SBIR 95-1 SOLICITATION
AUTONOMOUS CONTOL OF MINIATURE SPACECRAFT USING ADAPTIVE NONLINEAR MODEL PREDICTIVE CONTROL (MPC)
Spacecraft attitude control during propulsive maneuvers is complicated due to several factors,
some of which are: (i) nonlinear dynamics with time delays (ii) modeling and parameter
uncertainties (iii) flexible modes due to fuel sloshing and appendages (iv) constraints on
propulsive force and torque inputs (v) constraints on acceptable angular rates and attitudes
and (vi) autonomous reconfiguration requirements under failure conditions. The current
control approaches are based on frequency domain methods which assume linear time
invariant system dynamics. The advantages of these approaches are simplicity and ease of
stability and robustness analysis. However, the decreased performance and poor efficiency
translates to additional payload. Model Predictive Control (MPC) has been used successfully
in a number of industrial applications involving complex nonlinear processes with hard safety
and actuator constraints. The remarkable stability and robustness properties of MPC observed
in practice have been proven analytically in a number of recent publications. Based on this
experience and the availability of Megaflop chips and Gigaflop boards, MPC implementation
for spacecraft attitude control using micro thrusters is both feasible and practical. The
optimality of Nonlinear MPC design and its flexibility for reconfiguration make it an ideal
candidate for future spacecraft missions. Furthermore, suboptimal designs based on current
methods and approximations to MPC can be evaluated for performance tradeoffs, once the
maximum achievable performance using optimal MPC is known. Prof. John Wen, RPI will
act as a consultant on the project. Prof Wen has been closely associated with the Spacecraft
Attitude Control problem at JPL and RPI.
Potential Commercial Applications:
Model Predictive Control (MPC) supported by special coprocessors for implementation can
be applied across the board to a large number of aerospace and industrial applications.
Potential applications exist in chemical, automotive, electric power, pulp and paper,
manufacturing and metal processing industries, in addition to the defense market (tanks,
ships, submarines, missiles, aircraft, satellites etc.).
Name and Address of Offeror:
Scientific Systems Company Inc.
500 West Cummings Park
Woburn, MA 01801
Small Business Innovation Research Program (SBIR) &
Small Business Technology Transfer Program (STTR) Programs
Electronic Management System (EMS)
National Aeronautics and Space Administration (NASA)
The SBIR/STTR EMS site is maintained by Steve
Hu, Hughes STX.
For comments and questions, contact
Updated: Feb. 7, 1996