DISTRIBUTED MAGNETIC ACTUATORS FOR FINE SHAPE CONTROL

NEW SPACECRAFT DESIGNS FEATURE LARGE STRUCTURES CHARACTERIZED BY LOW NATURAL FREQUENCIES, LIGHTLY DAMPED STRUCTURAL MODES, AND STRINGENT SHAPE CONTROL REQUIREMENTS. THESE LARGE SPACE STRUCTURES (LSS) POSE UNIQUE AND DIFFICULT CONTROL PROBLEMS. AN IMPORTANT PART OF THE SOLUTIONS TO THESE CONTROL PROBLEMS IS THE DEVELOPMENT OF ACTUATORS THAT ALLOW THE APPLICATION OF FORCE AND OR TORQUE TO THE SPACE STRUCTURE. THIS PROPOSED RESEARCH PROGRAM WILL EXAMINE ADVANCED DISTRIBUTED LSS SHAPE CONTROL USING AN ARRAYS OF MAGNETIC COILS FIXED TO THE STRUCTURE. EACH COIL WILL PROVIDE SIX-DEGREE-OF-FREEDOM ACTUATION (FORCES IN AN TORQUES ABOUT THREE ORTHOGONAL AXES) WHEN IT INTERACTS WITH OTHER COILS IN THE ARRAY. THIS ACTUATION SCHEME IS EXPECTED TO HAVE A NUMBER OF ADVANTAGES OVER CONVENTIONAL ACTUATORS INCLUDING DC FORCE CAPABILITY, HIGH BANDWIDTH, EXTREMELY LOW MASS, AND NO MOMENTUM SATURATION EFFECTS. THE PROPOSED RESEARCH PROGRAM WILL DEVELOP THESE ACTUATORS AND ASSESS THEIR PERFORMANCE COMPARED TO CONVENTIONAL ACTUATORS.