Modeling a Hyperflexible Planar Bending Actuator as an Inextensible Euler–Bernoulli Beam for Use in Flexible Robots

We present a fast and simple predictive shape model for a hyperflexible actuator, capable of bending 180°. The quasistatic model is based on the Euler–Bernoulli beam model, with a simple modification introduced to include material hysteresis, improving the performance significantly, by up to ∼15% reduction in positional error. We used the Bi-Bellows actuator and report prediction errors in three different scenarios. The model is implemented with an iterative solver able to run at 140Hz, while the Bi-Bellows has a typical frequency of ∼2Hz.