Putting the New Electronic Stability Control System to the Test

By Dan Drella Jul 27, 2017

It may be July now, but pretend for a moment it’s February in the Midwest. You’re given the “opportunity” to go all the way north to Sault Ste. Marie, Michigan (where you can literally see the Canadian Border) and participate in outdoor winter truck and stability control system testing. Would you jump at the chance to work in near-zero temperatures and snow piled as high as your tractor?

Schneider instructors Kim Trent and Joe Sterling did! Their ultimate destination was the Smithers Winter Test Facility, a 400-acre former Air Force base, which is used by many truck, auto and vehicle-component manufacturers. They all come to the Winter Test facility to drive on one of 30 well-groomed test bed areas, which simulate various traction and weather conditions. The Schneider team worked with Meritor WABCO to test its Electronic Stability Control (ESC) system. The ESC system has been tested and proven effective by Meritor WABCO over several years, and it will become mandatory under a National Highway Traffic Safety Administration (NHTSA) federal rule on Class 8 vehicles in August 2017.

What is electronic stability control and how is it different from existing roll stability control?

The Electronic Stability Control system takes the capabilities of the Roll Stability Control (RSC) system, which has been standard on the Schneider fleet since 2004, and adds yaw protection. The ESC system can help a driver in a skid or jackknife situation. More specifically, the ESC system has two new sensors:

Yaw is movement to the right or left of the intended direction of motion/travel.

  • The yaw sensor detects if the vehicle is traveling in a direction in which the vehicle is not pointed – like when a truck is in a skid and angled in its lane, but still traveling forward. In this situation, as we emphasize in training, drivers should pick a fixed point and steer toward it. Electronic Stability Control helps you do that.
  • The steering angle sensor measures the direction and amount the steering wheel is turned. The system combines the yaw measurement with the amount of steer angle, and it then adjusts torque and selectively applies brakes to help you steer toward your target. In other words, if you are yawing to the right and steering to the left, the Electronic Stability Control system will work with the anti-lock brake system to selectively apply brakes on the left side of the truck to help you steer out of the situation.

Although the testing was completed on packed snow, the system can and will work on wet pavement or any conditions (including a curve or ramp) where the tractor is in a yaw condition.

How did Schneider test the Electronic Stability Control system?

Schneider truck with electronic stability control system

The testing consisted of running a current Cascadia tractor with Roll Stability Control through a series of maneuvers, then running a new Next Generation Cascadia Tractor with the Electronic Stability Control system through the same test. For the safety of the team, the weighted test trailer was equipped with protection cables to prevent a full jackknife. Joe and Kim took turns running through the J-turn test, which simulated a curve or exit ramp. After the test, Joe said, “With the ESC equipped tractor, you could feel the tractor slow as it began to slip in the curve, and you could hear the air actuators working with ABS, to maintain stability of the tractor. The ESC-equipped tractor maintained a more stable line through the curve.”

Double lane change image

Next, the team operated through a double lane change. They started traveling in a straight line, then made a lane change to the left and then back to the right through a marked series of steering points. The Roll Stability Control tractor made the move left, but under-steered (continued to go straight) when trying to come back to the right. The Electronic Stability Control tractor made the left move and crisply made the move back to the right because the ESC system sensed understeer and used selective braking to bring the unit back to the right. As Kim described it, “I felt much more able to make both turns through the course with the ESC-equipped tractor. It was much more responsive.”

Watch the full video above of Kim and Joe testing the stability control systems.

Like any safety system, ESC and RSC are there as a final safety net. It is always the responsibility of the driver to keep the vehicle under control and to adjust for roadway configuration and weather conditions. The ESC system may provide a final layer of protection to assist the driver to recover from a skid, but the best protection is to slow down, adjust to conditions and avoid the emergency situation.

The Electronic Stability Control system will become standard on the Schneider fleet with new tractors built in August 2017 or after.

Do you have any questions about the Electronic Stability Control system, the testing process or any of Schneider’s other equipment and technology?


About the Author

Dan Drella IMG

Dan Drella is a Director on the Schneider safety team. Dan is accountable for safety for the Intermodal, Logistics Transportation and Logistics Transloading and Distribution areas. He has been with Schneider for 17 years working in various areas, including equipment management, rail management and finance.  

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