Patent Description:
An important area when developing passenger vehicles, especially passenger cars, is to increase the safety for the occupants in the vehicle. A lot of progress has been made during the years. For example; seat belts, airbags, whiplash protection systems etc. have been introduced, which have significantly increased occupant safety.

However, vehicle occupant safety is an area which always can be improved further until reaching a state where no occupants of the vehicle are injured any longer.

<CIT> concerns an adjustable damper for use with a vehicle suspension. More particularly, and according to one embodiment, <CIT> discloses a zero gravity control mode is attained, at which vehicle suspension dampers that were operating in a "soft" mode, upon a detection of a zero gravity situation, are made to operate in the "firm" mode. For example, a vehicle that is operating in a "soft" mode is traveling in a straight line along a path that initially contains small bumps, but graduates into large rollers. The vehicle initially is placed in the "soft" mode in order to mitigate and/or nullify the effect (upon the vehicle rider) of the vehicle traveling over small bumps along the pathway. At a particular velocity, when the vehicle then moves up one side and over the top of the large roller, on the way down to the bottom of the other side of the roller, the vehicle experiences a free fall.

In view of the above, at least one object of the present invention is to provide an improved method and arrangement for a vehicle which reduces the risk of at least one user being injured during an accident or incident of the vehicle. More particularly, an object of the present invention is to prevent, or at least reduce the risk of a spine injury of at least one user in the vehicle.

The above and other objects may be provided by the subject matter as presented in the independent claims. Preferred and advantageous embodiments can be found in the dependent claims and in the accompanying description.

According to a first aspect, the objects are at least partially achieved by a method for a vehicle comprising at least one wheel suspension with at least one damper, wherein the at least one damper is such that it can adjust its damping resistance between a first damping mode and at least a second damping mode, wherein the at least second damping mode presents a larger damping resistance than a damping resistance of the first damping mode. The method comprises:.

According to the invention, the identifying step is defined as identifying if the vehicle is in a first situation during driving of said vehicle which will lead to a subsequent impact force on the at least one wheel suspension which is of a magnitude such that the at least one damper, when in its first damping mode, will reach a position where no further damping can be performed.

Optionally, the adjusting step may be performed when it has been identified that the vehicle is in the first situation.

The inventors have realized that it would be advantageous to use the above mentioned method for a vehicle and also to use a damper with the above-mentioned characteristics in order to reduce the magnitude of vertical component forces on the occupants' bodies and therefore the risk of serious spine injuries, and also other body related injuries, of users in the vehicle. More particularly, by increasing the damping resistance before a high impact force is exerted on the at least one wheel suspension, a larger portion of the impacted force on the wheel suspension may be damped and thereby a possible force transferred to any user in the vehicle may be reduced. Still further, with the present invention it may even be possible to adjust the damping resistance before a wheel of the wheel suspension touches ground after an airborne situation. In the event that the at least one damper would not adjust and increase its damping resistance in the above situations, it is more likely that the occupants in the vehicle would be injured. With the above mentioned method according to the first aspect, the risk of serious injuries, especially spine injuries, may be reduced. Optionally, the first damping mode of the damper may be a normal damping mode which is used during normal driving of the vehicle. Still optionally, the at least second damping mode may be a damping mode which is not used in normal driving conditions, and which also may have a too high damping resistance for a normal driving situation.

Optionally, the impact force may further be of a magnitude such that at least one user of the vehicle may, or will, get hurt when the at least one damper is in its first damping mode. Still optionally, the impact force may further be of a magnitude such that a spine of the at least one user may, or will, get injured when the at least one damper is in its first damping mode. In this document, the expressions user, passenger, driver and occupant of the vehicle is used. It shall be noted that unless expressed otherwise, a user/passenger/driver/occupant of the vehicle is anyone being located in the vehicle during a driving situation, and more particularly anyone who is positioned in a vehicle chair/seat in the vehicle.

In this document, driving of the vehicle may be defined as when the vehicle is moving in at least one direction, preferably in a forward or rearward direction of the vehicle. Still optionally, driving of the vehicle may be defined as when the vehicle is moving with a speed exceeding a certain value, such as a speed from <NUM> kilometers per hour (km/h), from <NUM>/h, from <NUM>/h, from <NUM>/h, or from <NUM>/h.

Optionally, the adjustment of the damping resistance may be performed when the first situation is identified. According to the invention, the adjustment of the damping resistance is performed at least before the subsequent impact force impacts the wheel suspension.

Optionally the first situation may be identified by measuring at least one of the following:.

Optionally, identifying if the vehicle is in the first situation may be performed by identifying if anyone or a combination of the above mentioned measured values exceeds predetermined values. Just as a matter of example, by measuring a change in acceleration and rotation of the vehicle the first situation may be identified.

In this document, the x-, y- or z axis and x-, y- or z direction refer to a three-axis Cartesian coordinate system presenting three separate axes which are oriented pair-wise perpendicularly to each other. The x-axis preferably relates to a driving direction, also a longitudinal direction, of the vehicle, the y-axis to an axis being transverse to the driving direction, and the z-axis to a vertical axis of the vehicle. Just as a matter of example, the impact force may be a force which substantially is directed in the z-direction, or the vertical direction, of the vehicle.

According to the invention, the first situation is a situation where at least one side of the vehicle is airborne, or the complete vehicle is airborne. Identifying if, or when, at least a side of the vehicle is airborne is sufficient for knowing that the at least one wheel suspension will, or most likely will be exposed of an impact force which is so high that the at least one damper will reach a position where no further damping can be performed. Thus, by identifying if the vehicle is at least partially airborne and then increasing the damping resistance, the risk of occupant injuries may be reduced. The identification that the vehicle is airborne may be made by for example measuring acceleration in a vertical direction, or z-direction, of the vehicle. Just as a matter of example, the identification of the first situation may be made by identifying if the vertical acceleration of the vehicle exceeds a predetermined value. As another non-limiting example, identifying that the vehicle is at least partially airborne may be performed by measuring if at least one wheel suspension has reached an extended outmost position. This is also known as rebound. More specifically, if there is no, or almost no, load exerted on the at least one wheel suspension the wheel suspension may be in an outmost position, i.e. the wheel is not in contact with ground.

Optionally, the first situation may be defined as a risk situation where the vehicle will, or at least it is very likely that the vehicle will, be in an accident or serious incident, such as crashing into another object, driving off the road etc. Still optionally, the first situation may be defined as the beginning, or an initial phase, of an accident, such as a crash, driving off the road etc..

According to a non-claimed example, the at least one damper further may be configured such that the damping modes may be manually adjusted. There may be situations where it may be advantageous for an occupant of the vehicle to manually adjust between the damping modes.

Optionally, the at least one damper may be further configured such that it can adjust its damping resistance to at least a third damping mode which presents a damping resistance which is larger than the damping resistance of the second damping mode. Just as a matter of example, it may be so that the method is able to identify the level of the coming impact force, and as a consequence, the damper adjusts to a corresponding damping resistance reflecting the level of the estimated impact force to give the optimal protection for the occupants. Thereby a more versatile method may be provided, which is adaptable to more situations. Optionally, the damping resistance may be adjusted from the first damping mode to the at least second or third damping mode depending on the magnitude of the subsequent impact force. Still further, the at least one damper may also be configured such that it can adjust its damping resistance in a continuous range of different resistances, thereby presenting a plurality of damping modes.

Optionally, the method may further comprise a step of identifying in which seat of the vehicle at least one user is present, and thereafter at least adjust the damping resistance of the at least one damper for a wheel suspension which has the largest impact on the seat where the at least one user is present. Thereby a further improved method may be provided.

Optionally, the at least one wheel suspension is a wheel suspension of a rear axle of the vehicle, thereby being able to reduce the risk of at least one occupant in the back seat of the vehicle being hurt. A vehicle rear axle may be located closer to a occupant seat compared to a front seat, and therefore it may be especially advantageous to make use of the method for a wheel suspension of the rear axle.

According to a second aspect, the object is at least partially achieved by a computer-readable storage medium storing a program which causes a computer to execute a method according to the first aspect of the invention. The advantages of the second aspect of the invention are analogous to the advantages of the first aspect of the invention. It shall also be noted that all embodiments of the first aspect of the invention are applicable to and combinable with all embodiments of the second aspect of the invention and vice versa.

According to a third aspect of the invention, the object is at least partially achieved by an arrangement for a vehicle, which comprises at least one wheel suspension with at least one damper, wherein the at least one damper is such that it can adjust its damping resistance between a first damping mode and at least a second damping mode, wherein the at least second damping mode presents a larger damping resistance than a damping resistance of the first damping mode. The arrangement is adapted to:.

According to the invention, the arrangement is adapted to identify if or when the vehicle is in a first situation during driving of said vehicle which will lead to a subsequent impact force on the at least one wheel suspension. The arrangement is adapted to adjust the damping resistance from the first damping mode to the at least second damping mode when it is identified that the vehicle is in the first situation.

The advantages of the third aspect of the invention are analogous to the advantages presented in relation to the first aspect of the invention. It shall also be noted that all embodiments of the third aspect of the invention are applicable to and combinable with any of the embodiments of the first and second aspect of the invention and vice versa, unless explicitly expressed otherwise.

Optionally, the at least one damper may further be such that it presents at least a third damping mode which presents a damping resistance which is larger than the damping resistance of the second damping mode.

Optionally, the at least one damper is anyone of a high impact damper, a pneumatic damper, a hydraulic damper or an electromagnetic damper. Just for the sake of clarity, any such damper is also applicable to the first aspect of the invention. A high impact damper may be defined as a damper that has at least one damping mode which is used in a normal driving situation and further at least a second harder damping mode with a larger damping resistance which may be used when or if the damper is exposed to larger forces. The high impact damper may for example be a hydraulic damper, such as an oil damper which is able to switch between at least two damping modes. Just for the sake of clarity, a damper may also be known as a shock absorber. A damper or shock absorber may for example transform kinetic energy into another form of energy, such as heat. Still optionally, the at least one damper may be electrically controlled such that it can adjust its damping resistance between a first and at least a second damping mode. By having an electrically controlled damper it may be possible to adjust the damping resistance before a high impact force is exerted on the at least one wheel suspension. Thereby an increased safety may be provided for the occupants of the vehicle. Still optionally, the at least one damper may be configured such that is able to adjust between a first and at least a second damping mode even if there is an electrical power failure. Thereby an even further improved safety may be provided since such a damper would still be able to increase its damping resistance even if there was an electrical power failure.

According to the invention, the arrangement comprises at least one sensing element configured to sense a condition indicative of the first situation. Just as a matter of example, the at least one sensing element may be anyone of an accelerometer, a gyro-sensor, a speed sensor, a force senor, a camera, a LIDAR (Light Detection And Ranging) sensor, an ultrasonic sensor, a radar (radio detection and ranging) sensor, a sonar (sound navigation and ranging) sensor, an altitude sensor, a wheel suspension position sensor, a seat force sensor or any other sensor that can detect and identify that the vehicle is in a situation where the at least one damper eventually may reach its position where no further damping can be performed. Just for the sake of clarity, any such sensing element is also applicable to the first aspect of the invention.

According to the invention, the first situation may be a situation where at least one side of the vehicle is airborne, or the complete vehicle is airborne. Identifying if, or when, at least a side of the vehicle is airborne is enough for knowing that the at least one wheel suspension will be exposed to an impact force which is so high that the at least one damper will reach a position where no further damping can be performed. Thus, by identifying if the vehicle is at least partially airborne and then increasing the damping resistance, the risk of occupant injuries may be reduced.

Optionally the first situation may be identified by the at least one sensing element measuring at least one of the following:.

Optionally, the impact force may further be of a magnitude such that at least one user of the vehicle may, or will, get hurt when the at least one damper is in its first damping mode. Still optionally, the impact force may further be of a magnitude such that a spine of the at least one user may, or will, get injured when the at least one damper is in its first damping mode.

According to a fourth aspect of the invention, the object is at least partially achieved by a vehicle comprising an arrangement according to the third aspect of the invention and/or a computer-readable storage medium according to the second and aspect of the invention. In a preferred embodiment, the vehicle is a passenger vehicle, most preferably a passenger car. The advantages of the fourth aspect of the invention are analogous to the advantages presented in relation to the first aspect of the invention. It shall also be noted that all embodiments of the fourth aspect of the invention are applicable to and combinable with any of the embodiments of the first, second and third aspects of the invention and vice versa, unless explicitly expressed otherwise.

Optionally, anyone of the embodiments of the present invention may also be advantageously combined with an active wheel suspension system. For example, an active wheel suspension system may be a system which continuously controls chassis characteristics of the vehicle and may further comprise active dampers. These systems may for example be able to adjust between different normal driving modes, such as comfort, sport etc. Such systems are well known and combining it with the present invention may further improve vehicle safety.

Exemplifying and preferred embodiments of the present invention will now be described more in detail, with reference to the accompanying drawings, wherein:.

In <FIG>, an example embodiment of an arrangement <NUM> according to the present invention is shown. The arrangement <NUM> comprises at least one wheel suspension <NUM> with at least one damper <NUM>, wherein the at least one damper <NUM> is such that it can adjust its damping resistance between a first damping mode and at least a second damping mode, wherein the second damping mode presents a larger damping resistance than a damping resistance of the first damping mode. The arrangement <NUM> is adapted to:.

The sensing elements, e.g. accelerometer and/ gyro sensor, identify that the vehicle <NUM> has become airborne with a certain altitude above the ground which will lead to that the first damping resistance of the damper <NUM> will not be large enough for damping the impact force that the wheel suspension <NUM> will be exposed to when touching the ground after the airborne situation. In this situation, the damper <NUM> will then adjust its damping mode from the first damping mode to the at least second damping mode with a larger damping resistance, which is performed before touch down or in some cases of non-claimed examples a fraction of a second after, in order to reduce the risk that a user in the vehicle <NUM> may get injured. When the ECU <NUM> has identified that the vehicle <NUM> is in the risk situation it sends a signal to the damper <NUM> which leads to that the damper <NUM> adjusts its damping resistance from the first to the at least second damping mode. The ECU <NUM> may comprise a computer-readable storage medium which comprises a method according to an embodiment of the first aspect of the invention.

In <FIG>, a cross section of a damper <NUM> according to an example embodiment of the invention is shown. The damper <NUM> comprises a piston <NUM> with a piston head <NUM> located within a cylinder <NUM>. The damper <NUM> is a hydraulic damper wherein the cylinder <NUM> is at least partially filled with a fluid, typically oil. The piston head <NUM> presents at least two separate fluid channels <NUM> and <NUM>, in which fluid can be transferred between a first and a second volume, <NUM> and <NUM> respectively, of the cylinder <NUM> when the piston <NUM> moves in the damper's longitudinal direction in the cylinder <NUM>. As can be seen in <FIG>, the two channels <NUM> and <NUM> present different diameters in the cross sectional view. The damper <NUM> is arranged to switch between a first damping mode and at least a second damping mode by using, i.e. allow fluid to be transferred in, both or only one of the first channel <NUM> and the second channel <NUM>. The channels <NUM> and <NUM> comprise a first and second respective valve (not shown), which can open and close the respective channels, thereby allowing fluid to pass in either the first channel <NUM>, corresponding to the first damping mode, or in the second channel <NUM>, corresponding to the at least second damping mode. Both channels <NUM> and <NUM> may also be open in the first mode and only one channel open in the at least second mode. In an example, the valves may be configured such that the flow is larger in one direction, such as in rebound direction. The valves for the channels are preferably controlled by the ECU <NUM> as seen in <FIG>. A volume <NUM> in the cylinder <NUM> is adjustable for compensating for that the total volume of <NUM> and <NUM> will change when the piston <NUM> moves into the cylinder <NUM>. The volume <NUM> may preferably be filled with a gas. As an alternative of using at least two valves, the damper <NUM> may alternatively comprise at least one valve which can adjust the flowing rate between at least two different damping modes. Additionally, the damper <NUM> may also comprise more than two valves. Moreover, the damper <NUM> has reached a position where no further damping can be performed when all, or almost all, of the fluid has been transferred from the volume <NUM> to the volume <NUM>. In other words, the piston head <NUM> has reached a position in the cylinder <NUM> where no further damping may be performed.

In <FIG>, a driver <NUM> of the vehicle <NUM> can be seen, which is exposed to a force Fp. The force Fp may be a substantially vertical force. Such a force Fp may for example be generated when the vehicle <NUM> touches ground after being airborne. The vehicle could for example become airborne after driving into a ditch in high speed or the like. With the present invention, the force Fp exerted on the driver <NUM> may be reduced since the damper <NUM> may adjust from its first damping mode, e.g. a normal or standard damping mode, to at least a second damping mode which presents a larger damping resistance than the first damping mode. Thereby a spine injury, or any other serious injury, of the user <NUM> may be prevented, or at least reduced.

In <FIG>, a vehicle <NUM> comprising an arrangement <NUM> (not shown) according to an embodiment of the present invention is shown. The vehicle <NUM> is in a first situation where it has become airborne and moves in a direction of the arrow as shown in the figure. The situation has been identified by the use of at least one sensing element in the vehicle <NUM>, which as described hereinabove may for example be a gyro sensor, an accelerometer, altitude sensor etc. Since it has been identified that the vehicle <NUM> is in the first situation, the damper <NUM> of at least one of the wheel suspensions <NUM> will adjust its damping mode to a second damping mode which present a larger damping resistance than the first damping mode, and thereby reducing the risk of a user <NUM> being exposed to a force Fp which is of a magnitude such that the user <NUM> may get seriously injured. The first situation may for example be identified by identifying if the acceleration or a change of acceleration, in anyone of the x-, y- or z-direction exceeds predetermined values. Also, the first situation may be identified by using a combination of input parameters, such as acceleration, speed, vehicle rotation, altitude of the vehicle etc. Moreover, it may also be identified by comparing such input parameters from the at least one sensing element of the vehicle <NUM> with empirical data. Empirical data may have been collected by testing different situations, i.e. subjecting a vehicle to different accidents and incidents, such as driving into a ditch, driving over a big bump on a road, releasing a vehicle from certain heights etc. Such empirical data may for example be collected by the vehicle manufacturer, or the like. The empirical data may comprise one or several different parameters which correspond to different situations where the vehicle <NUM>, or the wheel suspensions <NUM> of the vehicle <NUM>, subsequently may be exposed to a certain impact force F during driving which is of a magnitude such that the at least one damper <NUM>, when in its first damping mode, will reach a position where no further damping can be performed. Thereby, by comparing real-time data during driving of the vehicle <NUM> with the collected empirical data such risk situations may be identified. The collected data may for example be stored in a database <NUM> (as can be seen in <FIG>) in the vehicle <NUM>.

In <FIG>, a vehicle <NUM> comprising an arrangement <NUM> (not shown) according to an embodiment of the present invention is shown. Here it can be seen that one side of the vehicle <NUM> has become airborne. The arrow shows that the vehicle <NUM> is tilted and has rotated about the x-axis in relation to the ground during driving. The arrangement <NUM> is adapted to identify a first situation as described hereinabove and thereafter adjust the damping resistance from the first damping mode to the at least second damping mode of the at least one damper <NUM>. In this particular situation, it may only be the wheel suspensions <NUM> on the right side of the vehicle <NUM> that adjust its damping resistance. In certain embodiments, the arrangement <NUM> and the method for the vehicle <NUM> may thus be able to also identify which one(s) of the four wheel suspensions <NUM> of the vehicle that should be adjusted accordingly, and which one(s) that should not be adjusted. Just as a matter of example, in the situation shown in <FIG>, it may be so that it is preferred to not change the damping resistances of the wheel suspensions <NUM> for the wheels <NUM> on the left side of the vehicle <NUM>. Increasing the damping resistance for those wheel suspensions <NUM> could even lead to a worse situation.

In <FIG> a vehicle <NUM> comprising an arrangement <NUM> according to an example embodiment of the present invention is shown. The vehicle <NUM> comprises a database <NUM> stored in a memory unit which comprises data representing different risk situations, or first situations. Real-time data from at least one sensing element in the vehicle <NUM> is compared to the data in the database in order to identify if the vehicle <NUM> is in a first risk situation. The data may for example be empirical data as described hereinabove, but it could also be data that has been generated by performing computer simulations of different risk situations of a vehicle. Still further, the vehicle <NUM> may also communicate wirelessly with a data-cloud <NUM> where more data, such as empirical data, is stored. For example, empirical data may continuously be generated by learning from other accidents by other vehicles and then download this data to the database <NUM> from the data-cloud <NUM>. Thereby the vehicle <NUM> may be able to identify even more such risk situations. Of course, also further computer simulated data may be downloaded to the database <NUM> from the data-cloud <NUM>. As an alternative, such new data may also be downloaded to the database <NUM> via a cable when for example the vehicle is in a workshop.

<FIG> shows a flowchart of a method for a vehicle <NUM> according to an embodiment of the present invention. The vehicle <NUM> comprises at least one wheel suspension <NUM> with at least one damper <NUM>, wherein the at least one damper <NUM> is such that it can adjust its damping resistance between a first damping mode and at least a second damping mode, wherein the second damping mode presents a larger damping resistance than a damping resistance of the first damping mode. The method comprises the steps:.

Claim 1:
A method for a vehicle (<NUM>) comprising at least one wheel suspension (<NUM>) with at least one damper (<NUM>), wherein the at least one damper (<NUM>) is such that it can adjust its damping resistance between a first damping mode and at least a second damping mode, wherein the at least second damping mode presents a larger damping resistance than a damping resistance of the first damping mode, and with at least one sensing element of the vehicle (<NUM>), and with an electronic control unit (<NUM>) being in communicative contact with the damper (<NUM>), wherein the electronic control unit (<NUM>) is configured to receive at least one signal from the at least one sensing element,
characterized in that said method comprising:
- the electronic control unit (<NUM>) performing a step of identifying if the vehicle (<NUM>) is in a first situation during driving of said vehicle (<NUM>) which will lead to a subsequent impact force (F) on the at least one wheel suspension (<NUM>) which is of a magnitude such that the at least one damper (<NUM>), when in its first damping mode, will reach a position where no further damping can be performed by using the information of the sensing element, and wherein the first situation is a situation where at least one side of the vehicle (<NUM>) is airborne, or the complete vehicle (<NUM>) is airborne, wherein the step of identifying comprises using the sensing element to identify that the vehicle has become airborne with a certain altitude above the ground which will lead to that the first damping resistance of the damper (<NUM>) will not be large enough for damping the impact force that the wheel suspension (<NUM>) will be exposed to when touching the ground after the airborne situation; and, if this is the case,
- adjusting the damping resistance from the first damping mode to the at least second damping mode at least before the subsequent impact force (F) impacts the wheel suspension.