Study On The Influence Of Different Brush Material Characteristics On The Continuous Zoom Motor Control System

With the development of electronic technology,the continuous zooming function in the optical field is closely connected with the electric control technology sector.Such a link between optical sector and electronic control sector has become an important research direction.When electrically controlled zooming technology is enhancing,the application scope of image and video capture equipment in the optical sector is increasing.It makes us obtain the image and video more conveniently and gets much better images.There is obvious difference between electrically controlled zoom and traditional manual focus.The largest difference is that operators do not have physical contact with related components of optical system anymore.Moreover,electrically controlled zooming has a lot of advantages,such as the zoom error generated by manual operation.In the process of electrically controlled zoom,operators observe the image displayed by incident light,which is received by the image sensor of camera.Meanwhile,we can check the output image,adjust buttons and control the motor through Digital Signal Process(DSP)or electronic chips like single chip and change the focus distance of optical system.In optical measurement and collection of image and video,it is more accuracy than the naked eyes,which can give images with higher precision and definite zooming process faster.Electrically controlled zoom system is composed of high-speed analog digital conversion,digital signal analysis and motor precisely controlled modules,which make the zooming process be more precise and faster.Current optical system of electrically controlled zoom uses automatic method to realize zooming,inscribes the displacement curve of lens in the camshaft,realizes systematic focus.When the dimension of optical system is large,the weight and dimension of camshaft would also increase.Motors being able to drive the rotation of camshaft are few in this time.The displacement curve in camshaft raises high requirement on the manufacturing precision,which increases cost of camshaft.However,the zooming approach driven by motor is more convenient.Meanwhile,the cost of physical product is lower,while processing time and cost also decrease.In this paper,we analyze the influences of different materials on the performance of motor brush.If the abrasive resistance of motor brush material is low,it will improve the electric conductivity of the electric brush,but it will lead to shorten its service life.However,if the rigidity of material is large,it will increase the contact resistance between electric brushes.Therefore,it is vital to select a material for electric brush with reasonable resistance and rigidity.We designed an optical device of continuous zooming based on the characteristics of motor and zoom control principles,which included the overall designing plan,hardware design of control system,software design of control system and mechanical structure design.Finally,utilizing the digital signal processor,we designed brand-new motor control system with different module function.It realizes the electrically-controlled zoom function of optical system.The main contents are as follows:1.We studies conductivity,resistance and chemical stability of different materials of electric brush.It is found that the conductivity of material decreases with increasing electric brush resistance.The service life of motor shortens with the decrease of electric brush resistance.2.In accordance with the image-forming principle of zoom optical system,we use optical design software to modulate the displacement curve of focusing lens and compensation lens,which can replace the camshaft structure with motor.The optical system will not be restricted by camshaft manufacturing and the manufacturing cost through this method.3.We use the TMS320F28335 digital signal processor control system.It can increase the interface quality of zoom control system,while it can increase twice the performance than before.Moreover,we design new brushless dc motor drive circuit,which can automatically change the focus distance-displacement curve through driving lens.It simplifies control system.