Emulation of robots interacting with environment

In this paper, we present a methodology for emulation of a target robot operating in a complex environment by using an actual robot. The emulation scheme aims to replicate the dynamical behavior of the target robot interacting with an environment, without dealing with a complex calculation of the contact dynamics. This method forms a basis for the task verification of a flexible space robot. The actual emulating robot is structurally rigid, while the target robot can represent any class of robots, e.g., flexible, redundant, or space robots. Although the emulating robot is not dynamically equivalent to the target robot, the dynamical similarity can be achieved by using a control law developed herein. The effect of disturbances and actuator dynamics on the fidelity and the contact stability of the robot emulation is thoroughly analyzed. The concept of robot emulation is demonstrated by performing a number of preliminary experiments for emulation of flexible-joint robots.     

Real-time grasping-force optimization for multifingered manipulation: theory and experiments

Real-time grasping-force optimization is a vital problem in dextrous manipulation with multifingered robotic hands. In this paper, we review two prominent approaches that have recently been proposed for this problem, and identify their common need for an appropriate initial condition to start the recursive algorithms. Then, we propose an efficient algorithm that combines a linear-matrix-inequality method with a gradient method for automatic generation of initial conditions. By incorporating the initial conditions, optimal grasping forces can be generated efficiently in real time. Finally, we implement and evaluate all the algorithms for grasping-force control in the Hong Kong University of Science and Technology three-fingered hand platform. Experimental results demonstrate the efficiency of the proposed approach.     

Static balancing and dynamic decoupling of the motion of manipulation robots

The conditions for simplification of moment actions of the particular DOFs of a manipulator are derived, and the individual components of the moment actions are determined. Mechanical unloading of a multi-link manipulator from the moments due to gravitational forces are also analysed. The specificity of dynamic decoupling of the manipulator motion is considered. Examples of different types of balancing and unloading with manipulation mechanisms are given.     

From "macro" to "micro" manipulation: models and experiments

This paper addresses various problems related to manipulation in the micro domain, a field which is increasingly important for research and application. Grasping and manipulating parts with size ranging between a few micrometers and about 1 millimeter (defined in this paper as "micro parts") are required for an increasing number of applications: the assembly of micro systems and micro machines; and the operation in tiny and unpredictable environments, such as for inspection and interventions in pipes and for micro surgery. The aim of this work is to find out similarities and differences between traditional manipulation and micro manipulation, by investigating which requirements are still valid and which must be redefined when the object size scales down. The similarities between the two application domains "macro" and "micro" are pointed out along with the differences, and both are taken into account for the evaluation of different grasping typologies. Dedicated models for the adhesion forces arising at the micro level are presented, preliminarily tested, and discussed.     

Visual Control of robots with changes of visibility in image features

Visual servoing concerns several fields of research including vision systems, robotics and automatic control. Visual servoing can be useful for a wide range of applications and it can be used to control many different dynamic systems (manipulator arms, mobile robots, autonomous underwater vehicles, aircraft, etc.). However, visual servoing systems are not complete efficiency due to the numerous problems that are still unresolved. In this paper a new general solution to visibility restriction associated to all visual servoing techniques based directly or un-directly on image features is presented. This solution allows the temporary disappearance of image features during the control task versus the solutions proposed until now which are based on keeping always the object in the field of view. Taking into account this concept, the theoretical bases of a continuous and stable visual servoing approach that allows the temporary presence of features in the image have been defined and developed. Using them, the camera invariant visual servoing approach has been reformulated to adapt it to the temporary disappearance of image features during the control task.     

Visual Control of robots with changes of visibility in image features

Visual servoing concerns several fields of research including vision systems, robotics and automatic control. Visual servoing can be useful for a wide range of applications and it can be used to control many different dynamic systems (manipulator arms, mobile robots, autonomous underwater vehicles, aircraft, etc.). However, visual servoing systems are not complete efficiency due to the numerous problems that are still unresolved. In this paper a new general solution to visibility restriction associated to all visual servoing techniques based directly or un-directly on image features is presented. This solution allows the temporary disappearance of image features during the control task versus the solutions proposed until now which are based on keeping always the object in the field of view. Taking into account this concept, the theoretical bases of a continuous and stable visual servoing approach that allows the temporary presence of features in the image have been defined and developed. Using them, the camera invariant visual servoing approach has been reformulated to adapt it to the temporary disappearance of image features during the control task.     

Yoshihiro Kuroki: dancing with robots

Yoshihiro Kuroki is fulfilling his lifelong vision to build a personal humanoid robot at Sony's Entertainment Robot Co.     

Control of industrial robots that have transmission elasticity

A control scheme is presented for electrically driven, industrial robots that have transmission elasticity. Some feedback structures that have been described in the past have an inner control loop to cancel the elastic coupling torque between motor and link. An outer feedback loop is then used for the control of the arm position. A refinement of such a control scheme is analyzed using singular perturbation methods. A broad spectrum of control algorithms that were originally designed under the assumption of ideal, rigid joints can now be extended to the elastic transmission case with minor modifications. One contribution is that exact cancellation of the elastic torque is not necessary. In fact, the elasticity effects in some robots can be adequately damped by simply adding only a term that is proportional to the differential speed (difference between link velocity and motor velocity). Experimental results are also presented     

轮式机器人航向定位的控制策略

本文针对非完全约束移动机器人的航向定位问题提出了一种稳定的切换控制策略，针对定位问题提出了定位导向切换控制器，该策略避免了机器人反向运动，使其总是向目标点进行避障运动；实验结果显示，该策略是可行的，并具有良好的性能。     

使用组态软件实现过程监控

介绍了WinCC监控组态软件在过程控制中的应用,分析了系统软硬件结构,并应用于矫正机监控系统的方法。     

Control design of a novel compliant actuator for rehabilitation robots

Rehabilitation robots have direct physical interaction with human body. Ideally, actuators for rehabilitation robots should be compliant, force controllable, and back drivable due to safety and control considerations. Series Elastic Actuators (SEA) offers many advantages for these applications and various designs have been developed. However, current SEA designs face a common performance limitation due to the compromise on the spring stiffness selection. This paper presents a novel compact compliant force control actuator design for portable rehabilitation robots to overcome the performance limitations of current SEAs. Our design consists of a servomotor, a ball screw, a torsional spring between the motor and the ball screw, and a set of translational springs between the ball screw nut and the external load. The soft translational springs are used to handle the low force operation, while the torsional spring with high effective stiffness is used to deal with the large force operation. It is a challenging task to design the controller for such a novel design as the control system needs to handle both the force ranges. In this paper, we develop the force control strategy for this actuator. First, two dynamical models of the actuator are established based on different force ranges. Second, we propose an optimal control with friction compensation and disturbance rejection which is enhanced by a feedforward control for the low force range. The proposed optimal control with feedforward term is also extended to the high force range. Third, a switching control strategy is proposed to handle a transition between low force and high force control. The mathematical proof is given to ensure the stability of the closed-loop system under the proposed switching control. Finally, the proposed method is validated with experimental results on a prototype of the actuator system and is also verified with an ankle robot in walking experiments.     

滑模控制开关变换器的分析与实现

分析了滑模控制DC／DC变换器的滑模存在条件、到达条件及稳定性，通过选择适当的状态变量，建立系统状态方程模型。提出了一种实用性较强的双环控制方案，并以Buck电路为例，设计出滑模控制电路。实验结果表明，此控制方案是可行的，它可以有效地改善变换器的动态性能，提高其鲁棒性。     

Microprocessor Control of Cycloconverter: Techniques for Implementation and Testing

Since the 1930's, cycloconverter control circuits have been designed with vacuum tubes, transistors, and integrated circuits. With the advent of microprocessors, much more logical and computational power became available in much less space and cost. This led to the design of converter control circuits using microprocessors [2]-[9]. Each of these papers describes a specific implementation. Advancements in microprocessor technology are still going at full steam. To take full advantage of this technology and its continued advancements, a systematic and broad-based study of techniques that can be used for cycloconverter control-on microprocessor-based systems-is required. This paper reports the findings of such a study [10]. In this study a few general techniques were developed for cycloconverter control. In developing the various Techniques, accuracy of trigger timing and the system's speed of response were used as performance criteria. The techniques developed were tested on a system based on the 8085 CPU. Each technique was tested qualitatively by recording the cycloconverter waveforms produced by using it. For quantitative testing, first, the theoretical trigger timings were found by a digital computer simulation of the cycloconverter. These timings were then compared with those produced on the microprocessor-based system. From the test results it was concluded that an 8 bit data width suffices for cycloconverter control. The main bottleneck in achieving the desired performance is the execution time of the processor. In one of the techniques, when improvement in trigger timing accuracy was achieved it lead to reduction in the speed of response.     

双余度飞行显示控制计算机的设计与实现

飞行显示控制计算机是飞行员高效、直观地获取所需信息或发送控制命令的操作平台,其任务可靠性对飞机飞行安全至关重要,一旦失效将会造成系统部分或全部功能丧失,尽管不会直接危及飞行员人机安全,但会严重影响飞行和作战任务的完成。因而本设计采用了双余度设计方法,有效提高了任务可靠性、降低了失效风险,具备一定的工程实用价值。     

基于DSP和FPGA的机器人声控系统设计与实现

介绍了一种基于DSP和FPGA的机器人声控系统。在语音采集上,将DSP芯片TMS320C5509和音频芯片TLV320AIC23相结合进行语音的采集。在软件开发上,开发环境采用CCS 3.1,语音特征向量采用美尔频率倒谱系数,模式匹配和训练采用隐马尔可夫模型,实现了语音指令的识别。在动作控制上,采用FPGA作为机器人头部动作逻辑控制器,使机器人能够根据非特定人的语音命令做出规定的头部动作。     

PIMac: Multicast Access Control Implementation in PIM-SM

In this paper, we present an access control scheme for PIM-SM multicast domain. In order to avoid the overhead of digital signature algorithm, the proposed solution makes use of the Rendezvous Point to collect keys and implement a distributed shared-key based multicast access control system. As it supplies efficient host access control in PIM-SM domain, we name this scheme PIMac. Compared with the existing multicast admission control solutions, PIMac has following advantages: (1) support both receiver and sender access control; (2) realize host exclusion based on expire time; (3) compatibility with current PIM-SM protocol; (4) lower join latency; (5) anti-replay and DoS robustness; last but not least, (6) PIMac architecture is divided into two separated domains: AAA domain and multicast routing domain, entities in each domain do not rely on PKI interoperability or common secret to authenticate each other. The experimental results show that PIMac achieves flexible manageability and improves the performance of multicast access control systems effectively.     

数字卫星设备控制及其实现

本文介绍了数字卫星设备控制在数字卫星电视系统中的应用，并阐述了具体的实现方法。     

车身中央控制器的设计与实现

采用单片机MC9S12XS128实现了一款车身中央控制器,实现了对中央集控门锁、外部灯光、内部灯光、雨刷的控制,同时通过RF技术实现了防盗报警功能和遥控门锁控制,通过LIN总线实现了对四个车窗的控制.     

一种动态LED背光控制方案及其FPGA实现

针对分辨率为XGA（1,024×768像素）的液晶面板,利用FPGA技术实现高亮度白光LED背光源的动态控制。以FPGA作为主控芯片,获取调节LED背光源的控制信号,并采用乒乓操作协调两组SDRAM以完成对视频信号的实时读写,在保证显示效果的基础上,通过动态调节LED的亮度来达到节能降耗的目的。该方案电路结构简单、设计灵活性高,适当改进后可适用于更大尺寸的LED背光源。