Design team members: Aman Sikka, Roopkanwal Samra
Supervisor: Prof. David Wang
Background
With the advent of virtual reality technology, it is evident that the world of computers is attempting to imitate the real world. In our everyday lives, our haptic sense (sense of touch) is one of our primary sources of interaction with the environment. So, in order to have a complete imitation of reality, one would expect that a haptic interface would be necessary. A haptic interface is a device which allows a user to interact with a computer through tactile feedback. This feedback is achieved by applying a degree of opposing forces to the user using an actuated mechanism. Haptics devices find their use in the field of gaming, medical surgery and assistaive learning.
Project description
The scope of this project is to design a haptic device that has three degrees of navigational freedom. The goal is to build a compact form factor haptic device (preferably handheld) that will allow users to feel virtual objects with ease of navigation and manipulation in the virtual world. The system will comprise of two major units: a force feedback subsystem along with a navigational subsystem. The navigational subsystem will be used to navigate the virtual object. According the region where the avatar will make contact with the virtual object, the corresponding force will be fed back to the user via the force feedback subsystem. proSENSE® will be used to create the virtual objects and MATLAB will act as the interface between proSENSE® and the rest of the subsystems. Overall, the four main components of the system are motors, controller, navigation system and interfacing with proSENSE® and MATLAB software.
Design methodology
The major components of the project include software, the interface card, navigational system, an amplifier and a motor with an attached encoder. The torque supplied by the motor is a function of current input to the motor. Therefore, for highly stiff objects, high current needs to be supplied where as for soft objects, small amount of current is needed. This current supplied by the amplifier is a function of the input voltage. This voltage is controlled by the interface card which interfaces with the control algorithm implemented in MATLAB. The software continuously reads the torque being supplied by the motor and its position. It will then change its output based on the stiffness of the virtual object modelled in proSENSE®.