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The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS 3 -MN-11 LANDING DYNAMICS ON THE «LUNA-GLOB» PROJECT Sikharulidze Yu.G., Zhukov B.I., Tuchin A.G. (Keldysh Institute of Applied Mathemathics RAS) Zaiko Yu.K., Fedotov V.P., Likhachov V.N., Rozin P.E.
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The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 LANDING DYNAMICS ON THE «LUNA-GLOB» PROJECT Sikharulidze Yu.G., Zhukov B.I., Tuchin A.G. (Keldysh Institute of Applied Mathemathics RAS) Zaiko Yu.K., Fedotov V.P., Likhachov V.N., Rozin P.E. (Lavochkin Design Center)
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 1. Phases of Landing Trajectory
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 Range of the initial true anomaly -10oo+10o Variation of the initial time 3 min De-orbit point shift 306 km Propellant consumption 389 kg (initial Lander mass 911 kg) The optimal pitch angle guidance and linear pitch law Engine C1.154.0000.0-0 with thrust of 42020 kgf (tolerance) Regulation range 400480 kgf (+13-33 km) 2. Main Deceleration Phase 1 with Downrange Maneuver
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 Terminal guidance algorithm with numerical prediction of remaining trajectory (Numerical Predictor-Corrector NPC). Two-parametric guidance: (t)= 0+ t. Three predicted trajectories. Multistep process: tguid=1 s, tstab=0.05 s. Linear correction of guidance parameters: 0i =0i-1+0i i = i-1+i 3. Numerical Predictor-Corrector
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 Terminal conditions for the Phase 1: Vn1=0 (stop of prediction), Vr1=-5 m/s, h1=1500 m (corrected values). Adaptation algorithm: m(t)=? P(t)=? Phantom acceleration: W=P/m=P/(m0-│dm/dt│t)=g0Psp/(-t), where =m0/│dm/dt│- “total burning time”. Measurements W1 for t1 and W2 for t2 → parameters of adaptation , Psp 4. Algorithm of Adaptation
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 Numerical derivative ∂Φ/∂P=-0.021 deg/kgf. Predicted angular error due to thrust variation and de-orbit point shift: ΔΦi pred. Thrust correction: ΔP= -ΔΦi pred/(∂Φ/∂P). Thrust is unknown. 5. Thrust Correction
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 6. Phase 1. Trajectory with Linear Pitch Guidance
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 Engine C1.154.0000.0-0 with thrust of 42020 kgf (tolerance) Regulation range 400480 kgf Initial errors: ΔΦ1, Δh1, ΔVr1. Corrected values: Vr2=-5 m/s, h2=50 m, ΔΦ2=0 Parameters of control: 2(t2)= 02+ 2t2, tign2 – time ignition (ignition altitude hign2). Four predicted trajectories. Linear correction of guidance parameters: 0i =0i-1+0i, i= i-1+ i, tign2(i) =tign2(i-1)+tign2(i) 7. Phase 2. Precision Deceleration
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 After engine ignition: two-parametric control & thrust regulation 0i =0i-1+0i, i= i-1+ i Numerical derivative ∂P/∂h=1.14 kgf/m. Measurements of phantom acceleration W→ , Psp. Thrust correction ΔP=- Δh/(∂P/∂h), Δh=hpred2-h2. Thrust is unknown. 8. Phase 2. Adaptation Algorithm
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 9. Phase 2. Parameters of Nominal Trajectory
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 10. Phase 2. Correction of Initial Downrange Error
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 11. Phase 2. Correction of Initial Velocity Error
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 Engine 2554.487.00-0 Thrust 2x(65±5) kgf (tolerance), without thrust regulation. Specific thrust 287.7±5 s (tolerance) Terminal conditions: altitude 0.3 m, vertical velocity -2.5±1 m/s, side velocity ≤1 m/s Single control parameter: tign3 – time of engine ignition. 12. Phase 3. Landing on the Moon
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 13. Phase 3. Single-parameter guidance
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 14. Phase 3. Two-parameter guidance
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 15. Phase 3. Simulation Results
The Third Moscow International Solar System Symposium. Moscow, 8-12 October 2012 3MS3-MN-11 1. The terminal guidance algorithm (NPC) with adaptation to real motion conditions was developed for landing on the Moon. 2. For the Phase 1 NPC provides compensation of initial de-orbit point error within ±0.5o or ±15 km in downrange (±9 s). 3. For the Phase 2 NPC provides compensation of initial errors within ±40 m in downrange or ±2 m/s in side velocity by the pith angle of ±20o from the local vertical. 4. For the Phase 3 NPC provides adaptation to the real motion conditions. 16. Results