Student Projects
Contact Information:
Country: Switzerland
Year Submitted: 2018
University: ETH Zürich
List of Team Members (with year of graduation): Maximilian Stölzle (2018), Patric Bruni (2018), Michel Lüthi (2018), Marco Job (2018), Kerim Barhoumi (2018), Dominic Schmid (2018), Théophile Messin-Roizard (2018), Severin Meier (2018), Niklaus Laurin Schaffner (2018), Christian Miklautz (2018), Roger Guardiola Fortuny (2018), Samuel Renggli (2018), Lorenz Hetzel (2018), Jan Schubert (2018), Nicola Borrer (2018), Timo Flury (2018)
Faculty Advisers: Prof. Dr.-Ing. Konrad Wegener, Dr. Josef Mayr, Pascal Gehri, Marco Karch, Nils Reich, Marco Stalder, Fabian Stoop
Main Contact Email Address: ethec@ethz.ch
Website: www.ethec.ethz.ch
Project Information:
Title: ethec
Description: Our goal is to develop an electric motorcycle with two wheel hub motors and a driving range of 250 kilometers. We want to pave the way for the next step of electro-mobility on two wheels.
Products:
NI sbRIO-9627
RMC-9694, 2 mm IDC Connector Breakout Kit and CAN1 Interface
LabVIEW 2017
NI DIAdem
NI MAX
The Challenge:
Energy storages have limited capacities. Because of that, many electric motorcycles have a relatively short range. Our vision is an urban solution for mobility, which efficiently retrieves the own braking power through recuperation. With our recently developed technology, we want to use the available energy more efficiently and open new possibilities in the world of modern mobility.
ethec Team (Test day one)
The Solution:
Explain how your project works.
Two hub motors make for more efficiency by recuperating the energy that would get lost in the front wheel brake. The lithium-ion battery with its 1260 cells is cooled with a thermoelectric cooling unit. This ensures that the battery is always used at its optimal temperature and maintains its maximum of capacity during its lifespan. Depending on the cell temperature, the working fluid is heated or cooled by peltier elements. The battery is controlled through the battery management system which ensures an equal use of all cells through balancing. This way, there is no significant difference in maximum capacity between cells.
The main part of the motorcycle is controlled via the sbRIO-9627. The inputs and outputs of all controls on the handlebar and within the overall motorcycle are fed through the digital RMC pins and the analog IDC pins. Communication between the sbRIO-9627 and the display, the battery management system and the motor control is realized via ethernet (TCP) and via two separate CAN bus networks. The separation of the CAN network - one for the two inverters which control the motors, and another for the battery and all its peripherals - helps to create a more reliable motor control and communication with all other components in the system.
PCB for CAN1 interface
Soldering the CAN1 interface
CAN1 interface for RMC
The main loop of the main VI, which makes for most of the motorcycle control, is built up as a state machine. We implemented different states, which stand for the different states in which the motorcycle can operate. This approach guarantees maximum safety for the driver, because the allowed functions are clearly defined in each state. Since safety is the number one priority in modern mobility, very strict conditions must be met before the electronic control unit allows a change of state.
Explain the benefits using LabVIEW and NI tools.
As for our project reliability and safety played the most important role we needed an application that would provide these characeteristics. With the sbRIO - 9627 Embedded System the motorcycle control could be managed easily and with great effectiveness. The graphical coding made for rapid workflow and resulted in comprehensible and well organized code. During the project we dealt with different standard transmission protocols. Using the ready-to-go VIs of National Instruments, communication with standard protocol as for example CAN (Controller Area Network) was a conquerable obstacle.
In retrospect the use of NI material guaranteed a steady improvement of our coding skills and led to a fully functional motorcycle that accomplishes the intended functionality.
Statemachine
Level of completion: functional
Time to build: nine months
Additional revisions that could be made: In the world of motorcycling it is extremely rare to have a front wheel wich is driven by a motor. It was difficult to predict how the motorcycle would behave when driven at speeds, at which the gyroscopic effect becomes important. While testing we found out, that it really drives well and is fun to drive. More testing has to be done to fine tune the coordination between front and back motor. Also the torque produced while recuperation has to be optimized.
testing the motors
Link to YouTube channel
Link to Website
Poster
poster
