Autopilots at Mercedes-Benz
Automated driving - abrupt braking test
25th May, 2010
With an eye on future generations of driver assistance systems,
Mercedes-Benz is the first vehicle maker worldwide to introduce an innovative proving method into its test driving
portfolio – safety-critical driving manoeuvres that cannot be precisely reproduced by human drivers are now being
handled by autopilot on closed test tracks. “Automated driving” supports the development, testing and validation of
assistance systems and other vehicle safety features. Testing at the limit can now be carried out without danger and
health risks to development engineers, delivering clear benefits to Mercedes-Benz customers – because the tests are
carried out with the highest degree of precision, future assistance systems can be developed and validated to
Mercedes-Benz’s exacting quality standards despite increasing levels of complexity.
For years, Mercedes-Benz has been setting benchmarks in the development of new technologies for the continuous
improvement of active and passive safety in automobiles. Innovations in passive safety such as the rigid-form
passenger cell, crumple zone, airbag and three-point safety belt, plus active safety like ABS, ESP® and brake assist
all trace back to Mercedes-Benz. They have made a substantial contribution to improving traffic safety and to
reducing significantly the number of injuries and deaths among road users.
The current status of active safety technology is defined by intelligent assistance systems that turn the vehicle
into a “thinking partner” - one that can see and feel, and that can react in the event of danger. Systems like the
blind spot assistant, ATTENTION ASSIST and the night view assistant are focused specifically on accident problem
areas such as lane changes, fatigue or poor visibility at night.
“With future driver assistance systems, we will be able to address even more complex traffic situations and
therefore to ease the dangers of further accident hot spots – like intersections,” says Prof. Bharat
Balasubramanian, Head of Product Innovations & Process Technologies at Corporate Research and Advanced
Engineering Daimler AG. “Our new automated driving test methods help us to fulfil the extremely high quality and
operational safety demands placed on our safety systems more efficiently.”
Autopilots ensure greater precision and relieve development engineers
In addition to established methods, Mercedes-Benz will fulfil requirements for reliable functionality and
operational safety in future assistance systems through the “automated driving” of test manoeuvres on dedicated
proving grounds. Prototypes used for this purpose are usually series production vehicles equipped with “robots” for
steering, acceleration and braking. An on-board computer controls the autopilot so that a pre-programmed course is
followed exactly – even if several vehicles are involved in one manoeuvre.
Test engineers in the control centre monitor all events and can stop the vehicles at any time. In parallel, the
vehicles perform self checks and brake automatically if they register deviations. Thus, the test configuration is
safe, yet flexible. All Mercedes-Benz models can be equipped with the technical equipment for “automated driving”.
Moreover, a large variety of different safety systems and equipment can be tested.
Using “automated driving”, engineers analyse safety innovations under real-life conditions in the vehicle,
addressing two critical challenges:
- Reproducibility. In order to calibrate the systems under test exactly, extensive variations and repetitions of
tests are needed. In so doing, all parameters such as vehicle distances, speeds and steering angles have to meet
specifications and always need to be maintained precisely in order to guarantee comparability.
- Safety. Because the systems are intended to kick in only in critical situations, such scenarios must be induced
during testing. The manoeuvres demand precision timing and should not provide a real danger for anybody.
Both requirements are usually beyond human abilities – humans cannot react quickly enough and cannot repeat
manoeuvres with the desired accuracy. However, for complex in-vehicle electronic systems and for assistance systems
in particular, such driving tests are indispensible as their functional validation must be carried out in a manner
that is comprehensive and as close to reality as possible.
The repeat accuracy of the test methodology enables test vehicles to maintain a pre-determined speed and course
exactly and to brake very precisely. For example, if a vehicle drives a pre-planned course several times, the tracks
of all the runs vary from one another by less than two centimetres. Should the vehicle be brought to a complete halt
at a particular location, the end points of all braking manoeuvres are within a radius of three centimetres.
Alongside the proving of assistance systems, “automated driving” will also be used for so-called “extreme tests”
in future. These put the vehicle under loads that are well in excess of those reached under normal use in traffic.
The intention is to ensure, for instance, that airbags are not activated unintentionally should the car be driven
heavily over a ramp or against a kerb. Test drives that involve a high degree of physical stress for the driver can
thus be avoided.
State-of-the-art test methods for the highest safety demands
In their development work, Mercedes-Benz engineers use the results from the company’s in-house accident research,
which delivers important findings. Several combined validation methods guarantee that all systems function reliably
at any critical moment. Company philosophy insists on validation to go considerably farther than required by
regulatory standards. When it comes to passive safety, Mercedes-Benz internal crash test requirements go well beyond
meeting public crash test standards.
The combination of computer simulations and real-life crash tests ensures passive safety to Mercedes-Benz
standards. Mercedes-Benz also makes use of state-of-the-art, networked test methods when it comes to active safety.
Drive simulator tests combined with simulation procedures deliver a faster and more reliable development process and
complement test drives under real-life conditions. “In Sindelfingen, we are currently building a new driving
simulator. The state-of-the-art technology of this equipment will make the future development of new safety systems
even faster and more precise,” confirms Balasubramanian.
Automated driving as the basis of future innovations
Mercedes-Benz is the only vehicle maker in the world to use “automated driving” as an additional element in the
testing process. It will be used on dedicated proving grounds in tests that would be virtually impossible to
reproduce manually, like merging at different speeds and vehicle distances; high-risk tests where, for example, a
vehicle brakes heavily in front of another that swerves at the last minute; and safety-critical tests where, at an
intersection, one vehicle crosses just in front of or behind the path of a second vehicle.
With “automated driving”, Mercedes-Benz has developed a new, unique testing method for safety systems. It is yet
further proof of the innovative power of Mercedes-Benz. The new test method guarantees the fast and efficient
development of assistance systems to the highest levels of quality and reliability and also offers maximum safety
at work for employees.
Bharat Balasubramanian sums up: “In order to continue to set trends in the field of safety in future, our test
procedures must be able to keep pace with the wealth of ideas generated by our engineers. With automated driving, we
feel we are well equipped for the development of the next generation of assistance systems.”