3P2-K06 Position Control of an Antagonistic Redundant Robot by Pneumatic Actuators(Parallel Robot/Mechanisms and its Control)

Abstract This paper reports on design, fabrication, and kinematics modeling of a 3D printed soft parallel robot equipped with soft pneumatic actuators. Soft robotics is an emerging field of research which facilitates safe human machine interface. Soft elastomeric actuators made through molding process are one of the key elements of soft robotic systems. However, molding process is tedious and time consuming making the fabrication process undesirable. Recently reported 3D printed soft pneumatic actuators pave the way for manufacturing of novel soft actuators and robots with complex geometries. The current work can be considered as a proof of concept for 3D printing of a soft parallel robot. The robot consists of two soft pneumatic actuators that are connected to two passive links by mean of flexible hinges. The robot has two degrees of freedom and can be used in planar manipulation tasks. Moreover, a number of robots can be configured to operate in a cooperative manner to increase the manipulation dexterity. A kinematic model is developed to simulate the motion of robot end-effector. Through application of the kinematic model it has been shown that the robot is capable of following any planar trajectories within its workspace. Also, pseudo-rigid-body model (PRBM) is used to develop a dynamic model of the soft robot to more accurately predict the robot interaction with its environment and also develop advanced control system for robust position control of the robot.

Download Full-text

Proposal of a Decoupled Structure of Fuzzy-PID Controllers Applied to the Position Control in a Planar CDPR

Electronics ◽

10.3390/electronics10060745 ◽

2021 ◽

Vol 10 (6) ◽

pp. 745

Author(s):

Marco Carpio ◽

Roque Saltaren ◽

Julio Viola ◽

Cristian Calderon ◽

Juan Guerra

Keyword(s):

Position Control ◽

Control Structure ◽

Parallel Robot ◽

Pid Controllers ◽

Fuzzy Pid ◽

End Effector ◽

Robot Systems ◽

Decoupled Control ◽

The Mathematical Model ◽

Decoupled Structure

The design of robot systems controlled by cables can be relatively difficult when it is approached from the mathematical model of the mechanism, considering that its approach involves non-linearities associated with different components, such as cables and pulleys. In this work, a simple and practical decoupled control structure proposal that requires practically no mathematical analysis was developed for the position control of a planar cable-driven parallel robot (CDPR). This structure was implemented using non-linear fuzzy PID and classic PID controllers, allowing performance comparisons to be established. For the development of this research, first the structure of the control system was proposed, based on an analysis of the cables involved in the movement of the end-effector (EE) of the robot when they act independently for each axis. Then a tuning of rules was carried out for fuzzy PID controllers, and Ziegler–Nichols tuning was applied to classic PID controllers. Finally, simulations were performed in MATLAB with the Simulink and Simscape tools. The results obtained allowed us to observe the effectiveness of the proposed structure, with noticeably better performance obtained from the fuzzy PID controllers.

Download Full-text

Hybrid Force/Position Control of a Collaborative Parallel Robot Using Adaptive Neural Network

Lecture Notes in Computer Science - Interactive Collaborative Robotics ◽

10.1007/978-3-319-99582-3_29 ◽

2018 ◽

pp. 280-290

Author(s):

Seyedhassan Zabihifar ◽

Arkadi Yuschenko

Keyword(s):

Neural Network ◽

Position Control ◽

Parallel Robot ◽

Adaptive Neural Network

Download Full-text

Accurate Position Control of a Pneumatic Actuator

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2896202 ◽

1990 ◽

Vol 112 (4) ◽

pp. 734-739 ◽

Cited By ~ 46

Author(s):

Jiing-Yih Lai ◽

Chia-Hsiang Menq ◽

Rajendra Singh

Keyword(s):

Control Strategy ◽

Pulse Width Modulation ◽

Position Control ◽

Integral Control ◽

Pneumatic Actuators ◽

Actuator Dynamics ◽

Position Accuracy ◽

Modulation Mode ◽

Nonlinear Mechanical ◽

Accurate Position

We propose a new control strategy for on-off valve controlled pneumatic actuators and robots with focus on the position accuracy. A mathematical model incorporating pneumatic process nonlinearities and nonlinear mechanical friction has been developed to characterize the actuator dynamics; this model with a few simplifications is then used to design the controller. In our control scheme, one valve is held open and the other is operated under the pulse width modulation mode to simulate the proportional control. An inner loop utilizing proportional-plus-integral control is formed to control the actuator pressure, and an outer loop with displacement and velocity feedbacks is used to control the load displacement. Also, a two staged feedforward force is implemented to reduce the steady state error due to the nonlinear mechanical friction. Experimental results on a single-degree-of-freedom pneumatic robot indicate that the proposed control system is better than the conventional on-off control strategy as it is effective in achieving the desired position accuracy without using any mechanical stops in the actuator.

Download Full-text

Nonlinear Position Control of a Very Flexible Parallel Robot Manipulator

Multibody Dynamics 2019 - Computational Methods in Applied Sciences ◽

10.1007/978-3-030-23132-3_19 ◽

2019 ◽

pp. 155-162

Author(s):

Peter Eberhard ◽

Fatemeh Ansarieshlaghi

Keyword(s):

Position Control ◽

Robot Manipulator ◽

Parallel Robot

Download Full-text

Open-loop position control of a polymer cable–driven parallel robot via a viscoelastic cable model for high payload workspaces

Advances in Mechanical Engineering ◽

10.1177/1687814017737199 ◽

2017 ◽

Vol 9 (12) ◽

pp. 168781401773719 ◽

Cited By ~ 7

Author(s):

Jinlong Piao ◽

XueJun Jin ◽

Jinwoo Jung ◽

Eunpyo Choi ◽

Jong-Oh Park ◽

...

Keyword(s):

Position Control ◽

Parallel Robot ◽

Open Loop ◽

Cable Model ◽

High Payload

Download Full-text

Development of Low-Cost Wearable Servo Valve Using Buckled Tube Driven by Servo Motor

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.393.532 ◽

2013 ◽

Vol 393 ◽

pp. 532-537 ◽

Cited By ~ 5

Author(s):

Abdul Nasir ◽

Tetsuya Akagi ◽

Shujiro Dohta ◽

Ayumu Ono ◽

Yusuke Masago

Keyword(s):

Control System ◽

Flow Rate ◽

Position Control ◽

Low Cost ◽

Control Valve ◽

Artificial Muscle ◽

Pneumatic Actuators ◽

Servo Valve ◽

Precise Control ◽

Care Systems

Recently, power assisted nursing care systems have received much attention and those researches have been done actively. In such a control system, an actuator and a control valve are mounted on the human body. Designing the system, the size and weight of the valve become serious concerns. The purpose of our study is to develop a small-sized, lightweight and low-cost servo valve for precise control using wearable pneumatic actuators. In this study, a low-cost wearable servo valve that can control the output flow rate by changing the twisted angle of the buckled tube in the servo valve is proposed and tested. The position control system of McKibben rubber artificial muscle using tested valve and embedded controller is also proposed and tested. As a result, we confirmed that the tested servo valve can control the flow rate in both supply and exhaust in an analog way. In addition, the estimated cost of the proposed valve can be reduced about 100 times cheaper (10 US Dollar) compared with the typical servo valve.

Download Full-text