Abstract: The invention concerns an open-look speed control device for an induction motor to drive an elevator cabin, approaching a premarked where braking must be initiated point in advance of stopping at a marked point at a floor level to be approached at a creep speed, and for a VVVF inverter, which supplies current to the induction motor.The current supplied to the induction motor, is measured when the cabin travels at constant speed prior to reaching the premarked point.A slippage compensation unit determines a pertinent slippage frequency from the measured active current, and from it derives the frequency specification for the upcoming creep phase. A memory stores a function that indicates creep time as a function of the measured active current.A computer unit calculates a delay time for the next run from the measured creep time.

Abstract: Elevator door chain contacts are isolated from the safety chain in a separate circuit, thus enabling the use of a separate door chain coil for independently checking the status of the door chain itself and for enabling the remainder of the safety chain. The status of the door chain itself may be checked to make sure the doors are all closed when they should be. If it is determined the door are not all shut, the car door may be cycled open and shut in an attempt to correct a possible problem at the landing. The individual hoistway door contacts in the door chain may be checked, one at a time, while the car doors are fully opened at each particular floor to make sure that the door chain is not being incorrectly shorted, i.e., to make sure the hoistway door switch contact at the particular floor is opening when it should. A checking contact may be wired into the door chain and used to selectively open circuit the door chain to ensure that the door chain coil is not directly shorted to the power supply.

Abstract: Data is communicated between redundant channels formatted in blocks having an initial command word followed by a destination code, starting address and a variable number of data words including a word count. The blocks are transmitted between each channel and all of the channels over cross-channel data links, each channel receiving the data blocks and determining the validity thereof by counting the number of data words received and comparing that number to the word count transmitted for that block. An interrupt signal indicative of invalidity of a block is provided in the event of a miscompare. A stop address is generated for each block received for storage at the start address. A memory address is generated for each valid word received for storage in sequence starting immediately after the start address. The next block received has its start address placed immediately at the end of the previously received block.

Abstract: Start jerk and acceleration overshoot on elevator starting are reduced by bypassing and delaying application of an elevator closed loop velocity control system. A bypassing starting torque increases the torque of the motor before the onset of motion, at which time the starting torque is leveled off and held constant and the velocity speed reference profile is started. A small creep velocity dictation injected into the closed velocity loop in addition to the starting torque command causes the difference between the speed profile and the sensed speed to be very small during starting. Moreover, by selecting lift brake current in such a way as to promote a smooth brake opening and by selecting an increasing starting torque profile which overcomes the declining brake torque just after the brake begins to open, the torque needed to compensate for the load can be evenly balanced with the release of brake torque.

Abstract: The invention teaches determining position with light by providing amplitude modulated input light at an input light port of an optical cavity having a variable length dimension, detecting light at an output light port of the optical cavity and varying the frequency of amplitude modulation until a peak is detected. The maximizing frequency can then be related to the length of the cavity. The cavity may comprise an optical fiber inserted into a variable length cavity filled with a liquid having an index of refraction which matches that of the fiber. Mirrors may be placed at either end of the cavity.

Abstract: Images are provided to a pilot in an aircraft overflying the earth by means of a helmet mounted display system. The position and attitude of the aircraft with respect to the earth and the attitude of the helmet with respect to the aircraft are monitored in order to convert a plurality of stored earth position signals into helmet coordinates. Earth points which are viewable by the pilot are displayed using symbolic images thereof such that the symbolic images coincide, from the pilot's point of view, with the actual positions of the viewable points on the earth.

Abstract: A simplified elevator power system using an AC-DC converter, both to convert AC to DC during normal operation and to convert stored DC power to AC during power failures. A power source monitoring relay monitors AC power coming from a utility, and upon power failure, switches a battery from a charging mode to a power source mode wherein DC power is supplied, not only to an inverter for driving a motor, but also to a converter hooked up to run as an inverter during such power failure in order to provide stepped-up AC voltage to elevator control devices. In this way, the prior art addition of an extra inverter is avoided.

Abstract: A reduced instruction set computer (RISC) with a Harvard architecture is disclosed. The RISC may be designed to be used simply as a RISC or may be designed to be used to emulate a complex instruction set computer (CISC). Or, it may be designed for use as either. A CISC design methodology is disclosed whereby a RISC is designed and fabricated and whereby RISC emulation code is written concurrently with design and fabrication and also subsequent to fabrication.

Abstract: In an elevator provided with an inverter driven induction motor, output torque is determined by direct current of an inverter, slip frequency is determined from the thusly determined torque, the gap between an open-loop dictated speed pattern and the actual speed is compensated by the slip calculated during acceleration and constant speed movement, so that the open-loop control may be improved in terms of stop position precision.

Abstract: Tasks may be planned for execution on a single processor or are split up by the designer for execution among a plurality of signal processors. The tasks are modeled using a design aid called a precedence graph, from which a dependency table and a prerequisite table are established for reference within each processor. During execution, at the completion of a given task, an end of task interrupt is provided from any processor which has completed a task to any and all other processors including itself in which completion of that task is a prerequisite for commencement of any dependent tasks. The relevant updated data may be transferred by the processor either before or after signalling task completion to the processors needing the updated data prior to commencing execution of the dependent tasks. Coherency may be ensured, however, by sending the data before the interrupt.

Abstract: In an elevator, an electric motor is connected to a brake through a gearbox. The brake is controlled with an electromagnet. A torque signal is applied to the motor. Brake voltage characteristics are used to detect actual brake engagement and to signal a switch to substitute a decaying torque control signal to the motor for the motor torque signal supplied to the motor while the elevator is moving. Motor torque is thereby gradually rather than suddenly reduced to zero.

Abstract: A training or servicing kit comprises a portable electronic simulation of an apparatus, the simulation including manually operable means to sense and/or control parameters of the simulation, and a computer with associated software serving in use to lead an operator through a training or servicing programme in dependence upon the values of parameters determined by the operator by means of the manually operable means.

Abstract: Arbitration access to an IOC's RAM between the IOC's I/O bus and a signal processor is accomplished by always granting the signal processor access to the IOC's RAM for one machine cycle and disallowing any signal processor operations which would otherwise permit preemptive demand access to memory for more than one machine cycle. The signal processor's activity is then monitored for detecting the signal processor engaged in an activity which does not presently require access to the IOC's RAM and which will occupy the signal processor in a non-memory access activity for a predictable period of time. The IOC's I/O bus is then granted access to the IOC's RAM for a period of time less than the predicted period. In addition to this transparency feature, the present invention may be used in a context of a unique method of transferring data between sensors and actuators on one side of the IOC and the signal processor on the other side.

Abstract: A method and apparatus is disclosed for generating thyristor gating signals for a force commutated inverter in order to produce variable frequency pulse-width modulated output waveforms with the appropriate percent fundamental voltage content for reactive power control and with the correct phase relationship to the utility line for real power control. A signal processor in conjunction with a memory is used to store individual patterns for generating a wide variety of PWM waveforms at different frequencies over the entire modulation range so as to provide the designer with the flexibility to select the most advantageous harmonic cancellation for each operating point. An embodiment of the invention .disclosed uses three microprocessors to generate the PWM waveforms and a fourth microprocessor to synhcronize the other three and produce the required phase shift.

Abstract: A plurality of trapezoidal wedges in a channel for retaining a PCB heat sink are held in place by spring force provided by a compression spring inside the bottom end wedge. The compression forces provided by the spring are mainly effective to prevent twisting of wedges on the absence of a heat sink and to provide at least some degree of heat transfer between the heat sink and the chassis even if the responsible technician neglects to torque down the wedges.

Abstract: A plurality of n-dimensional modular entities are internally interconnected via as many as n duel port random access memory devices (DPRs), each memory device dedicated solely to the interchange of information between two modular entities in an n-dimensional lattice of modular entities. One or more of the modular entities may itself be a separate multiprocessor architecture.

Abstract: A star-connected sensing resistor at the A.C. output side of a PWM inverter detects an output voltage across the resistor, a PWM control according to the invention then amplifies the detected voltage, compares the amplified voltage with a sine wave voltage command signal, amplifies the compared output in a P-I amplifier having a definite gain for a D.C. current, compares the P-I amplified output to a carrier and thus provides a PWM output for controlling the inverter.

Abstract: Aircraft speed and direction are determined by sampling the sinusoid-like pressure variations at the end of a rotor and performing a Fourier analysis on the pressure samples. Fourier quadrature component signals are used to determine aircraft direction and are also used to determine, along with a steady state component, the aircraft's total velocity. A discrete Fourier analysis may be performed on the pressure samples using a plurality of subrevolution pressure samples averaged over each subrevolution interval.

Abstract: A backup software program is installed in an isolated portion in the memory of at least one of redundant computers. The backup program performs basically the same functions as the prime program but is dissimilarly programmed to prevent a common software error. Switchover to the backup program occurs either automatically in response to monitors, or manually by the operator (i.e. pilot) when he detects an anomaly.

Abstract: A sine wave locked in phase and frequency to a carrier having a high second harmonic content, carrying information on the magnitude of a parameter, is applied to an open loop operational amplifier which provides a trapezoidal waveform to a high speed, differential transistor pair which provides a pair of squarewave signals whose duty cycles are regulated by varying the threshold at which the differential pair switches. The squarewaves may be used as a second-harmonic-free demodualting signal. The fundamental premise is that if the amplitude levels of the squarewave levels of the squarewave are known to a high degree of accuracy, and they are equal in the positive and negative directions, then the average value is zero only for a 50% duty cycle. A current regulator generates a selected current to a constant value with a high gain amplifier. This current is switched from one side to the other of the differential pair by the trapezoidal waveform.