Simulation of Actuated Continuum Surfaces Undergoing Large Deformations Using Lumped-Mass Techniques

Large deformation continuum surfaces (LDCS) are progressively used across a wide range of engineering fields for improved performance and design flexibility. Potential applications range from deformable aerofoils in aerospace to healthcare soft actuation systems to support patients with motion disabilities. To achieve optimal usage of LDCS in such applications it is desired to control on-demand actuation of the surfaces in any desired profile of multiple, 3D curvature capable actuation elements (Figure 1). To date LDCS have largely operated in ‘open loop’ with the placement and control of actuation elements based mainly on user intuition and experience with limited work attempting to provide models for such actuated continuum surfaces. This results in largely ‘trial and error’ based methods in their design and control that increases production costs and reduces performance. To remove this problem an adaptive and efficient dynamic model needs to be developed to readily characterize exact positions and interactive forces applied by actuators and external force elements. This will enable surfaces to be accurately simulated and the resulting model made available for model based control methods. Previously Merino et al [1] presented an innovative mathematical approach by imagining the surface to be made up of an infinite number of interpolated curves parallel to the actuator. However, this represents only the kinematics of the surface and lacks inclusion of several factors such as material properties, a key characteristic that must be included to ensure accurate results.