IROS 2018 论文列表

Experimental Advanced Superconducting Tokamak (EAST) is the world's first fully superconducting tokamak fusion device with non-circular cross-section which was built in China The EAST articulated maintenance arm (EAMA) system is developed for real-time detection and rapid repair operations to damaged internal components during plasma discharges without breaking the EAST ultra-high vacuum (UHV) condition. To achieve the desired objectives, the EAMA system design should guarantee that the robot can stably run in the harsh environments of high temperature (80-120 °C) and high vacuum (~ 10-5Pa). Meanwhile, the errors caused by the deformation of long flexible robot arms should also be predicted and compensated in real-time to obtain high accuracy for maintenance operations. In this paper, the vacuum-available design scheme of the manipulator system was firstly introduced. Secondly, inverse kinematics and obstacle avoidance strategy of the highly redundant EAMA robot was built. Then, flexible errors were predicted utilizing a back-propagation neural network (BPNN) model which was established on the basis of real experimental data. Finally, an integrated control strategy for error prediction and compensation was developed.

In earlier work it has been shown how culture can be used as a parameter influencing human robot interaction in general (e.g. [1]). While this is a good starting point, in our work with concrete application fields we encounter that culture in its usual definition as national culture (e.g. [2]; [3]) is too general a concept to be useful in these concrete applications. Thus, we shifted our focus instead to a concept of local cultural practices, which is derived from situated practices as in Wengers communities of practice [4] and grounded loosely in Sperbers idea of an epidemiology of representations [5], i.e. culture or rather cultural practices as an emergent phenomenon from learning processes in a given group. Developing this new kind of culture-aware robots can then not start from a general definition of culture like Hofstede [2], Schwartz and Sagiv [6], etc. but has to take the actual group of users (and stakeholders) into account. We exemplify this approach with our work in a residency for citizens with acquired brain damage.

In this paper we propose a method to determine an optimal statically stable gait for a quadruped robot walking in the presence of an expected disturbance. There exists a tradeoff between a stable gait and an energy efficient gait. Our goal is to determine an energy efficient quadruped gait that will maintain stability while a human uses the device to stabilize themselves while walking. In order to determine an optimal gait, we present a cost function consisting of an energy term and a stability term. A method of evaluating the cost function using dynamics and quasi-static analysis is demonstrated. The optimization is implemented for a human assistive device currently being designed and the results are verified in simulation.

Swarm search and service (SSS) missions require large swarms to simultaneously search an area while servicing jobs as they are encountered. Jobs must be immediately serviced and can be one of several different job types - each requiring a different service time and number of vehicles to complete its service successfully. After jobs are serviced, vehicles are returned to the swarm and become available for reallocation. As part of SSS mission planning, human operators must determine the number of vehicles needed to achieve this balance. The complexities associated with balancing vehicle allocation to multiple as yet unknown tasks with returning vehicles makes this extremely difficult for humans. Previous work assumes that all system jobs are known ahead of time or that vehicles move independently of each other in a multi-agent framework. We present a dynamic vehicle routing (DVR) framework whose policies optimally allocate vehicles as jobs arrive. By incorporating time constraints into the DVR framework, an M/M/k/k queuing model can be used to evaluate overall steady state system performance for a given swarm size. Using these estimates, operators can rapidly compare system performance across different configurations, leading to more effective choices for swarm size. A sensitivity analysis is performed and its results are compared with the model, illustrating the appropriateness of our method to problems of plausible scale and complexity.

In the past decade many robots were deployed in the wild, and people detection and tracking is an important component of such deployments. On top of that, one often needs to run modules which analyze persons and extract higher level attributes such as age and gender, or dynamic information like gaze and pose. The latter ones are especially necessary for building a reactive, social robot-person interaction. In this paper, we combine those components in a fully modular detection-tracking-analysis pipeline, called DetTA. We investigate the benefits of such an integration on the example of head and skeleton pose, by using the consistent track ID for a temporal filtering of the analysis modules' observations, showing a slight improvement in a challenging real-world scenario. We also study the potential of a so-called “free-flight” mode, where the analysis of a person attribute only relies on the filter's predictions for certain frames. Here, our study shows that this boosts the runtime dramatically, while the prediction quality remains stable. This insight is especially important for reducing power consumption and sharing precious (GPU-)memory when running many analysis components on a mobile platform, especially so in the era of expensive deep learning methods.

Robotic picking of folded objects such as books is required for picking various objects. As a folded object is easily unfolded, it is difficult to carry it stably and place it in a desired pose due to its dangling part. For overcoming this difficulty, we propose a trial-and-error picking system using our Suction Pinching Hand, which can push the dangling part up with pinch grasp until the object lifted with suction grasp is folded. That system utilizes proximity sensors on the hand to predict whether folding will succeed with a current hand pose and decide whether to retry with another pose. Also, proximity sensors, flex sensors and an air pressure sensor are used to deal with uncertainty of the image recognition, the hand hardware and suction grasp. We evaluate our proposed system with experiments of picking and placing folded objects. It is confirmed that our proposed system realizes picking with the ability of our Suction Pinching Hand to carry folded objects stably and place them in desired poses. It is also proved that our proposed system is robust against the uncertainty.

Motion is a critical aspect of communication, required to create natural interactions between humans and robots. Robots for the classroom pose several constraints on motion, which make them challenging to design, including maintaining the safety of the child and the robot, responding in a timely fashion, and creating motions that are expressive and not scary. In this paper we present the mechanical design of a social robot and demonstrate that it is capable of safe motion within the proximity of children through analysis and empirical testing of the arms. The robot has a novel mechanical design for its two arms, which include torso-mounted, back-drivable, torque-limited stepper motors. The results suggest that our design succeeds at increasing safety levels while enabling the use of socially acceptable speeds of motion during the interaction. This study implies that the design of robotic agents for social interaction with children should consider the design of mechanical features that enable safe contact between the human and the robot while not limiting the robot to slow motions that would impair the timing of the interaction.

One of the major problems facing the development and road to practical usage of concentric tube continuum robots in surgical environments is that of instability. This issue, also known as the snapping problem, is caused by a tube having a high bending to torsional stiffness ratio (BTSR). Past efforts have shown that by cutting patterns on the tubes, this problem can be avoided. This paper seeks to redesign the topology of the tubes so that BTSR is decreased and the snapping problem is resolved in a particular tube set. The generated designs are then tested through finite element analysis as well as experimental testing to demonstrate the elimination of the snapping problem. Using this novel tube design on a concentric tube robotic system can increase its stable workspace because it allows the usage of greater tube curvatures and/or curve lengths.

This paper presents the design, implementation and validation of a novel spherical Autonomous Underwater Vehicle (AUV) prototype, developed for inspection and exploration of flooded mine tunnel networks. The unique mechanical, electrical and hardware design is presented, as well as the development of a theoretical 6 degree-of-freedom (DOF) high-fidelity dynamic model of the system. A series of underwater experiments were carried out in a controlled environment to test the standard motion patterns of the AUV with a Proportional-Integral-Derivative (PID) controller. The performance of the PID controller will be used as the baseline for comparison of more advanced control schemes. The experimental results demonstrated that the spherical AUV was able to realize the tested underwater motions with notable performance.

In this paper we present the design of a hybrid robotic arm using soft, inflatable bladders for actuation. Low cost switching valves are used for pressure control, where the valve model is identified experimentally. A model of the robotic arm is derived based on system identification and used to derive a linear quadratic Gaussian controller. A method to solve limitations of the employed switching valves is proposed and experimentally proven to improve tracking performance. The closed loop control performance of the robotic arm is demonstrated by stabilizing a rotational inverted pendulum known as the Furuta pendulum.

Currently, most of commercially available ankle foot prosthesis are passive, which don't exhibit appropriate biomechanics during walking and could not adapt to dynamic property of able-bodied walking. In this paper, we present a novel robotic ankle foot prosthesis with variable transmission series elastic actuator (SEA). Slider crank mechanism is applied to transform linear motion of series elastic actuator to rotary motion of ankle foot joint. And this could contribute to variable transmission ratio while ankle angle varies. Because of variable transmission ratio, ankle joint torque is increasing while ankle angle is flexed from plantar flexion to dorsiflexion, whose feature has similar increase trend with human's ankle joint torque-angle relationship, and exhibits an appropriate characteristic for developing robotic ankle foot prosthesis. Larger torque could be obtained in powered plantar flexion, and this indicates that variable transmission mechanism would help reduce required motor torque compared with traditional mechanism. Energy stored in springs of series elastic actuator contribute a torque to powered plantar flexion. Preliminary experiments with a transtibial amputee and a transferomal amputee have been performed to test the prototype.

Underground mines are a dangerous working environment and, therefore, robots could help putting less humans at risk. Traditional robots, sensors, and software often do not work reliably underground due to the harsh environment. This paper analyzes requirements and presents a robot design capable of navigating autonomously underground and manipulating objects with a robotic arm. The robot's base is a robust four wheeled platform powered by electric motors and able to withstand the harsh environment. It is equipped with color and depth cameras, lighting, laser scanners, an inertial measurement unit, and a robotic arm. We conducted two experiments testing mapping and autonomous navigation. Mapping a 75 meters long route including a loop closure results in a map that qualitatively matches the original map to a good extent. Testing autonomous driving on a previously created map of a second, straight, 150 meters long route was also successful. However, without loop closure, rotation errors cause apparent deviations in the created map. These first experiments showed the robot's operability underground.

Precision robotic pollination systems can not only fill the gap of declining natural pollinators, but can also surpass them in efficiency and uniformity, helping to feed the fast-growing human population on Earth. This paper presents the design and ongoing development of an autonomous robot named “BrambleBee”, which aims at pollinating bramble plants in a greenhouse environment. Partially inspired by the ecology and behavior of bees, BrambleBee employs state-of-the-art localization and mapping, visual perception, path planning, motion control, and manipulation techniques to create an efficient and robust autonomous pollination system.

Recent research on telepresence robots demonstrates that while they enable new heights of remote communication, there still exists challenges for both local and remote users in creating a connectedness one only encounters in face-to-face interactions. A large part of communication is beyond hearing and vision. Tangible interactions, expressive gestures, and physical referencing represent three of the primary social behaviors missing in the current telepresence experience. There is an inherent, subconscious quality to these physical actions that has been shown to allow more expressive and engaging communication. In this project we present the design, fabrication, and initial performance validation of a lightweight, ergonomic manipulator with a heavy, anthropomorphic end effector that enables gesturing capabilities for telepresence interactions.

A 2 motor 2 degrees-of-freedom (2M2D) coupled tendon driven joint module is proposed as a basic component for robot arms. Torque reallocation via tendon coupling can enhance the output torque of one single joint. According to the motor position, the joint module is classified into four types: the externally-actuated structure, the internally-coaxially-actuated structure, the internally-separately-actuated structure, and the hybrid-actuated structure. The four structures are analyzed and compared, and their implementation design examples are given. Experiments comparing the proposed joint module with directly-actuated traditional joint suggested that the 2M2D coupled tendon-driven joint module can obtain high control accuracy, and the torque reallocation via tendon coupling is effective to improve output torque. Additionally, an anthropomorphic robot arm with low weight and high payload was developed to show the utility of the proposed joint module.

In this paper, we present the system design and initial testing of SUPERball v2, a completely re-designed 2-meter spherical six-bar tensegrity robot designed to survive high-speed landings as well as locomote to desired locations. SUPERball v2 was designed to enable a host of new actuation and experimentation. The prototype features a fully actuated six-bar design (24 actuators), compliant nylon cables (up to 15% stretch), torque-control enabled motors, and a robust mechanical structure capable of surviving impact velocities upwards of 8 m/s.

Robotic systems for object handling and manipulation are hugely important for modern engineering and industry, with their efficiency, agility and robustness often depending on gripper design and performance. In this work, we investigate a gripper design that, when driven by a twisted string actuator, exhibits nearly-constant transmission ratio throughout its motion range. This allows for design of a highly-compact, modular and efficient robotic gripper driven by a low-power motor. We investigate kinematics of the device, experimentally verify developed models with a practical gripper testbed, and analyze transmission ratio and efficiency of the designed device. The resulting system has a nearly-constant transmission ratio of 550, with the constancy coefficient of 0.985.

A new lizard-inspired robot is presented in this paper, which enables to maintain its moving direction by lateral body motions even during high-speed bipedal running. First, a dynamic model for lizard-inspired robot is derived to simulate the lateral body motion of real lizard. Based upon the simulation using dynamic model, the lizard-inspired robot is tactfully built so that its hind leg is optimally designed on a 4-bar mechanism and its body is simplified to consist of two body links and a tail connected by two revolute joints. The experiments verify that the proposed robot can maintain its moving direction via proper lateral motions during high-speed bipedal running similar to that of real lizard.

We present the design of a new robotic human augmentation system that will assist the operator in carrying a heavy payload, reaching and maintaining difficult postures, and ultimately better performing their job. The Extra Robotic Legs (XRL) system is worn by the operator and consists of two articulated robotic legs that move with the operator to bear a heavy payload. The design was driven by a need to increase the effectiveness of hazardous material emergency response personnel who are encumbered by their personal protective equipment (PPE). The legs will ultimately walk, climb stairs, crouch down, and crawl with the operator while eliminating all external PPE loads on the operator. The forces involved in the most extreme loading cases were analyzed to find an effective strategy for reducing actuator loads. The analysis reveals that the maximum torque is exerted during the transition from the crawling to standing mode of motion. Peak torques are significantly reduced by leveraging redundancy in force application resulting from a closed-loop kinematic chain formed by a particular posture of the XRL. The actuators, power systems, and transmission elements were designed from the results of these analyses. Using differential mechanisms to combine the inputs of multiple actuators into a single degree of freedom, the gear reductions needed to bear the heavy loads could be kept at a minimum, enabling high bandwidth force control due to the near-direct-drive transmission. A prototype was fabricated utilizing the insights gained from these analyses and initial tests indicate the feasibility of the XRL system.