Patent Description:
Visual cues on the vehicle's interior panels have been extensively used to convey longitudinal motion. For example, patent document <CIT> relates to a lighting device having dynamic lighting effects to simulate the scrolling of the road inside a vehicle passenger compartment and aiming to restore a sensation of speed to the occupants of the vehicle. However, visual cues, as well as audio cues, are not fully effective as visual attention may be engaged elsewhere in an activity.

Haptic feedback has also been used to communicate navigational cues to the driver. <CIT>, <CIT> and <CIT> disclose examples of vehicles with haptic systems. However, existing systems do not allow conveying information to the occupants of the vehicle in an optimal manner, in particular in case of changes in vehicle travel, which can decrease passenger comfort. Therefore, there is a need for a new system for informing an occupant of a vehicle of upcoming changes in vehicle travel.

In order to at least substantially remedy the above-mentioned drawbacks, the present invention relates to a system for informing an occupant of a vehicle of upcoming changes in vehicle travel using haptic feedback, the system as defined in claim <NUM> comprising:.

An occupant of a vehicle is a person sitting in the passenger compartment, which is a compartment of the vehicle in which any occupant, including the driver and/or non-driving passengers, is supposed to travel.

In a known manner, a driving-assistance system is an electronic device using automated technology that assists drivers in driving and parking functions for increasing car and road safety, by way of sensors and cameras. Thus, it is understood that the present invention relates to a situation in which longitudinal driving-assistance system is on, such as intelligent speed assistance or adaptive cruise control. In other words, the change in vehicle travel is not initiated by the driver, but by the driving-assistance system.

It is understood by "haptic feedback" that the seat motor, in particular the actuators disposed within the seat are tactile actuators involving movements such as vibrations that the occupant sitting on the seat can physically feel, thus conveying information to the occupant.

The acceleration information is information about the acceleration of the vehicle in which the system is mounted. The acceleration information includes at least a direction or a magnitude of the vector representing this acceleration. As used herein, acceleration is a generic term including acceleration strictly speaking (i.e. positive acceleration) as well as deceleration (i.e. negative acceleration), in any direction, including longitudinal (forwards or backwards) or lateral (towards right or left) directions or a combination thereof. Generally speaking, acceleration is the derivative of speed.

In case of predetermined speed for example, input in the driving-assistance system, the driving-assistance system will trigger acceleration, for example after a break, in order to reach the predetermined speed. According to the present invention, based on the knowledge of the upcoming acceleration, the control unit actuates the seat motor prior to the actual start of the acceleration.

Thus, the cue, in particular the haptic feedback, is activated before the vehicle's acceleration which allows the occupant (the driver or a passenger), to prepare for the effect of G-force. In addition, the sequential actuation of the actuators allows to form patterns that can be adapted according to the information received by the control unit, for example the strength or the direction of the acceleration. Therefore, patterns can be used to intuitively and accurately present information regarding upcoming acceleration or other changes in vehicle travel.

The present invention thus allows improving vehicle occupant comfort, by efficiently assisting the occupant to anticipate and to take remedial action upon the activation of haptic cue, for example by adapting its position in the seat. Haptic feedback can also decrease cognitive demand in navigation. Additionally, haptic cue that reflects the vehicle's longitudinal motion (acceleration) may reduce motion sickness.

Preferably, the control unit is configured to actuate the seat motor <NUM> to <NUM> seconds (s) before change in vehicle travel starts. This allows improving timing and giving to the occupant just the time necessary to anticipate and to take remedial action upon the activation of haptic cue before the change in vehicle travel starts.

Preferably, the seat motor is disposed within at least one of the seat cushion or the seat back.

Preferably, each row of the plurality of rows comprises at least two actuators. Preferably, a row is an arrangement in which the actuators that composed the row are aligned in a width direction of the seat, which is a width direction of the vehicle in which the seat is mounted. A row may include two, three or more actuators. This arrangement allows applying tactile feelings to the occupant on a wider region of the seat, so that the occupant can obtain a more perceptive haptic feedback. The system's efficiency is thus improved.

Preferably, the rows are disposed one behind the other in the seat in a front-rear direction of the vehicle in which the seat is mounted. It is to be noted that when the actuators are disposed in the seat back (in place or in addition to the seat cushion), the front-rear direction corresponds to the bottom-up direction of the seat back. In other words, when the actuators are disposed both in the seat back and in the seat cushion, a front end of the seat in the front-rear direction corresponds to a front portion of the seat cushion, while a rear end corresponds to an upper portion of the seat back. Thus, a first row may be disposed at the front end, while second and subsequent rows are disposed behind the first row in the front rear direction, until the last row which may be disposed at the rear end of the seat, the rows being parallel to each other.

Preferably, the actuation of a row involves the simultaneous actuation of each of the actuators constituting the row. Thus, a pattern may correspond to the successive actuation of the rows, from the first row to the last row in the front-rear direction. In addition, haptic feedback may include between <NUM> to <NUM> patterns. This allows further improving the tactile perception felt by the occupant, thereby improving efficiency of the system.

Preferably, an actuation of each row is maintained constant for duration comprised between <NUM> and <NUM>.

Preferably, the actuators of the seat motor are vibration motors disposed within a seat back and/or a seat cushion of the seat of the vehicle. In case of several rows disposed one behind the other, the vibrations patterns can be recognized and understood by the occupant(s) in order to allow the occupant(s) to prepare mentally and physically to the change of motion, for example to the acceleration.

Preferably, the actuators of the seat motor are moving parts disposed within a seat back of the seat of the vehicle and configured to provide back pushes on the occupant through displacement of the moving parts and towards back of the occupant. Back pushes are realised by displacement of the moving parts located within the seat back towards the occupant's back, a maximal displacement being for example <NUM>. Back pushes can create a reflex response allowing the occupant to optimise his/her back posture to minimise discomfort during acceleration.

Preferably, the control unit is configured to allow the occupant to adjust the intensity of the haptic feedback. The system may include an interface connected to the control unit, the interface being controllable by the occupant to allow the occupant to adjust the intensity of the haptic feedback, for example the intensity of the vibrations.

The present invention also relates to a vehicle comprising such a system.

The present invention also relates to a method for informing an occupant of a vehicle of upcoming acceleration or deceleration of the vehicle using such a system, the method as defined in claim <NUM> comprising receiving acceleration information about an upcoming acceleration or deceleration of the vehicle and sequentially actuating the actuators of the seat motor with a pattern that is determined on the basis of the acceleration information received to provide haptic feedback to the occupant prior to the acceleration or deceleration of the vehicle, wherein the acceleration information received has a direction and a magnitude, and wherein a direction of actuation of the rows when the acceleration information is positive acceleration is opposite to a direction of actuation of the rows when the acceleration information is negative acceleration.

The acceleration information received by the control unit from the driving-assistance system may include information about the acceleration vector, in particular the direction of the vector and/or its amplitude. On the basis of this information, the control unit actuates sequentially the actuators with a pattern allowing the occupant to intuitively understand, through the haptic feedback, the information prior to the acceleration. For example, if the upcoming acceleration is small, the actuators may be actuated successively slowly, and if the upcoming acceleration is strong, the actuators may be actuated successively quickly. Alternately, the intensity and/or duration of vibrations in case of vibrating actuators, or the amount of displacement in case of moving parts, may be adapted by the control unit according to the strength of the acceleration. In this sense, preferably, the intensity of the haptic feedback is correlated to the strength of the acceleration.

Preferably, the actuators of the seat motor are vibration motors and the actuating of the seat motor comprises sequentially activating the vibration motors with a pattern that is determined on the basis of at least one of strength or of the acceleration information.

The upcoming acceleration is acquired by the driving-assistance system and provided to the control unit. The control unit thus modulates the pattern of actuation of the vibration motors, on the basis of a magnitude and/or a direction of the upcoming acceleration of the vehicle. In other words, the direction of the upcoming acceleration (upcoming acceleration vector) may be used to determine the manner the motors and the rows have to be successively actuated (for example the right motors of each row if the acceleration vector is directed toward right), and the magnitude of the upcoming acceleration (upcoming acceleration vector) is used to determine the intensity of the vibrations. Therefore, the system provides to the occupant an accurate and intuitive representation of the upcoming acceleration of the vehicle.

Preferably, the pattern is a wave-like vibration pattern. If haptic feedback comprises four patterns for example, four successive wave-like vibration patterns will be produced, each wave-like vibration pattern comprising the successive activation of the rows of actuators disposed within the seat. The intensity and/or the speed of the wave-like vibration pattern may be adjusted according to the strength of the upcoming acceleration. Wave-like vibration pattern provides to the occupant a more accurate and intuitive representation of the upcoming acceleration of the vehicle.

Preferably, the actuators of the seat motor are moving parts, and the actuating of the seat motor comprises sequential displacement of the moving parts towards the occupant's back to provide back pushes to the occupant, with a pattern that is determined on the basis of at least one of strength or timing of the acceleration information.

Preferably, the seat motor is actuated <NUM> to <NUM> before acceleration or deceleration of the vehicle starts.

Not according to the present invention, there may be a recording medium readable by a computer and having recorded thereon a computer program including instructions for executing the steps of the above described method. The recording medium can be any entity or device capable of storing the program. For example, the medium can include storage means such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or magnetic storage means, for example a diskette (floppy disk) or a hard disk.

Alternatively, the recording medium can be an integrated circuit in which the program is incorporated, the circuit being adapted to execute the method in question or to be used in its execution.

The invention and advantages thereof will be better understood upon reading the detailed description which follows, of embodiments given as non-limiting examples. This description refers to the appended drawings, wherein:.

A vehicle <NUM> comprising a system <NUM> according to the present invention is shown in <FIG>. The vehicle <NUM> is a car with a driving-assistance system <NUM>. The vehicle may be also an automotive vehicle. The vehicle has a vehicle passenger compartment <NUM>, in which at least one occupant, such as a driver or a non-driving passenger, may travel. The vehicle <NUM> comprises seats <NUM> (for example driver's seat in <FIG>) disposed inside the vehicle passenger compartment <NUM>, in which an occupant can sit. Each seat <NUM> comprises a seat cushion <NUM> and a seat back <NUM>.

A front-rear direction corresponds to a front-rear direction of the vehicle <NUM>, and an up-down direction corresponds to an up-down direction of the vehicle <NUM>.

The vehicle <NUM> comprises the system <NUM> according to the present invention, for informing an occupant of the vehicle <NUM> of upcoming acceleration or deceleration of the vehicle using haptic feedback, as will be explained hereafter.

The system <NUM> for a vehicle passenger compartment according to an embodiment is diagrammatically shown in <FIG>. The system <NUM> may be provided in the vehicle <NUM> and be used for the vehicle passenger compartment <NUM>. The system <NUM> comprises the driving-assistance system <NUM> of the vehicle. The driving-assistance system <NUM> allows for example intelligent speed assistance. In this case, the driver input a predetermined speed to the driving-assistance system <NUM>. The driving-assistance system <NUM> thus maintains speed at the predetermined value, by decelerating in case of obstacle (for example another vehicle) in front of the vehicle <NUM>, and by triggering acceleration in order to reach the predetermined speed when the obstacle is gone. It is understood that the driving-assistance system <NUM> comprises sensors (not illustrated) such as cameras mounted on the vehicle <NUM>.

The system <NUM> further comprises a control unit <NUM> configured to receive acceleration information about the vehicle <NUM> from the driving-assistance system <NUM>.

The control unit <NUM> may be an electrical control unit (ECU). The control unit <NUM> may have the hardware architecture of a computer, as diagrammatically illustrated in <FIG>. The control unit <NUM> may comprise a processor <NUM>, a read-only memory (ROM) <NUM>, a random access memory (RAM) <NUM>, a non-volatile memory <NUM> and communications means <NUM> for communicating with other components, such as the seat motor <NUM>, wirelessly or in wired manner.

The ROM <NUM> forms a recording medium that can be read by the processor <NUM> and on which can be recorded a computer program having instructions for executing the steps of a method for informing an occupant of a vehicle of upcoming acceleration, which will be described later on.

The acceleration information received by the control unit <NUM> from the driving-assistance system <NUM> has a direction and a magnitude.

<FIG> is a diagram in which X represents the longitudinal direction, corresponding to the front-rear direction of the vehicle <NUM>, and Y represents the lateral direction, corresponding to the width direction of the vehicle <NUM> which is perpendicular to the front-rear direction. On this diagram, the acceleration information A can be represented as a vector A, the direction of the vector A corresponding to the direction of the acceleration information and the length of the vector corresponding to a quantity associated with the acceleration information, such as the acceleration magnitude.

In <FIG>, positive X represents positive acceleration forwards, e.g. an acceleration when driving forwards or a deceleration when driving backwards. A positive acceleration may be induced by an intelligent speed assistant of the driving-assistance system <NUM> and/or a restart assistant (e.g. when the preceding vehicle moves again in a stop & go traffic, or when a traffic light becomes green). Conversely, negative X represents negative acceleration forwards, e.g. a deceleration when driving forwards or acceleration when driving backwards. A negative acceleration may be induced the intelligent speed assistant, when the preceding vehicle decelerates for example.

Positive Y represents a right turn and negative Y represents a left turn. The actuation of the seat motor <NUM> described hereinafter is made with a pattern determined on the basis of the longitudinal and/or lateral components of the acceleration information. Namely, the acceleration information is decomposed into a longitudinal component Ax and a lateral component Ay. More generally, the control unit <NUM> is configured to determine the pattern on the basis of at least one of a longitudinal component Ax and a lateral component Ay of the direction of the acceleration information A.

The system <NUM> comprises a seat motor <NUM> including a plurality of actuators <NUM> disposed within the seat cushion <NUM> and/or the seat back <NUM>. In a first example of the embodiment, the actuators are vibration motors. The vibration motors <NUM> are arranged within the seat cushion <NUM> and/or the seat back <NUM> in rows R1-Rn, n being a natural number greater than or equal to <NUM>, a row Rn comprising at least two vibration motors <NUM>. The vibration motors <NUM> of each row Rn are aligned with each other in the width direction of the vehicle <NUM>. In addition, the rows Rn are spaced from each other in the front-rear direction of the vehicle <NUM>. More specifically, the rows disposed in the seat cushion <NUM> are spaced from each other in the front-rear direction of the vehicle <NUM>, and the rows disposed in the seat back <NUM> are spaced from each other in the up-down direction of the vehicle <NUM>.

<FIG> represent different examples of arrangements of the vibration motors <NUM> within the seat. In <FIG>, the system <NUM> comprises three rows R1-R3 of vibration motors <NUM> disposed within the seat cushion <NUM>, each row comprising two vibration motors <NUM>. In <FIG>, the system <NUM> comprises a single row R1 of vibration motors <NUM> disposed within the seat back <NUM>, the row R1 comprising three vibration motors <NUM>. In <FIG>, the system <NUM> comprises five rows R1-R5 of vibration motors <NUM>, three rows R1-R3 being disposed within the seat cushion <NUM> and comprising two vibration motors <NUM>, and two rows R4-R5 being disposed within the seat back <NUM>, a first row R4 comprising three vibration motors <NUM> and a second row R5 comprising two vibration motors <NUM>. Disposing three vibration motors <NUM> instead of two in row R4, corresponding to a lumbar region of the occupant sitting in the seat <NUM> which may be more sensitive than other regions, allows improving tactile perception of the occupant, thereby improving efficiency of the transmission of information.

Upon receiving information from the driving-assistance system <NUM> about an upcoming acceleration, the control unit <NUM> controls the seat motor <NUM> by sequentially actuating the vibration motors <NUM> with a pattern that is determined on the basis of the acceleration information received by the control unit <NUM> to provide haptic feedback to the occupant, prior to the effective start of the acceleration, preferably between <NUM> and <NUM> sec before the acceleration starts.

<FIG> represents, according to the present invention, an embodiment of vibration pattern to convey information about the upcoming acceleration, on the basis of the arrangement of the vibration motors <NUM> illustrated in <FIG> comprising five rows R1 to R5. In this example, the control unit <NUM> sequentially actuates the rows, from the first row R1 disposed in a first end, which is in a front end region of the seat cushion <NUM>, to the fifth row R5 disposed in a second end, which is in an upper end region of the seat back <NUM>. More generally, the control unit <NUM> sequentially actuates the rows, from the first row R1 to the last row Rn, where n is the number of rows. The arrows in <FIG> represent a direction of actuation of the rows from R1 to R5, in case of positive acceleration (positive X). However, the direction of actuation of the rows is from R5 to R1 in case of negative acceleration (negative X), in other words in case of upcoming deceleration.

In this example, the actuation of a row means the simultaneous actuation of the vibration motors <NUM> composing the row. In the arrangement of <FIG> for instance, the actuation of the fourth row R4 means the actuation of the three vibration motors <NUM> composing this row. However, this example is not limitative, and the pattern may differ depending on the acceleration information received by the control unit <NUM>, in particular on the basis of at least one of strength or timing of the acceleration information.

For example, in case the acceleration vector A presents positive Y (<FIG>), representing a right turn, the control unit <NUM> may actuate only the vibration motor <NUM> disposed furthest to the right of each row in the width direction of the vehicle <NUM>. In the same manner, in case the acceleration vector A presents negative Y, representing a left turn, the control unit <NUM> may actuate only the vibration motor <NUM> disposed furthest to the left of each row in the width direction of the vehicle <NUM>.

Furthermore, in case of an acceleration vector A with a high magnitude, meaning a high strength of the upcoming acceleration, the control unit <NUM> may accelerate the sequential actuation of the vibration motors <NUM>, that is reducing the time lapse between the actuation of two successive rows, and/or actuate each row with a higher intensity of vibrations. In the same manner, in case of an acceleration vector A with a low magnitude, meaning a low strength of the upcoming acceleration, the control unit <NUM> may slow down the sequential actuation of the vibration motors <NUM>, that is increasing the time lapse between the actuation of two successive rows, and/or actuate each row with a lower intensity of vibrations.

In other words, patterns are determined by the control unit <NUM> to intuitively and accurately present information to the occupant regarding upcoming acceleration or other changes in vehicle travel.

In a method for informing an occupant of a vehicle of upcoming acceleration using the system <NUM>, the control unit <NUM> firstly receives information from the driving-assistance system <NUM> about an upcoming acceleration of the vehicle <NUM>, and secondly sequentially actuates the vibration motors <NUM> of the seat motor <NUM> with a pattern that is determined on the basis of the information received to provide haptic feedback to the occupant prior to the acceleration.

<FIG> represents the variation of the intensity of vibrations during a pattern as a function of time T, in a case of a system <NUM> comprising two rows R1 and R2 of vibration motors <NUM>. In a time lapse between <NUM> and <NUM> sec before the acceleration starts, and after receiving information from the driving-assistance system <NUM>, the control unit <NUM> actuates the first row R1 at a time t<NUM>. The slope S, which is the time for the vibration motors <NUM> of the row R1 to reach a maximum intensity of vibrations M from t<NUM> is between <NUM> and <NUM>. Once the maximum intensity of vibration M has been reached at time t<NUM>, the first row R1 then remains constant at this maximum intensity of vibration M during a time lapse between <NUM> and <NUM>, until time t<NUM>. Then, the vibration of row R1 decreases from t<NUM> to t<NUM>.

The second row R2, which is disposed behind the first row R1 in the front-rear direction of the vehicle <NUM>, is then actuated by the control unit <NUM> at time t<NUM>, and follows the same variation as the first row R1. An inter-delay I, between the end of the actuation of R1 and the actuation of R2, namely between t<NUM> and t<NUM>, is between <NUM> and <NUM>. The pattern is finished when the second row R2 is deactivated at time t<NUM>.

The amount of pattern loops, that is the number of time the above described pattern is realized, may be between <NUM> and <NUM>, depending on the number of rows and on the timing when the acceleration starts. For example, when the system <NUM> comprises one or two rows as described above, the actuation process may include four loops. On the other hands, when the system <NUM> comprises five rows, the actuation process may include only one loop. When the actuation process includes several loops, a delay L between two patterns, namely between t<NUM> and a new time t<NUM> of actuation of the first row R1, is between <NUM> and <NUM>. In this case, the acceleration information is conveyed via a wave-like vibration pattern.

The control unit <NUM> may determine the above parameters on the basis of the acceleration vector A, while remaining within the above ranges. For examples, in case of an acceleration vector with a high magnitude, the control unit <NUM> may reduce the inter delay I between actuation of two rows, by setting an inter delay I closer to the lower boundary <NUM> of the above range than the upper boundary <NUM>. In the same manner, in case of an acceleration vector with a low magnitude, the control unit <NUM> may increase the inter delay I between actuation of two rows, by setting an inter delay I closer to the upper boundary <NUM> of the above range than the lower boundary <NUM>, or by setting a maximum intensity of vibrations lower than M.

<FIG> represents a second example of the embodiment, wherein the vibrations motors <NUM> are replaced by moving parts <NUM> located within the seat back <NUM>. In this example, moving parts <NUM> are disposed within the seat back <NUM>, at a region of the chest back of the occupant, and at a lumbar region of the occupant. In this case, the control unit <NUM> is configured to sequentially actuate the moving parts <NUM> to cause displacement of the moving parts <NUM> towards the occupant's back to provide back pushes to the occupant. The moving parts <NUM> are actuated by the control unit <NUM> with a pattern that is determined on the basis of at least one of strength or timing of the acceleration information, in the same manner as with the vibration motors <NUM>. For example, the motor located at the lumber region of the occupant may include several moving parts <NUM> in a row, and the actuation of these moving parts <NUM> (actuation of the moving part disposed furthest to the right or to the left, or amount of displacement of the moving part) may depend on the direction and/or the magnitude of the acceleration vector A.

In this example, the moving parts <NUM> are also actuated <NUM>-<NUM> before acceleration starts. A maximum displacement of the moving parts <NUM> may be <NUM>, and a total duration of a pattern is lower than <NUM> sec. It is to be noted that although the actuation of the moving parts <NUM> (in the same manner as for the vibration motors <NUM>) starts <NUM>-<NUM> before acceleration starts, the pattern, or the following patterns when the process includes several loops, may overlap the beginning of acceleration. The fact that the actuation of the seat motor <NUM> starts <NUM>-<NUM> before acceleration starts allows the occupant (driver or passenger) to anticipate the acceleration.

The system <NUM> may also allow the occupants of the vehicle <NUM> to control parameters of the seat motor <NUM>, for example for adjusting the intensity of the haptic feedback, for instance the intensity of the vibrations, namely the maximum intensity M of vibrations of the vibration motors <NUM>, or the maximum displacement of the moving parts <NUM>. In view of that, the system <NUM> may comprise an interface, such as an in-vehicle interface <NUM>, or a remote interface <NUM> such as a smartphone application. The interface may be a graphical user interface (GUI).

Claim 1:
A system (<NUM>) for informing an occupant of a vehicle (<NUM>) of upcoming acceleration or deceleration of the vehicle using haptic feedback, the system comprising:
- a seat motor (<NUM>) comprising a plurality of actuators (<NUM>, <NUM>), that is configured to be disposed within a seat (<NUM>) of the vehicle and to provide haptic feedback to the occupant,
- a driving-assistance system (<NUM>), and
- a control unit (<NUM>) configured to receive acceleration information from the driving-assistance system (<NUM>) about upcoming acceleration or deceleration of the vehicle and to control the seat motor (<NUM>), wherein the control unit (<NUM>) is configured to sequentially actuate the actuators (<NUM>, <NUM>) of the seat motor (<NUM>) with a pattern that is determined on the basis of the acceleration information received by the control unit (<NUM>) to provide haptic feedback to the occupant prior to the acceleration or deceleration of the vehicle, the system comprising a plurality of rows of actuators (<NUM>, <NUM>), wherein the control unit (<NUM>) is configured to actuate successively each row in sequence, a pattern comprising one actuation of each of the rows, characterized in that the acceleration information received by the control unit (<NUM>) from the driving-assistance system (<NUM>) has a direction and a magnitude, and in that a direction of actuation of the rows when the acceleration information is positive acceleration is opposite to a direction of actuation of the rows when the acceleration information is negative acceleration.