MULTIPLE CONTROL EFFECTOR RATE-LIMITING

The effect of the choice of control allocation scheme upon individual control effector rate demands is examined. Three previously reported a nd one new variation of control allocation schemes are described and c ompared. The new allocation scheme exploits the maximum attainable mom ent rates of a given control effector configuration and is called mome nt-rate allocation. The bases of comparison are single-axis sinusoidal and triangular sawtooth, and multiaxis helical time-varying moment de mands placed upon the allocation schemes, It is shown that 1) the choi ce of allocation scheme greatly affects the onset of effective rate li miting for a particular time-varying input but not consistently for al l inputs; 2) widely varying results are obtained depending on whether the input is single or multiaxis and on the amplitude and shape of the input; 3) none of the observed behavior (except as regards generalize d inverses) was easily predictable for arbitrary time-varying inputs; and 4) from the point of view of moment and moment-rate generating cap abilities, moment-rate allocation clearly yielded best results.