A haptic interface enables human-computer interactions through body movements and sensations. Since users aren’t directly working with haptic devices, it allows personnel to work with dangerous or delicate materials in a safe, controlled way.
“With the development of human-robot interaction technologies, haptic interfaces are widely used for 3D applications to provide the sense of touch,” says Zeng-Guang Hou, professor at the State Key Laboratory of Management and Control for Complex Systems. “These interfaces have been utilized in medical simulation, virtual assembly, and remote manipulation tasks. However, haptic interface design and control are still critical problems to reproduce the highly sensitive touch sense of humans.”
Scientists from the Chinese Academy of Sciences have expanded the haptic interface, increasing its common three degrees of freedom to a total of seven.
Hou and his team based their design on a modified delta mechanism, which features a static base platform. Three identical chains connect the static base platform to a moving platform. As a result, the entire mechanism can easily move each chain in different directions.
“The main advantage of this architecture is its low inertia, the critical element of haptic device design, because its actuators can be mounted on the fixed platform,” says Hou. “In addition, a mechanical wrist can be added to the moving platform to realize the rotational degrees of freedom.”
In order to sense movement, the researchers developed a controller that displays the amount of force needed by the operator. The interface sustains equilibrium by a supporting algorithm.
The team believes an interface with expanded freedom can lead to true haptic interaction, including smartphone touch sense, assisted surgery, and teleoperation applications.
To learn more, read the article, “Development and evaluation of a 7-DOF haptic interface,” published in IEEE/CAA Journal of Automatica Sinica