Hardware design and distributed embedded control architecture of a mobile soccer robot

Designing robust, modular and fast mobile robots, operating in high dynamic environments is a challenging task. This includes design of the mechanics and the control system of the robot. This paper presents the modular hardware design of a mobile soccer robot platform, including the mechanics, electronic system and the low-level distributed control architecture of the robot. The basic idea behind this paper is not to introduce a new distributed control architecture, both at low and high levels of control, but to focus on a novel approach to manage the distributed control system of a single robot, consisting of a number of microcontroller based modules connected together through a data bus.     

Exploratory design and evaluation of a homecare teleassistive mobile robotic system

Telehealth assistive technologies for homes constitute a very promising avenue to decrease load on the health care system, to reduce hospitalization period and to improve quality of life. Teleoperated from a distant location, a mobile robot can become a beneficial tool in health applications. However, design issues related to such systems are broad and mostly unexplored (e.g., locomotion and navigation in-home settings, remote interaction and patient acceptability, evaluation of clinical needs and their integration into health care information systems). Designing a safe and effective robotic system for in-home teleassistance requires taking into consideration the complexities of having novice users remotely navigate a mobile robot in a home environment while they interact with patients. This paper presents the progress made by adopting an interdisciplinary and exploratory design methodology to develop a telepresence assistive mobile robot for homecare assistance of elderly people. Preliminary studies using robots, focus groups and interviews allowed us to derive preliminary specifications to design a new mobile robotic system named Telerobot. Telerobot’s locomotion mechanism provides improved mobility when moving on uneven surfaces, helping to provide stable video feed to the user. Its control system is implemented for safe teleoperation. A study involving 10 rehabilitation professionals confirms that the system is usable in-home environments. Analysis of teleoperation strategies used by novice teleoperators suggest that it is essential in a home environment that the teleoperation interface provides the user with a visual feedback of the objects surrounding the robot, their distances relative to the robot and the size of the robot in the environment. Enhanced user interfaces to augment the operator’s perception of the environment were elaborated and tested in controlled conditions. Based on the progress made so far, the paper outlines issues that will be addressed in future work with the objective of coming up with a complete, efficient and usable in-home teleassistance mobile robotic system.     

Hardware-Efficient Prediction-Correction-Based Generalized-Voronoi-Diagram Construction and FPGA Implementation

Sensor-based construction of different geometric structures has been an important development in the domain of autonomous robot navigation. This paper presents a hardware-efficient scheme to construct one such geometric structure, namely, the generalized Voronoi diagram (GVD), using a prediction-and- correction strategy. In this paper, an architecture to construct the GVD for an indoor environment with multiple obstacles whose geometry and location are not known beforehand is presented. A feature of the proposed approach is that it does not involve operations that are expensive in hardware. Furthermore, no explicit angle computation circuitry is needed. An efficient architecture based on hardware reuse is presented. The design is shown to be space efficient and fits in a low-end field-programmable gate-array (FPGA) device (with a small number of system gates). Detailed experiments with a mobile robot fabricated locally with a Xilinx XC2S200E FPGA and eight ultrasonic sensors onboard validate the efficacy of the proposed approach for static as well as dynamic environments.     

Automatic locomotion design and experiments for a Modular robotic system

This paper presents a design method and experiments for whole-body locomotion by a modular robot. There are two types of locomotion for modular robots: a repeating self-reconfiguration and whole-body motion such as walking or crawling. For whole-body locomotion, designing a control method is more difficult than for ordinary robots because a modular robotic system can form various configurations, each of which has many degrees of freedom. This study proposes a unified framework for automatically designing an efficient locomotion controller suitable for any module configuration. The method utilizes neural oscillators (central pattern generators, CPGs), each of which works as a distributed joint controller of each module, and a genetic algorithm to optimize the CPG network. We verified the method by software simulations and hardware experiments, in which our modular robotic system, named M-TRAN II, performed stable and effective locomotion in various configurations.     

TerminatorBot: a novel robot with dual-use mechanism for locomotion and manipulation

As part of a massively distributed heterogeneous system, TerminatorBot, a novel, centimeter-scale crawling robot, has been developed to address applications in surveillance, search-and-rescue, and planetary exploration. Its two three-degree-of-freedom arms, which stow inside the cylindrical body for ballistic deployment and protected transport, comprise a dual-use mechanism for manipulation and locomotion. The intended applications require a small, rugged, and lightweight robot, hence, the desire for dual use. TerminatorBot's unique mechanism provides mobility and fine manipulation on a scale currently unavailable. To facilitate manipulation, we have also developed a specialized force/torque sensor. This new sensor design has a biased distribution of flexures, which equalizes force and torque sensitivities at the operational point. This work describes the mechanism and design of TerminatorBot, the specialized force/torque sensor, and the mechanism-specific gaits.     

Quanta - A platform for rapid control and monitoring of heterogeneous rbots

Rapid prototyping, real-time control and monitoring of various events in robots are crucial requirements for research in the fields of modular and swarm robotics. A large quantities of resources (time, man power, infrastructure, etc.) are often invested in programming, interfacing the sensors, debugging the response to algorithms during prototyping and operational phases of a robot development cycle. The cost of developing an optimal infrastructure to efficiently address such control and monitoring requirements increases significantly in the presence of mobile robots. Though numerous solutions have been developed for minimizing the resources spent on hardware prototyping and algorithm validation in both static and mobile scenarios, it can be observed that researchers have either chosen methodologies that conflict with the power and infrastructure constraints of the research field or generated constrained solutions whose applications are restricted to the field itself. This paper develops a solution for addressing the challenges in controlling heterogeneous mobile robots. A platform named Quanta - a cost effective, energy efficient and high-speed wireless infrastructure is prototyped as a part of the research in the field of modular robotics. Quanta is capable of controlling and monitoring various events in/using a robot with the help of a light-weight communication protocol independent of the robot hardware architecture(s).     

HERMES - a versatile personal robotic assistant

We have developed a humanoid robot, HERMES, to study several key technologies that are important for personal robots, such as robot design, sensors and perception, locomotion, localization and navigation, manipulation, human-robot communication and interaction, adaptability and learning, system architecture and integration, and dependability. The robot's skill-based system architecture was derived from a qualitative model of human information processing and insights gained from psychological literature dealing with skill acquisition, human performance and motor learning. HERMES' system architecture, several of its skills and the design principles are introduced, and some experiments carried out with the real robot are presented, including a long-term test where HERMES served in a museum, far away from its home laboratory, for more than six months up to 12 hours per day. During this period the robot and its skills were regularly demonstrated to the public by nonexpert presenters. Also, HERMES interacted with the visitors, chatted with them in English, French and German, answered questions and performed services as requested by them.     

Development of a New Robot Controller Architecture with FPGA-Based IC Design for Improved High-Speed Performance

In this paper, a new robot controller architecture is proposed to implement various complex control algorithms for improved high-speed performance. The main thrust of the research is to remove the servo control loop from the digital signal processor (DSP) and implement the high-speed servo loop in a field programmable gate array (FPGA). The main objective of this architecture is to utilize the ultra-high-speed hardwired logic of the FPGA to enhance the overall computational capability and relieve the computational load of the DSP for other tasks. The control algorithm is partitioned into a linear portion and a nonlinear portion. The linear portion with position/velocity feedback represents the major control loop and is implemented in the FPGA. The nonlinear portion acts as dynamic compensation to the linear portion to calculate model-related control gains/parameters, and it is implemented in the DSP. In tandem, with the newly developed control hardware architecture, an FPGA-based motion control integrated circuit (IC) is designed. Experiments are conducted on an industrial robot manipulator to compare the closed-loop performance with this new control architecture and the traditional one, when the same control algorithm is used. The experimental results demonstrate that the proposed new control architecture exhibits much improved motion performance indeed, especially in high-speed motions.     

Full-state tracking and internal dynamics of nonholonomic wheeled mobile robots

In the paper, the stable full-state tracking problem is investigated for nonholonomic wheeled mobile robots under output-tracking control laws. Dynamics of such wheeled mobile robots are nonholonomic and pose challenging problems for control design and stability analysis. The dynamics formulated in terms of full-state tracking errors offer some properties that allow better understanding of the internal and zero dynamics of the tracking-error system and more insights to the trajectory tracking stability. Output functions are chosen as virtual reference points for various types of wheeled mobile robots in aid of output controller designs. Sufficient conditions are derived to ensure the stable full-state trajectory tracking under output-tracking control laws. A type (1,1) mobile robot of car-like configuration is studied in detail and further numerical analysis provides more results which are beyond the reach of analytical means. An example and simulation results are presented to confirm the theory and observations.     

Hierarchical autonomous switching control of a multi-modes omnidirectional mobile robot

Adequate control flexibility and tracking precision of the omnidirectional mobile robot (OMR) are difficult to be guaranteed with a fixed control mode. To address this challenge, this paper presents a modified hierarchical autonomous switching control scheme for an OMR with multiple maneuver-modes, which is capable of switching the alternative modes to adapt to the operational conditions and performing a satisfactory trajectory tracking control. Utilizing a hierarchical switching signal, the design begins by formulating a hybrid discrete OMR system with multiple subsystems cascading to its alternative kinematic states. Under the integrated system constraints, a new hierarchical switched fractional-order receding horizon control is presented to offer more adjusting flexibilities, which constructs a novel fractional-order cost function and then derives a numerical solvable solution. Meanwhile, with a Lyapunov-principle-based supervisory variable, an autonomous switching law is proposed so that the preferred subsystem can be selected to enhance the moving maneuverability. Under certain average dwell time conditions, the asymptotic stability of the resultant system is guaranteed. Finally, comparative experiments implemented on the real-world scenarios are provided to demonstrate the superior tracking performance and enhanced robustness of the proposed hierarchical autonomous switching control method as compared to traditional control schemes.     

A quad-rotor system for driving and flying missions by tilting mechanism of rotors: From design to control

This article presents the hybrid design and control of a quad-rotor system called Flymobile. Flymobile is a combined system of a mobile robot and a quad-rotor system aimed to perform both flying and driving tasks. Flymobile performs flying tasks in the same way as conventional quad-rotor systems while the tilting mechanism of each rotor allows Flymobile to navigate in its terrain for a driving task. The body frame with rotors is implemented by a calibration process through a test-bed equipped with a force sensor. The triangular wheel frame is designed to mimic motions of a mobile robot with three passive wheels. Sensor data of a gyro and an accelerometer are filtered and used for controlling the attitude of the system. Focusing on a practical approach of implementing a hybrid system, a non model-based approach is applied to control Flymobile. Experimental studies are demonstrated to show the feasibility of performing both driving and flying missions.     

基于分布式的移动机器人控制系统设计与实现

移动机器人是近年来研究的热点,针对机器人系统自由度多,可靠性和实时性要求高的特点,提出了一种基于分布式的移动机器人控制系统。利用多借点连接方式的网络拓扑机构,将其他设备和多个机器人连接组成机器人控制系统,以控制芯片ARM Cortex-A9和STM32F407为基础,将开源操作系统植入到开源嵌入式系统中,设计分布式上位机控制软件和下拉机程序,设计了基于分布式的移动机器人控制系统的搭建,实现对分布式移动机器人的控制。该分布式移动机器人软硬件开源、性能高、成本低、具有很好的可扩展性、实时性和稳定性。     

Behavior-based artificial intelligence in miniature mobile robot

An intelligent mobile robot that implements concepts of mechatronics, mobile robotics, and behavior-based artificial intelligence has been developed. The design process for such a mobile robot employs a concept of simple trade-off between the mechanical, electrical, and computational systems for the benefit of improving the robots overall system performance. The main features of the robot, named SCAVENGER, are to navigate freely in a controlled environment, search for one or more target objects with known characteristics (colored golf balls), and avoid the other objects as obstacles. A combination of infrared sensors, color detectors, and bumper skirts is used to facilitate navigation and object recognition. The robots brain consists of an on-board MC68HC11 microcontroller, which is programmed in C. The control software implements behavior-based artificial intelligence, where the robots overall intelligence is made up of layers of several simple and primitive behaviors similar to those observed in insects. In this work, the design of the robots subsystems, where the implementation of mechatronics is most in effect, is covered in more detail with a particular interest in object recognition and collection systems.     

Neurofuzzy control of modular and reconfigurable robots

In recent years, the concept of modular and reconfigurable robotics emerged as a means for flexible and versatile automation. This concept allows for the execution of many complex tasks that cannot be performed by fixed-configuration manipulators. Nevertheless, reconfigurable robots introduce a challenging level of complexity to the problem of design of controllers that can handle a wide range of robot configurations with reliable performance. This paper addresses the position control of modular and reconfigurable robots. We develop a practical intelligent-control architecture that can be easily used in the presence of dynamic parameter uncertainty and unmodeled disturbances. The architecture requires no a priori knowledge of the system-dynamics parameters. Adaptive control is provided using fuzzy gain tuning of proportional-integral-derivative parameters in the presence of external disturbances. The architecture also provides learning control using feedforward neural networks. Moreover, the architecture has the capability of updating the adaptive control under reconfigurability. Experiments on a modular robot test bed are reported to validate the effectiveness of the control methodology.     

An integrated robot system architecture

This paper describes the architecture of a robot system designed both to work in an integrated manufacturing environment and to support continuing research in programmable automation. Major system components include a controller, robot and sensor hardware, operator's pendant, and system software. A new high-level interactive language, AML, allows the user to combine manipulation, sensing, computational, and data processing functions provided by the system. Important aspects of the system design objectives, major functional components, and the AML language are described, and examples drawn from an actual production application are used to illustrate the interrelationship of the topics discussed.     

Adaptive connectivity management middleware for heterogeneous wireless networks

The trends of network convergence and mobile accessibility in the Internet are bringing new challenges to the connectivity management of end hosts. Concerning network convergence, the configuration of heterogeneous access networks should be taken into consideration. As for mobile accessibility, seamless handoff between diverse access points is a challenging issue. This article presents the design and implementation of connectivity management middleware (CMM), a channel-based architecture for context-aware connectivity management. This architecture can both provide network awareness to applications and manage network resources in an adaptive fashion. In the case of network awareness, the platform provides interfaces for applications to query network QoS and availability status, as well as subscribe connection events. As for adaptive resource management, channel-based transport services for seamless access switching and disconnection treatment are provided based on a policy mechanism. A prototype is implemented with which experiments were performed in a GPRS-WLAN integrated environment in order to demonstrate the operational correctness of the architecture. Performance metrics are measured and analyzed.     

Control of manipulation robots interacting with dynamicenvironment: Implementation and experiments

In this paper, simulation experiments with different control laws are given, based on a new approach to solving the control tasks for robots in contact with the environment. The comparison of these control laws with the improved versions of the traditional hybrid control are also analyzed. The simulation experiments performed on a real-scale six-degrees-of-freedom industrial robot demonstrate the advantage of the new control concept and improved performances of the robot interacting with a dynamic environment. The tests conducted on industrial robot Manutec r3 are also presented     

CrossTalk: cross-layer decision support based on global knowledge

The dynamic nature of ad hoc networks makes system design a challenging task. Mobile ad hoc networks suffer from severe performance problems due to the shared, interference-prone, and unreliable medium. Routes can be unstable due to mobility and energy can be a limiting factor for typical devices such as PDAs, mobile phones, and sensor nodes. In such environments cross-layer architectures are a promising new approach, as they can adapt protocol behavior to changing networking conditions. This article introduces CrossTalk, a cross-layer architecture that aims at achieving global objectives with local behavior. It further compares CrossTalk with other cross-layer architectures proposed. Finally, it analyzes the quality of the information provided by the architecture and presents a reference application to demonstrate the effectiveness of the general approach.     

Improving the energy efficiency and speed of walking robots

This study analyses the superior performance of gravitationally decoupled actuation in terms of energy efficiency, and hence autonomy. Based on the decoupling concept, a new design is presented for a 3 dof leg, and its performance is validated by including it in a 84 kg hybrid locomotion robot. The proposed leg obtains a straight-line constant-velocity motion of the foot as only one of its 3 motors is operated at constant speed. This feature, together with the hybrid structure, increases the robot’s efficiency and speed when operating on surfaces without obstacles, and drastically simplifies the walking operation control. A series of simulations have been done comparing the energy consumption of the hybrid robot including traditional coupled legs, and including the proposed decoupled legs. They show a superior performance of the later one. A real prototype has been built including the proposed mechanism. It shows a similar performance to that obtained from simulation, and a natural gait in flat terrains,at speeds up to 0.9 m/s.     

基于WiFi技术的智能搜救机器人

为了实现对地震、泥石流等灾害现场的实时监控,依托WiFi网络和遥控机器人技术设计了一台智能搜救机器人,引入多种传感器设备,实现灾后现场的实时监控和救援。通过无线传输技术实现机器人上位机与下位机之间的通信,下位机软件将机器人采集到的视频信息传送到上位机,上位机根据所接收到的视频信息向下位机发送控制命令,实现远距离移动监控。通过在机器人车体上搭载机械臂拓展机器人的搬运功能,实现作业现场障碍物清除工作。重点阐明了基于WiFi技术的智能控制机器人系统的硬件和软件设计。实验结果表明,本次设计的智能搜救机器人能有效实现灾后现场的远程移动监控和救援,具有一定的可靠性和实用性。