DESCRIPTION

Title:

CONTROL DEVICE FOR A VARIABLE DAMPER

The present invention relates to a method and system for allowing a user to set a damping curve of electronic shock absorber particularly, but not exclusively, for ground vehicles in accordance, respectively, with the preamble of claim 1 and 13.

The present invention also relates to an electronic programmable shock absorber in accordance to the preamble of claim 17.

In the present description, the term of damping curve refers to the dynamical response of a shock absorber during both compression and rebound, whenever the shock absorber is excited.

As known, suspensions may be divided into the following types: - passive: consisting of springs and mechanical shock absorbers whose damping curve is selected in the design step by the manufacturer and it may be changed by acting on appropriate mechanical control in order to obtain a limited number of settings; and semi-active: consisting of springs and electronic shock absorbers whose damping curve monitors the vehicle dynamics (such as chassis dynamics and wheel dynamics) and according to them a minimum or maximum damping is selected to obtain a limited set of possible settings.

In systems normally available on the market where it is possible to choose between the sport setting and the comfort setting, what are changed are the parameters of algorithms aiming at optimizing the sport and comfort respectively.

In particular, as regards the different type of adjustable shock absorbers, which have as a peculiar feature that of varying their damping coefficient according to the control signal, the following types may be distinguished:

CDC (continuously damping control) shock absorbers, whose operation is based on the variation of the sizes of orifices connecting the top and bottom chamber of the shock absorber piston, that is, it is possible to change the speed at which the suspension returns to the balance position; and

Rheological shock absorber, whose operation involves the use of rheological

fluids, that is, fluids which exhibit a variable viscosity based on a suitable electric and/or magnetic field (also called electro-rheological and magneto-rheological shock absorbers).

Said shock absorbers, both mechanical and electronic, find their application to several industrial fields, such as the automotive industry, the motorcycle industry, the industry of agricultural machines, the rail-way vehicles industry, domestic appliances industry and similar.

For example, with reference to figure 1, in the plane of the stroke speed with respect to the force, three different damping curves of a mechanical shock absorber are shown. In particular in this plane:

The reference numeral 1 denotes a damping curve representing the maximum capability c _max of damping of the mechanical shock absorber;

The reference numeral 2 denotes a damping curve representing the minimum capability c _min of damping of the shock absorber; and - The reference numeral 3 a possible damping curve of the mechanical shock absorber selected by the manufacturer and included between the damping curve 1, representing the maximum capability c _max of damping and the damping curve 2, representing the minimum capability c _min of damping.

In other words, in said figure 1 , it is shown one of the possible curves (that is the damping curve 3) which could be chosen by the manufacturer, in relation to the specific application which said mechanical damper is dedicated to.

To vary the damping curve 3 of the mechanical shock absorber chosen by the manufacturer, it is necessary to act on the mechanical controls of the shock absorber, if available; otherwise, as borderline case, it is necessary to change the shock absorber with another.

The possibility to adjust the damping curve of a mechanical shock absorber by the means of ring nuts or whatever always increases the complexity of the same shock absorber and it often involves the disadvantage of device redesign.

Thus to change the type of damping curve, that is the type of shock absorber setting, it is necessary the manufacturer to act on it with additional costs of new tuning and redesign.

It is worth noticing that in the case of electronic shock absorber the same problem arises as well.

In fact, even though the electronic shock absorbers normally available on the market allow the user to change the damping curve as function of user's needs and/or the user's way of driving, for example by acting on a graphic interface appropriately designed, however such shock absorbers allow to choose only among few possible damping curves.

Furthermore, it is worth pointing out that such damping curves are all previously selected by the manufacturer.

Thus the user has the possibility to choose only among the damping curves stored in the electronic control unit of the electronic shock absorber. In view of the prior art described above, the object of the present invention is to provide a method and a system which should be capable of solving the problems and the drawbacks found in the prior art herein reported.

In accordance to the present invention, such object is achieved by a method and a system for allowing a user to set a damping curve of an electronic shock absorber, for example, of a ground vehicle in accordance to the claim 1 and claim 13, respectively. Such object is also achieved by an electronic programmable shock absorber in accordance to the claim 17.

Thanks to the present invention is possible to obtain a method for allowing a user to set a damping curve of an electronic shock absorber within the structural limits of operation of the same shock absorber, since the damping curve is created by the user and not by the manufacturer of the shock absorber.

Therefore it is possible to allow the user to set and store in the electronic shock absorber the damping curve in accordance with the user's personal needs and sensitivity (damping curve for high and/or low comfort level, damping curves with high and/or low level of stiffness with respect the damping curves designed by the manufacturer) and/or in accordance with the specific application where the shock absorber is involved (ground vehicles, appliances, etc.).

This allows the user to set an infinite number of damping curves without the necessity of implementing mechanical regulations and/or electronic regulations and not even of replacing the shock absorber.

Furthermore, thanks to the present invention it is possible to obtain a simplification of the mechanical devices of the electronic shock absorbers since the diversification of the damping curve is obtained by a step of uploading some representative parameters

of the new damping curve into the electronic control unit of the shock absorber, such parameters are chosen by the user within the limits of maximum and minimum damping of the same shock absorber.

This guarantees the user and the shock absorber manufacturer to replicate known damping curves, developed for a specific shock absorber, for example a mechanical one, in any electronic shock absorber, compatibly with the requirements of the application.

In other words, the present invention allows to set into an electronic shock absorber a damping curve developed for another shock absorber, so that such damping curve is replicated in the same electronic shock absorber.

Thanks to the present invention it is also possible to obtain a programmable shock absorber capable of receiving, storing and actuating, whenever the user likes, a damping curve chosen and designed by the same user (or by the manufacturer) in accordance with the personal needs. Furthermore, thanks to the present invention it is possible to fully neglect the vehicle dynamics, since the present inventions concerns only the dynamic of the electronic shock absorber.

In particular, measuring appropriately the dynamic of compression and/or rebound of the electronic shock absorber and on the basis of such measurement it is possible to actuate a control signal for replicating a damping curve which has been defined by the user.

It is worth noticing that in accordance with the present invention the electronic shock absorber can be also used in a semi-active way, by adding the specific control software implementing the dynamics control, for example, of the ground vehicle. Finally, but not less important, thanks to the present invention by a software product stored in the memory of a computer and running on such computer, it is possible to allow a user to actuate the method in accordance with the present invention. The features and the advantages of the present invention will appear more clearly from the following detailed description of some practical embodiments thereof, made by way of a non- limiting example with reference to the annexed drawing, wherein: figure 1 shows typical damping curves of a mechanical shock absorber; figure 2 shows a schematic view of the system allowing a user to set a damping curve of an electronic shock absorber for a ground vehicle, in accordance to the present

invention; figure 3 shows more in details a possible graphic interface to allow a user to set a damping curve of an electronic shock absorber, in accordance with the present invention; - figure 4 shows a flow chart of the control of the electronic shock absorber.

With reference to the annexed drawings from 2 to 4, the reference numeral 4 denotes a system for allowing a user to set at least one damping curve 5A, 5B in an electronic shock absorber 6 for a ground vehicle (not reported in the figures).

It is worth noticing that the electronic shock absorber 6 is an electronic shock absorber which finds application particularly, but not exclusively, to a semi-active suspension, which can be used, for example, in the automotive industry, in the motorcycle industry, in the industry of agricultural machines, in the rail vehicles industry, in the industry of domestic appliances and similar.

Advantageously, the system 4 comprises: - An electronic shock absorber 6 provided by an electronic control unit 7 (ECU), which is devoted to the control of the compression and/or rebound dynamics of the same electronic shock absorber 6, and

A computer client 8 having at least one processor, one memory associated to the said at least one processor, one screen and a software product 9 which may be uploaded into said memory.

In particular, the electronic control unit 7 comprises: an interface of connection 10 for establishing a bidirectional signal communication between the computer client 8 and the same electronic control unit 7, a memory 15, - an interface of connection 18 for establishing a bidirectional signal communication between the electronic shock absorber 6 and the same electronic control unit 7, and means for computing 17 equipped with a firmware to rule and manage the functionalities of the previous devices constituting the electronic control unit. In a preferred realization, the electronic control unit 7 may be embedded into the electronic shock absorber 6, so that a smaller room is required.

Alternatively, the electronic control unit 7 may be realized as a device external to the same electronic shock absorber 6.

It is worth noticing that the electronic shock absorber 6 comprises one or more devices of regulation (not illustrated in the drawings) to control the dynamic of compression and/or rebound of the electronic shock absorber 6 controlled by the electronic control unit 7. In fact, as described more clearly in the rest of the description. The electronic control unit 7 is capable of controlling the above devices of regulation, such as electro -valves, for actuating the damping curve 5A,5B in order to control the dynamics of rebound and/or compression of the electronic shock absorber 6 by a data transfer thanks to the interface of connection 18. Advantageously, the software product 9 is capable of implementing a method which accordingly allows a user to set at least a damping curve 5A,5B in the electronic shock absorber 6.

To this end, also with reference to figure 3, the method comprises the following step: providing a model reference 11 of the typical parameters corresponding to the electronic shock absorber 6, wherein the model reference 11 comprises a first set of values Sl denoting the minimum capability of damping c _min of said electronic shock absorber 6, and a second set of values S2 denoting the maximum capability of damping c _max of said electronic shock absorber 6, receiving a user input or an input signal Sin into the computer client 8, wherein the user input Sin provides at least one characteristic parameter coi , ω ₂ of the electronic shock absorber 6, wherein the at least one characteristic parameter coi , ω ₂ is defined with respect to a model reference 11 , computing said at least one characteristic parameter coi , ω ₂ so that at least a new damping curve 5A,5B is generated, - using the new damping curve 5A,5B in the electronic control unit 7 to control the electronic shock absorber 6 of the ground vehicle.

It is worth noticing that the step of receiving a user input Sin into the computer client 8 comprises also the following step:

Interpolating at least one characteristic parameter coi , ω ₂ denoting the damping capability of the electronic shock absorber 6 so that a new damping curve 5A,5B is generated in order to have said new damping curve 5A,5B included between:

Said first set of values Sl denoting the minimum capability of damping c _min , and

Said second set of values S2 denoting the maximum capability of damping c _max of said electronic shock absorber 6.

Advantageously, hence, by interpolating the values represented by the input signal Sl, the method generates the new damping curve 5A,5B, which is a control source code for the electronic control unit 7.

In particular, as it will be detailed more clearly in the rest of the description, such control source code is uploaded into the memory 15 of the electronic control unit 7 and it is used by the firmware of the means for computing 17 to control the devices of regulation with the aim of implementing the damping curve 5A,5B, so that it is possible to manage the dynamics of compression and/or rebound of the electronic shock absorber. 6.

It is worth noticing that the step of interpolating is implemented by methods based polynomial interpolation or based on spline, according to the specific requirements of the application to which the electronic shock absorber 6 is dedicated. In particular, the at least one characteristic parameters coi , ω ₂ denoting the damping capability of the electronic shock absorber 6, is , for example, the rebound stroke speed wl as a function of the compression force ω ₂ , or viceversa.

Alternatively, it is possible to choose different characteristic parameters according to the specific requirements of the application. With reference to figure 3, it is worth remarking that, according the preferable embodiment of the present invention, the step of providing a model reference 11 of the characteristic parameters coi , ω ₂ for the electronic shock absorber 6 comprises also the following steps:

Showing a control panel 12 on the graphical interface of said computer client 8; - Showing said model reference 11 on the control panel 12.

In particular, the control panel 12 of the software product 9 is, for example, implemented by a Cartesian coordinate system, where the x-axes represents the stroke speed expressed as mm/sec and the y-axes represents the force expressed in Newton; in such control panel implemented by a Cartesian coordinate system, a first default damping curve is the first set of values Sl denoting the minimum capability of damping Cmin of the electronic shock absorber 6.

Similarly, a second default damping curve is the second set of values S2 denoting the maximum capability of damping c _max of the electronic shock absorber 6.

It is worth noticing that the first default damping curve and the second default damping curve define an area 13 which represents the set of characteristic points which the user may choose to set the new damping curve 5A,5B.

In other words, the area 13 defines the all points available for the user to set a new damping curve 5A,5B, in accordance to the characteristics of the electronic shock absorber.

In particular, the user selects the points in the area 13 as he likes, by the means of specific functional buttons 12Aof the control panel 12of the software product 9; the software product 9 interpolates said points selected by the user according to the user's specific requirements in order to set the new damping curve 5A,5B.

For example, the user may choose or insert the representative value if signal Sin by the means of specific functional buttons 12A of the control panel 12; the signal Sin hence corresponds to one point or more of the area 13.

Each of such points of the area 13 corresponds to specific values of the characteristic parameters (D ₁ , Co ₂ ; such points selected by the user are interpolated in order to generate a control source code which implements, for example, the damping curve 5A or the damping curve 5B.

For example, whether the user selects only a point in the area 13, the method generates by interpolation a damping curve 5A,5B which is a straight line passing in the origin of Cartesian coordinate system.

It appears evident that the precision of the generated damping curve 5 A,5B increases with respect to the number of points selected by the user in the area 13.

Therefore, whether the user aims at replicating a damping curve of mechanical shock absorber, whose tuning, for example, is considered as the best tuning for specific requirements of comfort or of grip, or alternatively whether the user aims at setting new damping curves according to their personal needs, the user has the possibility to choose or select a set of points in the area 13 which are interpolated to generate one or more damping curves 5A,5B.

To this end, with reference to figure 2, in the method the step of using a new damping curve 5A or 5B in said electronic control unit 7 comprises additional steps for establishing a bidirectional signal communication based on wireless communication, on a portable storage memory 14, or a wired communication.

In particular, in the preferable embodiment, the bidirectional signal communication is

implemented by the portable storage memory 14.

In this embodiment, the method comprises the following step:

Storing the new damping curve 5A and/or 5B in the portable storage memory

14, - Associating the portable storage memory 14 to the bidirectional interface 10 of the electronic control unit 7 of said electronic shock absorber,

Uploading the new damping curve 5 A and/or 5B in part of the memory 15 of the electronic control unit 7 of the electronic shock absorber 6.

It is worth noticing that the bidirectional interface 10 may be embedded in the electronic control unit 7 or may be located, for example in the ground vehicle, in a place visible for the user.

In particular, in the preferable embodiment, the firmware of the means for computing

17 is able to auto-execute the control source code representing the damping curve

5A,5B generated by the software product 9. In other words, the control source code representing the damping curve 5A,5B is uploaded automatically in the memory 15 and is auto-executed by the means for computing 17.

In a preferable embodiment the portable storage memory 14 is a pendrive, that is a

USB key normally available on the market. Alternatively, the portable storage memory 14 is a memory card port devoted to a

MMC card, or it is a hard disk.

Alternatively, the step of using the new damping curve 5 A and/or 5B in the memory

15 of the electronic shock absorber 7 may be a cable interconnection such as serial connection or RS32 connection. Alternatively, the step of using the new damping curve 5 A and/or 5B in the memory

15 of the electronic shock absorber 7 may be a wireless connection by the means of a transceiver wireless module.

It appears evident the advantage for the user. In fact, the user may set, generate and store in the pendrive 14 the personal damping curve 5A and/or 5B; furthermore the user may associate the pendrive 14 to the interface 10 if the electronic control unit 7 of the electronic shock absorber in order to set a new damping curve without any action by the manufacturer or by the mechanical tuner.

It is worth noticing that the method includes also the possibility of downloading the

damping curve stored in the memory 15 of the electronic control unit 7 of the electronic shock absorber 6 in order to depict said damping curve in the graphical interface 12 of said computer client 8.

The step of downloading the damping curve stored in the memory 15, in particular, consist in a logging of the data representing the damping curve currently stored, for example, in the portable storage memory 14 which was previously associated to the interface 10 of the electronic control unit 7.

In this case the functionality of telemetry is included, that is a functionality devoted to receive and interpret the data from the electronic control unit 7 by the interface 12. With reference to figure 4, which shows a flowchart of the control functionalities of the electronic shock absorber 6, it is interesting to notice that, first thanks to the graphical interface 12 the user sets the new damping curve 5A and/or 5B according to the model reference 11 of the characteristic parameters wl , w2 ; then such new damping curve is uploaded thanks, for example, to the association of the portable storage memory 14 to the interface of communication 10 of the electronic control unit 7; finally thanks to the presence of one or more sensors of dynamic 16, when it is used, the dynamic of the shock absorbers 6 is logged or monitored.

For example, sensors of dynamic 16 are force/stroke-speed sensors such as one accelerometer or one potentiometer in communication with the means of computing 17 by the interface of connection 18 of the electronic control unit 7.

A reference single F ref is generated according to the measurement made by said sensors 16 and according to the model reference 11 of the characteristics parameters (Q ₁ , , ω ₂ corresponding the electronic shock absorber 6. Furthermore, the firmware of the means of computing 17 generates a command signal Scomm according to the measurement made by the said sensors 16 and according to the damping curve 5A and/or 5B set by the user; such command signal Scomm is capable of controlling the devices of regulation of the electronic shock absorber 6 by the interface 18. In other words, the electronic control unit 7 generates the command signal Scomm as function of the force reference F ref and of the damping curve 5A,5B set by the user and as function of the shock absorber dynamics measured by the sensors 16; such command signal Scomm approximates at best both the damping curve 5A and/or 5B, set by the user, included at the same time in the area 13 as defined by the model

reference 11.

Preferably, the signal Scomm generated by the electronic control unit 7 is a current signal.

Therefore, first the user design the new damping curve 5 A and/or 5B of the electronic shock absorber 6 by inserting the input Sin thanks to the graphical interface 12; it is worth remarking that the input Sin denotes the characteristic parameters GO ₁ , , ω ₂ representing the damping capability of the electronic shock absorber 6; then, by interpolating the values represented by the input Sin, the method generates the control source code for the electronic control unit so that the electronic shock absorber 6 behaves according to the requirements set by the user.

Such control source code (that is the damping curve 5) is store, for example, in a pendrive 14 which is associated to the interface 10 of the electronic control unit 7; the means of computing 17 of the electronic control unit 7 interpret and execute such control source code and manage the electronic shock absorber 6 with the command signal Scomm in order to command electronic such shock absorber 6 according also to the data measured by the dynamic sensors 16.

The electronic control unit 7, in fact, measures the dynamics of the shock absorber by said sensors 16 and as a consequence it sets a damping as function of the damping curve 5 A and/or 5B uploaded into the memory 15. Thanks to the present invention the advantages and the goals previously mentioned and particularly introduced in the abstract are achieved.

Particularly, it is also possible to change the damping curve of the programmable shock absorber whenever the user likes without the intervention of the manufacturer with additional costs Of course, a man skilled in the art may make several changes ad adjustments to the configurations described above in order to meet specific and incidental needs, all falling within the scope of the protection defined in the following claims