Planar Peg-in-Hole Insertion Using a Stiffness Controllable Pneumatic Manipulator

2005 ◽  
Author(s):  
Yong Zhu ◽  
Eric J. Barth
Keyword(s):  
Sliding Mode ◽  
Impedance Control ◽  
Load Cell ◽  
Experimental Results ◽  
Impedance Parameters ◽  
Spool Valves ◽  
Intrinsic Stiffness ◽  
Cell Force ◽  
Control Methodology ◽  
Contact Tasks

This paper presents a method for the impedance control of a pneumatic manipulator for peg-in-hole tasks without using a load cell. The control methodology presented contains a sliding mode force controller and an adaptive pressure summation relationship, which enforces the controllable natural stiffness of the pneumatic actuator. This is accomplished by utilizing two three-way proportional spool valves for each degree-of-freedom instead of a four-way valve typically used in fluid power control. Combinations of intrinsic stiffness provided by the compressibility of air and closed-loop stiffness provided by impedance parameters are studied. Experimental results are shown demonstrating that gentle transition from non-contact to contact tasks can be achieved without the use of a load cell by taking advantage of the intrinsically low stiffness of a pneumatic manipulator. Experimental results are also shown demonstrating sensorless (no load cell) force-guided insertion of a planar peg-in-hole task with position uncertainties (hole location not precisely known).

Adaptive Impedance Control for Robot Based on Estimation of Environmental Parameters

2011 ◽  
Vol 328-330 ◽  
pp. 1713-1716 ◽  
Author(s):  
Zhan Ming Li ◽  
Er Chao Li
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Impedance Control ◽  
Environmental Parameters ◽  
Changing Environment ◽  
Unknown Environment ◽  
Adaptive Impedance Control ◽  
Impedance Parameters ◽  
The One ◽  
Contact Tasks

In order to realize precise contact tasks with an unknown environment, robotic force controllers have to adapt themselves to the unknown environment. Some impedance controllers are designed for several representative environmental parameters, A BP neural network is proposed to determine the one-to-one mapping relations between the environmental parameters and the impedance parameters. However, it is difficult to accurately know the environmental parameters in the case of a changing environment, RLS is proposed to estimate environmental parameters, then determine the impedance coefficients to control the robot. Simulations prove that the controller designed is feasible and effective.

Impedance Control Based Sliding Mode for Lower Limb Rehabilitation Robot

2014 ◽  
Vol 672-674 ◽  
pp. 1770-1773 ◽  
Author(s):  
Fu Cheng Cao ◽  
Li Min Du
Keyword(s):  
Dynamic Response ◽  
Sliding Mode Control ◽  
Lower Limb ◽  
Control Method ◽  
Sliding Mode ◽  
Impedance Control ◽  
Rehabilitation Robot ◽  
Active Rehabilitation ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

Aimed at improving the dynamic response of the lower limb for patients, an impedance control method based on sliding mode was presented to implement an active rehabilitation. Impedance control can achieve a target-reaching training without the help of a therapist and sliding mode control has a robustness to system uncertainty and vary limb strength. Simulations demonstrate the efficacy of the proposed method for lower limb rehabilitation.

Sliding Mode Control for Wheeled Inverted Pendulum

2014 ◽  
Vol 971-973 ◽  
pp. 714-717 ◽  
Author(s):  
Xiang Shi ◽  
Zhe Xu ◽  
Qing Yi He ◽  
Ka Tian
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
High Performance ◽  
Inverted Pendulum ◽  
Sliding Mode ◽  
Experimental Results ◽  
Control Law ◽  
Collaborative Simulation ◽  
Mode Control ◽  
Wheeled Inverted Pendulum

To control wheeled inverted pendulum is a good way to test all kinds of theories of control. The control law is designed, and it based on the collaborative simulation of MATLAB and ADAMS is used to control wheeled inverted pendulum. Then, with own design of hardware and software of control system, sliding mode control is used to wheeled inverted pendulum, and the experimental results of it indicate short adjusting time, the small overshoot and high performance.

scholarly journals Super-Twisting Algorithm Applied to Velocity Control of DC Motor without Mechanical Sensors Dependence

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6041
Author(s):  
Fredy A. Valenzuela ◽  
Reymundo Ramírez ◽  
Fermín Martínez ◽  
Onofre A. Morfín ◽  
Carlos E. Castañeda
Keyword(s):  
Controller Design ◽  
Sliding Mode ◽  
Dc Motor ◽  
Experimental Results ◽  
Resistive Load ◽  
Velocity Control ◽  
Velocity Sensor ◽  
Control Scheme ◽  
Mechanical Sensors ◽  
Twisting Algorithm

A DC motor velocity control in feedback systems usually requires a velocity sensor, which increases the controller cost. Additionally, the velocity sensor used in industrial applications presents several disadvantages such as maintenance requirements and signal conditioning. In this work, we propose a robust velocity control scheme applied to a DC motor based on estimation strategies using a sliding-mode observer. This means that measurements with mechanical sensors are not required in the controller design. The proposed observer estimates the rotational velocity and load torque of the motor. The controller design applies the exact-linearization technique combined with the super-twisting algorithm to achieve robust performance in the closed-loop system. The controller validation was carried out by experimental tests using a workbench, which is composed of a control and data acquisition Digital Signal Proccessor board, a DC-DC electronic converter, an interface board for signals conditioning, and a DC electric generator connected to an adjustable resistive load. The simulation and experimental results show a significant performance of the proposed control scheme. During tests, the accuracy, robustness, and speed response on the controller were evaluated and the experimental results were compared with a classic proportional-integral controller, which uses a conventional encoder.

Novel fractional hybrid impedance control of series elastic muscle-tendon actuator

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Javad Fotuhi ◽  
Zafer Bingul
Keyword(s):  
Contact Stress ◽  
Impedance Control ◽  
Robustness Analysis ◽  
Simulation Models ◽  
Experimental Results ◽  
Uncertain Environments ◽  
Content Type ◽  
Force Tracking ◽  
Comparative Results ◽  
Series Elastic

Purpose This paper aims to develope a novel fractional hybrid impedance control (FHIC) approach for high-sensitive contact stress force tracking control of the series elastic muscle-tendon actuator (SEM-TA) in uncertain environments. Design/methodology/approach In three different cases, the fractional parameters of the FHIC were optimized with the particle swarm optimization algorithm. Its adaptability to the pressure of the sole of the foot on real environments such as grass (soft), carpet (medium) and solid floors (hard) is far superior to traditional impedance control. The main aim of this paper is to derive the dynamic simulation models of the SEM-TA, to develop a control architecture allowing for high-sensitive contact stress force control in three cases and to verify the simulation models and the proposed controller with experimental results. The performance of the optimized controllers was evaluated according to these parameters, namely, maximum overshoot, steady-state error, settling time and root mean squared errors of the positions. Moreover, the frequency robustness analysis of the controllers was made in three cases. Findings Different simulations and experimental results were conducted to verify the control performance of the controllers. According to the comparative results of the performance, the responses of the proposed controller in simulation and experimental works are very similar. Originality/value Origin approach and origin experiment.

scholarly journals Design and Realization of a Miniature Capacitive Silicon Force Sensor for Loads up to 500 KG

2000 ◽  
Author(s):  
R. A. F. Zwijze ◽  
R. J. Wiegerink ◽  
G. J. M. Krijnen ◽  
T. Hien ◽  
M. C. Elwenspoek
Keyword(s):  
Force Sensor ◽  
Full Scale ◽  
Load Cell ◽  
Measurement Results ◽  
Previous Design ◽  
Cell Force

Abstract In this paper, a micromachined silicon load cell (force sensor) is presented for measuring loads up to 500 kg. The load cell has been realized and tested. Measurement results show a hysteresis error of ±0.02% of the full-scale output (fso). Creep at 500 kg after 30 minutes is within 0.01% of the fso. These measurements show that the performance has improved by a factor of 10 compared to the previous design.

Fault tolerant control based on backstepping nonsingular terminal integral sliding mode and impedance control for a lower limb exoskeleton

2021 ◽  
pp. 095440622110357
Author(s):  
Majied Mokhtari ◽  
Mostafa Taghizadeh ◽  
Pegah Ghaf Ghanbari
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Impedance Control ◽  
Fault Tolerant Control ◽  
Integral Type ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Control Scheme

In this paper, an active fault-tolerant control scheme is proposed for a lower limb exoskeleton, based on hybrid backstepping nonsingular fast terminal integral type sliding mode control and impedance control. To increase the robustness of the sliding mode controller and to eliminate the chattering, a nonsingular fast terminal integral type sliding surface is used, which ensures finite time convergence and high tracking accuracy. The backstepping term of this controller guarantees global stability based on Lyapunov stability criterion, and the impedance control reduces the interaction forces between the user and the robot. This controller employs a third order super twisting sliding mode observer for detecting, isolating ad estimating sensor and actuator faults. Motion stability based on zero moment point criterion is achieved by trajectory planning of waist joint. Furthermore, the highest level of stability, minimum error in tracking the desired joint trajectories, minimum interaction force between the user and the robot, and maximum system capability to handle the effect of faults are realized by optimizing the parameters of the desired trajectories, the controller and the observer, using harmony search algorithm. Simulation results for the proposed controller are compared with the results obtained from adaptive nonsingular fast terminal integral type sliding mode control, as well as conventional sliding mode control, which confirm the outperformance of the proposed control scheme.

Sign in / Sign up

Export Citation Format

Share Document