Showing papers in "Journal of Robotics in 2011"
TL;DR: This work reviews all current robotic systems to date for lower-limb rehabilitation, as well as main clinical tests performed with them, with the aim of showing a clear starting point in the field.
Abstract: This paper presents a survey of existing robotic systems for lower-limb rehabilitation. It is a general assumption that robotics will play an important role in therapy activities within rehabilitation treatment. In the last decade, the interest in the field has grown exponentially mainly due to the initial success of the early systems and the growing demand caused by increasing numbers of stroke patients and their associate rehabilitation costs. As a result, robot therapy systems have
been developed worldwide for training of both the upper and lower extremities. This work reviews all current robotic systems to date for lower-limb rehabilitation, as well as main clinical tests performed with them, with the aim of showing a clear starting point in the field. It also remarks some challenges that current systems still have to meet in order to obtain a broad clinical and market acceptance.
465 citations
TL;DR: A probabilistic framework for the characterization of the underlying multiscale dynamics of a wireless link and a realistic yet simple channel simulator is developed, which can be used to verify cooperative robotic operations in the presence of realistic communication links.
Abstract: The goal of this overview paper is to serve as a reference for researchers that are interested in the realistic modeling of wireless channels for the purpose of analysis and optimization of networked robotic systems. By utilizing the knowledge available in the wireless communication literature, we first summarize a probabilistic framework for the characterization of the underlying multiscale dynamics of a wireless link. We furthermore confirm this framework with our robotic testbed, by making an extensive number of channel measurements. To show the usefulness of this framework for networked robotic applications, we then discuss a few recent examples where this probabilistic channel characterization has been utilized for the theoretical analysis and communication-aware design of networked robotic systems. Finally, we show how to develop a realistic yet simple channel simulator, which can be used to verify cooperative robotic operations in the presence of realistic communication links.
55 citations
TL;DR: This paper describes the initial concept, design goals, and methods of this wearable overground robotic mobility device, which uses compliant actuation to power the hip and knee joints and has initiated sensory substitution feedback mechanisms to augment user sensory perception of his or her lower extremities.
Abstract: While most mobility options for persons with paraplegia or paraparesis employ wheeled solutions, significant adverse health, psychological, and social consequences result from wheelchair confinement. Modern robotic exoskeleton devices for gait assistance and rehabilitation, however, can support legged locomotion systems for those with lower extremity weakness or paralysis. The Florida Institute for Human and Machine Cognition (IHMC) has developed the Mina, a prototype sensorimotor robotic orthosis for mobility assistance that provides mobility capability for paraplegic and paraparetic users. This paper describes the initial concept, design goals, and methods of this wearable overground robotic mobility device, which uses compliant actuation to power the hip and knee joints. Paralyzed users can balance and walk using the device over level terrain with the assistance of forearm crutches employing a quadrupedal gait. We have initiated sensory substitution feedback mechanisms to augment user sensory perception of his or her lower extremities. Using this sensory feedback, we hypothesize that users will ambulate with a more natural, upright gait and will be able to directly control the gait parameters and respond to perturbations. This may allow bipedal (with minimal support) gait in future prototypes.
54 citations
TL;DR: The results of usability testing with 10 participants support the feasibility of developing and testing an interactive personal trainer robot to monitor and increase exercise adherence in older adults.
Abstract: Socially assistive robots have the potential to improve the quality of life of older adults by encouraging and guiding their performance of rehabilitation exercises while offering cognitive stimulation and companionship. This study focuses on the early stages of developing and testing an interactive personal trainer robot to monitor and increase exercise adherence in older adults. The robot physically demonstrates exercises for the user to follow and monitors the user's progress using a vision-processing unit that detects face and hand movements. When the user successfully completes a move, the robot gives positive feedback and begins the next repetition. The results of usability testing with 10 participants support the feasibility of this approach. Further extensions are planned to evaluate a complete exercise program for improving older adults' physical range of motion in a controlled experiment with three conditions: a personal trainer robot, a personal trainer on-screen character, and a pencil-and-paper exercise plan.
38 citations
TL;DR: This paper presents a lightweight Rao-Blackwellized particle filter- (RBPF-) based SLAM algorithm for indoor environments, which uses line segments extracted from the laser range finder as the fundamental map structure so as to reduce the memory usage.
Abstract: Simultaneous Localization and Mapping (SLAM) is an important technique for robotic system navigation. Due to the high complexity of the algorithm, SLAM usually needs long computational time or large amount of memory to achieve accurate results. In this paper, we present a lightweight Rao-Blackwellized particle filter- (RBPF-) based SLAM algorithm for indoor environments, which uses line segments extracted from the laser range finder as the fundamental map structure so as to reduce the memory usage. Since most major structures of indoor environments are usually orthogonal to each other, we can also efficiently increase the accuracy and reduce the complexity of our algorithm by exploiting this orthogonal property of line segments, that is, we treat line segments that are parallel or perpendicular to each other in a special way when calculating the importance weight of each particle. Experimental results shows that our work is capable of drawing maps in complex indoor environments, needing only very low amount of memory and much less computational time as compared to other grid map-based RBPF SLAM algorithms.
30 citations
TL;DR: A force feedback device that presents a reaction force to the distal segment of the operator's thumb, middle finger, and basipodite of the middle finger when the robot hand grasps an object is developed.
Abstract: A haptic feedback system is required to assist telerehabilitation with robot hand. The system should provide the reaction force measured in the robot hand to an operator. In this paper, we have developed a force feedback device that presents a reaction force to the distal segment of the operator's thumb, middle finger, and basipodite of the middle finger when the robot hand grasps an object. The device uses a shape memory alloy as an actuator, which affords a very compact, lightweight, and accurate device.
21 citations
TL;DR: Research into and development of various gait rehabilitation devices is currently underway to identify methods to alleviate the physical burden on therapists in central nervous system disease.
Abstract: Central nervous system diseases cause the gait disorder. Early rehabilitation of a patient with central nervous system disease is shown to be benefit. However, early gait training is difficult because of muscular weakness and those elderly patients who lose of leg muscular power. In the patient's walking training, therapists assist the movement of patient's lower limbs and control the movement of patient's lower limbs. However the assistance for the movement of the lower limbs is a serious hard labor for therapists. Therefore, research into and development of various gait rehabilitation devices is currently underway to identify methods to alleviate the physical burden on therapists. In this paper, we introduced the about gait rehabilitation devices in central nervous system disease.
19 citations
TL;DR: The development of a hybrid reconfigurable machine tool consisting of a tripod-based parallel kinematic machine (PKM) module with three degrees of freedom (DOF) and a serial linear 𝑋-𝑌 table with two DOF has been introduced.
Abstract: The development of a hybrid reconfigurable machine tool has been introduced. The machine tool consists of a tripod-based parallel kinematic machine (PKM) module with three degrees of freedom (DOF) and a serial linear 𝑋-𝑌 table with two DOF. The PKM is installed on a gantry system which is capable of reconfiguring its position and orientation. In the design of tripod-based parallel mechanism, a passive link is used to enhance the stiffness and increase the working load. To avoid the buildup of the heat of the extensive actuation, three joints are actuated via the actuators with a constant length. The geometries of the PKM have been optimized for the best and highest accuracy. In this paper, its control system and the prototyping development are focused. An open architecture is applied, the control methodologies are developed and validated, and the corresponding software tools have been implemented for the software reconfiguration of the control system.
19 citations
TL;DR: The proposed decentralized control law is extended to an adaptive synchronization control taking into account parameter uncertainties to address the time delay problems in the network communication channels and robustly synchronizes robots to track a given trajectory.
Abstract: This paper investigates the issue of designing decentralized control laws to cooperatively command a team of general fully actuated manipulators. The purpose is to synchronize their movements while tracking a common desired trajectory. Based on the well-known consensus algorithm, the control strategy consists in synchronizing the joint position and the velocity of each robot in the network with respect to neighboring robots' joints and velocities. Modeled by an undirected graph, the cooperative robot network requires just local neighbor-to-neighbor information exchange between manipulators. So, it does not assume the existence of an explicit leader in the team. Based above all on combination of Lyapunov direct method and cross-coupling strategy, the proposed decentralized control law is extended to an adaptive synchronization control taking into account parameter uncertainties. To address the time delay problems in the network communication channels, the suggested synchronization control law robustly synchronizes robots to track a given trajectory. To this end, Krasovskii functional method has been used to deal with the delay-dependent stability problem. A real-time software simulator is developed to visualize the robot manipulators coordination.
18 citations
TL;DR: The proposed controller is configured as a cascade system that allows the decoupling of the actuators dynamics from the arm dynamics and the consequent reduction of the order of the manipulator dynamic model.
Abstract: The output-based control of a redundant robotic manipulator with relevant and adjustable joint stiffness is addressed. The proposed controller is configured as a cascade system that allows the decoupling of the actuators dynamics from the arm dynamics and the consequent reduction of the order of the manipulator dynamic model. Moreover, the proposed controller does not require the knowledge of the whole robot state: only the positions of the actuators and of the joints are necessary. This approach represents a significant simplification with respect to previously proposed state feedback techniques. The problem of controlling simultaneously the position trajectory and the desired stiffness in both the joint and work space is investigated, and the relations between the manipulator redundancy and the selection of both the joint and work space stiffness of the manipulator are discussed. The effectiveness of the proposed approach is verified by simulations of a 3 degrees of freedom planar manipulator.
17 citations
TL;DR: A self-propelled patrolling vehicle which can move automatically to a wider range and record the monitored image by IPCAM within a predefined patrolling route and the build-in MSN module will notice users by sending messages to PC and smart phone.
Abstract: Self-propelled patrolling vehicles can patrol periodically in the designed area to ensure the safety like men do The proposed vehicle cannot only save manpower, but also ensure the performance without mistakes caused by man It is different from the traditional patrolling system which is limited by the manpower and the fixed camera positions To improve such situation, this paper proposes a self-propelled patrolling vehicle which can move automatically to a wider range and record the monitored image by IPCAM within a predefined patrolling route Besides, the user can use the mobile device or website to connect to the vehicle at anytime and anywhere and control it to move to the position to get the indoor image user wants The position of self-propelled vehicles can be detected by the RFID reader as a feedback and be shown on the PC screen and smart phone The recorded images can be also transmitted back to the server via WiFi system for face tracking and discriminating analysis On the other hand, the self-propelled vehicle patrolling routes can be modified by the Android smart-phone remote-control module When some defined events occur, the build-in MSN module will notice users by sending messages to PC and smart phone Experimental results are given in the paper to validate its performance
TL;DR: The problem of slow response time is resolved by using software for an array-type tactile sensor with high resolution that emulates the human sensor system.
Abstract: We have developed a universal robot hand with tactile and other sensors. An array-type tactile sensor is crucial for dexterous manipulation of objects using a robotic hand, since this sensor can measure the pressure distribution on finger pads. The sensor has a very high resolution, and the shape of a grasped object can be classified by using this sensor. The more the number of measurement points provided, the higher the accuracy of the classification, but with a corresponding lengthening of the measurement cycle. In this paper, the problem of slow response time is resolved by using software for an array-type tactile sensor with high resolution that emulates the human sensor system. The validity of the proposed method is demonstrated through experiments.
TL;DR: Not only are DSIs more accurate in predicting the workspace regions where manipulators can best perform translational movements along specific directions, but also they allow foreseeing satisfactorily the dynamic performance variations within the workspace, though being purely kinematic indexes.
Abstract: Performance indexes usually provide global evaluations of robot performances mixing their translational and/or rotational capabilities. This paper proposes a definition of performance index, called direction-selective index (DSI), which has been specifically developed for parallel manipulators and can provide uncoupled evaluations of robot translational capabilities along relevant directions. The DSI formulation is first presented within a general framework, highlighting its relationship with traditional manipulability definitions, and then applied to a family of parallel manipulators (4-RUU) of industrial interest. The investigation is both numerical and experimental and allows highlighting the two chief advantages of the proposed DSIs over more conventional manipulability indexes: not only are DSIs more accurate in predicting the workspace regions where manipulators can best perform translational movements along specific directions, but also they allow foreseeing satisfactorily the dynamic performance variations within the workspace, though being purely kinematic indexes. The experiments have been carried out on an instrumented 4-RUU commercial robot.
TL;DR: The differences between the output of simple sensor models and true sensors are highlighted using results from a field test exercise with the National Robotics Engineering Center's Crusher vehicle, indicating that higher fidelity models are required to truly capture the complex interactions of the sensors with complex objects.
Abstract: Simulations provide a safe, controlled setting for testing and are therefore ideal for rapidly developing and testing autonomous mobile robot behaviors. However, algorithms for mobile robots are notorious for transitioning poorly from simulations to fielded platforms. The difficulty can in part be attributed to the use of simplistic sensor models that do not recreate important phenomena that affect autonomous navigation. The differences between the output of simple sensor models and true sensors are highlighted using results from a field test exercise with the National Robotics Engineering Center's Crusher vehicle. The Crusher was manually driven through an area consisting of a mix of small vegetation, rocks, and hay bales. LIDAR sensor data was collected along the path traveled and used to construct a model of the area. LIDAR data were simulated using a simple point-intersection model for a second, independent path. Cost maps were generated by the Crusher autonomy system using both the real-world and simulated sensor data. The comparison of these cost maps shows consistencies on most solid, large geometry surfaces such as the ground, but discrepancies around vegetation indicate that higher fidelity models are required to truly capture the complex interactions of the sensors with complex objects.
TL;DR: A new type of finger rehabilitation system using a multifingered haptic interface that is controlled by the patient though a surface electromyogram that can provide active rehabilitation using sEMG.
Abstract: This paper presents a new type of finger rehabilitation system using a multifingered haptic interface that is controlled by the patient though a surface electromyogram. We have developed the multifingered haptic interface robot: HIRO III that can give 3-directional forces to 5 fingertips. This robot can also be used as a rehabilitation device that can provide various fingertip exercises and measure various types of information. The sEMG works together with the HIRO III to consider the patient's intent. The proposed system is intended for patients having paralysis in the hand and fingers, and the motions will be provided as biofeedback to the fingertips with the device. In contrast to completely passive rehabilitation, the proposed system can provide active rehabilitation using sEMG. The experiment involved finger opening and closing with this system by ten able-bodied subjects. The results show that almost all subjects felt appropriate motion support from the device.
TL;DR: The memory model is applied to time-variant information about obstacles and driveable routes in the workspace of the autonomous robot and used for solving the navigation cycle of the robot.
Abstract: This paper introduces an environmental representation for autonomous mobile robots that continuously adapts over time. The presented approach is inspired by human memory information processing and stores the current as well as past knowledge of the environment. In this paper, the memory model is applied to time-variant information about obstacles and driveable routes in the workspace of the autonomous robot and used for solving the navigation cycle of the robot. This includes localization and path planning as well as vehicle control. The presented approach is evaluated in a real-world experiment within changing indoor environment. The results show that the environmental representation is stable, improves its quality over time, and adapts to changes.
TL;DR: A solution to model the environment of the robot in order to make it capable of perceiving and avoiding collisions with the objects in its surroundings is shown and the model will be extended to take also into account the volume of theRobot tool inorder to extend the perception capabilities of the entire system.
Abstract: A fundamental aspect of robot-environment interaction in industrial environments is given by the capability of the control system to model the structured and unstructured environment features. Industrial robots have to perform complex tasks at high speeds and have to satisfy hard cycle times while maintaining the operations extremely precise. The capability of the robot to perceive the presence of environmental objects is something still missing in the real industrial context. Although anthropomorphic robot producers have faced problems related to the interaction between robot and its environment, there is not an exhaustive study on the capabilities of the robot being aware of its volume and on the tools eventually mounted on its flange. In this paper, a solution to model the environment of the robot in order to make it capable of perceiving and avoiding collisions with the objects in its surroundings is shown. Furthermore, the model will be extended to take also into account the volume of the robot tool in order to extend the perception capabilities of the entire system. Testing results will be showed in order to validate the method, proving that the system is able to cope with complex real surroundings.
TL;DR: A new design of flexible fluid actuator (FFA) is presented that enables more design options of attaching parts, as it is allowed by conventional actuators with a stationary centre of rotation.
Abstract: The aim of the project OrthoJacket is to develop a lightweight, portable, and active orthosis for the upper limps. The system consists of two special designed fluidic actuators which are used for supporting the elbow function and the internal rotation of the shoulder. A new design of flexible fluid actuator (FFA) is presented that enables more design options of attaching parts, as it is allowed by conventional actuators with a stationary centre of rotation. This advantage and the inherent flexibility and the low weight of this kind of actuator predestined them for the use in exoskeletons, orthoses, and prostheses. The actuator for the elbow generates a maximum torque of 32 Nm; the internal rotation is supported with 7 Nm. Both actuators support the movement with up to 100% of the necessary power. The shells for the arm and forearm are made of carbon reinforced structures in combination with inflatable cushions.
TL;DR: This paper presents a vision-based technology for localizing targets in 3D environment achieved by the combination of different types of sensors including optical wheel encoders, an electrical compass, and visual observations with a single camera.
Abstract: This paper presents a vision-based technology for localizing targets in 3D environment. It is achieved by the combination of different types of sensors including optical wheel encoders, an electrical compass, and visual observations with a single camera. Based on the robot motion model and image sequences, extended Kalman filter is applied to estimate target locations and the robot pose simultaneously. The proposed localization system is applicable in practice because it is not necessary to have the initializing setting regarding starting the system from artificial landmarks of known size. The technique is especially suitable for navigation and target tracing for an indoor robot and has a high potential extension to surveillance and monitoring for Unmanned Aerial Vehicles with aerial odometry sensors. The experimental results present “cm” level accuracy of the localization of the targets in indoor environment under a high-speed robot movement.
TL;DR: A novel concept of dynamic pole motion (DPM) is introduced for the design of an error-based adaptive controller (E-BAC) to make the system response reasonably fast with no overshoot where the system may be time varying and nonlinear with only partially known dynamics.
Abstract: Design of an adaptive controller for complex dynamic systems is a big challenge faced by the researchers. In this paper, we introduce a novel concept of dynamic pole motion (DPM) for the design of an error-based adaptive controller (E-BAC). The purpose of this novel design approach is to make the system response reasonably fast with no overshoot, where the system may be time varying and nonlinear with only partially known dynamics. The E-BAC is implanted in a system as a nonlinear controller with two dominant dynamic parameters: the dynamic position feedback and the dynamic velocity feedback. For illustrating the strength of this new approach, in this paper we give an example of a flexible robot with nonlinear dynamics. In the design of this feedback adaptive controller, parameters of the controller are designed as a function of the system error. The position feedback Kp(e,t) and the velocity feedback Kv(e,t) are continuously varying and formulated as a function of the system error e(t). This approach for formulating the adaptive controller yields a very fast response with no overshoot.
TL;DR: The construction of the user interface system for a manipulator system in order to support disabled people with less muscle strength such as muscular dystrophy patients is reported on using RT-Middleware which is an open software platform for robot systems.
Abstract: We are developing a manipulator system in order to support disabled people with less muscle strength such as muscular dystrophy patients. Such a manipulator should have an easy user interface for the users to control it. But the supporting manipulator for disabled people cannot make large industry, so we should offer inexpensive manufacturing way. These type products are called “orphan products.” We report on the construction of the user interface system using RT-Middleware which is an open software platform for robot systems. Therefore other user interface components or robot components which are adapted to other symptoms can be replaced with the user interface without any change of the contents. A single switch and scanning menu panel are introduced as the input device for the manual control of the robot arm. The scanning menu panel is designed to perform various actions of the robot arm with the single switch. A manipulator simulation system was constructed to evaluate the input performance. Two muscular dystrophy patients tried our user interface to control the robot simulator and made comments. According to the comments by them, we made several improvements on the user interface. This improvements examples prepare inexpensive manufacturing way for orphan products.
TL;DR: Assessment of effects and costs of ACRE training for frail elderly patients and to establish if ACRE can be a valuable addition to standard therapy in nursing home rehabilitation found no significant effects were found.
Abstract: The ACRE (ACtive REhabilitation) robotic device is developed to enhance therapeutic treatment of upper limbs after stroke. The aim of this study is to assess effects and costs of ACRE training for frail elderly patients and to establish if ACRE can be a valuable addition to standard therapy in nursing home rehabilitation. The study was designed as randomized controlled trial, one group receiving therapy as usual and the other receiving additional ACRE training. Changes in motor abilities, stroke impact, quality of life and emotional well-being were assessed. In total, 24 patients were included. In this small number no significant effects of the ACRE training were found. A large number of 136 patients were excluded. Main reasons for exclusion were lack of physiological or cognitive abilities. Further improvement of the ACRE can best be focused on making the system suitable for self-training and development of training software for activities of daily living.
TL;DR: An algorithm for adaptive transformation to load condition of the modular robots is proposed based on a simple idea that modules have tendency to gather around stress-concentrated parts and reinforce the parts.
Abstract: Self-reconfigurable modular robots are composed of modules which are able to autonomously change the way they are connected. An appropriate control algorithm enables the modular robots to change their shape in order to adapt to their immediate environment. In this paper, we propose an algorithm for adaptive transformation to load condition of the modular robots. The algorithm is based on a simple idea that modules have tendency to gather around stress-concentrated parts and reinforce the parts. As a result of the self-reconfiguration rule, the modular robots form an appropriate structure to stand for the load condition. Applying the algorithm to our modular robot named “CHOBIE II,” we show by computer simulation that the modules are able to construct a cantilever structure with avoiding overstressed states.
TL;DR: Through kinematic analysis of a novel forging manipulator, control strategy of the manipulator is proposed considering the function and motion of forging manipulators and hybrid pressure/position control of hydraulic actuators in forging manipator is realized.
Abstract: The increased demand for large-size forgings has led to developments and innovations of heavy-duty forging manipulators. Besides the huge carrying capacity, some robot features such as force perception, delicacy and flexibility, forging manipulators should also possess. The aim of the work is to develop a heavy-duty forging manipulator with robot features by means of combination of methods in mechanical, hydraulic, and control field. In this paper, through kinematic analysis of a novel forging manipulator, control strategy of the manipulator is proposed considering the function and motion of forging manipulators. Hybrid pressure/position control of hydraulic actuators in forging manipulator is realized. The feasibility of the control method has been verified by the experiments on a real prototype of the novel hydraulic forging manipulator in our institute. The intelligent control of the forging manipulator is performed with programmable logic controller which is suitable for industrial applications.
TL;DR: A potential field-based optimization algorithm is provided, along with a novel composition scheme, and its operation is demonstrated through both simulation and experimentation on a group of small robots.
Abstract: The swarm paradigm of multirobot cooperation relies on a distributed architecture, where each robot makes its own decisions based on locally available knowledge. But occasionally the swarm members may need to share information about their environment or actions through some type of ad hoc communication channel, such as a radio modem, infrared communication, or an optical connection. In all of these cases robust operation is best attained when the transmitter/receiver robot pair is (1) separated by less than some maximum distance (range constraint); and (2) not obstructed by large dense objects (line-of-sight constraint). Therefore to maintain a wireless link between two robots, it is desirable to simultaneously comply with these two spatial constraints. Given a swarm of point robots with specified initial and final configurations and a set of desired communication links consistent with the above criteria, we explore the problem of designing inputs to achieve the final configuration while preserving the desired links for the duration of the motion. Some interesting conclusions about the feasibility of the problem are offered. A potential field-based optimization algorithm is provided, along with a novel composition scheme, and its operation is demonstrated through both simulation and experimentation on a group of small robots.
TL;DR: Research is conducted on the plant named descoingsii x haworthioides (Pepe) obtaining the action potential signals and its responses to stimulations of different light modes, paving the way for an extensive research towards plant intelligence.
Abstract: In the area of biorobotics, intense research work is being done based on plant intelligence. Any living cell continuously receives information from the environment. In this paper, research is conducted on the plant named descoingsii x haworthioides (Pepe) obtaining the action potential signals and its responses to stimulations of different light modes. The plant electrical signal is the reaction of plant’s stimulation owing to various environmental conditions. Action potentials are responsible for signaling between plant cells and communication from the plants can be achieved through modulation of various parameters of the electrical signal in the plant tissue. The modulated signals are used for providing information to the microcontroller’s algorithm for working of the bio-machine. The changes of frequency of action potentials in plant are studied. Electromyography (EMG) electrodes and needle-type conductive electrodes along with electronic modules are used to collect and transform the information from the plant. Inverse fast Fourier transform (IFFT) is used to convert signal in frequency domain into voltage signal for real-time analysis. The changes in frequency of the plant action potentials to different light modes are used for the control of the bio-machine. This work has paved the way for an extensive research towards plant intelligence.
TL;DR: A unique concept is presented by combining ocean waves' formulation with the probabilistic velocity obstacle (PVO) method for autonomous navigation by applying the method of USV’s navigation in presence of waves.
Abstract: Most of the present work for unmanned surface vehicle (USV) navigation does not take into account environmental disturbances such as ocean waves, winds, and currents. In some scenarios, waves should be treated as special case of dynamic obstacle and can be critical to USV’s safety. For the first time, this paper presents unique concept facing this challenge by combining ocean waves' formulation with the probabilistic velocity obstacle (PVO) method for autonomous navigation. A simple navigation algorithm is presented in order to apply the method of USV’s navigation in presence of waves. A planner simulation dealing with waves and obstacles avoidance is introduced.
TL;DR: Using optimal search strategy based on minimal distance path between vibration parameter stage sets (amplitude and frequencies of robots gripe vibration) and recovery parameter algorithm, this paper can improve the robot assembly behaviour, that is, allow the fastest possible way of mating.
Abstract: This paper presents implementation of optimal search strategy (OSS) in verification of assembly process based on neural vibration learning. The application problem is the complex robot assembly of miniature parts in the example of mating the gears of one multistage planetary speed reducer. Assembly of tube over the planetary gears was noticed as the most difficult problem of overall assembly. The favourable influence of vibration and rotation movement on compensation of tolerance was also observed. With the proposed neural-network-based learning algorithm, it is possible to find extended scope of vibration state parameter. Using optimal search strategy based on minimal distance path between vibration parameter stage sets (amplitude and frequencies of robots gripe vibration) and recovery parameter algorithm, we can improve the robot assembly behaviour, that is, allow the fastest possible way of mating. We have verified by using simulation programs that search strategy is suitable for the situation of unexpected events due to uncertainties.
TL;DR: This work classifies obstacles as moving people by comparing movement of each point with robot movement using odometry data, dynamically changing thresholds to detect, which was four times higher than previous methods did.
Abstract: Navigation robots must single out partners requiring navigation and move in the cluttered environment where people walk around. Developing such robots requires two different people detections: detecting partners and detecting all moving people around the robots. For detecting partners, we design divided spaces based on the spatial relationships and sensing ranges. Mapping the friendliness of each divided space based on the stimulus from the multiple sensors to detect people calling robots positively, robots detect partners on the highest friendliness space. For detecting moving people, we regard objects’ floor boundary points in an omnidirectional image as obstacles. We classify obstacles as moving people by comparing movement of each point with robot movement using odometry data, dynamically changing thresholds to detect. Our robot detected 95.0% of partners while it stands by and interacts with people and detected 85.0% of moving people while robot moves, which was four times higher than previous methods did.
TL;DR: This work is suggesting a bioinspired vision system that helps to develop an advanced human-robot interaction in an autonomous humanoid robot and enhances the robot's vision accuracy online by applying a novel dynamic edge detection algorithm abstracted from the rules that the horizontal cells play in the mammalian retina.
Abstract: Building a human-like robot that could be involved in our daily lives is a dream of many scientists. Achieving a sophisticated robot's vision system, which can enhance the robot's real-time interaction ability with the human, is one of the main keys toward realizing such an autonomous robot. In this work, we are suggesting a bioinspired vision system that helps to develop an advanced human-robot interaction in an autonomous humanoid robot. First, we enhance the robot's vision accuracy online by applying a novel dynamic edge detection algorithm abstracted from the rules that the horizontal cells play in the mammalian retina. Second, in order to support the first algorithm, we improve the robot's tracking ability by designing a variant photoreceptors distribution corresponding to what exists in the human vision system. The experimental results verified the validity of the model. The robot could have a clear vision in real time and build a mental map that assisted it to be aware of the frontal users and to develop a positive interaction with them.