DocumentCode :
865299
Title :
Time-, fuel-, and energy-optimal control of nonlinear norm-invariant systems
Author :
Athans, M. ; Falb, P.L. ; Lacoss, R.T.
Author_Institution :
Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
Volume :
8
Issue :
3
fYear :
1963
fDate :
7/1/1963 12:00:00 AM
Firstpage :
196
Lastpage :
202
Abstract :
Nonlinear systems of the form \\dot{X}(t)=g[x(t);t]+u(t) , where x(t), u(t) , and g[x(t); t] are n vectors, are examined in this paper. It is shown that if \\parallel x(t) \\parallel = \\sqrt{{x_{1}}^{2}(t) + \\cdots + {x_{n}}^{2}(t)} is constant along trajectories of the homogeneous system \\dot{X}(t)=g[x(t); t] and if the control u(t) is constrained to lie within a sphere of radius M , i.e., \\parallel u(t) \\parallel \\leq M , for all t , then the control u^{\\ast}(t)= - Mx(t) / \\parallel x(t) \\parallel drives any initial state \\xi to 0 in minimum time and with minimum fuel, where the consumed fuel is measured by \\int_{0}^{T}\\parallel u(t) \\parallel dt . Moreover, for a given response time T , the control \\tilde{u}(t) = -\\parallel\\xi\\parallel x(t)/T \\parallel x(t) \\parallel drives \\xi to 0 and minimizes the energy measured by {1 \\over 2}\\int_{0}^{T}\\parallel u(t) \\parallel^{2}dt . The theory is applied to the problem of reducing the angular velocities of a tumbling asymmetrical space body to zero.
Keywords :
Fuel-optimal control; Minimum-energy control; Nonlinear systems; Time-optimal control; Angular velocity; Control systems; Delay; Energy measurement; Fuels; Linear systems; Nonlinear control systems; Nonlinear systems; Optimal control; Time measurement;
fLanguage :
English
Journal_Title :
Automatic Control, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9286
Type :
jour
DOI :
10.1109/TAC.1963.1105581
Filename :
1105581
Link To Document :
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