150 results about "Hyperbolic tangent function" patented technology

The present invention relates to a non-affine uncertain system self-adaptive control method with a range restraint. In combination with the characteristic that system input and states are subject to the range restraint, based on a mean value theorem, a non-affine system is converted into a time varying system (a strict feedback system) with a linear structure, and a varying interval of time-varying uncertain parameters of the time varying system is obtained. On the basis, a parameter adaptive projection technique is utilized to carry out online estimation on bounded uncertain time-varying parameters and external disturbances, and a parameter estimation error is compensated by using the nonlinear dynamic damping technology. Based on the nonlinear mapping technology, a restraint amount is mapped to the whole real number space to solve a state restraint problem of the system, thus to ensure the state is always within a restraint range. A hyperbolic tangent function and the Nussbaum gain technology are simultaneously utilized to solve the problem that system input is subject to the range restraint or the problem of input saturation and the potential problem of singular values of a controller, and the controller is designed in combination with a method of inversion, thereby solving the problem of self-adaptive control of the non-affine uncertain system with the range restraint.

The invention provides a sub pixel edge based circle center detecting method. The method includes steps of 1, utilizing a Canny operator to performing rough positioning on an image edge, acquiring the gradient magnitude and gradient direction of integer pixel point edge; 2, establishing a positive direction taking the integer pixel point as the origin and the taking the gradient direction as the x axis, taking 7 pixel points in central symmetry in the gradient direction, wherein the symmetry center which is the integer pixel point is among the 7 pixel points, performing gray level fitting on the 7 pixel points by adopting a hyperbolic tangent function in a formula of I(x)=-b / 2 tanh(p(x-R))+h+b / 2, wherein I(x) indicates the gray level in x position, x indicates the distance between the pixel point to the origin, h indicates background gray level, b indicates the gray level difference value of the edge and the background, p is a fuzzy factor, and R is the edge position; and 3, obtaining a sub pixel edge point according to the formula in the step 2, performing least square fit on the sub pixel edge point according to a circle and obtaining circle center coordinates.

An inverted pendulum self-adaptive iterative learning inversion control method is characterized in that: aiming at an inverted pendulum system containing unknown input saturation, a self-adaptive iterative learning inversion controller is designed through utilization of a neural network and an inversion control method in combination with self-adaptive iterative learning control; the construction of an integral lyapunov function solves the control problem caused by derivation of a unknown gain function; based on the median theorem, a hyperbolic tangent function is adopted to approximate an input saturation term; then, a radial basis function neural network is adopted to approximate and compensate uncertain unknown items of a system, and two combined self-adaptive laws are adopted to updatethe weight of the neural network and the bound of estimation errors. Under the condition that the system has input saturation, the invention provides the control method which can compensate the unknown uncertainty of the system, solve the control problem caused by derivation of the unknown gain function and realize two-norm convergence of a tracking error of the system to be near zero within limited iteration times.

The invention discloses a bridge type crane system APD-SMC controller, a bridge type crane system and a control method. The bridge type crane system comprises a trolley, a bridge frame and a load; a target position of the trolley is defined as pd, state vectors are formed by displacement x of the trolley and a swing angle theta of the load relative to a vertical direction, and therefore a state equation of the bridge type crane system can be obtained; a composite function xi x, an auxiliary function, a sliding mode surface s and a hyperbolic tangent function are introduced; a bridge type crane system APD-SMC controller is therefore obtained. According to the bridge type crane system APD-SMC controller, the bridge type crane system and the control method, a coupling relation between the displacement of the trolley and the swing angle of the load is strengthened, and therefore transient control performance of the system is improved.

The invention discloses a reversed-U-type dielectric waveguide wideband directional coupler used for a millimeter wave circuit, which is composed of two medium waveguide transmission lines and an earthing metal plate, wherein two medium waveguide transmission lines close to each other are oppositely bent, arranged separately and symmetrically at two sides of an axle wire and fixed on the earthing metal plate, so as to form an X-type structure; the coupler is characterized in that the reversed-U-type medium waveguide is used for reaching of the wideband plat coupling of the coupling section and the transition section of a coupler, and the waveguide axes of the transition section adopts hyperbolic tangent line type; the fluctuation of a coupling coefficient doesn't exceed plus or minus 0.5Db inside the frequency coverage of 6GHz, and the flat coupling property can be achieved inside wider bandwidth. Compared with the traditionally directional coupler which is completely composed of a medium mirror image line, the inverted-U-type dielectric waveguide wideband directional coupler has the advantages that transition waveguide section of the hyperbolic tangent line type is used, the metal side wall of the prior coupler which is vertical to ground in the transition waveguide section is unnecessarily used, radiation loss and metal loss are reduced, the volume of the coupler is decreased and manufacture complexity and cost are reduced, and can be conveniently produced in large quantity.

The invention relates to a rolling bearing residual life prediction method, which predicts the life of a rolling bearing by using vibration signals of the rolling bearing through training a multi-scale convolutional neural network model, and comprises the following steps: carrying out an accelerated degradation experiment by using a plurality of unused bearings to obtain full-life vibration signals of the bearings; converting the service life of the bearing into a health index by using an inverse hyperbolic tangent function; establishing a multi-scale convolutional neural network model, and training the model by using the obtained data; measuring a vibration signal of the rolling bearing with the life to be predicted by using an acceleration sensor; inputting the obtained vibration signalinto a trained multi-scale convolutional neural network model to obtain a health index of the rolling bearing with the life to be predicted; and converting the obtained health index into the residuallife of the rolling bearing with the life to be predicted. The invention aims to provide a rolling bearing residual life prediction method which can efficiently and accurately predict the residual life of a rolling bearing under complex actual working conditions.

This invention puts forward a simplified algorithm of two-layer weighted parallel interference cancellation algorithm which greatly reduces operation volume which keeping its performance. Since it relates to hyperbolic tangent operation in the two layer weighted parallel interference cancellation algorithm it nearly can't by realized. This invented simplified algorithm is to use sectional linear judgement method or looking-up table method to replace the hyperbolic tangent judgement. The substance is to use sectional linear judgement function L(x) or judgement function T(x) of looking-up tableto approach the hyperbolic tangent function tanb(x).

The invention discloses a line single-phase ground fault relay protection method capable of preventing distributed capacitive current and transitional resistance. The method comprises the following steps: a lumped parameter model is utilized for modeling at first; the fault location is calculated; then the physical properties of voltage and current transmission of a transmission line are described by adopting a long-line equation; the obtained fault location is utilized to calculate the offset current of the transmission line; further, the line fault impedance is calculated according to the hyperbolic tangent functional relationship between the voltage drop from the relay location of the transmission line to a single-phase ground fault point and the fault location; and determining whether an action trip signal is sent or not according to the judgment on the amplitude value of the line fault impedance. When the method provided by the invention is adopted for single-phase ground fault relay protection of an ultra / extra-high voltage AC transmission line, the circuit fault impedance from the relay location of the transmission line to the single-phase ground fault point can be accurately calculated, having no reference to the voltage, the distributed capacitive current, the transitional resistance and the load current of the ground fault point, and the action performance can meet the requirements for relay protection selectivity, reliability, sensitivity and quickness.

The invention discloses an electric turntable position tracking control method based on disturbance upper bound estimation. A turntable servo system pitching frame is selected as a study object, meanwhile, uncertainty and uncertain nonlinearity of system parameters are considered at the same time, and an excellent turntable position tracking controller is designed; for the uncertainty of the system parameters, a good parameter adaptation law is designed, and system parameters can be estimated and converged, thereby achieving good model compensation; for the uncertain nonlinearity of the system parameters, a good disturbance upper bound estimation law is designed, and the maximum upper bound of the uncertain nonlinearity is estimated; and a disturbance compensation term in the controller adopts a hyperbolic tangent function, thereby avoiding buffeting caused by a traditional sign function. Further, the effectiveness of the controller is verified through contrast simulation results.

The invention discloses a method for achieving circuit phase-to-phase fault relay protection with hyperbolic tangent function amplitude characteristics. The method includes the steps of calculating a hyperbolic tangent function amplitude at the position of an electric transmission circuit phase-to-phase short circuit fault point through single-end fault phase-to-phase electrical quantity by adopting distribution parameter modeling, judging whether the hyperbolic tangent function amplitude at the position of the electric transmission circuit phase-to-phase short circuit fault point is smaller than a hyperbolic tangent function amplitude at the electric transmission circuit protection setting range position or not, and giving out a motion tripping signal with a protection device if the hyperbolic tangent function amplitude at the position of the electric transmission circuit phase-to-phase short circuit fault point is smaller than the hyperbolic tangent function amplitude at the electric transmission circuit protection setting range position. According to the method, electric transmission circuit phase-to-phase short circuit fault relay protection is achieved, influences of transition resistance, distributed capacitance, fault positions and load currents on the protection motion performance are overcome, and the method is suitable for extra-high voltage alternating current electric transmission circuit phase-to-phase short circuit fault relay protection.