The significance of physical human-robot interaction (pHRI) with collaborative robots in the industry is growing steadily. Within this domain, an admittance controller is crucial for enabling robots to follow or assist human intentions. However, a persistent challenge with admittance controllers is ensuring their passivity. Various strategies have been developed to address this issue by adjusting the control signals derived from the admittance model. While these strategies achieve passivity, they often inadvertently impact collaborative performance, preventing the system from accurately aligning with the intended dynamics. Accordingly, this paper introduces an adaptive hierarchical control approach for redundant robots to handle this problem. This approach diverts non-passive power into the null space without diminishing the robot’s responsiveness to human input. Implementing this null-space controller involves the dynamic adjustment of compliance control error, ensuring joint limit avoidance while facilitating integration with energy tanks for enhanced reliability. Moreover, the method enables the calculation of adaptive error gain in a closed form, simplifying its real-time application. Experimental validation with a 7-DOF manipulator showed a reduction of non-passive energy from 1.61 J to 0.12 J without compromising task performance.

Super-coiled polymer (SCP) artificial muscles have many interesting properties that show potentials for making high performance bionic devices. To realize human-like robotic devices from this type of actuator, it is important for the SCP driven mechanisms to achieve human-like performance, such as compliant behaviors through antagonistic mechanisms. This paper presents the simultaneous position-stiffness control of an antagonistic joint driven by hybrid twisted-coiled polymer actuation bundles made from Spandex and nylon fibers, which is a common human compliant behavior. Based on a linear model of the system, which is identified and verified experimentally, a controller based on model predictive control (MPC) is designed. The MPC performance is enhanced by the incorporation of time delay estimation to estimate model variations and external disturbances. The controlled system is verified through simulations and experiments. The results show the controller's ability to control the joint angle with the highest position error of 0.6 degrees while changing joint stiffness, verified with step command and sinusoidal reference with composite frequencies of 0.01Hz to 0.1Hz.

Service robots with social intelligence are starting to be integrated into our everyday lives. The robots are intended to help improve aspects of quality of life as well as improve efficiency. We are organizing an exciting workshop at HRI 2019 that is oriented towards sharing the ideas amongst participants with diverse backgrounds ranging from Human-Robot Interaction design, social intelligence, decision making, social psychology and aspects and robotic social skills. The purpose of this workshop is to explore how social robots can interact with humans socially and facilitate the integration of social robots into our daily lives. This workshop focuses on three social aspects of human-robot interaction: (1) technical implementation of social robots and products, (2) form, function and behavior, and (3) human behavior and expectations as a means to understand the social aspects of interacting with these robots and products.

This paper introduces a force-controllable quadruped robot system consists of twelve Actuator Modules embedded a novel Capacitive-type Joint Torque Sensor (CJTS) which is accurate (0.05 Nm), robust to impact, and easy to manufacture at low cost. The Actuator Module with CJTS shows accurate joint torque controllability in range of ±70 Nm (90 % settling time 0.04 s). The leg made by the three Actuator Modules is capable of generating forces in the z-axis up to 350 N and shows force control performances with zero-force control and lifting weights in three-dimensional space. To reduce the reflected limb inertia, all the Actuator Modules are located on the body frame and light-weight limbs made of the carbon pipe (3.6 % of total body weight). The introduced robot performed the motion on various terrains with walking/trot gaits.

The Elastic Inflatable Actuators (EIAs) has several advantages such as the inherent compliance due to the body comprised of a soft materials such as silicone. Among them, the soft fiber reinforced actuator is based on the principle that the expansion of enclosure and constraint of fiber pattern lead to a desired operation. While lots of researches on the actuator has been attributed to linear and bending motions, however, there are only few researches on rotary, or torsional, motions. In this paper, we propose a new actuator that causes azimuthal deformation due to restriction of anisotropically distributed fiber element along the radial direction and expansion of the hyper elastic material. Structure design of the actuator and a fabrication process of the actuator are presented. Subsequently, FEM simulation and experiment are executed to measure rotation angles of the actuators corresponding to the applied pressure.

In this paper, we present a novel framework for quadrupedal stair climbing, which considers force interaction with stairs. For stable and robust climbing, a key issue is to avoid falling down on the stairs. From this point of view, control to minimize rate of change of angular momentum about Center of Mass (CoM) which is produced by ground reaction force (GRF) at contact of robot`s foot is necessary. Using this approach, direct force-based Zero Moment Point (ZMP) for motion planning of the CoM and landing force control are implemented. The direct force-based ZMP method allows the robot to lift its foot with reduced possibility of tilting on the stairs, and the landing force control prevents instant increase of the moment by impact of the GRFs. In addition, terrain recognition to estimate parameters of the stairs and find proper footholds by vision system mounted on the robot is presented. Proposed framework is implemented to quadruped robot, AiDIN-VI, that has torque sensor at each joint, through experiments, capability of ascending several stairs including 3-step stairs which have 21cm height (31% of its maximum leg length) and 26.5° inclination is validated.

This paper presents a 1-link robotic arm that is antagonistically driven by one pair of a high performance super-coiled polymer actuators with an embedded controller. The actuator which is made from Spandex and nylon fibers is low-cost, easy to fabricate and light-weight. Moreover, it can generate large displacement and provide Joule heating capability. The main contribution of the paper is the model-based impedance controller, which enables position control of the antagonistic joint with variable stiffness and damping. The impedance control is a torque-based law, which in turn depends on a proposed backstepping control law to control the force of each actuator. The control system is proved to be stable using dissipativity stability theory and verified through experiments. Experimental results show that our system can track the angular position reference with the worst position error of 0.43deg and root-mean squared error of 0.16deg at steady state for sinusoidal waveform tracking (with the frequency of 0.1Hz), and the worst position error of 0.2deg for set-point regulation.

This paper presents a fabric actuator consisting of ordinary polymer fibers, conductive fibers, and twisted and coiled soft actuators (TCAs). Previous studies have developed a Spandex TCA (STCA) that is driven at a lower temperature than the conventional Nylon TCA and exhibits greater actuation strain. However, no method to drive STCAs via electrical joule-heating has been developed yet. The fabric actuator presented in this paper offers a solution to this problem by employing an STCA multiple fabrication method, a continuous fabrication method, bundling technology, and weaving technology. Two types of samples (cylindrical and planar) are fabricated and their performances are evaluated experimentally. From the actuation test according to the loads, the maximum contraction strain of 34.3% is measured. The repeatability is also verified through 200 cycles of actuation. Using a linearized model, the dynamic performance of the fabric actuator is predicted and compared with experimental results. An actual human arm size mannequin is driven by applying the fabric actuator, and angle control can be achieved with an encoder mounted on the joint. In addition, fabric actuator is weaved to sweater showing the possibility of wearable assistive robot.

From being soft, flexible and producing movement by contracting, soft linear actuators are said to have muscle-like properties. Due to these similarities, they are often called “artificial muscle actuator.” However, the strain produced by these actuators is generally insufficient to be utilized in a large range of applications. Some solutions have been developed, but they sacrifice force to increase the displacement. Meanwhile, the force produced by skeletal muscles increases as it contracts due to its working principle, which is based on the “sliding filament mechanism.” The limitations of soft linear actuators could be overcome by mimicking the contraction process of skeletal muscles. Two types of muscle-inspired robotic joint mechanisms based on the sliding filament mechanism principle are proposed in this work. The mechanisms can be operated using any type of soft linear actuators as well as traditional actuators or motors, and this work realizes the implementation using shape memory alloy wires and 3D printed mechanical parts. The feasibility of both proposed mechanisms, and their capabilities were experimentally verified.

In the physical human-robot interaction system, improving transparency performance which allows humans to move as if there is no robot is a challenging topic. In general physical human-robot interaction, the multiaxial force sensor is used to control the robot. However the signal measured from the force sensor involves not only the force applied to the robot by the human motion intention but also the influence of the natural force feedback between the robot and the human hand due to the motion of the robot. Therefore, in order to improve the transparency performance, it is necessary to consider the dynamics of the human hand as well as the dynamics of the robot. In this paper, an novel algorithm to improve transparency performance is proposed. The proposed algorithm uses only the multiaxial force sensor and compensates the natural force feedback by using the human hand impedance and further improves the transparency performance which has a limitation adjusting admittance parameters. The validity of the proposed algorithm is described through the system model analysis and the experiment using the hydraulic upper limb exoskeleton.

This paper presents a hexapod crawling robot which has bioinspired design and locomotion posture from the insects. The robot, called S-Hex II, is an upgraded version of the different printable monolithic hexapod robot which is named as S-Hex I. The S-Hex II is studied for the project of developing mesoscale walking robots actuated by the soft dielectric elastomer actuators. In comparison with the S-Hex I, the S-Hex II owns smaller dimension, lighter weight, and significantly faster walking speed. We improve and increase the total number of degree-of-freedom (DOF) of the soft dielectric elastomer actuators (DEAs) from three, used in the S-Hex I, up to five, employed in the S-Hex II, and that provides the promising versatile locomotion ability to the S-Hex II robot. This robot has successfully demonstrated the back and forth ambulation on flat surfaces using the alternating tripod gait with the walking speed of 52 mm/s (approximately 0.35 body-lengths per second) at 7 Hz of actuation frequency.

Aiming to apply soft actuators in driving a walking robot, the design, fabrication and locomotion of a bio-inspired printable hexapod robot are studied. The robot mimics the insect's design and walking posture by driving six legs with alternating tripod gait which provides its locomotive adaptability on flat terrains. The versatile movements of the robot's leg are achieved by using soft and multiple degree-of-freedom actuators. The actuators are made by dielectric elastomers with a simple mechanism based on antagonistic configuration. By using 3D printing method, the actuator can be embedded into the frame of the robot and a control system is developed. Finally, the robot's locomotion is successfully demonstrated with variable speeds and stride lengths.

This paper presents a grasper-integrated force sensor that provides the capability of measuring dual axial forces at the tip of surgical robot for minimally invasive surgery (MIS). On the sensorized forceps, the combination of dual axial forces measured at each side of grasper presents three axial pulling and single axial grasping force sensing, which provide force feedback control using haptic device. It consists of simple structure of triangular prism shape and two capacitive-type pressure sensor cells based on elastomeric polymer which provides the information on normal and shear forces. The sensing principle is to compare the difference between responses of two pressure sensors when the surface of the sensor contacts to the tissue. A sensorized forceps is fabricated by employing the molding method and electronics for signal processing is embedded. Finally, experimental evaluations are performed and its feasibility is validated.

In this paper, novel mechanisms for an in-pipe robot are presented. Multi-axial differential gear mechanism is designed to be driven with only single motor at any elbow-pipe without additional control efforts while all three wheels keep driving power. Brake system was added to prevent slip of wheel. Active wall pressing mechanism allows controlling the contact forces. And additional rescue mechanism is designed for emergency situation. Lastly, their effectiveness is experimentally validated.

This paper presents a preliminary design and experimental results of a multi-axial contact force sensor for robotic surgery graspers. The sensor is a thin-film type capacitive one with a multiple cell structure capable of measuring normal and shear forces at contacts simultaneously. The structure of the sensor is determined via numerical optimization for maximizing sensitivity and based on the results, a prototype is fabricated by employing the silk-screening method. The characteristics of the sensor are evaluated with a multi-axial sensor calibration set-up and the sensitivities for two directional shear forces and a normal forces are measured to be 10.1, 10.3 and 6.1%, respectively. In this study, the feasibility of the sensor is confirmed as the proof-of-concept. In our future studies, a miniaturized pair of the proposed sensor will be embedded to a surgery grasper for in vitro validation.

This paper presents a mechanism for an in-pipe robot, called MRINSPECT VI (Multifunctional Robotic crawler for In-pipe inspection VI), which is under development for the inspection of gas pipelines with 150mm inside diameter. The mechanism is composed of multi-axial differential gear mechanism, wall pressing one, and driven by single motor. It is designed to adapt to the varying inside geometries of pipelines such as elbows by modulating the velocities of active wheels mechanically without any control effort. In this paper, the design features of the mechanism are detailed and its effectiveness is experimentally validated.

The differential drive mechanism, which is one of the mechanisms of wheeled mobile robots, is simple and useful for the motion of the mobile robot. The mechanism, however, has typical disadvantages of losing mobility, falling down, etc. when the robot moves over obstacles or uneven terrains. A novel suspension mechanism presented in this paper was designed to help the robot to overcome these problems. In particular, this mechanism is very suitable for a tall robot, which is susceptible to overturning because of the disturbance caused by acceleration, deceleration, and collision. The proposed mechanism called a Multilayered Suspension Mechanism is composed of the effective and well-directed combination of springs and dampers. It is very simple and cost-effective since it has no actuator for suspension. In this paper, mechanical construction and characteristics of the mechanism are described. Then, excellence and performance of the proposed mechanism are demonstrated by simulations and experiments.

In this paper, we present a smart handheld surgical tool with tactile feedback to help microsurgery. This device consists of force sensors attached to the tool tip and tactile displays on the position of the fingerhold. The sensor is capacitive one and measures not only the magnitude of force, but also the direction of force. The sensor can measure 9N of lateral forces along x-y-z direction. The tactile display is based on dielectric elastomer actuators and made up of three rigid coupling tactile display modules. The tactile displays provide stimuli of 170μm displacement and frequency of 10Hz at the surgeons fingertips. We fabricate the device and its performances are experimentally validated.

Recently, Dielectric Elastomer Actuator(DEA) comes to the market successfully by introducing commercial products such as tactile interfaces for mobile applications. As an advanced application, we present a tactile display device actuated with dielectric elastomer actuator(DEA) in this paper. By employing fluid coupling between the touch spot and the actuator, the device ensures the comfort of touch and the safety of operation from the high driving voltage while contacting with the human skin. In addition, it is compatible with SMT(Surface Mount Technology), which can be easily plugged into PCB(Printed Circuit Board)s like semiconductor chips and extend to the arrayed tactile display, easily. In this paper, its working principle is overviewed and the actual design with fabrication procedures are described in details. Finally, a prototype is made and its performance is evaluated experimentally.

This paper presents a simple method to control the motion of a quadruped robot in unknown rough terrains using a full dynamic model. First, using typical stiffness control method, the four legs' behavior is approximated to 3D spring damper systems. By this way, we can easily derive the dynamic equations of motion in Cartesian space. Based on these equations, a control strategy is proposed to obtain the asymptotical stability of the system. In addition, a reflex signal is also introduced to control the rotational disturbance of the robot body. Finally, dynamic simulation of a quadruped walking robot is performed on several unknown rough terrains to verify the proposed method.

This paper presents a comprehensive study on the design and implementation about 2-DOF decoupled kinematic actuator module based on the parallel structure with a high mechanical stiffness. The basic structure of 2-DOF decoupled kinematic actuator module has two motion units. Since one motion unit can be moved in only one direction, various applications are available and it can solve the parasitic motion fundamentally. The two motion units also have fine motion and coarse motion respectively. Besides it can be variously modified based on how the actuators are connected. Then the hardware of 2-DOF decoupled kinematic actuator module is implemented with one actuator and two additional locking devices. And the performance of the hardware will be evaluated by experimental system.

In this paper, we present the autonomous pipeline navigation method of an in-pipe robot, based on the landmark recognition system and 3D orientation sensor. The fittings of pipelines such as elbows and branches can be used as the landmarks. In this paper, we introduce a noise tolerant landmark detection method using a line laser beam projected on the internal surface of the pipeline. Once the line laser is projected on the surface of landmarks, a unique line pattern is generated. By using this line pattern, the robot can easily detect and distinguish these landmarks while recognizing the direction of the pipeline path. Simultaneously, the robot's pose information from the orientation sensor and the driving motor's encoder is continuously recorded and used to reconstruct a map of the pipelines. By using this map and a specific navigation strategy, the robot can navigate in the 3D pipeline autonomously. The effectiveness of the proposed method is validated by experiments using the in-pipe robot called MRINSPECT V.

The curvatures of an object play an important role in the shape reconstruction of that object. In this research, we suggest a method of estimating unknown curvatures using a coarse-resolution force torque sensor. First, a method of estimating unknown curvatures using large motions in terms of rolling and sliding is proposed. Next, a tracking algorithm for an unknown surface based on an inner position loop control algorithm is presented. An application of this method to the finger of a robot hand is also discussed. Finally, the algorithm is verified by simulations and experiments for several cylinders with different radii.

In this paper, we present a global localization and local pose error compensation method in a known structured environment using magnetic landmarks. In previous our research, it was possible to compensate the pose error (xe, ye, qe) of a mobile robot correctly on the surface of structured environment with magnetic landmarks. In this work, we propose a methodology of arranging magnetic landmarks on the map such that properly arranged magnetic patterns ease the global localization of a mobile agent. Among total six patterns of magnetic-bar in square arrangement, five unique landmarks are obtained. Therefore, a heuristic pattern search method is applied to build the virtual map using five landmarks. In order to obtain the global pose information, the robot identifies the pattern of magnets, and obtains the current global pose information by comparing the measured neighboring patterns with the map information that is saved in advance. Experimental results show the effectiveness of the magnetic-pattern landmarks for the global localization and local pose control of a mobile robot.

In this paper, we present an autonomous in-pipe robot navigating system using vision-based landmark recognition. We propose to use special features of the pipelines (such as elbows or branches) as landmarks by recognizing the shadows of the elbows and branches. To obtain consistent shadow images, the in-pipe robot equips with specially designed illuminator. By analyzing the shadow, the robot can easily identify these landmarks, detect the direction of the passage, and adaptively traverse through while continuously updating the map. The effectiveness of the proposed method is verified by real experiments using the in-pipe robot MRINSPECT V for inspecting inside of the miniature urban 8-inch gas pipeline structure.

Improvement of the adaptability of a quadruped robot in rough terrain is studied in this paper. First, the position and posture of the body of the robot are adjusted to maximize the number of choices for foot placement of the next swing leg. The more choices the robot has to select the next suitable foothold, the better it will be to cope with rough terrain. Second, an effective foothold search algorithm is developed. The foothold search algorithm not only tries to find a valid foothold but also tries to maintain high adaptability of the robot. For implementing the algorithm, some new concepts such as potential swing direction, complementary kinematic margin and elliptical set of candidate footholds are also proposed. The effectiveness of this procedure in improving the adaptability of a quadruped robot moving in challenging terrain is verified in both simulation and experiment.

Aiming to real easy application in several quadruped robot platforms, this paper introduces a new method of modeling central pattern generators (CPG) to control quadruped locomotion. Not only can this new model generate all the primary gaits of quadrupeds stably with limit cycle effect, but it also has the ability of tuning the periodic outputs with arbitrary waveforms. The core idea is to combine strong points of two mathematical tools: Fourier series and Recurrent neural networks. In addition, a new biomimetic controller is also introduced using the proposed CPG model and several reflex modules. Finally, dynamic simulations are performed to validate the efficiency of the proposed controller.

The requirement of effective reconstruction of surface texture has been raised by applications concerning interaction with objects; however, the reconstruction of precise details of texture is seldom discussed. In this paper, an algorithm for incremental reconstruction of the details of periodic textured surface is presented. The concept of polar spectrum is introduced to describe the spatial properties of the surface with respect to the direction of measurement. Based on the relation between spatial frequencies and directions, surface profiles in different directions can be rebuilt from with limited number of scans. Experimental results show the effectiveness of the proposed algorithm.

In this paper, we investigate comprehensive issues of modularized robot systems and present architecture for effective development of personal robots. The proposed architecture includes the interface and interaction methodology of the hardware modules and the software among the modules. Based on the architecture, we present a fully modularized personal robot dynamically reconfigurable personal robot I. Its hardware modules are easily added to or removed from the original system, and also the distributed software functions of the modules are rearrangeable accordingly. We focus on how to effectively build up the robot, and discuss the dynamically reconfigurable features of it for evaluating the proposed idea and approach.

This paper discusses the importance of iteration when performing the measurement update step for the problem of bearing-only SLAM. We focus on an undelayed approach that initializes a landmark after only one bearing measurement. Traditionally, the extended Kalman filter (EKF) has been used for SLAM, but the EKF measurement update rule can often lead to a divergent state estimate due to its inconsistency in linearization. We discuss the flaws of the EKF in this paper, and show that even the well established inverse-depth parametrization for bearing-only SLAM can be affected. We then show that representing the bearing-only update as a numerical optimization problem (solved with an iterative approach such as Gauss-Newton minimization) prevents divergence of the Kalman filter state and produces accurate SLAM results for a bearing-only sensor. More specifically, we propose the use of an iterated Kalman filter to resolve the issues normally associated with the EKF measurement update. Two outdoor mobile robot experiments are discussed to compare algorithm performance.

In this paper, we propose a method of sensing outdoor environments for a walking and climbing robot. The proposed method ensures the realtime perception of the surface geometry by integrating a range and a gyroscope with a novel arrangement of the sensors. In addition, a gait planning algorithm based on the sensing method is presented. The algorithm runs fast since it is simple, and the rich information from the sensing system helps the robot overcome the real environment, even an extremely complex one. The sensing system is implemented in a quadruped walking robot, called MRWALLSPECT IV and its effectiveness is proved experimentally.

In this paper we present an in-pipe robot, called MRINSPECT V (Multifunctional Robotic crawler for In-pipe inSPECTion V), which is under development for the inspection of pipelines with a nominal 8-inch inside diameter. To travel freely in every pipeline element, the robot adopts a differential driving mechanism that we have developed. Furthermore, by introducing clutches in transmitting driving power to the wheels, MRINSPECT V is able to select the suitable driving method according to the shape of the pipeline and save the energy to drive in pipelines. The robot aiming for autonomous navigation is configured with four modules serially connected. Two active driving modules are located in front and rear of the system, respectively. Passive modules are linked between the driving modules. This module-based robot can fit to narrow and winding pipelines by using the novel mechanism such as the specially designed module-joints. In this paper, the critical points in the design and construction of the proposed robot are described with the preliminary results of experiments that yield good mobility and increased efficiency.

In this paper, we introduce a wall climbing robotic system for visual inspection of man-made structures. The adhesion mechanism of our system consists of an impeller and two-layer suction seals which provide sufficient adhesion forces for supporting the robot body on the non-smooth vertical wall and horizontal ceiling by generating pressure difference between the inside of the pressure chamber and the ambient environment. A comprehensive study is performed on the dynamic fluid modeling of the adhesion mechanism and the adhesion force is controlled by adjusting the pressure inside of the chamber. In addition, stable differential-driving locomotion on non-smooth surface are achieved by adapting a suspension mechanism for each wheel. A wall climbing robot, called LARVA, is successfully developed and its effectiveness of locomotion is verified with experiments on non-smooth vertical wall and horizontal ceiling surface.

This paper presents a hybrid localization scheme for a mobile robot using the hierarchical atlas. The hierarchical atlas is a map that consists of a higher level topological graph with lower level feature-based metric submaps associated with the graph edges. Our method employs both a discrete Bayes filter and a Kalman filter to localize the robot in the map. This framework accommodates localization in a map with no prior information (global localization) and localization in a map with an incorrect pose estimate (kidnapped robot). Our approach efficiently scales to large environments without sacrificing accuracy or robustness. We have verified our method with large-scale experiments in a multi-floor office environment.

Distributed manipulation using passive air flows generally produces multiple equilibria. In this paper, a straight stationary barrier is considered in a manipulation problem using passive air flows. Such a system simplifies equilibrium analysis but raises problems on contact modes, rolling or sliding. Coulomb's friction model is employed to solve contact modes when an object sits on a straight barrier. This paper illustrates the relationship between contact modes and the location of a flow sink with respect to location of the straight barrier. Although the friction coefficient is poorly estimated, numerical prediction of contact modes quite well agrees with experimental results

Distributed manipulation systems induce motions on objects through the application of forces at many points of contact. Current forms of distributed manipulation include multiple mobile robots, vibrating plates, actively controlled arrays of air jets, and planar micro- and macro-mechanical arrays of actuators. The authors have presented a new form of distributed manipulation using passive airflow fields. This paper lays out infrastructure for manipulation algorithms using logarithmic potential fields applicable to passive airflow distributed manipulators. It uses a line-integral form of the lifted force equations, and provides a numerical approach to check the uniqueness of the robust pivot point for given objects in a logarithmic potential field. The numerical method is proved analytically to require a finite resolution to find all robust pivot points. It also proposes a squeeze-like sequential manipulation algorithm to bring an object with a unique robust pivot point to a unique final pose using airflow fields without sensors. The algorithm has been verified by experiments which are conducted for three different starting orientations, and end up with a unique final pose at the end of the manipulation sequence

Distributed manipulation systems induce motions on objects through the application of many external forces. Many of these systems are abstracted as planar programmable force fields. Quadratic potential fields form a class of such fields that lend themselves to analytical study and exhibit useful stability properties. This paper introduces a new methodology to build quadratic potential fields with simple devices using the naturally existing phenomena of airflow, which is an improvement to the traditional use of the complicated programmable actuator arrays. It also provides a basis for the exploitation, in distributed manipulation, of natural phenomena like airflow, which require rigorous analysis and display stability difficulties. A demonstration and verification of the theoretical results for the special case of the elliptic field with airflows is also presented.

Distributed manipulation systems induce motions on objects through the application of many external forces. Many of these systems are abstracted as planar programmable force fields. Quadratic potential fields, which belong to such a class of fields, lend themselves to analytical study and exhibit useful stability properties. This paper introduces a new methodology to build Quadratic fields with simple devices using the naturally existing phenomena of airflow which is an improvement to the traditional use of the complicated programmable actuator arrays. It also provides a basis for the exploitation, in distributed manipulation, of natural phenomena like airflow, which require rigorous analysis and display stability difficulties. A demonstration and verification of the theoretical results for the special case of the elliptic field with air flows is also presented.

Distributed manipulation systems induce motions on objects through the application of forces at many points of contact. Current forms of distributed manipulation include multiple mobile robots, vibrating plates, actively controlled arrays of air jets, and planar micro and macro-mechanical arrays of actuators. The authors have presented a new form of distributed manipulation using passive air flow fields, which has been experimentally demonstrated along with a computational method to locate equilibria. This paper presents a numerical approach to check the uniqueness of the pivot point of lifted logarithmic potentials. For objects with a unique pivot point, a squeeze-like sequential manipulation using air flow which brings the object to a unique final pose is presented and verified with experiments.

Distributed manipulation systems induce motions on objects through the application of forces at many points of contact. Current forms of distributed manipulation include multiple mobile robots, vibrating plates, actively controlled arrays of air jets, and planar micro and macro-mechanical arrays of actuators. The authors have presented a new form of distributed manipulation using passive air flow fields, which has been experimentally demonstrated and a computational method to locate equilibria. This paper presents a methodology for guaranteeing the existence of the equilibria and its synthetic usage for efficient manipulation of objects using passive air flow fields.

Many distributed manipulation systems are capable of generating planar force fields which act over the entire surface of an object to manipulate it to a stable equilibrium within the field. Passive air flow fields, previously introduced by the authors generate force fields through the linear superposition of logarithmically varying radial potential fields. The main advantage of these fields Is that they are realizable through very simple actuation. However, they do not lend themselves to analytical prediction of net forces or equilibria. The paper presents an efficient means of numerically computing the net force and moment exerted by such fields on objects composed of multiple simple shapes, as well as efficient means of finding equilibrium points on these fields.

Distributed manipulation systems induce motions on objects through the application of forces at many points of contact. Current forms of distributed manipulation include multiple mobile robots, vibrating plates, actively controlled arrays of air jets, and planar micro and macro-mechanical arrays of actuators. The paper presents a form of distributed manipulation using passive air flow fields, which has been experimentally demonstrated. Rather than directly actuating the flow at each point, potential flow assumptions allow a small number of simple point-generated fields to combine to form complex manipulation fields. The paper presents a methodology for efficiently computing equilibria of objects manipulated by arbitrary combinations of radially symmetric fields (such as potential flow fields).