Fumihito Sugai

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.

Development of humanoid robot system for disaster response through team NEDO-JSK's approach to DARPA Robotics Challenge Finals

This paper presents Team NEDO-JSKs approach to the development of novel humanoid platform for disaster response through participation to DARPA Robotics Challenge Finals. This development is a part of the project organized by New Energy and Industrial Technology Development Organization. Technology for this robot is based on the recent research of high-speed and high-torque motor driver with water-cooling system, RTM-ROS inter-operation for intelligent robotics, and generation of full-body fast dancing motion, due to the generic 10 years research of HRP-2 as a platform humanoid robot. Development target is the robot support in a variety of unsafe human tasks teleoperated by humans in case of a disaster response, equipped with body structure capability for use of human devices and tools in human environment, performance for dynamic full-body actions covering human-sized speed and power, and basic function for intelligent and integrated robot platform system for performing various tasks independently. we also describes NEDO-JSK teams approach to design methodology for robot hardware and architecture of software system and user interface for DRC Finals as a test case of disaster response.

Rotational Sliding Motion Generation for Humanoid Robot by Force Distribution in Each Contact Face

Recent studies have explored humanoid robots in contact with the environment in various ways. However, many of them assumed static rather than sliding contacts. Studies on humanoid shuffle motion planning have realized sliding motions, such as turning, but relied on quasi-static balance control. In this letter, we propose a dynamic balance control method for sliding contact motions. The proposed method consists of the distributed force contact constraint (D.F.C.C.), which describes rotational sliding contact constraints, and the slide friction control (S.F.C.), which controls humanoid dynamic balance based on the model predictive control by using the D.F.C.C. The D.F.C.C. segments a contact face into a grid of contact points and optimize the vertical component of the contact forces. This enables us to calculate the sliding friction forces at each contact point. The S.F.C. is the model predictive control for distributing contact forces to each contact face considering sliding frictional dynamics. The D.F.C.C. is simple and easy to apply to the S.F.C. In our online stabilizer, we control not only a ZMP, but also contact forces for realizing the contact force distributions planned in the S.F.C. Finally, we show our methods validity through the experiment using life-sized humanoid robot JAXON.

NanoBridge-Based FPGA in High-Temperature Environments

The authors demonstrate a field-programmable gate array (FPGA) based on NanoBridge, a novel resistive-change switch. NanoBridge, which is integrated in the back end of line (BEOL), features a high on/off conductance ratio, weak temperature dependence of its resistance, nonvolatility, endurance against soft errors, and a small footprint. In place of static RAM (SRAM) and a pass transistor, NanoBridge is utilized as a configuration switch in the FPGA. In this article, the authors evaluate the NanoBridge-based FPGA (NB-FPGA) for applications in harsh environments. Specifically, they implemented NB-FPGA in a humanoid robot and compared its performance with that of the conventional FPGA. Results showed that NB-FPGA exhibits small variation in performance over a wide range of temperature, from −55 to 150 °C, and has high immunity for fluctuations in the power supply voltage.

Development of a low-cost ultra-tiny line laser range sensor

To enable robotic sensing for tasks with requirements on weight, size, and cost, we develop an ultra-tiny line laser range sensor based on the Time-of-Flight (TOF) principle. With delicate circuit design and optical attachments, we create a sensor as small as 35[mm] × 27[mm] × 30[mm] and as light as 20[g]. The line sensor samples 272 pixels (256 effective pixels) uniformly distributed within the measurement field of view customizable using different laser lenses. The optimal measurement range of the sensor is 0.05[m] ~ 2[m]. Higher sampling rates can be achieved with a shorter range. The sensor can also extend its range to 3[m] with reduced accuracy. We model the overall errors of the sensor and formulate calibration methods, achieving repeatable accuracy and measurement bias both within 2[cm] with our tested ambient lighting conditions and measurement ranges. The sensor is applicable to range sensing tasks including humanoid hand-eye measurement, UAV safe landing, tiny robot range sensing, and object detection.

Achievement of localization system for humanoid robots with virtual horizontal scan relative to improved odometry fusing internal sensors and visual information

To achieve tasks in unknown environments with high reliability, highly accurate localization during task execution is necessary for humanoid robots. In this paper, we discuss a localization system which can be applied to a humanoid robot when executing tasks in the real world. During such tasks, humanoid robots typically do not possess a referential to a constant horizontal plane which can in turn be used as part of fast and cost efficient localization methods. We solve this problem by first computing an improved odometry estimate through fusing visual odometry, feedforward commands from gait generator and orientation from inertia sensors. This estimate is used to generate a 3D point cloud from the accumulation of successive laser scans and such point cloud is then properly sliced to create a constant height horizontal virtual scan. Finally, this slice is used as an observation base and fed to a 2D SLAM method. The fusion process uses a velocity error model to achieve greater accuracy, which parameters are measured on the real robot. We evaluate our localization system in a real world task execution experiment using the JAXON robot and show how our system can be used as a practical solution for humanoid robots localization during complex tasks execution processes.

Walking control in water considering reaction forces from water for humanoid robots with a waterproof suit

In this paper, we develop a waterproof suit for humanoid robots and propose an underwater walking control method. Although very few life-sized humanoid robots are completely waterproof, we can easily make these humanoid robots watertight by putting a waterproof suit on them. In water, humanoid robots are influenced by the two forces due to the water: buoyancy and drag force. We take buoyancy into account when generating a walking pattern because the force is large and easy to estimate before walking. However, drag force is small and difficult to precisely predict and therefore, we treat the force as an unknown disturbance. In our method, we modify footsteps based on the Capture Point in order to deal with large disturbances. We verify the effectiveness of the proposed methods through an experiment in which a life-sized humanoid robot walks on a floor, stairs and debris in water.

Online master-slave footstep control for dynamical human-robot synchronization with wearable sole sensor

In this study, the authors aim to let us control the whole body of humanoid robot dynamically as we want. For that, the authors focused on the direct control of the humanoid leg that is the most severe problem with humanoid tele-operation. The authors implemented online real-time human motion imitation system for humanoid with its dynamics influence considered. In that system, the authors assume both operator and robot as a linear inverted pendulum, and apply humans COM, ZMP, and both feet positions for robot control input. The system includes two 6-axis force sensor under the operators sole, and the sensors can precisely detect contact of humans sole. Finally the authors succeeded to control two robots that have different COM height configuration.

Achievement of dynamic tennis swing motion by offline motion planning and online trajectory modification based on optimization with a humanoid robot

In order for a humanoid robot to achieve higher physical performance, it is important to generate dynamic whole-body motion under the constraints of physical limitations and dynamic balance. In this paper, we propose the method for generating dynamic whole-body motion such as sports motion based on optimization techniques. Taking a tennis forehand swing as an example of dynamic motion, we aim to increase the swing speed. The proposed methods are composed of the following two methods: 1) the offline swing optimization and 2) the online swing modification. In the offline swing optimization, we use non-linear optimization techniques to maximize the swing speed and satisfy the constraints. We generate all joint trajectories by optimizing control points of uniform B-splines. In the online swing modification, we modify a part of the optimized trajectories online considering joint velocity limits, since the predicted ball trajectory might change before a robot hits the ball. These methods are validated through the following experiments. First, we carry out the experiment in which the actual robot JAXON executes the optimal swing motion. We confirm that the method of the offline swing optimization generates the feasible motion which reaches up to 14.6m/s. We also apply the online swing modification to the optimized motion in the simulation. Then we evaluate how accurately we have to predict the ball trajectory.