1032 results about "Differentiator" patented technology

A device (25) for drilling holes in bone and configured to determine bone screw length, the device (25) including a surgical power drill (2) comprising: a) a housing (12) and; b) a measuring device (1) releasably attached or fixed to the housing (12), wherein the measuring device (1) is configured to measure the distance (x) covered by the housing (12) in the direction of the longitudinal axis (7) and relative to a surface of an implant (26) or a bone during a drilling process, wherein the measuring device (1) comprises a processing unit (14) to record the distance (x) covered with respect to time; the processing unit (14) comprises one or more differentiators to determine at least the first and second derivatives of the distance (x) covered with respect to time; and the processing unit (14) further comprises a peak detector to analyze one or more peaks occurring in the graph of the highest derivative with respect to time, and wherein the measuring device (1) comprises a laser device or an ultrasound position sensor for displacement assessment.

A method and system for achieving stability while reallocating resources in a logically partitioned environment. The present invention comprises Performance Enhancement Program (PEP), Classification Program (CP), System Analysis Program (SAP), and System Evaluation Program (SEP). PEP allows a user to enter several performance parameters. CP classifies each of the virtual systems in the managed system based on their workload. SAP analyses the managed system to determine the configuration of the managed system. Managed systems configurations are classified according to the reciprocity of resource allocation and the overall symmetry of the managed systems. SEP evaluates the configuration of the managed system and recommends alterations for improved performance of the managed system. The managed system will be optimized when the functional differentiator (FD) of the virtual systems is small enough to allow reallocation of resources without an unacceptable sacrifice in managed system stability.

A transporter that includes a platform for supporting a load and at least one primary ground-contacting element. The transporter includes an actuator for applying torque to the at least one primary ground-contacting element for propelling the transporter with respect to a surface. The transporter also includes a controller for controlling the actuator, the controller includes an input for receiving specification by a user of a desired direction of travel based on a position of a member with respect to a fiducial axis, a differentiator for calculating a rate of change of the position of the member with respect to the fiducial axis, and a processor for generating a yaw command signal based at least on the position of the member and the rate of change of the position of the member which is weighted based on the level of experience of the user.

A high-frequency power supply system includes an anomaly detector 3 which detects an anomaly occurring in a circuit on the side of a load L as from an outputting end A of a high-frequency power source 1. The anomaly detector 3 includes a first detector 21 which detects a voltage value Vf of a high-frequency forward wave, a second detector 22 which detects a voltage value Vr of a high-frequency reflected wave, a reflection coefficient calculator 23 and a differentiator 24 which calculate a reflection coefficient differential value dΓ / dt from the forward wave voltage value Vf and the reflected wave voltage value Vr, and an anomaly determiner 25 which determines of an occurrence of an anomaly based on the reflection coefficient differential value dΓ / dt. When the anomaly detector 3 outputs an anomaly detection signal to the high-frequency power source 1, high-frequency power source 1 stops its power output operation.

In a coaxial two-wheeled vehicle, an attitude controller (84) calculates motor torque Tgyr for maintaining a base so that it has a target angle from deviation between base angle command θref serving as attitude command and current base angle θ0 calculated by using a gyro sensor (13) and an acceleration sensor (14). On the other hand, at a position proportional controller (86R), a differentiator (88R) and a velocity proportional controller (89R), there is performed PD control with respect to deviation between rotation position command Prefr of a motor rotor (92R) for right wheel and current rotation position θr of a motor rotor (92R). A current control amplifier (91R) generates motor current on the basis of added value of motor torque which is the control result and estimated load torque T1 calculated by using pressure sensors to drive the motor rotor (92R).

A transporter that includes a platform for supporting a load and at least one primary ground-contacting element. The transporter includes an actuator for applying torque to the at least one primary ground-contacting element for propelling the transporter with respect to a surface. The transporter also includes a controller for controlling the actuator, the controller includes an input for receiving specification by a user of a desired direction of travel based on a position of a member with respect to a fiducial axis, a differentiator for calculating a rate of change of the position of the member with respect to the fiducial axis, and a processor for generating a yaw command signal based at least on the position of the member and the rate of change of the position of the member which is weighted based on the level of experience of the user.

This invention introduces an oral-dental anatomy modeling method and an implant treatment planning system based on a full anatomy model (FAM). Dental Implant Treatment Planning systems place implants on 2D slices of DICOM files, and sometimes on 3D models of bones and remaining teeth. Because the final look and feel of implants and restorations depend on how well they go along with the remaining teeth and soft tissues, treatment planning without tissue model presents safety and aesthetics risks. A FAM consists of models for bones, teeth, soft tissues and nerves. They are created from CT and optical scans, and assembled together with model registration techniques. The tissue model is the real differentiator. A treatment planning system uses FAM as a unique reference throughout the workflow. Its implant placement, restoration preview and surgical guide design are all based on FAM.

The invention relates to a PMSM servo system control method based on fuzzy and active disturbance rejection control. A position signal is given by a differential tracker to arrange a transition process so that the contradiction between rapidness and overshoot of a system is solved, and uncertainty, friction torques and external disturbance due to modeling errors of the system are observed via an expansion state observer; according to the error between the differentials generated by the differential tracker and state variation generated by the expansion state observer, a fuzzy inference rule is obtained with application of experimental experience of technical staff, so that a fuzzy rule control table of an error proportion coefficient, a differential coefficient and an integration coefficient is established; accurate control amount is obtained after de-fuzzification, so that parameter self-adaptive adjustment of a nonlinear error feedback control law is realized; and compensation amounts of the nonlinear error feedback control law and the expansion state observer to the total disturbance forms the control amount, thereby realizing optimal control for an controlled object. The method of the invention improves both tracking precision and disturbance rejection capability of the system.

A method and a language processing and knowledge building system (LPKBS) for processing textual data, receives textual data and a language object; segments the textual data into sentences and each sentence into words; generates a list of one or more natural language phrase objects (NLPOs) for each word by identifying vocabulary classes and vocabulary class features for each word based on vocabulary class feature differentiators; creates sentence phrase lists, each including a combination of one NLPO selected per word from each list of NLPOs; groups two or more NLPOs in each sentence phrase list based on word to word association rules, the vocabulary classes, the vocabulary class features, and a position of each NLPO; replaces each such group of NLPOs with a consolidated NLPO; maps each segmented sentence to a sentence type; identifies a semantic item for each mapped NLPO; and identifies and stores associated attributes and relations.

In one embodiment, the present invention is a low-power, and high performance receiver including an IF demodulator for high data rate, frequency modulated systems, such as Bluetooth. The IF demodulator is implemented in analog domain for simplicity and lower power consumption and operates at an IF frequency. An IF demodulator comprises: a first IF differentiator for differentiating an I signal; a second IF differentiator for differentiating a Q signal; a cross-coupled multiplier for multiplying the differentiated I signal with the Q signal and multiplying the differentiated Q signal with the I signal to extract frequency information from the I signal and the Q signal; and a slicer for converting the frequency information to digital data.

A self-oscillating switching amplifier having an error amplifier output combined with the output of an output signal differentiator according predetermined weighing factors to force a small oscillation around the averaged output signal at a high frequency. The feedback voltage is sensed at the output of the switching amplifier. Additional feedback can be derived from a switching node of the power switch. The switching of the power switch can be dynamically changed from binary switching when the amplitude of the audio signal is low, to ternary switching when the amplitude of the input signal is high to minimize distortion of the output signal. The amplifier can be supplied with a pulsing voltage. In certain embodiments the output signal differentiator is simply a capacitor or a LC resonance circuit coupled directly to an appropriate speaker terminal for the highest possible self-oscillating frequency of the switching amplifier.

The invention discloses a method and a device for controlling speed of a permanent-magnet synchronous motor. The method includes that an active-disturbance-rejection control technology is adopted for a speed ring, speed setting and a speed detection value are taken as input of a first-order active-disturbance-rejection controller, a tracking differentiator reasonably arranges a transition process, an extended state observer observes an actual value of rotating speed of the motor, estimates total disturbance of a system and acquires output of the speed ring through a nonlinear state error feedback control ratio, a load torque observer is designed through detection values of a current and the speed, and observed load torque through output of a feedforward controller and the active-disturbance-rejection controller is taken as reference input of a quadrature-axis current. The method carries forward characteristics of overshoot freeness, high disturbance rejection capacity, good robustness and the like of the permanent-magnet synchronous motor in speed control in the active-disturbance-rejection control technology, and compensation is performed on the problem of load disturbance, so that the problem of fluctuation of the rotating speed under the circumstance of load disturbance is improved.

The invention relates to a quadrotor unmanned plane control method based on a fuzzy expansion state observer and an adaptive sliding formwork. The method comprises steps that a quadrotor unmanned plane system model is established, and a system state and controller parameters are initiated; a tracking differentiator is designed; a non-linear expansion state observer is designed; fuzzy rules are established; a parameter adaptive law is designed; an adaptive sliding formwork controller is designed. According to the method, the expansion state observer is designed to estimate indetermination of a system model and external disturbance; a pole assignment method is utilized to determine an initial value of an expansion state observer parameter; the fuzzy rules are introduced to realize online setting for the expansion state observer parameter; the parameter adaptive law is designed to acquire ideal controller gain; the adaptive sliding formwork controller is designed, rapid stabilization of a system tracking error and convergence to a zero point are guaranteed, and rapid and stable position tracking and pose adjustment of the quadrotor unmanned plane are realized. The method is advantaged in that system performance is improved, and rapid and stable system position tracking and pose adjustment are realized.

In a coaxial two-wheeled vehicle, an attitude controller (84) calculates motor torque Tgyr for maintaining a base so that it has a target angle from deviation between base angle command θref serving as attitude command and current base angle θ0 calculated by using a gyro sensor (13) and an acceleration sensor (14). On the other hand, at a position proportional controller (86R), a differentiator (88R) and a velocity proportional controller (89R), there is performed PD control with respect to deviation between rotation position command Prefr of a motor rotor (92R) for right wheel and current rotation position θr of a motor rotor (92R). A current control amplifier (91R) generates motor current on the basis of added value of motor torque which is the control result and estimated load torque T1 calculated by using pressure sensors to drive the motor rotor (92R).

Methods are provided for smoothing input signals having rapidly changing amplitudes, such as EMG signals from the tongue, which are detected by an intraoral device. One method calls for amplifying the EMG signals, converting the EMG signals to digital format, providing a moving average of the amplitudes of the EKG signals utilizing a moving the average processor, and windowing the averaged signals to discrete and stable amplitude levels. An adaptive moving average technique may be utilized, which includes a plurality of parallel moving average processes and a differentiator which determines which process is used, depending on the rate of change of the signal amplitude. Another method calls for the use of a plurality of moving average processes in series which calculate the moving average of the same number of signals as a single moving average process, but has a faster response time. An intraoral device is used to detect the EMG signals. The intraoral device includes acrylic maxillary and mandibular splints. The maxillary splint has reference electrodes attached to its palate side, while the mandibular splint has active electrodes attached to the gum side. The intraoral device is strengthened by the use of woven fiberglass imbedded in its acrylic body.

The invention relates to a flexible satellite locus linearization attitude control method based on a disturbance observer. The invention aims at solving problems that a single locus linearization control method is poor in capability of inhibiting interference, is poorer in robustness, and does not consider external interference and the impact from flexible accessories. The method comprises the steps: employing Euler angles for describing attitudes of a spacecraft, employing an idea of equivalent disturbance, and building a flexible spacecraft dynamics and kinetics equation; solving the pseudo-inverse of a controlled object under the condition of neglecting equivalent disturbance, designing a quasi-differentiator of a specific type, and obtaining the nominal control of an expected locus; and designing a linear time varying adjuster through proportion-integration control. The method gives consideration to the influence of equivalent disturbance, designs the disturbance observer, and guarantees the asymptotic convergence of a tracking error of a flexible spacecraft. The method improves the anti-interference capability of a system, and improves the robustness of the system. The method is used in the attitude control field of flexible satellites.

The invention is a control algorithm that uses detected current and voltage to estimate the real-time value of the stator resistance and speed of the wind power generator, and uses the speed estimated by the algorithm as speed feedback to control the permanent magnet synchronous wind power generator. The speed value is estimated in the following way: According to the motor stator voltage and current value obtained by detection, the stator resistance value of the wind turbine is identified online based on the model reference adaptive system (MRAS), and the estimated electrical angle and the actual electrical angle of the rotor are obtained based on the back electromotive force. Error calculation formula, the fan speed is estimated by eliminating this error. The current and voltage values ​​in the electrical angle error calculation formula are obtained by detection, the stator resistance value that changes during generator operation is obtained by MRAS identification, and the differential term of the stator current is realized by a tracking differentiator (TD), so that it can be estimated more accurately and quickly Rotating speed.

A mass flow sensor calibrator employs a variable-flow fluid source, a receptacle of known volume, and a pressure differentiator. The variable-flow fluid source supplies gas at varying rates to the mass flow sensor being calibrated and at proportional rates to a receptacle of known volume. A pressure differentiator computes the time derivative of gas flow into the receptacle of known volume and, from that, the actual flow into the receptacle. Given the actual flow, the proportionate flow into the mass flow sensor may be determined and the flow signal from the mass flow sensor correlated to the actual flow.

The invention discloses a structure and a design method of an improved active-disturbance-rejection position controller for a direct current (DC) motor; the DC motor is taken as a controlled object, and an output position signal is taken as a controlled variable; the controller mainly consists of four parts, i.e., a tracking differentiator, a nonlinear state error feedback part, an extended state observer and a disturbance compensation part. The improved active-disturbance-rejection position controller is mainly used to improve a fal function in a nonlinear function in the extended state observer, and the fal function is used to determine the tracking performance of the extended state observer and the controller; the concrete improvement measure is adding a linear feedback area into non-linear feedback; therefore, the problem that in the traditional method, timely control cannot be realized when the system error is too large and the gain is too low can be solved on the basis of guaranteeing system stability. By comparing simulation lines obtained before and after the improvement for the controller, the structure and the design method which are provided by the invention are proved to accelerate the output signal response speed under the condition that the position error of the DC motor is larger, thus improving the integral control performance of a system.

A frame timing synchronization technique for orthogonal frequency division multiplexing (OFDM) systems is presented. First, a coarse synchronization technique generates a coarse frame timing estimate. The coarse synchronization technique applies a sliding window differentiator to the output of a conventional auto-correlator to mitigate the plateau effect associated with conventional auto-correlation techniques. Second, a fine synchronization technique generates a fine frame timing estimate. The fine synchronization technique uses the coarse frame timing estimate to reduce the number of cross-correlation calculations. Additionally, the fine synchronization technique acquires a fine frame timing estimate based on a signal-to-interference ratio (SIR) metric, which is more robust to multi-paths and pseudo multi-paths caused by cyclic delay diversity (CDD) schemes than conventional cross-correlation synchronization techniques. A fine-tuning technique generates a desired frame timing estimate by searching a first signal path in a searching window around the fine frame timing estimate to further refine frame timing synchronization.

A hybrid method for dental implant treatment planning and a corresponding approach to make a surgical guide. After digital treatment planning is performed with CT scan data, a master model is created, which embodies the patient anatomy and entire treatment plan. Jaw bone, tooth surfaces, soft tissues and nerves are all contained by the master model. The plan details including implant sizes and positions, surgical guide drill options, as well as the choice of a surgical kit, are all conveyed by the master model. Meanwhile, models of specially designed “implant inserts (or replicas)” are also generated, which have one end that fits into the implant holes on the master model and another end to make the surgical guide. The master model and inserts are manufactured with rapid prototyping technology. A surgical guide is later on made from them with conventional lab processes. A main characteristic of this approach is that the master model and the inserts are the physical embodiment of a virtual treatment plan. With them, the surgeons can continue the treatment planning for operations like tooth extractions and bone modifications before making the surgical guides. Therefore the treatment planning workflow is a combination of digital treatment planning and a physical model based planning, in other words, a hybrid approach. A differentiator in this invention is the generation of a closed solid model of the soft tissue, as part of the master model, from the scan data. This approach can be applied to create both bone-borne and tissue-borne surgical guides with low cost process, which is a big advantage over other approaches.

A technique for generating motion vectors in video and film signal processing uses constraint equation based motion estimation. Simplifications of the processing and hardware are made possible by generating motion vectors based on the normalized constraint equation. The temporal and spatial image gradients are calculated using temporal and spatial differentiators (16, 17, 18). An angle (theta) corresponding to the orientation of the spatial image gradient vector and the motion speed (vn) in the direction of the vector are calculated using apparatus including a rectangular to polar coordinate converter (32). theta and vn are the parameters of the normalized constraint equation.

A system and method is disclosed that provides a digital self-adjusting power supply for semiconductor digital circuits. The power supply provides a substantially constant minimum supply voltage with regard to process corner, junction temperature, external voltage source, load variation, and operating frequency. The system comprises a slack time detector, a voltage adjuster, and a digital pulse width modulation (PWM) modulator. The system supplies a minimum required voltage without the used of a band gap or reference voltage. A finite state machine is also used to minimize oscillations introduced by start-up, load transients, frequency changes, and the like, thereby eliminating the need for a proportional integrator differentiator (PID) circuit.

Pre-distortion, whose magnitude—and preferably phase—are frequency-dependent, is applied to an input signal in order to reduce spurious emissions resulting from subsequent amplification of the signal. In preferred embodiments, the pre-distortion technique of the present invention is implemented in combination with the (frequency-independent) magnitude and phase pre-distortion technique described in U.S. patent application Ser. No. 09 / 395,490 (“the '490 application”), where the frequency-dependent pre-distortion corresponds to amplifier distortion that has a magnitude that is proportional to the frequency offset from the carrier frequency and a phase shift of ±90° on either side of the carrier frequency. Since these characteristics match those of a differentiator, a thorough correction of this part of the amplifier's distortion can be achieved using a differentiating filter. Embodiments of the present invention may be implemented in the baseband domain. Implementations may also be based on look-up tables that are adaptively updated to ensure optimal performance over time.

A tri-rotor attitude control method based on an auto-disturbance rejection controller (ADRC) includes determining a mathematic model of a tri-rotor aircraft, determining input-output variables suitable for the model, tracking differentiator design, building an expansion state observer, and selecting a non-linear error feedback rate. A core control panel based on Atmega 2560 serves as an execution module, the motor is powered through a drive circuit, and the PWM wave can be adjusted according to the rotating speed of the motor. An inertial navigation module is formed by a tri-shaft gyroscope sensor, an accelerometer, a GPS and a digital compass, and a power supply module provides appropriate voltage to power each module through a power distribution module. For a tri-rotor aircraft model, parameters of all modules are adjusted to achieve excellent effects for auto-disturbance rejection control method. Module design and parameter adjustment of all modules allow three rotors to retain an excellent flying state through an auto-disturbance rejection control system.

The invention discloses a reentry vehicle full-order non-singular terminal sliding mode posture control method, relates to a reentry vehicle full-order non-singular terminal sliding mode posture control method based on a robust differentiator, and belongs to the technical field of vehicle control. The method includes the steps: generating the state vector of a vehicle; building a mathematical model of a reentry vehicle; simplifying the model of the reentry vehicle by feedback linearization; giving command information yc=(alpha c, beta c and mu c) T of a progressive tracking system for posture angles alpha, beta and mu of the vehicle when external interference exists in the system and parameters are uncertain; controlling allocation to obtain a rudder reflection angle command delta=(delta e, delta a and delta r) T; inputting the obtained rudder reflection angle command to the vehicle and controlling the posture of the vehicle. Tracking errors can be converged into zero within limited time, singular problems of controller output can be avoided, measuring noise generated by a traditional differentiator is suppressed by estimating error second-order derivatives, and buffeting of control quantity is eliminated by boundary layer and low-pass filtering techniques.

The invention discloses an active-disturbance-rejection control method for the temperature of a constant stirring polypropylene reaction kettle. A discrete mode is adopted for the active-disturbance-rejection control method for the temperature of the constant stirring polypropylene reaction kettle, and a tracking differentiator module, an expanded state observer module and a non-linearity feedback controller module are involved. The method includes the steps that firstly, parameters of the tracking differentiator module and the expanded state observer module are set; then, a transient process is arranged, and disturbances are estimated; finally, an error signal is used for adjusting the non-linearity feedback controller module to control the temperature of the polypropylene reaction kettle. The control method has the advantages that the method is implemented on SIMATICPCS7 equipment without establishing a constant stirring polypropylene reaction kettle model, the dynamic response is rapid, and a system is high in adaptability and robustness under the working conditions of disturbances and variable loads.

The invention relates to an active-disturbance-rejection trajectory linearization control method suitable for hypersonic velocity maneuvering flight. The active-disturbance-rejection trajectory linearization control method regards a part different from a nominal model as a general disturbance, establishes a hypersonic aircraft attitude and angular velocity dynamic model with multi-source complex uncertainty and strict feedback form, designs attitude ring and angular velocity ring model auxiliary expansion state observers, adopts a non-linear tracking differentiator to arrange a transition process for a given guidance command and generate a nominal command of an attitude ring, designs an active-disturbance-rejection trajectory linearization attitude ring controller containing a feedforward tracking control law, a feedback stabilization control and a disturbance compensation term, and designs an active-disturbance-rejection trajectory linearization angular velocity ring controller containing a feedforward tracking control law, a feedback stabilization control and a disturbance compensation term. The active-disturbance-rejection trajectory linearization control method achieves high-precision anti-disturbance control under the given conditions of large-margin guidance command and control constraint, and has high adaptability for multi-source disturbance large-scale perturbation in hypersonic velocity long-span maneuvering flight.

A demodulation circuit for an Amplitude Shift Keyed (ASK) modulated signal includes an envelope detector, an alternating voltage amplifier, a differentiator circuit, and a comparator having a hysteresis connected in series. The envelope detector produces an envelope signal from the received ASK signal. The amplifier blocks the DC component of the envelope signal and amplifies AC components of the envelope signal to obtain a steeper slope of the rising and falling edges. The differentiator circuit then processes the transition edges to provide a differentiated signal having positive and negative electrical pulses. The comparator converts the pulses into a binary data stream which corresponds to the transmitted data stream. The combination of the differentiated signal and comparator having a hysteresis enables better stability and sensitivity of the ASK demodulation circuit.

The invention discloses an airplane angular rate signal reconstruction method based on unscented kalman filter. The method comprises the following steps of: (1), denoising an attitude angle measurement signal containing measurement noise through a nonlinear tracking differentiator to obtain a differential signal of an attitude angle, and constructing a virtual measurement equation; (2), constructing a state equation of a system on the basis of natural characteristics of an airplane and according to tri-axial angular rate signals and torque characteristics of the airplane; and (3), reconstructing an angular rate signal of the system by selecting the unscented kalman filter technology as the processing manner because both the state equation and the measurement equation are nonlinear and the estimation precision can be influenced by traditional operation for linearizing a nonlinear equation.