Why the descriptive geometry and engineering graphics are considered “ trudny “ objects?One of most “ difficult “ objects for students of the first courses engineering, especially construction, specialties of Higher education institutions the Descriptive geometry and Engineering graphics are.
Is traditional, in the teaching environment, it is considered that the main destination of a course the Descriptive geometry is a development of spatial thinking in students and creation of theoretical base for the subsequent course, Engineering graphics (technical drawing). At the same time, without challenging this thesis, it should be noted the following. In perception psychology it is known for a long time that initially only several percent of the population possess rudiments of spatial thinking. Purposeful selection, on the basis of presence of spatial thinking at entrants of the main technical specialties, is not conducted. Therefore, the most part of students just does not have what is supposed to be developed.
Attempt to develop spatial thinking “ from scratch “ together with lack of a clear idea (at training and trained) about that why all this is necessary and leads to such situation when the Descriptive geometry is included in the category “ difficult “ courses.
Historically Descriptive geometry developed as the applied mathematical discipline urged to solve inzhenerno - technical tasks with use of graphic methods. Until recently it was the only thing “ supplier “ algorithms of the solution of complex engineering challenges. Deeply formalized mathematical apparatus used by Descriptive geometry allows it to do also without spatial representation of process of the solution of this or that task. It is most characteristic tasks of multidimensional space.
From the point of view of applied mathematics Descriptive geometry is the system of modeling of space which is based on own method - projection. In this case projective drawings are considered as flat equivalents of spaces of various dimension.
At such approach to studying of Descriptive geometry comes a task of studying of formal methods of realization of models of objects of space on drawings (flat equivalents) to the forefront. And it does not demand presence at the trained spatial thinking any more. The solution of this or that task is consolidated to studying of system, the rules realizing methods of Descriptive geometry which are based on formal logic. Consideration of expanded Euclidean space (the space added with not own elements) allows to reduce number of such rules considerably. And approach to geometry of three-dimensional space from the point of view of multidimensional even more simplifies a task. All position and metric problems for objects of various dimension are solved with use of the same algorithms.
Consideration of a method of two images as three-dimensional expanded Euclidean space, basic for creation of drawings of objects, allows to approach uniformly construction as orthogonal drawings (epyur Monge), and evident (axonometries and linear prospect) that is very important further for studying of algorithms of machine graphics. Transition from classical Epur Monge to arifmetizirovanny (coordinate) does tangible communication of Descriptive geometry with computer technologies of design of difficult engineering objects.
Skilled teachers well know that even the weakest students upon transition from descriptive geometry to studying of bases of Technical drawing (Engineering graphics) as if find a second wind. It more is explained by the fact that transition from theoretical drawings of abstract geometrical objects, such as is carried out: points, lines, surfaces, to drawings of real objects. The abstract thinking necessary for theoretical drawings can be replaced practical, less labor-consuming for many trainees.
In spite of the fact that both courses, Descriptive geometry and Engineering graphics, use the general method of creation of drawings, technical drawings are not exact, they are conditional. Rules of their performance in, the main weight, are based on the restrictions imposed by state standard specifications. If to exclude the requirement of projective communication, then it is hardly possible to find something uniting theoretical and technical drawings. Creation of technical drawings is regulated by system of conventions and simplifications. Moreover, for drawings of different types of products these conventions and simplifications have various character.
Taking into account everything told the statement that the descriptive geometry is a base for Engineering graphics, is very disputable. This thesis is confirmed also by long-term experience with graduates of colleges and technical schools. Such students very competently carry out drawings of technical products and are absolutely helpless at implementation of theoretical drawings of abstract objects, drawings of Descriptive geometry. Summing up of
some intermediate result, one may say, that the Descriptive geometry does not provide formation and development of spatial thinking and is not base for studying of Engineering graphics.
So, arises a question what place is taken, now, by Descriptive geometry in system of training of specialists of a technical profile? Strangely enough it can seem to
, the answer to this, apparently, rhetorical question, can be following. The descriptive geometry is a fundamental subject when training the highly qualified specialist. And it is explained by the following.
Training of the modern expert is focused on use by him in the practical activities of computer aids modeling these or those productions, work of technical objects and objects. All this is based on the formal description of objects and processes. The last is impossible without appeal to objects of expanded Euclidean space, knowledge of position and their metric properties, methods of their transformation, without corresponding “ geometrical culture “ user.
this geometrical culture is also formed by Descriptive geometry. At a present stage become its main objectives:
- formation of formal model of expanded Euclidean space;
- formation of system approach to process of the decision pozitsion - ny and metric tasks;
- formation of abilities of geometrical modeling of processes, systems and irregular technical shapes.
the Solution of these tasks lies in the plane of modernization of working studies - ny programs. In the limits allowed by educational standards it is necessary to increase volumes of the hours planned for studying of sections of designing of curves and surfaces. Use in the industry of ideology of 3D design demands fuller coordination of methods of creation of orthogonal drawings with metric certain drawings “ evident images “ (axonometries and prospects).
When carrying out a practical training, first of all, needs to pay attention to development at students of steady skills in designing of geometrical objects on beforehand to the set properties. It is impossible to oppose the solution of tasks “ in space and on the drawing “ because the drawing, being a space equivalent, serves only for visualization of these or those its objects, in this or that form.
Various methods of the decision on drawings of tasks, generally are defined by features of receiving (construction) them as equivalents. The greatest attention should be paid to those methods of the solution of geometrical tasks which are used further in CAD/CAM systems. the Last is fair
also for a course engineering graphics (Technical drawing). First of all the student has to acquire that information which is necessary for control of system when performing this or that design task. Upon termination of a course Engineering graphics the student has to have a steady idea of those general conventions and simplifications which are applied at implementation of technical drawings.
Studying of rules of implementation of special drawings have to be carried on special courses. Understanding why and why these drawings are quite so carried out, in most cases, it is impossible without knowledge of the production technology. Training in drawing does not come to an end at the first year higher education institution. As V. S. Levitsky " wrote; … the engineer to learn to draw all the conscious life … “.