Research On A Kind Of Control Problem In Intelligent Instrument

Over the years,cooperative research and development of intelligent instrument in the laboratory and in the process of enterprise,intelligent instrument needs to ensure its accuracy and stability at the same time in engineering application,but also to meet the requirements of the rapid adjustment of the output control problem,the development of a double closed-loop control system.The analog inner loop of the double closed loop control system is based on the PI controller,which is controlled by the signal processing.At the same time,the output signal is introduced to the input of the PI controller by negative feedback,so as to achieve the control accuracy and stability of the intelligent instrument.In some engineering applications that require quick regulation of intelligent instruments,only the internal loop control system is used to regulate it.The adjustment time is too long to meet the engineering requirements.In order to shorten the adjustment time of the system and improve the speediness of the instrument,the digital outer loop control system is added on the basis of the analog inner loop.Sampled by the instrument output value,the output value of th e₀ error is obtained,and the error rate of e_c0,and according to the fuzzy control strategy for the input set value is corrected,so that the input deviation of inner loop PI controller fast zero output,fast and stable,has reached the purpose of regulating the output speed.The system principle and the traditional fuzzy PID control different,not modified PID controller K_p,K_i,K_d,parameters of double closed loop control system and the PI controller,but the input is modified,thus avoiding the change of controller parameters on the control precision and stability of the impact has reached to ensure the accuracy of instrument output and stability.Although the double closed loop control system has been implemented in engineering application,it is still prior experience in design,and the control performance is still described by fuzzy quantitative words such as"stable","quasi"and"fast".In the current system of double closed loop control theory literature,therefore,in order to control the quantitative relationship between the performance of the control system of double closed loop,the new high precision DC voltage source instrument based on a double closed-loop control system based on the identification of the knowledge of mathematics research model,and simulate the control performance by using MATLAB software.The simulation results show that compared with the single closed-loop control system,the regulation time of the double loop control system is reduced by 2.57².69 times on the basis of meeting the accuracy and stability of the system.And on the two problems often concern in intelligent instruments:the relationship between the resolution and the instrument of double closed loop control system of DAC and DAC precision control and instrumentation;cycle stability between the double closed loop control system,the intelligent instrument for subsequent experimental exploration,double closed-loop control system design reference.The actual test results show that the low resolution of DAC and ADC will restrict the accuracy of intelligent instrument,according to the need of precision instrument DAC and ADC to choose proper resolution in the design;in order to meet the demand of the accuracy of the instrument under the control cycle and intelligent instrument of double closed-loop control system stability has certain quantitative relationship select the control cycle cannot be too large,otherwise the instrument oscillation,also cannot be too small,too small and micro controller load is too large,affecting the service life of the meter,and with the control cycle is small,the instrument stability increases.