Modelling the Soft Robot Kyma Based on Real‐Time Finite Element Method

Abstract

Modelling soft robots is a non‐trivial task since their behaviours rely on their morphology, materials and surrounding elements. These robots are very useful to safely interact with their environment and because of their inherent flexibility and adaptability skills. However, they are usually very hard to model because of their intrinsic non‐linearities. This fact presents a unique challenge in the computer graphics and simulation scopes. Current trends in these fields tend to narrow the gap between virtual and real environments. This work will explain a challenging modelling process for a cable‐driven soft robot called Kyma. For this purpose, the real‐time Finite Element Method (FEM) is applied using the Simulation Open Framework Architecture. And two methods are implemented and compared to optimize the model efficiency: a heuristic one and the Model Order Reduction. Both models are also validated with the real robot using a precise motion tracking system. Moreover, an analysis of robot–object interactions is proposed to test the compliance of the presented soft manipulator. As a result, the real‐time FEM emerges as a good solution to accurately and efficiently model the presented robot while also allowing to study the interactions with its environment.

Priori Justification in Engineering Innovations: Using Computer Simulation Results without Validation to Accelerate Engineering Innovations and Discovery

“…It involves developing and applying algorithms, software, and simulations, often with high-performance computing, to translate mathematical and physical descriptions of engineering problems into computer languages. Computational engineering is increasingly important in various fields of academics and industries, such as materials [1][2][3][4][5][6][7][8][9], manufacturing [10][11][12][13][14][15][16][17][18][19], aerospace [20][21][22][23][24], healthcare [25][26][27][28][29][30], robotics [31][32][33][34], etc. Obviously, there is a long list of published computer simulation results showing the importance of computational engineering.…”

Model-Free Control of a Soft Pneumatic Segment

“…Although there are many successful examples of soft robot modelling and simulation using this technique [ 56 , 57 , 58 ], with errors near 5 , its large computational cost often makes its use in real-time closed control loops unfeasible. It is necessary, if acceptable simulation times are to be achieved, to use reduced-order models, such as done in [ 59 , 60 , 61 ].…”

The design and kinematic representation of a soft robot in a simulation environment

“…Various modeling methods for soft robots have been developed. Among these, Piecewise Constant Curvature (PCC) [8][9][10][11], continuum Cosserat [12][13][14], and finite element method (FEM) [15][16][17] techniques are the ones that are most frequently used. The PCC approach simplifies and represents the soft-robotic arm model as a finite set of mutually tangent constant curvature arcs defined by three parameters: arc length ( ), angle through which the arc bends (θ ), and angle of the plane containing the arc (φ) [18].…”

“…Although this method yields highly accurate results, the obtained equations to manipulate the soft robot are computationally expensive and more challenging from the control point of view [19]. The FEM modeling approach is the most accurate and computationally expensive one of these three modeling approaches [15, 17, 20]. Furthermore, the preprocessing stage of FEM, which is necessary for modeling, is more extensive and time-consuming compared to the other two methods, thereby also increasing the required human effort.…”