IEC TR 63344-2021 Conceptual model of standardization for haptic multimedia systems.
4.4 Purposes of haptic feedback In general, the purposes of haptic feedback are classified into Reproduction, Notification, and Guidance as follows. Haptic reproduction is creating realistic haptic sensation in VR and tele-manipulation, targeting a real sensation. Producing the touch feel of a commercial product for Internet shopping is an example of Reproduction. In a tele-manipulation system, reproduced stimulation enables the user to handle the remote object as if touching it directly. In a communication system, users can feel the remote partner with the reproduced haptic sensation. Many applications such as computer games, sports broadcasting, and cinemas potentially need haptic reproduction. Haptic notification is sending necessary information to users by haptic channel. A vibration from a mobile phone is a familiar example of notification. In an automobile, the driver can receive haptic signals from the seat and foot pedal to be alerted to the abnormal situation of the car, change of the road condition, and danger approaching the car. In addition to these passive cases, it is also useful in active motions. For example, a click felt by a finger notifies the completion of input action. Periodic resistance in a dial notifies the quantity that the user is controlling. These sensations facilitate the operations. Haptic guidance is leading a user or the parts of the body to a desirable state regarding the position, direction, velocity or posture sometimes synchronized with a specific task. Haptic stimulation can inform a pedestrian of the direction to the destination. Stimulation on a steering wheel can indicate the direction suggested by the navigation system. Vibrations given on the limbs teach which limb to move at what timing. In addition to the motion guidance, haptic stimulation can induce relaxation and control the mental condition.
4.5 Reality class Consensus on the reality is a crucial premise for practical use of haptics technologies. Users and developers need to share the reality class supposed in each application as:
• Class 1 : physically faithful stimulation to real experience;
• Class 2: physically different but indistinguishable from real experience;
• Class 3: distinguishable but useful. For example, a dot of an HD display produces Class 2 reality since it creates a faithful colour but a different spectrum from the real one. Lossy audio compression also ensures the reproduced sound satisfies the Class 2 reality. In haptics, the major applications would belong to Class 3 while Class 2 reality is achieved in only limited applications. A standard is necessary to define the reality class before sharing the haptic information. Such a standard also facilitates the technological advancement. Subclasses would follow after Class 3.
4.6 Interaction modality In general, haptic sensation is formed by multiple sensory perceptions. Haptic feeling is strongly affected by visual and auditory information and the context. Even within haptic modality, force perception is created by combining almost independent perception channels: cutaneous perception, and proprioception, including kinesthetics. In many haptic feedback systems, the haptic experiences are created by integrating these fragmented stimulations given to a part of the body. Therefore, it is useful to standardize the adequate modalities to achieve the desired haptic effects and ensure the compatibilities among different sets of modalities.IEC TR 63344 pdf download.