University: Université de Paris Sud
Team Members: More than 40 students and trainee engineers of the Université de Paris Sud have participated in the project. They were or are students from the IUT Cachan and trainee engineers from the Polytech Paris-SudPolytech Paris-Sud‘s Engineering school
Faculty Advisers: Ghislain REMY, Pascal MARTINELLI, Gilles RAYNAUD
Email Address: firstname.lastname@example.org
Ni.com/Community Profile: https://decibel.ni.com/content/people/G_Remy_-_IUT_Cachan
Submission Language: English
Title: The Hublex Transporter
Description: Design of a new type of Electric Personal Transporter
Products: myRIO, sb-RIO 9636, CompactRIO, myRIO Mechatronics Kit, LabVIEW, LabVIEW Robotics Simulator, LabVIEW Real-time and FPGA Modules,
Design a new type of electric personal transporter: the Hublex. The prototype design has required various tests and measurement modifications. Fortunately, LabVIEW enabled easy code reuse and natural maintainability between different types of hardware used: NI CompactRIO, NI sb-RIO and finally NI myRIO.
A collaboration between the mechanical, the power electronics and the electronics departments of the IUT de Cachan (Université de Paris Sud) has been in progress since 2010. The purpose was to analyze, design and prototype a Segway-like transporter using hubless technology, in order to divide the total cost of the device by three. Hence, as the main innovation of the Hublex transporter resides in the gearbox removal, the mechanical department made a patent deposit in France (Number: 1155334) in June 2011 and an international patent deposit has been placed in 2012. In 2014, former students began to enroll in a start-up in order to commercialize the Hublex. Launch is set for late 2014 or early 2015 and the price of the Hublex will be around 1000 € only.
Figure 1: The Hublex Personnal Transporter controlled by a myRIO at NIDays 2014
A few years ago, in September 2010, this exciting project started when students decided to attach a NI CompactRIO to a Segway PT to identify the electrical consumption and the energy exchanges between the battery pack and the motors. The results helped to emphasize the transporter functioning and, more importantly, to motivate new colleagues and students to join the project.
Figure 2: The Segway PT instrumented using NI CompactRIO at NIDays 2011 France
But it is only in September 2011, following an intense and inspiring coffee talk between colleagues, that the crazy idea of designing a Segway-like transporter emerged. The keystone was simply to use a hubless transmission instead of a classical and costly gearbox. Since then, the project has been developing at a steady rate: national patent deposit; enrolling of new students in each of the three departments…While the mechanical department was focused on the design of a fully industrialized prototype of the Hublex, in the meantime students of the electrical engineering department have developed a control simulation in a virtual environment using LabVIEW Robotics Simulator. This part was a direct application of their automatic control engineering lectures as the system can be seen as a classical invert pendulum.
Figure 3: Simulation of the Hublex Control using LabVIEW Robotics Simulator (in French)
In 2012, students focused on the angle measurement of the handlebar which can be used to control the steering of the Hublex, but also for the unlocking of the device at startup. They use an AS5040 sensor, “10Bit 360° Programmable Magnetic Rotary Encoder” from Austriamicrosystems, which offers contacless angular measurements. It allows the Hublex to have the handlebar removed without having to disconnect cables. Another group of students was also working on the data fusion between accelerometer and gyroscope sensors to compensate for the shifting of the gyroscope angle due to temperature impact on the gyroscope.
Figure 4: LabVIEW Diagram of the unlocking procedure of the Hublex
In September 2013, the trainee engineers designed a synchronous motor using finite element analysis and experimental identification of motors performances. As new motors were not available at that time, the students had to first define the motor control directly on the existing Segway motors. The control was performed using a NI sb-RIO 9636 which controls a 3-phase inverter. The first demonstration of the open-loop controlled motor mounted on the wheel was performed during NIDays 2014 in February.
Figure 5: Test Bench of open-loop controlled inverter using NI sb-RIO 9636
Figure 6: PWM Generation using NI sb-RIO 9636 for the motor control
Figure 7: Demonstration of the open-loop controlled motor mounted on the wheel performed during NIDays 2014 (in French)
Figure 8: NI myRIO FPGA Programming using LabVIEW
Recently, some endurance tests have been carried out to validate the hubless technology used. The Hublex has undergone a 1000-km trial on a test bench.
Facebook Link to IUT Cachan profile and the 1000-km trial. https://www.facebook.com/IUTdeCachan
Finally, the Hublex design process includes the conception of the full mechanical structure and the electric motor. Indeed, an electric motor is at the final stage of prototyping and will be produced before summer 2014 in order to improve the efficiency of the transporter. Specific developments have also been done for the assembly of the battery pack, the power electronics, the sensing devices and the connectivity of the control board. Besides, all the work has been performed by students only and a guidance by three passionate teachers.
Figure 9: Some of the students and trainee engineers from 2010 to 2014
We have chosen LabVIEW and National Instruments hardware to be able to make easy code reuse regarding hardware evolution and the renewing of student teams each academic year. Indeed, various tests have been performed since 2010 including datalogging, embedded measurements, monitoring and control. Thus, NI embedded systems have been integrated: NI CompactRIO, NI sb-RIO and finally NI myRIO. Remarkably, the Wifi features of the myRIO have greatly improved the students’ access to the embedded data, and so the prototyping process has been greatly accelerated.
Additionally, graphical programming has been an important tool for developing project. Indeed, despite the gap in LabVIEW programming skills between students and trainee engineers, graphical programming gives an instant understanding of the code and facilitates the interaction among them.
Although the studies have started in September 2010, since then students have only actually spent a total of 6 months of work on the project.
The system is now Beta functional, but the new electrical motors need to be tested and fully specified before finalizing the prototype. At last, rolling tests will be performed to uphold the results obtained using the control simulation and to adapt travelling comfort and speed safety.
Nominate Your Professor (optional)
Ghislain REMY, Associate Professor in Electrical Engineering,
Pascal MARTINELLI, Teacher in Mechanical Engineering,
Gilles RAYNAUD, Teacher in Electrical Engineering.