1 MAGISTER-P: A 6 URS Parallel Haptic Device with Open Control Architecture J. M. Sabater Miguel Hernández University Elche, Alicante (Spain)

2 Introduction  Definitions:  Haptic Display:  Haptic Display: A device configured to provide haptic information to a human is called a haptic display.  Impedance Display.-  Impedance Display.- A mechanical device which is configured to render a commanded force while providing a measurement of its position and/or velocity.  Admittance Display.-  Admittance Display.- A device configured to track a commanded position or velocity while providing a measurement of force is called an admittance display.  Parallel Platform:  6 URS Parallel-Platform:  6 URS Parallel-Platform: Parallel platform whose kinematics chains are composed by a Universal joint, an articulated parallelogram with a Rotational driven joint, and a Spherical joint.

3 Parallel Platforms as haptic devices  Advantages:  Low Inertia  High stiffness  Low friction  Gravitationnal counterbalancing  High ratio load/power  work as admittance  Easy construction  Disadvantages:  Small workspace  Difficult control  Numerical dinamic model  Difficult real-time implementation transparency

4 Features: 6 dof with large workspace. Low friction and sensed inertia. Open control architecture with C-interface Cable transmission without gears. Transmission rate= 13 High bandwidth Work Modes. As Impedance Display As Admittance Display Aluminium structure with low weight. Hardware architecture Pc controlled multi-axis board DC motors

5 Theoretical Frame for kinematics algorithms Geometrical Model Multibody Theory: Constraint Vector

6 Inverse Kinematics  Geometrical Solution:  Geometrical Solution: The movement of the device is defined by the time variation of C angle between the even and odd links.   A reference system must be assigned to each link. Auxiliar reference system: Geometrical Model

7 Inverse Kinematics (ii) Even links reference system: Odd links reference system: are obtained by a rotation ofaround vector are obtained rotatingthe vectoraround

8 Forward Kinematics  Multibody theory:  Constraint vector of a 6 URS parallel platform  Newton-Raphson method

9 Simulations of an Impedance Display

10 MAGISTER-P: Control Modes  Open loop:  Position loop:

11 Force - Position experiment

12 THANKS FOR YOUR ATTENTION