MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION GRADUATION THESIS MAJOR: AUTOMATION AND CONTROL ENGINEERING TECHNOLOGY FLEXIBLE ROBOT INSTRUCTOR: DANG XUAN BA PHD. STUDENT: DANG TRAN MINH KHOI Ho Chi Minh city, June 2024 CHAPTER 1. OVERVIEW HO CHI MINH CITY OF TECHNOLOGY AND EDUCATION FACULITY FOR HIGH QUALITY TRAINING Graduation Thesis Major: AUTOMATION AND CONTROL TECHNOLOGY ENGINEERING Project Title Flexible Robot STUDENT: DANG TRAN MINH KHOI STUDENT ID: 18151014 SUPERVISOR: Dr. Dang Xuan Ba Ho Chi Minh City, 20 June 2024 HO CHI MINH CITY OF TECHNOLOGY AND EDUCATION FACULITY FOR HIGH QUALITY TRAINING Graduation Thesis Major: AUTOMATION AND CONTROL TECHNOLOGY ENGINEERING Project Title Flexible Robot STUDENT: DANG TRAN MINH KHOI STUDENT ID: 18151014 SUPERVISOR: Dr.
Dang Xuan Ba Ho Chi Minh City, 18 June 2024 i ACKNOWLEDGEMENT First of all, I would like to sincerely thank the teachers in the Faculty of High- Quality Training, especially Dr. Dang Xuan Ba, the subject guide for guiding and exchanging valuable experiences and help me complete my graduation thesis. The complete of graduation thesis marked a significant milestone in the time which I have been learning over 6 years at University of Technology and Education. This is a foundation for a student like me to prepare for a new chapter of my live and open the new door to achieve opportunities in the future.
After over 6 years learning in the university also gives me many valuable lessons and experience, which I believe it will have great contributions in a long run. The past 4 months of studying and completing the project has been a special precious time for me. Although I have tried myself, there are still shortcomings in terms of knowledge as well as experience. Personally, I hope that the teachers will consider, ignore, and give suggestions to me so that I can improve my work and learn from experience and apply it in the future.
I wish all the teachers working at Ho Chi Minh City University of Technology and Education! Ho Chi Minh City, 18 June 2024 Performer ii GRADUATION PROJECT TASK Student Name: Dang Tran Minh Khoi Student ID: 18151014 Student Class: 18151CLA1 Major: Control and Automation Engineering Phone: 0986525543 Instructor’s name: Dr. Dang Xuan Ba Submission date: Receipt date 1. Name of project: ………………………………………………………………………………. Initial data and documents ……………………………………………………………………………….
Project implementation content ………………………………………………………………………………. HEAD OF DEPARTMENT SUPERVISOR (Sign & Full name) (Sign & Full Name) iii SUPERVISOR'S COMMENTS Student Name: Dang Tran Minh Khoi Student ID: 18151014 Major: Control and Automation Engineering Name of project: Flexible Robot Instructor’s name: Dr. Dang Xuan Ba Comment : 1. Content of the project and the amount of work performed.
Recommendation to allow defense or not?. Score…………………… (in words:…………………………. Ho Chi Minh City, 20 June 2024 Instructor (Signature and full name) iv THESIS ADVISOR'S COMMENTS Student Name: Dang Tran Minh Khoi Student ID: 18151014 Major: Control and Automation Engineering Name of project: Flexible Robot Thesis advisor’s name:……………………………………………………………… Comment: 1. Content of the project and the amount of work performed.
Recommendation to allow defense or not?. Score…………………… (in word:…………………………. Ho Chi Minh City, 20 June 2024 Thesis advisor (Signature & full name) v TABLE OF CONTENTS ACKNOWLEDGEMENT. ii SUPERVISOR'S COMMENTS.
iv THESIS ADVISOR'S COMMENTS. v TABLE OF CONTENTS. vi LIST OF TABLES. viii LIST OF FIGURES .2 THE OBJECT OF THE PROJECT .1 THEORY OF DIRECT CURRENT (DC) MOTOR .2 MATHEMATIC MODEL OF A DC MOTOR .1 THEORY OF GRAVITY COMPENSATION.2 APPLICATIONS OF GRAVITY COMPENSATION IN REALITY .1 Gravity compensation by Counterweights with Cables and Pulleys .2 Gravity compensation by springs .3 PD WITH GRAVITY COMPENSATION IN ROBOTICS .2 Block diagram of PD with Gravity Compensation control.
DESIGN AND IMPLEMENTATION .1 DESGIN AND SIMULATION .2 Design Robot with Simcape Toolbox in Matlab .3 Simulation on Matlab Software .4 Simulation on Arduino Software .2 ARM ROBOT DESIGNED WITH SOLIDWORK SOFTWARE .1 Set links and frames for robot .2 Design Model in SolidWorks .4 SELECT MOTOR INTRUCTION .1 WHAT IS FORCE CONTROL .1 Compliance or Stiffness control .2 HOW EFFECTIVE OF FORCE CONTROL IN MOTOR .1 Force control on 3-DOF Arm Robot model. CONCLUSION AND DEVELOPMENT. 71 vii LIST OF TABLES Table 1. Value parameters of DC motor.
Arduino Mega 2560 Parameters. JGB37 520 – 111 rpm DC motor specifications. JGB37 520 – 37 rpm DC motor parameter. LCD Display 16x2 parameter.
Behive power source parameter. 30 viii LIST OF FIGURES Figure 1. Various Types of Electromotive Force Wave. Schematic of the electromechanical dynamics of a DC motor.
Gravity compensation using cables, wires, and counterweight. Application of gravity compensation in elevators. Gravity Compensation using spring. PD with Gravity Compensation block diagram.
JGB37-520 geared DC with encoder. Geared DC GB37-545 with Encoder. Behive power source 12V-15A-280W. Model of Robot 1-DOF.
Solver Configuration Block. World Frame block. Mechanism Configuration block. Set gravity value.
Cylindrical Solid Block. World to Base Tranform block. World to Base parameters. Specifications of robot 1-DOF desgin.
Base to Joint 1 parameters. Revolute Joint Block. Brick solid (Link 1) block. Joint 1 to Link-1 transform parameter.
Fixed joint block. Link-1 to Fixed-Joint Transform parameters. Parameters of End-effector (EE. Jee to EE Transform parameter.
Block diagram connections. Run-test 1-DOF model. Block diagram of ROBOT1. Joint Space Mass Matrix block.
Velocity Product Torque block. Gravity Torque block. Matrix multiply block. Computed Torque blocks diagram.
Trapezoidal Velocity Profile Trajectory block. Finished Computed Torque with Robot simulation wiring diagram. PD with Gravity Compensation when Kp = 100 Kd = 20. PD with Gravity Compensation when Kp = 10000 Kd = 20.
PD with Gravity Compensation when Kp = 100 Kd = 200. Run on Model using Gravity Compensation (target 120 degree). Read position value of 120 degree. Plot chart position value from 90 to 120 degree.
Run on Model using Gravity Compensation (target 90 degree). Read position value at 90 degree. Plot chart change from 120 to 90 degree. Run on Model using Gravity Compensation (target 60 degree) .Read position value at 60 degree.
Change value from 120 to 90 and 60 continously. Pin definition for 3 encoder motors. Set fomular and pulses for encoder. Set value of Kp, Kd and Gravity components.
Read data of 3 motor positons on Serial Monitor. Link Frames of 3-DOF hand robot. Model of 3-DOF Arm Robot. 3D Printed 3 DOF Arm Robot.
Example of the Importance of Compliance Control in Robotics. Compliance control applied in Robot Arm in a low position. Compliance control applied in Robot Arm in higher position. Compliance control applied in Robot Arm in the right position.
Initial state when the power is off. Positon change when human's interaction applied. Position change continuously in compliance mode. Gravity compensation applied in healthcare sector.
70 xi ABSTRACT In an age where automation and efficiency are paramount, electric motors have become the heartbeat of modern industry, propelling advancements in fields as diverse as manufacturing, transportation, and healthcare. Their versatility allows them to be tailored to a vast array of applications, from the precision required in robotic surgery to the brute force necessary in electric vehicles. The critical role of motors is further magnified when considering the push towards sustainable energy, with electric motors central to this transition, driving both innovation and environmental stewardship. Amidst this backdrop, the advent of PD (Proportional-Derivative) controllers augmented with gravity compensation marks a significant milestone, particularly in the realm of assistive technology.
This methodology aims to refine the interaction between motor systems and their load-bearing tasks. By accounting for the gravitational pull on connected limbs or objects, such controllers can deliver smoother and more energy-efficient operation. The benefits are manifold, especially in developing exoskeletons for the elderly or disabled, where compliant control is not just a technical requirement but a means to restore mobility and independence. By integrating sensors and artificial intelligence, PD controllers with gravity compensation can learn and predict user intentions, leading to even more personalized and responsive support.
Furthermore, this technology holds promise for the future of work, where collaborative robots (cobots) equipped with such advanced motor control can work alongside humans safely and more effectively. The potential applications are endless, ranging from aiding workers in heavy lifting to providing gentle assistance for delicate tasks, making it a pivotal development in the field of robotics and automation.1 PROBLEM STATEMENT In the realm of assistive robotics and automated systems, optimal control strategies are essential for enhancing human-technology interaction. While traditional PID (Proportional-Integral-Derivative) controllers offer stability, they often fall short in assistive devices for the elderly or those with mobility impairments. PD (Proportional-Derivative) control with gravity compensation provides a transformative solution to tackle these limitations.
This project aims to compare traditional PID control with PD control enhanced by gravity compensation. Integrating gravity compensation can significantly improve assistive devices in terms of energy efficiency, user comfort, and alignment with natural human movement. The study involves a systematic analysis, applying both control methods to identical assistive robotic systems, considering criteria such as response time, stability, and energy consumption. Gravity compensation ensures smoother, effortless movements, especially beneficial for the elderly.
Furthermore, this project tackles user fatigue and discomfort associated with prolonged device use. Tailoring the control system to counteract gravitational forces reduces physical strain, vital for exoskeletons and mobility aids. The project also explores future implications, adapting control algorithms for intuitive user behavior responses and scalability. These findings promise valuable insights into optimizing control strategies for assistive devices, enhancing the quality of life for users.2 THE OBJECT OF THE PROJECT Successfully program the PD and gravity compensation including impedance and compliance algorithm for position control of a one-directional motor using an Arduino microcontroller.3 RESEARCH METHOD - Drawing upon research topics found in books, journals, scientific publications, etc., I conduct an in-depth study to develop the project.
- I utilize the trial-and-error design method to determine the impedance control parameters, leveraging the experience gained from theoretical courses such as "Automatic Control Systems" and practical training in "Automatic Control." - I employ the Arduino software to program the impedance and compliance control algorithm for the position control of a one-directional motor.4 RESEARCH CONTENT The remaining sections of the content are: Chapter 2: Theoretical Foundation of DC motor This chapter presents the theory regarding one-directional motors and the mathematical model of the motor. Chapter 3: Gravity Compensation Theory and Agorithm Development This chapter discusses the theoretical aspects of the gravity compensation algorithm and the methodology for constructing gravity compensation rules for the position control system of a one-directional motor. Chapter 4: System Design and Implementation This chapter provides an overview of the Arduino, including its connection diagram. It covers data collection and the programming of the gravity compensation - impedance control.
Also, including the models of 3-DOF Robot via Solidworks software. Chapter 5: Force control In this chapter, I will discuss the importance of force control and its significant impact on mechanical systems, such as motor gear systems and load-bearing capacities. When external environmental forces act upon these systems, they can lead to critical failures like shaft breakage. This 3 section will also delve into the analysis of compliance and impedance in controlling forces effectively.
Chapter 6: Conclusion and Evaluation This chapter presents the achieved objectives in terms of hardware and software, the results of position control of a one-directional motor using the gravity compensation algorithm with Arduino Mega. It outlines the issues that the project has addressed successfully, and any limitations encountered. The chapter also discusses the potential for expanding the topic and future development directions.5 LIMITATION In this project, I conducted experiments on a real model with a relatively small and inexpensive motor.