117 results about "Periodic excitation" patented technology

A method and apparatus for concealing frame loss and an apparatus for transmitting and receiving a speech signal that are capable of reducing speech quality degradation caused by packet loss are provided. In the method, when loss of a current received frame occurs, a random excitation signal having the highest correlation with a periodic excitation signal (i.e., a pitch excitation signal) decoded from a previous frame received without loss is used as a noise excitation signal to recover an excitation signal of a current lost frame. Furthermore, a third, new attenuation constant (AS) is obtained by summing a first attenuation constant (NS) obtained based on the number of continuously lost frames and a second attenuation constant (PS) predicted in consideration of change in amplitude of previously received frames to adjust the amplitude of the recovered excitation signal for the current lost frame. Speech quality degradation caused by packet loss can be reduced for enhanced communication quality in a packet network environment with continuous frame loss.

The present invention proposes a parameter identification method for the dynamic model of an industrial robot, comprising: establishing a dynamic model of an industrial robot with six joints connected in series; setting a periodic excitation signal, and using the periodic excitation signal to optimize the identification track of the dynamic model of the industrial robot ;Measure the data of the dynamic model of the industrial robot at multiple time points, and average the data; estimate the parameters of the dynamic model of the industrial robot according to the data average processing results, and obtain the estimator of the unknown parameter vector; The industrial robot dynamics model and estimated parameters are verified, including: calculating the prediction error of the estimated parameters and the measured parameters of the industrial robot dynamics model, and using the residual root mean square of the prediction error to verify and evaluate the industrial robot dynamics model. The invention reduces the influence of measurement noise on parameter estimation and improves the precision of dynamic parameter identification.

A motor controller architecture and method of operating the same. The motor controller includes a function for estimating the low speed operation of the motor, for example by evaluating the response to a periodic excitation signal injected into the control loop of the controller architecture. A periodic excitation signal in the form of a square wave allows for analysis of the response of the motor without requiring demodulation, which allows the frequency of the excitation signal to be above the audible range. Control logic for controlling the motor at transitional speeds between low speed control and high speed (back emf) control is provided in some embodiments.

A method and mechanism of producing a suction and periodic excitation flow. The method includes providing fluid flow from jet port with diameter d1 at a controlled input pressure (Pin), directing the flow to a conduit with diameter d2, >d1, allowing additional fluid to join the flow through suction slot(s) to create an amplified flow in the conduit, further directing the amplified flow in a first direction by applying a transverse pressure differential, further redirecting the amplified flow in another direction by modifying an angle by which the transverse pressure differential is applied and iteratively repeating the further directing and further redirecting so that the amplified flow oscillates between the directions. The suction and periodic excitation flows may be employed, for example, to effectively control boundary layer separation. A mechanism for automated performance of the method is also disclosed.

The present invention describes an order tracking system (200) and method (100) for tracking at least one order from mechanical and / or acoustic vibrations generated by a periodic excitation process of a physical system. The order tracking system (200) comprises a means for obtaining (212) a mechanical and / or acoustic vibration data of a physical system and a means for obtaining (214) system reference data. It further comprises a means for combining (224) the mechanical and / or acoustic vibration data with the system reference data and a means for applying (226) a digital FIR filter to at least the mechanical and / or acoustic vibration data for deriving based thereon at least one order.

Apparatus and associated methods reduce harmonic distortion of a excitation current by diverting the excitation current substantially away from a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level, and ceasing the current diversion while the excitation current or voltage is substantially above the predetermined threshold level. In an illustrative embodiment, a rectifier may receive an AC (e.g., sinusoidal) voltage and deliver unidirectional cur not rent to a string of series-connected LEDs. An effective turn-on threshold voltage of the diode string may be reduced by diverting current around at least one of the diodes in the string while the AC voltage is below a predetermined level. In various examples, selective current diversion within the LED string may extend the input current conduction angle and thereby substantially reduce harmonic distortion for AC LED lighting systems.

A method and detector for providing a noise resistant utterance detector is provided by extracting a noise estimate (15) to augment the signal-to-noise ratio of the speech signal, inverse filtering (17) of the speech signal to focus on the periodic excitation part of the signal and spectral reshaping (19) to accentuate separation between formants.

The invention provides a multi-dimensional force sensor dynamic experiment device based on a stable-state sine exciting force, comprising a T-shaped rack and an L-shaped rack, wherein when a force sensor to be detected is fixedly arranged on the an end face of a horizontal plate of a base and is loaded by the T-shaped rack, the loading of the exciting force or an exciting force moment is realized; when the force sensor to be detected is fixedly arranged on the end face of a vertical plate of a base and is loaded by the L-shaped rack, the L-shaped rack is used as a switchover piece of the force sensor to be detected and the T-shaped rack and is used for changing a stressing direction of the force sensor to be detected and realizing different combined types of loading. When a motor is rotated at a certain rotating speed, sine exciting forces with different amplitudes can be obtained through adjusting the position of an adjusting block in a diameter-changing slide groove in an eccentric exciting block, so as to realize an amplitude-frequency property test. In the rotation process of the eccentric exciting block, a permanent magnet steel block periodically stimulates a Hall sensor to output a pulse signal and utilizes a pulse signal triggering moment to determine the maximum value time slot of a component force amplitude of an eccentric force at a certain stressing direction, so as to recover the known sine exciting force signal and realize a phase-frequency property test.

The invention belongs to the field of vibration control, in particular relating to a buffer device which prevents a boat body from generating vibration caused by water jet impact; wherein, an elastic part and a baffle are arranged on at least part of the contact surface between the boat body and the water; the elastic part is positioned between the baffle and the corresponding boat body, and the baffle is connected with the boat body through the elastic part. A buffering vibration-reducing device of the invention can isolate the impact outside the boat body from the boat body and has good effect of vibration reduction and can also prolong the service life of the boat body through most of the inertia balance of the baffle and the buffering of the elastic part. The invention can be widely applied in the vibration control over impact of buffering water on the boat bodies of various boats and is not only suitable for the situations which bear the periodic excitation force such as blade water but also the situations of random impact or other sudden impacts produced by buffering wind waves, etc.

In accordance with an embodiment, a method of performing a measurement with a capacitive sensor includes generating a periodic excitation signal that includes a series of pulses and smoothing edge transitions of the series of pulses to form a shaped periodic excitation signal that includes a flat region between the smoothed edge transitions. The method further includes providing the shaped periodic excitation signal to a first port of the capacitive sensor and measuring a signal provided by a second port of the capacitive sensor.

An apparatus with an excitation unit for mechanically exciting an object with a periodic excitation signal and a camera for capturing the thermal images of the object are used to capture thermal images of the object. The thermal image has a plurality of pixels, where a pixel is respectively intended to represent a heat signal acquired from the object. The apparatus matches a capture of the thermal images of the object and the periodic excitation signal in such a manner that thermal images captured in a plurality of periods of the periodic excitation signal can be used to determine information relating to the heat signals respectively represented by the pixels during a period.

A system of analysis with the naked eye and by fluorescence of a field in an illuminated area comprising a periodically-excited first low-remanence white light illumination source; a second light source for exciting fluorescent elements located in said field, active at least during part of the time periods when the first source is off; and a fluorescence analysis device active during time periods when the first source is off and the second source is on.

A motor controller architecture and method of operating the same. The motor controller includes a function for estimating the low speed operation of the motor, for example by evaluating the response to a periodic excitation signal injected into the control loop of the controller architecture. A periodic excitation signal in the form of a square wave allows for analysis of the response of the motor without requiring demodulation, which allows the frequency of the excitation signal to be above the audible range. Control logic for controlling the motor at transitional speeds between low speed control and high speed (back emf) control is provided in some embodiments.

The invention belongs to the technical field of ultrasonic flow rate meter design, and particularly relates to a flow rate detection method for a low-energy-consumption ultrasonic flow rate meter and a system realizing the method. The method comprises the following steps that a main control module generates continuous excitation signals with the period being T and outputs the excitation signals to an excitation signal number control circuit; the excitation signal number control circuit processes the continuous and periodic excitation signals into excitation signals in specific period numbers, and the specific period number is greater than or equal to 6; a first energy converter receives the specific period number of excitation signals and then sends ultrasonic signals; the second energy converter receives the ultrasonic waves and then outputs echo signals to a timing circuit in an echo signal processing module for timing, in addition, the result is output to the main control module, and the main control module calculates the flow rate according to the ultrasonic wave down-flow and reverse-flow output timing difference values. The continuous excitation signals are processed into the specific period number of excitation signals, the first energy converter cannot be always in the work state, the energy loss is reduced, and the service life of the system is prolonged.

The invention provides a method for a multi-dimensional sensor dynamic test device based on a stable-state sine excitation force. Known sine excitation force signals can recovered by a centrifugal force, which is generated by that a rotary motor drives an eccentric excitation block and the output shaft of the rotary motor to synchronously rotate, through adjusting the rotating speed of the rotary motor, the mass center position of the eccentric excitation block, and the mounting directions of the rotary motor and a to-be-measured force sensor in a process of loading a T-shaped rack and an L-shaped rack, and using a permanent magnet steel block to periodically excite a Hall sensor to output a pulse response signal, so as to realize the sine excitation force and the excitation force moment with continuously varied frequency and amplitude value in each dimension direction of the to-be-measured force sensor. By utilizing a physical method of the multi-dimensional sensor dynamic test device based on the stable-state sine excitation force, the sine excitation signals which are not influenced by an external environment and are foreseeable are generated, so as to realize the sine excitation force with stable amplitude, easiness for adjustment and continuously-varied frequency. The method is simple and convenient to operate, and the dynamic transmission property of the to-be-measured force sensor within an entire use frequency band range can be obtained.

In a method for functional testing of a mechanical vibration sensor, a vibration signal is generated on the vibration component of the vibration sensor with the aid of a periodic excitation signal, the frequency of which excitation signal is varied, and a post-vibration process of the vibration component of the vibration sensor is analyzed once the excitation signal has been switched off.

The invention provides a vocoder based on residual signal spectrum reconfiguration. The vocoder based on residual signal spectrum reconfiguration comprises a parameter extracting module, an inverse filtering module, a periodic signal branch, a nonperiodic signal branch and a parameter voice synthesizer module. The parameter extracting module is used for receiving to-be-analyzed voice data and calculating fundamental frequency parameters and frequency spectrum parameters. The inverse filtering module is used for designing an inverse filter according to the frequency spectrum parameters to inversely filter the voice data to obtain residual signals. The periodic signal branch is connected with the inverse filtering module and used for generating periodic excitation signals according to the fundamental frequency parameters and the residual signals after inverse filtering. The nonperiodic signal branch is connected with the inverse filtering module and used for generating nonperiodic excitation signals according to the fundamental frequency parameters and the residual signals after inverse filtering. The parameter voice synthesizer module is connected with the periodic signal branch and the nonperiodic signal branch and used for calling a voice synthesizer to synthesize voices according to the periodic frequency spectrum parameters, the periodic excitation signals and the nonperiodic excitation signals. The residue signals after inverse filtering is modeled to enable the excitation signals to be higher in accuracy, and quality of synthesized voice is improved.

A method and device for high speed broadband testing of systems and substances using a binary, spectrally sparse sequence (SSS) as a periodic excitation waveform. The sequences with controllable frequency and magnitude spectra content are designed by component manipulation method or by edge manipulation method. The excitation waveform is typically pre-calculated, and kept in waveform memory, from where it is shifted out into digital to physical quantity converter (DQC).The sparse spectrum of the SSS makes it easy to create plenty of uncorrelated frequency sets with adjacent, but sufficiently different frequencies to form multi-path test systems, where all the paths can be measured simultaneously.The response of the sample under test (SUT) is sampled and the complex transfer function is calculated directly or indirectly via Impulse Response by Discrete Fourier Transform technique and its derivatives. The sequence bit interval and sampling interval have a predetermined ratio.

Apparatus and associated methods involve operation of an LED light engine in which a relative intensities of selected wavelengths shift as a function of electrical excitation. In an illustrative example, current may be selectively and automatically diverted substantially away from at least one of a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level. The diversion current may be smoothly reduced in transition as the excitation current or voltage rises substantially above the predetermined threshold level. A color temperature of the light output may be substantially changed as a predetermined function of the excitation voltage. For example, some embodiments may substantially increase or decrease a color temperature output by a solid state light engine in response to dimming the AC voltage excitation (e.g., by phase-cutting or amplitude modulation).