METHOD AND MEANS FOR PROVIDING A SYNTHETIC REAL WORLD RUNWAY DISPLAY

• US 3,643,213 A
• Filed: 11/24/1969
• Issued: 02/15/1972
• Est. Priority Date: 11/24/1969
• Status: Expired due to Term

• Current Assignee: Abner Owens Jr, John F. Yurasek
• Original Assignee: Abner Owens Jr, John F. Yurasek
• Inventors: Yurasek, John F., Owens, Abner Jr.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US04/879,069
• Time in Patent Office: 813 Days
• Field of Search: 340/25,26,27NA 343/18R
• US Class Current: 340/972
• CPC Class Codes: G01C 23/005 Flight directors indicating arrangements specially adapted for rotary gyroscopes G01C19/32
• CPC Class Codes: G01S 1/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G05D 1/0676 specially adapted for landing

Abstract

A system for providing a perspective of a synthetic real world runway on a cathode-ray tube in a heads-up display system for guiding a pilot while landing an aircraft on the real world runway when visibility is poor. The perspective of the synthetic runway changes in accordance with changes in the position of the aircraft to the real world runway. A waveform generator provides waveforms corresponding to the synthetic runway to a computer which modifies the waveforms in accordance with received signals from the airport, such as instrument landing system (ILS) and range signals, and signals corresponding to sensed conditions, such as altitude, pitch, roll and yaw, to provide deflection voltages to the cathode-ray tube which displays the perspective synthetic real world runway in accordance with the deflection voltages from the computer.

Claims

1. A system in an aircraft for displaying a perspective synthetic runway corresponding to a runway at an airport;

comprising means for providing deflection voltages and bright-up pulse voltages for displaying a synthetic runway;

means for providing signals corresponding to the location of the aircraft with respect to the airport runway;

means for providing signals corresponding to the attitude of the aircraft;

means for providing a signal corresponding to the altitude of the aircraft;

means connected to the voltage means and to each signal means for modifying the deflection voltages in accordance with the location, attitude and altitude signals;

a cathode-ray tube connected to the modifying means and to the voltage means for displaying the perspective synthetic runway corresponding to the airport runway in accordance with the modified deflection voltages from the modifying means and with the bright-up pulse voltages from the voltage means;

each cycle of a predetermined proGram of deflection voltages divided into eight time periods and the voltage means including means for providing a first horizontal deflection voltage, means for providing a second horizontal deflection voltage, means for providing a vertical deflection voltage, means for providing bright-up pulse voltages, and program means connected to each deflection voltage means and to the bright-up pulse voltage means for controlling said means in accordance with said predetermined program to provide deflection voltages and bright-up pulse voltages for the synthetic runway display;

the second horizontal deflection voltage means including a voltage divider dividing a positive direct current voltage and providing a plurality of outputs, and first switching means connected to the program means and to the voltage divider for sequentially passing the outputs from the voltage divider during the fourth through seventh time periods in accordance with a signal from the program means to provide a negative going step voltage as the second deflection voltage.

2. A system of the kind described in claim 1 in which the first horizontal deflection voltage means includes switching means connected to the program means and controlled by the program means to pass a negative direct current voltage during the first and second time periods and to pass a positive direct current voltage during third through seventh time periods and not to pass a voltage during the eight time period, means connected to the program means and controlled by the program means for counting timing pulses from the program means and providing a digital output corresponding thereto, a bipolar digital-to-analog converter connected to the counting means and to the switching means converts the digital output from the counting means to an analog voltage having the same polarity as the passed direct current voltage from the switching means, second switching means connected to the program means and controlled by the program means to pass another positive direct current voltage during the second time period, to pass another negative direct current voltage during the fourth through seventh time periods, and a zero amplitude voltage during the first and third time periods, and summing means connected to the digital-to-analog converter and to the second switching means for summing the outputs from the converter and from the second switching means to provide the first horizontal deflection voltage.

3. A system of the kind described in claim 1 in which the first switching means includes a plurality of switches connected to the voltage divider, each switch receiving a different output from the voltage divider, and a counting means connected to the program means and to the switches receiving a pulse during each time period and providing outputs during the fourth through seventh time periods, each output enabling a different switch to pass the voltage received by that switch from the voltage divider.

4. A system of the kind described in claim 1 in which the vertical deflection voltage means includes second switching means connected to the program means and controlled by the program means to pass the first mentioned negative direct current voltage during the first and third time periods, to pass another positive direct-current voltage during the second time period, and to pass a zero amplitude voltage during the fourth through seventh time periods, a bipolar digital-to-analog converter connected to the second switching means and to the counting means and controlled by the passed direct current voltage to convert the digital output from the counting means to an analog voltage in accordance with the passed direct-current voltage from the second switching means, third switching means connected to the program means and controlled by the program means to pass the zero amplitude voltage during the first and third through seventh time periods and to pass another negative direct current voltage during the second time period, an inverter connected to thE first switching means and inverting the signal passed by the first switching means, and summing means connected to the converter, to the inverter and to the third switching means for summing the outputs from the converter, inverter and third switching means to provide the vertical deflection voltage.

5. A system of the kind described in claim 1 wherein:

the location signals from the location signal means include a signal corresponding to the range of the aircraft from the airport and a signal corresponding to the ground track error angle between the aircraft and the airport runway;

the attitude signals from the attitude signal means include a signal corresponding to the roll attitude of the aircraft a signal corresponding to the pitch attitude of the craft and a signal corresponding to the yaw attitude of the aircraft; and

the modifying means includes a means connected to the vertical deflection voltage means and to the location signal means for dividing the vertical deflection voltage by the range signal from the location signal means and providing a signal corresponding thereto, means connected to the dividing means and to the altitude signal means for providing a signal corresponding to the product of the signal from the dividing means and the altitude signal from the altitude signal means, summing means connected to the multiplying means and to the attitude signal means and providing a signal corresponding to the sum of the product signal from the multiplying means and the pitch attitude signal from the attitude signal means, and means connected to the summing means and to the attitude signal means for affecting the signal from the summing means in accordance with the roll attitude signal from the attitude signal means to provide a modified vertical deflection voltage.

6. A system of the kind described in claim 1 in which the modifying means also includes means connected to the first horizontal deflection voltage means and to the location signal means for dividing the first horizontal deflection voltage by the range signal from the location signal means and providing a signal corresponding thereto, switching means connected to the first and second horizontal deflection voltage means and to the program means and positively controlled by the program means to pass the first horizontal deflection voltage during the first through third time periods and to pass the second horizontal deflection voltage during the fourth through seventh time periods and to block the horizontal deflection voltages during the eighth time period, means connected to the location signal means and to the switching means for providing a signal corresponding to the product of the passed horizontal deflection voltage from the switching means and the ground track error angle signal from the location signal means, subtracting means connected to the dividing means and to the multiplying means for providing a signal corresponding to the difference between the signal from the dividing means and the signal from the multiplying means, summing means connected to the dividing means and to the multiplying means and providing a signal corresponding to the sum of the signals from the dividing means and the multiplying means, second switching means connected to the multiplying means, to the subtracting means, to the summing means and to the program means and controlled by the program means to pass the signal from the subtracting means during the first time period, to pass the signal from the summing means during the second and fourth through seventh time periods and to pass the signal from the multiplying means during the third time period and to pass no signal during the eighth time period, second summing means connected to the attitude signal means and to the second switching means providing a signal corresponding to the sum of the passed signal from the second switching means and the yaw attitude signal from the attitude signal means, and means connected to the second summing means and to the attitude signAl means for affecting the signal from the second summing means in accordance with the roll attitude signal from the attitude signal means to provide a modified horizontal deflection voltage.