Design Of Self-latching Actuator For Full-page Braille Display Device

Currently,there are huge contradictions between the traditional slowly updated paper braille books and the increasing reading requirements of blind people.It arises out of profound significance to devise a full-page,refreshable braille display device that can replace paper braille books.Presently,the absence of an applicable actuator with a self-latching function that can satisfy the Braille display requirement blocks the development of braille display devicesBuilt on the problems existing in the current braille display device actuator,the present paper innovatively proposes a self-latching actuator that utilizes the magnetic principle to carry out the latching function and utilizes the electromagnetic coil to drive.The main contents of this thesis are self-latching actuator structure design,calculation of structural parameters,simulation analysis,and verification test.The main contents are arranged as follows:1.Combining the current research status of the Braille display device actuator and the actuator design requirements for the full-page Braille display device,propose a self-latching actuator capable of dual-position latching.In order to assist the subsequent development test,designing a Braille display module based on a self-latching actuator.And designing some parts of the self-latching actuator2.According to the basic theory of the magnetic field,analyzing the magnetic field distribution of the upper and lower permanent magnets,and using the finite element method to calculate the force of the iron core under different air gaps when the upper and lower permanent magnets are single-acting iron core.Associated with the design requirements,the design core is in two The critical position and the air gap of the upper and lower permanent magnets.The minimum ampere-turn number of the coil winding is calculated by the force calculation formula of the energized coil and the force analysis of the actuator core at two critical positions.3.According to the structural parameters of the self-latching actuator,using the electromagnetic field analysis software to simulate and analyze the influence of the height of the upper and lower permanent magnets of the self-latching actuator,the radius the iron core on the static characteristics of the actuator.The results demonstrate that the increase of the height of the lower permanent magnet will increase the force of the core in the downward direction,which will have a greater impact on the core when it is latched at the lowest position and moves downward from the highest position.After the force and height increase to a certain extent,the driver cannot complete the intended function;the change in core radius has a great effect on the core force.The larger the radius,the greater the core force.The simulation analysis of the transient magnetic field verifies that the design structure is reasonable and feasible,and can meet the design requirements.4.Assembling the braille display module based on the self-latching actuator to test the latching force at the highest position,and the test result explains that the latching force is greater than 50 mN,which satisfies the design requirements.Using the Arduino development board and the L298N driver module to design the drive circuit to control the power-on duration of the actuator,to test the response time of the self-latching actuator from the lowest position to the highest position.The test results demonstrate that the response time is about 200ms and the response frequency is about 5Hz,which can comply with the usage requirements.