Conti opens Automated Indoor Braking Analyzer

Continental has opened the first fully-automated tyre testing facility in the world at Contidrom, near Hanover. In addition to the ability to perform braking tests without drivers, helping to test consistently for longer hours, Conti has built a 300x30m air conditioned hall to house the Automated Indoor Braking Analyzer (AIBA), reducing the influence of atmospheric conditions on test results. The manufacturer will also be able to control the friction coefficient, as the hall enables the company to switch the 75m surfaces used as a braking area, in addition to using a low temperature hall for testing on ice. The main hall is also fitted with a sprinkler system for wet testing. Conti estimates that the AIBA will perform around 100,000 braking procedures, on passenger car, van, and 4×4 summer and winter tyres, when fully operational.

“With this new facility at our test track, we benefit from the most accurate braking test procedures in the world,” says David O’Donnell, head of R&D for passenger and light truck tyres at Continental. “Here, we can combine the advantages of laboratory testing with those of outdoor testing for vehicles. This has enabled us to improve reproducibility by 70 per cent, which means that we can measure development progress with an optimum degree of precision.

“Previously, tyre testers had to carry out their tests under fluctuating environmental conditions such as temperature and wind on a Contidrom test track exposed to the elements. The AIBA enables us to conduct tests all year round under fully air-conditioned test conditions on interchangeable road surfaces with constant friction coefficients.” In addition to the somewhat distorted results due to the reaction times and forces exerted, the air and track temperatures always produced a degree of scatter in the results.

“We can now completely avoid this system-related interference,” says O’Donnell. “Another positive effect is the considerably reduced physical strain on our test drivers and of course our ability to conduct testing 24 hours a day, 365 days a year.” In previous braking tests, vehicles were guided along a set of rails and the tyre testers had to apply the brakes themselves at a specific point, even in the ABS range. And, being in Hanover, low temperatures made it impossible to carry out summer tests at Contidrom during winter.

During a highly detailed presentation on AIBA, Dr Burkhard Wies, Continental head of tyre line development worldwide explained how the facility’s “rollercoaster technology” – a railed linear drive acceleration and braking system, with turntables at either end of the 300m hall – would improve testing quality in terms of reproducibility, stability or “trend” as Wies put it, and most of all precision. Conti says AIBA will see repeated tests yield results with a deviation of only 1.5 per cent, compared to the current deviation in results of around five per cent. In terms of the stability of results in repeated tests, Conti says AIBA helps to reduce deviation from over two per cent to under one per cent, while the accuracy of measurements are said to be more than twice as good.

Exemplifying the facility’s accuracy, Conti ran a series of eight braking tests, measured under a controlled temperature between 20.1 and 20.2 degrees Centigrade. The vehicles entered the braking measurement zone with velocity in the range 84.78-85.10kmh, while the final braking distances – the amount of tarmac covered between 80 and 20kmh – of the eight cars ranged between 25.70 and 26.37m; when out of “preparation mode” and working at full pace Conti expects to achieve a deviation from the mean result of ±20cm.

This level of precision is particularly relevant given the requirements tyre labelling has placed on manufacturers’ testing facilities. Dr Wies made the point that existing test procedures for the purposes of labelling allow manufacturers to achieve result sets covering multiple grade bands: “Without precision there is the potential to grade a tyre between A and C depending on track surface and temperature.” While some manufacturers may use the current testing procedures to yield an improved result – indeed, it could be argued that it makes sense for tyre-makers to make the most of the chance to optimise their label grades – Conti argues that it is more important to the company to obtain the most accurate picture of its tyres’ performance characteristics.

In increasing the accuracy of the testing procedure, Conti has also developed another important device to ensure the control of the surface temperature and friction coefficient: the High Speed Linear Friction Tester. The HS-LFT, as Conti snappily calls it, effectively scrapes a tread block sample across the road surface at high speed. Conti showed a portable version of the device, developed in conjunction with the University of Hanover, to visitors to the Contidrom – the portable linear friction tester represents an improvement in the precision of data obtained against that of the extant pendulum method, the company says, in addition to the speed in determining the friction coefficient of different rubber compounds and surfaces. Conti suggests the LFT could be applied to fields such as accident investigation too.

Increased testing efficiency is described by Conti as a necessity too, as demand grows alongside the diversification of the sector. Conti has four standard summer and winter tyres for passenger cars, SUVs, transporters, and vans, but specially designed tyres are also required for different vehicle types, applications, and regions of operation. And then there’s the original equipment market to supply. “It takes a lot of work to test all of these models,” explains O’Donnell. “The increased capacity achieved by AIBA therefore represents a very welcome reduction in our workload. Furthermore, the AIBA technology will enable us to make further advances in improving braking distances even more.”

Conventional dry-road braking tests are conducted at 100 km/h, and standard wet-road braking tests at 80 km/h. The brakes are engaged remotely using the standard Digitalker 3 system combined with the control centre communication unit and the vehicle’s ABS. The braking procedure is recorded by various sensors fitted on the wheels and inside the vehicle. One test run – which involves everything from fitting the tires and driving to the starting line to accelerating and braking to a standstill – takes four minutes to complete. Theoretically, 15 test runs can be done every hour, 24 hours a day. “Thanks to our new facility, we can now perform even more accurate and flexible tests at more than double the capacity,” boasts O’Donnell.

45 Years of Contidrom

In its 45 years, the company estimates that Contidrom has tested almost two million tyres. Opened in 1967, it initially consisted of the high-speed oval with two test straights. Along with the full range of tracks added at Contidrom, the company has established testing centres around the world, such as those at Arvidsjaur in northern Sweden, Idiada in Spain, and Wanaka in New Zealand. At tracks in the US and Japan, Conti test engineers perform tests to check Hanover developed tyres meet the requirements of end users and vehicle manufacturers. Contidrom currently has a staff of 90, ranging from test engineers to tyre installers.

Conti says Contidrom has become an indispensable part of its R&D department, with almost two million passenger car, truck, and motorbike tyres tested since 1967. At the test track in Uvalde, Texas, owned by the Conti brand General Tire since 1989, exact replicas of the small handling course, the large and small circles, and the rail-guided system have been built to make the test results transferrable and create comparable working conditions for test engineers. Tests taking place between spring and late fall involve test engineers in Wietze-Jeversen traveling around the world to scrutinise new tyres and new chassis components produced by the Continental Automotive Systems division. AIBA is designed as the future of high-tech facilities at the Contidrom.

Conti’s “Vision 2025”

In addition to the opening of the AIBA, the head of the Tires Division at Continental AG, Nikolai Setzer gave a rundown of the division’s “Vision 2025” strategy during the Conti Technik Forum. “Tyres,” Setzer said, “are a strategic pillar which we want to grow and extend” reflected by the “solid results” achieved in 2011 by the then-separate passenger and commercial tyre divisions. Combined on 1 August 2011 with 42,814 employees, the tyre division accounted for 8.8 billion euros, or 28 per cent of Continental Corporation’s 2011 sales. In the first nine months of 2012 Conti’s tyres achieved 7.2 billion euros in sales – “we will definitely be up this year,” Setzer said.

Cooperation between commercial (CVT) and passenger (PLT) units has benefitted the company, Setzer explained, with formerly specialised PLT taking the overall lead in territories such as Brazil, and CVT doing the same in India, for example. “Wherever it’s synergetic, we do it,” Setzer said, though where customer interaction demands specific service from one side or the other “we stay dedicated”.

Conti currently finds itself in the central portion of its three-part, 25 year strategy – or “Vision 2025” – having completed the value creation objectives of stage one in 2010. Between 2011 and 2015, the company is focusing global growth acceleration on the large, newly economically advanced BRIC countries. While improving its technology to compete at the top end – Setzer stressed the importance of being “the braking company”, referencing AIBA as a means of achieving this – Conti will also attempt to “leverage its cost position”. The final stage, between 2016 and 2025 is to “enhance value”, which Setzer characterises as “basically copy-paste”, balancing its global footprint, with increased activity in Asia for example, and achieving “podium position” in worldwide technology. Ultimately Setzer characterises the strategy as balancing growth, value creation, and technological leadership.

Conti currently has 17 plants in 15 countries, including recent investment in Hefei, China and Brazil. In China particularly, Conti is “in ramp-up mode” with a “four million tyre plant” ramping up to eight million, approved this year. Conti has a total of three plants in the works in China, Moscow and South Carolina scheduled by 2015. Setzer said growth in the US market in particular has made the company “desperate for this plant” to come on line some time in 2014, helping it to fulfil this increased demand. In addition to the billion euro fund for these developments, Conti also invests 350m euro per annum in expansion projects.

Explaining that Conti still depends on Europe for around 70 per cent of its sales, Setzer concluded that “there is still a long way to go” in achieving a globally balanced footprint, splitting passenger, truck, speciality consumer and speciality commercial segments in more equal proportions between the Americas, EMEA and APAC regions. For example, passenger and light truck tyres are currently split proportionally 21:74:5 (Americas:EMEA:APAC); Conti wishes to reduce the EMEA share to under 50 per cent, growing steeply in APAC, and slower in the Americas by 2025. In truck tyres, it is a similar story, though with APAC only accounting for four per cent of current sales, market share growth will be focused on this region exclusively.