208 results about "Sinusoidal excitation" patented technology

A capacitive sensing system are configured to sense a capacitance value and convert the sensed capacitance value to a digital format. The capacitive sensing system provides good selectivity and immunity to noise and interference, which can be further enhanced by enabling spread spectrum excitation. In some embodiments, the capacitive sensing system utilizes a sinusoidal excitation signal that results in low electromagnetic emissions, limited to narrow frequency band. In some embodiments, the capacitive sensing system is configured to operate in a spread spectrum mode, in which the majority of the excitation signal power is carried in the assigned bandwidth. The excitation frequency and the bandwidth of the spread spectrum excitation signal are programmable in a wide range, which allows for avoiding frequency conflicts in the operating environment.

Disclosed is a system for dead time switching in a sinusoidally excited PM electric machine. The system comprises: a PM electric machine; a position sensor configured to measure a position of the electric machine and transmit a position signal; and a controller, where the controller receives the position signal. The controller executes a method comprising: obtaining a duty cycle command; generating a first control command signal to an upper switching device and a second control command signal to a lower switching device configured to drive the electric machine in response to the duty cycle command; and applying a dead time to the first control command signal to ensure that the upper switching device and the lower switching device are not conducting simultaneously; and wherein the dead time comprises a turn on delay and an advance turn off.

The invention discloses an alternating electric field-based time grating angular displacement transducer. The transducer comprises a probe matrix and a fixed disc matrix, wherein inner and outer circles of uniformly distributed electrodes are coated on the lower surface of the probe matrix; inner and outer circles of uniformly distributed electrodes are coated on the upper surface of the fixed disc matrix; the initial position of the inner circle of the electrodes on the fixed disc is half electrode central angle from the initial position of the outer circle of the electrodes on the fixed disc; the lower surface of the probe matrix and the upper surface of the fixed disc matrix are oppositely arranged and retain a certain gap delta to form inner and outer circles of differential capacitors; the probe matrix and the fixed disc matrix are coaxially arranged and can relatively rotate; inner and outer circles of electrodes of the fixed disc are connected with sine excitation voltages withphase difference of 90 degrees respectively; two paths of electric field coupling signals which are respectively generated by inner and outer circles of electrodes of the probe are synthesized into apath of travelling wave signal Uo, and are subjected to phase comparison after shaped with a phase fixed same frequency reference signal Ur; the phase difference of two paths of signals are expressedby an interpolated clock pulse, and an angular displacement value is acquired by conversion. The alternating electric field-based time grating angular displacement transducer has the advantages of low power consumption, light weight, high resolution and low cost.

A time grating linear displacement sensor based on an alternating electric field comprises two parts, namely a head measuring base body and a sizing base body, wherein a left electrode and a right electrode are coated on the lower surface of the head measuring base body; a left row of electrodes and a right row of electrodes are coated on the upper surface of the sizing base body; the distance between the start position of the left row of electrodes and the start position of the right row of electrodes of the sizing base body is 1/2 electrode width; the lower surface of the head measuring base body is relatively parallel to the upper surface of the sizing base body; a fixed clearance theta is formed between the lower surface of the head measuring base body and the upper surface of the sizing base body; a left group of differential capacitors and a right group of differential capacitors are formed; the head measuring base body and the sizing base body are relatively moved; the left rowof electrodes and the right row of electrodes of the sizing base body are respectively connected with sinusoidal excitation voltages with equal amplitude and equal frequency, wherein the difference between the phases of the sinusoidal excitation voltages is 90 degrees; two routes of electric field coupling signals respectively generated by the left electrode and the right electrode of the head measuring base body are combined into one route of travelling wave signals Uo through an adding circuit; after the route of travelling wave signals Uo is shaped with one route of common-frequency reference signals Ur with fixed phase, phase comparison is performed; and the phase difference between the two routes of signals is represented by an interpolated clock pulse and is transformed to generate a linear displacement value. The time grating linear displacement sensor based on the alternating electric field has the advantages of low power consumption, light weight, high resolution and low cost.

The invention relates to a libration simulator for a space laser communicating platform and is provided with a laser emission unit (6), an optical power adjusting unit (7), a beam servounit (8), a beam extending unit (9), a communicating optical transmitter and receiver (10) for the tested laser, a beam servo drive unit (11), a DA transfer card (12), a power spectrum generating unit (13) and an optical table (14). The invention can simulate on low frequency agitation and high frequency libration and can effectively inspect and verify the APT tracing precision of a space laser communicating system. A simulative bandwidth can reach to 100Hz, the maximum simulative extent of low frequency can reach to 20mrad, and the controlling precision of high frequency extent can reach to Mu rad magnitude. The invention has broader dynamic range, can librate randomly according to the wide spectrum of a power spectrum simulative platform, can also simulate the movement of a relative angle and sinusoidal excitation, and can detect on the dynamic lag error of the APT system, realize two-dimensional libration simulation, realize optical power adjusting and big caliber parallel beam emission and meet the test requirement for the tracing precision of the space laser communicating APT.

The invention relates to a real-time vibration-aging vibration level testing system. The real-time vibration-aging vibration level testing system comprises a processor, a signal generator, a driver, a vibration exciter, an acceleration sensor, a charge amplifier, an oscilloscope and a support device, wherein a member is fixedly connected with the vibration exciter; the processor controls the signal generator to output sinusoidal excitation signals, of which the amplitude and frequency are independent and are continuously adjustable; the processor comprises a voltage waveform reading module, a voltage identification module, a vibration level detection module and a critical threshold setting module. An automatic vibration level adjustment method comprises the steps that the member is fixedly connected with the vibration exciter; the vibration level detection module is subjected to parameter value setting; the voltage waveform reading module acquires a voltage waveform displayed by the oscilloscope; the voltage identification module acquires voltage peaks; the processor determines first excitation frequency of vibration aging; the processor determines second excitation frequency of vibration aging and enables the vibration exciter to carry out vibration aging treatment on the member at the second excitation frequency. The system and the method have the advantages that the vibration level can be accurately tested in real time, and the vibration level can be adjusted automatically.

The invention relates to a storage battery impedance detection device excited by a SPWM signal generated by a single-chip microcomputer, and relates to a four-wire detection device for the internal resistance of a sealed valve-regulated lead-acid battery. One wire is connected to the voltage detection device to form a voltage sampling circuit, and the other two wires are connected to a current constant current source to form a current injection circuit. The excitation signal comes from the SPWM signal generated by the microcontroller through programming, and the modulation frequency of the SPWM excitation signal It can be adjusted according to the actual measurement situation. The invention obtains sinusoidal excitation signals of different frequencies through the SPWM modulation method to measure the internal impedance distribution of the sealed valve-regulated lead-acid battery VRLA, and can comprehensively grasp the internal resistance of the sealed valve-regulated lead-acid battery VRLA in the working state of the sealed valve-regulated lead-acid battery. line detection device.

The invention discloses a magnetic core loss separation calculating method. The method includes the following steps: under the condition of the given magnetic flux density variable quantity, , forming a magnet loss construction separation equation set to separate magnetic hysteresis loss from vortex loss by using loss data of any two working points with different frequency under sinusoidal excitation, simulating corresponding relation of resistance rate of magnetic core materials and frequency of the magnetic core materials through a linear interpolation method, and gathering the additional vortex loss of the rest loss to a classical conduction vortex loss. The magnetic core loss separation calculating method has the advantages of being clear in physical concepts, simple in separation calculation process, capable of effectively separating loss components of the magnetic core without dependence on a special instrument, and being widely applied to simulation software to simulate size of loss of the magnetic core materials in power electronic application under different frequency and magnetic induction intensity.

The invention discloses a method for realizing the resistance measurement of an asynchronous motor fixed rotor. The method is used for quickly measuring the resistance of the motor fixed rotor when the motor is static. The method comprises the following steps of: applying two currents with different sizes between any two phases of an asynchronous motor, and collecting the theoretical output voltage of an inverter to obtain equivalent stator resistance; obtaining the inverter error voltage under different current values of the inverter according to the equivalent stator resistance; applying sine-excited theoretical voltage onto any one phase of the asynchronous motor, and collecting the motor current of the phase from the zero crossing point of the sine-excited theoretical voltage to obtain a motor current sampling value of the phase within one period; obtaining the motor practical voltage sampling value of the phase within one period according to the inverter error voltage and the sine-excited theoretical voltage; carrying out discrete fourier transformation on the motor current sampling value and the motor practical voltage sampling value to obtain fundamental wave component; and obtaining the rotor resistance of the asynchronous motor according to the current of the motor and the fundamental wave component of the motor practical voltage.

The invention relates to a method and device for calibrating a piezoelectric ceramic sine-excited acceleration meter, installing a tested acceleration meter by bolt on a sine exciter composed of piezoelectric ceramic and installation disc and applying a sine drive voltage to piezoelectric ceramic so that the sine exciter will make a corresponding sine output shift. And the device is composed of piezoelectric ceramic, installation disc and base, where the piezoelectric ceramic is bonded with the installation disc with resin glue, the piezoelectric ceramic is installed on the base via resin glue. And the device is simple and low-cost.

The invention discloses a method for diagnosing faults of an analog circuit of multi-fractional order information fusion, belonging to the field of network fault test and diagnosis of the analog circuit. The method comprises the following steps of: A inputting N types of effective sinusoidal excitation signals with different frequencies in series at the input end of a circuit to be tested to obtain an initial dataset; B randomly dividing a sample set into k feature space subsets by adopting a random subspace method; C mapping the feature space subsets into k diverse fractional-order time-frequency spaces by using fractional-order Fourier transform; and D obtaining a final diagnosis result by utilizing the weight of a failure class and fusing the diagnosis results of k basic classifying models, and dynamically updating the weight of the failure class after completing the diagnosis on each batch of test data. The invention improves the difference degree of the feature space subsets, increases complementarity among basic classifiers, combines with the gradual change characteristics of device faults and effectively improves the precision of a diagnosing system.

The invention discloses a rotary transformer system and a control method thereof. A digital signal control chip modulates and outputs a sinusoidal excitation signal with preset frequency, the sinusoidal excitation signal is used as rated voltage of a rotary transformer after being conditioned; a zero passage moment of the sinusoidal excitation signal is used as an interrupt signal of the digital signal control chip; a timer of the digital signal control chip starts to count by taking the zero passage moment as a time reference, the digital signal control chip collects an AD sample of a sine and cosine signal of the rotary transformer after 1/4 period is delayed; the rotary transformer outputs two sine and cosine modulation and simulation signals; a signal conditioning circuit is used for conditioning the two sine and cosine modulation and simulation signals to obtain the conditioned simulation signals to be transmitted to the digital signal control chip; and the digital signal control chip synchronously samples the conditioned simulation signals to obtain an AD conversion result and output a rotor position angle value. According to the method, a special calculating chip is removed, so that the integration level of a control system is improved, and the cost of the control system is reduced.

The invention provides a fixed frequency calibration test method of spacecraft vibration. The method comprises the following steps that: a corresponding relation between a support reaction force per unit length and a strain of a spacecraft root is determined, wherein the support reaction force per unit length is generated by the spacecraft during a sinusoidal vibration test, and an auxiliary basis is provided for determination on a concave downward condition of a main frequency range during the sinusoidal vibration test of the spacecraft; more particularly, at an off-resonance range of the spacecraft, by using a lowest working frequency that is allowed by a vibrating table and is normally from 2 to 5 Hz, sinusoidal excitation with a fixed frequency is carried out on the spacecraft under a certain order. After test evaluation is completed, the test method can be applied to vibrating tests of various spacecrafts, so that rationality and effectiveness of the test can be determined. According to the invention, problems that are common in the vibrating test process of a spacecraft can be solved, wherein the problems include a problem of overloading or underloading; and beneficial effects are as follows: the test is reasonable and reliable; the method can be realized simply; and the adaptability is strong and the like.

The invention discloses a high-efficiency thyristor valve assembly testing system. The system comprises a signal generation module, a signal collection module, a signal processing module, an optical communication control module and a thyristor valve assembly; variable-frequency high-voltage sinusoidal excitation is applied to the whole thyristor valve assembly by the signal generation module, and the thyristor valve assembly can be subjected to routine inspection by the aid of a distributed voltage measurement unit with multiple node potentials, a current measurement unit and an impedance calculation method. Meanwhile, the invention further discloses a method for testing electrical performance of thyristor levels of a thyristor valve. According to the system and the method, the thyristor valve assembly formed by connecting a random number of thyristor levels in series can be subjected to an impedance test, a short-circuit test and a low-voltage trigger test simultaneously, so that the testing efficiency is greatly improved, and maintenance duration and predelivery test period of the thyristor valve are shortened.

The invention provides a shock absorber noise detection device. The device comprises an indicator, and a sensor, a signal acquisition system and a signal analysis system which are connected in turn. When the shock absorber is under sinusoidal excitation with certain vibration amplitude and frequency and a certain temperature, the shock absorber noise detection device performs data acquisition, data conversion and data post-treatment to various signals such as acceleration, displacement and acoustic pressure to obtain the judgment limit values of the noise of the shock absorber in different conditions, and the limit values are used as the judgment standards of the noise level of the shock absorber. By using the shock absorber noise detection and judgment method, the judgment standards of noise can be determined; and after the judgment standards are determined, the same method can be adopted to screen noise to the same type of shock absorber products on the production line without verifying on the finished automobile so that essential data and control basis can be accumulated for the noise control of the shock absorber and optimization direction is pointed out.

A monitor supersonic motor is composed of a rotor, a stator, spring plate, a hollow shaft, piezoelectric ceramic plates, the stator is fixed at the shell by screws, the rotor generates a pressure to press on the stator relying on the deformation of the spring plate, adjustment of pad thickness determines the deformation volume of the spring and the pre-pressure. The rotor and the spring, the spring and the shaft are driven by keyslot connection and the shaft applies a clamped way for bearings at both ends. When a sine- exciting signal with two-phase difference of 90deg.is inlet into the ceramic plate on the stator, mass points on its surface move elliptically to drive the rotor.

A resolver excitation apparatus that adjusts amplitude of a sinusoidal excitation source signal to generate an excitation signal having predetermined amplitude in order to excite an exciting winding of a resolver. A parallel resonant circuit having a parallel resonant element that functions as parallel resonant impedance for impedance of the excitation winding. A series resonant circuit having a series resonant element that functions as series resonant impedance for the impedance of the excitation winding.

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.

The invention discloses an SCARA robot joint friction force identification method based on a LuGre friction model. The SCARA robot joint friction force identification method comprises the following steps that S1, robot joint friction force is modeled through the LuGre friction model, a sinusoidal excitation curve is utilized to sequentially excite robot joints, and thus a robot joint friction force-speed mapping relation is obtained; and S2, in all stages of the friction phenomenon, LuGre friction model parameters are identified according to the robot joint friction force-speed mapping relation. The SCARA robot joint friction force identification method is simple and effective and can be used for a robot with the limited movement space, and the great significance for improving the performance of the robot is achieved.

The invention provides a plane chord linear displacement sensor. The plane chord linear displacement sensor comprises a sizing ruler and a measuring head, wherein silicon wafers are connected to the sizing ruler and a substrate of the measuring head in a bonding mode, an MENS photolithography is adopted to conduct even line etch on the silicon wafers to form electric conduction coils, wherein the electric conduction coil on the sizing ruler is single-phase and rectangular, the electric conduction coil on the measuring head is a three-phase sinusoid-shaped coil which is staggered by a 1/3 polar distance, and the sizing ruler coil and the measuring head coil are arranged in a relatively parallel mode. When in the sizing ruler coil, a sine is used for driving a signal, three routes of sensing signals are generated in the three-phase measuring head coil, the three routes of sensing signals are made to respectively conduct phase shift by 0 degree, 120 degrees and 240 degrees according to time and then be added together so as to obtain an electricity traveling signal, and the phase position of the electricity traveling signal corresponds to linear displacement. The plane chord linear displacement sensor has the advantages of being high in precision, low in weight, small in size and low in power consumption.