ABSTRACT
Measurement-based modeling is a technique for creating virtual environments based on real-world interactions. For the purpose of haptic rendering, measurement-based models are formed from data recorded during contact between an instrumented tool and a real environment. The created model can be a database of recorded responses to various haptic stimuli, an empirical input-output mapping, or a set of physics-based equations (Figure 21.1). In the database approach, recordings of a movement variable, such as position or force, are played back during haptic rendering, similar to audio recordings played on a stereo. Input-output models are created by fitting simple phenomenological models to the recorded data and tuning the haptic response as needed to provide the desired feel. Physics-based models are constructed from a fundamental understanding of the mechanical principles underlying the recorded haptic interaction; numerical values for the model’s physical parameters can be selected either by fitting the model’s response to the recorded data or by derivation from basic material properties. Prior work has used all three of these methods in various forms to create virtual environments that feel significantly more realistic than models that are designed and tuned without incorporation of real-world
measurements. The complete process of acquiring real-world data, building an appropriate model, and authentically rendering it through a haptic interface has been coined haptography [Kuchenbecker 06].
