234results about How to "Eliminate chatter" patented technology

A sliding bearing (1) includes an upper casing (3) which is made of polyacetal resin as a synthetic resin, has an annular surface (2), and serves as a first bearing body; a second bearing body (5) which is made of a synthetic resin, is superposed on the upper casing (3) so as to be rotatable about an axis (O), and has an synthetic resin-made annular surface (4) opposed to the annular surface (2); and a synthetic resin-made annular sheet (6) which is interposed between the annular surfaces (2) and (4) and slidably abuts against at least one of the upper casing (3) and the bearing body (5).

The invention provides a sliding-mode control method of a permanent magnet synchronous motor based on reaching law and disturbance observation compensation. A new reaching law algorithm is designed, and applicable in design of a speed controller in a sliding-mode variable structure; simultaneously, a saturation function is used in a disturbance observer control law, and used for improving a disturbance observer; a value observed by the disturbance observer is compensated in the speed controller; and therefore, a new control strategy is formed. The new control method is applicable in a vector control system of the permanent magnet synchronous motor; a current-speed double-closed-ring control structure is adopted; for buffeting and anti-interference problems in the sliding-mode control, an integral sliding-mode surface and a new reaching law are added based on the conventional sliding-mode speed controller; simultaneously, the disturbance observer is added; disturbance due to load changeis effectively inhibited; the responsiveness of the system is improved; buffeting of the system is reduced; and the anti-interference performance and the robustness of the system in a complex environment are obviously improved.

A sliding bearing (1) includes an upper casing (3) which is made of polyacetal resin as a synthetic resin, has an annular surface (2), and serves as a first bearing body; a second bearing body (5) which is made of a synthetic resin, is superposed on the upper casing (3) so as to be rotatable about an axis (O), and has an synthetic resin-made annular surface (4) opposed to the annular surface (2); and a synthetic resin-made annular sheet (6) which is interposed between the annular surfaces (2) and (4) and slidably abuts against at least one of the upper casing (3) and the bearing body (5).

The invention belongs to the field of miniature rotor type unmanned aerial vehicle autonomous flight control and research, and provides a method for controlling an unmanned aerial vehicle and for making an unmanned helicopter quickly and accurately stabilized and controlled. A controller less depends on prior knowledge of models and has good robustness on uncertainty of a system. According to the technical scheme, a nonlinear robust control method of the posture of the single-rotor unmanned helicopter based on fuzzy feedforward includes the following steps that firstly, the form of a single-rotor unmanned helicopter dynamical model and the form of a single-rotor unmanned helicopter posture dynamical model are as follows; secondly, the nonlinear semicontinuous robust controller based on fuzzy feedforward is designed (img file=' DDA0000463767750000011.TIF' wi=' 754' he=' 72' /) (/ maths). The method is mainly applied to the design and manufacture of the miniature rotor type unmanned aerial vehicle.

The invention discloses a sliding-mode variable structure control method of a single phase grid-connected inverter based on a multi-resonant sliding mode surface. The method comprises the steps of: firstly, building a linear sliding mode surface according to detected current i1 of an inverter side filter inductor of the single phase grid-connected inverter, the voltage vc of a filter capacitor, the current i2 of a network side filter inductor, and the target output current i1* of a grid-connected inverter system, the target voltage vC* of the filter capacitor and the grid-connected target current i2*; adding a resonant item into the linear sliding mode surface so as to obtain the multi-resonant sliding mode surface; designing a sliding-mode variable structure controller by the multi-resonant sliding mode surface, leading a linear state feedback controller to an original nonlinear controller to obtain a final control quantity modulation wave d(s), and finally comparing the modulation wave with a carrier wave to generate a driving signal for driving a switch tube to act. According to the control method disclosed by the invention, the robustness and dynamic response ability of the grid-connected inverter system are improved; the tracking accuracy of grid-connected current is also improved; the harmonic content is removed, and the control method is simple and easy to achieve.

The invention discloses a neural network full order slip form control method for a mechanical arm servo system, which, aiming at the mechanical arm servo system containing a dynamic execution mechanism, is designed by utilizing the full-order slip form control method and combining with the neural network. The full order slip form is designed to guarantee the finite time convergence of the system and can eliminate buffeting and singular problems by avoiding the differential item in a practical control system. Besides, the neural network is used for approaching unknown non-linearity of the system and non-determinacy of internal-external disturbance. The neural network full order slip form control method for a mechanical arm servo system realizes provides a method to eliminate the buffeting and the singularity problem of the surface of the slip form, effectively complements the unknown linearity and the control method of the internal-external disturbance, and realizes fast and stable control of the system.

The invention relates to a nonlinear control method for a small unmanned helicopter, especially to an attitude control method for the small unmanned helicopter based on a second-order self-adaptive terminal sliding mode controller, and realizes rapid attitude error convergence and maintains relatively accurate attitude tracking control effect and relatively high system robustness under the condition that external interference of the small unmanned helicopter exists. According to the technical scheme of the invention, a second-order self-adaptive terminal sliding-mode method is applied to attitude system control of the small unmanned helicopter under the condition that the small unmanned helicopter has external interference. The method comprises the following steps that 1) an attitude dynamics model of the small unmanned helicopter is determined; 2) an attitude angle tracking error is defined, and a dynamics error model is arranged; 3) a control law is designed; and 4) self-adaptive control gain is designed. The method of the invention is mainly used for nonlinear control of the helicopter.

The invention relates to a method for removing chattering of sliding mode control of a permanent magnet synchronous motor, which can realize the removal of the chattering phenomenon of the sliding mode control of the permanent magnet synchronous motor. The method has the technical characteristics that: 1, a nonlinear mathematical model of the permanent magnet synchronous motor is established; 2, the nonlinear mathematical model is subjected to decoupling by adopting feedback linearization theory of a nonlinear system; and 3, a corresponding high-order sliding mode controller is designed on the basis of decoupling control respectively. By adopting a high-order sliding mode control algorithm with a differentiator, although indeterminate parameters, external interference, and other factors are present in the system, a robust controller aiming at a multi-input multi-output nonlinear permanent magnet synchronous motor is designed. The controller has the advantages of removing the chattering of the traditional sliding modes, having control accuracy and strong robustness of the traditional sliding modes, and making the control rules not limited by the degree of correlation of the system.

The invention belongs to the technical field of machining and discloses a method for milling and vibration-damping a blisk. The method comprises the following specific process steps of: (1) preparing a filling material according to the proportion; (2) melting the filling material; (3) mounting a pouring clamp; (4) pouring a filling agent; (5) condensing the filling agent at normal temperature, secondarily condensing the filling agent and checking the condensing state of the filling agent; (6) mounting a filtering clamp; and (7) carrying out the abutted milling processing and chip removal processing. By pouring the filling agent between the blisk and vanes in the milling processing of vane profile five coordinates of the blisk, the method enhances the rigidity of parts in the milling processing of the vanes, eliminates the chatter marks generated at the vent tip part of the vanes during milling and reduces the roughness of the surfaces of the vanes. Meanwhile, the rigidities of the parts and a clamping system thereof are enhanced, so that the milling feed rate is increased and the milling speed can be improved.

The invention provides a double-linear-motor contour compensation device and method based on a fuzzy RBF network integral sliding mode with respect to a double-linear-motor numerical control feeding system with the axial direction being in mutual vertical movement. A real-time contour error is used as the input of a controller, the powerful self-learning ability of the controller enables the contour error to tend to zero within limited time, and thus contour machining precision is improved. The double-linear-motor contour compensation device comprises a commutating and voltage-stabilizing unit, an IPM inverter, a DSP, a Hall sensor, a grating ruler, a current detection unit, a position and speed detection unit, an optical coupling isolation circuit, a driving protection circuit and a fault detection and protection circuit. The DSP comprises a QEP circuit of an event manager EVA, an ADC module, a PWM unit, a Flash storage module, a program storage, a timer and a PDPINT pin. A PI controller of a position signal setter, a linear motor position loop, a speed loop and an electric current loop, a contour error calculator, a fuzzy RBF network integral sliding mode contour compensator and a driver device are further arranged inside the DSP. The double-linear-motor contour compensation device is good in robustness, suitable for contour machining tasks of any track and capable of achieving high-precision contour control.

The invention discloses a fuzzy control method based on an event trigger strategy for a non-linear inverted pendulum system. The method comprises the following steps: 1, establishing a dynamic mathematical model of an inverted pendulum system with a delay resonator; 2, setting an event trigger strategy of the inverted pendulum system, and constructing a fuzzy controller for the inverted pendulum system with the delay resonator; and 3, transmitting a control instruction to an actuator of the inverted pendulum system by virtue of an event trigger mechanism by a fuzzy controller u(k), thereby realizing the objective of control. The fuzzy control method disclosed by the invention has complete robustness on changes of system parameters and external interference, buffeting is eliminated, and thesystem has excellent stability. Moreover, due to the use of the event trigger mechanism, the inverted pendulum system effectively suppresses time-varying delay characteristics, communication burdensare effectively alleviated, and bandwidth resources are saved.

The invention discloses a motor servo system additivity fault detection and fault tolerant control method based on a slip form. The method includes building a motor servo system mathematical model containing additivity fault description, designing a slip form disturbance observer to observe additivity fault level and demonstrate observation accuracy, designing an initiative fault tolerant controller according to the observed additivity fault, and demonstrating system overall gradual stability according to the Lyapunov nonlinear stability principle. By means of the control method, the reasonable fault tolerance degree can be set to ensure that effects caused by various model uncertainties are kept in the designed fault tolerance range all the time when the system has no fault, false alarming of the system is avoided, and fault detection robustness is improved. The additivity fault level of the system can be observed on line, real-time performance of additivity fault detection is guaranteed while system control performance is not affected, active detection missing and fault tolerant control of minor faults can be achieved, and timely warning of severe faults is also achieved.

The invention relates to an extended-state-observer-based full-order sliding mode control method of a chaotic system of permanent magnet synchronous motor. The method comprises: a chaotic model, an initialization system state, and correlated control parameters of a permanent magnet synchronous motor system are established; on the basis of coordinate conversion, the permanent magnet synchronous motor chaotic model is converted into one based on a standard extended state observer design suitable for a non-linear extended state observer design; a full-order sliding mode controller is designed based on the extended state observer to eliminate a buffeting phenomenon in the sliding mode control and guarantee that the system state can be convergent to a zero point rapidly and stably. According to the full-order sliding mode control method, the buffeting phenomenon in sliding mode control can be prevented and the chaotic state of the system can be guaranteed to be convergent to the zero point rapidly and stably.

The invention relates to a control method and device for eliminating system buffeting during sliding mode control of a linear motor. In the method, a sign function in the conventional sliding mode control formula is replaced by a diffusion hysteresis function, so that control voltage on a mover coil is evaluated. Due to the soft switching property of the diffusion hysteresis function, buffeting during sliding mode control is eliminated. Parameters in a formula are obtained by second-order approximation and an experiment. The device comprises a linear motor, a displacement sensor, a signal processor, a driving circuit and the like, wherein a control signal of the signal processor is connected to the driving circuit; the signal processor comprises a central processing unit, an A/D (Analog to Digital) circuit, a D/A (Digital to Analog) circuit, an ROM (Read Only Memory) module, an RAM (Random Access Memory) module, a pulse width modulation module and a signal receiving circuit, and is used for storing a formula and parameters of a sliding mode control method; and the central processing unit is used for obtaining a voltage signal of the mover coil according to the mover displacement data of the displacement sensor and regulating the voltage of the mover coil through the pulse width modulation module so as to realize stable linear movement of the mover. By adopting the method and the device, system buffeting is eliminated effectively, and the running reliability is enhanced; and the method and the device are easy to realize.

The invention discloses a sliding mode attitude control method for a quadrotor UAV based on a proportional integral observer. The method comprises steps that a dynamic model of the quadrotor UAV withinterference only is established, and expressions of a rolling angle, an elevation angle and a yaw angle of the quadrotor UAV are transformed into second-order system models; the second-order system models are utilized to construct the corresponding proportional integral observer; a sliding mode attitude controller is designed according to the proportional integral observer, and the sliding mode attitude controller in combination with the rolling angle, the elevation angle and the yaw angle is utilized for flight control of the quadrotor UAV. The method is advantaged in that the proportional integral observer is combined with the sliding mode attitude controller, the partial feedback function of the proportional integral observer is utilized to estimate the shape and position input interference state of the quadrotor UAV, steady state tracking accuracy of the proportional integral state observer is improved, through the sliding mode attitude controller, relatively strong robustness andanti-interference to uncertain factors of the quadrotor UAV are achieved, and design and calculation are simple.

The invention discloses a balancing vehicle system and a control method thereof. According to a difference equation model and a drift error model of attitude signals of the balancing vehicle system, astate equation of an extended Kalman filter and a mathematical model of a permanent magnet linear motor are established. A second-order dynamic Terminal sliding film is used to drive permanent magnetsynchronous motor. Particle Swarm Optimization (PSO) is used to optimize the parameters of tracking controller, synchronization controller, clearance elimination controller and switching function ina two-motor system. The invention realizes that the signal collected by the sensor of the balancing vehicle has large noise and zero drift error, and solves the problem of poor robustness and the problem that the Brush motor structure is complex, fault, maintenance workload, short life, commutation spark easy to produce electromagnetic interference, as well as in the balance of the car in the process of running jitter, deviation is too large, and low security.

The invention relates to a method for the vibration of band steel in high-speed rolling process, wherein said method is characterized in that: the first frame inlet of cold rolling machine is arranged with three-roller stabilizer which comprise left low roller, right low roller and upper middle roller; the upper middle roller is above the left and right low rollers, and above the rolling line; the left and right low rollers are under the rolling line; the band steel is through between the upper middle roller and left low roller and right low roller, the upper middle roller is lifted by hydraulic cylinder; when in normal rolling, the upper middle roller compresses the band steel; the last frame outlet of machine has single-roller vibration resistor; when in normal rolling, the vibration-resistant roller extends out driven by the hydraulic cylinder, to tension the bane steel.

The invention discloses an automatic electromagnetic nondestructive testing method and device for an in-use steel rail. The device comprises a semi-circular tubular rail frame, a slide block, arrayed eddy current probes, arrayed metal magnetic memory probes, electronically-controlled wire take-up and pay-off racks and a steel wire rope. According to the method and the device, based on the principle of electromagnetic nondestructive testing, a rail slide testing method is adopted, the slide block is fixed outside a testing face of the steel rail, a probing face of the slide block is matched with the testing face of the steel rail to be tested, arrayed electromagnetic detection probes and arrayed metal magnetic memory detection probes are fixed on the probing face of the slide block, and the slide block is electromechanically and automatically controlled to slide along the testing face of the steel rail to be tested so as to carry out testing; various defects of the surface of the steel rail to be tested can be tested by adopting differential eddy current scanning rules and absolute eddy current scanning rules in an array eddy current testing method, and meanwhile, the interference and influence caused by vibration and lift-off are eliminated; the situations of early fatigue and stress concentration of the steel rail can be evaluated by an array metal magnetic memory testing method; and the device is high in testing efficiency and testing accuracy, facilities and equipment are not required for being in operation suspension, and the in-use testing can be carried out.

The invention discloses a second order sliding mode control method for an autonomous vehicle based on visual dynamics, and belongs to the field of intelligent vehicles. The method includes the steps that firstly, a two-freedom vehicle lateral dynamic model and a visual dynamic model are established and combined, and a curvature of rho of a desired path on a preview point is taken as the input of external disturbance, and a vehicle dynamic model is reconstituted; and according to an actual offset distance of y<L> between a front viewpoint of vehicle heading and the desired path and an actual tangential angle of epsilon<L> between the vehicle heading and the desired path, a control law of a first order sliding mode controller is designed; based on the control law of the first order sliding mode controller, by reconstructing a sliding mode variable of s, a value range of weighting coefficients of lambada and alpha in a control law u<s> of a second order sliding mode controller of super-twisting is obtained; the value range of weighting coefficients of lambada and alpha is applied to the control law u<s> of the second order sliding mode controller to achieve automatic driving of vehicles. According to the second order sliding mode control method for the autonomous vehicle based on the visual dynamics, a series of problems such as nonsequence of traditional sliding mode control andchattering in a nonlinear system control theory are solved, and strong robustness is achieved.

The invention relates to a space tether capturing system keeping stage tether in-plane and out-plane angle stable control method. Firstly, a space tether capturing system keeping stage kinetic model is built; according to a sliding mode variable equation, a space tether capturing system keeping stage kinetic equation is sorted; a space tether capturing system keeping stage Super-Twisting control law is designed; and the magnitude of the space tether capturing system keeping stage tether in-plane and out-plane angle stable control torque is calculated. The method of the invention has the beneficial effects that the designed control law can quickly eliminate swing of in-plane and out-plane angles in an interference condition, and the tether in-plane and out-plane angles can be controlled to be expected values; and in comparison with the traditional sliding mode method, the designed control law can realize continuous control input and eliminate chattering.

A multi-cable suspended lift with tail cable for balancing is composed of drive drum, overhead pulley set for bearing all load of suspending steel cable and lift container, driving steel cable, lift contain and tail cable. The active load of driving steel cable and lift container is borne by drive drum.