Shunichi Nozawa

Home-Assistant Robot for an Aging Society

Many countries around the world face three major issues associated with their aging societies: a declining population, an increasing proportion of seniors, and an increasing number of single-person households. To explore assistive technologies that can help solve the problems faced by aging societies, we have tested several information and robot technologies. This paper introduces research on a home-assistant robot, which improves the ease and productivity of home activities. For people who work hard outside the home, the assistant robot performs chores in their home environment while they are away. A case study of a life-sized robot with a humanlike functional body performing daily chores is presented. An integrated software system incorporating modeling, recognition, and manipulation skills, as well as a motion generation approach based on the software system, is explained. Moreover, because housekeepers perform chores one after another in their daily environment, we also aim to develop a system for continuously performing a series of tasks by including failure detection and recovery.

Development and verification of life-size humanoid with high-output actuation system

Life-size humanoids which have the same joint arrangement as humans are expected to help in the living environment. In this case, they require high load operations such as gripping and conveyance of heavy load, and holding people at the care spot. However, these operations are difficult for existing humanoids because of their low joint output. Therefore, the purpose of this study is to develop the highoutput life-size humanoid robot. We first designed a motor driver for humanoid with featuring small, water-cooled, and high output, and it performed higher joint output than existing humanoids utilizing. In this paper, we describe designed humanoid arm and leg with this motor driver. The arm is featuring the designed 2-axis unit and the leg is featuring the water-cooled double motor system. We demonstrated the arms high torque and high velocity experiment and the legs high performance experiment based on water-cooled double motor compared with air-cooled and single motor. Then we designed and developed a life-size humanoid with these arms and legs. We demonstrated some humanoids experiment operating high load to find out the arm and legs validity.

Development of life-sized high-power humanoid robot JAXON for real-world use

This paper presents the development of life-sized high-power humanoid robot JAXON. Humanoid robots for disaster relief assistance need the same degree of physical performance as humans. We have developed STARO as the high-power humanoid robot with a high degree of physical performance. However this is not enough for practical use of the humanoid robot in a disaster site. We consider the following as additional conditions to operate humanoid robots for disaster relief assistance outside of the lab in outdoor environments. 1) Robots have humanlike body proportion to work in infrastructure matched to human body structure. 2) Robots have energy sources such as batteries and act without tethers. 3) Robots walk with two legs or four limbs and continue to work without fatal damage in unexpected rollover. JAXON satisfied these conditions. We demonstrates the performance of JAXON through the experiment of getting out of a vehicle, stepping over walls, and operating on batteries. Further more, we assesses the performance of the strong armor and the shock absorbing structure through a backward over-turning accident.

Controlling the planar motion of a heavy object by pushing with a humanoid robot using dual-arm force control

Pushing heavy and large objects in a plane requires generating correct operational forces that compensate for unpredictable ground-object friction forces. This is a challenge because the reaction forces from the heavy object can easily cause a humanoid robot to slip at its feet or lose balance and fall down. Although previous research has addressed humanoid robot balancing problems to prevent falling down while pushing an object, there has been little discussion about the problem of avoiding slipping due to the reaction forces from the object. We extend a full-body balancing controller by simultaneously controlling the reaction forces of both hands using dual-arm force control. The main contribution of this paper is a method to calculate dual-arm reference forces considering the moments around the vertical axis of the humanoid robot and objects. This method involves estimating friction forces based on force measurements and controlling reaction forces to follow the reference forces. We show experimental results on the HRP-2 humanoid robot pushing a 90[kg] wheelchair.

System integration of a daily assistive robot and its application to tidying and cleaning rooms

This paper describes a software system integration of daily assistive robots. Several tasks related to cleaning and tidying up rooms are focused on. Recognition and motion generation functions needed to perform daily assistance are developed, and these functions are used to design various behaviors involved in daily assistance. In our approach, the robot behaviours are divided into simple units which consist of 3 functions as check/plan/do, it provides us with high reusable and flexible development environment. Because sequential task execution can be achieved only after functions about failure detection and recovery, we also try to implement such functions in keeping with this approach. In addition to using simple behavior unit, multilayer error handling is effective. Experiments doing several daily tasks with handling daily tools showed the effectiveness of our system.

Humanoid full-body controller adapting constraints in structured objects through updating task-level reference force

Manipulation of structured objects connected to the environment by a kinematics chain involves two problems: (a) The objects have movable directions and unmovable directions. An undesired reaction force in the unmovable directions prevents a robot from successful manipulation; (b) The reaction forces from the objects could fluctuate during manipulation. Related works have enabled robots to manipulate objects by integrating position control in movable directions and force control in unmovable directions at the hands. However, in the case of a humanoid robot, too large undesired reaction forces in movable directions cause the robots falling down and slipping. In this paper, we propose a controller system controlling reaction forces at the hands and successively updating reference forces based on reaction forces. For problem (a), we apply force control both to the movable and unmovable directions in order to satisfy both maintaining full-body balance and achieving manipulation. For problem (b), the update of the reference forces enables the humanoid robot to adapt to fluctuation of the reaction forces. We show experimental results on the cmanipulating four doors and a drawer.

Robust vertical ladder climbing and transitioning between ladder and catwalk for humanoid robots

This paper presents a novel control method to stabilize the whole-body motion of humanoid robots when climbing vertical ladders and transitioning between ladders and catwalks. In such environments, the body of the robot tends to incline and rotate because of the slippery surfaces. The inclination and rotation may cause the robot to fail to grasp and thus collide with the rungs. The proposed method modifies the subsequent contact position in real time based on the error of the current robot posture estimated with inertial measurement units (IMUs) and actual joint angles. This paper also presents a method of generating motion by minimizing the contact wrench. This method satisfies hardware limitations, such as collision avoidance, joint torque limits, and joint limits. Applying these methods to a humanoid robot, we realize the robust climbing and descending of multiple rungs of a vertical ladder and bidirectional transitioning from ladders to catwalks.

A full-body motion control method for a humanoid robot based on on-line estimation of the operational force of an object with an unknown weight

In this paper we propose a new method to manipulate heavy objects for a humanoid robot. In this method the manipulation strategy is determined based on on-line estimation of the operational force. We integrate these functions with a real-time controller that controls the external force and maintains full-body balance. The feature point of our work is that since a full-body control system includes switching of the manipulation strategy based on the operational force estimated on-line the system enables a humanoid robot to manipulate heavy objects as well as light objects. The effectiveness of our whole system is confirmed in our experiments, in which a humanoid robot manipulates up to 12[kg] while estimating the objects weight.

Wheelchair support by a humanoid through integrating environment recognition, whole-body control and human-interface behind the user

In this paper, we treat with wheelchair support by a life-sized humanoid robot. It is quite essential to integrate whole-body motion, recognition of environment and human-interface behind the user in order to achieve this task. Contributions of this paper is whole-body control including pushing motion using the offset of the ZMP and observation of the attitude outlier, recognition of the wheelchair using particle filter and human-interface behind the person using face detection and recognition of gesture.

On-line next best grasp selection for in-hand object 3D modeling with dual-arm coordination

Humanoid robots working in a household environment need 3D geometric shape models of objects for recognizing and managing them properly. In this paper, we make humanoid robots creating models by themselves with dual-arm re-grasping (Fig.1). When robots create models by themselves, they should know how and where they can grasp objects, how their hands occlude object surfaces, and when they have seen every surface on an object. In addition, to execute efficient observation with less failure, it is important to reduce the number of re-grasping. Of course when the shape of objects is unknown, it is difficult to get a sequence of grasp positions which fulfills these conditions. This determination problem of a sequence of grasp positions can be expressed through a graph search problem. To solve this graph, we propose a heuristic method for selecting the next grasp position. This proposed method can be used for creating object models when 3D shape information is updated on-line. To evaluate it, we compare the result of the re-grasping sequence from this method with the optimal sequence coming out of breadth first search which use 3D shape information. Also, we propose an observation system with dual-arm re-grasping considering the points when humanoid robots execute observation in the real world. Finally, we show the experiment results of construction of 3D shape models in the real world using the heuristic method and the observation system.