This paper presents a 3D laser scanner that can gaze at an arbitrary region. By modulating the secondary rotation speed of roundly swinging 3D laser scanner, it gazes at a specific region and measures with high density measurement points. The proposed method uses a secondary rotation motor to control the measurement point density and no extra motor is required. The 3D scanner can keep the field of view of and scan cycle time while gazing at any region. The system is evaluated on experimental targets for different scenarios using a mobile robot.

This paper provides valuable information about 3-D map construction using a tracked vehicle at Disaster City. Disaster City is a training facility for the Federal Emergency Management Agency (FEMA) in the United States. FEMA staff used our rescue robot Kenaf to conduct simulated emergency testing. Kenaf is a tele-operated tracked vehicle that has high mobility suitable for use in outside terrains and inside buildings. We equipped Kenaf with a 3-D laser scanner that can measure dense and wide angle 3-D shapes. We collected about 50 3-D mapping data sets during the tests. A part of these data sets can be accessed at our website. In this paper, we explain the Kenaf's tele-operation system, the 3-D mapping system, and the comments about the usability of the 3-D mapping from FEMA staff. In addition, we discuss about the limit of our mapping method on the basis of the trials at Disaster City. This information will be helpful for researchers in the robotics to improve their method of 3-D map construction and their tracked vehicles.

The goal of rescue robotics is to extend the capabilities and to increase the safety of human rescue teams. During a rescue mission a mobile robot is deployed on a rescue site and is operated from a safe place by a human operator. The operator can not see the robot and the environment and a decision on the path selection is very complicated. Our goal is to provide a kind of automatic “pilot system” to propose an operator a good direction or several options to traverse the environment, taking into an account the robot's static and dynamic properties. To find a good path we need a special path search algorithm on debris and a proper definition of a search tree, which can ensure smooth exploration. While the main goal of the algorithm is to keep the robot maximally stable at every step of its path, in some cases we need the robot to lose its balance and to change a 3D orientation discontinuously. Losing balance on purpose is an important feature for safe climbing up and going down the debris and it is the central issue of this paper. Exhaustive simulations were used to structure and analyze data and experiments were used to verify our approach to removing unsuitable directions of the search from the search tree.

Tracked vehicles are frequently used as search-and-rescue robots for exploring disaster areas. To enhance their traversability on rough terrain, some are equipped with “active flippers.” However, manual control of such flippers also increases the operator's workload, particularly for teleoperation with limited camera views. To eliminate this tradeoff, we developed a shared autonomy system using an autonomous controller for flippers that is based on continuous three-dimensional terrain scanning. In our system, real-time terrain slices near the robot are obtained using three laser range sensors, and these are integrated to generate three-dimensional terrain information. In this paper, we introduce the autonomous controller for the flippers and validate the reliability of the shared autonomy system through experimental results on actual rough terrain.

This paper proposes a light-weight sensor platform that consists of gyro-assisted odometry and a 3D laser scanner for localization of human-scale robots. The gyro-assisted odometry provides highly accurate positioning only by dead-reckoning. The 3D laser scanner has a wide field of view and uniform measuring-point distribution. Robust and computationally inexpensive localization is implemented on the sensor platform using a particle filter on a 2D grid map generated by projecting 3D points on to the ground. The system uses small and low-cost sensors, and can be applied to a variety of mobile robots in human-scale environments. Outdoor navigation experiments were performed at the Tsukuba Challenge 2009, which is an open proving ground for human-scale robots. Our robot successfully navigated the assigned 1-km course in a fully autonomous mode multiple times.

We are developing robots for inspection of the under floor of houses. The developed robot system is reported in this paper. The mobile robot platform is based on a crawer type robot developed for rescue purposes. As sensors, a pan-tilt-zoom camera, top-view camera and SOKUIKI sensor are used. We constructed a test field and verified the performance of the robot.

Active flippers for tracked vehicles are very useful to improve traversability on uneven terrain. However it is widely known that control of flippers also increases the work-load for operators, particularly where the vehicle and the operator are far apart. To reduce the work-load, we aim to realize a sensor-based autonomous controller of flippers to enable a “semi-autonomous operation” of tracked vehicles. The “semi-autonomous operation” means that the only requirement for an operator is to indicate the robot’s direction. In this way, the robot is navigated autonomously through its sensors and actuators to surmount or avoid obstacles. In this research, two laser range sensors are used for terrain sensing, and gyro sensors are used for the measurement of the robot’s attitude. Based on such sensor system, we propose a strategy of simple sensor-based motion of active flippers for tracked vehicles to enable a semi-autonomous operation. In this paper, we introduce a strategy of motion of active flippers, and the stability analysis of tracked vehicles with active flippers. Finally, we report several experimental results to verify the validity of our approach.

Active flippers for tracked vehicles are very useful to improve traversability on uneven terrain. However it is widely known that control of flippers also increases the work-load for operators, particularly where the vehicle and the operator are far apart. To reduce the work-load, we aim to realize a sensor-based autonomous controller of flippers to enable a ‘semi-autonomous operation’ of tracked vehicles. In this research, two laser range sensors are used for terrain sensing, and gyro sensors are used for the measurement of the robot’s attitude. Based on such sensor system, we propose a strategy of simple sensor-based motion of active flippers for tracked vehicles to enable a semi-autonomous operation. In this paper, we introduce a strategy of motion of active flippers. Finally, we report several experimental results to verify the validity of our approach.

A rescue crawler robot having flipper arm has high ability to get over rough terrain, but it is hard to control its flippers in remote control. The authors aim at development of a semi-autonomous control system for the crawler robot. In the system, moving direction is specified by an operator at remote place. Joypad (Sony PS2 controller) is used as input devise. For increasing its stability and robustness about change of the environment, its flippers are controlled according to sensor informations which can be obtained in real-time. Concretely, the robot recognizes the environment (upward step or downward step) using its physical model, its postural information, flippers' contact and distance between the body and ground, and controls these flippers. In this movie, we show you performance of our proposed control method using "Aladdin".

A rescue crawler robot with flipper arms has high ability to get over rough terrain, but it is hard to control its flipper arms in remote control. The authors aim at development of a semi-autonomous control system for the solution. In this paper, the authors propose a sensor reflexive method that controls these flippers autonomously for getting over unknown steps. Our proposed method is effective in unknown and changeable environment. The authors applied the proposed method to Aladdin, and examined validity of these control rules in unknown environment.

Despite that omni-directional mobile robots have been investigated and used popularly, there are rarely useful command systems and control methods for practical applications. In this research, a command system to describe the navigation task for an omni-directional mobile robot is developed, and a motion generation method considering the robot geometry and the given trajectory is proposed. Furthermore, a control method to track the given linear and circular trajectories is proposed. A closed form kinematic model was utilized for motion generation and control as well. A redundantly actuated omni-directional mobile robot that consists of three caster-type wheel mechanisms with high performance embedded controller module was developed for the experiments. And some experiments in the real environment were carried out to verify the effectiveness of the proposed command system and the performance of the motion generation and the trajectory control method.

We propose a new mechanism of a unicycle. One feature of this robot is the shape of the wheel which is similar to a rugby ball. The other feature is that the body is separated into upper and lower parts. We give the details of a mechanism of the robot, simple controller system, and some results of a performance experiment using the designed controller. We present experimental results that show that the robot can move in a straight line and steer itself by the proposed mechanism.