Human perception of robot safe speed and idle time

Operators and users of robotic systems perform tasks which require close proximity to dangerous moving parts. Two experiments were performed to assess human perception of safe robot arm speed and idling times. Experiment 1 was designed to determine the maximum safe speed of robots. Subjects were asked to adjust the robot speeds. Perceived safe speeds were indicated for two different types of robots. Experiment 2 was designed to determine safe programmed idle time of robots. Subjects were asked to enter the robot work envelope when a programmed idle was perceived to be caused by a malfunction. Safe idle times were reported for two different robot speeds during operational cycles.     

Perception of safe robot idle time in virtual reality and real industrial environments

The main objective of this study was to investigate human perception of safe idle time of an industrial robot in a virtual reality environment. Studying operators' perception of robot operational characteristics such as safe robot idle time can help develop hazard prevention strategies, and ultimately improve robot safety. Results of data collected from 32 participants showed that robot size and speed had significant effects on the perception of safe robot idle time. This study also examined operators' perceived acceptability level for the robot speed, perceived level of hazard of robot motion, perceived chance of error, and self-reported mental workload. Results of this study were compared to the findings of Rahimi, M., Karwowski, W. [1990. Human perception of robot safe speed and idle time. Behaviour & Information Technology 9(5), 381–389], in which their experiment was conducted in a real industrial environment. This study demonstrated the feasibility of testing human perception of dynamic moving objects in a virtual reality environment. The virtual reality technology is believed to be capable of modeling a complex machinery system such as a robotic system.Relevance to industry: Human perception of the operational characteristics of industrial robots is an important concern for robot safety since misperception can cause robot operators to err, which in turn can cause injuries and fatalities. Through this study we (1) understand human perception, safety behavior, and decision making in a robotic system and (2) demonstrate the capability of modeling a complex machinery system using virtual reality technology. Our experiments designed to study human perception of safe robot idle time could lead to safety interventions and guidelines or hazard prevention strategy development.     

Perception of safe robot speed in virtual and real industrial environments

The purpose of this project was to study the influences of dynamic virtual objects in an Internet‐based virtual industrial environment. The main objectives of this study were to investigate perception of safe robot speed and perception of acceptability. Virtual industrial environments were designed and developed to conduct the experiment. The hypotheses specifying the relationships between perceptions of the robot size, type, different robot starting speed conditions, and gender were tested through data collected from 32 participants. The results indicated that the perception of safe speed was significantly different depending on robot sizes and the initial robot speed conditions. This was consistent with results shown in previous literature for tests in a real industrial environment. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 369–383, 2006.     

A review for control theory and condition monitoring on construction robots

The application of robotic technologies in building construction leads to great convenience and productivity improvement, and construction robots (CRs) bring enormous opportunities for the way we conduct design and construction. To get a better understanding of the trends and track the application of CRs for on-site conditions, this paper conducts a systematic review of control models and status monitoring of CRs, which are two key aspects that determine construction accuracy and efficiency. Control accuracy and flexibility are primary needs for CRs applied in different scenes, so the control methods based on driving models are vitally important. Status monitoring on CRs contains knowledge in fault detection, intelligence maintenance, and fault-tolerant control, and multiple objectives need to be met and optimized in the whole drive chain. Moreover, the state-of-the-art is comprehensively summarized, and new insights are also provided to carry on promising researches.     

Identification and idle speed control of internal combustion engines

This paper presents an integrated approach for the identification and control of internal combustion engines in idle-speed conditions. The inputs of the nonlinear identification model are the position of the idle speed air actuation system and the spark advance, while its outputs are the pressure inside the air intake manifold and the crank shaft speed. The estimated model is then used to synthesize an idle speed controller with the linear quadratic technique. The design procedure outlined here is currently being used by Magneti Marelli for the synthesis of commercial idle-speed regulators. Some identification and control results obtained by applying this method to a 1400 cm³ commercial engine are reported to witness the effectiveness of the proposed approach.     

An algorithm for safe navigation of mobile robots by a sensor network in dynamic cluttered industrial environments

Mobile robots have been widely implemented in industrial automation and smart factories. Different types of mobile robots work cooperatively in the workspace to complete some complicated tasks. Therefore, the main requirement for multi-robot systems is collision-free navigation in dynamic environments. In this paper, we propose a sensor network based navigation system for ground mobile robots in dynamic industrial cluttered environments. A range finder sensor network is deployed on factory floor to detect any obstacles in the field of view and perform a global navigation for any robots simultaneously travelling in the factory. The obstacle detection and robot navigation are integrated into the sensor network and the robot is only required for a low-level path tracker. The novelty of this paper is to propose a sensor network based navigation system with a novel artificial potential field (APF) based navigation algorithm. Computer simulations and experiments confirm the performance of the proposed method.     

Decoupling force and motion control in industrial robots

A theoretical approach to force control design for industrial robots involved in surface-following tasks is described in this paper, assuming an infinitely stiff environment. Independent Joint Control techniques, based on standard (PID) algorithms, are adopted for position control. Force control acts as an outer loop, by adding a bias to the position set points in the joint space. A simple model and compensation of the joint flexibility effects, that play an important role in determining the dynamic behavior of the system, are also presented, leading to a force control decoupled from motion control. Some experimental results are discussed, with reference to the industrial robot SMART.     

Two strategies of position and force control for two industrial robots handling a single object

The simultaneous position and force control problem for two industrial robots in handling a single object is studied in this paper. Two strategies, position-position control and position-force control, are first proposed. Stability analysis is then conducted for the strategies. Both strategies result in a stable system for simple robotic models. Steady state error is also studied for the strategies. Finally, experimental results are presented to evaluate the two strategies.     

Technology and corporate culture of industrial robots in Japan

This paper describes with examples of some typical industrial robots developed in Japan the process of development, which industrial robots in Japan took. It also describes citing the differences of cultural basis between Japan and western countries the influences of automation to man, culture and society, and survey the future industrial robots.     

A selection framework for infrastructure condition monitoring technologies in water and wastewater networks

The global water sector faces significant challenges to maintain secure and reliable service provision in the context of ageing infrastructure, urban growth, and with investment capacity constrained by user affordability. As part of an on-going effort to meet these challenges, research has been undertaken to facilitate the diffusion of technological innovations within the concept of “Intelligent Networks”. This diffusion has been facilitated by the formation of a consortium of water utilities in Victoria, Australia. The consortium has engaged with Intelligent Network concepts due to a need to prolong network asset life where possible; defer or remove the need for asset augmentation, reduce the operational expenditure (by reducing asset failures and incident response times), and minimise the impact of asset failures on communities and the environment. The literature on innovation diffusion indicates that the uptake of new technologies is influenced by subjective perceptions. As such, key research challenges were to understand where technologies could be used to improve asset management, identify potential condition monitoring techniques, elicit best available knowledge with respect these technologies and provide advice on where their application was likely to reflect a rational economic decision. To ensure a targeted review, “failure pathway” diagrams were first constructed to identify and relate influences controlling asset deterioration and failure. Elements of failure pathways were used to identify parameters that, by effective monitoring, could provide an early indication of asset distress and the opportunity to intervene and avoid reactive maintenance costs. Alternatively, parameters were also identified that could inform the deferral of capital expenditure on asset replacement and augmentation. The failure pathway provided the basis for the identification of 19 candidate monitoring technologies which were subsequently reviewed. Each technology identified was assessed against capital and on-going maintenance costs and the perceived benefit of implementation. Benefits were expressed in terms of how the new information acquired would enhance the asset owner’s ability to defer asset augmentation/renewals and avoid reactive maintenance costs/externalities. The project provided a prioritised set of monitoring technologies that are currently progressing towards pilot trials in the field.     

An anatomy of industrial robots and their controls

In the United States, commercially available industrial robots perform very well in limited areas of industrial tasks such as arc welding, paint spraying, etc. These tasks mainly involve synchronization but no task interaction. A close examination of the basic structure and controls of the robots reveals their resulting limitations which lead to unnatural specifications and inefficient performance of task interactions. It is our opinion that, to expand the range of robot tasks to include labor intensive jobs such as product assembly, sensors of multiple purposes must be added onto the robots and integrated into their control systems. Computer command language must be developed to enable nonexpert users to operate the robots, and a work-method must be available for analyzing robot time-motion so that the robots can be programmed to achieve best efficiency with least production cost.     

混合迭代学习法在发动机怠速稳速控制中的应用

发动机怠速工况作为发动机主要工况之一,是典型的非线性、滞后性、多变量时变系统,很难建立其准确的数学模型,控制系统的设计也非常复杂。应用传统的PID控制策略,结合比例积分的混合迭代学习控制,介绍了混合迭代学习控制原理并应用在发动机状态变量模型下的怠速控制。在Simulink中建立仿真模型验证该方法的控制效果。结果表明,使用该控制法的发动机状态变量模型有更快的收敛速度、更小的绝对偏差和调节时间,跟踪期望输出用时少,保持怠速转速快速稳定在期望值,性能表现更优。     

Ergonomics considerations and management action in the implementation of industrial robots

To obtain maximum benefit from the implementation of industrial robots, it is necessary to identify specific ergonomics problems and provide answers to such problems. Special features of a typical industrial robot are described. Specific ergonomics problems are identified and discussed: sociopsychological factors, systems safety design, communications, training, and workplace design. For the successful implementation of industrial robots, management should take timely action with regard to advanced planning procedures, user involvement plans, communication channels, company labor policies, and continuous training programs. The technological change from conventional to advanced manufacturing, such as industrial robots, must be jointly supported by all levels of management and workers. © 2001 John Wiley & Sons, Inc.     

Human factors of industrial robots and robot safety management in Japan

Japan has the largest world market share of industrial robots and also two fatal accidents due to robots. Ergonomics points of view should be applied to robotics to prevent new types of accidents. The concern of this paper is to explain Japan's situation concerning the installation of robotics and current safety regulations. Three experiments about the possibility of unsafe behaviour are described, and the man-robot system failure is analysed based on Fault Tree Analysis and the actual data. The appropriate safety measures are compared in terms of their cost-effectiveness. Finally, ergonomics points of view are provided to prevent accidents due to industrial robots.     

Interpolation of orientation for precise path generation in industrial robots

Industrial robots are versatile mechanical systems that require accurate tracking of continuous end-effector trajectories. However, a variety of control problems are encountered due to the deviation between the desired and actual paths.In this study, a new continuous path planning method based on an interpolation of orientation scheme is applied for precise path generation in robot welding. This method guarantees minimum deviation of positioning and orientation errors. Also, a new trajectory error evaluation strategy is developed to describe the trajectory errors at the effect points, which are very important in some robot jobs such as arc-welding operations.The simulation study of circular motions in arc-welding operations shows the effectiveness of the proposed approach.     

Selection of industrial robots using compromise ranking and outranking methods

Selection of a robot for a specific industrial application is one of the most challenging problems in real time manufacturing environment. It has become more and more complicated due to increase in complexity, advanced features and facilities that are continuously being incorporated into the robots by different manufacturers. At present, different types of industrial robots with diverse capabilities, features, facilities and specifications are available in the market. Manufacturing environment, product design, production system and cost involved are some of the most influencing factors that directly affect the robot selection decision. The decision maker needs to identify and select the best suited robot in order to achieve the desired output with minimum cost and specific application ability. This paper attempts to solve the robot selection problem using two most appropriate multi-criteria decision-making (MCDM) methods and compares their relative performance for a given industrial application. The first MCDM approach is ‘VIsekriterijumsko KOmpromisno Rangiranje’ (VIKOR), a compromise ranking method and the other one is ‘ELimination and Et Choice Translating REality’ (ELECTRE), an outranking method. Two real time examples are cited in order to demonstrate and validate the applicability and potentiality of both these MCDM methods. It is observed that the relative rankings of the alternative robots as obtained using these two MCDM methods match quite well with those as derived by the past researchers.     

工业机器人浇铸控制系统的设计与应用

根据浇铸机器人的功能需求和特点,设计了具有良好通用性和开放性的工业机器人浇铸控制系统的软硬件结构.以三轴浇铸机器人为应用实例,分析了其运动学正逆解算法,并根据实际生产需求,通过PLC程序中定义的M指令实现整个浇铸系统的I/O信号交互控制.实际应用结果表明,该浇铸控制系统有效地提高了浇铸生产效率,并且运行稳定可靠.