Winter test centre in Sweden celebrates 10th anniv

Everything about Arjeplog, Sweden, is somehow different. The community counts some 3,100 inhabitants on an area about ten times the size of New York City, which has a population of 8.3 million. In Arjeplog, there are long empty streets, temperatures can remain well below zero for weeks on end, and there are countless frozen lakes. It is difficult to imagine anything more than reindeer and northern lights in a place like this. And yet thousands of automotive engineers flock to Arjeplog each year: the region's isolation and consistent winter conditions offer just the right environment for the testing of vehicle prototypes. Bosch was one of the first companies to test its technologies here. In fact, this winter marks the 40th anniversary of Bosch's activities in Arjeplog. For the past decade, the company has been using a comprehensive test facility on the Vaitoudden peninsula. Establishing the facility required an investment of 20 million euros.

“Northern Sweden is the perfect place to fine-tune safety systems such as ABS and ESP® on snow and ice,” says Gerhard Steiger, president of the Chassis Systems Control division. For braking control systems, low friction-coefficient roads are particularly challenging. “If maneuvers are under control under such conditions, all other situations are also covered,” Steiger says.

Bosch conducted its first minor test drives in northern Sweden as early as 1971. In 1973, the company heard of an airstrip on a frozen lake in Arjeplog. It was the first to use the runway to develop its ABS anti-lock braking system – without interrupting flight operations. Since then, Bosch has returned to Arjeplog each year. The region, which is located 60km south of the Arctic Circle, has become a veritable mecca for European automotive testers. Several times a week, direct flights from the German automotive cities of Stuttgart, Munich, Frankfurt, and Hannover land at a nearby airport in Arvidsjaur.

Over the years, engineers faced increasingly demanding requirements and a growing number of projects. For this reason, Bosch built a new, much larger testing facility in 2003. It is located at a lake outside of town. “Some 11 km of streets wind through an area of 420 hectares,” says Andrew Allen, the British head of the Swedish Bosch subsidiary. “The location offers all of the conditions that can cause drivers headaches throughout the winter.” Driving surfaces that are icy on one side, steep hills with a range of inclines, and a number of other test courses are elements on the landside. The centre also features the frozen lake with several track sections. Here, test drivers try out modern braking control systems under the most extreme conditions on a sheet of ice that is at least 30 centimetres thick. Up until a few years ago, even paved courses were built on the lake each year to carry out “µ-split” braking, which sees half the vehicle driving on a tarred surface with good grip, while the other half is on slick ice. In such conditions, only a well-adjusted ABS system can keep a vehicle on course in the event of emergency braking. For the past several years, Bosch has also been testing powertrain components in Arjeplog: the performance of hybrid and electric vehicles at temperatures of minus 20 degrees Celsius is tested there. For this reason, appropriate charge spots in special garages were added to the facility in 2012.

Today, some 500 Bosch associates spend several intensive weeks working in the far north, where they drive a total of 500,000km on the test tracks. Each year, the cost of transporting associates and vehicles to Sweden and back is high. But it is a worthwhile investment, as the location provides engineers with the best possible conditions in which to perfect the control behavior of the ABS and ESP® active safety systems. For instance, the constant low temperatures ensure the consistent presence of the driving conditions that place the greatest demands on the quality of the control systems. Icemakers, the local specialists responsible for ensuring that the road surfaces are constant, water and smooth the courses several times a day. They also use special machinery to give the ice the desired friction coefficient. All this ensures that even the smallest change in driving behavior can be effectively analyzed following software adjustments, without the risk of driving being influenced by changes in the road surface. Here, experts refer to the reproducibility, or comparability, of measured data. For example, the software of an electronic stability program comprises more than 2,000 parameters which influence the way the system reacts in extreme situations.

The specialists will have more than enough work in the coming years, as braking control systems become standard features around the world. In the United States, Europe, and many other countries, legislation is increasingly making ESP mandatory. In Brazil, India, and southeast Asia, ABS anti-lock braking systems are becoming ever more widespread. Today, some 86 percent of newly produced vehicles around the world are equipped with one of the two electronic safety systems.

Assistance and automation further enhance driving safety and comfort

Bosch will continue to push vehicle development forward in the future. The company's aim of further improving driving comfort and safety and the continuing trend toward powertrain electrification call for new brake technologies as well as new, increasingly networked vehicle functions. With the ESP hev in the Mercedes-Benz S400 Hybrid, Bosch brought an innovative braking system to series production in 2013. The system is the world's first to integrate a regenerative braking function without the need for additional components. The Bosch iBooster is a further solution for regenerative braking. This electromechanical brake booster permits practically complete recuperation of kinetic energy. Deceleration values of up to 0.3 g, which is sufficient for all braking maneuvers in normal traffic, are achieved solely by means of the electric motor. The new brake booster can operate without any vacuum from the internal-combustion engine and has premiered in VW's all-electric e-up. “Bosch offers a building block system that makes it possible to put together customized braking systems for every car,” Steiger says. “It provides assistance functions for the full range of currently available powertrain technologies, regardless of equipment level.”

A growing number of surround sensors already now complement the brake control system. In combination with powertrain and steering technologies, a number of high-performance functions can be realized, including adaptive cruise control, predictive emergency braking, road sign recognition, and self-steering parking assistance. In the future, increasing networking and connectivity will make the car even more intelligent. For instance, drivers will one day be aware of potential hazards behind upcoming bends in the road well in advance, and will know when they need to slow down or accelerate. The level of automation also continues to grow. Cars are already parking semi-automatically and helping drivers keep to their lanes. “A few years from now, cars will be able to find spots in parking garages entirely on their own, and they will be able to navigate through morning traffic jams on the freeway in a highly automated manner,” says Dr. Dirk Hoheisel, the member of the Bosch board of management responsible for this topic. In this scenario, drivers will be able to use their smart phones without danger, for instance. But since such functions do not require extensive winter testing until now, the engineers working on them are not likely to experience the cold and charm of Arjeplog.