In recent years, multi-rotor helicopters are applied to many tasks. Force control is effective for a task with a contact with an environment. Force control of single-rotor helicopter is proposed. However, the force control of a dual rotor helicopter has not been proposed. This paper proposes a force control system using Dual-rotor helicopter. The proposed system is based on attitude and total thrust control. The validity of the proposed control system is verified by simulation and experiment.

In recent years, the damage to crops caused by wild animals increases and becomes serious problems. In general, fences or nets are used to avoid damage to crops. However, it does not lead to dramatic decrease. In this research, we develop a small-size quadcopter for support of agricultural activities. Quadcopter can fly around agricultural fields without being obstructed by obstacles on the ground. It might be able to patrol agricultural fields, search and detect wild animals from the sky excepting human and scare wild animals away. In this paper, we develop a small-size quadcopter with thermal camera and propose the method for detecting wild animals excepting human.

This paper presents measurement of trees using depth camera mounted on multicopter for application to forestry. In our previous paper, we have developed a multicopter with depth camera and have proposed the environmental map generation method using the depth camera mounted on multicopter. In this paper, we verify accuracy of generated environmental maps by measuring diameters of poles which is indoors and a tree which is outdoors. Moreover, we develop path generation method for autonomous flight to be achieved in the forest.

In recent years, the number of the aging dams are increasing. In Japan, more than 3,000 dams are existing and cracks are generated in some of these dams. So, we present an underwater multirotor helicopter as the underwater investigation tool. In this study, we developed the underwater multirotor helicopter that prevents accidents due to water, and investigated the performance of diving maneuver. We used the rotor which is able to do positive rotation and negative rotation. The underwater multirotor helicopter moves in air by spinning rotor to provide the ascending thrust. On the other hand, the underwater multirotor helicopter moves in water by spinning rotor to provide the descending thrust.

Laser range finder is often used for an interface robot to detect people. Sometimes there is a blind spot in its scan area because it scans by infrared. The blind spot causes an error for people detection. In this study, we have considered using a linear unit and moving a laser range finder horizontally. In this paper, we confirmed that blind spot how much is reduced by calculations and experiment. If two persons are walking parallel to the linear unit, the blind spot is reduced about 80 percent by linear unit move to 300 mm. In the case of maximum blind spot, it is reduced about 54 percent. Half of a person in blind spot is found from laser range finder by using linear unit.

Our objective of this study is the development of a perfect voice recognition system using multi-SEMG that are measured from the human neck. In order to establish this objective a SEMG analyzing system is experimentally developed. In this paper, we will talk about the voice recognition results using this system. Actually, we conducted experiment which investigated whether this system can distinguish korea language vowel and consonant. In this experiment, we used 4 channel SEMG measured from subject’s neck. Positions of electrodes were determined using our developed Monte Carlo method. This method is able to select suitable positions of electrodes to detect pronounced voice. An experiment was carried out to see whether korea language pronunciations were distinguished each other using our developed method. In this paper we will talk about the results of this experiment.

In recent years, the music market has changed from CD to digital distribution. MP3 is the representative compressed sound source of online music distribution services. However, MP3 formatted quality is inferior to uncompressed sound sources such as CD-DA formatted. Because MP3 formatted quality has less information as compared to pre-compressed data and MP3 sound source is changed data on the basics of audio property. The object of study is by analyzing EEG to determine if people can recognize such difference sound. This time we divide into two subject patterns which worry about less information quality data such as MP3 formatted whereas others don't worry about less information data. And we compered uncompressed sound and compressed sound while LPCM(CD-DA,16bit/44.1Hz) sound source and MP3 (64kbps,128kbps,256kbps,320kbps) sound sources by use of EEG analysis. As a result we cloud find the difference. So we report the progress of this study.

This paper introduces practical design and hardware implementation issues of a sensor-positioner prototype toward enlarging the field-of-view (FoV) of robots. When human beings intend to carefully look the unseen side of an object located on their front, they move their head from side to side. Based on such an inspiration experienced, a translating and rotating sensor positioner prototype is designed and implemented. Furthermore, the prototype with a particular emphasis on variable rotation range and speed, as well as 360-degree observation capability has been developed. This paper provides a detailed presentation on how to realize the sensor positioner and integrate it with a mobile robot. The functionality of the positioner mounted on a mobile robot and the effectiveness of the observation scheme are verified through extensive experiments.

This paper reports near-infrared light (NIR) sensing system for non-contact pulse measurement. Measurement of the physiological conditions such as heart beat rate (HBR) and heart rate variety (HRV) in daily life becomes important subjects in aging society. Pulse wave is considered to be important parameter to estimate the health condition. However, conventional pulse sensors constrain the body of the measured person during measurement, and is not suitable for the life logging. Although pulse measurement using CCD achieved non-contact measurement, this method is easily affected by fluctuation of ambient light intensity. We fabricated non-contact pulse measurement system using nearinfrared light for stable measurement of HBR and HRV. This sensor corrects the scattering light to improve S/N ratio. We also investigate the suitable area of pulse measurement in face by our developed unconstraint pulse sensor. Finally, we demonstrated pulse measurement and compare the HBR and LF/HF calculated by HRV with unconstraint pulse sensor.

Stereo microscope is a relatively low magnification, without the observation sample to such thinly sliced an optical microscope that can be observed as it is, mainly, assembly and disassembly, such as machinery and electronic parts, used in such as a biological sample anatomy. On the other hand, it has been used a variety of optical measurement method for evaluation of the optical material, able to quantitatively measure and observe inter alia optical anisotropy leads to quality improvement of the optical product. For such evaluation, it is necessary to perform the birefringence measurement of the material, equipment is complex and often may require a skilled technique for the measurement. In this study, the easy evaluation of such optical materials, and for performing quantitatively, for the purpose of developing birefringence stereo microscope using circularly polarized illumination.

There are many types of artificial hands which are used EMG. Must of them are used some SEMG signals which are measured from user’s forearm. Because forearm muscles dominate hand and finger motions, from these signals we can estimate various hand motions. However, most of traditional artificial hands only can move according to estimated results, and they cannot display power with motion. So, we are trying to develop the artificial hand which can display power according to each hand motions. We made clear that EMG amplitude was related with power generated in muscle in previous studies. In this paper, we propose the new method to display grip power to the operator using a cuff.

We proposed a proximity and tactile sensor using self-capacitance measurement for human collaboration robot. The proposed sensor consists of the two electrodes (E₁ and E₂) and elastic body. The capacitance between E₁ or E₂ and GND is measured by switching between E₁ and E₂. The sensor can detect the object both before and after contact. In this paper, we produce the 4 sensors on same I²C line for covering the robot surface. The prototype sensors measure the object at the proximity range and on contact. The sensors may be applicable to tactile sensor for robot.

Surface wettability is one of most important indexes for understanding material characteristics, especially physico-chemical properties such as hydrophilicity and water repellency. Recently, non-contact wettability assessment by monitoring the behavior of liquid covering a sample during jet-flow application to the liquid has been proposed. This method is applicable to the in-liquid assessment of high wettability materials such as cultured cells in a liquid culture medium. Because liquid-squeezed area is the main index of surface wettability, this method is supposed to be compatible with image instrumentation without any contact between sample surface and instruments excluding jet-flow. When the flow is dirty, the contamination of particles (e.g. microorganisms, virus, and aerosols) into cell culture system may occurs. This study developed an automated non-contact wettability assessment system with clean jet-flow application, image processing, and a motorized alignment device.

The objective of this study is the development of the device gives direction of power for the human. The device made up of 4 stack linear oscillatory actuators on each 3-axis (X-axis, Y-axis, Z-axis). These actuators are mounted on the acrylic base plate. This base plate was embedded in the resin sphere with a diameter of 50mm. We can feel the direction of power using this device. Displayed angles transform Spherical Polar Coordinates. The microprocessor makes PWM based on Spherical Polar Coordinates. PWM signals drive 12 actuators. In the future, it will be possible to guide the visually-impaired in arbitrary direction.

Palpation is important medical diagnostic technic to make right diagnosis of symptomatic state. It requires a lot of palpation experience under leadership of experienced medical doctors. However, there is few practical training for maxillofacial palpation in the dental education in Japan. Then, a palpation training system with virtual model of an affected part is useful to get better at the skill. The coauthor dental doctors hope to develop the virtual training system which can be used to educate dental students to undergo maxillofacial palpation. Hence, a palpation training system for maxillofacial disorder is developed using virtual reality and a haptic interface. The system is consisted of a PC and the haptic device (PHANToM Omni). In particular, it is mainly improved that elastic calculation time is reduced by simplified mesh free method. Consequently, the virtual maxillofacial palpation training system successfully works at the real-time operation.

This research studies haptic interface with a virtual coupling including fractional derivative. Virtual coupling in virtual reality is commonly composed of virtual stiffness and damping between virtual objects and the real world. In a system with long sampling rate, however, the virtual stiffness has to be low and it only presents virtual objects with soft surface. For this issue, this research proposes a virtual coupling with virtual stiffness and fractional derivative instead of virtual damping using finite impulse response; FIR approximation. In this paper, we propose a method to simultaneously optimize coefficients and orders of fractional derivatives in virtual coupling and analyze the passivity of the optimized virtual coupling. Finally, we perform experiments to show the effects in a haptic display.

The desktop type force feedback device restricts the human’s motion because the human must sit on a chair while the device is rendering force. However, a wearable force feedback devices lets us dynamically interact with virtual objects while moving in virtual space. We have developed a wearable 1-DOF force feedback device with pneumatic artificial muscles and magnetorheological (MR) brake. This device shows quick response, lightweight and high power density by these actuators. However, the previous device had problems that this device tilted and operator was difficult to find virtual objects by any part. In this paper, we redesign this device to reduce the weight difference between the left and right of an upper arm part and add a handle that means a marker for rendering force. Next, basic property of the proposed device is measured. Lastly, the proposed device is applied to augmented reality (AR) space.

This study is engaging on the development of a virtual training system for maxillofacial palpation. This paper firstly discusses the functions of a haptic interface that should be have for our system, because doctors recognize not only the elasticity but also the shape of a tumor in palpation. We newly developed a prototype of our haptic interface, where seven pins are nearly allocated and moves independently to present both of shape and elasticity of an object onto the surface of a finger.

This paper proposes a method of wireless feeding for an electrostatic haptic display which consists of multiple contact pads and a non-segmented electrode. We have developed a multi-user haptic display that provides haptic feedback with electrostatic friction modulation by applying voltage between multiple contact pads and a non-segmented base electrode. The display requires feeding wire for each contact pad, which impairs its operability. For this technical challenge, this work investigates use of the base electrode as a transmitter electrode of wireless feeding. To facilitate that, the electrode of the pad is split and connected with a coil so that resonance current runs and boosts the voltage between the pad and the base electrode. Experiments with a prototype demonstrate its robustness to alignment of pad position and its possibility of multi-pad feeding with frequency division.

During surgery, a surgeon uses a variety of surgical instruments. Therefore, a haptic interface for surgical training should be able to display reaction force through various surgical instruments. Based on this concept, a novel encountered-type haptic interface using MR (Magneto-Rheological) fluid for neurosurgery simulators have been developed. This paper presents design of an 8 DOF haptic interface which can display independent reaction force on each hand. This haptic interface has two display parts which consists of MR fluid, a container of the fluid, a force sensor, an electromagnet coil and a yoke. The display part is miniaturized based on magnetic field analysis and moved by a 4 DOF motion table for the application of neurosurgery training.

This paper proposes a pocket-size device that enables users with no prior long-time trainings to intuitively read text letters using only their haptic sense. The device forces the user's finger-tip to trace trajectories of alphabet characters. Vibrotactile stimuli are superposed on fingers so that users can distinguish writing strokes from transient movements of fingers between strokes. The device structure, displayed motions, and experimental results of character reading are shown. The results suggest that the access to symbolic information via haptic modalities would turn into practical applications for people with late blindness or even people with normal vision.

A handy switch interface has been developed to allow a surgeon in a sterilized area to control a locally operated forceps manipulator (LODEM) with five-DOFs. The proposed made-to-order interface with adjustable switch position is designed based on the finger length of human hand. The ergonomic interface consists of an analog pad switch for a forefinger, and two small push switches for a middle finger and a ring finger respectively. Two large or small sizes of prototypes based on the measurement of finger length were made by a 3D printer. The control time was evaluated while performing a task model using prototypes by two groups with large or small hand sizes. The difference between task times was not shown, but tiredness under control was indicated by all subjects. An ergonomic handy interface was designed that allows minimally invasive robotically assisted endoscopic surgery.

Currently, it is desired to incorporate force feedback into medical robots. In this study, a three-axis load measurement sensor mounted on the tip of forceps was developed. The newly developed sensor electrodes are three-dimensionally arranged. From the simulation, the effect of aspect ratio on the load measurement was revealed. The aspect ratio was found to be little effect on the load calculation. As a result, by measuring the normal load applied to each zone, this sensor can calculate the normal load and shear load.

In late years, endoscope surgery attracts attention as a low invasive in a field of the surgery. There are many merits, but high technique is demanded, and the doctor increased with it for a patient for the operative time. The doctor continues restriction-like standing position posture in endoscope surgery with much being performed by standing position work for a long time, and it's said that, as a result, the burden on hips, lower limbs grows big. So, we measured a physical burden at the time of the standing position posture work and inspected the development of the wearing type lower limbs instruction device for the purpose of the burden reduction, the effectiveness.

In this paper, we introduce the non-contact blood level real time measurement method from outside a venous reservoir using a pressure sensor. We have confirmed that there is a linear relationship to the reservoir weight and blood level detection information. From this result, the blood level can be estimated from the weight of the reservoir volume. In addition, even if the weight of the reservoir has been changed for some reason, this relationship indicates the linearity. These can measure the blood levels adapted to weight change by one point initializing.

Recently robotic laparoscopic surgery has been widely performed. Most of surgical manipulator has RCM (Remote Center of Motion) mechanism, so operator must precisely adjust the center of motion to the insert port before the operation. If there is misalignment between the center point and the port, undesirable loads act on in active joints. The loads cause the friction negatively affecting position tracking and force estimation. In this research, we develop a manipulator that doesn’t require corresponding the center of motion and insert port precisely. Here we present the design of a pneumatically-driven surgical manipulator with a passive joint.

Haptic feedback in teleoperated surgical robot systems enhances safety and efficiency of the surgery. In this paper, a haptic device, which displays the grasping force, is developed. The proposed device adopts welded metal bellows, which can be used as actuators by supplying compressed air. The device has three sets of bellows so that it has 2-DOFs and can display both positive and negative grasping force. A control method is developed, which converts the reference force to the thumb and the index finger to the reference pressure, and then controls the internal pressure of the bellows. An experiment using the proposed device and a virtual environment is conducted. The tracking performance of the force is shown.

A method to recognize surgical scenes using only image processing has been developed to control endoscope robot semi-automatically. Some basic methods of image processing are designed for the scene to make a triangle working area using forceps required for endoscopic surgery. The FAST (Features from Accelerated Segment Test) for the corner detection and the Delaunay diagram for the triangle automatic generation were applied to a still surgical image. The binarization and Hough transform using HSV model for the feature-point detection were applied to sill endoscopic images. The MoG (Mixture of Gaussian Distribution) and GMG (Godbehere, Matsukawa, Goldberg) for probabilistic background subtraction were applied to moving endoscopic images. The expected triangle was not shown, but the results indicated the feature design to allow robotically assisted endoscopic surgery.

Echography is inexpensive and indispensable equipment in every medical field but examination with echography greatly need the expertise and experience of an operator. So, person who is not skill in echography not easy inspect. We estimated the mental rotation matrix by focusing on the echogram change and probe movement. In echography, mental rotation ability was defined as the probe displacement to follow the organ moved by body motion and breathing. As the result of evaluation experiments, we can seize the invisible Ultrasound Probe Skilled Procedure. On the hand, we have developed the ReDAT (Robotic-echography for Diagnostic and Treatment support system) to be able to diagnose by cooperative operation. In this paper, we have constructed transformation matrix convert to a force sensor value to the intention of the operator. So, we have confirmed the possibility for an assistant system in echography by robot system.

The spine tester which authors presented at this lecture in 2005 [1] is a device which is applied the robot technology. It has been used more than 10 years, and has brought a lot of medical knowledge. This paper shows a typical medical knowledge obtained by this tester, the left problems, and the future developments, especially for the application to the development of next-generation spinal instrumentation.

Among various medical problems facing us in today's Japan are rapidly aging society, localization of medical doctors, concentrated visits of patients to large hospitals, etc. We have developed an ultrasound diagnosis and treatment support system for reducing the burden of doctor and patient so far. We succeeded in the tracking of the organ which moved a dislocation image by body movement or breathing. However, the conventional ultrasound probes, for tracking the three-dimensional movement of the organ has been difficult. In this paper, we performed experiments using gallbladder by echogram processing software and measured the distance of organ. As a result, we determined the index of visual feedback to track the center of the gallbladder always. Next, we improved the image processing system so as to change the region of interest of echogram. Based on this feature amount, we discussed about the three-dimensional movement of an organ.

Needles used in percutaneous insertion must be as thin as possible to minimize invasiveness of procedures. However, using extra-thin needles can cause needle deflection. Needle deflection can be minimized by axial rotation along the needle shaft. However, although high rotation speeds may decrease needle deflection, this may increase tissue damage. Few studies mentioned histological evaluation of tissue damage caused by rotational needle insertion. In this paper, we present histological evaluation of tissue damage caused by the rotational needle insertion. We used histological techniques to confirm tissue damage caused by rotational needle insertion. As the results show, it was confirmed that the hole areas of needle path in the condition of unidirectional rotation in case of attached tissue to the needle was increased compared to the case of no attached tissue. Needle insertion with unidirectional rotation into human bodies might be dangerous due to winding of tissues.

We have been developing the ultrasonic diagnosis support robot for prenatal care. This robot can be controlled remotely. With this robot, a novel teleoperation prenatal care service called “offline prenatal care” is proposed. The offline prenatal care service reconstructs ultrasonic images acquired by the robot previously. The robot should scan the whole uterus automatically. To actualize the service, the automatic scanning method (two line scanning) and the fetus image reconstruction method are developed. In the experiment, the robot scanned a pregnant woman abdomen model by two line scanning and the specific ultrasonic image for prenatal care diagnosis (AC) was reconstructed from the scanned images in offline. It certified the proposed method's availability for the offline prenatal care.

Recently, surgical method using the image processing apparatus called Interventional Radiology(IR) is conducted well. IR surgery is a minimally invasive surgical method without an incision. Patients have less burden with IR surgery rather than that with conventional surgery. The surgical method of treating by puncturing the needle using computed tomograph(CT) apparatus requires the situation that the surgeon stands nearby the equipment. Therefore radiation exposure to doctor becomes a problem for doctors who engaged in IR surgery. Thus, we have developed a robot system which conducts IR surgery with remote operation. We report the function to change posture of a needle around tip of it, that is called remote center motion. In order to calculate desired trajectory of remote center motion, we derive Jacobian matrix between world coordinate system and tip of needle. Finally, effectiveness of proposed method is confirmed through experiment.

Water-Filled Laparo-Endscopic Surgery (WaFLES) is a surgical technique which is performed by irrigating the abdominal cavity with liquid. By applying WaFLES to laser surgery, heat effect from the laser irradiation is reduced by cooling effect of the fluid irrigation in abdominal cavity. However, it is difficult to perform laser irradiation accurately inside the abdomen, because the organ is always floating in water by buoyancy. Therefore, we introduced a surgical robot system that enables a high-precision laser irradiation to a moving organ in abdominal cavity. In this study, as a fundamental consideration for carrying out a laser irradiation in WaFLES environment, we evaluated the irradiation accuracy of this robotic system while irradiating moving objects.

This paper proposes an estimation algorithm of the arterial viscosity using cuff pressures and cuff pulse waves measured from an automatic oscillometric sphygmomanometer. A change in the arterial viscosity %η during the enclosed zone flow-mediated dilation (ezFMD) test is calculated as an index for vascular endothelial function.The index %η was measured and the receiver operating characteristic (ROC) analysis for the arterial viscosity change %η was performed in the experiment. The mean arterial viscosity change for the healthy subjects and that for the subjects at high-risk of arteriosclerosis were 13.4 ± 55.1 ％ and -32.7 ± 34.0 ％ (mean ± S.D., p < 0.05), respectively, and the area under the curve calculated from the ROC analysis was 0.77. It was thus concluded that the proposed method may evaluate vascular endothelial function.

This paper presents the 3D vessel model having a temperature responsive function for evaluation of thermal damage during surgery. The materials of model are polydimethylsiloxane(PDMS) and thermochromic dye which indicates irreversible color change according to temperature increase. Temperature increase of the materials can be measured from their color change. The accuracy of the temperature measurement is approximately from -3.5 / + 2.4 ℃ and the precision is ±3.1 ℃ in the range from 60 to 100 ℃. The vessel model is fabricated by dip coating on 3D wax model and lost wax method. However, acetone for removing wax prevents the temperature responsive function of the material. Thus, the surface of the model is coated with protective layer of polyvinyl alcohol(PVA). Finally, we succeeded in fabricating the renal artery model for catheter ablation.

Robotic assistance enables surgeons to perform dexterous and precise manipulations; however, robot assisted neurosurgery in deep and narrow spaces in the brain has a risk of unexpected collisions between the shafts of robotic instruments and their surroundings out of the microscopic view. Thus, we propose to provide the surgeon with feedback using a truncated cone shaped virtual fixture generated by marking the internal surface of the workspace. Three types of feedback methods, namely force feedback, visual feedback, and motion scaling feedback, were developed and implemented to the microsurgical robotic system in order to present the risk of collision to the surgeon. Performance of each feedback and their combinations was evaluated, and the experimental results showed that the combinations including visual feedback were effective in collision avoidance.

TURBT(TransUrethral Resection of Bladder Tumor) is now popular surgical treatment for bladder tumor, but devices currently used in this operation have two problems; one is that because bladder tumor tissue is cut into several pieces in TURBT with the devices, there is a risk of dissemination of tumor, and the other is that they increase a risk to damage normal tissue. In this research, we proposed a new TURBT device which enables en bloc resection in low inner pressure of bladder, and then we developed a prototype of the device and evaluation experiment was performed.

In laparoscopic surgery, surgeons do not feel accurate force applied to surgical devices. Therefore, development of force sensors for surgical devices is highly required. In this paper, we propose a non-contact whistle sensor together with a method of thermal compensation. The principle of the non-contact whistle sensor is based on the change in frequency when the distance between the air plenum and the slider is varied, which plays the role of air resistance while keeping non-contact. This sensor removes the problems with friction and loading on surgical devices which the previous contact-type whistle sensor has. The non-contact whistle sensor can measure vertical and axial displacements within error of 2 percent of the measuring range.

In brachytherapy of oral cancer, surgeons are exposed to radiation because of radioactive ¹⁹⁸Au sources. To reduce the exposure dose, we developed a remotely operated device for the brachytherapy. This paper introduces a newly developed insertion device. This device consists of four units: surgical arm, insertion mechanism, rotation mechanism and diameter adjuster. The main feature of the device is that the insertion movement can be done by simply pushing the wire. We confirmed that the device can perform circumferential insertion with the rotation mechanism. Moreover, the device was able to perform insertions on a gripped tongue analog.

We have been developing a intelligent surgical knife with LED level meter for liver surgery. When the knife approaches a part that must not be cut, it alerts by lighting LEDs gradually. Multiple markers are attached on the top of the knife to estimate the tip position during surgery. We conducted experiments to confirm the validity of operator’s navigation by using this knife. The task is a tracing of an invisible circle with the tip of the knife by only the information of the displayed LEDs.

The purpose of this study was to develop the device when they simulate the orthodontics and to simulate the effect of orthodontic force by temperature change. Using 6-axis force sensors, we developed the device which is possible to measure in up to three of teeth model at the same time. We calibrated the sensors which we used. As for the result, the error of forces and moments was maximum 2.06 %, and they were enough for the measurement. We measured forces and moments which occurred in the case of 2 types of different temperature change. The experimental results show that a small difference of temperature change causes big difference forces and moments.

Autonomous decentralized control could be the key to design adaptive multi-legged robots that can function in unpredictable and unstructured environments. To address this issue, we focus on centipedes with a large number of legs and aim to understand the ingenious decentralized control mechanism underlying their highly adaptive locomotion. For this purpose, we employed an approach to construct a simple mathematical model on the basis of behavioral experiments. We then found that the ground reaction force plays a significant role in generating rhythmic leg movement, and that the motion of each leg is likely affected by sensory input from its neighboring legs. On this basis, we proposed a two-dimensional model wherein a simple local reflexive mechanism was implemented. As a result, our simulated centipede robot could move adaptively in response to the changes in the environment, like real centipedes.

We have constructed the pursuit-evasion algorithm which enables security robots to corner a fugitive. In this paper, following on from our latest study, we develop the new pursuing algorithm to corner the fugitive with two security robots. To develop the pursuing algorithm, we focus on two behaviors which are decreasing the area where the fugitive is able to reach faster than the security robots and preventing the fugitive from heading for the exit. The evaluation function and voronoi diagram are used to achieve these behaviors. Moreover, to avoid collisions between the security robots and the fugitive, we combine these methods with artificial potential method. We conduct the simulation experience and compare our algorithm with our latest study to show effectiveness.

Legged animals exhibit adaptive and resilient locomotion through their inter-limb coordination. Our motivation is to elucidate the inter-limb coordination mechanism underlying various legged animals from a unified viewpoint. However, it still remains elusive because the locomotion mechanism of multi-legged animals has not been well studied. To address this issue, in our previous work, we focused on millipede and proposed an autonomous decentralized control scheme for myriapod locomotion on the basis of behavioral experiments. In this study, we performed real-world experiments with a multi-legged robot developed and reproduced myriapod locomotion farily well.

Snakes actively utilize terrain irregularities and move effectively by pushing their body against the scaffolds that they encounter. Clarifying the underlying mechanism will help develop robots that can work well in unstructured real-world environments. Although several studies have been conducted to reproduce the above behavior with robots, they still had a problem that the robots could not move effectively depending on the alignment of pegs. To address this issue, we previously proposed an autonomous decentralized control scheme based on TEGOTAE, a Japanese concept describing how well a perceived reaction matches an expectation. In this scheme, reaction forces from environment are evaluated in real time and those beneficial for propulsion of the body are selectively exploited. In this paper, we performed experiments using a snake-like robot to investigate the validity of the proposed control scheme.

The study of passive dynamic walking, among other techniques, is used to understand how animals walk. In our previous study, a quadrupedal robot inspired by passive dynamic walking was developed. This robot, named “Duke”, has only two actuators, which simply provide a rocking motion. The robot was able to walk by exerting little energy in the lateral direction using inverted pendulums. We call this locomotion quasi-passive dynamic walking. For this paper, a new robot named “Duke-II” was developed in order to investigate this type of motion more analytically. Duke-II is based on the design of the original Duke, and equipped with pressure and acceleration sensors. Using these sensors, we are able to more accurately measure the locomotion. In the experiments, we found that the robot was able to show a gait transition depending on specific parameters. The phenomenon has not been seen in previous study, which are analyzed in this paper.

This paper is concerned with a control methodology for group agents: what controller would be designed to an individual in order to perform collective motions. We propose a method of using a potential field which is made by sound (Sound field) intentionally in the space. On this method, each robot selects its own movement based on the strength or gradient of the field and is induced indirectly. We design a way to generate a sound field and robot’s behavioral algorithm, and we demonstrate the effectiveness of the proposed method in the real world. Throughout the experiments, we verified that the behavior of robots was well controlled only by the regulation of a sound field.

Snakes can change their locomotion patterns in response to the environments in real time. Inspired by this ability, various snake-like robots have been developed thus far. However, they could not reproduce the innate behavior of real snakes. To address this issue, in our previous work, we proposed an autonomous decentralized control scheme based on TEGOTAE, a Japanese concept that describes relationship between intended action and resulting reaction, and succeeded in realizing scaffold-based locomotion, a locomotion pattern observed in unstructured environments, via real-world experiments. However, applicability of this control scheme to other locomotion patterns is still unclear. In this study, we demonstrated via simulations that concertina locomotion observed in narrow spaces can be reproduced by using the TEGOTAE-based control scheme.