Dynamic Identification and Control Parameter Re-Correction System and Method
I. Technical Field The present invention relates to a dynamic identification and control parameter re-correction system and method, particularly to a dynamic identification and control parameter re-correction system and method suitable for a coal cutter. II. Background Art As mining machines are developed toward energy-saving, intelligent and unmanned operation, the frequency conversion energy-saving control technique and the fault diagnosis technique have been widely applied in the field of mining machinery. The coal cutters is one of fully mechanized mining automation equipment, the failure rate of the permanent magnet short-range drive system directly impacts the coal mining efficiency and the safe operation of equipment. However, at present, in the application of the frequency conversion energy-saving control technique, the parameter identification for the permanent magnet short-range drive system is mainly the first identification of frequency conversion control parameters according to the design of system parameters, and the processes of fault diagnosis techniques are mostly completed offline. In the coal rock cutting process of a coal cutter, the motor of the permanent magnet short-range drive system heats up with the running time and then the parameters of the motor system change with the temperature; in addition, the terminal cutting moment varies with the hardness of the coal seam being cut. and therefore, the motor parameters to be regulated are also different. However, at present, the identification of the parameters of the motor system always employs the first identification of the frequency conversion control parameters according to the design of system parameter, and cannot adjust the parameters of the motor in real time according to the actual circumstance. Consequently, there is a potential risk in such a method, i.e., it is very difficult to ensure that the model data used in the control system completely matches the data of the machine under real-time operating conditions. As a result, the designed control parameters do not match the actual conditions, the method cannot achieve the expected control effect, can't improve cutting efficiency, can't save energy, can't decrease failure rate, and directly impactsthe safe and reliable operation of the cutting unit of the coal cutter. III. Contents of the Invention In view of the above-mentioned problems in the prior art, the present invention provides a dynamic identification and control parameter re-correction system and method, which can correct the control parameters in real time according to acquired real-time operating data during the operation of the permanent magnet short-range drive system, and thereby can improve cutting efficiency, save energy, decrease failure rate, and ensure safe and reliable operation of the cutting unit of a coal cutter. To achieve the object described above, the present invention adopts the following technical scheme: a dynamic identification and control parameter re-correction system, comprises a data acquisition module, an online dynamic model identification module for the permanent magnet short-range drive system, a control parameter re-correction module and a main control system, wherein, the data acquisition module acquires and transfers the operating data of a permanent magnet short-range drive system to the online dynamic model identification module for permanent magnet short-range drive system, the online dynamic model identification module for permanent magnet short-range drive system identifies the data acquired by the data acquisition module and inputs an identification result to the control parameter re-correction module, the control parameter re-correction module corrects and adjusts the control parameters of the permanent magnet short-range drive system according to the identification result of the permanent magnet short-range drive system and outputs the corrected control parameters to the main control system, and the main control system controls the operation of the permanent magnet short-range drive system according to the corrected control parameters.
Furthermore, the online dynamic model identification module for permanent magnet short-range drive system comprises a real-time identification unit for the motor system parameter, an identification unit for the terminal load torque, and an identification unit for the structural mode of the permanent magnet short-range drive system; wherein, the real-time identification unit for the motor system parameter performs the real-time motor system parameter identification on the operating data of the permanent magnet short-range drive system acquired by the data acquisition module, and inputs the result of the real-time motor system parameter identification to the control parameter re-correction module; the identification unit for the terminal load torque identifies a given motor output torque signal and an actual terminal load torque feedback signal from the operating data of the permanent magnet short-range drive system acquired by the data acquisition module, and inputs an identified result to the control parameter re-correction module; the identification unit for the structural mode of the permanent magnet short-range drive system performs the structural mode identification for a gear system on the data acquired by the data acquisition module, and inputs an identified result to the control parameter re-correction module. A dynamic identification and control parameter re-correction method comprises the following steps: A. Data acquisition: During the operation of a permanent magnet short-range drive system, the data acquisition module acquires the operating data of the permanent magnet short-range drive system in real time, and transfers the operating data to the online dynamic model identification module for the permanent magnet short-range drive system, wherein, the operating data comprises a real-time motor system parameter, a given motor output torque signal, an actual terminal load torque feedback signal, a motor speed, a gear meshing frequency, and an acceleration of drive system; B. Data identification: The online dynamic model identification module for permanent magnet short-range drive system reads the data acquired by the data acquisition module; the real-time identification unit for the motor system parameter, the identification unit for the terminal load torque and the identification unit for the structural mode of the permanent magnet short-range drive system read and identify the real-time motor system parameters, the given motor output torque signal, the actual terminal load torque feedback signal, the motor speed, the gear meshing frequency, and the acceleration of drive system respectively, and input the identified data to the control parameter re-correction module respectively; C. Control parameter re-correction: The control parameter re-correction module compares and analyzes the data identified by the online dynamic model identification module for the permanent magnet short-range drive system with the initially set control parameters, corrects the initially set control parameters according to the identified data, and then inputs the corrected control parameters to the main control system; D. Regulation of operation of the permanent magnet short-range drive system: The main control system controls and regulates the operating data of the permanent magnet short range drive system, according to the corrected control parameters. Furthermore, the specific identification processes of the real-time identification unit for the motor system parameter, the identification unit for the terminal load torque, and the identification unit for the structural mode of the permanent magnet short-range drive system are as following: Identification process of the real-time identification unit for the motor system parameter is: the acquired operating data of the permanent magnet short-range drive system is calculated and processed according to the first identified motor system parameters, then an identification time interval is set to 10min to allow the real-time identification unit for the motor system parameter to identify automatically every 10min, the specific identification is that the motor system parameter acquired in the previous time is updated in real time with an improved recursive least square algorithm, and the identification result obtained in each time is input to the control parameter re-correction module; Identification process of the identification unit for the terminal load torque is: a given motor output torque signal and an actual terminal load torque feedback signal is identified from the acquired operating data of the permanent magnet short-range drive system, the specific identification is that a first order system and a delay link model is used for equivalent simulation, by reading the given motor output torque signal and the terminal load torque feedback signal, the delay time and the time constant of the first order system are compared, and then the identified data is input to the control parameter re-correction module; Identification process of the identification unit for the structural mode of the permanent magnet short range drive system is: the time domain signals, including motor speed, gear meshing frequency and acceleration of drive system, are identified and read from the acquired operating data of the permanent magnet short-range drive system, the time domain signals is converted into frequency spectrum signals to obtain the distribution of power spectrum density, and then the structural mode of the permanent magnet short-range drive system is analyzed and input to the control parameter re correction module. Furthermore, the specific process of control parameter re-correction is: the control parameter re correction module matches each real-time operating parameters identified by the online dynamic model identification module for the permanent magnet short-range drive system with the initially set control parameters; if any of the real-time operating parameters does not match the corresponding initially set control parameter, a re-correction model for the control parameters is reestablished on the basis of the real-time operating parameters, and the control parameter in the re-correction model is obtained, and finally the corrected control parameters is input to the main control system. Compared with the prior art, the present invention utilize a combination of a data acquisition module, an online dynamic model identification module for the permanent magnet short-range drive system and a control parameter re-correction module. In the operation of the permanent magnet short-range drive system of a coal cutter, after acquiring the operating data of the drive system in real time and identifying the acquired operating data, the identified result is input to the control parameter re correction module; then the control parameter re-correction module corrects the control parameters in real time, so that the real-time control parameter is matched with the parameter required for actual operation, thereby achieving the expected control effect, improving the cutting efficiency, saving energy, decreasing failure rate and ensuring safe and reliable operation of the cutting unit of a coal cutter. IV. Brief Description of Drawings Fig. 1 is a block diagram of the overall system structure according to the present invention; and Fig. 2 is a block diagram of the working principle of the online dynamic model identification module for permanent magnet short-range drive system according to the present invention.
V. Detailed Description of the Drawings Hereunder the present invention will be detailed with reference to the embodiments and the drawings. As shown in Fig. 1, the present invention provides a dynamic identification and control parameter re correction system, which comprises a data acquisition module, an online dynamic model identification module for the permanent magnet short-range drive system, a control parameter re correction module and a main control system, wherein, the data acquisition module acquires and transfers the operating data of a permanent magnet short-range drive system to the online dynamic model identification module for permanent magnet short-range drive system, the online dynamic model identification module for permanent magnet short-range drive system identifies the data acquired by the data acquisition module and inputs an identification result to the control parameter re-correction module, the control parameter re-correction module corrects and adjusts the control parameters of the permanent magnet short-range drive system according to the identification result of the permanent magnet short-range drive system and outputs the corrected control parameters to the main control system, and the main control system controls the operation of the permanent magnet short-range drive system according to the corrected control parameters. As shown in Fig. 2, furthermore, the online dynamic model identification module for permanent magnet short-range drive system comprises a real-time identification unit for the motor system parameter, a identification unit for the terminal load torque, and a identification unit for the structural mode of the permanent magnet short-range drive system; wherein, the real-time identification unit for the motor system parameter performs the real-time motor system parameter identification on the operating data of the permanent magnet short-range drive system acquired by the data acquisition module, and inputs the identified result of the real-time motor system parameter to the control parameter re-correction module; the identification unit for the terminal load torque identifies a given motor output torque signal and an actual terminal load torque feedback signal from the operating data of the permanent magnet short-range drive system acquired by the data acquisition module, and inputs an identified result to the control parameter re-correction module; the identification unit for the structural mode of the permanent magnet short-range drive system performs the structural mode identification for a gear system on the data acquired by the data acquisition module, and inputs an identified result to the control parameter re-correction module. The present invention further provides a dynamic identification and control parameter re-correction method for coal cutters, comprising the following steps: A. Data acquisition: During the operation of a permanent magnet short-range drive system, the data acquisition module acquires the operating data of the permanent magnet short-range drive system in real time, and transfers the operating data to the online dynamic model identification module for the permanent magnet short-range drive system, wherein, the operating data comprises a real-time motor system parameter, a given motor output torque signal, an actual terminal load torque feedback signal, a motor speed, a gear meshing frequency and an acceleration of drive system; B. Data identification: The online dynamic model identification module for permanent magnet short-range drive system reads the data acquired by the data acquisition module; the real-time identification unit for the motor system parameter, the identification unit for the terminal load torque and the identification unit for the structural mode of the permanent magnet short-range drive system read and identify the real-time motor system parameters, the given motor output torque signal, the actual terminal load torque feedback signal, the motor speed, the gear meshing frequency, and the acceleration of drive system respectively, and input the identified data to the control parameter re-correction module respectively; C. Control parameter re-correction: The control parameter re-correction module compares and analyzes the data identified by the online dynamic model identification module for the permanent magnet short-range drive system with the initially set control parameters, corrects the initially set control parameters according to the identified data, and then inputs the corrected control parameters to the main control system; D. Regulation of operation of the permanent magnet short-range drive system: The main control system controls and regulates the operating data of the permanent magnet short range drive system, according to the corrected control parameters. Furthermore, the specific identification processes of the real-time identification unit for the motor system parameter, the identification unit for the terminal load torque, and the identification unit for the structural mode of the permanent magnet short-range drive system are as following: Identification process of the real-time identification unit for the motor system parameter is: the acquired operating data of the permanent magnet short-range drive system is calculated and processed according to the first identified motor system parameters, then an identification time interval is set to 10min to allow the real-time identification unit for the motor system parameter to identify automatically every 10min; the specific identification is that employing an improved recursive least square algorithm, introducing a recursion formula P,=F, into the improved recursive least square algorithm, simplifying the square algorithm under a matrix inversion principle [A+B.C-D],=A,- A .B.[D-A-B+C] -D-A1, and finally introducing a forgetting factor within a value range of 0.95-0.99, such that the motor system parameters acquired in the previous time is updated in real time, and then the identification result obtained in each time is input to the control parameter re-correction module; Identification process of the identification unit for the terminal load torque is: a given motor output torque signal and an actual terminal load torque feedback signal is identified from the acquired operating data of the permanent magnet short-range drive system, the specific identification is that a first order system and a delay link model is used for equivalent simulation, by reading the given motor output torque signal and the terminal load torque feedback signal, the delay time and the time constant of the first order system are obtained by comparison, and then the identified data is input to the control parameter re-correction module; Identification process of the identification unit for the structural mode of the permanent magnet short range drive system is: the time domain signals, including motor speed, gear meshing frequency and acceleration of drive system, are identified and read from the acquired operating data of the permanent magnet short-range drive system, the time domain signals are converted into frequency spectrum signals to obtain the distribution of power spectrum density, and then the structural mode of the permanent magnet short-range drive system is analyzed and input to the control parameter re correction module. Furthermore, the specific process of control parameter re-correction is: the control parameter re correction module matches each real-time operating parameters identified by the online dynamic model identification module for the permanent magnet short-range drive system with the initially set control parameters; if any of the real-time operating parameters does not match the corresponding initially set control parameter, a re-correction model for the control parameters is reestablished on the basis of the real-time operating parameters, and the control parameter in the re-correction model is obtained, and finally the corrected control parameters is input to the main control system.