135 results about "Phase plane" patented technology

The present invention provides an urban traffic system state visualization evaluation method based on traffic flow characteristics. Said method includes the following steps: A, in specific road section collecting real-time signal waveform whose continuous time is not less than three months, forming traffic flow state parameter; B, making traffic flow state parameter undergo the process of signal filter treatment so as to obtain traffic flow sample population; C, calculating average value and standard difference of all the samples in sample population, and using ratio value of standard difference and average value as sample discrete coefficient; D, according to traffic flow multidimensional state parameter strong aggregation characteristics forming and optimizing standard characteristic-phase plane graph for evaluation; and E, placing historical data, current data and predictive data of traffic system on the standard phase graph, and visually distinguishing running state of traffic system and its change tendency.

The invention discloses a method and a device for planning a robot time optimal trajectory based on a dynamic model. The method for planning the robot time optimal trajectory comprises the following steps: converting joint motion constraint and geometric path constraint to a parameter space through a robot motion trajectory predetermined by dynamics modeling and parameterization; taking shortest time as an objective structural optimization problem, and solving through a numerical integration method to obtain an optimal motion parameter of the robot; and carrying out spline curve smoothing on acceleration for three times on a phase plane by considering the problem of joint vibration caused by sudden change of the acceleration. Compared with the conventional trapezoid acceleration trajectoryplanning method, the motion parameter of the robot can be optimized under the joint motion constraint and the geometric path constraint; the high-speed motion of the robot can be achieved; the performance of a joint motor is fully used; the motion speed of the robot can be further improved; pitch time for executing tasks is reduced, so that the operation efficiency of the robot is improved; and the method and the device have great significance to improvement of overall performance of the robot.

The invention provides a high-performance elastic alloy material for an aerial hyperbaric cabin. The production method of the high-performance elastic alloy material comprises the following steps: (1) vacuum melting; (2) electroslag refining; (3) forging an ingot billet; (4) hot-rolling molding; (5) cold drawing; and (6) performing heat treatment. The high-performance elastic alloy material obtained by the method has high tensile strength up to 160/250(MPa); a wrapping test proves that the alloy material is not ruptured after being wound around not less than 15 circles, which is obviously superior to the national standard; and in the eventthat the alloy material is bent for 90 degrees forwardly and reversely on the same phase plane, the outer side of the bent position is not cracked and ruptured.

The invention relates to a parameter re-calibration method for a structured light three-dimensional measurement system, and equipment; and an auxiliary camera is added in a system with a camera and a projector to realize re calibration on a parameter inside the projector. A high-precision white flat plate is arranged; the projector projects a structured light pattern; and the original system camera and the auxiliary camera collect a white flat plate pattern. The two cameras are calibrated to obtain the parameter of the auxiliary camera; on the basis of a stereoscopic vision principle, a white flat plate is reconstructed by using a shot picture; a reconstructed point cloud is projected to an emission phase plane of the projector in a back projection mode, a corresponding projection phase is calculated, and a difference between the calculated projection phase and an actual phase to obtain a phase residual difference value; and then on the basis of a principle of least squares, calculation is carried out to obtain error values of a transverse equivalent focal distance and a lateral optical center of the projector, thereby completing re calibration of the parameter inside the projector. Therefore, the calibration accuracy of the structured light three-dimensional measurement system is improved.

A phase plane correlation motion vector determination method identifies images areas in which motion took place. A reference image is shifted by the candidate motion vectors obtained from the phase plane correlation. The shifted reference image is correlated to determine similarity with the current image and to eliminate spurious motion vectors. Candidate motion vectors are validated to determine valid motion vectors and identify problem areas. In a preferred embodiment, a correlation resolution is set to a sub-block size. Sub-blocks of the reference image are shifted by candidate motion vectors for corresponding blocks. Shifted sub-blocks are correlated with sub-blocks of a current image using a sub-block neighborhood to determine valid vector assignments. Where an assignment proves invalid, global motion parameters are determined to assign motion vectors to sub-blocks where correlation fails.

The invention discloses an implementing method for front vehicle following. The implementing method comprises the following steps of expressing following characteristics of vehicle distance control on a phase plane plot, wherein the transverse axis is the relative distance R of the two vehicles, and the vertical axis is the relative speed V of the two vehicles; adopting a straight line and curve combining method to determine an ideal target following characteristic curve in the phase plane plot; setting an ideal working point and a relatively ideal working point on the phase plane plot; adjusting the relative distance of the two vehicles in the front vehicle following way to approximate to the amplitude Ra; in the initial phase when the Ra is not reached, adopting the fixed acceleration and deceleration to approximate to the vehicle distance of the ideal working point; in the adjusting phase after the Ra is reached, reducing an accelerator or braking to reach the ideal working point, wherein the ideal working point is that the relative speed of the two vehicles is zero and the relative distance of the two vehicles is the ideal and safe vehicle distance set by a driver. The implementing method for the front vehicle following is applied into a vehicle cruising control system, so the comfortability and safety of the vehicle cruising control system are improved, and the easiness in accepting by the driver is realized.

A phase plate (10) for phase-contrast electron microscopes is characterized by comprising a conductive core phase plate (14) which has a phase plate body (11) and a phase plate support (12) supporting it and is arranged in the path of electrons having passed through the objective lens of an electron microscope and in which the phase plate body (11) is so supported on the phase plate support (12) having an opening (13) as to cover at least a part of the opening (13) and a conductive shield thin film (15) covering the periphery of the core phase plate (14) including the upper and lower sides thereof. Consequently, a phase plane for phase-contrast electron microscopes preventing the lens effect incident to charging completely and applicable to the field of material science, its manufacturing method and a phase-contrast electron microscope can be provided.

A video codec of a preferred embodiment is suitable for implementation on a variety of platforms, including platforms where devices require both encoding and decoding engines. Various features of preferred embodiment codecs reduce complexity for operations such as motion determination. Channel resources are allocated in preferred embodiments unequally, with an allocation being determined based upon channel conditions and the error level in a frame being encoded. A decoder of a preferred embodiment, provided with an error frame and motion vector information may conduct decoding with motion compensation. In an example encoder of the invention, a motion estimator identifies motion vectors using a phase plane correlation technique based on phase quantization, where the phase difference between the Fourier transformed version of blocks in a reference frame and a current frame is estimated by dividing the complex plane into sectors and assigning the Fourier domain difference to the sectors.

The invention discloses a distributed electric vehicle yaw stability control method and system. The distributed electric vehicle yaw stability control method includes the steps that a road surface adhesion coefficient of the road surface on which a vehicle is and the state data of the vehicle at current time are obtained; a centroid inclined angle-centroid inclined angle velocity phase plane diagram corresponding to the road surface on which the vehicle is is determined based on the road adhesion coefficient; a maximum stable area and a minimum stable area of the phase plane diagram are determined; and the positions of phase trajectory points of the vehicle in the phase plane diagram in a current state are determined; a centroid inclined angle weight coefficient is determined according to the positions; the expected yaw angular velocity and expected centroid inclined angle of the vehicle are calculated; a sliding mode surface switching function is established; according to the state data, the centroid inclined angle weight coefficient, the expected yaw angular acceleration and the expected centroid inclined angle velocity and the sliding mode surface switching function, a desired additional yaw moment is calculated; and the steering of the vehicle at the current moment is controlled based on the expected additional yaw moment. According to the distributed electric vehicle yaw stability control method and system, the stability degree of the vehicle can be accurately judged, and the steady-state steering of the electric vehicle is realized.

The invention discloses a phase plane vehicle stability determination method. The phase plane vehicle stability determination method comprises steps of establishing a two-freedom-degree vehicle analysis model according to a driving condition input parameters, using a vehicle two-freedom-degree model to draw a whole working condition vehicle stability phase plane graph, wherein the phase plane graph is a vehicle-side-slip-angle-and-yaw-velocity phase plane graph with the yaw velocity as an ordinate and the side slip angle as an abscissa, 2) determining a type of a stability domain where the vehicle is positioned according to the working condition of the vehicle, 3) using a stability domain type database to obtain a vehicle stability domain according to the vehicle working condition and 4) determining whether the vehicle is unstable through determining whether the vehicle driving state is beyond the stability domain. The phase plane vehicle stability determination method can fully characterize a stability state of a full working condition vehicle and provides an accurate determination basis to involvement and exit of the vehicle stability control.

The invention relates to a weak periodic signal detecting method based on a phase-locked loop and a Duffing oscillator, and belongs to the field of signal processing. According to the method, the phase-locked loop and the Duffing oscillator are used for setting up a combined weak signal detecting system; signal frequency is detected through the phase-locked loop to detect weak periodic signals with unknown frequency; according to the curve characters of a time history of chaotic signals, and a sequence diagram method and a phase plane diagram method are matched to serve as the criterion for detecting a system state and detecting whether the system state changes or not; a precise threshold value at which the system jumps into a periodic state from a chaotic state is obtained, and the threshold and quality for detecting the weak periodic signal are improved. Compared with a traditional method, the weak periodic signal detecting method can detect the signals with the unknown frequency, is easier to implement, saves a lot of simulation time, is of great signification in practical application and thereby has very good application prospects.

The invention discloses a wireless power transfer system sliding-mode control method based on a Buck link, the method comprising the following steps of S1, determining the optimal switching point andthe steady state point on a uC1-iL phase plane by using the output capacitor voltage uC1 and the freewheeling inductor current iL of the Buck link as detection objects; S2, determining the slope of asliding-mode line and the longitudinal-axis intercept according to the optimal switching point and the steady state point; S3, determining whether current limiting control is needed, and if so, adjusting the slope of the sliding-mode line; S4, determining whether load switching occurs, and if so, adjusting the longitudinal-axis intercept of the sliding-mode line; S5, obtaining the output capacitorvoltage uC1 and freewheeling inductor current iL in real time, and controlling the state of a switch tube in a Buck circuit according to the sliding-mode control strategy. The method can accelerate the dynamic response, shortens a dynamic process, limits the current overshoot by changing the slope of the sliding-mode equation, quickly restores the output voltage of the secondary side to an original state during load switching, and improves the robustness and adaptability of the control.

The invention discloses an orbital angular momentum (OAM) multiplexing transmission system based on phase surface relaying. The OAM multiplexing transmission system comprises a signal transmitting end, a signal receiving end and a central receiver, wherein the signal transmitting end is used for collecting user data, modulating the user data into OAM electromagnetic waves of a plurality of modes,and transmitting the OAM electromagnetic waves to the signal receiving end; the signal receiving end comprises a plurality of relay repeaters which are distributed on a circular ring covered by a mainlobe; each relay repeater forwards received signals at different locations on a phase plane circular ring; the relay repeaters are independent of each other, and the number of the relay repeaters isno less than the mode number of the OAM electromagnetic waves; the signals are forwarded to the central receiver in a wireless or wired way; the central receiver comprises a second receiving and transmitting antenna for receiving the signals relayed and forwarded by the plurality of relay repeaters, a phase plane correction module for carrying on phase plane correction on the distributed transmitted signals, and a demodulation module for demodulating the signals being subjected to phase plane correction. By adopting the system, electromagnetic wave orbital angular momentum transmission of longdistance, high capacity and high spectral efficiency can be realized.

The invention discloses a method for accurately positioning bridge cranes and planning tracks in an online manner on the basis of phase plane analysis. The 32t bridge cranes can be automatically controlled by the aid of the method, and the method is excellent in positioning and anti-swing performance. The method includes simplifying system dynamics models and providing principles of phase plane processes; testing running characteristics of the industrial cranes in fields, analyzing the running characteristics and providing a process for planning the tracks in an online manner according to the running characteristics. The method has the advantages that track planning parameters are adjusted on an online manner by the aid of data of laser range finders in crane running procedures, grade braking schemes are adopted, theoretical analysis is carried out by the aid of analysis processes on the basis of phase planes, and system swing angles are proved to be close to zero when the bridge cranes reach target locations; the method is applied to automatic control systems of the 32t bridge cranes, excellent control effects can be realized, and accordingly the method has excellent practical application value.

The invention provides a method for controlling the liquid level of a four-hold water tank based on phase plane method. The invention has the main characteristics that the liquid levels of two water tanks which are positioned at the lower layer are respectively controlled by adopting two independent controllers. A phase plane partition control method is used as a control strategy. The method provided by the invention can directly calculate controlled quantity adapted to current ERROR and CHANGE IN ERROR according to the current ERROR and CHANGE IN ERROR without modeling for a system, has a stronger anti-interference performance and is suitable for controlling a coupling system. Aiming at the problem of time lag of a multi-hold water tank, the overshoot caused by the time lag can be restrained through adding the derivation feedback; and by organically combining the time lag and the derivation feedback, finally, a set value can be quickly and stably tracked by the liquid level.