Frequency-shaped large-angle maneuvers

Chun, Hon M.; Turner, James D.; Juang, Jer‐Nan

doi:10.2514/6.1987-174

Cited by 12 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(10)] and Eqs. (5) and (7) for this problem can be obtained as The solution r 2 = r 3 = 0 implies a singular control problem because u 2 and w 3 cannot be determined by Eq. (12).…”

Section: Optimal Controlmentioning

confidence: 99%

Numerical approach for solving rigid spacecraft minimum time attitude maneuvers

Bainum

1990

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

The minimum time attitude slewing motion of a rigid spacecraft with its controls provided by bounded torques and forces is considered. Instead of the slewing time, an integral of a quadratic function of the controls is used as the cost function. This enables us to deal with the singular and nonsingular problems in a unified way. The minimum time is determined by sequentially shortening the slewing time. The two-point boundary-value problem is derived by applying Pontryagin's maximum prinicple to the system and solved by using a quasilinearization algorithm. A set of methods based on the Euler's principal axis rotation is developed to estimate the unknown initial costates and the minimum slewing time as well as to generate the nominal solutions for starting this algorithm. It is shown that one of the four initial costates associated with the quaternions can be arbitrarily selected without affecting the optimal controls and thus simplifying the computation. Several numerical tests are presented to show the applications of these methods.

show abstract

“…(10)] and Eqs. (5) and (7) for this problem can be obtained as The solution r 2 = r 3 = 0 implies a singular control problem because u 2 and w 3 cannot be determined by Eq. (12).…”

Section: Optimal Controlmentioning

confidence: 99%

Numerical approach for solving rigid spacecraft minimum time attitude maneuvers

Bainum

1990

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

show abstract

“…where x is the state vector and A and B are constant, and the outputs are related to the states by the equation y = Cx, then the vector y f is given by c *('/) (10) H n _j]u (4) where $ = e AAt is the state transition matrix for the time step At. It is apparent from this that if a finite-order system is observable by means of the outputs in y, then the final state can be specified exactly by this approach.…”

Section: Pulse Response Based Controlmentioning

confidence: 99%

“…Turner and Chun 3 extend the approach of Turner and Junkins for the case in which a number of actuators are distributed throughout the structure. Chun et al 4 obtain a frequency-shaped open-loop control for the rigid body modes, using a continuation method to handle nonlinearity, and then design a feedback control for the flexible motion by linearizing the flexible response about several points in the open-loop rigid body trajectory. In a later paper, they replace the solution of the open-loop problem for the rigid body modes with a programmed-motion/inverse dynamics approach, where the trajectories of the rigid body modes are simply specified as smooth functions and the required control torques are obtained from the nonlinear rigid body equations of motion.…”

Section: Introductionmentioning

confidence: 99%

Minimum time pulse response based control of flexible structures

Bennighof

Chang

Subramaniam

1993

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

This paper presents the pulse response based control method for minimum time control of structures. An explicit model of a structure is not needed for this method, because the structure is represented in terms of its measured response to pulses in control inputs. Minimum time control problems are solved by finding the minimal number of time steps for which a control history exists that consists of a train of pulses, satisfies input bounds, and results in desired outputs at the end of the control task. There is no modal truncation in the pulse response representation of the response, because all modes contribute to the pulse response data. The precision with which the final state of the system can be specified using pulse response based control is limited only by the observability of the system with the given set of outputs. A special algorithm for solving the numerical optimization problem arising in pulse response based control is presented, and the effect of measurement noise on the accuracy of the final predicted outputs is investigated. A numerical example demonstrates the effectiveness of pulse response based control and the algorithm used to implement it. The pulse response based control method is applied to linear problems in this paper.

show abstract

“…This approach enables the underactuated system to generate suboptimal control profiles that are free of jump discontinuities. It is desirable to eliminate control jump discontinuities because they can excite the higher mode flexural degrees of freedom because of the high frequency content of the control profiles [4][5][6]27]. By eliminating jump discontinuities, this work seeks to minimize spill-over to the response of the flexural degrees of freedom.…”

Section: Introductionmentioning

confidence: 99%