Novel parameter estimation schemes in microsystems

This paper presents two novel estimation methods that are designed to enhance our ability of observing, positioning, and physically transforming the objects and/or biological structures in micromanipulation tasks. In order to effectively monitor and position the microobjects, an online calibration method with submicron precision via a recursive least square solution is presented. To provide the adequate information to manipulate the biological structures without damaging the cell or tissue during an injection, a nonlinear spring-mass-damper model is introduced and mechanical properties of a zebrafish embryo are obtained. These two methods are validated on a microassembly workstation and the results are evaluated quantitatively

Meeting irrigation demands in a water-challenged environment

Presented at Meeting irrigation demands in a water-challenged environment: SCADA and technology: tools to improve production: a USCID water management conference held on September 28 - October 1, 2010 in Fort Collins, Colorado.Includes bibliographical references.Delivering water efficiently through distribution networks is a priority for irrigation districts but often is a difficult goal to achieve. SCADA shows promise of improving operational efficiency, increasing flexibility in the amount and timing of water deliveries, and reducing spills and other losses in distribution networks. However, implementing SCADA in a district for the first time is a difficult process. Districts often do not understand or are distrustful of the technology. They often do not know or understand how their system actually operates, thus making it difficult to design SCADA systems and to determine operational parameters and control algorithms. Selecting equipment that is easy to integrate into district operations is not a simple decision. Simple tasks such as selection of sensors and communication hardware become time consuming because of the need to explain advantages and disadvantages of each component. District boards of directors are normally reluctant to spend money, which further complicates the process. Once SCADA is installed, district personnel have to be trained on how to use the equipment to perform daily operations. In this paper we discuss the process of implementing SCADA projects for the first time in a district that had no previous experience with such technology or control systems. The paper will cover both hardware aspects as well as human consideration, and discuss some of the many lessons learned

Microsystems technology: objectives

This contribution focuses on the objectives of microsystems technology (MST). The reason for this is two fold. First of all, it should explain what MST actually is. This question is often posed and a simple answer is lacking, as a consequence of the diversity of subjects that are perceived as MST. The second reason is that a map of the somewhat chaotic field of MST is needed to identify sub-territories, for which standardization in terms of system modules an interconnections is feasible. To define the objectives a pragmatic approach has been followed. From the literature a selection of topics has been chosen and collected that are perceived as belonging to the field of MST by a large community of workers in the field (more than 250 references). In this way an overview has been created with `applications¿ and `generic issues¿ as the main characteristics

Measuring 3D indoor air velocity via an inexpensive low-power ultrasonic anemometer

The ability to inexpensively monitor indoor air speed and direction on a continuous basis would transform the control of environmental quality and energy use in buildings. Air motion transports energy, ventilation air, and pollutants around building interiors and their occupants, and measured feedback about it could be used in numerous ways to improve building operation. However indoor air movement is rarely monitored because of the expense and fragility of sensors. This paper describes a unique anemometer developed by the authors, that measures 3-dimensional air velocity for indoor environmental applications, leveraging new microelectromechanical systems (MEMS) technology for ultrasonic range-finding. The anemometer uses a tetrahedral arrangement of four transceivers, the smallest number able to capture a 3-dimensional flow, that provides greater measurement redundancy than in existing anemometry. We describe the theory, hardware, and software of the anemometer, including algorithms that detect and eliminate shielding errors caused by the wakes from anemometer support struts. The anemometer has a resolution and starting threshold of 0.01 m/s, an absolute air speed error of 0.05 m/s at a given orientation with minimal filtering, 3.1° angle- and 0.11 m/s velocity errors over 360° azimuthal rotation, and 3.5° angle- and 0.07 m/s velocity errors over 135° vertical declination. It includes radio connection to internet and is able to operate standalone for multiple years on a standard battery. The anemometer also measures temperature and has a compass and tilt sensor so that flow direction is globally referenced regardless of anemometer orientation. The retail cost of parts is $100 USD, and all parts snap together for ease of assembly

Improving Dynamics Estimations and Low Level Torque Control Through Inertial Sensing

In 1996, professors J. Edward Colgate and Michael Peshkin invented the cobots as robotic equipment safe enough for interacting with human workers. Twenty years later, collaborative robots are highly demanded in the packaging industry, and have already been massively adopted by companies facing issues for meeting customer demands. Meantime, cobots are still making they way into environments where value-added tasks require more complex interactions between robots and human operators. For other applications like a rescue mission in a disaster scenario, robots have to deal with highly dynamic environments and uneven terrains. All these applications require robust, fine and fast control of the interaction forces, specially in the case of locomotion on uneven terrains in an environment where unexpected events can occur. Such interaction forces can only be modulated through the control of joint internal torques in the case of under-actuated systems which is typically the case of mobile robots. For that purpose, an efficient low level joint torque control is one of the critical requirements, and motivated the research presented here. This thesis addresses a thorough model analysis of a typical low level joint actuation sub-system, powered by a Brushless DC motor and suitable for torque control. It then proposes procedure improvements in the identification of model parameters, particularly challenging in the case of coupled joints, in view of improving their control. Along with these procedures, it proposes novel methods for the calibration of inertial sensors, as well as the use of such sensors in the estimation of joint torques

Monitoring of Voltage and Load Current Integration of Solar Panels with Electric Grids Android-Based

Energy has been a human need since ancient times which has been an indicator of prosperity. However, that doesn't mean there won't be problems. The longer the petroleum reserves are getting depleted, so sooner or later humans must make more use of non-fossil alternative energy. An example is solar energy whose availability will never run out. Therefore, the application of Solar Power Generation (PLTS) technology to utilize its energy potential. The goal of the project is to develop a system for integrating solar power with electrical grids that can track the voltage and current of the applied load. The PZEM004T sensor produces an accuracy of 99.4 percent on the voltage variable test, which compares favorably with the ACS712 current sensor's accuracy of 97.8 percent. The lowest light intensity measured in the current variable test is 24351 lux with an output voltage of 17.32V at the time range between 4-5 pm, and the highest is 103901 lux with an output voltage of 18.9V at the time range between 11-12 am. Accuracy is 98.5 percent with light loads and 99.2 percent when the charger is used. Relays' ability to switch between resources has been tested, and the results have met expectations

H∞-based Position Control of a 2DOF Piezocantilever Using Magnetic Sensors.

International audienceThe article addresses the position control problem of a 2 degrees of freedom (DOF) piezoelectric cantilever by means of an embedded magnetic-based position sensor. The active part of the piezocantilever used in the experimental setup is similar to cantilevers previously developed and already used for low-frequency micro-actuators in microrobotics devices. The contribution relies on the estimation of the biaxial displacement of the piezocantilever via conventional Hall-effect (HE) sensors, reducing the mechanical complexity and cost aspects.The actual sensing approach is validated via the implementation of a real-time position control based on the H1 scheme. In comparison with high resolution sensors, as laser or confocal chromatic (high-cost) or capacitive displacement (bulky), the actual sensor-control system is provides a satisfactory performance to cope with traditional micro-positioning tasks requiring a micrometer resolution. The performanceof the embedded magnetic-based position sensor is evaluated, in open- and closed-loop, with respect the measurements provided by a Keyence laser sensors

Opportunities for improving irrigation efficiency with quantitative models, soil water sensors and wireless technology

Increasingly serious shortages of water make it imperative to improve the efficiency of irrigation in agriculture, horticulture and in the maintenance of urban landscapes. The main aim of the current review is to identify ways of meeting this objective. After reviewing current irrigation practices, discussion is centred on the sensitivity of crops to water deficit, the finding that growth of many crops is unaffected by considerable lowering of soil water content and, on this basis, the creation of improved means of irrigation scheduling. Subsequently, attention is focused on irrigation problems associated with spatial variability in soil water and the often slow infiltration of water into soil, especially the subsoil. As monitoring of soil water is important for estimating irrigation requirements, the attributes of the two main types of soil water sensors and their most appropriate uses are described. Attention is also drawn to the contribution of wireless technology to the transmission of sensor outputs. Rapid progress is being made in transmitting sensor data, obtained from different depths down the soil profile across irrigated areas, to a PC that processes the data and on this basis automatically commands irrigation equipment to deliver amounts of water, according to need, across the field. To help interpret sensor outputs, and for many other reasons, principles of water processes in the soil–plant system are incorporated into simulation models that are calibrated and tested in field experiments. Finally, it is emphasized that the relative importance of the factors discussed in this review to any particular situation varies enormously