The virtual studio which can make composite real image and computer graphics is indispensable equipments for broadcasting stations. However, it's difficult to use handy type cameras in such kind of studios, because it requires the precise camera movement data. So, we devised the new sensor which could measure angle and the 3 dimensional position of the camera, using Micro Electro Mechanical Systems (MEMS) and Particle Image Velocimetry (PIV) technology. We clarified the method of MEMS's noise control, and the development of a new image processing algorithm, we can get precision around 0.2[deg] by the new MEMS sensor, and within 3% to moving distance in a rate of 59.94[Hz] (video rate) by PIV process.
Human Support Robot (HSR), a safe and lightweight assistant robot with large range of tasks, has been developed to support disabled or aged people and their caregivers. In order for HSR to move around one's house autonomously, its path planning process needs to generate a path which can go through narrow spaces without collision with surroundings. However, determining such paths is a difficult task for wheeled robots with non-holonomic constraints like HSR because the path planning process needs to carefully detect collisions considering configurations of the robot while keeping smoothness of the path. To address this issue, we proposed a path planning method which is based on path optimization using three imaginary springs. With the proposed methods, collision-free smooth paths going through narrow spaces were generated in real time, and the HSR prototype was able to move through narrow spaces smoothly.
Pivoting manipulation is an effective method for carrying large and heavy objects which have high friction between the floor. In this paper, we propose the motion generation and control method for pivoting manipulation adaptive to the object state and contact force. The robot estimates the actual object motion and the required manipulation force online based on the kinematic and physical sensor feedback, and modifies the object path and the whole-body posture for pivoting manipulation. By this pivoting system, a robot can pivot the object without the knowledge of the object mass and friction parameter. Finally, we confirm that the proposed pivoting system enables a robot to acquire the adaptability to the variation of the object weight and the error of the object motion by the experiment, in which the life-sized humanoid robot carries the large furniture.
This paper focuses on the various movements of a human upper–limb on a horizontal plane and investigates the relationship among the muscle synergies, equilibrium–point (EP) trajectories and endpoint stiffness through the estimation of the EP trajectories and endpoint stiffness by two methods: (1) a novel estimation method by analyzing EMG signals under the concept of the agonist–antagonist (A–A) muscle pairs and (2) a conventional estimation method by using mechanical perturbations. The experimental results test the validity of the new method and suggest that (1) three muscle synergies represent the muscle activities of the human upper–limb movements on a horizontal plane; (2) each muscle synergy shows the balance among the coactivations of A–A muscle pairs; (3) the first and second muscle synergies are the invariant bases for the EP trajectory which is described in the polar coordinates centered on the shoulder joint. One synergy plays a role for the movement in the radius direction and another plays for the movement in the angular direction; and (4) the third muscle synergy is the invariant basis for additionally adjusting the endpoint stiffness. It influences the direction and size of the endpoint stiffness.
Human has a strong spine which can generate dynamic and flexible motion. We focus on its mechanisms and implement them to a robot spine of a musculoskeletal humanoid through hardware design. First, this paper describes methods to develop the robot spine which has both strength and flexibility. We separated 3 vertebra groups from the spine like a human and applied some machining methods to each group. Second, we show a human-like muscle arrangement of the spine including planar muscles. The planar muscles have larger surface and power than linear muscles designed with conventional methods. Therefore, the spine can keep its posture even if it receives force by a dynamic arm motion. Finally, we show a variable stiffness system of the spine to resist an impact by which the spine structure and muscles damage. We tested the system in the situation of whiplash injury which often occur in rear-end collision in a vehicle body.
Ultrasonic thrapy such as high intensity focused ultrasound and acoustic drug/gene delivery has a potential to provide minimal invasive and safe procedure. However, positioning of an ultrasound transducer accurately on a patient body is required. This paper provides a robotic approach to control position of a transducer and contact condition with a body surface. The robot which consists of three parallel links has six degrees of freedom. To control contact force with body surface, a six-axis force sensor is attached at the robot end-effector. The system has following three features: 1) measurement of body surface position and shape by using an optical tracking system, 2) collision avoidance path generation to automatically approach the robot to body surface, 3) contact force control between the transducer and the body surface, and 4) transducer direction control with keeping of contact force to a target in an intraoperative echogram. To valildate the system feasibility, corectness of body surcace reconstruction, positioning accuracy of the robot without contact, applied force to body surface using contact force control, and positioning accuracy to a target defined on an intraoperative echogram plane with contact force control. From the results, contact force is kept in appropriate range (1–6[N]) to emit ultrasound in the body and positioning accuracy in normal breathing is 0.5 ± 0.27[mm] and 1.6[mm] in the worst. The results demonstrated that the system has a great potential to realize accurate transducer positioning with contact to body surface.
Humanoid robots have been considered as a universal machine which can operate in place of human. This kind of universal machine requires human-like biped walking capability. In particular, it is important to avoid falling by appropriately switching behaviors even if there are unknown disturbances. This paper addresses a novel approach for switching of two types of motion controllers: standing balance controller and stepping motion controller. The former is designed as a regulator of the Center of Gravity (COG) and the latter is designed as a trajectory tracking controller. In the previous study, the authors presented the Maximal Output Admissible (MOA) set for the regulator. If the current COG state is included in the MOA set, it is possible to apply the regulator with the constraint on the center of pressure satisfied. In this paper, the author extends the MOA set to the trajectory tracking controller. This extension makes it possible to prevent a robot from falling by switching these controllers. The effectiveness of the proposed method is verified with simulations.
In this paper, we propose a new system for field robot under the environment without network infrastructure, called Simultaneous Environment-Modeling and Networking (SEMAN). With this system, field robot deploys the mobile wireless module to build up a wireless network for communication with base station, while modeling the environment such as mapping for navigation simultaneously. In our research, we apply this new system to aerial robot(quad-rotor), which can drop wireless modules in order. In this paper, firstly, we propose a deployment method of on-demand network, by dropping wireless modules based on the measurement of radio field intensity. We also present the topology of wireless network generated from wireless modules as well as the route search method for data transmission from robot to base station. Secondly, we show the control mechanism of quad-rotor and robot platform using the method of Simultaneous Localization and Mapping(SLAM) for navigation. Finally, we show the effectiveness of this SEMAN system quad-rotor in the flight experiment in indoor environment.
This paper describes an algorithm to reduce risks for personal mobility robots. The algorithm we propose is designed for mobility assistance robots that move around in everyday spaces such as pedestrian roads and shopping centers. Since such robots must be designed to remain safe while moving, we based our risk assessment on limiting their speed. Our algorithm allows for the completion of tasks safely based on the risk analysis, and can be used to calculate a speed limit for mobility assistance robots based on their environments. The algorithm is optimized for ensuring safe operation of practical life support robots. It is based on a 2D occupancy polar grid map updated in real time, with information on nearby obstacles. It can be adapted to various environments through the use of laser range finders, and is implemented in a low-cost microprocesser-based system. The implemented risk reducing algorithm has been evaluated through successive practicality tests at Robot Safety Center as well as public environments of the mobility robot special district at TSUKUBA, showing the validity of our approach.