real time fire control solution for individual and crew-served direct firing infantry weapons - algorithm and implementation A. Kuhrt H. Rothe
Mazár-e-Sharif 08 0730 D may 08 rh: 60% T: 71 F target range: 1500m -2 -
target range: 1500m Mazár-e-Sharif -3 -
Agenda 1. Status quo 2. Requirements 3. Theoretical Approach 4. Algorithm 5. Testing and Accuracy 6. Performance 7. Implementation 8. Conclusions -4 -
Status Quo LRF DMC PDA GPS thermal sight video sight -5 -
Requirements requirement fulfilled range- and crosswind arbitrary angle of site muzzle velocity coriolis force magnus force multiple ammunitions height dependent air temperature height dependent air pressure user-defined targeting sights time fuze capability -6 -
Approach Point Mass Trajectory Model only drag and gravity acting on projectile height adding flat fire assumptions range Adding generalized power drag law analytically solvable set of differential equations of motion -7 -
Approach Point Mass Trajectory Model only drag and gravity acting on projectile adding flat fire assumptions normalized height above LOS Adding generalized power drag law normalized range analytically solvable set of differential equations of motion -8 -
Approach Point Mass Trajectory Model only drag and gravity acting on projectile adding flat fire assumptions Adding generalized power drag law analytically solvable set of differential equations of motion -9 -
Algorithm super elevation striking veloctiy time of flight strinking energy calculated using o Mach dependent analytical solutions o splitted solutions for slant range and gravity drop o gravity corrected projectile velocity -10 -
Algorithm -11 -
Algorithm requirement range- and crosswind arbitrary angle of site muzzle velocity coriolis force magnus force multiple ammunitions height dependent air temperature height dependent air pressure user-defined targeting sights time fuze capability fulfilled -12 -
Testing and Accuracy -13 -
Accuracy 0,1 weapon: M82A1 ammunition: M8.50BMG range: 0 1500 m 0-0,1-0,2-0,3-0,4 1,5 1 0,5 0-0,5-1 -1,5-2 0,4 0,2 0-0,2-0,4-0,6-0,8-1 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 Error in Elevation in Clicks 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 Error in TOF in ms 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 Error in velocity in m/s -14 -
Met Variations weapon: HK G3 ammunition: M80.308 range: 0 800 m error in clicks 0,8 0,6 0,4 0,2 0-0,2-0,4-0,6-0,8 0 100 200 300 400 500 600 700 800 range in m Standard 900mbar 1100mbar -20 C 30 C -15 -
Model Limitations weapon: HK GMG ammunition: 40mm range: 0 2000 m 1 0-1 -2-3 -4-5 -6-7 -8-9 0,16 0,14 0,12 0,1 0,08 0,06 0,04 0,02 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 elevation error in mils flattening R 0 200 400 600 800 1000 1200 1400 1600 1800 2000-16 -
Performance algorithm usage in an automated fire control system 1 ms compute fire control solution typically 0.1 to 1.2 ms depending on options used 20 ms sensor readout typically every 20 ms 100 ms re-align weapon typically 100 to 1000 ms -17 -
Performance Comparing analytical solution with numerical RK4 integration for a.50bmg rifle: times faster than numerical integration 1000 900 800 700 600 500 400 300 200 100 0 100 300 500 700 900 1100 1300 1500 range in m -18 -
Implementations DSP based stand alone fire control computer Optimized MISRA-C source code compiled for TI DSP system Windows demonstrator front end C# source code compiled for MS Windows Pocket PC implementation C# source code compiled for MS Pocket PC 2003-19 -
Implementations using spare computational power using spare computational power -20 -
Conclusions An analytical solution for the differential equations of motion was found - thermodynamic state of the atmosphere was considered - Multi region drag fitting - uphill/downhill shooting - wind / coriolis / spin deflection An optimized algorithm was developed - Optimized to minimized computation time - Multi weapon / ammunition capabilities - compact code size - approved accuracy under nearly all conditions Sample implementations were introduced - handheld fire control for sniper teams - in-sight automatic fire control for crew weapons -21 -
Contact Helmut-Schmidt-University University of the Federal Armed Forces Holstenhofweg 85 22043 Hamburg Germany Institute for Automation Engineering www.hsu-hh.de/mit rothe@hsu-hh.de Dipl.-Ing. Alexander Kuhrt kuhrt@hsu-hh.de -22 -