Mobile Robot For Rough Terrain Research Articles

Development of rough terrain mobile robot with non-circular wheel

Development of rough terrain mobile robot with non-circular wheel

Realization of Rough Terrain Mobile Robot with an Elastic Telescopic Arm

Realization of Rough Terrain Mobile Robot with an Elastic Telescopic Arm

Development of Rough Terrain Mobile Robot Control Strategy Capable of Position and Direction Estimation by a Single Marker

In the present study, a mobile robot control strategy of rough terrain capable of position and direction estimation by a single marker was proposed, and the effect was performed. To realize wheel / caterpillar mobile robot movement on the rough terrain such as house farm, two major problems (1) the precise position estimation and (2) the direction estimation are important before the development of the control theory. Generally, the position / direction have been estimated by the wheel rotation (odometry) and gyro or acceleration sensor’s output integration, but there are many problems such as many impacts from the ground and the wheel slipping on the rough ground to the precise estimation. The aim of this study is to develop a method (algorithm) to estimate the mobile robot direction using a single marker placed at the top of the robot by changing the front movement and the target direction movement periodically. The reason using a single marker is that it is difficult process to find and analyze positions of the many markers attached on the robot in the camera image from a long distance, and the positions of many markers have been unstable by the tilting of the robot, agricultural product’s shadow, getting dirty of the body and so on.Our proposed method would be effective in the difficult situation to find or analyze the marker position of the robot surfaces by the reason of camera position and the environment, and it could realize wheels / caterpillar type mobile robot movement on the muddy situation.

Development of rough terrain mobile robot with non-circular wheel

Development of rough terrain mobile robot with non-circular wheel

Proposal of detachable 2-DoF tail mechanism for rough terrain mobile robots

Proposal of detachable 2-DoF tail mechanism for rough terrain mobile robots

Development of rough terrain mobile robot with non-circular wheel

Development of rough terrain mobile robot with non-circular wheel

多機能フリッパーアームを有する不整地移動体の開発

Natural disasters and terrorism occur frequently around the world in recent years, and the damage site may be in a situation where it is difficult for people to enter. When people investigate, explore and rescue such environments, it is very dangerous to consider the occurrence of secondary disasters due to building collapse and fire. It is considered effective to use a robot for dangerous work such as a disaster. Many robots with flipper arms have been developed as rough terrain mobile robots, but few researches have been done on the shape of flipper arms. Our laboratory has developed a special shaped multi-function flipper arm and a rough terrain mobile robot ALACRAN-3.

Gyro-based odometry associated with steering characteristics for wheeled mobile robot in rough terrain

Mobile robot used for planetary exploration performs several scientific missions over long distance travel and needs to have a high degree of autonomous mobility system because the communication delay from the Earth impedes its direct teleoperation. Localization of a mobile robot is of particular importance on the autonomous mobility. Classical localization methods such as wheel/visual odometry have been widely investigated and demonstrated, but they possess a well-known trade-off between computational cost and localization accuracy. This paper proposes an accurate gyro-based odometry method for a wheeled mobile robot in rough terrain. The robot in rough terrain is often subject to large wheel slip or vehicle sideslip related with its steering maneuver, and those slips degrade the localization accuracy. The basic approach of the proposed method is to exploit odometry data for the robot distance traveled as well as gyroscope data for the robot heading calculation; however each data-set is weighted in accordance with steering characteristics of a robot in rough terrain. The usefulness of the proposed method is examined through field experiments using a wheeled mobile robot testbed in Martian analog site. The experimental result confirms that the proposed method accurately estimates the robot trajectory.

不整地移動ロボット搭載を目的とした2次元移動距離センサの開発と性能評価

This paper describes a development of a planar travel distance sensor for a mobile robot in rough terrain. The sensor system with an optical flow device is relatively simple and achieves high sampling rate of millisecond order. The sensor performance is experimentally evaluated from the following points; measurement accuracy, velocity response, varied height with respect to terrain, disturbance light and terrain surface characteristics. The experimental results confirm that the developed sensor system is accurate, having less than a few percent error of distance traveled, and possesses wide dynamic range for traveling velocity of the robot, enabling wheel/vehicle slip detection. The paper also discusses the applicability of the sensor for practical scenario based on findings the experiment.

2A2-L02 GPSとジャイロドメトリのカップリング処理を用いた不整地移動ロボットの自己位置推定手法

2A2-L02 GPSとジャイロドメトリのカップリング処理を用いた不整地移動ロボットの自己位置推定手法

Design, Development, and Mobility Evaluation of an Omnidirectional Mobile Robot for Rough Terrain

Omnidirectional vehicles have been widely applied in several areas, but most of them are designed for the case of motion on flat, smooth terrain, and are not feasible for outdoor usage. This paper presents the design and development of an omnidirectional mobile robot that possesses high mobility in rough terrain. The omnidirectional robot consists of a main body with four sets of mobility modules, called an active split offset caster (ASOC). The ASOC module has independently driven dual wheels that produce arbitrary planar translational velocity, enabling the robot to achieve its omnidirectional motion. Each module is connected to the main body via a parallel link with shock absorbers, allowing the robot to conform to uneven terrain. In this paper, the design and development of the ASOC‐driven omnidirectional mobile robot for rough terrain are described. A control scheme that considers the kinematics of the omnidirectional mobile robot is presented. The mobility of the robot is also evaluated experimentally based on a metric called the ASOC mobility index. The mobility evaluation test clarifies a design tradeoff between terrain adaptability and omnidirectional mobility due to the shock absorbers. In addition, an odometry improvement technique that can reduce position estimation error due to wheel slippage is proposed. Experimental odometry tests confirmed that the proposed technique is able to improve the odometry accuracy for sharp‐turning maneuvers.

Longitudinal Associated Stability Analysis of Mobile Robot in Rough Terrain

Focusing on the longitudinal adaptability of a three-fuselage articulated with separated differential mechanism in rough terrain, the associated factor which could be a criterion for the judgment of longitudinal associated stability of mobile robot has been proposed, and the analysis results of the longitudinal associated stability under different situation have been obtained based on static stability theory of mobile robot.

Modeling and multiobjective optimization of traction performance for autonomous wheeled mobile robot in rough terrain

Application of terrain-vehicle mechanics for determination and prediction of mobility performance of autonomous wheeled mobile robot (AWMR) in rough terrain is a new research area currently receiving much attention for both terrestrial and planetary missions due to its significant role in design, evaluation, optimization, and motion control of AWMRs. In this paper, decoupled closed form terramechanics considering important wheel-terrain parameters is applied to model and predict traction. Numerical analysis of traction performance in terms of drawbar pull, tractive efficiency, and driving torque is carried out for wheels of different radii, widths, and lug heights, under different wheel slips. Effects of normal forces on wheels are analyzed. Results presented in figures are discussed and used to draw some conclusions. Furthermore, a multiobjective optimization (MOO) method for achieving optimal mobility is presented. The MOO problem is formulated based on five independent variables including wheel radius r, width b, lug height h, wheel slip s, and wheel rotation angle θ with three objectives to maximize drawbar pull and tractive efficiency while minimizing the dynamic traction ratio. Genetic algorithm in MATLAB is used to obtain optimized wheel design and traction control parameters such as drawbar pull, tractive efficiency, and dynamic traction ratio required for good mobility performance. Comparison of MOO results with experimental results shows a good agreement. A method to apply the MOO results for online traction and mobility prediction and control is discussed.

험한 지형 주행 운반 로봇 플랫폼의 개념 설계 및 분석

This paper presents conceptual design and analysis of the rough terrain mobile robot. The requirement list of the robot is derived to make it possible to deliver small robots and communication equipment to certain place. In addition, detailed analysis of the existing mobile mechanisms is performed. Based on the requirement list and analysis, the proposed rough terrain mobile robot is systematically designed and through extensive simulations, its capability of moving on various rough terrains is successfully verified.

1A2-G10 Theta^*を用いた不整地移動ロボットの自律ナビゲーションシステム(車輪型/クローラ型移動ロボット(2))

1A2-G10 Theta^*を用いた不整地移動ロボットの自律ナビゲーションシステム(車輪型/クローラ型移動ロボット(2))

2A2-L07 不整地移動ロボットRT-Moverのシートスライド機構による静的安定性向上に関する研究(特殊移動ロボット)

2A2-L07 不整地移動ロボットRT-Moverのシートスライド機構による静的安定性向上に関する研究(特殊移動ロボット)

Analysis, Design, and Control of an Omnidirectional Mobile Robot in Rough Terrain

An omnidirectional mobile robot is able, kinematically, to move in any direction regardless of current pose. To date, nearly all designs and analyses of omnidirectional mobile robots have considered the case of motion on flat, smooth terrain. In this paper, an investigation of the design and control of an omnidirectional mobile robot for use in rough terrain is presented. Kinematic and geometric properties of the active split offset caster drive mechanism are investigated along with system and subsystem design guidelines. An optimization method is implemented to explore the design space. The use of this method results in a robot that has higher mobility than a robot designed using engineering judgment. A simple kinematic controller that considers the effects of terrain unevenness via an estimate of the wheel-terrain contact angles is also presented. It is shown in simulation that under the proposed control method, near-omnidirectional tracking performance is possible even in rough, uneven terrain.

각가속도 변화에 의해 탐지된 슬립에 기반한 주행로봇의 견인력 제어

The common requirements of rough terrain mobile robots are long-term operation and high mobility in rough terrain to perform difficult tasks. In rough terrain, excessive wheel slip could cause an increase in the amount of dissipated energy at the contact point between the wheel and ground or, even more seriously, the robot could lose all mobility and become trapped. This paper proposes a traction control algorithm that can be independently implemented to each wheel without requiring extra sensors and devices compared with standard velocity control methods. The proposed traction algorithm is analogous to the stick-slip friction mechanism. The algorithm estimates the slippage of wheels by angular acceleration change, and controls the increase or decrease state of torque applied to wheels Simulations are performed to validate the algorithm. The proposed traction control algorithm yielded a 65.4% reduction of total slip distance and 70.6% reduction of power consumption compared with the standard velocity control method.

A Controller Design Method Based on a Neural Network for an Outdoor Mobile Robot

A wheeled mobile mechanism with a passive and/or active linkage mechanism for travel in rough terrain is developed and evaluated. In our previous research, we developed a switching controller system for wheeled mobile robots in rough terrain. This system consists of two sub-systems: an environment recognition system using a self-organizing map and an adjusted control system using a neural network. In this paper, we propose a new controller design method based on a neural network. The proposed method involves three kinds of controllers: an elementary controller, adjusted controllers, and simplified controllers. In the experiments, our proposed method results in less oscillatory motion in rough terrain and performs better than a well tuned PID controller does.

2P2-D16 ニューラルネットワークコントローラの不整地走行ロボットへの適用と実機検証 : 第3報 : ニューラルネットワークを用いた制御パラメータの決定(車輪移動ロボット)

A wheeled mobile mechanism with a passive and/or active linkage mechanism for rough terrain environment is developed and evaluated. In our previous research, we developed a switching controller system for wheeled mobile robots in rough terrain. In this paper, we focus on the decision of controller parameters using hyperplane of adjusted neural network. Our proposed controller shows almost same performance of adjusted neural network controller in the experiments of the climbing over the stairs, even though that controller consists of less parameter than neural network controller. And also, that controller shows better performance than well-tuned PID controller.