The Silent Hero of Autonomous Vehicles

Autonomous vehicle technology is no longer the exclusive domain of the R&D departments of giant automotive brands. University teams are also developing their own prototypes and pioneering new technologies in this field. Especially when sustainability-oriented projects are combined with autonomy, very interesting engineering solutions emerge.

As ITU ZES Solar Car Team, we have been developing solar cars for years. In recent years, we have gone one step further and are working on electric vehicles with autonomous driving capability. In this article, we will focus on a part that may not be very noticeable from the outside, but is of vital importance in terms of engineering: Rollbar. Let's take a look at why this safety component is becoming so important with autonomous driving systems.

What is a Rollbar? What Does It Do?

Rollbar can be translated into Turkish as “rollover protection bar”. Its main task is to protect the interior cabin area and increase the chances of survival of the occupants when a vehicle overturns or flips over. This structure, usually made of durable metal alloys, is frequently used in racing cars, buggies, off-road vehicles and prototype vehicles.

Since the rollbar also increases the rigidity of the vehicle, it contributes not only to safety but also to structural stability. Especially in cars where the weight/performance ratio is very important, rollbar design requires serious engineering calculations. Because excess weight can reduce range, while poor design can pose serious risks in tests or in real accidents.

Why is the rollbar even more critical in autonomous vehicles?

In a conventional vehicle, the driver perceives the environment, analyzes risks and intervenes with reflexes. In an autonomous vehicle, however, these tasks are left to camera, lidar, radar and software systems. No matter how advanced these systems are, they cannot yet be guaranteed to react 100% flawlessly to unexpected factors from the outside world.

For example, a sensor may not detect an object that suddenly jumps out onto the road, or GPS data may deviate momentarily. In such cases, an accident may be inevitable. This is where passive safety systems come into play as much as active safety. This is where the rollbar becomes a life-saving element.

In autonomous driving test vehicles, whether in a racing or demo environment, the robustness of the rollbar is not only a technical requirement but also an ethical responsibility. Because any possibility that may pose a risk to the operators or bystanders sitting inside during the test must be considered in advance and precautions must be taken.

ARIba Autonomous II: A Real Example

ARIba Autonomous II, developed by ITU ZES Solar Car Team, is a fully electric vehicle with autonomous driving capabilities. The rollbar system used in this vehicle was specially manufactured from carbon fiber composite plate. Achieving an optimal balance between both lightness and durability is a critical priority for us.

The rollbar structure is positioned to surround the driver's seating area of the vehicle. The attachment points were directly integrated into the chassis and tested for strength in crash and rollover scenarios with FEA (Finite Element Analysis) simulations. In other words, we are talking about a system that is not only “visual” but also full of engineering.

In addition, even if the operator is not sitting in the vehicle traveling within the safe area limits during autonomous software tests, the rollbar system protects the safety of the vehicle's outer form, increasing the vehicle's rigidity and ensuring the healthy completion of the test.

How Autonomous and Safety Go Hand in Hand in the Future

As autonomous driving systems evolve, humans will be removed from the driver's seat, but vehicles will still interact with the physical world. Therefore, physical safety measures will become more important as well as software safety.

Structural measures such as roll bars may become standard not only in race cars, but also in urban autonomous service vehicles in the future. The design of such components, especially in student projects, offers a great opportunity to gain real engineering experience.

Rollbar systems are often mandatory for vehicles to pass technical inspections in races. In this way, the level of safety becomes not only a domestic policy but also compliant with international technical rules.

Safety is in the Details

When we look at autonomous vehicles, we often focus on their lidar systems, cameras or intelligent algorithms. However, many parts that form the backbone of safety are not visible from the outside. The rollbar is one of them. It may seem simple, but it is an important component that can make the difference between life and death.

When we design such systems in ARIba projects, we think not only about today, but also about the transportation systems that will be shaped by autonomy in the future.

In the engineering of the future, safety is never an option; it is a necessity.