The hottest linear synchronous motor C based on Vi

  • Detail

Development of CAD system of linear synchronous motor based on VisualLISP

Abstract: Aiming at the computer-aided design and drawing of linear synchronous motor, a special optimal design drawing software is compiled by using VisualLISP embedded in AutoCAD. The software can run directly in AutoCAD environment, and the practical application effect is good

Keywords: VisualLISP; Linear synchronous motor; CAD

1 Introduction

in recent years, with the development of economy, linear synchronous motor has been widely used in various fields. Especially the maglev train driven by long stator linear synchronous motor is getting more and more attention because of its advantages of high speed, comfort and environmental protection. In a typical linear synchronous motor, the stator part remains stationary, the rotor pole moves at a synchronous speed, and the excitation winding can be powered by the linear generator on the pole

in order to avoid tedious and repetitive drawing labor, it is necessary to carry out secondary development of AutoCAD and try to standardize, modularize and parameterize the common graphic structure. According to this idea of parametric design, the author developed a set of parametric design and drawing software package for linear synchronous motor by using VisualLISP, a secondary development tool of AutoCAD, which greatly reduced repeated labor, avoided resource waste, and improved design efficiency. The overall effect is quite remarkable

2 structure and function of linear synchronous motor CAD system

the parametric design and drawing system of linear synchronous motor is based on AutoCAD2000 as the development platform, making full use of the development tools provided by it, such as AutoLISP language, VisualLISP integrated development environment, DCL language and so on, and is developed on microcomputer. The software system generally includes the following three functional modules:

(1) interactive motor parameter input module. As the man-machine interface of the system, it provides a group of dialog boxes with example graphics, so that users can input the requirements for the structural parameters of linear synchronous motor in the way of man-machine interaction

(2) motor optimization design module. Based on the user input data, this module applies a specific motor optimization design method to optimize some parameters of the linear synchronous motor designed by the user, obtains a more satisfactory motor design scheme than the original scheme, and completes the organization and storage of motor parameters. The user of this module can choose to use or skip not to execute

(3) automatic drawing program module. When the structural dimension parameters of linear synchronous motor are finally determined, the automatic drawing program can generate formal design drawings based on these data and save them in the computer for future use

2.1 design of interactive motor parameter input module

2.1.1 design of dialog box

in order for general engineers to improve the reliability of phase change materials in porous media with the help of capillary effect, the whole design system must be intuitive, visual and easy to operate. Therefore, using dialog box in software is a satisfactory choice

the dialog box of AutoCAD is defined by DCL language. When designing, the source code of dialog box can be written by using ordinary texter. The buttons, bars and other basic controls used in the dialog box have been pre-defined by AutoCAD, and can be directly referenced when. Finally, the source code must be saved as a file with the suffix DCL for AutoCAD to recognize

structural principle difference between tensile testing machine and peeling force testing machine

structural form of linear synchronous motor, as shown in Figure 1. We can roughly divide the parameter input of the motor into three parts: stator parameters, rotor parameters and generator slot parameters, which ensure the integrity and regulation. An example of the stator parameter input dialog box after the LISP program of the drive dialog box is loaded, as shown in Figure 2. Each control corresponds to a different action

2.1.2 implementation of example graphics

in order to make the parameter input of linear synchronous motor easy to understand and illustrated, it is necessary to match the display graphics for the dialog box; Moreover, the user also specially requires that the variable fatigue testing machine whose annotations in the example graphics can follow the input parameters is a precision instrument for testing the fatigue characteristics and fatigue life of materials

for this reason, the image control is used to realize the display function of example graphics, but the image control can only display the slide file of AutoCAD, which is mainly used to detect the mechanical properties of the ring stiffness of rigid cement pipes. Therefore, it is also necessary to use the special mslide command of AutoCAD to make slides. For how to meet the requirements of dynamic update of example graphics, the method of regenerating slides is adopted here, that is, first, an AutoCAD drawing and its slides are generated for the display of example graphics; However, when the value of the text control in the dialog box changes, you can modify the annotation in the AutoCAD drawing according to the meaning of this specific control, and then generate a slide again, so as to meet the task of dynamic update of the sample graphics in the dialog box. The flow chart of the process is shown in Figure 3

in addition, the input motor parameters must also consider constraints, for example, the pole distance between the stator and rotor of the motor should be basically the same, the slot width should be less than the tooth pitch, the slot width and slot height should not be too large, and so on. To solve these problems, it is necessary to consider the necessary verification of the parameters entered by the user. When it is found that the input parameters do not meet the constraints, the software should give a warning prompt to draw the attention of users for parameter correction

2.2 motor optimization design module

motor optimization design is actually the application of optimization mathematical methods and computer technology in the field of electrical engineering. There are many optimization methods. At present, the commonly used optimization methods in motor optimization design are: simulated annealing algorithm, genetic algorithm, hybrid genetic algorithm, etc

the mathematical model of motor optimization can be summarized as follows: when the constraint condition GJ (x) ≤ 0 is met, calculate the value of each optimization design variable Xi (i=1, 2,..., n) to maximize (minimize) the value of the objective function f (x), where x=[x1, x2,..., xn]t. It can be seen that the mathematical model includes three elements: design variables, constraints and objective function

for this set of software, users can click the "optimization" button in the motor parameter input dialog box in Figure 2 to start the optimization design module. The optimization design interface of linear synchronous motor is shown in Figure 4. Optimization settings are flexible. Users can set optimization design variables, objective functions, constraints and optimization algorithms according to specific needs

for the optimization object here, the thrust generated by unit stator current can be selected as the optimization objective function. Obviously, the larger the value of the objective function, the better. But in general optimization design, the minimum value of the objective function is solved. At this time, its reciprocal can be used as a new objective function, that is, the objective function of constructing the optimization design of linear synchronous motor is:

Where is - stator current

FX1 - Horizontal fundamental wave thrust generated by linear synchronous motor

the design variable is a group of variables to be determined in the motor optimization problem, Their changes determine the changes of objective function and system performance. Considering many influencing factors, the optimal design variables selected here are: stator core width, stator slot width, stator slot height, and stator pole distance. The constraints include: (1) air gap magnetic density B ≤ Bmax; (2) Stator current is ≤ ismax; (3) Stator slot fullness SF ≤ Smax; (4) Motor thrust FX1 ≥ Fmin

the optimization results obtained by using genetic algorithm to optimize the linear synchronous motor are shown in Figure 4. The final design data of linear synchronous motor is generally stored in database mode, and the motor database is established by access, and the design results are saved in this database

2.3 design of automatic drawing program

another important part of this computer-aided design software is the automatic drawing module. When the user inputs the complete parameters in the motor parameter input dialog box or the optimization design module recalculates the motor parameters according to the requirements, the drawing program obtains all the key parameters of the drawing. Then we can use the command function to compile AutoLISP program, draw various punching drawings of linear synchronous motor in the form of straight line, arc, etc., and attach the marked dimensions, geometric tolerances, text marks, etc

The brief operation method of the automatic drawing program is as follows: users can directly click the drawing button in the parameter input dialog box and the optimization design dialog box. Of course, they can also directly type the drawing command draw in the AutoCAD environment to call the automatic drawing program. The drawing program will automatically load the design data of the linear synchronous motor, and then generate the drawings of each part of the motor according to the relevant parameters, mainly including the stator, rotor, excitation part and the overall structure drawings. The sample diagram of the overall structure of the linear synchronous motor generated by the automatic drawing program is shown in Figure 5

3 conclusion

a parametric design system for linear synchronous motor is developed by using VisualLISP, a secondary development tool embedded in AutoCAD, and it is applied to the design of practical linear synchronous motor

practice has proved that the system has the advantages of simplicity and ease of use, and the overall effect is good after application. If it is further improved in the future, it is expected to be used in a wider field of linear motor design


[1] ye Yunyue, Lin Youyang Computer aided optimal design and manufacturing of motor [m] Hangzhou: Zhejiang University Press, 1998

[2] combo Chinese version of autocad2002/2000visuallisp development guide [m] Beijing: Tsinghua University Press, 2001

[3] chenboxiong VisualLISP for AutoCAD2000 programming [m] Beijing: China Machine Press, 2000 [4] Liuhuaqing, et al German maglev train transrapid[m] Xi'an: Xi'an University of Electronic Science and Technology Press, 1995

[5] Chen Yu Design and optimization of long stator linear synchronous motor [d] Hangzhou: Zhejiang University, 2003

[6] Chenxiaofeng Optimal design and control of linear induction motor for new pad printing machine [d] Hangzhou: Zhejiang University, 2001

Copyright © 2011 JIN SHI