Apollo Micro Systems

QRSAM Actuator

The Quick Reaction Surface-to-Air Missile (QRSAM) is an indigenous servo actuation system designed to deliver precise aerodynamic control during missile flight. The system comprises four rotary actuators arranged at 90° apart, coupled with a quad-channel digital controller for synchronized operation.
Aerodynamic control is achieved through deflection of control surfaces, which generate lateral forces and moments about the vehicle’s center of gravity (CG). Each actuator drives its corresponding fin via a gear train mechanism, ensuring accurate angular positioning. The compact design, high torque capability, and robust feedback architecture make the QRSAM actuation system highly reliable under extreme combat and environmental conditions.

Key Features :

System Specifications :

Maximum Angular Command Range: ±28.5° ±1°.
Maximum Aerodynamic Axis Moment (per fin): 11300 N.
Maximum Force on Fin (at 87 mm offset): 11300 N.
Bandwidth (@10 A, -90°): 27–38 Hz.
Frequency Flatness: ±0.5 dB, ±300.
Voltage Supply (Servo Motors & Amplifiers): 50–95 V (via 100 V SRV Bus, 2040 V Battery).
Auxiliary Supply (Electronics): 28 V ELC.
Communication Interface: RS422 Full Duplex.

Format: 1 start bit, 8 data bits, 1 stop bit, Bi-Endian.
Baud Rate: 2 Mbps (400 Hz refresh).

Command Resolution: 0.1°.
Minimum Command Error: 0.15° (for <3° commands under load).
Steady-State Error (excluding backlash): ≤5% of command (>3°).
Length of Rear Servo: 153 mm.
Annular Space: 42.5 mm.
Weight (w/o fins): 7.5–8.5 kg.
Total Time for FBIT: 0.3 sec (max).
Maximum Power from 28 V ELC Bus: 16 W.
Maximum Power from WCS Supply: 16 W.
Maximum Backlash (Motor-to-Fin Shaft): ≤0.6°.
Maximum Overshoot: ≤10%.
Total Operation Duration: 240 sec.
Time from Power-On to PBIT Completion: ≤1 sec.
Maximum Power (WCS & 28 V combined): ≤350 W.
Actuator Stiffness: ≥8 Nm/deg.