Research Of Foot 3D Measurement And Instrument Development

The design of customized shoe last is the trend of social development, It has important research meanings and extensive application value for the study of foot 3D measurement instrument. This paper is mainly about the automatical measurement of whole foot, the principle is based on laser scanning. After the analysis of foot characteristics, in line with the existing machine and the practical requirements, a formula is given. Control system, optical system, mechanical system and image acquisition module are designed. Image extraction and analysis is implemented by self-developed software system, contour of the foot can be rebuilt in a short time.The control system based on MCU is achived, including the basic peripheral circuits, stepper motor drive circuit, CCD and laser control circuit, power supply control system as well as RS-232 communication circuit. We take anti-inference in considering and adopt many measures to improve the reliability and performance of the circuit. This paper also combines computer simulation and practical experiments to improve the efficiency of circuit designing and debugging.The scanning system which combines four groups of CCDS and lasers with high-speed stepper motor is proposed. The stepper motor drives screw bars, which makes the linear slide move backward and forward. The four laser lines form an area which likes a circle. Through the move of platform, the four CCDS capture laser lines, and then we can obtain the changes of heights of the foot. The mechanical system includes a shelf, floor, sliding platform and a holder which supports the foot, this design method has reduced its size to be a portable equipment.In software system, it includes upper computer configuration design and lower MCU software design. The MCU software realizes the directly control of stepper motor based on A3972 and CCD together with lasers. The upper configuration software gives a working window; it is very convenient for the operation of engineers.Considering the object blind area when collecting 3D information, registration of unorganized point clouds based on inheriting and optimizing algorithm is studied. It performed well through examination. It indicates that the proposed algorithm can realize precise registration of unorganized point clouds, and it is better than ICP algorithm in registration precision and convergence velocity. Registration error is less than 0.1mm, and the required iterative number is reduced by 5 times.The high-performance and intelligence of this 3D foot measuring machine plays an important role in improving the automatically level of personal last customization.