Abstract: A method and apparatus are disclosed for determining a trajectory for a vehicle, wherein the method includes: identifying a starting position (p0) for the vehicle; identifying a desired terminal position (P) for the vehicle; linearly approximating dynamics of the vehicle; and using the starting position (p0), the desired terminal position (P), and the linear approximation, determining the trajectory for the vehicle. The linear approximation can be constrained by a requirement (e.g., specification) that a magnitude of a velocity of the vehicle is greater than or equal to a threshold value for the velocity. The vehicle may have a curvature limit.

Abstract: A method and apparatus are disclosed for a turboprop-powered medium altitude long endurance (MALE) aircraft, having: a heat exchanger with a heat-storage material, for example a heat-storage wax; and an air recirculation path. The heat exchanger can be arranged to cool air recirculating around the air recirculation path which is arranged to provide cooling to the MALE aircraft, for example to an equipment bay. The heat-storage material may be cooled by ground-based cooling apparatus when the aircraft is on the ground and/or by ram air when the aircraft is in flight. The heat-storage material may have a melting point selected so as to be rendered solid during ground-based cooling and/or ram air cooling, and/or selected so as to undergo melting whilst cooling the air recirculating around the air recirculation path.

Abstract: An apparatus and a method are disclosed for tracking a plurality of targets (e.g. land-based vehicles). The method can include: for a first time-step, estimating a state of each respective target; at a second time-step, measuring values for a state of each target; for the second time-step, estimating a state of each target using the estimated target states for the first time-step; updating the estimated target states for the second time-step by performing a Joint Probabilistic Data Association process using the measured values; and performing an identity management process to estimate a probability that a particular state measurement corresponds to a particular.

Abstract: A method of detecting defects in a welded metal structure, comprising mounting an ultrasonic transducer at or adjacent to a weld seam, and emitting ultrasonic signals so that the signals are propagated in the weld seam acting as a wave guide, and detecting reflections of the signals that may be indicative of defects in or adjacent to the weld seam. Waveguiding occurs within the weld principally because it is thicker than the plate, and thus the phase velocity in the plate is greater than that in the weld. This results in total internal reflection within the weld. In addition, an evanescent wave propagates in a region adjacent to the weld. The common problem with non destructive testing of excitation and reception of unwanted modes is greatly reduced, since it has been found that for certain frequency regions, transmitted waves will propagate only in a single mode at a predetermined frequency. As preferred the fundamental symmetric Lamb wave mode S0 is employed.

Abstract: A separator is disclosed for separating particles of at least first and second mass/size ranges from an ambient fluid (e.g. gaseous) medium in which they are present, particles of the first range being of generally larger size/mass than particles of the second range. The separator is especially designed for use in an air monitoring device which is designed for rapid detection of micro-organisms such as bacteria, viruses, pathogens and the like, and is designed to be portable so that it can be readily and rapidly deployed in both civilian and military environments and can be used indoors and outdoors; it can also be designed for personal use.

Abstract: The accelerometer has a base (2), an outer planar ring-like support frame (17) fixedly bonded to the base (2), and an inner planar ring-like support frame (18) flexibly suspended within the outer frame (17) by mounts (19) connecting the inner frame (18) to the outer frame (17) so that the inner frame (18) is spaced from the base (2), co-planar with the outer support frame (17) so as to provide flexible suspension for the inner support frame (18) reducing compressive and/or tensile forces on mounting legs (4) flexibly mounting a proof mass (3) in the inner support frame (18).

Abstract: A control apparatus comprising a movable control member, a positional servo loop consisting of a motor having a movable armature thereby maintaining the position of the control member at any one of a plurality of positions in a range of movement thereof in accordance with a demand signal, and means for detecting a force applied to the control member and for providing the demand signal which varies in accordance with the magnitude of the applied force, wherein the control member is rigidly attached to the armature so that movement of the control member is precisely mirrored by movement of the armature. The force is detected by measuring the current applied to the motor (which is proportional to the force). Direct drive of the control member eliminates backlash from the system.