Investigation of force analysis Stewart platform actuated by Shape Memory Alloy (SMA)

The design and the manufacture of a 2–dof (degree of freedom) Stewart platform with diameter 150 mm and 300 mm with actuated by Shape Memory Alloy (SMA) is presented. This Stewart platform has a comparable structure with a stationary plate and a moving plate. The plate is connected with 6 shape memory alloy and a mechanical coil in the center. SMAs are the smart materials for the actuators which has the capability to restrict the freedom of movement when external forces are applied. Possible application was ankle/foot rehabilitation exercise for Continuous Passive Motion (CPM). Static equilibrium plays a very important role in mechanical engineering, precisely in static equilibrium towards quantitative description of loads. The paper explains the kinematic model of the Stewart platform and static deflection calculation were conducted and tested. The 150 mm base diameter Stewart platform triggered by 0.508 mm diameter SMA is found to be best suited for creating significant deflection of a platform for ankle and foot. Validation through experimental and theoretical results has proven its feasibility and design.