Thursday, August 13, 2009

Phantom devices in QUARC

QuaRC is expanding itself to support more third-party hardware every day to make it possible for its users to access a variety of hardware in their designs. As a step in this process, QUARC is going to support Phantom haptic devices. Phantom devices are categorized into 4 main types: Omni, Desktop, Premium A, and Premium 6 DOF. The first 3 types have 6 degreees of freedom sensing and 3 degrees of freedom actuation, and the Premium 6 DOF has 6 degrees of freedom sensing and actuation.

A block is going to be added to the QUARC library which is in charge of working with these devices. This block reads data from the device, and sends user commands to it. User can choose the type of inputs and outputs of the device from the block. For example, it is possible to read raw encoder values, position, or joint and gimbal angels of the device, so user can choose the most suitable format. The same flexibility is provided for the actuation commands, and they can be either force or torque for each joint separately, or the force and torque in Cartesian space.

Multiple devices can be controlled by a single model using a phantom block per device. Moreover, QUARC provides the option to limit the maximum velocity of the device's arm to ensure safty. User can choose to activate this option and change the maximum acceptable value for the velocity. Another safety feature is that the block saturates the force commands to the device based on its spec.

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