Customer Solutions

Students Use NI PCMCIA-CAN and LabVIEW to Design Robot

Author(s):

Alexis L. Desbien, Sherbrooke University; Éric Lespérance, Sherbrooke University; Marc-André Roux, Sherbrooke University

Industry:

University/Education

Product:

Industrial Communications, LabVIEW

The Challenge:

Designing a six-legged pneumatic running robot to participate at the Society of Automotive Engineers (SAE) Walking Machine Challenge using a basic control system while keeping the option of adding and removing some modules as the project progresses.

The Solution:

Using the National Instruments PCMCIA-CAN Series 2 card to link the controller area network (CAN) on the robot to the laptop and NI LabVIEW to develop the software

Walking Machine Challenge
Sponsored by the SAE, the Walking Machine Challenge is a contest for which students design, build, and test a walking machine with a self-contained power source. During the competition, the machines perform in six events that challenge students to think creatively. Students participating in this competition have the opportunity to familiarize themselves with technologically advanced components and systems necessary for the construction and development of robots and other complex intelligent machines.

Functions of the Robot
Our robot, Captain Basile, is a dynamic insect-like walking robot that participated in the SAE Walking Machine Challenge. We designed the robot by examining insects and by using more than 1,000 hours of computing time to understand dynamic walking, select the components of the robot, and optimize its performance.

The robot has six legs and weighs 30 kg. It has only 12 degrees of freedom and only six are actuated. Simulations showed we can achieve straight-line running in an open loop at a speed of 0.72 m/s, with a lateral drift of only 0.12 m after completing 12 m. We are just beginning experiments with the robot, and the results are encouraging. The robot, before any tuning, travels at 0.9 m/s. This corresponds with results obtained from simulations.

We used the NI PCMCIA-CAN Series 2 card to link the CAN network on the robot to the laptop reading a game pad controller to issue commands to the robot. We used a Pentium III 800 MHz laptop running Windows XP as the control station. On the robot, each node used a PIC 18F458 (40 MHz microcontroller with built-in CAN bus). It was easy to use a built-in LabVIEW VI to develop the software on the laptop. This ease of development was critical at the competition, as we had to adjust the controller in less than 10 minutes between each event. The CAN link between the robot and the laptop gave us a fast (1 Mbps) and error-free link that we used to monitor the controller on the robot, acquire sensors data, and send commands to the robot.

NI Products Ease Development Time
With the NI products, we completed all events in tether mode and eased the development of the other mode by directly monitoring the CAN network on the robot. The NI sponsorship was incredible. We saved a tremendous amount of time, and cannot imagine such a system without this kind of product.

For more information, contact:
Sherbrooke University
Team Perius
Team Web site: http://www.perius.gel.usherbrooke.ca/
Competition Web site: http://www.sae.org/students/walking.htm