Position and Speed Control of 2 DOF Industrial Robotic Arm using Robust Controllers

With the continuous improvement of control technology and the continuous improvement of people’s living standards, the needs of disabled people for high-quality prosthetics have become increasingly strong. A control method of robotic arm based on surface electromyography signal (sEMG) of forearm is proposed. Firstly, the 16-channel EMG data of the forearm is obtained via the multi-channel EMG acquisition instrument and the electrode cuff as input signals, the features are extracted, then the gestures are classified and identified by the support-vector machine (SVM) algorithm, and the signals are finally transmitted to the robotic arm, so that people can teleoperate the robotic arm via sEMG signals in real time. Reduce the number of channels to lower the cost while ensuring a high and usable recognition rate. Experiments were performed by collecting EMG signals from the forearm surface of eight healthy volunteers. The experimental results show that the system’s overall gesture recognition accuracy rate can reach up to 90%, and the system responds fast, laying a good foundation for manipulating artificial limbs in the future.

Download Full-text

Motion-Assist Arm with a Passive Joint for an Upper Limb

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2020.p0183 ◽

2020 ◽

Vol 32 (1) ◽

pp. 183-198

Author(s):

Hiroaki Kozuka ◽

Daisaku Uchijima ◽

Hiroshi Tachiya ◽

◽

Keyword(s):

Upper Limb ◽

Control Method ◽

Degree Of Freedom ◽

Robotic Arm ◽

Robot Arm ◽

Passive Joint ◽

Target Path ◽

Three Degree Of Freedom ◽

Actuated Joints ◽

Human Upper Limb

This study proposes a motion-assist arm that can accurately support the positioning of a human upper limb. The motion-assist arm is a three-degree-of-freedom (DOF) planer under-actuated robotic arm with a 1-DOF passive joint that can be driven by an human. A control method for the robot arm is as follows. First, when the human moves an output point of the arm manually, the passive joint is rotated with the movement of the output point. Then, for accurate positioning of the output point on a target path, the actuated joints are controlled according to the displacement of the passive joint. Based on the above method, the human can adjust the velocity of the output point deliberately while its position is accurately corrected by the actuated joints. To confirm its effectiveness, the authors conducted tests to assist the human’s upper limb movement along straight target paths, a square path, and free curves paths such as italic letters with the proposed robot arm prototype. From the results of the tests, the authors confirmed that the proposed robot arm can accurately position the upper limb of the human on the target paths while the human intentionally moves the upper limb. It is expected that the proposed arm will be used for rehabilitation because it can aid patients to move their arms correctly. In addition, the proposed arm will enable any human to achieve complex work easily.

Download Full-text

Research on Control Strategy of Manipulator Based on Simulation

Journal of Physics Conference Series ◽

10.1088/1742-6596/2093/1/012007 ◽

2021 ◽

Vol 2093 (1) ◽

pp. 012007

Author(s):

JiaLei Su

Keyword(s):

Control Method ◽

Impedance Control ◽

Rapid Development ◽

Space Robot ◽

Space Environment ◽

Robotic Arm ◽

Control Element ◽

Feedback Signal ◽

Robot Arm ◽

Control Effect

Abstract The force supple control method of robotic arm has been widely researched internationally for many years, and its specific use varies according to the structure of the robotic arm, the location of the sensor, the working space environment, and other factors. Based on the force control principle and control method of the space robot arm, this paper adopts the position-based Cartesian spatial impedance control and proposes an effective forcesmoothing control method after pre-processing the feedback signal of the six-dimensional force sensor installed at the end of the space robot arm with the coordinate system conversion. In addition, the proposed position-based Cartesian spatial impedance control method is modeled and simulated to analyze the effect of each control element on the force-following control effect, to find out the control conditions that can optimize the force-position control effect, and finally to optimize the impedance parameters. This study aims to promote the rapid development of the field of robotic arm control.

Download Full-text

Design & Control of Vehicle Boom Barrier Gate System using Augmented H2 Optimal & H infinity Synthesis Controllers

10.20944/preprints202007.0585.v1 ◽

2020 ◽

Author(s):

Mustefa Jibril ◽

Messay Tadese ◽

Tesfabirhan Shoga

Keyword(s):

Angular Position ◽

Open Loop ◽

Response Analysis ◽

H Infinity ◽

Set Point ◽

Input Signals ◽

Gate System ◽

And Control

A vehicle boom barrier gate system is one of the recently developed technologies operating at the entrances to the restricted areas. This paper aims to design and control of vehicle’s boom barrier gate system using robust augmentation technique. H 2 optimal and H infinity synthesis controllers are used to improve the performance of the system. The open loop response analysis of the vehicle boom barrier gate system shows that the input of the system need to be improved. Comparison of the vehicle boom barrier gate system with H2 optimal and H infinity synthesis controllers have been done to track a set point desired angular position using a step and operational open and close input signals and a promising results have been observed.

Download Full-text

Hybrid Impedance-Admittance Control for Upper Limb Exoskeleton Using Electromyography

Applied Sciences ◽

10.3390/app10207146 ◽

2020 ◽

Vol 10 (20) ◽

pp. 7146

Author(s):

Lucas D. L. da Silva ◽

Thiago F. Pereira ◽

Valderi R. Q. Leithardt ◽

Laio O. Seman ◽

Cesar A. Zeferino

Keyword(s):

Upper Limb ◽

Degrees Of Freedom ◽

Control Method ◽

Hybrid Control ◽

Impedance Control ◽

Robotic Arm ◽

Average Error ◽

Acceptable Error ◽

Upper Limb Exoskeleton ◽

Input Signals

Exoskeletons are wearable mobile robots that combine various technologies to enable limb movement with greater strength and endurance, being used in several application areas, such as industry and medicine. In this context, this paper presents the development of a hybrid control method for exoskeletons, combining admission and impedance control based on electromyographic input signals. A proof of concept of a robotic arm with two degrees of freedom, mimicking the functions of a human’s upper limb, was built to evaluate the proposed control system. Through tests that measured the discrepancy between the angles of the human joint and the joint of the exoskeleton, it was possible to determine that the system remained within an acceptable error range. The average error is lower than 4.3%, and the robotic arm manages to mimic the movements of the upper limbs of a human in real-time.

Download Full-text

Design and performance analysis of an industrial robot arm for robotic drilling process

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-06-2018-0124 ◽

2019 ◽

Vol 46 (1) ◽

pp. 7-16 ◽

Cited By ~ 2

Author(s):

Longfei Sun ◽

Fengyong Liang ◽

Lijin Fang

Keyword(s):

Control Method ◽

Industrial Robot ◽

Industrial Robots ◽

Ball Screw ◽

Robotic Arm ◽

Drilling Process ◽

Robot Arm ◽

Content Type ◽

Robotic Drilling

Purpose The purpose of this paper is to present a robotic arm that can offer better stiffness than traditional industrial robots for improving the quality of holes in robotic drilling process. Design/methodology/approach The paper introduces a five-degree of freedom (DOF) robot, which consists of a waist, a big arm, a small arm and a wrist. The robotic wrist is composed of two DOFs of pitching and tilting. A parallelogram frame is used for robotic arms, and the arm is driven by a linear electric cylinder in the diagonal direction. Double screw nuts with preload are used in the ball screw to remove the reverse backlash. In addition, dual-motor drive is applied for each DOF in the waist and the wrist to apply anti-backlash control method for eliminating gear backlash. Findings The proposed robotic arm has the potential for improving robot stiffness because of its truss structure. The robot can offer better stiffness than industrial robots, which is beneficial to improve the quality of robotic drilling holes. Originality/value This paper includes the design of a five-DOF robot for robotic drilling tasks, and the stiffness modeling of the robot is presented and verified by the experiment. The robotic system can be used instead of traditional industrial robots for improving the hole quality to a certain extent.

Download Full-text

Position Control of a Solenoid Based Linearly Movable Armature System using Robust Control Technique

10.20944/preprints202006.0119.v1 ◽

2020 ◽

Author(s):

Mustefa Jibril

Keyword(s):

Robust Control ◽

Control Systems ◽

Position Control ◽

Sine Wave ◽

Pole Placement ◽

Control Technique ◽

H Infinity ◽

Armature System ◽

Reference Track ◽

Regional Pole Placement

In this paper, a solenoid based linearly movable armature system is designed using robust control theory in order to improve the performance of the system. Reference track method is the best performance analysis for position control systems. Among the robust controllers, H infinity mixed-sensitivity and Mixed H 2 /H∞ with Regional Pole Placement Controllers are used to improve the performance of the system. Comparison of the proposed controllers for tracking a reference displacement signals (step and sine wave) and a promising simulation result have been obtained.

Download Full-text

Modelling And Control Of Automated Polishing/Deburring Process

10.32920/ryerson.14656821 ◽

2021 ◽

Author(s):

Liang Liao

Keyword(s):

Feedback Linearization ◽

Closed Loop ◽

Control Method ◽

Minimum Degree ◽

Open Loop ◽

Pole Placement ◽

Control Performance ◽

Nonlinear Controller ◽

Loop Control ◽

And Control

In this thesis, a new approach is presented for the modelling and control of an automated polishing/deburring process that utilizes a dual-purpose complaint toolhead mounted on a parallel tripod robot. This toolhead has a pneumatic spindle that can be extended and retracted by three pneumatic actuators to provide tool compliance. By integrating a pressure sensor and a linear encoder, this toolhead can be used for polishing and deburring. For the polishing open-loop control, the desired tool pressure is pre-planned based on the given part geometry. To improve control performance, a closed-loop controller is applied for pressure tracking through pressure sensing. For the deburring control, another closed-loop controller is applied to regulate the tool length through tool extension sensing. The two control methods have been tested and implemented on a polishing/deburring robot, and the experiment results demonstrate the effectiveness of the presented methods. To future improve the control performance, an adaptive controller is developed to deal with the uncertainties in the compliant tool. This control method combines the adaptive control theory with the constant stress theory of the contact model. A recursive last squares (RLS) estimator is developed to estimate the pneumatic plant model, and then a minimum-degree pole placement (MDPP) is applied to design a self-tuning controller. Afterwards, the simulation and experiment results of the proposed controller are presented and discussed. Finally, a nonlinear model of the pneumatic plant is developed. The nonlinear controller developed by using feedback linearization method is applied on the nonlinear pneumatic system of the compliant toolhead. The simulation is carried out to test the effectiveness of the pressure tracking for the polishing process.

Download Full-text

Modelling And Control Of Automated Polishing/Deburring Process

10.32920/ryerson.14656821.v1 ◽

2021 ◽

Author(s):

Liang Liao

Keyword(s):

Feedback Linearization ◽

Closed Loop ◽

Control Method ◽

Minimum Degree ◽

Open Loop ◽

Pole Placement ◽

Control Performance ◽

Nonlinear Controller ◽

Loop Control ◽

And Control

In this thesis, a new approach is presented for the modelling and control of an automated polishing/deburring process that utilizes a dual-purpose complaint toolhead mounted on a parallel tripod robot. This toolhead has a pneumatic spindle that can be extended and retracted by three pneumatic actuators to provide tool compliance. By integrating a pressure sensor and a linear encoder, this toolhead can be used for polishing and deburring. For the polishing open-loop control, the desired tool pressure is pre-planned based on the given part geometry. To improve control performance, a closed-loop controller is applied for pressure tracking through pressure sensing. For the deburring control, another closed-loop controller is applied to regulate the tool length through tool extension sensing. The two control methods have been tested and implemented on a polishing/deburring robot, and the experiment results demonstrate the effectiveness of the presented methods. To future improve the control performance, an adaptive controller is developed to deal with the uncertainties in the compliant tool. This control method combines the adaptive control theory with the constant stress theory of the contact model. A recursive last squares (RLS) estimator is developed to estimate the pneumatic plant model, and then a minimum-degree pole placement (MDPP) is applied to design a self-tuning controller. Afterwards, the simulation and experiment results of the proposed controller are presented and discussed. Finally, a nonlinear model of the pneumatic plant is developed. The nonlinear controller developed by using feedback linearization method is applied on the nonlinear pneumatic system of the compliant toolhead. The simulation is carried out to test the effectiveness of the pressure tracking for the polishing process.

Download Full-text