Design and Analysis of a Compliant Gripper Integrated with Constant-Force and Static Balanced Mechanism for Micro Manipulation

2018 ◽  
Author(s):  
Duc-Chuong Nguyen ◽  
Thanh-Vu Phan ◽  
Huy-Tuan Pham
Keyword(s):  
Constant Force

The study for constant force characteristic of C-shaped superelastic SMA

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1253-1259
Author(s):  
Minghui Wang ◽  
Hongliu Yu
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Medical Device ◽  
Soft Tissues ◽  
Computational Simulation ◽  
Force Characteristic ◽  
Constant Force ◽  
Curve Shape ◽  
Artificial Sphincter ◽  
Round Bar

Clamping devices with constant force or pressure are desired in medical device, such as hemostatic forceps and the artificial sphincter, to prevent soft tissues from injures due to overloading. It is easily obtained by stretching an SMA wire. However, studies with SMA bending round bar have seldom been reported before. This paper studied constant force characteristic of C-shaped round bar with shape memory alloys. Optimization designs of the components were carried out with computational simulation. Numerical results show that the phenomenon of constant force strongly depends on contour curve shape and geometric dimensions of the C-shaped round bar of SMA component.

Design of a Single-Acting Constant-Force Actuator Based on Dielectric Elastomers

2008 ◽  
Author(s):  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Gabriele Vassura ◽  
Vincenzo Parenti Castelli
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compliant Mechanism ◽  
Structural Parameters ◽  
Dielectric Elastomer ◽  
Constant Force ◽  
Element Analysis ◽  
Body Model ◽  
Rigid Body Model ◽  
Supporting Frame

The interest in actuators based on dielectric elastomer films as a promising technology in robotic and mechatronic applications is increasing. The overall actuator performances are influenced by the design of both the active film and the film supporting frame. This paper presents a single-acting actuator which is capable of supplying a constant force over a given range of motion. The actuator is obtained by coupling a rectangular film of silicone dielectric elastomer with a monolithic frame designed to suitably modify the force generated by the dielectric elastomer film. The frame is a fully compliant mechanism whose main structural parameters are calculated using a pseudo-rigid-body model and then verified by finite element analysis. Simulations show promising performance of the proposed actuator.

scholarly journals An Improved PID Controller for the Compliant Constant-Force Actuator Based on BP Neural Network and Smith Predictor

2021 ◽  
Vol 11 (6) ◽  
pp. 2685
Author(s):  
Guojin Pei ◽  
Ming Yu ◽  
Yaohui Xu ◽  
Cui Ma ◽  
Houhu Lai ◽  
...  
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Pid Control ◽  
Pid Controller ◽  
Experimental Validation ◽  
Control Method ◽  
Smith Predictor ◽  
Constant Force ◽  
Matlab Simulation ◽  
Adjustment Time

A compliant constant-force actuator based on the cylinder is an important tool for the contact operation of robots. Due to the nonlinearity and time delay of the pneumatic system, the traditional proportional–integral–derivative (PID) method for constant force control does not work so well. In this paper, an improved PID control method combining a backpropagation (BP) neural network and the Smith predictor is proposed. Through MATLAB simulation and experimental validation, the results show that the proposed method can shorten the maximum overshoot and the adjustment time compared with traditional the PID method.

Synthesis of Single-Input and Multiple-Output Port Mechanisms with Springs for Specified Energy Absorption

1994 ◽  
Vol 116 (3) ◽  
pp. 937-943 ◽  
Author(s):  
J. G. Jenuwine ◽  
A. Midha
Keyword(s):  
Energy Absorption ◽  
Output Port ◽  
Constant Force ◽  
Plane Symmetry ◽  
Multiple Precision ◽  
Linear Spring ◽  
Single Input ◽  
Force Mechanism ◽  
Closure Method ◽  
Constant Force Mechanism

A means of synthesis of single-input and multiple-output port mechanisms for specified energy absorption is formulated for multiple precision points. The synthesis presented makes use of an extension of the loop closure method which includes expressions for energy absorption by linear spring elements. The configuration considered locates spring elements at two output ports of a multi-loop, planar mechanism. Economies realized for the symmetric mechanism are discussed for both one- and two-plane symmetry. Synthesis examples are included for both the general and symmetric mechanism. Special applications presented include synthesis of a constant force mechanism and synthesis of a mechanism suited to the energy absorption requirements of an automotive crashworthiness system.

Clinical Evaluation of a Constant Force Electronic Probe

1993 ◽  
Vol 64 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Marc Quirynen ◽  
Ann Callens ◽  
Daniel van Steenberghe ◽  
Marken Nys
Keyword(s):  
Clinical Evaluation ◽  
Constant Force ◽  
Electronic Probe

Extensional flows with viscous heating

2007 ◽  
Vol 571 ◽  
pp. 359-370 ◽  
Author(s):  
JONATHAN J. WYLIE ◽  
HUAXIONG HUANG
Keyword(s):  
Critical Value ◽  
The Other ◽  
Viscous Heating ◽  
Constant Force ◽  
Temperature Dependent ◽  
Downstream Location ◽  
Temperature Dependent Viscosity ◽  
Pulling Forces ◽  
Extensional Flows ◽  
Dependent Viscosity

In this paper we investigate the role played by viscous heating in extensional flows of viscous threads with temperature-dependent viscosity. We show that there exists an interesting interplay between the effects of viscous heating, which accelerates thinning, and inertia, which prevents pinch-off. We first consider steady drawing of a thread that is fed through a fixed aperture at given speed and pulled with a constant force at a fixed downstream location. For pulling forces above a critical value, we show that inertialess solutions cannot exist and inertia is crucial in controlling the dynamics. We also consider the unsteady stretching of a thread that is fixed at one end and pulled with a constant force at the other end. In contrast to the case in which inertia is neglected, the thread will always pinch at the end where the force is applied. Our results show that viscous heating can have a profound effect on the final shape and total extension at pinching.

Constant force control for aluminum wheel hub grinding based on ESO + backstepping

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shijie Dai ◽  
Yufeng Zhao ◽  
Wenbin Ji ◽  
Jiaheng Mu ◽  
Fengbao Hu
Keyword(s):  
Control Strategy ◽  
Force Control ◽  
Control Method ◽  
Response Speed ◽  
Backstepping Control ◽  
Constant Force ◽  
Content Type ◽  
Disturbance Rejection Control ◽  
The Stability ◽  
Differential Control

Purpose This paper aims to present a control method to realize the constant force grinding of automobile wheel hub. Design/methodology/approach A constant force control strategy combined by extended state observer (ESO) and backstepping control is proposed. ESO is used to estimate the total disturbance to improve the anti-interference and stability of the system and Backstepping control is used to improve the response speed of the system. Findings The simulation and grinding experimental results show that, compared with the proportional integral differential control and active disturbance rejection control, the designed controller can improve the dynamic response performance and anti-interference ability of the system and can quickly track the expected force and improve the grinding quality of the hub surface. Originality/value The main contribution of this paper lies in the proposed of a new constant force control strategy, which significantly improved the stability and precision of grinding force.

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