GB2511098A

GB2511098A - Power saving vehicle tracking, particularly for a boat

Info

Publication number: GB2511098A
Application number: GB1303212.3A
Authority: GB
Inventors: Mark Downing
Original assignee: Scorpion Automotive Ltd
Current assignee: Scorpion Automotive Ltd
Priority date: 2013-02-22
Filing date: 2013-02-22
Publication date: 2014-08-27
Also published as: GB201303212D0

Abstract

The vehicle tracking device (2) configured to be mounted on a vehicle (boat 20, fig 1), wherein the device is configured to have a normal operating mode and an energy saving operating mode. The device also includes a heading measurement module (29) for detecting, in the energy saving mode of the device, a variation of a heading of the vehicle in a predetermined period of time, and wherein the heading measurement module (29) is configured to provide an operating mode instruction to the device, responsive to the detecting. The instruction is adapted to trigger the device to operate in the normal mode if the variation of a heading of the vehicle is greater than a threshold corresponding to 30Â° per minute.

Description

Power saving vehicle tracking, particularly for a boat The invention relates to an improved vehicle tracking system.

Fig. 1 schematically shows a known vehicle tracking system, which usually combines an electronic device 2 mounted in a vehicle 20 such as a boat and a central apparatus 4 (usually a server), in order to enable a user (such as the owner of the vehicle or a provider of the vehicle tracking service) to track the vehicle 20.

The device 2 is adapted to collect data, notably GFS location, at regular intervals and to transmit in real-time or at regular intervals the collected data to the apparatus 4 via a communication network 6, usually a cellular or satellite network.

The apparatus 4 is adapted to receive the collected data from the device 2, and serve them on demand to the user on a user terminal 40, which may comprise a computer terminal and/or a handheld terminal such as a smartphone. The vehicle location can thus be viewed on the user terminal 40, such as on electronic maps, for example via the Internet or specialized software.

The known tracking systems may supply a provider of the tracking service, and subsequently the Police who can thus track and locate the stolen vehicle 20, with location accuracy of less than 100 metres, depending on local terrain. It is appreciated that the vehicle tracking systems are thus desirable for vehicle theft prevention and retrieval.

The device 2 may be self-powered with a battery or wired into the vehicle power system (battery), and the device is therefore usually configured to have a normal operating mode and an energy saving operating mode. The device therefore usually comprises a module for detecting physical displacement of the device, and configured to provide an operating mode instruction to the device, responsive to the detecting. The instruction is adapted to trigger the device to operate in the normal mode if the module detects physical displacement. However one of the drawbacks of the known devices is that there are numerous false alarms in a number of applications of the device, such as when the vehicle is a boat subject to waves at mooring.

However the inventors have discovered that, surprisingly, it is possible to efficiently track vehicles, whilst avoiding false alarms and thus saving power (which thus reduces the contribution to global CO2 production).

Aspects and preferred examples of the present invention are set out in the appended claims.

In one aspect! it is provided a vehicle tracking device configured to be mounted on a vehicle, wherein the device is configured to have a normal operating mode and an energy saving operating mode, wherein the device further comprises a heading measuiement module for detecting, in the energy saving mode of the device, a variation of a heading of the vehicle in a predetermined period of time, and wherein the heading measurement niodule is configured to provide an operating mode instruction to the device, responsive to the detecting, wherein the instiuction is adapted to trigger the device to operate in the noirnal mode if the variation of a heading of the vehicle is greater than a threshold corresponding to 3Q0 per minute.

The device may further comprise a detection module for detecting, in the energy saving mode of the device, at least one of a linear acceleration and an angular acceleration corresponding to a physical displacement of the device, and wherein the detection module may be configured to provide an operating mode instruction to the device, responsive to the detecting, wherein the instruction may be adapted to trigger the device to operate in the normal mode if the detected linear acceleration or the angulai acceleration of the device is gleater than a thieshold of at least one of O.3m.s2 and O.30.s2.

The device may comprise an information collector configured to collect position inforniation indicating the position of the device; and/or a transmittei configured to transmit the position information to a remote apparatus using a communication network, and wherein the information collector and/or the transmitter may be configured to operate: in an eneigy saving operating mode when the device operates in the eneigy saving operating mode; and in a noimal operating mode when the device operates in the noimal operating mode.

The device may comprise a controller of the device configured to: control a heading measurement module when the device opelates in both the energy saving operating mode and the normal operating mode, wherein the controller may be configured to operate in a specific energy saving mode when controlling a heading measurement module when the device opelates in the energy saving operating mode; and control the information collector and/or the transmitter in the normal operating mode of the device.

The controller may further be configured to control the detection module when the device operates in both the energy saving operating mode and the normal operating mode, wherein the controller may be configured to operate in a specific energy saving mode when controlling the detection module when the device operates in the energy saving operating mode.

The information collector may further be configured to validate the trigger responsive to the collection of the position information once operating in the normal operating mode. The information collector may be configured to collect satellite position information, preferably global positioning system, GPS, position information.

The detection module may comprise an accelerometer and/or a gyrometer. The heading measurement module may comprise a compass and/or a heading indicator.

The device may comprise a rechargeable battery.

In another aspect, it is provided a method of tracking a vehicle, comprising: detecting, in an energy saving mode of a device configured to be mounted on a vehicle and to have a normal operating mode and an energy saving operating mode, a variation of a heading of the vehicle; providing an operating mode instruction to the device, responsive to the detecting, wherein the instruction is adapted to trigger, responsive to the detecting, the device to operate in the normal mode if the variation of a heading of the vehicle is greater than a threshold corresponding to 3Q° per minute.

The method may further comprise: detecting, in an energy saving mode of a device, at least one of a linear acceleration and an angular acceleration corresponding to a physical displacement of the device; providing an operating mode instruction to the device, responsive to the detecting, wherein the instruction may be adapted to trigger, responsive to the detecting, the device to operate in the normal mode if the detected linear acceleration or the angular acceleration of the device is greater than a threshold of at least one of O.3m.s2 and O.30.s2.

The method may comprise: collecting position information indicating the position of the device when the device operates in the normal operating mode; and/or transmitting the position information to a remote apparatus using a communication network when the device operates in the normal operating mode.

The method may comprise: controlling the detection when the device operates in both the energy saving operating mode and the normal operating mode, wherein controlling is performed in a specific energy saving mode when the device operates in the energy saving operating mode; and controlling the collecting of the position information indicating the position of the device and/or the transmitting of the position information to the remote apparatus when the device operates in the normal operating mode.

The method may comprise: validating the trigger responsive to the collecting of the position information once operating in the normal operating mode.

Collecting the information may comprise collecting satellite position information, preferably global positioning system, GPS, position information.

The threshold corresponding to 300 per minute, may be at least one of: 0.5° in a predetermined period of one second; 3° in a predetermined period of 6 seconds; 15° in a predetermined period of 30 seconds; 30° in a predetermined period of one minute.

In another aspect it is provided a computer program, a computer program product or a computer readable medium comprising instructions for carrying out a method according to aspects of the invention.

The inventors have therefore invented an improved tracking device, having several advantages above the prior art. One example of advantages is that the invention provides an improved power saving device, because the device may only trigger the device to operate in the normal mode if the trigger is validated. Another advantage is that the GPS functionality, which is battery consumption intensive, will only be switched on if an important enough physical displacement is detected. In the energy saving operating mode, the controller of the device operates at a specific energy saving operating mode, i.e. sufficient to enable control of the detection module but insufficient to control the GPS functionality, thereby saving energy.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1, already discussed, schematically shows a known tracking system; Figure 2 schematically shows an example tracking system according to the invention; and Figures 3A, 3B and 3C show a flow diagram of a method performed on a system of Figure 2.

With reference to the drawings in general, it will be appreciated that similar features or elements bear identical reference signs. It will also be appreciated that the Figures are not to scale and that for example relative dimensions may have been altered in the interest of clarity in the drawings. Also any functional block diagrams are intended simply to show the functionality that exists within the device and should not be taken to imply that each block shown in the functional block diagram is necessarily a discrete or separate entity. The functionality provided by a block may be discrete or may be dispersed throughout the device or throughout a part of the device. In addition, the functionality may incorporate, where appropriate, hardware elements, software elements or firmware elements or any combination of these.

With reference to the Figures, it will be appreciated that according to an example embodiment of the present invention, a device 2, which is hidden within a vehicle 20, such as a boat, includes a sensing unit 21.

The device 2 usually also comprises a radio frequency identification (RFID) module 22, an information collector 23, a transmitter 24 configured to transmit position information to a remote apparatus 4 using a communication network 6, a controller 26 and a memory 27.

The sensing unit 21 is configured to detect an external or internal status of the vehicle 20, for example by means of information input from at least one sensor hidden within the vehicle 20 (such as an impact sensor and/or an ignition of the engine).

In some embodiments, the device may also comprise a detection module 28 for detecting a physical displacement of the device 2. The detection module 28 is configured to detect a physical displacement of the device such as at least one of a linear acceleration and an angular acceleration corresponding to a physical displacement of the device 2, and preferably comprises an accelerometer and/or a gyrometer. However the physical displacement detected by the module 28 excludes vibration of the device, i.e. sustained oscillating change in location and/or orientation, such as vibration caused by the operation of an engine of the vehicle. This enables avoiding false alarms detected by the sensing unit 21 as explained in further detail below.

In some embodiments, the device comprises a heading measurement module 29 for detecting, in the energy saving mode of the device, a variation of a heading of the vehicle. The heading measurement module 29 may comprise a compass and/or a heading indicator.

The REID module 22 may be configured to act as a receiver or a transmitter of radio-frequency electromagnetic fields, in order to act as an RFID tag or an REID reader for the vehicle 20.

The information collector 23 is configured, in a normal operating mode, to collect position information, for example periodically receive position information obtained by a position receiver interface 230 of the device 2.

The controller 26 is typically implemented with a microprocessor or some form of programmable controller.

The device is configured to have a normal operating mode and an energy saving operating mode.

In Si the device 2 operates in an energy saving mode. The heading measurement module 29 is however configured to be operable during the energy saving operating mode of the device 2. The controller 26 of the device is configured to operate in a specific energy saving mode (e.g. the microprocessor operates with a lower frequency than in a normal operating mode) insufficient for controlling the module 22 or the collector 23 or the transmitter 24, thus saving energy, however sufficient for enabling controlling of the heading measurement module 29 when the device operates in the energy saving operating mode.

When the device operates in the energy saving operating mode, the information collector 23 and the transmitter 24 are configured to operate in an energy saving operating mode, thereby saving energy.

In embodiments, the detection module 28 is also configured to be operable during the energy saving operating mode of the device 2. The controller 26 of the device may be configured to control the detection module 28 when the device operates in the energy saving operating mode in the specific energy saving mode.

The heading measurement module 29 determines in S2 information on whether or not the variation of a heading of the vehicle, excluding normal variation of a heading due to the waves when the vehicle is e.g. at mooring, is greater than a threshold. In embodiments, the module 29 is configured to detect, in the energy saving mode of the device! if the variation of a heading of the vehicle is greater than a threshold corresponding to 300 per minute, such as 0.5° in a predetermined period of one second, or 3° in a predetermined period of 6 seconds, or 15° in a predetermined period of 30 seconds, or 30° in a predetermined period of one minute. Other predetermined periods are possible.

If the detected variation of the heading of the vehicle corresponds to normal variation due to waves and/or is inferior to the threshold in 52 (i.e. the heading may vary, sometimes rapidly, and may oscillate respective to an initial heading, but overall the variation of the heading varies less, in a same direction respective to an initial heading, than a threshold corresponding to 30° per minute), Si is performed again.

When the detected variation of the heading, as detected by the module 29, is determined in S2 as not being due to waves and is superior to the threshold (i.e. the heading varies more, overall in a same direction respective to an initial heading at a beginning of the predetermined period of time, than a threshold corresponding to 30° per minute, such as 0.5° in a predetermined period of one second, or 3° in a predetermined period of 6 seconds, or 15° in a predetermined period of 30 seconds, or 30° in a predetermined period of one minute)! i.e. for example the module 29 determines a potential illegal movement (such as towing or lifting of the vehicle), in 53 the measurement module 29 provides an operating mode instruction to the device, responsive to the detecting. The instruction may be provided via e.g. the sensing unit 21 connected to the module 29, and the controller 26 which collects data from the unit 21. The instruction is adapted to trigger the device to operate in the normal mode.

In embodiments, the module 28 may also determine in S2 information on whether or not the detected physical displacement of the device, excluding vibration of the device, is greater than a threshold. In embodiments, the detection module 28 is configured to detect, in the energy saving mode of the device, if the linear acceleration or the angular acceleration of the device is greater than a threshold of at least one of 0.3m.s2 and Q302, or greater than a threshold of at least one of 0.4m.s2 and 0.40.s2, or greater than a threshold of at least one of 0.5m.s2 and 0.50.52, or greater than a threshold of at least one of 1 m.s2 and 1 O52 If the detected physical displacement of the device corresponds to vibration and/or is inferior to the threshold in 52 (i.e. the linear acceleration or the angular acceleration of the device is lower than a threshold), Si is performed again.

Optionally when the detected physical displacement of the device, as detected by the module 28 is determined in S2 as not being vibration and is superior to the threshold (i.e. the linear acceleration or the angular acceleration of the device is greater than a threshold), i.e. for example the module 28 determines a potential illegal movement, in 53 the detection module 26 provides an operating mode instruction to the device, responsive to the detecting. The instruction may be provided via e.g. the sensing unit 21 connected to the module 28, and the controller 26 which collects data from the unit 21. The instruction is adapted to trigger the device to operate in the normal mode.

In embodiments, in the normal operating mode of the device, the module 22, the collector 23 and the transmitter 24 are operating in a normal operating mode, and the controller 26 also collects data from the module 22 and/or the collector 23 in S4.

The controller 26 determines in 55 information on whether or not the detected status of the vehicle 20 deviates from a predetermined normal status, for example an abnormal status and/or illegal movement. The determination may be derived from: the unit 21 may detect the generation of an impact or a movement in excess of a reference value (e.g. from the modules 29 and/or 28) and/or ignition of the engine of the vehicle and/or a door being opened without using a key or a remote control; and/or the module 22 may detect a case where an ID of the RFID is not matched with a RFID tag and/or reader of the owner of the vehicle; and/or the collector 23 may detect an unauthorized position of the vehicle and/or that the vehicle exits and/or enters a predetermined GPS geofence, i.e., as known by those skilled in the art, a virtual perimeter of a physical geographic area which may be dynamically generated, e.g. as a radius around a point location or a custom-digitized drawn zone around an area.

The device is thus further configured to validate the trigger of the modules 29 or 28 responsive to the collection of the position information.

If the status is determined as not abnormal in 55, 54 is performed again.

When the status of the vehicle 20, as detected by the sensing unit 21 (e.g. via the modules 29 and/or 28) and/or the module 22 and/or the collector 23, is determined in as deviating from a predetermined normal status by the controller 26, i.e. for example the controller 26 determines an abnormal status and/or illegal movement, in 56 the information collector 23 periodically receives position information obtained by the position receiver interface 230 of the device 2.

In 57 the transmitter 24 transmits the position information, periodically received from the information collector 23, to a central apparatus 4, preferably operated by a provider of a vehicle tracking service. The transmission is preferably performed using a communication network 6, such as preferably a Global System Mobile Communications (GSM) using a communication interface 240 of the device 2, but other networks may be used, such as satellite networks.

In embodiments, the transmitter 24 is adapted to: transmit the position information in real time, when the communication network 6 is available or in range of the interface 240, and to store the position information to a memory, usually the memory 27 internal to the device 2, when the network 6 is not available or not in range of the interface 240, and to transmit the stored position information to the appaiatus 4 later, when the communication network 6 becomes available again.

In embodiments, in S7 the transmitter 24 further transmits a notification, such as an alarm message, e.g. a SMS message an/or an e-mail, indicating to the apparatus 4 a possible theft of the vehicle 20, without the transmission of the notification appearing on any device of the vehicle 20.

In embodiments the transmitter 24 may further transmit data including at least one of the following: locating technology parameters, such as number of GPS satellites in view, etc., and/or vehicle parameters, such as speed, heading direction, fuel amount, engine temperatuie and/or RPM, altitude, tire pressuie, battery status, etc., andloi a trigger event, such as key on/off, head/tail lights on/off, door open/closed, etc. The apparatus 4 preferably comprises one or more servers, in a single location or several locations, and the one or more servers are connected to access points, such as wireless access points 41. The apparatus 4 stores the parameters foi the operation of the tracking service, and also stores user profiles (containing the user name), created by the users when registering, as explained in greater detail below.

In SB the apparatus 4 receives the transmitted information and notification, and securely stoics them. As it will be appreciated in greater detail below, the appaiatus 4 is configured to serve the intormation, and sometimes notification, on demand to at least one user (such as the piovidei and/or the ownei of the vehicle and/oi the Police) on a user terminal 40, which may comprise a computer terminal and/or a handheld terminal such as a smaitphone.

As known by the person skilled in the art, the user terminal 40 typically compiises at least a processor, a memory, a display 42 and telecommunications means comprising a radio frequency signal receiver 401 (including access to cellular and/or communications network such as the Internet), such that the vehicle location can thus be viewed on the display 42, such as on electronic maps, for example via the Internet or specialized software.

In 59 the apparatus 4 contacts the owner of the vehicle 20, for example via a phone call and/or a SMS message and/or an email on the terminal 40, and provides vehicle movement details, and determines whether the possible theft is confirmed or not by the user.

If the theft is not confirmed in S9, S4 is performed again.

If the theft is confirmed in S9, in SlO the apparatus 4 continues to receive at least the position information from the transmitter 24, and starts a tracking and recovery procedure, in line with current Police legislation and procedures.

In Si 1 the apparatus 4 obtains a crime reference number from the Police.

In 512 the apparatus 4 liaises preferably with the Police (and/or the owner of the vehicle) by sending the data transmitted by the transmitter 24 and stored on the apparatus 4 to the terminal 40, such as a smartphone, used by the Police or the owner, in order to enable to track and to recover the vehicle 20.

It is appreciated that the position information, preferably the GPS location information, transmitted by the transmitter 24 enables location of the vehicle 20.

In Si3 the terminal 40 locates and approaches the stolen vehicle 20.

In S14 the vehicle is recovered.

The module 400 may incorporate hardware elements in a more specifically dedicated terminal 40, such as a terminal 40 used by the Police, but preferably comprises mainly software elements or firmware elements or any combination of these, for example for a general purpose terminal 40 such as a smartphone used e.g. by the owner of the vehicle 20.

Modifications and Variations Detailed embodiments have been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above embodiments whilst still benefiting from the inventions embodied therein, and will not be described in further detail here.

It should also be appreciated that Figure 2 shows functional block diagrams and that in practice the individual blocks shown in Figure 2 may exist as discrete elements or their functionality may be distributed in different combinations or not individually discernable.

In the embodiments described above, the device includes circuitry. Typically this circuitry will be formed by dedicated hardware circuits. However, in some embodiments, part of the circuitry may be implemented as software run by the corresponding controller. It should be appreciated that the functionalities may also be provided, where appropriate, by firmware and/or software and/or hardware or any combination thereof. A software implementation may however be preferred to facilitate the updating of the functionality of an element.

Where software are provided, they may be provided, as appropriate, in compiled or un-compiled form and may be supplied, as the case may be, as a signal over a computer or telecommunications network, or on a computer storage medium such as for instance a disc, an optical disc or a CD ROM.

In embodiments GLONASS, Radio Frequency or cellular technology (such as GSM) may be also used for locating the device 2, instead of or in complement to using GPS, and the data transmitted to the apparatus may also further include GSM and/or GSM area code/cell code.

The device 2 may be self-powered with a rechargeable battery or wired into the vehicle power system (battery).

In embodiments, the position receiver interface and/or the communication interface may be at least partially merged.

It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described in relation to any other embodiment.

Although the invention was described in relation to stolen vehicle recovery such as a a boat, it is understood that the invention may be implemented in other applications, such as for such as a caravan, a car, a bus, a trailer, or a truck, notably for fleet management. e.g. urban public transit or commercial trucks.

Claims

CLAIMS1. A vehicle tracking device (2) configured to be mounted on a vehicle (20), wherein the device is configured to have a normal operating mode and an energy saving operating mode, wherein the device further comprises a heading measurement module (29) for detecting, in the energy saving mode of the device, a variation of a heading of the vehicle in a predetermined period of time, and wherein the heading measurement module (29) is configured to provide an operating mode instruction to the device, responsive to the detecting, wherein the instruction is adapted to trigger the device to operate in the normal mode if the variation of a heading of the vehicle is greater than a threshold corresponding to 300 per minute.
2. The device according to claim 1, further comprising a detection module (28) for detecting, in the energy saving mode of the device, at least one of a linear acceleration and an angular acceleration corresponding to a physical displacement of the device (2), and wherein the detection module (28) is configured to provide an operating mode instruction to the device, responsive to the detecting, wherein the instruction is adapted to trigger the device to operate in the normal mode if the detected linear acceleration or the angular acceleration of the device is greater than a threshold of at least one of 0.3m.s2 and 0.30.s2.
3. The device according to any one of claims 1 or 2, comprising: an information collector (23) configured to collect position information indicating the position of the device (2); and/or a transmitter (24) configured to transmit the position information to a remote apparatus (4) using a communication network (6), and wherein the information collector (23) and/or the transmitter (24) are configured to operate: in an energy saving operating mode when the device operates in the energy saving operating mode; and in a normal operating mode when the device operates in the normal operating mode.
4. The device according to any one of claims 1 to 3, comprising: a controller (26) of the device configured to: control a heading measurement module (29) when the device operates in both the energy saving operating mode and the normal operating mode, wherein the controller is configured to operate in a specific energy saving mode when controlling a heading measurement module (29) when the device operates in the energy saving operating mode; and control the information collector (23) and/or the transmitter (24) in the normal operating mode of the device.
5. The device according to claims 2 to 4, wherein the controller (26) is further configured to control the detection module (28) when the device operates in both the energy saving operating mode and the normal operating mode, wherein the controller is configured to operate in a specific energy saving mode when controlling the detection module (28) when the device operates in the energy saving operating mode.
6. The device according to any one of claims 3 to 5, wherein the information collector (23) is further configured to validate the trigger responsive to the collection of the position information once operating in the normal operating mode.
7. The device (2) according to any one of claims 3 to 6, wherein the information collector (23) is configured to collect satellite position information, preferably global positioning system, GPS, position information.
8. The device according to any one of claims 2 to 7, wherein the detection module (28) comprises an accelerometer and/or a gyrometer.
9. The device according to any one of claims 1 to 8, wherein the heading measurement module (29) comprises a compass and/or a heading indicator.
10. The device (2) of any one of claims 1 to 9, comprising a rechargeable battery (29).
11. A method of tracking a vehicle (20), comprising: detecting, in an energy saving mode of a device (2) configured to be mounted on a vehicle (20) and to have a normal operating mode and an energy saving operating mode, a variation of a heading of the vehicle; providing an operating mode instruction to the device, responsive to the detecting, wherein the instruction is adapted to trigger, responsive to the detecting, the device to operate in the normal mode if the variation of a heading of the vehicle is greater than a threshold corresponding to 30° per minute.
12. The method according to claim 11, further comprising: detecting, in an energy saving mode of a device (2), at least one of a linear acceleration and an angular acceleration corresponding to a physical displacement of the device (2); providing an operating mode instruction to the device, responsive to the detecting, wherein the instruction is adapted to trigger, responsive to the detecting, the device to operate in the normal mode if the detected linear acceleration or the angular acceleration of the device is greater than a threshold of at least one of 0.3m.s2 and 0.30.s2.
13. The method according to any one of claims 11 or 12, comprising: collecting position information indicating the position of the device (2) when the device operates in the normal operating mode; and/or transmitting the position information to a remote apparatus (4) using a communication network (6) when the device operates in the normal operating mode.
14. The method according to claim 13, comprising: controlling the detection when the device operates in both the energy saving operating mode and the normal operating mode, wherein controlling is performed in a specific energy saving mode when the device operates in the energy saving operating mode; and controlling the collecting of the position information indicating the position of the device (2) and/or the transmitting of the position information to the remote apparatus (4) when the device operates in the normal operating mode.
15. The method according to any one of claims 13 or 14, comprising: validating the trigger responsive to the collecting of the position information once operating in the normal operating mode.
16. The method (2) according to any one of claims 13 to 15, wherein collecting the information (23) comprises collecting satellite position information, preferably global positioning system, OPS, position information.
17. The device of any one of claims 1 to 10 or the method of any one of claims 11 to 16, wherein the threshold corresponding to 30° per minute, is at least one of: 0.5° in a predetermined period of one second; 3° in a predetermined period of 6 seconds; 15° in a predetermined period of 30 seconds; 30° in a predetermined period of one minute.
18. A computer program, computer program product or computer readable medium comprising instructions for carrying out a method according to any one of claims 11 to 17.