JPH02125285A - Map display device - Google Patents

Abstract

PURPOSE:To make a display of the current position of a moving body which looks very smooth by estimating and calculating the current position of the moving body by a display position arithmetic means when the display image plane of a display means is updated by rewriting. CONSTITUTION:The history of the current position and its calculation intervals are found by a current position calculating means 1 and a current position calculation interval arithmetic means 2 and stored in a temporarily storage means 3. A display control means 6, on the other hand, sends out a control signal for rewriting and updating the display image plane of the display means 4 periodically to the display position arithmetic means 8. The display position arithmetic means 8 estimates and calculates the position of the moving body which is more accurate than the current position found by the current position calculating means 1 at the time of the display image plane rewriting update from the control signal and the history of the current position and arithmetic intervals stored in the temporary storage means 3. Consequently, the accurate calculation is performed from the current position of the moving body nearly as fast as the display image plane update capability of the display means and the motion of the moving body on the display image plane is made smooth regardless of the limitation of the calculation time of the current position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a map display device mounted on a moving object such as a car.

2. Description of the Related Art Conventional map display devices include, for example, Japanese Patent Application Laid-open No. 60-29
This is shown in Publication No. 77.

FIG. 8 shows the configuration of this conventional map display device. 81 is a current position calculation means for calculating the current position of the moving body; 82 is a display means for displaying map information and the current position of the moving body; 83 is a map storage means for storing map information; 84
85 is a display control means for reading map information from the map storage means 83 and sending it to the display means 82; 85 is a map information display for displaying on the display means 82 from the current position of the moving body calculated by the current position calculation means 81; A display area control means that defines an area and sends it to the display control means 84 is shown.

In the conventional map display device configured as described above,
Based on the current position calculated by the current position calculation means 81,
The display area control means 85 specifies the display area of the map information to be displayed on the display means 82 so that, for example, the current position is displayed at a fixed point on the display means 82. From the information in the designated display area, the display control means 84 reads map information necessary for display from the map storage means 83 and outputs and displays the current position of the mobile object and the map information of its surroundings in a format suitable for the display means 82. The information is displayed on the means 82.

Problems to be Solved by the Invention However, in the above configuration, the timing at which the current position displayed on the display means 82 is switched to the newly calculated position and displayed is controlled by the display control means 84. The timing of periodic rewriting and updating of the display screen of the means 82 (limited to the calculation time of the current position in the current position calculating means 81).For example, the display means 82 may be a CRT, the current position calculating means 81 may be a distance sensor. -If we consider a direction sensor 7 microprocessor, a microprocessor as the display area control means 85, and a graphic display controller as the display control means 84, periodic rewriting and updating of the display screen is performed in synchronization with the vertical synchronization signal. The speed is about 60 times per second, but it usually takes longer for the microprocessor to calculate the current position from the output of the distance sensor and direction sensor. Current position calculation means 81 is a means for calculating the position of a moving object using radio wave information.
Even in this case, calculating the current position similarly takes time. Therefore, the update of the displayed map contents including the current position of the moving object always has to wait for the calculation time of the current position, and the movement of the moving object on the display screen becomes step-like and not smooth (problem of difficulty in viewing). It had

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a map display device that allows the movement of a moving object to be smoothly displayed on the display screen of a display means without depending on the time limit for calculating the current position.

Means for Solving the Problems The present invention provides a current position r for calculating the current position of a moving object such as a car.
! 1'R output means; current position calculation interval calculation means for calculating the calculation interval of the current position in the current position calculation means;
The coordinates of at least two positions among the current positions calculated by the current position calculation means and the calculation interval of at least two current positions among the calculation intervals of the current position calculated by the current position calculation interval calculation means. A temporary storage means for recording, a map storage means for storing map information, a display means for displaying the map information and the current position of the moving body, and a display control means for reading the map information from the map storage means and sending it to the display means. and the position of the moving object at the time of rewriting and updating the display screen from the control signal for rewriting and updating the display screen of the display means sent by the display control means, the history of the current position stored in the temporary storage means, and the calculation interval thereof. and a display position calculating means for calculating the display position calculating means, and determining a display area of map information to be displayed on the display means from the position of the moving object at the time of rewriting and updating the display screen calculated by the display position calculating means and sending it to the display control means. This is a map display device including display area control means.

According to the present invention, with the above-described configuration, the current position calculation means and the current position calculation interval calculation means calculate the history of the current position and its calculation interval, and record it in the temporary storage means. On the other hand, the display control means sends a control signal to the display means and the display position calculation means for periodically rewriting and updating the display screen of the display means. Based on the control signal for updating both sides of the display, the history of the current position stored in the temporary storage means, and the calculation interval, the display position calculation means has a higher accuracy than the current position calculated by the current position calculation means at the time of rewriting and updating the display screen. Estimate and calculate the position of a high moving object. This makes it possible to calculate the current position of a moving object with higher accuracy at a speed equivalent to the display screen updating ability of the display means, and allows the movement of the moving object on the display screen to be calculated without depending on the time limit for calculating the current position. You will be able to make it look smooth.

Embodiment FIG. 1 shows a block diagram of a map display device in a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a current position calculation means for calculating the current position of a moving object such as a car. 2 is current position calculation means 1
This is a current position calculation interval calculating means for calculating the calculation interval of the position of the moving body which is periodically calculated. Reference numeral 3 denotes a temporary storage means for recording the history of the current position calculated by the current position calculation means 1 and the calculation interval of the current position of the moving body calculated by the current position calculation interval calculation means 2. 4 is a display means, 5 is a map storage means,
6 is a display means 4 for reading map information from the map storage means 5;
This is a display control means that converts information into a format suitable for and sends it out. 7 is a display area control means for specifying to the display control means 6 the display area of the display screen to be displayed on the display means 4; 8
is calculated by the current position calculation means 1 at the time of rewriting the display screen from the history of the current position recorded in the temporary storage means 3, the current position calculation interval, and the display screen rewriting update control signal sent from the display control means 6. This display position calculation means estimates and calculates the position of the moving body with higher accuracy than the current position. FIG. 2 shows a more specific block diagram of the map display device in the first embodiment of the present invention. In FIG. 2, reference numeral 9 denotes a distance i sensor such as a pickup coil that detects the travel distance of a moving object, 10 a direction sensor such as a geomagnetic direction sensor, 11 a microprocessor, and 12
13 is a register; 14 is a CRT; 15 is a ROM in which map information is stored; and 16 is a graphic display controller that reads map information from the ROM 15, converts the information into a form suitable for the CRT 14, and sends it out. 17 is a display position that calculates a more accurate position of the moving object when updating the display screen from the history of the current position recorded in the register 13, the calculation interval of the current position, and the vertical synchronization signal sent from the graphic display controller 16. It is a calculation means. Details of the register 13 and display position calculating means 17 are shown in FIG. In Figure 3, 131.13
2,133,134,135,136.1707.17
08.1709.1710 is a register, 1701.17
02.1706 is a selector, 1713, 1714. is a latch, 171515 is a counter, 1704, 1711 .
1712 is an adder, 1705 is a multiplier, and 1703 is an inverter.

Next, the operation of the above embodiment will be explained. The moving distance mr and the traveling direction θ of the moving object are determined by the distance sensor 9 and the direction sensor 1.
o is detected and input to the microprocessor 11. If the current position of the mobile object just before moving is (X', Y'), then the new current position f (X', Y') is calculated from the calculated movement distance r and traveling direction θ as X=X' + r cos θ Since Y=Y'+r s in θ is calculated, the microprocessor 11 calculates a new current position. By periodically calculating this current position using the timer 12, the history of the current position of the moving object that changes sideways is obtained, and the X coordinate of the latest current position is sent to the register 131, and the X coordinate is sent to the register 132. , stores the X coordinate of the previous current position in the register 133, and stores the X coordinate in the register 134. The calculation interval of the current position is kept at a constant value Δt by the microprocessor 11 setting a value in the timer 12, and is normalized by the repetition period Δτ using the vertical synchronization signal sent from the graphic display controller 16.・Since Δt and Δτ are both constant values, Δt/Δτ/ and Δτ/Δt are calculated by the microprocessor 11 using a software method, and Δt/Δτ is stored in the register 136 and then Δτ/Δt
Store in register 135. By the way, this graphic Debray controller 16 is a control LSI for displaying characters and figures on a rusk scanning type CRT, and is a known one that is open to the public. Once the coordinates of each current position are set in the registers 131 to 134, the selector 170
Registers 131 and 133 are selected at 1.1702, and subtraction is performed using an inverter 1703 and an adder 1704. The multiplier 1705 multiplies the result by the value of the register 135, and sends the result to the selector 1706.

Selector 1706 first selects register 1707 to store the calculation result of the multiplier. Next, selector 1701,1
At 702, registers 132 and 134 are selected, and subtraction is performed using an inverter 1703 and an adder 1704. The result is multiplied by the value of register 135 using multiplier 1705, and the result is sent to selector 1706. At this time, selector 17.06 selects register 1709,
Stores the calculation result of the multiplier. This register 1707.
The values stored in 1709 each correspond to the estimated movement distance in the X direction and the X direction of the current position of the moving body during the repetition period Δτ of the vertical synchronizing signal of the CRT 14. register 170
7. The initial value of 1709 is zero, but register 1708
．． In 1710, the first calculated X and Y coordinates of the current position of the moving object are stored as initial values. register 1
707 and 1708 are added by an adder 1711, and the result is latched by a latch 1713 at vertical synchronization timing. The output is sent to the microprocessor 11 as the X coordinate of the current position of the moving body for display, and is also sent to the register 1708. Similarly, registers 1709 and 1710 are added by an adder 1712, and the result of the operation is latched by a latch 1714 at vertical synchronization timing. The output is sent to the microprocessor 11 as the Y coordinate of the current position of the moving body for display, and is also sent to the register 1710. That is, register 17
08.1710 is always set to the position of the moving object at the latest vertical synchronization timing calculated, so registers 1707.1709 are set at the next vertical synchronization timing.
The estimated moving distance of the current position of the moving object in the X direction and the X direction during the repetition period Δτ of the vertical synchronization signal set to Ru. This repeated addition is controlled by a counter 1715. counter 17
15 subtracts the value of the register 136 by 1 at the timing of value vertical synchronization, and determines whether the subtraction result is smaller than 1 or not. Therefore, when the counter 1715 becomes smaller than 1, that is, when the new current position is calculated by the microprocessor 11 and new values are set in the registers 131 to 134, the registers 1707 and 1709
The current position of the moving object is calculated by recalculating the value of The designated microprocessor 11 sends the display area of the display screen on the CRT 14 to the graphic display controller 16.However, the graphic display controller has the function of displaying the display area on the CRT simply by specifying the display area with coordinates. Such a function is a known function that can be easily realized by using a window function.The graphic display controller 16 reads the necessary map information from the ROM 15 based on the sent display area information. C
It is converted into a form suitable for RT14 and sent.

FIG. 4 shows a display example of a moving object. This is an example of fixing the map and displaying the current location. microprocessor 11
The current position of the moving body determined by is indicated by a white circle, and the estimated position of the moving body at the timing of the vertical synchronization signal determined by the display position calculating means is indicated by an X mark. In this way, since the moving object is moving even while the current position is being calculated, the movement of the moving object will not appear smooth on the display if only the current position of the moving object determined by the microprocessor 11 is displayed. . However, since the current position is linearly interpolated and the calculation interval is divided proportionally by repeated synchronization of the vertical synchronization signal to calculate the position where the moving object is estimated to exist at the timing of vertical synchronization, it is synchronized with the display rewriting speed of the CRT. As a result, the movement of the moving object can be estimated, and the movement of the moving object will appear smoother.

As described above, according to this embodiment, the display position calculation means configured by hardware is used to perform linear interpolation of the current position and the repetition period of the vertical synchronization signal at each display means update timing of the display means (vertical synchronization signal in the case of a CRT). Because the moving position of the moving object is estimated and calculated at high speed by proportional division, it is possible to calculate the moving position of the moving object at a speed equivalent to the display updating ability of the display means, which limits the time required to calculate the current position. The movement of the moving object on the display screen can be shown smoothly regardless of the situation.

In the first embodiment, the display position calculation means 17 is configured by hardware, but it may be implemented by software using a microprocessor if the processing speed is sufficiently fast. A flowchart in that case is shown in FIG. First, in step 51, the X coordinate of the previous current position is set to A,...B
The Y coordinate Y of the previous current position. Substitute -1. Next, in step 52, Δt/Δτ is calculated from the calculation interval Δt of the current position and the repetition synchronization Δτ of the vertical synchronization signal, and the value is k.
Assign to . In step 53, the calculated value of k and the X coordinate of the latest current position. , Y coordinate Y. .

Using XY, (Xn-Xn,,) / k to Yn
-I'n-1 ゜-Yn, )/k is calculated and assigned to k in each case x
y Ru. At step 54, A, at the timing of the vertical synchronization signal,
Send B as the X and Y coordinates of the current position of the moving object. Next, in step 55, it is determined whether k is smaller than 1. If k is 1 or more, proceed to step 56, and A+
Assign kx to A, B+ky to B, and k-1 to k.

Then, the process returns to step 54. If k is less than 1, the process returns to step 51. With the above method, the current position of the moving object at the time of rewriting the display screen can be determined. Further, in the first embodiment, the value set in the timer 12 may be set to a constant value, or may be set to a specific value every time. In the first embodiment, the display position calculation means 17 linearly interpolates the current position of the moving object and divides the calculation interval proportionally by the repetition period of the vertical synchronization signal, thereby determining the position of the moving object used for display on the CRT 14. has been calculated, but this may be interpolated in a curved manner, or the calculation interval may not be divided proportionally by the repetition period of vertical synchronization. Further, in the first embodiment, the current position calculation means 1 is replaced by a distance sensor 9. Orientation sensor 10. Although it is configured by the microprocessor 11, it may also include a system such as a global positioning system (GPS) that determines the current position based on radio wave information from the outside.

FIG. 6 is a block diagram of a map display device showing a second example of the present invention. In the figure, 18 is a current position calculation means, 19 is a current position calculation interval calculation means, 21 is a temporary storage means, 22 is a display means, 23 is a map storage means, 24 is a display control means, 25 is a display area control means, Reference numeral 26 denotes a display position calculating means, which has the same structure as that shown in FIG. 1. What is different from the configuration shown in FIG. 1 is a speed detection means 20 that detects the speed of the moving body based on a display screen rewriting control signal sent from a display control means 24 and sends it to a temporary storage means 21.
This is the point where it was established.

The operation of the map display device of the second embodiment configured as described above will be explained below.

The speed detection means 20 is, for example, a combination of an acceleration sensor and a separator, and detects the average speed in a repeating period in synchronization with a control signal for rewriting and updating the display screen sent from the display control means 24, and temporarily stores the speed in the temporary storage means 21. I am sending it to In addition to the speed history, the temporary storage means 21 records the current position history and its calculation interval. FIG. 7 shows a flowchart in the case where a microprocessor is used as the display position calculation means 26 and the position of the moving body is determined by software means when the display screen is updated. First, in step 71, the Y coordinate Yn of the previous current position is substituted for the X coordinate Xn-1°B of the previous current position. Next, in step 72, the current position calculation interval Δt and the vertical synchronization signal repetition period Δ
Calculate Δt/Δτ from τ and assign the value to k. In step 73, the summation V of the average velocity V in the repetition period of the display screen in the calculation interval of the two current positions is calculated.

In step 74, using the calculated value of V, the X coordinate X, Y coordinate Y, and X\n n-I' n-I of the latest current position, (X
, -X, , )/V and (Yn-Yn-I)/V are calculated and substituted into kx, respectively, and zero is substituted into m. In step 75, the X and Y coordinates of the current positions of moving bodies A and B are sent out at the timing of the vertical synchronization signal. Next, in step 75, it is determined whether k is smaller than 1. If k is 1 or more, proceed to step 76 and calculate A+k Xv
Assign V end to A, B+kXvGB, k-1 to, and m+1 to m. Then, the process returns to step 75. If k is less than 1, the process returns to step 71. With the above method, the current position of the moving body at the time of rewriting the display screen can be determined. Using the calculated coordinates of the current position, the display area is set by the display control means 25 and sent to the display area control means 24. Based on this information, the display control means 24 reads necessary map information from the map storage means and sends it to the display means 22.

As described above, according to this embodiment, the display position calculating means linearly interpolates the current position plane, and divides the interpolated straight line in proportion to the average speed of the moving object in the repetition period of the display update control signal. Since the moving position of the moving object is estimated and calculated, it is possible to accurately calculate the moving position of the moving object at a speed equivalent to the display updating ability of the display means, and it is not dependent on the time limit for calculating the current position. The movement of a moving object on the display screen can be shown smoothly.

In the second embodiment, the display position calculating means 26 is configured by a microprocessor, but it can also be easily configured by hardware. Furthermore, in the second embodiment,
The display position calculation means 26 linearly interpolates the current position of the moving object, and divides the interpolated straight line in proportion to the average speed of the moving object in the repetition period of the display update control signal to estimate and calculate the moving position of the moving object. l-Taga・This may be interpolated in a curved manner.

As described in detail, according to the present invention, since the display position calculation means estimates and calculates the current position of the moving object when the display screen of the display means is updated, only the current position determined by the current position means is used. Unlike the case where the current position is displayed, the current position is displayed in synchronization with the display rewriting speed of the display means, so it is possible to display the current position of the moving object in an extremely smooth manner, which has a great practical effect.

[Brief explanation of the drawing]

1 is a block diagram of a map display device according to an embodiment of the present invention, FIG. 2 is a block diagram of a more specific map display device according to the same embodiment, and FIG. 3 is a block diagram of a more specific map display device according to the same embodiment. A circuit diagram of the display position calculation means, FIG. 4 is a diagram showing an example of displaying the current position of a moving object in the same embodiment, FIG. 5 is a flowchart of the same embodiment, and FIG. 6 is a map of another embodiment of the present invention. FIG. 7 is a block diagram of the display device, FIG. 7 is a flowchart of the same embodiment, and FIG. 8 is a block diagram of a conventional map display device. 1.18.81...Current position calculation means, 2,1
9...Current position calculation interval calculation means, 3, 21.
...Temporary storage means, 4.22.82...
Display means, 5.23.83...Map storage means,
6,24.84...display control means, 7,25.
85...display area control means, 8.26...
... Display position calculation means, 9 ... Distance sensor, 1
0... Orientation sensor, 11... Microprocessor, 12... Timer 13...
...Register, 14...CRT, 15...
ROM, 16... Graphic display controller, 17... Display position calculation means,
20... Speed detection means, 131, 132, 13
3,134,135.136,170? , 1708.1
709.1t10...Register, 1701,1
702.1706...Selector, 1704.1
711.1712... Adder, ], 705.
...Multiplier, 1713°1714...Latch, 1715...Counter. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (4)

[Claims] (1) Current position calculation means for calculating the current position of a moving body, current position calculation interval calculation means for calculating the calculation interval of the current position in the current position calculation means, and current position calculation means for calculating the calculation interval of the current position in the current position calculation means, and temporary storage means for recording the coordinates of at least two positions and calculation intervals of at least two current positions among the calculation intervals of the calculated current positions; a map storage means storing map information; a display means for displaying the current position of a moving body; a display control means for reading map information from the map storage means and sending it to the display means; and control for rewriting and updating the display screen of the display means sent by the display control means. a display position calculation means for calculating the position of the moving object at the time of rewriting and updating the display screen from the signal, the history of the current position stored in the temporary storage means, and the calculation interval; and a display calculated by the display position calculation means. A map display device comprising display area control means for determining a display area of map information to be displayed on the display means based on the position of the moving object at the time of screen rewriting and updating, and transmitting the determined display area to the display control means. (2) The display position calculation means performs curve interpolation on the history of the current position stored in the temporary storage means, and divides the current position calculation interval of the moving body by the display screen rewriting period of the display means, and calculates the current position calculation interval when the display screen is rewritten. 2. The map display device according to claim 1, wherein the map display device calculates the position of a moving object. (3) The map display device according to claim 1, further comprising a speed detecting means for a moving object, and recording a speed history of the moving object determined by the speed detecting means in a temporary storage means. (4) The display position calculating means interpolates the history of the current position stored in the temporary storage means by a curve, and moves the interpolated curve by dividing it in proportion to the speed of the moving object at each display screen rewriting cycle of the display means. 4. The map display device according to claim 3, wherein the map display device calculates a body position.