| The regional air pollution problem in my country is severe,and rapid and accurate measurement of the concentration changes and spatiotemporal distribution of air pollutants is the premise to curb the aggravation of air pollution.Differential absorption spectroscopy(DOAS),as a spectroscopic telemetry method,can retrieve vertical column concentrations of tropospheric trace gases and also provide profile information of aerosols and trace gases.The technology is applied to the vehicle-mounted mobile monitoring platform,which can flexibly and quickly obtain the spatial and temporal distribution characteristics and concentration changes of air pollutants in the region.In order to obtain high-quality low-altitude spectral data,the light-collecting lens of the spectrometer needs to be installed on a high-precision gimbal.During field vehicle experiments,the gimbal fixed on the roof may be disturbed by uncertain factors such as the road surface or airflow,resulting in the deviation of the viewing axis of the lighting lens.Therefore,it is of great significance and value to study the stabilization technology and motor control technology to design the stabilization gimbal.This paper studies and designs a portable stabilization gimbal using a servo motor as the actuator,which can adjust the attitude of the load in real time and maintain the stability of the load in the inertial space.The main research contents and work are as follows:The structural composition and working principle of the stabilization gimbal are studied,the disturbance factors affecting the stability of the gimbal are analyzed,and the control scheme of the two-axis gimbal is proposed.In the stabilization control strategy,the principle of attitude angle calculation by gyroscope and accelerometer is analyzed,and finally the attitude calculation is carried out by the quaternion method,and the optimal estimation of the attitude angle is output by the Kalman filter algorithm.In the motor control strategy,the field-oriented control(FOC)based on coordinate transformation is used to decouple the complex three-phase current into intuitive and clear quadrature axis and direct axis components.Combined with the PID principle and SVPWM technology output,the three-phase power can be controlled.The PWM pulse signal of the inverter drives the motor to realize three closed-loop control of current,speed and position.The motor mathematical model is established in the natural coordinate system,and the phase voltage equation,flux linkage equation,electromagnetic torque equation and mechanical motion equation are analyzed.Using the Simulink toolbox of MATLAB to build the simulation model,the simulation results of the current loop show that the research and design are reasonable.According to the above research,a prototype of the two-axis stabilization gimbal was built.The static experiments confirmed that the gimbal has high angle control accuracy,small torque ripple,fast response speed,low overshoot,and good anti-shake ability.The two-axis stabilization gimbal combined with the vehicle-mounted DOAS system to carry out field experiments.In the comparison experiment of whether the gimbal uses the stabilization effect,it is found that the pollutant gas column concentration data measured after the stabilization effect is closer to the standard value,which once again confirmed The gimbal has a good stabilization effect.Figure [67] table [8] reference [80]... |
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