1 image of the substantially vertical load F due for example to the weight.

In addition, it is necessary to provide a possibility of voluntarily modifying the suspension stiffness of the suspended vehicle or to obtain another operating mode called for example: handling mode.

An advantageous arrangement of the invention provides that the hydraulic valve 125, 130, is controlled, in addition, by a second pressure P3 in functional relation with
P3 = f (V) at least one external parameter V, determined.

The functional diagram in FIG. 4a shows a conversion means, for example, electro-hydraulic making it possible to transform a discrete or continuous control signal V to create a discrete or continuous pressure P3, which controls the hydraulic valve 130.

An example of an external parameter V is shown in FIG. 9, as already explained - the negative stiffness K2 must be increased in proportion along curve 2, by the speed V of the boat towing 1 the submerged object. The pressure P3 will therefore modify the compensation pressure P2 to maintain the stiffness of suspension Kr substantially invariant or to control it for example, according to the functional relationship:
(3 ') P2 = f (P1; V) ~ K. [P1-PT] + P3
According to a characteristic of the invention, the valve means 125, 130 is also controlled in dependence on a second pressure P3 which is in proportion with at least one external parameter V determined to modify the so-called compensation pressure
P2 according to a functional relationship in order to obtain a stabilized semi-active suspension capable of adapting to an external control of suspension stiffness, determined or to a handling mode.

FIG. 4b shows an embodiment of the hydraulic valve 125, 130 in accordance with the functional diagram, reference 130.

The hydraulic supply pressure arrives through the orifice P, the hydraulic return takes place through the orifice T. The pilot pressure P1 is exerted on the surface of the piston S1 of the slide 140 in the bore 143 of the body 150 , while the pilot pressure P3 is exerted on the piston surface S3 in the bore 144. The compensation pressure P2 supplying the actuating means 120-124, also acts through an orifice 142 of the drawer 140 to supply the piston surface S2 in the bore 145. Means for adjusting 146 the initial calibration: PT of drawer opening in line with the control edge 141 according to FIG. 2 are provided. Damping means are provided by way of example, on the pilot holes 142 and P1.

According to a second embodiment of the invention shown in Figure 5, there is provided - control electronics 180 which will develop a negative stiffness signal K2 according to a so-called control law according to the functional relationship P2 = f (Pl; V) to obtain a substantially invariant stiffness suspension Kr, or controllable to control a compensation pressure control means P2 functionally equivalent by means of hydraulic or electro-hydraulic valve 130 already described,.

motorization means for controlling movement of the pivot 122, for example by a motor 171 controlled by a signal from said control electronics 180, the motor driving the carriage 172 pivot carrier 122 by a screw-nut system,
According to a characteristic of the invention, the jack means 120 has a pivot point 122 on the base which can be moved by a motor means 170 in order to obtain a change in the average angular position of the lever 100,
Additional means 113,180,181,190, for performing the function of maintaining a variable load F at a predetermined average attitude e0 of said lever 100, by an angular detection means 190 of the lever 100, sending an angular position signal e to said control electronics 180 which implements a correction relationship for controlling by a signal 181 the control and adjustment means 113 of the first pressure P1, which is in particular an average pressure P10 image of the load exerted Fo around an operating point O predetermined or variable.

Clearly, the so-called complementary means 113,180,181,190 perform substantially the same function as the means known per se 80,109 perform, already described in the first embodiment shown in FIG. 3.

According to a characteristic of the invention
Stabilized suspension assembly with stiffness controlled according to the load, characterized in that it comprises, in addition to the stabilized suspension system already described, an electronic control unit 180 which receives the position measurement signals of the lever 100, of the first pressure P1 and at least one determined external parameter V, to implement - the control means 113 of the average pressure P1 prevailing in the circuit of the support means 105,112, - the control means 130,160 of the pressure called compensation P2 compensation means 120-124, - the motorization means 170 for moving the pivot point 122 of the actuator means 120, by a process treated by means of internal processing of the control electronics, in order to obtain a semi suspension -active of a vehicle and, or suspended object.

The first embodiment of the invention makes it possible to obtain a semi-active suspension of a vehicle of conventional hydraulic technology.

The second embodiment of the invention, based on control electronics 180 which can incorporate a microprocessor as a processing means, makes it possible to obtain, according to the invention, an active suspension of an electro-hydraulic technology vehicle.

A third embodiment of the invention shown in Figure 6 is an application to the vehicle suspension showing two adjacent wheels. Each wheel is equipped with the stabilized suspension device with invariant or controllable stiffness according to the invention. The homologous means are marked ('). The compensation means 120-124,125,130,160 are common to the two wheels.

The microprocessor receives external information delivered, by sensors placed in the vehicle and by a signal for choosing a road behavior, according to a mode known per se: therefore, at least one parameter of control of external stiffness V, will be received by the centralized control electronics 180. In addition, this processes the signals internal to the suspension system, object of the invention} to the other wheels which are marked 185 in FIG. 6 and do not call for comment, due to the similarity of operation
The support means 105, 112; 105 ', 112' are specific to each wheel suspension. A hydraulic pipe connects the means 112, 112 'on which is placed an anti-roll damping means 128 known per se. A characteristic of the invention makes it possible to invariant the stiffness of suspension Kr. In addition, a damping adjustment means 114 makes it possible to obtain a variable suspension damping, controlled by the control electronics 180, according to the road behavior decided by the microprocessor and, or the driver, without varying the frequency of suspension because independent and acting differently from the damping of the support means.

An alternative embodiment of the damping means 114 is shown in FIG. 6a, applicable to the damping of the support means 111.

It includes a 2-way electro-valve - 2 positions controlled by a signal 185, placed in parallel with the damping member 116 to vary the damping by braking of the outgoing or incoming flow / or of one of the chambers of the actuator 120,120 'means of compensation.

According to a characteristic of the invention, the control electronics 180 controls a damping adjustment means 114 of the compensation means 120-124 in order to obtain a controllable damping of suspension in particular d of a pair of adjacent wheels, independently of the damping by means 111, 111 'of the support means of each wheel of an active suspension of a motor vehicle.

A fourth embodiment of the invention shown in FIG. 18 is an application to a suspension of a submerged object, towed by a surface building using a cable 92 subjected mainly to swell. The lever 100 is provided to compensate for the movement of the swell shown by the curves marked h, in Figures 16 and 17 already commented on. The lever is pivotally mounted around C on its bearings 93 supported by the base. A winch winch means 90 is provided for winding or unwinding the faired cable 92 led by the pivoting pulley 91 located at the end 102 of the lever. The towed object creates a force F on the cable 92 directed at the angle t at the pulley outlet 91. When the cable is unwound its apparent weight increases creating a weight component P which increases. It is therefore necessary to compensate by additional means 113,180,181,190, support means by a first pressure P1 exerted on the cylinder piston 105 according to a method of maintaining a constant or controllable GO average attitude already explained. FIGS. 8 and 9 show that the influence of the parameters V, lcd on the first pressure are low, requiring only a small stiffness compensation. On the other hand, if the towing speed V increases the drag
T increases in proportion to it according to a law as shown on the curve: 2 of FIG. 9. In addition, this drag T includes the drag of the faired towing cable 92 which is substantially proportional to the length of unwound cable lcd, measured by a sensor means 193. This signal is received by the control electronics 180 to calculate a stiffness correction order 181 which commands by means of control 130,160, in order to adjust the pressure P2 called compensation to maintain the stiffness of suspension Kr substantially invariant, according to a functional relationship stored in an internal calculation means of the control electronics 180, such as a microprocessor
P2 = f (Pl; V; lcd)
The damping of the suspension can be adjusted by the damping means 111 controlled by a signal 182 from the control electronics 180.

According to a characteristic of the invention, a control electronics 180 receives, in addition, a signal of unwound cable length lcd in addition to an external parameter signal V in particular of displacement speed V of the towing vessel and, possibly of the pressure compensation P2 reigning in the circuit of the cylinder means 120 g an acceleration signal Y of the lever end 102 to implement - the control means 113 of the support means, - the control means 130,160,126, compensation means , - the motorization means 170, - the damping means 111 of the support means, by a process treated by an internal processing means of the control electronics, in order to obtain a suspension / active with maximum travel minimizing the substantially vertical absolute displacement of the end of the lever 100 to reduce the change in attitude of the submerged object, towed by a cable 92 driven by a pivoting pulley 91 of a surface building winch, subjected mainly to swell.

The fourth embodiment of the invention shows in FIG. 21a an associated electronic device 200 for controlling the angular position of the lever 100 provided for being able to handle the submerged towed object when the latter is no longer in passive stabilized suspension mode or semi-active as already described.

According to a characteristic of the invention, the lever 100 is controlled by control electronics associated 200 with the control electronics 180, and by means of valves 188, 188 ', 189, 189', provided to allow actuating at least one jack 105, 105 'of the support means in relation to a selected mode, either of handling, or of active stabilization, and in that the selected mode of - handling is a command in angular position of the lever 100 by comparison of the command displayed by the means proportional 207 with the position copy of the lever 190 being adapted by a circuit 204 of predetermined gain, and after summation by a first means 205 and adaptation by a means 206 which controls the valve means with proportional control 188,188 '.

A variant of the fourth embodiment of the invention is shown in Figure 21b.

The associated electronics 200,200 'is designed to achieve active stabilization of the suspended object by means of a control loop in position and stiffness known per se, to take account of poor stabilization when the swell stressing the boat is weak and of particularly long period. Indeed, the energy communicated to the suspension device which is the subject of the invention may be insufficient to overcome the mechanical losses in the actuation means of the support means 105, 105 ', of the stiffness compensation means 120-124, and in the associated pivoting means. A detection of the acceleration Y measured at the end of the lever 100, on the pivoting pulley 91 is sent to the control electronics 180. This develops, according to the principle of an acceleration servo correction, a corrective signal 208, according to a technique known per se that we will not describe in detail.

According to a characteristic of the invention, the so-called active stabilization mode can be used in addition to the semi-active stabilized suspension and in that the switching means of the associated electronics 201, 202 controlled by the control electronics 180 form a substantially stiffness controlled loop comprising a gain circuit which can be variable 203 and in that, in addition, the control electronics 180 can generate a correction signal 208 introduced into the so-called stiffness control loop 190,202,203,205,209 by a second summing means 205 ′ to make the acceleration measured substantially along the direction of mobility of the end 91, 102 of the lever 100 controlled substantially by the proportional valve means 188, 188, substantially zero.

 According to a characteristic of the invention, the switching valve means 189, 189 'is a valve controlled by a first signal 187 coming from the control electronics 180 for switching the hydraulic supply of at least one jack 105, 105' of the support means for allow operation in handling mode or in active stabilization mode, and in that, in addition, one of the means for controlling the compensation means is a switching valve 126 controlled by a second signal from the control electronics 180 to switch the supply circuit of the actuator means 120, 120 ′ in order to make it possible to reduce or cancel the action of the actuator means on the cooperation means 107 of the lever 100 in order to obtain operation in so-called handling mode.

According to a characteristic of the invention, the proportional valve means is a so-called 3-way valve 188 supplying at least one cylinder 105, 105 'through the section on the cylinder rod side 106 or else can be a so-called 4-way valve 188' supplying a first double cylinder effect 105 ′ in parallel with a second jack 105 with simple load compensation effect F, the two jacks simultaneously actuating the lever 100.

A variant of the fourth embodiment is shown in FIG. 22. The jack 120 is split into two jacks 120, 120 'mounted in parallel, on each side of the lever 100 which frames the winching means 90 of cable 92.

FIG. 22 shows single-acting cylinders with compressed rod, FIG. 22a shows single-acting cylinders with stretched rod, the pivot point of the cylinder 122 on the base, being placed respectively at dimension f and f ′. The hydraulic supply ports OS2 are placed in correspondence, so that the action of the jack subjected to a pressure P2 creates a compensation torque relative to the point C of pivoting of the lever in relation to the characteristic of the invention to obtain a negative stiffness.

This advantageous arrangement of the invention makes it possible to reduce the size of the stabilized suspension device as well as the forces exerted on the pivot 101 of the lever 100.

According to a characteristic of the invention, the pivot point 122 by means of at least one jack 120-120 'on the base, can be placed near the pivot point 101 of the lever 100, the hydraulic supply ports OS2 of the jack 120,120 'being placed in order to obtain the force necessary for the stiffness of negative compensation, with a reduced bulk.

The implementation of the invention can be carried out according to a method stored in memory, for example in a microprocessor of the control electronics 180. This memory contains the functional relationships cited in particular the second which implements the compensation means 120 -124,125,130,160,170, of variation in stiffness in particular, from the detection of the first pressure P1 by the sensor means 191.

According to a characteristic of the invention
Method for implementing the entire stabilized suspension system with controlled stiffness according to the load, for suspended vehicle and object, characterized in that it comprises the following sequences
a) Detection of the variation in average load: F by a sensor means 190,191,193 located on the support means 105,112 and lever 100 in order to develop a correction order to maintain the determined average angular position of the suspension lever 100 by the command 180 and control means 109,112,113 regulating a first pressure P1 which is the image of the load F by a first functional relationship
P1 = f (F)
b) Correction of the suspension stiffness according to a second functional relation which takes account of at least one external parameter V, here:
P2 = f (Pl, V, lcd) in order to obtain an invariant or controllable suspension stiffness,
c) Change of average angular position of the lever 100 to allow in particular an optimum deflection of the suspension according to a third predetermined functional relationship
P1 = f (e, V, lcd) the clearance which can be dissymmetrized by the motorized displacement means 170 of the pivot point of the jack 120,120 ′ to obtain an asymmetrical deflection of the suspension adapted to the type of stress experienced by the suspension, in particular at rebound, from the suspended wheel of a vehicle or due to the swell undergone by the boat towing the submerged object, towed by cable.

d) Possible correction of the suspension amortization
- by the control means 114 of the means
120-124.124 'of the suspension device of a
pair of adjacent vehicle wheels, or
- by means of depreciation control
111 of the support means 105,112 of the
suspension of submerged object, towed by building, in order to obtain optimum damping with the greatest possible angular movement of the suspension system.

The inventive concept is presented in nonlimiting embodiments. Any other variant of this concept, within the reach of those skilled in the art, does not depart from the scope of the invention.

Claims (19)

1 - Stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object comprising - a tilting means (100) which can pivot on an axis (101), resting on a base, having one end provided with a support d 'fixed or rotating member (91,102) intended to support and / or transmit a load (F), - support means (105,109,112,113) to maintain the tilting means around an angular position (eO) t allowing handling operations and, or of stabilized load suspension, in particular of suspension of at least one vehicle wheel or of suspension of an object, in particular of an immersed object towed by a surface vessel, characterized in that it also comprises compensation means (120-124,125,130,160,170) to make the stiffness of the suspension substantially invariant or controllable depending on the variation: of the load (F) on the end (102) of the tilting means (100) and, or of the stiffness r of said support means and, or of an external control of stiffness (V) of determined suspension, in order to obtain a stabilized suspension of said base or of the suspended object. 2 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to claim 1 characterized in that the compensation means (120-124,125,130,160,170) are distinct from the support means (105,109,112,113), and in that '' they have a part of cooperation (107) with the tilting means (100) and, in addition, in that the compensation means comprise at least one actuation means (120,120 ') and at least one accumulation means of energy (124) to create a negative stiffness which opposes in whole or in part: the stiffness of the support means and, or the stiffness created by the load (F) in order to obtain a predetermined stiffness of stabilized suspension which can be invariant and, or substantially zero over most of the angular displacement (e) of the lever, and consuming substantially no energy. 3 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to claim 2, characterized in that the actuating means (120) is in particular at least one hydraulic cylinder (120,120 ') associated with the least a hydropneumatic energy storage means (124) in order to obtain a stabilized suspension device whose energy storage capacity (v10) of the support means can be reduced, while obtaining a period of oscillation very long suspension. 4 - stabilized suspension system with stiffness controlled according to the load, for vehicle and suspended object, according to any one of claims 2, 3 characterized in that the actuating means which is at least one jack (120,120 ') is mounted pivoted by its ends, one (122) on the base and the other on the cooperation part (107) of the tilting means, which can be a lever (100) to create a negative stiffness (K2) in relation with the hydro-pneumatic and kinematic characteristics of the compensation means (120-124) associated with those of said support means (105-112) in order to obtain a predetermined stiffness (Kr) of the stabilized suspension device and, in addition, to at least one end of the angular movement, an elastic end-of-travel stop means allowing suspension of optimum performance. 5 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to any one of claims 2 to 4 characterized in that the actuating means which is at least one jack (120,120 ') is mounted , by one end on the base by a pivoting means (122) which can be moved in a direction substantially parallel to the direction of mobility of the lever, in order to obtain a variable mean angular position (eO), adapted to allow more large angular movement (e eO) of the lever in a preferential determined direction. 6 - stabilized suspension system with controlled stiffness according to the load, for a suspended vehicle and object, according to any one of claims 1 to 5, characterized in that the suspension stiffness is substantially invariant or controllable by a control means (125,130,160 ), functionally associated with a detection means (81,191) of a said first pressure (P1) in order to obtain a stabilized semi-active suspension capable of adapting to load variations (F) and, or stiffness of the means support (105,109,112,113) and, or an external stiffness control (V). 7 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to claim 6 characterized in that the control means (125,130,160) is a hydraulic or electro-hydraulic valve means (125, 130,160) controlled depending on a first pressure (P1) prevailing in the circuit of the main means (105,112) to create a pressure called compensation (P2) which is in proportion to the first pressure (P1) to act on the compensation means (120 -124) in order to compensate for the variation in stiffness of the support means (105,109,112,113). 8 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to claims 6, 7 characterized in that the valve means (125,130,160) creates the so-called compensation pressure (P2) according to a functional relationship with the first pressure (P1), the first pressure (P1) being in particular the average pressure which corresponds substantially to the average angular position (8,) which can vary from the lever (100), so that the compensation pressure (P2) is not not dependent on rapid variations of the first pressure (P1). 9 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to any one of claims 6 to 8 characterized in that the control means which is a valve (125,130) is also controlled depending on a second pressure (P3) which is in proportional relationship with at least one external parameter (V) determined to modify the so-called compensation pressure (P2) according to a functional relationship in order to obtain a stabilized semi-active suspension capable of adapting to an external control of specified suspension stiffness, or to a handling mode. 10 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to claim 5 characterized in that the jack (120) has a pivot point (122) on the base which can be moved by means motorization (170) in order to obtain a change in the average angular position (eO) of the lever (100). 11. Stabilized suspension assembly with stiffness controlled according to the load, for a vehicle and suspended object characterized in that it comprises, in addition to the stabilized suspension system according to any one of claims 1 to 10, control electronics (180) which receives the signals of: measurement of angular position (e) of the lever (100), of the first pressure (P1) and of at least one determined external parameter (V), to implement - the control means (113 ) of the average pressure (P1) prevailing in the circuit of the support means (105,112), comprising a lever, - the control means (130,160) of the so-called compensation pressure (P2) of the compensation means (120-124) , - the motorization means (170) for moving the pivot point (122) of the jack (120), by a process treated by means of internal processing of the control electronics (180), in order to obtain a suspension semi-active vehicle and / or suspended object. 12 - stabilized suspension assembly with stiffness controlled according to the load, for vehicle and suspended object, according to claim 11, characterized in that, in addition, the control electronics (180) controls a damping adjustment means (114 ) compensation means (120-124) by acting on the flow of fluid leaving or entering one or more chambers of the jack (120, 120 '), in order to obtain controllable damping of the active suspension of a motor vehicle, in particular of a pair of adjacent wheels, independently of the damping of the support means. 13 - stabilized suspension assembly with stiffness controlled according to the load, for vehicle and suspended object, according to claim 11, characterized in that the control electronics (180) receives, in addition, a signal of unwound cable length (lcd ) in addition to an external parameter signal (V) which is in particular a displacement speed (V) of the towing vessel, possibly of the compensation pressure (P2) prevailing in the cylinder means circuit (120) and a signal lever end acceleration (g) (102) for implementing - the control means (113) of the support means, - the control means (130,160,126) of the compensation means, - the motorization means ( 170), - the damping means (111) of the support means, by a process treated by an internal processing means of the control electronics, in order to obtain a semi-active suspension with maximum clearance minimizing the absolute displacement noticeably green ical from the end of the lever (100) to reduce the change in attitude of the submerged object, towed by a cable (92) driven by a pivoting pulley (91) of a surface building winch, subjected mainly to the swell. 14 - stabilized suspension assembly with stiffness controlled according to the load, for vehicle and suspended object, according to any one of claims 9, 11 to 13, characterized in that, the lever (100) is controlled in a so-called handling mode or in a so-called active stabilization mode by associated control electronics (200) to the control electronics (180), and in that, valve means (188,188 ', 189,189') are additionally provided to allow actuate at least one jack of the support means (105, 105 ') in relation to the selected mode, and, in that the selected handling mode is a command controlled in angular position of the lever (100) by summation of the command displayed by the proportional means (207) with the position of the lever (190) which controls the proportional control valve means (188,188 '). 15 - stabilized suspension assembly with stiffness controlled according to the load, for a suspended vehicle and object, according to claim 14, characterized in that, in addition, the so-called active stabilization mode is used in addition to the semiactive stabilized suspension and in that that the switching means of the associated electronics (201, 202) controlled by the control electronics (180) form a substantially stiffly controlled loop comprising a gain circuit which can be variable (203) and in that, in in addition, the control electronics (180) produces a correction signal (208) introduced into the so-called stiffness control loop (190,202,203,205,209) by a second summing means (205 ') to make acceleration (1) substantially zero Y) measured substantially along the direction of mobility of the end (91.102) of the lever (100) controlled by the proportional valve means (188.188 '). 16 - stabilized suspension assembly with stiffness controlled according to the load, for vehicle and suspended object, according to any one of claims 14,15, characterized in that the valve means (189,189 ') is a switching valve controlled by a first signal (187) from the control electronics (180), for switching the hydraulic supply of at least one jack to the support means (105, 105 '), to allow operation in handling mode or in active stabilization mode, and in that, in addition, one of the means for controlling the compensation means is a switching valve (126) controlled by a second signal from the control electronics (180) for switching the supply circuit of the means cylinder (120,120 ') to allow reduction or cancellation of the action of the cylinder (120,120') on the cooperation means (107) of the lever (100) to obtain operation in handling mode. 17 - stabilized suspension assembly with stiffness controlled according to the load, for vehicle and suspended object, according to any of claims 13 to 16 characterized in that, in addition, the proportional valve means is a so-called 3-way valve (188) supplying at least one cylinder (105,105 ') through the section on the cylinder rod side (106) or else it may be a so-called 4-way valve (188') supplying a first double-acting cylinder (105 ') in parallel with a second cylinder (105) simple load compensation effect (F), the two jacks simultaneously actuating the lever (100). 18 - stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to any one of claims 5,10 characterized in that the pivot point (122) of the means of at least one jack (120- 120 ') on the base, is placed near the pivot point (101) of the lever (100), the hydraulic supply orifices (OS2) of the cylinder 120, 120' being placed to obtain the negative compensation stiffness, with a space requirement reduced. 19 - Method for the implementation of the entire stabilized suspension system with controlled stiffness according to the load, for vehicle and suspended object, according to any one of claims 11 to 13 characterized in that it comprises the following sequences  a) Detection of the variation in average load: (F) by a sensor means (190,191,193) located on the main means (105,112) and lever '100) in order to develop a correction order to maintain the average angular position ( 8,) determined by the suspension lever (100) by the control (180) and control (109,112,113) means regulating a first pressure (P1) which is the image of the load (F) by a first functional relation  Pi = f (F)  b) Correction of the suspension stiffness according to a second functional relationship which takes account of at least one external parameter (V, lcd)  P2 = f (Pl, V, lcd) in order to obtain an invariant or controllable suspension stiffness,  c) Change in average angular position (8,) of the lever (100) to allow in particular an optimum movement of the suspension according to a third predetermined functional relationship:  Pi = f (e, V, lcd) the clearance which can be dis symmetrized by the motorized displacement means (170) of the pivot point of the jack (120,120), in order to obtain an asymmetrical deflection of the suspension adapted to the type of stress experienced the suspension, in particular of rebound, of the wheel suspended from a vehicle or else due to the swell undergone by the boat towing the submerged object, towed by cable.  - by the damping control means (111) of the support means (105, 112) of the device for suspending an immersed object, in order to obtain the optimum damping and the greatest possible angular movement (e) of the suspension.  - By the control means (114) of the compensation means (120-124,124 ') of the suspension device for a pair of adjacent wheels of a motor vehicle, or   d) Possible correction of the suspension amortization - Winch for handling and towing submerged object towed by a building, characterized in that it incorporates an assembly or a stabilized suspension system with controlled stiffness according to the load for vehicle and suspended object according to any one of claims 1 to 11 , 13 to 18 and, in addition, in that it implements a method according to claim 19.