鈴木 智

In this study, the optimal mechanical design method for fixed-pitch coaxial-rotor helicopter is proposed. The fixed-pitch coaxial-rotor helicopter has several advantages compared with any single-rotor type or variable-pitch rotor type helicopters. For example, it has great simplicity of the mechanisms, well maintainability, and well energy conversion efficiency, and so on. However, fixed-pitch coaxial-rotor helicopter has a drawback in forward flight named pitch-up phenomenon. The pitch-up phenomenon causes a little cruise speed of the helicopter, and it is fatal problem in the practical operations. To overcome such a problem, optimal mechanical design of the fixed-pitch coaxial-rotor helicopter is proposed. The optimal design is based on the precise mathematical model of the helicopter and numerical optimization method. The mechanical parameters are examined to maximize the cruise speed of the helicopter. First, the dynamics of a fixed-pitch coaxial-rotor helicopter is modeled by using multi-body dynamics technique and aerodynamics theory. In the modeling, the helicopter is considered as a rigid body system consist of multiple rigid bodies, mission and frame unit, and rotors. Additionally, the aerodynamic interaction between upper and lower rotor is considered in the model. Second, mechanical parameter optimization based on derived mathematical model and Particle Swarm Optimization (PSO) method is proposed. Finally, the fundamental optimization of mechanical parameter is performed to show the validity of proposed optimal design method. In the simulation, the position of the universal joint is optimized to maximize the cruise speed of the helicopter.

Autonomous mobility robots are required a high performance to traverse rough terrain like loose soil with steeps. Our proposed robot has high mobility performance, especially; it can traverse loose soil with steep slopes. The proposed mechanism can support on surface of loose soil with steep slope because of it has "piles" which are penetrated into the soil. In this study, we research the optimal piles, for instance, the optimal diameter and the optimal penetrated length. We will furthermore carry out traversing experiments using slope actually, 20°, 25 °, 30°. From these results, we discuss traversing performance of the proposed mechanism.

In planetary explorations, rovers are required to traverse rough terrain that often includes craters (traces of meteorite impacts) and rear cliffs (walls that become bare as a result of not being covered with soil). Hence, it is important for the rovers not to overturn or lose mobility while traversing such terrain. Planetary rovers therefore are required a high performance to traverse rough terrain like loose soil with steeps. Our proposed robot has high mobility performance, especially; it can traverse loose soil with steep slopes. The proposed mechanism can support on surface of loose soil with steep slope because of it has "piles" which are penetrated into the soil. In other word, this robot can use earth pressure to support itself weight on loose soil with steep slope. The proposed robot has two bodies and four pile's units. Two bodies are connected two ball screws units. Therefore, the mobility motion of bodies is fro-back system. Then, the piles can be penetrated into soil by mechanism with up-down system. In this study, we research the optimal piles, for instance, the optimal diameter and the optimal penetrated length. We will furthermore carry out traversing experiments using slope actually, 20°, 25°, 30°. The supporting force of a pile moreover is measured by using the proposed experiment device. From these results, we discuss traversing performance of the proposed mechanism.

© 2014 The Japan Society of Mechanical Engineers. In this paper, collision-free guidance control of multiple small unmanned helicopters is designed. Collision avoidance of the helicopters should be considered in the control system design for safe operation. Therefore, a guidance control system using a distributed nonlinear model predictive control (DNMPC) is proposed to realize the collision avoidance. A constraint for the relative position vector between the each helicopter is considered in the design for efficient avoidance. Small single rotor helicopter is considered as controlled object, and the guidance control system is designed for the nonlinear translational model treated a helicopter as an ellipsoid. DNMPC is designed with three constraints, an input constraint, a state constraint, and a relative position vector constraint. An input constraint and a state constraint realize collision avoidance in input within the constant limits. If the moving path of the one helicopter is significantly affected by the moving path of other helicopter, the relative position vector constraint makes the helicopters exchange their relative position each other. By using these constraints, smooth collision avoidance is realized. The helicopters exchange information about current state and optimal input sequence each other for calculating the predictive trajectory of others. Based on the calculated trajectories, each helicopter solves its local optimization problem. Here, sharing the velocity information is difficult because calculation processing capability of the small sensor and communication capability between UAVs are restricted. Therefore, a dynamic compensator for velocity compensation is introduced. By introducing the dynamic compensator, collision avoidance using only exchange on the position and the input sequence information is accomplished without exchanging velocity information. The effectiveness of the proposed control system is verified by numerical simulations.

In this study, we aim to achieve an autonomous locomotion of the mobile robot in the unknown environment regardless of indoor and outdoor. An information obtained from indoor and outdoor environment are completely different. In indoor case, dense information like a wall could be obtained. However, only sparse information is obtained in outdoor case. Therefore, in this study, dense information of indoor environment is convert to sparse information and same navigation algorithm is performed in the indoor and outdoor environment. For the first step of the study, the autonomous locomotion of the mobile robot in unknown indoor environment is realized. In particular, a novel landmark construction and detection method are proposed. The landmark is generated by combined image and shape features. By combining these features, some fault of each features are filled up and robust landmark detection in various environment could be achieved. In the landmark detection step, we represent the new matching method with automatic weighting for each features. The confidences are made from image and shape indicators of degree of the characteristic. The effectiveness of the proposed landmark is verified by experiment. Moreover, we introduce the novel landmark based graph SLAM. In our method, the landmark detection is performed on each node of pose graph. Then, if the robot find the landmark which is detected once, local loop closure is generated and optimization is performed. The main advantage of the method is that we can perform graph optimization before find global loop-closure. Hence, our method can minimize global error of the graph even if the robot don't come back the place visited at once. The effectiveness of the proposed graph SLAM is verified by numerical simulation and experiment.

In this study, a control scheme and controller design for automatic take off and landing of a small unmanned helicopter are proposed. First, acceleration feedback controller is designed for stabilizing horizontal motion of the helicopter. In acceleration feedback controller, horizontal acceleration is estimated by using Kalman filter, and desired attitude to cancel out horizontal acceleration is generated by using estimated acceleration. Second, altitude controller by using ultrasonic sensor is designed to stabilize altitude of the helicopter near ground. Finally, each control system is verified by flight experiment, and automatic landing experiment is also carried out. © 2013 Springer-Verlag.

In this study, a control scheme and controller design for automatic takeoff and landing of a small unmanned helicopter are proposed. First, acceleration feedback controller is designed for stabilizing horizontal motion of the helicopter. In acceleration feedback controller, horizontal acceleration is estimated by using Kalman filter, and desired attitude to cancel out horizontal acceleration is generated by using estimated acceleration. Second, altitude controller is designed to make the altitude of the helicopter follow the desired altitude near ground. We employ ultrasonic sensor to measure the height above the ground. Finally, each control system is verified by flight experiment.

In order to estimate attitude by using a quaternion based on extended Kalman filter (EKF), the attitude sensor detects a direction of the gravity by using a tri-axis accelerometer. However, accelerometers are usually sensitive to both the gravity and dynamic accelerations. The attitude sensor mounted on unmanned systems takes attitude estimation errors by using directly outputs of accelerometer under dynamic acceleration environment. In this paper, the dynamic accelerations are dealt with explicitly, and two types of algorithms are proposed. In the first approach, measured accelerations are filtered, and divided into the gravity and dynamic accelerations. Using only the gravity, EKF estimates high accuracy of attitude. The second approach demonstrates adequate performance with EKF which includes the dynamical model of accelerations. This paper shows a critical comparison of attitude estimation algorithms under the dynamic acceleration environment for the autonomous control of unmanned systems.

In this study, we design the navigation and guidance control system for small four-wheel ground vehicle. Small and low-accuracy sensors (low-cost GPS, low-accuracy accelerometers) are used for navigation and control. Firstly, INS/GPS navigation system is designed to obtain high-accuracy position and velocity of the vehicle by using low-accuracy sensors. Secondly, velocity and heading controller for the vehicle are designed. Lastly, whole systems designed in this research are validated by the experiments. In the experiment, we use novel waypoint navigation method based on spline interpolation.

Unmanned helicopter is convenient at many situations like rescue and monitoring. However, radio control helicopter, which is known generally, is able to be operated only in the visible area of the operator. Moreover, unmanned helicopter of this type is difficult to control. In this background, many studies about autonomous control of unmanned helicopter have been carried out. In this paper, we present a fully autonomous control system for a small electric helicopter. First, we construct sensor system used for control. Next, we design the autonomous control system consist of rotor revolution control, attitude control, velocity control and position control. Finally, we verify the effectiveness of the autonomous control system by flight experiment.

In this paper, the design of a nonlinear adaptive controller for a single-rotor type small helicopter is described. First, the configuration of small autopilot device, which can be applied any single-rotor helicopters is presented. We construct the hardwear of the autopilot device based on FPGA (Field Programmable Gate Array). In the case of small helicopter, payload limitation of them is so tight. Therefore, we have to use only small and light weight sensors and computer for the control. All sensors we use are light enough and low cost, the total weight of the autopilot device with box is about 300 g. Next, the nonlinear adaptive attitude controller is designed by using backstepping method. We guarantee that the attitude of the helicopter can follow arbitrary time varying reference attitude, even when the helicopter model has the parameter uncertainty, such as inertia moment or aerodynamic uncertainties. Finally, the effectiveness of the adaptive attitude controller is verified by simulation with parameter uncertainties.

In this paper, the development of a quaternion-based navigation and autonomous control system for a small single-rotor helicopter is described. First, a quaternion-based small attitude sensor and an INS-GPS navigation system are constructed. The performance of the small attitude sensor is shown via a comparison with a commercial attitude sensor that is precise and heavy. A nonlinear attitude controller for a single-rotor helicopter is designed by using quaternion feedback, and a guidance controller is constructed with the attitude control system as an inner loop. Finally, a flight experiment is performed with a small electric helicopter, and the results indicate the effectiveness of the proposed navigation and control system.

Worldwide demand for robotic aircraft such as unmanned aerial vehicles (UAVs) and micro aerial vehicles (MAVs) is surging. Not only military but especially civil applications are being developed at a rapid pace. Unmanned vehicles offer major advantages when used for aerial surveillance, reconnaissance, and inspection in complex and inhospitable environments. UAVs are better suited for dirty or dangerous missions than manned aircraft and are more cost-effective. UAVs can operate in contaminated environments, for example, and at altitudes both lower and higher than those typically traversed by manned aircraft. Many technological, economic, and political factors have encouraged the development and operation of UAVs. New sensors, microprocessors, and propulsion systems are smaller, lighter, and more capable, leading to levels of endurance, efficiency, and autonomy that exceed human capacities. Comprising the latest research, this book describes step by step the development of small or miniature unmanned aerial vehicles and discusses in detail the integrated prototypes developed at the robotics laboratory of Chiba University. With demonstration videos, the book will interest not only graduate students, scientists, and engineers but also newcomers to the field. © Springer 2010. All rights are reserved.

本研究では, 上下方向速度を出力できない低精度GPSと気圧計を用いて, 小型電動ヘリコプタの3次元的な誘導制御を実現することを目的とする．まず，各センサのデータを複合させることで精度の高い3次元位置及び速度を出力する航法システムを構築する．続いて, 航法演算により得られたデータを用いた誘導制御系の構築を行い, 最後に, 飛行制御試験によってシステム全体の有効性を検証する.

In this paper, we propose an autopilot system which can be applied any single rotor helicopters. First, we construct the hardware of the autopilot system based on FPGA (Field Programmable Gate Array). In the case of small helicopter, payload limitation of them is tight. Therefore, we have to use only light weight sensors and computer for the control. All sensors we use are light weight, then the total weight of autopilot device with box is about 300g. Next, nonlinear adaptive attitude controller is designed by using adaptive backstepping method. We guarantee that the attitude of helicopter can follow any time varying reference attitude even if the helicopter has unknown model parameters, such as inertia moment or aerodynamic uncertainties. Finally, the effectiveness of the autopilot system is verified by flight experiments of multiple helicopters

In this paper, we propose an autonomous attitude control of a quad tilt wing-unmanned aerial vehicle (QTW-UAV). A QTW-UAV can achieve vertical takeoff and landing; further, hovering flight, which are characteristic of rotary-wing aircraft such as helicopter. And high cruising speeds, which is a characteristic of fixed-wing aircraft, can be also achieved by changing the angle of the rotors and wings by a tilt mechanism. First, we construct an attitude model of the QTW-UAV by using the identification method. We then design the attitude control system with a Kalman filter-based linear quadratic integral (LQI) control method; the experiment results show that a model-based control design is very useful for the autonomous control of a QTW-UAV.

In this paper, we propose an autonomous hovering control of hobby class small scale unmanned helicopter by using model based control method. Firstly, we make the model of small-scale unmanned helicopter analythically.Secondly, we designed control system with kalman filter based LQI control method. The control system consists of the attitude controller and the velocity controller. And we connect these two controllers to series. Finally, the hovering control experiment is carried out, and experiment result shows that analytic modeling method and model based control design are very useful for autonomous control for small scale unmanned helicopter.

In this paper, guidance control of small electric helicopter with low cost GPS is presented. In the case of small helicopter, the payload limitation is tight by comparison with larger one. So, we should use light weight, low cost and low accuracy GPS. At first, we combine the low cost GPS and a inertial navigation system(INS) with low accuracy inertia sensor, and INS/GPS composition navigation system is designed. And next, horizontal velocity and position model of small helicopter is derived, and then, guidance controller for small unmanned helicopter are designed by using model base control method. Finally, a flight control experiment with INS/GPS system is carried out, and the experimental results show the effectiveness of suggested navigation system and controller.

小型無人ヘリコプタはその機動性や利便性から多くのミッションへの利用が期待されている。 小型無人ヘリコプタにおいて重要なことは、高度、回転数を思い通りにコントロールすることである。高度と回転数の間には互いに連成があり、それらを考慮した制御系を設計することが求められる。 本稿では、高度、回転数制御の同時制御を実現する。

本研究では，小型無人ヘリコプタの主なアプリケーションである空撮等の作業の高効率化や，取得した情報の中継を行うシステムの構築を目指し，複数機を用いた編隊飛行制御を行うことを目的とする．規範モデル追従型モデル予測制御を各機体の誘導制御に適用し，軌道追従と衝突回避を考慮したリーダ・フォロイング型の編隊飛行制御系を構築し，シミュレーションと実験により制御系設計の有効性について検証を行う．

本研究では, 人工衛星等の制御に多く用いられているクォータニオンベースの姿勢制御則を小型電動ヘリコプタに適用し, 任意の目標姿勢に対して機体姿勢を追従させることを目的とする. まず, クォータニオンを用いたヘリコプタのMIMO非線形姿勢モデルを導出する. 続いて, 非線形制御の一手法であるバックステッピング法を用いて, 誤差システムの原点における漸近安定性を補償し, シミュレーションにより制御系の有効性を検証する.

本研究では, 軽量・低コストのセンサを複数組み合わせたセンサユニットを小型無人ヘリコプタに搭載し, 軌道追従制御などの自律制御を行うことを目的とする. まず, 前半部分において低精度センサデータより機体の位置・速度・姿勢を推定するための航法アルゴリズムを構築し, 続いて, 後半部分において航法演算により得られたデータを用いた誘導・姿勢制御系の構築を行う. そして最後に, 制御試験によってシステムの有効性を検証する.

近年，取り扱いの容易さや安全性の面から小型無人ヘリコプタが注目されている．本研究では，小型無人ヘリコプタの編隊飛行制御について述べる．目標値追従と機体間の衝突，通信の制約等を考慮した制御系を構成し，シミ ュレーションおよび実験により検証する．

QTWは科学観測等での利用を目的として開発中の無人航空機で、プロペラ付翼のティルト角を変更することにより、ヘリコプタモードからエアプレンモードへと連続的に飛行することが可能である。ヘリコプタモードの姿勢ダイナミクスをシステム同定手法により分析し、LQIコントローラを設計した。また、任意のティルト角でのマニュアル飛行を可能にする装置（PFCS）と自律制御器を組み合わせ、オペレータ支援用自律制御システムを設計し、有効性を検討した。

An autonomous unmanned helicopter is useful to check of electric line, shooting from mid-air etc, and if we can operate multiple helicopters, we can get the information more efficiently. In this paper, we discribe a formation flight control of Autonomous Small-Scall Unmanned Helicopters. We design the control system as leader following configuration, and model predictive controller is used for translational position control for each helicopter. The state constraint is considered in control calculation by using penalty function. To guarantee the stabilty, we use a terminal state cost on model predictive control. The stability analysis show that model predictive control has asymptotic stability. Minimal order disturbance obsever is used to estimate the unobsevable state variables and disturbance. Simulation results show the feasibility of the control strategy. For preparation of the formation flight control test, we carry out the experiment with single helicopter. The experimental results show that accurate control performance, constraint capability, and robustness against wind is achieved.

Helicopters have the mobilities of vertical take-off and landing and hovering not possible with fixed-wing aircraft. And they have been used for disaster prevention extinguishing fire airborne photographing , rescue, pesticide spraying, news report and transportation. Unmanned small helicopters are more convenient than manned helicopters. But their flight is very difficult and usually limited to flight visible to the operator. So training take long time. Which is why autonomous flight control is indispensable to practical unmanned helicopter use. Now height control use governor which conserve revolution. And this appliance is switched by the hand. So revolution control behoove for autonomous flight. This thesis carry on research which is revolution control. We use system identification approach for revolution data and derived engine model. And we analytically derived resistance torque based on aerodynamics. So we combined them and derived control model. We designed controller based on derived model using Plcontrol theory and actualize revolution control.

オイラー角を用いた姿勢制御系は，ホバリング付近でのみ適用が可能となっている．また，小型無人ヘリコプタの高速高機動性を生した自律飛行を行うためには，姿勢角が大きな場合における３軸姿勢制御が必要となると考えられる．そのため，姿勢表現法としてクォータニオン（四元数）を用いて姿勢制御系の設計を行う．

近年，航空機を多方面に活用するという観点から小型無人航空機の研究が活発に行われており，中でもヘリコプタはその3次元的な飛行形態を活かして様々な分野への応用が期待されている．小型無人機の自律飛行には精度のよい位置・速度情報をコストをかけずに取得することが重要となる．そこで，本研究では低価格なセンサを用いたINS/GPS複合航法システムを提案し，自律制御系に組み込み有効性を検証する．

本研究では、UAV/MAVに搭載することを目的とした小型のオートパイロットユニットの開発のための基礎研究として、オートパイロットユニット試作機をホビークラスの小型ヘリコプタSST-Eagleに搭載し、そのユニットを用いたホバリング制御を行うことを目的とします。<BR>具体的な進め方としては、センサシステムとヘリコプタのダイナミクスを複合したモデルを求め、そのモデルを元に設計された制御器をユニットに実装し自律制御を行います。

In this paper, we propose a method of autonomous take-off and landing of small unmanned helicopter in time of peace or emergency. On a concrete target, the algorithm which can perform take-off and landing safety in time of peace, is built on basis of velocity control of helicopter. On the other hand, the flight called autorotation landing as a landing means in emergencies, such as an engine trouble, is automated. Autorotation is a flight method of getting energy from air and obtaining a thrust by falling. And we verified the validity of the method by performing experiment.

This paper presents the optimal model for model based control of small-scale unmanned helicopter. We designed a multi-input/multi-output model of small-scale helicopter which refer Mettler's model, and we identified this model by frequency domain identification. Frequency domain and time domain validation results have shown that identified model can describe actual dynamics of helicopter, and we derive simple SISO model based on this MIMO model, so we prove experimentally that this SISO model is optimal model for model based control of small-scale unmanned helicopter.

小型無人ヘリコプタは、ホバリング飛行や垂直離着陸といったフレキシブルな飛行形態を持つ事から高所危険作業に広く用いられている。本研究では、そういった小型無人ヘリコプタのモデルベース制御に用いるためのモデルをシステム同定ソフトCIFERを用いて求めることを目的とする。