81results about How to "Reduce singularity" patented technology

The invention provides a fuzzy sliding mode trajectory tracking control method for an SCARA robot with modified sliding mode surface and reaching law. The method has the advantages that no precision dynamical model is required, and robustness is high; a fast terminal sliding mode surface which is modified is adopted, so that convergence rate of a system is increased, and singularity of the traditional terminal sliding mode surface is eliminated; the fast reaching law is adopted, the exponential approach law features fast reaching when leaving the sliding mode surface, power reaching law features smooth reaching when reaching the sliding mode surface, and tracking speed is increased, and meanwhile trajectory tracking precision is guaranteed; a sign function is replaced with a hyperbolic tangent function, and accordingly, high frequency chattering of the system is eliminated effectively; exponential term coefficient of the reaching law is corrected with a fuzzy adaptive controller, and the problem of moment shock caused by large system initial error is improved.

The invention pertains to the oil geophysical prospecting technique, relates to a method using the characteristic the amplitude changes with the vibration of the bias distance to improve the oil gas testing accuracy, which includes: 1, exciting and recording the earthquake wave process into a trace gather for AVO analyzing after time difference correcting; 2, executing an angular trace gather transformation to the input data; 3, obtaining two property section planes: delta(lambada/mu+2)/ (lambada/mu+2) and delta (mu* rho) /(mu* rho), taking the work area argillite wire trend, beta=0.86alpha-1172 as a restriction; 4, inversion after stack; 5, combining delta(lambada/mu+2)/ (lambada/mu+2) and delta (mu* rho) /(mu* rho) to execute analyzing of unconventionality boundary containing oil-gas. The inventive AVO analysis has the approximately same accuracy with Fatti, reduces indeterminacy in routine inversion method, improves the feasibility and reliability, and reduces the irregularity of the inversion matrix. The invention is very sensitive to the formation lithology and small opening fluid constituents, which is convenient for directly recognizing formation lithology variation and small opening fluid constituents.

The invention relates to a parameter identification based multi-motor servo system synchronization and tracking control method. The parameter identification based multi-motor servo system synchronization and tracking control method comprises the steps that 1, a multi-motor driven servo system containing unknown parameters is analyzed, and a mathematic model of the multi-motor driven servo system containing unknown parameters is established according to a motor structure and a physical law; 2, a load model established in the step 1 is analyzed, and unknown parameters in the load are estimated by utilizing a variable-gain self-adaptive parameter identification method; 3, synchronization and tracking control is conducted on the multi-motor driven servo system by utilizing neural network integral sliding-mode control algorithm according to a parameter identification result obtained in the step 2. The control method can ensure the steady-state accuracy of synchronization and tracking, effectively ensure transient-state and steady-state performance of parameter estimation, decrease the complexity and calculated quantity of algorithm design and effectively improves the response speed and robustness of the multi-motor driven servo system.

The invention provides an endogenous-safety cloud task execution device and method. The device comprises a heterogeneous cloud data center, an executor resource pool and an executor resource pool management module, wherein the heterogeneous cloud data center comprises multiple heterogeneous levels, and each heterogeneous level is configured with at least one resource; the executor resource pool comprises multiple executors, and each executor is obtained when resources of the multiple heterogeneous levels are subjected to resource combination with a preset executor carrier as a carrier; and theexecutor resource pool management module comprises an executor resource pool manager, a task manager and multiple sub task managers, the executor resource pool manager is connected with the executorresource pool, and the multiple sub task managers are connected with the executor resource pool manager and the task manager respectively. The method adopts a dynamic execution and mimetic combinationmechanism and serially uses a multi-safety mechanism. Thus, the reliability and the safety of cloud task execution can be improved.

The invention provides an adaptive fault tolerance control method for a vertical take-off and landing reusable launch vehicle. The method comprises the steps of: Step 1: obtaining a guidance command;Step 2: establishing a landing section fault tolerance control model; Step 3: designing a fixed time convergence and expansion state observer; step 4: designing a non-singular fast terminal sliding mode surface; and Step 5: designing an adaptive fault tolerance controller. According to the adaptive fault tolerance control method, this design pattern not only effectively improves the rejection capability of the system to the complex external interference and the adaptive fault tolerance performance under various engine failure modes, but also guarantees the rapid and accurate tracking of the attitude guidance command.

The invention relates to a method for synthesizing seismic records based on three-dimensional Gaussian beam ray tracing and a frequency domain. The method comprises the following steps of: 1) performing kinematics tracking by utilizing a common ray tracing way to obtain a ray path and kinematics characteristics; 2) performing dynamics tracking by utilizing a Gaussian ray beam to calculate dynamics characteristics; 3) synthesizing the seismic records in the frequency domain. As a Futyterman equation based attenuation algorithm, a frequency based green function and a weak anisotropic model of a coupling ray theory can be considered for the synthesis of the seismic records in the frequency domain, the dynamics characteristics of a seismic wave field can be described more delicately in comparison with a conventional method, and the seismic records synthesized by utilizing the ray theory is close to the precision of the wave theory. The method for synthesizing the seismic records based on the three-dimensional Gaussian beam ray tracing and the frequency domain can calculate information such as ray amplitude and phase shift conveniently, can be applied to the fields such as manufacturing of synthesized records, prestack depth migration and waveform tomography inversion.

The invention discloses a robust adaptive nonsingular terminal sliding-mode control method of automatic train operation. The method comprises that S1) the bearing condition of vertical movement of a train is analyzed, and a train vertical movement power equation including unknown parameters, uncertainty and external interference is established; S2) a nonsingular terminal sliding-mode surface is constructed; S3) an adaptive law of estimated values of the unknown parameters and a parameter equation of parameters of the sliding mode surface are designed; and S4) the nonsingular terminal sliding-mode surface, the adaptive law of estimated values of the unknown parameters and the parameter equation of parameters of the sliding mode surface are substituted into the train vertical movement power equation including the unknown parameters, uncertainty and external interference, a nonsingular terminal sliding-mode closed-loop control equation is obtained, and the nonsingular terminal sliding-mode closed-loop control equation is used to implement robust adaptive nonsingular terminal sliding-mode control of automatic train operation. Thus, position and speed tracking errors of an ATO system can reach the sliding surface within limited time and converged to 0 within limited time.

A circuit, method, and system for intelligently soft starting switching regulators are provided. The circuit, method, and system provide for a switching circuit operable to couple an input voltage to an output of the switching regulator in response to a control signal, a controller operable to generate the control signal to control the switching of the switching circuit based in part on a reference voltage, and a soft start circuit operable to provide the reference voltage to the controller responsive to the switching of the switching circuit.

Cutting elements include an ultra-hard body, e.g., comprising diamond, that is attached to substrate, e.g., comprising a cermet. An interface exists between the body and the substrate, and an angle of departure as measured between the interface and a free edge of the cutting element within one or both of the body and substrate, is less than about 90 degrees to provide a desired stress reduction along the interface. The angle of departure can be from about 3 to 87 degrees. The desired reduced angle of departure is provided by a surface feature disposed along an outer side surface of the cutting element adjacent a free edge of the interface. The surface feature can in the form of a groove disposed circumferentially around the body and/or substrate outer side surface, that is configured to provide the desired reduced angle of departure within the body and/or substrate.

The invention provides a parallel-series mixing device with four branched chains driving a single branch chain for servo. The parallel-series mixing device comprises a base, a moving platform, electric cylinders, cross hinges, ball hinges and a servo branch chain; the lower end of each electric cylinder is connected with the upper surface of the base through the corresponding cross hinge, and theupper end of each electric cylinder is connected with the lower surface of the moving platform through the corresponding ball hinge, the lower end of the servo branch chain is connected with the middle of the base through the cross hinges, the upper end of the servo branch chain is connected with the lower surface of the moving platform, the moving platform is provided with two rotational freedomdegrees and one lifting freedom degree, all electric cylinders work synergistically, and the rotation in any direction and the lifting within a certain range are achieved.

An ambiguity fixing method based on sequential least squares of the present invention can improve the success rate of measuring the ambiguity between two antennas in real time by using the single-frequency or double-frequency navigation satellite signals in a dynamic environment, provides the data support for the subsequent high-precision baseline measurement, attitude determination and the like,and is characterized by introducing the priori information in the ambiguity real number solution estimation process to serve as the state information to be transmitted to a filter, and accelerating convergence while reducing the morbidity of a design matrix. According to the method, the thought based on a measurement error modeling theory and a matrix triangulation decomposition technology is applied under a sequential condition, the additional calculation burden is not increased while the measurement information is accumulated, an ambiguity real number solution and the cofactor matrix information are calculated by constructing an ambiguity filter in a least square form, and finally, the ambiguity real number solution information is processed by using an LAMBDA method to search an ambiguity integer solution, thereby solving the problem of low ambiguity solving success rate of navigation satellite signals in a dynamic environment in a traditional method.

The invention discloses a numerical control machine tool kinematic chain design method considering a nonlinear error and a generalized modal. The method includes the steps of constructing a kinematicchain design and calculation model, with solving goals of minimizing a cumulative nonlinear error and minimizing the reciprocal of the generalized modal; generating a kinematic chain configuration population, for each kinematic chain configuration, calibrating a workpiece coordinate system, and subjecting cutter location data to the rotation transformation and the straight line transformation without travel constraints to obtain N groups of machine tool attitudes; determining whether the kinematic chain configuration matches the machine tool motion needed to realize the workpiece forming, andif not, carrying out the kinematic chain reconfiguration; calculating the generalized modal using a neural network model and calculating the cumulative nonlinear error using a differential method; andsolving the kinematic chain design and calculation model to obtain a Pareto solution set, and obtaining an optimal kinematic chain configuration by a TOPSIS method. The method of the invention overcomes the defects that a traditional kinematic chain design method relies on experience, only considers the forming characteristics of parts and has poor applicability, improves the kinematics and dynamics characteristics of a machine tool, and improves the machining accuracy of the machine tool.

Edge designs, especially for ePTFE-reinforced membranes for proton exchange membrane (PEM) fuel cells, wherein the designs provide a proton barrier at the electrode edge of the PEM fuel cell membrane electrode assembly (MEA) to provide, among other things, resistance to membrane chemical degradation. A portion of the ePTFE layer is imbibed with a proton-impermeable polymer at the electrode edge. The polymer can include, without limitation, B-staged epoxides, B-staged phenolics, hot melt thermoplastics, and/or thermosets or thermoplastics cast from liquid dispersions.

The invention provides a nonsingular adaptive non-smooth attitude tracking control method for a quadrotor unmanned aerial vehicle. The method includes the following steps: presetting a given attitudeangle, given rotational speed and given rotational acceleration; obtaining a current attitude angle and current rotational speed of the quadrotor unmanned aerial vehicle; calculating calculation errorvalues between the given attitude angle and given rotational speed and the current attitude angle and current rotational acceleration, and calculating a regression vector according to the attitude angle and the rotational acceleration; calculating a non-smooth control item according to the calculation error values; obtaining a parameter estimator according to the regression vector and the calculation error values; obtaining control quantity according to the regression vector, the parameter estimator and the non-smooth control item; and calculating and generating rotor rotational speed according to the control quantity, required lift and a rotor type. The nonsingular adaptive non-smooth attitude tracking control method for a quadrotor unmanned aerial vehicle solves the singular problem caused by smooth control, improves the performance of a controller, improves the attitude tracking control dynamic and static quality of the quadrotor unmanned aerial vehicle, and improves the practicality of the controller.

The invention discloses a planar parallel mechanism control device driven through double five-bar mechanisms and a planar parallel mechanism control method. The device comprises a planar parallel mechanism body and a control unit. The planar parallel mechanism body comprises a movable platform, a passive movement branch chain and two planar five-bar mechanisms. Three-axis acceleration sensors are arranged on the movable platform. Each planar five-bar mechanism comprises two direct driving rotary motors, two active bars and two passive bars. The passive movement branch chain comprises a bearing assembly and two passive bars. The control unit is connected with the three-axis acceleration sensors and the direct driving rotary motors. The two planar five-bar mechanisms serve as active movement branch chains and are driven through the direct driving rotary motors, and closed loop feedback is performed through the acceleration sensors, so that the advantages of being high in control accuracy, being fast in closed loop control response, eliminating singularity of existing parallel mechanisms and the like are achieved.

Wearable user interface devices are described. A wearable user interface device can include a wearable base connected to a trackable device component by a linkage. The linkage can connect to a pivoted support that the trackable device is mounted on, and which maintains poses when the user interface device is not manipulated by a user's hand The pivoted support has several orthogonal axes intersecting at a center of rotation located inside a device body of the trackable device. Other embodiments are also described and claimed.

The invention discloses a singularity processing method of a terminal maneuver small-overload guidance command. The method comprises the steps of calculating to obtain a longitudinal guidance force Fycx and a horizontal guidance force Fzcx according to a preset terminal maneuver phase guidance law and scheme; performing singularity processing on the guidance force: if Kc*m*g0 is greater than Fycx, Fyn=sign(Kc*m*g0)*|Kc*m*g0|, otherwise, Fyn=Fycx; calculating an angle of heel required by guidance according to the guidance force after the singularity processing; and calculating a normal force required by guidance according to the longitudinal guidance force Fycx and the horizontal guidance force Fzcx. The method provided by the invention can solve the problem of singularity an aircraft with a high lift-to-drag ratio in a terminal maneuver flight phase caused by a small-overload guidance command, reduces unnecessary large-amplitude missile body roll, and improves the guidance accuracy.

According to a method provided in the invention, the time analysis integration is carried out on a basic solution of an acoustic boundary element method, the segmentation integration about time is obtained through definition of principal value integration and finite part integration, singular principal value separation is carried out on segmentation singular integration in each time period to regularize the segmentation singular integration, and segmentation analysis is carried out on the principal value integration to eliminate singularity. For the near-singular integral, the wave pitch is combined with the shortest distance from the source point to the integral unit to construct a near-singular integral solving method. According to the method, singular integration in a transient acousticboundary element method is effectively solved, and a Laplace equation basic solution does not need to be used. The near singular integral method combining the wave pitch and the shortest distance from the source point to the integral unit can effectively process the fluctuation singularity and near singularity of the transient acoustic boundary element method, improve the calculation precision and convergence of the transient acoustic boundary element method, and improve the accuracy of transient acoustic radiation noise prediction.

The invention discloses a multipoint harmonic responsibility division method, which comprises the following steps of acquiring synchronous harmonic phasor measurement data of a concerned bus and each monitoring bus in a power system monitoring network, and establishing a multipoint harmonic responsibility division model according to the synchronous harmonic phasor measurement data of the concerned bus and each monitoring bus, and conducting harmonic wave responsibility division based on elastic network regression, reducing singularity of a measurement matrix by introducing a small amount of deviation, solving an ill-conditioned problem caused by multiple collinearity, considering influence of network normal degree fluctuation on harmonic wave measurement data, and estimating harmonic wave responsibility more accurately. The influence of different types of harmonic measurement scenes on the correlation degree of harmonic measurement data is considered, adaptability and robustness are achieved, and compared with traditional multipoint harmonic responsibility division, better accuracy and robustness are achieved under different harmonic responsibility division scenes.

The invention relates to the technical field of vibration control, and particularly discloses a structural decentralized vibration control system design method, which comprises the following steps of:1, dividing substructures; 2, calculating the modal information of the substructure; 3, constructing residual modal information; 4, constructing a modal transformation matrix; step 5, establishing asubstructure interface force physical expression; step 6, assembling the substructures; step 7, establishing a substructure state space equation; step 8, converting a controllable standard form; 9, calculating the local state feedback gain of the substructure; step 10, constructing a substructure interaction matrix; and step 11, designing a closed-loop control system. By the adoption of the technical scheme, the control capacity of the structure can be improved.