ABS is a strategy used to improve the service brakes, says Dr Herman Hamersma, De Abreu’s supervisor in the Department of Mechanical and Aeronautical Engineering at the University of Pretoria

Hamersma unpacks the new off-road ABS algorithm:

Service brakes, emergency brakes, and parking brakes are the three types of braking systems in most automobiles. How can ABS algorithms be added as the fourth one?

ABS is a strategy used to improve the service brakes. You are correct that a passenger car has three braking systems, but the emergency brake and parking brake are usually combined. The service brake is the pedal you push to slow down and stop during normal driving. The emergency brake is used when there is a failure on the service brake, for instance if your brake line has lost pressure and your car can’t stop. In that case, you can use the ‘hand brake’ to slow and stop the car. The hand brake is also used as the parking brake to keep the car stationary. In other vehicles, such as trucks, or mining/agricultural/earth-moving machines, these brakes are often three separate systems. However, ABS is only intended for the service brakes. It is an enhancement of service brakes.

What is the future of the ABS algorithm - braking system?

ABS has been in the market for several decades, specifically in passenger vehicles and in the last decade for heavy vehicles (trucks and their trailers) too. ABS opened avenues to other safety systems, like stability control and traction control; systems which prevent the vehicle from spinning when on a slippery road and spinning wheels when you accelerate aggressively. Current research is focused on maximising the potential of vehicle safety systems by combining them, in other words, having the ABS, stability control and other modern controllers working together to make the vehicle safer and more efficient. This is known as Integrated Chassis Control.

What are the characteristics of a good braking system or what makes ABS algorithms different from other brake systems?

A good braking system minimises stopping distance without locking the car’s wheels. This allows the driver to maintain steering even when braking harshly, so that the driver can still follow the road, stay in the correct lane and avoid an obstacle. This performance should be maintained even when on a slippery or uneven road.

How will ABS function on an Electric Vehicle (EV)?

EVs present interesting opportunities, because you can recover some of the energy lost during braking. Traditional brake systems use friction brakes – think of your brake pads that wear away and need replacing every few years. If you watch F1, you will see how hot the brakes become. The same happens with your car – the brakes heat up a lot when braking. This heat is energy lost. With EVs, you can break with the electric motor, in the process charging the batteries. Modern EVs contain both traditional friction brakes and electric regenerative brakes. The technical challenge is to blend these two systems to maximise both braking performance (i.e. short stopping distance, while driver can steer) and optimum energy recovery so that you can recharge the batteries during braking.