DE3011556C2 - Area navigation device for air and / or water vehicles - Google Patents

Description

the statistical Kcrrelationsvcrverfahren development is currently recorded and via a converter stage and em ^ S ^^ S of the optima data network system are fed to the correlator

3lSto * 5Son ** iem according to claim 1, especially in the case of aircraft for military or 2 in that the correlation is very important because the success of the respective M »- special areas (16 M) within a control region depends on it until now known thrown C? «The mt Terrain Correction promise

SSSiSJ ^ h 1 or lation working the highest accuracy, wöbe · die

bhk satzhehe

SJ ^ claim 1 or lation working the highest exact,

2 d ^ h ^ keSJS. that the coordination existing station-independent keu an additional ket. within a control area a finite, 0 Fongrungnac Bc ^ _{U =} ^^

je ^ iis "first correlation area (16) within a suitable Navigauonsvenan Can« ™ «» £ »« ';

% control area (15) improves over the entire width of the E.ngangsda en fu das ^ o re ^ t.onsver

i> j and that the subsequent correlation 50 * · .._.- .. position with

S miei. Korrelalio _nS area (16) in _e i "= m con- r.nzdaun serving GelMde.nForm.non d, e true '

⁽⁴⁾ "^ s ^ SenSs p

An * Wh ». to discre.en points in, »n.i.ieMer form

22) is checked, which is the navigation computer seen with respect to the GelanlLbi ^ f, ^^ _S ^ J ^^^^^^^

^ge 9: Area navigation gcrä. after one of the approaches in the direction of any flight paths, mt d.this fi-

:;: Sorüche 1 to 8, characterized in that the chennavigationsgerat is not possible.

Another area navigation device with digital data processing is shown in DE-OS 28 01 045. This Area navigation device is for a recursive generation of current signal samples, for example with a Kalman filter, provided and on a particularly precise acquisition and processing of the altitude data aligned. A feedback from the navigation computer to the correlator is not provided.

From US-PS 31 33 439 finally a surface navigation device known that works with analog data and mass-afflicted device levels Such a navigation device is much too sluggish for the aircraft and watercraft used today and therefore useless.

The navigation devices that have become known up to now require a fixed one for a pre-planned mission Target course. Although this target course does not have to represent a straight path, it is still unsatisfactory, because any non-prescribed travel routes are generally more appropriate for military operations.

The invention is based on the object of providing a navigation device of the type mentioned at the beginning for use to train any, non-prescribed travel outs. According to the invention this object is achieved solved that the correlator with a course and / or position reference device via a course preparation stage is in connection, which from the supplied data, initiated by the simultaneously recorded height data, Position data for positioning a movable one, the path of the future path in the opei ation area The following correlation window is determined and that the altitude data of the operating area stored in the memory processed for correlation with the recorded height data according to the path data of the future path and be rearranged.

With a corresponding design of the correlator, in particular with a corresponding Storage of sufficient terrain data, not to follow any prescribed travel routes. Here, the course preparation level of the operating area can consist of individual correlation areas Divide control areas, the lengths and / or widths of the correlation areas variable correlation windows according to the optimal correlation length the correlation result and the characteristic determined by the respective type of terrain Size for the statistical correlation method entered as a freely selectable parameter of the course editing level can be. The correlation areas within a control area can connect seamlessly, overlap or have a finite distance from one another. It is also useful to have the each first correlation area within a control area extend over the entire width let and the subsequent correlation areas depending on the determined in the first correlation area To connect position with reduced width. This procedure also offers the possibility of a command when the limits of the control area are reached through a correlation area in the correlator to trigger correction. The extent of the respective course correction can then be in the correlation area be checked, which follows the correlation area triggering the command.

The course preparation stage can be carried out simultaneously with the altitude measurement and the resulting initiation preparation of the altitude values the mean course angle from the upcoming course data as the entry angle for Calculate the respective control area and add this data to the correlalor for transforming the control area for the subsequent fine correlation of the control area divided into several correlation areas. The altitude data stored in the memory can be used in the navigation device according to the invention also depending on the data of the respective lane in straight razor lines following lanes to carry out a line correlation can be rearranged.

The invention is explained in more detail with reference to the drawing. It shows

F i g. 1 is a block diagram of a navigation device for any travel route,

F i g. 2 the functional principle for a fine correlation method,

Fig. 3 the functional principle for re-sorting the Elevation data for a line correlation and

4 shows the functional principle for determining the entry angle into a control area.
As the block diagram according to FIG. 1 shows, the navigation device according to the invention consists of a TER-COM unit i (TERCOM = Terrain Contour Matching), an altitude measuring device 2, for example a radar altimeter and / or a barometric altimeter and a course and position reference device 3 DieTERCOM unit 1 consists of a correlator 4, a microprocessor 5, a mass memory 6 and two main memories 7, 8. All these construction stages are connected to one another within the TERCOM unit 1 via a data bus 9. Instead of the correlator 4, a plurality of appropriately tailored microprocessors can also be used. The data bus 9 continues to run via an outside of the TERCOM unit! provided converter stage 10 to a data network system 11, which is connected to both a processing stage 12, the height measuring device 2 and a course processing stage 13 of the course and position reference device 3 Construction stages, for example display devices, in the respective *! Carrier vehicle can be used.

The navigation device according to the invention can be based on a modular correlation concept, such as in the patent application P 28 30 992 described, built and operated. This concept ensures extensive freedom of movement for any travel routes within an operating area with regard to different ones Courses, different types of tracks, different entry angles and different Entry points. For taking into account the influences of different courses and different types of tracks it is necessary that the course and position reference reference £ '. has a sufficient short-term accuracy, but this is what the devices available today guarantee.

When operating the navigation device, the preparation of the Course information initiated. During the measurement de; " Height values in acr height measuring device 2 and the subsequent processing in the processing stage 12, the orbit data is calculated from the course signal and / or the position signal of the course and position reference frame. Before the actual correlation calculation is carried out, the height setpoints stored are in the SpeicSiern 6, 7, 8 processed and re-sorted according to the data of the railway. To this This ensures that the influences of any orbit shapes; uif the correlation result and thus the

Accuracy of the navigation statements taken into account will. The train signals processed in the course preparation stage 13 are transmitted via the interface - Data network system 11 - in the TERCOM unit 1 transfer.

When operating the area navigation device according to the invention, three different functional principles are depending on the route, possible. What these principles have in common is the method of calculating the improvement the position input data for the correlation method (»Updating«) and also the determination of course and speed information. As shown in FIG. 2, a control area 15 is defined, which is made up of individual correlation areas 16, 17 ... 22 exists. The individual correlation areas 16, 17 ... 22 can either overlap, as shown, have a finite distance to each other or connect seamlessly. The length of the correlation region c are chosen according to the optimal correlation length, the one characteristic of the respective type of terrain and the statistical correlation method Represents size. While the width of the first correlation area 16 in the control area 15 is the width of the Corresponds to the control area, the following correlation areas 17, 18 ... 22 close with reduced Width. This procedural principle, which practically represents a fine correlation, increases the security of the Navigation statement significantly increased because this eliminates outliers. Before calculation the final improved input data for the correlation procedure ("updates") will be correspondingly the number of correlation areas determined several position information. With a simple Decision logic (quality of the correlation criterion or smoothing) becomes the first current position in the correlator 4 determined. If the length of the control area is sufficiently significant, repeated Calculate the travel route within the control area and determine additional course errors.

The in Fig. The principle of Fcinkorrclalion illustrated in FIG. 2 with the associated flight path determination is facilitated also the search process. Starting from the correlation area 16, in which because of maximum entry errors The search strategy must extend to the entire width of the control area can be used in the following Correlation areas 17 ... 22 the correlation process on a predicted around the last position Area can be restricted. There appears to be a correlation window over the entire length of the control area constant or reduced width moved according to the travel route, the criterion being the course is the correlation function. The feed takes place with an integral multiple of the grid spacing equivalent cycle The synchronization between setpoint and actual values is done via the speed information the course and position reference device 3 ensured, so that in this way from the continuously recorded height measurement sequence for the correlation over the respective correlation window (area) valid actual value strips can be selected. The individual correlation calculations are not carried out along the saved grid lines, but along the current path

As the embodiment of FIG. 3 shows, it is also possible to perform the correlation on curved paths along straight lines. Here, the principle of line correlation along stored grid lines is applied after re-sorting. The main difference compared to the other functional principles is that before the correlation calculation is carried out, the setpoint values of the stored terrain height matrix are rearranged according to the prepared path. Like F i g. 3 shows, a control area 30 is covered with a grid, as a result of which 64 grid cells 31 are created in this control area. The correlation between the re-sorted target values and the measured actual values is carried out along the new grid lines 33, 34 shown next to them, that is, there is an apparent correlation with the path 32 , 34 is transformed and then a line correlation is carried out, with the calculation of the current position taking place according to the previously described method.
With this functional principle, the following steps can be distinguished in the construction stages of the TERCOM unit 1, depending on the programming:

1. Initiation of altitude measurement and course preparation,

2. Determination of the actual terrain height profile,

3. Calculation of the data of the path;

After performing a correlation
4. Adoption, decompression (i.e. regression of the absolute altitude values and storage of the measured altitude profiles along the travel route,

5. Transmission of the path data,

6. Preparation of the setpoints,
6.1 index calculation,

6.2 Relocation of work memories 7 to work memories 8,
63 weighted interpolation,

7. Multiple correlation along the new grid lines.

8. Determination of the current position by means of an emigration logic,

9. Back transformation into the geodetic system and 10. Transfer of the current position values.

In addition to the course preparation initiated by the altitude measurement, it is also possible to adjust the course angle capture.

F i g. 4 shows the functional principle for determining the mean course angle ec and the transformation of the correlation area 25 within the control area 24 in a phase that is not time-critical for the entire execution of the correlation. The time criterion required for the correlation time remains unaffected due to the recursive operation. The coarse correlation around the mean course angle cc along the transformed grid line 27 lying parallel to the path 26 gives a very precise first approximation for the position to be determined. With the subsequent fine correlation, which takes place with the processed web 26, an exact determination of the position is carried out in a narrowly delimited sector around the position determined in the first approximation. This considerably reduces the signal processing effort and the time to carry out a correlation

During a position determination process, in the construction phases of the TERCOM unit 1, determined by appropriate programming, the following steps

30 11 55b

carried out:

1. Initiation of altitude measurement and course preparation,

2. Determination of the terrain height profile, ■>

3. Determination of a mean course angle (Ausglekhsstraight),

4. Transformation of the correlation area around the mean course angle,

H)

Decompression to absolute height, determination of the coordinates to be transformed icnx.y.

Index calculation,

Interpolation, r,

Calculation of the values related to the mean value,

Surrounding a control area.

After completing a correlation process in the TERCOM unit 1, also depending on the programming carried out, the following Steps carried out:

Takeover. Decompression and storage

(ie regression of absolute height values) of the measured height profiles along the travel route, acquisition of the middle course angle, rough correlation of the stored and gemesse- • ^ s height profile in gedrahteten grid of μ operation area,

Fine correlation with the path in the restricted search area.

Determining the position,

Back transformation into the geodetic system, r>

Transfer of the current position values.

The Flächcnnavigationsgcräl invention is based on the detection and corresponding to the price and Aufberoilung Gcschwindigkeilsinformalioncn in w, to follow the position desired, not predetermined routes and therefore particularly suitable for military missions. The prerequisite for this is that the elevation data of the operating area are available in the memories 6, 7 and, but this is possible without great effort due to today's memory technology.

For this purpose 3 sheets of drawings

50

Claims (1)

Course preparation level (13) at the same time as the p _at . _ntansDrüche . height measurement and the processing initiated Claims. ^ ^ _H | _{h data the mean} course angle («) mmMmmm The data are also processed - ™ / _m ™ f4, _{en grid} lines following path (33, i ^nB ^ ^C i ^ 1iÄiSSSe? «S5. W- implementation of a line correlation ne course preparation level (13) is connected, 15 are sorted, which from the supplied course and position values taking into account the simultaneously recorded Height data, position data for positioning a ^ SiS ^ SiSi "The invention relates to a ^ SiSTiSKSSeWete (16 22) determines data acquisition device for aircraft and / or watercraft with «- 53 dSmfpSer (6 λ 8) stored in the front memory, the data of which is previously known altitude values sheets AÄaten 'according to the' data of an operation area "ß" ^^, J ^