ESP – electronic stability program

Variables for the electronic stability program ESP

A system for controlling ride dynamics

If a vehicle threatens to tip over or to skid, the driver has to recognise the danger fast and react immediately to bring the vehicle under control again. ESP constantly monitors the ride dynamics of the vehicle and intervenes automatically using the engine management and brake systems if the vehicle is in danger of tipping over or skidding. It is therefore able to estimate the situation quicker than even the most experienced driver and to keep the vehicle under control within the limits of physics. Typical accident constellations such as cornering too fast, slippery roads, emergency braking and hectic evasion manoeuvres can be defused and the accident risk reduced.

Function and operation

ESP comprises two main functions: DSP (dynamic stability program) and ROP (rollover prevention). DSP mainly ensures that the vehicle remains stable (e.g. on wet roads, ice and snow). It intervenes only in the event of a low coefficient of friction when there is a noticeable difference between the direction the driver wants to take and the actual movement of the vehicle. Roll Over Prevention (ROP) reduces the risk of the vehicle's overturning in the event of a high coefficient of friction on dry roads.

The following variables are constantly measured and compared with the momentary speed of the vehicle:
• Steering angle
• Lateral acceleration
• Yawing rate (sped of rotation of the vehicle about its vertical axis)


Video 1: Test drive on a road with and without ESP	Video 2: Effect of ESP on a slalom course