37results about How to "Easy digital control implementation" patented technology

The invention discloses a method for controlling the real-time waveform replication of an electro-fluid servo system, comprising the following steps; setting a reference signal; utilizing RLS adaptive filtering algorithm to implement real-time online regulation on the weight of an adaptive filter I, recognizing the frequency response functions of the electro-fluid servo system and constructing a filter IV based on the recognition result; time-delaying the reference signal; utilizing the RLS adaptive filtering algorithm to implement real-time online regulation on the weight of an adaptive filter II, recognizing the frequency response functions of the adaptive filter I and constructing a filter III based on the recognition result; utilizing the filter III to filter the reference signal and regarding an output signal thereof as a position input signal of the electro-fluid servo system. The convergence of the RLS adaptive filtering algorithm utilized by the method ensures the convergence of recognizing the frequency response functions and the impedance functions of the system when the characteristics of the electro-fluid servo system and specimens are changed, thus ensuring the convergence of reference waveform during real-time online iteration.

The invention provides a resonance suppression method for an electrohydraulic servo vibration bench. A random wave signal is generated by utilizing a signal generator, the frequency characteristic curve of the electrohydraulic servo vibration bench is measured, and the position of the resonance peak is found out; the frequency of the reference signal of an adaptive notch filter is the frequency ofthe resonance peak of the vibration bench; an error signal can be acquired from the difference of the input acceleration speed and the acceleration response signal of the electrohydraulic servo vibration bench; an LMS adaptive filtering algorithm adjusts the weight of the adaptive notch filter online in real time according to the error signal, an output of the adaptive notch filter is acquired from the reference signal of the adaptive notch filter after the weighting effect of the weight, and the output signal and the acceleration speed input signal added as a new input signal of the vibration bench to affect on the vibration bench. The invention is easy to be realized through the digital control of a computer, and the suppression to the resonance peak can be realized on line in real time, therefore, the bandwidth of the vibration bench can be expanded, and the reproducing precision of the power spectrum can be improved.

The invention discloses a pose control method for a dual-degree-of-freedom dual-electro-hydraulic vibration table array simulation system. The method comprise steps that an input signal and an outputsignal of a PI controller are obtained; a pose signal yf fed back by the array simulation system is obtained; a redundant force compensation signal xf is calculated; an input signal and an output signal of the PID controller are obtained; the array simulation system is driven to move. The method is advantaged in that the redundant force compensation signal is calculated by collecting differentialpressure signals of hydraulic cylinders in 10 valve-controlled cylinder mechanisms, driving signals of the valve-controlled cylinder mechanisms are adjusted through utilizing the redundant force compensation signal, so the redundancy force in each valve-controlled cylinder mechanism is reduced to within 15% of the rated oil supply pressure, the test is performed on an Advantech industrial controlcomputer IPC-610 with a CPU of Intel PD 2.6G and a memory of 1G, the algorithm's run cycle is less than 1ms, and experimental requirements of the array simulation system can be met.

The invention discloses a waveform reproduction control method of an electro-hydraulic servo system based on a Kalman filter, comprising the following steps of: setting a reference signal; utilizing single-step prediction Kalman filtering algorithm to adjust the weight number of a Kalman filter I, identifying frequency response function of the electro-hydraulic servo system, and constructing a filter IV on the basis of identification result; delaying the reference signal; utilizing the single-step prediction Kalman filtering algorithm to adjust the weight number of a Kalman filter II, identifying impedance function of the Kalman filter I, and constructing a filter III on the basis of identification result; and using the filter III to filter the reference signal, and taking the output signal as a position input signal of the electro-hydraulic servo system. The method utilizes the convergence property of the single-step prediction Kalman filtering algorithm to ensure the identification convergence of the frequency response function and the impedance function of the system when the characteristics of the electro-hydraulic servo system and a test piece are changed, thus guaranteeing the on-line iterative convergence property of a reference waveform.

The invention discloses a random wave reproduction control method of an electro-hydraulic acceleration servo system, which identifies the impedance characteristics of the electro-hydraulic acceleration servo system based on a frequency domain method, and can ensure accurate identification of resonance peaks and resonance valley frequency bands in the impedance characteristics of the electro-hydraulic acceleration servo system , thereby ensuring the control accuracy of the waveform reproduction of the resonant peak or resonant valley frequency band. Moreover, the present invention corrects the impedance in real time according to the input and output characteristics of the electro-hydraulic acceleration servo system under the time-varying condition, and the correction calculation method can ensure the convergence of the impedance correction result, thus improving the waveform reproduction under the time-varying condition of the electro-hydraulic acceleration servo system control precision. The invention can control the time-domain peak value error between the acceleration output signal and the acceleration reference signal of the electro-hydraulic acceleration servo system within 15%. The operating cycle of the invention is less than 1 ms, which can meet the experimental requirements of random wave reproduction of the electro-hydraulic acceleration servo system, and is easy to realize by computer digital control.

The invention discloses a method for suppressing interference force of a six-degree-of-freedom electro-hydraulic vibrating table, which comprises the following steps: multiplying a six-degree-of-freedom acceleration reference signal to the left by a matrix J and using it as an input signal of a reference signal generator module; The output signal of the module r a ; will r a As the input signal of the integrator 1 module, the output signal r v ; will r v As the input signal of the integrator 2 module, the output signal r x ; Collect the displacement signal x, velocity signal v, acceleration signal a of the hydraulic cylinder piston rod of each valve-controlled cylinder mechanism and the pressure difference signal P between the two chambers of the hydraulic cylinder L ; put the signal r x 、r v 、r a ,x,v,a,p L As the input signal of the interference force suppression controller module, calculate the output signal u of the interference force suppression controller module; use the output signal u of the interference force suppression controller module as the driving signal of the six valve-controlled cylinder mechanisms, and input it to the six valves The cylinder control mechanism drives the movement of the six-degree-of-freedom electro-hydraulic vibration table. The invention obviously improves the control precision of the six-degree-of-freedom electro-hydraulic vibrating table.

The invention discloses a position control method of a six-degree-of-freedom hydraulic moving platform with a connection rod. Through local coordinate transformation, an expression of the center coordinates of a hinge point of a hooke joint under the connection rod is obtained through displacement of a horizontal hydraulic cylinder, a position signal of an upper platform is obtained through the displacement signal of the hydraulic cylinder, a position positive solution algorithm of the six-degree-of-freedom hydraulic moving platform with the connection rod is achieved, and the precision of transformation from six hydraulic cylinder displacement signals to six-degree-of-freedom position signals of the moving platform is improved. By combination of a Jacobian matrix, the position control method of the six-degree-of-freedom hydraulic moving platform with the connection rod is given out, and the control precision of the six-degree-of-freedom hydraulic moving platform with the connection rod is obviously improved. Testing is conducted on an Advantech industrial personal computer IPC-610 with the internal memory being 1G, the operation period is shorter than 0.5 ms, the real-time requirement of a moving control system can be met, and therefore the method can be easily implemented by computer digital control.

The invention discloses a posture control method of a six-freedom-degree double electro-hydraulic vibrostand array simulation system. The posture control method comprises the following steps that an input signal and an output signal of a PI controller are obtained; a posture signal yf fed back by the array simulation system is obtained; redundant force s of 10 valve-controlled cylinder mechanismsis obtained; an input signal and an output signal of a PID controller are obtained; the array simulation system is drive to move. According to the posture control method, pressure difference signals of hydraulic cylinders in the 10 valve-controlled cylinder mechanisms are collected, a redundant compensation signal is gained through a freedom degree decomposing matrix, and driving signals of the valve-controlled cylinder mechanisms are adjusted through the redundant force compensation signal, so that the redundant force in the valve-controlled cylinder mechanisms is reduced to be within 15% ofrated oil supply pressure. According to the posture control method, testing is carried out on an Advantech industrial personal computer IPC-610 with the CPU being Intel PD 2.6 G and the internal storage being 1 G, the operation cycle of the algorithm is shorter than 1 ms, and the experimental requirement of the array simulation system can be met.

The invention discloses a method for controlling the random vibration of an electro-hydraulic servo system based on self-adaptive filters, which comprises the steps of: designing a filter III with an acceleration power spectral density reference signal, filtering a white noise signal, and outputting the white noise signal to be taken as an acceleration time domain drive signal; adjusting the weight number of the a self-adaptive filter I and a self-adaptive filter II with a RLS self-adaptive filtering algorithm, and respectively identify a frequency response function of the electro-hydraulic servo system from an impedance function of the self-adaptive filter I; and building a filter IV based on an identifying result of the impedance function of the self-adaptive filter II, filtering the acceleration time domain drive signal, and outputting the acceleration time domain drive signal to be taken as an acceleration input signal of the electro-hydraulic servo system. The method obtains the acceleration time domain drive signal by filtering the white noise signal with the filter III, thereby simplifying a process for generating the time domain drive signal. The method adopts the astringency of the RLS self-adaptive filtering algorithm to guarantee the astringency of power spectrum density real-time online iteration.

The invention discloses a method for compensating interference force of a two-degree-of-freedom electro-hydraulic vibrating table, which comprises the following steps: taking the two-degree-of-freedom acceleration reference signal as the input signal of a reference signal generator module by multiplying it to the left by a matrix J; The output signal of the module r a ; will r a As the input signal of the integrator 1 module, the output signal r v ; will r v As the input signal of the integrator 2 module, the output signal r x ; Collect the displacement signal x, velocity signal v, acceleration signal a of the hydraulic cylinder piston rod of each valve-controlled cylinder mechanism and the pressure difference signal P between the two chambers of the hydraulic cylinder L ; put the signal r x 、r v 、r a ,x,v,a,p L As the input signal of the disturbance force compensation controller module, calculate the output signal u of the disturbance force compensation controller module; use the output signal u of the disturbance force compensation controller module as the driving signal of the two valve control cylinder mechanisms, and input it to the two valves The cylinder control mechanism drives the movement of the two-degree-of-freedom electro-hydraulic vibration table. The invention obviously improves the control precision of the two-degree-of-freedom electro-hydraulic vibrating table.

The invention discloses a rigidity control method of a six-degree-of-freedom dual-electro-hydraulic vibrostand array simulation system. The method comprises the following steps of building an O-XYZ coordinate system with a geometric center O of a bridge plate, and calculating driving signals x0 of valve-controlled cylinder mechanisms; calculating array simulation system six-degree-of-freedom posefeedback signals y; calculating rigidity compensation signals s; regarding the rigidity compensation signals s as input signals of a PID controller, and regarding output signals of the PID controlleras compensation signals xd of the valve-controlled cylinder mechanisms; making difference between the signals xo and the signals xd to obtain deviation signals xa of the valve-controlled cylinder mechanisms, and driving the six-degree-of-freedom dual-electro-hydraulic vibrostand array simulation system to move. According to the method, by reasonably controlling the redundant force in the 10 valve-controlled cylinder mechanisms, k61 element values in a rigidity matrix can be increased, and the system rigidity is improved. When the oil supply pressure of a hydraulic source is 21 MPa, the maximumvalue of kRzDx in the rigidity matrix can be increased by 7% by means of the control method.

The invention discloses a disturbing force compensation method of a six-degree-of-freedom double-electro-hydraulic shaking table array simulation system. The six-degree-of-freedom double-electro-hydraulic shaking table array simulation system comprises a lower platform, an upper platform, a pier, a bridge plate, ten valve-controlled cylinder mechanisms and three reaction walls. According to the disturbing force compensation method of the six-degree-of-freedom double-electro-hydraulic shaking table array simulation system, by collecting pressure difference signals of two cavities of hydraulic cylinders and acceleration signals of hydraulic piston rods in the ten valve-controlled cylinder mechanisms, and a disturbing force compensation signal is obtained through calculation. Driving signalsof the valve-controlled cylinder mechanisms are adjusted by using the disturbing force compensation signal, so that the purpose of improving the control precision of the shaking table array simulationsystem is achieved. According to the disturbing force compensation method of the six-degree-of-freedom double-electro-hydraulic shaking table array simulation system, the fluctuation of the amplitude-frequency characteristic of a closed-loop transfer function at a transverse freedom position at 20dB near 8Hz can be reduced within 5dB, and the control precision of the shaking table array simulation system is obviously improved.

The invention discloses a six-degree-of-freedom electro-hydraulic vibration table active disturbance rejection control method. The six-degree-of-freedom electro-hydraulic vibration table comprises three horizontal valve-controlled cylinder mechanisms, three vertical valve-controlled cylinder mechanisms, an upper platform and a lower platform. The method comprises acquiring the position, the velocity and the acceleration signal of each hydraulic cylinder piston rod in the six valve-controlled cylinder mechanisms, calculating a generalized disturbance compensation signal, and adjusting the driving signals of the valve-controlled cylinder mechanisms by using the generalized disturbance compensation signal so as to improve the control precision of a vibration table system. The control method provided by the invention can reduce the fluctuation of the amplitude-frequency characteristic of a lateral-degree-of-freedom acceleration closed-loop transfer function from 12dB to less than 3dB in the frequency band of 50 Hz, and obviously improves the control precision of the six-degree-of-freedom electro-hydraulic vibration table. The method has an operation cycle less than 1ms and can satisfythe experimental requirements of a vibration simulation system. Thus, the method is easy to be implemented through computer numerical control.

The invention discloses a method for suppressing interference force of a two-degree-of-freedom electro-hydraulic vibrating table, which comprises the following steps: taking the two-degree-of-freedom acceleration reference signal as an input signal of a reference signal generator module by multiplying it to the left by a matrix J; module output signal r a ; will r a As the input signal of the integrator 1 module, the output signal r v ; will r v As the input signal of the integrator 2 module, the output signal r x ; Collect the displacement signal x, velocity signal v, acceleration signal a of the hydraulic cylinder piston rod of each valve-controlled cylinder mechanism and the pressure difference signal P between the two chambers of the hydraulic cylinder L ; put the signal r x 、r v 、r a , x, v, a, P L As the input signal of the interference force suppression controller module, calculate the output signal u of the interference force suppression controller module; use the output signal u of the interference force suppression controller module as the driving signal of the two valve-controlled cylinder mechanisms, and input it to the two valves The cylinder control mechanism drives the movement of the two-degree-of-freedom electro-hydraulic vibration table. The invention obviously improves the control precision of the two-degree-of-freedom electro-hydraulic vibrating table.

The invention discloses a control method for a six-degree-of-freedom hydraulic motion platform with connecting rods. The control method comprises the following steps: setting a six-degree-of-freedom position and posture command signal of an upper platform, and inputting the command signal in a position and posture inverse solution calculation module; carrying out position and posture inverse solution calculation through the position and posture inverse solution calculation module so as to acquire the displacement of each of six hydraulic cylinders, and taking the displacement as the displacement command signal of each of the six hydraulic cylinders; and inputting the displacement command signals of the six hydraulic cylinders in a valve-controlled cylinder position control system, drying the hydraulic cylinders to move, and driving the upper platform to realize the six-degree-of-freedom movement through the hydraulic cylinders. According to the control method for the six-degree-of-freedom hydraulic motion platform with connecting rods, through the transformation of local coordinates, the center coordinate expressions of lower hook joint hinge points of the connecting rods are acquired by utilizing the displacement of each of the horizontal hydraulic cylinders, the displacement of each of the horizontal hydraulic cylinders is acquired through solving equations, the position and posture inverse solution operation of the six-degree-of-freedom motion platform with the connecting rods is realized, and the conversion accuracy between the six-degree-of-freedom position and posture command signal of the upper platform and the displacement command signals of the six hydraulic cylinders is improved.