The future of autonomous driving: steering via gamepad and smartphone

S eighth, but the Tiguan rolls off a little jerkily . First straight ahead for a few meters, then around the pylons. There can be no question of slalom driving, however, we tend to wobble awkwardly to the right and left. Even a drunk novice driver would probably do better. But have you ever controlled a car with a gamepad or even a smartphone from the passenger seat? Your own coordination is desperately looking for the right finger movements in the right dosage.

Steering without a mechanical handlebar

What is this gimmick about? It shows possible applications of a steer-by-wire steering system that works without a mechanical steering rod. Instead, a so-called force feedback actuator behind the steering wheel generates the usual steering feel for the driver and translates the commands to the rack via software. The steering characteristics and gear ratio can of course be changed variably, so that comfortable cranking is just a click away from the crisp go-kart feeling with ultra-direct gear ratio. It is also possible to completely decouple the steering wheel from the steering - so that it either no longer moves with autonomous driving or can be lowered into the dashboard, for example.

Volkswagen /Martin Meiners

The computer technology in the trunk ensures that the autonomous systems also work.

Thinking one step further, you can of course do without the steering wheel entirely and translate signals from the gyrometer in your smartphone or a separate controller into steering commands. That could be interesting even before fully autonomous driving,For example, to be able to control the car from outside with a parking assistant.

From corporate research to advance development

However, the engineers here are not interested in the actual implementation in series-compatible functions for the time being. Corporate research only develops the basic technologies from initial ideas. Around 70 to 80 percent of all projects are then passed on to the pre-development departments, where they are further specified.

As will the future strategies for taking over and handing over the steering for autonomous driving. We are now sitting in a Golf and first let the vehicle steer along the route, while the steering wheel is still. However, if we decide in between to spontaneously determine the direction ourselves, the steering angle, steering torque and wheel movements must be coordinated within a few seconds, if possible unnoticed, so that the car reacts as desired. This can happen, for example, in a fixed time window or depending on the steering angle. Here, too, a few clicks and changed lines of code in the software change the driving impression.

Volkswagen /Martin Meiners

The driving behavior is not changed on the hardware, but digitally via laptop.

Playground for programmers

Vehicle development has therefore become a great playground for nerds. Because the fine-tuning and interaction of all components is controlled by software. Before one of the functions or a system is tried out in practice, programmers spend many hours typing the necessary scripts and testing them in simulations. Only then do the various departments meet at longer intervals to test the results on closed-off routes in the vehicles.

However, this is not possible in just any car, the cars have to be specially converted for this. On the one hand, hardware components such as the steer-by-wire steering system are installed; on the other hand, the trunk is packed with computers and control units that carry out the calculations based on the programs and send the commands directly to the CAN bus of theSend vehicle. Depending on the computing power, separate cooling is then even necessary. A separate GPS device is also used, with which the car can orientate itself on the route with an accuracy of a few centimeters. This reduces the complexity, since other sensors for exact position determination can be dispensed with. The disadvantage: Even in the simpler version, the devices cost around 60,000 euros each.

Self-driving cars with their own character

But all the effort is worth it - as if from a completely normal one A high-tech machine in series production is impressive. And for the developers it is not just a piece of sheet metal; we are talking very lovingly here of Dieter, Walter and Norbert. For safety reasons, they always have a specially trained driver on the race track. So the uncomfortable feeling of sitting in a ghost car does not arise. On the contrary, the very own characteristics of the autonomous car can still be felt. And that is also the goal of one of the projects. Because even with autonomous driving without a steering wheel and brakes, the manufacturers want to give passengers an individual driving impression that matches the brand. A Porsche should still feel sporty and can choose a more dynamic line, while the VW Passat may focus more on comfort.

Volkswagen /Martin Meiners

The computer controls the red VW Golf GTI close to the limit.

The way there leads again, you guessed it, through the programmer. The software gives the system certain limits. Not only visible ones such as the lane boundaries, but also specifications for driving dynamics such as top speed and maximum permitted lateral forces and accelerations. From all these values, the system then calculates in real time - approximately every 100 to 200 milliseconds - the lines that the car should drive, including optimal braking points, steering angles and the like. If the engineers then want to change the characteristics, they basically only have to adjust the default parameters. But this is exactly what requires immense experience to be able to assess which parameters have which effects. During the testthat means: Load the software, drive, let the popometer feel and evaluate the data and then reset the parameters or optimize the program - and the process starts all over again.

Walter sometimes drives evenly, Norbert close to Limit

How much effort this is can only be guessed at, but the result is clearly noticeable. While Walter, the Audi RS7 used for the tests, pushes us hard in one lap, slows down into the corners and accelerates again from the apex, a few clicks later he drives us over much more gently and evenly the course. Norbert, on the other hand, another test Golf, moves much more often to the limit and drives us over the track with around 95 percent of what is physically possible. The engineers are working on software characteristics and also use methods of artificial intelligence to be able to include tire wear in the calculations. In future, aspects such as the current weight distribution in the vehicle or the coefficient of friction on the road will also be taken into account. This is particularly important in emergency situations and evasive maneuvers - also for future driver assistance systems.