A passive-type dynamic absorber is usually effective for pre-determined narrow frequency range.Design of the damper following well-known optimal tuning theory could extend the effective range,whereas the damping performance remains at a certain amount and yet the vibration caused by transient disturbances could not be sufficiently reduced.A frequency-tunable dynamic absorber with variable stiffness property can be a measure for placing adaptability to the structure against non-stationary disturbances.In this paper,the stiffness controllable elastomer known as MRE is applied to the dynamic absorber whose natural frequency is tunable by magnetic field.Investigations show that the vibration of the structure can be reduced by the proposed absorber with variable stiffness functionality.

View full abstract

This paper deals with experimental and analytical study of free rocking response and analytical of rocking due to harmonic shaking.An equation of motion of rigid brock of free rocking is built.This equation of motion changes into the non-linear equation.Numerical analysis based equation of free rocking is conducted.Experiment of free rocking is conducted and experimental result and numerical-analysis result are compares.Thus optimal coefficient of restitution is presumed.An equation of motion of rigid brock of rocking vibration induced by base excitation is built.This equation of motion changes into the non-linear equation.Numerical analysis based this equation of motion is conduct.From numerical-analysis result of various excitation amplitude and pitch,consideration of response characteristic of rigid block of rocking vibration induced by base excitation.It is concluded that grasp of optimal coefficient of restitution and characteristic of rigid block of rocking vibration induced by base excitation amplitude and pitch is possible.

View full abstract

Spark test is a test for examining compositions of steel such as the amount of containing carbon and that different materials are not mixed.The spark test is made by a skilled person who grinds an end surface of the steel using a hand grinder to determine the contained material by watching the shape and density of the spark.Technical tradition of the spark test is one of the severe concerns in production sites due to aging population.It is important to quantify the grinding operation for technology education and automation.We designed and fabricated the experiment equipment with force and torque measurement device.We derive a formula to calculate the force on the test piece surface based on statics analysis from the force and torque measured by the sensor.Also we analyzed difference of the calculated force on the end surface of the test piece between a beginner and Meister.We found a tendency that fluctuation of pressing force by Meister to be smaller than it by beginner.

View full abstract

This paper deals with two dimensional base-isolating device for sick person's bed in ambulance.An automobile receives vibration in the up-and-down direction by the unevenness and hollow of the road surface.Moreover,a centrifugal force is received by running a curve at a certain speed.When receiving the force and vibration,in the state where sickness-and-wound people are sitting on the seat of the vehicle usual,they do not feel much comfortable.Furthermore the body has lain down,sickness-and-wound people gets force and vibration to the head directly.Therefore sickness-and-wound people could be worse of physical condition.So,it is necessary to isolate vibration in the up-and-down direction by the device.In order to reduce vibration of the up-and-down direction,the springs and frictions are used.This study aims at the development of isolation device of bed for ambulances to reduce displeasure by traffic vibration

View full abstract

Now,global warming is one of the biggest problem in the world.High efficiency becomes important in the industrial field.The brushless DC motor has good control performance and high efficiency.So brushless DC motor is used electric vehicles and air-conditioners and other industrial machines.To control this motor,mbed micro computer is used.A three phase inverter is made using three full bridges.

View full abstract

Parallel-link mechanisms possess high power,high stiffness,and high precision owing to parallel arrangement of actuators; their workspace is,however,smaller,in comparison with typical serial-link mechanisms.This paper proposes a parallel-link robot driven by pneumatic actuators with a variable actuator-inclination mechanism.This parallel-link robot is principally based on the type of parallel-link mechanisms in which linear actuators fixed on a base plate enable a high degree of freedom of the motion of an end plate.For the purpose of enlarging the workspace,a system to arbitrarily change an inclination of each individual actuator is incorporated into the robot.Using pneumatic actuators in the realization of the proposed parallel-link robot leads to lightweight,compact,and low-cost construction.Workspace and motion transmissibility are evaluated for the proposed parallel-link robot through simulations based on the kinematics.Furthermore,an experimental parallel-link robot is built,and investigated.

View full abstract

This paper presents a tubular frame for Micro Electric Vehicle(MEV).Recently,various type of MEV are announced from various company.However,these MEVs are concerned for crash safty.Moreover,the MEV should be manufactured easily to develop the new markets.Therefore,our concept of MEV is safety for collision we apply the tubular frame design.Our designed tubular frame are constituted of round pipe and square pipe.Therefore the tubular frame is produced by a simple production facility such as a pipe bender and welding machine.For experiments,we perform the static analysis and dynamic analysis using Autodesk simulation.We show the weak point of our tubular flame for collision.

View full abstract

A bicycle is a major and commonly-used transportation for parents with small children.Bicycles riding with children are rapidly widespread,and those bicycles tend to carry an electrically-assisted pedaling system for riders to reduce pedaling load.A typical assist method may cause speed fluctuation due to pedaling torque fluctuation during low-speed biking.This study tried to overcome this problem by introducing the combination of a bias control and a repetitive control synchronizing with the crank angle.The effectiveness of the proposed control system is verified through numerical simulations and experiments.

View full abstract

This study discusses the development of tensegrity structure.This structure is composed of compressive members like aluminum pipes and tensile members like strings.The members connected to the joints can rotate freely.Thus each member is influenced only by simple axial forces.As a result,it has some advantages including high specific strength and deformability.Nonetheless it has been hardly applied to practical use in industrial fields for some reasons such as difficulty in assembly.We have explored the possibility of its application to the wing structure of airplanes.To begin with,we designed and produced a model of this structure for experiments.This process taught us how to design and assemble such a structure.Using this experimental model,we confirmed the properties of the structure of this kind.For instance,we measured the deformation ratio of the compressive members when the entire wing structure is cantilevered.The results show that this system is effective for designing lightweight systems.

View full abstract

In this study,we investigate the change of structural dynamic reliability of piping systems supported by elasto-plastic damper subjected to multiple nonstationary random input excitation,for various setting conditions of elasto-plastic damper.The elasto-plastic damper is assumed to have a bilinear hysteretic characteristics.The piping system is modeled by a simple cantillever beam with a weight at the top end.Analytical model of a piping system is constructed by using finite element method.The support force is expressed by a bilinear model.The inputs are given by white Gaussian noises.In this study,we will maintain the structural integrities of both the piping systems and the elasto-plastic supporting devices by taking three indexes; dynamic reliability of pipings,accumulated energy of support and dynamic reliability of support,into account.Furthermore,the optimal conditions of parameters such as the supporting location,the capacity of supporting devices are searched.Numerical simulations are perfomed using a simple piping system model for multiple random inputs based on probablistic vibration theory.This study is applicable to the seismic design of piping systems supported by elasto-plastic dampers subjected to the actual earthquake inputs.

View full abstract

In this study,we propose high performance and high reliability analysis method for eigen problem of the system with large degree of freedom.Analysis method is composed by applying transfer stiflhess coefficient method to the inverse iteration method.With respect to the inverse iteration method,the iteration process is regarded as the forced vibration analysis of large scale linear system.To this process,we apply transfer stiflhess coefficient method,which is able to compute the vibration solution of linear system at high-speed.By this combination,computational efficiency and computational accuracy can be dramatically improved.In this report,we apply this method to an eigen problem of a three-dimensional beam structure.We investigate the effectiveness of the proposed method by comparing analysis results of this method and conventional method.

View full abstract

The sound insulation performance of building materials can be evaluated by transmission loss,which refers to the volume difference between the reverberation room and the adjoining room in which the sound was produced.At present,measurement of this value requires the use of special equipment and entails huge cost because it is measured on the basis of JIS,which requires the use of large amounts of actual sound insulation materials.If the results of the measurement value could be predicted,this could lead to reducing the development cost of sound insulation materials.Recently,some attempts have been made to predict this value by numerical analysis using FEM.However,the prediction using theoretical analysis has not yet been done.In this study,we analyzed the cuboid acoustic field for the purpose of prediction of transmission loss of sound.We used the analytical solution of a single dimension acoustic pipe.The validity of the analytical solution was verified by comparing the calculated results with the experimental measurements.

View full abstract

To connect a pipe spool between existing pipes with high accuracy for power plant constructions,a calculation approach which figures out appropriate cutting positions and angles of extra length areas of the spool has been developed.In this approach,center positions and axes of end surfaces are modeled numerically based on three-dimensional measurement of each pipe,and the appropriate cutting surfaces are calculated by geometric analysis of the models with considering for ease of cutting work at the construction site.This paper described a modeling method of pipes,a calculation algorithm of the proper cutting surfaces of the spool,and a verification result of the calculation.

View full abstract

In recent years,the demand of the glass for FPD has been increasing.Therefore,the development of new cutting technology with higher manufacturing efficiency is desired.Usually,there are two processes in cutting the FPD glass.The first process is to scribe on the glass by laser or wheel cutter.Next process is to cut the glass along the scribe line by bending stress.In this process,the glass is cut using the way that runs along the scribe line while pressing by the rubber roller.If you want to cut the direction orthogonal to the two,you must repeat the same process after the glass is rotated by 90 degrees.If this process of rotation can be eliminated,it will be possible to shorten the processing time.Therefore,using the tensile stress generated by the loop of the vibration mode,we hypothesized that glass could be cross-cut at once.As a result,it is possible to cross-cut by using the sound waves superposed two resonance frequencies.By using this method,it will be possible to cut the glass in non-contact.

View full abstract

This study presents the generation of a quiet space in a rectangular cavity based on active wave control,demonstrating the validity of the proposed method from an experimental point of view.Firstly,a wave solution of a rectangular cavity is derived.This is followed by the derivation of wave filtering equation which is used for constructing wave filters.It is found from the equation that the wave filter mainly consists of modal filters and wave decomposition filters.Then,the limitation of the past method is pointed out,the improved methodology of the filter implementation presented.In the proposed method,the wave decomposition is conduction only in the frequency range slightly higher than a cut-on frequency.In the frequency range where the wave decomposition is not conducted,the average of the sound pressure is suppressed.Such methodology leads to the global noise suppression in the target space since progressive waves do not propagates under the cut-on frequency.Finally,experiment on the generation of a quiet space using the proposed wave filters is carried out,demonstrating that a quiet space is realized by the proposed method.

View full abstract

Planarization of silicon wafer is necessary for photolithography or thinner process.Therefore polishing process and grinding process are carried out.In such processes,hydrostatic bearings are needed as bearings of rotary tables of grinding machines.In this case,higher bearing stiffness is significantly important to achieve precise grinding.Bearing restrictor is a part of the most important elements of hydrostatic bearing.Bearing performance is significantly affected by the dimensions of restrictors.Design of the restrictors of a hydrostatic thrust bearing maximizing bearing stiffness is considered in the paper.In particular,the paper focuses on a design of restrictors used in the hydrostatic thrust bearings sustaining vertical loads.In such cases the table supported by the bearing moves from its neutral position due to gravity force.Numerical analysis indicates that an achievable highest stiffness for various bearing positions can be represented by an envelope curve derived.Using proposed design procedure,the bearing stiffness of our water hydrostatic thrust bearing becomes 1.5 times of that of the previous design at given operational condition.

View full abstract

The abrasive property of ML belts is superior to endless belts.In recent years,they are used for grinding a train rail.The train rail grinding machine has developed and the abrasive property has been investigated with the ML belt.The ML belts grinding is superior to the face grinding by grinding wheel at a point of Quantity and efficiency.In this study,the ML belt was improved with the target of more effective grinding.The 3B belt was a kind of the ML belt and was consist of Zirconium abrasive cloth and CBN abrasive cloth.The abrasion experiment using seven kinds of belts including this 3B belt was carried out and the quantity of abrasion was compared.The quantity to grind with the 3B belt which the ratio of Zirconium abrasive cloth and CBN abrasive cloth was 2 to 1 was most of all belts.

View full abstract

A bifilar suspension pendulum,a uniform density bar suspended at its two points by two strings of same length,may swing in a vertical plane or make torsional oscillation about a vertical axis.The swinging in a co-plane of the strings and the bar is called Mode 1,and the swinging in a vertical plane perpendicular to the bar is Mode 2.Mode 3 is the torsional oscillation about a vertical axis.Typical features of Mode 1 are studied here using the method of multiple scales and method of harmonic balance.It is shown that the configuration of strings supporting the pendulum leads to the nonlinear softening/hardening,which may be applicable to mitigation technology.

View full abstract

In addition to the usual static nonlinear terms due to potential energy in many oscillation systems,inertia type nonlinear terms are involved in equations of motion,which may work as hardening/softening,depending on an angular frequency of forcing.The mechanism is revealed in this report using method of harmonic balance and method of multiple scales and numerical computations,to be expected to apply effectively to mitigation.

View full abstract

In this paper,a motion controller of a three link underactuated robot based on behaviors of the horizontal bar gymnast is discussed.Proposed controller is designed forcusing on an Equivalent Center of Mass(ECM) of the robot and the gymnast.At first,the behaviors of the ECM of the gymnast are analyzed by using a motion capturing technique,and then an efficient motion for a swing-up and giant-swing action are identified from analysis results.Next,a controller which can realize that the ECM of the robot replicates this efficient motion is designed.An effectiveness of proposed controller is verified by the numeric simulation by using MATLAB/Simulink.

View full abstract

Digital control uses microcomputer.The computer uses shift operator instead of differential operator because it is discrete system in digital control.In many cases,Euler's method is used to get discrete system from continuous system.Euler's method,might make system unstable.Therefore,in this study,the stability condition is shown.We propose new conversion method that keeps a frequency response at any one point

View full abstract

A uniform density bar is suspended at its two supporting points by two strings whose two end points are attached to an upper static wall,and works as a bifilar suspension pendulum of three oscillation modes: two swinging modes and one torsional mode.There are three configurations of this pendulum: the distance between the two points at the wall is longer or shorter than that on the bar,and it is just the same.These give rise to the effects just as softening/hardening of nonlinear spring,as studied in a previous paper.When the vertical motion is included with forcing and vertical excitation,the nonlinear effects due to inertia type terms are shown to change in various ways,using the method of multiple scales and harmonic balance.The nonlinear hardening/softening may be applicable to mitigation technology

View full abstract

In order to measure the natural vibrations of solid large-scale structure like building that cause resonance,we suggest a new way to excite the natural vibrations through the multi-axis exciting test controlled by the decentralized control.First of all,we prepared the experimental apparatus that has natural vibrations in three dimensions as well as general solid large-scale structure and a small and lightweight shaker with inertial force.Because we can employ shakers anywhere,we can put them inside the structure to oscillate.Next,we installed a number of the shakers in multi-direction inside the structure since solid large-scale structure has the natural vibrations in multi-direction.Moreover,since the actuators can excite the structure at the resonant frequency of the structure,we excited all the natural vibrations in multi-direction without any force command signals by using the decentralized control in which the actuators synchronize with each other to form the natural vibration modes by themselves.

View full abstract

In this report,we propose optimal setting manner of an attenuate material for improving the performance of the L-shaped beam frame isolator.The isolator consists of two thin plate beams joined perpendicularly.One beam is fixed vertically to the base and the other is fixed horizontally.An isolation object is set at the joint.When the mass of the object exceeds the buckling load,these beams buckle and behave in the alternative of two buckling modes,that is,stable buckling mode and unstable mode.These buckling modes indicate softening non-linearity and we can get good performance in the vertical vibration isolation.However,vibration transmissibility at natural frequency high order becomes large,so it is necessary to reduce the transmissibility at high frequency.The purpose of this paper is considering the effective reduction method of transmissibility in cantilever,and then,we will apply the obtained results to the L-shaped beam frame isolator.

View full abstract

Recent years,social demand for high-performance anti-vibration device for machines and structures is growing as the performance of machines and structures have been improved.Generally,the performance of a passive vibration ilolator is improved by lowering the natural frequency of the system.Here,considering a passive isolator for vertical vibration,it is desired that the isolator possess the characteristics of high-static-low-dynamic-stiffness in order to keep low vibration transmissibility and avoid large static deflection.In this study,we propose a passive vibration isolator using the post-buckled L-shaped beam structure and examine restoring force,free vibration characteristics and the frequency response of proposed system.

View full abstract

This paper dealt with the relationship between internal defects and tool wear properties of diamond tools.FT-IR analysis were done to determine qualitative amount and kind of internal defects.The analysis suggested that N_2 impurities as an internal defect significantly affected the crater wear significantly.

View full abstract

The cemented carbide is attracting attention as a die material.However,cemented carbide is a difficult-to-cut materials and the tool wear becomes hard in the machining.Electric discharge machining is used for the die machining with complex curved surfaces.Electric discharge machining layer is required polishing.Cleanup operation of electrical discharge machining layer is manual labor,there is a problem such as an increase in manufacturing cost,and work efficiency decline.Therefore,it is possible to improve the efficiency of the die manufacture by total automation and polishing of complex surfaces by using the five axis machine tools.The purpose of this paper is to investigate the effect to the tool by the Electric discharge machining layer.Cutting the cemented carbide before and after the Electric discharge machining with CBN tools carried out,and the influence of the tool angle and tool wear characteristics were examined.The cobalt in the cemented carbide was less,the maximum width of flank wear was bigger.In case of Electric discharge machined materials,the tool life became extremely shorter.When changing the tool angle,the tool angle was in the order of 15 °> 30 °> 60 °,the maximum width of flank wear was increased.

View full abstract

A water driven stage,which is composed of water hydrostatic bearings and the water hydraulic piston mechanism,was developed for liner stage for ultra-precision machine tool,especially,for machining small parts in size.Speed of the water driven stage can be controlled by the supplied water flow rate into the piston-cylinder by use of electromagnetic proportional flow control valve.The purpose of this study is to control the speed of feed motion of the table.In this paper,influence of step load changing on the table of the stage is evaluated by experiments and simulations.It is then verified that the designed feedback control system effectively reduces the influence of the external load acting on the table.

View full abstract

This paper proposes a novel evaluation method for worked metal surface using haptic information.With the decrease in production due to the decreasing birthrate and aging population as a background,the development of technology to replace the human delicate motion is strongly required.Haptic information,which is the one of important factor of human senses,is focused on in this paper.The main subject of this paper is to propose a method for quantitative treating the haptic information.In particular,the vibration component of in rubbing motion is evaluated.To evaluate the haptic information in frequency domain,Cepstral analysis is utilized.Cepstral analysis,which is used in audio analysis,is useful method to check the characteristics in detail in the frequency domain.The validity of the proposed method was confirmed by experiments by 2-DOF system.With the proposed method,the technology relying on the human sense can be quantified.

View full abstract

In this study,we study a one-legged robot.A one-legged robot has a problem that the robot falls down if it has no stand.This study deals with an attitude stabilization control to continuously jump without falling.First,models of the robot and equations of motion are derived.The attitude control is achieved by PID control.As a result of simulation,it is confirmed that the robot can continuously jump without falling.

View full abstract

There are studies on a monopode jumping robot.In order to avoid an obstacle for a monopode jumping robot,the robot has to recognize the obstacle.In this study,three infrared sensors are attached on front and rear of the robot and recognize environment.It is assumed that there is a step as an obstacle.The robot recognizes a step when a point measured by rear sensor is on the plane estimated by front three sensors.The experimental results show evaluation of the recognition accuracy.

View full abstract

This paper describes the posture control of vertical jumping pattern for an one-legged jumping robot.The jumping robot is can jump from standing to landing.The jumping robot has a total of 13 actuators: 10 mono-articular types and 3 bi-articular types.The problem using pneumatic actuator is difficult to keep the fine posture.Therefore,our target is to keep the fine posture after landing.For a vertical jump,a joint angle pattern is developed based on the linear momentum and the angular momentum.The effectiveness of the mechanism and the jumping pattern of the jumping robot areverified through simulation and experiments.

View full abstract

This paper describes a whole motion pattern generation based on the preview control.Also,a walking stability control which consists of ZMP compensatory control and inverted pendulum control for a biped humanoid robot to walk.The ZMP compensatory control updates the gravity position of the waist according to ZMP,the inverted pendulum control accelerates ZMP to the falling direction of the robot.In order to verify the effectiveness of the pattern generation and the control method,the simulation of the whole body motion is conducted by using Adams and MATLAB/Simulink.

View full abstract

There are some methods for self-localization for a mobile robot.For example,odometory calculates the robot's movement by rotation of wheels,and ICP algorithum calculates the robot's movement by the scan data of LRF obtained at two points.In this research,we realize three-dimensional self-localization by using odometry and ICP scan matching algorithum together.In addition,we conduct a stairs climbing experiments using a mobile robot developed in our laboratory,and we examine the usefulness of the self-localization method.

View full abstract

Legged robots have been studied and developed as a mobile robotic platform.In many types of legged robots,a quadruped robot has both compactness and stability.To make a quadruped robot be useful,it is required to walk dynamically and to move fast.We propose an algorithm to achieve a dynamic gait pattern.The dynamic gait which we deal with is trot gait that the robot swings the pair of the legs on the diagonal line at the same time.Generally,in order to estimate the motion of the robot walking dynamically,we have to calculate the complex dynamics.Therefore we model the quadruped robot by an inverted pendulum in order to simplify the equation of motion of the robot.Then we generate the trot gait patterns by using the equation of motion of the inverted pendulum.The quadruped robot does not always walk correctly.Therefore we propose the swing leg trajectory which is composed of ellipse and straight lines in order to reduce the influence of wrong behaviors of the robot.We conducted experiments that the quadruped robot was walked by the trot pattern which we made.As a result,the quadruped robot walked successfully.

View full abstract

This study discusses a position control of a four rotor flying robot using a fuzzy controller.In recent years,a flying robot is expected to work in a danger area.A control of flying robot is difficult to keep stabilized position in wind blowing environment.We prove the flight control method to adapt for outdoor environment.We apply the controller for the robust.For experiment,we show the hovering control at high attitude which a wind is blowing,and it confirmed that this flying robot controller demonstrated robustness to disturbance.

View full abstract

Recently,VTOL aerial robots are expected to be used for collecting any information at the time of a disaster.The aerial robot called X4-Flyer can control at least three attitudes and one position by changing the rotor speed of four rotors.However,the control performance of a controller for the X4-flyer is deteriorated due to measurement noises generated by the rotational vibration of the rotors.Therefore,it is important to reduce the effect of such measurement noises on the controlled system.In this paper,when using a nonholonomic control method based on the Lyapunov stability theory to design a basic controller for the X4-Flyer,it aims at reducing the deterioration of the controller performance,which is caused by the influence of measurement noises,by processing such noises with an extended Kalman filter.The effectiveness of the proposed method is checked through numerical simulations.

View full abstract

In recent years,autonomous unmanned underwater vehicles(AUVs) attract the attention of researchers who work in the field of underwater investigation.Fishes have some fins,so that acceleration,deceleration and turning characteristics are superior to the screw propeller in the ability of underwater propulsion.Among them,a Manta controls the position and attitude using the oscillation of two pectoral fins,and swims in a variety of movements by changing the waveform of the pectoral fins.In this paper,we develop a robot that mimics a Manta for underwater exploration.The Manta robot has a pair of pectoral fins,one of which has six fin-rays that are driven by waterproofed servo-motors.The Manta robot is controlled by a micro-controller.The usefulness of the developed Manta robot is verified through some experiments,where the maximum amplitude,the frequency and the phase difference are changed in the waveform of the pectoral fins.The propulsion speed of the Manta robot is computed by measuring the time required when a fixed distance is promoted.It is shown from experimental results that adjusting the maximum amplitude of pectoral fins can easily change the propulsion speed of the Manta robot.Moreover,the frequency of a pectoral fin depends on the body length of the Manta robot.The phase difference of the adjacent fin-rays can be used for controlling the propulsion speed of the Manta robot in a restricted region.

View full abstract

The swimming motion of Tuna type fishes has excellent ability for its speed and efficiency.In the former studies,we made 1/1 scale model of Blue Fin Tuna body and caudal fin.The body resistance in the water flow are measured,and the lift and drag force of caudal fin are also measured.By using these data,this paper shows a design example of fish type robot which can swim maximum 2m/s speed.

View full abstract

Although micro air vehicle(MAV) is useful for the surveillance from the sky,3-dimensional terrain measurement,etc.,it is pointed out that as the mechanism becomes more complex,the MAV does not function well.In this study,we attempt to develop a new ejection type MAV which does not have any propulsion and electrical control system.In this paper,we introduce a mechanical launching device that mimics the rotation of the shaft by hand.

View full abstract

In this study,we study an articulated vehicle robot which achieves self-localization and mapping on two dimensional space.Each vehicle of the robot equips infrared sensors to measure the distance and encoders to measure the amount of rotation of the crawler.We propose an algorithm to improve the self-localization estimated by odometry.It is realized by using the ICP scan matching algorithm with scaned range data by infrared sensors redundantly.The experimental results shows the validity of the proposed method.

View full abstract

The ability to estimate self-position accurately and robustly is widely regarded as one of the fundamental preconditions to achieve next-generation car navigation and driver assistance systems.The authors have proposed a localization technology that estimates self-position by matching the three-dimensional map and entire circumference fish-eye cameras' images with a particle filter.It has been confirmed that this technology can estimate self-position with high accuracy and strong robustness if the vehicle moves at low speed on a flat road.In order to estimate self-position on the slopes and during high-speed moving,the authors improve this technology to be able to set the scattering range of particles dynamically by referring to the running condition and gradientin formation of three-dimensional map.

View full abstract

In this paper,we proposed a robot manipulator with collision force suppression mechanism that can suppress collision force passively.The collision force suppression mechanism consists of a release air pad,two transmission rack,a clutch gear and two compression spring.An air cushion bag is installed the surface of the robot manipulator.If the robot manipulator collides with a human or object while working,the joint of robot manipulator is disjointed by the collision force suppression mechanism and joint is rotated collision direction.As a result,the collision force suppression mechanism is suppressed to about 30% of collision force.Through collision force suppression experiments,the effectiveness of the collision force suppression mechanism is verified.

View full abstract

In order to use the robot arm,we developed a lifting machinery with features such as bending elasticity using VGT structure.We compared the centroid coordinates obtained from the simulation and centroid coordinates obtained from the experimental equipment for static loads in various ways.We examined the differences between experimental and simulation results and variation in centroid at no load and there is load on the top surface was also examined.Vertex coordinates of the equipment was calculated using Frame-DIAS IV system.CAD-simulation was calculated using the Pro / ENGINEER.We also examined more than one load patterns.Difference in measurement data and CAD became larger as the amount of movement of the top surface centroid increased.

View full abstract

Study of the arc sensor to had turning to detection accuracy,in this study,As we look to the reliability of the various disturbances,and develop arc sensor to incorporate the theoretical formula of welding phenomena.Use in direct-type four-axis robot,and performs welding by generating arc actually to program control.Experimental results arc length was found that the variation of the voltage becomes larger and longer.lt was possible to make uniform the dispersion of the arc voltage by applying the filter.Graph of simulation graphs and measurement experiments he want you to match,but I understood that the voltage is high graph came out in the experiment,the voltage difference between the end and the center is large.Seems robot has a high position when a welding voltage higher than the experimental expression is measured.More accurate values issued by applying a filter in the graph of the approximation curve.

View full abstract

The purpose of this study is to develop a turning algorithm for a weeding robot in a rice paddy field.The capacitive touch sensor is used to detect the rice plant line.The weeding robot that we use in this study can autonomously move along the rice plant line.In this paper,we proposed the turning algorithm,using both the capacitive touch sensor and the azimuth sensor for the weeding robot.In order to evaluate the effectiveness of the proposed turning algorithm,we carried out experiments in a sandbox.The effectiveness of the turning algorithm is verified by the experiments.

View full abstract

Recently,power assisted nursing care systems have received much attention and those researches have been done actively.In such a control system,an actuator and a control valve are mounted on the human body.Designing the system,the size and weight of the valve become serious concerns.The purpose of our study is to develop a small-sized,lightweight and low-cost servo valve for precise control using wearable pneumatic actuators.In this study,a low-cost wearable servo valve that can control the output flow rate by changing the twisted angle of the buckled tube in the valve is proposed and tested.The position control system of McKibben rubber artificial muscle using the tested valve and embedded controller is also proposed and tested.As a result,we confirmed that the tested servo valve can control the flow rate in both supply and exhaust in an analog way.In addition,the pressure control type wearable servo valve is proposed and tested.As a result,the valve can control the output pressure with a bandwidth frequency of 2.2 Hz.The estimated cost of the proposed valve can be reduced to about 1/100(9 US Dollars) compared with the typical servo valve.

View full abstract

An inspection of water supply pipe is required in Japan.The cost of the inspection will be decreased by using an inspection robot.As a background of such a situation,the inspection robot for pipe has been developed in the various laboratories.In the case of pipe inspection,the robot is required higher mobility.In this paper,we developed the flexible sliding mechanism using the flexible pneumatic cylinder to travel in the narrower space smoothly.A flexible bending unit using three McKibben artificial muscles that can change the direction of the mechanism was also proposed and tested.The whole inspection robot that consists of the sliding mechanism,the bending unit and CCD camera was also tested.The driving test of the robot in the pipe with inner diameter of 100mm was done.As a result,the robot can move and bend smoothly in the pipe that includes the T and L joints.We can confirm that the tested robot is useful as a pipe inspection robot.

View full abstract

In this paper,an envelope-type pneumatic thin actuator that can hold thin shape without supply pressure,and generate large force in expansion was proposed and tested.The tested actuator is made of laminating plastic sheets and papers.It has an envelope shape.The envelope-type actuator with larger displacement and force was also proposed and tested.The actuator consists of two serial envelope-type actuators.They are alternately folded.By this method,the actuator can generate the larger displacement that is about 27 times of the initial thickness.We also propose a simple analytical model of the actuator to predict the static characteristics between the supply pressure and the generated force of the actuator.We also redesigned the actuator based on the proposed analytical model to get the desired generated force and displacement.As a result,the redesigned actuator was able to drive the load of 490N by moving a vertical direction only.

View full abstract

The purpose of this study is to develop a power assist device that can hold the user's arm to reduce the burden on farm workers.This paper describes the mechanism and the design procedure of the device.This device consists of a linkage mechanism in order to use a single actuator.To ensure efficiency of fruit growing the user puts the upper limb on the power assist device.The effectiveness of the power assist device is verified through experiments.

View full abstract