37results about How to "Improve disturbance suppression ability" patented technology

The invention discloses a dual-frame MSCMG frame system high-precision control method based on self-adaptive sliding mode compensation. Firstly, a dual-frame servosystem kinetic model is established; Input and output inverse mapping of a frame system is derived in a differential geometry approach, and then a a pseudo-inverse system of a frame system is obtained so as to realize kinetic decoupling control of the frame system and eliminate influences by coupling moments between frames; then on the basis of a differential algebraic spectrum theory, a tracking error stable control law is derived so as to enable the frame system to have certain response characteristics and guarantee the stability of the frame system; and finally, on the basis of an RBF neural network and a sliding mode control theory, a self-adaptive sliding mode compensation controller is designed to carry out compensation control on residual coupling, involved toques and nonlinear friction to enhance the disturbance inhibition ability of the frame system to realize high-precision angular rate tracking control of the dual-frame system. The method of the invention is simple and is simple to implement. The method is applicable to high-precision decoupling control of the dual-frame Magnetically Suspended Control Moment Gyroscope frame servosystem.

The invention discloses a disturbance suppression method based on a compound disturbance observer, and aims at the problem that system requirements can not be stably controlled at high accuracy sincethe low-frequency and middle-frequency disturbance suppression capability of a control system stable platform is poor. By use of the method, on the basis of multi-closed-loop control, a traditional disturbance observer design is improved, the compound disturbance observer structure is put forward, and a design method for an inner and outer ring feedforward compensation controller in the compound disturbance observer is given. By use of the method, an outer ring in the compound disturbance observer is utilized for estimation, inverse feedforward of a middle-frequency band and external disturbance, and an inner ring is used for estimation, inverse feedforward of a low-frequency band and external disturbance. The inner ring and the outer ring of the compound disturbance observer simultaneously act, finally, the purposes of simultaneously improving the disturbance suppression capability of the low frequency band and the middle-frequency band of the system and improving and controlling system stability accuracy are achieved.

The invention discloses a virtual multi-closed loop-based disturbance measurement feedforward suppression method. The virtual multi-closed loop-based disturbance measurement feedforward suppression method is used for improving the disturbance suppression capability of a control system stable platform so as to meet the demand of a higher-accuracy stable control system. A virtual gyro is obtained bya method of integrating an accelerator and a position sensor, and a fiber gyro of the stable platform is substituted by the virtual gyro. On the basis that virtual multi-closed loop control is achieved by the virtual gyro, the substituted fiber gyro is arranged on a carrier rack and is used for measuring an external disturbance speed, and an ideal feedforward compensation controller is used for feedforwarding the external disturbance to a control loop so as to actively suppress the influence of disturbance. On the premise that the system stability is not completely affected, the load and space requirement of the stable platform is effectively reduced, the disturbance suppression capability of the system is effectively improved, so that the stable platform obtains higher stability accuracy.

The invention discloses a design method of dual compensators of a dual-way feedforward disturbance observer. A system stability control platform has insufficient low frequency and medium frequency disturbance suppression capability, thereby failing to meet higher precision demand of system stability control. Design of the traditional disturbance observer is improved based on multi-closed loop control, so as to provide a design method of dual compensators of a dual-way feedforward disturbance observer. Design of the dual-compensator is based on system stability at first, and then design of disturbance suppression based on different frequencies is conducted, wherein an inner loop disturbs a feedforward loop to suppress low frequency disturbance, and an outer loop disturbs the feedforward loop to suppress medium frequency disturbance, and the dual compensators act simultaneously so as to improve low frequency and medium frequency disturbance suppression capabilities of the system, therefore, the system stability is ensured, and system stability control accuracy is improved effectively.

The invention discloses a novel AGC control method of a circulating fluidized bed boiler. The novel AGC control method comprises the following steps that S1, the step response coefficient of a controlled object is acquired; S2, the state space approximate expression form of the controlled object is acquired; S3, a prediction model of predictive control is acquired; S4, rolling optimization of the control method is carried out; and S5, feedback compensation of the control method is carried out. According to the method, the dynamic adjustment function of primary air on the boiler side on the unit power of the steam engine side in the dynamic process of the circulating fluidized bed boiler is fully utilized, hearth bed materials are fully utilized for energy storage, the lagged effect of the boiler fuel amount is reduced, and the disturbance suppression capacity of a system can be improved through an improved predictive control algorithm.

The invention discloses a tilting mirror vibration suppression method based on an improved disturbance observer. Since mechanical vibrations of an astronomical telescope make the closed-loop performance of a telescope control system decline and these vibrations cannot be well remedied by a classical control structure, the method adopts a tilting mirror to suppress the vibrations. According to themethod, by designing an improved Q filter., a sensitivity function of a tilting mirror control system is optimized, the large-amplitude vibrations are effectively suppressed, and the influence of a water bed effect on the system performance is reduced. Under the case that the system disturbance frequency is known, the control method can achieve optimal correction, and the disturbance suppression capability of the system is effectively improved. According to the method, the system is optimized from a control algorithm, only one image sensor is needed, and the cost is saved. At the same time, the method is clear, the structure is simple, there is no dependence on models, and the method is easy to operate and implement.

The invention discloses a low-frequency-band disturbance suppression method based on acceleration measurement. The problem is solved that outside low-frequency disturbance exists in a control system and it is difficult to further improve the low-frequency-band disturbance suppression capability of the system by an accelerometer and a control method in the environment where a large amount of driftin a low frequency band. An improved disturbance observer structure and a designed special feedforward compensation controller are added based on the three closed loops of acceleration, speed and position. The low-frequency-band disturbance suppression method can eliminate most of the influence of the drift amount of an acceleration sensor, reversely feeds forward the outside disturbance amount ofthe low frequency band to a driving circuit to offset the influence of the outside disturbance, and effectively improves the low-frequency-band disturbance suppression capability of the system. The method optimizes the system in control algorithm, requires no additional sensor, saves cost and has good practicability, is easily implemented by engineering, and is also suitable for other sensors that have a large amount of drift due to low signal to noise ratio, and is used for suppressing the influence of the drifting amount of the sensors.

The invention provides a high-precision controller for an ultra-low-speed control moment gyroscope frame servo system. Firstly, a discrete time system state-space equation is obtained according to a continuous time system state-space equation of the ultra-low-speed frame servo system, then accurate estimation of instantaneous speed and lumped disturbance is achieved by designing a double-sampling-rate extended state observer, and finally, a composite sliding mode control algorithm is designed based on sliding mode control and disturbance compensation in a speed ring to suppress lumped disturbance. According to the high-precision controller for the ultra-low-speed control moment gyroscope frame servo system, provided by the invention, the double-sampling-rate extended state observer is designed to solve the problem that the estimation performance of an existing estimation method becomes poor under the influence of factors such as model parameter change of the ultra-low-speed frame servo system; the composite sliding mode control algorithm is further designed to enhance the disturbance suppression capability of the system; and starting from two aspects of sensing detection and disturbance suppression, the angular rate control precision of the ultra-low-speed frame servo system is comprehensively improved.

The invention discloses a specific frequency disturbance suppression method for a precision motion platform. The method comprises the following steps of 1, generating an expected position signal r of a precision motion platform P by a track generator Cr; 2, measuring an actual position signal y of P; 3, subtracting the r from the y to obtain a position error signal e, and enabling the e to pass through a feedback controller C to obtain a feedback control signal ufb; 4, the control signal u of the previous period passing through a filter Q to obtain a signal uQ; 5, calculating the inverse product of Q and the nominal model P0 of the precision motion platform, and obtaining uPQ after y passes; and 6, subtracting uPQ from uQ to obtain a disturbance signal estimated value; seventhly, subtracting ufb from uQ to obtain a current period control signal u, and enabling the sum up of u and an external disturbance signal d to act on P to generate a position signal y. According to the method, disturbance within a certain frequency range can be suppressed to a certain extent, and the suppression capability can be enhanced for specific frequency disturbance, so control performance of the precision motion platform is further improved.

The invention discloses an SCR denitration system disturbance suppression prediction control method based on a converted ammonia injection amount. The method comprises the steps: defining a transfer function matrix of a system; converting into a discrete state space model; setting a controlled quantity constraint condition; calculating a model matrix required by calculation of the incremental disturbance observer; obtaining an estimated value of the generalized state of the system; calculating an optimal control vector; calculating by an incremental disturbance observer; calculating a conversion ammonia spraying instruction at the current moment; sending the real-time control quantity to an actuator. According to the method, the disturbance inhibition capability of the control system can be remarkably improved, meanwhile, the robustness is high, the influence of model mismatch on the control system can be effectively coped with, the deviation level between the NOx concentration at theoutlet of the denitration device and the set value is reduced, and the control effect is improved.

The invention relates to a disturbance suppression system and method based on the combination of a model inverse structure and a multi-ring frequency division disturbance observer. The method mainly comprises the following steps that: a virtual synchronous motor controller is selected to pass through a control system based on the model inverse structure and the disturbance observer when a distributed power supply is connected to a main power grid through a voltage type inverter; the distributed power supply can actively participate in active frequency modulation and reactive voltage regulation processes of a power system, and voltage and current reference values are obtained at the same time; and the voltage and current controller is used for finely adjusting the injected voltage and current. The reliability of an inverter control system can be effectively enhanced, the stability is improved, current change and load power fluctuation caused by loop switching can be avoided when the operation mode of the micro-grid is switched through a static switch, and smooth switching of the operation mode of the micro-grid is realized.

The invention relates to an input signal shaping control method in a multi-sampling-rate system, and the method comprises the steps: converting a step signal inputted by an outer ring into an input signal with a limited frequency band in a limited beat of inner ring sampling through an input signal shaping control method on the basis of a hardware architecture of an existing multi-sampling-rate stable tracking system; high-frequency quantization information caused by low sampling rate of an outer loop is eliminated, and effective signals of a low-frequency band are reserved. By means of the advantage of high sampling rate of an inner loop, a transition process is arranged, an input signal is changed according to an expected form, excitation to an inner loop is reduced, good compromise between rapidity and stability indexes of a control system is achieved, the disturbance suppression capacity of the photoelectric stable tracking system is enhanced, the dynamic characteristic of the system is improved, and the method has wide application prospects.

The invention discloses an improved double-port internal model control method suitable for an unknown input tracking system, which is used for improving the tracking capability and disturbance suppression capability of the unknown input tracking system so as to meet higher-precision tracking control requirements. A standard dual-port internal model method requires input signals of a known system,so that the standard dual-port internal model method cannot be used in an unknown input tracking system. According to the improved dual-port internal model control method provided by the invention, the control effect of the dual-port internal model can still be realized under the condition that the input is unknown; and meanwhile, the tracking capability and the disturbance suppression capabilityof the system are improved. According to the method, the limitation of a standard dual-port internal model control method is broken through, the idea of internal model control is used under the condition that input is unknown, the tracking capacity and disturbance suppression capacity of the system are effectively improved, and the unknown input tracking system can obtain higher tracking precision.