34 results about "Nonlinear observer" patented technology

The invention discloses a power battery SOC estimation method based on a nonlinear observer. The method comprises the steps of: performing an intermittent discharging-standing experiment on a power battery, and obtaining a SOC and OCV expression; establishing a battery equivalent circuit model; determining each parameter value of the model; establishing a discrete state space model of the battery; designing a self-adaptive nonlinear observer; determining an optimizing target function; solving an optimal parameter value; an calculating an estimated value of the battery SOC. A power battery SOC estimation system based on the optimal self-adaptive nonlinear observer comprises a power battery SOC-OCV expression determining module, an equivalent circuit model establishing module, a parameter determining module, a power battery SOC estimation discrete state space model determining module, a self-adaptive nonlinear observer designing module, a parameter optimizing target function determining module, an optimal parameter solving module and a power battery SOC estimation module. According to the invention, the SOC estimation precision is improved, the algorithm calculated quantity is reduced, hardware realization is facilitated, and the power battery SOC estimation method and system based on the nonlinearity observer are applied to the field of electric vehicle power battery managing systems.

The invention provides an accurate on-line compensation method for the nonlinear effect of an inverter, which belongs to the technical field of motor drive control. The present invention first needs to identify the parameters for designing the nonlinear observer of the inverter, that is, the dq-axis inductance. The used dq-axis inductance identification method fully considers the defects of the classical seven-segment SVPWM modulation method, and rearranges the position of the zero vector , at the same time, without considering the influence of inverter nonlinearity, a flux linkage sliding mode observer based on super-helix algorithm can be designed using the identified dq-axis inductance, and the observed inverter nonlinear voltage can be compensated to the αβ axis voltage reference command . Aiming at the situation 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 proposes a method for accurately compensating the nonlinearity of the inverter online, which can avoid the dead zone error caused by switching the switch tube. ; Realize precise compensation of inverter nonlinearity.

The invention discloses an ammonia coverage rate nonlinear observer design method based on synovial membrane control, which mainly comprises the following contents: building a simplified two-order urea SCR (selective catalytic reduction) system model; providing an ammonia coverage rate synovial membrane observer design method; providing an ammonia coverage rate synovial membrane observer stability analysis process. The two-order urea SCR system model provided by the invention can substantially describe system dynamic characteristics, and the complexity is suitable for designing an ammonia coverage rate synovial membrane observer. The ammonia coverage rate synovial membrane observer provided by the invention provides a value range of a gain on the premise of guaranteeing the stability, is applicable to engineering application, and has higher robustness for external interference under an instant condition.

The invention discloses an output and feedback control method of a motor position servo system based on a non-linear observer, and belongs to the field of motor servo controlling. The method comprises the following steps: establishing a math model of a motor position servo system; and designing a non-linear state observer, designing an output and feedback controller of the motor position servo system based on the non-linear observer. According to the invention, the output and feedback control method of the motor position servo system based on the non-linear observer is provided and aims at handling the circumstances with known position states and unknown velocities or accelerated velocities, which reduces hardware cost and is conducive to application in actual engineering. According to the invention, the designed controller takes full consideration of the characteristics of non-linear friction of the system and external interference, etc., guarantees the system remains balanced within limited time period, and increases tracking property of the system.

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.