GB2575847A

GB2575847A - A compact telematics device for a vehicle

Info

Publication number: GB2575847A
Application number: GB1812168.1A
Authority: GB
Inventors: Adam Cowley Timothy
Original assignee: Trakm8 Ltd
Current assignee: Trakm8 Ltd
Priority date: 2018-07-26
Filing date: 2018-07-26
Publication date: 2020-01-29
Anticipated expiration: 2038-07-26
Also published as: GB201812168D0; GB2575847B

Abstract

A telematics device 5 for attaching to a vehicle's on-board diagnostic system comprises: a housing 10; a printed circuit board 20 mounted within the housing; and at least one antenna. The housing comprises a base 12 comprising a connector for connecting to a diagnostic connector 30 on the vehicle and comprising side walls extending from the base. The side walls 40 are formed of a non-conductive material and the at least one antenna comprises a pattern of conductive material on at least one of the side walls. The side walls may be plastic and antenna(s) may be formed on the side wall(s) by laser direct structuring. The antenna can be suitable for receiving and transmitting cellular wireless communication signals, such as a GSM antenna. Otherwise the antenna may be suitable for receiving GPS signals. A GSM antenna and a GPS antenna may be provided. The base may have two longer sides and two shorter sides, with the antenna(s) provided on the short side wall(s). The side wall antenna is isolated from the interference of proximate circuitry or other antennas. Two antennas should be designed to reduce cross-coupling and have reduced overlap and increased separation in the frequency domain.

Description

A COMPACT TELEMATICS DEVICE FOR A VEHICLE

FIELD OF THE INVENTION

The invention relates to telematics devices or boxes for mounting in a vehicle connected to the vehicle’s on-board diagnostic system.

BACKGROUND

Many modern vehicles have complex diagnostic systems that allow for both the engine functionality and the driver’s behaviour to be analysed. Such vehicles contain a multitude of sensors for sensing the engine’s operation. The parameters sensed may include different variables such as acceleration, deceleration, temperature and noise. These sensors send their readings along a CAN (control area network) bus to a data output in the form of an on-board diagnostic (OBD) socket. When servicing a vehicle, monitoring equipment can be connected to the OBD socket and readings from the various sensors taken.

The presence of this OBD socket also allows for this data to be accessed during vehicle use as well as in a garage situation. The data provided by these sensors during use provides an indication of both driver behaviour and engine functionality and there may be advantages to being able to monitor this continually and to transmit collected data to a remote analyser using a wireless communication system.

In addition to the data collected from vehicle mounted sensors, it may be advantageous to collect further data relevant to the vehicle use that can be sent along with the data collected from the on-board diagnostic system. A GPS antenna for example, that is able to collect GPS data would allow information about the location of the vehicle and journeys taken to be collected.

Although the collection of data during use may be advantageous, it requires a telematics device or box to be fitted to the OBD socket for the collection and transmission of this data. It is desirable for such a box to be small and discrete, so that it can be attached to an OBD socket located somewhere in the vehicle without extending unduly into the useful space of the vehicle.

The desire for the box to be small and discrete competes with the desire for it to provide increasingly complex circuitry for monitoring and transmitting increasing amounts and diversity of data. Furthermore, where cellular wireless communication capabilities are i

provided then an antenna of a reasonable size is required, given that such communication frequencies may be as low as 700MHZ. Such an antenna will also need to have some protection from interference from signals from other circuitry within the box.

Conventionally the circuitry of such telematics boxes has been mounted on printed circuit boards which are themselves mounted to form a stack within a housing. It is difficult with such a construction to mount an antenna, particularly one of a suitable size for wireless communications or one able to detect low power signals and suitable for GPS reception, at a position where interference from other circuitry and from any other antenna is not too great.

It would be desirable to provide a telematics box which is compact and has at least one antenna.

SUMMARY

A first aspect of the present invention provides a telematics device for connecting to an output of a vehicle’s on-board diagnostic system, said telematics device comprising: a housing; a printed circuit board mounted within said housing; and at least one antenna; said housing comprising: a base with a connector for connecting to a diagnostic connector on said vehicle and with side walls extending from said base; wherein said side walls are formed of a non-conductive material and said at least one antenna is formed as a pattern of a conductive material on at least one of said side walls.

Telematics devices that attach to the output or socket of an on-board diagnostic system, have increasingly complex circuitry that is required for the increased functionality provided by such devices. There is however, a competing desire to reduce the size of such devices and this provides challenges. In particular, where an antenna is required, then the requirement for such an antenna to have a size sufficient for the wavelengths of the signals it is to transmit or receive and yet be sufficiently isolated from interference of neighbouring circuitry and/or other antennas make its location within a compact telematics device housing a particular problem.

Telematics devices have conventionally addressed the requirement of a high number of components in a small space by mounting the components on printed circuit boards and stacking the printed circuit boards within the housing. The antenna(s) has been located stacked in a similar way. The inventor of the present invention recognised that side walls of the housing are generally unused and provide available space for mounting an antenna that is substantially perpendicular to the other circuitry, which may then act as a ground plate for the antenna. In particular, forming an antenna as a conductive pattern on a non- conductive surface makes it ideal for mounting on a side wall and provides not only a convenient location for such an antenna but also provides a surface area that is relatively large when compared with the size of the telematics device. Such a location also provides some isolation from the other circuitry.

In some embodiments, said side walls are plastic and said at least one antenna is formed by laser direct structuring techniques on said plastic.

A particularly convenient way of forming an antenna is by using laser direct structuring techniques which enables a high quality antenna of a desired design to be formed in a relatively low cost manner. Such a technique allows different patterns to be formed in a controllable and accurate manner such that a shape that is appropriate for the wavelengths of the signals to be received and/or transmitted can be formed. Laser Direct Structuring (LDS) allows the antenna design to be directly transferred onto the moulded surface of the telematics box. The LDS process is used on a thermoplastic material, doped with a (non-conductive) metallic inorganic compound that can be activated by means of laser. The laser is then used to trace the required circuit onto the plastic. Where the laser beam hits the plastic a micro-rough track is formed. The track forms the nuclei for subsequent metallization.

In some embodiments, said printed circuit board is mounted to lie flat on said base.

In some embodiments the printed circuit boards are mounted to lie flat on and parallel to the base and in this way much of the surface of the antennas which extend up and away from the base on the side walls are relatively remote from the printed circuit board and the printed circuit board which has a conductive layer will act as a ground plate for the antenna helping to shape the beams.

Although the telematics device may have a number of forms, in some embodiments it has a box like shape with a rectangular cross section, said base comprising two longer sides and two shorter sides; said side walls comprising two correspondingly longer and two correspondingly shorter side walls.

Although the telematics device may only have a single antenna, in some embodiments said telematics device comprises multiple antennas, in some embodiments two antennas.

In some embodiments, where there are two antennas, then they are each mounted at least partially on respective shorter side walls, such that they are spaced apart by the longer side walls.

The substantially rectangular shape of the telematics device can be used to distance the two antennas from each other by mounting them at least partially on the two shorter walls such that they are separated by the longer walls.

In this regard, the two antennas have different functions and different requirements. For example, in some cases one may be a GPS antenna and the other may be an antenna for cellular wireless transmissions. The latter has to have a reasonable size for the wavelengths it is to transmit and receive and furthermore, the power of the transmissions will be relatively large, typically in the region of 2 Watts. The GPS antenna by contrast will receive lower power signals and as such, the proximity of the cellular wireless antenna may be a problem. Arranging the two antennas on opposite ends of the telematics device makes use of the full size of the device to separate them.

In some embodiments, said side walls are configured in two portions, said two shorter and one of said longer side walls being formed as a larger side wall portion, said larger side wall portion comprising said at least one antenna and said other longer side wall comprising a smaller side wall portion.

In order for the telematics device to be assembled in a simple way, it maybe convenient if the side walls are configured in two portions with one of the longer side walls being one of the portions and the other three side walls, two shorter side walls and a longer one forming the other portion. This allows these side walls to be slid onto the base in an assembly process.

In some embodiments, at least one of said at least one antenna extends around a corner of said larger side wall portion such that at least a portion is on one of said larger side walls and at least a portion is on said smaller side wall.

Although, by mounting the antennae on shorter side walls they are separated from each other by the longer side walls the surface area available for these antennas is reduced. Thus, in some embodiments it may be convenient if at least one of the antennas extends around the corner between the two side walls and extends along at least a portion of the longer side wall. This provides a greater surface area for the mounting of the antenna. This may be convenient where the antenna is for example a cellular wireless antenna and requires a reasonably large shape to accommodate the wavelength it transmits and receives.

In some embodiments, said larger side wall portion comprises connecting portions in electrical communication with said antennas and configured to connect with corresponding connecting portions on said base when said larger side wall portion is mounted on said base.

In order for the antennas when slid on to the base to be able to connect with the rest of the circuitry mounted on the base it may be convenient for them to have connecting portions which when slid on to the base connect with corresponding connecting portions on the base allowing an electrical connection between the printed circuit board and the antennae.

In some embodiments, said housing comprises a cover configured to fit around said side walls and attach to said base.

In some embodiments, said side walls and at least one antenna are substantially perpendicular to said base

In some embodiments, said at least one antenna is on an outer surface of said side walls.

It may be convenient to mount the antenna on the outer surface of the side walls as this has a larger surface area and where the housing has a cover configured to fit around the side walls and attached to the base the antenna will be protected from damage by this housing.

In some embodiments, said housing comprises a substantially rectangular cross section.

In some embodiments, said at least one antenna is an antenna suitable for receiving and transmitting cellular wireless communication signals.

In some embodiments, said at least one antenna comprises a GSM antenna.

In some embodiments, said at least one antenna comprises a GPS antenna for receiving signals from GPS satellite.

A GPS antenna for receiving signals from GPS satellites is a useful addition to a telematics device allowing information regarding the location of a vehicle and any journeys undertaken to be derived. However, GPS signals are weak and difficult to detect and thus in order for the GPS antenna to be in a convenient position for detecting such signals, it is advantageous if it is mounted on a side wall of the telematics device extending perpendicular to and away from devices mounted on a printed circuit board and at a distance from any other antennas.

In some embodiments, said telematics device comprises a GPS antenna and a cellular wireless communication antenna.

In some embodiments, said at least one antenna comprises a linear antenna type.

In some embodiments the one or more antennas are of a linear antenna type. Conventionally GPS antennas in such devices are formed as a ceramic patch antenna. With the GPS signal being circularly polarized, a linear GPS antenna potentially allows more (3dB) signal to be received because it can accept both right hand and left hand polarisations, however, it also makes it more susceptible to interference from other antenna such as the GSM antenna. Forming the two antennas using laser direct structuring, allows the two antenna patterns to be adjusted and optimised using techniques such as a simulation modelling tool shift so that the two antennas’ responses can be designed with reduced overlap and increased separation (typically quoted in dB) in the frequency domain.

In this regard, where there are multiple antennas, such as a GSM and GPS antenna, then the antennas are designed in such a way as to reduce cross coupling effects, i.e signals from the GSM transmission are rejected by the GPS antenna, that is they do not produce resonant effects. As noted above using manufacturing techniques such as laser direct structuring allows the characteristics of the antennas to be finely adjusted and optimised for a particular operating bandwidth.

In some embodiments said at least one antenna comprise an antenna for short range communications.

It may be convenient for the telematics device to be able to communicate with close range devices such as a driver’s mobile phone. In such cases an antenna for short range communications such as near field of Bluetooth® communications may be arranged on a side wall within the device.

In some embodiments, a length of said side walls between said base and a top of said device is less than 23mm.

The arrangement of the antennas on the side walls allows the device to have a lower height, the height of the device being less than 23mm allows it to fit into a greater number of car types.

The components on the telematics device may comprise a number of things including a modem for wireless communications, antennas as mentioned before, processors, data stores, an accelerometer, a gyro sensor, a short distance wireless communication module and other circuitry, such as a power supply.

Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate, and in combinations other than those explicitly set out in the claims.

Where an apparatus feature is described as being operable to provide a function, it will be appreciated that this includes an apparatus feature which provides that function or which is adapted or configured to provide that function.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which:

Figure 1 shows a cross section of a telematics device according to an embodiment;

Figure 2 shows a side wall portion of the telematics device according to an embodiment;

Figure 3 shows a side wall portion of the telematics device according to a further embodiment; and

Figure 4 shows an end view of some of the components of the telematics device in a semi assembled state.

DESCRIPTION OF THE EMBODIMENTS

Modern vehicles have sensors for sensing operational conditions of the vehicle such as temperature, acceleration and deceleration. Signals from these sensors are transmitted via a CAN bus to the OBD socket where they can be output for analysis when, for example, the vehicle is being serviced. The signals can also be collected when the vehicle is operational by plugging a telematics device into this socket. Such a device should be compact so as not to impede a driver’s movement. Figure 1 schematically shows a cross-section through such a telematics device 5 according to an embodiment.

The telematics device 5 comprises connector pins 30 each configured to mate with a different socket on the OBD output socket and each receiving different signals and/or power from this socket.

The telematics device 5 receives signals from the OBD socket and may process these signals and output them for remote analysis. Thus, such devices comprise processing circuitry (within printed circuit board 20) along with antennas which in this embodiment are mounted on side walls 40.

Telematics devices require increasingly complex analysis of the data collected during operation to be performed and in some cases additional data to that available from the CAN bus is required in these analysis. Thus, the number and complexity of components within such devices is increasing. These components may include a modem for wireless communications, antennas, processors, data stores, an accelerometer, a gyro sensor, a short distance wireless communication module and other circuitry, such as a power supply. Thus increasingly additional circuitry is being included in the telematics device and yet the requirement for the device to be compact and discrete remains. Furthermore, the mounting of one or more antennas leads to particular challenges with interference between the signals received and/or transmitted by the different antennas and the circuitry potentially causing problems.

The telematics device 5 of Figure 1 comprises a protective cover 10 mounted to a base 12 and enclosing side walls 40. The base mounts a printed circuit board PCB 20 that comprises much of the circuitry of the telematics device 5. The side walls mount the antennas for the telematics device, such that the antennas extend substantially perpendicularly to the base and PCB 20, the PCB 20 acting as a ground plate or plane for the antennas, helping to shape the beams and improve the effectiveness of the antennas. The antennas are formed as a conductive pattern on the non-conductive side walls 40. The conductive pattern forms a resonant structure for receiving and transmitting wireless signals. The size of the antenna is dictated by the wavelength and frequency of these signals. Furthermore, it should be located relatively remotely from the components within the telematics device to reduce interference. Mounting the antenna on a side wall 40, and in some cases on one of the end side walls with any other antenna mounted on the opposing side wall distances the antennas from each other and from the PCB 20 which is mounted on the base.

Figure 2 schematically shows a side wall portion 42 of the telematics device 5 of Figure

1. The telematics device 5 may in some embodiments be formed in sections for ease of manufacture and assembly. In such a case the side wall sections are formed as separate portions to the base and are slid onto the base and held in place by some clip mechanism prior to the cover 10 being on the base 12 to cover and protect the antenna(s) and circuitry.

The side wall potion shown in figure 2 is a larger side wall portion 42 which comprises two shorter end walls, and a longer wall. In this embodiment, each of the end walls comprises an antenna. One of these is shown schematically as antenna 50. Antenna 50 is formed by laser direct structuring as a conductive pattern on the end wall. Although this is shown schematically as a square in reality it will have a pattern formed from conductive areas and non-conductive areas, the pattern being designed to be effective for the wavelength of the signals the antenna is designed to receive/transmit and also to be effective at rejecting signals of a wavelength that the antenna on the opposing end wall is designed to receive/transmit. The pattern may be on an outer surface of the side wall of the telematics device and be configured to form a lobe which points outwardly from the telematics device away from the circuitry and any other antenna. There will be connecting portions extending from the antenna 50 towards the base and adapted to electrically connect with other connecting portions on the base 12 when the side wall 42 is attached to the base 12 allowing signals from the antenna to travel between the PCB 20 and antenna 50.

In some embodiments, there may only be one antenna in the device. In such a case the antenna may be on the longer side wall, or it may be on both the longer and at least one of the shorter side walls.

Figure 3 shows an alternative embodiment of the larger side wall portion 42. This has an antenna 52 that is adapted for longer wavelength signals such as GSM signals and as such the antenna extends across both the end wall and around onto the longer side wall. In this embodiment there may be an antenna adapted for shorter wavelength signals such as GPS signals on the other end wall. In some embodiments one of the antenna may be configured for near range communication such as Bluetooth® allowing it to communicate directly with a driver’s phone for example.

In this embodiment as in the previous one the antennas are formed by laser direct structuring as conductive patterns on the non-conductive plastic side walls. This technique provides a freedom in the design of the antennas, in that a variety of shapes and patterns can be formed by control of the lasers. This allows an iterative process to be performed in the design phase to generate a pattern that is effective both at receiving and transmitting the desired signal and at not receiving or rejecting signals at a wavelength and frequency of the other antenna in the device. A side wall portion having one longer side wall and one or two shorter end walls formed as a single piece allows the antenna to be formed on both the end and a portion of the side wall. This allows a larger surface area antenna to be formed that is still relatively remote from an antenna on the other end wall.

Figure 4 shows a partially assembled telematics device according to an embodiment. Base 12, is adapted to mount a PCB 20 and to mount and retain side walls 40 which can be slid into place on the base and held in position by recesses and protrusions on the mating surfaces that form clips. In this figure, the side walls 40 are formed in two portions, a smaller portion 44 comprising a single longer side wall and being shown mounted on the base, and the larger portion 42 comprising the two end walls and one longer wall being shown ready to be slid into positon. Once the side walls are in position the cover 10 is then slid over the side walls and this holds the whole device together and protects the antennas and PCB.

Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiment and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A telematics device for connecting to an output of a vehicle’s on-board diagnostic system, said telematics device comprising:

a housing;

a printed circuit board mounted within said housing; and at least one antenna;

said housing comprising a base comprising a connector for connecting to a diagnostic connector on said vehicle and comprising side walls extending from said base; wherein said side walls are formed of a non-conductive material and said at least one antenna comprises a pattern of conductive material on at least one of said side walls.

2. A telematics device according to claim i, wherein said side walls are plastic and said at least one antenna is formed by laser direct structuring on said plastic.

3. A telematics device according to any preceding claim, wherein said printed circuit board is mounted to lie flat on said base.

4. A telematics device according to any preceding claim, wherein said base comprises two longer sides and two shorter sides; said side walls comprising two correspondingly longer and two correspondingly shorter side walls.

5. A telematics device according to claim 4, said telematics device comprising two antennas, said two antennas each being mounted at least partially on respective shorter side walls.

6. A telematics device according to any one of claims 4 or 5, wherein said side walls are configured in two portions, said two shorter and one of said longer side wall being formed as a larger side wall portion, said larger side wall portion comprising said at least one antenna and said other longer side comprising a smaller side wall portion.

7. A telematics device according to claim 6, wherein at least one of said at least one antenna extends around a corner of said larger side wall portion such that at least a portion is on one of said larger side walls and at least a portion is on said smaller side wall.

8. A telematics device according to claim 6 or 7, wherein said larger side wall portion comprises connecting portions in electrical communication with said antennas and configured to connect with corresponding connecting portions on said base when said larger side wall portion is mounted on said base.

9. A telematics device according to any preceding claim, wherein said side walls are configured to slide onto said base and to clip into place.

10. A telematics device according to any preceding claim, wherein said housing comprises a cover configured to fit around said side walls and attach to said base.

11. A telematics device according to any preceding claim, wherein said side walls are configured in two portions, said two shorter and one of said longer side wall being formed as a larger side wall portion, said larger side wall portion comprising said at least one antenna and said other longer side comprising a smaller side wall portion.

12. A telematics device according to any preceding claim, wherein said at least one antenna is on an outer surface of said side walls

13. A telematics device according to any preceding claim, wherein said housing comprises a substantially rectangular cross section.

14. A telematics device according to any preceding claim, wherein said at least one antenna is an antenna suitable for receiving and transmitting cellular wireless communication signals.

15. A telematics device according to claim 14, wherein said at least one antenna comprises a GSM antenna.

16. A telematics device according to any preceding claim, wherein a length of said side walls between said base and a top of said device is less than 23mm.

16. A telematics device according to any preceding claim, wherein said at least one antenna comprises a GPS antenna for receiving signals from GPS satellite.

17. A telematics device according to any preceding claim, wherein said telematics device comprises a GPS antenna and a cellular wireless communication antenna.

18. A telematics device according to claim 17, wherein said at least one antenna comprises a linear antenna type.

19· A telematics device according to any preceding claim, wherein a length of said side walls between said base and a top of said device is less than 23mm.

25 07 19

Amendments to the claims have been filed as follows

5 a housing;

a printed circuit board mounted within said housing; and at least one antenna;

said housing comprising a base, said base comprising a connector for connecting to a diagnostic connector on said vehicle and comprising side walls io extending from said base; wherein said side walls are formed of a non-conductive material and said at least one antenna comprises a pattern of conductive material on at least one of said side walls;

said base comprises two longer sides and two shorter sides;

said side walls comprising two correspondingly longer and two correspondingly

15 shorter side walls, said telematics device comprising two antennas, said two antennas each being mounted at least partially on respective shorter side walls.

2. A telematics device according to claim 1, wherein said side walls are plastic and said at least one antenna is formed by laser direct structuring on said plastic.

4. A telematics device according to any preceding claim, wherein said side walls

25 are configured in two portions, said two shorter and one of said longer side wall being formed as a larger side wall portion, said larger side wall portion comprising said at least one antenna and said other longer side comprising a smaller side wall portion.

5. A telematics device according to claim 4, wherein at least one of said at least one

30 antenna extends around a corner of said larger side wall portion such that at least a portion is on one of said larger side walls and at least a portion is on said smaller side wall.

6. A telematics device according to claim 4 or 5, wherein said larger side wall

35 portion comprises connecting portions in electrical communication with said antennas and configured to connect with corresponding connecting portions on said base when said larger side wall portion is mounted on said base.

7- A telematics device according to any preceding claim, wherein said side walls are configured to slide onto said base and to clip into place.

8. A telematics device according to any preceding claim, wherein said housing comprises a cover configured to fit around said side walls and attach to said base.

9. A telematics device according to any preceding claim, wherein said at least one antenna is on an outer surface of said side walls

10. A telematics device according to any preceding claim, wherein said housing comprises a substantially rectangular cross section in a plane parallel to said base.

11. A telematics device according to any preceding claim, wherein said at least one antenna is an antenna suitable for receiving and transmitting cellular wireless communication signals.

12. A telematics device according to claim n, wherein said at least one antenna comprises a GSM antenna.

13. A telematics device according to any preceding claim, wherein said at least one antenna comprises a GPS antenna for receiving signals from GPS satellite.

14. A telematics device according to any preceding claim, wherein said telematics device comprises a GPS antenna and a cellular wireless communication antenna.

15. A telematics device according to claim 14, wherein said at least one antenna comprises a linear antenna type.