34 results about "Nonlinear observer" patented technology

The invention provides a diagnosis and recognition method for a failure fault of a distributed hub motor driven vehicle. According to the movement condition of the distributed hub motor driven vehicle, an inherent sensor of the vehicle is utilized to obtain a state parameter of the vehicle in real time, a vehicle nonlinear observer is designed, based on whole vehicle dynamics analysis and tire dynamics analysis, the actual torque of each hub motor and an expected motor torque sent by a vehicle controller are obtained; by performing ratio analysis on the actual torque of each hub motor and thedesired motor torque, a ratio of the actual torque of the hub motor to the expected motor torque and a rate of change of the ratio at the same moment are obtained; by using a fuzzy diagnosis device, arelationship between the torque ratio and the failure fault is obtained by utilizing a fuzzy rule to judge whether the hub motor has a failure fault. The diagnosis and recognition method can be usedfor effectively recognizing the failure fault of the distributed hub motor driven vehicle, realizing real-time diagnosis and alarm functions on the failure fault, and is used for improving the drivingsafety of the vehicle.

The invention relates to a singular perturbation composite learning control method of an elastic aircraft based on interference observation. According to the method, a longitudinal channel model of the elastic aircraft is decomposed into a speed subsystem and a posture subsystem at first; and PID control is adopted for the speed subsystem, the posture subsystem is analyzed by using the singular perturbation theory, and rigid-flexible mode decoupling and fast and slow time scale separation are realized. A sliding mode control method is designed to control an elastic fast-changing subsystem; anda back stepping method is designed to control a posture slow change subsystem, meanwhile unknown dynamics is approached by using a composite neural network, and a nonlinear observer is designed to compensate the external disturbances. Based on the controller designed above, precise tracking of height and speed is achieved.

At least one example embodiment discloses a drive system including a motor including a rotor, the motor configured to receive a measured current, a controller configured to generate a voltage for the motor at a stationary reference frame, the voltage having a frequency and the measured current being based on the voltage, a filter configured to obtain position information of the rotor based on the measured current and a nonlinear observer configured to estimate a rotor position of the motor during the stationary reference frame based on the position information. The controller is configured to control the motor based at least in part on the estimated rotor position.

The invention discloses an unmanned ship position and speed estimation structure and a design method. The structure comprises an accelerometer unit, a gyroscope unit, a magnetometer unit, a global positioning system signal acquisition unit, a coordinate system conversion unit, a state recombining unit, a comparing unit, an inertia navigation system data resolving unit and a nonlinear observer navigation filtering algorithm unit. According to the unmanned ship position and speed estimation structure disclosed by the invention, the unmanned ship position and speed information containing measurement noise is utilized, multi-sensor information fusion treatment is performed through a method based on a nonlinear observer, and actual unmanned ship position and speed information can be estimated;thus, not only is the convergence characteristic of the designed nonlinear observer is more accurate, but also convenience is brought to a parameter adjusting process, and the calculated amount is reduced. According to the unmanned ship position and speed estimation structure disclosed by the invention, the problem of measurement noise of the sensor is taken into consideration, the actual positionand speed information can be obtained from the state information with the measurement noise, more continuous and more stable navigation data can be formed, and estimation of a course angle can be more accurate.

The invention provides a design method of a position and attitude observer for an airborne parallel platform. According to the design method of the position and attitude observer for the airborne parallel platform, a six-degree-of-freedom parallel machine platform serves as the airborne platform, the position and attitude of a fixed end of the platform dynamically changes along with a body, and the position and attitude of a workbench which is controlled by six parallel extensible rods and universal hinges is always located in the horizontal state; the actual length of the extensible rods is measured through a sensor and the position and attitude of the platform is estimated through a nonlinear observer; a measurement error of the length of the extensible rods serves as an input signal of position and attitude estimation through a state observer; the nonlinear observer is transformed into a linear observer with a nonlinear perturbation through differential homeomorphism for calculation; meanwhile the estimation of a gain matrix is achieved by an automatic differential technology and accordingly the solving speed of the gain matrix is greatly improved.

The invention discloses an unmanned aerial vehicle course angle error compensation system based on active disturbance rejection control. The system comprises a first acquisition unit used for acquiring course angles, a first active disturbance rejection controller unit and a second active disturbance rejection controller unit, wherein the first active disturbance rejection controller unit comprises a first tracking differentiator and a first extended state observer; the first extended state observer is a linear observer when the tracking error of the first extended state observer is greater than a preset value; when the tracking error is smaller than or equal to a preset value, a nonlinear observer is adopted; the second active disturbance rejection controller unit comprises a second extended state observer; the second extended state observer is a linear observer when the tracking error of the second extended state observer is greater than a preset value; and when the tracking error issmaller than or equal to the preset value, a nonlinear observer is adopted. According to the invention, the anti-interference capability and the control precision of the course angle of the quad-rotor unmanned aerial vehicle are improved.

The invention relates to an out-of-step discrimination method for a two-phase hybrid stepping motor. A two-phase sine and cosine current tracking open-loop control is adopted. A two-phase voltage anda two-phase current are used as input signals. The electric angle position of the rotor of the two-phase hybrid stepping motor is observed through a nonlinear observer. The rotor electric angle position is differentiated to obtain a rotor speed estimation value, and a relative error between the rotor speed estimation value and a given speed signal is calculated. If the relative error exceeds a setthreshold value, the open-loop control of the two-phase stepping motor is judged to be out of step. The motor driving is closed, so that the safety of a low-cost stepping motor servo system is improved.

The invention provides an accurate inverter nonlinear effect online compensation method, and belongs to the technical field of motor drive control. According to the method, firstly, parameters, namelydq-axis inductance, for designing the inverter nonlinear observer need to be identified, the used dq-axis inductance identification method fully considers the defects of a classic seven-segment SVPWMmodulation method, the position of a zero vector is rearranged, and meanwhile, the influence of inverter nonlinearity does not need to be considered, a flux linkage sliding mode observer is designedbased on a superspiral algorithm by utilizing the identified dq-axis inductance, and the observed inverter nonlinear voltage is compensated to an [alpha]-[beta]-axis voltage reference instruction. Aiming at the conditions that the nonlinear model of the inverter is not clear and the compensation is not accurate enough when the phase current is small, the invention provides the method for accurately compensating the nonlinearity of the inverter on line, so that the dead zone error caused by switching a switching tube can be avoided; and non-linear accurate compensation of the inverter is realized.

The invention discloses a dual-motor steer-by-wire system and a fault-tolerant control method thereof. The dual-motor steer-by-wire system comprises a steering wheel module, a steering execution module and a control module, a steering wheel module; the control module is electrically connected with the steering wheel angle sensor, the steering wheel torque sensor, the vehicle speed sensor, the yaw velocity sensor, the first current Hall sensor, the second current Hall sensor, the road sensing motor driver, the first steering motor driver and the second steering motor driver. According to the method, an extended Kalman filtering algorithm is adopted, a parameter and state coupling self-adaptive nonlinear observer is established based on a dual-motor steer-by-wire system model, and the motor failure coefficient and the whole vehicle state are accurately observed in real time.

The invention provides an automobile road slope estimation method based on information fusion, and aims to solve the problem that an existing automobile slope estimation method cannot give consideration to low cost, low calibration difficulty, high precision and high real-time performance at the same time. The method comprises the following steps of: 1, acquiring a corresponding signal from a bus, and ensuring that available information is fully utilized to improve the precision; 2, carrying out low-pass filtering and other processing on the original signal, and solving a signal required to be used later at the same time; 3, establishing a longitudinal dynamic model of the whole vehicle and a longitudinal kinematics model related to the road gradient according to the parameters in the step 1 and the step 2; 4, solving gradients under dynamics and kinematics conditions by using a nonlinear observer and a least square method with a forgetting factor respectively; and 5, fusing the two methods to obtain a final gradient estimation result.

The invention provides a mobile mechanical arm robust control method and system based on a non-linear disturbance observer. The method comprises the steps that geometric structure data and motion state data of a mobile mechanical arm are acquired; a kinetic equation of the mobile mechanical arm is constructed by utilizing a Lagrange principle according to the acquired data; and according to the obtained kinetic equation of the mobile mechanical arm, inner and outer ring motion control is carried out, an inner ring uses robust control based on the non-linear disturbance observer, and an outer ring uses a backstepping method to realize conversion from an expected task space trajectory to a joint space. According to the method, a PD + SMC controller with the non-linear disturbance observer is used to track a virtual speed, the problem that a kinetic model cannot be accurately modeled is solved, and for sudden time-varying unknown disturbance, the non-linear observer is used to realize dynamic compensation for observation of the sudden time-varying unknown disturbance.

The invention discloses a disturbance attenuation controller for a hub motor of an electric automobile in the field of automobile drive control. An output signal matrix of a hub motor system is inputinto a nonlinear observer; an integrated total disturbance estimated value output by the nonlinear observer is respectively input into a sliding mode control module and a reference current calculationmodule; a rotating speed difference value is respectively input into the sliding mode control module and the sliding mode variable calculation module; reference current output by the reference current calculation module is input into the sliding mode control module; the current difference value is input into the sliding mode variable calculation module, the sliding mode variable output by the sliding mode variable calculation module is input into the sliding mode control module, the control voltage output by the sliding mode control module is respectively input into the hub motor system and the control input module, and the control input module outputs the modified control voltage to the nonlinear observer; the nonlinear observer uses a nonlinear design function to effectively estimate integrated disturbance, and adopts sliding mode control to ensure the control performance of the hub motor system in the aspects of robustness and fast transient response.

The invention discloses a generator car nonlinear robust fault detection method based on an observer, and the method comprises the steps: 1, building a dynamic model of a generator car, considering a distributed model of the generator car and a phasor measurement unit at a high-voltage side of a transformer, and obtaining a needed output measurement value on a bus at the high-voltage side of the transformer; (2) observing by an observer to obtain a state space model expression, and establishing a Lipschitz nonlinear equivalent model; (3) fault modeling is carried out, fault vectors representing all possible faults are obtained, residual errors are calculated, and a fault threshold value is calculated through a residual error peak value; and (4) designing a fault diagnosis filter, and providing a fault detection (FD) scheme based on a nonlinear observer. According to the method, the influence of interference and model uncertainty is considered, a nonlinear model influenced by disturbance is adopted, and the method can be used for nonlinear robust fault detection of the generator car.