Earthmoving construction automation with military applications: Past, present and future

© ISARC 2018 - 35th International Symposium on Automation and Robotics in Construction and International AEC/FM Hackathon: The Future of Building Things. All rights reserved. Amongst increasing innovations in frontier engineering sciences, the advancements in Robotic and Autonomous Systems (RAS) has brought about a new horizon in construction applications. There is evidence of the increasing interest in RAS technologies in the civil construction sector being reflected in construction efforts of many military forces. In particular, Army or ground-based forces are frequently called upon to conduct construction tasks as part of military operations, tasks which could be partially or fully aided by the employment of RAS technologies. Along with recent advances in the Internet of Things (IoT) and cyber-physical system infrastructure, it is essential to examine the current maturity, technical feasibility, and affordability, as well as the challenges and future directions of the adoption and application of RAS to military construction. This paper presents a comprehensive survey and provides a contemporary and industry-independent overview on the state-of-the-art of earthmoving construction automation used in defence, spanning current world’s best practice through to that which is predicted over the coming years

Automatic Wall Plastering and Repairing Robot using Artificial Intelligence

Due to increase in population, the demand for the civil construction increases proportionally. The major activities like plastering, painting, flooring, roofing, etc are carried out manually or manual assisted and lead to more fatigue, with arbitrary qualities, shortages of skilled labor, etc. Because, the civil R&D activities in robotics and automation is less concentrated. So in this research, an attempt had been made and succeeded in developing an intelligent automatic wall plastering and repairing robot, which can plaster and repair the plastering for both commercial and residential buildings with good quality. These had been achieved through sensor, microcontroller and the actuators. The developed robot was validated by testing with the brick wall with cement mortar and the performance found satisfactory

Learning and Reacting with Inaccurate Prediction: Applications to Autonomous Excavation

Motivated by autonomous excavation, this work investigates solutions to a class of problem where disturbance prediction is critical to overcoming poor performance of a feedback controller, but where the disturbance prediction is intrinsically inaccurate. Poor feedback controller performance is related to a fundamental control problem: there is only a limited amount of disturbance rejection that feedback compensation can provide. It is known, however, that predictive action can improve the disturbance rejection of a control system beyond the limitations of feedback. While prediction is desirable, the problem in excavation is that disturbance predictions are prone to error due to the variability and complexity of soil-tool interaction forces. This work proposes the use of iterative learning control to map the repetitive components of excavation forces into feedforward commands. Although feedforward action shows useful to improve excavation performance, the non-repetitive nature of soil-tool interaction forces is a source of inaccurate predictions. To explicitly address the use of imperfect predictive compensation, a disturbance observer is used to estimate the prediction error. To quantify inaccuracy in prediction, a feedforward model of excavation disturbances is interpreted as a communication channel that transmits corrupted disturbance previews, for which metrics based on the sensitivity function exist. During field trials the proposed method demonstrated the ability to iteratively achieve a desired dig geometry, independent of the initial feasibility of the excavation passes in relation to actuator saturation. Predictive commands adapted to different soil conditions and passes were repeated autonomously until a pre-specified finish quality of the trench was achieved. Evidence of improvement in disturbance rejection is presented as a comparison of sensitivity functions of systems with and without the use of predictive disturbance compensation

Design, Modelling and Fabrication of a Robotic Retractor for Colorectal Surgery

PhDThis research presents the design, fabrication and controller development of a robotic retractor which driven by a robotic manipulator for laparoscopic colorectal surgery. The system consists of a dual-head fan retractor and a manipulator. The dual-head fan retractor comprises two fan devices, retractor wrist, tubular element and handle. The fan device is facilitated with a fan end-effector, an expansion mechanism and a clutchspring mechanism. Two fan devices have been used in the system to provide an anthropoid hand-holding shape which is specifically advanced for surgical purpose because intestine tends to slip when subject to disturbance and the anthropoid handholding shape can effectively halt that. One of the two fan devices is rotatable which makes the anthropoid hand-holding shape achievable. The retractor wrist possesses a triggering device, based on clutch-spring mechanism, for rotating the rotatable fan device. The clutch-spring mechanism has an impact on rotating the palms of the fan devices. In front of the handle, it is the so called front body which includes two fan devices, retractor wrist and tubular element. The front body can be controlled and is motorised using two motors fixed to the tubular element. The dual-head fan retractor is modelled in SolidWorks, and stress analysis of the retractor has been carried out by SolidWorks Simulation. Then, the mathematical model of the fan blades is developed. A 3-joint manipulator is modelled and controlled by a computed torque PD control approach as part of an investigative study to fit such a system to the retractor for robotic manipulation. Based on this investigation, the retractor is attached to a 2-joint robotic manipulator which has one rotational joint and a prismatic joint. This manipulator is mathematically modelled, and the dynamic equations are obtained. Control methods from Azenha and Khatib are simulated and compared. Azenha & Machado’s method has fewer input parameters and less oscillation when utilising the same control gains. Timeoptimal control is then successfully developed for the above 2-joint manipulator. This study clearly indicates that a retractor to be used for laparoscopic surgery can be effectively controlled using a multi-joints and multi degrees of freedom robotic manipulator

Evaluating Industrialization Rate in Construction: A Quantification Model

The concept of construction industrialization, first raised in the 1960s, refers to the transfer of on-site construction work to an off-site factory to improve quality and reduce cost, time, and safety issues. In some countries, industrialization of construction projects is highly recommended and promoted by governments and local construction institutions to minimize waste and pollution. The industrialization rate in construction is an important factor that is widely accepted to evaluate the level of industrialization in the industry. It is believed that construction industrialization rate (CIR) is associated with construction performance in terms of cost, schedule, safety, quality, and other measures. The construction industry currently utilizes volume of concrete use to evaluate the CIR, which is not necessarily accurate and convincible. No other formal method or model is available to objectively calculate the rate of construction industrialization. The author sets this knowledge gap as the point of departure and aims to develop a formal model for quantifying the CIR value of projects. To combine all of the units associated with the various construction operations and resources on a project, the researcher utilizes energy expenditure as a means for determining the percentages of human work and machine work. All activities and tasks could be measured with energy expenditure; energy is the most commonly-used unit that could be applied to all construction tasks, including both worker activities and machine activities. The researcher evaluates energy expenditure by quantifying all construction tasks and the associated energy expenditures for both on-site and off-site construction to record the amount of energy expended by machines and by laborers. During the model creation and validation process, the author utilized quantification, literature reviews, surveys, site observations, video comparisons, and cross-reference spreadsheets as the research methods. By applying the model to sample case projects, the author confirmed the feasibility of applying the model, and was able to find and solve issues and defects during application. The findings from the research provide evidence and statistical measures to calculate the CIR, and provide project owners/developers and construction contractors with a quantitative means to evaluate and market their projects based on the extent of industrialization used to construct the projects

On-Board Electronic Control Systems of Future Automated Heavy Machinery

The level of automation and wireless communication has increased in heavy machinery recently. This requires utilizing new devices and communication solutions in heavy machinery applications which involve demanding operating conditions and challenging life-cycle management. Therefore, the applied devices have to be robust and hardware architectures flexible, consisting of generic modules. In research and development projects devices that have various communication interfaces and insufficient mechanical and electrical robustness need to be applied. Although this thesis has its main focus on machines utilized as research platforms, many of the challenges are similar with commercial machines.The applicability of typical solutions for data transfer is discussed. Controller area network with a standardized higher level protocol is proposed to be applied where data signalling rates above 1 Mb/s are not required. The main benefits are the availability of robust, generic devices and well-established software tools for configuration management. Ethernet can be utilized to network equipment with high data rates, typically used for perception. Although deterministic industrial Ethernet protocols would fulfil most requirements, the conventional internet protocol suite is likely to be applied due to device availability.Sometimes sensors and other devices without a suitable communication interface need to be applied. In addition, device-related real-time processing or accurate synchronization of hardware signals may be required. A small circuit board with a microcontroller can be utilized as a generic embedded module for building robust, small and cost-efficient prototype devices that have a controller area network interface. Although various microcontroller boards are commercially available, designing one for heavy machinery applications, in particular, has benefits in robustness, size, interfaces, and flexible software development. The design of such a generic embedded module is presented.The device-specific challenges of building an automated machine are discussed. Unexpected switch-off of embedded computers has to be prevented by the control system to avoid file system errors. Moreover, the control system has to protect the batteries against deep discharge when the engine is not running. With many devices, protective enclosures with heating or cooling are required.The electronic control systems of two automated machines utilized as research platforms are presented and discussed as examples. The hardware architectures of the control systems are presented, following the proposed communication solutions as far as is feasible. Several applications of the generic embedded module within the control systems are described. Several research topics have been covered utilizing the automated machines. In this thesis, a cost-efficient operator-assisting functionality of an excavator is presented and discussed in detail.The results of this thesis give not only research institutes but also machine manufacturers and their subcontractors an opportunity to streamline the prototyping of automated heavy machinery

Robotic excavation in construction automation

An overview of the robotic excavation project at the Australian Center for Field Robotics at The University of Sydney is presented. The experimental machine, retrofitted from a commercial mini-excavator, and its instrumentation are described. Estimation and control strategies applied to the robotic excavator digger are briefly presented. Variable-structure-based techniques are employed to implement impedance control of excavator dynamics, and position/force control of the electrohydraulic systems for each working axis. This control takes into consideration uncertainties in modeling, friction, and bucket-soil interactions