WO2009091308A1

WO2009091308A1 - Rf-controllable vehicle side-light unit and method for providing a vehicle with a vehicle lightning system

Info

Publication number: WO2009091308A1
Application number: PCT/SE2008/050939
Authority: WO
Inventors: Lena Larsson; Werner Hilliges; Torbjörn Birging
Original assignee: Datachassi Dc Ab; Combiport Ab
Priority date: 2008-01-17
Filing date: 2008-08-20
Publication date: 2009-07-23

Abstract

A side-light unit (20) for use in a vehicle (12) having a plurality of side- light units (20) mounted on each long side thereof. The side-light unit (20) comprises: a first signal-emitting device comprising a day-running light source 5 (24); a second signal-emitting device (26; 31; 32; 33); an RF-receiver (28) for receiving RF-signals transmitted by a control unit (27) comprised in the vehicle (12), the RF-signals encoding control data; and a controller (27) connected to the second signal-emitting device (26; 31; 32; 33) and to the RF-receiver (28). The controller (27) is configured to: receive the control data 10 from the RF-receiver (28); and control the second signal-emitting device (26; 31; 32; 33) to operate in accordance with the control data.

Description

RF-controllable vehicle side-light unit and method for providing a vehicle with a vehicle lightning system

Technical Field of the Invention

The present invention relates to a side-light unit having a day-running light-source, and to a vehicle lighting system comprising a plurality of such side-light units.

Technical Background

Heavy vehicles, such as trucks, busses etc. are generally provided with a plurality of day-running side-light units mounted on the sides of the vehicle. Conventional day-running side-light units provide the single functionality of emitting position-indicating light when the vehicle is in operation.

Summary of the Invention In view of the above-mentioned and other drawbacks of the prior art, a general object of the present invention is to provide an improved side-light unit, and in particular an RF-controllable side-light unit having additional functionality as compared to conventional day-running side-light units.

According to a first aspect of the present invention, these and other objects are achieved through a side-light unit for use in a vehicle having a plurality of side-light units mounted on each long side thereof, the side-light unit comprising a first signal-emitting device comprising a day-running light source; a second signal-emitting device; an RF-receiver for receiving RF- signals transmitted by a control unit comprised in the vehicle, the RF-signals encoding control data; and a controller connected to the second signal- emitting device and to the RF-receiver, the controller being configured to: receive the control data from the RF-receiver; and control the second signal- emitting device to operate in accordance with the control data.

By "signal-emitting device" should be understood any device capable of emitting any kind of signals, including electromagnetic signals, and acoustic signals. Examples of signal-emitting devices include light-emitting devices, sensors relying on reflection of emitted signals, sound generators etc. The present invention is based upon the realization that a "multifunction day-running side-light unit" for mounting on trucks, trailers, busses or similar long vehicles can be achieved by enabling remote control through RF- signals of a signal-emitting device comprised in the side-light unit. Hereby, a vehicle can be provided with new functionality using an existing infra-structure of the vehicle. National regulations frequently require that side-light units be distributed along the sides of trucks, buses or similar long vehicles. Therefore, the mounting and the electrical infra -structure of the vehicle, presently used for conventional day-running side lights, are already in place and could be used for the inventive multi-function side-light units in order to provide a vehicle surveillance system.

Furthermore, through the provision of an RF-receiver in the side-light unit according to the present invention, such new functionality requires no additional wiring in the vehicle. Especially, this is major advantage when using the multi-function side-light units on detachable trailers, whereby additional wiring between the trailer and the towing vehicle is avoided.

In embodiments of the side-light unit according to the present invention, the second signal-emitting device may comprise a controllable light-emitting device, and the controller may be configured to control the light- emitting device between first and second different light-emitting states in response to the control data.

Hereby, additional information can be conveyed using the side-light units mounted on a vehicle. Such information may indicate a state of the vehicle and/or the driver, and can be used to signal certain driving settings or an alarm condition.

Advantageously, the light-emitting device comprised in the second signal-emitting device may be arranged to provide visible illumination in a direction substantially in parallel with a side of the vehicle, when being provided on the vehicle and being controlled to emit light. For example, the light-emitting device may be arranged to illuminate the side of the vehicle to facilitate inspection of the vehicle, for instance with regards to the integrity of the cargo space cover.

The light-emitting device may also, or alternatively, be arranged to illuminate the ground adjacent to the vehicle to reduce the risk of reversing the vehicle into or over an obstacle.

To provide the desired degree of illumination, the light-emitting device may preferably be controllable to emit at least 60 cd. Moreover, the controller may be connected to the first signal-emitting device and configured to control the day-running light-source between first and second different light-emitting states in response to the control data.

Hereby, the intensity of the side-light units mounted along the long sides of the vehicle can be modulated to more clearly indicate that the driver intends to make a turn or change lanes.

To this end, the provision of control data to the side-light unit may advantageously be triggered by activation by the driver of the blinker of the vehicle. It should be noted that it in many states is required by law that the sidelight units always emit light when the vehicle is in operation. Hence, conventional blinking between an off-state and an on-state is currently generally forbidden.

Hence, both of the first and second different light-emitting states are preferably non-zero states, with the state having the lowest intensity being having a sufficiently high intensity to comply with various authority regulations.

The side-light unit may additionally include a third signal-emitting device comprising a sound-generator connected to the controller, and the controller may be configured to control the sound-generator to generate an audible alarm in response to the control data.

The control data encoded in the RF-signals transmitted by the control unit comprised in the vehicle may advantageously be indicative of and/or occasioned by a driver action, such as turning the steering wheel to change direction of the vehicle, activating the blinker to indicate an intended direction change, selecting a reverse gear, and activating an alarm system including the side-light unit.

To further enhance the capabilities thereof, the multi-function side-light unit according to the present invention may additionally comprise an RF- transmitter for transmitting RF-signals, the RF-transmitter being connected to the controller.

In various embodiments of the present invention, the second signal- emitting device may comprise an active sensor for defining a surveillance zone adjacent to the vehicle, the sensor being arranged to detect an object or a movement of an object within the surveillance zone; and the controller may be configured to: control an extent of the surveillance zone in response to the control data; and provide a signal indicative of detection of an object of a movement of an object within the surveillance zone to the RF-transmitter for transmission to the control unit comprised in the vehicle.

Hereby, an adaptive surveillance system can be achieved, in which the total surveillance area around the vehicle can be adapted to a specific surveillance situation.

For instance, the surveillance zones of side-light units positioned on a side of the vehicle close to a an area with many moving objects, such as a busy sidewalk, can be reduced to the absolute vicinity of the vehicle to prevent or at least reduce the occurrence of false alarms. Alternatively, the control of the surveillance zones of the side-light units may be based on control data indicative of or occasioned by the driver placing the vehicle in reverse, activating a blinker or turning the steering wheel. Hereby, accidents may be prevented in situation when the driver's vision is hindered by the vehicle. To visibly indicate the current state thereof, the side-light unit may further comprise a fourth signal-emitting device comprising a light-emitting indicator device for indicating a state of the sensor, wherein the controller may further be configured to control the indicator device between first and second different light-emitting states in response to the control data. For example, the light-emitting indicator may be controlled by indicate that the sensors are active by blinking.

Moreover, the side-light unit may comprise a battery arranged to enable autonomous operation of the side-light unit. Such a battery enables the system in which the side-light unit is comprised to be active even if the light source of the unit is not powered, e.g. when the vehicle is parked at night. However, preferably the side-light unit is also connected to a conventional electrical system of the vehicle, especially when converting existing vehicles by replacing their conventional side-light units with the inventive units. According to a second aspect of the present invention, the above- mentioned and other objects are achieved through a vehicle lighting system comprising a plurality of side-light units, each comprising an RF-transmitter, for mounting on the sides of a truck, bus, train or a similar long vehicle, the plurality of side-light units, when in use, forming an RF-communication network on the vehicle. Thus, a plurality of multi-function side-light units may provide a multifunction system on a vehicle. The side-light units will form nodes or node- points in the RF communication network on the vehicle.

The network may be used for operating the vehicle lighting system, but may be used for different purposes at the same time.

In a preferred embodiment, the vehicle lighting system may further comprise central unit including a control unit configured to: acquire data indicative of a driver action; and determine control data for at least one of the side-light units based on the acquired data; and a central RF-transmitter for transmitting central RF-signals encoding the control data to the at least one side-light unit.

Hereby, the added functionality of the side-light units comprised in the vehicle lighting system can be made responsive to driver actions, which may include actions involving the operation of the vehicle as well as other driver actions, which may related to the vehicle lighting system as such.

For example, the vehicle lighting system may be a surveillance system, which may detect an object or a movement of an object within the surveillance zones of the multi-function side-light units when these comprise sensors configured to detect such a presence or movement of an object. The central control unit may be arranged, in response to an incoming

RF detection signal from one or more side-light units of the system, to transmit a central RF alarm signal to all of the side-light units of the system.

The central control unit may be arranged to transmit said central RF alarm signal only if one or more criteria have been met. One criterion may be that the central control unit has received RF detection signals from at least two adjacent side-light units of the system. Another criterion may be that the central control unit has received at least two consecutive RF detection signals from one and the same side-light unit during a predetermined time interval. If the system is to be used as a blind-spot detection system, a criterion may that a blinker of the vehicle is being activated on the same side of the vehicle on which an object or movement of an object has been detected.

Each side-light unit of the system may be arranged to operate its light source and/or an audible alarm in the unit in response to the side-light unit receiving said central RF alarm signal from the central unit. In the inventive vehicle lighting system, each side-light unit may, in response to the side-light unit receiving the central RF-signals, be arranged to relay the received central RF-signals to one or more other side-light units of the system.

The vehicle lighting system according to the present invention may advantageously be installed in a vehicle, which may preferably be a truck, bus, train or a similar long vehicle.

According to a third aspect, there is provided a method for providing a vehicle with a vehicle lighting system, comprising the step of replacing existing, day-running side-light units of the vehicle with vehicle day-running side-light units according to the present invention.

Brief Description of the Drawings

These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing a currently preferred embodiment of the invention, wherein: fig. 1 illustrates a vehicle provided with a vehicle lighting and surveillance system according to an embodiment of the invention; fig. 2 is a top-view of the vehicle in fig. 1 ; fig. 3 schematically illustrates overlapping surveillance zones of the surveillance system in fig. 1 ; fig. 4 is a perspective view of a day-running side-light unit according to an embodiment of the invention; fig. 5 is a schematic block diagram of the side-light unit in fig. 3; fig 6 is a schematic block diagram of the vehicle lighting and surveillance system in fig 1 ; fig. 7a and 7b schematically illustrate a relay function of the surveillance system in fig. 1 ; fig. 8 schematically illustrates a plurality of communicating surveillance systems operating in parallel; fig. 9 illustrates a blind-spot application of a surveillance system; and fig. 10 illustrates vehicle status monitoring application.

Fig. 11 illustrates a further application of a surveillance system.

Fig. 12 illustrates another application of a surveillance system.

Fig. 13 illustrates yet another application of a surveillance system.

Detailed Description of Preferred Embodiments

In the present description, embodiments of the present invention are mainly described with reference to a vehicle lighting and surveillance system comprising a plurality of multi-function day-running side-light units, each being equipped with an RF transceiver and several individually controllable signal- emitting devices, in the form of a motion detection sensor and two individually controllable sets of light-emitting devices. It should be noted that this by no means limits the scope of the invention, which is equally applicable to other RF-controllable side-light units, which may, for example, be equipped with an RF receiver rather than an RF transceiver, and/or may have fewer individually controllable signal-emitting devices.

Fig. 1 discloses a heavy vehicle 10 which in this example is in the form of a truck 12 and a trailer 14. The vehicle 10 is provided with a vehicle lighting and surveillance system in accordance with an embodiment of the present invention.

The vehicle lighting and surveillance system comprises a plurality of multi-functional day-running side-light units 20 mounted on the truck 12 and the trailer 14 at opposite sides thereof, as illustrated in Figs 1 and 2. The sidelight units 20 may be installed during the manufacture of the vehicle 10. However, an existing vehicle which already is provided with conventional day- running side-lights (e.g. due to law requirements) may be quickly "converted" into a vehicle having a surveillance system, simply by replacing the conventional side-light units with the multi-functional side-light units, and using the existing mounting positions and electrical infrastructure of the vehicle.

A first embodiment of a multi-function side-light unit 20 providing surveillance of the heavy vehicle, as well as controllable auxiliary lighting in the form of a controllable downlight will now be described with reference to Figs 4 and 5. Optionally, the side-light unit 20 has an outer appearance which is very similar to the outer appearance of a conventional side-light unit, as shown in Fig. 4. However, the side-light unit 20 may also have another outer appearance differing from conventional side-light units. Referring to fig. 4, the side-light unit 20 comprises a transparent cover

22 and a base 23 to be mounted on the vehicle 10. Preferably, the base 23 may be provided with standard electrical wiring and connectors (not shown) for connecting the side-light unit 20 to an electrical infrastructure of the vehicle 10, without any constraints regarding polarity. Due to authority regulations, the cover 22 of the side-light unit 20 is generally yellow. To increase the efficiency of the downlight, a side portion 25 of the cover 22 is made transparent to allow for illumination by white light of the ground adjacent to the truck 12 and trailer 14.

As schematically illustrated in Fig. 5, the side-light unit comprises a day-running light source 24, a sensor 26, an RF transceiver 28, a controllable downlight 31 , a sound generator 32 for generating an audible alarm, an indicator light 33 for indicating whether the sensor 26 is activated, and a controller 27.

The controller 27 may be provided in the form of one or several microprocessors, which may or may not be integrated in one or several of the sensor and other devices comprised in the sidelight unit.

The controller 27 is configured to receive control data from the RF transceiver 28, and to control one or several of the devices connected thereto in accordance with the control data. In one example of the embodiment illustrated in figs 4 and 5, the controller is configured to individually control the sensor 26, the downlight 31 , the indicator light 33 and the sound generator 32 based on the received control data.

Additionally, the multi-function side-light unit 20 may include a rechargeable a battery unit (not shown). The battery unit may be used to power the electronics comprised in the side-light unit e.g. when the vehicle is parked. The battery unit may be recharged when the engine of the vehicle is running. Although the battery unit provides the advantage of enabling autonomous operation of the multi-function side-light unit 20, the multifunction side-light unit 20 may also be at least partly powered directly by the ordinary electrical infrastructure of the vehicle. The day-running light source 24 may be in the form of an LED or any other conventional type of light-emitting device. As conventional, and as frequently required by national regulations, the light source 24 provides a constant noticing side-light, thereby increasing the visibility of the vehicle 10. Depending on national regulations, all or some of these lights may be lit during driving for providing a constant noticing light to the surrounding.

In use, each sensor 26 is arranged to define a surveillance zone 50 (see Fig. 3) on the side of the vehicle 10 for the detection of an object or a movement of an object within the surveillance zone 50. Non-limiting examples of sensor types are ultrasonic sensors, IR sensors, Doppler sensors, radar sensors or any range-finding detector or motion detector well-known in the art. If an ultrasonic sensor is used, objects may be detected within a detection zone of the sensor by the sensor 26 transmitting ultrasonic pulses and listening for an ultrasonic echo. The ultrasonic sensor 26 may apply a unique code or modulation to the ultrasonic pulses. This enables the ultrasonic sensor to distinguish between echoes from its own transmitted ultrasonic pulses and echoes of other ultrasonic pulses. In response to detecting an ultrasonic echo, the ultrasonic sensor may generate and output an electrical signal.

Fig. 3 is a top-view illustrating the activated surveillance system. The multi-function side-light units 20 are mounted such that at least some of the individual surveillance zones 50 overlap, thereby forming a collective surveillance zone 60 surrounding the vehicle 10. If needed to establish a continuous zone 60 also at the front and at the rear, the vehicle 10 may be provided with multi-function side-light units 20 also at the front and at the rear, as illustrated in Fig. 3.

It should especially be noted that the overlap ensures that the collective surveillance zone 60 surrounds the vehicle 10 even if the trailer 14 is at an angle with the truck 12. The surveillance system is thus arranged to detect an object or movement of an object within the collective surveillance zone 60. The collective surveillance zone 60 may be regarded as an invisible "fence" around the vehicle 10.

In the presently disclosed embodiment, the controller 27 is further configured to process sensor data. Based on sensor data, the controller 27 can distinguish between static and moving objects by comparing consecutive measurements. The controller 27 may also control the sensor 26 to enable determination of the distance to detected objects. Furthermore, the controller 27 may determine whether an object detected by the sensor 26 is within the surveillance zone 50 of the sensor 26.

The term "surveillance zone" does not necessarily correspond to the total detection zone of the sensor 26, i.e. the zone in which the sensor 26 is able to detect objects or motion of an object. In contrast, the surveillance zone 50 may in some instances be equal to the zone in which the sensor 26 will respond to detected objects. In such cases, the surveillance zone may be set by a central unit 100 as will be further described below. The controller 27 may further be configured to increase a detection counter by one each time the sensor 26 detects an object within the surveillance zone 50. If the detection counter exceeds a set value, the controller may transmit an RF Detection signal RFD via the RF transceiver 28, otherwise no signal is sent. The detection counter may be restored to zero when no object or motion has been detected for a time interval. This mechanism may be used to avoid transmitting RF detection signals in response to objects entering and leaving the surveillance zone 50 only briefly.

In the disclosed embodiment, the RF transceiver 28 of the multifunction side-light unit 20 comprises an RF transmitter and an RF receiver. The RF transmitter and RF receiver may implement any RF communication protocol such as ZigBee, Bluetooth, WLAN, CAN or any other conventional wireless communication technology suitable for providing wireless communication. The RF transceiver may comprise logic and data structures for implementing routing/relaying functionality and/or any of the above- mentioned communication protocols, thus enabling the multi-function sidelight unit 20 to operate as a node in the wireless network formed on the vehicle 10.

Optionally, the RF transceiver 28 may comprise a MAC (Media Access Control) address to be used for enabling identification of the RF transceiver means 28 during communication. However, such identification may be provided by other means, such as a software implemented ID, static network addresses, IP addresses or similar.

The RF transmitter is preferably arranged to transmit an RF signal from the side-light unit 20 in response to the RF receiving of the side-light unit 20 receiving an incoming RF signal from another side-light unit 20 in said system. The RF signal may, depending on the communication protocol used in the communication network, comprise a plurality of data blocks. Each data block may comprise a header portion, a data portion and a checksum portion. The header portion may comprise a destination address, a sender address, the MAC address of the sender, message type etc. The message type may, for example, be a "detection message" transmitted by a multi-function sidelight unit 20 if an object is detected within its surveillance zone 50, or an "alarm message" transmitted by the central unit 100 to instruct the receiving multi-function side-light units 20 to activate their light sources 24. Further alternatives are also possible and well-known in the art. The RF transceiver may be controlled by the controller 27 to transmit an RF detection signal RFD from the side-light unit 20. The RF transceiver 28 is further arranged, in response to receiving an incoming RF signal from a second side-light unit in the system, to transmit an outgoing RF signal from the first side-light unit to a third side-light unit in said system.

The vehicle lighting and surveillance system comprising a plurality of the above-described side-light units 20 and a central unit will now be described in more detail with reference to fig 6 The central unit 100 may preferably be arranged within the cabin 13 of the truck 12, but may for certain applications be located at another location in the vehicle 10.

In fig 6, a vehicle lighting and surveillance system 90 for implementation in a heavy vehicle, such as a truck 12 or the like is schematically shown, comprising a central unit 100 and a plurality of side-light units 20a-c. The central unit 100, comprises a control unit 101 and a central

RF transceiver 102.

In various embodiments of the present invention, the control unit 101 is configured to acquire data indicative of a driver action and to determine control data for at least one of the side-light units 20a-c based on the acquired control data. The control unit 101 is further configured to provide this control data to the central RF transceiver 102 which transmits central RF- signals encoding the control data.

In the presently illustrated embodiment, the side-light units 20a-c form an RF communication network, which relays the central RF-signals from the first side-light unit 20a and on, as is schematically shown in fig 6.

The data indicative of a driver action may advantageously be acquired via a communication network internal to the heavy vehicle 12, such as a

CAN-bus or equivalent. According to one exemplary application, the driver action may be that the driver puts the truck 12 in reverse. Data indicative of this action is acquired by the control unit 101. The control unit 101 then determines appropriate control data for controlling all or some of the side-light units 20a-c to activate the downlight 31 (referring to fig 5). This control data is converted to central RF-signals, which are transmitted through the central RF transceiver 102 comprised in the central unit 100.

In the side-light unit 20a, referring to fig 5, the central RF-signals are received through the RF transceiver 28 in the side-light unit 20a and then relayed on to the next side-light unit 20b, and further in the communication network formed by the side-light units in the vehicle lighting and surveillance system 90. The controller 27 in the side-light unit 20 receives the control data encoded by the central RF-signal from the RF-transceiver 28 and, in the present example, provides a signal to the light-emitting device(s) comprised in the downlight 31 to activate the downlight 31 and thereby illuminate the ground adjacent to the truck 12 and trailer 14. Hereby, the visibility of the truck 12 is further increased, and the driver can easier ensure that there is no obstacle in the intended path of the truck 12.

According to another exemplary application, the driver action may be that the driver activates the blinker to make a turn, as is illustrated in fig 9. As described above, data indicative of this action is acquired by the control unit 101. The control unit 101 then determines appropriate control data for controlling all or some of the side-light units 20 on the left side of the truck 12 and trailer 14 to modulate the day-running light-sources 24 comprised in the side-light units 20 between two non-zero intensity levels. The control data determined by the control unit 101 is converted to central RF-signals, which are transmitted through the central RF transceiver 102 comprised in the central unit 100.

In the side-light unit 20a, referring to fig 6a, the central RF-signals are received through the RF transceiver 28 in the side-light unit 20a and then relayed on to the next side-light unit 20b in the communication network formed by the side-light units in the vehicle lighting and surveillance system 90.

The controller 27 in the side-light unit 20 receives the control data encoded by the central RF-signal from the RF-transceiver 28 and, in the present example, provides a modulated signal to the light-emitting device(s) comprised in the day-running light-source 24 to blink all or some of the sidelight units on the left side of the truck 12 and trailer 14 between a first predetermined intensity level, which should be higher than the intensity level prescribed by regulation, and a second, higher intensity level, to thereby indicate the intension to turn the heavy vehicle clearer and thereby help avoid accidents.

According to a further exemplary application, which is also schematically illustrated in fig 9, the side-light units 20 on one of the sides of the truck 12 (here, the left side) may be controlled to have an extended surveillance zone in response to a certain driver action or combination of driver actions. For example, the control unit 101 in the central unit 100 may acquire that the driver has activated the left blinker, and may then generate and send control data to at least the side-light units 20 on the left side of the truck 12. The control data is, in analogy to the exemplary applications described above, received via the RF transceiver 28 in the side-light unit, and interpreted by the controller 27, which, in response thereto controls the sensor 26 to temporarily extend the surveillance zone thereof.

This functionality may, for example, be very useful for preventing accidents when a truck 12 with trailer 14 is passing another vehicle. When the driver of the truck 12 thinks that he has passed the other vehicle and activates the blinker to go back in front of the overtaken vehicle, the surveillance zones of the side-light units 20 on the relevant side of the truck 12 and trailer 14 will be extended. If the side-light units 20 detect an object when the driver starts to change lanes, the driver can then be alerted as is described in detail further below.

In yet another exemplary application, the driver action may be to activate the vehicle lighting and surveillance system in an alarm mode. Similar to what has been described above, the central unit then generates and transmits a central RF-signal indicative of this driver action to the first side-light unit 20a. In accordance with the control data encoded in the central RF-signal, the controller 27 comprised in the first side-light unit 20a controls the indicator light 33 to blink to indicate that the sensor 26 in the first side-light unit 20a is active. The first sidelight unit 20a may advantageously relay the central RF-signal with a predetermined delay to the second sidelight unit 20b whereby the indicator light 33 of the second sidelight unit 20b is made to blink with the same frequency as the indicator light in the first sidelight unit 20a but with a delay. By relaying the central RF-signal around the truck 12 and trailer 14 in this manner, the effect of a "running" light around the entire truck 12 and trailer 14 assembly can be created, clearly indicating that both the truck 12 and the trailer are protected by an "electronic fence". Of course, this kind of running light can be realized by other methods, such as by sequentially transmitting the central RF-signal from the central unit 100 to each sidelight unit 20a-c.

It should in this context be noted that the driver actions mentioned above are simply non-limiting examples. Other possible driver actions which may be used to control one or several of the devices comprised one or several of the sidelight units 20a-c may include actions such as speeding, acting "strange" (being incapacitated or intoxicated), etc, braking very hard etc. The central unit 100 may be a computer such as an Onboard Computer (OBC) or Personal Digital Assistant (PDA), laptop or similar. The central unit 100 implements logic for processing data and controlling the operation of the surveillance system 100. The logic may be in the form of processor instructions stored in a memory of the central unit 100 or stored and executed by a microcontroller or similar.

The central unit 100 comprises RF transmitting means arranged to transmit RF signals to at least one of the multi-function side-light units 20 of the system, and RF receiving means arranged to receive RF signals from at least one of the multi-function side-light units 20. Said RF receiving and transmitting means may be implemented by any RF communication protocol such as ZigBee, Bluetooth, WLAN, CAN or any other conventional wireless communication technology suitable for providing wireless communication. Regardless of protocol, the RF receiving and transmitting means preferably comprises logic and data structures for implementing routing/relaying functionality and/or any of the above-mentioned communication protocols, thus enabling the central unit 100 to operate as a node in the wireless communication network formed on the vehicle 10.

The wireless communication network set up by the side-light units 20 and the central unit 100 enables bi-directional wireless communication (i) between multi-function side-light units 20 and (ii) between multi-function sidelight units 20 and the central unit 100.

The signals may relate to surveillance information but may also be used to communicate any kind of information and data. The multi-function side-light units 20 and the central unit 100 thus operate as nodes in the wireless network.

By using the side-light units 20 as relay nodes, RF signals may be transmitted in the communication network between the nodes/units 20 along the vehicle 10 even if all of the nodes are not within RF transmission range of each other. As a first non-limiting example, Fig. 7a schematically illustrates how an RF signal S1 is being generated at and relayed from a rear-most multi-function side-light unit 20-1. The signal S1 is relayed to the central unit 100 via a number of intermediate multi-function side-light units 20. Fig. 7a also schematically illustrates how the signal S1 in a meshed network may take different routes in case some units 20-2 for some reason are not working. Thus, if a node is removed or damaged, the network may be dynamically updated, allowing an RF signal to be relayed via another multi- function side-light unit 20 instead. The update may be accomplished by transmitting broadcast signals or by other techniques implemented in the above-mentioned protocols, well-known in the art

Fig. 7a also schematically illustrates how another RF signal S2 may be generated at another unit 20-3 along the vehicle 10.

As illustrated in Fig. 7b, the relaying may also be carried out in the opposite direction, i.e. from the central unit 100 to the multi-function side-light units 20. This may especially be the case if the central unit 100 is to transmit some alarm activation signal to all of the units 20, as will be described below. The central unit 100 may be arranged to activate alarms in the units 20 by transmitting a central RF alarm signal CA to the multi-function side-light units in response to receiving an RF detection signal RFD from a multifunction side-light unit 20 of the system. Optionally, the central unit 100 may also be arranged to activate e.g. the head-lights or other lights of the vehicle 10 or to transmit an alarm signal to a remote security center via e.g. GPRS/3G or GSM cellular network.

The central unit 100 may be arranged to activate alarms if one or more alarm criteria are met. A criterion may for example be that RF detection signals RFD have been received by the central unit 100 from at least two adjacent the side-light units 20. Another criterion may be that at least two consecutive RF detection signals RFD are received by the central unit 100 from a side-light unit during a specified or predetermined time interval.

The criterion may for example be implemented as follows: the central unit 100 stores a table with entries of the MAC addresses or IP addresses of the RF means 28 of each multi-function side-light unit 20 together with the location of the respective unit. The table may further comprise a detection counter for the multi-function side-light units 20. Each time an RF detection signal RFD is received by a multi-function side-light unit, the detection counter is increased by one. The detection counter is restored to zero when a side- light unit has been inactive for a time interval. The criterion for activating an alarm may thus be that a detection counter exceeds a set value. The criterion may also be that the detection counters of at least two adjacent multi-function side-light units exceed a set value simultaneously. Such criteria may be used to avoid activating alarms in response to persons entering and leaving the surveillance zone only briefly.

It should be understood that these specific criteria only are given by way of example and that a plurality of further criteria are possible without departing from the inventive concept. It should further be noted that this functionality may reside in the central unit 100 alone, in the multi-function side-light units 20 alone, or a combination thereof.

The above described surveillance system has two basic modes of operation. The operation of each mode will now be described separately.

In the first mode of operation, the surveillance system is arranged to detect intrusion in the collective surveillance zone 60 and to activate one or more alarm functions in response to an intrusion. This mode may preferably be used when the vehicle 10 is parked. During system activation, the central unit 100 transmits an RF activation signal to all multi-function side-light units 20 for initializing the surveillance system. The RF activation signal may instruct the sensors 26 to set the surveillance zone to a range value. The range value determines how large the surveillance zone will be. Finally, each side-light unit 20 starts to survey its detection zone 50. The central unit 100 may further be arranged to occasionally transmit RF polling signals requesting the multi-function sidelight units 20 to report their status. The central unit 100 may thus ensure that the surveillance system 100 is operating correctly.

If an intruder enters the detection zone 50 of a sensor 26, a detection signal is generated which the sensor 26 processes to determine if the intruder is within the surveillance zone 60 or not. The determination may be made by simply comparing the measured distance to the intruder with the range value received from the central unit 100. If it is not, the detection will be ignored. If the intruder is determined to be within the collective surveillance zone 60, i.e. the invisible fence has been broken, an RF detection signal RFD is transmitted via the RF transmitting means of the detecting multi-function side-light unit 20 to the central unit 100. As have been previously described, the sensor 26 may also evaluate if a criterion has been met to determine if the RF detection signal should be transmitted. The RF detection signal RFD may be relayed via intermediate multi-function side-light units 20 to the central unit 100 as have been previously described. The RF detection signal may also be directly transmitted to the central unit 100, especially if the detecting side-light unit is located close to the central unit.

The central unit 100 receives the RF detection signal RFD. The multi- function side-light unit 20 from which the RF detection signal RFD originates may be identified by its MAC address or IP address. Furthermore, the central unit 100 may determine if an alarm criterion is met. For instance, testing if more than one multi-function side-light unit have reported an intrusion recently, or has this specific multi-function side-light unit reported additional intrusions recently.

If the alarm criterion has been met, the central unit 100 transmits a central RF alarm signal CA to (preferably all) the multi-function side-light units 20. The central RF alarm signal CA is received, directly or via relay function, by each multi-function side-light unit 20. In response thereto, each multifunction side-light unit 20 activates its light source 24 and its audible alarm 32. The light source 24 may provide a constant alarm light or a blinking alarm. The blinking frequency may be transmitted in the central RF alarm signal CA. Furthermore, the multi-function side-light unit 20 which has detected the intrusion may receive a specific RF alarm signal instructing the multi-function side-light unit to use a specific blinking frequency (e.g. higher or lower). This facilitates identification of what caused the detected intrusion and where it occurred.

The central unit 100 may further activate the horn of the truck 12 or other light-equipment than the multi-function side-light units 20 on the vehicle 10. The central unit 100 may also transmit an intrusion signal to a remote receiver e.g. at a security company or the police. The intrusion signal may be transmitted via GPRS, GSM or other cellular communication technology. If the system comprises a GPS equipment, the intrusion signal may also comprise the GPS coordinates of the current vehicle position.

The activation of the alarm will thus alert the surrounding that an intruder has been noticed and further scare off the intruder. To summarize, an RF detection signal RFD is transmitted from one or more multi-function side-light units 20 detecting an object or motion of an object within its surveillance zone. The RF detection signal RFD is received by the central unit 100. In response thereto, the central unit 100 transmits a central RF alarm signal CA to the multi-function side-light units 20. In response thereto, each side-light unit 20 activates its day-running light source 24 and/or its audible alarm 32.

According to a further embodiment, two or more surveillance systems may operate in conjunction, as illustrated in Fig. 8 where three vehicles 10-1 , 10-2 and 10-3 are parked next to each other. The central units 100 of the respective surveillance systems are configured to allow communication between the networks of the three individual surveillance systems (black arrows in Fig. 8), thus forming an enlarged communication network for the three vehicles.

In response to a detected intrusion at say vehicle 10-1 (as indicated at position P) the originating RF detection signal RFD is relayed from position P to at least one of the central units 100, optionally all of the three central units. An alarm may then be activated by: (1 ) each central unit transmitting an RF alarm signal to the multi-function side-light units of its surveillance system (2) one central unit transmits an RF alarm signal to the multi-function side-light units of all surveillance systems or (3) a combination of (1 ) and (2). The RF signals may be transmitted between the surveillance systems via communicating multi-function side-light units or directly between the central units.

The second mode of operation of the surveillance system - blind spot detection - will now be described with reference to Fig. 9. The surveillance system 100 is activated and is arranged to detect an object or detect motion of an object 200, such as another vehicle, a bicycle, a pedestrian or similar, within the surveillance zone 60.

Preferably, the sensors 26 are arranged to detect both static objects and moving objects, thus enabling the surveillance system to detect both objects in motion relative to the reference system of the vehicle 10 and also to detect objects stationary relative to the reference system of the vehicle 10, e.g. a vehicle traveling alongside with the vehicle at the same speed. The surveillance zone is preferably set to cover the adjacent lanes of the road. One or more of the multi-function side-light units detect the object 200 or movement of the object within the surveillance zone and transmit an RF detection signal which is received by the central unit 100. The central unit determines if a criterion has been met. According to this embodiment, the criterion is could be that a vehicle blinker has been activated on the same side of the vehicle as the "detection side". If the blinker is activated, the central unit may preferably activate an audible and/or visual indicator within the driver's cabin 13 to warn the driver of the danger, thereby avoiding an accident. In addition, the central unit 100 may communicate with the side-light units 20 as described in the first mode of operation. While the multi-function side-light units 20 in the above-described embodiments comprise both RF transmitting and RF receiving means, in another alternative all multi-function side-light units do not have to comprise RF receiving means. In a surveillance system, such a multi-function side-light unit may transmit its RF detection signal RFD directly to the central unit 100 or via multi-function side-light units comprising both RF receiving means and RF transmitting means. The wireless vehicle communication network provided by the multifunction side-light units 20 may advantageously be used to transmit other types of information and data and may be used for a plurality of different applications. Further, the inventive concept is not limited to a specific network technology. Any wireless network technology may be used. For example, as schematically illustrated in Fig. 10, the network may be used to wirelessly communicate output measurement data from sensors that are e.g. continuously checking the vehicle status. For instance, a temperature sensor 70 for sensing bearing temperature may be mounted at the vehicle bearings and may be provided with an RF transmitter compatible with the RF receiving means of the multi-function side-light units 20. The temperature measurement data MD is transferred from the sensor 70 via the wireless system to e.g. the cabin 13.

Other monitoring is also possible, such as monitoring the tire pressure or transferring video images wirelessly to the cabin from a camera mounted on the vehicle.

Range-finding detectors, e.g. ultrasonic sensors 300 in Fig. 11 , may be mounted on the rear section of the truck or trailer, to measure the distance to e.g. a loading/unloading terminal and transmit this distance information Dl wirelessly to the central unit. This information may be presented to the driver during backing up of the truck and trailer.

According to another application of the wireless communication network, sensors provided with RF transmission means may be mounted at the back doors for detecting if the back doors are open or closed. These may be used to alert the driver if he attempts to drive away during loading and unloading. A very common cause for accidents in the freight industry. According to another application of the wireless communication network, intrusion detectors and RF transmitters on the diesel or petrol tank of a vehicle and transmit an RF detection signal if an intruder tries to tamper with the tank. An advantageous feature of the inventive wireless network is identification of individual multi-function side-light units 20 comprising identification means. This may be used to render use of stolen multi-function side-light units more difficult. For instance, the central unit 100 may be designed not to grant a multi-function side-light unit access to the network if the MAC address is not recognized. Optionally, when the surveillance system is initially installed on a vehicle, all units may be put into an initialization state, waiting for an initial RF signal comprising identification information of the other neighboring side-light units. The identification information could be stored in each side-light unit and used for determining if the RF receiving means or RF transmitting means should be deactivated or not.

As an alternative, the granting may be based on the value of a control flag (e.g. one or more control bits or similar ) in the RF signals received from the multi-function side-light units. The control flag may indicate a "new" and a "used" state. During a normal installation of a side-light unit, the central unit receives an RF signal and extracts the corresponding state information from the received RF signal. If the control flag indicates a "new" state the side-light unit is accepted. The side-light unit then changes its control flag to the "used" state. However, if the control flag during installation indicates a "used" state, the central unit will not accept the side-light unit to form part of the surveillance system. Preferably, the control flag may only be initialized to the "new" state through a protected restoration procedure, thus making it more difficult to use stolen units.

Furthermore, the inventive wireless network may be used to wirelessly transfer CAN data between for example a trailer and a truck. Thus, the wires between the truck and trailer which are needed in a conventional system may be dispensed with. The CAN data may be transmitted as raw data. The CAN data may also be transmitted as encapsulated data. Preferably, the CAN data transmission is occasionally temporarily halted to allow the multi-function side-light units to access the transmission medium.

In another application, the inventive wireless communication network may be used to transmit and receive transportation payment information, delivery information or traffic information from stationary transceivers at the roadside.

Fig. 12 schematically shows a vehicle equipped with a surveillance system communicating with a roadside transceiver station TS. In conventional technology, the vehicle usually comprises a single RF transceiver to communicate with roadside transceiver stations. The vehicle and roadside station thus only get one attempt to communicate with each other. Consequently, to ensure successful communication the transmission power must be relatively high.

In contrast, the inventive wireless communication system, provided by the plurality of multi-function side-light units 20, will be much more effective and reliable. Due to the placement of the RF means in the multi-function sidelight units 20, a longer time-window for transmitting information is ensured. Further, since the RF signals may be relayed within the network, any of the multi-functional side-light units 20 may carry out the communication with the roadside transceiver station TS. As a result, the vehicle and the transceiver station TS have several connection opportunities.

According to one embodiment, at least one of the plurality of multifunction side-light units are provided with RFID readers. The RFID reader may be any commercially available RFID reader. The RFID reader may be provided as a separate RF unit or the RF transceiver means 28 may include RFID reading functionality. The RFID reader allows RFID information to be received by any multi-function side-light unit of the surveillance system and wirelessly transmitted to the central unit 100. The RFID information may be transmitted as encapsulated data within the RF signals or as raw data.

The RFID readers enable the communication network to be used in a plurality of further applications. According to one application illustrated in Fig. 13, RFID information from RFID tagged cargo TC may be wirelessly transmitted, via the side-light units 20, to the central unit in the cabin during loading and unloading. The information may be used to ensure that the correct cargo is being loaded and unloaded at the correct location. For example, if the central unit receives information indicating that cargo is loaded or unloaded, the cargo ID may be checked against entries of a database comprising entries with cargo ID and their corresponding loading/unloading location (e.g. in the form of GPS coordinates or other location information). If the location of the vehicle doesn't match the loading/unloading location in the database, the central unit may activate notification means to inform the driver, the loader/unloaded or a remote host.

According to a further application, the driver of the vehicle may carry an RFID tag with a trusted ID or code known to the inventive system. Any RFID reader of the surveillance system receiving the ID may forward the ID to the central unit 100. If the ID matches the trusted ID, the surveillance system is deactivated by the central unit 100. Correspondingly, the surveillance system 100 may be automatically activated if no RFID reader of the surveillance system 100 detects a presence of the specific RFID tag during a time interval. Compared to prior-art key-less solutions for locking/unlocking cars, this provides the advantage that the driver may approach the vehicle from any angle without risking to activate the alarm of the vehicle. Although in the above a surveillance system has been disclosed for intrusion detection or blind-spot detection, the communicating multi-function side-light units may be regarded as an independent inventive concept usable in a surveillance system. As understood from the detailed description above, a wireless communication network may thus be formed on a vehicle, such as a truck and trailer, by mounting a plurality of multi-function side-light units not having the sensor 26. The communication network may support the ZigBee or Bluetooth protocol or any other protocol supporting wireless relaying or ad- hoc and/or mesh network communications.

The communication system may further comprise a central unit corresponding to the central unit of the previously described surveillance system.

Further, the communication network may be used for communicating other kinds of information and may further be used in all the applications and embodiments mentioned above.

Claims

1. A side-light unit (20) for use in a vehicle (12) having a plurality of side-light units (20) mounted on each long side thereof, the side-light unit (20) comprising: a first signal-emitting device comprising a day-running light source (24); a second signal-emitting device (26; 31 ; 32; 33); an RF-receiver (28) for receiving RF-signals transmitted by a control unit (27) comprised in said vehicle (12), said RF-signals encoding control data; and a controller (27) connected to said second signal-emitting device (26; 31 ; 32; 33) and to said RF-receiver (28), the controller (27) being configured to: receive said control data from said RF-receiver (28); and control said second signal-emitting device (26; 31 ; 32; 33) to operate in accordance with said control data.

2. The side-light unit (20) according to claim 1 , wherein said second signal-emitting device (31 ; 32; 33) comprises a controllable light-emitting device, and wherein said controller (27) is configured to control the light- emitting device between first and second different light-emitting states in response to said control data.

3. The side-light unit (20) according to claim 2, wherein said light- emitting device (31) is arranged to provide visible illumination in a direction substantially in parallel with a side of said vehicle (12), when being provided on the vehicle and being controlled to emit light.

4. The side-light unit (20) according to claim 2 or 3, wherein said light- emitting device (31 ) is controllable to emit light having an intensity of at least 60 cd.

5. The side-light unit (20) according to any one of the preceding claims, wherein said controller (27) is further connected to said first signal-emitting device and configured to control said day-running light-source (24) between first and second different light-emitting states in response to said control data.

6. The side-light unit (20) according to any one of the preceding claims, further comprising a third signal-emitting device comprising a sound- generator (32) connected to said controller (27), wherein said controller is configured to control said sound-generator to generate an audible alarm in response to said control data.

7. The side-light unit (20) according to any one of the preceding claims, wherein said control data is indicative of a driver action.

8. The side-light unit (20) according to claim 7, wherein said driver action includes at least one of turning the steering wheel to change direction of the vehicle, activating the blinker to indicate an intended direction change, selecting a reverse gear, and activating an alarm system including the side- light unit.

9. The side-light unit (20) according to any one of the preceding claims, further comprising an RF-transmitter for transmitting RF-signals, said RF- transmitter being connected to said controller.

10. The side-light unit (20) according to claim 9, wherein: said second signal-emitting device comprises a sensor (26) for defining a surveillance zone (50) adjacent to said vehicle (10), the sensor (26) being arranged to detect an object or a movement of an object within the surveillance zone; and said controller (27) is configured to: control an extent of said surveillance zone in response to said control data; and provide a signal indicative of detection of an object of a movement of an object within the surveillance zone to said RF-transmitter for transmission to the control unit comprised in the vehicle.

11. The side-light unit (20) according to claim 10, further comprising a fourth signal-emitting device comprising a light-emitting indicator device (33) for indicating a state of said sensor (26), wherein said controller (27) is further configured to control said indicator device between first and second different light-emitting states in response to said control data.

12. A vehicle lighting system (90) comprising a plurality of side-light units (20) according to any one of claims 9 to 11 for mounting on the sides of a truck, bus, train or a similar long vehicle (10), said plurality of side-light units, when in use, forming an RF communication network on said vehicle (10); and a central unit (100) including: a control unit (101 ) configured to: acquire data indicative of a driver action; and determine control data for at least one of said side-light units (20a-c) based on said acquired data; and a central RF-transmitter (102) for transmitting central RF-signals encoding said control data to said at least one side-light unit.

13. The vehicle lighting system (90) according to claim 12, wherein each side-light unit, in response to the side-light unit receiving said central RF-signals (CA), is arranged to relay the received central RF-signals (CA) to one or more other side-light units (20) of the system.

14. The vehicle lighting system (90) according to claim 12 or 13, wherein at least one of the side-light units in the system is arranged to transmit an RF-signal in response to said at least one side-light unit receiving an incoming RF-signal from another side-light unit in said system.

15. The vehicle lighting system (90) according to any of claims 12 to 14, wherein said RF-communication network is a mesh network.

16. A vehicle (10) comprising a vehicle lighting system according to any one of claims 12 to 15 installed thereon.

17. The vehicle (10) according to claim 16, being a truck, bus, train or a similar long vehicle.

18. A method for providing a vehicle (10) with a vehicle lighting system, comprising the step of replacing existing, day-running side-light units of the vehicle with vehicle day-running side-light units according to any of claims 1 to 11.