Tomi Makkonen

Comparison of position control algorithms of embedded shape memory alloy actuators

This paper presents a comparison of the algorithms for control of shape memory alloy (SMA) actuators. An adaptive airfoil is a case of smart composites which utilize embedded SMA actuators. The airfoil is deformed by the SMA actuators which are heated with electric current. The controller adjusts the electric current of the actuators to reach the desired shape of the airfoil.

Reopening an Abandoned Underground Mine - 3D Digital Mine Inventory Model from Historical Data and Rapid Laser Scanning

The decision to reopen a mine abandoned for 30 years is going to be complex because a significant financial commitment is going to depend on a reevaluation of both the remaining mineral resource and the surviving mine infrastructure. Historical pre-digital records will need to be assessed and new data acquired both to prove up an ore reserve and to assess the status of existing mine development and infrastructure. We describe how historic mining data were collected and compiled on the mine infrastructure (tunnels, buildings) and how mineral resource data were prepared and transferred into a 3D digital mine inventory for the Otanmaki Mine in Finland. We also demonstrate the applicability of rapid handheld laser scanning for simultaneous localization and mapping to supplement the available mine plans. Point-cloud laser scans were collected in the hoisting tower and evacuation shelter.

The Applicability of the Rapid Handheld Laser Scanner to Underground Tunnel Suveying

Laser scanned point clouds are important part of the modern work processes in mine industry. Inertia corrected handheld laser scanners are new type of apparatus commercially available from the year 2013 to gather point clouds. These devices are fast to use as the person scanning can walk when holding the device and the map is then automatically produced, however the resulted point cloud is most likely not as accurate as it is with standard industrial laser scanner. Having major advances in fast and easy scanning and a drawback of not so great accuracy might do the usage of the attained point cloud non trivial in industry. Based on experiments accuracy of the ZEB1 handheld laser scanner from Geoslam Ltd is studied in three underground field experiments. Obtained RMSE varied between 0.15 – 0.43 meters. It’s important to remember that these results are not mostly about accuracy of the ZEB1 (Zebedee) but about the accuracy of the whole measurement chain of personnel, measurement devices and the coordinate system used in the mine. Scanning speeds in experiments were astonishing from 5 to 13.5 tunnel meters per minute.

Model-Based Control of SMA Actuators with a Recurrent Neural Network in the Shape Control of an Airfoil

This paper describes the development of a neural network control for shape memory alloy (SMA) actuators as well as the control tests. Precise control of SMA actuators that are integrated in the composite structure is difficult because of the hysteretic behaviour of SMA and time delays in the control system. The weakness of the static model of SMA is that it does not take into account the actuator dynamics. The NARMA-L2 neural network model enables us to solve the inverse dynamic model of the nonlinear discrete-time dynamical system. In this study the NARMA-L2 model of the airfoil (a cross section of wind turbine blade) was created using Matlab Simulink software and neural networks. Data for network training was measured from the specimen. The performance of the constituted NARMA-L2 controller was tested in control tests. According to the control tests the NARMA-L2 controller is well suited for controlling embedded SMA actuators. The constituted controller enabled fast and stable actuation in step responses and it was also able to compensate for changes in cooling conditions.

FEA in Road Engineering Applications

The current urbanization, industrialization and planning of new city-districts require efficient design to manage the energy, ecology and economical demands set for living environment. The efficiency of Building Information Model (BIM) design in construction sites has been proven through many projects. The full overview and control of design, construction and life-cycle of a structure brings sustainability to buildings and provides optimized purpose for their use. Residential and nonresidential buildings, bridges and other civil and structural engineering products will adopt BIM next to benefit from advanced control of infrastructure and related services. Road design is a complex process requiring collaboration in planning, designing, constructing and execution of designs. The design must consider soil investigations, infrastructure planning, various ecologic aspects and the construction designs to achieve the set durability and efficiency goals. This includes the economic implications and planned maintenance during the entire life-cycle of the construction. The impacts of these features could be improved by detailed analysis and monitoring of the physical behavior of the structure during construction and operative use. The physical performance of the structure may be efficiently analyzed by using numerical modelling, such as Finite Element Analysis (FEA). Integration of FEA in the BIM of road design may significantly improve the road construction and its features during the

Using SLAM-based Handheld Laser Scanning to Gain Information on Difficult-to-Access Areas for Use in Maintenance Model

Laser scanning is the de-facto system to collect large amounts of geometrical information, especially indoors. Total stations are usually used for accuracy and information-rich results. However, in some cases the target area is not suitable for using a terrestrial laser scanner. For instance, too cramped or difficultto-access space can be a limiting factor. In complex cases, standard scanning methods are usually timeconsuming, leading to unexpected costs and sometimes scanning can be omitted for time and cost

Integration of Structural Health Control in BIM for Current and Future Residential Buildings

Currently the structural engineering and construction technologies go through substantial paradigm shift and development between energy conservation, health and living cost issues. Increasing energy consumption for e.g. heating and cooling and the constant effort to energy preservation in all forms promotes the manufacture of sustainable low-energy or near-zero energy houses, often with some independent energy production capability included. As a subtheme in controlling the building performance and energy uses, there has been interest in applying Building Information Model (BIM) to building designs to store, optimize and use buildingrelated information during its entire life-cycle. The BIM methodology is mostly limited for new buildings as the needed open access data on generic structures and materials is most often not available. Similarly, health considerations in current buildings are also poorly controlled and more detailed knowledge on the content and conditions of thermal transport, air exchange and moisture control would benefit the energy efficiency and sustainability of the buildings. Common issues with moisture entrapment leading to microbial growth and indoor air quality related respiratory illnesses are a practical, and extreme, example of insufficient understanding of structural design and control issues also in in public

Suitability of a Three-Axis Inclinometer to the Automated Blade Control System of Excavator

Partly automated blade control of excavator has been studied. Main focus of the study were to find means to control one of the excavator’s work cylinders automatically while machine operator controls the rest of non-automated work cylinders. This article concentrates on the suitability of a certain inclinometer sensor for partly automated blade control of excavator. Test device was built where inclinometers output data controlled hydraulic cylinder and the statical and dynamical properties of the cylinder and the controlling sensor were studied. In statical tests the inclinometer was attached to the milling tools distributing board along with the reference sensor. The positioning accuracy and the positioning repeatability were studied with the statical tests. In dynamical tests the inclinometer was attached to the pendulum and the dynamical properties of the inclinometer were researched with the pendulum oscillation experiments. Test device contained angular potentiometer which purpose was to function as inclinometers reference sensor. The LVDT displacement transducer was attached to the side of the cylinder which functioned as cylinders integrated displacement sensors (VRVT) reference sensor. In dynamical tests the inclinometers and reference sensors data responses were measured with different pendulum rod lengths and attachment setups. Centripetal accelerations and angular frequencies were calculated from the measured data and their effects for angular error are introduced. Results indicate that cylinders positioning accuracy was ± 1.5 millimetres and the inclinometers angle accuracy was ± 0.3 angle of degrees with delay of 600 ms. Accuracies are sufficient but the delay is too long for partly automated blade control.

Automation of an Excavator Based on a 3D CAD Model and GPS Measurement

This study examines the possibilities of controlling a six degrees of freedom excavator with the final objective of controlling the movements of the excavator by using a CAD model of the road surface. Compared to the traditional excavator with 4 DOF, the excavator was provided with two additional degrees of freedom by applying the 2 DOF Rototilt, an accessory commonly in use. The advantages of automation are faster process of working and less demands on the operator. To study this problem, an Msc.Adams with Matlab/Simulink simulation environment was used.