Microscale and nanoscale robotics systems [Grand Challenges of Robotics]

Depending on their overall size, sensing and actuation precision, part or tool size, and task space, robotic systems can be classified as microrobotics or nanorobotics, respectively. Micro/nanorobotics represents these two different scale robotics areas jointly while keeping their clear scale differences in mind. At its current early infancy, the field of micro/nanorobotics has two major research thrust areas. Analogous to the manipulation area in macroscale robotics, the first area explores new methods for programmable manipulation and assembly of micro- and nanoscale entities. Here, the overall micro/nanorobotic system size can be very large, while only the manipulation tools, manipulated objects, and sensing, actuation, and manipulation precision are required to be at the micro/nanoscale. On the other hand, the second research area focuses on overall miniaturization of mobile robots down to mum overall sizes with various locomotion capabilities such as flying, swimming, walking, hopping, rolling, and climbing. In these mobile robotic systems, overall system size is very limited, which induces severe constraints in utilized actuators, sensors, motion mechanisms, power sources, computing power, and wireless communication capability. These two research thrusts are described in detail in the following sections     

The power dissipation method and kinematic reducibility of multiple-model robotic systems

This paper develops a formal connection between the power dissipation method (PDM) and Lagrangian mechanics, with specific application to robotic systems. Such a connection is necessary for understanding how some of the successes in motion planning and stabilization for smooth kinematic robotic systems can be extended to systems with frictional interactions and overconstrained systems. We establish this connection using the idea of a multiple-model system, and then show that multiple-model systems arise naturally in a number of instances, including those arising in cases traditionally addressed using the PDM. We then give necessary and sufficient conditions for a dynamic multiple-model system to be reducible to a kinematic multiple-model system. We use this result to show that solutions to the PDM are actually kinematic reductions of solutions to the Euler-Lagrange equations. We are particularly motivated by mechanical systems undergoing multiple intermittent frictional contacts, such as distributed manipulators, overconstrained wheeled vehicles, and objects that are manipulated by grasping or pushing. Examples illustrate how these results can provide insight into the analysis and control of physical systems.     

Household robots look and learn: environment modeling and localization from an omnidirectional vision system

The work illustrates that a catadioptric omnidirectional vision system can be successfully applied for basic mobile robot navigation tasks, such as localization and environment learning. In combination with other capabilities of such a sensor, such as the recognition and tracking of humans, and because the price of such systems can be made low, this system is particularly suited for systems that are expected to operate in offices and homes in the near future, such as robotic servant systems, entertainment robots, and help for the elderly and disabled.     

Micro magnetic gyromixer for speeding up reactions in droplets

We report a novel micro magnetic gyromixer designed for accelerating mixing hence reactions in droplets. The gyromixer is fabricated with magnetite-PDMS composite using soft lithography. The mixer spins and balances itself on the droplet surface through the gyroscopic effect, rapidly homogenizing the enclosed reagents by stretching and folding internal fluid streamlines to enhance mixing. We examined the capability of the gyromixer for improving biochemical reactions in droplets by monitoring the biotin-streptavidin binding as a linker in a quantum dot fluorescence resonant energy transfer (QD-FRET) sensing system. The remotely controlled gyromixer exhibits high flexibility and potential for integration in a variety of droplet-based miniaturized total analysis systems (μTAS) to reduce turnaround times.     

用于避障研究的微型仿生机器鱼3维仿真系统

基于VC++6.0开发环境和OpenGL（open graphics library）国际图形标准,在Windows系统下开发了微型仿生机器鱼3维仿真系统。该系统可以降低用实体机器鱼进行机器鱼避障能力研究的成本和减少在研究过程中对实体机器鱼造成的损害。采用多边形建模的方法构建了虚拟微型仿生机器鱼模型,模拟了鱼类尾鳍的摆动。提出了一种模拟红外传感器探测障碍物的虚拟射线方法。并采用实时模糊决策算法设计了基于多传感器信息的复合模糊控制器,决策微型仿生机器鱼的避障行为。仿真实验表明,复合模糊控制器实时性好、效率高;无论是单个任意形状的障碍物还是多个连续障碍物,复合模糊控制器都能有效地引导仿生机器鱼避开障碍物,到达目标点。微型仿生机器鱼3维仿真系统为研究仿生机器鱼的自主避障能力提供了可靠、逼真、便利的平台。     

Illumination setup planning for a hand-eye system based on an environmental model

In hand-eye systems for advanced robotic applications such as assembly, the degrees of freedom of the vision sensor should be increased and actively made use of to cope with unstable scene conditions. Particularly, in the case of using a simple vision sensor, an intelligent adaptation of the sensor is essential to compensate for its inability to adapt to a changing environment. This paper proposes a vision sensor setup planning system which operates based on environmental models and generates plans for using the sensor and its illumination assuming freedom of positioning for both. A typical vision task in which the edges of an object are measured to determine its position and orientation is assumed for the sensor setup planning. In this context, the system is able to generate plans for the camera and illumination position, and to select a set of edges best suited for determining the object's position. The system operates for stationary or moving objects by evaluating scene conditions such as edge length, contrast, and relative angles based on a model of the object and the task environment. Automatic vision sensor setup planning functions, as shown in this paper, will play an important role not only for autonomous robotic systems, but also for teleoperation systems in assisting advanced tasks.     

Implementation of real-time distributed control for discrete event robotic systems using Petri nets

This article presents a systematic method of modeling and implementing real-time control for discrete-event robotic systems using Petri nets. Because, in complex robotic systems such as flexible manufacturing systems, the controllers are distributed according to their physical structure, it is desirable to realize real-time distributed control. In this article, the task specification of robotic processes is represented as a system control-level net. Then, based on the hierarchical approach, it is transformed into detailed subnets, which are decomposed and distributed into the local machine controllers. The implementation of real-time distributed control through communication between the system controller and the machine controllers on a microcomputer network is described for a sample robotic system. The proposed implementation method is sufficiently general, and can be used as an effective prototyping tool for consistent modeling, simulation, and real-time control of large and complex robotic systems.     

Vision-Based Robotic Motion Control for Non-autonomous Environment

A visual servo control system with SOPC structure is implemented on a retrofitted Mitsubishi Movemaster RV-M2 robotic system. The hardware circuit has the functions of quadrature encoder decoding, limit switch detecting, pulse width modulation (PWM) generating and CMOS image signal capturing. The software embedded in Nios II micro processor has the functions of using UART to communicate with PC, robotic inverse kinematics calculation, robotic motion control schemes, digital image processing and gobang game AI algorithms. The digital hardware circuits are designed by using Verilog language, and programs in Nios II micro processor are coded with C language. An Altera Statrix II EP2S60F672C5Es FPGA chip is adopted as the main CPU of the development board. A CMOS color image sensor with 356 ×292 pixels resolution is selected to catch the environment time-varying change for robotic vision-based servo control. The system performance is evaluated by experimental tests. A gobang game is planned to reveal the visual servo robotic motion control objective in non-autonomous environment. Here, a model-free intelligent self-organizing fuzzy control strategy is employed to design the robotic joint controller. A vision based trajectory planning algorithm is designed to calculate the desired angular positions or trajectory on-line of each robotic joint. The experimental results show that this visual servo control robot has reliable control actions.     

A HUMANLIKE GRASPING FORCE PLANNER FOR OBJECT MANIPULATION BY ROBOT MANIPULATORS

Recently robot manipulators have been expected to perform sophisticated tasks such as object manipulation, assembly tasks, or cooperative tasks with human workers. In order to realize these tasks with robot manipulators, it is important to understand the human strategy of object grasping and manipulation. In this study, we have examined how a human being decides the grasping force necessary to manipulate an unknown object in order to apply human object-grasping strategy for robotic systems. Experiments have been performed with several kinds of objects under several kinds of conditions to investigate how much grasping force human subjects generate. Adjustment strategy of human grasping force when the object is manipulated or in contact with an environment is also examined. Neural networks (the desired grasping force planner) that generate the humanlike desired grasping force are then designed for robotic systems. The effectiveness of the proposed desired grasping force planner is evaluated via experiments.     

Autonomous navigation and environment modeling for MAVs in 3-D enclosed industrial environments

In many applications, the industrial environments are typically 3-D indoor spaces enclosed by shell style structures, which are highly complex with known or unknown non-convex obstacles. GPS signal is unreliable or even unavailable inside, which poses significant technical challenges for the state estimation of micro aerial vehicles (MAVs) performing exploration and modeling tasks in such environments. In this paper, requirements and challenges for 3-D enclosed industrial environments exploration are analyzed firstly, and then state-of-art developments of MAV systems, environment modeling, visual navigation and guidance technologies are reviewed. A robust RGB-D odometry is introduced into the system to provide airborne 6-DOF state estimates of the MAV, which are fused with inertial measurements. Then the fused state information is used to assist the RGB-D based real time 3-D environment modeling. An improved closed-loop RRT based path planning approach (BI-RRT) is developed for information-efficient environment explorations. A flight experimental platform is constructed and the proposed system is validated in flight experiments.     

微小管道涡流检测机器人系统研究

微小机器人系统Tubot II型是适应20mm管道内缺陷的自动探测系统,它由一个两级 计算机控制的管内移动机构携带涡流探头,外加涡流分析仪和记录设备等组成．本文专述Tu bot II系统设计、关键技术和性能试验．这套机器人系统经产品化开发后可望应用于诸如核 电、化工、制冷和公用事业等的非磁性金属管道的定期检查．     

Robust Adaptive Control for Robotic Systems With Input Time-Varying Delay Using Hamiltonian Method

This paper addresses the problem of robust adaptive control for robotic systems with model uncertainty and input time-varying delay. The Hamiltonian method is applied to develop the stabilization results of the robotic systems. Firstly, with the idea of shaping potential energy and the pre-feedback skill, the n degree-of-freedom (DOF) uncertain robotic systems are realized as an augmented dissipative Hamiltonian formulation with delay. Secondly, based on the obtained Hamiltonian system formulation and by using of the Lyapunov-Krasovskii (L-K) functional method, an adaptive controller is designed to show that the robotic systems can be asymptotically stabilized depending on the input delay. Meanwhile, some sufficient conditions are spelt out to guarantee the rationality and validity of the proposed control law. Finally, study of an illustrative example with simulations shows that the controller obtained in this paper works very well in handling uncertainties and input delay in the robotic systems.      

Model continuity in the design of dynamic distributed real-time systems

Model continuity refers to the ability to transition as much as possible a model specification through the stages of a development process. In this paper, the authors show how a modeling and simulation environment, based on the discrete event system specification formalism, can support model continuity in the design of dynamic distributed real-time systems. In designing such systems, the authors restrict such continuity to the models that implement the system's real-time control and dynamic reconfiguration. The proposed methodology supports systematic modeling of dynamic systems and adopts simulation-based tests for distributed real-time software. Model continuity is emphasized during the entire process of software development $the control models of a dynamic distributed real-time system can be designed, analyzed, and tested by simulation methods, and then smoothly transitioned from simulation to distributed execution. A dynamic team formation distributed robotic system is presented as an example to show how model continuity methodology effectively manages the complexity of developing and testing the control software for this system.     

LUNARES: lunar crater exploration with heterogeneous multi robot systems

The LUNARES (Lunar Crater Exploration Scenario) project emulates the retrieval of a scientific sample from within a permanently shadowed lunar crater by means of a heterogeneous robotic system. For the accomplished earth demonstration scenario, the Shakelton crater at the lunar south pole is taken as reference. In the areas of permanent darkness within this crater, samples of scientific interest are expected. For accomplishment of such kind of mission, an approach of a heterogeneous robotic team consisting of a wheeled rover, a legged scout as well as a robotic arm mounted on the landing unit was chosen. All robots act as a team to reach the mission goal. To prove the feasibility of the chosen approach, an artificial lunar crater environment has been established to test and demonstrate the capabilities of the robotic systems. Figure 1 depicts the systems in the artificial crater environment. For LUNARES, preexisting robots were used and modified were needed in order to integrate all subsystems into a common system control. A ground control station has been developed considering conditions of a real mission, requiring information of autonomous task execution and remote controlled operations to be displayed for human operators. The project successfully finished at the end of 2009. This paper reviews the achievements and lessons learned during the project.     

<Emphasis Type="Italic">HumanPT</Emphasis>: An Open-source,HumanPT Architecture-based,Robotic Application for Low Cost Robotic Tasks

In this paper, first HumanPT architecture for low cost robotic applications is presented. HumanPT architecture differs than other architectures because it is implemented on existing robotic systems (robot  robotic controller) and exploits the minimum communication facilities for real-time control that these systems provide. It is based on well-known communication methods like serial communication (USB, RS232, IEEE-1394) and windows sockets (server–client model) and permits an important number of different type of components like actuators, sensors and particularly vision systems to be connected in a robotic system. The operating system (OS) used is Microsoft Windows, the most widely spread OS. The proposed architecture exploits features of this OS that is not a real-time one, to ensure – in case that the robotic system provide such a facility – control and real time communication with the robotic system controller and to integrate by means of sensors and actuators an important number of robotic tasks and procedures. As implementation of this architecture, HumanPT robotic application and experimental results concerning its performance and its implementation in real tasks are provided. HumanPT robotic application, developed in Visual C++, is an integrated, but simultaneously an open-source software that can be adapted in different types of robotic systems. An important number of robotic tasks or procedures including sensors and particularly vision systems can be generated and executed. Small enterprises by means of the proposed architecture and the open source software can be automated at low cost enhancing in this way their production.     

Development and Model-Aided Performance Measure of a Sensor-Augmented Industrial Robotic System for Handling Steel Bearing Races in an Unstructured Environment

Industrial application of robotic system for material handling operations has progressively become more challenging in situations of unstructured environments, in comparison to the same under somewhat known perspectives. Gripping under an unstructured robotic workspace poses serious challenges, which are beyond the purview of traditional grasp models and those need to be tackled only through customized modeling of the robotic environment. The present paper describes the details of such an application at the shop-floor of TATA STEEL, India, encompassing installation of the four degrees-of-freedom SCARA type industrial robotic system, design and construction of the magnetic gripper, sensory and hardware interfaces, safety measures (viz. design and development of electronic guarding system), environment model, application programming and final commissioning of the system for the intended use of handling steel bearing races of various sizes. Besides technical paradigms, the paper focuses on the performance measure of this maiden application of robotics in Indian steel industries.     

Motion control of a magnetically levitated microrobot using magnetic flux measurement

Recent advancements in micro/nano domain technologies have led to a renewed interest in ultra-high resolution magnetic-based actuation mechanisms. This paper deals with the development of a novel research-made magnetic microrobotic station (MMS) with promising potential in biological/biomedical applications. The MMS consists of two separate basic components: a magnetic drive unit and a microrobot. The magnetic drive unit produces and regulates the magnetic field for non-contact propelling of the microrobot in an enclosed environment. Our previous research findings have reported that the MMS should be equipped with high accuracy laser sensors for the position determination of the microrobot in the workspace. However, the laser positioning techniques can be used only in highly transparent environments. This paper seeks to address microrobot position estimation in non-transparent environments. A novel technique based on real-time magnetic flux measurement has been proposed for position estimation of the microrobot in the case of the laser beam blockage. A combination of Hall-effect sensors is employed in the structure of the magnetic drive unit to find the microrobot’s position using the produced magnetic flux. The most effective installation position for the Hall-effect sensors has been determined based on the accuracy sensitivity of experimental measurements. We derived a mathematical function which relates Hall-effect sensors’ voltage output and the position of the microrobot. The motion control capability of the Hall-effect-based positioning method is experimentally verified in the horizontal axis, and it was demonstrated that the microrobot can be operated in most of the workspace range with an accuracy of 0.3?mm as the root-mean-square of the position error.     

Symbiotic robotic systems: humans, robots, and smart environments

In general symbiotic robotic systems can be considered three-agent systems in which the agents are performing interdependent tasks. In such systems the robot's actions are generally controllable and observable the environment's actions are partially controllable and partially observable, and the human's actions are not (directly) controllable but are partially observable. This new paradigm will enable us to incorporate techniques from AI and robotics in everyday, smart environments. Symbiotic robotic systems will shift our focus from the development of fully autonomous, almighty robot servants to the development of an open, extensible environment in which humans will cohabitate with many cooperating robotic devices.     

Evaluation of a grey scale tactile array sensor pad for robotic applications

Since sensory feedback is an important part of robot control and the acquisition, manipulation, and recognition of objects, incorporating a sense of touch into a robotic system can greatly enhance the performance of that system. This article describes the evaluation of a recently developed low-resolution tactile array sensor pad system for use in robotic applications. Computer algorithms are developed which acquire data from the sensor pad and display the data on a CRT screen. Vision algorithms are implemented in order to extract the necessary information from the tactile data which will aid in the acquisition, manipulation, and recognition of objects. An object's pose is estimated by calculating its center of gravity (position) and principal axis (orientation). Recognizing an object and distinguishing between different objects is accomplished by implementing algorithms which estimate an object's perimeter (shape) and area (size). This work demonstrates that a low-resolution tactile array sensor is capable of providing the information that is required for many robotic applications in which objects must be acquired, manipulated, and recognized. Such a system provides a low-cost alternative to more conventional vision-based systems.