Abstract: Systems and vehicle are provided. A vehicle system for a vehicle includes: a trajectory selection module configured to select a potential vehicle path relative to a current vehicle movement condition; a trajectory movement condition module configured to estimate a modeled movement condition of the vehicle along the potential vehicle path; a limit comparison module configured to determine whether the modeled movement condition violates vehicle limits; and a violation indicator module configured to generate an indication of impending violation.

Abstract: An aerial drone parcel delivery/transfer management system includes an aerial drone parcel delivery/transfer management server (ADPTMS) and a plurality of aerial drone landing pads (ADLPs). Each ADLP has a corresponding ADLP address with a unique ADLP identifier (e.g., a manufacturing serial number); most-recently known ADLP geolocation data (e.g., geospatial coordinates); and possibly most-recently known ADLP elevation data. The ADPTMS communicates with order management/fulfillment servers associated with online stores, which communicates with aerial drone parcel delivery/transfer services for dispatching aerial drones to particular ADLPs corresponding to particular ADLP addresses as part of online orders fulfillment. An ADLP presents a machine readable code such as a quick response (QR) code that is captured by an aerial drone and processed to verify the ADLP's identity. An ADLP can output local RF and/or optical guiding signals to aid aerial drone navigation to the ADLP.

Abstract: Herein is disclosed a bounding-volume based unmanned aerial vehicle illumination management system comprising one or more processors, configured to define a plurality of bounding volumes within a region of unmanned aerial vehicle flight; determine a subset of unmanned aerial vehicles within a bounding volume according to an unmanned aerial vehicle flight plan; determine a combined lighting value of the subset of unmanned aerial vehicles according to an unmanned aerial vehicle illumination plan; and determine a surface illumination corresponding to the combined lighting value of one or more bounding volumes.

Abstract: A vehicle driving assist apparatus includes a traveling environment recognizer, a target traveling path setting unit, a traveling controller, a lane changing path setting unit, a lane change controller, and a lane change urgency determining unit. The lane changing path setting unit is configured to set a lane changing path that allows an own vehicle to make a lane change when making of the lane change is determined, in an automatic driving mode, as being necessary. The lane change urgency determining unit is configured to change thresholds of a maximum steering speed to a second threshold greater than a first threshold when urgency of making the lane change is high. The lane changing path setting unit is configured to restrain or prohibit the making of the lane change when the maximum steering speed, upon the setting of the lane changing path, is equal to or greater than the second threshold.

Abstract: A lane deviation prevention control device for a vehicle includes a target steering torque calculator, a rate limit processor, and a rate limit value calculator. The target steering torque calculator calculates target steering torque to be applied to a steering system of an own vehicle in a lane deviation prevention control. The lane deviation prevention control includes preventing the own vehicle from deviating from a lane on which the own vehicle is traveling. The rate limit processor performs rate limit processing. The rate limit processing includes limiting a speed of change in the target steering torque to a rate limit value. The rate limit value calculator calculates the rate limit value in accordance with a deviation state of the own vehicle from the lane.

Abstract: A lane deviation prevention control device for a vehicle includes a target steering torque calculator, a friction torque estimator, and a friction compensation rate variable controller. The target steering torque calculator calculates target steering torque to be applied to a steering system of an own vehicle in a lane deviation prevention control. The friction torque estimator estimates friction torque of the steering system. The friction compensation rate variable controller performs, on the basis of steering torque produced by a driver's steering operation and on the basis of a traveling state of the own vehicle, a variable control of an addition rate at which the friction torque is added to the target steering torque to compensate friction of the steering system.

Abstract: A lane deviation prevention control device for a vehicle includes first and second target amount of turn calculators and a target amount of turn switchover determiner. The first target amount of turn calculator calculates a first target amount of turn until an arrival at a first target point. The second target amount of turn calculator calculates a second target amount of turn from the first target point to a second target point. The target amount of turn switchover determiner obtains a yaw angle estimated value until the arrival at the first target point, estimates, on the basis of the yaw angle estimated value, arrival time until the arrival at the first target point, and compares the arrival time with a threshold, to determine timing of a switchover from the first target amount of turn to the second target amount of turn.

Abstract: A lane deviation prevention control device for a vehicle includes an exterior information detector and a lane deviation prevention control start determiner. The lane deviation prevention control start determiner determines to start a lane deviation prevention control even when an own vehicle has already deviated from an own lane on which the own vehicle is traveling, on the condition that the exterior information detector detects an approaching vehicle that is approaching the own vehicle, on an adjacent lane on deviation side on which deviation is taking place, and that a lateral position of the own vehicle is equal to or smaller than a control start threshold.

Abstract: A lane deviation prevention control device for a vehicle includes a target yaw rate calculator, a target steering torque calculator, and an integration permission determiner. The integration permission determiner determines, on the basis of a state of an own vehicle with respect to a lane and on the basis of a state of an actual yaw rate with respect to a target yaw rate, whether or not to permit an integral control in a proportional integral differential control, in executing a feedback control on the target yaw rate by the proportional integral differential control.

Abstract: A system for localizing an autonomous vehicle to a target area can include a position indicator adapted for association with the vehicle in a three dimensional configuration, a detection device configured to detect the position indicator, a computation device configured to compute a position of the vehicle based on the detected position indicator and the relationship of the configuration to the vehicle orientation, a transmitter configured to receive information from the computation device and produce a signal carrying the information, a receiver configured to receive the signal from the transmitter and filter the information therefrom, and a control system configured for association with and control of one or more directional control components of the vehicle, the control being based on the information received from the receiver relating to localizing the vehicle to the target area. A method of for localizing a vehicle to a target area is also disclosed.

Abstract: The present invention extends to methods, systems, devices, apparatus, and computer program products for gimbal stabilized components for remotely operated vehicles. Aspects of the invention include a gimbal stabilized radar system. A radar unit is mounted on a vertical (or horizontal) gimbal attached to a remotely operated aerial vehicle. In aspects, a radar unit is mounted to a gimbal having multiple degrees of freedom. When the remotely operated aerial vehicle rotates and/or changes its orientation in space, the gimbal compensates keeping the direction and elevation angle of the radar essentially constant.

Abstract: A user interface presented to an operator of an unmanned aerial vehicle (UAV) may be presented to facilitate the ease of operation of the UAV. The information displayed in the user interface may be customized by the operator to display selected data. The display configuration data may be saved and imported into other systems for future use. Various entities related to one or more UAVs may be presented in a hierarchical tree structure illustrating the relationship between the entities. Electronic checklists may be presented to a user to facilitate addressing common and emergency situations.

Abstract: Systems and aircraft are provided. An avionics system for an aircraft includes: a trajectory selection module configured to select a potential aircraft path relative to a current aircraft flight condition; a trajectory flight condition module configured to estimate a modeled flight condition of the aircraft along the potential aircraft path; a limit comparison module configured to determine whether the modeled flight condition violates aircraft limits; and a violation indicator module configured to generate an indication of impending violation.

Abstract: A method and a device for monitoring a deviation of a first rotational speed of a first drive unit for an aircraft from a second rotational speed of an at least second drive unit of an aircraft. The monitoring of the deviation of the first rotational speed of the first drive unit from the second rotational speed of the at least second drive unit is carried out as a function of a comparison of a detection of a first event of the first drive unit to a detection of a second event of the at least second drive unit.

Abstract: Methods and apparatus of notification of a flight asymmetry influencing an aircraft are disclosed herein. An example method includes monitoring a roll characteristic of an aircraft and determining an output of an autopilot system of the aircraft to control the roll characteristic. The example method further includes generating an alert based on the output and an authority of the autopilot system to control the roll characteristic.

Abstract: A control method for an unmanned aerial vehicle (UAV) is provided. The method includes: obtaining, from a depth-sensing camera, images of a surface below the unmanned aerial vehicle; obtaining, from a gyroscope, current pitch angle of the unmanned aerial vehicle; determining, at the unmanned aerial vehicle, a current altitude of the unmanned aerial vehicle based on the images and the current pitch angle; determining, at the unmanned aerial vehicle, whether the current altitude of the unmanned aerial vehicle is less than a predefined value; and controlling, at the unmanned aerial vehicle, a drive unit to rotate so as to cause the unmanned aerial vehicle to slow down in a balanced condition if the current altitude of the unmanned aerial vehicle is less than a predefined value.

Abstract: A seat arrangement of a passenger cabin includes at least two seat groups. The at least two seat groups are arranged consecutively between two passenger aisles running parallel to a longitudinal direction of the passenger cabin and each have two outer seat units and just one central seat unit. The seat units are set in a seating configuration. A central seat unit of at least one of the at least two seat groups is arranged offset with respect to at least one of the outer seat units of the same seat group in the longitudinal direction of the passenger cabin, as a result of which each seat unit has obstacle-free access to at least one cabin aisle.

Abstract: A user interface presented to an operator of an unmanned aerial vehicle (UAV) may be presented to facilitate the ease of operation of the UAV. The information displayed in the user interface may be customized by the operator to display selected data. The display configuration data may be saved and imported into other systems for future use. Various entities related to one or more UAVs may be presented in a hierarchical tree structure illustrating the relationship between the entities. Electronic checklists may be presented to a user to facilitate addressing common and emergency situations.

Abstract: Bi-directional personal communication systems and processes may be utilized to control unmanned systems. Such systems and processes may enable operator interface with unmanned systems as a replacement or a supplement to use of specialized hardware and rich, graphical interfaces. The bi-directional communication systems and methods also may be integrated as a subsystem within a ground control station. The system may include a personal communications device with a native interface for an operator to select command, control and/or communication (C3) messages to interact with the unmanned system, and a communication link operable to send the C3 messages selected by the operator to the unmanned system, wherein the unmanned system includes a receiver that receives the C3 messages over the communication link and an onboard computing device that processes and responds to the C3 messages received by the receiver.

Abstract: An aircraft defining an upright orientation and an inverted orientation, a ground station; and a control system for remotely controlling the flight of the aircraft. The ground station has an auto-land function that causes the aircraft to invert, stall, and controllably land in the inverted orientation to protect a payload and a rudder extending down from the aircraft. In the upright orientation, the ground station depicts the view from a first aircraft camera. When switching to the inverted orientation: (1) the ground station depicts the view from a second aircraft camera, (2) the aircraft switches the colors of red and green wing lights, extends the ailerons to act as inverted flaps, and (3) the control system adapts a ground station controller for the inverted orientation. The aircraft landing gear is an expanded polypropylene pad located above the wing when the aircraft is in the upright orientation.

Abstract: A landing alert system and method for preventing runway excursions may include determining, during an approach of an aircraft to landing on a runway, a target touchdown point on the runway, determining a boundary descent path configured to permit safe approach and touchdown of the aircraft on the runway at or before the target touchdown point, and, in response to the aircraft crossing within a selected margin of the boundary path, alerting an operator of the aircraft.

Abstract: A vehicle comprises a platform, a propulsion system, a communications system, a sensor system, and a computer system. The propulsion system, communications system, sensor system, and computer system are associated with the platform. The propulsion system is configured to move the platform on a ground. The communications system is configured to establish a wireless communications link to a remote location. The sensor system is configured to generate sensor data. The computer system is configured to run a number of control processes to perform a mission and configured to perform operations in response to a number of commands from the number of operators if the number of requests is valid.

Abstract: Disclosed is a flight control support device which sets a flight restricted area W along a terrain, thereby achieving improvement in safety of a small aircraft A and sufficiently securing the degree of freedom of flight course selection of a pilot. The flight control support device includes a terrain information acquirer, an aircraft information acquirer, a flight restricted area setter which sets the flight restricted area W along the terrain on the basis of the terrain information acquired by the terrain information acquirer and the aircraft information acquired by the aircraft information acquirer, and a flight control supporter which supports flight control of a flying object on the basis of the flight restricted area set by the flight restricted area setter.

Abstract: Present novel and non-trivial system, device, and method for generating altitude data and/or height data are disclosed. A processor receives navigation data from an external source such as a global positioning system (“GPS”); receives navigation data from multiple internal sources; receives object data representative of terrain or surface feature elevation; determines an instant measurement of aircraft altitude as a function of these inputs; and generates aircraft altitude data responsive to such determination. In an additional embodiment, the processor receives reference point data representative of the elevation of the stationary reference point (e.g., a landing threshold point); determines an instant measurement of aircraft height as a function of this input and the instant measurement of aircraft altitude; and generates aircraft height data responsive to such determination.

Abstract: The invention relates to an aircraft comprising a force transmission element which detachably connects a cabin structural segment to an aircraft primary structure and which comprises a cabin bearing element and a structure bearing element, the cabin bearing element being connected to the cabin structural segment and the structure bearing element being connected to the aircraft primary structure. The force transmission element is designed in such a manner that a force transmission can take place between the cabin structural segment and the aircraft primary structure with at least one degree of freedom of movement.

Abstract: A method, apparatus, and computer program product for identifying a number of air states for a vehicle. A deflection of a control surface associated with an actuator is identified to form an identified deflection. A current in the actuator is identified to form a measured current. The number of air states for the vehicle is estimated using the identified deflection and the measured current.

Abstract: A passenger seat assembly for a vehicle, particularly an aircraft, which is adapted to provide self-contained, individual seating and sleeping accommodation for a passenger, said seating assembly includes a supporting structure (42) for supporting said assembly off the floor of a vehicle; one or more movable, passenger-bearing, structural components (71,72); and means for connecting said movable, structural components to said structure such that said components can be selectively moved between a seat configuration, in which a plurality of passenger-bearing surfaces on said one or more structural, movable components (71,71) or said supporting structure form a seat for the passenger, and a bed configuration, in which a plurality of said bearing surfaces (47,48,67,74,76) are disposed substantially coplanarly and substantially contiguously to form a bed for the passenger; characterized in that at least one of said movable components (72) is double-sided, comprising first and second opposite sides, one of said sid

Abstract: A method and a device for an aircraft for detecting noise in a signal of LOC type. A first step includes estimating a first lateral speed of the aircraft according to a first set of parameters. Concurrently, at least one second lateral speed of the aircraft is estimated according to at least one second set of parameters, among which at least one parameter is of different nature from each parameter of the first set of parameters. A second step includes comparing the first lateral speed and the at least one second lateral speed according to a threshold. If the difference between the first lateral speed and the at least one second lateral speed is greater than the threshold, the presence of noise in the signal of LOC type is detected.

Abstract: The invention relates to a method for calculating an approach trajectory of an aircraft (200) to an airport The aircraft is slaveable in terms of trajectory, thrust and/or speed. The aircraft is able to advance at reduced engine revs. The airport has a runway The approach trajectory terminates in an impact point (205) on the runway and has a high-altitude descent segment (217) and an intermediate geometric segment (207), to which the aircraft is slaved in terms of trajectory and speed. A step of calculating a final approach segment (208) at reduced engine revs and a landing segment is performed with a greater thrust than the reduced revs so as to prepare a possible go-around (209), to which the aircraft is slaved in terms of thrust and speed.

Abstract: A system for supervising the landing of an aircraft by a supervisor in a control station, each of the aircraft being incapable of being controlled by any personnel onboard, the system comprises a control station and onboard aircraft control apparatus. The station includes an input device, responsive to the supervisor, for producing a control signal for controlling the landing of the aircraft; and a transmitting device, coupled to the input device, for communication with the aircraft. The aircraft apparatus includes a receiving device for communication with the station; a logic device, coupled to the receiving device, for controlling the aircraft which is programmed to pilot the aircraft to the vicinity of the airfield. The control signal is selected by the supervisor, based on the supervisor's observations of the aircraft and is transmitted to the logic device; in response thereto, the logic device controls the aircraft.

Abstract: Methods and systems for a position indicating display system for an aircraft are provided. The system includes a map display unit configured to display a map representative of an area being traversed by the aircraft, and an overlay comprising an own ship depiction, said overlay displayed on the map for a period of time in response to an input from at least one of a user and an aircraft sensor.

Abstract: A method of automatic piloting of an aircraft during a phase of approach to a predetermined airdrop position includes automatically applying a speed profile with decreasing speed such that the aircraft will reach the airdrop position at a predetermined theoretical arrival time with a predetermined speed, the speed profile having a plurality of constant-speed levels separated by deceleration phases. An actual arrival time is automatically determined and a difference between the theoretical and actual arrival times is calculated. If the calculated difference differs from zero, the speed profile is corrected by modifying the length lengths of time that at least two constant-speed levels are applied to the aircraft so as to cancel the difference.

Abstract: This invention relates to the concept of managing the rate of change of energy in a helicopter or other aeronautical vehicle. The invention uses energy management calculations to determine the maximum longitudinal and lateral inputs that can be made while still enabling the vehicle to maintain a desired vertical state. The results of the calculations can be cued to the pilot either tactilely, aurally, or visually, or used for internal software limiting.

Abstract: A method and system for providing a bearing from a vehicle to a transmitting station are described. The method includes accessing a database to obtain transmitter position information for the transmitter, obtaining vehicle position information based on a GPS signal, and generating the bearing from the vehicle to the station utilizing the transmitter position information and the vehicle position information. The system includes a database storing transmitter position information identifying a position of the transmitter, a GPS receiver obtaining vehicle position information identifying a current position of the vehicle based on a GPS signal, and a controller generating a bearing from the vehicle to the transmitter utilizing the transmitter position information and the vehicle position information.

Abstract: A method and system for alerting an aircrew of terrorist activity in a cabin of an aircraft. When a terrorist or emergency situation is detected by a flight attendant, the flight attendant speaks an activation word, which turns the personal alert unit to an active mode. The flight attendant then says one or more specific words stored as a vocabulary within the personal alert unit. Upon recognition of a spoken word stored in the personal alert unit, the personal alert unit converts the recognized word or words into a signal sent to the cockpit via the ASU to the CDU. The CDU provides an indicator to the cockpit crew of the recognized words spoken by the flight attendant.

Abstract: An energy systems management method includes steps of providing a hierarchically arranged, interrelated set of synoptic displays interfaced to an energy system for receiving information from and providing command inputs to the energy system. One synoptic display of the set of synoptic displays is an overall energy synoptic, and the other synoptic displays of the set of synoptic displays are synoptics displaying the status of corresponding energy systems. The method also includes steps of acquiring human inputs through the synoptic displays, for example, by means of a computer user interface device, and controlling the energy system by processing the human inputs through the synoptic displays to provide command inputs to the energy system.

Abstract: A terrain avoidance system, method and computer program product for reducing nuisance alarms. The system includes a geometric altitude component, first and second vertical safety margin generators, and an alert component.

Abstract: A robotic or remotely controlled flying platform (10) with reduced drag stabilizing control apparatus constructed having an air duct (12) with an air intake (14) on the top and an exhaust (16) at the bottom, containing supported therein a clockwise rotating fan (22) and a counter-clockwise rotating fan (24). Directly below the perimeter of the air duct exhaust are mounted a plurality of trough shaped air deflection assemblies (32) each including a rotatably adjustable half trough (44) for selectively scooping a portion of the drive air, and a stationary adjacent half trough (36) for receiving the scooped drive air and redirecting it outward and upward from the air duct.

Abstract: The present invention relates to a method and a device for guiding an aircraft (A) according to a prescribed vertical flight path (T).According to the invention:the vertical distance he between said aircraft (A) and said flight path (T) is determined;the difference ve between the actual vertical velocity (Vz) of the aircraft (A) and the vertical velocity (Vzth) which it would have on the flight path (T) is determined;a vertical acceleration variation Anz is calculated:.DELTA.nz=((k1.(he-hc))+(ve-vc)).k2k1 and k2 being characteristic coefficients, hc and vc being precontrol terms, and k1.(he-hc) being restricted; andsaid restricted variation Anz is applied to the aircraft.

Abstract: A self adaptive limiter for use in aircraft control systems during approach and landing is disclosed. Estimated flight path angle is continuously computed during the glidepath tracking phase until a predetermined lock altitude above ground when a nominal flight path angle is latched. Nominal vertical speed is continuously computed below the lock altitude as a function of the latched nominal flight path angle and ground speed of the aircraft. A vertical speed limit function is generated as a function of the nominal vertical speed and radio altitude. During approach and landing a pitch limit is computed from the vertical speed limit, vertical speed, ground speed, and pitch. When a pitch command to the autopilot exceeds the pitch limit(i.e. commands excessive pitch down attitude), it is limited to the pitch limit thus preventing the aircraft from descending below a safe altitude.

Abstract: A portable holder for holding containers for feeding a product from the container to the human body such as intravenous feeding or colon flushing in which the holder is strapped to the upper torso of the human body. Being strapped to the body, it enables the person to be mobile without having to push along a cart or a stand. It also gives the person an unlimited range since the container goes with the person.

Abstract: An automatic landing system for guiding an unmanned aerial vehicle along a predetermined path to a predetermined point on the ground. The system includes an image processing means resident in the motion compensation processor that computes aerial vehicle parameters. The computed parameters are altitude, changes in altitude, changes in pitch and yaw angles, roll angle and changes thereto, and changes in cross range and down range position. These computations are based on the movement of elements in the video of an imaging sensor onboard the aerial vehicle. The motion compensation processor also measures the distance (in pixels or picture elements) between two beacons placed a known distance apart on either side of the apparent touchdown point. A recovery control processor uses these parameters to compute both desired and actual altitude as a function of range from the vehicle to the apparent point of touchdown and to provide offset error in azimuth from the desired flight path to the landing area.

Abstract: An aircraft control system for computing a yaw compensated angle of attack is disclosed. The system includes an angle of attack sensor for generating a signal which represents an aircraft's angle of attack as determined by an angle of attack vane and a transverse accelerometer for generating a signal in response to the lateral acceleration of the aircraft. A summing device sums the two signals to thereby provide a yaw compensated angle of attack signal. The system may also include a rudder deflection sensor for generating a signal which represents the deflection of an aircraft's rudder. The rudder deflection signal is then subtracted from the yaw compensated angle of attack in the summing device. A stall warning system incorporating the yaw compensation system includes a stall warning computer for comparing the yaw compensated angle of attack signal to a predetermined value.

Abstract: An aircraft autoland flare control system which augments the autopilot's aircraft flare control commands in the event the aircraft exceeds defined flare envelopes, monitors aircraft longitudinal position, altitude, altitude rate, lateral position and lateral position rate during flare, and outputs commands to correct aircraft position thus minimizing touchdown dispersion in both the longitudinal and lateral axes. When the aircraft deviates from the flare envelopes, such as may be due to extreme atmospheric conditions such as wind gusts, a signal commanding pitch or roll correction is output to the pitch or roll control loop which subsequently acts to adjust aircraft position such that the aircraft's flarepath is returned to within the flare envelopes.

Abstract: A path indicating apparatus for indicating a path so that a moving vehicle movable in the horizontal and vertical directions, such as an aircraft, may move along such a predetermined path. The predetermined path is defined as an intersecting line of two scanning planes which are formed by scanning signals having a narrow beam width in a horizontal plane and a vertical plane, respectively. The vehicle is provided with a plurality of detectors arranged in the horizontal and vertical directions for detecting the signals being scanned in the horizontal and vertical planes, respectively, so that the detectors arranged in the vertical and horizontal directions may detect deviation of the vehicle in the horizontal and vertical planes, respectively. The vehicle is responsive to the detected signals from the respective detectors to determine the moving direction to be taken by the vehicle so that the vehicle may move along the path and the vehicle is steered responsive to the determined direction outputs.

Abstract: The present invention deals with a flight control process and device for an aircraft approach and landing. More in particular, the invention in use simulates ILS by using an infrared radiation source at the desired landing site. The invention comprises the steps of determining an axis defined by the infrared radiation source, forming a predetermined guide slope line with respect to the horizontal and oriented according to a determined approach magnetic heading, recording the aircraft position with respect to the source, determining the angular deviations in azimuth and in elevation of the sighting axis with respect to the said glide slope line, and operating the aircraft flight controls to return said deviations to zero.

Abstract: Flight path angle is displayed relative to the aircraft reference indicator in a unique display and aircraft control system particularly useful during approach operations. Flight path angle is computed as a function of vertical velocity of the aircraft and air speed. Angle of attack is displayed as an angle relative to the flight path angle and is derived by computing the difference between pitch and flight path angle. Thrust command is displayed vertically relative to the aircraft reference indicator while heading command is displayed laterally with respect to the aircraft reference indicator.

Abstract: Method and apparatus for providing a helicopter with a decelerated approach owards a landing site. An MLS system provides the aircraft with azimuth, elevation, range and range rate information. The aircraft flies towards the approach path and once it is acquired, the aircraft is decelerated until a predetermined range rate is achieved, typically 40 knots, at which point the aircraft's heading is frozen and further corrections to the aircraft's lateral position are made by exclusive use of lateral roll commands.

Abstract: 1. A system adapted to guide an aircraft along a path defined by frequency modulated signals of a transmitted conical scan pattern, comprising a receiver carried by said aircraft to receive said signals, means to detect from said signals and the amplitude modulation of said signals caused by the movement of said aircraft relative to the axis of said conical scan pattern any rate of change of the direction of movement of said aircraft with respect to the nutation axis of said conical scan pattern, and means responsive to said detected rate of change to direct the movement of said aircraft along a path within said conical scan pattern defined by any line of constant scan modulation.