m MOBI CMDM
CMDM docs access
j.m.d - Syn
or
jm9g$Syn
CMDM use cases workbook
https://docs.google.com/spreadsheets/d/16PW-BByHELJ9SFdo7_QWsMXZoCrg5cCy/edit#gid=369050856
CMDM google drive
https://drive.google.com/drive/folders/1q7vjx8A2-f93M78_oWecVjmQvQnKW83E
Key Points
References
CMDM team
Connected Mobility & Data Marketplace Core team .xlsx
Key Concepts
add a Google doc to Confluence - gdocs-ex
use case dependencies
users, orgs, accounts, orders, sales, returns, payments, delivery
payment model - item, purchase, buyer, seller, payer, payment, delivery method, status, order, escrow payment ??
order life cycle
infra - net, protocol, accts - authn, authz rbac, bank - ach or tokens
wallets
Data Quality standards for Data Services
SOC 2 Data Quality Standard
https://www.imperva.com/learn/data-security/soc-2-compliance/
SOC 2 is an auditing procedure that ensures your service providers securely manage your data to protect the interests of your organization and the privacy of its clients. For security-conscious businesses, SOC 2 compliance is a minimal requirement when considering a SaaS provider.
Developed by the American Institute of CPAs (AICPA), SOC 2 defines criteria for managing customer data based on five “trust service principles”—security, availability, processing integrity, confidentiality and privacy.
Notes
cmdm 200114 - use case reviews in detail
signed up for external temperature sensor
meeting notes
cmdm.191210 - William Whyte - Qualcomm - V2X communications
Today, we had William Whyte from Qualcomm come and deliver a presentation. Below are the notes from that presentation.
- Core concerns around v2x are security and privacy. How do we prevent hackers and terrorists from causing mass damage? How do we trust information? How will we ensure the privacy of location and movement?
- Things between v2x and connected vehicles are becoming blurred. His work has been primarily v2x - sending messages to vehicles, etc.. If you move deeper into applications, there are many applications that require a cellular internet connection (weather data reporting, for example).
- Vehicle’s sensors are vulnerable to failure (weather, degradation, etc.), so while many modern vehicles have robust anti-accident features, they rely on these vulnerable sensors. V2x assists here.
- Regardless of the communication protocol you use, the real question is if you can communicate with the latency and other requirements that you need. With ……, the answer is yes.
- There have been examples of people being convicted by having alibis overturned by their toll tags showing their alibi is wrong. Clearly, there are privacy issues to consider.
- Communication security
- It’s really about access control. You have a system, which can alert the driver. You are trying to access the resources to raise that alert. So it’s a good model for security here.
- Two different access control models:
- Network access controls - identity based. Present name and password, validates the pair, and then doles out the access rights.
- In v2x, it isn’t like that. Latency is critical when looking at safety. If you get another car’s identity, you don’t want to go to the cloud to send a message. You want to send it on the ground.
- 1609.2 certs come in here.
- Example: BSM Sending
Bottom line is that the car has a certificate to validate that they can send a message. If they send a signal preemption message, the cars will reject it, as their certificate does not provide them such access.
Certificate more specifically whether the car is entitled to use its private key to sign that kind of message. - IEEE 1609.2 certificates.
Transmit authorizations, not identities. Authorizations are indicated by Provider Service Identifier (PSID) and Service Specific Permissions (SSP)
Certificates are issued by a Certificate Authority. This is sufficiently secure and easily verifiable. - Sidebar: if you use the same certificate, you can be tracked by its use. Solution? Issue each vehicle a large number of certificates (100 or more per week). Even the CA doesn’t know which certificates go together.
- Linkability exists in other cases. Aggregating vehicle data is one vulnerable area.
- Example: evacuation. Evacuation message > web server > phone app, or Evacuation message > RSU > OBU. For the phone example, it’s pretty easy, as identity is already established. With vehicles, it’s a bit more complicated.
- Day 1 v2x applications about observing events and sharing messages between vehicles. These messages have short periods of relevance. Blockchain does not fit well there, but perhaps in future applications there will be.
Outside of blockchain, how would you handle misbehavior reporting? Where does that information gets stored? You need to create a behavior model for a vehicle.
The thing about that question is that it’s easy to answer how I think that should be done. If you get more than a threshold number of reports, each report weighted for the kind of misbehavior, then that would partly address. Include other protections like rejecting a message sent by multiple parties at multiple locations.
Action item: MOBI to research IEEE 1609.2
Vehicle Security and Certificate Management Concepts
IEEE 1609.2 overview
client - server TLS communications for vehicles
https://tools.ietf.org/id/draft-msahli-ipwave-extension-ieee1609-00.html
William Whyte - 2017 presentation on v2x communication standard 16092
https://www.slideshare.net/OnBoardSecurity/certificate-management-protocols-for-16092-certificates
Secure Certificate Management System for Vehicles
pdu = physical data unit = packet
psid = process id for pdu
what is an implicit certificate?
https://www.certicom.com/content/certicom/en/code-and-cipher/explaining-implicit-certificate.html
implicit certificates are made up of three parts: identification data, a public key and a digital signature which binds the public key to the user’s ID data and verifies that this binding is accepted by an authority (or trusted-third-party).
Within a conventional certificate, the public key and digital signature are distinct data elements. In contrast, the public key and digital signature are ‘super imposed’ in implicit certificates and allow the recipient to extract and verify the public key of the other party from the signature portion. This substantially reduces the bandwidth required as there is no need to transmit both the certificate and the verification key.
As devices proliferate and become more mobile, managing relationships between them will be critical. Devices will move in and out of range of each other and can interact using wireless protocols and peer-to-peer connections, taking advantage of temporary or semi-permanent secure connections to share information and access services.
Using digital certificates is considered the best-known method of establishing identity in network communications. A certificate provides a binding between identity information and a public key; a key pair can subsequently be used for key exchange to set up secured communications and for digital signatures, to validate transactions.
However, digital certificates can represent a substantial investment, both in infrastructure (to protect the keys used), memory (to store and manipulate the certificate), and bandwidth (in repeatedly transferring the certificate to various entities). Implicit certificates, known in the cryptographic community but not widely used, are smaller and faster than those in common use. Implicit or “bullet certificates” can enable a low-resource trust model for resource-constrained settings, ad-hoc networks and applications requiring printed certificates. They can also enable applications in these special situations that will not work using conventional certificates.
cmdm.191029 - use case review
mobi.cmdm>
A>- charter review
- use case review
which are important
data sources ... models
vehicles, users, connections, sensors, orgs ( associated )
smart data
when data not recognized how to handle with human or reprocess
ML use cases
I> what mobility data is available from what sources now?
I> is the data recognized?
I> is the data normalized for the training use case?
I> is the sensor calibrated?
roger berg - review existing stds - denso
assoc for std of automation measurements ... europe ...
oems, suppliers, svc providers
autosar, iso basis for the stds
ocean - chalid mannaa
ocean does not have av data now
data set directories, management
kaggle data sets - see what they have now that's relevant
private vs public issues ( see insurance co for underwriting db )
univ of pitt
certified data sets have custody details
V> normalize, define data stds, certified data mgt stds ( custody etc)
V> data quality remediation based on source quality
sukesh tedia - unbiased data marketplace for data sets
can the data be trusted ? shared ?
certified data ?
useful, compliant, valid, certified
data X is transformed to data Y for a purpose
data source, data events, data collection ( push, pull ),
annotated data sets with metadata, performance metrics
data quality, calibration, normalization, anonymization,
related context, bc for custody of data,
certified data sets
I> how data will be consumed ??
function runs where data is or move aggregates
payment model - item, purchase, buyer, seller, payer, payment, delivery method, status, order, escrow payment ??
order life cycle
infra - net, protocol, accts - authn, authz rbac, bank - ach or tokens
wallets
cmdm191203 - meeting
- Spoke with William Whyte from Qualcomm. He worked in v2x, lots of standardization experience. He’ll be coming and presenting on December 10th during the standard CMDM meeting time. We’ll be sending out links to the consortium and the standard for reading material. (LH)
- We left off at the Ocean Protocol use cases, however, this seems to be in the application level. (LH)
- Does blockchain apply? Yes, but very similar to other use cases, as it’s really just providing the distributed marketplace for the services. (RB, LH)
- This is done already without blockchain, so why does blockchain provide value? Blockchain provides value here by providing provenance on what has been changed, IE, version control in a transparent way. (RB, MV)
- Use case: v2x data exchange for traffic management.
- This use case is very relevant to MOBI, given our focus on coordinated mobility.
- The MOBI process is standard —> proof of concept. At that level, I don’t mind going use case by use case, as we’ll have to pick a few at the end. Since the first output is a standard. (MF)
- Use case: buying and selling services
- Decouple the payment and the payment logic. Have automated sharing of contextual information for payments. (TH)
- This seems like this would be largely covered by VID. (LH)
- There are many services that go beyond what would be covered in VID. Basic vehicle info is covered, but many use cases will demand real-time telematics data. (MV)
- Add in more details, perhaps from the parking work you’re doing with r3 (LH)
- Use case: accurate driving history
- This is largely covered by UBI. (LH)
- Use case: direct and instantaneous AV to AV communications
- Currently, AVs communicate like humans do (turn signals, etc.). They can exchange information much more effectively by sending each other data. (TH)
- Blockchain would come in when cars from different makes and models. The p2p connection would make it much easier to integrate between the walled gardens of each automaker. (TH)
- Let’s ask William Whyte how they achieve this type of use case without DLT. (LH)
- Use case: Securing AV streaming data/their data pipelines.
- This is partially covered by UBI. (LH)
- Touched on this a few calls back - have the car validate the data as it generates it and sends it off. (BD)
- What about spoofing the data? You don’t need a catastrophic sensor failure for a failure to occur. (MV)
- Bring in other data at that point. Where/when was it created? Do the timestamps make sense? Use machine learning and other techniques to determine that the actor is malicious. (BD)
- Use case: Automated vehicle systems health checks.
- Does this go beyond basic health checks? (IE, engine in good condition, brakes functioning, etc.? Error codes already exist. (LH)
- The current level of engineering in vehicle systems is limited. In bad weather conditions, the car just complains at me. Intelligent fault tolerance is key. The use case here may be embedded in other use cases. (JM)
- Are there issues around privacy for OEMs to share data like this?
- Yes, but that may not be a damning problem soon as the legal and cultural values shift (MV)
- VW is already rolling this out right now where the data is shared. (MV)
- Does this go beyond basic health checks? (IE, engine in good condition, brakes functioning, etc.? Error codes already exist. (LH)
- Consent management for drivers
- Perhaps I need to be legally notified or asked if data is to be harvested from my vehicle. We need to check for consent for each “ask” we make of the driver or vehicle owner. (JM)
- Have you seen this worked on? (LH)
- Yes, in healthcare. All they do is leverage the same infra on the vehicle side. Wallets, ID, etc.. These are likely application level. (JM)
- Increasing the accuracy of location services.
- Sensors and GPS can be low accuracy. But what’s the blockchain application? (LH)
- What type of sensors are out there? We should start populating a sheet with all the potential sensors out there - how do we bucketize them? What are the underlying technologies? (MV)
Action items to prepare for next week: Read on the V2I work below and prepare questions for William Whyte:
USDOT/CAMP Connected Vehicle Infrastructure Technology Demonstration Landing Page link: http://campv2itechreview.com/
Car-2-Car Communications Consortium Website link: https://www.car-2-car.org/
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cmdm191210 - meeting
resources
https://standards.ieee.org/standard/1609_2-2016.html
EAST-ADL -auto architecture modeling language
https://www.maenad.eu/public/conceptpresentations/EAST-ADL_WhitePaper_M2.1.12.pdf
The four abstraction levels covered by the EAST-ADL are (see Figure
- Vehicle Level Feature trees characterizing the vehicle content as it is perceived externally.
- Analysis Level An abstract functional architecture defining systems from a functional point of view.
- Design Level The detailed functional architecture allocated to a hardware architecture.
- Implementation Level The implementation of the embedded system represented using AUTOSAR elements
The EAST-ADL language is formally specified as a meta-model that captures domain specific (i.e. automotive) concepts. The meta-model follows guidelines originating from AUTOSAR for definition of templates. Modeling concepts are represented by the basic notions of MOF(www.omg.org/mof/) supplemented by the AUTOSAR template rules[2]. The meta-model thus fits as a specification of a domain specific tool environment, and also defines an XML exchange format. This domain model represents the actual definition of the EAST-ADL language and constitutes the heart of the EAST-ADL language specification.
AUTOSAR is the implementation layer now
the EAST-ADL language is also implemented as a UML2 profile. UML profiles are standard extension mechanisms in the UML2 language, in which domain-specific concepts are provided as tags applicable to a selected subset of UML2 elements (such as classes, properties, ports, etc.) giving them different meaning and extra properties. The profile allows users to do system modeling according to the EAST-ADL semantics by using off-the-shelf UML2 tools.
AUTOSAR for electronic systems design
https://en.wikipedia.org/wiki/AUTOSAR
AUTOSAR provides a set of specifications that describes basic software modules, defines application interfaces and builds a common development methodology based on standardized exchange format. Basic software modules made available by the AUTOSAR layered software architecture can be used in vehicles of different manufacturers and electronic components of different suppliers, thereby reducing expenditures for research and development and mastering the growing complexity of automotive electronic and software architectures.[3]
Based on this guiding principle, AUTOSAR has been devised to pave the way for innovative electronic systems that further improve performance, safety and environmental friendliness and to facilitate the exchange and update of software and hardware over the service life of the vehicle. It aims to be prepared for the upcoming technologies and to improve cost-efficiency without making any compromise with respect to quality
The AUTOSAR Classic Platform architecture distinguishes on the highest abstraction level between three software layers that run on a microcontroller: application, runtime environment (RTE) and basic software (BSW). The application software layer is mostly hardware independent. Communication between software components and access to BSW happens via RTE, which represents the full interface for applications.
Relation of EAST-ADL to AUTOSAR
https://en.wikipedia.org/wiki/EAST-ADL
Instead of providing modeling entities for the lowest abstraction level, i.e. implementation level, EAST-ADL uses unmodified AUTOSAR entities for this purpose and provides means to link EAST-ADL elements on higher abstraction levels to AUTOSAR elements. Thus, EAST-ADL and AUTOSAR in concert provide means for efficient development and management of the complexity of automotive embedded systems from early analysis right down to implementation. Concepts from model-based development and component-based development reinforce one another.
An early, high-level representation of the system can evolve seamlessly into the detailed specifications of the AUTOSAR language. In addition, the EAST-ADL incorporates the following system development concerns:
- Modeling of requirements and verification/validation information,
- Feature modeling and support for software system product lines,
- Modeling of variability of the system design,
- Structural and behavioral modeling of functions and hardware entities in the context of distributed systems,
- Environment, i.e., plant model and adjacent systems, and
- Non-functional operational properties such as a definition of function timing and failure modes, supporting system level analysis.
The EAST-ADL metamodel is specified according to the same rules as the AUTOSAR metamodel,
Microsoft modeling of view logical architecture
https://pdfs.semanticscholar.org/85b6/00ad4d1e0486c33b95b76ee50336bb7e8bc6.pdf
Several divisions / teams are responsible for various features•Feature= functionality perceptible by customers and/or engineer (e.g. braking system)•aka serviceRequirementsfor features captured mainly textually (using e.g. DOORS)Specification of software architecture, description of hardware architecture (ECUs and busses), mappingrequirements for featureslogical architecturesoftware architecturetechnical architecture......realizationDOORSAUTOSARMethodolog
How Car computers work
https://auto.howstuffworks.com/under-the-hood/trends-innovations/car-computer5.htm
smart sensors
Clusters are now being used on a smaller scale for sensors. For instance, a traditional pressure sensor contains a device that outputs a varying voltage depending on the pressure applied to the device. Usually, the voltage output is not linear, depends on the temperature and is a low-level voltage that requires amplification.
Some sensor manufacturers are providing a smart sensor that is integrated with all the electronics, along with a microprocessor that enables it to read the voltage, calibrates it using temperature-compensation curves and digitally outputs the pressure onto the communications bus.
This saves the carmaker from having to know all the dirty details of the sensor, and saves processing power in the module, which otherwise would have to do these calculations. It makes the supplier, who is most up on the details of the sensor anyway, responsible for providing an accurate reading.
Another advantage of the smart sensor is that the digital signal traveling over the communications bus is less susceptible to electrical noise. An analog voltage traveling through a wire can pick up extra voltage when it passes certain electrical components, or even from overhead power lines.
Electrical Power Basics
What is Electrical Power?
Electric Current
https://circuitglobe.com/electric-current.html
Electric current is defined as the rate of flow of negative charges of the conductor. In other words, the continuous flow of electrons in an electric circuit is called an electric current. The conducting material consists a large number of free electrons which move from one atom to the other at random
Current vs Voltage
https://www.diffen.com/difference/Current_vs_Voltage
Current is the rate at which electric charge flows past a point in a circuit. In other words, current is the rate of flow of electric charge. Voltage, also called electromotive force, is the potential difference in charge between two points in an electrical field. ... Current is the effect (voltage being the cause).
Voltage
https://simple.wikipedia.org/wiki/Voltage
Voltage is what makes electric charges move. It is the 'push' that causes charges to move in a wire or other electrical conductor. ... Voltage is also called, in certain circumstances, electromotive force (EMF). Voltage is an electrical potential difference, the difference in electric potential between two places.
Ampere
https://www.techopedia.com/definition/4653/current
Current is the flow of electrical charge carriers like electrons. Current flows from negative to positive points. The SI unit for measuring electric current is the ampere (A). One ampere of current is defined as one coulomb of electrical charge moving past a unique point in a second.
Current is measured in amps
https://www.softschools.com/formulas/physics/electric_current_formula/520/
It is measured in amperes (A). Electric current = Voltage / Resistance. The equation is: I = V/R.
where I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.[3] Ohm's law is an empirical relation which accurately describes the conductivity of the vast majority of electrically conductive materials over many orders of magnitude of current
https://www.autozik.com/how-many-amps-is-a-car-battery/
A typical car battery with 12 volts rating has a capacity of 48 Ah.
AC Power - Active vs Reactive
https://en.wikipedia.org/wiki/AC_power
Power in an electric circuit is the rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals of the direction of energy flow.
The portion of power that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as active power (more commonly called real power to avoid ambiguity especially in discussions of loads with non-sinusoidal currents). The portion of power due to stored energy, which returns to the source in each cycle, is known as reactive power.
Current - Volt-Ampere
https://en.wikipedia.org/wiki/Volt-ampere
With a purely resistive load, the apparent power is equal to the real power. Where a reactive (capacitive or inductive) component is present in the load, the apparent power is greater than the real power as voltage and current are no longer in phase. In the limiting case of a purely reactive load, current is drawn but no power is dissipated in the load.
Some devices, including uninterruptible power supplies (UPSs), have ratings both for maximum volt-amperes and maximum watts. The VA rating is limited by the maximum permissible current, and the watt rating by the power-handling capacity of the device.
Watts
https://en.wikipedia.org/wiki/Watt
Electric Power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Electric power is usually produced by electric generators, but can also be supplied by sources such as electric batteries.
The watt (symbol: W) is a unit of power. In the International System of Units (SI) it is defined as a derived unit of 1 joule per second,[1] and is used to quantify the rate of energy transfer. In SI base units, the watt is described as k g m 2 s − 3 {\displaystyle kg\,m^{2}s^{-3}} , which can be demonstrated to be coherent by dimensional analysis.[
When an object's velocity is held constant at one meter per second against a constant opposing force of one newton, the rate at which work is done is one watt.
1 W = 1 J s = 1 N ⋅ m s = 1 k g ⋅ m 2 s 3 {\displaystyle \mathrm {1~W=1~{\frac {J}{s}}=1~{\frac {N{\cdot }m}{s}}=1~{\frac {kg{\cdot }m^{2}}{s^{3}}}} }
In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the volt-ampere (the latter unit, however, is used for a different quantity from the real power of an electrical circuit).
1 W = 1 V ⋅ 1 A {\displaystyle \mathrm {1~W=1~V\cdot 1~A} }
Two additional unit conversions for watt can be found using the above equation and Ohm's law.
1 W = 1 V 2 Ω = 1 A 2 ⋅ Ω {\displaystyle \mathrm {1~W=1~{\frac {V^{2}}{\Omega }}=1~A^{2}{\cdot }\Omega } }
Where ohm ( Ω {\displaystyle \Omega } ) is the SI derived unit of electrical resistance.
- A person having a mass of 100 kilograms who climbs a three-meter-high ladder in five seconds is doing work at a rate of about 600 watts. Mass times acceleration due to gravity times height divided by the time it takes to lift the object to the given height gives the rate of doing work or power.[i]
- A laborer over the course of an eight-hour day can sustain an average output of about 75 watts; higher power levels can be achieved for short intervals and by athletes.[3]
How do Car Electrical Systems Work?
knowhow.napaonline.com/car-electrical-system-basics/
Batteries provide power to vehicles
To power something like a motor, we have developed man made chemical cells with high electric potential: batteries. Batteries in turn lend power to starting, charging and security systems, lights, ABS, computers, sensors, climate control and onboard accessories
Current is AC or DC
There are two types of electricity, alternating current (AC) and direct current (DC). When batteries discharge they emit a constant DC power in one direction, supplying electricity through the positive terminal to the negative. Most automotive components require this DC charge to work properly, but it is limited because batteries will eventually discharge completely, with no remaining power to give.
Alternators
To address this problem, cars also have alternators. Alternators are actually small generators capable of turning mechanical into electrical energy. Driven by the engine belt, alternators use a small signal from the battery to energize a field current that turns a rotor inside a set of stators. Since this energy is driven by the polarity of magnetic fields, the current produced as a result changes direction as the rotor turns, producing current in opposite or alternating directions (hence AC). Alternators produce significantly higher currents than initially supplied by the battery, so they are used to recharge the battery itself and power other electrical components.
How do Batteries Work?
https://www.science.org.au/curious/technology-future/batteries
https://www.quora.com/Is-a-car-battery-AC-or-DC-volts
The battery outputs Direct Current ( DC )
When paired with an AC Converter it can output Alternating Current.
Car battery voltage ranges
A perfect voltage with the engine running is between 13.7 and 14.7V.
With the engine off, you should get a reading of 12.6 volts. If the battery isn’t fully charged,
it will diminish to 12.4V at 75%,
12V when it’s only operating at 25%,
and down to 11.9V when it’s completely discharged.
Battery Sensors
https://www.samarins.com/glossary/battery-sensor.html
Some cars have two sensors, one on each terminal.
How the battery sensor works: it measures the current to and from the battery.
It may also monitor the voltage, state of charge and state of health of the battery (aging).
In some cars, it even measures the temperature of the battery.
High Performance Batteries are more efficient on the working range
https://www.keihin-corp.co.jp/technology/pdf/ti/tec_vol6_file10e.pdf
Battery Management System - BMS
A conventional BMS has multiple components: a battery control unit ( BCU ) cell voltage sensors ( CSV ) and a leakage sensor.
the CSVs for the 12 cells of a battery are in a series connection where cell info is sent to the BCU on a bus. Each cell is controlled by the BCU.
This is a high cost model so an integrated BMS combines the BCU, CSVs and leakage sensor into 1 unit.
Voltage sensors
https://www.electrical4u.com/voltage-sensor/
What is a voltage sensor ?
A voltage sensor is a sensor is used to calculate and monitor the amount of voltage in an object. Voltage sensors can determine both the AC voltage or DC voltage level. The input of this sensor can be the voltage whereas the output is the switches, analog voltage signal, a current signal, an audible signal, etc.
Sensors are basically a device which can sense or identify and react to certain types of electrical or some optical signals. Implementation of voltage sensor and current sensor techniques have become an excellent choice to the conventional current and voltage measurement methods.
Ohm's Law
Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance,[1] one arrives at the usual mathematical equation that describes this relationship:[2]
I = V R , {\displaystyle I={\frac {V}{R}},}
where I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.[3]
https://en.wikipedia.org/wiki/Ohm%27s_law
The advantage of voltage sensors include:
- Small in weight and size.
- Personnel safety is high.
- Degree of accuracy is very high.
- It is non-saturable.
- Wide dynamic range.
- Eco-friendly.
- It is possible to combine both the voltage and current measurement into a single physical device with small and compact dimensions.
Types of Voltage Sensors
In this article, we can discuss in detail about voltage sensor. A voltage sensor can in fact determine, monitor and can measure the supply of voltage. It can measure AC level or/and DC voltage level. The input to the voltage sensor is the voltage itself and the output can be analog voltage signals, switches, audible signals, analog current level, frequency or even frequency modulated outputs.
That is, some voltage sensors can provide sine or pulse trains as output and others can produce Amplitude Modulation, Pulse Width Modulation or Frequency Modulation outputs
n voltage sensors, the measurement is based on a voltage divider. There are two main types of voltage sensors are available- Capacitive type voltage sensor and Resistive type voltage sensor.
Capacitive Voltage Sensor
As we know that a capacitor comprises of two conductors or simply two plates and in between these plates, a non-conductor is kept. That non-conducting material is termed as dielectric. When an AC voltage is provided across these plates, current will start to pass owing to either the attraction or the repulsion of electrons by means of the voltage present on the opposite plate. The field among the plates will create a complete AC circuit without any hardware connection. This is how a capacitor works.
Next, we can discuss about the voltage division in two capacitors which are in series. Usually in series circuits, high voltage will develop across the component which is having high impedance. In the case of capacitors, capacitance and impedance (capacitive reactance) are always inversely proportional.
The relation between voltage and capacitance is
Q → Charge (Coulomb)
C → Capacitance (Farad)
XC → Capacitive reactance (Ω)
f → Frequency (Hertz)
From the above two relations, we can clearly state that the highest voltage will build up across smallest capacitor. The capacitor voltage sensors work based on this simple principle. Consider we are holding the sensor in our hand and then placing the tip of it near a live conductor.
Resistive Voltage Sensor
There are two ways in converting the resistance of the sensing element to the voltage. First one is the simplest method that is to provide a voltage to the resistor divider circuit comprises of a sensor and a reference resistor which is represented below.
The voltage that is developed across the reference resistor or sensor is buffered and then given to the ADC. The output voltage of the sensor can be expressed as
The drawback of this circuit is the amplifier present here will amplify the whole voltage developed across the sensor. But, it is better to amplify only the voltage change due to the change in resistance of the sensor. This is achieved by the second method implementing the resistance bridge which is shown below.
Here, the output voltage is
When R1 = R, then output voltage becomes approximately
A → Gain of Instrumentation Amplifier.
voltage sensor applications
The application of voltages sensors include:
- Power failure detection.
- Load sensing.
- Safety switching.
- Temperature control.
- Power demand control.
- Fault detection.
Voltage sensors are included in many of the best arduino starter kits, as they are very useful in many electronics projects.
Categories of Voltage Sensors on Vehicles
https://mechanicbase.com/engine/car-sensors/
Pressure Sensors - convert pressure to an analog voltage
https://www.variohm.com/news-media/technical-blog-archive/working-principle-of-a-pressure-sensor
A pressure sensor works by converting pressure into an analogue electrical signal.
we measure pressure electronically using pressure transducers and pressure switches
static Pressure (P), is calculated as force (F) divided by area (A).
P=F/A
How pressure sensors work
Pressure transducers have a sensing element of constant area and respond to force applied to this area by fluid pressure. The force applied will deflect the diaphragm inside the pressure transducer. The deflection of the internal diaphragm is measured and converted into an electrical output. This allows the pressure to be monitored by microprocessors, programmable controllers and computers along with similar electronic instruments.
Most Pressure transducers are designed to produce linear output with applied pressure.
resources
https://www.mpoweruk.com/soc.htm
Why different voltage sensors on vehicles operate differently
Now to the 5.0 v reference voltage. A vehicle ignition and fuel system will operate on voltages as low as about 10 volts. If an 11.0 reference voltage is used and there is a problem with the battery or charging system and voltage begins to go down and the sensors begin to send invalid signals. This can cause fuel and ignition problems which in turn can cause damage to the catalytic converter.
As I said 9.0 volts was a reference voltage before 5.0 became the standard. There are no ignition or fuel systems that will operate on 5.0 volts. It was possible for some engines to run on 9.0 volts. During a battery or charging system malfunction, as the voltage decreases the sensor data is valid, until the engine shuts off due to the ignition and/or the fuel system stopping due to the low voltage. Thereby, the engine ran efficiently until it died. Causing no damage to the catalytic converter.
Many sensors are fed the 5.0 volt reference voltage and return a voltage signal proportional to whatever parameter it is monitoring. This signal from the sensor is compared to the data stored in the computer memory. In this way the sensor data is converted to temperature, position or speed information. This information is in turn used to operate the fuel, ignition and emission system. As well as transmission operation and even things such as climate control and brake system for example.
SAE Vehicle Standards including voltage
https://www.sae.org/binaries/content/assets/cm/content/standards/p90475.pdf
SAE-vehicle-standards-p90475.pdf
Potential Value Opportunities
Applications, Infrastructure sensors for Waste management
a> waste mgt sensor research ..
weight when can picked up ???
visual camera when can picked up ???
other ???
n> study - net value of smart waste in different types of communities
city, poor suburb, rich suburb
Presentation Pages for Waste Management Sensors
Waste Management
Detection of rubbish levels in containers to optimize the trash collection routes
goal
target higher value waste mgt applications
- Boston parking, not Providence parking
- campus trash pickup vs residential pickup
- where high trip reductions possible
- expensive trash - eg oil field waste water pickups
keys ..
iot, networking, distributed data, sometimes blockchain
https://www.maxbotix.com/articles/how-ultrasonic-sensors-work.htm
https://www.maxbotix.com/articles/smart-waste-management.htm
https://www.maxbotix.com/product-category/all-environments/xl-trashsonar-wr-products
https://www.maxbotix.com/ultrasonic-sensor-hrlv%E2%80%91maxsonar%E2%80%91ez-guide-158
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https://www.youtube.com/watch?v=rGHI8-tpzX0
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https://iotify.help/virtual-lab/smart-trash/index.html
https://github.com/iotify/smarttrash
is it cost justified for a given application?
need to collect data on current solution
retail house pickup
industrial pickup
office pickup
hotel pickups
Waste cans are normally HDPE plastic
How distance sensors work
https://www.maxbotix.com/articles/wireless-distance-sensor.htm
normal distance sensor
long range wireless distance sensor
https://www.maxbotix.com/articles/long-range-wireless-tank-sensor.htm
How ultrasonic sensors work
https://www.maxbotix.com/articles/how-ultrasonic-sensors-work.htm
waste-mgt-ultrasonci-sensors-maxbotix.com-Understanding How Ultrasonic Sensors Work.pdf
Ultrasonic sensors with cellular communications
https://www.maxbotix.com/articles/smart-waste-management.htm
ultrasonic sensor w some communication ( bluetooth? cellular ?)
https://www.maxbotix.com/archive.htm
Where does it pay to change trash pickup routes?
The bins with the highest potential for operational cost reduction with IoT sensors include remotely located and far apart containers, bins with versatile filling patterns, and bins that hold high-value recyclables. In order to delay collecting the bins until they are at least 90% full, it is also better for the containers to hold non-decomposing materials. Ideal targets include also bins with difficult access, as well as large overground and underground containers, silos and tanks.
waste-mgt-ibm-test-iotify.help-Smart Trash Can.pdf
https://iotify.help/virtual-lab/smart-trash/index.html
The measurement of Trash can fill level could be done by multiple means such as measuring the distance between the lid and trash content level. Another possible measurement could be measuring the weight of the trash can via a load cell (weight sensor). However due to the fact that trash contents could vary in nature (such as solid waste vs plastic or paper) measuring weight could not guarantee an accurate fill level. Therefore measuring empty space remains most practical way to measure the fill contents. It also simplifies the design because all the circuitry could be contained at one place, i.e. the top of trash can.
ecube sonic waste can fill detection
https://www.ecubelabs.com/iot-waste-management-detect-a-full-trash-can-remotely/
waste-mgt-sonce-detector-ecubelabs.com-IoT waste management detect a full trash can remotely.pdf
One of the leading solution providers of IoT waste management sensors is a South Korean company called Ecube Labs, which provides not only fill-level sensors and a smart waste collection optimization platform, but also IoT based solar-powered waste compacting bins.
solar powered trash compactors
https://www.ecubelabs.com/solar-powered-trash-compactor/
waste-solar-powered-trash-compactor-1.pdf
Biological Sensors for Health Management
Who needs to prove something is clean at a point in time?
- healthcare facilities
- public facilities
- restaurants
- stores
- delivery services
- transportation facilities
- shipping facilities
- schools
- campuses
Who needs to prove that someone had contact at a point in time?
- People working, travelling, visiting etc
What types of sensors apply for biological use cases?
thermal for people
virus sensors for surfaces
location for contact tracing history
Virus detection sensor technology
https://www.sensortips.com/featured/what-sensors-are-used-to-detect-the-coronavirus/
Infrared thermal sensors and cameras
Thermography is the front-line sensing technology to detect and isolate victims of the coronavirus (COVID-19). The non-contact thermal sensors have been ubiquitous over the past few weeks as the numbers of those contracting the virus and dying as the result of it have risen. Accuracy of the infrared (IR) thermometer gun’s measurements depends on several factors from proper operation (the right distance from the person’s forehead) to environmental factors, including recent exertion by the person being measured to temperature suppression due to taking drugs as well as their usage outside of carefully controlled health care settings.
A far more accurate technique uses infrared cameras. For example, Infrared Cameras Inc. (ICI) line of medical thermal infrared cameras have FDA 510(k) Clearance for medical use. Offering two fever detection systems priced at $5,000 and $10,000, the P-Series IR Camera is a 640 x 512 radiometric imager. The camera operates on less than 1 watt of power and uses a USB 2.0 connection to provide real time radiometric data streamed directly to a display.
Unlike the hand-held thermometer guns, the screening process involves the person being screened to stand still, look into the camera and remove any distraction such as a cap or glasses. The display includes a blackbody object for known level of infrared emissions. They provide accurate skin surface temperature readings from the first 1/1000th inch of epidermal layer.
ICI also offers a non-contact thermometer gun that costs about $25. With their gun, readings can be taken as close as 5 cm or as far as 15 cm from the target and achieve a display resolution of 0.1 °C (0.1 °F).
Mobile health tracking in smart phones
Google, Apple adding tracing data to POS
https://www.cnet.com/news/how-youll-get-apple-and-googles-contact-tracing-update-for-your-phone/
For Google, the update to enable the tracking tools won't be like a normal operating system upgrade. It will instead come through a set of tools called Google Play Services, which lets Android sidestep some fragmentation issues by pushing updates directly, without the approval of device and wireless partners. The company normally uses Google Play Services to update its own apps, like Gmail and Maps, and to push changes like a new app icon. The contact tracing tools will be available for phones running software as old as Android Marshmallow, the version of the operating system released in 2015
Potential Challenges
questions
- will all OEMs, other providers deliver OTA subscriptions for services to vehicles ( like Tesla's $6K self driving upgrade )?
- is there a standard bus architecture that is redundant for all vehicle systems coming in the future? who's working on the new bus now as stds?
Candidate Solutions
companies to review
- Microsoft
- Aptiv
- Harman
- ZF industries
- BMW
- qualcomm
- nvidia
- nxp semi - cloud gateway chip for cellular ( or wifi ? )
Step-by-step guide for Example
sample code block