WO2005120874A1

WO2005120874A1 - Control system

Info

Publication number: WO2005120874A1
Application number: PCT/GB2005/002199
Authority: WO
Inventors: Atmane Baroudi
Original assignee: Nissan Motor Manufacturing (Uk) Limited
Priority date: 2004-06-05
Filing date: 2005-06-03
Publication date: 2005-12-22
Also published as: GB2414846A; GB2414846B; GB0511287D0; EP1755910A1; GB0412598D0

Abstract

A control system for a cabriolet or convertible vehicle having a trunk lid (19) which rotates from the front to the rear in order to provide access to a roof storage compartment (18A) comprises sensing means (32) for detecting the presence of an object within a predetermined distance behind the vehicle. If an object is detected within the predetermined distance then the system hinders or prevents movement of the roof (10) and/or the trunk lid (19) so as to prevent the trunk lid from striking the object.

Description

CONTROL SYSTEM

The present invention relates to a control system for a vehicle and particularly, but not exclusively, to a system or apparatus for controlling the operation or movement of a movable part or structure of a vehicle. The invention finds advantageous application in controlling the operation or movement of a retractable or foldable vehicle roof structure. The invention also relates to a vehicle folding roof structure and to a vehicle having such an apparatus or roof structure.

Vehicles, such as automobiles, having folding roof structures are well known and are commonly referred to as "convertibles" or "cabriolets". There are two main types of cabriolet vehicle: the first, more common type, is the "soft-top cabriolet" having a roof structure formed almost entirely from a flexible fabric material which is stretched over a folding frame. The frame is collapsible between non-folded and folded positions of the roof, the flexible material folding or creasing naturally as the frame collapses towards the folded position, and is stored in a roof storage area in the rear of the vehicle. The roof storage area may comprise either a compartment located between the vehicle seats and the luggage compartment or an area located on top of the luggage compartment or parcel shelf.

The second form of cabriolet vehicle is the "hard-top cabriolet". Hard-top cabriolet vehicles, which are less common than the "soft-top" cabriolet vehicle described in the preceding paragraph, feature' a so-called "retractable hard-top" (RHT), this being a roof structure formed of two or more rigid panels which are pivotally connected together. A linkage, such as a parallelogram linkage, supports the panels and permits movement of the panels between a first, non- folded position of the roof structure and a second, folded position. In the first, non-folded position, the roof structure covers the passenger compartment or cabin of the vehicle giving the appearance of a conventional, non-convertible or fixed roof vehicle. In the folded position, the roof structure is folded on the frame, each panel pivoting relative to each other, often in a "clam-shell" type movement.

In both soft-top and hard-top vehicles, the folded roof structure may be stored in a roof storage compartment comprising an upper region of the vehicle luggage compartment, the hatch door or tailgate of which is arranged to open to permit access of the folded roof structure therein. A vehicle having this type of arrangement is described in US 6,299,234.

Where the roof is stored in such a storage compartment, it is usual for the vehicle trunk lid to open from the front to the rear, i.e. in the opposite direction to a conventional trunk lid, in order to provide access to the roof storage compartment. In some vehicles, however, such a rearward pivoting movement causes the trunk lid to extend beyond the rear bumper of the vehicle when in the open position. The present applicants have identified that if the vehicle is parked too close to an object behind, it is possible for a part of the trunk lid, most frequently the upper rear edge thereof, to strike the object when it is moving towards the open position: This can result in significant and costly damage to the trunk lid.

It is an aim of the present invention to address this newly identified problem associated with vehicles having retractable roofs.

According to one aspect of the present invention, therefore, there is provided a control system for a vehicle having a retractable or foldable roof, a storage compartment for storage of the roof in a retracted or folded position thereof, a trunk lid rotatable from the front towards the rear thereby to provide access to the storage compartment and drive means for moving the roof and the trunk lid, wherein the control system comprises sensing means for detecting the presence of an object within a predetermined distance behind the vehicle and control means for confrolling the operation of the drive means in dependence thereon thereby to hinder or prevent movement of the roof and/or the trunk lid.

In one embodiment, the control means is arranged to prevent the drive means from moving the roof and/or the trunk lid if the sensing means detects the presence of an object witnin a first predetermined threshold distance from the vehicle.

In one embodiment, the control means is arranged to control the drive means to reduce the speed of movement of the roof and/or the trunk lid if the sensing means detects the presence of an object within a second predetermined threshold distance from the vehicle.

The first predetermined threshold distance may be smaller than the second predetermined threshold distance.

The sensing means may be arranged to continue detecting for the presence of objects behind the vehicle during movement of the roof and/or trunk lid. In this embodiment, the control means may be arranged to halt and/or reverse movement of the roof and/or trunk lid if the distance between the vehicle and an object behind the vehicle reduces below the first predetermined threshold distance.

The system may further comprise warning means for generating an audible and/or visible warning to the vehicle user if the sensing means detects the presence of an object wit in the predetermined threshold distance from the vehicle.

The sensing means may comprise at least one sensor for measuring the distance between the rear of the vehicle and an object. The sensing means may comprise at least a part of a conventional reverse-parking sensor system. In one embodiment, the sensing means additionally comprises one or more sensors mounted in or on the trunk lid of the vehicle.

According to another aspect of the invention, there is provided a vehicle having a control system as described in the preceding paragraphs.

According to a further aspect of the invention there is provided a method of controlling the movement of the trunk lid of a vehicle having retractable or foldable roof, a storage compartment for storage of the roof in a retracted or folded position thereof, a trunk lid rotatable from the front towards the rear thereby to provide access to the storage compartment and drive means for moving the roof and the trunk lid, the method comprising, upon operation of a switch or the like to select movement of the roof and/or trunk lid, detecting for the presence of an object behind the vehicle and, if no object is detected within a predetermined threshold distance behind the vehicle, then moving the roof and/or trunk lid but, if an object is detected within a predetermined distance behind the vehicle, then controlling the operation of the drive means thereby to hinder or prevent movement of the roof and/or the trunk lid.

The invention advantageously enables the movement of the retractable roof and/or the trunk lid of a cabriolet or convertible vehicle to be hindered or prevented if an object is detected behind the vehicle in a position which interferes with the movement of the trunk lid. In this manner, damage to the trunk lid through contact with the object can be reduced or eliminated.

Embodiments of the invention may be implemented individually or in combination.

The present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 illustrates a known folding roof structure for a cabriolet or convertible vehicle in its non-folded position;

Figure 2 shows the roof structure of Figure 1 in its folded position;

Figure 3 is a block diagram of a known system for controlling operation of the roof structure of Figure 1 ;

Figure 4 is a block diagram of a known form of parking aid system for a vehicle;

Figure 5 illustrates a vehicle having the system of Figure 3; and

Figure 6 is a block diagram of a control system embodying the invention;

In the drawings and the following description, as far as possible, like reference numerals indicate like parts. Furthermore, the use of the term "roof structure" throughout this specification and in the claims is intended to mean the entire roof "module" including, but not limited to, the roof and the trunk lid.

Referring firstly to Figures 1 and 2, a known folding roof structure for a vehicle is shown generally at 10. The roof structure is formed of two main parts, a roof part 12 and a rear-window part 14 which is pivotally connected thereto. In a first, closed or non-folded position of the roof structure 10, as illustrated in Figure 1, the roof part 12 is oriented generally horizontally and a front edge region 13 thereof engages with a frame 15 of the vehicle windscreen. In this position, the rear-window part 14 engages with the roof part 12 substantially to cover the cabin or passenger compartment 6 of the vehicle.

Both the first and second parts 12, 14 are substantially rigid and are generally formed from metal, glass or similarly rigid materials so as to give the appearance, when in the first, non-folded position, that the vehicle is a conventional fixed-roof vehicle and not a cabriolet. This is in contrast with so- called "soft-top" cabriolets whose roof structure is formed from a fabric material and is generally highly flexible.

The roof structure 10 is arranged to be moved or folded from the first non- folded position shown in Figure 1 to a second, folded position illustrated in Figure 2. A linkage (not shown) is provided which allows the rear-window part 14 to pivot or rotate in a rearward direction (clockwise in the drawings) about a pivot point 17 over an arc of approximately 90°. This pivoting movement is achieved by a positive drive mechanism (not shown) drivingly connected to the linkage.

As the rear-window part 14 rotates, it carries with it the roof part 12 which, due to the nature of the linkage and the pivoting connection between the two parts, remains substantially horizontal throughout the rearward movement of the roof structure 10. The movement of the roof structure 10 is such that, when the rear- window part 14 has pivoted through its full range of rotation, the entire passenger compartment 6 is uncovered, as illustrated in Figure 2.

Storage of the roof structure 10 in its second, folded position is achieved by means of a roof storage compartment 18a, located towards the rear of the vehicle. In practice, the roof storage compartment forms an upper part of the luggage compartment 18b of the vehicle, and is not separated or divided therefrom or compartmentalised in any way.

Movement of the folded roof structure 10 into the roof storage compartment 18a is achieved by the opening of a rearwardly pivoting trunk lid or tailgate 19 which provides access to the roof storage compartment 18a. The mechanism that permits such rearward movement of the trunk lid 19 whilst also perrnitting conventional forward pivoting movement is well known and is not described in detail herein. One such mechanism is described in German Patent No. DE4445944.

It can be seen particularly from Figure 1 that, in the rearwardly open position of the trunk lid 19, in which access to the roof storage compartment is provided, the rear edge of the trunk lid 19 extends significantly beyond the rear bumper 20 of the vehicle. In Figure 1, the distance by which the trunk lid extends beyond the rear bumper is denoted by X. It will be appreciated, therefore, that if an object or obstruction is positioned behind the vehicle within a distance X from the rear bumper, then the trunk lid 19 may, on opening rearwardly as illustrated, strike the object, potentially causing damage to the trunk lid and the associated mechanism.

Referring next to Figure 3, this illustrates, in block schematic form, a known control system for controlling movement of the roof structure between the folded and non-folded positions. The system, indicated generally by reference numeral 30, includes a control unit 32 which is powered by the vehicle's battery (not shown) to which it is connected via the vehicle's ignition switch 34.

An output of the control unit is connected to drive means in the form of a motor 36 or other drive apparatus which is arranged, on application of a DRIVE signal from the control unit 32, to cause the roof structure to move between the folded and non-folded positions and the trunk lid to pivot rearwardly as shown in Figure 1 from the closed position to the open position. A further output of the control unit 32 is connected to a sounder 38 or other, possibly visual, indicator, the purpose of which is described below.

A first input of the control unit 32 is connected to a sensor or switch 42 which is arranged to detect the presence of an object in the roof storage compartment which may interfere with the correct operation of the roof structure. Specifically, if the vehicle luggage compartment contains a significant amount of luggage, there may be insufficient room within the roof storage compartment at the top of the luggage compartment for the roof to be stored. The luggage may impede the full movement of the roof into the roof storage compartment potentially damaging the roof or drive mechanism.

A second input of the control unit 32 is connected to a roof control switch 40 which, when actuated, causes the control unit to generate and apply the DRIVE signal to the motor 36 if the sensor 42 determines that there is no obstruction in the luggage compartment.

The system of Figure 3 is well known in the field of cabriolet vehicles.

Turning now to Figure 4, this illustrates in block form a known form of vehicle parking aid system. The system, indicated by reference numeral 50 comprises a plurality of sensors, in the form of acoustic transducers 52, which are disposed in or on the rear bumper 70 of the vehicle, as shown in Figure 5.

The transducers 52 are each electrically connected to respective outputs of a control unit 56 by means of a shielded cable 54. The control unit 56, which may be the vehicle body control unit, is powered by the vehicle's battery to which it is connected via the vehicle's ignition switch 34. An input of the control unit 56 is connected to a second switch 58 which is actuable, i.e. closed, when reverse gear is selected within the vehicle. A further output of the control unit 56 is connected to an alert device in the form of a sounder 60.

In use, when the vehicle's ignition is switched on, i.e. the switch 34 is closed, the control unit 56 is also switched on. However, the control unit 56 remains in a quiescent state and is not activated. When reverse gear is selected in the vehicle, the reversing switch 58 is closed. This is detected by the control unit 56 which responds by generating an electrical signal which is applied to each of the transducers 52 via the cables 54.

The electrical signal generated by the control unit 56 is in the form of a 40KHz signal which is amplitude modulated to define a train of pulses, each pulse having a duration of between approximately 1ms and 10ms at intervals of approximately 100ms. This signal is applied to each of the transducers 52 sequentially so that no more than one transducer is being applied with the signal at any one time. Each transducer therefore receives the pulses at the rate of approximately 2.5 times per second, i.e. 2.5Hz.

Each transducer 52 is arranged to convert the electrical signal into an acoustic signal of the same frequency and structure, i.e. that is to say a 40KHz pulse having a duration of between 1ms and 10ms approximately which is repeated at a rate of approximately 2.5 Hz.

The ultrasonic pulses generated by the transducers 52 are radiated away from the vehicle and may be reflected by nearby objects. The reflected signals are received by the transducers 52 during the interval between successive pulses and applied to the control unit 56. It will be understood from the above that the transducers 52 are operable alternately to act as transmitters and receivers.

The control unit 56 determines the time taken between transmission of the ultrasonic pulse and reception of the reflected signal by the transducers 52 and calculates from this the distance between the vehicle and the object from which the acoustic signal was reflected. In addition, the approximate position of the object can be estimated by monitoring the differences in the time delays detected by the different transducers 52 and using a method of triangulation.

This operation is repeated by the control unit 56 such that it continues to apply the pulsed signal to the transducers 52 whilst the reverse gear switch 58 is closed. The transducers 52 convert the signal into an acoustic signal and transmit it away from the vehicle in a series of discrete pulses. During the interval between successive pulses, the transducers 52 detect the reflected ultrasonic signal and the control unit 56 then calculates the distance between the vehicle and the object from which the signal was reflected.

When the distance between the vehicle and the object falls below a predetermined threshold distance, the control unit 56 activates the sounder 60 to produce an audible alert signal. The volume, pitch, tone or structure of the alert signal is then varied by the sounder 60 in dependence on the distance between the vehicle and the object. For example, the control unit 56 may control the sounder 60 to emit a succession of "beeps" which increase in frequency as the distance between the vehicle and the object decreases until, when the vehicle is less than, for example, 0.5 m away from the object, the sounder emits a substantially continuous tone.

Again, such parking aid systems are well known.

Referring now to Figure 6, a control system for a vehicle embodying the invention is shown, in block schematic form, generally at 100. The system 100 includes confrol means in the form of a control unit 102 which is connected to sensing means in the form of a plurality of acoustic transducers 52a - 52d of the type described with reference to Figure 4. The transducers 52a - 52d are mounted in or on the vehicle's rear bumper, as shown in Figure 5.

The system 100 also includes drive means, in the form of a motor 36 or other drive mechanism which is mechanically connected to the vehicle roof structure and arranged selectively to pivot the trunk lid 19 rearwardly so as to open a way to/from the roof storage compartment in response to a DRIVE signal generated by the control unit 102 and applied thereto. The motor 36 is also operable to move the roof structure between a first, non-folded position and a second, folded position, following the rearward movement of the trunk lid 19.

The control unit 102 which, in the illustrated embodiment, is part of the vehicle body control unit (BCU), is powered by the vehicle's battery (not shown) to which it is connected via the vehicle's ignition switch 34. A first input of the control unit 102 is connected to a second switch 58 which is actuable, i.e. closed, when reverse gear is selected within the vehicle. A second input of the vehicle is connected to a third switch 40 which is manually actuable by the vehicle user to initiate movement of the roof structure between the first and second positions.

A further output of the control unit 102 is connected to an alert device in the form of a sounder 60 or visual indicator.

In use, with respect to the parking aid function, the system operates in a substantially identical manner to the system described with reference to Figure 3. Specifically, when the reverse gear switch 58 is actuated by virtue of the user selecting reverse gear in the vehicle, the control unit 102 generates and applies a TRANSMIT signal to the transducers 52a - 52b causing them to transmit an acoustic signal away from the vehicle and to detect any reflected signals from nearby objects. The time difference between transmission of the initial acoustic signal and reception of the reflected signal is measured by the control unit 102 and the distance between the vehicle and the object or objects is determined. The control unit 102 generates an audible signal via the sounder 60 to indicate the presence of the object to the user.

With respect to the movement of the roof structure between the first and second positions, operation of the system 100 is as follows. In order to move the roof structure from, for example, the first, non-folded position to the second, folded position, the user operates the roof control switch 40 which causes a voltage to be applied to the corresponding input on the confrol unit 102. In response to this voltage, the control unit 102 generates and applies the TRANSMIT signal to the transducers 52a - 52d which convert the signal into an acoustic signal which is transmitted away from the vehicle in the manner described above.

If an object or obstruction is present behind the vehicle, the acoustic signal is reflected and received by the transducers which applies the reflected signal to the confrol unit 102, again in the manner described above. The confrol unit 102 calculates the distance of the object or obstruction from the vehicle and, if the calculated distance is greater than a predetermined threshold distance, the control unit 102 generates and applies a DRIVE signal to the motor 36 causing firstly the trunk lid 19 to be pivoted rearwardly so as to open a way to/from the roof storage compartment and then the roof structure to move between the first and the second positions.

On the other hand, if the distance between the object or obstruction and the vehicle, as calculated by the control unit 102, is less than a predetermined distance, wherein rearward rotation of the trunk lid may result in the trunk lid striking the object during rearward movement, the control unit 102 does not generate the DRIVE signal but instead generates an ALERT signal and applies this to the sounder 60.

Thus, the trunk lid 19 is not rotated rearwardly and the sounder 60 generates an audible signal to alert the driver that the vehicle is positioned too close to an object behind to permit operation of the roof structure.

It will be appreciated that actuation of the roof control switch 40 causes the system 100 to activate the transducers in order to detect the presence of an object behind the vehicle, in substantially the same manner as if reverse gear had been selected. In the invention, however, the confrol unit 102 is arranged to control movement of the trunk lid and/or the roof in dependence on the distance of an object from the vehicle.

In one embodiment, the trunk lid is prevented from being pivoted rearwardly if the distance between the vehicle and the object is less than a first predetermined threshold distance. In another embodiment, if the distance between the vehicle and the object is less than a second predetermined threshold distance, movement of the trunk lid is permitted but at a reduced rate. In other words, the confrol unit 102 is arranged to control the speed of the motor 36 so as to reduce the speed of movement of the trunk lid.

In this other embodiment, if the distance between the vehicle and the object reduces below the first predetermined threshold distance during movement of the trunk lid and or roof, the control means 102 is arranged to halt such movement and/or to reverse the motor 36 thereby to return the roof to its previous position and to close the trunk lid. In this case, a visible and/or audible warning may be generated to the user.

It will be appreciated that the present invention provides a simple yet highly effective system for controlling the movement of a foldable or retractable vehicle roof structure which reduces or eliminates damage to the vehicle though contact of the trunk lid with an object behind the vehicle. The system does not require any hardware or components in addition to those already provided on many convertible vehicles, that is to say a roof control unit and a reverse parking aid system, and may therefore be implemented simply by means of a modification to the software used in the control unit 102.

Nevertheless, a number of modifications may be made to the invention. For example, as described, the system employs pre-existing parking sensors which are mounted in the rear bumper of the vehicle. Alternatively, or in addition, the system may include sensors mounted at a higher level on the vehicle to detect objects specifically at a height which may cause damage to the trunk lid 19 if it is rotated rearwardly.

This arrangement provides the advantage that a) low height objects behind the vehicle, such as kerbs or low walls which would be detected by the normal parking sensors but which are too low to cause damage to the trunk lid, do not prevent the roof structure from being moved; and b) objects of greater height behind the vehicle such as railings or the like which could cause damage to the trunk lid but are not at a height which can be detected by the parking sensors in the bumper, do prevent the roof structure from being moved.

The additional sensors could be mounted in the trunk lid itself.

It will be appreciated that, since the trunk lid extends behind the vehicle by only a relatively small amount (often less than approximately 0.3m and usually between approximately 0.1m - 0.2m) then the system should be capable of detecting objects located anywhere within this distance from the rear of the vehicle. However, those skilled in the art will appreciate that many conventional parking aid systems suffer from dead regions in the coverage provided by the sensors, particularly at small distances from the vehicle.

The selection of sensors or fransducers for the system of the invention should therefore be made having regard to the coverage and distance resolution achievable in this area.

The control unit 102 may comprise the body control unit for the vehicle or may be a separate, dedicated confrol unit. The confrol unit 102 may be arranged to cause the transducers 52a - 52d to transmit a single acoustic pulse prior to the movement of the roof structure or to continuously monitor for the presence of objects behind the vehicle whilst the trunk lid and/or roof structure is in motion. This would enable the system to determine if, for example, another vehicle approaches from behind to wilhin the predetermined threshold distance whilst the trunk lid is being moved. If such a condition is detected, the control unit 102 may be arranged to halt further movement of the trunk lid 19.

The invention is applicable to both soft-top and hard-top convertible vehicles where the trunk lid is pivoted to provide access to the roof storage compartment.

Although particular embodiments of the invention have been disclosed herein in detail, this has been done by way of example and for the purposes of illustration only. The aforementioned embodiments are not intended to be limiting with respect to the scope of the appended claims.

Claims

1. A confrol system for a vehicle having a retractable or foldable roof, a storage compartment for storage of the roof in a refracted or folded position thereof, a trunk lid rotatable from the front towards the rear thereby to provide access to the storage compartment and drive means (36) for moving the roof and/or the trunk lid, wherein the control system comprises sensing means (52a - 52d) for detecting the presence of an object within a predetermined distance behind the vehicle and confrol means (102) for controlling the operation of the drive means (36) in dependence thereon thereby to hinder or prevent movement of the roof and/or the trunk lid.

2. A system as claimed in claim 1 wherein the control means (102) is arranged to prevent the drive means (36) from moving the roof and/or the trunk lid if the sensing means (52a - 52d) detects the presence of an object within a first predetermined threshold distance from the vehicle.

3. A system as claimed in claim 2 wherein the control means (102) is arranged to control the drive means (36) to reduce the speed of movement of the roof and/or the trunk lid if the sensing means (52a - 52d)detects the presence of an object within a second predetermined threshold distance from the vehicle.

4. A system as claimed in claim 3 wherein the first predetermined threshold distance is smaller than the second predetermined threshold distance.

5. A system as claimed in claim 3 or claim 4 wherein the confrol means (102) is arranged to halt and/or reverse movement of the roof and/or trunk lid if the distance between the vehicle and the object reduces below the first predetermined threshold distance.

6. A system as claimed in any preceding claim further comprising warning means (60) for generating an audible and/or visible warning to the vehicle user if the sensing means (52a - 52d) detects the presence of an object within the predetermined threshold distance from the vehicle.

7. A system as claimed in any preceding claim wherein the sensing means (52a - 52d) comprises at least one sensor (52a - 52d) for measuring the distance between the rear of the vehicle and an object.

8. A system as claimed in claim 7 wherein the sensing means (52a - 52d) comprises at least a part of a conventional reverse-parking sensor system.

9. A system as claimed in claim 8 wherein the sensing means (52a - 52d) additionally comprises one or more sensors mounted in or on the trunk lid of the vehicle.

10. A vehicle having a system as claimed in any preceding claim.

11. A method of confrolling the movement of the trunk lid of a vehicle having retractable or foldable roof, a storage compartment for storage of the roof in a retracted or folded position thereof, a trunk lid rotatable from the front towards the rear thereby to provide access to the storage compartment and drive means for moving the roof and the trunk lid, the method comprising, upon operation of a switch or the like to select movement of the roof and/or trunk lid;

detecting for the presence of an object behind the vehicle; and

if no object is detected within a predetermined threshold distance behind the vehicle then moving the roof and/or trunk Ud but if an object is detected within a predetermined distance behind the vehicle then controlling the operation of the drive means thereby to hinder or prevent movement of the roof and/or the trunk lid.