GB2584964A

GB2584964A - Systems and methods for interactive vehicle transport networks

Info

Publication number: GB2584964A
Application number: GB2009916.4A
Authority: GB
Inventors: Gardner David; Bradley Andrew
Original assignee: IR Kinetics Ltd
Current assignee: IR Kinetics Ltd
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2020-12-23
Anticipated expiration: 2040-06-29
Also published as: GB202009916D0; GB2584964B

Abstract

A device for tracking a vehicle in a transport network comprises an infra-red (IR) sensor 10 to detect IR radiation emitted from or reflected by the vehicle 12 within its field of view; a receiver to receive unique identification data and an initial position of the vehicle; a processor to determine current kinematic data of the vehicle based upon the IR radiation, the received unique identification data and the received position; and transmitter to transmit the determined current kinematic data of the vehicle to that vehicle and optionally to other vehicles or a traffic management system. The vehicle may be one of multiple autonomous ground based or airborne vehicles (20, Fig.2). The transmitter may also transmit a control signal for controlling the vehicle to alter its velocity of position. The device may be installed on existing roadside infrastructure 16 and may be one of a network of such devices (Figs.6-7) wherein a first vehicle tracking device transmits the current kinematic data and identifier of a vehicle to a second vehicle tracking device.

Description

SYSTEMS AND METHODS FOR INTERACTIVE VEHICLE TRANSPORT NETWORKS

FIELD OF THE INVENTION

[0001] The present invention is concerned with systems and methods for interactive vehicle transport networks, such as those involving autonomous vehicles. More particularly though not exclusively the present invention is directed to improvements in or relating to systems and methods for the operation of transport networks involving ground-based or airborne vehicles providing transportation of passengers or goods within cities, urban areas or along, above or near designated motorways, freeways, roads, railways or other routes between cities and urban areas. Any or all of the vehicles may be anywhere on the scale from fully autonomous to fully driver/pilot controlled. Also, they may or may not be linked to local, regional, or national traffic management systems.

BACKGROUND OF THE INVENTION

[0002] With ongoing developments in autonomous vehicle operation, there exists a need to adapt traffic management systems which take advantage of the new capabilities of autonomous vehicles. In particular, as vehicles are increasingly capable of regulating their own movement, some of the disadvantages of user operation are removed, such as a driver or pilot's reaction speeds, concentration levels, tiredness etc. As a result, autonomous vehicles are more able to react quickly to environmental hazards and as a result, higher speeds and higher densities of vehicles are able to be safely achieved than when compared to user operated vehicles, where factors such as thinking distance must be applied when considering safe stopping distances.

[0003] In order to enable such traffic management, it is necessary for the vehicles to have access to accurate kinematic data regarding itself and each of the vehicles in its proximity, which enable appropriate actions to be taken. This will include kinematic data of both a particular vehicle which is to take an action, as well as other vehicles in its vicinity which may affect the decision of which actions should be taken.

[0004] Current technology architecture relies on the principle that sensors onboard the vehicles provide each vehicle independently with its own situational awareness with which it can then reason about its environment and make and enact its own decisions.

[0005] Over recent years, commercially available situational sensing and geo-location technologies including RADARF(dio Detection And Ranging), LIDAR (Light Imaging, Detection & Ranging), GNSS (Global Navigation Satellite Systems), EO (Electro-Optic) sensors and IR (Infra-Red) sensors have all reduced in mass, size, power consumption, heat output and susceptibility to environmental hazards such as mechanical shock, vibration and electro-magnetic interference to the extent that in principle they can be integrated into commercial vehicles (e.g. buses, trucks, taxis, drones) and domestic vehicles (e.g. cars, personal flying vehicles) to work in combination to provide situational awareness, potentially enabling driverless or pilotless operation. However, the complexity of all such approaches to situational awareness based on multiple sensors and sensor fusion in the safety critical application of driverless/pilotless vehicles is considerable. The authors' experience in defence and aerospace is that this complexity inevitably drives up vehicle cost and increases safety hazard risks. Furthermore, it becomes increasingly difficult to adopt a common approach, such that standardisation becomes challenging. Despite the huge investments made by a number of large technology companies in driverless cars the past decade has shown extremely slow progress, with safety hazard risks becoming increasingly of concern to the extent that the potential for regulatory approval of driverless vehicles is brought into question.

[0006] In some known systems, an attempt is made to implement roadside, in road or above road sensing equipment to detect, localise, track, and communicate with vehicles for the purpose of, for example, traffic flow management. However, typically these systems are unable to achieve such detection with the real-time kinematic accuracy and reliability necessary for safe autonomous navigation in traffic streams at currently legislated speeds and advisory vehicle separations, let alone any increased traffic flow rates.

[0007] Using a representative example of traffic flowing at a typical speed of 100 km/h (28 m/s) on a motorway or freeway, if the ground truth (i.e. the physical reality) of a vehicle's longitudinal position is to be measured every 50cm of travel to an accuracy of 5cm, then the measurement must be performed to that accuracy and provided repeatedly with a periodicity of around 20ms, equivalent to a frequency of around 50Hz. Existing roadside systems are unable to achieve such accuracy and frequency.

[0008] It is an object of the present invention to overcome one or more of the problems described above.

SUMMARY OF THE INVENTION

[0009] According to one aspect of the present invention, there is provided a vehicle tracking device for tracking one or more vehicles at a geographic location of a transport network within which the one or more vehicles are able to move. The vehicle tracking device comprises one or more infra-red (IR) sensors having a field of view and being configured to detect IR radiation being emitted from or reflected by the one or more vehicles at the geographic location within the field of view. The vehicle tracking device further comprises a receiver configured to receive unique identification data which uniquely identifies each of the one or more vehicles and position data which indicates an initial position of each of the one or more vehicles when the one or more vehicles enter the field of view at the geographic location. The vehicle tracking device additionally comprises a processor configured to determine current kinematic data of the one or more vehicles in at least two dimensions based upon the IR radiation detected by the one or more IR sensors, the received unique identification data and the received position data. The vehicle tracking device additionally comprises a transmitter configured to transmit the determined current kinematic data of a particular vehicle of the one or more vehicles to the particular vehicle.

[0010] In this way, this aspect of the present invention solves at least one of the problems of the prior art outlined above. It is possible with the present invention to accurately externally determine and track the kinematic data of one or more moving vehicles and provide this information to the one or more moving vehicles to enable the vehicles to operate safely in an environment comprising several vehicles moving at potentially high velocities. In particular, the present invention enables accurate measurements of kinematic data to be made externally to the vehicles to be detected in a manner which is procedurally efficient and to a degree of accuracy which is higher than is possible in known prior art systems. In so doing, some of the safety issues associated with the prior art are eliminated. Further, this invention enables this kinematic data to be generated externally to the vehicle, enabling the adoption of standardised approaches which is not possible using on-board vehicle based tracking.

[0011] In some embodiments, the particular vehicle is a ground-based vehicle.

[0012] In further embodiments, the vehicle tracking device is provided with terrain mapping data, and the processor is configured to determine current kinematic data in three dimensions based upon one or more of the detected IR radiation, the unique identification data, previously-determined kinematic data of each of the one or more vehicles and the terrain mapping data.

[0013] In some embodiments, the particular vehicle is an airborne vehicle. This ability to monitor airborne vehicles may be particularly advantageous in environments in which airborne drones or other similar technologies are being afforded an increasing amount of utility such as for delivery of items, security surveillance, mobile recharging etc. By enabling monitoring of airborne vehicles, the present invention aids in the creation of a "road in the sky," in which a plurality of drones or other airborne vehicles may operate safely at the same time in order to perform a variety of functions.

[0014] In further embodiments, one or more vehicles comprises at least two vehicles and one of the vehicles is a ground-based vehicle and the other vehicle is an airborne vehicle, and the one or more IR sensors comprises at least two sensors, one IR sensor being configured to detect IR radiation being emitted from or reflected by the ground-based vehicle and the other IR sensor being configured to detect IR radiation being emitted from or reflected by the airborne vehicle. This may be particularly advantageous in scenarios in which interaction between airborne and ground based vehicles may be expected, for example in mid journey recharging of vehicles or exchange of items between an airborne and ground based vehicle.

[0015] In some embodiments, the processor is configured to use previously determined current kinematic data of the one or more vehicles as an input to the determination of the current kinematic data for each of the one or more corresponding vehicles.

[0016] The processor may be configured to determine current kinematic data of the one or more vehicles at a frequency of at least 50Hz. Such an arrangement enables extremely high accuracy tracking.

[0017] In further embodiments, the receiver is additionally configured to receive data relating to a ground-space envelope or an air space envelope of the one or more vehicles and the processor is arranged to use the ground-space envelope or air space envelope to determine relative positioning of the one or more vehicles. This may be particularly advantageous in determining safe positioning of vehicles whilst minimising processing requirements. In particular, by providing a ground space envelope or an air space envelope, a footprint of a particular vehicle may be generated indicating a "safe-zone" in which a vehicle may be positioned, and this is achieved without requiring full image processing of a vehicle to determine the space it occupies.

[0018] The vehicle tracking device may be configured to be installed on existing roadside, trackside or urban/city infrastructure.

[0019] In additional embodiments, the vehicle tracking device further comprises an IR emitter configured to emit IR radiation toward the one or more vehicles.

[0020] The transmitter may be configured to transmit the determined current kinematic data of each of the one or more vehicles to a respective one of the one or more vehicles.

[0021] In some embodiments, the determined kinematic data is also transmitted to a Traffic Management System (TMS).

[0022] In further embodiments. the processor is further configured to generate a control signal for controlling the particular vehicle of the one or more vehicles based upon the determined current kinematic data of the at least one of the one or more vehicles, wherein the control signal includes instructions which when executed by the particular vehicle cause an alteration of a velocity or position of the particular vehicle, and where the transmitter is further configured to transmit this control signal to the particular vehicle. This may be particularly advantageous when the system is implemented using fully autonomous vehicles. In particular, a control signal may be generated and transmitted to one or more vehicles for enactment, allowing the one or more vehicles to be safely operated in view of the other vehicles in its proximity.

[0023] In some embodiments, at least one of the one or more IR sensors is configured to detect IR radiation emitted from or reflected by a fixed geographical reference point, and the processor is further configured to determine a position of the vehicle tracking device with respect to the fixed geographical reference point and use the determined position of the vehicle tracking device when determining the current kinematic data of the one or more vehicles.

[0024] The current kinematic data of the one or more vehicles determined by the processor, may comprise at least a geographic position over time of the corresponding vehicle.

[0025] The current kinematic data of the one or more vehicles determined by the processor may comprise data corresponding to at least a longitudinal and latitudinal coordinate of the vehicle.

[0026] In further embodiments, the vehicle tracking device is configured to monitor an entry point with a fixed position, and to receive data relating to the fixed position at a particular point in time as the initial position of each of the one or more vehicles.

[0027] In further embodiments, the processor is further configured to generate a pull request to be transmitted by the transmitter which requests the transmission of the unique identifier data and initial position data from the one or more vehicles.

[0028] According to a second aspect of the present invention, there is provided a vehicle tracking system for tracking one or more vehicles, the vehicle tracking system comprising a plurality of vehicle tracking devices as described in any of the above embodiments arranged in a network, and where the transmitter of a first vehicle tracking device is configured to transmit the current kinematic data determined at the first vehicle tracking device and unique identification data of the one or more vehicles to a second vehicle tracking device of the plurality of tracking devices and the receiver of the first vehicle tracking device is configured to receive current kinematic data determined at a third vehicle tracking device of the plurality of vehicle tracking devices and unique identification data of the one or more vehicles from a third vehicle tracking device.

[0029] In this way, this aspect of the present invention solves at least one of the problems of the prior art outlined above. In particular, this aspect enables efficient monitoring of one or more vehicles over an extended area. By exchanging calculated information between a plurality of tracking devices, once a vehicle has initially provided identification data, the system is able to monitor the vehicle without further input from the vehicle for so long as it remains within view of a tracking device of the vehicle tracking system. This provides a more procedurally efficient method of tracking vehicles over an extended area than is available from presently known systems which independently monitor vehicles without interacting. In addition, the advantages discussed with respect to the first aspect are similarly maintained in the second aspect.

[0030] In further embodiments of this second aspect, the processor of the second vehicle tracking device is further configured to compare current kinematic data of at least one ofthe one or more vehicles determined locally at the second device with current kinematic data received from and determined at the first vehicle tracking device to determine an agreement between the locally determined current kinematic data and the received kinematic data. Optionally in these embodiments, the second vehicle tracking device receives current kinematic data from at least two other vehicle tracking devices and the processor of the second tracking device is configured to compare the received current kinematic data and to prevent transmission of any current kinematic data which disagrees with the other kinematic data, received or determined at the second tracking apparatus, to the particular vehicle. This advantageously mitigates the possibility of error within a tracking device within the tracking system, wherein erroneous data may be quickly identified and disregarded where necessary.

[0031] In some embodiments of the second aspect, the second vehicle tracking device receives the results of data comparisons between at least two other vehicle tracking devices and the processor of the second tracking device is configured to use voting to identify a tracking device that is behaving inconsistently.

[0032] In some embodiments of the second aspect, at least two of the plurality of vehicle tracking devices are arranged to be located geographically adjacent to each other and the IR sensors of the adjacently-located vehicle tracking devices have partially overlapping fields of view.

[0033] According to a third aspect of the present invention there is provided a method of tracking one or more vehicles at a geographic location in a transport network within which the one or more vehicles are able to move, the method comprising: receiving unique identification data which uniquely identifies each of the one or more vehicles and position data which indicates an initial position of each of the one or more vehicles at the geographic location; detecting IR radiation being emitted from or reflected by the one or more vehicles at the geographic location; determining current kinematic data of the one or more vehicles based upon the detected IR radiation, the received unique identification data of each of the one or more vehicles and the position data; and transmitting the determined current kinematic data of a particular vehicle of the one or more vehicles to the particular vehicle. It is to be appreciated that the third aspect is a method of operating the inventions described in one or more of both the first and second aspects and so the advantages of such an aspect are identical to those described above with respect to these aspects.

[0034] In further embodiments of this third aspect, the transmitting step further comprises transmitting the current kinematic data to at least one other vehicle tracking device of a plurality of tracking devices.

[0035] The above described features of the embodiments are combinable in different ways and can be added to the following specific description of the embodiments of the present invention if not specifically described therein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order that the invention may be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is an isometric view of a vehicle tracking apparatus in a use scenario; Figure 2 is an isometric view of the vehicle tracking apparatus of Figure 1 in an alternate use scenario; Figure 3 is an isometric view of a vehicle to be tracked by the vehicle tracking apparatus of Figure 1. Figure 4 is a schematic view of the vehicle tracking apparatus of Figure 1; Figure 5A is a flow diagram illustrating a method of operation of the vehicle tracking apparatus of Figure 1; Figure 5B is a flow diagram illustrating a further method of operation of the vehicle tracking apparatus of Figure 1; Figure 5C is a flow diagram illustrating a yet further method of operation of the vehicle tracking apparatus of Figure 1; Figure 6 is an isometric view of a vehicle tracking system comprising a plurality of the vehicle tracking apparatuses of Figure 1 in a use scenario; Figure 7 is an isometric view of the vehicle tracking system of Figure 6 in an alternate use scenario; and Figure 8 is a flow diagram illustrating a method of operation of the vehicle tracking system of Figure 6; DETAILED DESCRIPTION [0037] Specific embodiments are now described with reference to the appended figures.

[0038] It is to be appreciated that references made herein to a vehicle to be tracked may refer to a variety of mobile mechanical objects, including objects which travel along the ground and in the air. By way of a non-exhaustive list, these vehicles may include cars, lorries, motorcycles, drones, and small aircraft. These vehicles may additionally be configured to be operated manually by a user, or the vehicles may be configured to be autonomous, or a combination of the two, namely semi-autonomous.

[0039] Turning firstly to Figure 1, there is shown a vehicle tracking apparatus 10 for detecting one or more vehicles 12 and determining various kinematic data in respect of the detected vehicles 12. Whilst the term apparatus is used throughout this document, it is to be appreciated that this term is to be interpreted as being synonymous to a "device." The vehicle tracking apparatus 10 is shown placed above a road 14 securely mounted on existing road infrastructure 16 and is configured to be arranged to monitor vehicles 12 which enter the fixed field of view of the vehicle tracking apparatus 10. The existing road infrastructure 16 to which the vehicle tracking apparatus 10 may comprise lampposts, traffic lights, gantries, traffic monitoring equipment and bridges. It is to be appreciated that this is an illustrative example and the vehicle tracking apparatus 10 may be mounted to other existing road infrastructure 16. Alternatively, the vehicle tracking apparatus 10 may be provided with dedicated support structures to which the vehicle tracking apparatus 10 may be attached.

[0040] The vehicle tracking apparatus 10 is configured to receive data which uniquely identifies the vehicles 12 that enter its field of view. Such unique identification data may comprise a vehicle registration of the vehicle. The vehicle tracking apparatus 10 is additionally configured to receive data indicating an initial position of the vehicle 12 relative to itself, as it enters its field of view of the vehicle tracking apparatus 10 relative to the vehicle tracking apparatus 10. Alternatively, all these positions could simply be provided as absolute coordinates such as the latitude and the longitude of the vehicle. The vehicle tracking apparatus 10 is then further configured to use the received unique identification data in conjunction with the initial position data in order to associate the unique identification data with the initial position data. Further details explaining how this is may be achieved are given below with reference to Figure 3.

[0041] It is to be appreciated that the term 'initial position' as used throughout this document refers to the position the vehicle 10 is situated at when it first comes into functional view of a vehicle tracking apparatus 10. In addition, in embodiments in which a plurality of vehicle tracking apparatuses 10 are used in a networked system (as described below), the initial position of the vehicle, which is received by the current vehicle tracking apparatus, may be the last tracked position of the vehicle in the field of view of an adjacent vehicle tracking apparatus from which the vehicle is exiting. Given that the fields of view of two vehicle tracking apparatus are typically abutting or slightly overlapping each other, the last sensed vehicle position in a field of view of a first vehicle tracking apparatus can provide a very good indicator of the position the vehicle 10 is situated at when it enters the field of view of a second adjacent vehicle tracking apparatus 10.

[0042] The vehicle tracking apparatus 10 is further configured to receive IR emissions, which are either emitted or reflected by vehicles 12 which enter the field of view of the vehicle tracking apparatus 10. The vehicle tracking apparatus 10 is configured to determine various kinematic data of the vehicles 12 based upon the received IR emissions. Such kinematic data may comprise a position, a velocity, an acceleration, or other kinematic properties of the vehicles 12. In some embodiments, the kinematic data determined by the vehicle tracking apparatus 10 is used in conjunction with the unique identifier data and initial position data in order to associate the received data with the detected IR emissions.

[0043] Once a vehicle 12 has entered the field of view of the vehicle tracking apparatus 10, the vehicle tracking apparatus 10 may be configured to constantly monitor current kinematic data of the vehicle 12 until such a time as it leaves the field of view of the vehicle tracking apparatus 10. As such, once a vehicle 12 enters the field of view of the vehicle tracking apparatus 10 and the unique identifier information and initial position data are received, the vehicle tracking apparatus 10 is configured to specifically monitor incremental movements of the vehicle 12 by receiving consecutive IR emissions from the vehicle at regular time intervals. Each of the detected IR emissions can be used by the vehicle tracking apparatus 10 to determine a position of the vehicle, and the combination of successive position determinations allows the calculation of other kinematic data such as velocity and acceleration. The measurement of the position at regular time intervals may also be used to determine if a detected vehicle 12 is moving transversely (i.e. changing lanes) as well as longitudinally (i.e. along the road). The length of the time intervals between consecutive detected IR emissions may be used to determine the latency and accuracy of the kinematic data that is calculated. For example, if IR emissions are detected to an accuracy of 5cm with a periodicity of 20ms (a frequency of approximately 50Hz), this translates to a measurement every 50cm of travel by a vehicle travelling at 100Km/h. This is considered to be highly accurate for the purposes of vehicle control and navigation and will also enable vehicle velocity, acceleration/deceleration rates, or other useful kinematic data to be calculated quickly and accurately. These figures should be considered as illustrative only since if less demanding accuracies and latencies prove adequate in practice then they can be substituted and if more demanding accuracies and latencies prove necessary in practice they can be substituted.

[0044] The vehicle tracking apparatus 10 may be further configured to transmit the determined current kinematic data to the one or more detected vehicles 12. The transmitted kinematic data may comprise any one of the kinematic data determinations made by the vehicle tracking apparatus 10. The provision of the kinematic data enables the one or more detected vehicles 12 to adjust a kinematic quantity (for example speed, or direction of travel) of the relevant vehicle 12 in accordance with the received kinematic information. In some embodiments, the vehicle tracking apparatus 10 is configured to only transmit determined current kinematic data relating to the vehicle 12 it relates to. In such an embodiment, the vehicle 12 is then able to adjust kinematic quantities based on this knowledge (e.g. to reduce or increase velocity, to move within a lane if it is indicated that vehicle is straying into a different lane etc). In further embodiments, the vehicle tracking apparatus 10 is configured to transmit determined kinematic data relating to a plurality of the detected vehicles 12 to each vehicle. In such an embodiment, each vehicle 12 then may adjust kinematic qualities both with knowledge of the vehicle's 12 own kinematic data, as well as the kinematic data of other vehicles 12 in the vicinity. By way of example, a first vehicle 12 is provided with current kinematic data indicating that the velocity and position of second vehicle 12 directly in front of the first vehicle, such that it is possible for the first vehicle to safely move closer to the second vehicle 12.

[0045] The current kinematic data is transmitted to one or more vehicles 12 which may be either partially or entirely autonomously operated or may be operated with input from a driver or pilot of the vehicle 12. The format of the transmission made by the vehicle tracking apparatus 10 may be arranged to suitably meet the needs of the recipient vehicle 12. In further embodiments of the present invention, the vehicle tracking apparatus 10 is configured to additionally send a control signal to the one or more vehicles 12, causing the vehicle to take a particular action. The control signal may be formed on the basis of the calculated current kinematic data of the one or more vehicles 12. By way of example, if it is determined that two detected vehicles 12 in the field of view of the vehicle tracking apparatus 10 are within a predetermined distance of one another based upon the calculated velocities of the two vehicles 12, the vehicle tracking apparatus 10 generates a control signal to be transmitted to one of the vehicles 12 informing the vehicle to either speed up or slow down accordingly.

[0046] In additional embodiments, the vehicle tracking system 10 is also configured to transmit determined current kinematic data to local or regional Traffic Management Systems (TMSs) to provide a shared, common picture comprising the high-accuracy kinematic data for vehicles 12 across a wider field spanning multiple IR tracking sensors. This provides the TMSs with live, accurate data for each vehicle 12 and allows the TMSs to augment the determined current kinematic data provided to the one or more vehicles 12 about their immediate locality with advisory or compulsory information that the onboard systems of the one or more vehicles 12 deal with relating to traffic management.

[0047] It is to be appreciated that the vehicle tracking apparatus 10 may be securely mounted at various heights. The height at which the vehicle tracking apparatus 10 is mounted typically determines the ground envelope within the field of view of the vehicle tracking apparatus 10 i.e., a vehicle tracking apparatus 10 which is mounted at a higher position may have a greater area within its field of view than a vehicle tracking apparatus 10 which is mounted at a lower position. The height at which the vehicle tracking apparatus 10 is mounted therefore will largely depend upon the field of view requirements. Typically, a vehicle tracking apparatus 10 which is mounted at a height of 10m will need to have a field of view of 140° longitudinally (i.e. along the road) and 50° transversely (i.e. across the road) in order to cover a ground envelope typically associated with a lamppost on a motorway or freeway.

[0048] In further embodiments of the vehicle tracking apparatus 10, it is desirable to be able to alter the field of view of the vehicle tracking apparatus 10 in use, perhaps at the time of installation in order to cover the required ground envelope. For example, it may be desirable to move the field of view such that the vehicle tracking apparatus 10 is able to view a different carriageway of a motorway. In such embodiments, the vehicle tracking apparatus 10 is configured to rotate around at least one axis in order to adjust the ground envelope within the field of view, and possibly to have adjustable optics to vary the field of view, thereby providing the apparatus 10 with a variable ground envelope coverage within the field of view. In such embodiments, the apparatus 10 is configured to take into account the current position and orientation of the vehicle tracking apparatus 10 when determining current kinematic data of the one or more vehicles 12.

[0049] Where a plurality of vehicles 12 are present in the field of view of the vehicle tracking apparatus 10, the vehicle tracking apparatus 10 may be configured to receive relevant data and IR emissions from, and calculate current kinematic data of each of the vehicles 12 simultaneously, in accordance with embodiments described herein.

[0050] It is envisaged that in some cases, the vehicle tracking apparatus 10 operates in an environment in which not all of the vehicles which pass into its field of view have the capability to either emit or reflect IR radiation to be detected by the vehicle tracking apparatus 10. In such cases, these vehicles may be restricted to a particular, possibly slowest lane(s) by physical barriers, road signage, on-board vehicle lane-tracking control or any combination of these or other methods. It is further envisaged that in some situations one vehicle may obscure the IR emissions or reflections from another vehicle -for example if a small car is travelling behind and close to a large truck as they approach a sensor. In such cases, either the IR sensor can be fixed at a greater height or the traffic flows can be restricted by traditional means to keep similar sized vehicles in appropriate lanes. Further, a vehicle tracking apparatus 10 may be configured to receive IR emissions from multiple angles, such that IR emissions may still be received even where at certain angles the emissions are blocked from view of the vehicle tracking apparatus 10. In this regard, the vehicle tracking apparatus may comprise a plurality of different IR sensors located at different positions, for example at different heights. In such embodiments, where emissions are detected from multiple angles, the vehicle tracking apparatus 10 may be configured to compare the detected emissions to verify the veracity of the emissions.

[0051] Referring now to Figure 2, there is shown an alternate use scenario for the vehicle tracking apparatus 10 described in Figure 1. In this embodiment, the vehicle tracking apparatus 10 is shown mounted on existing road infrastructure. However, in this scenario, the vehicle tracking apparatus 10 is configured to monitor airborne vehicles 20. It is to be appreciated that embodiments described above may be suitably adapted in order to monitor airborne vehicles rather than ground-based vehicles. Further discussions of how this is achieved are given below with reference to Figure 4.

[0052] It is to be appreciated that in the use scenario of Figure 1, the vehicle tracking apparatus is configured to monitor ground-based vehicles 12 which are generally restricted to travel along predefined paths (i.e. roads in cities, countryside and motorways). In the use scenario of Figure 2 however, the airborne vehicles 20 which are to be monitored are not physically restricted in such a manner, and as such it is envisaged that it may be necessary to mount the vehicle tracking apparatus 10 in places outside of purely road-based infrastructure. Therefore, in use scenarios as illustrated in Figure 2, the vehicle tracking apparatus 10 is configured to be securely mounted on any existing infrastructure, regardless of its proximity to a roadside. Alternatively, the vehicle tracking apparatus 10 may also be provided with dedicated support structures to which the vehicle tracking apparatus 10 may be attached. Additional considerations regarding such arrangements will be discussed in further detail with reference to Figure 4. Whilst it is envisaged that it will be possible to mount the vehicle tracking apparatus 10 for monitoring airborne vehicles 20 in places outside of purely road-based infrastructure, it is to be appreciated that airborne vehicles 20 may also still be configured to travel along existing road and rail infrastructure in a manner analogous to that of the ground-based vehicle 12 example. As a result, even when monitoring airborne vehicles 20, the vehicle tracking apparatus 10 may still be configured to be mounted to the same existing roadside / rail-side infrastructure as described previously.

[0053] Whilst the use scenarios of Figures 1 and 2 are shown separately, it is to be appreciated that a single vehicle tracking apparatus 10 may be provided which is configured to monitor both ground-based 12 and airborne vehicles 20. This is achieved by providing sensors, which are oriented in different directions (namely having different fields of view) to monitor the two types of vehicle. In such scenarios, the vehicle tracking apparatus 10 is configured to only send determined current kinematic data regarding airborne vehicles 20 to the one or more airborne vehicles 20, and similarly is configured to only send determined current kinematic data regarding ground-based vehicles 12 to the one or more ground-based vehicles 12. Additionally or alternatively, the vehicle tracking apparatus 10 may be configured instead to be able to send determined current kinematic data regarding airborne vehicles 20 to one or more ground-based vehicles 12 and vice versa. This advantageously enables ground-based vehicles 12 and airborne vehicles 20 to coordinate their locations. For example, this may be used for ground-to-air battery charging, where airborne vehicles operating under electrical power provided from a battery could dock with a battery recharging truck. It may also be used in a use scenario of a delivery lorry with a swarm of airborne delivery drones that travel with the lorry into the delivery area and then split off, deliver to door, and return. It may further be used in a use scenario where collector drones pick up consignments and deliver to trucks for long-distance transportation. One further advantage of sharing airborne vehicle data with ground-based vehicles and vice versa is that physical spaces can be created in the ground-based vehicles positions above which airborne vehicles can travel. This would be a safety configuration such that if the airborne vehicle were to lose altitude or crash, there would be no ground-based vehicles below the airborne vehicles, which would minimise the risk for collision. It is to be appreciated that these use scenarios are for illustrative purposes only, and it is intended that such an embodiment may be utilised in many other applications. Further details regarding these embodiments are described in further detail with reference to Figure 4 below.

[0054] Turning to Figure 3, there is shown an example of a ground-based vehicle 12, which the vehicle tracking apparatus 10 of Figure 1 is configured to detect. Figure 3 shows a vehicle 12 which is fitted with IR emitters 30A, 30B, 30C, 30D, 30E placed on an upward facing surface of the vehicle 12. Whilst five emitters 30A, 30B, 30C, 30D, 30E are shown in Figure 3, it is to be appreciated that this is for illustrative purposes only and any suitable number of emitters may be used which enable the functionality of the vehicle tracking apparatus 10. It is also to be appreciated that emitters may be fixed to the front, rear or sides of vehicles. The use of these in relation to a ground space envelope of the vehicle is described later.

[0055] The vehicle 12 is also provided with a transmitter 32 and receiver 34 (or a combined transceiver) configured to transmit and receive wireless signals respectively. Upon entering the field of view of a vehicle tracking apparatus 10, the vehicle 12 is configured to transmit a wireless signal to the vehicle tracking apparatus 10. The wireless signal comprises unique identification data of the vehicle 12 as well as the data indicating an initial position of the vehicle 12 with respect to the vehicle tracking apparatus 10 or indicating absolute position of the vehicle. This provision of initial positioning may be particularly useful if the vehicle is unknown to the system, namely at an entry point to the system. However, it is not envisaged that the network of sensors would require this information once the vehicle was being tracked by the system. The information which can be received from the vehicle once known to the network is described below.

[0056] The vehicle 12 may typically be configured to transmit data indicating the position of the IR emitters 30A, 30B, 30C, 30D, 30E with respect to a ground-envelope 36 of the vehicle 12. The ground-envelope 36 provides an indication of the two-dimensional footprint of the vehicle representing the space that the vehicle 12 occupies on the road as it is travelling. When IR emissions emitted from the IR emitters 30A, 30B, 30C, 30D, 30E are detected by the vehicle tracking apparatus 10, the emissions may be used in conjunction with the information regarding the ground-space envelope in order to determine the two-dimensional space that the vehicle 12 occupies. In this way, it is not necessary for the vehicle tracking apparatus 10 to fully resolve an image of the vehicle for the purposes of determining in a safe and reliable manner the vehicle's proximity to other vehicles. In some embodiments, the ground-space envelope additionally includes some space surrounding the vehicle to act as a safety zone around the perimeter of space that the vehicle occupies. In addition, the provision of the position of the IR emitters 30A, 30B, 30C, 30D, 30E with respect to the ground-envelope 36 may also help in determining the orientation kinematic data, in which the vehicle tracking apparatus 10 is able to determine the orientation of the relevant vehicle 12 on the road (i.e. whether it is aligned precisely along the road or whether it is angled, so as to change position across the road). In embodiments in which an airborne vehicle 20 is to be tracked, a ground space envelope 36 is not appropriate. In such cases, the airborne vehicles 20 may be configured to provide an air space envelope. In some embodiments, the air space envelope may again provide a two-dimensional footprint of the vehicle representing the two-dimensional space that the vehicle 20 occupies in the air as it is travelling. In further embodiments, the air space envelope may provide a three-dimensional footprint of the vehicle representing the three-dimensional space that the vehicle 20 occupies in the air as it is travelling.

[0057] In Figure 3, the IR emitters 30A, 30B, 30C, 30D, 30E are shown arranged in a particular formation. It is to be appreciated that in addition to the number of IR emitters 30A, 30B, 30C, 30D, 30E being variable, the pattern in which they are arranged in may similarly be variable. In some embodiments of the present invention, the vehicle tracking apparatus 10 is configured to associate a particular pattern of IR emitters with a particular type of vehicle (e.g. lorry, car, drone, motorcycle etc). When a particular spatial pattern of IR emission is detected, the vehicle tracking apparatus 10 is configured to recognise the type of vehicle that is being detected. Such patterns preclude misidentification due to adjacent vehicle coincidences. Standard configurations for particular vehicle types may comprise, for example, a triangular array of 3 IR emitters for cars and a domino array of 5 IR emitters for trucks and vans. These configurations help to enable unambiguous sensing and determination of kinematic data (such as position, velocity, acceleration, deceleration, orientation, etc). Information related to the type of vehicles 12 in the field of view of the vehicle tracking apparatus 10 may also be transmitted to the one or more detected vehicles 12 in the field of view of the tracking apparatus. Furthermore, in embodiments where the vehicle tracking system 10 is configured to generate a control signal, the vehicle tracking apparatus 10 is configured to use information relating to the type of vehicle being detected to determine the content or type of control signal to be generated. For example, when two adjacent vehicles 12 are determined to be in the vicinity of one another, the control signal generated by the vehicle tracking apparatus 10 typically differs for a truck and a car, due to the associated differences in stopping distance.

[0058] In some embodiments, the IR emitters 30A, 30B, 30C, 30D, 30E are replaced by IR reflectors. This embodiment is used in cases where the vehicle tracking apparatus 10 is provided with one or more IR emitters which are configured to emit IR radiation into the field of view of the vehicle tracking apparatus 10 and to detect IR radiation which is reflected by IR reflectors on the one or more vehicles 12 in order to track them.

[0059] Turning to Figure 4, there is shown in greater detail a schematic view of the vehicle tracking apparatus of Figure 1. The vehicle tracking apparatus 10 firstly comprises a receiver 40 configured to wirelessly receive transmitted data in accordance with embodiments above. In particular, the receiver 40 is configured to at least receive unique identification data of one or more vehicles 12 in the field of view of the vehicle tracking apparatus 10 and to receive data indicating an initial position of the one or more vehicles 12 relative to the vehicle tracking apparatus 10. The receiver 40 may be configured to wirelessly receive data transmitted from the one or more vehicles 12 via an external communications network 42. The receiver 40 may be configured to receive this data via a low-latency radio frequency communication. Alternatively, the receiver 40 may receive this data using any suitable form of communication, which enables the data to be received from the one or more vehicles 12. In some embodiments, the receiver 40 is additionally configured to receive data originating from sources other than the one or more vehicles 12, such as other vehicle tracking apparatuses 10 or centralised traffic management systems (not shown). Such data is again transmitted via the external communications network 42. In some embodiments, the receiver 40 is configured to receive data through wired communications where appropriate, i.e. where the receiver 40 is configured to receive data from fixed locations (such as a centralised traffic management system or adjacent tracking apparatuses).

[0060] In some embodiments of the present invention, the vehicle tracking apparatus 10 is configured to monitor an area or "entry point" whose position is preconfigured to be known to the vehicle tracking apparatus 10 (e.g. by storing this position in a memory 48 of the vehicle tracking apparatus). In such embodiments, it may not be necessary for the vehicle tracking apparatus 10 to receive information from the one or more vehicles 12 regarding an initial position of the one or more vehicles 12. In such embodiments, the vehicle tracking apparatus 10 may be configured such that the initial position of a particular vehicle 12 will always be the position that is preconfigured to be known to the vehicle tracking apparatus 10 as described above. In further embodiments, the vehicle tracking apparatus 10 is configured to monitor several locations in an entry point (e.g. a plurality of lanes), each of these with their own known preconfigured position. In such embodiments, when a vehicle 10 enters an entry point, the vehicle tracking apparatus 10 may be configured to select one of the plurality of preconfigured positions as being the initial position of the vehicle 10. The method by which such a selection may be made is described in further details with reference to the "association" procedure described below. Such an entry point embodiment may manifest at a toll booth, where a vehicle is configured to stop at a particular location which is known by the vehicle tracking apparatus 10. In some embodiments, the vehicle 12 will not need to be stationary when approaching the known location.

[0061] In additional or further embodiments, the vehicle tracking apparatus 10 may also be configured to determine unique identification data of one or more vehicles 12 rather than receive it from the respective vehicle 12. This may be achieved by providing the vehicle tracking apparatus 10 with a sensor (not shown in the accompanying figures) which is able to determine a unique identifier of a vehicle 10 (for example, a license plate / number plate of the vehicle). Such a sensor may comprise an Automatic Number Plate Recognition (ANPR) camera or other suitable camera or sensor which is able to uniquely identify a particular vehicle 10. Such embodiments may also be used in combination with embodiments described above where the vehicle tracking apparatus 10 is configured to monitor an area or "entry point" whose position is preconfigured to be known to the vehicle tracking apparatus 10. In such cases, it may not be necessary for the vehicle tracking apparatus 10 to receive any data transmissions from the one or more vehicles 10 whatsoever, with the determination and assignment of initial positions, and determination of unique identification being performed entirely by the vehicle tracking apparatus 10. However, where information relating to ground-space envelopes is also to be received by the vehicle tracking apparatus 10, this may still need to be provided by the respective vehicle 12.

[0062] Additionally, the vehicle tracking apparatus 10 may comprise one or more IR sensors 44 configured to detect IR radiation, and specifically to detect IR radiation either being emitted from or reflected by the IR emitters or reflectors 30A, 30B, 30C, 30D, 30E of the one or more vehicles 12 to be tracked in accordance with embodiments described above. In Figure 4, only one IR sensor 44 is shown, but it is to be appreciated that this is for illustrative purposes only and that in some scenarios, it is beneficial to include a plurality of IR sensors 44. For example, a plurality of IR sensors 44 may be provided, where each IR sensor has a different field of view of a road or perhaps a road intersection which it is directed towards. This enables dedicated IR sensors 44 to be provided for each lane of the road. Alternatively, and in accordance with embodiments described above, multiple IR sensors 44 may be provided, where one or more of the IR sensors 44 are configured to monitor a road, and one or more of the IR sensors 44 are configured to monitor the sky. In this way, a single vehicle tracking apparatus 10 may be configured to monitor both airborne vehicles 20 and ground-based vehicles 12 in accordance with embodiments described above. The IR sensors 44 may be configured to detect IR radiation in a predetermined range of wavelengths, where the predetermined range is decided by a user of the vehicle tracking apparatus 10. In particular, the predetermined range of wavelengths may specifically correspond to a range of wavelengths emitted or reflected by the one or more vehicles 12. This enables the vehicle tracking apparatus 10 to reduce detection of IR noise, which may be emitted by sources other than the one or more vehicles 12 to be tracked.

[0063] The vehicle tracking apparatus 10 of the current embodiment, further comprises a processor 46, which is communicably coupled to the receiver 40 and the one or more IR sensors 44. The processor 46 is configured to receive data which is received by the receiver 40 in accordance with embodiments described above, as well as information related to the detected IR emissions received by the one or more IR sensors 44. The processor 46 is further configured to track the one or more vehicles 12 on the basis of the received data and the detected IR emissions. This tracking comprises the calculation of various kinematic data relating to the one or more vehicles 12. In particular, the processor 16 is configured to at least determine a position that the IR emissions originate from. This may be determined, for example, by processing the IR image within the sensor, or by determining an angle that the IR emission has entered the IR sensor 44 at and combining this with known information relating this angle to a particular position on the road. The information received by the processor 46 may comprise any relevant information, which enables the processor to determine a position that the IR emissions originate from (e.g. time that the emissions are received, angle that the IR emissions enters the IR sensor 44 at etc).

[0064] The processor 46 is configured to receive the unique identification data of one or more vehicles 12 in the field of view of the vehicle tracking apparatus 10 and to receive data indicating an initial position of the one or more vehicles 12 relative to the vehicle tracking apparatus 10, and to correlate this data with the information related to the detected IR emissions received by the one or more IR sensors 44. In this way, the processor 46 is able to associate a particular IR emission with a unique identifier of the vehicle 12 that emitted or reflected the IR radiation. This correlation may comprise comparing the initial position data received by the receiver 40 with a determined position that the received IR emissions originate from to establish whether the two positions are in agreement. Where the two positions are in agreement, the processor 46 is configured to associate the received IR emissions with unique identifier data of the vehicle 12 whose initial position data agrees with the position of origin of the IR emissions. Upon agreement, the processor 46 may be configured to denote the now identified vehicle 12 as having a particular position in accordance with the initial position data and/or the origin point of the IR emissions. In some embodiments, agreement is determined where the initial position data and the position of the IR emissions lie within a margin of error of one another. In embodiments where a single vehicle is provided with a plurality of IR emitters or reflectors 30A, 30B, 30C, 30D, 30E, the processor 46 is configured to associate the received IR emissions from the plurality of IR emitters or reflectors 30A, 30B, 30C, 30D, 30E with the unique identifier of the vehicle 12 that emitted or reflected the IR radiation. This may be achieved analogously to the above described embodiments, but in addition the received unique identification may comprise initial position data for each of the a plurality of IR emitters or reflectors 30A, 30B, 30C, 30D, 30E and an indication of the total number of IR emitters or reflectors 30A, 30B, 30C, 30D, 30E on the vehicle 12.

[0065] In accordance with some embodiments described above, the vehicle tracking apparatus 10 is configured to monitor an area or "entry point" whose position is preconfigured to be known to the vehicle tracking apparatus 10 and which may be utilised as the initial position data for a vehicle 12. As mentioned above, such a position may be stored in a memory 48 of the vehicle tracking apparatus 10. In these embodiments, when the processor 46 associates a detected IR emission with unique identification data, the initial position of the vehicle 12 is assigned as being the preconfigured position known to the vehicle tracking apparatus 10. This position may be retrieved from the memory 48 by the processor 46 accordingly. In further embodiments in which the vehicle tracking apparatus 10 is configured to monitor several locations in an entry point (e.g. a plurality of lanes), each of these with their own known preconfigured position, the processor 46 is configured to determine which of the plurality of preconfigured positions should be assigned as an initial position of the vehicle 12. This may be accomplished by comparing the origin positions of the received IR emissions to each of the preconfigured positions and assigning the initial position based on this comparison. In some embodiments, this assignment is performed when a comparison between the origin positions of the received IR emissions and a preconfigured position lie within a margin of error of one another. In other embodiments, this assignment is performed by comparing all preconfigured positions with the origin positions of the received IR emissions and assigning the initial position as being the preconfigured position which lies closest to the origin positions of the received IR emissions. The above provided examples are provided for illustration only and any suitable comparison method may be performed which achieves the required functionality described above.

[0066] Following the association of a vehicle 12 with a particular detected IR emission or emissions in accordance with embodiments described above, the processor 46 is configured to store information related to the association in a memory 48 to which the processor 46 is communicably coupled. The information stored in the memory 48 comprises the unique identifier of the associated vehicle 12 as well as its determined position. The information stored in the memory 48 may additionally comprise any other determined kinematic data in accordance with embodiments described herein. The memory 48 may be configured to be accessed by the processor 46 at a later time to retrieve information related to one or more previously associated vehicles 12. This retrieval may be used to determine other kinematic data of the vehicle or vehicles 12 in accordance with embodiments described herein.

[0067] Upon receipt of information related to the detected IR emissions received by the one or more IR sensors 44, the processor 46 may additionally be configured to determine whether the detected IR emissions have been emitted or reflected by a vehicle 12 whose unique identification has previously been associated with detected IR emissions. This is achieved by retrieving from the memory 48 information regarding determined positions of vehicles 12 which have been stored in accordance with embodiments described above and comparing these with the origin position of the currently detected IR emissions. If it is determined that the origin of the current IR emissions is sufficiently close to a previously determined position of a vehicle 12 after a known time interval, the processor 46 is configured to associate the presently detected IR emission with this vehicle and to denote the origin of the presently detected IR emission as a new position of the vehicle 12. The determination of whether the origin is sufficiently close may be achieved by calculating the difference in the position between the origin of the IR position and the previously determined position of the vehicle 12, and where the difference is below a predetermined threshold, the processor 46 associates the origin of the IR emissions as being the new position of the vehicle 12. The predetermined threshold may be set by a user. The predetermined threshold may also be based on other factors, such as a velocity of the vehicle 12 and the refresh rate of the IR sensor 44. This new position may then be stored in the memory 48. In some embodiments, the new position overwrites the previously determined position. In other embodiments, the new position is stored in addition to the previously determined position or positions with a timestamp, creating a record of all positions that the vehicle 12 has been at since it was first detected. In such embodiments, when determining whether subsequent emissions relate to the vehicle 12 record, the origin of the IR emissions is compared with the most recent position of the vehicle 12 in accordance with the timestamp. The processor 46 may be configured to perform this determination as frequently as the IR sensor 44 receives emissions. As noted above, the length of the time intervals between consecutive detected IR emissions may be used to determine the accuracy of the kinematic data which is calculated. For example, if IR emissions are detected with a periodicity of 8ms (a frequency of approximately 120Hz), this translates to a 20cm distance of travel by the vehicle. This is considered to be highly accurate for the purposes of vehicle control and navigation and also enables vehicle velocity, acceleration/deceleration rates, or other useful kinematic data to be calculated quickly and accurately. These figures should be considered as illustrative only since if less demanding accuracies and latencies prove adequate in practice then they can be substituted and if more demanding accuracies and latencies prove necessary in practice they can be substituted.

[0068] The processor 46 may additionally be configured to retrieve information from the memory 48 in relation to a particular vehicle in order to calculate additional kinematic data of the vehicle 12. In particular, the processor may be configured to retrieve a plurality of positions of a particular vehicle 12 and their associated timestamps (known as a vehicle track record over a period of time) in order to calculate a velocity and/or an acceleration of the vehicle 12. The velocity and acceleration may be calculated in two dimensions (i.e. along the road and across the road). The calculation may be performed in accordance with techniques known to the person skilled in the field and so do not need to be described further here. By calculating this additional kinematic data, more information may be determined regarding the vehicle 12, which may additionally be used for more accurate control of the vehicle 12 when the information is provided to the vehicle 12. The calculated kinematic data may additionally be stored in the memory record of the relevant vehicle 12.

[0069] In further embodiments of the present invention, the processor 46 is configured to additionally generate a control or warning signal to be enacted by the one or more vehicles 12, causing the vehicle to take a particular action. The control signal may be formed on the basis of the calculated current kinematic data of the one or more vehicles 12 in accordance with the embodiments above. In such embodiments, the processor 46 is configured to retrieve kinematic data from the memory 48 for all vehicles 12 in the field of view of the tracking apparatus 10 in order to determine an action to be taken. By way of example, if it is determined that two detected vehicles 12 in the field of view of the vehicle tracking apparatus 10 are within a predetermined distance of one another based upon the calculated velocities of the two vehicles 12, the processor 46 generates a control or warning signal to be transmitted to one of the vehicles 12 telling the vehicle to either speed up or slow down accordingly.

[0070] In some embodiments, when a vehicle 12 moves out of the field of view of the vehicle tracking apparatus 10, the processor 46 is configured to instruct the memory to delete any stored information relating to the vehicle 12.

[0071] In embodiments in which the vehicle tracking apparatus 10 is configured to receive information indicating the position of the IR emitters 30A, 30B, 30C, 30D, 30E with respect to a ground-envelope 36 of the vehicle 12, the processor 46 may be additionally be configured to combine this information with the information related to the detected IR emissions received by the one or more IR sensors 44 to determine a position/orientation of the ground envelope 36 of the vehicle 12. In some embodiments, the position of the ground envelope 36 is determined relative to the vehicle tracking apparatus 12 and/or is determined as an absolute position of the ground envelope 36.

[0072] In these embodiments, where the vehicle 12 that the ground envelope 36 relates to has not previously been associated, the calculation of the position of the ground envelope 36 is performed as part of the initial association step. When the correlation of the detected IR emissions and the unique identification data of a vehicle 12 is performed to indicate an initial position of the vehicle 12, the processor 46 will additionally combine the initial position data of each of the IR emitters 30A, 30B, 30C, 30D, 30E with the information regarding the position of each of the IR emitters 30A, 30B, 30C, 30D, 30E with respect to the ground envelope 36. In this manner, the initial position of the ground envelope 36 is generated and an indication of the two-dimensional space that the vehicle 12 initially occupies is generated without requiring an image of the vehicle 12 to be fully resolved. As described in above embodiments, the ground space envelope may additionally include some space surrounding the vehicle to act as a safety zone around the perimeter of space that the vehicle 12 occupies. Once the initial ground envelope 36 position is determined, this information is stored in memory 48 analogously to the procedure described above regarding the initial positions of the IR emitters 30A, 30B, 30C, 30D, 30E, in addition to the ground space envelope 36 information which has been provided regarding the position of the IR emitters 30A, 30B, 30C, 30D, 30E relative to the ground space envelope 36.

[0073] Where the ground envelope 36 is to be calculated for a vehicle 12 whose unique identification has already been associated in accordance with embodiments described above, the processor 46 may additionally retrieve the stored ground envelope 36 information from the memory 48. When it is determined that the IR emissions relates to a vehicle 12 that has previously been associated, the processor 46 will retrieve information regarding the position of the IR emitters 30A, 30B, 30C, 30D, 30E relative to the ground space envelope 36 which has previously been stored. This information may then be combined with the detected origin points of the IR emitters 30A, 30B, 30C, 30D, 30E in an analogous manner to the above. Similarly, any calculated new position of the ground envelope 36 may similarly be stored in the memory 48 along with the positions of the IR emitters 30A, 30B, 30C, 30D, 30E and any associated time stamps.

[0074] Whilst a position/orientation of a ground space envelope 36 has been discussed as being calculated, it is to be appreciated that other kinematic data (such as velocity and acceleration) may be equally calculated in respect of the ground space envelope 36 of the vehicle 12 and subsequently stored in the memory 48. Furthermore, any of the functionality of the vehicle tracking apparatus 10 described herein which relates to the ground space envelope is also applicable to an air space envelope for airborne vehicles.

[0075] The vehicle tracking apparatus 10 may additionally comprise a transmitter 50 which is communicably coupled to the processor 46. The transmitter 50 may be configured to receive the determined kinematic data from the processor 46 and subsequently transmit this to one or more vehicles 12 in the field of view of the vehicle tracking apparatus 10. The transmitter 50 may be configured to transmit this data via a low-latency radio frequency communication. Alternatively, the transmitter 50 may transmit this data using any suitable form of communication, which enables the data to be received by the one or more vehicles 12.

[0076] The transmitter 50 may be configured to transmit the determined kinematic data of a vehicle 12 only to the vehicle 12 that it relates to. In such embodiments, the data is received by the vehicle in order to self-regulate a position and/or velocity of the vehicle 12 based on only its own kinematic data. To this end, each vehicle 12 may have a unique, or locally unique, communication frequency through which it may transmit and receive data. This information may be provided as part of the unique identification data in accordance with embodiments described above. In some embodiments, the communications channel may be encrypted in order to prevent unauthorised interception of or interference with the transmissions.

[0077] In further embodiments, the transmitter 50 is configured to transmit determined kinematic data of one or more vehicles 12 to a plurality of the one or more vehicles 12. The data may be transmitted in accordance with embodiments described above. In such embodiments, the data is received by the vehicle in order to self-regulate a position, velocity and/or acceleration of the vehicle 12 based on its own kinematic data as well as the kinematic data of vehicles 12 in its vicinity. For example, a vehicle 12 may be configured to receive kinematic data relating to itself as well as that of the vehicles around it, and based on all of this information, the acceleration or velocity and hence position of the vehicle 12 is adjusted accordingly (e.g. if it is noted that another vehicle in the vicinity is further away than a particular threshold distance, the vehicle 12 is configured to adjust its own position to close this distance, or vice versa).

[0078] Where kinematic data is transmitted in accordance with the above, in embodiments where a ground space envelope 36 position of the vehicle 12 (and any other associated kinematic data) is calculated, this kinematic data may equally be transmitted in an analogous manner.

[0079] In embodiments where the processor 46 generates a control or warning signal, the transmitter 50 is additionally configured to transmit the generated control or warning signal to the one or more vehicles 12. In this embodiment, the transmitter 50 is configured to only transmit the control or warning signal to the vehicle 12 to which it relates. This may be achieved analogously to the way in which kinematic data may only be transmitted to the vehicle 12 to which it relates as described above.

[0080] In embodiments in which a control signal or warning is generated and kinematic information regarding a ground space envelope 36 of one or more vehicles 12 is provided and/or calculated, the control signal or warning may be generated based on the kinematic information of the ground space envelope 36. As previously discussed, the ground space envelope 36 of a vehicle may be provided with a safety zone around the perimeter of space that the vehicle 12 occupies. By basing a control signal or warning on the basis of the kinematic data of the ground space envelope 36, this safety zone is taken into account. This may act so as to offer an additional safety mechanism to the system such that the one or more vehicles 12 are maintained at a safe proximity to one another. This may be particularly advantageous in mitigating against small positional determination errors of the one or more vehicles 12.

[0081] The transmitter 50 may also be configured to transmit determined current kinematic data to local or regional Traffic Management Systems (TMSs) to provide a shared, common picture comprising the high accuracy kinematic data for vehicles 12 across a wider field spanning multiple IR tracking sensors. The advantages of such a transmission are described above.

[0082] Where the receiver 40 is configured to receive data from the vehicles 12, the vehicle tracking apparatus may further be configured to constantly generate a request signal for this data which is to be transmitted by the transmitter 50 to the one or more vehicles 12 which requests the required data as the vehicle enters the field of view of the vehicle tracking apparatus 10. Alternatively, the vehicles 12 may also be configured to simply continually broadcast this information to be received by the vehicle tracking apparatus 10 as the vehicle 12 comes within range.

[0083] In further embodiments of the vehicle tracking apparatus 10, there are additionally provided one or more IR emitters (not shown). These IR emitters may be provided in scenarios in which each of the one or more vehicles 12 to be detected comprises one or more IR reflectors rather than emitters. In such embodiments, the IR emitter of the vehicle tracking apparatus 10 is configured to emit IR radiation in the direction of the vehicles 12 to be detected, which is then reflected by the IR reflectors of the vehicle 12, to be detected again by the vehicle tracking apparatus 10. This detected IR radiation may then be used again in accordance with the embodiments described above.

[0084] In further embodiments, the vehicle tracking apparatus 10 additionally comprises an additional fixed IR emitter or reflector (not shown) that is located remotely from the IR sensors 44 and is constantly in the field of view of the IR sensors. The IR sensors 44 continuously monitor the position of this fixed emitter/reflector and use any detected offset from the fixed position to measure any movement of the other elements of the vehicle tracking apparatus 10 due to environmental conditions (such as wind). The processor 46 is configured to calculate this offset based on the received IR emissions from the fixed IR reflector or emitter. Where any offset is calculated, this can be used to feed into the kinematic data calculations for both ground-based and airborne vehicles to maintain tracking accuracy. This is particularly advantageous where adverse weather conditions which lead to movement of the vehicle tracking apparatus 10 is to be expected and helps to prevent the inaccurate calculation of kinematic data.

[0085] In some embodiments of the vehicle tracking apparatus 10, the processor 46 is additionally configured to calculate kinematic data in three dimensions. In such embodiments, the vehicle tracking apparatus 10 is additionally configured to receive via the receiver 40, or have previously stored in memory 48, three-dimensional terrain mapping data which is used to correlate a particular detected two-dimensional position with a height of the terrain at that point. This three-dimensional positional data is stored and used in calculations analogously to the two-dimensional data described above. Where the vehicle tracking apparatus 10 is configured to detect and track airborne vehicles, the vehicle tracking apparatus 10 is also configured to receive altitude data from the airborne vehicle in order to ascertain three-dimensional positional data. This can be assumed by the current embodiment of the present invention due to the general availability of small, low-power, low-weight radar altimeters which have performance characteristics (60Hz measurement rate, 20cm accuracy) compatible with the current embodiment. Alternatively, horizontal, 360 degree laser beacons may be deployed on fixed structures at the appropriate height (for example on the top of tall buildings in an urban area, to provide an altitude homing reference signal for airborne vehicles. Alternatively, the vehicle tracking apparatus 10 may be configured to receive a plurality of emissions from a plurality of sensors on an airborne vehicle in order to perform a triangulation operation, which enables three-dimensional positional data to be ascertained. With a combination of these and possibly other methods height hold can be maintained by airborne vehicles to the required safety level.

[0086] Examples of required receipt and transmission rates and data requirements in order to maintain an accurate calculation are discussed below. It is to be appreciated that these are given by way of example only, and exact figures may be dependent upon the requirements of the user.

[0087] Typical current advisory separations between road vehicles travelling at 100 km/h are based on stopping distance being the sum of thinking distance and braking distance in the ratio of 1:3. The current embodiments of the present invention may enable the elimination of thinking distance thereby immediately increasing safe traffic flow rates by 25%. It will be possible progressively to increase this envelope as confidence in the safety of the system and methods develops, to at least double and potentially multiples of current traffic flow rates.

[0088] On a typical motorway/freeway the separation between lampposts to which a vehicle tracking apparatus 10 may be attached is approximately 30 metres (m), the height of a lamppost is approximately 10m and the width of a carriageway is approximately 11m, all of which requires the vehicle tracking apparatus 10 to have a field of view of typically 140° longitudinally (along the carriageway) and 55° transversely (across the carriageway). The vehicle tracking apparatus 10 can be produced in a standard configuration with settings that can be adjusted at installation forthe longitudinal and transverse field of view, thus allowing a standard vehicle tracking apparatus 10 of the above described embodiments to be deployed in a wide variety of situations. The vehicle tracking apparatus 10 resolves all of the multiplicity of vehicles within its field of view. For a 3-lane carriageway this could be up to around twenty small vehicles 12, assuming they are all cars travelling with only 1m nose-totail separation (a limiting case which may be achieved only after progressively deploying and proving the system with gradually increasing traffic densities). In this limiting case, around 60 IR emitters/reflectors of the vehicles 12 will be in view and it is considered practical to resolve and analyse this number to create and communicate kinematic data for each vehicle 12.

[0089] IR radiation emitted by typical commercially available beacons has strong characteristics through normal atmosphere and weather at the distances proposed with the system and methods of the embodiments of the present invention. With the vehicle tracking apparatus 10 being arranged at a height of around 10m and a field of view of around 140 by 55 degrees, a focal plane array CCD detector of around 4 megapixels, i.e. 2K x 2K pixels, will give a bearing accuracy of approximately 0.1 degrees, achieving the resolution of around 5cm and able to track up to twenty vehicles 12 = 60 IR emitters (this is the maximum vehicle occupancy within the field of view, based on all being small cars with a longitudinal separation of 1m). A detection refresh rate of around 100Hz is required in order to track vehicles to the require accuracy at speeds up to 200kph. These parameters are at or approaching those that can be achieved by the latest technology IR tracking sensors (which is improving year on year).

[0090] A 2D positional accuracy of approximately 5cm x 5cm in a field of view 30m x 11 m requires 18 bits of digital data; hence, for the limiting case of 20 small vehicles 12 (= 60 emitters) each with a longitudinal/transverse location of 18 bits, equates to 1080 bits. At 120Hz, this will generate a 110Kbit/sec data-stream, which is passed through the communication equipment to the vehicle 12. For short distance transmission back down to the vehicles' antennae within the field of view, this is practical and an encryption device (not shown) can be added for extra security. It is envisaged that the means of transmitting data between a vehicle tracking apparatus 10 and vehicles 12 could be an integral part of the 5G/6G digital small-cell network technology which will have air latencies of <1 ms and ranges from around 10m and hence fit within the performance and design envelope of the current invention. Alternatively, the data transmission may be by means of a dedicated datalink. Indeed, embodiments of the present invention may be the critical enabler for the envisioned vehicle-to-vehicle and vehicle-toinfrastructure networks to be used to support autonomous, semi-autonomous and managed autonomous driving.

[0091] It is to be appreciated that the above described embodiments may be used in determining and transmitting kinematic data for both ground-based and airborne vehicles where appropriate.

[0092] Turning now to Figure 5A, there is shown a method of operation 60 of the vehicle tracking apparatus 10 described in embodiments above. In particular, Figure 5A is concerned with the method by which the vehicle tracking apparatus receives unique identification data and associates this with a received IR emission.

[0093] The method 60 begins by receiving, at Step 62, transmitted unique identification data of one or more vehicles 12 in the field of view of the vehicle tracking apparatus and transmitted data indicating an initial position of the one or more vehicles 12 relative to the vehicle tracking apparatus 10. Alternatively, this initial position can be provided as absolute position coordinates, for example latitude and longitude coordinates. This data is received by the receiver 40 in accordance with embodiments described above. Following this, the method 60 continues by detecting, at Step 64, IR radiation either being emitted from or reflected by the IR emitters or reflectors 30A, 30B, 30C, 30D, 30E of the one or more vehicles 12 to be tracked in accordance with embodiments described above. The IR radiation is detected by the one or more IR sensors 44. It is to be appreciated that whilst Steps 62 and 64 are shown sequentially, the two transmissions may equally be received in the opposite order, or simultaneously.

[0094] Following this, the method 60 continues by determining, at Step 66, the origin point of the detected IR radiation. This may be achieved in accordance with embodiments described above and may be performed by the processor 46. This step enables a position to be associated with the received IR radiation. Following this determination, the vehicle tracking apparatus 10 then proceeds to associate, at Step 68, the received IR emissions with the received unique identification data of one or more vehicles 12. This may be achieved by comparing the determined position of the IR emissions with the received initial position of the vehicle 12, in accordance with embodiments described above. In some embodiments, multiple sets of IR emissions with different origin positions may be received simultaneously. In these embodiments, the method 60 comprises comparing the initial position of the vehicle 12 with each of the sets of IR emissions until a suitable emission is found that the vehicle 12 can be associated with. Once the vehicle 12 has been associated with an IR emission, the method 60 continues by storing, at Step 70, the unique identification data of the vehicle 12 and the initial position of the vehicle 12 in the memory 48, in accordance with embodiments described above. The method then proceeds to end at Step 72.

[0095] In the above method 60, there is discussion regarding the association of detected IR emissions with transmitted data indicating an initial position of the one or more vehicles 12 relative to the vehicle tracking apparatus 10. It is to be appreciated that whilst the method 60 is discussed in context of the provision of the position of IR emitters or reflectors 30A, 30B, 30C, 30D, 30E, in some embodiments, information regarding a ground space envelope 36 is additionally provided in accordance with embodiments discussed above. In such embodiments, when an association is performed at Step 68, a calculation of a ground space envelope 36 of the vehicle 12 is additionally performed using the provided ground space envelope 36 information in accordance with above embodiments and this information is used to perform the association (i.e. a vehicle 12 may be configured to provide an initial position of its ground space envelope 36, and the vehicle tracking apparatus 10 is configured to compare this information with the calculated ground space envelope). This information may then also be stored at Step 70.

[0096] It is to be appreciated that the vehicle tracking apparatus 10 may receive multiple sets of unique identification data and initial position data simultaneously. In such cases, the method 60 is configured to repeat itself for each set of unique identification data and initial position data simultaneously and concurrently. Alternatively, the method 60 may be configured to operate simultaneously for each set of unique identification data and initial position data.

[0097] Referring to Figure 5B, there is shown a further method of operation 80 of the vehicle tracking apparatus 10 described in embodiments above. In particular, Figure 5B describes the method 80 by which the vehicle tracking apparatus 10 associates IR emissions with a vehicle 12 which has previously been detected and associated with IR emissions.

[0098] The method 80 begins by detecting, at Step 82, IR radiation either being emitted from or reflected by the IR emitters or reflectors 30A, 30B, 30C, 30D, 30E of the one or more vehicles 12 to be tracked in accordance with embodiments described above. Following this, the method 60 continues by determining, at Step 84, the origin point of the detected IR radiation. This may be achieved in accordance with embodiments described above and may be performed by the processor 46. This step enables a position to be associated with the received IR radiation.

[0099] Once the origin point of the IR emissions has been determined, the method 80 continues by retrieving, at Step 84, the positions of previously identified vehicles from the memory 48 of the vehicle tracking apparatus 10. This may comprise retrieving all previously stored data. Alternatively, the processor 46 may be configured to only retrieve a subset of this data. This may comprise only retrieving the most recent position stored for each vehicle 12. This may also comprise retrieving filtered information, where the filter may specify only retrieving information relating to vehicles whose position is within a predetermined distance of the origin point of the IR emissions.

[0100] Once the positions have been retrieved, the method 80 continues by determining, at Step 86, which of the vehicles 12, whose information has previously been stored, the IR emissions relate to. This may be achieved by determining whether any of the retrieved position data lies sufficiently close to the origin of the IR emissions in accordance with embodiments described above. When this is complete, the method 80 continues by associating, at Step 88, the position of origin of the IR emissions with the vehicle identified in Step 86. This association may comprise updating the identified vehicle's 12 current position as being the position of origin of the IR emissions. The method 80 continues by storing, at Step 90, the current position in the memory 48 in the memory record of the identified vehicle 12, in accordance with embodiments described above. As noted, this storing may additionally comprise storing a timestamp at which the IR emissions were received. The method then proceeds to end at Step 92.

[0101] As discussed with reference to Figure 5A, in embodiments where ground space envelope 36 information has previously been provided and stored in the memory 48, where information is retrieved at Step 86, this may also comprise retrieving the ground space envelope 46 information. This may then be utilised to calculate kinematic data regarding the ground space envelope 36 as discussed previously to determine which vehicle 12 the detected IR information relates to (i.e. a previously calculated position of the ground space envelope 36 of a vehicle 12 may be compared to a, currently calculated ground space envelope 36 to determine the vehicle 12 that the detected IR information relates to). Again, this new kinematic information may then be stored in memory 48 at Step 92.

[0102] Turning now to Figure 5C, there is shown a method of operation 100 of the vehicle tracking apparatus 10 described in embodiments above. In particular, Figure 5C describes the method 80 by which the vehicle tracking apparatus 10 determines and transmits kinematic data for one or more vehicles 12 in the field of view of the vehicle tracking apparatus 10.

[0103] The method of operation 100 begins by obtaining, at Step 102, position data for a particular vehicle 12 in the field of view of the vehicle tracking apparatus 10. This may comprise receiving IR emissions, determining their origin position and associating this with a particular vehicle in accordance with the methods 60, 80 of Figures 5A and 5B above. This may also comprise retrieving position data from the memory 48 for a particular vehicle.

[0104] Following this, the processor 46 then uses the obtained position information to determine, at Step 104, kinematic data of the vehicle 12. In some cases, this simply comprises determining a position of the vehicle 12 in one or two dimensions, in which case the obtaining and determining steps are the same. In other embodiments, the kinematic data comprises calculating quantities such as velocity and acceleration in one or two dimensions, which requires a plurality of positions to be obtained, in conjunction with the time at which that position was determined. In such embodiments, the processor will typically obtain a plurality of positions and associated timestamps from the memory 48. The retrieval of positions from the memory 48 may be combined with IR emission origin data, which has not yet been stored in the memory 48. The calculation of velocities and accelerations using position and temporal data is well known and will not be described further here.

[0105] Once the required kinematic data has been determined, the determined data is stored, at Step 106, in the memory 48 of the vehicle tracking apparatus 10. Following this storage, the method 100 continues by transmitting, at Step 108, the determined kinematic data to one or more of the vehicles 12 in accordance with embodiments described above. This may comprise transmitting the data only to the vehicle to which it relates. This may also comprise transmitting the data to a plurality of the vehicles 12 in the field of view of the vehicle tracking apparatus 10. In embodiments in which the kinematic data is to be transmitted, at Step 108, to a TMS, also comprises transmitting the kinematic data to the TMS. The method of operation 100 then proceeds to end at Step 110.

[0106] In embodiments in which the processor is additionally configured to generate a control or warning signal to be transmitted to one or more vehicles 12, the method 100 comprises an additional step between Steps 106 and 108 in which the control or warning signal is calculated and determined in accordance with embodiments described above. This control or warning signal is then additionally transmitted with the kinematic data at Step 108 or may be transmitted instead of the kinematic data.

[0107] In embodiments where ground space envelope 36 information is provided, the calculation of kinematic data of the vehicle 12 at Step 104 may comprise determining kinematic data in relation to the ground space envelope 36 of the vehicle 12 in accordance with embodiments described above. This data relating to the ground space envelope 36 may then be stored, at Step 106, and transmitted, at Step 108.

[0108] Referring now to Figure 6, there is shown is an isometric view of a vehicle tracking system 150 comprising a plurality of the vehicle tracking apparatuses 10 of embodiments described above for detecting one or more ground-based vehicles 12 and determining various kinematic data in respect of the detected vehicles 12. For the purposes of clarity, not all of the vehicle tracking apparatuses 10 have been labelled in the figure. More specifically, the vehicle tracking system 150 shown comprises a plurality of vehicle tracking apparatuses 10 installed in an urban environment and is configured to determine various kinematic data in respect of the detected vehicles 12 over an area which is greater than the field of view (or 'cell' 152) of any one of the individual vehicle tracking apparatuses 10. In this manner, the vehicle tracking system 150 enables tracking of one or more vehicles 12 over a large area. It is to be appreciated that whilst the vehicle tracking system 150 is shown installed in an urban environment in which a plurality of obstacles may obstruct the field of view of a vehicle tracking apparatus 10 (e.g. buildings, road infrastructure), the vehicle tracking system 150 may equally be employed to track vehicles 12 over a large area where such obstructions are not present, such as on an extended length of road, for example a highway or motorway. The vehicle tracking apparatuses 10 of the vehicle tracking system 150 may again be affixed to existing infrastructure, such as lampposts, traffic lights, gantries and buildings.

[0109] The vehicle tracking system 150 shown comprises a plurality of vehicle tracking apparatuses 10 as described in embodiments above, each in its own cell 152. The plurality of cells 152 make up a network, which covers an area monitored by the vehicle tracking system 150. Each of the vehicle tracking apparatuses 10 may comprise any of the elements above in order to achieve the desired functionality associated with those features. In particular, each apparatus 10 may comprise features which allow for unique identification data for each vehicle 12 to be received, IR emissions to be detected, and various kinematic data to be calculated and transmitted to one or more vehicles 12. It is to be appreciated that each vehicle tracking apparatus 10 in the vehicle tracking system 150 may be provided with features from different embodiments to achieve different functionalities in each cell i.e. each vehicle tracking apparatus 10 in the system 150 need not be provided with the same features. For example, one apparatus 10 in the system 150 may be configured to monitor an entry point into the system 150 and be configured to receive information from a vehicle 12 or to be provided with preconfigured position information in accordance with embodiments described above. Other apparatuses 10 in the system 150 may not need such functionality since they do not monitor this entry position.

[0110] In the vehicle tracking system 150 of Figure 6, each vehicle tracking apparatus 10 may additionally be configured to transmit the calculated kinematic data to one or more of the other vehicle tracking apparatuses 10 in the vehicle tracking system 150. This may be achieved through suitable configuration of the receiver 40, processor 46 and transmitter 50 of each of the vehicle tracking apparatuses. Furthermore, each vehicle tracking apparatus 10 may similarly be configured to transmit unique identification data of a vehicle 12 to one or more of the other vehicle tracking apparatuses 10 in the vehicle tracking system 150 in conjunction with the calculated kinematic data. In this way, when a vehicle 12 passes through and out of the field of view of a particular vehicle tracking apparatus 10, the various data may be passed to another vehicle tracking apparatus 10 whose cell 152 the vehicle 12 is now passing into. This data may be used analogously to the data originally transmitted to the vehicle tracking apparatus 10 by the vehicle 12 to associate a received IR emission with a vehicle 12, which is entering the first cell of the vehicle tracking system 150. Where kinematic data is transmitted, any positional data may also be provided with respect to the vehicle tracking apparatus 10 which calculated it. Alternatively, when the positional data is transmitted, it may first be processed such that the position of the vehicle 12 is given with respect to the vehicle tracking apparatus 10 it is being sent to rather than the apparatus 10 it is being sent from. Alternatively, the vehicle tracking apparatus 10, which receives the positional data, may be configured to convert this data itself Alternatively, an absolute position of the one or more vehicles 12 may be transmitted (for example, longitude and latitude coordinates).

[0111] In embodiments in which each vehicle tracking apparatus 10 is configured to transmit unique identification data and calculated kinematic data to other vehicle tracking apparatuses 10, it is not necessary for each vehicle tracking apparatus to receive unique identification data from the vehicle itself. In such embodiments, the system 150 is configured to initially receive unique identification data and initial position data from a vehicle 12 at designated vehicle tracking apparatus 10, in accordance with embodiments described above. This vehicle tracking apparatus 10 is configured to monitor a designated "entry point" (or entry cell) where the vehicles are configured to enter the area being monitored by the vehicle tracking system 150. Alternatively, such a vehicle tracking apparatus 10 may be configured to monitor a preconfigured known position as described in embodiments above. As such initial position information and/or unique identification information may not need to be provided by the vehicle. Following this, the relevant information is then transmitted to the other vehicle tracking apparatuses 10 by the vehicle tracking apparatus which has received the data from the vehicle. In such embodiments, any vehicle tracking apparatus 10, which is not monitoring an entry cell is configured not to receive this information from the one or more vehicles 12, and instead only receive transmissions from other vehicle tracking apparatuses 10.

[0112] In further embodiments, the cell 152 being monitored by each of the vehicle tracking apparatuses 10 is configured to overlap with other cells, such that there are points at which the one or more vehicles 12 being tracked is in the field of view of a plurality of the vehicle tracking apparatuses 10. In such embodiments, each of the relevant vehicles tracking apparatuses 10 is each configured to calculate kinematic data for the one or more vehicles. In some embodiments, the calculated kinematic data for each vehicle, is transmitted to each of the other vehicle tracking apparatuses 10 that the one or more vehicles 10 are in the cell of, and the data is compared. The processor of each vehicle tracking apparatus is then configured to compare the data and use a voting algorithm to determine whether the data is in agreement, and where it is not, to veto the data which is not in agreement such that it is not transmitted to the vehicle 12 (or other transmission destination). This allows checking of data consistency or continuity between each vehicle tracking apparatus 10 and its first, second and possibly third overlapping tracking devices and in the latter 2 cases enables a failed tracking apparatus 10 to be detected and voted out. This creates a 'triplex' or 'quadruplex' redundant architecture capable of achieving the required safety integrity for information provided to vehicles of better than 1 x 10-8 failures per vehicle mile whilst allowing tracking apparatus failures to be tolerated and hence repaired to achieve high information availability. In addition, status information from diagnostic or prognostic equipment on each vehicle 12 can be communicated back to the vehicle tracking apparatus 10 enabling neighbouring vehicles 10 or any involved traffic management system to be alerted to any failures or predicted failures, particularly failed IR emitters, further improving overall system integrity.

[0113] In further embodiments, the voting algorithm may be employed in an alternate manner in which data consistency or continuity is determined between a plurality of tracking apparatuses 10 where cells abut, or nearly abut but do not overlap. In such embodiments, a comparison between the measured positions of one or more vehicles 10 by a plurality of vehicle tracking apparatuses 10 is performed by the voting algorithm. Through this comparison, the voting algorithm is able to detect to a very high integrity level consistent with that of the previous paragraph where an inconsistent position is produced by one of the vehicle tracking apparatuses 10. By way of illustrative example, the voting algorithm employed by a group of four adjacent vehicle tracking apparatuses 10 may determine by a rolling pairwise comparison communicated to the fourth tracking device which one of the tracking apparatuses 10 is inconsistent with the other three. In such an example, the voting system may flag the errant apparatus 10 as being faulty and ignore, override, replace with an interpolation or otherwise deal with any measurements it makes until the faulty equipment is repaired. The voting algorithm may additionally be configured to await a plurality of erroneous measurements being determined before an apparatus is highlighted as being faulty. Whilst this example mentions the use of four vehicle tracking apparatuses 10, it is to be appreciated that a voting algorithm may be employed by any plurality of vehicle tracking apparatuses 10, such as a triplex or quadruplex or higher orders of apparatuses 10. In some embodiments, the vehicle tracking apparatuses 10 that employ the voting algorithm are tolling' along a system of vehicle tracking apparatuses (i.e. where the voting algorithm is between four apparatuses 10, apparatus numbers 1 to 4 will vote between themselves, then numbers 2 to 5, 3 to 6 etc). As a variant on this architecture, the vehicle tracking apparatuses 10 can be arranged in groups of 3 or 4 or more with fixed voting algorithms between the 3 or 4 or more and track consistency checking both within and at the handovers between the groups of 3 or 4. In some embodiments, there may be cells abutting or nearly abutting in some parts of the network and cells overlapping in other parts, perhaps where the traffic safety risk is higher. Such embodiments with said abutments and overlaps can enable fewer vehicle tracking apparatuses 10 to be used over an extended area whilst still enabling a plurality of vehicle tracking apparatuses 10 to monitor a common area.

[0114] The embodiment of the vehicle tracking system 150 of Figure 6 shows an implementation in which the vehicle tracking system 150 is configured to detect and determine kinematic data of ground-based vehicles. However, the vehicle tracking system 150 may equally be configured to monitor airborne vehicles 20. An example of such a configuration is shown in Figure 7, where the system is again arranged in an urban environment. Again, for the purposes of clarity, not all vehicle tracking apparatuses 10 and airborne vehicles 20 have been labelled. It is to be appreciated that in this configuration, the same features and functionalities of the vehicle tracking system 150 are included, except that the vehicle tracking system 150 is configured to monitor for IR emissions being received from above the system 150 rather than below. Each vehicle tracking apparatus 10 of the vehicle tracking system 150 has a field of view in this configuration, or alternatively "sky cells." In the present embodiments the tracking systems for airborne cells must be orientated off vertical, towards north (south in southern hemisphere), to avoid solar glare. Abutting sky cells that form a 'lane in the sky' must be at a safe separation from lanes in the contraflow direction.

[0115] It is also to be appreciated that whilst the two ground-based and airborne monitoring configurations are shown as separate embodiments, the two embodiments may be combined in a third embodiment in which monitoring of airborne and ground-based vehicles is achieved simultaneously. This is achieved in accordance with appropriate configurations of the described embodiments of the vehicle tracking apparatus 10 above. In addition, the vehicle tracking system 150 may be configured at certain points, to only detect and calculate kinematic data for either ground-based or airborne vehicles. By way of example, this may be achieved by providing upward facing or downward facing IR sensors 44 in a vehicle tracking apparatus 10 in dependence upon whether airborne or ground-based vehicles are to be detected in the field of view of a particular vehicle tracking apparatus 10. In this manner, redundant components may be removed where a particular type of monitoring is not required in a particular area. Figure 7 also shows a horizontal, 360° laser beacon 160 giving a horizontal, wide-area reference signal that airborne vehicles can use to maintain precise altitude.

[0116] Referring to Figure 8, there is shown a method of operation 170 of the vehicle tracking system 150 described above. In particular, the method 170 relates to how a vehicle tracking apparatus 10 of the vehicle tracking system 150 in one cell 152 receives information from another vehicle tracking apparatus 10 in another typically adjacent cell 152 and uses this to determine kinematic data for a vehicle 12 entering its field of view. It is to be appreciated that initial acquisition of data and determination of kinematic data by a first vehicle tracking apparatus 10, at a cell where the vehicle enters the network of cells, may be achieved using relevant steps of the method 60 of Figure 5A, and the present method 170 relates to the procedure followed by a vehicle tracking apparatus 10 subsequent to the first vehicle tracking apparatus 10.

[0117] The method 170 begins by receiving, at Step 172 identification data, kinematic data (position, velocity, acceleration, deceleration, orientation or other useful kinematic data) and vehicle geometry data transmitted from its upstream neighbour about each vehicle that is about to enter its field of view. This occurs analogously to Step 62 of Figure 5A where information is received from the vehicle 12 in so much as the relevant data is received from its upstream neighbouring vehicle tracking apparatus 10 via the receiver 40. In this case, the initial position data of the vehicle 12 which is transmitted may comprise a position calculated by the upstream neighbouring vehicle tracking apparatus 10 [0118] The method 170 continues by detecting, at Step 174, IR radiation either being emitted from or reflected by the IR emitters or reflectors 30A, 30B, 30C, 30D, 30E of the one or more vehicles 12 to be tracked in accordance with embodiments described above. The IR radiation is detected by the one or more IR sensors 44. It is to be appreciated that whilst Steps 172 and 174 are shown sequentially, the two transmissions may equally be received in the opposite order, or simultaneously.

[0119] Following this, the method 170 continues by determining, at Step 176, the origin point of the detected IR radiation. This is achieved in accordance with embodiments described above and is performed by the processor 46. This step enables a position to be associated with the received IR radiation. Following this determination, the vehicle tracking apparatus 10 then proceeds to associate, at Step 178, the received IR emissions with the received unique identification data of one or more vehicles 12. This is achieved by comparing the determined position of the IR emissions with the received position data of the vehicle 12, in accordance with embodiments described above. In some embodiments, multiple sets of IR emissions with different origin positions are received simultaneously. In these embodiments, the method 60 comprises comparing the received position of the vehicle 12 with each of the sets of IR emissions until a suitable emission is found that the vehicle 12 can be associated with. Once the vehicle 12 has been associated with an IR emission, the method 170 continues by storing, at Step 180, the unique identification data of the vehicle 12 and the initial position of the vehicle 12 in the memory 48, in accordance with embodiments described above.

[0120] It is to be appreciated that the vehicle tracking apparatus 10 may receive multiple sets of unique identification data and initial position data simultaneously. In such cases, the method 170 is configured to repeat itself for each set of unique identification data and initial position data simultaneously concurrently. Alternatively, the method 170 is configured to operate simultaneously for each set of unique identification data and received position data simultaneously.

[0121] The method of operation 170 continues by using the obtained information to determine, at Step 182, kinematic data of the vehicle 12. In some cases, this simply comprises determining a position of the vehicle 12 in one or two dimensions, in which case the obtaining and determining steps are the same. In other embodiments, the step of determining kinematic data comprises calculating quantities such as velocity and acceleration in one or two dimensions, which requires a plurality of positions to be obtained, in conjunction with the time at which that position was determined. In such embodiments, the processor typically obtains a plurality of positions and associated timestamps from the memory 48. The retrieval of positions from the memory 48 may be combined with IR emission origin data, which has not yet been stored in the memory 48. The calculation of velocities and accelerations using position and temporal data is well known and will not be described further here.

[0122] Once the required kinematic data has been determined, the determined data is stored, at Step 184 in the memory 48 of the vehicle tracking apparatus 10. Following this storage, the method 100 continues by transmitting, at Step 186, the determined kinematic data to one or more of the vehicles 12 in accordance with embodiments described above. This may comprise transmitting the data only to the vehicle to which it relates. This may also comprise transmitting the data to a plurality of the vehicles 12 in the field of view of the vehicle tracking apparatus 10. In embodiments in which the kinematic data is to be transmitted to a TMS, Step 186 also comprises transmitting the kinematic data to the TMS.

[0123] Following this, the method 170 continues by determining, at Step 188, whether the vehicle 12 whose kinematic data has been determined is about to pass out of the field of view of the present vehicle tracking apparatus 10. This determination may comprise comparing a determined position of the vehicle 12 to a known end position of the field of view of the vehicle tracking apparatus 10. Where the vehicle 12 is within a predetermined range of this end position, it may be determined that the vehicle is passing out of the field of view of the vehicle tracking apparatus 10. Where it is determined that it is not, the method 180 returns to Step 174 and detects new IR emissions to be associated with the vehicle 12. Where it is determined that the vehicle 12 is passing out of the field of view of the tracking apparatus 10, the method 170 proceeds to transmit, at Step 190, transmits the identification data and kinematic data about the vehicle 12 that is about to leave its field of view to its downstream neighbouring IR tracking sensor. The method then proceeds to end at Step 192.

[0124] In embodiments where it is intended to provide one or more vehicles 12 in the field of view of the vehicle tracking apparatus 10 with kinematic data regarding a plurality of vehicles 12 in the field of view of the vehicle tracking apparatus 10, it is to be appreciated that the method 170 of Figure 8 may be modified in order to achieve this. Such modification may comprise, at Step 182, the processor 46 being configured to determine kinematic data for a plurality of vehicles 12 in its field of view simultaneously. This may comprise retrieving from the memory 48 data relating to all the vehicles in the field of view of the vehicle tracking apparatus 10 as determined in accordance with embodiments described above. The relevant kinematic data may then be calculated for each of these vehicles 12 and subsequently stored in accordance with Step 184. Then, at Step 186, the kinematic data for all the vehicles 12 in the field of view may be transmitted to the one or more vehicles 12. It is also to be appreciated that only a subset of the calculated kinematic data may be transmitted to each vehicle 12. This subset may be determined on the basis of the vehicles which are in the vicinity of the vehicle 12 to which the data is to be transmitted. For example, if there are 10 vehicles in the field of view of the vehicle tracking apparatus 10, there may only be four in the immediate vicinity of a particular vehicle 12 (i.e. one in front, one behind and one to either side). In this example, the vehicle tracking apparatus 10 may be configured to only provide kinematic data to the particular vehicle 12 in relation to the vehicle itself 12 and the four vehicles in its immediate vicinity.

[0125] The method 170 of Figure 8 relates to a process in which kinematic data is only transmitted to another vehicle tracking apparatus 10 when a vehicle is about to pass out of the field of view of a particular tracking apparatus 10. However, in some embodiments, the vehicle tracking system 150 is configured to constantly transmit calculated kinematic data to other vehicle tracking apparatuses 10 in the system 150. This may be used where a voting system is employed to ascertain whether determined kinematic data is agreed upon by a plurality of the apparatuses 10 and to prevent transmission of incorrectly calculated data. In such an embodiment, the method 170 may be adapted such that when kinematic data is transmitted to a vehicle 12 at Step 186, it is concurrently sent to other vehicle tracking apparatuses 10.This may be transmitted to all other apparatuses 10 in the system 150, or just a subset (for example, upstream and downstream neighbouring apparatuses 10). In such embodiments, Steps 188 and 190 may be omitted as it is not necessary to determine whether a vehicle is passing out of the field of view of a particular apparatus 10. Alternatively, these steps may still be carried out in order to inform a downstream neighbouring apparatus 10 that data regarding a particular vehicle 12 will no longer be received from the present apparatus 10.

[0126] It is to be appreciated that the method 170 of Figure 8 may be suitably modified in order to take into account the various modifications of each vehicle tracking apparatus 10 in the vehicle tracking system 150. In particular, information regarding ground space envelopes 36 may be utilised in methods analogous to those described above in order to determine vehicle 12 positions.

[0127] Having described several exemplary embodiments of the present invention and the implementation of different functions of the device in detail, it is to be appreciated that the skilled addressee will readily be able to adapt the basic configuration of the system to carry out described functionality without requiring detailed explanation of how this would be achieved. Therefore, in the present specification several functions of the system have been described in different places without an explanation of the required detailed implementation as this not necessary given the abilities of the skilled addressee to implement functionality into the system.

[0128] Furthermore, it will be understood that features, advantages and functionality of the different embodiments described herein may be combined where context allows.

Claims

CLAIMS1. A vehicle tracking device for tracking one or more vehicles at a geographic location of a transport network within which the one or more vehicles are able to move, the vehicle tracking device comprising: one or more infra-red (IR) sensors having a field of view and being configured to detect IR radiation being emitted from or reflected by the one or more vehicles at the geographic location within the field of view; a receiver configured to receive unique identification data which uniquely identifies each of the one or more vehicles and position data which indicates an initial position of each of the one or more vehicles when the one or more vehicles enter the field of view at the geographic location; a processor configured to determine current kinematic data of the one or more vehicles in at least two dimensions based upon the IR radiation detected by the one or more IR sensors, the received unique identification data and the received position data; and a transmitter configured to transmit the determined current kinematic data of a particular vehicle of the one or more vehicles to the particular vehicle.
2. The vehicle tracking device of Claim 1, wherein the particular vehicle is a ground-based vehicle.
3. The vehicle tracking system of Claim 2, wherein the vehicle tracking device is provided with terrain mapping data, and where the processor is configured to determine current kinematic data in three dimensions based upon one or more of the detected IR radiation, the unique identification data, previously-determined kinematic data of each of the one or more vehicles and the terrain mapping data.
4. The vehicle tracking device of Claim 1, wherein the particular vehicle is an airborne vehicle.
5. The vehicle tracking device of Claim 1, wherein the one or more vehicles comprises at least two vehicles and one of the vehicles is a ground-based vehicle and the other vehicle is an airborne vehicle, and wherein the one or more IR sensors comprises at least two sensors, one IR sensor being configured to detect IR radiation being emitted from or reflected by the ground-based vehicle and the other IR sensor being configured to detect IR radiation being emitted from or reflected by the airborne vehicle.
6. The vehicle tracking device of any previous claim, wherein the processor is configured to use previously determined current kinematic data of the one or more vehicles as an input to the determination of the current kinematic data for each of the one or more corresponding vehicles.
7. The vehicle tracking device of any previous claim, wherein the processor is configured to determine current kinematic data of the one or more vehicles at a frequency of at least 50Hz.
8. The vehicle tracking device of any previous claim, wherein the receiver is additionally configured to receive data relating to a ground-space envelope or an air space envelope of the one or more vehicles and the processor is arranged to use the ground-space envelope or air space envelope to determine relative positioning of the one or more vehicles.
9. The vehicle tracking device of any previous claim, wherein the vehicle tracking device is configured to be installed on existing roadside infrastructure.
10. The vehicle tracking device of any previous claim, further comprising an IR emitter configured to emit IR radiation toward the one or more vehicles.
11. The vehicle tracking device of any previous claim, where the transmitter is configured to transmit the determined current kinematic data of each of the one or more vehicles to a respective one of the one or more vehicles.
12. The vehicle tracking device of any previous claim, wherein the determined kinematic data is also transmitted to a Traffic Management System (TMS).
13. The vehicle tracking device of any previous claim, where the processor is further configured to generate a control signal for controlling the particular vehicle of the one or more vehicles based upon the determined current kinematic data of the at least one of the one or more vehicles, wherein the control signal includes instructions which when executed by the particular vehicle cause an alteration of a velocity or position of the particular vehicle, and where the transmitter is further configured to transmit this control signal to the particular vehicle.
14. The vehicle tracking device of any previous claim, wherein at least one of the one or more IR sensors is configured to detect IR radiation emitted from or reflected by a fixed geographical reference point, and the processor is further configured to: determine a position of the vehicle tracking device with respect to the fixed geographical reference point; and use the determined position of the vehicle tracking device when determining the current kinematic data of the one or more vehicles.
15. The vehicle tracking device of any previous claim, wherein the current kinematic data of the one or more vehicles determined by the processor, comprises at least a geographic position over time of the corresponding vehicle.
16. The vehicle tracking device of any previous claim, wherein the current kinematic data of the one or more vehicles determined by the processor comprises data corresponding to at least a longitudinal and latitudinal coordinate of the vehicle.
17. The vehicle tracking device of any previous claim, wherein the vehicle tracking device is configured to monitor an entry point with a fixed position, and to receive data relating to the fixed position at a particular point in time as the initial position of each of the one or more vehicles.
18. The vehicle tracking device of any previous claim, wherein the processor is further configured to generate a pull request to be transmitted by the transmitter which requests the transmission of the unique identifier data and initial position data from the one or more vehicles.
19. A vehicle tracking system for tracking one or more vehicles, the vehicle tracking system comprising a plurality of vehicle tracking devices as described in any of Claims 1 to 18 arranged in a network, and where the transmitter of a first vehicle tracking device is configured to transmit the current kinematic data determined at the first vehicle tracking device and unique identification data of the one or more vehicles to a second vehicle tracking device of the plurality of tracking devices and the receiver of the first vehicle tracking device is configured to receive current kinematic data determined at a third vehicle tracking device of the plurality of vehicle tracking devices and unique identification data of the one or more vehicles from a third vehicle tracking device.
20. The vehicle tracking system of Claim 19, wherein the processor of the second vehicle tracking device is further configured to compare current kinematic data of at least one of the one or more vehicles determined locally at the second device with current kinematic data received from and determined at the first vehicle tracking device to determine an agreement between the locally determined current kinematic data and the received kinematic data.
21. The vehicle tracking system of Claim 20, wherein the second vehicle tracking device receives the results of data comparisons between at least two other vehicle tracking devices and the processor of the second tracking device is configured to use voting to identify a tracking device that is behaving inconsistently.
22. The vehicle tracking system of any of Claims 19 to 21, wherein at least two of the plurality of vehicle tracking devices are arranged to be located geographically adjacent to each other and the IR sensors of the adjacently-located vehicle tracking devices have partially overlapping fields of view.
23. A method of tracking one or more vehicles at a geographic location in a transport network within which the one or more vehicles are able to move, the method comprising: receiving unique identification data which uniquely identifies each of the one or more vehicles and position data which indicates an initial position of each of the one or more vehicles at the geographic location; detecting IR radiation being emitted from or reflected by the one or more vehicles at the geographic location; determining current kinematic data of the one or more vehicles based upon the detected IR radiation, the received unique identification data of each of the one or more vehicles and the position data; and transmitting the determined current kinematic data of a particular vehicle of the one or more vehicles to the particular vehicle
24. A method of claim 23, wherein the transmitting step further comprises transmitting the current kinematic data to at least one other vehicle tracking device of a plurality of tracking devices.