University: Boise State University, Boise, Idaho
Team Member(s): Adrian Rothenbuhler, Dave Schenker, Jen Kniss, Patrick Johnston, Seth Feuerborn, Ken Fukumoto, Mike VanKirk, Jared Arave, Luke Granden
Faculty Advisors: Dr. John Gardner
Email Address: firstname.lastname@example.org
This student design competition entry describes the data-logging, monitoring, and control system of the world's fastest vegetable oil powered vehicle built by the student club Greenspeed at Boise State University.
|NI cRIO-9074||8-slot chassis with real-time processor and FPGA|
|4-Ch, +/-5V ADC, 24-Bit|
|NI 9807||8-Ch +/-20mA Analog Input, 8-Ch +/- 10V Analog Input|
|NI 9265||4-Ch 20mA 16-Bit Analog Output|
|NI 9403||32-Ch TTL Digital Input/Output|
|32-Ch 24V Sourcing Digital Output|
|NI 9425||32-Ch 24V Sinking Digital Input|
|NI 9213||16-Ch, 24-Bit Thermocouple input|
|NI 9870||4-port RS232|
|NI 9853||2-Port High-Speed CAN|
Besides the hardware listed in the table above, the vehicle is also equipped with a wireless 3G/4G router from Cradlepoint, which provides a connection to the cRIO and its embedded webserver for remote access anywhere in the world.
|-||NI Sound and Vibration Assistant|
Greenspeed is a student club at Boise State University with the goal of building the world’s fastest vegetable oil powered vehicle and to provide an environment where students can apply classroom knowledge and theory to a real world problem. Most importantly, however, we want to raise awareness that alternative fuels, like vegetable oil, are a viable source of energy and that using “green” fuels doesn’t mean sacrificing power. Last November we broke the existing vegetable oil speed record of 98 mph and bumped it up to 155 mph. After breaking the vegetable oil speed record, Greenspeed was invited to showcase the truck at the Washington D.C Auto Show in January 2012. This year we hope to break the petroleum-diesel based land speed record, currently set at 215 mph, with our modified 1998 Chevrolet S10 running on nothing but pure vegetable oil.
Building and racing a land speed racing vehicle running on an unconventional fuel poses some challenges that require careful monitoring and control of the engine and other vital vehicular systems. A sophisticated data-logging and monitoring system based on a cRIO real-time processor was built to allow real-time monitoring, data-logging, engine control, and most importantly to ensure safe operation of the vehicle.
As mentioned above, the entire electrical system revolves around the NI cRIO 9074, which is connected to various sensors (i.e. temperature, pressure, vibration, displacement, etc.). Most sensors are preprocessed by the FPGA and then sent over to the real-time processor for analysis.Besides logging each sensor value at a high rate, the system also allows us to analyze the vehicle's status in real time and to provide valuable feedback to the driver, enhancing safety. A more detailed explanation about the system's functionality is given below:
Sensor monitoring: Measure all sensors and compare against boundary values to determine faults and irregularities and alert the driver in such case. All sensor data is preprocessed/converted on the FPGA and then sent to the real-time processor.
Data logging: Record all sensor values every 200ms for post-processing and analysis purposes
Vibration analysis: Four vibration sensors are placed by each wheel to capture the vibrations on the vehicle’s frame. This real-time DSP application provides vital information about engine vibration, structural integrity of the frame at high speeds, and resonance frequencies of the frame.
Turbo charger controller: Controls the wastegate of the twin turbo charger system using a feedback control loop to maximize engine efficiency. This is a vital part of our project, especially since vegetable oil has only about 90-95% of the energy that diesel has. Breaking a land speed record with a fuel that is potentially less powerful than the fuel which was used to set the current petroleum-diesel based record heavily depends on maximizing efficiency. Our unique system is unlike any other turbo charger system, giving us an advantage over other contenders. This system can also be used on any diesel engine. As emission standards go up, engine manufacturers are using twin-turbo systems to attain higher efficiency. Our system can therefore offer an advantage over the typical mechanical system as if further increases efficiency and can easily adapt to different conditions. We are currently in the process of patenting our system (United States Patent Pending 61/656,971).
Ride Height and Down force calculation: When attempting to drive at speeds of 200+ mph, every vehicle will start acting like a wing, creating lift (unless airodynamic changes are performed). Since our truck is entered in the stock class, we are not allowed to make any aerodynamic modifications to increase down force, keeping the truck on the ground. Adding weight to the vehicle is the simplest solution and does not impact top speed much as the race track is 5 miles long, providing ample length for acceleration. Ride height sensors are added to measure lift, alerting the driver when a critical value is reached. After each run, the lift situation is assessed and weight added, if necessary. Down force is automatically calculated using the ride height, the weight of the truck, and the spring constant of the suspension. This information is then used to create a better and more accurate model for fluid analysis.
Embedded Web server: The embedded web server of the NI cRIO 9074 is used to broadcast sensor values/vehicle state to client computers connected through wireless LAN and WAN.
Tweeting: The system automatically tweets to Greenspeed’s Twitter page when a record is broken through the internet connection established with Cradlepoint’s COR IBR600 3G/4G wireless router.
The Greenspeed truck was built from scratch over the summer of 2011 by 5 students. National Instruments products (LabView and cRio) allowed Adrian Rothenbuhler (in 2011 he was the only electrical engineer on the team) to quickly design and build a state of the art data-logging and control system. Thanks to the flexibility and ease of use of LabView and NI's hardware, the system was quickly realized and put to use in a harsh and demanding environment. The team firmly believes that without LabView the project would not have advanced as fast as it did. This is expecially true for the turbo charger controller, which started as an idea and was implemented during our record breaking trip to the El Mirage dry lake bed in California. This idea is now fully realized and is currently being patented.
The Greenspeed team after breaking the vegetable oil record in El Mirage, California. From left to right: Dave Schenker (Driver), Jen Kniss (Crew Cheif), Seth Feuerborn (Lead Design), Ken Fukumoto (Treasurer), Patrick Johnston (Lead Fabrication), Ed Johnston (Community Member), Adrian Rothenbuhler (Systems Engineer).
The Greenspeed truck at the 2012 Washington D.C Auto Show.
a) View of the main VI showing the dashboard tab. This VI is remotely accessed through the cRio's webserver and the onboard wireless WAN/LAN router. b) View of the main VI showing the turbo charger tab. Here, all turbo parameters are shown in real time.
As can be seen in both a) and b), more tabs are available, giving us (remote) access to all sensor values and a detailed overview of the vehicle's status.
The "Flux Capacitor". This is the box containing the cRio and other peripheral devices seen from the driver's seat. During the Auto Show we installed green lights and replaced the cover with a plexiglas plate. A lot of people visiting our booth looked through the truck's windows and said "Oh look, it's a flux capacitor". Since then the "box" has a new name.
Shown here is the twin-turbo charger system with the wastegate during the building phase of the engine. The PID control loop adjusts the wastegate's position to maximize engine power. During a dynamometer test, the power of the engine was measured to be 708 hp and 1100 ft.lb torque at the rear wheels. Since then, the boost pressure has been increased and the overall power has been estimated to be over 800 hp at the wheels.
Video of the record breaking run at the El Mirage dry lake bed near Victorville, CA.
Greenspeed is currently actively working on rebuilding the truck with a redesigned front suspension (performed by Dave Schenker and Patrick Johnston as part of an independent study through Boise State University) and a completely new engine with piezo-electronic injection. Furthermore, the electrical system will be interfaced with the engine’s ECU (through CAN bus), allowing engine tuning on the fly. A 900 MHz wireless transceiver system is added to downstream larger amounts of sensor data to the pit. The existing vibration analysis and turbo charger control system will be improved to deliver more flexibility. Since the number of sensors (temperature, pressure, vibration, speed, displacement, etc.) rose to over 60, the cRIO system is being expanded to two chassis (NI cRIO-9074 and NI 9144 EtherCat Slave Chassis).
During Speedweek 2012 held August 11-17 at the Bonneville Salt Flats in Wendover, Utah, the team will be attempting to break the diesel based land speed record of 215 mph with pure vegetable oil.
For more information on the project please visit www.greenspeed.me and www.facebook.om/greenspeedbsu. More videos are available at our youtube channel (http://www.youtube.com/user/greenspeedbsu?feature=results_main)
The entire Greenspeed team would like to thank National Instruments and all other sponsors for supporting our project. We would like to express our gratitude towards Boise State University for helping to make this possible. Special thanks also to Dr. John Gardner and the Office of University and Industry Ventures. Last but not least, we are grateful for all the continued help and support we have received from the community.