Abstract: A plurality of silicon pressure transducers 10 are formed by processing two conductive silicon wafers 11, 14, one of the wafers including a layer of borosilicate glass 32, a thin portion of which 17 is on the surface 12 of one of the plates of a capacitor formed by field-assisted bonding together of the two wafers, the thin layer of borosilicate glass avoiding arcing during the field-assisted bonding process.

Abstract: For each of two computer systems, logic flowcharts describe background program in which highly detailed memory checksum tests of fixed memory and complementary tests of variable memory are performed, the background program being interrupted for utility programs which are for the most part responsive to transducer or other sensor and discrete inputs to calculate control values for operation of control actuators or other responsive devices. The utility programs include specific self test routines. A direct memory access unit is included in each computer for moving data between inputs of either computer and memories of both, and between the memories of both computers. Periodic testing of fault codes registering the health of each computer is done during utility program routines, any variation from normal causing further health-analysis routines to be performed until dispositive action-causing conditions are determined.

Abstract: A silicon capacitive pressure transducer 34 comprising two wafers of silicon 14, 32 separated by borosilicate glass 18, 21, one of the wafers 14 having a borosilicate glass pedestal 26 thereon which is metallized 30 to provide one plate of a capacitor, the other plate of which is the surface of one of the silicon wafers 32. The distance between the upper surface of the glass pedestal and the lower surface of the silicon wafer is defined by a portion 18 of the borosilicate glass, the portion 21 of borosilicate glass being the same height as that of the glass pedestal 26. An embodiment of a transducer 34b employs a silicon pedestal 26b, wherein the glass portion 21b only provides separation of the silicon wafers 14b, 32b with lower parasitic capacitance.

Abstract: An elevator system employs a microprocessor-based group controller to control the service of a group of elevator cars to a plurality of floor landings in a building. The group controller includes zone-control type operation, including up peak traffic handling, down peak traffic handling, and distributing of cars around the building during periods of low traffic or no demand, when in a cars-to-floors mode of operation. The group controller can assign any unanswered call to any car in the builing, in dependence upon factors relating the desirability of assigning any call to a car, in a calls-to-cars mode of operation. The group controller is in the cars-to-floors mode of operation whenever there is up peak traffic conditions, down peak traffic conditions, or no registered hall calls, provided that the cars-to-floors mode of operation cannot be entered into as a consequence of no registered hall call until at least one car is located at the lobby.

Abstract: An aircraft automatic flight control system having a roll channel (FIG. 1), a yaw outer loop trim system (bottom of FIG. 2) and a yaw stability inner loop (top of FIG. 2) provides proportional (129) and integral (114) lateral acceleration inputs to the yaw trim system (106, 93) during coordinated turns, and provides proportional (130) and lagged (131) roll rate inputs to the trim system to provide initial coordination to the turns.

Abstract: In an aircraft automatic flight control system, a flight path controlling, full authority outer loop actuator (37) operated in response to the integral (41) of commands thereto, is shutdown (111, 113-115) in response to the sensing (31, 32) of force on the related pilot control member (27). After removal of force (118), the outer loop is continued to be shut down for a time interval (119) to allow the aircraft to resettle toward the trim point before building up error in the integrator, unless high input demand (122) is indicated.

Abstract: In an aircraft automatic flight control system (FIG. 4) the application of force to a control member (35R, FIG. 5) forces (222, 216, 217, 212, 213) the flight path controlling, full authority outer loop to be disengaged. Once disengaged by force, the outer loop remains disengaged (224) until force is removed (225) and a signal indicates (226) a need to reestablish the outer loop. Reestablishment may be indicated by beeping (228) or by the controlled attitude (54R, 55R) being restored to within a predetermined level (230).

Abstract: In an aircraft automatic flight control system, proportional commands (54, 55) provided to fast, limited authority inner loop actuators (12, 13) are integrated (41), and when the integrator output indicates that the inner loop actuators 12, 13 have been driven a certain percentage of their authority, a comparator (130, 132) activates a pulse generator (137, 138) to provide timed excitation of an actuator (150), thereby to position the aircraft control system outer loop by a commensurate increment. Driving the actuator for a longer time than the desired pulse width is detected (165-169) and causes automatic shutdown (190) of the actuator. Resetting the integrator at the start of each pulse (162, 104), and pulse-controlled gating of the pulse circuits (172, 135, 136) allow sensing of authority transitions which occur within a pulse, and permit a subsequent pulse in response thereto.

Abstract: An aircraft automatic flight control system includes a pair of fast, limited authority inner loop actuators (12, 13) responsive to signals (52-55) indicative of aircraft attitude (68, 69) or other flight parameters such as airspeed (84), the inner loop being recentered by an outer loop actuator (37) responsive to attitude or other aircraft parameter-indicating signals (54, 55). Commands (40) applied to the outer loop are applied in a lagged fashion (58, 59) in opposite direction so as to drive the inner loop actuators (12, 13) back toward the center of their authority. The rate of response of the outer loop (FIG. 2, FIG. 5) is adaptive in dependence upon airspeed (93, 96, 212, 213) and in response to magnitude of inner loop input (101, FIG. 2). An integral gain (41), pulsed (39), open loop drive of the outer loop actuator (37) and outer loop automatic shutdown (38) are disclosed.

Abstract: In a helicopter automatic flight control system having both automatic pitch attitude retention (70, 71) and automatic airspeed hold (84) and responsive both to pitch attitude error (206) and integrated (241) airspeed error (230), saturation of either the attitude error or integrated airspeed error circuitry is avoided by sensing (171) integrated airspeed error buildup to a threshold magnitude (which may be a significant fraction of the instantaneous authority of the automatic flight control system), and causing (169, 167) automatic slewing of the pitch attitude reference signal toward the current pitch attitude and reduction of the integrated airspeed error. In a disclosed embodiment, the correction of attitude reference and reduction of airspeed error is effected by utilizing an equal effective time constant (220, 221; 258, 259) for both actions over the same period of time (170, 168, 175).

Abstract: In an aircraft automatic flight control system (FIG. 1) beeping of the reference voltage in attitude synchronizing and beeping circuits (70, FIG. 4; 70R, FIG. 6) is inhibited (196, 201; 278, 282) in response to proportional commands (54, 55; 54R, 55R) in excess of a predetermined magnitude (183-186, 283-286). Beeping is inhibited only in the direction of the high proportional command, but not in the other direction. In a dual system (FIG. 1) pitch attitude beeping is inhibited only if both channels of the system have excessive proportional commands (195, 200, FIG. 3) whereas roll attitude beeping is inhibited if either channel has excessive proportional command (294, 295).

Abstract: A bias voltage, which can be added to force commands applied to a helicopter control stick actuator, to compensate for static null offset errors, is generated as the average of the summation or integral of actuator pressure, or pressure differential, sensed while the force is moved from a first position which is halfway aft through null to a second position which is halfway forward and back through null to the first position, the pressure readings which are averaged being taken only through the central portion of the motion, the motion being controlled to be extremely slow compared to normal permissible stick motion.

Abstract: A helicopter pitch axis autopilot system, including airspeed hold at cruise speeds and pitch attitude hold below cruise speeds, includes integrated longitudinal acceleration drift corrected by heavily filtered Pitot static airspeed as a filtered airspeed reference, use of a beeper to nudge the airspeed reference above cruise speeds or the pitch attitude reference below cruise speeds, resynchronizing of airspeed reference, pitch attitude reference, pitch autopilot integrator and stick trim position reference, momentarily in response to airspeed transitions between cruise and sub-cruise speeds or in response to initiation of beeping, and continuously during trim release.

Abstract: A multi-elevator system operable in response to a group controller (FIG. 1) operates in a first phase (FIG. 9) in which each car is selected in a sequence to be run in a first phase (FIG. 4) in which each car is commanded to run to a designated landing (FIGS. 5 and 6). When an attempt has been made to recover all cars (30, FIG. 9; 22, FIG. 8), a second attempt is made, if necessary (28, FIG. 9; 11, 13, 15, FIG. 8). Then, in a second phase, cars are selected on a priority basis in which the highest level are cars with firemen in them or cars not at a designated landing (8, FIG. 10). A second priority level includes cars designated as preferred by the customer (22, FIG. 10) and a third level includes any available car (29, FIG. 10). Any car not recovered is caused to become available (10, FIG. 3) for selection (8, FIG. 10) on a periodic basis, the priority level section automatically deselecting one of the service cars for operation so as to permit selecting the unrecovered car for operation.

Abstract: The foldable rotor blades (12) of a helicopter are automatically adjusted to pitch angles where they can be locked as a prerequisite to folding, by commands generated (98, 112) to cause trim actuators (39-41) to drive swash plate servos (17-19) to the correct positions, initially (98) in response to stored trim references (120) and eventually (112) in response to the difference (109) between stored swash plate servo positions (120) and current servo positions (20-22). A claimed embodiment uses values of servo positions (20-22), just before unlocking the blades upon re-spreading them, to store, in nonvolatile memory (138), deviations (131) from nominal positions stored in read only memory, and generates (159) trim references in a subsequent folding operation in response to integrated values (166) to reduce actual position errors (162) toward zero from desired positions indicated by the stored deviations (148).

Abstract: In an automatic flight control system (FIG. 1) an airspeed control engage function (84) is automatically engaged (136, FIG. 2; 244, FIG. 4) in response to airspeed above a threshold magnitude, such as 45 knots (88, FIG. 2) and will remain engaged (subject to a fault condition, 135) until the airspeed command (75) reaches a predetermined, insignificant magnitude (132). An airspeed error integrator 241 which accommodates the difference between a reference attitude and an attitude required for a reference airspeed, does not react to large airspeed errors as a consequence of pilot maneuvering due to pilot force on the control stick (35, 109) opening the input (252, FIG. 4) to the airspeed error integrator.

Abstract: In an aircraft automatic flight control system (FIG. 1) having an airspeed controller (84), the engagement of the airspeed control function (244, FIG. 4 ) is initiated (123, FIG. 2 ) only in response to airspeed being greater than a 45 knot threshold (88). But once the speed threshold is attained, should the pilot override the airspeed control by applying force (35, 109) to the pitch attitude controller, airspeed engagement is retained (122) until a small airspeed error (126) indicates that the system has substantially regained the reference airspeed.

Abstract: The engagement (83) of a flight director (82) that provides automatic steering by roll angle of an aircraft which includes an automatic yaw trim system (FIG. 2) that will automatically coordinate turns induced by the flight director establishes (155, 157, 138) a heading hold disengagement mode which is maintained even if the flight director becomes disengaged (160) until the aircraft roll attitude is indicated as being nearly level (163). Exemplary roll channel (FIG. 1) and yaw channel (FIG. 2 ) of an automatic flight control system which may incorporate the invention are disclosed.

Abstract: In an aircraft automatic flight control system (FIG. 1) having pitch attitude synchronizing and beeping circuits 70-71 and airspeed control circuits 84, trimming of airspeed (233, 165) is achieved by beeping (104) or releasing trim (45) to adjust the pitch attitude synchronizer reference (208), causing the airspeed reference (232) to be synchronized (233, 165) for 25 seconds (156), unless the pilot applies force to the longitudinal axis (31, 32, 35) of the cyclic pitch stick (27), which causes (160, 156) termination of airspeed synchronizing.

Abstract: A mechanical scanning apparatus adapted for oscillating the focus zone of a beam of radiation having high power to modify and control the nature and extent of the interaction zone on a workpiece is disclosed. The apparatus includes a compound beam adapted for being vibrated in a vibratory mode resulting in oscillatory motion of at least a first end of the compound beam; a reflective surface attached to the first end of the compound beam and adapted for focussing radiation incident thereon to a focus zone, and means for vibrating the compound beam to induce oscillatory motion of the reflective surface resulting in oscillatory motion of the focus zone. For vibration frequencies greater than the characteristic thermal response time of the workpiece material, the effect is a broadening of the interaction zone with a beam-material interaction characteristic of a reduced incident average power intensity while maintaining a high local intensity essential to the establishment of effective radiation-material coupling.