An advanced haptic system for improving man-machine interfaces

The continuing emergence of virtual reality (VR) for training, industrial and entertainment applications increases the need for highly capable haptic interfaces into these VR environments. For certain subsets of tasks in these application areas, existing methods for interfacing haptic devices to VR applications suffice. However, for operators performing manual control tasks, many of the pre-existing methods lack key capabilities that allow them to be employed for a variety of application areas with a variety of haptic input devices. The paper describes a newly develop method that overcomes these short-comings by integrating the core technologies of force feedback, reality registration and virtual fixtures to achieve significant operator performance improvements. Introduction A key area in which man-machine interfaces can be improved is the area of haptics. Haptics means “relating to the sense of touch.” A haptic display is a device that allows the user to manipulate virtual environments through his sense of touch. The addition of the sense of touch to the man-machine interface adds a new, high-bandwidth modality of interaction compared to applications that may only provide sight and sound interaction [10]. Haptic interaction is made possible using force feedback hardware and software. Many force feedback devices have been developed in recent years, including but not limited to [2,7,8,11,12]. One important application area in which haptic devices can provide significant performance improvement is the area of remote device manipulation [4]. In a manner similar to using tools and fixtures, such as Bezier curves and straight edges as guides for drawing lines in a real world; virtual tools and fixtures can be used to help guide mechanical devices in a virtual workplace. A virtual fixture is a computer generated perceptual overlay on a virtual representation of a real device. Virtual fixtures help guide manual operations by providing haptic feedback, which has been proven to reduce mental workload and increase precision [13]. When performing tasks that involve hand/eye coordination with a system that provides visual feedback only, a very high level of mental concentration is needed. By introducing the modality of touch into such tasks, the level of mental concentration needed is greatly reduced. With the addition of still another modality, such as aural, the work task becomes even more easier to successfully accomplish. The virtual fixture provides overlaid sensory information which can be perceived visually, haptically and aurally by the user.