automated-greenhouse climate-controlled eco system (aces) · automated-greenhouse...

Johns Hopkins University | Systems Engineering Master’s Project | May 7, 2016

Miku White

Automated-Greenhouse Climate-Controlled Eco System (ACES)

Biography Project Objective Systems Engineering Approach System Introduction & Need Project Deliverables

– Requirement Analysis – Functional Analysis – Conceptual Design – Trade Study – Test Plan – Risk Management – System Specification

Schedule Assessment Lessons Learned

Agenda

2

Born and raised in Tokyo, Japan

B.A. in Mathematics and Computer Science – Notre Dame of Maryland University (2010)

Naval Air Systems Command (NAVAIR) – Operations Research Analyst – AIR 4.10 Warfare Analysis and Integration Department (2010 – 2014) – AIR 4.1.8 Combat Survivability Division (2015 – Present)

Hobbies/Interests – Playing tennis – Cooking – Traveling – Playing fetch (with my dogs) – Learning foreign languages

Biography

3

Demonstrate Systems Engineering (SE) knowledge through application of the SE process from an initial concept through system specification development

Project Objective

4

Concept Development Stage – Need Analysis Phase – Concept Exploration Phase – Concept Definition Phase

Systems Engineering Approach

Requirement Analysis

Functional Analysis

Physical Definition

Design Validation

Objectives

Solution(s)

5

“Transforms needs and requirements for the next level of development”

Iterative Process

System concept idea – Personal Experiences – Research Current greenhouse deficiencies and technical opportunities

One out of three households in the U.S. are now involved in gardening activities (U.S. National Gardening Association)

Need exists for a system that automate gardening activities with minimal user involvement required – Allows user to keep their garden alive while they are away from home

Currently available automated climate-controlled greenhouse is not suitable for the residential use

System Introduction & Need

6

7

Context Diagram – Depicts the

primary items of the system: System External

Interactions – Sources

– Destinations

– Inputs – Outputs

System Introduction

Concept of Operations (CONOPS)

8

Operational Modes: – Gardening

– Maintenance – Training

System Objectives – Based on system needs and

current capability gap identified during Project Proposal

Requirement Definition – Based on research findings, user

interview results, and personal expertise User Interview was conducted.

Interviewees were selected across three demographics

User needs ensure stakeholder’s requirements and expectations

Requirement Analysis OBJ 1.0

To provide safe and reliable autonomous gardening operations to

grow various produces at home

OBJ 1.1 To provide gardening

operations

OBJ 1.2 To provide home-use

capability

TLR 1 TLR 2

Number Name Description Type Rationale

TLR 1.0 Gardening Operation

The system shall provide continuous gardening operations.

Composite Mission Needs

TLR 2.0 Usability / Constraints

The system shall be available and maintainable to provide easy, safe, and reliable operation capability to users.

Composite Mission Needs

9

Requirements organization – Operational, Performance, Functional, and Constraints – Quantitative and Qualitative – Verification method was identified

Inspection Analysis Demonstration Test / Measurement

Key Performance Parameters (KPPs) were identified

Iterative process – Requirements were updated iteratively throughout the conceptual development phase – New requirements were generated and some requirements were combined or eliminated


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Key Performance Parameters (KPPs) : Define the minimum acceptable value achievable operational goals


11

KPP # Number Name Description

1 FNC.1 Accurate Data The system shall provide greenhouse environment data with 95% accuracy (T). (O = 98%)

2 OPR.1 Automation The system shall be capable of performing greenhouse operations without human intervention 95% (T) of the time. (O = 98%)

3 OPR.2.3 System Interoperability with External Device

The system shall be capable of interfacing with a designated paired device to control greenhouse environment remotely. (T = 1 device) (O = T)

4 OPR.3 Continuous Garden Operation The system shall provide continuous gardening operations from the user selected start point, 24 hours/day for 14 consecutive days. (T) (O = 21 consecutive days, 24 hrs/day)

5 OPR.9 Programmed Command The system shall be capable of interpreting and conducting at least 95% of the preprogrammed system commands. (T) (O = 98%)

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Requirements Traceability Matrix (RTM)


Number Name Description Origin Basis Of Refines Refined By Verified By

FNC.1 Accurate Data The system shall provide greenhouse environment data with 95% accuracy (T). (O = 98%)

Derived Function F.4 Perform Greenhouse Gardening Operations

Requirement FNC Functional

System Demonstration System Test/Measurement

OPR.6 Operational Environment

The system shall provide continuous reliable operations in various outdoor environment as follows: - weather/climate (temperature, humidity, wind, precipitation) - outdoor surfaces

Originating Function F.4 Perform Greenhouse Gardening Operations

Requirement OPR Operational

Requirement OPR.6.1 Humidity Requirement OPR.6.2 Operational Surfaces Requirement OPR.6.3 Precipitation Requirement OPR.6.4 Temperature Requirement OPR.6.5 Wind Speed

System Analysis

PRF.7 Electricity The system shall receive power from city provided electricity. (T: 100-240V, 50-60Hz) (O = T)

Derived Function F.1.1 Receive Power Function F.10 Manage Electricity Function F.10.1 Receive Electricity Function F.10.2 Convert Electricity Function F.10.3 Measure Electricity Function F.10.4 Distribute Electricity

Requirement PRF Performance

System Demonstration System Test/Measurement

SFT.1 Hazardous Material and Components

The system shall not contain material or components that would cause any hazardous situation at temperature below 200 degree F. (T) (O = T)

Derived Requirement SFT Safety

System Test/Measurement

Total Requirements: 76 Quantitative: 43 (56.6%) Qualitative: 33 (43.4%)

13

Translating the requirements into system functions – Actions and interactions each level of a system must perform

CONOPS was used to shape functional analysis – 10 High level functions defined – High level functions were decomposed into lower level functions

Interfaces were established – Inputs and outputs were defined for each function

Traceability was checked to ensure each function identified during functional analysis process traced to a requirement and vice versa

Functional Analysis

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Functional Flow Block Diagram (FFBD) Example for Top-Level Function

Functional Analysis

N2 Diagram Example for Top-Level Function – Current (mostly…):

“Tightly Coupled, Loosely Bound” – Ideal:

“Loosely Coupled, Tightly Bound”

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Functional Traceability Matrix

Functional Analysis

Number Name Input Output Based On Decomposes Decomposed By

F.10 Manage Electricity

Item City Electricity Item Managed Power Requirement PRF.7 Electricity

Function F Use ACES System

Function F.10.1 Receive Electricity Function F.10.2 Convert Electricity Function F.10.3 Measure Electricity Function F.10.4 Distribute Electricity

F.10.1 Receive Electricity

Item City Electricity Item Received City Electricity

Requirement PRF.7 Electricity

Function F.10 Manage Electricity

F.10.2 Convert Electricity

Item Received City Electricity

Item Converted Power Requirement PRF.7 Electricity


F.10.3 Measure Electricity

Item Converted Power

Item Measured Power Requirement PRF.7 Electricity


F.10.4 Distribute Electricity

Item Measured Power

Item Managed Power Requirement PRF.7 Electricity


Total Requirements: 76 Total Functions: 129

16

Visualizing the functional architecture of the system – Translating functional design into hardware and software components

Context Diagram defines the system boundary and external interactions

Conceptual Block Diagrams depicts physical designs and interfaces of the system – For each function, one component was assigned – Components were “linked” to show relationships

Conceptual Design

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Preliminary Conceptual Block Diagram – No SW elements

Conceptual Design

18

Conceptual Design

Finalized Conceptual Block Diagram – Incorporated top-level

SW component

– More interactions between ACES and the external elements

– More interactions between external elements

19

ACES Main Computer Unit – Depicts main software

elements

– The use of USB Hub or console control must be considered in order to maximize modularity and simplify interfaces

Conceptual Design

20

Conceptual Design

Number Name Type Performs Connected To

P.6.1.1 Humidity Sensor

HW Element

Function F.4.3.2.2 Monitor Humidity Link ACES Computer - Humidity Sensor Wire Link Plant Area - Humidity Sensor Wire

P.6.1.2 Position Sensor

HW Element

Function F.4.1 Detect Produce / Soil Location Link ACES Computer - Position Sensor Wire Link Plant Area - Position Sensor Wire

P.6.1.3 Soil Moisture Sensor

HW Element

Function F.4.3.1.1 Monitor Soil Moisture Level Function F.6.2.2 Send Soil Moisture Level Information

Link ACES Computer - Soil Moisture Sensor Wire Link Plant Area - Soil Moisture Sensor Wire

Number Name Inputs Outputs Based On Decomposed By

Allocated To

F.4.3.2.1 Monitor Temperature

Item Control Temperature Command Item Decreased Temperature Item Greenhouse Environment Status Item Increased Temperature Item Weather/Climate

Item Measured Air Quality Information

Requirement FNC.2 Air Quality

Function F.4.3.2 Control Air Quality

Component P.6.1.5 Thermometer

F.4.3.2.2 Monitor Humidity

Item Control Humidity Command Item Decreased Humidity Item Greenhouse Environment Status Item Increased Humidity Item Weather/Climate

Item Measured Air Quality Information

Requirement FNC.2 Air Quality

Function F.4.3.2 Control Air Quality

Component P.6.1.1 Humidity Sensor

Total Functions: 129 Total Components: 35 Total Links/Interfaces: 70

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Purpose: Determine the best material solution to satisfy a ACES requirement – Tool used to evaluate alternate concept design

Both informal and formal trade study on ACES computing unit – Informal study was conducted to down select the “type” of computer unit Desktop Computer Laptop Computer Tablet Computer

– Formal study was conducted to down select the optimum laptop to be used as ACES main computing unit

Trade Study

Pre-selected microcomputer “type”

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Applicable requirements and functions – 10 total requirements – Cost is not a requirement

5 Alternatives – Selected from online retailer – User review considered to incorporate customer satisfaction

5 Selection Criteria – Processing Power (CPU): Ability to manipulate data

How fast a computer machine can perform its operation?

– Random Access Memory (RAM): Ability to process tasks simultaneously Temporary storage for computer to access data and retrieve information

– Graphic Processing Unit (GPU): Ability to process scientific, engineering, and analytic applications Works together with CPU

– Weight – Cost

Trade Study

ID Criteria Name Unit

A Processor Power Ghz

B RAM GB

C GPU "Type"

D Weight lbs

E Cost $

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Pair-Wise Comparison – Each selection criterion

was assigned “value”

– Selection weighting factor was computed with and without cost

Trade Study

Processor Power

RAM GPU Weight CostProducts of Row Values

Nth Root of Products of Row

Weighting Factor

Processor Power

1.000 0.333 5.000 8.000 3.000 40.00 2.091279105 0.293769667

RAM 3.000 1.000 5.000 8.000 3.000 360.00 3.245342223 0.455885158

GPU 0.200 0.200 1.000 3.000 3.000 0.36000 0.81519311 0.114513174

Weight 0.125 0.125 0.333 1.000 0.200 0.00104 0.253247842 0.035574656

Cost 0.333 0.333 0.333 5.000 1.000 0.18519 0.713709123 0.100257345

7.118771403 1.000000000TOTAL SUM OF Nth ROOTS

Processor Power

RAM GPU Weight CostProducts of Row Values

Nth Root of Products of Row

Weighting Factor

Processor Power

1.000 0.333 5.000 8.000 13.33 1.910885584 0.31440182

RAM 3.000 1.000 5.000 8.000 120.00 3.30975092 0.544559926

GPU 0.200 0.200 1.000 3.000 0.12000 0.588566191 0.09683797

Weight 0.125 0.125 0.333 1.000 0.00521 0.268642483 0.044200284

6.077845178 1.000000000TOTAL SUM OF Nth ROOTS

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Utility Curve – Based on the specification data collected for each alternatives

– Threshold as minimum score & objective as maximum score – Full range as min/max score if threshold and objective values are not available

Trade Study

Processor Power (GHz) Scores3.5 13.2 0.82.9 0.62.6 0.42.3 0.2< 2 0

25

Trade Study Matrix

Trade Study

Not Including Cost

Selection Criteria Weights Utility Score

Weighted Score

Utility Score

Weighted Score

Utility Score

Weighted Score

Utility Score

Weighted Score

Utility Score

Weighted Score

Processing Power 0.31440182 0.33 0.1037526 1 0.31440182 0 0 0.4 0.12576073 0.13 0.04087224

RAM 0.54455993 1.00 0.54455993 1 0.54455993 0.5 0.27227996 1 0.54455993 1 0.54455993

GPU 0.09683797 1.00 0.09683797 0.8 0.07747038 0.2 0.01936759 0.6 0.05810278 0.4 0.03873519

Weight 0.04420028 0.43 0.01900612 0.12 0.00530403 0.95 0.04199027 0.63 0.02784618 0.73 0.03226621

0.76415662 0.94173616 0.33363783 0.75626961 0.65643356TOTAL SCORE

AlternativesASUS G751JT G751SERIES

MSI GE62 APACHE-276

Dell InspironHP Envy 17t M9X68AV_1

Lenovo Z70 80FG00DCUS

Including Cost

Selection Criteria Weights Utility Score

Weighted Score

Utility Score

Weighted Score

Utility Score

Weighted Score

Utility Score

Weighted Score

Utility Score

Weighted Score

Processing Power 0.29376967 0.33 0.09694399 1 0.29376967 0 0 0.4 0.11750787 0.13 0.03819006

RAM 0.45588516 1.00 0.45588516 1 0.45588516 0.5 0.22794258 1 0.45588516 1 0.45588516

GPU 0.11451317 1.00 0.11451317 0.8 0.09161054 0.2 0.02290263 0.6 0.0687079 0.4 0.04580527

Weight 0.03557466 0.43 0.0152971 0.12 0.00426896 0.95 0.03379592 0.63 0.02241203 0.73 0.0259695

Cost 0.10025735 0.25 0.02506434 0.5 0.05012867 0.985 0.09875349 0.44 0.04411323 0.6 0.06015441

0.70770376 0.895663 0.38339462 0.70862619 0.62600439TOTAL SCORE

ASUS G751JT G751SERIES

MSI GE62 APACHE-276

Dell InspironHP Envy 17t M9X68AV_1

Lenovo Z70 80FG00DCUS

Alternatives

26

Sensitivity Analysis – Performed to identify critical parameters – Used “zero-out” methodology and recalculated each category – For both with and without cost factor, alternative 2 was still the most preferred solution except

when Processing Power criterion was not included in a factor

Summary – Alternative 2: MSI GE62

Analysis supports the recommendation on physical component decision Cost was considered in the analysis but did not influence the ending result Sensitivity analysis showed that the result change when processing power is not a factor

Recommendation – Perform further research that MSI GE62 meets all associated ACES requirements and functions

when other external/internal components are added – Perform further research for its ability to operate in its corrosive operating environment and at

its temperature limit

Trade Study

27

Test and Evaluation is a process of transferring a design concept to real world

Test determines that system and its component function as expected – Test engineers: Does the system do what it is supposed to do in its intended

environment? Can we break it?

– Systems engineers: What are deficiencies present in the component? If test fails, why?

Test Plan ensures methodical approach and successful completion of test events – Scoped, funded, and executed

Test Plan

28

Scope – The test plan encompasses

the developmental testing of the Water Control Subsystem (WCSS)

– Ensure that the system meets the relevant requirement

Test Plan

Number Name Based On Verified By Allocated To

F.4.3.1 Control Watering FNC.14 Watering System Demonstration System Test

P.8 Water Control Subsystem OPR.3.1 Environment

Control F.4.3.1.4 Monitor Water

Amount Stored FNC.14 Watering System Demonstration

System Test P.8 Water Control Subsystem

F.4.3.1.6 Measure Water Distribution Amount

FNC.14 Watering System Demonstration System Test

P.8 Water Control Subsystem

F.4.3.1.7 Distribute Water to Greenhouse



F.4.3.1.8 Receive Water Control Command



F.6.2.1 Send Remaining Stored Water Level Information

FNC.10 Interface with User: Send

System Demonstration P.8 Water Control Subsystem

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Controlled test environment – Testing facility equipped with resources capable of simulating operational environment

– Tool that is capable of collecting test data for analysis required

Successful Criteria: defined by ACES requirements allocated for WCSS components

Test Plan

Test No.

Scenario Success Criteria Threshold

1 Monitor, Track, and Notify Remaining Water Level

WCSS detect current stored water level. WCSS send alert signal to ACES main computer when the remaining water level is under 10% of original water level (instructed in gardening plan).

Water Level < 10% of original level set in gardening plan

2 Receive Water Control Command

WCSS receives water control command from ACES main computer and assign tasks within 0.5 seconds.

Data processing lag time < 0.5 seconds

3 Measure Water Distribution Amount

WCSS measures distribution water amount with accuracy ±5 ml. Accuracy within 5 ml

4 Distribute Water to Greenhouse

WCSS distribute water to greenhouse in accordance with the water control command.

Measured water is delivered to greenhouse

30

Continuous risk management process throughout the lifecycle of the project to identify, assess, and mitigate program risk (system uncertainty)

Purpose: Reduce potential future risks to an acceptable level before the occurrence to reduce the impact of risk to project schedule, cost, and technical performance

Risk Management

31

Total of 6 risks identified

General Risk management process 1. Risks were identified

2. Risks were categorized as cost, schedule, or technical 3. Risk summary worksheet was developed for each risk

Assessed for likelihood and consequence

4. Risk waterfall chart was developed for each risk 5. Risks were tracked, updated, mitigated

Risk Management

32

Risk Management Risk ID Risk Description Initial Risk Level Current Risk Level

01 Unable to meet project schedule

If there are issues which impact project timelines such as requirement creep as well as project design and execution failure, then project will not be completed in the allotted time frame.

3-3 2-3

02 Interviewees Availability

If the designated interviewees are not available during the planned interview scheduled timeline or do not respont in a timely manner, then establishing user needs will be delayed and the overall ACES project execution schedule will be greatly impacted. If user needs cannot be established, then stakeholder requirements cannot be well developed.

4-3 1-3

03 ACES Sensor Integration Risk

If there are possible sensor control software and sensor components compatibility issues, then the integration of ACES software with the multitude of ACES hardware components may fail.

4-4 2-4

04 Loss of Communication with Portable Device

The ACES hardware component can be communicated through a portable device which plans and monitor ACES environment while user is away from home. If the communication between the ACES and a portable device is lost while user is away from home, then ACES operation may fail.

3-4 2-3

05 Sensor Data Handling Risk

If ACES system may not able to hangle large amount of sensed data, then ACES gardening operation will fail as its function depends on sensor information.

4-4 2-4

06 System Cost If system cost is high, then it may result in low marketability. Consideration of cost, however, is project objective, not a requirement. Although achieving cost was an objective of this project reflecting user preferences (from user interview), this cost risk was not tracked due to high project workload.

33

Reduction follows completion of risk mitigation action

Risk Management

RISK ID # : 03

Description of Risk Risk Type

Statement of Basic Cause 5

4 X

3 1

2 2

Consequence if Risk is Realized 1 3

1 2 3 4 5

Like

lihoo

d

RISK SUMMARY WORKSHEETRISK TITLE : ACES Sensor Integration RiskRISK OWNER : Miku White PROJECT NAME : ACESDATE CREATED : 6-Jan-16 LAST UPDATED : 20-Apr-16

Place X, 1, 2, ...in the appropriate cells

If there are possible sensor control software and sensor components compatibility issues, then the integration of ACES software with the multitude of ACES hardware components may fail.

Interface is poorly managed. Requirements and functios are not managed properly and the lack of traceability cause integration issues in the final product.

23-Mar-16 2

Consequence

Risk Reduction PlanAction / Event Date Success Criteria

Risk Level if SuccessfulComments

Scheduled Actual Likelihood

The ACES system may not be able to meet the system requirements and require design reconsideration/evaluation. Cost of the ACES system may also be affected.

Consequence

4

4Software and hardware architectures, functionality allocation is managed in CORE

(3) Perform system architecting and develop Interface Design Document for critical interface elements.

Perform system architecting for sensor syubsystems and its critical interface element, then document in IDD.

1 4

(1) Use systems engineering software tools to trace and manage requirements and system architecture.

13-Jan-16 13-Jan-16

User comes to agreement on negotiated system performance with cost considerations.

3

(2) Re-evaluate user requirements and conduct trade-study.

28-Feb-16 Conduct thorough research on reliable and effective components for the ACES system.

Interface management is conducted in CORE.

Technical

Schedule

Cost

Other

X1

2

3

Current Timeline

HIGHRisk

MEDIUMRisk

LOWRisk

TIME →

34

From Requirement Analysis until A-Spec: – Additional requirements during each phase

– Refined requirement from Qualitative to Quantitative – KPPs were refined and updated

For both hardware and software describing the functions which ACES must perform in order to meet its operational requirements – Used as a base to establish the general nature of the system

– Further defined to develop the maturity of the system during Engineering Development stage

System Specification (A-Spec)

35

System Specification (A-Spec)

Total # 0f Requirements

Quantitative Quantitative

(Binary) Qualitative

# % # % # %

RAR 76 43 56.6% 0 0% 33 43.4%

A-Spec 100 88 88% 8 8% 4 4%

Operational 32 28 28% 0 0% 4 4%

Performance 19 15 15% 4 4% 0 0%

Functional 37 35 35% 2 2% 0 0%

Constraints 12 10 10% 2 2% 0 0%

KPPs 5 5 100% 0 0% 0 0%

Growth from RAR to A-Spec 31.6%

36

Requirement/functional analysis caused significant schedule delay in early stage of the project – Resulting in the ACES schedule getting extended

Schedule Assessment

37

Risks – Current overall risk is MEDIUM: Pass on to development contractor Risk 03 Sensor Integration Risk Risk 05 Sensor Data Handling Risk

Trade Study – Perform further research that MSI GE62 meets all associated ACES requirements

and functions when other external/internal components are added – Perform further research for its ability to operate in its corrosive operating

environment – Formal trade study on other key components such as Sensor Subsystem and Air

Quality Subsystem – Perform Cost Analysis

Next Step

38

CORE is evil……but helpful – Take time and be familiar with its functionality – Interface vs Link – Transfer

Research – Performing adequate and up-front research of SE process, project guidelines, mentor

videos, relevant technologies helped significantly in focusing on appropriate aspects of the project

– Researching trade study materials and information takes time – Performing research online (open sources) has limitations

Office Hours – Going to office hours was extremely helpful – Every student should maximize its benefit

Lessons Learned

39

Project Schedule – Developing report is more time-consuming than anticipated – Do not get lazy when ahead of schedules – Keeping track of actual work hours could get lost easily – Submitting Requirement Analysis Report, along with Project Proposal, prior to the

start of semester would allow more time to conduct thorough analysis

Project Pitfall – Traceability, traceability, traceability! – Very easy to go too deep into functional analysis during requirement analysis (top-

down process, not bottom-up process!) – Think modularity in design and simplify interfaces as much as possible during

functional analysis and physical allocation

Lessons Learned

40

QUESTIONS?

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