To maintain separation with other traffic, terrain, threats and special use airspace independent of control link availability, UAVs require the capability of autonomous conflict detection and resolution. In previous research it has been illustrated how conflict probing provides the basis for a framework to integrate the results from multiple conflict prediction functions and how conflict probing can be used to find two-dimensional resolution maneuvers.Conflict resolution should be able to use the full performance capabilities of the UAV, rather than command standard resolution maneuvers designed to accommodate the worst performing class of UAVs. The available 3D space for conflict resolution can be maximized by combining vertical and lateral maneuvers. This requires integrated control authority allocation and envelope protection functionality, taking into account the effect of lateral maneuvering on the vertical performance and load factor margin. The maximum safe maneuvering space should also utilize the ability to convert the available speed margin relative to V min or V max (excess kinetic energy) into altitude (potential energy). For humans it is almost impossible to maximize the maneuvering performance in this way without violating one or more maneuvering constraints such as angle of attack, stall speed, load factor and bank angle.The goal of the current research is to develop an autonomous conflict resolution system which uses (well) balanced lateral and vertical maneuver authorities, and if needed, can safely utilize the most aggressive possible vehicle maneuver capability. This paper discusses an approach to provide integrated vertical and lateral airplane maneuver authority allocation and envelope protection functions. These functions have been implemented in the Total Energy Control System / Total Heading Control System (TECS/THCS) design to generate example time responses of single and combined vertical and lateral maneuvers, including energy exchange ("zoom") maneuvers. The methodology also provides for 3D end-state prediction and display on an enhanced SVS PFD. It is also illustrated how information about the maximum safe maneuvering authority is integrated into the conflict prevention/resolution function.

No abstract

No abstract

In previous work it has been illustrated, that the use of a zoom-maneuver as an option for conflict prevention/resolution maneuvers can extend the solution space. When performing a zoom-maneuver as part of a conflict prevention maneuver the velocity changes, affecting the time to the predicted loss of separation. Furthermore, the exchange from kinetic to potential energy is not completely lossless. With a higher load factor, the increase in drag will reduce the efficiency of the conversion, yielding a smaller amount of gained potential energy (altitude) for the same amount of kinetic energy. Finally, the rate at which excess kinetic energy can be exchanged for altitude is limited by the allowable load factor. An important aspect is the predictability of the effects. These factors have to be taken into account when designing a conflict prevention / resolution function that relies on the ability to perform a zoom maneuver to extend the solution space. To evaluate the impact of these factors, and identify possible trade-offs, the Total Energy Control System has been enhanced with an autonomous zoom capability. Using the resulting implementation, a number of simulations have been performed for different initial conditions, load factors and vehicle configurations. This paper discusses the concept, design questions, implementation and evaluation in more detail.

No abstract