Session: 07-03-02: Design and Control of Robots, Mechanisms and Structures

Paper Number: 95054

95054 - In-House Built Robust and Adaptable System Architecture for Virtual Reality Haptic Interface 

This work presents an in-house developed adaptable system architecture for controlling the robotic
motion and supply power to a full-body scale virtual reality (VR) haptic interface. The VR haptic interface maps the human pilot motion into a virtual avatar, and applies force feedback that results in a high-fidelity sensory of live interaction. The full-body haptic interface is named ForceBot, which utilizes a pair of VR haptic gloves (Make: HaptX), a pair of 7-DoF PANDA robotic arms (Make: Franka Emika), and a pair of in-house built planar gantry robots, which provide the haptic sensory feedback on the human pilot’s hands, arms, and foot respectively. ForceBot applies haptic feedback on hands through a pair of pneumatically actuated wearable VR haptic gloves which creates an artificial sense of touch in user's hands. The robotic arms and the gantry systems are connected to the user's arms and feet by mounting on a base frame alongside the human pilot. With the ability to create force feedback at both the arms and the feet, the user will experience forces for locomotion as well as finer interactions by allowing 6-DoF on each arm, 3-DoF on each foot of the user. Thus, the system simulates a virtual environment and generates the required motions at the arms and feet to simulate the user experience of interacting with the VR environment. Overall, the combination of these sub-systems in the ForceBot creates a full-body scale high-fidelity sensory feedback, by deploying a force sensor on each contact point measuring the interaction forces between the human pilot and the robot. The measured forces are used to synchronize the robot's motion with the human by allowing a transparent experience during movement and governing desired interaction forces. Therefore, high power actuator and low-latency computer communication are desired in haptic interface applications, since both contribute to the physical system delay that influences the immersive experience.

Hence, the primary motive of this work is to design and develop an in-house expandable and flexible system architecture that will be low-cost and easily adaptable for the ForceBot and its applications. The whole system architecture consists of mainly three units: a central computer, a VR rendering computer, and a motor control unit. The central computer is responsible for control and operate the system in a real-time capable IHMC open-source robotic software and expanded to manage communications with all the robotic sub-systems in ForceBot via Ethernet-based communication. This computer also serves as high-level controller coordinates between the robotic systems, sensors, and virtual environment information to generate commands for robotic sub-systems. The VR rendering computer forms the VR world, characterizes the virtual avatar with the mapped user information, and specifies virtual environment boundaries for the central computer to calculate the interaction forces. Finally, a motor control unit built with commercially available components has been developed, it consists of motor drives, a wireless emergency-stop mechanism, and electrical safety components. This in-house developed motor control unit ensures the motor behavior with the safety and efficiency for distributing the sheer amount of electrical power required for the gait simulator to provide support and generate rapid motion. The developed robust and adaptable system architecture can be efficiently implemented to other haptic interface platforms. This will be helpful for the designers and researchers to further study the control and interaction between the robotic motion and the human pilot under VR
environments.

Keywords: Virtual Reality, Haptic Interface, Motor Control Unit, System Architecture, Sensory Feedback

Presenting Author: An-Chi He Virginia Polytechnic Institute and State University

Presenting Author Biography: An-Chi finished his master's degree at the University of Illinois in Chicago with the primary focus of building a portable foot orthoses actuator. To pursue his further research, An-Chi joined TREC lab as a Ph.D. student in Mechanical Engineering. His current project is the Force-Bot which serves as a full-body haptic interface device by utilizing technologies such as VR and robot manipulation, which create the experiences of live interaction between the user and the VR world. His research interest broadly focuses on the haptic interface, virtual reality, exoskeleton, assistive devices, and robotic control.

Authors:

An-Chi He Virginia Polytechnic Institute and State University
Connor Herron Virginia Polytechnic Institute and State University
Bhaben Kalita Virginia Polytechnic Institute and State University
Alexander Leonessa Virginia Polytechnic Institute and State University