College team develops an autonomous robotic snow plow

Citation

Bloss, R. (2012), "College team develops an autonomous robotic snow plow", Industrial Robot, Vol. 39 No. 3. https://doi.org/10.1108/ir.2012.04939caa.005

College team develops an autonomous robotic snow plow

Article Type: Mini features From: Industrial Robot: An International Journal, Volume 39, Issue 3

Students at Dunwoody College of Technology in Minneapolis, MN participate in an annual robotic snow plow challenge sponsored by the Institute of Navigation. The goal each year is to build a robotic snow plow to clear a 1-m wide path of snow from a U-shaped course in the fastest time. The student team is assisted by three members of the college staff.

For the 2011 challenge, against four other college teams, the Dunwoody student team started with an off-the-shelf homeowner style riding tractor that is just less than 2 m long. The gasoline powered unit was then equipped with a snow plow blade (Figure 1). A Siemens programmable logic controller (PLC), Model OBA4 that operates on 12 V DC, was selected to control the robot. The plowing path for the challenge is preprogrammed into the PLC memory.

Figure 1 Dunwoody Snow Devil autonomous snow plow robot in action plowing the challenge course

A pneumatic cylinder was installed to activate the clutch, brake and engage the drive belt. A spring actuator which develops 68 kg of force engages the brake automatically if there is a power failure to prevent the plow from running away. The cylinder extends to activate motion (clutch and drive belt) and retracts to brake. Air pressure for activating the cylinder is provided by a storage tank on board so activations are limited by the capacity of the tank.

Steering is activated by a 12 V DC servo motor that turns the tractor steering wheel. Feedback for the steering function is a pulse encoder that provides a signal each 15 degrees of rotation. Distance traveled is encoded by a separate analogy encoder which provides feedback to the PLC.

As a safety device, the front of the tractor has a Banner U-Gage ultrasonic sensor attached. This sensor can detect obstacles up to 1 m in front of the tractor and signal soon enough to prevent a collision. The sensor provides a safe stopping distance for the tractor which moves at 1 m/s.

For easy of loading and unloading the snow plow from the transport vehicle as well as driving around for challenge setup, a manual joy stick is provided for a human operator to use.

Richard Bloss