Haptic interactions have become increasingly important as an interface to computer-generated simulations in virtual-reality (VR) applications. Many haptic devices are designed to be used as a force feedback mouse, where the user's hand is in contact with the haptic device while the object contact and force generation occur on a computer screen. In this paper, we present an approach using a “virtual probe” to interact with the environment and introduce a new method to generate impedance-based haptic forces based on the use of a virtual manipulator. The virtual probe is connected directly to the haptic device and is projected from the hand to the environment, much like a scalpel or sword. As the probe comes in contact with the environment, the haptic device generates appropriate forces on the hand. We extend this approach to include underactuated haptic devices, which do not have fully powered joints. We show that the approach compensates for missing joint actuation in the underactuated haptic devices. We show experimental results for a simple case of haptic interaction; we also present an experimental implementation in six degrees of freedom (DOF) using one of the most popular devices: the PHANTOM.

Haptic interactions with computer generated simulations has become almost routine in Virtual Reality (VR) applications. While general interaction requires six degrees of freedom, some haptic devices are designed with fewer degrees of freedom, and so have problems representing general haptic contact. In this work, we present a new approach to the control of a general haptic device, and extend this approach to compensate for missing forces in under-actuated haptic devices. We present an experimental implementation using one of the most popular devices, the PHANTOMreg, and show experimental results for a simple case of haptic interaction.

Mechanical manipulators are commonly used in manufacturing applications to aid in the handling of large, bulky, or dangerous materials. Often these heavy lift assist devices are designed to lift a variety of payloads and are controlled by a human operator A recent trend has been to automate more of the function of the manipulator and collocate the human input with the payload. In this research, an existing heavy lift assist device is equipped with joint actuators and a force transducer to allow the operator to move the payload in a natural and intuitive manner. Intelligence is added to the assist device by inserting impedance fields in the workspace to affect the trajectory commanded by the operator. Repulsive fields are used to avoid obstacles and attractive fields are added to help the operator reach desired positions. Simulation results are compared to experimental results for the system under operation.

This paper explores using industrial robotics equipment in a haptic (or kinesthetic) force display system conceived for mechanism design applications. The dynamics and kinematics of an aircraft flight control column/wheel are simulated as a human interacts directly with the end effector of a commonly available robotic manipulator. An admittance control paradigm is used for developing a haptic system wherein realistic simulation of the dynamic interaction forces between a human user and the simulated virtual object or mechanism is required. Experimental results are presented which demonstrate human user interaction with the virtual mechanism.

Force feedback from the virtual world can greatly enhance the sense of immersion even for simple applications. The ISU force reflecting exoskeleton enables the user to interact dynamically with simulated environments by providing an electro-magnetic haptic interface between the human and the environment. This paper describes the force and trajectory control interface for the PUMA 560 manipulator that supports the ISU force reflecting exoskeleton hand tracking system. The combined exoskeleton-PUMA system allows the application of virtual forces to the digits of the human finger. Two different typical synthetic environments are programmed and tested using the ISU force reflecting exoskeleton haptic interface device. The experimental results shows that the magnetic interface gives adequate force levels for perception of virtual objects, enhancing the feeling of immersion in the virtual environment, and that the PUMA 560 provides adequate tracking and free motion capabilities for the ISU exoskeleton system.

Virtual manipulators are a new concept in the area of force feedback for virtual reality. This control approach does not make use of any specialized haptic display hardware but instead is formulated for implementation with any general industrial robot that allows six degree of freedom motion. Using this approach many commonly available manipulators can be used as an interface device to a virtual environment. This work extends the virtual manipulator concept, to allow haptic interaction with more complex virtual objects. The time varying virtual manipulator developed here constrains the end effector of a robot to trace along a NURBS surface. This virtual mechanism provides interaction forces consistent with the sensation of contacting the surface. These interaction forces can be coupled with a graphical display to provide a more complete feeling of immersion.