“The computer-based controller we’ve developed will adjust the brake forces on the right and left sides of the cab independently to stabilize the vehicle by reducing the spin which causes rollover,” said Dr. Moustafa El-Gindy, director of the Vehicle Simulation Research Center at Penn State’s Transportation Institute (PTI). “We expect to have a prototype to test on a vehicle in about a year.”
El-Gindy detailed the approach in a paper, “Nonlinear Active Rollover Prevention Control Strategies for a 5-axle Tractor/Semitrailer.” A. Scott Lewis, research associate at Penn State’s Applied Research Laboratory, is first author of the paper.
Lewis said a computer simulation of a 75,000-lb tractor was used to demonstrate the effectiveness of the proposed active control system. However, he added that the approach is applicable to any configuration of truck or tractor-trailer.
El-Gindy says the biggest problem the team had to overcome was developing a computer program that could adjust to the continuous changes that take place in a tractor-trailer as it maneuvers around a corner. However, the simulation tests have shown that the controller they developed can prevent rollover without significantly changing the direction of the vehicle.
El-Gindy said that in the application he envisions the controller would engage differential braking automatically only if the lateral acceleration of the vehicle or its spin at its center of gravity exceeded a danger threshold.
“It only takes a few seconds of differential braking to steady the vehicle. If the driver responds and gets the truck under control via other means, the controller will not deploy,” El-Gindy said.