Soft robotic grippers with compliance have great superiority in grabbing objects irregular shape or fragility compared traditional rigid grippers. The main limitations of such systems are small grasping force resulted from properties soft actuators and lacking variable stiffness grippers, which prevent them a larger wide range applications. This article proposes shape-memory alloy (SMA)-based gripper composed three fingers for compliantly at low holding robustly high stiffness. Each finger...

Abstract This paper proposes a data-driven sliding mode control (SMC) method with tracking error constraint for shape memory alloy (SMA) actuated system. More specifically, new SMC prescribed performance is investigated by adopting the equivalent dynamic linearization technique and novel transformed algorithm to guarantee that can converge into preassigned region. Meanwhile, proposed effectively ensure convergence rate steady-state within bound, merely depending on input/output data without...

Purpose This study discusses the tracking trajectory issue of exoskeleton under bounded disturbance and designs an useful control method to solve it. By using proposed method, error can be successfully convergence assigned boundary. Meanwhile, chattering effect caused by actuators is already reduced, performance pneumatic artificial muscles (PAMs) elbow improved effectively. Design/methodology/approach A prescribed sliding mode was developed in this fulfill joint position task on driven two...

Manual lifting tasks involve repetitive raising, holding and stacking movements with heavy objects. These arm are notable risk factors for muscle pain, fatigue, musculoskeletal disorders in workers. An upper-limb wearable robot, as a 6-DOF dual-arm exoskeleton, which was designed to augment workers’ strength minimize muscular activation the during tasks. To adjust robot joint trajectory, user needs apply an interactive torque operate when standard virtual mechanical impedance control...

Humanoid robotic hand actuated by shape memory alloy (SMA) represents a new emerging technology. SMA has wide range of potential applications in many different fields, ranging from industrial assembly to biomedicine applications, due the characteristic high power-to-weight ratio, low driving voltages and noiselessness. However, nonlinearities complex dynamic models SMA-based hands result difficulties controlling. In this paper, humanoid composed five fingers is presented with ability...

In this study, a model-free adaptive sliding mode control method was developed in combination with the prescribed performance method. On basis, study attempted to fulfill joint position tracking trajectory task for one-degree of freedom (DOF) upper-limb exoskeleton passive robot-assisted rehabilitation. The proposed is capable addressing defect initial error controller design and application by adopting tuning function, as compared other methods. Moreover, here not determined dynamic model...

In this paper, a novel data-driven model-free adaptive fractional-order sliding mode controller with prescribed performance is proposed for the shape memory alloy (SMA) actuator. Due to strong asymmetric saturated hysteresis nonlinear characteristics of SMA actuators, it not easy establish an accurate model and develop effective controller. Therefore, we present without using actuators. other words, depends merely on input/output (I/O) data To obtain reasonable compensation hysteresis,...

The upper-limb exoskeleton is capable of enhancing human arm strength beyond normal levels, whereas deriving the operator’s desired action straightforward turns out to be one significant difficulties facing human-robot interaction research. In study, interface was presented regulate tracking elbow motion trajectory that employed contact force signals between and its operator as primary means information transportation. were recorded by adopting novel soft skin sensors attached bracket on...

In this study, a fuzzy adaptive impedance control method integrating the backstepping for PAM elbow exoskeleton was developed to facilitate robot-assisted rehabilitation tasks. The proposed uses logic adjust parameters, thereby optimizing user adaptability and reducing interactive torque, which are major limitations of traditional methods. Furthermore, repetitive learning algorithm an strategy were incorporated improve performance position accuracy, addressing time-varying uncertainties...

In order to explore the value of traditional industrial robots, a solution was discussed upgrade 5R series joint robot into desktop lightweight game by transforming some components. Based on dynamic analysis, forward kinematics equations and inverse were solved using method double quaternion method. mechanical static equilibrium equation kinematic system obtained. As result, can complete basic functions game. However, an universal significance analysis be obtained from article.

Passive training was of importance to stroke patients. Exoskeleton robot could effectively assist patients complete the task. However, often suffered from convulsions and other interference factors in tasks these uncertainties would decrease tracking accuracy position controller. Therefore, a sliding mode anti-interference controller designed this paper increase for spastic phase passive on upper-limbs. The method verified by simulation experiments. Some results had practical significance...

Providing effective physical human-robot interactive control is one of the most important considerations in designing an exoskeleton robot. The purpose study to develop a variable impedance method for providing reliable approach different users operate by using torque and spring-damper model. proposed based on model-based reinforcement learning structure model predictive frame, designed neural network dynamic replace state-action value function linear estimate fit action generated from...