Embedded Systems Prelim 1

Embedded systems

A combination of hardware and software parts. When these two parts are combined, embedded systems bring together products such as a cell phone, a music player, a network router, an aircraft guidance system, and many others.

Ubiquitous computing (Pervasive computing)

Describes that computing focuses more on providing information anytime, anywhere. (Weiser, 1988)

Ubiquitous

Connotes to everywhere.

Pervasive

Connotes to diffused throughout every part of.

Invisible computer

Implicates that computers are going to be integrated into products that it will become invisible. This is in the sense of being more miniscule and unseen in today's interpretation.

Ambient intelligence

Implies that intelligence can be implanted in our everyday environments and makes those environments sensitive.

Embedded systems

Are information processing systems embedded into enclosing products. (Marwedel, 2017)

Cyber-Physical Systems (CPS)

Are integrations of computation and physical processes. (Lee, 2017)

Internet of Things

"... describes the pervasive presence of a variety of devices - such as sensors, actuators, and mobile phones - which, through unique addressing schemes, can interact and cooperate to reach common goals." (Giusto, et al., 2010)

Apollo Guidance Computer

Real-time embedded computing system

Sensor

It measures the physical quantity and converts it to an electrical signal which can be read by an observer or by any electronic instrument like an ADC.

A-D Converter

It converts the analog signal sent by the sensor into a digital signal.

Processor

It processes the data to measure the output and store it in the memory.

D-A Converter

It converts the digital data fed by the processor to analog data

Actuator

It compares the output (from DAC) to the actual output stored in it and stores the approved output.

Memory

It is the storage unit of the whole system.

Safety

It is the state of being 'safe', the condition of being protected from harm or other non- desirable outcomes".

Security

A system is secure if it is protected against harm caused by attacks originating from outside the system.

Confidentiality

The information can only be accessed by the intended recipients.

Reliability

This term refers to malfunctions of systems resulting from components not working.

Repairability

It is the probability that a failing system can be repaired within a certain time.

Availability

It is the probability that the system is available.

Real-time constraints

It refers to not completing computations within a given time frame can result in a serious loss of the quality provided by the system or may cause harm to the user.

Hard Real-time

A  system designed to meet all deadlines. A missed deadline is a design flaw. Ex: Nuclear reactor monitoring system, Anti-lock braking system.

Firm Real-time

A system designed to meet all deadlines, but occasional missed deadline is allowed. Ex: In multimedia systems, audio or video quality is affected due to interference.

Soft Real-time

A system designed to meet as many deadlines as possible. It will do its best effort to complete a task within specified time, but it may be late. Ex: Switch or router.

Energy

Electronic information processing uses electrical energy for information processing. For embedded systems, the availability of electrical power and energy is a deciding factor.

Run-time

Embedded systems should exploit the available hardware architecture. It implies optimization of execution times in processes and avoidance of wasting process cycles.

Code Size

There may be constraints on the storage capacity of the system.

Weight

All portable systems must be lightweight.

Cost

A minimum amount of resources should be used for implementing the required functionality.

Reactive

Many embedded systems must continually react to changes in the system's environment.

Heterogeneity

 It implies that the availability and compatibility of design and materials are needed for producing components.

Behavioral hierarchies

 These hierarchies contain objects necessary to describe the system behavior.

Structural hierarchies

These describe how systems are composed of physical components.

Concurrency

Real-life systems are distributed, concurrent systems composed of components.

Timing behavior

Time is one of the key dimensions of running systems.

State-oriented behavior

Automata (states) provides a mechanism for modeling reactive systems.

Exception-oriented behavior

To design dependable systems, it must be possible to describe actions to handle exceptions easily.

Event handling

 Due to the reactive nature, mechanisms for describing events must exist. Such events may be external (caused by the environment) or internal events (caused by components of the system under design)

Executability

Executing the specification is a means of plausibility checking.

Readability

Specifications should be captured in languages that are readable by humans and by computers.

Portability and flexibility

An embedded system should be independent of specific hardware platforms so that they can be easily used for a variety of target platforms.

Non-functional properties

An embedded system exhibits some non-functional properties, such as fault tolerance, size, extendibility, expected lifetime, power consumption, weight, disposability, user-friendliness, and others.

Cyber-physical systems

These systems are combining computations with physical processes. Embedded systems execute monitoring and control of physical processes. Feedback loop included in these systems.

Real-time systems

These systems are based on the time of response in which it determines the quality of the system. It means that the computations should be executed with a given time frame

Dedicated systems

These systems execute only calculations connected with this algorithm.

Reactive systems

These systems execute when events are triggered depending on the state of a controlled object. The events are determined by signals on the system inputs.

Systems with a dedicated user interface

These systems have a dedicated user interface including steering wheels, pedals, push buttons, small LED displays.

Automotive electronics

These include engine control systems, anti-braking systems (ABS), electronic stability programs (ESP), GPS systems, driver assistance systems, and others.

Avionics

 Includes flight control systems, pilot information systems, autopilots, and autonomous flying (drones).

Factory automation

CPS/IoT technology is the key toward a more flexible production, being the target of "Industry 4.0". Example: RFID technology provides easy identification of every object.

Health sector

These technologies allow significantly improved result monitoring, giving doctors a better means for checking certain ailments or treatment.

Smart buildings

Information processing is used to increase the comfort level in buildings. It can reduce the energy consumption within buildings, and can improve safety and security.

Public safety

 Identification/authentication of people - fingerprint sensors or face recognition systems.

Robotics

Robotics is also a traditional area in which embedded/cyber-physical systems have been used.

Military applications

Information processing has been used in military equipment such as improvement of military radar signals.

Telecommunication:

It includes mobile phones, radio frequency design, digital signal processing, low-power design, and IoT.