JPH0217056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a course display device using a direction sensor such as a magnetic compass.

(b) Prior art and its drawbacks To steer a ship in the intended direction, an autopilot that includes a direction sensor such as a gyro compass or magnetic compass is generally used. However, the disadvantage is that the device is very expensive, and when using a magnetic compass, it is necessary to perform time-consuming deviation correction for each ship in order to obtain a certain level of accuracy, making it difficult to handle. There were flaws. Furthermore, even if a highly accurate direction sensor is used, if the boat is swept sideways by currents or wind, the actual direction of travel may differ from the value displayed on the compass, making it difficult to proceed in the desired direction. It was often difficult. Furthermore, methods have been put into practical use in which the ship's position is determined by radio navigation using a LORAN, etc., and the ship's course is calculated and displayed based on changes in the ship's position. Therefore, even if the course was changed by maneuvering the ship, the results were not immediately fed back, and there was an inconvenience that the results could not be used directly as information for automatic steering.

(c) Purpose of the Invention The purpose of the present invention is to make it possible to know the correct direction in which a ship should proceed even if there is an error in the direction sensor or if the ship is swept sideways by currents or winds. An object of the present invention is to provide a course display device that displays a course error.

(d) Structure and effect of the invention
(n-1) and the actual moving direction; and a direction error calculation means for calculating the error eH between the direction (n-1) and the direction actually moved; The course D(n) found this time
The present invention is characterized by comprising: a course error calculation means for calculating a course error dD from the difference between the two, and a course error display means for displaying the course error dD as a mark or text on a display.

FIG. 1 is a diagram showing the principle of determining the course error obtained by the course display device, and FIG. 2 is a diagram illustrating the outline of the operation of the course display device.

If the ship is now at point A, the course D(n-1) can be determined if the destination WP is set.
When the ship obtains this course D(n-1), it moves along the course accordingly. At this time, if there is an error in the compass or other direction sensor, or if the ship is pushed sideways by currents including tides or wind,
The ship will no longer proceed along the course of course D(n-1). Suppose, then, that the ship moves from point A to point B due to compass errors and errors due to drifting currents. The position of this point B is assumed to be obtained from a navigation device such as Loran, and its accuracy is assumed to be relatively high.

When the ship has proceeded to point B, the first thing to do is to change the previously determined course D.
Find the error eH between (n-1) and the actual direction of movement from point A to point B. This eH is the amount (azimuth correction data) that should substantially change the actual course of the ship. Therefore, if the azimuth data (heading) indicated by the azimuth sensor at point B is H, in order to proceed in the direction indicated by this azimuth sensor, the compass direction must move counterclockwise from H to H' by eH. This is achieved by steering the vehicle to change course. In addition, the first
In the figure, the objective value at point B is WP, so
The overall course error of the ship at point B is actually the error eH plus the correction angle Δd, which is the difference between H and D(n).
(n) is added. Therefore, the new course D determined between point B and the destination WP
(n), a corrected heading H' is obtained by adding the above-mentioned heading correction data eH to the heading data H at point B, and the above correction angle Δd(n) is added (subtracted) to this corrected heading H'. ), calculate the orientation H″,
Steering the ship in that direction. In this case, whether the correction angle Δd(n) becomes an addition value or a subtraction value of H' depends on the azimuth relationship between the azimuth data H and D(n).

In the present invention, the heading error dD, which is the difference between the new heading D(n) determined from the target value and the corrected heading H', is displayed on the display. Therefore, by looking at the magnitude of this heading error dD, it is possible to immediately judge how much the course should be corrected at point B.

In FIG. 2, 20 and 21 are heading error calculation means, and the calculation unit 20 adds azimuth correction data eH and azimuth data H. Also, calculation section 2
1, the difference between the corrected heading H' and the new course D(n) is determined. The output of the calculation unit 21 is the heading error.
dD and is displayed on the display section 3. This operation is repeated every time the ship travels a certain distance, and the course D(n) determined this time becomes the previous course D(n-1) in the next operation. In this way, by displaying the course error dD on the display unit 3 every time the ship travels a certain distance, the current course error dD can be grasped at all times.

As described above, according to the present invention, it is possible to know the actual direction in which the ship should proceed without knowing anything about the error of the direction sensor or the state of currents and winds, making it extremely easy to maneuver the ship, and also making it possible to use an autopilot. When using , it is possible to accurately move the ship in the desired direction by using the course error dD as information for automatic steering. In addition, it is possible to know the actual direction the ship is heading without having to use an expensive gyro compass as a direction sensor, or even if a magnetic compass is used, without having to correct the deviation for each ship. , the orientation sensor can be made low-cost and extremely easy to handle.

(e) Embodiment FIG. 3 is a front view of a track recording device to which a course display device according to an embodiment of the present invention is applied. In the figure, 1 is a keyboard, 2 is a CRT, 3 is a brightness adjustment volume, and 4 is a keyboard illumination volume.

The keyboard 1 consists of a total of 33 touch key switches, and is used to operate the screen, set destinations and event marks, transfer data between memories, initial settings, etc.

Screen operations are performed using the screen/cursor movement key 101, scale change key 102, cursor on/off key 103, and own ship center key 104. Cursor on/off key 10
3 displays or erases a cursor on the display screen each time the operation is performed. The screen/cursor movement key 101 moves the cursor when the cursor is displayed on the display screen, and moves the screen when the cursor is not displayed. A scale change key 102 enlarges and reduces the screen. The own ship center key 104 sets the own ship mark at the center of the display screen when the cursor is not displayed, and sets the cursor intersection at the center of the display screen when the cursor is displayed.

Settings such as destination marks and event marks are performed using the numerical keys 106. For example, when displaying the number 1 destination mark at a predetermined position on the display screen, first specify the display color of the destination, then operate the destination key 106a, and then operate the 1 key. . Color designation is performed by designating codes 1 to 7. For example, when the 3 key is operated, green is specified, and when the 5 key is operated, purple is specified.

Memory operations such as data transfer between memories are performed by operating a memory operation function key 109. For example, when the user wants to transfer the data in the memory in which the track is stored (memory number 0) to another additional memory, the user operates the memory transfer key. Also, to erase all destination marks, event marks, tracks, etc., operate the memory erase key. Furthermore, when transferring the current track storage data to the additional memory, the erasable key is operated to erase the additional memory prior to operating the memory transfer key.

Initial settings are performed using numerical keys 106 and screen switching keys 110. The screen switching key 110 is a key for selecting whether the display screen is a track display screen or an initial setting screen, and the display screen is switched each time it is operated. On the initial setting screen, you can select the type of navigation device, set the acquisition interval of position data sent from the navigation device, that is, the storage interval of position data in the track storage memory (memory 0), Select the smoothing coefficient to reduce fluctuation, select whether to issue a buzzer alert when approaching the currently selected destination, and set the approach distance at which you want the alert to be issued. . In this case, the setting of the storage interval time and the warning approach distance are performed using the numerical keys 106.

Note that the track interrupt key 111 is used to interrupt or restart the display of the track, and when the track is interrupted, only the own ship mark is displayed, and if you operate it again in that state to restart the display of the track, Start drawing the wake from the position of your ship's mark at that time. The wake color designation and color deletion key 105 is used to designate the color of the wake, or to delete one of the wakes that have been designated as a color.
Specify the color and erase it temporarily or permanently. The track redisplay key 112 is used to display the track temporarily erased by the track color erase key to its original state. In addition, function keys 1 such as mark erase key, destination number key, and release key are also included.
07 erases event marks, destination marks, etc., selects any of the destinations set using the numerical keys 106, or erases destination data on the initial setting screen. Perform actions such as stopping the alarm buzzer. Furthermore, the display of the expansion screen and the number key 108 are used to display the track memory memory (0
Select whether to display the data in the additional memory (current track screen) overlapping the data in the additional memory (current track screen), or to display only one of them. The extension screen number key specifies the extension memory, that is, the extension screen at that time.

FIG. 4 is a diagram showing an example of the display on the display screen.

In the figure, CX and CY represent the cursor, and CP
indicates the cursor intersection. LAT represents a latitude line, LON represents a longitude line, and S represents a coastline set using nine of the numeric keys 106. Furthermore, WP1,
WP2 represents the destination mark set using the numerical key 106, and E1 to E3 also represent the destination mark set using the numerical key 10.
6 represents the event mark set by 6. Also, the marks and character data displayed at the top and bottom of the display screen represent the following contents.

When cursors CX and CY are displayed,
A + mark as shown will appear. Also, when the cursor is not displayed, if the own ship mark is within the screen, the own ship mark is displayed, and if the own ship mark is outside the screen, the direction (8
An arrow indicating one of the directions will appear.

When the cursor is displayed, the position of the cursor intersection (latitude, longitude) is displayed, and when the cursor is not displayed, the position of the own ship is displayed.

The specified color of the current track is displayed on the first line,
On the second line, the currently specified color is displayed in brackets.

When the cursor is displayed, the distance and direction from the own ship to the cursor intersection are displayed, and when the cursor is not displayed, the ship speed and the second line are displayed.
The route is displayed on the first line. Note that these ship speed and course are data sent from a navigation device.

If a water thermometer or fish finder is connected to the navigation device, the first line will display the water temperature, and the second line will display the water depth.

The first line displays the number of miles of screen width, and the second line displays the screen designation status.

When a destination is selected, the latitude and longitude of the selected destination are displayed. The illustrated example shows a state where destination WP1 is selected.

If a destination is selected, the distance and direction to the destination will be displayed.

When a destination is selected, the error in the course is displayed when taking into account the deviation of the flow rate and the error of the compass. When the upper and lower triangular marks match, the correct course will be taken to reach the destination.

Next, the control section of the track recorder will be explained.

FIG. 5 is a block diagram of the same track recording device.

The CPU 10 receives input data from the keyboard 1.
Navigation data is also input from the navigation device. Navigation devices such as Loran, NNSS, compass, and gyro are used to obtain position and orientation data. The ROM 11 stores a program that defines the operating procedure of the track storage device, and the RAM 12 stores position data input from the navigation device or destination marks, event marks, etc. input and set using the keyboard 1, up to a maximum of 1000 points. this
The RAM 12 constitutes the aforementioned track storage memory (memory number 0), and is treated as the 0 screen, which is the reference screen. The CPU 10 can further optionally be connected to a plurality of RAMs and a plurality of ROMs, and data in memory number 0 can be transferred to each RAM. RAM and ROM for this expansion
The screen numbers are 1 to n, and the storage capacity of each is 1000 points, similar to the RAM 12. In the example shown, there are three RAMs with screen numbers 1 to 3.
has been added, and the screen numbers are 4 and 5.
ROM has been added. In addition, the RAM of 0 screen
12. The RAM for screens 1 to 3 is each backed up by a battery, so that the stored data can be retained even when the power is turned off.

The data in memory No. 0 constituting the track storage means is written into the refresh memory 13 in response to the operation of the keyboard 1. In this case, by operating the additional screen display and number keys 108 as described above, only the data of the 0 screen, only the data of the specified screen, or the data in which the data of the 0 screen and the data of the specified screen are superimposed are displayed. written, CRT2
will be displayed. The refresh memory 13 includes three graphic memories for displaying tracks, event marks, maps, etc. in up to seven colors, and a character display for displaying latitude, longitude data, and other characters. Contains a nerator. The color conversion circuit 14 converts the data stored in the graphic memory into a predetermined color signal based on the color data of the wake specified by the wake color designation key or the numeric key 106, or the color data of other event marks. output to CRT2.

Figure 6 shows the above RAM 1 that stores 0 screen data.
FIG. 7 is a diagram showing the main part of the expansion memory (RAM or ROM).

In FIG. 6, area M1 has numeric key 10.
The location of the destination WPT set in step 6 is memorized.
The destination is set by placing the cursor on the destination, setting the destination number, and then operating the destination setting key 106a, as described above. In this case, if a color is specified using keys 1 to 7 before setting the destination number, the newly specified color data is added to the destination data and stored. If no color is specified, the color data already specified at that time is added.

Area M2 stores the type of navigation device NAV selected on the initial setting screen.

Area M3 has the interval for capturing position data sent from the navigation device by the CPU 10, that is,
The storage interval t of position data for the RAM 12 is stored.

Area M4 stores the scale ratio s of the display screen. This scale ratio s is changed when the scale change key 102 is operated.

Area M5 stores the center position c of the display screen. The CPU 10 constantly monitors the center position c of the display screen, determines the coordinates of the display screen from this center position c and the scale ratio s, and calculates the display position of the current position, track, etc.

The number of points currently stored in the RAM 12 is stored in area M6. As aforementioned
The maximum number of memory points of RAM12 is 1000,
When the number of points exceeds 1000, old data is automatically discarded and new data is stored.
The CPU 10 controls data updates to the RAM 12 by monitoring the number t of storage points stored in this area M6. Also RAM12
(0 screen) data is also sent to the refresh memory 13 while monitoring the number of storage points t.

The designated color of the current track is stored in area M7. If the specified color of the current track is displayed in the first line of the position of Fig. 4, this specified color will be displayed in the area M.
7 will be stored. As described later,
Every time the CPU 10 receives position data from the navigation device, it adds the color data stored in the area M7 to the position data and stores it in the RAM 12 (memory number 0).
I will remember it. Note that the color is specified using the numerical keys 1 to 7 as described above. Since the graphic memory is composed of three memories, it is possible to display up to seven colors, and the CPU 10 controls writing to the graphic memory based on the color data set with numerical keys 1 to 7. will be carried out.

Area M8 stores a course D from the current position to the selected destination.

Area M9 stores the course error dD, which is the amount of deviation of the triangular mark displayed at the position in FIG. This heading error is the difference between the above-mentioned course D and the course that should actually be set, which is caused by the error of the compass itself and the unbalanced flow of the tidal current.
This is determined from the difference between the previously set course and the direction in which the vehicle actually moved along that course (this direction is determined from at least two pieces of position data).

Area M10 contains azimuth correction data eH, which is the difference between the previously set course D and the actual direction of movement based on that course, that is, the azimuth amount to be corrected.
is memorized. This azimuth correction data eH is equal to other azimuth errors excluding the error of the compass itself. For example, errors due to drifting can occur in this direction correction data.
Equivalent to eH. The data stored in areas M8 to M10 is used to display the marks shown in Figure 4, and the display positions of the upper and lower triangular marks are controlled according to the size of the heading error dD, and when the heading error dD becomes 0, Display control is performed so that the positions of both triangle marks match.

Area M11 stores direction data H input from the compass of the navigation device. Since this azimuth data H includes errors of the compass itself, it is used together with the data stored in areas M8 and M10 to determine the course error dD of area M9.

In the area M12, position data input from the navigation device or event marks and destination marks set using the numerical keys 106 are stored in the order in which they were input, up to a maximum of 1000 points. 1
Data corresponding to a point is composed of latitude and longitude data, color data added thereto, and ID data for identifying the type of data. ID data is position data input from the navigation device and numeric key 106
The event mark and destination mark set by When the data constituting one point is the position data input from the anti-legal device, the color data becomes the color data set in area M7 as described above. Further, when the data constituting one point is an event mark or destination mark set by the numerical key 106, the color data becomes data of the currently specified color. The currently specified color is set by the numerical key 106 displayed on the second line at the position of FIG.

The additional memory includes area M1 of RAM12 above.
Position data, event marks, destination marks, etc. are stored in the same state as in 2, with a maximum of 1000 points. The ROM in the additional memory stores map data that does not need to be changed, and the RAM in the additional memory stores tracks, event marks, destination marks, etc. that you want to keep by transferring them from the RAM 12. be remembered.

FIGS. 8 and 9 show the basic operating procedure of the track recorder.

FIG. 8 is a flowchart of the data recording operation procedure for storing position data sent from the navigation device in the RAM 12 (memory number 0). First, in step n1 (hereinafter, step ni is simply referred to as ni), position data is received from the navigation device. Next, it is determined whether the received data is received data from the navigation device set in area M2 (n2), and if so, the storage interval t set in area M3 is the same as the previous data. Determine whether time has passed since reception (n3). If t has elapsed, the received data is stored as current position data in memory number 0 with the color data set in area M7 and ID data for identifying the position data from the navigation device added. (RAM
12) is written in area M12. This data storage operation procedure is performed when data is sent from the navigation device.
It is executed every time an interrupt is issued to the CPU 10. As a result, based on the determination of n2 and n3, the received data from the selected navigation device is taken in every t and written into memory No. 0.

FIG. 9 is a flowchart showing a display operation procedure for displaying data stored in memory No. 0.

First, at n10, scale ratio s and center position c
is read from areas M4 and M5 and the current display range is calculated. Since the display area of the CRT 2 is fixed, the display range can be easily determined by knowing the scale ratio s and the center position c. After determining the display range, the pointer POINT allocated within the CPU 10 is then set to 1. Next, data Pn of memory No. 0 set by pointer POINT is read (n12). Then, based on the scale ratio s and the center position c, the latitude and longitude data read out at n12 are subjected to coordinate transformation, the writing position to the refresh memory 13 is specified (n13), and the writing is executed at n14. This n12~n14
The steps for incrementing the pointer at n16,
And by comparing the number of recording points p set in area M6 and the value of pointer POINT (n15),
This process is performed for all points stored in memory No. 0 and ends.

The above display operation procedure is performed every time new data is stored in memory No. 0, that is, as shown in FIG.
This is executed each time position data is written in n4 or a destination mark or event mark is stored using the numerical key 106.

As described above, the position data sent from the navigation device can be selectively stored in the memory No. 0, and the stored data can be displayed on the CRT 2.

Next, the operation procedure for displaying the course error dD at the position shown in FIG. 4 will be explained. FIG. 10 is a flowchart showing the course error display operation procedure.

First, in n20, the orientation correction data eH is initially set to 0. Next, a course D(n) is calculated from the current position and the currently selected destination WPT (n21). Next, the azimuth correction data eH is added to the current azimuth H to obtain azimuth data H' (n22). This azimuth data H' is data in which all error components including errors of the azimuth sensor and errors due to drift such as tidal currents are taken into consideration. When the direction data H' is obtained, the data H' and the course D(n) to the destination are calculated.
Calculate the course error dD from (n23) and set the triangular mark 3a, which is separated by a length proportional to the course error dD.
3b (see FIGS. 2 and 4) is displayed on the display at the position (n24). Furthermore, the course D(n) is displayed on the right shoulder at the same time. Then, after the ship has sailed a further certain distance (n25), new heading correction data eH is determined using the course D(n) obtained in n21 above as the previous course D(n-1) (n26), and again
Execute n21 and below. By repeating steps n21 and below in this way, the course error dD can be determined by the two marks 3a and 3b at the position of the indicator.
can be displayed. If the autopilot is not used, the operator should correct the heading of the ship so that these two marks 3a and 3b face each other at the same position, that is, so that the course error dD becomes 0, and the ship will head toward its destination. It will now run correctly. When using an autopilot, if the heading error dD is controlled to always be 0, the ship will travel with the two marks 3a and 3b always facing each other at the same position.

Note that in the above embodiment, the course error dD for causing the ship to travel along a new course D(n) when reaching point B from point A is displayed.
As shown in Fig. 11, the direction H' and the course C (n-
Find the intersection Q with 1) and connect this intersection Q with the destination WP.
Set the midpoint of the distance as the temporary destination WP',
Course D from point B to the above tentative destination WP'
If (n)' is replaced with the course D(n) and the above operation (FIG. 10) is executed, the ship can be quickly returned to the initially set course C(n-1). In other words, azimuth data H'' is obtained by adding the course error dD to the course D(n)', and this azimuth data H'' and the course D
If we express the difference from (n) as heading error dD′, then
The ship approaches course C(n-1) of the original course D(n-1) without traveling along course D(n),
The vehicle starts moving toward the destination WP along the course C(n-1). In this way, the ship can be driven along the initially determined course.

Furthermore, in the above embodiment, the course error is displayed based on the degree to which the two triangular marks approach each other.
It is also possible to directly display the course error by text without using marks.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of determining a course error in a course display device according to the present invention, and FIG. 2 is a diagram illustrating an outline of the operation of the course display device. Fig. 3 is a front view of a track recording device to which a course display device according to an embodiment of the present invention is applied, Fig. 4 is a diagram showing an example of display on a display screen, and Fig. 5 is a block diagram of the track recording device. , Figure 6 is a configuration diagram of RAM12, Figure 7 is a configuration diagram of RAM12.
8 is a flowchart showing the data recording operation procedure, and FIG. 9 is a flowchart showing the display operation procedure. Also the 10th
The figure is a flow chart showing the course error display operation procedure, and FIG. 11 is a diagram illustrating a method for determining a course error using a course display device according to another embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. Direction error calculation means for calculating the error eH between the previously determined course D(n-1) to the destination and the actually traveled direction, and the current direction H and the currently determined course D.
(n) and a heading error calculating means for calculating a heading error dD based on the difference between the heading error eH and the heading error eH, and a heading error displaying means for displaying the heading error dD as a mark or a letter on a display. Course indicator. 2 The mark displayed by the course error display means is
The course display device according to claim 1, which is two opposing marks separated by a length proportional to the magnitude of the course error dD.