Design And Analysis Of Portable Polar Axis Sun Position Tracing Platform

In this paper,an ultra-light collapsible radial rib structure reflector is researched,and a spring-driven portable polar-axis solar position tracking device is proposed,which is expected to be used for tracking the sun position and improving the collection efficiency of solar energy.The solar power generation device includes a radial rib reflecting surface,a heat collector,and a solar position tracking device.Then a detailed structural analysis and design of the solar positon tracking device is carried out.The platform has the advantages of light weight,simple installation,easy portability,low cost,energy saving and environmental protection,and no motor drive.First,the principle of solar azimuth tracking and positioning is introduced.This paper briefly introduces the movement law between the sun and the earth and two coordinate systems which describe the positional relationship between the sun and the earth.On this basis,the solar distribution and position parameters are calculated,and the solar azimuth and position tracking system is introduced in detail from the two aspects of tracking axis number and control mode.Then,the analysis and selection of the plan for the solar positon tracking platform is carried out.According to the characteristics of the radial rib structure reflector,a lightweight portable solar position tracking platform scheme is proposed.The installation and workflow of the platform are introduced,and the structural concept design is carried out,including the latitude range of the platform,the overall size of the platform,the design of the telescopic rod,the support member design of the reflector,the concentrating lens,and the fixing method of the platform.Next,the structural design and analysis of each component are performed on the drive unit.The drive unit uses a purely mechanical drive,including a power unit powered by a spring,a drive train,and an escapement that controls the reflector to rotate at a fixed angular velocity and a single swing.By deducing the torque variation equation of reflector during the rotation process,the torque of the reflector in the extreme working condition to the polar axis is calculated.According to the calculation result,the specific parameters of the box spring are designed,and the starting box is made by 3D printing.The physical model, and the choice of the real thing of the clockwork.For other diameter reflectors,it is proposed to compensate the rotational moment by changing the weight of the sleeve.Then the control system is analyzed and designed in detail.The workflow of the control system is introduced.The anti-reverse mechanism,escapement and single pendulum of the clockwork shaft are designed.The connection error between the single pendulum and the escapement is analyzed under different poses.According to the connection relationship between the barrel,the polar shaft,the transmission wheel train and the escapement mechanism,the motion period of the escapement wheel is calculated by calculating the motion period of the single pendulum,and the input end is calculated by combining the angular velocity of the pole axis.The angular velocity ratio of the output end determines the total gear ratio of the gear train,compares several meshing transmission schemes,and finally selects the transmission scheme of the harmonic gear plus spur gear.Then the parameters of the harmonic gear are calculated,the error of the transmission train is derived,and the installation form of the drive device in the side ring is determined.Finally,the motion simulation of the visual tracking platform is carried out.The static and dynamic analysis of the main components in the platform is carried out by software,including the structural strength check of the sleeve ring,the side ring,the telescopic rod and the fixed length rod under gravity load,and the installation angle of the platform is established.The finite element model at two kinds of angle finally derives the wind formula,analyzes the stability of the platform under wind load conditions,and the modal characteristics of the tracking platform,which verifies the reliability of the structural design of the entire tracking system.And provide a basis for the optimization of the platform.The analysis in this paper has a certain significance for the future application of small portable solar position tracking devices in solar energy engineering.