Method and apparatus for determination of position

SWEDEN (12) PATENT (13) C2 (ii) 521 860

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(19) SE (₅₁)

International class ⁷

G01S 5/00, G08G 1/127

PATENT AND REGISTRATION (45) (41) (22) (24) (62) (86) (86)

Patent filed Application widely available The patent application was submitted on expiration date

Tribal application number

2003-12-16

2002-03-18

2000-08-14

2000-08-14 (21) Patent Application Number 0002931-4

Application received as:

(83)

International filing day

Filing date for European patent application Deposit of microorganism Swedish patent application completed international patent application with number □ converted European patent application with number (30) Priority information (73) (72) (74) (54) (56) (57)

PATENT HOLDER Volvo Technical Development AB, CTP 412 88 Gothenburg SEE INVENTOR Sven Jonsson, Bollebygd SE, Stefan Gudmundsson, Gothenburg SEE VENDOR Volvo Technology Corp

NAME Method and apparatus for determining the position of a moving object

CALLED PUBLICATIONS:

WO Al 95 135 94 (G07C 5/08), WO Al 00 100 27 (G01S 5/00),

WO Al 00 349 32 (G08G 1/127), US Ä 5 598 167 (342/457)

SUMMARY:

A method and apparatus for determining the position of a moving object by selecting and storing an instantaneous position P as a breaking point W if the following conditions are met:

1) The instantaneous distance D along the route between position P and the last breaking point is greater than a first parameter X; or

2a) the instantaneous distance D along the route between position P and the last breaking point is greater than a second parameter Y, where Y &lt;X, and

b) the deviation A between the instantaneous travel direction of the object and the direction obtained by a line through the last two breaking points is greater than a third parameter Z, and

c) the velocity of the object is greater than a minimum velocity which is a fourth parameter S.

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The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

521 860

Summary

A method and apparatus for determining the position of a moving object by selecting and storing an instantaneous position P as a breaking point W if the following conditions are met:

1) The instantaneous distance D along the route between position P and the last breaking point is greater than a first parameter X; or

2a) the instantaneous distance D along the route between position P and the last breaking point is greater than a second parameter Y, where Y &lt;X, and

b) the deviation A between the instantaneous travel direction of the object and the direction obtained by a line through the last two breaking points is greater than a third parameter Z, and

c) the velocity of the object is greater than a minimum velocity which is a fourth parameter S.

The stored breakpoints allow the direction of travel to be determined, which is advantageous for locating vehicles driven on parallel, unidirectional lanes.

(Fig. 3)

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The present invention relates to a method and apparatus for determining the position of a moving object such as a vehicle, aircraft or vessel, preferably along a predetermined route.

Navigation systems to determine position using GPS (Global Positioning System) are well known not only for use in aircraft and ships, but are also of increasing importance in determining a vehicle position.

This field of application requires a receiver and an evaluation unit that are compact and affordable. Furthermore, the information is concentrated as much as possible to reduce the connection time and the connection cost, while the information must be sufficiently significant for a computer to be able to determine the position of the vehicle.

It is an object of the invention to provide a method and apparatus for determining the position of a movable object according to the first paragraph, which is very simple to realize and which requires only minimal hardware expenditure.

Another object of the invention is to provide a method and apparatus for determining the position of a moving vehicle which allows an accurate position determination even taking into account two parallel, opposite lanes of a highway.

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These and other objects are achieved by a method according to claim 1

These and other objects are further achieved with a device according to claim 5.

The subclaims refer to advantageous embodiments of the invention according to claims 1 and 5 respectively.

Further details, aspects and advantages will become apparent from the following description of a preferred embodiment of the invention, with reference to the drawings, in which:

Fig. 1 schematically shows the environment of an inventive method and apparatus,

Fig. 2 schematically shows the choice of breakpoints, and Fig. 3 shows a vehicle's route with marked breakpoints.

A preferred environment for an inventive method and apparatus is illustrated in Fig. 1. It includes a customer service center 10 with an operator 11. At least one vehicle 20, at least one boat or vessel 24, as well as one or more stationary equipment 25, such as a remote device or facility, communicates with customer service center 10 over a mobile network 30 such as GSM (European standard) or AMPS (US standard) and / or a satellite network 31, both for exchanging information, data and voice communications in both directions. Software can also be transferred if needed.

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Emergency vehicles, such as an ambulance 22 or a tow truck 23, communicate with the customer service center 10 in a similar way or otherwise, and are commanded by the customer service center if required from any of the items 20, 24, 25. Each item's position can be obtained by a global position system (GPS) 40.

Vehicles, especially trucks, which are guided or monitored by the customer service center, are equipped with a suitable transmitter for transmitting position data to the customer service center.

In the event of an accident or in an emergency when an emergency vehicle 23 is needed, the driver of the emergency vehicle must know the exact position of the emergency vehicle, especially when the vehicle is driven on a motorway or other road with separate, opposite lanes. The display of the position of the user's GPS is normally not good enough to be able to distinguish two parallel, opposite lanes and thus be able to show in which lane a vehicle traveled.

The method according to the invention and the device allow such a distinction by determining not only the position but also the direction of movement of the object. This is achieved by storing a series of previously determined positions in a corresponding memory and, if necessary, being sent to the customer service center or an emergency vehicle, so that the object's current position but also its distance traveled path before this position and thus its direction of movement can be determined. This allows the determination of the lane on which the vehicle is located.

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The position of the object is determined e.g. every second in known manner by evaluating the GPS signal. In order to save memory and to reduce the processor requirements, connection time and connection costs, only selected position information is stored in the memory and transmitted as waypoints along the traveled route if necessary.

The choice of breaking points is described in reference to Fig. 2. The solid line shows the path of the object and point P is the instantaneous position of the object. Points WO and W1 are a first and second breaking point, respectively. D describes the instantaneous distance between the second (last) breaking point and the instantaneous position P along the road. X and Y are parameters describing a predetermined distance value from the last breaking point, which is the second breaking point W1 in Fig. 2. A is the deviation between the instantaneous travel direction of the object and the direction obtained by a line through the two last breaking points WO and W1.

The criterion for selecting and storing an instantaneous position P as a new breaking point W is as follows:

1) The instantaneous distance D along the route between position P and the last breaking point is greater than a first parameter X; or

2a) the instantaneous distance D along the route between position P and the last breaking point is greater than a second parameter Y, where Y &lt;X, and b) the deviation A between the object's instantaneous direction of travel and the direction obtained by a line through the two last breaking points is greater than a third parameter Z, and

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c) the velocity of the object is greater than a minimum velocity which is a fourth parameter S.

If one of the conditions 1) or 2a-c) is fulfilled, the instantaneous position of the object is saved as a breaking point. Preferably, the last seven breakpoints are stored in the memory.

sharp corner conditions 2c)

Conditions 1) ensure that breakpoints are stored after at least certain intervals even when the object travels along a road that is substantially straight. Condition 2a) gives a shorter distance between the intersection points if, according to condition 2b), a highway turns or if a street has or roundabouts. The speed S according to is a low speed limit to ensure that breakpoints are not stored when the object travels very slowly, e.g. in a parking lot, even when conditions 2a) and 2b) are met.

As shown in Fig. 2, the instantaneous position P is selected and stored as a new breaking point when the object's velocity is greater than the minimum velocity S and when the distance D from the second breaking point W1 is greater than Y and when the deviation angle A is greater than Z degrees. If one or more of these conditions are not met when the object is at the distance X from the second breaking point W1, then a new breaking point is stored anyway. The instantaneous velocity of the object and the distance D as well as the deviation angle A are estimated based on GPS data and compared with the above conditions and stored by a calculation unit comprising a memory (not shown) inside the object.

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The parameters (X, Y, Ζ) are predetermined depending on the speed of the object as a fifth parameter. In the case of a vehicle that is usually driven in city traffic or on a highway in normal speed areas, a speed limit L. The speed limit L is chosen to distinguish between city traffic and highway traffic so that a suitable value can be approximately 50 km / h. Accordingly, a first set of parameters (XI, Y1, Z1) for speeds below the speed limit L and a second set of parameters (X2, Y2, Z2) for speeds above the speed limit L. are determined. parameters such as (500m, 50m, 45 °) and for the second set of parameters such as (1000m, 100m, 45 °). The minimum speed S was set to 5 km / h.

Although the deviation angle Z was set to 45 ° in both speed ranges, the value of Z should ideally be slightly smaller in the speed range above the speed limit L and slightly larger in the speed range below the speed limit L, especially as most turns in city traffic are made around 90 ° street corners. However, at present, 45 ° seems to be a reasonably good compromise for both speed ranges.

Preferably, the last seven breakpoints are stored in memory and sent to a customer service center if needed. At the customer service center, the breakpoints are transferred to a road map or displayed on a display together with an electronic road map. The most recent break point shows the car's last position while the order of the break points shows the direction of movement so that the car's

521 860 position can also be determined with respect to roads or highways having two parallel, opposite lanes.

Fig. 3 schematically shows a map, as can be seen at a customer service center, where a road 10 leads through a town 11 and a surrounding countryside 12. A vehicle 13 travels along the road. The previous positions of the vehicle which have been selected as break points according to the invention are shown by a cross (W). The last seven breaking points WO to

W6 is stored in the calculator's memory inside the vehicle.

This figure shows how the breakpoints are grouped close to each other in the city and how the distance between the breakpoints increases with the speed as the journey continues on a straight road in the countryside.

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