Hideaki Minakata

A Study of Energy-Saving Shoes for Robot Considering Lateral Plane Motion

In this paper, we propose a flexible shoe system for biped robots to optimize energy consumption of the lateral plane motion. This shoe system is made to deform decline outside in the lateral plane and it can absorb the kinetic energy of the robot in the lateral plane. Furthermore, this hardware (shoes) and software (controller) can be easily applicable to the ordinary walking robot system. The effectiveness and characteristics of this system are confirmed by computer simulations and experimental results. It is confirmed that the stiffness of the shoe is a very important parameter for energy consumption by using computer simulations and experimental results.

A study of CPG based walking utilizing swing of arms

In this paper, we propose CPG (central pattern generator) based walking utilizing swing of arms. This method is aiming the effective use of upper-body of the humanoid. In sense of CPG applications, CPG based pattern generation technique for lower-body was proposed by other researchers. So, we apply CPG technique to swing of arms. It can be expected that the utilization of arm swing provides good performance to yaw moment stability, and recovery from stumbling. The effectiveness of this method is confirmed as improvement of accuracy of straight walking

A study of flexible shoe system for biped robot

We have extended the idea of passive walking from the viewpoint of energetic efficiency, to realize medical, nursing and home-use robots. In this paper, we propose flexible shoe system to apply passive walking manner to ordinary humanoid biped. This flexible shoe system works as an arc-shaped foot. Besides, a 2DOF(Feedforward & Feedback) control scheme is used in this system, that realizes walking with less ankle torque. Computer simulation study confirmed that this shoe system reduces about 80% of energy consumption of ankle joint in some cases. Using an actual small biped, we also confirmed that suitable stiffness shoes reduce about 8% of walking energy of the robot.

A method of single camera robocup humanoid robot localization using cooperation with walking control

The target of robocup soccer is to beat humans world cup champion by 2050. Many kinds of technologies must be studied and developed for this purpose. In case of humanoid soccer league, the required technology level becomes higher and higher in every year. Besides, situations become closer to the practical use of humanoid robots for house, office, nursing and so on. The ideology of robocup is realized with the rules of each league. That is, there are many limitations for robocup kid-size soccer humanoid, such as robot height, foot size, and restrictions on sensors. We think that the most challenging subject under these limitations is the harmony of cost, mobility and intelligence. Our robot thus consists of single camera and small computers. In other words, our robot must estimate its field location with a costless equipment. In this paper, a method with single camera robot localization is presented. The maximum field of view is limited to 180 degrees (in 2008.) The camera can catch 2 landmarks (corner pole and goal) in usual cases. The global position information of each landmark can be used, so that the robot can get its field location by triangular surveying. The robot localization informed by two object distances is not so accurate, because the object distance from local vision system includes significant noises. Also, humanoid is not so suitable for camera carrier due to the vibrations occurred on high speed walking in actual matches. As a result, the cooperation of localization with walking control must be needed. We proposed here a method using error vector between estimation and command. In this method, the robot location can be estimated within 40 cm in most cases, with very small calculation cost.

Operationality improvement control of Electric power assisted wheelchair by fuzzy algorithm

This paper describes the operationality improvement control for electric power assisted wheelchairs. “Electric power assisted wheelchair” which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people, however, the performance of the straight and circular road driving must be further improved because the two wheels drive independently. This paper proposes the operationality improvement control by fuzzy algorithm to realize the stable and reliable driving on straight and circular roads. The suitable assisted torque of the right and left wheels is determined by fuzzy algorithm based on the posture angular velocity, the posture angle of the wheelchair, the human input torque proportion and the total human torque of the right and left wheels. Some experiments on the practical roads show the effectiveness of the proposed control system.

A study of energy-saving shoes for robot considering 3D motion

In this paper, we propose flexible shoe system for biped robot to optimize energy consumption of sagittal and lateral plane motion. This shoe system is made to deform decline outside in lateral plane and it can absorb the kinetic energy of the robot in lateral plane. Besides, this system supports sagittal plane motion like a rocking chair. Furthermore, this hardware (shoes) and software (controller) can be easily applicable to the ordinary walking robot system. The effectiveness and characteristics of this system is confirmed by computer simulations and experimental result. It is confirmed that stiffness of shoe is very important parameter for energy consumption

CIT Brains KidSize Robot: RoboCup 2014 Best Humanoid Award Winner

In this paper, we describe the system design of the robots developed by our Team CIT Brains for the RoboCup soccer humanoid KidSize league. We have been participating in the Humanoid League for eight years. Two years ago, we redesigned the system to put a large weight on maintainability and usability. In RoboCup 2014, we won the first prizes of 4on4 soccer and technical challenge. Consequently, we were awarded the Louis Vuitton Humanoid Cup. The system we developed has high mobility, well-designed control system, position estimation by a monocular camera, user-friendly interface and a simulator. The robot can walk speedily and robustly. It also has a feedback system with a gyro sensor to prevent falls. It detects positions of landmarks by color-based image processing. A particle filter is employed to localize the robot in the soccer field fusing the motion model and landmark observation.

A study of leg-extender exoskeleton

A leg extender exoskeleton is very useful when doing work involving tall shelves, looking around for security, etc. Therefore, we developed an exoskeleton with an active ankle joint. Its weight is approximately 12 kg and it extends the leg length by 40 cm. The operational feeling of exoskeleton may depend on the link length configuration. In this pager, the Linearity Index is introduced to realize natural feel of exoskeleton.

Gait characteristics of speed variable biped walking robot

Minakata and Hori (1998) proposed a method for real-time variable speed biped walking. From experimental results using that method, we found that there is a suitable relationship between walking speed and step cycle time. Besides, this relationship (we call this the gait characteristic) is similar to that of human walking. We consider the reason for these characteristics. Walking stability at various speeds and cycles was simulated. We found that shorter step cycle is more stable in higher speed walking. Also we tried a walking experiment with human characteristics. Acceptable walking speed range becomes smaller than the case with a suitable parameter for our robot. In addition, a 2-link passive joint biped walking model is considered for energy saving walking. Touchdown impact force is simulated and examined by an experimental system. Various gait patterns are simulated and classified to 3 patterns. From computer simulation, pattern B is superior for reduction of touchdown impact.

A study of foot strike phenomenon for piped walking machine

Biped walking has been regarded as a promising locomotion applicable to medical, nursing and home-service robots. However, the influences of foot strike have not been widely discussed. In this paper, we present the experimental result about the collision between the tip of a 2-link system and the floor. We compare the result with computer simulation. These considerations are used to improve the walking stability and energy efficiency with our actual biped machine.