What is ESP?
It referred as electronic stability program (ESP) or dynamic stability control (DSC), is a computerized technology that improves the safety of a vehicle’s stability by detecting and reducing the loss of skidding. Today more than half of the tourist coaches and intercity buses delivered by Volvo are equipped with this stability-enhancing program.
ESP reduces the risk of the driver losing control over his vehicle in critical situations, for example in sharp curves or on slippery surfaces.
How does it work?
When ESP detects loss of steering control, it automatically applies the brakes to help “steer” the vehicle where the driver intends to go. Braking is automatically applied to wheels individually, such as the outer front wheel to counter oversteer or the inner rear wheel to counter understeer. Some ESC systems also reduce engine power until control is regained. ESC does not improve a vehicle’s cornering performance; instead, it helps to minimize the loss of control.
Different sensors in the system monitor the behavior of the coach and interacts with individual wheel braking and even reduction of engine power, if necessary.
- Obstacle avoidance maneuvers with sudden steering input – risk of skidding (e.g. steering from the shoulder back on the road, avoiding animal or vehicle)
- Overestimating curve speed limit – risk of rolling over (e.g. closing curves, highway exits)
See a demonstration of how the system works in the ESP-film.
According to Insurance Institute for Highway Safety and the U.S. National Highway Traffic Safety Administration, one-third of fatal accidents could be prevented by the use of the technology.