Research On Key Technology Of Digital Intraoral Impression Based On Structured Light

With the rapid development of modern computer science and technology,digital implant navigation technology has been applied to the dental field and become the mainstream technology of modern dental implantation.In this paper,around the popularity and development of digital dental care,we study the error control,positional attitude solution and data filtering processing of MEMS implant navigation based on the calibration of MEMS sensor devices for experiments,and the selection and improvement of both positional solution algorithms for comparison and traditional complementary filtering.This paper includes the following main research aspects.（1）Due to the limitation of the tiny environment of the oral cavity,the experimental equipment（MEMS sensor,surgical lathing needle,and military navigation attitude solver）is therefore chosen in this paper,and the working principle and experimental scheme of this experimental equipment are introduced.Then the calibration experiment of the MEMS sensor was conducted and the inter-axis parameters of the MEMS device were recorded.Compared with the actual data,the errors of the calibration experiment meet the requirements of the experiment.According to the calibration results,the inter-axis calibration of the MEMS sensor was performed and the corrected inter-axis data were obtained.（2）In this paper,the quaternion based method is used as the solution method for the spatial attitude solution,and the Euler angular method,rotation vector method and direction cosine method are compared.Finally,the quaternion spatial posture solution algorithm is adopted as the posture solution algorithm in this paper.It solves the problems of large computational volume,high hardware requirement,and easy error during navigation surgery,and uses the quaternion method to solve the attitude for settlement.The experiment proves that the spatial attitude solution algorithm based on quaternion proposed in this paper can quickly perform attitude solution,and it is convenient to calculate and not very demanding on hardware.（3）The data values between each axis obtained from the attitude solution are complementarily filtered according to the traditional complementary filtering algorithm.In this paper,the data between each axis obtained are experimented with the improved complementary filtering algorithm,and the accelerometer and gyroscope data are processed by adding proportional and integral methods with high efficiency and accuracy.And according to the filtering algorithm after adding proportional integration control.In this paper,based on the calculation through the data of the gyroscope,an improved algorithm is proposed to feedback the attitude update error information obtained from the accelerometer back to the gyroscope.The experimental results show that compared with the traditional complementary filtering algorithm,the operation efficiency based on the improved complementary filtering algorithm is significantly improved in the oral implant navigation process,and the error accuracy is improved to within 0.2mm compared with the existing 0.35 mm.It has a great improvement for the precise positioning of implant navigation and finally realizes the error control of digital intraoral implant navigation.