GROUNDSPEED AND TIME-TO-GO COMPUTER

• US 3,649,818 A
• Filed: 12/17/1969
• Issued: 03/14/1972
• Est. Priority Date: 12/17/1969
• Status: Expired due to Term

• Current Assignee: Frederick B. Sylvander, Murray Putzer, Richard L. Cohen
• Original Assignee: Frederick B. Sylvander, Murray Putzer, Richard L. Cohen
• Inventors: Sylvander, Frederick B., Cohen, Richard L., Putzer, Murray
• Primary Examiner(s): Morrison, Malcolm A.
• Assistant Examiner(s): Dildine, Jr., R. Stephen
• Application Number:
  US04/885,779
• Time in Patent Office: 818 Days
• Field of Search: 235/150.27,151.32,150.2 324/160,178 73/178R
• US Class Current: 702/144
• CPC Class Codes: G01S 13/785 Distance Measuring Equipment [DME] systems
• CPC Class Codes: G06F 7/62 Performing operations exclusively by counting total number of pulses ; Multiplication, division or derived operations using combined denominational and incremental processing by counters, i.e. without column shift G06F7/68 takes precedence

Abstract

A groundspeed and time-to-go computer for an aircraft. The groundspeed computation is implemented by counting the pulses from a fixed frequency pulse generator during an interval established by the units transmitter of distance-measuring equipment (DME), and which interval is inversely proportional to groundspeed. The time-to-go computation is implemented by counting down the count from units, tens and hundreds DME transmitters until zero is reached and noting the interval.

Claims

1. Apparatus for aircraft, comprising:

distance measuring means for measuring distance of the aircraft from a station;

clock means for providing fixed frequency pulses;

first counting means connected to the distance-measuring means and to the clock means for counting the fixed frequency pulses between increments established by the distance-measuring means;

an accumulator;

first gating means connecting the counter to the accumulator and connected to the distance-measuring means and operative at the increments established by the distance-measuring means for initiating cycles to transfer the count from the counter to the accumulator;

second counting means connected to the accumulator for counting the number of transfer cycles until the accumulator content reaches a predetermined constant, and for thereupon providing an output;

converting means connected to the distance-measuring means for converting the distance measured thereby to natural binary outputs;

third counting means;

second gating means connecting the converter to the third counting means and connected to the distance-measuring means, and operative at the increments established by the distancemeasuring means for transferring the outputs from the converting means to the third counting means;

command means connected to the distance-measuring means, the clock and the third counting means, and responsive to pulses from the clock accumulated between the increments established by the distance-measuring means for commanding the third counting means to count down and to provide a controlling output upon reaching zero; and

display means connected to the second counting means and to the last-mentioned means and responsive to the outputs therefrom for providing displays of aircraft groundspeed and time-to-go to the station, respectively.

2. Apparatus as described by claim 1, wherein the distance-measuring means includes:

units, tens and hundreds transmitters;

the first counting means, the first gating means, the second gating means and the command means connected to the units transmitter; and

the converting means connected to the units, tens and hundreds transmitters.

3. Apparatus as described by claim 2, wherein:

the units, tens and hundreds transmitters each include an angularly displaceable rotor energized by a voltage source and a stator inductively coupled to the rotor for providing outputs varying as the sine and cosine of the rotor angular displacement.

4. Apparatus as described by claim 3, including:

means connected to the stator for detecting when one of the sine and cosine outputs are at zero and for thereupon providing an output; and

means connected to the last-mentioned means and responsive to the output therefrom for providing a controlling output.

5. Apparatus as described by claim 4, including:

signal-generating means connected to the last-mentioned means and responsive to the controlling output therefrom for providing a plurality of output pulses in a predetermined timing sequence;

the first counting means connected to the signal generating means so as to be reset by one of the pulseS therefrom to count the fixed frequency pulses from the clock;

the first gating means connected to the signal generator and responsive to another of the pulses therefrom for transferring the count from the counter to the accumulator; and

the second gating means connected to the signal generator and responsive to still another of the pulses therefrom for transferring the outputs from the converting means to the third counting means.

6. Apparatus as described by claim 1, including:

a pulse source connected to the second counting means and responsive to an output therefrom when the distance to he station is less than a predetermined minimum for providing an output pulse;

means for providing a system enabling output; and

a gate connected to the pulse source and to the enabling means and responsive to the outputs therefrom for providing a controlling output; and

the display means connected to the gate and responsive to the controlling output therefrom for being locked to inpart memory to the apparatus.