Transportation Automation Reliability, Safety and Security ... · Transportation Automation Reliability, Safety and Security in the Vehicle Industry Stipendium Hungaricum 2017/2018

Transportation Automation

Reliability, Safety and Security in the Vehicle Industry

Stipendium Hungaricum

2017/2018 Spring Semester

Balázs Sághi P.hD, István Ferenc Lövétei

BMEKOKAM202

BMEKOKAM660

SAFETYLecture 7.

3

Depandability

• Depandability is a property of a system that justifies placing one’s reliance on it.

• RAMS - Depandability:

09/04/2018 Safety, Hazard, Risk

4

Safety

• Safety (def) is a property of a system, that it will not endanger human life or the

environment.

• freedom from uneccaptable risk – in railway standards, EN 50126

• is freedom from accidents or losses,

• The state in which risks associated with aviation activities, related to, or in direct support of the

operation of aircraft, are reduced and controlled to an acceptable level. - ICAO (International

Civil Aviation Organization),

• freedom from unacceptable risk of harm - EUROCONTROL

• Safety - related (or critical) system is one by which the safety of equipment or plant is

assured.


Not exists a system that can be absolutely safe.

• our goal in a designing a system is to make it adequately safe for its given role……

• safety is subjective-ex. many people are afraid of flying…

09/04/2018 Safety, Hazard, Risk 5

Safety

6

Safety – Critical Processes

• transportation is a dangerous facility:

• it endangers the safety of:

• persons,

• objects,

• and the environment,

• by causing injuries.

• examples of other hazardous processes and systems:

• chemical processes, energy industry,

• manufacturing processes (production line, industrial robots),

• material handling, warehousing,

• medical tehnologies,

• a hazard is caused by one ore more source of hazard concerning the functions of thegiven process, appliance or system.


Safety, Hazard, Risk 7

Expectations Against the Transportation System

Safety Capacity

• Problem:

• increased capacity

causes the decreasing

safety:

• increased speed,

• increased traffic density

• Expectations

09/04/2018


Safety, Hazard, Accident

(Accident Chain of Events)

• The source of a hazardis not a direct danger. No hazards.

The source of threat is passive.

• The source of a hazardis a direct danger.

The source of a hazard is active.

• Occurence of an accident.

Injury

09/04/2018




• Safety:

probability, that there is no hazards

• Accident-free:

probability, that there is no injuries

P

A

I

safe state

dangerous state the source of a hazard is active

the source of a hazard is passive

injury

accident

technical error, faulty actiona*Δt

b*Δt 𝑃𝑃(𝑡 + ∆𝑡) = 𝑃𝑃(𝑡)-𝑃𝑃(𝑡)a∆𝑡𝑃𝐴(𝑡 + ∆𝑡) = 𝑃𝐴(𝑡)+𝑃𝑃(𝑡)a∆𝑡−𝑃𝐴(𝑡)b∆𝑡𝑃𝐼(𝑡 + ∆𝑡) = 𝑃𝐼(𝑡)+𝑃𝐴(𝑡)b∆𝑡

09/04/2018

Concept of the Risk

• risk expresses the significance of a hazardous effect

• can be described by:

• frequency,

• severity,

• other parameters (eg. possibility of the escape)

• Risk (def) is a combination of the frequency or a probability of a specified hazardous event, and itsconsequence.

Safety, Hazard, Risk09/04/2018 10


Socially Tolerable Risk

• risk tolerance is influenced by subjective

standpoints:

• eg. responsability

• risk reduction means costs:

• absolutely safe state not exists…

• it’s needed to find the appropriate ratio of the

costs (efforts) and available results.

Ka

costs

risk reduction

risk

Ri

Ri

Ri4

Ri3

Ri2

Ri1

Kb

K1 K2 K3 K4


Active and Passive RiskReduction

• The source of a hazardis not a direct danger. No hazards.

The source of threat is passive.

• The source of a hazardis a direct danger.

The source of a hazard is active.

• Occurence of an accident.

Injury

09/04/2018

safety-critical processcontrol systems

protection systems

passive risk reduction


Traffic Rules

• Rules used continuously, applied in the same way:

• ex. right-hand rule, right-

keeping obligation,

• it is important to know the

rules, that’s why we limit the

access to the system (driver

license)

• Rules that vary depending on traffic or different situation:

• Traffic management systems

– permissions/instructions are given to the

vehicles for movements,

– vehicles may move according to the permit.

• Tasks of the traffic management:

– creating conditions for secure movements,

– achieving other management goals (eg.

reducing the energy consumption)


Managing of the Instructions and Their Compliance

ProperInstructions

Complianceof the

InstructionsSafety

TrafficManagement

VehicleManagement



Road Traffic

• Automatically SupervisedInstructions, Indications (Lights)

• Control mechanisms esure, thatdangerous traffic situation does notappear due to the indications (lights).

• in a case of a failure too.

• Compliance of the instructions is based on a human decision.

• Controlled system-access.

• Nowdays: driver-assistence systems in the vehicles.


• Handling instructions is a human

decision.

• Compliance of the instructions is a

human decision.

• With the aim of:

• supporting systems,

• high-quality education,

• continous training.


Air Traffic



Rail Traffic

• Signalling systems – movement authority:

• automatically supervised signals,

• interlocking systems,

• Compliance of the signals:

• supervised by controlling mechanisms (since 1900s)

• train stopping, train controlling systems.


Automated Systems in the Traffic Management

• Problem:

• How can these systems have the same „competence” like humans (eg. railwaysignallers, air traffic managers), that is ensured by continous training?

• In general:

• If the responsability of a human manager is big, it’s needed more stringenttraining requirements.

• In the case of technical systems:

• If the risk reduction role of a given system is big, it is strictly forbidden toallow to miss its given tasks,

• so we need a high-level of the safety.


Inherent Safety of the Safety-Critical Process Control

Systems

• Safety Functions:

• Functionality of the safety-criticalprocess control and protection systems.

• The risk in the process controlled is reduced by safety functions.

• The safety functions protect against theexternal hazards.

• Safety Integrity:

• The inherent safety of the equipment.

• The process controlled has to be adequately protected from the internal hazards of the control system.

• How big has to be the degree of theprotection?

Summary

• The risks of the transportation systems are bigger, than the sociallytolerable risk,

• that’s why the application of the risk reducing systems is required.

• These systems are safety-critical systems, if it’s allow to miss itsgiven tasks, hazards will appear.

• It is needed to claim higher rquiremets against to the safety-criticalsystems.

• Other interesting chapters:– safety of the vehicle control systems,

– risks of the autonomous vehicles.

Safety, Hazard, Risk 2009/04/2018

Source of Hazards, Hazards


Expectations Against the Transportation System

The importance of each factor is relative,

but safety is always in the first place.

Safety-Critical Process Control Systems in the Transportation

- vehicle – controlling systems

- traffic management systems

- other systems (eg. power supply management systems)

Expectations

• costs

• frequency

• speed

• travel speed

• safety

• reliability

• level of comfort

• etc..

compliance with expectations: efforts (costs)

attractiveness


Safety-Critical Processes

• transport is a hazardous facility, it endangers the safety of:

• persons,

• objects,

• environment

• by causing injuries.

• other hazardous processes:

• chemical processes, energy industry,

• manufacturing processes (production line, industrial robots),

• material handling, warehousing,

• medical tehnologies.

A hazard (def.) is a situation in which there is actual or potential danger to people or to theenvironment.




• Safety:

probability, that there is no hazards (P)

• Accident-free:

probability, that there is no injuries (P, A)

P

A

I

safe state

dangerous state:• the subject of the hazard is exposed

to the danger

• it is a not safe state of the system,

that can lead to an accident.

the source of a hazard is active - „almost”

an accident


injury

accident

technical error, faulty actiona*Δt

b*Δt

09/04/2018


Hazards in the Transportation

• in a case of a single vehicle:• track failure,

• persons, objects on the track, dangerous approach of the track,

• incorrect loading of cargo,

• inappropriate behaviour of passengers,

• vehicle failure,

• changing of the track-vehicle connection,

• driving error.

• in the case of multiple vehicles:• misjudgment of the traffic situation,

• dangerous approach:• from behind,

• frontwise,

• sidewards.

• longer braking distance than the foreseeable distance

• energy supply system of the vehicle

technical or

human error

human error(rarely technical error)

attributions



The rules and tools of the traffic management system exclude or

mitigate the effects of the hazards in some cases, thereby it enables

the travel with higher speed and the better exploitation of the track

capacity

Nonetheless, the errors connected to the traffic management

systems also imply hazards.



• the:

• insufficiency

• incorrect interpretations

• ignoring

• of the traffic control rules

• the:

• lack, deterioration, unnoticed

• incorrect interpretations

• ignoring

• of the traffic signs

• incorrect indication of traffic signalserrors of the traffic management systems

human error

technical errors

human error

human error

human error


Possible Hazards (External and Internal)

• The

• systematic failure – human based:

• HW,

• SW

• random failure :

• HW,

• of a component of the system.

• The:

• functionality;

• normal operating mode;

• error states;

• emergency mode;

• misuse;

• interfaces;

• operation, maintenance and servicing;

• scrapping;

• of the system.

• Wrong human action during:

• the designing process,

• the operation:

• passengers,

• staff (operative, maintenance).

• Effects of the

• mechanical,

• electrical,

• meteorological, natural,

• environment.

-------------------------------------------------------

• Intentional hazards - security


Role of the Process Control Systems

controlled processes

(transportation, vehicle)

process control systems

environmental effects

control functions

safety functions

external hazards

internal hazards


Hazard Identification – (not the part of the curriculum!)

• Analytical techniques (systematic procedures)

• based on checklists,

• breakdown the system to smaller units,

• based on the functions.

• Based on the identified hazards:

• identification (eg. sequence number),

• designation of the hazards,

• causes of the hazards,

• possible outcome: accident


the source of a hazard is active

P

A

a technical error, faulty action, environmental effects

Determination of the events that lead to a hazardous situation


Hazard Analysis– (not the part of the curriculum!)

• Analytical techniques (systematic procedures):

• failure modes and effects analysis – FMEA - https://www.youtube.com/watch?v=BZWuUn93Sq4&t=735s

https://www.youtube.com/watch?v=BZWuUn93Sq4&t=735s




• failure modes effects and criticality analysis – FMECA – with criticality




• hazard and operability studies– HAZOP – https://www.youtube.com/watch?v=AYtBUkjbVWc

https://www.youtube.com/watch?v=AYtBUkjbVWc




• event tree analysis – ETA – https://www.youtube.com/watch?v=mPC-CjCOrvs

https://www.youtube.com/watch?v=mPC-CjCOrvs




• fault tree analysis – FTA – https://www.youtube.com/watch?v=rg0CrfXk304

https://www.youtube.com/watch?v=rg0CrfXk304

Safety Risk


Safety Risk

• The significance of a hazardous effect in an application is called „safety risk”.

• Safety risk is the combination of the :

• frequency or probability,

• and the consequence of

• a specified hazardous event.

• The safety risk can be influences other risk parameters.

• The risk can be determined by:

• quantitatively,

• or risk classification/qualitatively.

Severity

Frequency

Risk

End of Lecture 7.

Thank you for your attention!

Documents

Transportation Automation Reliability, Safety and Security ... · Transportation Automation Reliability, Safety and Security in the Vehicle Industry Stipendium Hungaricum 2017/2018