Research on Self-balancing Two Wheels Mobile Robot Control System Analysis

The paper presents the research on self-balancing two-wheels mobile robot control system analysis with experimental studies. The research problem in this work is to stabilize the mobile robot with self-control and to carry the sensitive things without failing in a long span period. The main objective of this study is to focus on the mathematical modelling of mobile robot from laboratory scale to real world applications. The numerical expression with mathematical modelling is very important to control the mobile robot system with linearization. The fundamental concepts of dynamic system stability were utilized for maintaining the stability of the constructed mobile robot system. The controller design is also important for checking the stability and the appropriate controller design is proportional, integral,and derivative – PID controller and Linear Quadratic Regulator (LQR). The steady state error could be reduced by using such kind of PID controller.The simulation of numerical expression on mathematical modeling was conducted in MATLAB environments. The confirmation results from the simulation techniques were applied to construct the hardware design of mobile robot system for practical study. The results from simulation approaches and experimental approaches are matched in various kinds of analyses. The constructed mobile robot system was designed and analyzed in the control system design laboratory of Yangon Technological University (YTU)

Saturable absorption measurement of platinum as saturable absorber by using twin detector method based on mode-locked fiber laser

This paper illustrates the absorption measurement of Pt as saturable absorber (SA) by using mode-locked fiber laser system. The SA is fabricated by depositing 10 nm of Pt on the fiber ferrules using sputtering method. The absorption measurement of Pt is characterised by employing a balanced twin detector method based on mode-locked fiber laser with central wavelength of 1532.25 nm, repetition rate of 2.833 MHz and pulse duration of 34.3 ns. The Pt-SA produce modulation depth of 21.9% and saturation intensity of 21.6 MW cm-2

Synchronizing of Stabilizing Platform Mounted on a Two-Wheeled Robot

This paper represents the designing, building, and testing of a self-stabilizing platform mounted on a self-balancing robot. For the self-stabilizing platform, a servo motor is used and for the self-balancing robot, two dc motors are used with an encoder, inertial measurement unit, motor driver, an Arduino UNO microcontroller board. A PID controller is used to control the balancing of the system. The PID controller gains (Kp, Ki, and Kd) were evaluated experimentally. The value of the tilted angle from IMU was fed to the PID controller to control the actuated motors for balancing the system. For the self-stabilizing control part, whenever the robot tilted, it maintained the horizontal position by rotating that much in the opposite direction

Fabrication, Balancing and Analysis of Two Wheeled Robot

Two wheeled self balancing robot is based on the concept of inverted pendulum, which center of mass is above the pivot point. Generally the pendulum is an unstable system on its horizontal plane and must be balanced to remain upright. This can be achieved by applying require amount of torque to the pivot point. Similarly here in two wheeled balancing robot being unstable will deflect from its vertical position and try to fall down. The angle of tilt is calculated by IMU sensor and sends to the microcontroller, which further gives a command to the motor through the motor controller to move in the same direction where the robot has been tilted. When the motor will rotate, it will give an opposite torque to the robot through the pivot point which will counter the angle of deflection and the robot will be stable. This will happen for both the direction of the deflection and hence the robot will move forward and backward and finally it will be balanced. So it require both mechanical and electronics equipment for the robot to achieve the goal

Design and Control of a Two-Wheeled Robotic Walker

This thesis presents the design, construction, and control of a two-wheeled inverted pendulum (TWIP) robotic walker prototype for assisting mobility-impaired users with balance and fall prevention. A conceptual model of the robotic walker is developed and used to illustrate the purpose of this study. A linearized mathematical model of the two-wheeled system is derived using Newtonian mechanics. A control strategy consisting of a decoupled LQR controller and three state variable controllers is developed to stabilize the platform and regulate its behavior with robust disturbance rejection performance. Simulation results reveal that the LQR controller is capable of stabilizing the platform and rejecting external disturbances while the state variable controllers simultaneously regulate the system’s position with smooth and minimum jerk control. A prototype for the two-wheeled system is fabricated and assembled followed by the implementation and tuning of the control algorithms responsible for stabilizing the prototype and regulating its position with optimal performance. Several experiments are conducted, confirming the ability of the decoupled LQR controller to robustly balance the platform while the state variable controllers regulate the platform’s position with smooth and minimum jerk control

Mechatronics Design Process with Energy Optimization for Industrial Machines

The need for designing industrial machines with higher energy efficiency, reliability, flexibility, and accuracy has increased to satisfy market demand for higher productivity at reduced costs in a sustainable manner. As machines become more complex, model-based design is essential to overcome the challenges in mechatronic system design. However, a well-designed mechanical system with a well-designed and tuned control system are not sufficient for machines to operate at high-performance conditions; this also heavily depends on trajectory planning and the appropriate selection of the motors controlling the axes of the machine. In this work, a model-based design approach to properly select motors for single-axes or multi-axes coordinated systems was proposed. Additionally, a trajectory planning approach was also proposed to improve performance of industrial machines. The proposed motor selection process and trajectory planning approach were demonstrated via modeling, simulation, and experimental validation for three systems: two-inertia system, planar robot, and self-balancing transporter. Over 25% of the electric energy delivered in the U.S. in 2013 was used in the industrial sector according to the U.S. Energy Information Administration, with an estimated efficiency of 80% according to the Lawrence Livermore National Laboratory. This entails major responsibility by the industry to utilize energy efficiently and promote sustainable energy usage. To help improve the energy efficiency in the industrial sector, a novel method to optimize the energy of single-axis and multi-axis coordinated systems of industrial machines was developed. Based on trajectory boundaries and the kinetic model of the mechanism and motors, this proposed energy optimization method performs iterations to recalculate the shape of the motion profile for each motor of the system being optimized until it converges to a motion profile with optimal energy cost and within these boundaries. This method was validated by comparing the energy consumption of those three systems while commanded by the optimized motion profile and then by motion profiles typically used in industrial applications. The energy saved was between 5% and 10%. The implementation cost of this method in industrial systems resides in machine-code changes; no physical changes are needed

Modeling, Control and Automatic Code Generation for a Two-Wheeled Self-Balancing Vehicle Using Modelica

The main goal of this project was to use the Modelica features on embedded systems, real-time systems and basic mechanical modeling for the control of a two-wheeled self-balancing personal vehicle. The Elektor Wheelie, a Segway-like vehicle, was selected as the process to control. Modelica is an object-oriented language aimed at modeling of complex systems. The work in the thesis used the Modelica-based modeling and simulation tool Dymola. The Elektor Wheelie has an 8-bit programmable microcontroller (Atmega32) which was used as control unit. This microcontroller has no hardware support for floating point arithmetic operations and emulation via software has a high cost in processor time. Therefore fixed-point representation of real values was used as it only requires integer operations. In order to obtain a linear representation which was useful in the control design a simple mechanical model of the vehicle was created using Dymola. The control strategy was a linear quadratic regulator (LQR) based on a state space representation of the vehicle. Two methods to estimate the platform tilt angle were tested: a complementary filter and a Kalman filter. The Kalman filter had a better performance estimating the platform tilt angle and removing the gyroscope drift from the angular velocity signal. The state estimators as well as the controller task were generated automatically using Dymola; the same tasks were programmed manually using fixed-point arithmetic in order to evaluate the feasibility of the Dymola automatically generated code. At this stage, it was shown that automatically generated fixed-point code had similar results compared to manual coding after slight modifications were made. Finally, a simple communication application was created which allowed real-time plotting of state variables and remote controlling of the vehicle, using elements of Modelica EmbeddedSystems library

Dual Mode Control of an Inverted Pendulum: Design, Analysis and Experimental Evaluation

We present an inverted pendulum design using readily available V-slot rail components and 3D printing to construct custom parts. To enable the examination of different pendulum characteristics, we constructed three pendulum poles of different lengths. We implemented a brake mechanism to modify sliding friction resistance and built a paddle that can be attached to the ends of the pendulum poles. A testing rig was also developed to consistently apply disturbances by tapping the pendulum pole, characterizing balancing performance. We perform a comprehensive analysis of the behavior and control of the pendulum. This begins by considering its dynamics, including the nonlinear differential equation that describes the system, its linearization, and its representation in the s-domain. The primary focus of this work is the development of two distinct control modes for the pendulum: a velocity control mode, designed to balance the pendulum while the cart is in motion, and a position control mode, aimed at maintaining the pendulum cart at a specific location. For this, we derived two different state space models: one for implementing the velocity control mode and another for the position control mode. In the position control mode, integral action applied to the cart position ensures that the inverted pendulum remains balanced and maintains its desired position on the rail. For both models, linear observer-based state feedback controllers were implemented. The control laws are designed as linear quadratic regulators (LQR), and the systems are simulated in MATLAB. To actuate the physical pendulum system, a stepper motor was used, and its controller was assembled in a DIN rail panel to simplify the integration of all necessary components. We examined how the optimized performance, achieved with the medium-length pendulum pole, translates to poles of other lengths. Our findings reveal distinct behavioral differences between the control modes

Lab experiences for teaching undergraduate dynamics

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.Includes bibliographical references (p. 443-466).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.This thesis describes several projects developed to teach undergraduate dynamics and controls. The materials were developed primarily for the class 2.003 Modeling Dynamics and Control I. These include (1) a set of ActivLab modular experiments that illustrate the dynamics of linear time-invariant (LTI) systems and (2) a two wheeled mobile inverted pendulum. The ActivLab equipment has been designed as shareware, and plans for it are available on the web. The inverted pendulum robot developed here is largely inspired by the iBOT and Segway transportation devices invented by Dean Kamen.by Katherine A. Lilienkamp.S.M