DK179009B1

DK179009B1 - Automatic parking disc

Info

Publication number: DK179009B1
Application number: DKPA201670925A
Authority: DK
Inventors: James King-Yin Leung
Original assignee: Gopark Aps
Priority date: 2016-11-21
Filing date: 2016-11-21
Publication date: 2017-08-14
Also published as: DK201670925A1

Abstract

Automatic parking disc (1) comprising a housing (2) and fixing means for fixing the electronic parking disc in connection with an engine driven vehicle (18). The automatic parking disc comprises - an accelerometer (10), - a timer (8), - an autonomous power supply (6), - a display (3) and - a control system (12). Based on accelerometer signals generated by said accelerometer (10), said control system (12) is configured for assessing changes of a state of the vehicle (18) from parked to driving and from driving to parked and to control the display (3) correspondingly to indicate a starting time for the parking of the vehicle, when parked, and to indicate non-parking, when the vehicle is in the driving state. The control system is configured to determine fulfilling of a first condition on the basis of said accelerometer signals, when a vibration pattern corresponding to an idling vibration pattern for said vehicle is detected, and to determine fulfilling of a second condition when a vibration pattern caused by actual driving of said vehicle is detected. The control system is configured to determine a change of state from parked to driving when said first condition is fulfilled and said second condition is fulfilled as well, and the control system is further configured to determine a change of state from driving to parked when said first condition is not fulfilled. The invention further relates to a method of assessing a state of an engine driven vehicle.

Description

Automatic Parking Disc

Field of the invention

The invention relates to an automatic parking disc and a method of assessing a state of an engine driven vehicle.

Background of the invention

The use of a parking area for vehicles is often restricted to a specific and limited time period and it is the responsibility of the vehicle user to indicate the arrival time of the vehicle in the parking area. The arrival time may be indicated by a display of a parking disc fixedly installed inside the vehicle so that the arrival time can be read from the outside of the vehicle through the windshield.

Manual parking discs have been known for many years but automatic parking discs have gained a significant popularity recently as they function without requiring any actions from the vehicle user. The automatic parking discs will automatically indicate the arrival time of a vehicle in a parking area when detecting a shift from driving mode to parked mode of the vehicle.

An example of a simple automatic parking disc for a vehicle is disclosed in DE utility model no. 91/01216. The parking disc has a display that displays arrival time when the parking disc enters parking mode after the vehicle has parked in a parking area. The parking disc may change to a driving mode when a motion sensor in the parking disc - over a time period - detects that the number of vehicle vibrations have increased above a predefined threshold value. The actual time is displayed in the display when the parking disc is in the driving mode. A problem with this type of parking disc is the possibility of fraudulent change of the arrival time of the vehicle by a person rocking the vehicle from side to side for a brief time period. The vibrations rise above the predefined threshold value and fool the automatic parking disc to believe that the vehicle is in driving mode. The displayed arrival time in the parking disc is changed to the end of the rocking period and the valid period that the vehicle may be parked in the parking area is thus extended.

An example of a more advanced automatic parking disc is disclosed in EP patent no. 1 639 556. The parking disc includes an accelerometer that has to measure above a minimum value of acceleration in a uniform direction over a predetermined period of time before the parking disc changes from parking to driving mode. The functionality of the parking disc is explained as measuring the acceleration over a relative long time period before changing to driving mode which is practically exemplified by a driver having to move the vehicle from the parking area and onto the road before the parking disc changes to driving mode. A problem with the less sensitivity and accuracy in detecting a driving mode with the automatic parking disc disclosed in EP patent no. 1 639 556 is the inability to update the arrival time of the parking disc when the vehicle is moved over a short distance or at low speed.

Another example of an automatic parking disc is disclosed in international patent publication no. WO 2010/131059. The parking disc includes an accelerometer that measures an acceleration signal representing movement of a vehicle, e.g. moving from parked to driving mode or from driving to parked mode. The signal is sampled, filtered to suppress any signals outside a window and integrated over a time interval before it is determined whether the vehicle is parked or moving by comparing the integrated signal with either a lower threshold or an upper threshold, depending on the present state.

It is an object of the invention to provide an automatic parking disc which is precise in detecting driving and parking mode of a vehicle in order to display the correct arrival time in a parking area and avoid any fraudulent change of the arrival time.

Summary of the invention

According to a first aspect, the invention relates to an automatic parking disc comprising a housing and fixing means for fixing the electronic parking disc in connection with an engine driven vehicle, said automatic parking disc comprising an accelerometer, a timer, an autonomous power supply, a display and a control system, wherein, based on accelerometer signals generated by said accelerometer, said control system is configured for assessing changes of a state of the vehicle from parked to driving and from driving to parked and to control the display correspondingly to indicate a starting time for the parking of the vehicle, when parked, and to indicate non-parking, when the vehicle is in the driving state, wherein said control system is configured to determine fulfilling of a first condition on the basis of said accelerometer signals, when a vibration pattern corresponding to an idling vibration pattern for said vehicle is detected, and to determine fulfilling of a second condition when a vibration pattern caused by actual driving of said vehicle is detected, wherein said control system is configured to determine a change of state from parked to driving when said first condition is fulfilled and said second condition is fulfilled as well, and wherein said control system further is configured to determine a change of state from driving to parked when said first condition is not fulfilled.

Hereby, it is achieved that the automatic parking disc is able to perform with great precision and is able to detect changes between parking and driving mode and vice versa detect changes between driving and parking mode on the basis of vibration signals only. Thus, the switching between modes is not depending on calculating or measuring e.g. acceleration values for the acceleration of the vehicle in the actual driving direction, the velocity of the vehicle, etc.

According to an embodiment, the fulfilling of said first condition may comprise determining a vibration count Vf for a predetermined time interval Tf and when said vibration count Vf exceeds a predetermined threshold Vfthreshoid, said first condition is fulfilled.

Hereby, it is achieved that the presence of an idling vibration pattern can be performed in an expedient manner, e.g. by counting the number of vibrations for a time period of the relatively high frequency pattern signal and on the basis of this determine with accuracy whether the idling vibration pattern is present.

According to an embodiment, the fulfilling of said first condition may further comprise determining the vibration count Vf for a subsequent time interval Tf that also exceeds said predetermined threshold Vfthreshoid.

Hereby, it is achieved that the fulfilling of the first condition can be determined with greater certainty.

According to an embodiment, the fulfilling of said second condition may comprise providing a low frequency pattern, based on said accelerometer signals, and determining whether within a time interval T1 an increasing vibration cycle period is present, in which case it is determined that said vibration pattern caused by actual driving of said vehicle is present.

Hereby, it is achieved that the presence of a low frequency pattern that is originating from the driving only (cf. Graph B), can be assessed in an expedient manner and whereby the fulfilling of the second condition can be determined to be fulfilled with certainty.

According to an embodiment, said time interval T1 may comprise at least 3 vibration cycle periods, wherein it is determined whether at least one half cycle period is longer than a previous half cycle period.

Hereby, it is achieved that the fulfilling of the second condition can be determined with greater certainty and accuracy.

According to an embodiment, said accelerometer may comprise a multiple-axis accelerometer, e.g. a 3-axis accelerometer.

Hereby, it is achieved that the accelerometer signals that are used as input for the processing that leads to the correct indication of mode of the automatic parking disc, i.e. parking mode or driving mode, can be provided using e.g. standard accelerometers, g-sensors or the like that are well-known within the technical field and that furthermore, due to the multiple axis, e.g. 3-axis configuration, the positioning of the automatic parking disc in the vehicle will be indifferent as regards the direction, tilting, etc.

According to an embodiment, said multiple-axis accelerometer may be a 3-axis accelerometer and wherein the accelerometer generated by said accelerometer are provided by sampling and as x-axis data (x), y-axis data (y) and z-axis data (z), wherein furthermore the accelerometer or the control system may be configured to provide summed data in the form SUM=x+y+z and/or in the form SUM2= x2 + y2 +z2.

Hereby, it is achieved that data for the further processing are provided, based on the generated and sampled accelerometer signals, said data being stored by e.g. the control system, e.g. in buffers, which data in the suggested two forms expediently can be used for the assessing of the fulfilment of the first and the second condition.

According to an embodiment, the automatic parking disc is configured for using said summed data SUM2 in connection with determining fulfilling of said first condition and/or wherein the automatic parking disc is configured for using said summed data SUM in connection with determining fulfilling of said second condition.

Hereby, a particular expedient embodiment is achieved, whereby the fulfilment of the first condition and the second condition can be determined in expedient manners, based on particular suitable data material.

According to an embodiment, the automatic parking disc may be configured for providing said vibration count Vf by analysing the respective signals as regards a slope status of the signals, e.g. said slope status being rising or falling.

Hereby, it is achieved that the vibration counts can be provided in an expedient manner.

According to an embodiment, the automatic parking disc may be configured for analysing the respective signals as regards a slope status change of the signals, e.g. a point of changing slope and/or a zero crossing.

Hereby, it is achieved that the analysis of the respective data material corresponding to the respective signals can be provided in an expedient manner.

According to an embodiment, the control system may be configured to indicate nonparking by indicating real time on the display.

Hereby, it is achieved that the automatic parking disc can indicate non-parking, i.e. driving mode, in an expedient manner by letting the display indicate real time as provided via the timer of the automatic parking disc. It will be apparent to the skilled person that other manners of indicating non-parking, i.e. driving mode can be used instead, e.g. letting the display be empty, by using a character, letter or the like to indicate driving mode, etc. Also, it is noted that the display of the automatic parking disc may comprise a digital display as shown in the figures, but that instead or in addition an analog displaying system may be used, e.g. a clock face, in which case parking mode can be displayed by the clock hand being fixed to show the start of the parking time and where driving mode for example may be indicated via the absence of a clock hand on the display. Other manners, variations and combinations are possible, which will be apparent to the skilled person.

According to an embodiment, said control system may be configured to indicate a starting time for the parking of the vehicle, when parked, in accordance with national, regional and/or local regulations.

Hereby, it is achieved that the automatic parking disc, when in parking mode, will show the time that corresponds to the start of the parking period as stipulated by e.g. national law or regulations, whether the start of the parking period is the actual arrival time, the nearest upcoming quarter of an hour, etc. The actual setting of the automatic parking disc as regards such a national or local criterion may be set up by the user, when mounting the automatic parking disc in a vehicle. Furthermore, such a setting up may be changed by the user, e.g. when going to another country or region with other basic rules in this regard.

According to a second aspect, the invention relates to a method of assessing a state of an engine driven vehicle, said state being parked or driving, whereby, based on accelerometer signals generated by an accelerometer, determining fulfilling of a first condition, said first condition being fulfilled when a vibration pattern corresponding to an idling vibration pattern for said vehicle is detected, and determining fulfilling of a second condition, said second condition being fulfilled when a vibration pattern caused by actual driving of said vehicle is detected, wherein a change of state from parked to driving is determined when said first condition is fulfilled and said second condition is fulfilled as well, and wherein a change of state from driving to parked is determined when said first condition is not fulfilled.

Hereby, it is achieved that when using the method, the state or mode of a vehicle can be assessed with great precision and it is made possible to detect changes between parking and driving mode and vice versa detect changes between driving and parking mode on the basis of vibration signals only and with accuracy. Thus, the switching between modes is not depending on calculating or measuring e.g. acceleration values for the acceleration of the vehicle in the actual driving direction, the velocity of the vehicle, etc.

According to an embodiment, said may be applied using an automatic parking disc according to anyone of claims 1-12.

The figures

The invention will be explained in further detail below with reference to the figures of which

Figs, la-b show an example of an automatic parking disc with key electronic components schematically indicated and a parked vehicle with the automatic parking disc visible through the windshield,

Fig. 2 shows an example of an accelerometer signal, which has been captured in a parked vehicle with the engine idling,

Fig. 3 shows an example of an accelerometer signal, which has been captured in the same car being driven,

Figs. 4a-c show the relationship between the graphs shown on figs. 2 and 3 together with a graph B showing a vibration pattern that originates from the driving only,

Fig. 5 is a flow chart illustrating the operation of an automatic parking disc according to an embodiment of the invention,

Fig. 6a shows a detailed preferable embodiment of part of the flow chart of fig. 5 relating to the initial processing,

Fig. 6b shows a detailed preferable embodiment of the part of the flow chart of fig. 5 relating to determining of the fulfilment of the first condition,

Fig. 6c illustrates an example with consecutive predetermined time intervals Tf, where two consecutive of these intervals means that the first condition is fulfilled,

Fig. 6d shows a detailed preferable embodiment of the part of the flow chart of fig. 5 relating to determining of the fulfilment of the second condition, Fig. 6e shows an example of a low frequency vibration pattern, which is analysed to determine that condition 2 has been fulfilled, and Fig. 6f illustrates an example with consecutive predetermined time intervals Tf, where five consecutive of these intervals means that the further step is fulfilled.

Detailed description

The invention will be explained in further detail with reference to the drawings and with reference to various non-limiting examples and embodiments as it will be elucidated in the following.

Figs, la and lb show an example of an automatic parking disc 1 according to an embodiment of the invention. The parking disc 1 comprises a housing 2 for housing various components of the automatic parking disc preferably located on a circuit board 5, such as e.g. display means 3, a power supply 6, which may be autonomous, e.g. a battery, a timer 8 for providing real time information, an accelerometer 10, e.g. a g-sensor or the like, and a control system 12, which may comprise microcontroller means, data storage means, etc. as it will be apparent to a skilled person. Further, the automatic parking disc 1, e.g. the housing 2 may comprise fixing means 15 for positioning automatic parking disc in connection with an engine driven vehicle 18, e.g. behind the windshield 17 of a car in such a manner that the display is visible from the exterior of the car. Such fixing means may be adhesive pads or the like or another type of fixing means may be utilized.

Even further, the automatic parking disc 1 comprises user input means 16, e.g. keys, buttons, etc. for e.g. setting the time, if necessary, setting the automatic parking disc to adjust the parking initiation time according to e.g. national regulations, if necessary, etc.

Initially, figures 2 and 3 show accelerometer signals that have been retrieved by positioning an accelerometer in an engine driven vehicle, e.g. a car.

In fig. 2 is shown an example of an accelerometer signal, which has been captured and registered (Graph A) in a car, which is parked, i.e. in park mode, and with the engine turned on and idling.

In fig. 3 is shown an accelerometer signal that has been captured and registered (Graph C) in a car, which is being driven on the road, i.e. in drive mode. The two characteristic graphs showing the vibration patterns have been captured for a similar time period and further, it is noted that similar graphs/vibration patterns have been captured for various types of vehicles, whereby it is seen that essentially similar graphs/vibration patterns have been captured, showing in the park mode graphs qualitatively similar to graph A and in the drive mode graphs qualitatively similar to graph C.

In connection with the invention it has been realized that the vibration pattern captured as accelerometer signals in the drive mode can be seen as a superposition of two accelerometer signal patterns, i.e. two vibration patterns, namely the idle or park mode vibration pattern as shown in fig. 2 and a vibration pattern that originates from the driving only. This is illustrated in fig. 4, where fig. 4a is Graph A as shown in fig. 2 and fig. 4c is Graph C as shown in fig.3. Fig. 4b shows a graph B, which, when superposed with Graph A from fig. 3a results in Graph C as shown in fig. 4c, i.e.

Graph A + Graph B => Graph C.

This observation is utilized in connection with the present invention, e.g. that the idle mode vibration pattern comprises a relatively high frequency and that the frequency will increase with engine revolutions. In contrast to this the vibration pattern that originates from the driving only (Graph B) has e.g. a low frequency pattern, i.e. longer periods.

Thus, it has been realized that an idle mode vibration pattern (Graph A) will be present in an accelerometer signal when a car is parked with the engine running, e.g. at idle, and when the car is being driven on the roads, but that it will not be present when the car is parked and the engine is stopped. Further, it has been realized that a vibration pattern in driving only (Graph B) will only be comprised in an accelerometer signal captured in a car when the car is being driven on the roads, in traffic, etc.

The above observations can be used for controlling an automatic parking disc to indicate whether the car is in a park mode or in a drive mode and for controlling the automatic parking disc 1 to change from park mode to drive mode and vice versa correspondingly.

This can be implemented in various forms and embodiments as it will be exemplified in the following.

It is noted that the automatic parking disc 1 can indicate non-parking, i.e. driving mode, by letting the display 3 indicate real time as provided via the timer 8 of the automatic parking disc. It will be apparent to the skilled person that other manners of indicating non-parking, i.e. driving mode can be used instead, e.g. letting the display 3 be “empty”, by using a character, letter or the like to indicate driving mode, etc. Also, it is noted that the display 3 of the automatic parking disc 1 may comprise a digital display as shown in figures 1 and 2, but that instead or in addition an analog displaying system may be used, e.g. a clock face (not shown in the figures), in which case parking mode can be displayed by the clock hand being fixed to show the start of the parking time and where driving mode for example may be indicated via the absence of a clock hand on the display. Also, it is noted that the rear side of the automatic parking disc may comprise a display for the benefit of e.g. the driver. Other manners, variations and combinations are possible, which will be apparent to the skilled person.

Further, it is noted that the automatic parking disc 1, when in parking mode, will show the time that corresponds to the start of the parking period as stipulated by e.g. national law or regulations, whether the start of the parking period is the actual arrival time, the nearest upcoming quarter of an hour, etc. The actual setting of the automatic parking disc 1 as regards such a national or local criterion may be set up by the user, when mounting the automatic parking disc in a vehicle 18, e.g. by means of the user input means 16, e.g. keys, buttons or the like. Furthermore, such a setting up may be changed by the user, e.g. when going to another country or region with other basic rules in this regard.

In fig. 5 is shown a flow chart illustrating the operation of an automatic parking disc according to an embodiment of the invention. Here, it is shown at 50 that the accelerometer signal is captured by sampling. The acceleration signal may be provided by a multiple-axis accelerometer, e.g. a 3-axis accelerometer, which thus provides x-axis, y-axis and z-axis signals that may be processed. Subsequent, it is determined at 52 whether an idle vibration pattern is present. If not, the steps are repeated. If an idle vibration pattern is present, it will then be determined at 54 whether a driving vibration pattern is present. If not, the steps are repeated. If a driving vibration pattern is present, it is then at 56 decided that the automatic parking disc 1 shall indicate drive mode. Assuming that when starting, the car 18 was parked and the automatic parking disc 1 was indicating park mode, the automatic parking disc will here switch to indicating drive mode.

When in the drive mode, the automatic parking disc will monitor the signal for presence of an idle vibration pattern only, e.g. at 58. As long as this is the case, the automatic parking disc 1 will continue to indicate drive mode.

In case it is determined that an idle vibration pattern is no longer present, it is decided at 58 that the automatic parking disc shall change and indicate parking mode at 60. Subsequent to this, the functioning of the automatic parking disc will revert to the initial steps, e.g. testing for an idle vibration pattern as indicated at 50 and 52, etc.

The respective steps in this flow chart can be implemented in a multitude of variations and embodiments, as it will be apparent to a skilled person. Examples hereof will be elucidated in the following with reference to figs 6a-6e.

Further, as shown in fig. 6a, it is noted that when capturing the accelerometer signals, these may be provided by sampling from a 3-axis accelerometer (e.g. a g-sensor as it may also be designated in this context), thus providing x-axis data (x), y-axis data (y) and z-axis data (z), as indicated at 62. The sampling frequency may be selected from suitable intervals or values, but may as an example be 64 Hz. Lower or higher sampling frequencies may be utilized instead, depending on the particular circumstances.

The automatic parking disc, e.g. the control system may be configured to process the captured and sampled data to provide summed data in the form of SUM=x+y+z and/or in the form of SUM2= x2 + y2 +z2, as indicated at 64 and 66.

As shown in fig. 6b, the data that is provided as SUM2= x2 + y2 +z2 may be used when it is determined at 52 whether an idle vibration pattern is present. The SUM2 data may be processed further, e.g. to remove noise, etc., but the data is as shown in fig. 6b supplied to a step of getting a count Vf of the vibrations for a predetermined time interval Tf, e.g. for a time interval corresponding to 64 samples, as indicated at 70. However, it will be apparent that the length of the predetermined time interval Tf may be shorter or longer.

In case it is determined as indicated at 72 that the vibration count Vf is larger than a predetermined threshold value Vfthreshoid, it is as shown in fig. 6b preferably checked that a similar result is achieved for the next predetermined time interval Tf. Thus, the step of getting a count Vf of the vibrations for a predetermined time interval Tf for the next time interval corresponding to e.g. 64 samples is repeated and compared with a predetermined threshold value Vfthreshoid, as indicated at 74 and 76.

In case both vibration counts are larger than the predetermined threshold value Vfthreshoid, the first condition is determined to be fulfilled.

It is a possibility that three (or more) consecutive predetermined time intervals Tf must prove to have vibration counts Vf larger than the threshold value in order for the first condition to be fulfilled.

In case the vibration count Vf for the second time interval Tf, e.g. corresponding to 64 samples, is not larger than (or equal to) the predetermined threshold value Vfthreshoid, the steps are repeated by searching for another two sets, one following directly after the other, that both have vibration counts that are larger than (or equal to) the predetermined threshold value Vfthreshoid., in which case the first condition is fulfilled. This has been illustrated by the example shown in fig. 6c. The search continues until an e.g. 20 seconds time-out is over.

As shown in fig. 6d (at 80), the data that is provided as SUM=x+y+z may preferably be used when it is determined at 54 whether a driving vibration pattern is present, i.e. in order to determine whether the second condition is fulfilled. The SUM data may be processed further, e.g. to remove noise, by averaging, etc., to provide a low frequency vibration pattern corresponding to the vibration originating from the driving only, cf. Graph B as shown in fig. 4B.

The thus provided low frequency vibration pattern is analysed, e.g. by determining slopes and turning points etc. for a time interval Tl, as indicated in 80, 82 and 84 e.g. to determine whether an increasing vibration cycle period is present, as indicated in 86 in which case it may be determined that said vibration pattern caused by actual driving of said vehicle is present.

As shown in fig. 6e, the specific time interval Tl may comprise at least 3 vibration cycle periods comprising positive and negative slopes 94, 96 and turning points 90, 92, wherein it is determined whether at least one half cycle period is longer than a previous half cycle period.

Specifically, it can be checked whether the following is fulfilled, using the time references as shown in fig, 6e:

IF t2 — 11 >= ConstLow or t2 - tO >= ConstLow or tC - tB >= ConstLow or tC - tA >= ConstLow

THEN one vibration pattern caused by actual driving of the vehicle is present and condition 2 is fulfilled.

The constant value ConstLow may be selected in dependence on the particular circumstances, but it may for example be 7 x a time delay in msec, but lower or higher values may be selected instead. Also, other manners of determining that a low frequency vibration pattern is caused by actual driving of the vehicle is present.

It is a possibility to include a further step or check when it has been decided that both the first and the second condition have been fulfilled, before letting the automatic parking disc 1 indicate drive mode. For example, after having determined that condition 2 has been fulfilled, it can be checked as indicated in fig. 6f that for example at least 5 sets of consecutive vibration counts have vibration counts Vf larger than the threshold value, before letting the automatic parking disc 1 indicate drive mode. If not at least 5 sets of consecutive vibration counts having vibration counts Vf larger than the threshold value, then the search continues until an e.g. 20 seconds time-out is over.

Also, it is noted as a possibility to include a further step or check when in the drive mode, where the automatic parking disc will monitor the signal for presence of an idle vibration pattern only (e.g. as shown at 58 in fig. 5). It can be checked that for example out of at least the last 5 sets of consecutive vibration counts there are at least 4 with vibration counts Vf larger than the threshold value, in which case the automatic parking disc will stay in the driving mode. If this is not the case, the automatic parking disc can change to parking mode.

In the above description, various embodiments of the invention have been described with reference to the drawings, but it is apparent for a person skilled within the art that the invention can be carried out in an infinite number of ways, using e.g. the examples and embodiments disclosed in the description in various combinations, and within a wide range of variations within the scope of the appended claims.

List of reference numbers 1. Automatic parking disc for a vehicle 2. Housing for housing various components of the automatic parking disc 3. Display in the automatic parking disc 5. Circuit board in the housing of the automatic parking disc for mounting and interconnection of various components 6. Autonomous power supply for the automatic parking disc such as one or more batteries located in the housing of the parking disc 8. Timer for providing real time information to the control system 10. Multiple axis accelerometer or gravity sensor such as a three axis accelerometer 12. Control system in the automatic parking disc comprising a microcontroller unit or means (MCU) e.g. an integrated circuit comprising a processor core, memory / data storage means and programmable input/output peripherals 15. Fixing means of the automatic parking disc to a part of the vehicle such as the windshield e.g. fixing means in the form of adhesive pads or the like or another type of fixing means 16. User input means such as keys, buttons, etc. for setting the actual time, setting the automatic parking disc to adjust the parking initiation time according to e.g. national regulations or similar adjustments 17. A windshield of the vehicle 18. A vehicle driven by an engine such as a car 50-60. Flow chart including process and decision blocks illustrating the operation of an automatic parking disc according to an embodiment of the invention 62-66. A more detailed example in getting or capturing the accelerometer signals as disclosed in process block 50 of the flow chart 70-76. A more detailed example in determined whether an idle vibration pattern is present as disclosed in decision block 52 of the flow chart 80-86. A more detailed example in determined whether a driving vibration pattern is present as disclosed in decision block 54 of the flow chart 90, 92. Examples of turning points in the low frequency vibration pattern 92, 94. Examples of positive and negative slopes in the low frequency vibration pattern

Claims

An automatic parking disc (1) comprising a housing (2) and fasteners for securing the electronic parking disc in connection with a motor vehicle (18), said automatic parking disc comprising an accelerometer (10), a timer (8), an autonomous power supply (6), a display (3) and a control system (12) wherein, based on accelerometer signals generated by said accelerometer (10), said control system (12) is configured to assess changes in the state of the vehicle (18) ) from parked to driving and from driving to parked and to control the display (3) correspondingly to indicate a start time for parking the vehicle when parked and to indicate non-parking when the vehicle is in the driving state, characterized by said control system being configured to determine fulfillment of a first condition on the basis of said accelerometer signals when a vibration pattern corresponding to an idle vibration model tests for said vehicle are detected and to determine fulfillment of a second condition when a vibration pattern caused by actual driving of said vehicle is detected, wherein said control system is configured to determine a change of state from parked to run when said first condition is fulfilled and said second condition is also fulfilled and wherein said control system is further configured to determine a change of state from driving to parked when said first condition is not fulfilled.

An automatic parking disc according to claim 1, wherein the fulfillment of said first condition comprises determining a vibration count Vf for a predetermined time interval Tf, and when said vibration count Vf exceeds a predetermined threshold value Vfthreshoid, said first condition is fulfilled.

Automatic parking disc according to claim 2, wherein the fulfillment of said first condition further comprises determining that the vibration count Vf in a subsequent time interval Tf also exceeds said predetermined threshold value V fthreshold.

An automatic parking disc according to any of claims 1-3, wherein the fulfillment of said second condition comprises providing a low frequency pattern based on said accelerometer signals and determining whether an increasing vibration cycle period is present within a time interval T1. , in which case it is determined that said vibration pattern caused by actual driving of said vehicle is present.

An automatic parking disc according to claim 4, wherein said time interval T1 comprises at least three vibration cycle periods, wherein it is determined whether at least one half cycle period is longer than a previous half cycle period.

An automatic parking disc according to any one of claims 1-5, wherein said accelerometer comprises a multi-axis accelerometer, e.g. a 3-axis accelerometer.

The automatic parking disc of claim 6, wherein said multi-axis accelerometer is a 3-axis accelerometer and wherein the accelerometer signals generated by the accelerometer are provided by sampling and as x-axis data (x), y-axis data (y) and z-axis. axis data (z), where the accelerometer or control system may further be configured to provide summed data in the form SUM = x + y + z and / or in the form SUM2 = x2 + y2 + z2.

An automatic parking disk according to claim 7, wherein the automatic parking disk is configured to use said summed data SUM2 in determining compliance with said first condition, and / or wherein the automatic parking disk is configured to use said summed data SUM in connection with determination of fulfillment of said second condition.

An automatic parking disc according to any one of claims 2-7, wherein the automatic parking disc is configured to provide said vibration count Vf by analyzing the respective signals with respect to a slope status of the signals, said slope state, for example being rising or falling.

An automatic parking disk according to any one of claims 1-9, wherein the automatic parking disk is configured to analyze the respective signals as to a slope status change of the signals, e.g. a point for changing the slope and / or a zero crossing.

Automatic parking disc according to any one of claims 1-10, wherein said operating system is configured to indicate non-parking by indicating real time on the display.

An automatic parking disc according to any one of claims 1-11, wherein said operating system is configured to indicate a start time for parking the vehicle when parked, in accordance with national, regional and / or local regulations.

A method for assessing a state of a motor vehicle, said state being parked or driven, based on accelerometer signals generated by an accelerometer, characterized by determining the fulfillment of a first condition, said first condition being fulfilled when a vibration pattern corresponding to an idle vibration pattern for said vehicle is detected and determination of the fulfillment of another condition, said second condition being met when a vibration pattern caused by actual driving of said vehicle is detected, where a change of state from parked to driving is determined when said first condition is fulfilled and said second condition is also met and where a change of state from driving to parked is determined when said first condition is not fulfilled.

A method according to claim 13, which method is used using an automatic parking disc according to any one of claims 1- 12.