INTRODUCTION

The UTP9060 series is a haptics test stand for combined vision tests, thermal imaging and force measurement, which has been developed in cooperation with Fraunhofer UMSICHT. The UTP9060 allows categorizing subjective impressions regarding surface, texture and shore hardness of a material. It connects objective measurement data and subjective perceptions regarding a material.

As a test person analyzes the material sample, which is attached to the test stand, physical measurement data is generated and recorded. At the same time, the personal evaluation by the test person is recorded. With a subsequent analysis it is possible to correlate measurement data with personal impressions for generating criteria for a suitable haptics design according to the personal impressions.

The test stand includes numerous systems for measuring physical qualities of the material and the behaviour of the test person, such as a measurement system for three-dimensional forces, a movement tracking system and a temperature analysis by means of infrared technology. All measurements are acquired and stored with reference to the particular test person and the device/material under test.

 

As the test person moves his finger all over the surface of the material, an infrared camera records the thermal image. All emerging forces are measured and recorded in order to estimate how far pressure can influence the subjective evaluation of a material. A video camera records the movement of the finger so that the motion speed can be calculated and included into calculations as well.

A moving dot can be projected onto the material’s surface for showing the route for the finger’s movement. This way, different test persons will take the same route on the material’s surface and different test cycles will be conducted identically.

A simple and intuitive GUI allows generating test profiles, which guide test persons and investigators reliably through the whole test sequence. A test profile can be based on two types of analysis:

Inquiry

The combination of subjective impressions, physical measurement data and movement profiles allows a detailed analysis of the haptic interaction. Complete and parallel recording of all data allows a comprehensive analysis of the material’s properties with regard to the impressions of the test person.

For the implementation of an intuitive GUI and for the recording of the measurement data, NI LabVIEW has been used. For a versatile analysis, all data is transferred to NI Diadem after recording. This tool offers the chance to analyse all data flexibly and to make various calculations with them.

The complete haptics test stand consists of:

  • IPC including touch panel
  • Project-specific NI data acquisitions and control cards
  • 3D Kistler force measurement unit
  • Thermal imaging camera by Flir
  • Projector for defining the movements
  • Firewire cameras for tracking the finger’s movement
  • Special structure of the NOFFZ UTP rack for an ergonomic stand-up workstation providing a touch panel for simple handling
  • NOFFZ UTP software framework including an integrated database for recording all data regarding test person an material under test

Advantages

  • Conversion of subjective, haptic impressions into physically measureable units
  • Combined vision test, thermography and force measurement
  • Intuitive GUI for simple generation of new test profiles
  • Recording of all measurement data and of the personal impressions of the test person
  • Identification of the correlation of subjective impressions, temperature of the material, the performed pressure and the speed of the movement

Conclusion

The UTP 9060 series is a modular haptics test stand for combined vision tests, thermography and force measurement. It allows generating a concatenation of measurement data and subjective impression of a test person.

The system records physical quantities such as pressure, temperature and speed of motions and combines them with the subjective impression of the test person so that it is possible to judge a material’s quality because of its haptics.

For evaluating a material’s properties even better, it is possible to upgrade the system by implementing additional measurement systems such as an acoustic measurement device.

Besides the subjective and physical evaluation of different kinds of material, the system can also be used for testing the manual control elements of automobile navigation or broadcast radio systems. In this case, the system analyses the required force for operating a switch or a wheel and the pressure point of each element. It is also possible to implement this tester as an automated, robotic system.