1. OVERVIEW

The term “Cyber Physical system” was initially coined by Ellen Gill in 2006. CPS is a category of embedded system.  It is often called a Next Generation Computing System which uses smart computation techniques associated with physical world and computational units. The CPS can interact with the real-world systems by means of Computation, Communication and controls. The interaction of computational and physical units leads to advanced implementations of Internet of Things (IoT). IoT and CPS are designed to support real time applications which can manage many environmental datasets. In other words, CPS is a combination of digital controls and the physical environment.

2. INTRODUCTION

The Cyber Physical System consists of cyber components and physical components, so we call it as cyber physical system. CPS is based on an information processing computer system, which is embedded into a product, like a car, plane or other device. These computer systems are used to perform specific tasks.

For Example, in a car an embedded system would be the ABS (Anti-lock / Anti-Skid Braking System) to control break force. This computer system interacts with the physical environment by means of Sensors and Actuators. These embedded systems are no longer standalone, they share their data via communication networks such as the internet with cloud computing where data from many embedded systems can be collected and processed. Thereby creating a system of systems. Connected embedded systems can be controlled and decentralized by a computational unit. The collected data can be processed automatically or by Human Machine Interface (HMI).

IoT is a technology, in which devices are connected through the internet and enables the remote collection of real time information which can them be processed or shared with other devices.

CPS’s are powered by two types of computing system:

(i) Notebooks, Desktop servers and PCs. Computers at every desk to do business activities
(ii) Embedded Computing - Transformation of Industry and Invisible part of Environment.

The main characteristics of CPS are:

(i) Intelligence - Adaptive and Robustness
(ii) Network – Communication, Cooperation and Cloud solutions
(iii) Functionality
(iv) User friendly. The main features are as follows: CPS is said to be closely integrated with computation and physical processes, the software is embedded with physical systems and CPS networks use wireless sensor networks.

3. APPLICATIONS

The application of CPS have the potential to introduce significant changes in information intensive technology sectors such as manufacturing, water distribution systems, transportation, healthcare and smart buildings.

Manufacturing:

In manufacturing environment CPS’s are used for self-monitoring the production operations and control. CPS improves manufacturing processes by sharing information between machines, supply chain, suppliers, business systems and customers. Smart manufacturing provides high visibility controls on the supply chain which results in improving the traceability and security of goods. The impact of IoT and CPS in manufacturing industry is significantly growing. Sensors are used to predict equipment wear and diagnose faults. The analytics reduces the maintenance cost and increases operation performance.

Manufacturing industries works under a five-level architecture.

Connection- Data is generated by machines, tools and the product
Conversion- Using algorithms it converts the data to information.
Cyber- Processes the information and creates additional value. Cyber level acts a hub (cloud) and performs complex operations. Cyber level runs on sophisticated manufacturing methods, runs deep learning algorithms to identify large data patterns. This level focuses on standalone systems which uses the data from the system to attain additional knowledge.
Cognition- Converts machine signals to information to compare the information with other outcomes. In this level the machine monitors and diagnoses its own failures and become aware of potential problems.
Configuration- a machine can track and detect failures early and sends information to the operation level. Machines can amend their operation depending on workloads or malfunctions.

These measures produce a system in which machines can defend themselves from difficulties by finding alternate solutions and preventing operation failures.

The 5c structure uses different levels of operations:

Component level: Contains virtual twins that exists in cyber space. The twin models the critical components of a machine. It captures the changes in the operations on the cloud. The system would gain self awareness by this mechanism.
Machine Level: Incorporates the information gathered in the component level which is combined with machine operations to create new modules for each machine. Similar Virtual twins are compared with other machines to quantify performance.
Fleet Level: Optimize production processes through the performance of machines and component status from component and machine levels. These level result in self configuring and self maintenance and has the benefit of maximizing the life span of all components, leading to increased production quality.
Enterprise Level: This level incorporates the outcome of previous levels to produce a high-performance production rate.

Water Distribution Systems:

Water Distribution systems are becoming increasingly automated. These systems consist of reservoirs, tanks, pumps, wells and pipes that deliver water to our taps. As well as devices to monitor activity such as sensors to detect the level of overflow of water from a tank or the pressure from the pipe. And programmable Logic Controls which can automatically open valves and supervisory controls and data acquisition systems that monitor controls all the devices in the network. While all these innovations allow the system to run more efficiently and reliably. They also expose the system to potential attacks on the software that controls it. If the hacker can remotely access the components of the CPS, they could do all sorts of damage ranging from stealing data, cutting of water supplies, damaging the equipment or even releasing chemicals used in processing into the system. Hackers can spy on the system with eavesdropping attacks or by initiating deception attacks.

It is difficult to detect the attacks on the system by human oversight and by machine detection algorithms. In order to overcome these attacks two types of tools are used. The first one is an ‘Attack Model’ the other is a ‘Toolbox’. The Attack model describes the different way the hackers might compromise the system and the Toolbox runs on a MATLAB which is widely used engineering computing software. The Toolbox gathers the attack models and automatically runs on Epanet. An Epanet is an industry standardized software modeling tool which describes how water flows through the system. The Epanet utilizes the CPA toolbox to track the actual physical status of the system and the reported cyber status of the system which detects external changes introduced by the hackers.

Smart Greenhouse:

CPS play a vital role in the field of agriculture; it improves productivity and prevents starvation. The system focuses on an adaptive method with several parameters such as temperature, humidity, irrigation and amount of light. This responds to the parametric changes according to specific computer programs which are designed to ensure a better growth. Further it reports feedback continuously to the users to keep them informed about the condition of the greenhouse. Feedback can be managed easily by remote locations using network service. The design consist of sensors which act as a station sensor which includes temperature, humidity, soil moisture and light sensors and it adds other sensors like temperature and humidity control system in which the fan, sprinklers and other devices can be used for increasing and decreasing the temperature.

Benefits:

• It saves the farmers money, time and effort
• Provides better environment and increases in productivity
• The amount of water needed is controlled and supplied automatically

Health Care:

Most of medical systems use cyber physical systems, they use real time monitoring and remote sensing of physical conditions of the patients. This leads to improved treatments for disabled and elderly patients and limits patient hospitalization. In future these systems will be combined into a network closed loop system incorporating a human loop to improve the safety and workflows.

Transportation:

Vehicles can communicate with each other by sharing real time information such as traffic, locations and issues to prevent from accident and improve safety. Vehicles function will be executed in a distributrd manner by enhancing performance and emission reduction. For example, the branking system not only stops the car also it avoids a potential collision.

Buildings:

CPS enabled buildings are called “smart buildings”. The function significantly improves energy efficiency and decreases energy consumption and greenhouse gas emissions. A network is used to sense the temperature, humidity and operate actuators (HVAC, fans, water heater) is embedded into the building to detect changes in the environment.

Claytronics:

Claytronics – a technology to create virtual reality with which human interaction is possible. IT combines nano scale robots and computer theory to make nanometer-scale systems called claytronic atoms / catoms. These catoms can interact with others to make 3D structures. The goal of claytroics is to create dynamic motion in three dimensional objects. Two types of algorithms are being used in Claytronics, shape sculpting and localization. The collective actuation and hierarchal planning require shape sculpting algorithms by which it converts the catoms into the desired structure and dimension. The localization algorithm enables the positioning of catoms in the ensemble.

4. CONCLUSION

Cyber physical systems are intelligent system that combine hardware and software and are connected through a network as the physical world merges with the virtual world into cyberspace. The innovation of CPS’s relies on the input of many disciplines and requires a skilled workforce to support and maintain its development. It has the potential to change and improve lives and to address many critical challenges.