Real-time-based control system for a group of autonomous walking robots

The design target of complex control systems for novel robots with advanced motion abilities is to produce controllers (hardware and software) which are easy to program, re-program and debug. Those systems must be enabled to implement different motion principles with different hardware extensions (actuators, sensors, etc.). This paper introduces the problem of evaluation of hardware architecture together with the hardware type. We use the experience collected during realization of several prototypes of walking machines. The dedicated communication scheme elaborated for an embedded system is addressed in detail. The communication scheme can be used in every other system controlling the walking machine or controlling other robotic device. The navigation principles applied for a group of hexapods are briefly discussed for a better explanation of the functional structure of the implemented control system. The system actions are introduced. The system structure can be used for the control not only of a single mobile robot, but also a robot as a member of a group.     

Homogeneous coordinate definition of work method

Computer-based motion analysis systems are able to supplant and extend chronocyclegraph analysis techniques. When coupled with the homogeneous coordinates commonly used to analyze robotic manipulators, they can provide a new work method definition.     

Development of a biomimetic robotic fish and its control algorithm

This paper is concerned with the design of a robotic fish and its motion control algorithms. A radio-controlled, four-link biomimetic robotic fish is developed using a flexible posterior body and an oscillating foil as a propeller. The swimming speed of the robotic fish is adjusted by modulating joint's oscillating frequency, and its orientation is tuned by different joint's deflections. Since the motion control of a robotic fish involves both hydrodynamics of the fluid environment and dynamics of the robot, it is very difficult to establish a precise mathematical model employing purely analytical methods. Therefore, the fish's motion control task is decomposed into two control systems. The online speed control implements a hybrid control strategy and a proportional-integral-derivative (PID) control algorithm. The orientation control system is based on a fuzzy logic controller. In our experiments, a point-to-point (PTP) control algorithm is implemented and an overhead vision system is adopted to provide real-time visual feedback. The experimental results confirm the effectiveness of the proposed algorithms.     

Dual dynamics: Designing behavior systems for autonomous robots

This paper describes the “dual dynamics” (DD) design scheme for robotic behavior control systems. Behaviors are formally specified as dynamical systems using differential equations. A key idea for the DD scheme is that a robotic agent can work in different “modes,” which lead to qualitatively different behavioral patterns. Mathematically, transitions between modes are bifurcations in the control system. This work was presented, in part, at the Second International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1997     

State Space Constrained Iterative Learning Control for Robotic Manipulators

Real‐life work operations of industrial robotic manipulators are performed within a constrained state space. Such operations most often require accurate planning and tracking a desired trajectory, where all the characteristics of the dynamic model are taken into consideration. This paper presents a general method and an efficient computational procedure for path planning with respect to state space constraints. Given a dynamic model of a robotic manipulator, the proposed solution takes into consideration the influence of all imprecisely measured model parameters, making use of iterative learning control (ILC). A major advantage of this solution is that it resolves the well‐known problem of interrupting the learning procedure due to a high transient tracking error or when the desired trajectory is planned closely to the state space boundaries. The numerical procedure elaborated here computes the robot arm motion to accurately track a desired trajectory in a constrained state space taking into consideration all the dynamic characteristics that influence the motion. Simulation results with a typical industrial robot arm demonstrate the robustness of the numerical procedure. In particular, the results extend the applicability of ILC in robot motion control and provide a means for improving the overall trajectory tracking performance of most robotic systems.     

Dynamic Analysis and Distributed Control of the Tetrobot Modular Reconfigurable Robotic System

Reconfigurable robotic systems can be adapted to different tasks or environments by reorganizing their mechanical configurations. Such systems have many redundant degrees of freedom in order to meet the combined demands of strength, rigidity, workspace kinematics, reconfigurability, and fault tolerance. In order to implement these new generations of robotic system, new approaches must be considered for design, analysis, and control. This paper presents an efficient distributed computational scheme which computes the kinematics, dynamics, redundancy resolution, and control inputs for real-time application to the control of the Tetrobot modular reconfigurable robots. The entire system is decomposed into subsystems based on a modular approach and Newton's equations of motion are derived and implemented using a recursive propagation algorithm. Two different dynamic resolution of redundancy schemes, the centralized Jacobian method and the distributed virtual force method, are proposed to optimize the actuating forces. Finally, distributed dynamic control algorithms provide an efficient modular implementation of the control architecture for a large family of configurations.     

Robotic smart house to assist people with movement disabilities

This paper introduces a new robotic smart house, Intelligent Sweet Home, developed at KAIST in Korea, which is based on several robotic agents and aims at testing advanced concepts for independent living of the elderly and people with disabilities. The work focuses on technical solutions for human-friendly assistance in motion/mobility and advanced human-machine interfaces that provide simple control of all assistive robotic systems and home-installed appliances. The smart house concept includes an intelligent bed, intelligent wheelchair, and robotic hoist for effortless transfer of the user between bed and wheelchair. The design solutions comply with most of the users’ requirements and suggestions collected by a special questionnaire survey of people with disabilities. The smart house responds to the user's commands as well as to the recognized intentions of the user. Various interfaces, based on hand gestures, voice, body movement, and posture, have been studied and tested. The paper describes the overall system structure and explains the design and functionality of some main system components.     

Integrated Environment for Modelling, Simulation and Control Design for Robotic Manipulators

In this paper an integrated environment for the design of robotic controllers implemented on a PC is described. It is based on the Planar Manipulators Toolbox for dynamic simulation of redundant planar manipulators. The tools are fully integrated in the MATLAB/SIMULINK and hence, a lot of standard tools are available for the analysis and control design. Using the real-time simulation it is possible to apply the developed controllers to a real robot manipulator, which can be included in the system via corresponding interfaces, without any additional coding. The main advantage is the flexibility in fast prototyping of different algorithms in the field of control of robotic systems, especially for redundant manipulators.     

进 化 机 器 人

进化机器人(evolutionary robots)是一种基于进化思想设计的机器人系统，是 机器人设计领域的新方向，它把人工生命的概念和思路引入到这个领域．本文介绍了进化机 器人的基本概念、设计方法、发展历程、研究现状、发展前景，并详细介绍了一个进化机器 人的设计实例．     

Determining maximum payloads for cooperating robots under time-optimal control

This work presents an algorithm which evaluates the dynamic performance limit of a cooperating robotic system using movements planned for minimum time. Minimum-time movements characteristically require that a set of motors in the robot be driven at their maximum torque throughout the motion. These movements are limited by the combination of motor performance, mechanical advantage of the kinematic chain, and the location of the start and goal positions. By increasing the payload for a motion until a minimum-time solution is no longer feasible the payload limit of the system for the associated path is obtained. To illustrate the algorithm a detailed analysis of a robotic arm developed at Odetics Inc. is presented. The analysis includes numerical results for cooperating Odetics robotic arms using their maximum payload under time-optimal control. Furthermore, the maximum payload for the cooperating robotic system to perform the same motion with a 1 sec time constraint is determined.     

Modular Design of a Reconfigurable Electromagnetic Robot

This paper discusses the modular design of distributed reconfigurable robots. The design concept, mechanical structure, electrical processing unit, actuator dissection and reconfiguration examples of the proposed robotic modules are presented in detail. The reconfigurable robotic motion is realized via a collection of the proposed modules with the capability of connecting and disconnecting with adjacent modules. The key actuation of the robotic reconfiguration is driven only by the E-type electromagnets and different shapes of the modules are implemented for versatile applications. Finally, the feasibility of the proposed robotic modules has been extensively tested.     

基于PLCopen的六轴工业机器人运动控制功能块设计

针对工业机器人控制系统的开放性要求,设计符合PLCopen规范的六轴工业机器人运动控制功能块。基于CodeSys软件开发环境,结合SMC_CNC库中数组、结构体和功能块,采用IEC61131-3编程语言开发了六轴工业机器人运动控制功能块,包含：坐标变换、正逆运动变换、直线与圆弧插补运动等;在此基础上,开发了一系列机器人运动控制指令和可视化编程界面。最后,以埃夫特ER50六轴工业机器人为实验对象,采用研制的机器人运动控制器,实施机器人编程控制实验,结果表明所开发的机器人运动控制功能块及其指令达到了设计要求。     

Further explorations in evolutionary humanoid robotics

The field of evolutionary humanoid robotics is a branch of evolutionary robotics specifically dealing with the application of evolutionary principles to humanoid robot design. Previous studies demonstrated the possible future potential of this approach by evolving walking behaviors for simulated humanoid robots with up to 20 degrees of freedom. In this paper we examine further the evolutionary process by looking at the changes in diversity over time. We then investigate the effect of the immobilization of an individual joint or joints in the robot. The latter study may be of potential future use in prosthetic design. We also explore the possibility of the evolution of humanoid robots which can cope with different environmental conditions. These include reduced ground friction (ice) and modified gravitation (moon walking). We present initial results on the implementation of our simulated humanoid robots in hardware using the Bioloid robotic platform, using a model of this robot in order to evolve the desired motion patterns, for subsequent transfer to the real robot. We finish the article with a summary and brief discussion of future work. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

On Climbing Winding Stairs in an Open Mode for a New Robotic Wheelchair

This paper presents the mechanical design, locomotion and associated dynamic models of a new robotic wheelchair on climbing winding stairs. The prototype stair-climbing robotic wheelchair is constructed comprising a pair of rotational multi-limbed structures pivotally mounted on opposite sides of a support base so that the robotic wheelchair can ascend and descend stairs; in particular, the capability of climbing winding stairs is addressed. Based on the skid-steering analysis, the dynamic models for climbing winding stairs are developed for the trajectory planning and motion analyses. These models are required to ensure a passenger's safety in such a way that the robotic wheelchair is operated in an open mode. Moreover, an equivalent constraint method is proposed for the prescribed motion of the robotic wheelchair on climbing winding stairs. The results of the simulation and maneuver are reported that show the behavior of the prototype as it climbs winding stairs in a dynamic turning.     

Criteria for robot performance in path-following activities

Commercial robotic systems often include ambiguous information in their specifications for path-following capabilities and regarding the feasibility of improving path-following through adaptive control. It is necessary to establish criteria to differentiate between the various levels of path following. This paper presents a set of motion criteria and demonstrates how to construct a check scheme according to these criteria. The proposed check scheme provides a powerful tool for assessing robot motion performance and comparing the performance of different systems.     

Controllability of kinematic control systems on stratifiedconfiguration spaces

This paper considers nonlinear kinematic controllability of a class of systems called stratified. Roughly speaking, such stratified systems have a configuration space which can be decomposed into sub-manifolds upon which the system has different sets of equations of motion. For such systems, considering the controllability is difficult because of the discontinuous form of the equations of motion. The main result in this paper is a controllability test, analogous to Chow's theorem, is based upon a construction involving distributions, and the extension thereof to robotic gaits     

基于松散偏好规则的群体机器人系统自组织协作围捕

针对群体机器人协作围捕,提出了一种基于松散偏好规则的自组织方法.首 先给出了个体机器人的自由运动模型和围捕行为的数学描述.通过对围捕行为的分解,构造松散偏好 规则来使个体机器人在自组织运动过程中相互协调最终形成理想的围捕队形.在此基础上,设计了个体自组织运动控制器.最后运用Lyapunov稳定性定理证明系统的稳定性.仿真和实验结果表 明,本文给出的自组织方法对于群体机器人协作围捕是行之有效的.     

基于力测试的掰手腕机器人系统设计

在分析比较当前同类机器系统研究进展的基础上,介绍了ROBOAM-I系统的功能和设计原理,详细分析了机器人手臂部分的结构和力测试功能的实现。     

A parallel robotic attachment and its remote manipulation

This paper discusses a 3-dof (degree of freedom) parallel robotic attachment and its remote manipulation. This attachment is designed as a tripod that provides two rotary motions and one linear motion. The attachment can be mounted onto a variety of machines for different applications, including CNC milling machines, industrial robots, and CMM. Java technologies are used to develop a remote manipulation system for the parallel robotic attachment, including remote monitoring and control. The main difference of this system from the existing web-based or internet-based remote systems is the way to control the motion of the machine from a remote site. Instead of using a camera for monitoring, the tripod is modeled using 3D computer graphics with behavioral control nodes embedded. Compared with camera-based solutions, network traffic is largely reduced, thereby making real-time remote device manipulation practical on the web. Our parallel robotic attachment is one type of parallel kinematic mechanisms (PKM). With PKM emerging as a new way of building flexible systems or agile machines, its advantage over serial mechanism is also presented.