Agus Budiyono

Hardcover: 250 pages
Publisher: Springer (April 2009)
Language English
ISBN-10: 3642002633
ISBN-13: 978-3642002632

The book largely represents the extended version of select papers from the International Conference on Intelligent Unmanned System ICIUS 2007 which was jointly
organized by the Center for Unmanned System Studies at Institut Teknologi Bandung, Artificial Muscle Research Center at Konkuk University and Institute of Bio-inspired
Structure and Surface Engineering, Nanjing University of Aeronautics and Astronautics.
The joint-event was the 3rd conference extending from International Conference on Emerging System Technology (ICEST) in 2005 and International Conference on
Technology Fusion (ICTF) in 2006 both conducted in Seoul. ICIUS 2007 was focused on both theory and application primarily covering the topics on robotics, autonomous
vehicles and intelligent unmanned technologies.

Table of contents

Image Processing in Optical Guidance for Autonomous Landing of Lunar Probe.- Locomotion Mechanism of Intelligent Unmanned Explorer for Deep Space Exploration.- Global Linear Modeling of Small Scale Helicopter.- Control of Small Scale Helicopter Using s-CDM and LQ Design.- Discontinuous Control and Backstepping Method for the Underactuated Control of VTOL Aerial Robots with Four Rotors.- An Insect-Like Flapping-Wing Device Actuated by a Compressed Unimorph Piezoelectric Composite Actuator.- Designing Cicada-Mimetic Flapping Wing with Composite Wing Structure and Application to Flapping MAV.- Robot-System for Management of Environmental Conditions Using Multiple Mobile Robot Types - Sample Application for Position Estimation.- Locomotion Elicited by Electrical Stimulation in the Midbrain of the Lizard Gekko gecko.- How Does "Intelligent Mechanical Design Concept" Help Us to Enhance Robot’s Function?.- Multiple Moving Obstacles Avoidance for Wheeled Type Robots Using Neural Network.- Virtual Reality Simulation of Fire Fighting Robot Dynamic and Motion.- Monotonic Decreasing Energy and Switching Control for Underactuated Manipulators.- Positive Real Synthesis of Networked Control System: An LMI Approach.- Controlled Switching Dynamical Systems Using Linear Impulsive Differential Equations.- Structural Damage Detection Using Randomized Trained Neural Networks.- Fault and Mode Switching Identification for Hybrid Systems with Application to Electro-Hydraulic System in Vehicles.

The document was used as a lecture note for the graduate course on flight control system at the Malaysian Institute of Aviation Technology (MIAT), Kuala Lumpur, Malaysia. Some parts of the document represent an enhanced version of the material given as an elective undergraduate course and a graduate course in optimal control engineering in the Department of Aeronautics and Astronautics at ITB, Bandung, Indonesia. Singgih S Wibowo helped prepare the typesetting of the formulas and check the MATLAB programs. The constructive inputs and feedback from students are also gratefully acknowledged.

The content of the text was developed from 15 years of experience in the aerospace industry. Authors were associated with Flight Test Center of Indonesian Aerospace Inc. (formerly Nusantara Aircraft Industry) where the first author was the founding director.  Case studies and examples were drawn from N-250 aircraft, the first fly-by-wire commuter in its class. Overall, the lecture note can suitably be used for teaching introductory flight control course at the undergraduate level. MATLAB codes associated with examples of control design are given as part of the text.

A model helicopter is more difficult to control than its full scale counterpart. This is due to its greater sensitivity to control inputs and disturbances as well as higher bandwidth of dynamics. This work is focused on designing practical tracking controller for a small scale helicopter following predefined trajectories. A tracking controller based on optimal control theory is synthesized as a part of the development of an autonomous helicopter. Some issues with regards to control constraints are addressed. The weighting between state tracking performance and control power expenditure is analyzed. Overall performance of the control design is evaluated based on its time domain histories of trajectories as well as control inputs.
Keywords: small scale helicopter, optimal control, tracking control, rotorcraft-based UAV

Small scale helicopters have been increasingly deployed for diverse scientific and commercial applications in the recent past. Their versatility has made them an ideal option for various missions ranging from film making, agriculture, volcanic surveillance to power line inspection. Compared to their full scale counterparts, however, the small scale helicopters posses a higher bandwidth of dynamics and a greater sensitivity to control inputs which make them more difficult to control. The paper deals with the control system design and testing for an autonomous small scale helicopter. A nonlinear dynamics model of the helicopter is derived from the Euler-Newton equations of motion. The nonlinear model is used as part of Hardware In the Loop Simulation (HILS) environment developed for the simulation, validation and testing of an autonomous control system. Linear control system is designed for the motion decoupled into longitudinal and lateral directional modes. The gains of the cascaded control architecture are optimized within the HILS environment. Various autonomous flight operations are achieved and it is demonstrated that the prediction from the simulations are in a good agreement with the flight experiment.

The paper presents the modeling of RUAV and the development of robust controllers to handle parameter uncertainties and disturbances. The model was developed by Prediction Error Minimization (PEM) system identification method. The PEM method is used in the time domain to extract a linear state space model from flight data. The result of the PEM-based optimization was a linear model which demonstrates a good match with the measured flight data and represents physical properties. The model was then used to synthesize a high performance controller for a small scale helicopter which is robust against wind disturbances. The synthesis of H-Infinity robust controller was elaborated and its performance was demonstrated for maintaining an autonomous hover.

An uninhabited air vehicle has found diverse applications for both civil and military missions. To achieve the stated mission, the vehicle needs to have a certain level of autonomy to maintain its stability following a desired path under embedded guidance, navigation and control algorithm.
To meet the increasingly more stringent operation requirements, the UAVs rely less and less on the skill of the ground pilot and progressively more on the autonomous capabilities dictated by a reliable onboard computer system.
A model helicopter was proposed and used as a flying test-bed for the purpose of developing the autonomous capability. The ability of the helicopter to operate in the hovering mode makes it an ideal platform for a step-by-step autonomous capability development. On the other hand, a
small helicopter exhibits not only increased sensitivity to control inputs and disturbances, but also a much richer dynamics compared to conventional UAVs including: higher bandwidth, hybrid modes, non-holonomic, under-actuation, multi-input-multi-output, and non-minimum phase. These factors make model helicopters, as a flying robot, more difficult to control. The paper addresses the challenge of building an autonomous aerial system using a mini scale rotorcraft.
The enabling technology building blocks were identified and a development scheme was proposed based on available resources. Recent progresses were reported in the modeling, design and development of embedded robust control system for autonomous helicopter.

Recent decades have witnessed increased interest in the design, development and testing of unmanned underwater vehicles for various civil and military missions. A great array of vehicle types and applications has been produced along with a wide range of innovative approaches for enhancing the performance of UUVs. Key technology advances in the relevant area include battery technology, fuel cells, underwater communication, propulsion systems and sensor fusion. These recent advances enable the extension of UUVs’ flight envelope comparable to that of manned vehicles. For undertaking longer missions, therefore more advanced control and navigation will be required to maintain an accurate position over larger operational envelope particularly when a close proximity to obstacles (such as manned vehicles, pipelines, underwater structures) is involved. In this case, a sufficiently good model is prerequisite of control system design. The paper is focused on discussion on advances of UUVs from the modeling, control and guidance perspectives. Lessons learned from recent achievements as well as future directions are highlighted.

There have been increased interests in the research on mechanical and control system of underwater vehicles in the recent past. These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys, military purposes, ecological and waters environmental studies, and also for entertainments. However, the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability. The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult.
On the other hand, fishes and other aquatic animals are efficient swimmers, posses high maneuverability, are able to follow trajectories, can efficiently stabilize themselves in currents and surges, create less wakes than currently used underwater vehicle, and also have a noiseless propulsion. The fish’s locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins part. They are classified into BCF (Body and/or Caudal Fin) and MPF (Median and/or paired Pectoral Fins). The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism.
There have not been many studies on underwater vehicles or fish robots using paired pectoral fins as thruster. The work presented in this paper represents a contribution in this area covering study, design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot. The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.

The recent decade has witnessed rapid progress in the design and development of autonomous flying robots. The paper closely examines the evolution of modeling and control for such vehicles. Modeling is viewed as an integral part of model-based control synthesis. The first half of the paper is focused on the review of modelling method for unmanned flying robot dynamics. The second half of the paper discusses a wide array of control methodologies that have proposed and reported in the literature. The state of the art of collision avoidance system as well as control for multi flying robots is highlighted.

RUAV (Rotorcraft based Unmanned Aerial Vehicle) have been exploited in various fields such as surveillance, reconnaissance and search. Most of the study in this area is focused on single RUAV; however using multiple unmanned vehicles is big advantage to accomplish the mission in a short time and effective way. Moreover little amount of research has been undertaken in the development of multiple RUAV control systems. This paper proposes a behavior-based decentralized approach that allows an RUAV to carry out its own mission of flying to a specified region while the distances between RUAVs are maintained constantly to avoid collision. The main goal of the proposed controller is to make the RUAV cooperate among each other to achieve the defined task. In this research Reynold's flocking model based behavior approach has been utilized. Along with this the testing environment for multiple RUAV is developed to validate proposed control algorithm. Complete setup is implemented and run under QNX RTOS, based on PC104 embedded board. The multiple RUAV is tested and evaluated using HILS (Hardware-In-the-Loop Simulation). To validate the proposed approach, simulation is performed to achieve the waypoint with multiple RUAVs.

In this paper additive fault detection and isolation method coupled with fault tolerant control architecture are developed in order to deal with component faults for a rotorcraft based unmanned aerial vehicle (RUAV). The failure considered is malfunction with internal components of the helicopter which occurs during the maneuvers: rotor angular rate variations, etc. These faults lead from trivial to catastrophic damage of the system. The proposed fault detection and reconfiguration control is based on a parameter estimation approach which drives a reconfigurable control system (RCS) build with the Pseudo-inverse method. The complete setup is implemented under Hardware-in-the-loop-simulation (HILS). The PC104 board with QNX RTOS platform is used for simulation. Simulation results illustrate the efficiency and effectiveness of the proposed approach.

A mini scale helicopter poses complex dynamics and is difficult to control. Compared to its full size counterparts, the model of mini scale helicopter exhibits not only increased sensitivity to control inputs and disturbances, but also higher bandwidth of its dynamics. The transition dynamics between modes can be formulated as a hybrid system. This paper investigates safety analysis of a helicopter model during modes transition using timed automata hybrid systems approach. The investigation is limited to hover and cruise modes in the helicopter model.

Design and development of unmanned aerial vehicles has attracted increased interest in the recent past. Rotorcraft UAVs, in particular have more challenges than its fixed wing counterparts. More research and experiments have been conducted to study the stability and control of RUAVs. A model-based control system design is particularly of our interest since it avoids a tedious trial and error process. To be able to successfully stabilize and control the RUAVs therefore a sufficiently accurate model is necessary. There are many methods in modeling small-scale rotorcraft. Using a standard first-principle based modeling approach, considerable knowledge about rotorcraft flight dynamics is required to derive the governing equation. Another method is system identification from flight data. This paper presents a method for system identification using Neural Networks. Input-output data are provided from nonlinear simulation of X-Cell 60 small scale helicopter. The data is used to train the multi-layer perceptron combined with NNARXM time regression input vector to learn nonlinear behavior of the vehicle.

Developing an autonomous rotorcraft-based unmanned aerial vehicle presents higher level and difficult challenges than most of the robots in general. A miniature rotorcraft, with four control inputs and six degrees of freedom, has an inherently multivariable behavior that exhibits coupling effects among the different axes of motion. The dynamics of this type of aerial vehicle is characterized by instability, high-order and sensitivity to disturbance. For rotorcraft to function as a stable mobile platform in changing flight conditions, therefore, its dynamics must be understood and modeled as the basis for controlling such a vehicle. The paper presents a development of linear model of a small scale helicopter using multi input multi output time domain identification system. The results from first principle approach are used as initial condition in the prediction error minimization scheme to achieve convergence. It is demonstrated that the proposed technique can enhance the accuracy of dynamics model obtained from the first principle prediction. Using the technique, the establishment of global helicopter linear model can be achieved for a practical design of linear control laws.

There is a growing interest in developing an autonomous small-scale helicopter due to its unique capabilities such as vertical take-off and landing from unprepared sites, wide ranges of flight capabilities (hover, cruise, pirouetting, nap-of-the-earth flight), and high maneuverability in tightly constrained environments. Developing an autonomous unmanned small-scale helicopter presents difficult challenges due to its dynamic behavior which is inherently unstable, of high-order and cross-coupled. The control design of such a vehicle thus should be conducted in a systematic way taking into account the risk associated with the flight testing of autonomous unmanned aerial vehicles.
The contribution of the paper is centered on the development of Hardware in the Loop simulator (HILs) for the purpose of control synthesis validation of an autonomous rotorcraft-based unmanned aerial vehicle (RUAV). An instrumented miniature helicopters GR-260 PUH and Xcell-60 were used as the research test-beds. The dynamic model of the mini helicopter was derived by using Newton-Euler equation. The nonlinear dynamic model was configured to be run in the real-time simulation environment. The simulation architecture consists of two xPC target computers along with servo motor board that drives the helicopter actuators. The first computer runs the real time simulation of vehicle dynamics while the second one configured as the controller. The overall real time hardware configuration was setup using xPC toolbox and Real Time Workshop (RTW) within MATLAB/Simulink environment. The performance of real time hardware facility is critically evaluated based on its fidelity with respect to actual flight data as well as its feasibility as a medium for the validation of control system design in general

A mini scale helicopter poses a difficult control
problem due to its complex dynamics. Compared to its full-size counterparts, the model helicopter exhibits not only increased sensitivity to control inputs and disturbances, but also higher bandwidth of its dynamics. We specifically investigate the control for transition dynamics between hover and cruise by formulating the phenomena as a hybrid system. We consider piecewise quadratic Lyapunov-like functions that leads to linear matrix inequalities (LMIs) characterization for performance analysis and controller synthesis. State jumps of the controller responding to switched of plant dynamics are exploited to improve control performance. The transition control
performance is demonstrated by SIMULINK and STATEFLOW
and compared to that of LQR approach.

The control of small-scale helicopter is a MIMO problem. To use the classical control approach to formally solve a MIMO problem, one needs to come up with multidimensional Root Locus diagram to tune the control parameters. The problem with the required dimension of the RL diagram for MIMO design has forced the design procedure of classical approach to be conducted in cascaded multi-loop SISO system starting from the innermost loop outward. To implement this control approach for a helicopter, a pitch and roll attitude control system is often subordinated to a, respectively, longitudinal and lateral velocity control system in a nested architecture. The requirement for this technique to work is that the inner attitude control loop must have a higher bandwidth than the outer velocity control loop which is not the case for high performance mini helicopter. To address the above problems, an algebraic design approach is proposed in this work. The designed control using s-CDM approach is demonstrated for hovering control of small-scale helicopter simultaneously subjected to plant parameter uncertainties and wind disturbances.

The establishment of global helicopter linear model is very precious and useful for the design of the linear control laws, since it is never afforded in the published literatures. In the first principle approach, the mathematical model was developed using basic helicopter theory accounting for particular characteristic of the miniature helicopter. No formal system identification procedures are required for the proposed model structure. The relevant published literatures however did not present the linear models required for the design of linear control laws. The paper presents a step by step development of linear model for small scale helicopter based on first-principle approach. Beyond the previous work in literatures, the calculation of the stability derivatives is presented in detail. A computer program is used to solve the equilibrium conditions and then calculate the change in aerodynamics forces and moments due to the change in each degree of freedom and control input. The detail derivation allows the comprehensive analysis of relative dominance of vehicle states and input variables to force and moment components. Hence it facilitates the development of minimum complexity small scale helicopter dynamics model.

A rotorcraft-based unmanned aerial vehicle exhibits more complex properties compared to its full-size counterparts due to its increased sensitivity to control inputs and disturbances and higher bandwidth of its dynamics. As an aerial vehicle with vertical take-off and landing capability, the helicopter specifically poses a difficult problem of transition between forward flight and unstable hover and vice versa. The LPV control technique explicitly takes into account the change in performance due to the real-time parameter variations. The technique therefore theoretically guarantees the performance and robustness over the entire operating envelope. In this study, we investigate a new approach implementing model identification for use in the LPV control framework. The identification scheme employs recursive least square technique implemented on the LPV system represented by dynamics of helicopter during a transition. The airspeed as the scheduling of parameter trajectory is not assumed to vary slowly. The exclusion of slow parameter change requirement allows for the application of the algorithm for aggressive maneuvering capability without the need of expensive computation. The technique is tested numerically and will be validated in the autonomous flight of a small scale helicopter.

A mini scale helicopter exhibits not only increased sensitivity to control inputs and disturbances, but also higher bandwidth of its dynamics. These properties make model helicopters, as a flying robot, more difficult to control. The dynamics model accuracy will determine the performance of the designed controller. It is attractive in this regards to have a controller that can accommodate the unmodeled dynamics or parameter changes and perform well in such situations. Coefficient Diagram Method (CDM) is chosen as the candidate to synthesize such a controller due to its simplicity and convenience in demonstrating integrated performance measures including equivalent time constant, stability indices and robustness. In this study, CDM is implemented for a design of multivariable controller for a small scale helicopter during hover and cruise flight. In the synthesis of MIMO CDM, good design common sense based on hands-on experience is necessary. The low level controller algorithm is designed as part of hybrid supervisory control architecture to be implemented on an onboard computer system. Its feasibility and performance are evaluated based on its robustness, desired time domain system responses and compliance to hard-real time requirements.

The last decade has witnessed increasing worldwide interest in the research of underwater robotics with particular focus on the area of autonomous underwater vehicles (AUVs). The underwater robotics technology has enabled human to access the depth of the ocean to conduct environmental surveys, resources mapping as well as scientific and military missions. This capability is especially valuable for countries with major water or oceanic resources. As an archipelagic nation with more than 13,000 islands, Indonesia has one of the most abundant living and non-organic oceanic resources. The needs for the mapping, exploration, and environmental preservation of the vast marine resources are therefore imperative. The challenge of the deep water exploration has been the complex issues associated with hazardous and unstructured undersea and sea-bed environments. The paper reports the design, development and testing efforts of underwater vehicle that have been conducted at Institut Teknologi Bandung. Key technology areas have been identified and step-by-step development is presented in conjunction with the need to meet the challenge of underwater vehicle operation. A number of future research directions are also highlighted.

In response to the interest to re-use Palapa B2R satellite nearing its End of Life (EOL) time, an idea to incline the satellite orbit in order to cover a new region has emerged in the recent years. As a prolate dual-spin vehicle, Palapa B2R has to be stabilized against its internal energy dissipation effect. This work is focused on analyzing the dynamics of the reusable satellite in its inclined orbit. The study discusses in particular the stability of the prolate dual-spin satellite under the effect of perturbed field of gravitation due to the inclination of its elliptical orbit. Palapa B2R physical data was substituted into the dual-spin's equation of motion. The coefficient of zonal harmonics J2 was induced into the gravity-gradient moment term that affects the satellite attitude. The satellite's motion and attitude were then simulated in the perturbed gravitational field by J2, with the variation of orbit's eccentricity and inclination. The analysis of the satellite dynamics and its stability was conducted for designing a control system for the vehicle in its new inclined orbit.

In general, most of communication satellites were designed to be operated in geostationary orbit. And many of them were designed in prolate dual-spin configuration. As a prolate dual-spin vehicle, they have to be stabilized against their internal energy dissipation effect. Several countries that located in southern hemisphere, has shown interest to use communication satellite. Because of those countries southern latitude, an idea emerged to incline the communication satellite (due to its prolate dualspin configuration) in elliptical orbit. This work is focused on designing Attitude Stability System for prolate dual-spin satellite in the effect of perturbed field of gravity due to the inclination of its elliptical orbit. DANDE (De-spin Active Nutation Damping Electronics) provides primary stabilization method for the satellite in its orbit. Classical Control Approach is used for the iteration of DANDE parameters. The control performance is evaluated based on time response analysis.

This paper presents one approach in designing a Fire Fighting Robot which has been contested annually in a robotic student competition in many countries following the rules initiated at the Trinity College. The approach makes use of computer simulation and animation in a virtual reality environment. In the simulation, the amount of time, starting from home until the flame is destroyed, can be confirmed. The efficacy of algorithms and parameter values employed can be easily evaluated. Rather than spending time building the real robot in a trial and error fashion, now students can explore more variation of algorithm, parameter and sensor-actuator configuration in the early stage of design. Besides providing additional excitement during learning process and enhancing students understanding to the engineering aspects of the design, this approach could become a useful tool to increase the chance of winning the contest.

A computational method on damage detection problems in structures was conducted using neural networks. The problem that is considered in this works consists of estimating the existence, location and extent of stiffness reduction in structure which is indicated by the changes of the structural static parameters such as deflection and strain. The neural network was trained to recognize the behaviour of static parameter of the undamaged structure as well as of the structure with various possible damage extent and location which were modelled as random states. The proposed techniques were applied to detect damage in a simply supported beam. The structure was analyzed using finite-element-method (FEM) and the damage identification was conducted by a back-propagation neural network using the change of the structural strain and displacement. The results showed that using proposed method the strain is more efficient for identification of damage than the displacement.

As part of a continuous research and development of underwater robotics technology at ITB, a vision- based distance
measurement system for an Unmanned Underwater vehicle (UUV) has been designed. The proposed system can be used to predict horizontal distance between underwater vehicle and wall in front of vehicle. At the same time, it can be used to
predict vertical distance between vehicle and the surface below it as well. A camera and a single laser pointer are used to obtain data needed by our algorithm. The vision-based navigation consists of two main processes which are the detection of a laser spot using image processing and the calculation of the distance based on laser spot position on the image.

The operational demand for unmanned underwater vehicles has been growing rapidly in the recent past. For long range operations, such as oceanographic exploration and surveying, autonomous underwater vehicles (AUVs) which are equipped with on-board power and advanced control and navigation, have more promises to carry out tasks with the minimum operator intervention. Unlike other fixed platforms, autonomous underwater vehicles are particularly of interest due to theirability to provide continuous spatial and temporal observations. The safe operation of AUV relies on its autonomous navigation and control system. The paper is concerned with the synthesis of control system for an autonomous underwater vehicle using a coefficient diagram method. CDM is an algebraic approach applied to polynomial loop in the parameter space, where the so-called coefficient diagram is used as the means to convey the necessary design information and as the criteria of good design. The effectiveness of the control technique is demonstrated through a number of automatic control designs for motions in the longitudinal mode of AUV Squid, an autonomous underwater robotic designed and developed at Institut Teknologi Bandung.

Shrimp ROV is the most recent underwater vehicle that has been developed at Center for Unmanned System Studies (CentrUMS)-ITB. This type of vehicle is typically designed for environmental or scientific surveillance mission as well as for Small Observation ROV with military functions. One of them is Minesweeper ROV. The present study consists of the thruster design of ITB SHRIMP-ROV as its main propulsion device. In the thruster design, we used and applied Finite Element Analysis for calculating structural strength and Computational Fluid Dynamics (CFD) for identification of fluid characteristic on thruster. All the testing at this stage is performed in the laboratory.

Unmanned Underwater Vehicle (UUV) is developed for various applications from civil until military requirement. One of the most important UUV missions is surveillance including mapping of marine resources and monitoring of the sea environment to prevent the destructive activities. Underwater security becomes more crucial for the country that’s have thousands island. The study comprises the design of special Unmanned Underwater Vehicle, the SHRIMP-ROV (Remotely Operated Vehicle). This UUV has special configuration and mechanism that can be functioned as a surveillance agent (observation UUV) and as minesweeper agent. The detail idea, design background and step by step of design methods were observed in this study.