Everything at a glance Instrument cluster from Bosch in the new Touareg Four dials behind anti-glare real glass

With its four dials behind anti-glare, coated real glass, you wouldn't think on first glance that the instrument cluster is based on a uniquely modular concept. It affords high flexibility and scalability for different model versions of the Touareg as well as for other premium vehicles made by the VW Group. The main component group and heart of the device is the display module. It consists of the cluster ECU with two microcontrollers including the periphery as well as device plugs and uses a 7-inch color display as its electronic display unit.

New structural concept allows model-specific design
The module is connected via two side-mounted plug connectors with the two side printed circuit boards, which take charge of such design-relevant instrumentation components as the light-emitting diodes, step motors and instrument dials. While the display module is identical for the entire platform, the engineers have included different requirements in the design of the circuit boards. For the VW Touareg, for example, two step motors have been used for the pointers of the two outside dials – i.e. for the coolant temperature and the fuel gauge. A cleverly designed structural concept allows this freedom: while the back plate with the speaker and display module is the same for all the variants, the remaining instrument components, starting with the reflector assembly, can be adapted to accommodate differences for different models.

This mechanical concept was optimized for the VW Touareg so that the interior diameter of the large speedometer and rev counter dials could be increased to 102 mm. Extremely thin walls in the front frame and for the chrome-plated dial rings create an appearance that remains unequalled in its clarity, high quality and good legibility. This claim to premium quality is supported all the more by the use of real glass. It protects the 3D dials and the red pointers from dust and curious fingers, is anti-glare in a neutral color and reinforced with respect to thickness and workmanship.

A new type of production process was used for the first time for the sealing concept of the glass; it applies the pliable sealing material evenly and directly onto the inside of the glass surface. Glass prepared in this way can be installed with high reliability; it is hermetically sealed towards the vehicle interior and noise-free for the entire service life of the product.

Two high-performance processors
In terms of hardware, a duo made up of a 32-bit instrument cluster processor and a 64-bit graphics engine ensures that there is no flickering in any of the elaborate operating menus or for image changes. Despite a high image resolution of 800 x 480 pixels, the entire display contents are built up smoothly without any annoying jitter or freeze; even animated presentations, such as the softly rotating compass rose, look completely natural. There is also ample memory available to accommodate the many color graphics, texts and fonts: 16 MB of flash ROM – which can be easily upgraded by the factor of 4 for later extensions. With these core features, the instrument cluster in the new Touareg reliably provides clear-cut, high-quality presentations of the different display scenarios.

Quick data exchange
In addition to the classic CAN bus system, there is also a LIN interface available for communication with the vehicle network; this interface simplifies the wiring of the sensors and actuators as well as the optical MOST connection used for quick data exchange with the infotainment system and for the graphics display as well: radio station lists, telephone contacts and MP3 titles can thus also be displayed in the instrument cluster, making it possible to select individual entries – just one example of the convincing, intuitive menu-prompted system operation.

Quick data exchange under real-time conditions requires complex, powerful software. In addition to Autosar-compatible components (Automotive Open System Architecture) and such standard functions as network management or diagnosis, the system also includes priority-controlled warning and information messages, such as “Please fasten your seatbelt”, which are always emitted at just the right moment, and even acoustically, if necessary. From the development point of view, a database approach was chosen for the first time to allow changes virtually at the touch of a button during the development phase. With this kind of flexibility, the instrument cluster from Bosch also sets new standards in the premium vehicle class.

Many of the other systems and components used in the new Touareg are also the result of Bosch and Volkswagen joint projects: the hybrid drive with the integrated motor generator, for example, the inverter, which converts direct current into alternating current, the ECU and sensors. In addition, Bosch also delivers the airbag control unit, adaptive cruise control (ACC), the wiper drive, the starter and the front camera as well as a common rail fuel injection system for diesel engines.