United Technologies Corporation

Hamilton Sundstrand Corporation

Otis Elevator Company

John E Games

William W Bitterli

Michael W Hmelovsky

David M Healey

Mark A Johnston

Douglas A Parsons

Howard Simmons

Gerald L DePardo

Paul A Carvalho

Douglas P Modeen

Kirk Sumner Walworth

Raymond C Perra

Henry E Martin

Norman J Faust

Richard L Bonnanzio

Richard E Rosien

Stephen B Wilmot

A signal conditioning circuit time share multiplexes anti-aliasing filters and an A/D converter. A plurality of first tier multiplexers each time share multiplex one of a plurality of antialiasing filters between a plurality of AC or baseband input signals from a plurality of sensors. A second tier multiplexer selects its inputs from the outputs of the first tier multiplexers. The output of the second tier multiplexer feeds a high speed A/D converter. Thus, the A/D converter is time share multiplexed by the second tier multiplexer. In this manner, a plurality of sensors can share a single A/D converter. After allowing a settling time for the multiplexers and antialiasing filters, a plurality of samples of the input signals are taken, such as for one period. The samples of each AC input signal are multiplied by a sine vector and a cosine vector. The product vectors are then each averaged and the root mean square of the two averages yields the magnitude of the input signal. Mechanical angle of the input signal can be determined based upon the sign of the sine and cosine product vector averages.

Method and apparatus for sampling and converting a signal

Multiplexed signal conditioner

A system for controlling an electric motor includes a controller and a position indicator that provides position information regarding at least one motor component to the controller. The controller utilizes phase relationships indicative of the position information to determine the actual position of the component of interest. The phase information in one example is derived from the output of a resolver that provides two output signals corresponding to sin (&#x3b8;) and cos (&#x3b8;), where &#x3b8; is the angular position. Utilizing the phase relationship simplifies the task of determining accurate position information that is useful to modify motor control signals to compensate for latency when making position determinations, velocity calculations or both. The inventive system makes it possible to use less expensive electronics to arrive at more reliable results.

Electric motor control system including position determination and error correction

A commutation and velocity control system of a brushless DC motor receives a velocity command signal and provides command signals to drive the brushless DC motor. The system includes a summer that receives the velocity command signal and a velocity feedback signal and provides a velocity error signal indicative of the difference. A velocity loop compensator receives said velocity error signal and provides a compensated velocity error signal. A magnitude sensing circuit senses the magnitude of said compensated velocity error signal and provides a velocity magnitude signal indicative thereof. A polarity sensing circuit senses the polarity of the said compensated velocity error signal and provides a velocity polarity signal indicative thereof. The system also includes an integrated circuit having: (i) a velocity calculation circuit that receives a first sampled digitized signal indicative of resolver position at a first time and a second sampled digitized signal indicative of resolver position at a second time, and determines velocity based upon the difference between said first and second sampled digitized signals and provides a sensed digitized velocity signal indicative thereof; (ii) a commutation logic circuit that receives said first sampled digitized signal, said velocity magnitude signal and said velocity polarity signal, and provides said command signal; and (iii) a counter that receives a signal indicative of said sensed digitized velocity signal and provides a pulse width modulated output signal indicative thereof. A filter receives said pulse width modulated output signal and generates said velocity feedback signal.

Commutation and velocity control system for a brushless DC motor

A method of testing an actuation system for positioning an actuator, the actuation system including a primary electronic system, a secondary hydro-mechanical system is disclosed. The method includes the steps of measuring the actual position of the actuation device as set by the primary electronic system; measuring the system inputs and computing an ideal actuator position based thereon; determining the difference between the actual actuator position and the ideal position. The difference is then compared to a first threshold value which represents a disturbance beyond which the system cannot safely operate. Control is transferred from the primary control to the secondary control if the difference exceeds the first threshold. If the difference is less than the first threshold, the difference is compared to a second threshold value which represents an operating condition that can be tolerated for a period of time. Control is transferred from the primary control to secondary control if the difference exceeds the second threshold for longer than the time period.

Robust engine variable vane monitor logic

Pitch change for a variable pitch propeller or fan of the type utilized in a gas turbine engine is effectuated by the unique application of a bidirectional electrical induction AC motor and an electrical DC induction brake operatively connected to the pitch change actuator. The motor can be utilized in a slip speed range encompassing from a positive slip speed to zero slip speed and negative slip speeds which removes the limitations on the gear ratio.

Propeller pitch change machanism with inductive brake and motor

A engine control system for helicopters and the like in which free turbine speed is isochronously controlled by a more robust control system having increased bandwidth due to loop architecture and filter implementation accomplished via closed loop control. Dual notch (feedback compensation) is used with design forward path compensation, including variable lead/position of the lead, variable gain and implementation of integrator/proportional. Superior transient control is achieved by the use of a multi-loop governing design using different error compensations when on 'NF' loop control and when not on 'NF' loop control, and with 'bumpless' inner loop reference by the combination of compensation switching and re-initialization of a common integrator. Parallel select logic with dynamic compensation is used separating the system control loops and the selection process of the controlling functions, as they pertain to the application of control loops designed form small signal stability to large transients. A torque loop limitation as a direct function of the speed loop gains provides a predetermined limit to the governed speed excursion in the event of an in-range failure of the torque signal, or an unannounced fail fix on one engine or system of the twin engine application.

Control system for gas turbine helicopter engines and the like

Recurring data sample values of a common parameter are stored in nonvolatile memory at different addresses so as to limit the maximum number of entries at any one location to less than that which results in loss of storage ability.

EAROM and EEPROM data storage management

An elevator system has a microprocessor-based cab controller mounted directly on the elevator car, the elevator door mechanism is connected to a transducer which provides signals as a function of the position of the door mechanism, and the cab controller controls the door motion in a closed loop manner by providing door command signals to the elevator door mechanism in dependence upon the deviation of the present door velocity from a current value of a dictated velocity in accordance with a desired door traverse velocity profile which includes desired increasing and decreasing rates of acceleration and deceleration, and desired maximum velocity, acceleration and deceleration. The disclosure includes a typical elevator system, an exemplary cab controller, and an exemplary door control program flowchart as an environment for the present invention, in addition to details concerning the invention.

Time controlled elevator door motion

An elevator system includes a microprocessor-based cab controller mounted directly on an elevator car, which controls the operation of the elevator door. Elevator door motion is commanded in response to the difference in actual door velocity from a desired, dictated door velocity in accordance with desired rates of acceleration and deceleration, maximum velocity, acceleration and deceleration, the point at which deceleration is to begin, and a velocity at which deceleration is to decrease. The disclosed invention provides selective modification in maximum velocity along with the point at which deceleration is to begin, the velocity at which deceleration is to decrease along with the point at which deceleration is to begin, and/or simply the point where deceleration is to begin, so that door velocity profiles may be tailored to suit any particular door of a given type. An exemplary environment for and details of the present invention are disclosed.

Elevator door motion modification

An elevator door motion control is operative in either of two modes, the first mode being set in the case where door motion begins with the doors fully open and closed and no special conditions, such as initiation, exist. In this mode, door motion is controlled as the difference between door velocity and a dictated velocity in accordance with desired rates of acceleration and deceleration, and desired maximum velocity, acceleration and deceleration. The second mode of operation takes into account initiation at start-up, door reversals, nudging commands, high force conditions created by obstructions, and resumption of door motion following stall, other than when the door is either fully open or closed in stall. In the second mode of operation, the door is commanded by the difference between its present velocity and a dictated velocity which is selected as the lesser of an acceleration to a maximum desired velocity and a function of the distance of the door remaining to a target distance. As an environment for the present invention, an exemplary elevator system and microprocessor-based cab controller mounted directly on the elevator car, a general door control program logic flowchart are disclosed, together with details of the invention.

Elevator door motion mode control

A terminal reheat HVAC system which regulates the temperature in a plurality of temperature controlled spaces by modulating the temperature of cool discharge air presented to each of the spaces from an air handler source, each space receiving the cool discharge air through an associated space distribution unit which includes heating apparatus supplied from a common heat source for reheating the cool air to provide temperature regulation within the space in response to a space temperature error signal from an associated space temperature control, is controlled by electronic processing means in combination with dedicated sensing and control apparatus which provide actuation of the air handler and common heat source only in response to actual sensed space temperatures outside of a temperature band established by heat and cool temperature reference signals stored in the electronic processing means, the electronic processing means further providing modulation of the cool discharge air temperature from the air handler, following actuation in response to an actual sensed space temperature higher than the cool temperature reference, in dependence on the temperature difference between the actual space temperature and the cool reference.

Energy conservative control of terminal reheat heating, ventilating, and

Apparatus is provided for controlling, during unoccupied periods, the operation of an HVAC system and perimeter heating system providing hot air and hot fluid, respectively, to a temperature controlled living space having occupied and unoccupied periods, the apparatus including an electronic processing means in combination with dedicated sensing apparatus, the apparatus providing controlled actuation of the HVAC and permieter heating system in dependence on the temperature difference between an actual space temperature signal and unoccupied space heat and cool reference temperature signals, the apparatus further providing an optimum start-up procedure including simultaneous actuation of the HVAC and perimeter heating system to accelerate the heating of the space, the HVAC discharge temperature being modulated during the start-up procedure in dependence on the temperature difference between the actual space temperature and an occupied space heat reference temperature signal, the perimeter heating system discharge temperature being preset to a start-up reference discharge temperature having a value greater than that maximum perimeter heating system discharge temperature permitted in normal operation.

Temperature control of unoccupied living spaces

A central control system includes a central processing unit (CPU) installed in a central location of a facility, and interconnected with a plurality of remote controllers, each located in an associated one of several buildings in the facility and each including a remote microprocessor (RMP), the CPU automatically controlling, simultaneously from the central location, the closed loop operation of individual environmental conditioning systems in the several buildings comprising the facility in combination with the RMP associated therewith and in dependence on the sensed temperature conditions within the living spaces associated with each system. The CPU includes a keyboard responsive to operator control for receiving selected parameter reference values provided by the operator at the central location, the reference values establishing the closed loop gains and reference temperatures for the individual environmental systems, the reference values being instantaneously changeable by the operator in one, or all of the environmental systems to accommodate changes in operating conditions. The central control including two CPUs, each fully capable of providing automatic control of the facility environmental conditioning systems in combination with the RMPs, the system further including redundant interconnecting lines between each CPU and the plurality of RMPs, each line including a liner receiver for each RMP, to provide the simultaneous control of the closed loop operation of the individual environmental conditioning systems in each of the buildings in such a manner as to provide fail-safe control of each from the centralized location.

Growing community of inventors

Granby, CT, United States of America

John E Games