Internship Report At Robert Bosch
This report is a short description of my six-month internship carried out as a compulsory component of My master program “Analytical Instruments, Measurement and Sensor technology (AIMS)” at Coburg University. The internship was carried out within the organization Robert Bosch GmbH (Bamberg) during my third semester, from 19th September 017 to 10th March 018. Since I am interested in Robotics, Automation and especially in sensor technology and its major and inescapable role in the automotive industry, the work was concentrated on the topic “Im Bereich Lambdasondenentwicklung (In the area of Lambda sensor Development)”. The sensor is the first pillar for any innovations. A machine without the sensor and its correct implementation are the same as an animal without its hands, legs and controller. At the beginning of my internship, I had many mindsets and goals to achieve. Some of them are:
- to understand the functioning and working conditions of a professional environment in the organization and its protocols for planning discussions, preparation and permissions;
- to see how can I use my gained skills and knowledge and also which kind of upgrades are needed in my skills for my work during the internship;
- to get experience in working in another country and culture and to develop good relations and contacts and to see if I can help others by adjusting my time;
- to enhance my communication skills especially my German Language skill.
This report contains my activities that have been contributed and a description of the organization Robert Bosch GmbH, also a glimpse of a particulate matter sensor on which I have done several tasks. At last, I share my internship experience and knowledge which I gained from my team and supervisor during this internship.
I have done my internship at Robert Bosch GmbH, Bamberg. Today, it is not necessary to give information about this giant networked organization, because it is too hard to find the person who doesn’t know about “BOSCH” brand. Robert Bosch founded the “Workshop for Precision Mechanics and Electrical Engineering” in Stuttgart in 1886, and today’s globally operating company was born. From the beginning, it has been characterized by innovation and social commitment. If you see in daily life routine; you will find at least one application which uses Bosch product direct or indirect way. For example, Cars which is a most useful machine in our daily lifestyle in which Bosch plays a core role to start, run and for safety purposes. Same like this Home appliances. Bosch is involving in four major divisions.
- Mobility Solution (Automotive Industry)
- Industrial Technology (Automation)
- Consumer goods (Home appliances)
- Industry and Building technology (Smart Home system).
The automotive industry is thriving in the current century, where transportation plays an important role in the rapid pace of life. Bosch's contribution to this field includes injection technologies and auxiliary means used in internal combustion engines, as well as various power solutions for drive electrification, steering systems, safety and assistance systems, convenient entertainment technologies, information and vehicle to vehicle communications. Workshop concepts, technology and service from Bosch are for trade in vehicles. The department combines expertise in three areas of mobility - automation, electrification and networking - and offers its customers integrated mobility solutions for interacting with other modes of transport, such as bicycles, trains and buses. Major automotive innovations come from Bosch and one of the open examples of it is electronic engine management.
The division of Industrial Technology includes a division of Drive and Control Technology, one of the world's leading suppliers of drive and control technology. It includes individual solutions for management, control and relocation in the areas of industrial automation, engineering systems and engineering networks, as well as mobile work equipment and commercial vehicles. In addition, Drive and Control offer comprehensive services, implements large international projects and increasingly develops solutions for network production. Business Unit of Packaging Technology is one of the world's leading suppliers of technological and packaging solutions for the pharmaceutical, food and confectionery industries, as well as for some segments of the beverage industry.
These include Power Tools, one of the world's leading suppliers of power tools, accessories and gardening equipment. Innovation targets are powerful wireless tools and more and more network devices. The business line of consumer goods also includes BSH Hausgeräte GmbH. It is one of the leading international manufacturers and offers a full range of modern, energy-efficient and increasingly networked devices such as stoves, ovens, dishwashers, refrigerators and freezers, as well as small household appliances such as vacuum cleaners and automatic coffee machines, washing machine.
The associated Building Technologies division develops products and solutions for video surveillance and access control, security and fire alarm systems, audio and conference systems and remote monitoring services. Building Technologies is part of the new global company Integrator Business, which provides business customers with intelligent services and services in the field of energy and construction. The new mission of Bosch Global Service Solutions is to expand its business with the help of external services, which were previously part of security systems. In Bosch, it also becomes a service provider for common services functions. The department of Thermotechnology offers products for heating and hot water supply, which are energy efficient and are becoming more and more networked.
During my internship, I learned a lot regarding the development process of exhaust gas sensors used in the diesel vehicle exhaust system. I enrolled for the Lambda sensor development area, where I have seen overall process of production and its testing line. I was also responsible for PM (Particulate matter) sensor testing and evaluation for its challenges.
Using a particle sensor, we can diagnose a particulate filter. Based on well-proven multi-layer technology, Bosch has developed a ceramic exhaust gas sensor for solid particles, which is shown in Figures 1 and . Fine line printing of platinum paste and layers of zirconium dioxide and the Aluminum oxide is shown in Figure . After several processes this Sensor Element is fitted in the case as shown in Figure 1. It is integrated into the exhaust pipe downstream below the filter.
Functional Principle
The PM sensor function is based on resistance measurements: DC voltage is applied to the scanning surface on two interdigital electrodes (IDE), on which soot particles are adsorbed form conductive tracks. A characteristic resistance drop due to the formation of electrically conductive soot paths between the electrodes can be used to determine soot emissions. The sensor element is periodically regenerated when heated by the integrated heater, and the operation is controlled by a temperature measurement sensor, by oxidation deposited soot at elevated temperatures.
Diagnostic software uses the measured current to evaluate the DPF functionality. This sensor is used for cars and commercial vehicles. The sensor element is protected by the case and arranged so that the exhaust gas flows over the IDE as shown in Figure 3. Because of voltage drop occurred in IDE combs particles accumulated and gathered between and over IDE grids. As the particle deposited, the voltage drop is decreased and the current increased. As the current reaches its threshold Sensor regeneration starts as shown in Figure 4. Sensor regeneration takes place by a heater which burns all particles and the ash goes out with exhaust gas flow and IDE cleaned for next cycle to reach its threshold. This time is measured and by the algorithm in control unit calculates particles per time available in the exhaust gas and track Particle filter’s operation and its fault and send a signal if it needs to be changed.
My tasks during Internship
I was responsible for several tasks during my internship, which is as below:
I have to support the production of new sensor element generation.
Electrical, Mechanical and optical testing of particle (PM) sensors (Including determination of layer thickness and line widths using various measuring devices, resistance measurement, light microscopy, evaluation and presentation of results using statistical analysis with software such as Excel and PowerPoint)
Evaluation of existing production data for special characteristics and presentation of the results in the expert panel to get more analysis and get correct conclusive ideas and solutions in the meeting.
Also, I have done several jobs for evaluation and reporting for; RTM (Resistance of T-Measurement) measurement, Humidity data from sintering process, Soak and Hotplate test for different chemical effects on sensor element and its reporting, evaluation for Fine line printing errors, and some time I joined my supervisor for Electrical testing for and HIT (Heat interruption test) for Heater temperature and current characteristic testing. To sum up all this work, it seems short to write but it has taken much longer time as it was not only for one sensor element but, was many complete bunches of many sensors to have accurate evaluation data. At the end of each work, I had many questions and doubts, which I cleared with my supervisor and they cleared very well to me until I didn’t satisfy.
Conclusion
This internship was a rewarding experience. I gained new knowledge, met new people and I have achieved many of my learning goals. But some of the conditions were not permitted for me. After finishing my internship I could not ignore, the confidence level which I gained because of this internship. During Internship, I got wonderful support from my supervisors and my team with whom I worked. In fine line printing work I gave some suggestions for sorting faulty sensor elements at the final inspection line problems which I faced and evaluated during testing components for its different printing failure class which could be solved by changes in the algorithm, but it needs to be done by passing this through protocol channel for approval. Also, I gave some suggestions like Laser drilling, or to generate Electrical voltage drop by making sandwich electrode comb in two layers rather than in single layer which could remove short failure of IDE grids. Also, I learned professional reporting of evaluated data and protocols to follow in working office environment during this internship. Since last two decades, Government’s rules and regulations are going to be more and more strict for pollution control because of vehicle exhaust gases. To cope with this PM (Particle sensor) is playing important role in the automotive industry. At last this internship has given me new insights and motivation to enrol myself more in the automotive industry and sensor development area for which I was already interested from the beginning of my study of the engineering field.
