9results about How to "Reduce distortion rate" patented technology

This invention discloses a video lens and an electronic device. The video lens has an object side and an image side arranged opposite to each other along the optical axis. The video lens includes a lens barrel and a lens group disposed within the lens barrel. The lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a photosensitive chip arranged sequentially from the object side to the image side. The video lens satisfies the following condition: 0.1≤FA / TTL≤0.25, where FA is the optical focal length of the video lens, and TTL is the distance between the object side surface of the first lens and the imaging surface of the video lens on the optical axis. Through the reasonable arrangement of the five lenses, the optical focal length FA and the total optical length TTL of the optical system of the video lens satisfy the relationship: 0.1≤FA / TTL≤0.25, and the distortion rate reaches below 3%, so as to provide a video lens with small size, low distortion rate, and 4K high pixel resolution.

This invention discloses a grating galvanometer device and its control system and method. The grating galvanometer device includes: a grating galvanometer motor with a motor output shaft; a galvanometer clamp mounted on the end of the motor output shaft for clamping and fixing a laser reflector; a triangular chuck-type quick clamp with one end coaxially fixedly connected to the motor output shaft; a DD motor with a motor output shaft, the other end of which is rigidly connected to the quick clamp to allow the motor output shaft to rotate coaxially with the galvanometer; and a motor bracket for supporting the grating galvanometer motor and the DD motor. This invention uses real-time feedback data from the DD motor as a precision benchmark, enabling the acquisition, modeling, and iterative correction of short-cycle errors during the operation of the galvanometer motor. This solves the short-cycle error problem existing in low-resolution grating galvanometer motors, achieves real-time correction of the galvanometer motor's angle positioning error, improves the accuracy and consistency of laser processing, reduces equipment hardware costs, and enhances adaptability to various working conditions.

A kind of energy storage converter multi-machine parallel system stability analysis method, comprising: modeling and control of single PCS;Application of capacitor current feedback type active damping control strategy;Analysis of stability of single PCS under PI control;Mathematical modeling of multiple PCS parallel system;Establishment of parallel system norton equivalent circuit;Using logarithmic frequency characteristic curve, verify that active damping control can have better inhibitory effect on resonance peak of parallel system.Capacitor current feedback type active damping method can not only compensate resonance peak of parallel system, improve the stability of system, but also effectively reduce grid-connected current distortion rate, improve power quality.The stability analysis method for PCS multi-machine parallel system provided by the present application can be used for judging the operating state of parallel system, ensure the stable operation of system, and provide theoretical basis for parameter design of PCS controller.

The present invention discloses a lightweight low-light-level night vision device optical system, which comprises an objective lens mechanism, an image intensifier and an eyepiece mechanism. The objective lens mechanism comprises a first double convex lens, a second concave-convex lens, a double glued lens, a rear glued lens and a third concave-convex lens. The eyepiece mechanism comprises a plano-convex lens, a fourth concave-convex lens, a front double glued lens and a rear double glued lens. The lightweight structure is adopted to reduce the mass, the distortion rate is low, the imaging is clear, the structure is compact, and the device is convenient for wide range use.

The invention discloses an active vibration suppression method for random frequency mixing of a three-phase surface-mounted permanent magnet motor, and the method comprises the steps: firstly carrying out the LMS and peak estimation of a real domain signal collected by a vibration acceleration sensor in a segmented manner with the step length of 1Hz, and finally obtaining a series of peak radial vibration frequencies x1, x2, x3... xk; establishing a current injection model under a rotating coordinate system, and for each peak radial vibration frequency xk, calculating a positive-sequence symmetric current of xk + f frequency and injecting the positive-sequence symmetric current into the model; combining and injecting all obtained frequency current injection models into the rear end of a current loop PI regulator, and obtaining the vibration of each peak frequency; multi-target vibration deep learning is carried out on the vibration of each peak frequency to obtain an optimal frequency mixing current, and the motor frequency is adjusted to realize active vibration suppression; according to the comprehensive vibration suppression algorithm based on vibration feedback, the coupling problem of vibration of each frequency generated by multi-frequency current is solved, the vibration suppression effect is improved, the stability and the anti-interference capability of the system are enhanced, and the method is easy to implement.

The invention discloses a fractional order nonsingular terminal sliding mode control method for a single-phase quasi-Z-source rectifier, and the method comprises the steps: carrying out the voltage and current double-closed-loop PI control at an AC side of the quasi-Z-source rectifier, obtaining a sinusoidal modulation wave, introducing a fractional order item into a sliding mode surface at a DC side, and obtaining an equivalent control law of a fractional order nonsingular terminal sliding mode controller. And combining a global control law with sinusoidal modulation waves, and controlling a rectifier bridge and a switch tube in the quasi-Z-source network through the generated driving signal so as to realize a control target. The fractional order nonsingular terminal sliding mode control can enable the system to converge within finite time, and compared with integer order nonsingular terminal sliding mode control of a single-phase quasi-Z-source rectifier, the fractional order nonsingular terminal sliding mode control has the advantages that the input side alternating current distortion rate is reduced, the fluctuation of the output side direct current voltage is reduced, the dynamic response speed of the output side direct current voltage is increased, and the system reliability is improved. The control precision is higher, and the dynamic and static performance of the system is improved.

The invention relates to the technical field of motors, in particular to a high-magnetism-gathering anti-saturation less rare earth permanent magnet and electromagnetic salient pole hybrid excitation motor which comprises a front end cover, a machine shell, a rear end cover, a rotating shaft, a stator and a rotor. The rotor is composed of a rotor iron core, neodymium iron boron permanent magnet steel, ferrite permanent magnet steel and an excitation winding, an even number of salient poles are uniformly distributed on the rotor iron core, arc-shaped contours are processed on two sides of a pole body of each salient pole to form a gourd-like excitation winding groove, the excitation winding is wound in the gourd-like excitation winding groove, and the excitation winding is wound in the excitation winding groove. Magnetic steel grooves for placing ferrite permanent magnet steel are formed in the outer sides of the gourd-like excitation winding grooves; and magnetic steel grooves for placing neodymium iron boron permanent magnet steel and arc-shaped magnetic isolation grooves are formed in the salient pole shoes. According to the invention, the magnetism gathering performance of the salient pole rotor can be effectively improved, the air gap flux density waveform can be improved, the distortion rate can be reduced, and the design of the gourd-like excitation winding grooves can effectively reduce the magnetic circuit saturation of the rotor and improve the torque performance of the motor.

A synchronous motor control algorithm is proposed to solve the inherent DC side capacitor midpoint voltage offset of NPC structure three-level inverter and the traditional SVPWM algorithm with multiple sector divisions and complex calculations. A target flux linkage simplified tracking algorithm with hidden midpoint vector is proposed in this paper. The input voltage space vector is divided into large and small sectors to improve the SVPWM algorithm: based on the principle of hiding the midpoint vector and using zero vector, small vector and large vector for modulation, the area where the voltage space vector passes is divided into 18 asymmetric sectors to form an SVPWM control model. Finally, a Simulink simulation platform is built to verify the correctness of the improved algorithm under different modulation degrees. The correctness of the line voltage output waveform and the feasibility of balanced control of the midpoint potential of the DC side capacitor of the three-level inverter. This design can not only realize the balanced control of the midpoint potential, but also reduce the amount of calculation by half and the waveform distortion rate is small.

The invention relates to the technical field of sintering equipment, in particular to a silicon carbide ceramic production vacuum sintering furnace and a sintering technology.The silicon carbide ceramic production vacuum sintering furnace comprises a furnace body, a heating source, a supporting ring and a driving part, the supporting ring is located between a first heating sleeve and a second heating sleeve, and after the supporting ring moves into a heating cavity, the driving part drives the supporting ring to rotate; a blocking cover is used for blocking a feeding opening, a sucking pump is started to suck gas in a heating cavity, the interior of the heating cavity is in a relatively vacuum environment, the influence of oxygen in air on a silicon carbide ceramic blank is reduced, when a first heating sleeve and a second heating sleeve are started, a driving piece drives a support to rotate around the axis of the support, and in the rotating process, the support rotates around the axis of the support. The silicon carbide ceramic is uniformly heated in a stable state, and the probability of distortion of the silicon carbide ceramic is reduced.