The major reason for the availability of such equipment has been the development of computers and microprocessors which are used as sophisticated, flexible and yet low cost controllers.
However, the operation of such systems would be very poor, if possible at all, if the computer’s decision making programs were not being supplied with suitable, up to date, quality information about the state of the external system.
Electrical noise (i.e. unwanted signals) may be generated by variation in contact resistance, by mechanical wear due to contact fiction, and by contact vibration transmitted from the sensing element.
电噪声（即不需要的信号）可能由接触电阻的变化、接触摩擦引起的机械磨损和传感元件传输的接触振动产生。
When a specification refers to a dead-zone or dead-band, it is referring to the largest change in the quantity to be measured to which the output does not change, or the change of input to which there is no output.
当一个规范是指一个死区或死区时，它指的是待测量中输出不变的最大变化，或是没有输出的输入变化。
This means that if we take a temperature measurement with the thermometer and find it to be ±20.1°C, then the actual temperature lies somewhere between 15.9°C and 20.3°C.
Actuators are basically the muscle behind a mechatronics system that accepts a control command (mostly in the form of an electrical signal) and produces a change in the physical system by generating force, motion, heat, flow, etc.
The stepper motor is a discrete (incremental) positioning device that moves one step at a time for each pulse command input. Since they accept direct digital commands and produce a mechanical motion, the stepper motors are used widely in industrial control applications.
Normally, due to the spring force, the soft iron core is pushed to the extreme left position; when the solenoid is excited, the soft iron core will move to the right extreme position thus providing the electromagnetic actuation.
A/D conversion is essentially a quantizing process, whereby an analog signal is represented by discrete states.
A / D转换本质上是量化过程，通过这个过程将模拟信号用离散状态表示。
An A/D converter requires a certain amount of time, called conversion time, to change an analog signal into the corresponding digital signal. If the analog signal changes during the conversion time, the converter output may be in error. To prevent this, a sample-and-hold circuit is used to sense the analog signal at the start of conversion, and store it on a capacitor during the remaining conversion time.
As a result, rudimental control systems were developed. Relays were attached to the instruments so that processes could respond to parametric changes. Soon, the single relay grew into more than one, allowing for multipoint control. Then, rate detectors were added and finally integrators, creating the PID control system.
It became normal for a measuring instrument to accept a signal; condition the input by linearizing, shaping, band limiting, etc.; and then digitize the result. The digital output was manipulated in a special, onboard processor in order to provide control or analytical decisions.
At the same time, the sphere of measurement and control systems expanded from merely measuring electrical and electronics parameters to encompassing all ancillary technologies including the mechanical, chemical, civil, and medical fields.
The speed and capability of general-purpose computers advanced exponentially. It soon became possible to adapt standard, high-speed computers to the online applications required in real time measurement and control.
With the addition of computers and computational capability, the cost of the instruments increased, How do we improve performance without adding cost?
随着计算机和计算能力的增加，仪器的成本增加，如何在不增加成本的情况下提高性能？
Consider what a virtual instrument and control system might contain. For a measurement instrument, there must be a sensor. If the parameter being measured is not electrical, this must incorporate a transducer to change the information to an electrical signal.
Control systems designed by humans are used to extend their physical capabilities, to compensate for their physical limitations, to relieve them of routine or tedious tasks, or to save money.
Freed of this routine task, the pilot can perform other tasks, such as navigation and/or communications, thus reducing the number of crew required and consequently the operating cost of the aircraft.
The definition of the transfer function requires the system to be linear and stationary, with continuous variables and with zero initial conditions. The transfer function is most useful when the system is also lumped parameter and when transport lags are absent or neglected.
One of the methods for controlling the output voltage employs switching at a constant frequency (hence, a constant switching time period TS=ton+toff), and adjusting the on-duration of the switch to control the average output voltage.
In transfer function models these equations are transformed and variables are eliminated between them to find the relation between selected input and output variables.
The interest of investigating offshore wind characteristics is receiving growing attention worldwide, which mainly attempts to boost the development of offshore wind energy and accelerate sustainable development. In particular, the understanding of offshore wind characteristics at the hub heights of wind turbines is of great significance in regard to the assessment of economic feasibility and structural design of wind turbines. Since traditional meteorological masts have limitations in height due to economic and technical considerations, remote sensing techniques have increasingly been employed for offshore wind observations.
This paper presents a comprehensive assessment of offshore wind characteristics on the basis of measurements from a light detection and ranging (LiDAR) system at an offshore site in Hong Kong. The fidelity of the wind LiDAR measurements was firstly examined by comparing with those obtained from anemometers on a nearby meteorological mast. Statistical analysis of wind speed was performed by means of the Weibull distribution function, and the results were subsequently used to facilitate the determination of several characteristic parameters associated with wind energy applications. The vertical profiles of wind speed derived from the LiDAR system were compared with existing models. Characteristics of wind shear coefficient were examined within different height ranges. Furthermore, the offshore turbulence characteristics were investigated, including the turbulence intensity and gust factor. The outcomes of this study are expected to provide useful information for the development of offshore wind energy.
The fundamental issues and open challenges in the SG are lack of awareness, consumer acceptance, cyber terrorism, data collection management, energy metering, dynamic optimization and energy control. Considering above, in this paper, a comprehensive review exploring information of development, technologies, and techniques in the SG. The main goal is to investigate and reveal the key enabling technologies, to obtain better picture about the current status of SG development. The focus areas of this review study are Architectural Model focusing Consumer Empowerment (CE), Demand Response Program (DRP), and Demand Side Management (DSM). Our survey discusses in detail the Communication Technologies, such as Wireless Advance Metering Infrastructure (AMI), Phasor Measurement Unit (PMU), Supervisory Control and Data Acquisition (SCADA), and Machine to Machine Communication (M2M). The power systems such as Micro Grid, Nano Grid, Pico Grid, Inter Grid, Virtual Power Plants, and Distributed Generation are also elaborated in this review study. Renewable Energy Resources (RERs) Integration with the SG and Integration issues related to Distributed generation (DG) are presented in this survey. This survey also analyzes Architectural Model of the Smart Grid focusing consumer empowerment and prosumers interaction. The aim of this study is to provide deep understanding of technologies and their applications in the SG.
The game of Go has long been viewed as the most challenging of classic games for artificial intelligence due to its enormous search space and the difficulty of evaluating board positions and moves. We introduce a new approach to computer Go that uses value networks to evaluate board positions and policy networks to select moves. These deep neural networks are trained by a novel combination of supervised learning from human expert games, and reinforcement learning from games of self-play. Without any lookahead search, the neural networks play Go at the level of state-of-the-art Monte-Carlo tree search programs that simulate thousands of random games of self-play. We also introduce a new search algorithm that combines Monte-Carlo simulation with value and policy networks. Using this search algorithm, our program AlphaGo achieved a 99.8% winning rate against other Go programs, and defeated the European Go champion by 5 games to 0. This is the first time that a computer program has defeated a human professional player in the full-sized game of Go, a feat previously thought to be at least a decade away.
