LDM
This video presents the teardown of a vintage Ground Position Indicator which was used in Avro Vulcan aircrafts.
If someone knows something about this device please let me know, particularly the purpose of the various controls on the front panel.
00:00 - Intro
03:54 - Teardown
05:16 - Disc & Ball integrator
07:33 - Mileage computations
13:44 - Normal / Fix modes
15:16 - Synchronous motor
16:14 - Test with manual heading change
17:26 - Mileage simplified electro-mechanical diagram
Notes:
At that time the goal of the third disk and ball integrator (on the bottom side) is unknown
Edit 07/03/24: according to @Pulsynetic the disk and ball integrator is used for a cosecant function which permits the correction of the meridians convergency to give the longitude.
On the simplified electro-mechanical diagram the outputs of the disk and ball integrators are not the latitude nor longitude but the E-W and N-S mileages.
Mileages computation:
The mileages are computed using two disc and ball integrators. The disc of each integrator is linked to the same M-type stepper motor. The frequency of the signals which drive the motor must be proportional to the ground speed.
The input of the integrator (the displacement of the balls) is an image of the sine and the cosine of the heading. This is simply done using slides and levers linked to the heading shaft.
The angle of the output shaft is therefore an image of the integral of V(t)*sin(Theta(t)) and of V(t)*cos(Theta(t)), that is to say respectively the mileage on each axis.
Links:
Dead reckoning on Wikipedia:
https://en.wikipedia.org/wiki/Dead_re....
Disc and ball integrator on Wikipedia:
https://en.wikipedia.org/wiki/Ball-an...
on YT:
• Mechanical Computer (All Parts) - Basic Me...
Other navigation computers on my channel:
• LDM #313: Starfighter F-104 PHI Navigation...
• LDM #336: RAF Avro Vulcain Electrical Indi...
• LDM #337: RAF Avro Vulcain Electrical Indi...
Ball resolver:
• LDM #294: Navigation computer and Ball Res...
THE V-FORCE : 1955 to 1966
http://www.blackmanbooks.co.uk/naviga...
Book Computing mechanisms and Linkages by ANTONÍN SVOBODA (1965)
https://www.randomwraith.com/document...