31results about How to "Reduce phase lag" patented technology

The invention discloses a SINS self-aided navigation method for a deep diving manned submersible. The method comprises the following steps: 1, taking angular motion and linear motion measurement provided by an inertial measurement unit (IMU) on the manned submersible as input of a strapdown inertial navigation system (SINS), executing two navigation calculation algorithms in parallel, and outputting two groups of identical navigation parameters, thus obtaining two sets of identical strapdown inertial navigation systems SINS1 and SINS2; 2, performing frequency difference characteristic analysison a horizontal speed output by the SINS1 in the step 1; 3, designing a high-pass time-delay-free digital filter, and filtering out a low-frequency speed error component contained in the horizontal speed output by the SINS1, thereby obtaining the real horizontal speed of the manned submersible; and 4, commonly constructing speed matching integrated navigation through Kalman filtering and the SINS2 by utilizing the real horizontal speed obtained in the step 3, thus obtaining an integrated navigation result of which the positioning error is not accumulated along with time. According to the method, auxiliary speed information under a navigation system can be obtained, and the positioning errors are not accumulated along with time.

The invention discloses an immune algorithm based method for estimating the square wave injection rotate speed of PMSM high-frequency voltage. The immune algorithm based method is specifically implemented according to the following steps: step one, injecting a high-frequency voltage square-wave signal in an estimated rotating coordinate system, using a high-pass filter based on immune algorithm on-line optimization to extract high-voltage current response corresponding to the high-frequency square-wave voltage signal; step two, obtaining a rotor position error signal through signal processing by the high-frequency current response obtained in the step one; and step three, estimating the rotate speed and rotor speed of a PMSM by a Romberg observer through the rotor position error signal obtained in the step two. According to the immune algorithm based method for estimating the square wave injection rotate speed of PMSM high-frequency voltage disclosed by the invention, the time constant of the filter is adjusted on line through the online learning immune algorithm, and the purpose of autonomously optimizing the time constant of the filter is reached, so that the actual rotor position is tracked preferably through the rotor position estimated by the high-frequency injection method, and the phase lag caused by the filter is reduced.

The embodiment of the invention discloses a vascular intervention robot system master end control method based on self-adaptive force feedback. The method comprises the steps that a motor model is constructed; constructing a slide rail model; acquiring a slave end sensor signal, and filtering the slave end sensor signal; constructing a reference model of the motor, and setting a controller to correct parameters of the motor model in real time based on the reference model; estimating a friction force based on the corrected motor model and the sliding rail model, and compensating the friction force; and based on the processed sensor signal, the reduced torque force borne by the slave end equipment and the reduced resistance in the horizontal direction borne by the slave end equipment act on an operating rod, and the reduced force acting on the operating rod is force feedback. According to the method, accurate force feedback can be realized, so that the vascular intervention robot system has high interference resistance and robustness, and output fluctuation can be avoided to a greater extent.

The invention discloses a method for detecting motor kinematics parameters based on pulse feedback. The method comprises the following steps: by continuously collecting the pulse count of N times before the signal reading time, linearly fitting the collected N pulse count and the corresponding time thereof to an N-1 order function, so as to obtain a relational function of a motor position and the time; solving a first-order derivative of the relational function of the motor position and the time to obtain a relational function of motor speed and the time; solving the first-order derivative of the relational function of the motor speed and the time to obtain a relational function of accelerated speed of a motor and the time; judging whether the signal reading time and the pulse count time are synchronous, and putting corresponding constraint conditions to obtain the detection results of the position, the speed and the accelerated speed of the motor. According to the method, the position, the speed and the accelerated speed of the motor as well as the speed range of expanded speed measurement at the signal reading time are calculated at the same time, so that the calculation accuracy and instantaneity of the position, the speed and the accelerated speed of the motor are improved.

The invention discloses a composite control method for improving an anti-interference capability of a brushless direct current motor. The method comprises the steps: S1, building a brushless direct current motor state equation, concluding parameter perturbation and external load interference as total disturbance, and building a brushless direct current motor servo system state space model; S2, taking the total disturbance as an extended state variable, and reconstructing a system equivalent state space model by separating a measurable state and an unmeasurable state of the system; S3, constructing a reduced-order extended state observer, and estimating the total disturbance and the unmeasurable state of the system online; and S4, designing a backstepping controller based on disturbance dynamic compensation by using the estimated value of the reduced-order extended state observer and the measurable state of the system, suppressing the influence of disturbance on the output of the system, improving the dynamic performance and robustness of the system, and ensuring the accurate tracking of the output of the system on reference input. The method is easy to implement, high in control real-time performance, high in tracking precision and the like.

The invention belongs to the field of the digital speed measuring technology and particularly relates to a median-value average filtering principle-based digital speed measuring method, wherein a speed feedback value is resolved based on the displacement. According to the median-value average filtering principle-based digital speed measuring method provided in the invention, firstly, the number N0of sampling points is selected, and a median-value average filtering-based digital speed measuring scheme is determined. The speed measuring scheme is subjected to mathematical simulation test. In this way, whether the signal characteristic and the phase margin characteristic of the speed measuring scheme meet the requirements at the same time or not can be verified. After that, the entity test is carried out on a motor connected with an absolute displacement sensor, wherein whether the characteristic of the speed feedback signal of the motor and the characteristic of the phase margin of thecontrol loop meet the requirements at the same time or not are verified. According to the invention, the method overcomes the defects of a traditional method in an initial operation stage and reducesthe resolution error. Meanwhile, the introduced phase lag is reduced. The control characteristic in the initial acceleration stage is improved. The method is suitable in all application scenes whereincorresponding speeds need to be resolved by using linear displacement values or angular displacement measurement values. The method has great practical engineering application value.

The invention relates to a disturbance suppression system and method based on the combination of a model inverse structure and a multi-ring frequency division disturbance observer. The method mainly comprises the following steps that: a virtual synchronous motor controller is selected to pass through a control system based on the model inverse structure and the disturbance observer when a distributed power supply is connected to a main power grid through a voltage type inverter; the distributed power supply can actively participate in active frequency modulation and reactive voltage regulation processes of a power system, and voltage and current reference values are obtained at the same time; and the voltage and current controller is used for finely adjusting the injected voltage and current. The reliability of an inverter control system can be effectively enhanced, the stability is improved, current change and load power fluctuation caused by loop switching can be avoided when the operation mode of the micro-grid is switched through a static switch, and smooth switching of the operation mode of the micro-grid is realized.

The invention provides a vehicle motor controller harmonic current detection system and method. The system comprises a front-end coordinate transformation unit, a current harmonic residual unit, and a filtering unit. The front-end coordinate transformation unit is used for carrying out coordinate transformation on three-phase current input by the vehicle motor to obtain the sum of d-q axis fundamental wave current and harmonic current of each time; the current harmonic residual unit is used for removing each harmonic current of the d-q axis or removing the fundamental current of the d-q axis and other harmonic currents of the d-q axis except a certain harmonic current of the d-q axis in the sum of the fundamental current of the d-q axis and each harmonic current; and the filtering unit is used for filtering the first, second,..., Nth residual current. On one hand, phase lag introduced in the filtering process of other harmonic components by the low-pass filter is reduced, the response speed of harmonic current extraction is improved, on the other hand, the attenuation coefficient of other harmonic components by the low-pass filter is increased, and the fluctuation quantity of the extracted harmonic current is reduced.

The invention discloses a method for simulating a DAC function based on PWM, a digital-to-analog conversion circuit and a storage medium. The method for simulating the DAC function based on PWM comprises the following steps: obtaining the digit W1 of a first PWM signal and the digit W2 of a second PWM signal used for forming the first PWM signal; determining the number A of second PWM signals required for forming a first PWM signal according to the digit W1 and the digit W2; acquiring a signal parameter H1 of the first PWM signal; determining a signal parameter H2 of the second PWM signal according to the signal parameter H1; and outputting a first PWM signal composed of A continuous second PWM signals according to the digit W2 and the signal parameter H2. According to the method for simulating the DAC function based on the PWM, the harmonic frequency can be improved, so that the cut-off frequency of the low-pass filter is improved, the phase lag of DAC output is reduced, the time constant of the RC filter is reduced, the response speed is improved, and the requirement of a system for the response speed is met.

The embodiment of the invention, which belongs to the field of permanent-magnet synchronous motor control, provides a low-frequency control method and device of a permanent-magnet synchronous motor, a compressor and an air conditioner. The method comprises: after starting of a permanent-magnet synchronous motor, an electromagnetic torque is obtained and a first mechanical position angle is determined; according to the electromagnetic torque and the first mechanical position angle, an instantaneous load torque of the permanent-magnet synchronous motor is determined; a torque compensation current is determined by using the determined instantaneous load torque and a mapping relationship between an instantaneous load torque and a torque compensation current; and torque compensation is carried out on the permanent-magnet synchronous motor based on the torque compensation current. According to the low-frequency control method and device, the electromagnetic torque and the mechanical position angle are used as inputs; and compared with the mechanical rotation speed, the high-frequency noises are reduced; and no filter link needs to be set additionally for inputted noises. Therefore, accurate compensation currents are provided; the phase lag is small; and the anti-interference capability is high.