Navigation assisting apparatus, aircraft in which the navigation assisting system is mounted, navigation assisting method and navigation assist processing program recorded in a storage medium

• US 20030139876A1
• Filed: 12/16/2002
• Published: 07/24/2003
• Est. Priority Date: 12/20/2001
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shinagawa, Yuichi
• Granted Patent: US 6,970,784 B2
• Time in Patent Office: Days
• US Class Current: 701/204
• CPC Class Codes: G01C 23/005 Flight directors indicating arrangements specially adapted for rotary gyroscopes G01C19/32

Abstract

An arithmetic unit calculates an estimated time of arrival (ETA) of an aircraft at a target point, and obtains a difference between ETA and a required time of arrival (RTA) at the target point. It multiplies a time error corresponding to the difference in time by the velocity of the aircraft, thereby converting the time error to a distance error. The distance error is symbol-displayed as ΔP_TIME in a display unit. Thus, the time error concerning a flight of the aircraft is visually displayed as a distance error. If the distance error exceeds a preset threshold value, a caution such as a display message or a voice message is generated.

Claims

1. A navigation assisting apparatus mounted in an aircraft, comprising:

an error calculator which obtains an estimated time of arrival of the aircraft when the aircraft is estimated to arrive at a target point for which a required time of arrival of the aircraft is set in advance, calculating a time error between the estimated time of arrival and the required time of arrival;

a converter which converts the time error calculated by the error calculator to a distance error based on a velocity of the aircraft; and

a display which visually displays the distance error obtained by the converter.

2. The navigation assisting apparatus according to claim 1, wherein the display displays an aircraft symbol representing the aircraft and an error symbol having a length corresponding to the distance error.

3. The navigation assisting apparatus according to claim 2, wherein the display displays the error symbol one of ahead and behind the aircraft symbol in a direction of travel of the aircraft in accordance with a sign of the time error calculated by the error calculator.

4. The navigation assisting apparatus according to claim 2, wherein the display displays the error symbol along a preset flight route of the aircraft.

5. The navigation assisting apparatus according to claim 1, further comprising a caution generator which generates a caution if the distance error obtained by the converter exceeds a threshold value.

6. The navigation assisting apparatus according to claim 5, wherein the caution generator varies a level of the caution stepwise in accordance with a difference between the distance error and the threshold value.

7. The navigation assisting apparatus according to claim 5, wherein the caution generater varies the threshold value in accordance with an accuracy of the distance error.

8. An aircraft comprising:

an error calculator which obtains an estimated time of arrival of the aircraft when the aircraft is estimated to arrive at a target point for which a required time of arrival of the aircraft is set in advance, calculates a time error between the estimated time of arrival and the required time of arrival;

a converter which converts the time error calculated by the error calculator to a distance error based on a velocity of the aircraft; and

a display which visually displays the distance error obtained by the converter.

9. A navigation assisting method for use in an aircraft, comprising:

a first step for obtaining an estimated time of arrival of the aircraft when the aircraft is estimated to arrive at a target point for which a required time of arrival of the aircraft is set in advance;

a second step for calculating a time error between the estimated time of arrival obtained in the first step and the required time of arrival;

a third step for converting the time error calculated in the second step to a distance error based on a velocity of the aircraft; and

a fourth step for visually displaying the distance error obtained in the third step.

10. The navigation assisting method according to claim 9, wherein the first step comprises:

a fifth step for obtaining a current position and a velocity of the aircraft;

a sixth step for calculating a distance to the target point from the current position obtained in the fifth step;

a seventh step for calculating a time required to arrive at the target point based on the distance obtained in the sixth step and the velocity obtained in the fifth step; and

an eighth step for adding the time required to arrive at the target point calculated in the seventh step to a current time, thereby calculating the estimated time of arrival.

11. The navigation assisting method according to claim 9, further comprising a ninth step for generating a caution if the distance error obtained in the third step exceeds a threshold value.

12. The navigation assisting method according to claim 11, further comprising a tenth step for varying a level of the caution stepwise in accordance with a difference between the distance error obtained in the third step and the threshold value.

13. The navigation assisting method according to claim 9, wherein the first step to the fourth step are periodically repeated.

14. A navigation assist processing program recorded in a storage medium to control a computer mounted in an aircraft, comprising:

a command to cause the computer to perform a first step for obtaining an estimated time of arrival of the aircraft when the aircraft is estimated to arrive at a target point for which a required time of arrival of the aircraft is set in advance;

a command to cause the computer to perform a second step for calculating a time error between the estimated time of arrival obtained in the first step and the required time of arrival;

a command to cause the computer to perform a third step for converting the time error calculated in the second step to a distance error based on a velocity of the aircraft; and

a command to cause the computer to perform a fourth step for visually displaying the distance error obtained in the third step.