0 INTRODUCTION

China is a large country of engineering education, and engineering education accounts for one-third of the total number of higher education majors set and graduates in China, so the effect of engineering education will directly affect the level of higher education and the level of scientific and technological development in China, meanwhile, the concept of engineering certification education has become the centralized direction of teaching quality improvement, student training quality improvement and teaching reform in all higher education institutions.

At present, engineering education accreditation has become the key direction of China’s engineering education career reform, and all institutions of higher education are taking the opportunity of joining the Washington Agreement, are making active efforts to promote professional accreditation education of various majors, taking international substantial equivalence as the criterion, profoundly integrating the concept of engineering accreditation, constructing engineering education accreditation system, supervising the implementation of engineering education process, actively analyzing and making decisions and actively promoting the continuous improvement of cultivation process, and Ensure the continuous improvement of student cultivation quality.

Case teaching is an open and interactive teaching method, which was introduced by Christopher Columbus, former dean of Harvard Law School in 1870. Columbus? Langdell (C.C. Langdell) was first created in 1870 and successfully introduced to China in 1980s.

Case teaching was first used in medical teaching, in order to inspire students to master the diagnosis and treatment of diseases, medical professors record the diagnosis and treatment process of different diseases into cases for classroom analysis, in order to cultivate students’ diagnostic reasoning ability. Case teaching is a student-centered teaching method with the main output goal of problem identification and solving complex engineering problems, so this method is highly compatible with the concept of engineering certification, and is a common way of classroom teaching for engineering education certification.

For this reason, based on the focus on the concept of engineering certification education and case teaching, we also focus on the construction method and construction principles of integrated case teaching under the concept of engineering certification education, and on this basis, we take robotics in mechanical engineering majors as the object of case teaching, and from the perspective of case teaching, integrate the cultivation requirements of knowledge, ability and quality of engineering education certification into the integrated mechanical engineering majors teaching process and cultivate students’ comprehensive problem-solving ability.

1 Analysis of the problems faced by the case mode under the concept of engineering education

The concept of engineering certification education mainly includes three aspects: student-centered, output-oriented, and continuous improvement.

Engineering education is oriented to the output of students, i.e. the output of “knowledge, ability and quality” required for graduation, arranging course training objectives, teaching activities, management activities, etc., and analyzing them in the process of implementation, making scientific decisions to continuously improve the weak points in the process of student training, and improving students’ training ability. Engineering education takes “students’ ability” as the baton, and the graduation requirements should reflect students’ ability characteristics, including what students can do, reflecting students’ professional knowledge, skills and ability to apply their knowledge; what students should do, reflecting students’ moral value orientation, social responsibility and humanistic care; what students can do, reflecting students’ comprehensive quality and career development ability; and what students can do, reflecting students’ ability to develop their career. What students should do reflects students’ moral value, social responsibility and humanistic care; what students can do reflects students’ comprehensive quality and career development ability; and complex engineering as the focus of ability cultivation, only through the cultivation of complex engineering ability can students better engage in engineering practical application. 　　

The cultivation of engineering education is a systematic project, and the following problems exist in the process of implementing engineering education certification.

①Students have less understanding of the professional knowledge structure, loose knowledge structure and poor learning effect.

For the person in charge of the major, the graduation requirements and knowledge system of the major are very clear, but for the teachers and students, it is difficult to understand the professional education from the professional level, so students often can only follow the teaching plan to learn gradually, and the learning process is rather passive. It is not clear to students what kind of knowledge and ability quality is needed for the profession, even if there is a textual introduction, but without an image of concrete cases, it is difficult for students to understand. Therefore, students’ learning is passive and they don’t know why they need to learn these contents, how to learn and how they should be applied, which is contrary to the effect of engineering education concept.

②Complex engineering problems are more abstract, and the cultivation of the ability to solve complex problems needs to be strengthened.

Different people have different ideas about the understanding of complex engineering. Under the current model, complex engineering often increases the complexity of problems from the perspective of a single discipline in a far-fetched way, but this complexity is limited to certain fields, while the real complex engineering is often coupled with multiple fields. In the process of professional engineering education what exactly is complex engineering, what characteristics does complex engineering have, how to carry out problem discovery and problem solving for complex engineering, are very abstract, no specific content focus, so it is difficult and less effective in implementation.

For this reason, case teaching will solve the problem of abstract teaching content in the teaching process and facilitate students to establish rational understanding based on the establishment of perceptual understanding, so as to enhance the teaching effect; and integrated case, that is, using the same case object, from the graduation requirements index point, to build various aspects of knowledge and ability quality application cases, will be in the establishment of students’ perceptual understanding, based on the convenience of students to knowledge It will facilitate students’ cognition of system structure and cultivation of complex engineering solution ability, and improve the quality of students’ training.

2 Construction of integrated case teaching mode suitable for engineering education concept

2.1 Principles of selecting objects of integrated cases

2.1.1 The object of integrated case should meet complex engineering characteristics

The selection of the object of integrated case under the concept of engineering education should meet the engineering education accreditation standards. According to the 2015 version of engineering education?J certification standards formulated by China Engineering Education Accreditation Association, it especially emphasizes that the graduation requirements point to solving complex engineering problems rather than general engineering problems. The relevant interpretation materials of the accreditation standard also explain complex engineering problems, and the “complex engineering problems” mentioned in the standard must have the following characteristics.

① with the following characteristics ② ~ ⑧ part or all: ② must be in-depth use of engineering principles and analysis before it can be solved; ③ need to involve a variety of technical, engineering and other factors, and may have some conflict with each other; ④ need to establish a suitable abstract model to solve, in the modeling process needs to reflect the creative; ⑤ not only rely on common methods can be completely solved; ⑥ problem involved may not be fully included in the professional standards and specifications; (7) the interests of all parties involved in the problem are not fully aligned; (8) it is highly comprehensive and contains multiple interrelated sub-problems.

Therefore, the selection of the integration case object should be able to cover multiple features such as (1) to (8), so as to facilitate the construction of an integration case that meets the graduation requirements.

2.1.2 The integrated object should meet the characteristics of the times

The human resources training of the profession has obvious characteristics of the times, so the integration object should also have the characteristics of the times. The so-called characteristics of the times refers to the mainstream characteristics representing the current mainstream or future technological development, that is, the object should be oriented to the current mainstream objects in engineering, and can be adapted to the current level of advanced technology or economic development, so that the object can be advanced, can attract students’ interest in learning, and is also easy for students to understand and apply.

2.1.3 Integrated objects should have universality

A universal object is easy for students to know and understand, and it can also shorten the time for students to know the object itself, so that students can have a better perceptual understanding, and it is easy to rise from perceptual to rational understanding. At the same time, the object with universality is relatively low cost, so it provides conditions for the acquisition of the object and facilitates students to build the knowledge system of this specialty and the ability to solve complex projects.

2.2 The way of constructing integrated cases

The construction of integrated cases aims to build several cases corresponding to the objects in a systematic and comprehensive way under the guidance of the engineering professional certification concept and with the output required to be achieved by graduation. Therefore, the design of cases should be considered in an overall comprehensive way, with a larger coverage, smaller design cases, and the continuity of knowledge learning, etc. The design cases should be built in a comprehensive way. Its case design approach is as follows: firstly, decompose the index points according to the graduation requirements, and correspond the index points to the curriculum, and construct the appropriate case set by integrating the knowledge, ability and quality needed for design. The designed case set will eventually cover all the graduation requirements and reduce the repetitive coverage, where the way of constructing flow of integrated cases is shown in Figure 1.

.3 Example of constructing integrated case teaching system – taking mechanical engineering as an example

According to the rules of selecting the object of integrated case study, it is necessary to select the object that meets the characteristics of “complex engineering” and has obvious characteristics of the times and universal characteristics. For this reason, robots are used here as the object of integrated case study.

Robotics integrated case construction is to take robotics as the object and build corresponding teaching cases from various aspects of robotics design, manufacturing and control, which together support the structure of mechanical engineering professional knowledge system and also can very reasonably support the training of complex engineering solution ability. The construction of robotics integration case system should cover the vast majority of knowledge, ability and quality corresponding to the graduation requirements of mechanical engineering majors. At the same time, a corresponding undertaking relationship should be established between each case to facilitate students’ better understanding of the graduation requirements of mechanical engineering. The way of constructing the robotics integration case set is shown in Figure 2.

Here the robot control case construction is used as an example to introduce how to build a case. Robot control involves control knowledge, sensor knowledge, motor drive knowledge, which can cultivate students’ ability to analyze problems, innovation ability, and comprehensive application ability, and finally, by judging students’ mastery of engineering fundamentals and professional knowledge required to solve mechanical engineering problems and their application ability, as well as using mathematics, natural science, engineering fundamentals and In the end, students will be evaluated whether they meet the graduation requirements by judging their mastery of engineering fundamentals and professional knowledge required to solve mechanical engineering problems and their ability to apply mathematics, natural science, engineering fundamentals and professional knowledge to solve engineering problems in mechanical design, mechanical manufacturing, electromechanical system integration and control.

Attention is also paid to the content related to robot structure design in the robot control case, and the need to establish the interrelationship between the two. Other robot structure design cases, robot manufacturing cases and many other cases are constructed in this way, when it is necessary to meet the graduation requirements of covering more with fewer cases to achieve the construction of a high-quality case system.

Through the teaching of these integrated cases, students will be easier to establish the knowledge system of mechanical engineering, comprehensive problem solving ability, and be able to understand the relevant qualities needed, so students will learn systematically and autonomously, and the learning effect will be improved.