Search results
1 – 6 of 6Rini Akmeliawati, Taesam Kang, Spot Srigrarom and Agus Budiyono
JeongHwan Kim, Steven Aurecianus, Seonglok Nam, Jungkeun Park and Taesam Kang
The purpose of this paper is to introduce a low-cost quadrotor that can be used for educational purposes and investigate the applicability of a low-cost MEMS laser sensor for…
Abstract
Purpose
The purpose of this paper is to introduce a low-cost quadrotor that can be used for educational purposes and investigate the applicability of a low-cost MEMS laser sensor for accurate altitude control.
Design/methodology/approach
A single printed circuit board is designed to form the structure of the quadrotor. A low-cost MEMS motion sensor, a microcontroller and four small motors are mounted on the board. A separate laser sensor module measures the altitude. A remote controller is designed to control the quadrotor’s motion. The remote controller communicates with the quadrotor via wireless connection. Roll and pitch attitude stabilization is achieved using the proportional and derivative control algorithm. The applicability of an MEMS laser sensor for altitude control is also studied.
Findings
The low-cost quadrotor works well even though its body structure is made using a printed circuit board. Low pass and Kalman filters work well for attitude estimation and control application. The laser sensor is very accurate and good for altitude feedback; however, it has a relatively short measurement range and its sampling rate is relatively slow, which limits its applications. The vertical velocity obtained by differentiating the laser altitude has delay and inhibits suitable damping. Using the vertical velocity obtained by integrating the vertical accelerometer’s output, the damping performance is improved.
Originality/value
Developing a low-cost quadrotor that can be used for educational purposes and successfully implementing altitude control using a laser sensor and accelerometer.
Details
Keywords
Hardian Reza Dharmayanda, Agus Budiyono and Taesam Kang
The purpose of this paper is to design a model‐based robust controller for autonomous hovering of a small‐scale helicopter.
Abstract
Purpose
The purpose of this paper is to design a model‐based robust controller for autonomous hovering of a small‐scale helicopter.
Design/methodology/approach
The model is developed using prediction error minimization (PEM) system identification method implemented to flight data. Based on the extracted linear model, an H∞ controller is synthesized for robustness against parametric uncertainties and disturbances.
Findings
The proposed techniques for modelling provide a linear state‐space model which correlates well with the recorded flight data. The synthesized H∞ controller demonstrates an effective performance which rejects both sinusoidal and step input disturbances. The controller enables the attitude angle follow the reference target while keeping the attitude rate constant about zero for hover flight condition.
Research limitations/implications
The synthesized controller is effective for hovering and low‐speed flight condition.
Practical implications
This work provides an efficient hovering/low‐speed autonomous helicopter flight control required in many civilian UAV applications such as aerial surveillance and photography.
Originality/value
The paper addresses the challenges of controlling a small‐scale helicopter during hover with inherent modelling uncertainties and disturbances.
Details
Keywords
Agus Budiyono, Gigun Lee, Gyou Beom Kim, Jungkeun Park, Taesam Kang and Kwang Joon Yoon
– The purpose of this paper was to present the process of building hardware and software for a collision avoidance system of a quadrotor capable of an indoor autonomous flight.
Abstract
Purpose
The purpose of this paper was to present the process of building hardware and software for a collision avoidance system of a quadrotor capable of an indoor autonomous flight.
Design/methodology/approach
The system development was carried out in two steps. First, the quadrotor system was designed to mount mission equipments for an indoor flight. The prediction error minimization (PEM) method was used for system identification of the quadrotor, and the linear quadratic regulator (LQR) control method was used for the attitude control. Second, a collision detection system was realized by using a Kinect sensor, an embedded board and a ground control system (GCS). A Kinect sensor with embedded board can send the 3D depth information to GCS and then the GCS displays the 3D depth information with a warning message.
Findings
As the controller design requires a linear model, the PEM method was used in system identification. The LQR was used in controller design. It was found that the use of the PEM method for system identification was effective for developing a linear model required for a practical control system using LQR. As 3D depth information from a Kinect sensor is quite accurate in an indoor environment, a collision detection system with Kinect was successfully developed.
Practical implications
The step-by-step approach presented in this paper can be used to develop an autonomous aerial vehicle capable of navigating in an indoor environment with obstacles.
Originality/value
The primary contribution of the paper is the presentation of a practical method for developing a low-cost collision avoidance system for a quadrotor vehicle.
Details
Keywords
Nigar Ahmed, Abid Raza and Rameez Khan
The aim of this paper is to design a nonlinear disturbance observer-based control (DOBC) method obtained by patching a control method developed using a robust adaptive technique…
Abstract
Purpose
The aim of this paper is to design a nonlinear disturbance observer-based control (DOBC) method obtained by patching a control method developed using a robust adaptive technique and a DO.
Design/methodology/approach
For designing a DOBC, initially a class of nonlinear system is considered with an external disturbance. First, a DO is designed to estimate the external disturbances. This estimate is combined with the controller to reject the disturbances and obtain the desired control objective. For designing a controller, the robust sliding mode control theory is used. Furthermore, instead of using a constant switching gain, an adaptive gain tuning criterion is designed using Lyapunov candidate function. To investigate the stability and effectiveness of the developed DOBC, stability analysis and simulation study are presented.
Findings
The major findings of this paper include the criteria of designing the robust adaptive control parameters and investigating the disturbance rejection when robust adaptive control based DOBC is developed.
Practical implications
In practice, the flight of quadrotor is affected by different kind of external disturbances, thus leading to the change in dynamics. Hence, it is necessary to design DOBCs based on robust adaptive controllers such that the quadrotor model adapts to the change in dynamics, as well as nullify the effect of disturbances.
Originality/value
Designing DOBCs based on robust control method is a common practice; however, the robust adaptive control method is rarely developed. This paper contributes in the domain of DOBC based on robust adaptive control methods such that the behavior of controller varies with the change in dynamics occurring due to external disturbances.
Details