Learning Based Speed Control of Soft Robotic Fish

Author(s):  
Sunil Kumar Rajendran ◽  
Feitian Zhang

Bioinspired robotics takes advantage of biological systems in nature for morphology, action and perception to build advanced robots of compelling performance and wide application. This paper focuses on the design, modeling and control of a bioinspired robotic fish. The design utilizes a recently-developed artificial muscle named super coiled polymer for actuation and a soft material (silicone rubber) for building the robot body. The paper proposes a learning based speed control design approach for bioinspired robotic fish using model-free reinforcement learning. Based on a mathematically tractable dynamic model derived by approximating the robotic fish with a three-link robot, speed control simulation is conducted to demonstrate and validate the control design method. Exampled with a three-link reduced-order dynamic system, the proposed learning based control design approach is applicable to many and various complicated bioinspired robotic systems.

Author(s):  
JIAN-XIN XU ◽  
XUE-LEI NIU ◽  
QIN-YUAN REN

In this paper, the modeling and control design of a biomimetic robotic fish is presented. The Anguilliform robotic fish consists of N links and N - 1 joints, and the driving forces are the torques applied to the joints. Considering kinematic constraints, Lagrangian formulation is used to obtain the dynamics of the fish model. The computed torque control method is applied first, which can provide satisfactory tracking responses for fish joints. Since this robotic fish is essentially an underactuated system, the reference trajectories for the orientation of the N links are planned in such a way that, at a neighborhood of the equilibrium point, the tracking task of N angles can be achieved by using N - 1 joint torques. To deal with parameter uncertainties that exist in the actual environment, sliding mode control is adopted. Considering feasibility and complexity issues, a simplified sliding mode control algorithm is given. A four-link robotic fish is modeled and simulated, and the results validate the effectiveness of reference planning and the proposed controllers.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 517
Author(s):  
Dániel Fényes ◽  
Balázs Németh ◽  
Péter Gáspár

This paper presents a novel modeling method for the control design of autonomous vehicle systems. The goal of the method is to provide a control-oriented model in a predefined Linear Parameter Varying (LPV) structure. The scheduling variables of the LPV model through machine-learning-based methods using a big dataset are selected. Moreover, the LPV model parameters through an optimization algorithm are computed, with which accurate fitting on the dataset is achieved. The proposed method is illustrated on the nonlinear modeling of the lateral vehicle dynamics. The resulting LPV-based vehicle model is used for the control design of path following functionality of autonomous vehicles. The effectiveness of the modeling and control design methods through comprehensive simulation examples based on a high-fidelity simulation software are illustrated.


2020 ◽  
Vol 53 (2) ◽  
pp. 14028-14033
Author(s):  
Micha S. Obergfell ◽  
Steven X. Ding ◽  
Frank Wobbe ◽  
Christoph-Marian Goletz ◽  
Michael Folkers ◽  
...  

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