Apparatus and method to simulate driving a land vehicle

Abstract

Apparatus (10) and method to simulate driving a land vehicle, wherein the apparatus comprises a chassis (11; 27) enclosing a cockpit (13; 23) for accommodating the driver and comprising a seat (S), a heel plate (H) and a steering wheel (SW); a plurality of actuators (16; 35) for moving the cockpit (13; 23) and 5 a plurality of shakers (45, 46, 47) connected to the seat (S), the heel plate (H) and the steering wheel (SW) for making them vibrate, wherein the actuators (16; 35) and the shakers (45, 46, 47) are controlled by a control unit (60) that move them according to a different motion frequency range.

Description

[0001] “APPARATUS AND METHOD TO SIMULATE DRIVING A LAND VEHICLE”

[0002]

[0003] FIELD OF THE INVENTION

[0004] The present invention concerns an apparatus and a method to simulate driving a land vehicle such as a car, a sports car, a bus, a truck or suchlike.

[0005] In particular, the apparatus and the method according to the invention are able to simulate the driving conditions of the vehicle by reproducing the best possible perception, i.e., a perception that is as much realistic as possible, of multi-sensorial inputs to the driver’s body.

[0006] The apparatus of the present invention can be configured as a multi-attribute driving simulator able to manage the full spectrum of vehicle dynamics, that is the ability to simulate handling, ride and noise-vibration-harshness (NVH) of the vehicle.

[0007] BACKGROUND OF THE INVENTION

[0008] Apparatuses are known for simulating driving land vehicles, which comprise a main chassis to which a seating element for the driver, command means that can be actuated by the user, such as a steering wheel, brake, clutch and accelerator pedals, and a projection screen onto which the driving environment is projected in which the driver is immersed during the simulation are associated.

[0009] In one solution known in the art, described in the International Patent application WO 2013 / 114179 of the same Applicant, there are provided a mobile platform carrying the main chassis and a fixed platform having a flat surface on which the mobile platform is positioned resting and sliding thereon. Linear actuators are connected to the fixed platform and the mobile platform to determine a sliding movement of the latter on the fixed platform. On top of the base sliding platform, six additional actuators move the vehicle cabin in six degrees of freedom relative to the base sliding platform. The combination of movements given by the linear actuators move the main chassis in space both by translating it along the three coordinate axes, and also by providing rotations around said axes so as to provide six degrees of freedom.

[0010] In another solution known in the art, described in the International Patent application WO 2017 / 021323 of the same Applicant, the mobile platform is movedby a plurality of cables, constrained to the mobile platform on one side and to respective actuators to move the cables on the other side. In this case the cables move the mobile platform on a sliding planar surface both by translating it along the two coordinate axes X and Y, and also by providing rotation around the axis normal to the sliding planar surface. On the top of the mobile platform, six additional actuators move the vehicle cabin in six degrees of freedom relative to the base sliding platform.

[0011] Regardless the platform is actuated by linear actuators or cables, both these known solutions allow to simulate accurate motion of the vehicle chassis, in order to reproduce the motions of a land vehicle, but are not designed to accurately simulate vibrations and sounds in a maimer that is faithful to a real vehicle.

[0012] Other solutions known in the art relate to so called “compact” simulators in which the chassis is fixed to the floor and the simulator is able to reproduce vibrations at all driver’s touchpoints together with sound but with no overall motion.

[0013] A real vehicle generates and transmits high frequency vibrations through tireroad contact, engine vibrations, air flows, etc.: each source of vibration is reasonably well isolated from all human body contacts, depending on the subsystem quality of the vehicle.

[0014] However, it is very difficult for the apparatuses known in the art to reproduce realistic vibrations coming from different sources because such vibrations are perceived by the driver with different amplitude, frequency and phase on each contact point between the driver’s body and the corresponding vehicle’s part, such as seat, heel plate and steering wheel.

[0015] It should be kept in mind that the displacement of typical contact point acceleration amplitudes during normal driving are very small.

[0016] In the solutions known in the art the cockpit is a stiff structure moved by a main actuator as a quasi-rigid body to which high frequency vibrations are provided as a broadband of random excitation, coming from accurately laser scanned road surfaces. These are then possibly mixed with occasional rather harsh multifrequency impacts to simulate road irregularities.

[0017] One disadvantage of the solutions known in the art is that typically the motion platform (designed to be rigid to have fast response) behave often like a “tuningfork” (due to the need to have a stiff and fastly reactive system) and the cockpit is excited with the natural frequencies of the electro-mechanical chain instead of the desired frequencies of the vehicle to be simulated.

[0018] Disadvantages of the solutions known in the art are listed below:

[0019] 1. it’s difficult for the main actuators to bring the high frequency vibrations correctly to the human body contact points, especially considering also the excitation of cockpit structural resonances;

[0020] 2. the vibrations are transmitted to the cockpit via different mechanisms than the real vehicle, and the effects at the contact points are completely different than those on target simulated vehicle;

[0021] 3. the high energies needed at the frequencies mentioned above, due to the high inertias of the motion platform components, necessarily bounce around the installation infrastructure in an uncontrollable way, destroying any accurate possible vibro-acoustic calibration done on board the vehicle chassis;

[0022] 4. in the indicated frequency range, the signal is polluted by the complexity of the mechanical chain connecting the main actuators, the quasi-rigid body and the performance of the control system, resulting in challenging frequency response function (FRFs) and unrealistic cross talks (undesired contribution of vibration along non excited axis) between the contact points. In the automotive field there is the need for the development engineers engaged in vehicle’s design to experience handling, ride comfort, NVH and all other characteristics of a vehicle at once to truly assess and understand the data and what the vehicle will feel and sound like once built, like is done in real tests.

[0023] Since making a physical prototype for each new vehicle’s models is very lengthy and costly, car makers are looking for a single apparatus and method to simulate the whole vehicle dynamics in a realistic immersive driving experience that is comparable to that of real vehicles.

[0024] In this maimer the development engineers could have a virtual prototype that can be considered a “digital twin” of the real vehicle to faithfully anticipate the real experience perceived by the driver. In absence of the physical prototype, thanks to the apparatus and method of the invention it will be possible to take on time tough decision with a high degree of confidence that such decisions arecorrect.

[0025] Purpose of the present invention is to provide:

[0026] 1. an apparatus and a method to simulate driving a land vehicle which would allow the best realistic perception of multi-sensorial inputs to the driver body in all the frequency spectrum a real vehicle is subjected to.

[0027] 2. an apparatus and a method able to accurately simulate using the same model and at the same time all features relative to handling, ride and noisevibration-harshness (NVH) of the vehicle.

[0028] 3. an apparatus comprising contact points, as the steering wheel column, the heel plate and the seat (and potentially other, such as elbow rest) which are designed so that they can be at the same time source and target of controllable, realistic and correctly phased high frequency vibrations, delivering high fidelity inputs to all human body contact points.

[0029] 4. an apparatus and a method able to minimize the latency so as to improve the acceptance of the virtual environment and reduce cyber motion sickness, where the term latency means the delay between the command given by the simulation computer and the time in which the related movement is measured by accelerometers mounted on target vibration surfaces.

[0030] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0031] SUMMARY OF THE INVENTION

[0032] The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

[0033] In accordance with the above purposes, and to resolve the technical problem disclosed above in a new and original way, also achieving considerable advantages compared to the state of the prior art, an apparatus to simulate driving a land vehicle is provided according to the present invention which comprises a chassis enclosing a cockpit for accommodating the driver comprising a seat, a heel plate and a steering wheel.

[0034] According to one aspect of the invention, the apparatus comprises a plurality of actuators supporting the cockpit to allow the rotation of said cockpit around tworotation axes respectively parallel to a first direction and a second direction and the translation of said cockpit in a third direction, wherein the first direction and the second direction are perpendicular with respect to one another and the third direction is perpendicular to both the first and second directions.

[0035] According to one aspect of the invention, the apparatus comprises a plurality of shakers connected to the seat, the heel plate and the steering wheel for making them vibrate.

[0036] According to one aspect of the invention, the apparatus comprises a control unit to command in a coordinated maimer said actuators for moving the cockpit and said shakers for vibrating said seat, heel plate and steering wheel according to a different motion frequency range.

[0037] According to one embodiment of the invention, the cockpit is fixed on a support base mounted on a mobile platform through the interposition of a kinematic mechanism having six degrees of freedom. Said kinematic mechanism comprises said actuators, embodied as a plurality of connecting rod-crank mechanisms connected to respective motors mounted inside the mobile platform and further comprises a plurality of inextensible rigid rods, each connected with a first lower end thereof to a corresponding one of the connecting rod-crank mechanisms, and with an opposing second upper end to the support base by means of respective first and second joints. The rigid rods are supported sliding, in correspondence with their first joints, on linear guide means that are mounted on the mobile platform. The mobile platform is disposed above a fixed base platform and provided with sliding means associated with the mobile platform and configured to allow said mobile platform to slide on a support surface of said fixed base platform. According to one aspect of the invention, the apparatus comprises drive members for translating said mobile platform on said support surface in said first direction and in said second direction, and for rotating the mobile platform around said third direction.

[0038] The present invention also concerns a method to simulate driving a land vehicle using an apparatus according to the present description.

[0039] According to one aspect of the invention, the method provides the control unit to command said actuators so as to translate said cockpit in said third direction and to rotate around two rotation axes respectively parallel to said first direction andsaid second direction.

[0040] According to one aspect of the invention, the control unit commands the shakers to vibrate the seat, the heel plate and the steering wheel in a maimer that is coordinated with the command of the linear actuators so that the linear actuators move the cockpit and the shakers vibrate said seat, heel plate and the steering wheel according to a different motion frequency range.

[0041] One advantage of the apparatus and method of the present invention is given by the fact that there is a customizable separation between each couple of ride-handling-NVH characteristic features thanks to the fact that the various parts of the apparatus are subjected to vibrations belonging to different frequency range. Another advantage of the apparatus and method of the present invention is that of obtaining the high-frequency vibrations at each driver’s contact point (seat, heel plate, steering wheel) minimizing the energy to be delivered at each contact point. This is obtained by demanding the vibrations at high frequency only to shakers which are placed close to the respective contact points so as to avoid to subjecting the whole apparatus to these frequencies which could instead create problem of resonance of the structure and of delay due to an increased latency in view of the great masses and inertia of the whole apparatus. In this manner the other part of the apparatus, as the mobile platform and the kinematic mechanism mounted thereon, are not affected by the high-frequency vibrations with a beneficial effect both on their structure making easier to control their movement.

[0042] The cockpit can be made of a carbon fiber material to be very much lighter and stiffer than cockpits usually known in the art.

[0043] Providing shakers close and connected to each driver’s contact point allows little energy to be required to reproduce the tiny displacements determined by the vibration common in a real vehicle.

[0044] Another advantage of the apparatus and method according to the invention is that of covering a full spectrum of frequencies so that the driver can experience a full six degree of freedom motion together with images, sounds and vibrations reproducing faithfully those of a real vehicle allowing the best realistic perception of multi-sensorial inputs to the driver.

[0045] Another advantage of the apparatus and method according to the invention is that of providing calibrated, phase related vibration at the driver’s contact pointsin conjunction with calibrated audio, and the necessary visual cues to provide the right degree of anticipation of any coming stimuli.

[0046] BRIEF DESCRIPTION OF THE DRAWINGS

[0047] These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0048] - fig. 1 is a schematic perspective view of a first embodiment of an apparatus to simulate the driving of a land vehicle according to the present invention;

[0049] - fig. 2 is a schematic perspective view of a second embodiment of an apparatus to simulate the driving of a land vehicle according to the present invention;

[0050] - fig. 2A is a schematic perspective view of a kinematic mechanism comprised in the apparatus shown in fig. 2;

[0051] - fig. 3 is a block diagram showing some parts of the apparatus of fig. 2, which are enlarged and schematically exploded;

[0052] - fig. 4 is a schematic perspective view of an enlarged detail of the cockpit’s inside; - figs. 5 to 8 are schematic perspective views of enlarged details of the cockpit; - fig. 9 is a block diagram showing a method to simulate driving a land vehicle according to the present invention.

[0053] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

[0054] DETAILED DESCRIPTION OF SOME EMBODIMENTS

[0055] With reference to fig. 1, a first embodiment of an apparatus to simulate driving a land vehicle, according to the present invention, is indicated in its entirety by the reference number 10, and comprises a chassis 11 enclosing a cockpit 13 and resting on the floor through four telescopic moving actuators 16. The inside the cockpit 13, best shown in fig. 4, comprises a seat S for the driver, a pedal structure H comprising the accelerator, brake and clutch pedals, overall indicated with reference letter P, and a steering wheel SW.

[0056] The cockpit 13 comprises a gear lever GL placed next to the seat S and a dashboard D placed behind the steering wheel S W.

[0057] The chassis 11 could be made in composite carbon fiber and specially designedto be much lighter than chassis used in the prior art, with significantly lower inertia. The chassis structure has a much lower center of mass than a reference chassis. The chassis 11 can have a structural stiffness to guarantee the lowest free frequency mode of vibration to be higher than the maximum frequency excitation of the motion platform which the chassis 11 is mounted on.

[0058] Thanks to these structural features the chassis 11 could transmit the whole vehicle motions subjected to motion cueing filtering, and to support at the same time the mechanical components present in the cockpit 13, such as the seat S the heel plate H and the steering wheel SW together with the associated shakers, allowing control of extremely small displacements thereof whilst vibrating.

[0059] The apparatus 10 comprises a plurality of chassis actuators for selectively moving the chassis 11 according to three degrees of freedom.

[0060] In the exemplary embodiment of fig. 1 the chassis actuators comprise four linear actuators 16, as piston-cylinder assembly actuated through pneumatic or hydraulic or electric force. The chassis 11 is connected to ground by means of the linear actuators 16, each one of the latter being placed at a respective comer of the chassis 11.

[0061] The three movements that can be obtained by the linear actuators 16, in the real solutions attributed to the kinematics of suspensions of the vehicles, allow to simulate pitching and rolling and vertical movement by translating along the actuator’s axes.

[0062] In particular, the linear actuators 16 allow to translate the cockpit 13 along the vertical direction Z.

[0063] Selectively commanding the linear actuators 16 to carry out different stroke from one another results in a movement of the chassis 11 that simulate pitching and rolling of the vehicle. This movement is a combination of rotations around directions X and Y, which lye horizontal and form a Cartesian tern with vertical direction Z.

[0064] By way of non-limiting example, the kinematic mechanism can allow to translate the cockpit 13 by a stroke depending on the actuator translational limits along the vertical direction Z and to consequently and independently rotate the cockpit 13 (both clockwise and counterclockwise) around both the pitching and rolling rotation axes.With reference to fig. 2, a second embodiment of an apparatus to simulate a driving a land vehicle, according to the present invention, is indicated in its entirety by the reference number 20, and comprises a fixed base platform 21, a mobile platform 22, and a cockpit 23 that is mounted on the mobile platform 22.

[0065] In this embodiment the cockpit 23, that can be the same as the cockpit 13 described above with reference to fig. 4, can be enclosed by a chassis 27 that could be made in composite carbon fiber and that can be specially designed according to the features described above with reference to the chassis 11 of the first embodiment of the invention.

[0066] The mobile platform 22 is positioned and selectively movable on a flat support surface 24 of the base platform 21.

[0067] The support surface 24 defines a movement space that delimits the space inside which the mobile platform 22 can move.

[0068] The support surface 24 is suitably finished to allow the mobile platform 22 to slide upon it by means of a combination of air and magnetic bearings.

[0069] The apparatus 20 comprises drive members 28 for moving the mobile platform 22 on the base platform 21.

[0070] The drive members 28 allow both the translation of the mobile platform 22 on the support surface 24, that is, in the horizontal directions X and Y and also its rotation around an axis parallel to the vertical direction Z, that is, orthogonal to the support surface 24. The rotation of the mobile platform 22 around the vertical direction Z allows to simulate the yawing of a vehicle.

[0071] With the drive members 28 it is therefore possible to control three degrees of freedom of the mobile platform 22.

[0072] By way of non-limiting example, the mobile platform 22 can be moved along the horizontal directions X and Y.

[0073] By way of non- limiting example, the mobile platform 22 can be rotated around the vertical direction Z.

[0074] In the example described here with reference to fig. 2, the drive members 28 comprises a plurality of cables 30 connected with a first end to the mobile platform 22 and with a second end, opposite the first end, to respective actuation members 31 of the drive members 28 and configured to move the cables 30 whilst keeping them always correctly tensioned and to vary the distance between the connectionzone of the cable 30 to the mobile platform 22 and the connection zone of the cable 30 to the actuation members 31, and to determine a movement of the mobile platform 32 with respect to the base platform 31.

[0075] The actuation members 31 are driven by electric motors 32. Both the actuation members 31 and the electric motors 32 are installed in a fixed position with respect to the base platform 21, for example near the four perimeter comers of the platform as shown in fig. 2, just outside the platform.

[0076] The detailed structure of the mobile platform 22 and the details of the connection between the latter and the cables 30 can be as those described in international patent application published as WO 2017 / 021323 of the same applicant, which is incorporated herein by reference.

[0077] In other embodiments of the invention, not shown, instead of the cables 30 the drive members 28 can comprise linear actuators, as ball-screw electrically driven telescopic actuators.

[0078] The cockpit 23 is fixed to a support base 33 mounted on the mobile platform 22 through the interposition of a movement unit 40 comprising a kinematic mechanism able to give the cockpit 23 a plurality of degree of freedom, in particular six degree of freedom.

[0079] One example of this movement unit is described in the international patent application published under publication number WO 2024 / 105105 of the same Applicant.

[0080] The movement unit 40 allows the cockpit 23 to move both through linear translation and also rotation with respect to three directions to simulate movements called pitch, roll and yaw in the field.

[0081] The kinematic mechanism, as best shown in fig. 2A, comprises six connecting rod-crank mechanisms 35 able to be moved on horizontal movement planes and connected to respective motors, not shown, mounted inside the mobile platform 22.

[0082] The kinematic mechanism further comprises six inextensible rigid rods 34, all having, advantageously but not necessarily, the same length, connected with a first lower end thereof to a corresponding one of the connecting rod-crank mechanisms 15, and with an opposing second upper end to the support base 33 by means of respective first and second joints 36, 37, allow the movement of the support base33 thanks to the motion generated by the motors and transmitted to the connecting rod-crank mechanisms 35.

[0083] According to some embodiments, the first and secondjoints 36, 37 are spherical joints or universal joints.

[0084] The rods 34 are supported sliding, in correspondence with their first joints 36, on linear guide means 38 that are mounted on the mobile platform 22.

[0085] Both the embodiments of the apparatus 10, 20 described above with reference to figures 1 and 2 comprise a plurality of shakers installed in the cockpit 13, 23 that allow to deliver high frequency vibrations to the driver’s contact points. For example, there are provided nine shakers which are distributed in the cockpit 13, 23 to impart high frequency vibrations to the driver’s contact points, as shown in fig. 4, where the shakers associated to different driver’s contact points are indicated with different reference number for the sake of clarity.

[0086] By way of example, the shakers, which can have structures that per se are known in the art, can impart to the driver’s contact points vibrations at frequency comprised between 20 and 200 Hz.

[0087] In the example described here, the driver’s contact points to which the shakers are connected are the seat S, the pedal structure H and the steering wheel SW. The seat S is mounted on seat rails 42, which are secured to a support plate 43, preferably lying in a horizontal plane. The support plate 43 is directly mounted on the four bushing 41, which are for example placed at the four comers of the support plate 43, below the plate (figs. 4-7).

[0088] In this maimer the support plate 43 is mounted on the support base 33 through the bushing 41, which therefore isolate the seat S from the chassis 27.

[0089] There are three shakers 45 connected to the seat S that hang downwards from the support plate 43 (figs. 5 and 7).

[0090] Each of these three shakers 45 connected to the seat S can impart vibrations to the seat S in one of the three directions X, Y and Z so as to confer overall to the seat S the possibility of vibrating in three degrees of freedom.

[0091] The heel plate H is directly mounted on a plurality of bushing 41, which rest in turn on the support base 33. In this manner the heel plate H is mounted on the support base 33 through the bushing 41, which therefore isolate the heel plate H from the chassis 27.There are two shakers 46 connected to the heel plate H that hang below the support plate 43 (fig. 6).

[0092] Each of these two shakers 46 connected to the heel plate H imparts vibrations to the heel plate H in only one of the two directions Y and Z so as to confer overall to the heel plate H the possibility of vibrating in two degrees of freedom.

[0093] The steering wheel SW is mounted on a steering wheel column C to which are associated further four shakers 47 imparting vibrations to the steering wheel SW (best shown in fig. 8). The arrangement of the four steering wheel SW, at 90° from one another gives the steering wheel SW the possibility of vibrating overall in two degrees of freedom one parallel to the direction Y and another one parallel to vertical direction Z.

[0094] The method of the present invention provides to control the phase of one contact point relative to another.

[0095] To obtain this result, it is provided to separate as far as possible the support and actuation systems for each degree of freedom to have the least the least cross-talk / cross-coupling between them.

[0096] Therefore, preferably each of the shakers 45, 46, 47 is dedicated to produce vibrations in only one degree of freedom, namely in only one of the directions X, Y, Z.

[0097] Both the embodiments of the apparatus 10, 20 described here comprises a projection screen 50 and video projection devices (not shown), configured to project onto the projection screen 50 images relating to the environment in which the driver is immersed during the driving simulation.

[0098] The projection screen 50 can be shaped like a semi-spherical shell and is secured on the floor in front of the cockpit 13 in the embodiment of fig. 1 or on the fixed based platform 21 in front of the cockpit 23 in the embodiment of fig. 2.

[0099] In another variant, not shown, the projection screen can be integrated in the chassis 11, 27, for example in correspondence with a windscreen, windows and / or mirrors of the body of the vehicle.

[0100] In still another variant of the embodiment of fig. 2, not shown, the projection screen can be secured on the floor outside the fixed based platform 21.

[0101] Sound reproduction devices are also associated with the projection screen 50 and / or possibly with the video projection device, and are able to reproduce withhigh fidelity the sounds of the vehicle during driving.

[0102] In another variant, not shown, in addition or in alternative to the sound reproduction devices integrated in the projection screen 50, the apparatus 10, 20 may comprises headphones to be worn by the driver.

[0103] The apparatus 10, 20 comprises a programmable control unit 60 (fig. 1 and 2) which controls the independent or synchronized actuation of the shakers 45, 46, 47 and of the linear actuators 16 in the embodiment of fig. 1, or of the motors 32 associated with the actuation members 31 and the actuation members 39 in the embodiment of fig. 2. The command of the control unit 60 can be transferred to the shakers 45, 46, 47 and the motors via cable (as shown in fig. 2) or wireless. Both the video projection device and the sound reproduction device can be managed by the control unit 60 to coordinate the reproduction of both images and sounds in relation to the driving modes set by the driver.

[0104] The control unit 60 implements mathematic algorithms, also known as motion and vibrations cueing algorithms, which allow to render the functioning of the apparatus 10, 20 as much realistic as possible, when it is being driven by an operator.

[0105] An example of how the control unit 60 operates to control the apparatus 10, 20 during the simulation is described below with reference to the block diagram shown in fig. 9, which also reflects an example of a method to simulate driving a land vehicle according to the present invention.

[0106] In particular, some units aimed to provide the parameters related to the simulation of ride and handling features are run through parametric modelling where the model is calculated in real-time from the interaction of a tyre model with a scanned road surface and a suspension and vehicle model above. Other units, aimed to provide the parameters related to the NVH simulation run the calculations off-line using totally different techniques, for example combining test data with CAE data in a hybrid modelling approach, and the pre-calculated database is then used to generate stimuli using real-time synthesis in response to driver inputs. These two data streams are then merged in real-time.

[0107] There is provided a low-frequency modelling unit (block 101) which predict the vehicle behavior at low frequency.

[0108] The low-frequency modelling unit may consider the following parameters:- vehicle running condition as RPM, speed, load (sub-block 101a);

[0109] - external condition as the kind of contact surface type between the road and the tyre (sub-block 101b);

[0110] - the characteristics at the connection between tires and wheel hub (sub-block 101c);

[0111] - the motion of the vehicle (sub-block lOld).

[0112] The low-frequency modelling unit predictions are outputted to the processor unit (block 102), which comprises a processing part (block 103) and a command part (block 104).

[0113] In particular, the low-frequency modelling unit is connected to the corresponding sub-blocks of the processing part 103 of the processor unit 102. In detail, sub-blocks 101a and 101b are meshed together to elaborate corresponding information about the vehicle to be processed in sub-block 103a. Data of sub-block 101c are elaborated to provide information about the vibrations given by the road contribution, see block 103b.

[0114] Parameters related to vehicle motion (sub-block 10 Id) are elaborated to provide corresponding information about the vehicle motion to be simulated (sub-block 103d).

[0115] The information about vehicle motion is then sent to the motion cueing algorithm (sub-block 104b of the command part 104), which command in turn the overall motion of the chassis 11, 27 (block 108e) and the actuation of the seat S and possibly of the seat belts (block 108f).

[0116] It is pointed out that the command obtained by running the motion cueing algorithm includes the command to actuate either the linear actuators 16 in the embodiment of fig. 1 or the motors 32 associated with the actuation members 31 and the actuation members 39 moving the kinematic mechanism described above with reference to the embodiment of fig. 2.

[0117] The information about vehicle motion is sent to the projection screen 50, see block 110.

[0118] There is provided also a NVH simulation unit (block 105) divided in a receiving section (block 106) and a model simulating section (block 107).

[0119] Information elaborated by sub-blocks 103a and 103b of the processing part 103 are sent to the receiving section 106 of the simulation unit 105, which thereforeknows both the vehicle information and the vibration condition to which the vehicle is subjected to (sub-blocks 106a and 106b).

[0120] With these information’s the model simulating section 107 outputs the models according to which the chassis and the driver’s contact points have to behave during the simulation.

[0121] These models are sent in input to sub-blocks 103c (split in one block for the Seat S, one for the steering wheel SW and another for the heel plate H) of the processing part 103 of the processor unit 102 which takes the models and send them to the vibration cueing algorithm, see the block 104a of the command part 104 of the processor unit 102. In possible embodiments, the sub-blocks 103c elaborate the model to impart the necessary adaptations required to match with the vibrations cueing algorithm.

[0122] The vibration cueing algorithm then commands the vibrations of the driver’s contact points, namely of the seat S, of the steering wheel SW and of the heel plate H (see sub-blocks 108a- 108c), by appropriately acting on the shakers 45, 46, 47. In possible embodiments, the vibration cueing algorithm can send different command to each shaker so that the shakers are all independently driven, possibly imparting vibrations at different range of frequencies.

[0123] In other possible embodiments, the vibration cueing algorithm send the same command to a group of shakers 45 or 46 or 47 connected to the same contact point, which can be different from the command sent to another group of shakers 45 or 46 or 47 connected to another contact point.

[0124] There are provided some accelerometers (not shown in the figures) associated to the seat S, the steering wheel SW and the heel plate H, which detects the information about the vibrations of these driver’s contact points and send the corresponding signal as feedback to a shaker tuning sub-block 104c, which is comprised in the command part 104 of the processor unit 102. In this maimer it is possible to tune some operating parameters of the shakers 45, 46, 47, whether the accelerometers detect that they behave differently from the expected behavior based on the command imparted by the vibration cueing algorithm.

[0125] The model simulating section 107 outputs also the model of the audio to be reproduced to the driver during the simulation, which is sent to the sound reproduction device of the apparatus 10, see sub-block 108a.The method according to the invention provides a step of moving the mobile platform 22 and the kinematic mechanism mounted thereon, if present, and the linear actuators 16. The linear actuators 16 in the embodiment of fig. 1 and the motors 32 together with the actuation members 39 in the embodiment of fig. 1 are commanded by the control unit 60 through the motion cueing algorithm, in the maimer explained above with reference to fig. 9.

[0126] This step of moving the mobile platform 22 allow to divide the translation movements in the first direction X and the second direction Y, and the rotation movement around the third direction Z (yaw) of the mobile platform 22 as a function of their characteristic frequency. The same is true for the translation in the third direction Z and the rotations about the pitching and rolling axes and the obtained through the kinematic mechanism.

[0127] In the embodiment of fig. 2, the actuations of the actuation members 39 can be controlled and coordinated with the actuations of the actuation members 31. The combined effect of actuating the both these actuation members 39, 31 allows to obtain minimum latency times, thus guaranteeing high congruency with reality. In this way, this step of moving provides to command the first movement means 28 so that the mobile platform 22 moves with slow movements, characterized by low frequency, for example comprised between 0 and 15 Hz, and at the same time to command the kinematic mechanism to move with rapid movements characterized by medium frequency, up to 30 Hz.

[0128] Similarly, in the embodiment of fig. 1 the linear actuators 16 are commanded to move with rapid movements characterized by medium frequency, up to 30 Hz.

[0129] The method according to the invention provides a step of vibrating at high frequency the shakers 45, 46, 47 connected to the driver’s contact points inside the cockpit 13, 23 namely the seat S, the heel plate H and the steering wheel SW. The method according to the invention provides to reproduce the sound through the sound reproduction device so as to allow the user to perceive both the context sound and the sound related to the contact with the road surface.

[0130] The method according to the invention provides to reproduce a video on the projection screen 50 showing in real time to the driver the view of the surrounding environment during drive.

[0131] It is clear that modifications and / or additions of parts may be made to thesimulation method and apparatus 10, 20 as described heretofore, without departing from the field and scope of the present invention.

[0132] By way of example, in a variant of the embodiment shown in fig. 2, 2 A and 3, the cockpit 23 is directly mounted on the movement unit 40 and the support base 33 is absent.

[0133] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of simulation method and apparatus 10, 20 having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

CLAIMS1. Apparatus (10; 20) to simulate driving a land vehicle comprising a chassis (11; 27) enclosing a cockpit (13; 23) for accommodating the driver comprising a seat (S), a heel plate (H) and a steering wheel (SW); the apparatus (10; 20) further comprising a plurality of actuators (16; 35) supporting the cockpit (13; 23) to allow the rotation of said cockpit (13; 23) around two rotation axes respectively parallel to a first direction (X) and a second direction (Y) and the translation of said cockpit (13; 23) in a third direction (Z), wherein the first direction (X) and the second direction (Y) are perpendicular with respect to one another and the third direction (Z) is perpendicular to both the first and second directions (X, Y), the apparatus being characterized by comprising a plurality of shakers (45, 46, 47) connected to the seat (S), the heel plate (H) and the steering wheel (SW) for making them vibrate and by comprising a control unit (60) to command in a coordinated maimer said actuators (16; 35) for moving the cockpit (13; 23) and said shakers (45, 46, 47) for vibrating said seat (S), heel plate (H) and steering wheel (SW) according to a different motion frequency range.

2. Apparatus (10) as in claim 1, characterized in that said control unit (60) commands said actuators (16) to move with rapid movements having medium frequency, up to 30 Hz.

3. Apparatus (10) as in claim 1 or 2, characterized in that said chassis (11) is supported by said plurality of actuators (16), each one of the actuators (16) being a linear actuator placed at a respective comer of the chassis (11) and being a telescopic moving actuator.

4. Apparatus (20) as in claim 1, characterized in that the cockpit (23) is fixed on a support base (33) mounted on a mobile platform (22) through the interposition of a movement unit (40) comprising a kinematic mechanism having six degrees of freedom.

5. Apparatus (20) as in claim 4, characterized in that said kinematic mechanism comprises said actuators, embodied as a plurality of connecting rod-crank mechanisms (35) connected to respective motors mounted inside the mobile platform (22) and in that the kinematic mechanism further comprises a plurality of inextensible rigid rods (34), each connected with a first lower end thereof to a corresponding one of the connecting rod-crank mechanisms (15), and with anopposing second upper end to the support base (33) by means of respective first and second joints (36, 37).

6. Apparatus (20) as in claim 5, characterized in that the rigid rods (34) are supported sliding, in correspondence with their first joints (36), on linear guide means (38) that are mounted on the mobile platform (22).

7. Apparatus (20) as in any one of claims 4-6, characterized in that said mobile platform (22) is disposed above a fixed base platform (21) and provided with sliding means (25) associated with the mobile platform (22) and configured to allow said mobile platform (22) to slide on a support surface (24) of said fixed base platform (21), and by comprising drive members (28) for translating said mobile platform (22) on said support surface (24) in said first direction (X) and in said second direction (Y), and for rotating the mobile platform (12) around said third direction (Z).

8. Apparatus (20) as in claim 7, characterized in that said drive members (28) comprises a plurality of cables (30) connected at one end to said mobile platform (22) and at the other opposite end to actuation members (31) connected each to a respective motor (32).

9. Apparatus (20) as claim 7 or 8, characterized in that said control unit (60) commands the drive members (28) to move the mobile platform (22) with slow movements having low frequency.

10. Apparatus (10; 20) as in any preceding claim, characterized in that said control unit (60) moves the shakers (45, 46, 47) with high-frequency movements, comprised between 20 and 200 Hz.

11. Apparatus (10; 20) as in any preceding claims, characterized in that said seat (S) is mounted on seat rails (42), which are secured to a support plate (43) directly mounted on a plurality of bushing (41), and by comprising a plurality of shakers (45), in particular three shakers (45), hanging below the support plate (43).

12. Apparatus (10; 20) as in any preceding claims, characterized in that said heel plate (H) is connected to brake, clutch and accelerator pedals (P) and mounted on a plurality of bushing (41), and by comprising a plurality of shakers (46), in particular two shakers (46), hanging below the heel plate (H).

13. Apparatus (10; 20) as in any preceding claims, characterized in that said steering wheel (SW) is mounted on a steering wheel column (C) to which areassociated a plurality of shakers (47), in particular four shakers (47).

14. Apparatus (10; 20) as in any preceding claims, characterized in that each shaker (45, 46, 47) impart vibrations to the seat (S), the heel plate (H) and the steering wheel (S W) in only one of the first, second and third directions (X, Y and Z)- 15. Apparatus (10; 20) as in any preceding claims, characterized in that said plurality of shakers (45, 46, 47) confer overall to the seat (S) the possibility of vibrating in three degrees of freedom, parallel to first, second and third directions (X, Y and Z) and confer both the heel plate (H) and the steering wheel (SW) the possibility of vibrating overall in two degrees of freedom each, parallel to the second and third directions (Y and Z).

16. Apparatus (10; 20) as in any preceding claims, characterized by comprising a projection screen (50) visible from the cockpit (13 ; 23) and video projection device configured to project images onto said projection screen (50) and managed by said control unit (60).

17. Apparatus (10; 20) as in any preceding claims, characterized by comprising a sound reproduction device managed by said control unit (60) to provide the driver both the context sound, which reflect the sounds intrinsically produced by the vehicle during driving simulation, and the external sounds due to the road surface.

18. Method to simulate driving a land vehicle using an apparatus (10; 20) as in any preceding claim, wherein the method provides the control unit (60) to command said actuators (16; 35) so as to translate said cockpit (13; 23) in said third direction (Z) and to rotate around two rotation axes respectively parallel to said first direction (X) and said second direction (Y), and the method is characterized in that the control unit (60) commands the shakers (45, 46, 47) to vibrate the seat (S), the heel plate (H) and the steering wheel (SW) in a maimer that is coordinated with the command of the actuators (16; 35) so that the actuators (16; 35) move the cockpit (13, 23) and the shakers (40) vibrate said seat (S), heel plate (H) and steering wheel (SW) according to a different motion frequency range.

19. Method as in claim 18, characterized in that in said step of moving the cockpit (13; 23) through said actuators (16; 35) is obtained by rapid movements having medium frequency, up to 30 Hz.

20. Method as in claim 18 or 19, characterized in that said mobile platform (12)is moved by the drive members (28) with slow movements having low frequency.

21. Method as in any one of claims 18-20, characterized in that said step of vibrating the seat (S), the heel plate (H) and the steering wheel (SW) comprises actuate the shakers (45, 46, 47) to vibrate at high-frequency, comprised between 20 and 200 Hz.

22. Method as in any one of claims 18-21, characterized in that in said step of vibrating, each shaker (45, 46, 47) imparts vibrations to the seat (S), the heel plate (H) and the steering wheel (SW) in only one of the first, second and third directions (X, Y and Z).

23. Method as in any one of claims 18-22, characterized in that in said step of vibrating said plurality of shakers (45, 46, 47) confer overall to the seat (S) the possibility of vibrating in three degrees of freedom, parallel to first, second and third directions (X, Y and Z) and confer both the heel plate (H) and the steering wheel (SW) the possibility of vibrating overall in two degrees of freedom each, parallel to the second and third directions (Y and Z).

24. Method as in any one of claims 18-23, characterized by comprising a step of projecting a video on a projection screen (50) visible from the cockpit (13; 23) by a video projecting device managed by said control unit (60).

25. Method as in any one of claims 18-24, characterized by comprising a step of reproducing sounds by a sound reproduction device managed by said control unit (60) to provide the driver both the context sound, which reflect the sounds intrinsically produced by the vehicle during driving simulation, and the external sounds due to the road surface.

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