| High precision sensor and instrument have the important role in national economy,scientific research,modern war etc.Currently,all the displacement(angular displacement and linear displacement)sensor including grating,inductosyn,rotating transformer,gate,in order to improve the measurement accuracy,are achieved by increasing the number of grid lines and increase the reading head number and rely on parent high precision instrument as a benchmark,to realize the error correction.However,to improve the grating displacement sensor and the precision of groove density could not like the world without end;The installation requirements of multiple read-heads are very high;High precision master meter can improve the accuracy of the sensor,but sometimes in the field without a master or unable to install the master correction,Even if the sensor is corrected,the accuracy of the subsequent use of the process will also be reduced or lost.In view of the above problems,this paper puts forward the multiple read-heads displacement sensor based on arithmetic phase.A plurality of read-heads are formed on the stator by means of a specific winding way to fix the phase difference.The read-heads are distributed on the same stator,and shares the same rotor,which have high consistency.It brings great convenience to the error processing of the sensor.This topic relies on the Key Laboratory of Chongqing City,according to the sensor signal processing and error correction,carry out the following research work:(1)The basic mechanical structure of the sensor and the construction of multi-reading head are introduced in this paper.Describes the measuring principle of sensor and the arithmetic phase construction principle reading head.and then,The feasibility of the sensor is verified by ASOFT simulation.(2)According to the signal processing of the sensor,the design of the signal processing system is put forward.The function of each module of the signal processing system and its hardware circuit diagram are described in detail.(3)Combined with the mechanical structure and electrical characteristics of the sensor,the error components of the sensor are analyzed.According to the characteristics(high consistency)of sensor readings,Classify the error as the impact on the read-heads are not the same part of the error and the impact on the read-heads are not the same part of the error.And explores the ways to correct these errors.(4)Analyzed and modeled the impact on the read-heads are not the same part of the error,and reveal its influence on the measurement accuracy of the sensor system.A kind of displacement solver model based on DSP processor is proposed to complete the correction of he impact on the read-heads are not the same part of the error.(5)In the light of the impact on the read-heads are not the same part of the error,without using the laser interferometer,grating displacement measurement datum equiangular case,Applying measurement system error identification theory and MATLAB software to establish the error characteristic parameter identification model to complete the correction of he impact on the read-heads are the same part of the error.(6)The hardware circuit of the signal processing system is debugged and the experimental platform is built.The displacement calculation model and the error characteristic parameters are verified by experiments,and the error correction of the sensor is accomplished.This topic through the study of the error characteristics of the sensor.According to the error characteristics of the sensor,displacement solver model and error parameter identification model are built and successfully applied in experiment.By using displacement solution model and error characteristics parameter identification model,the error of peak to peak for read-head A is 4.1 ",the error of peak to peak for read-head B is 4.3".This method can also be applied to capacitive,inductive synchronizer,rotary transformer and time grating displacement sensor and so on. |
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