Soft robots undergo large nonlinear spatial deformations due to both inherent actuation and external loading. The physics underlying these is complex, often requires intricate analytical numerical models. complexity of models may render traditional model-based control difficult unsuitable. Model-free methods offer an alternative for analyzing the behavior such complex systems without need elaborate modeling techniques. In this paper, we present a model-free approach open loop position soft...

Complex controlled motions, soft human interaction, and minimal moving mass all drive the need for robots using fluid filled fiber reinforced elastomer enclosures (FREEs). While a narrow class of FREEs known as McKibben's actuators have been extensively studied, there is wide unexplored with complex sets motion patterns. Combining these in parallel can yield versatile patterns resulting large overall workspace. Mobility individual enforced by inextensibility fibers incompressibility fluids,...

Fluid filled fiber reinforced elastomeric enclosures (FREEs) have been a popular choice for actuators in prosthetics and soft robots owing to their high power density cost effective manufacturing. While narrow class of FREEs known as McKibben's extensively studied, there is wide unexplored that could be potentially used structural members. This paper analyzes the mobility generalized based on simple geometric relationships result from inextensibility fibers fluidic actuation. The analysis...

The shortage of qualified human labor is a key challenge facing farmers, limiting profit margins and preventing the adoption sustainable diversified agroecosystems, such as agroforestry. New technologies in robotics could offer solution to limitations. Advances soft arms manipulators can enable agricultural robots that have better reach dexterity around plants than traditional equipped with hard industrial robotic arms. Soft be far less expensive manufacture significantly lighter their...

Soft Continuum Arms (SCAs) are challenging to control due their highly nonlinear characteristics and sensitivity external loading. Recent efforts address the problem using machine learning techniques limited simple SCA architectures. In this paper, we train a model-free reinforcement policy based on Deep Deterministic Policy Gradient (DDPG) for end effector path tracking BR <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> SCA. Unlike...

There are a number of instances in nature where long and slender objects grasped by continuum arm spirally twirling around the object, thereby increasing area contact stability between gripper object. This paper investigates design modeling spiral grippers using pneumatic fiber-reinforced actuators. The proposes two reduced order models, pure helical model, spatial Cosserat rod model to capture deformed behavior mechanics actuators presence self-weight. While former can yield closed form...

Fiber-reinforced soft pneumatic actuators can generate a wide variety of deformation behavior, making them popular in the field robotics. Designing an actuator to meet specified deformed shape is important step toward design robots. We present two-step methodology that matches given planar curve on pressurization. In first step, divided into series constant curvature (CC) segments best approximate its shape. The second involves designing bending by determining fiber orientations for each CC...

Abstract We present a dynamic position and orientation controller for hybrid rigid-soft manipulator arm where the soft is extruded from two degrees-of-freedom rigid link. Our approach involves learning dynamics of operating at 4 Hz leveraging it to generate optimal trajectories that serve as expert data learn control policy. performed an extensive evaluation policy on physical capable jointly controlling actuation. show with single policy, reaching arbitrary poses in workspace 3.73 cm...

Fiber reinforced elastomeric enclosures (FREEs) are soft and smart pneumatic actuators that deform in a predetermined fashion upon inflation. This paper analyzes the deformation behavior of FREEs by formulating simple calculus variations problem involves constrained maximization enclosed volume. The model accurately captures deformed shape for with any general fiber angle orientation, its relation actuation pressure, material properties applied load. First, accuracy is verified existing...

Due to labor shortages in specialty crop industries, a need for robotic automation increase agricultural efficiency and productivity has arisen. Previous manipulation systems perform well harvesting uncluttered structured environments. High tunnel environments are more compact cluttered nature, requiring rethinking of the large form factor grippers. We propose novel codesigned framework incorporating global detection camera local eye-in-hand that demonstrates precise localization small...

Displacement-amplifying compliant mechanisms (DaCMs) reported in literature are widely used for actuator applications. This paper considers them sensor applications that rely on displacement measurement, and proposes methods to evaluate design such mechanisms. The motivation of this work is increase the sensitivity a micromachined capacitive accelerometer minute mechanical force using DaCMs. A lumped spring-mass-lever (SML) model, which effectively captures effects appending DaCM sensor,...

In this paper, we implement a characterization based on eigentwists and eigenwrenches for the synthesis of compliant mechanism at given point. For 2D mechanisms, involves characterizing compliance matrix unique point called center elasticity, where translational rotational compliances are decoupled. Furthermore, may be represented graphically as an ellipse coupling between components vectors. These representations facilitate geometric insight into operations serial parallel concatenations....

Abstract Soft continuum arms (SCAs) have a large workspace, dexterity, and adaptability, but at the cost of complex design construction highlighted by concatenating several serial segments. In this paper, we propose new architecture for SCAs composed parallel combination pneumatic actuators. The BR2 SCA featured in work is asymmetric as it combines one soft bending (B) actuator two rotating (R2) actuators opposed to state art symmetric architectures that adopt Spatial deformation obtained...

In this paper, we introduce a new type of spatial parallel robot that is comprised soft inflatable constraints called trichamber actuators (TCAs). We extend the principles freedom and constraint topologies (FACT) synthesis approach to enable analysis robot. The concepts passive active spaces are introduced applied design general systems consist (i.e., can be actuated impart various loads onto system's stage) both drive desired motions guide degrees (DOFs). provide fabrication details TCA in...

Fiber reinforced elastomeric enclosures (FREEs) are soft pneumatic actuators that can contract and generate forces upon pressurization. Typical engineering applications utilize FREEs in their straight cylindrical configuration derive actuation displacement from ends. However, there several instances nature, such as an elephant trunk, snakes grapevine tendrils, where a spiral of muscle systems is used for gripping, thereby establishing mechanical connection with uniform force distribution....

This paper presents the design and testing of a bio-inspired soft pneumatic robot that can achieve locomotion along outside cylinder. The uses actuators called FREEs (Fiber Reinforced Elastomeric Enclosure), which have wide range deformation behavior upon pressurization. being compliant grasp move cylinders varying dimensions. Two different types are used in namely (a) extending (b) bending FREEs. These arranged such way to grip pipe while generate forward motion as well for direction...

For soft continuum arms, visual servoing is a popular control strategy that relies on feedback to close the loop. However, robust challenging as it requires reliable feature extraction from image, accurate models and sensors perceive shape of arm, both which can be hard implement in robot. This letter circumvents these challenges by presenting deep neural network-based method perform smooth 3D positioning tasks arm using camera mounted at distal end arm. A convolutional network trained...

Purpose Pressure ulcers (PUs) are prevalent among immobile bed or wheelchair-reliant individuals who experience prolonged sedentary positions. relief and frequent repositioning of body posture help to mitigate complications associated with PUs. Adherence regular is difficult maintain due nursing labour shortages constraints in-home caregivers. Manual repositioning, transferring, lifting patients physically demanding tasks for This review aimed explore categorize these devices, discuss the...