All-new Austral: a meaningful touch

In the ‘Laboratories’’ building located at the Guyancourt Technocentre, a small room is home to the future interiors of Renault vehicles. In this room, dozens of fabric and parts samples are placed on the table, waiting for assessment. From hard to soft, sticky to dry, soft or rough, materials are classified according to twelve criteria using a device created by Renault in 2004, the Sensotact. It was a factor in choosing the material to replace the leather on All-new Austral steering wheel, as well as the those used for the seats, dashboard, and armrests.

Sensotact: senses and scientific precision

Working on how a car feels is an essential part of its perceived quality. The driver-vehicle relationship is very tactile by nature. Everything is controlled mainly with one’s hands and fingers. Physical contact must therefore remain pleasant to enhance the perfect driving experience. Each part that the driver touches, such as the steering wheel, dashboard, gear stick, armrest, or door rim, is assessed by testers using Renault's Sensotact sensory tool to ensure that they are up to specifications. Sensotact was designed to assess the parts for which tactile criteria feature in the vehicle’s technical specs. Since its inception, customer surveys have been used to constantly improve and refine the tool kit.

It combines human senses and scientific precision to obtain the most accurate results. Presented in the form of a briefcase, the Sensotact contains 12 ‘descriptors’ that correspond to a simple feeling, such as hardness, memory effect, slippery, and so on. Each descriptor is composed of control samples graded from 0 to 100, in 25-point increments. By comparing materials that will be used in future vehicles to the Sensotact control samples, testers can evaluate specific criteria for each part in an unbiased and precise manner.

“When defining criteria for part specifications, we used customer surveys to determine a hedonic value: “I like” or “I don’t like”. As such, we can then use the Sensotact and panellists in the lab to assess whether parts are in line with the specifications,” explains Carla.

While some simple descriptors have objective criteria, such as hardness and the memory effect, other descriptors such as the hand-slip on the steering wheel require testing by a panel of people to assess what it will feel like for the end customer when driving.

The way something feels can be altered by an array of factors, like whether the person's hands are freshly washed or a hormonal change, yet the test results will remain reliable as they are compared against the Sensotact reference set. Values are always identical, meaning that it is possible to calculate an average, standard deviation, and final statistics to determine a value for the part's intrinsic tactile value.

"The touch test results when comparing the old leather and new plastic covered steering wheels were objectively identical and the customers reported being perfectly happy with the feel. It was reassuring to know we succeeded in finding an environmentally friendly to replace the previously used leather while still procuring the same sensations," adds Carla.

Other parts on the Austral were also put through tactile testing with 18 sessions held in the lab. Each session lasts between 15 to 20 minutes for each panellist.