Subject: POWERTRAIN TESTING, CALIBRATION AND HOMOLOGATION (A.A. 2021/2022)
Unit Powertrain Testing, Calibration and Homologation
Mechanical Engineering (lesson)
The main objective of the Course is to introduce and discuss the main aspects related to an internal combustion engine test cell, to allow the students to become familiar with such environment and its applications.
An introductory part will be provided to analyze the following topics:
- Main theoretical aspects regarding homologation procedures and regulations;
- Main engine sensors and actuators;
- Modern calibration methodologies such as Design Of Experiments;
- Main experimental activities and facilities used during the engine and vehicle development process.
During the course, students spend several hours in the test cell, conducting different types of tests (starting from standard power curves to calibration-oriented tests, or tests focused on combustion analysis, ...). The rest of the time is spent in the classroom/computer room, introducing the experimental activity and analyzing the data that have been acquired, with a calibration-oriented approach.
Internal Combustion Engines
PART 1 (3 CFUs)
The class lectures will offer an introduction to several experimental activities, some of which will be carried out in the engine test cell if it will be possible respecting logistic and safety constraints.
• Introduction to engine testing: test cell layouts, motivations and related activities carried out in industrial environments.
• Engine and dynamometer installation. The main types of dynamometers and the corresponding criteria for choosing the right one.
• Sensors and instrumentation to be used in a test cell environment.
• Exhaust gas emissions measurement and control.
• Homologation procedures and regulations.
• Signal acquisition systems and signal post-processing systems. Data analysis and interpretation.
• Engine calibration. Design of Experiments methodology and test cell automation systems.
PART 2 (3 CFUs)
Several examples of data processing with a calibration-oriented approach will be provided, and the students will be asked to develop Matlab code to analyze experimental data that are typically acquired in an engine test cell, producing reports based on engineering considerations, diagrams and graphical material.
The course is held in English. The theoretical aspects of engine testing are introduced during class lectures, while the experimental activity in the test cell should provide hands-on applications of engine-dynamometer control and measurement systems. Finally, Matlab-based sessions will introduce the students to data pre- and post-processing, with a calibration-oriented approach (possibly, each student will use a personal computer running Matlab during such sessions). The educational material is uploaded before each lecture on the University online platform. Attendance is strongly recommended for better learning of concepts and methodologies, but does not affect the final evaluation process.
Learning assessment is finalized through a final oral examination, which takes place for about 60-90 minutes, answering a few questions in writing (diagrams, equations, diagrams, drawings, ...) and then discussing them with the instructor. The student can also produce a report about the analysis of experimental data acquired during test cell activity. This test is intended to verify the student knowledge about the main subjects of the course. The final vote takes into account the ability to solve problems in the matters discussed during the lectures, and the acquisition of engineering methodologies for developing, testing and calibrating automotive powertrains. The evaluation, expressed in thirtieths, will be higher the more the student is: • autonomous in articulating answers to the questions and mathematical procedures for data pre- and post-processing; • exhaustive in explaining the topics and the experimental approach to powertrain testing; • capable of synthesizing the most important parameters and relationships through graphs, sketches, and schematics. During the exam, students are not allowed to use the lecture notes or other material and they are required to have an identity document.
Knowledge and understanding: Through lectures and technical seminars by specialists, the students learn the correct approach to engine testing, from the point of view mechanical measurements, test cell layout, components selection, and signal processing and data acquisition techniques, with examples in the field of engine calibration and diagnosis.
Applying knowledge and understanding: hands-on sessions in the test cell and Matlab-based data processing analyses provide the students with the skills and abilities to develop advanced signal processing algorithms, produce clear and effective technical reports, and calibrate the main engine control functions.
Making judgments: students develop the ability to integrate knowledge and handle complexity to formulate judgments even on the basis of incomplete or limited information, evaluate the reliability of the mechanical, electronic and digital domains of measurement systems, and identify the best approach to identify mathematical models using experiments, and to calibrate the corresponding control functions.
Communication skills: the discussion with the teacher and with their colleagues and the production of technical reports helps students to develop the ability to critically communicate, especially using the engineering language, technical information, ideas, problems and solutions to both specialist and non-specialist individuals.
Learning skills: At the end of the course, also thanks to the autonomous project development and practical exercises related to engine testing and calibration, students will be able to :
- design and manage a complex system such as an engine test cell;
- develop and implement advanced engine calibration methodologies and algorithms;
- setup a data acquisition system and develop algorithms for data pre- and post-processing.
Handouts concerning some elements of the program, exercises and examples, are available via intranet. The following list presents the main publications that could be used by the students to deepen specific topics, or to complement their background on the subject.
• "Introduction to modeling and control of internal combustion engine systems", L. Guzzella, C. H. Onder, Springer-Verlag, 2004.
• “Engine Testing", M. Plynt, A. Martyr, Ed. Butterworth-Heinemann, 2007.