| 摘要 |
A flight management system that provides an airspeed command to control a flight profile pursuant to minimum total cost. Total cost is the sum of direct operating cost and arrival time error cost and direct operating cost is the sum of fuel cost plus flight-time cost. A predictor, in response to trial cost index values, generates direct operating cost and arrival time values corresponding to the trial cost index values. A parabolic function approximator generates a parabolic approximation to the direct operating cost vs. arrival time function corresponding to the trial cost index values. An arrival error cost function is added to the direct operating cost function and the minimum of the combined function is obtained to provide an optimum arrival time signal. The trial cost index values and the corresponding arrival time values are applied to a parabolic approximator to obtain a cost index vs. arrival time function. The optimum arrival time signal is applied to this function to provide the optimum cost index signal corresponding thereto. A speed generator is included for generating an airspeed signal corresponding to the optimum cost index signal in accordance with minimum direct operating cost. A predictor generates a predicted arrival time signal in accordance with the optimum cost index signal. A speed adjuster adjusts the airspeed signal to provide the airspeed command signal in accordance with the difference between the optimum arrival time signal and the predicted arrival time signal.
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