THINGS I LEARNT AT UW ECOCAR
I. Table of Contents:
1. Competition Background Information
2. Project Introduction
3. Project Description
3.1. Car Re-wiring
3.2. ADAS (Advanced Drivers Assistance System) Integration Report
3.3. New Eagle J1772 Charge Integration
3.4. Charger Wake Functionality
4. Results
4.1. Showroom Quality car wiring
4.2. Successful ADAS Integration
4.3. Successful J1772 Integration
4.4. Fully Functioning Charger
5. Additional Work Remaining
6. Conclusion
II. Table of Figures:
Figure 1: Example of poorly loomed and taped wire.
Figure 2: Right sided view showing the location of the BRUSA Charger.
Figure 3: Pre-existing connections between the BRUSA Charger and the ESS.
Figure 4: Block diagram showing the new connections between the BRUSA and ESS
Figure 5: The New Eagle J1772 Controller
Figure 6: The prototype circuit implemented by the Electrical Team to try and make the charger fully functioning
Figure 7: The car outside the lab
III. Table of Tables:
1.0 - Competition Background Information:
EcoCAR 3 builds on a proud 25-year history of U.S. Department of Energy (DOE) Advanced Vehicle Competitions that demonstrate the influence of public/private partnerships in providing invaluable experience and training to promising, young minds readying to enter the job market.
Over the past three years, the UW EcoCAR 3 team has modeled a Chevrolet Camaro as well as its potential drivetrain architecture and launched an outreach program intended to educate consumers on green vehicle technology. Our main goal for the fourth and the final year of the competition was to successfully pass the safety technological tests as well as fix major issues to make sure that the car fulfils the criterions for a showroom quality hybrid vehicle.
2.0 – Project Introduction:
For the first half of the quarter, the team’s primary aim was to make the car ready for Dyno testing as well as pass the Safety Technical Inspection that was held in Ohio. Thus, the Electrical Team was given the responsibility of making sure that the wiring inside the car was properly loomed and tightened. Furthermore, the Electrical Team was also responsible to troubleshoot and fix problems that were stopping the car from being in a drivable condition.
Once the car was back from Ohio after testing, our team had to fix some major issues with the car charger. The Electrical team had to assist the ADAS (Advanced Drivers Assistance System) team in integrating certain parts such as the radar, S-32 board and the camera. This required the team to come up with a plan to route wires from the front of the car to rear as well as design specific CAN Connectors for ADAS parts and try to implement the connections on a test bench before actually performing actual integration in the car. Another major issue that the team was facing was that the car charger was only working with the charge-port that is inside the EcoCAR lab but wasn’t getting power when used with other communal chargers situated on the university campus.
As an active member of the Electrical Team and an undergraduate research assistant, I was responsible to attend team meetings each week and be up to date with any and every project that was being undertaken by the team. Furthermore, through the course of this quarter, I was also able to learn some important skills such as soldering, stripping and crimping wires, designing circuits on breadboards, as well as using electrical equipment such as oscilloscopes, function generators, and multi-meters.
3.0 - Project Description:
3.1 – Car Rewiring
One of the first projects that I undertook this quarter involved improving the wiring throughout the car so as to make it consumer ready. This project was completed successfully within the first few weeks of the quarter. The main challenge presented during this project was that we had to make sure that each and every wire inside the car was properly secured and free of any sort of damage. This was particularly hard to make sure for some wires which were surrounded by equipment or wire looms and were only remotely accessible. Once all the imperfect wires were located, I had to come up with solutions to the fix the problem once and for all. This usually involved using zip-ties to tighten the wires properly, epoxying new mounts to provide proper support, or re-soldering weak connections. Fig. 1 below shows a couple of poorly wired components in the car. It can be observed that the epoxy mount for the red cable in Fig. 1 is very carelessly prepared and can fall off if high amounts of strain is applied on it.
3.2 – ADAS (Advanced Drivers Assistance System) Integration Report
I was also involved in the radar integration project this quarter. This project involved a lot of hands-on work. The electrical team had to successfully coordinate with the ADAS team to implement this project. The ADAS team had already taken care of the integration plan and the mounting location for the radar. I had to follow their specification to come up with a plan to actually integrate the camera. To do this, I first collaborated with other electrical team members and came up with a masterplan to properly integrate the camera as well as the other ADAS devices into the car. This involved reading the documentation of the car to understand the car wiring and finding places where the specific wire could be integrated. It was decided that the camera would be integrated between the rear-view mirror and the windshield. The mechanical team also helped us in the mounting process by making a 3D- printed mount to bound the camera and keep it safe. The camera connection required me to run a wire the coax cable. I, along with the other electrical members, came up with three different routing plans to do the aforementioned task. Two of the solutions involved running this wire through the car interior while the third method involved routing the wire through the headliner. After proper deliberation, it was decided that routing the wire across the headliner would be the cleanest, most efficient, and the better hidden approach. Although, this method was fairly difficult to implement as compared to the other ones because it would require considerable work to completely remove the headliner, the team still decided to pursue it.
3.3 – Charger Problems Troubleshooting
This was one of the most important projects that was undertaken by me this quarter. The car charger had major issues communicating with the wall charger which was leading to complications during the charging process. This was because the control pilot line wasn't communicating properly because there wasn't a variable pull down resistance on the line. The car was only able to charge when connected to the wall charger located inside the EcoCAR lab. However, when the team tried to use any standardized level 2 chargers to charge the car, there was no response. The Electrical team coordinated with the controls team to debug this problem. It was understood that the reason why the charger was only working with the wall charger located in the lab was because we had a single pulldown resistor that just happened to work for our wall charger in the lab.
After learning more through reading documentations of various equipment that communicate to charge the car, the electrical team had to design as well as implement a solution to this problem. This involved making block diagrams for connections between the ESS (Electric Storage System), the BRUSA Charger that is installed in the car (Fig. 3), as well as the main five pin port charger connection.
Furthermore, me and the group members that were involved with me in this project, had to come up with a plan to connect a new product called the ‘New Eagle J1772 Vehicle Power Interface Module (VPIM) Controller’ alongside the BRUSA Charger as well as the ESS.
The controller would essentially provide a variable pull down resistance which was predicted to solve the problem as the resistance would change according to the level of wall charger which the car is connected to. The block diagram depicting the connections that were already existing is shown in Fig. 4 above. We had to come up with a plan to alter these connections so as to properly integrate the new product which would change the way the charger communicates information about the energy needs of the car with the charge port. The block diagram showing the new connections between the BRUSA Charger, the ESS and the J1772 Controller is shown in Fig. 5 below.
Figure 5. Block diagram showing the new connections between the BRUSA and the ESS
3.4 – New Eagle J1772 Charger Integration
The final project undertaken by me this quarter was actually implementing the plan created by the team to integrate the ‘New Eagle J1772 Controller’ (see Fig. 5) and perform rigorous testing to prove that the new plan does actually fix the problem successfully in various conditions.
As the documentation for this product was a little vague, our team had to reach out to the EcoCAR 3 team at Arizona State University to ask for assistance. After proper discussion and hours of testing, the team was able to figure out the proper pinout. This process involved a lot of stripping and crimping of wires and connecting properly crimped wires to CAN Connectors.
4.0 - Results:
4.1 – Showroom Quality Car Wiring
After the successful completion of this project by the team, there were no improperly loomed, taped, or strain relieved wires. The team was able to successfully pass the safety technical tests and received good reviews by the judges on the overall car wiring and the lack of carelessly hanging wires.
4.2 – Successful Camera Integration
The Electrical team successfully integrated the camera into the car. The ADAS team was able to use the equipment that were integrated by the team to log data successfully.
4.3 – Completely Functioning Charger
This was one of the most important projects undertaken by the Electrical Team this quarter and it had to be made sure that the charger was working properly. After, a lot of time was spent on reading the documentations and coming up with design plans. The project was a success as the team was able to come up with a solution that enabled the car to work with different chargers which could draw current that were higher/ lower than the one inside the lab. The documentation for the new circuit was added and a prototype circuit (see Fig. 7) was implemented to conduct tests.
4.4 – Successful J1772 Integration
The final project undertaken by me this quarter was making sure that that the aforementioned plan was executed on the car. This project required me and the team to follow the plan that we came up with in the last few weeks. Wires were stripped and crimped to successfully insert into the connecter that came with the ‘New Eagle J1772’. All the connections were done as specified in the documentation under proper guidance by the team leads. The Mechanical team provided proper assistance in mounting the J1772 onto the car. Our team made sure that all the wires were routed into looms properly so that no part of the wires were left exposed. Moreover, we taped over the loom in orange to indicate that the wires contained within were related to the high voltage system (per competition requirements).
Some wires had to be soldered onto already routed wires. This was done successfully by stripping a part of the existing wire and then using the heat shrink as well as a solder to merge the copper from the two wires.
5.0 - Additional Work Remaining:
Now that most of the major issues in the car have been resolved and the safety technical inspections have been passed, all the teams at UW EcoCAR are gearing towards making sure that the car performs well in the competition in Arizona which is just a few weeks away. The only additional work that remains is adding miles to the car before the competition and fixing minor issues that come along the way. Teams have to make sure that proper safety guidelines are followed, and the car is completely safe to be driven by an experienced driver.
Some of the undergoing projects haven’t been able to be done up until now because of lack of proper equipment. Some projects are still waiting for proper apparatus to arrive before they could be finished. Spring quarter would thus involve trying to finish projects already under way and trying to improve the efficiency even further by implementing minor refinements.
6.0 - Conclusion:
The fourth year of EcoCAR is coming to a close as the competition looms around the corner. This year and more specifically in the winter quarter, the team has done a lot of work to make sure that the car was ready for the dyno testing and the safety technical tests.
I, specifically, was mostly involved in making the car look cleaner from the inside as well fixing wire for the first half of the quarter. However, as the quarter progressed, I got involved in more challenging projects such as ADAS Integration and charger troubleshooting. Lastly, I also got some hands-on experience and honed important industry skills such a soldering, crimping wires etc. while working on the J1772 Charger integration.
EcoCAR has definitely made me a better overall Electrical Engineer and allowed me to implement the skills that I learnt inside the closed doors of a classroom on an actual car. Not only, was I provided with a plethora of new opportunities, but the challenging projects that I undertook allowed me to improve my decision-making skills. The connections that I’ve made in the EcoCAR lab have provided me with some good mentorship as well as professional guidance. I look forward to working at EcoCAR for the rest of my time here at the University of Washington and learn more about automotive systems and Electrical Engineering.