466 results about "Dead time" patented technology

A data storage device is provided. A disk device is combined with a non-volatile memory device to provide much shorter write access time and much higher data write speed than can be achieved with a disk device alone. Interleaving bursts of sector writes between the two storage devices can effectively eliminate the effect of the seek time of the disk device. Following a non-contiguous logical address transition from a host system, the storage controller can perform a look-ahead seek operation on the disk device, while writing current data to the non-volatile memory device. Such a system can exploit the inherently faster write access characteristics of a non-volatile memory device, eliminating the dead time normally caused by the disk seek time.

A control system simultaneously controls a multi-zone process with a self-adaptive model predictive controller (MPC), such as temperature control within a plastic injection molding system. The controller is initialized with basic system information. A pre-identification procedure determines a suggested system sampling rate, delays or “dead times” for each zone and initial system model matrix coefficients necessary for operation of the control predictions. The recursive least squares based system model update, control variable predictions and calculations of the control horizon values are preferably executed in real time by using matrix calculation basic functions implemented and optimized for being used in a S7 environment by a Siemens PLC. The number of predictions and the horizon of the control steps required to achieve the setpoint are significantly high to achieve smooth and robust control. Several matrix calculations, including an inverse matrix procedure performed at each sample pulse and for each individual zone determine the MPC gain matrices needed to bring the system with minimum control effort and variations to the final setpoint. Corrective signals, based on the predictive model and the minimization criteria explained above, are issued to adjust system heating / cooling outputs at the next sample time occurrence, so as to bring the system to the desired set point. The process is repeated continuously at each sample pulse.

Systems, methods, and apparatuses are disclosed for determining dead-times in switched-mode DC-DC converters with synchronous rectifiers or other complementary switching devices. In one embodiment, for example, a controller for a DC-DC converter determines dead-times for switching devices of a synchronous rectifier or other complementary switching device of the converter in which a dead-time is derived from an output voltage or current that is already sensed and used in the output regulation of the converter. In another embodiment, a controller is provided for controlling a switched-mode DC-DC converter comprising a pair of power switches. The controller comprises an input, a reference generator, a comparator, a compensator, a dead-time sub-controller, and a modulator. In another embodiment, the controller may adjust the dead-times during the operation of the converter to adjust periodically and / or in response to changes in operating conditions. In addition, methods of determining dead-times of control signals for a switched-mode DC-DC converter comprising a pair of power switches and of controlling a DC-DC converter are also disclosed.

A system for controlling a switching power converter and includes a digital controller that receives an analog signal representing the output DC voltage of the power converter for comparison to a desired output voltage level and generates switching control signals to control the operation of the power supply to regulate the output DC voltage to said desired output voltage level. At least two of the switching control signals having a dead time between a first edge of a first control signal and a second edge of a second control signal. The dead time is programmable such that the second edge of the second control signal may occur at a selected point in time either before or after the first edge of the first control signal.

A method of creating and using an adaptive DMC type or other MPC controller includes using a model switching technique to periodically determine a process model, such as a parameterized process model, for a process loop on-line during operation of the process. The method then uses the process model to generate an MPC control model and creates and downloads an MPC controller algorithm to an MPC controller based on the new control model while the MPC controller is operating on-line. This technique, which is generally applicable to single-loop MPC controllers and is particularly useful in MPC controllers with a control horizon of one or two, enables an MPC controller to be adapted during the normal operation of the process, so as to change the process model on which the MPC controller is based to thereby account for process changes. The adaptive MPC controller is not computationally expensive and can therefore be easily implemented within a distributed controller of a process control system, while providing the same or in some cases better control than a PID controller, especially in dead time dominant process loops, and in process loops that are subject to process model mismatch within the process time to steady state.

A non-linear dynamic predictive device (60) is disclosed which operates either in a configuration mode or in one of three runtime modes: prediction mode, horizon mode, or reverse horizon mode. An external device controller (50) sets the mode and determines the data source and the frequency of data. In prediction mode, the input data are such as might be received from a distributed control system (DCS) (10) as found in a manufacturing process; the device controller ensures that a contiguous stream of data from the DCS is provided to the predictive device at a synchronous discrete base sample time. In prediction mode, the device controller operates the predictive device once per base sample time and receives the output from the predictive device through path (14). In horizon mode and reverse horizon mode, the device controller operates the predictive device additionally many times during base sample time interval. In horizon mode, additional data is provided through path (52). In reverse horizon mode data is passed in a reverse direction through the device, utilizing information stored during horizon mode, and returned to the device controller through path (66). In the forward modes, the data are passed to a series of preprocessing units (20) which convert each input variable (18) from engineering units to normalized units. Each preprocessing unit feeds a delay unit (22) that time-aligns the input to take into account dead time effects such as pipeline transport delay. The output of each delay unit is passed to a dynamic filter unit (24). Each dynamic filter unit internally utilizes one or more feedback paths that are essential for representing the dynamic information in the process. The filter units themselves are configured into loosely coupled subfilters which are automatically set up during the configuration mode and allow the capability of practical operator override of the automatic configuration settings. The outputs (28) of the dynamic filter units are passed to a non-linear analyzer (26) which outputs a value in normalized units. The output of the analyzer is passed to a post-processing unit (32) that converts the output to engineering units. This output represents a prediction of the output of the modeled process. In reverse horizon mode, a value of 1 is presented at the output of the predictive device and data is passed through the device in a reverse flow to produce a set of outputs (64) at the input of the predictive device. These are returned to the device controller through path (66). The purpose of the reverse horizon mode is to provide essential information for process control and optimization. The precise operation of the predictive device is configured by a set of parameters. that are determined during the configuration mode and stored in a storage device (30). The configuration mode makes use of one or more files of training data (48) collected from the DCS during standard operation of the process, or through structured plant testing. The predictive device is trained in four phases (40, 42, 44, and 46) correspo

A power converter uses a control method to optimize efficiency by dynamically optimizing a controlled parameter. A change in efficiency of the converter after changing at least one controlled parameter is determined. The direction of change in efficiency of the converter is compared to a direction of the change in the controlled parameter. The controlled parameter is changed in a positive direction when the direction in the change in the efficiency of the converter and the direction of the change in the controlled parameter are the same and changed in a negative direction when the direction in the change in the efficiency of the converter and the direction of the change in the controlled parameter are opposite. The controlled parameters may include dead time between turn-on and turn-off and between turn-off and turn-on of the primary and corresponding secondary side switches of the controller, drive voltage(s) for the switches, and intermediate bus voltages.

A novel monolithic step-down dc-dc buck converter that uses two or more ("n") parallel slices to achieve a high output current with a small filter capacitor is provided. Each of the n slices may be operated with a phase difference of 360° / n. Each of the converter slices may be based on a synchronous rectifier topology to avoid the excessive power losses introduced by the diode component of conventional step-down buck converters. Hysteretic control may be used (with or without pulse-width modulation and pulse-frequency modulation) to provide an internal gate-drive waveform without the need to provide a dedicated clock signal or oscillator circuit. The hysteretic control is further refined using digital control techniques to enforce a brief dead time between the activation of each slice such that undesirable circulating currents are prevented. A significant advantage of the proposed multi-slice step-down dc-dc buck converter and its associated control is that the semiconductor switches, filter inductors and capacitor, and the control circuit may be fabricated as part of a single monolithic integrated circuit.

Method for setup of parameter values in a RF power amplifier circuit arrangement (200), wherein the amplifier circuit arrangement (200) comprises a first (210) and a second (220) amplification branch and is operated in an out-phasing configuration for amplification of RF input signals with modulated amplitude and modulated phase and respective circuit arrangements are disclosed. According to a first aspect a re-optimization of the dead-time or conversely the duty-cycle, respectively, the phase of the output signal after the combiner can be kept linear with respect to the out-phasing angle. Further, according to a second aspect, additionally to introduction of an optimally chosen dead-time, a non-coherent combiner (Lx, Lx*) can reduce crowbar current and switching losses due the output capacitance (Cds). Furthermore, according to a third aspect the reactive compensation can, additionally or alternatively, be controlled by operating both amplification branches at different duty-cycles.

Apparatus for setting dead time between ON times of two series connected switches of a power converter circuit connected across a supply potential, the apparatus comprising a circuit for monitoring a power converter circuit parameter and providing an output corresponding to the circuit parameter; a memory addressed by a signal related to the output of the monitoring circuit, the memory having values stored therein related to the dead times and associated with values of the circuit parameter; a processor providing an output of the memory associated with the value of the circuit parameter to set the dead time corresponding to the stored value in the memory, and a dead time implementing stage for implementing the dead time in accordance with the output of the memory.

System and method for adaptively altering a power supply's dead time. A method comprises detecting a start of a dead time, detecting an ending condition of the dead time, and ending the dead time. The detecting of the ending condition is based on a first current flowing through a lower portion of the power supply or a second current flowing through a gate driver of a lower switching element in the power supply.

The invention relates to a method for recognizing parameters of asynchronous motor. The stator resistance of motor is measured by a method of DC volt-ampere. The rotor resistances as well as leakage inductance of stator and rotor of motor is obtained by short circuit test. Mutual inductance of stator and rotor of motor can be taken from method of no-load test. Compensating voltage drop in on state, switch time delay and dead time raises the accuracy and stability of recognized parameter. The resistance values of rotor at frequency of rating sliding difference are calculated by method of two points through test of locked rotor at two frequencies. Since skin effect is overcome, the resistance values of rotor are accurate enough so as to meet the requirement of vector control system completely.

The invention provides a method and circuit for measuring on-chip, cycle-to-cycle, jitter. Copies of a circuit comprising a programmable delay line, a programmable phase comparator, and two counters are placed at different locations on an IC near a clock signal. The programmable delay line creates a clock signal that is delayed by one clock cycle. This delayed clock signal is compared in time to the original clock signal by the programmable phase comparator. If the difference in time between the delayed clock signal and the clock signal is greater than the dead time, the first counter is triggered. If the difference in time is negative and the absolute value is greater than the dead time, the second counter is triggered. A statistical distribution, based on the values of the counters, is created. This distribution is used to predict on-chip, cycle-to-cycle jitter.

A method of creating and using an adaptive DMC type or other MPC controller includes using a model switching technique to periodically determine a process model, such as a parameterized process model, for a process loop on-line during operation of the process. The method then uses the process model to generate an MPC control model and creates and downloads an MPC controller algorithm to an MPC controller based on the new control model while the MPC controller is operating on-line. This technique, which is generally applicable to single-loop MPC controllers and is particularly useful in MPC controllers with a control horizon of one or two, enables an MPC controller to be adapted during the normal operation of the process, so as to change the process model on which the MPC controller is based to thereby account for process changes. The adaptive MPC controller is not computationally expensive and can therefore be easily implemented within a distributed controller of a process control system, while providing the same or in some cases better control than a PID controller, especially in dead time dominant process loops, and in process loops that are subject to process model mismatch within the process time to steady state.

Apparatus for minimizing power losses associated with dead time between ON times of two series connected switches of a power converter connected across a supply potential, the apparatus comprising a control arrangement for monitoring a selected parameter associated with power loss during the dead time of the converter; the control arrangement changing the dead time from a first dead time to a second dead time and comparing power loss associated with the selected parameter for the first and second dead times and determining which of the power losses associated with the two dead times is smaller; a dead time implementing stage for implementing the two dead times; and the control arrangement selecting the dead time associated with the smaller power loss and providing a signal to the dead time implementing stage to set the selected dead time.

A non-linear dynamic predictive device (60) is disclosed which operates either in a configuration mode or in one of three runtime modes: prediction mode, horizon mode, or reverse horizon mode. An external device controller (50) sets the mode and determines the data source and the frequency of data. In the forward modes (prediction and horizon), the data are passed to a series of preprocessing units (20) which convert each input variable (18) from engineering units to normalized units. Each preprocessing unit feeds a delay unit (22) that time-aligns the input to take into account dead time effects. The output of each delay unit is passed to a dynamic filter unit (24). Each dynamic filter unit internally utilizes one or more feedback paths that provide representations of the dynamic information in the process. The outputs (28) of the dynamic filter units are passed to a non-linear approximator (26) which outputs a value in normalized units. The output of the approximator is passed to a post-processing unit (32) that converts the output to engineering units. This output represents a prediction of the output of the modeled process. In reverse horizon mode, data is passed through the device in a reverse flow to produce a set of outputs (64) at the input of the predictive device. These are returned to the device controller through path (66). The purpose of the reverse horizon mode is to provide information for process control and optimization. The predictive device approximates a large class of non-linear dynamic processes. The structure of the predictive device allows it to be incorporated into a practical multivariable non-linear Model Predictive Control scheme, or used to estimate process properties.

The invention relates to the medical slice imaging and nuclear-imaging field, in particular to a first-group board card, a signal buffering unit, a second-group receiving board card, a data buffering unit, a reference clock 17, a clock adjusting unit and an on-site programmable gate array that are used for a conforming system in a positron slice scanning device; the method is characterized in that the on-site programmable gate array is utilized to judge the time, the position and the energy among all matters, and two matters that pass through the judging and selecting regulations form a conforming case. By inducting the on-site programmable gate array, the case information captured by a front-end detector module of a PET apparatus can be processed fast and high-efficiently by compiling hardware description language, so as to ensure whether the conforming matters happen or not. The method is an improvement of the process of the prior PET conforming system. The method can finish the process of the conforming system high-efficiently and fast by using a piece of FPGA and can lead the system not to be inducted into the dead time while the high system sensitivity is obtained.

The invention particularly relates to a design and setting method for an active disturbance rejection control system of a time delay system. According to the method, based on the active disturbance rejection technology, firstly, complex controlled objects are fit into a one-order inertial element plus dead time delay mathematic model, meanwhile, time delay comes down to the disturbance quantity, a time delay reduction linear extended state observer is applied to estimation of unknown total disturbance including the time delay, active compensation for the influences of the total disturbance on the system is achieved, the time delay system is restored into a system in an integrator tandem type in an ADRC standard, and then compensation for the time delay system is achieved; finally, a closed-loop transfer function of the system is deduced, a dead time delay link in a characteristic equation is eliminated, and the numerical relationship between an ADRC single-parameter setting formula with universality and adjustable parameters is correspondingly provided. The simulation result verifies that designed practical ADRC has good stability, rapidity, accuracy and disturbance rejection.

An objective of the present invention is to provide an autonomous control method that autonomously controls a small unmanned helicopter toward target values, such as a set position and velocity, by deriving model formulas that are well suited for the autonomous control of small unmanned helicopters, by designing an autonomous control algorithm based on the model formulas, and by calculating the autonomous control algorithm. The autonomous control system for a small unmanned helicopter of the present invention comprises: sensors that detect the current position, the attitude angle, the altitude relative to the ground, and the absolute azimuth of the nose of the aforementioned small unmanned helicopter; a primary computational unit that calculates optimal control reference values for driving the servo motors that move five rudders on the helicopter from target position or velocity values that are set by the ground station and the aforementioned current position and attitude angle of the small unmanned helicopter that are detected by the aforementioned sensors; an autonomous control system equipped with a secondary computational unit that converts the data collected by said sensors and the computational results as numeric values that are output by said primary computational unit into pulse signals that can be accepted by the servo motors, such that these components are assembled into a small frame box, thereby achieving both size and weight reductions; a ground station host computer that can also be used as the aforementioned computational unit for the aforementioned autonomous control system; if the aforementioned ground station host computer is used as the aforementioned computational unit for the aforementioned autonomous control system, in the process of directing the computational results that are output from said ground station host computer to said servo motors through a manual operation transmitter, a radio control generator that converts said computational results as numerical values into pulse signals that said manual operation transmitter can accept; a servo pulse mixing / switching apparatus, on all said servo motors for said small unmanned helicopter, that permits the switching of manual operation signals and said control signals that are output from said autonomous control system or mixing thereof in any ratio; an autonomous control algorithm wherein the mathematical model for transfer function representation encompassing pitching operation input through pitch axis attitude angles in the tri-axis orientation control for said small unmanned helicopter is defined as Gθ⁡(s)=e-Ls⁢Kθ⁢ωns2(s2+2⁢s⁢ωn⁢ ⁢s⁢s+ωn⁢ ⁢s2)⁢(Tθ⁢s+1)⁢swherein Gθ: parameter e−Ls: dead time element Kθ: model gain Tθ: model gain ωns: natural frequency s: laplace operator ξs: damped ratio such that the aforementioned small unmanned helicopter is controlled autonomously based on the aforementioned mathematical model.

A semiconductor device includes: a digital control circuit configured to supply two semiconductor switching elements connected in series in a switching power supply circuit with a pulse signal for turning on / off the semiconductor switching elements; and a dead time setting circuit configured to set a dead time in which the two semiconductor switching elements are both turned off. The dead time setting circuit includes: a delay generation circuit including a plurality of delay elements connected in series and having mutually different delay values; and a delay adjustment circuit configured to adjust the delay values of the delay generation circuit so that a setting value of the dead time is determined on basis of correlation between the dead time and the duty cycle of the pulse signal.

When the output of the AFR ratio sensor is stable in a steady operating state, the amount of fuel is increased by step inputting to detect a point where the gradient of change in the sensor output exceeds a threshold value as a point of start of change. The time from the timing of increasing the fuel until the point of start of change is detected as a dead time. A response time is calculated until the amount of change in the sensor output reaches a predetermined ratio of the amount of change (AA−BA) of up to the steady value AA of the sensor output after the amount of the fuel is increased from the steady value BA of the sensor output before the amount of the fuel is increased. The fail condition in the AFR ratio sensor is determined based on the dead time TA and the response time TB.