Novel Design and Position Control Strategy of a Soft Robot Arm

Abstract

This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their performances. The contraction and extension behaviour have been illustrated with single contractor actuators and single extensor actuators, respectively. The tensile force for the contractor actuator and the compressive force for the extensor PMA are thoroughly explained and compared. Furthermore, the bending behaviour has been explained for a single extensor PMA, multi extensor actuators and multi contractor actuators. A two-section continuum arm has been implemented from both types of actuators to achieve multiple operations. Then, a novel construction is proposed to achieve efficient bending behaviour of a single contraction PMA. This novel design of a bending-actuator has been used to modify the presented continuum arm. Two different position control strategies are presented, arising from the results of the modified soft robot arm experiment. A cascaded position control is applied to control the position of the end effector of the soft arm at no load by efficiently controlling the pressure of all the actuators in the continuum arm. A new algorithm is then proposed by distributing the x, y and z-axis to the actuators and applying an effective closed-loop position control to the proposed arm at different load conditions.

A Hybrid Jamming Structure Combining Granules and a Chain Structure for Robotic Applications

“…One of the challenges in soft robotics is that the soft robotic arms may not maintain their weight, since the soft-bodied system that has excessive softness and variable stiffness with limited operating radius has hardly been developed due to the limited stiffness tunable structure. 14,[30][31][32] The multilink hybrid jamming structure was demonstrated as a robotic arm for pickand-place task (Supplementary Video S5), as shown in Figure 10. A previously developed soft pneumatic gripper was assembled for the pick-and-place task.…”

Continuum Robots for Manipulation Applications: A Survey

“…e material of choice for bioinspired continuum robots is polyamide-a polymerized molecular chain made of nylon braided blend or carbon amalgamation (e.g., borax and vinyl alcohol) whose strength, elasticity, and flexibility can be customized per the application. Other materials used in construction of continuum robots are [192][193][194][195][196][197][198][199][200][201][202][203][204][205][206][207] Produced using weaving and knitting methodology.…”

Self-Sensing Pneumatic Artificial Muscle with Unilateral Expansion and High Contraction Ratio for Wearable Robotics

“…With the continuous innovation and improvement of researchers, there are more and more kinds of pneumatic artificial muscles, including braided type [8], [9], wrinkled type [10]- [13] and curved type [14]- [17]. These pneumatic arti ficial muscles were optimized in weaving methods and fabrication materials, which improve the contraction performance of artificial muscles.…”