54Survey of the Human-Centered Approachto Micro Air Vehicles

Stuart Michelson

Contents

54.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131254.2 Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131354.3 Incorporating an HSI-Centric Design Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131454.4 MAV Concept of Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131554.5 MAVs and the Man-Machine System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131554.6 Automation, Situation Awareness, and Workload. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131854.7 Test, Evaluation, and Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132154.8 MAV Ground Control Station Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132354.9 Ruggedization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132554.10 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1326References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1327

AbstractA detailed overview of some of the Human Systems Integration (HSI) andHuman Factors Engineering (HFE) issues involved with the newest and per-haps fastest growing research area in unmanned systems, micro air vehicles(MAVs), will be presented. This work will be useful to those studying MAVsystem concepts and designs, managers of HSI programs, users of MAVsystems, and those who design MAVs and the resources to support them.The importance of a total systems engineering approach to MAV design, howMAVs fit into commonly accepted Human Systems Integration domains, and anexposure of some emerging issues with MAVs that require further research arediscussed.

S. MichelsonHuman Systems Integration Division, Georgia Tech Research Institute, Atlanta, GA, USAe-mail: stuart.michelson@gtri.gatech.edu

K.P. Valavanis, G.J. Vachtsevanos (eds.), Handbook of Unmanned Aerial Vehicles,DOI 10.1007/978-90-481-9707-1 90,© Springer Science+Business Media Dordrecht 2015

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The unique attributes of MAVs in terms of their size and control methods,combined with the challenges of the dynamic operational environments wherethey are deployed (such as the battlefield), represent HFE issues exclusiveto the MAV platform that require special consideration. The importance ofdesigning for the human operator is paramount for successful outcomes withMAV platforms.

Literature currently addressing HFE issues with unmanned platforms gener-ally lump all flying systems together, making no distinction between the largehigh-altitude platforms and smaller ones, despite there being a unique set ofchallenges that are specific to smaller platforms. Specifically highlighted aresome areas where currently researched HFE issues are particularly applicableto MAVs as opposed to large-scale systems.

54.1 Introduction

Successfully implementing micro air vehicle (MAV) programs requires one tomaintain a total systems approach, and Human Systems Integration (HSI) mustbe an integral part of that approach. These are presuppositions to the remainderof the content in this work. Acquiring a human-centered approach to analyzingthe observable problems with unmanned systems is essential, but one might feelinclined to question what the human has to do with such systems at all, especiallywhen the hallmark of the domain is the absence of humans. While it is importantto comprehend that the human is an integral part of the design of any unmannedsystem, humans are particularly important to the MAV platform where operatorsare thought to have more active roles in commanding the craft, and systems havea wider spread across the levels of automation. This reality can complicate systemdesign and function allocation. A failed systems approach that deemphasizes thehuman in the loop will result in human-related challenges such as unmanageableoperator workload or poor situational awareness (SA) culminating in compromisedsafety for warfighters.

The Defense Acquisition Guidebook indicates that a total system approach“includes not only the prime mission equipment, but also the people who operate,maintain, and support the system; the training devices; and the operational andsupport infrastructure” (United States Department of Defense 2012). It would bea grave error for designers to assume that just because a human is not physicallypresent onboard the vehicle that they do not need to be knowledgeable about humanattributes and limitations. Testing and evaluating these attributes and limitations isa major aspect of Human Factors Engineering (HFE), and given the uniquenessof the manner in which MAVs are deployed, special design considerations mustbe given to elements such as human anthropometry and cognitive, physical, andsensory abilities. While not every engineer needs to be an expert in these areas, theyshould at least be able to discuss them intelligently with HFE/HSI practitioners andunderstand their extreme importance to successful system design, as it is their jobto guarantee that the human is considered throughout every portion of the designprocess.

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54.2 Terms

Introducing system designers and operators to HSI and HFE considerations associ-ated with MAVs requires one to recognize the finer distinctions between commonlyused terms within the systems engineering domain.

A brief discussion of terms used in this work is necessary for clarity sincemany use some of the common terms interchangeably while the author does not.Note that while there are many definitions of Human Systems Integration, theauthor ascribes to the United States Air Force’s definition of Human SystemsIntegration which is “the integrated and comprehensive analysis, design, and as-sessment of requirements, concepts and resources for system manpower, personnel,training, environment, safety, occupational health, habitability, survivability, andhuman factors engineering, with the aim to reduce total ownership cost, whileoptimizing total mission performance” (United States Department of Defense 2009).While different branches of the armed forces emphasize varying arrangementsof domains (see MANPRINT, for example), the underlying theme is that HSIis a vital element that optimizes system design to enhance system performancewhile maximizing the abilities and mitigating the limitations of humans. In sodoing, the abilities of the warfighter are enhanced and total ownership costs ofa system are reduced (Air Force Human Systems Integration Office 2009). It isimportant to emphasize that HSI from an engineering standpoint not only dealswith requirements and concepts but people and equipment. In this way, HSIshould be understood to be a broader concept than HFE although many incorrectlyuse the two terms interchangeably. The major motivation for incorporating HSIinto MAV programs is to control total ownership costs while maximizing systemeffectiveness.

Note that Human Factors Engineering is included as one of the domains of HSI.HFE deals more exclusively with the realization of design criteria, psychologicalelements of human behavior, as well as physical and mental limitations of humans.By understanding human attributes (anthropometry, for example), HFE analysisseeks to enhance performance (to required levels), increase safety, and increaseuser satisfaction (Wickens et al. 2003). The science of human factors can be saidto rest upon generalization and prediction. With respect to unmanned systems,researchers should be interested in generalizing common problems and predictingsolutions – all while accounting for the humans in the loop and reducing design-induced failures.

The importance of incorporating HSI and HFE analyses into the design processearly cannot be stressed enough. The Department of Defense specifies that designchanges can cost 1,000 and 10,000 times more in initial production phases thanthe same change would cost during a product’s earlier design phases (United StatesDepartment of Defense 2005). While the human element is a vital considerationthroughout the entirety of the design process, it has been shown time and timeagain that design changes made early are less costly because they do not involvethe modification of existing hardware and software. A human-centered approach toMAV development should be early and iterative but also should span throughout theentirety of the design process.

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54.3 Incorporating an HSI-Centric Design Approach

A proper approach to system design must include HSI as a consideration ofprime importance. So much so that the Department of Defense’s acquisition policyindicates that HSI should be central to the formation of integrated product teams(IPTs), which are a vital part of the integrated product and process developmentmethod. The Defense Acquisition Guidebook states that the product and processdevelopment method is a “management technique that integrates all acquisitionactivities starting with capabilities definition through systems engineering, produc-tion, fielding/deployment and operational support in order to optimize the design,manufacturing, business, and supportability processes. At the core of the IPDDtechnique are IPTs. Human Systems Integration should be a key considerationduring the formation of IPTs” (United States Department of Defense 2012). It isimportant for HSI experts who are considering the human element for each HSIdomain to be included as members of the various IPTs so that the human element isconsidered throughout the entire design process. This design concept places thosecharged with including the human element in positions to comprehensively impactthe system’s design (United States Department of Defense 2012). HSI professionalsshould be included in the development of a MAV platform’s concept of operationsrather than being invited into the design later to comment. In reality this rarelyoccurs, but doing so allows HSI considerations to impact the concept of operationsand in turn create systems where total ownership costs are reduced and systemeffectiveness is maximized.

It is not to be unexpected for engineers to resist the involvement of HSIprofessionals. Those that do are likely victims of a bad definition of HSI and donot understand how it will positively impact their work, or they think it is anunnecessary cost not realizing that without it their program will be more expensive.Unfortunately, many engineers treat HSI and HFE as checkboxes for after their workis considered complete. A tendency may exist among some engineers to place lessemphasis on designing for the human when managing unmanned systems programssuch as MAVs. The development of an HSI plan is one way to make sure that humanconsiderations are not deemphasized. Managers must develop an HSI strategy fortheir program. This takes the form of an HSI plan that should be established early inthe design process before any manufacturing takes place (United States Departmentof Defense 2012). Each phase of the program should include how the HSI plan willaddress issues associated with each HSI domain. In systems where new technologiesare expected to replace or supplement human activities, HSI plans should anticipatethe possibility that delays in development might still prevent such measures frombeing implemented, and therefore, program managers should have alternatives thatstill account for appropriate levels of human operator workload.

While the finer points of the accepted defense acquisition strategy are beyondthe scope of this work, a brief understanding of the context in which MAVs arebeing developed is valuable. Within the unmanned systems category, incorporatinggood HSI plans is particularly important for MAVs where typically more involve-ment is expected of the human operator in terms of direct control of the craft.

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This distinction of the MAV platform requires a close look at all of the HSI domainsbut specifically those that deal with the cognitive, physical, and sensory abilitiesof humans and their knowledge, skills, abilities, and experience levels as systemoperators (the personnel, training, and human factors engineering domains).

54.4 MAV Concept of Operations

In contrast to larger, more traditional unmanned systems being widely deployedaround the world, MAVs are deployed in a distinctive manner. DARPA’s definitionof a MAV specifies that the vehicle be smaller than 15 cm (about 6 in.) in anydimension (McMichael and Francis 1997). The MAV was originally thought to be amilitary asset that could be included in every warfighter’s loadout, enabling him/herto engage in intelligence, surveillance, and reconnaissance (ISR) missions whilein the field (Michelson 2008). This methodology stands in contrast to larger-scalesystems with expansive ground control stations used with popular unmanned aerialvehicles (UAVs) such as Northrop Grumman’s Global Hawk or General Atomics’Predator. In such systems, multiple human operators are involved in the commandand control of the system from either homeland-based command centers or mobiletrailer style units.

From a technical standpoint, MAVs, being craft measuring in mere centimeters,represent a number of issues that have been written about in detail elsewhere.Some of these issues include robustness in inclement weather, endurance, antennaaperture, and strains on command and control due to limited storable energy onboard the craft. While these are very real challenges deserving consideration, onecannot look to solve these problems while ignoring or merely paying lip serviceto the importance of a human-centered approach to design of MAV platforms.The aforementioned issues should be handled considering their effects on humans,but there are other specific issues that are perhaps not often thought of regarding thehuman’s interaction with MAV systems. The remainder of this chapter is dedicatedto addressing some common considerations to MAV design and implementationfrom a human-centered perspective while comparing and contrasting their unique-ness against larger high-altitude UAV systems. HSI professionals involved in thedevelopment of a MAV’s concept of operations should emphasize that a system isdriven by humans. Unmanned systems should be just as concerned with designingfor the human in the loop as manned systems. The main difference between the twois that a human is not physically onboard the craft, but UAVs such as Predator havehundreds of humans involved in their operation, maintenance, and support.

54.5 MAVs and the Man-Machine System

As the popularity of UAVs has increased, so has the interest in shrinking theirsize. This reduction in size has expanded the range of applications for whichhumans can utilize them. No longer are UAVs limited to outdoor flight at altitude.

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Recent developments in research and technology have afforded MAVs the prospectof flying into buildings, down hallways, through air ducts, sewer systems, or evenacting as micro spies no bigger than a housefly on the wall. All of these abilitiespresent new challenges not only to the MAV platform’s hardware and software butalso to the human system designers and operators. The challenges associated withindoor flight such as obstacle avoidance and navigating environments without theassistance of GPS are difficult to overcome and are only enhanced by difficultiessuch as transmitting valuable location information back to human operators frominside of a structure.

Engineers may feel inclined to meet these challenges with a reductionistapproach to systems design. This traditionally popular approach is characterizedby a focus on each physical and technical component of a system alone whilenot emphasizing the behavioral components of systems. This approach has beenassociated with catastrophic system failures on the order of magnitude of oil spillsand commercial aircraft crashes because it does not consider the interaction amongall of a system’s parts and does not view system components in terms of theirrelation to accomplishing overall system goals (Czaja and Nair 2012). The bestway to avoid this pitfall is to incorporate a good HSI plan which dictates that allthe various domains of HSI are considered together.

Since HFE is concerned with enhancing the interactions between humans andall other components of a system, good systems theory sees the understanding ofthe entirety of a system’s components being in concert as implicit to good systemsdesign (Czaja and Nair 2012). As the levels of autonomy continue to increasewith MAVs, the complexities of automation and the system components requiredto support them also increase. As the emphasis continues to be on advancing thestate of MAV technology, equal consideration in the realm of system design mustbe given to the human element or systems will underperform. This is an acceptedtenant within the HFE field (Czaja and Nair 2012).

While there are many ways to classify a system, classifying MAV systems interms of levels of feedback mechanisms is particularly useful to the characterizationof the platform. A closed-loop system provides feedback to an operator that iscontinuous for error correction. This type of system provides human operatorswith real-time information so that they can determine the difference between actualand desired system states. An open-loop system does not afford an operator thefeedback necessary for continuous control (Czaja and Nair 2012). MAVs exhibitlevels of autonomy ranging across the spectrum from 100 % remotely piloted robotsto entirely autonomous robots making their own decisions in real time based on theirenvironment apart from a human operator. For this reason, MAVs as a category canbe closed-loop systems, open-loop systems, or both.

This can complicate the design strategy one should employ since open- andclosed-loop systems require varying design strategies. Designers should pay closeattention to the consequences of dynamic function allocations to ensure thatrealistic expectations are being placed on human operators in certain circumstanceswhere the human has more control. Extensive experimentation and testing usingrealistic scenarios that cover the breadth of possible human and computer workloadshould be undertaken to mitigate potential workload-related errors. For a more full

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discussion of scenario development strategies and workload analysis techniques thatextend beyond the scope of this work, see Mental Workload and Situation Awareness(Vidulich and Tsang 2012).

When considering the capabilities and limitations of humans for MAV systems, itis important to recognize the way in which advancing vehicle autonomy has changedthe nature of man-machine systems. Not only have new technologies enhanced themanner in which human operators can control their vehicles (spoken commands,for instance), but also the capacity for intelligence of the vehicles themselveshas changed the relationship between the human and the system. This trend willcontinue as flying robots are increasingly able to perform more tasks previouslyrestricted to humans. Historically the model for human machine interfaces has beenbased around control. Humans were said to interact with a system by controlling it.Under such circumstances, the system was subservient to the human. The currentstate of affairs is that intelligent MAVs are evolving into entities that can extendthe capabilities of their human partners (Czaja and Nair 2012). With respect toMAVs, the robot should be viewed and treated as a member of the team working toaccomplish the stated goals of the system. This reality of the human’s relationshipwith MAVs will only be enhanced further as each human operator becomesresponsible for swarms of MAVs in the future.

Perhaps the most prominent example of MAVs advancing the state of theart in robotic flight behavior is the International Aerial Robotics Competition.It has consistently highlighted the importance of the interdependent relationshipof human operators and their aerial robots to accomplish tasks. Starting in 1991,the International Aerial Robotics Competition is the longest ongoing university-based robotics competition in the world. In addition to exposing the next generationof aerial robotics engineers to the process of system design from concept toreality, the competition has always been driven by pushing the advancement ofautonomous robotic technology to levels previously unattainable by governmentsor industry. While earlier competition challenges involved outdoor flight tasksincluding mapping hazardous environments, searching for disaster survivors, col-lecting and moving objects, locating specific buildings and their attributes, andtransmitting information back to command and control stations, the most recentchallenges have involved smaller flying robots that are tasked with penetratingstructures and negotiating confined spaces full of obstacles with no GPS guidance.Small air vehicles are designed to penetrate openings in structures, deactivatesecurity systems, read signs (in languages foreign to the human operators), avoidobstacles (furniture and debris), negotiate disturbances to the airspace (such as fans),and successfully retrieve and replace an object that must be located in a limitedamount of time.

These advanced robots systems are fully autonomous, making decisions on theirown with no human operator control inputs, and are typical of the relationshipbetween humans and their MAVs because they assist the human to accomplish a taskthat cannot be achieved without both entities working together. An attribute typicalof all International Aerial Robotics Competition missions has been using unmannedtechnology to enhance the capabilities of humans by going places and doing thingsthat are either not possible or too dangerous for humans to attempt. In this way,

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the missions when accomplished become excellent case studies exemplifying therelationships of man-machine systems that can extend the capabilities of humans.

For a detailed examination of some considerations that can assist one tocreate, test, and evaluate autonomous systems that are designed to extend humancapabilities and not merely mimic human attributes, the author recommends TenChallenges for Making Automation a “Team Player” in Joint Human Activity (Kleinand Bradshaw 2004). This essay highlights the importance of focusing researchobjectives on promoting healthy human robot teamwork, not merely on how to makesystems more autonomous.

54.6 Automation, Situation Awareness, and Workload

It has been established that human operators and MAVs should be thought of asteam members working toward the satisfaction of mission goals. But how does onedetermine what should be an automated function and what should not with MAVsystems? Traditionally, designers might reference a Fitts List (an exhaustive listoutlining the abilities of humans against the abilities of machines) to attain an overallunderstanding of the types of activities humans excel at versus the types of activitiesat which machines excel. However, one should do so with caution, making sure thatby examining individual activities their interrelation as a whole within the system isnot overlooked.

There are several primary reasons why a function might be considered a goodcandidate for automation. The first is when a task is considered too dangerous fora human to attempt without resulting in bodily harm or death. Another is when thenature of a task is something at which humans do not excel. A final example is whenthe safe and successful operation of a system requires a reduction in the workloadof the human operator. To achieve optimal system performance, the capacity ofthe human to take on tasks successfully as well as the system’s limitations mustultimately direct which functions should be allocated to which team member andwhen (Hopcroft et al. 2006).

Recent studies in the area of workload and adaptive automation have revealedthat automation should be thought to redistribute workload, not reduce it (Vidulichand Tsang 2012). Too much automation on the other hand could lead to operatorboredom, which could separate the human operator from the current state of thesystem resulting in difficulty for the human if they had to take over control tomitigate unusual crisis events. The concept behind adaptive automation is to im-plement automation that negotiates the fine balance between appropriate workloadlevels for human operators (the author advocates 75–80 % workload as a rule ofthumb) without inhibiting situational awareness (SA) (Vidulich and Tsang 2012).Particularly when human operators are monitoring MAVs in flight, it is essentialthat ground control stations provide solid feedback in real time lest the operatorlose track of actions taken by the vehicle resulting in incorrect mental models of thesystem state. Such a situation enhances the likelihood of errors and reduces human

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trust in automation. Conversely, human trust in automation might be too high dueto poor feedback resulting in less attentive monitoring and the overlooking of error(Hopcroft et al. 2006).

Advocates of adaptive automation prescribe that predetermined fixed (or static)allocations do not compliment complex dynamic systems because individual factorscan rapidly and unexpectedly change confounding human operators (Vidulich andTsang 2012). This is a particularly important observation for MAVs deployed on thebattlefield where the operational environment can quickly change not just in termsof threats from enemy combatants but also from environmental changes such assandstorms or blinding rainfall.

Since MAV operators on the battlefield may be involved in direct and supervisorycontrol of aerial robots during a firefight, one should expect that the cognitive work-load demands are enhanced greatly as a variety of stressors have the opportunity tooverwhelm the operator (Parasuraman et al. 2009). In such cases, automation shouldbe employed effectively to support the human’s performance with the system.Limitations such as mistrust in automation, a poor balance of workload betweenthe human and the system, overreliance, and SA reductions are just a few of thechallenges that can prevent automation from successfully aiding the warfighter insuch high-stress operational environments (Parasuraman et al. 2009).

Dynamic environments such as battlefields are excellent case studies for whystatic function allocations are not ideal. The solutions to the limitations thewarfighter faces in the operational environment with MAVs can be addressed withproper adaptive automation where conditions in which the system intervenes are notfixed but rather avail themselves at the appropriate time depending on the context ofthe battlefield environment. This sort of context-sensitive system assistance can betriggered by mission events, human operator performance levels, or even the humanoperator’s physiological status (Parasuraman et al. 2009). For a further discussionof adaptive automation, reference Adaptive Automation for Human Supervision ofMultiple Uninhabited Vehicles: Effects on Change Detection, Situation Awareness,and Mental Workload (Parasuraman et al. 2009). It encompasses a more thoroughexamination of the means of deploying effective adaptive automation with un-manned systems in general for warfighters on the battlefield.

To fully understand the relationship between SA and workload for warfightersremotely piloting vehicles on the battlefield, human operators who have sent MAVsinside of structures that they cannot see, or human operators who are piloting MAVsthat have left their line of sight outdoors, a brief discussion of what SA entails iswarranted. The author’s description of SA offered below is designed to familiarizethe reader with the basic concepts of SA, which is a topic that has been widelyresearched and written about. For a more full discussion of SA and the commonchallenges associated with it, reference Situation Awareness (Endsley 2012).

SA is a human attribute derived from cognitive processes and is therefore not anattribute of computers. Endsley’s widely accepted definition of situational awarenessis “the perception of the elements in the environment within a volume of time andspace, the comprehension of their meaning, and the projection of their status in the

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near future” (Endsley 1995). Using this definition, one must accept that situationalawareness has three vital elements (perception, understanding, and prediction) andthat each of them must be applied to exact circumstances.

Each of the three elements of situational awareness (perception, understanding,and prediction) requires different levels of human operator skill. Perception relieson selective attention, understanding relies on working and long-term memory,and prediction encompasses plan generation based on processed cues. Operatorexpertise is a major factor in SA (Endsley 2012). Applying the elements ofsituational awareness to the task of MAV flight monitoring, evaluators should expectto consider the following human tasks:1. The assimilation of new information into preexisting knowledge bases within the

human operator’s working memory2. The perception of relationships and their significance3. The projection of what will occur in the future given current information so that

appropriate actions can be takenIt is being suggested that evaluations studying ground control station effective-

ness address each of the three tasks in order by representing information so thatit can be comprehended, depicting relationships among stimuli and integrating withheuristics to aid the human in making predictions about future system states. Humancognition naturally attempts to organize and make sense of visual and auditorystimuli. Human cognition is attuned to spatial and temporal relationships. Specif-ically with regard to perception, the human mind organizes stimuli into sourcesand streams that have identity and continuity over time (Endsley 2012). Harnessingthese tendencies to create appropriate system feedback and data presentations to thehuman operator is important. In assessing successful user outcomes, it is importantto highlight that good SA is not the same as good performance. Good SA ismeasured as appropriate and timely responses to unexpected events taking placewithin the system being studied.

An appropriate framework that considers the team members within a man-machine system working toward the accomplishment of mission goals must beadopted if one is to effectively manage the issue of automation with varying degreesof SA with a MAV system. One such framework has been proposed, which under-scores the importance of considering which team members need awareness of otherteam members’ states. Using the warfighter as an example, human operators needinformation about the MAV’s state, humans need to know about each other (othersoldiers involved with the mission), the MAV needs to know about the human’s state,and MAVs need to know about each other (Drury and Scott 2008). The human-UAVawareness framework should “accommodate the asymmetrical information needs ofpeople and UAVs, be independent of any particular instantiation of a UAV, and bespecific to the types of information needed in the UAV domain” (Drury and Scott2008). While geared toward UAVs at large, the framework is well suited to MAVsand even refers to specific MAV platforms. The framework does well to address acommon pitfall of SA analyses which is to paint an entire system’s human interfaceas either having good or bad SA because it considers a deeper level analysis of the

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types of awareness various agents exhibit and require within a system in the contextof levels of automation (Drury and Scott 2008).

As stated earlier, HFE is concerned with generalization and prediction. One chal-lenge worth noting with regard to conducting workload and SA analyses on MAVsystems is that generalizing can be challenging. In the example of the warfighter,while one can simulate weather effects to some degree, it is not possible to simulatethe stresses of live fire from a battlefield into one’s HFE evaluation protocolwhen studying a MAV system. Therefore, the actual levels of workload and stressobserved during system evaluation cannot be considered to mirror what actualconditions would be. This reality is furthered by individual differences in humanoperator’s skill and SA needs in a given situation.

Another generalization issue associated with MAVs is that one should be carefulnot to generalize workload assessments conducted on large-scale UAV platformsto MAV platforms because the concept of operations and the manning conceptsare different. For instance, researchers at the Georgia Tech Research Institutehave conducted workload analyses of large-scale high-altitude UAV platforms todetermine the optimal crew size and workload levels under varying conditions forrealistic operational scenarios (Georgia Tech Research Institute 2008). It would notbe appropriate to generalize their findings about crew size and workload to a MAVbecause MAV flights are shorter in duration and typically do not involve handoffsof control as one would expect to see with a crew shift in order to support a largesystem for days at a time. Human operators within the large control centers servingUAVs such as Global Hawk find themselves in a more routine work cycle than thewarfighters launching ISR missions with backpack MAVs from dynamic battlefieldsto see what is over the next hill. Depending on the MAV platform, soldiers may findthemselves handing control off to one another to accomplish a mission, but thiswould not be because of operator fatigue like in large command and control centers.Two elements of workload that are often overlooked are what other routine tasks anoperator was already involved in prior to the introduction of a new set of tasks forthe MAV system, and how the introduction of the MAV system effects other agents(maintainers for example). Conducting a detailed task/job analysis as part of a goodHSI plan should mitigate such an error.

54.7 Test, Evaluation, and Training

A unique attribute of MAV platforms distinguishing them from their larger un-manned counterparts is their low risk in terms of testing and evaluation. The testingof MAV platforms begins in wind tunnels but progresses to outdoor test flights muchmore rapidly than larger platforms that can ill afford costly crashes (Michelson2008). AeroVironment’s Wasp MAV with a radius of just 5 nm was selected forDisruptive Technology Fund by the Navy which, among others things, specified acost goal of 5,000 USD per vehicle (United States Department of Defense 2005).Using the Wasp as an example, testing a vehicle with this price point is a very

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affordable prospect. For perspective, the popular large platforms being deployedtoday cost well over 10 million USD. At such a nominal cost in comparison,one could crash thousands of Wasps before equaling the cost of one of thosesystems.

The affordability of test flights with MAVs is an advantage to the platform thatis uniquely suited to its needs. Assessments of MAV performance during flight testsis generally completely reliant on stored information from testing instrumentationbecause the vehicle’s responses to control prompts become unobservable to oper-ators on the ground. Fine-tuning stability can often be a trial and error process(Michelson 2008), and therefore the ability to crash early test flights with fewerfinancial consequences is an advantage of the platform. The often-repeated mantraof “crash early, crash often” can be adopted with MAVs, allowing designers andresearchers to conduct a higher number of test flights early on in the design processthan with larger-scale unmanned systems.

Although there are advantages to testing with the MAV platform in comparisonto larger craft, there are drawbacks. Perhaps one of the most challenging drawbacksis how one handles test instrumentation. As mentioned previously, MAVs generallyhave to rely on test instrumentation onboard to store flight data. It is often difficultto outfit MAVs with this special test instrumentation, and given that the majorityof them operate with 50 % of the gross takeoff weight dedicated to propulsion andenergy and the other 50 % to airframe and payload (Michelson 2008), some MAVshave very little payload to spare. The test instrumentation needs to be unique in sizeand weight, which has numerous implications on its cost, power, and versatility.In this way, MAV test instrumentation exists at the cost of fuel and endurance.

Because these platform-specific challenges to test and evaluation are unique,program managers need to have tasked HSI practitioners to address human concernsfor each of the domains of HSI. Testing and evaluation falls within the bounds ofthe HFE domain because it deals not only with the satisfaction of design criteriabut also with making sure that systems operation, maintenance, and support areappropriately suited to the capabilities and limitations of human operators andmaintainers of the system (Air Force Human Systems Integration Office 2009).Due to the technical and manning requirements specific to MAVs, one should neverattempt to reuse or adjust an existing test plan for a larger system and apply it to aMAV system. Doing so could result in major deficiencies in the test plan resultingin key attributes not being tested appropriately or at all.

When considering the training and selection for UAV operators, it is importantto note that there are no common standards across the branches of the U.S. military.The Air Force restricts UAV pilots to military pilots only, while the Navy, Marines,and Army require a pilot to have only a private pilot’s license. While human factorsresearch has shown that appropriate levels of positive knowledge transfer is possiblefrom manned flight to UAV control, further research is required to ascertain whethermanned flight experience should be required (McCarley and Wickens 2004). Thesequestions surrounding training standards and qualifications become more complexfor MAVs where the desired model may be to place the common foot soldier incommand of one or many vehicles. Further analysis, and ethnographic research,

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for instance, should be required to determine what levels of training is appropriatefor the piloting of MAVs from the battlefield. Manned flight experience may proveto be unnecessary as novel approaches to the command and control of MAVs aredeveloped. Ideally, ground control station interface designs should incorporate goodusability attributes that enhance the operator’s ability through good affordances toremotely pilot vehicles without extensive prior flight experience.

54.8 MAV Ground Control Station Considerations

If the design of a new system or product is to be successful, a considerable amountof time must be spent trying to understand who the users will be and what theirneeds are. Failure to do so will result in products that do not accommodate theirintended users or their environments. One of the greatest pitfalls for designers isto design for themselves and fail to consider their actual users. Ground controlstations for MAVs are more mobile in nature compared to other UAV platforms.Many of them are carried in backpack rigs by soldiers or deployed from trunks ofvehicles. Further, a real possibility exists that MAV ground control stations will beused in harsh outdoor battlefield environments. Although incorporating solid userinterface design principles into ground control station concepts, such as elementrecognition over recall, clear affordances, and continuous feedback, is crucial forsuccessful outcomes in general, this section is concerned with addressing a few ofthe unique challenges that MAV ground control stations have to overcome in orderto be successful.

The most popular types of ground control stations serving MAVs are laptop-styledesigns. These come in many forms, and some of them are packed into ruggedizedplastic boxes to prevent damage to system components. An advantage to the laptopstyle as a design is that training can be reduced because operators most likely alreadyhave familiarity with laptops in general. This style system is also advantageousbecause it can be rapidly deployed if necessary.

Recently, there has been an interest within industry to develop universal groundcontrol stations that promote interoperability. Achieving interoperability increasesthe efficiency of MAV systems and capabilities of military units to share informa-tion. Designers should pay attention to preexisting standards and requirements forinteroperability established by various branches of the armed forces as well NATO’sstandardization agreement (STANAG) when developing their own ground controlstation requirements.

Even the best interoperable ground control station designs are subject to degra-dation under certain conditions. In bright urban environments or desert battlefields,direct sunlight can render a ground control station’s display useless. While hoodsand shields can be helpful, they come at the cost of safety to the operator. If aMAV operator has his/her head buried in a display to interpret it or to maintaindirect control over the vehicle, they can no longer observe their immediate physicalsurroundings. On battlefields or other environments where threats to the operatormay abound, flying a MAV can be a high-risk activity. Minimally, the operator’s

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colleagues will have to guard the operator. In other situations, the operator maybe able to operate the MAV from within an armored vehicle, offering protectionas well as reduction in direct sunlight on the display. Designers should considerhow obvious their ground control station designs make an operator to potentialenemies in order to avoid increasing their likelihood of becoming a special target.Therefore one should not discount the manner in which the introduction of MAVsat the platoon level impacts the operators’ preexisting job descriptions. Accountingfor HSI early in a program (during the development of the concept of operations)can deter design induced manning and safety issues.

There are other environmental concerns apart from sunlight. Ground controlstations can fall victim to excessive heat, cold, moisture, sand, and dust to name afew. These sorts of design considerations are often addressed in standards and guide-lines. Designers should reference these when making sure that their hardware isappropriately engineered to handle these sorts of threats to functionality. What mightbe overlooked however is that the human operator interacting with the groundcontrol station is also subject to the adverse effects of those elements. Soldiers,for instance, may not have the luxury of choosing their operational environment,and their performance can be limited due to these elements degrading their sensoryand physical abilities. As mentioned previously, proper human interface designprinciples can help to reduce these negative effects by ensuring that displays andcontrols are simple to use.

It is important for designers to remember that the human operator while remotelypiloting a MAV from a ground control station is separated from the sensory inputsthat pilots receive in manned aircraft. This means that displays showing flightinformation need to be easy to read and operators should be able to trust thembecause their physical bodies are not actually feeling the effects of the forces that thevehicle is. For this reason, one should never assume that findings from studies aboutworkload and cockpit control layout are scalable from manned aircraft to MAVground control stations. The MAV ground control station should be considered as aunique entity with its own challenges in terms of workload and design layout.

While a pilot’s inability to feel the forces of flight can be seen as a disadvantage, itcan also be seen to enable the human operator, who may be able to remain calmer inriskier situations where his/her physical well being is not tied to the fate of the MAV.Designers might consider implementing haptic feedback to augment the physicaleffects that the MAV may be encountering. This can greatly enhance flight conditionfeedback to the operator.

The display of ground control stations should not overburden a human operator’smental resources. Selective attention and working memory are required becausethese two processes are particularly important to enhancing SA (Vidulich andTsang 2012). An important consideration for MAVs that will be remotely pilotedis the viewpoint that the display will show the operator. There are advantages anddisadvantages to choosing an egocentric (one where the viewer sees what theywould see as a pilot physically sitting in the vehicle) versus exocentric (a viewfrom directly behind the vehicle) display, and one should consider the tradeoffscarefully. From one point of view, the environment is moving and the vehicle is

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seen to be stationary, and from another, the environment is fixed and the vehicle ismoving. An egocentric display may be preferable for obstacle avoidance, while anexocentric display may be better for acquiring an overall awareness of the terrain andenvironment (Vidulich and Tsang 2012). When designing for certain applications,it may be possible and advisable to create a display that affords the user both viewssimultaneously or the ability to switch easily. Whichever display type is selected,the design should support the human by accounting for his/her cognitive resources.

Another consideration for designers of ground control stations is the design ofcontrols. Designing for gloved operation is normally a good idea for joysticks,buttons, and latches. Any testing and evaluation of a system should reflect as closelyas possible the actual operational environment in which the system will be deployed,and therefore test participants should be outfitted with all their equipment for anappropriate context including gloves or other elements which could inhibit mobilityor fine motor control required for delicate articulation. For some applications, theadherence to certain MILSPEC guidelines and standards might be required withregard to design features such as gloved operation, button size, and spacing.

In certain environments where the warfighter will be launching and commandingMAVs, light and noise discipline may hinder ground control station effectiveness.Systems that rely on light and audio to function are poor designs for this application.One should not design command and control to be limited to a single type of controlinput such as speech recognition. Alerts and alarms should not be audible in suchconditions and displays should be designed to consider the potential for immediatemuting. The necessity of night vision integration may also prove useful in certainapplications. Another element to consider for the battlefield is that if the recognitionof audible alerts and alarms is vital to proper system use, they can easily be muffledby the sounds produced by a firefight.

54.9 Ruggedization

The primary attribute of MAVs that distinguish them from other man-made flyingthings is their small size. This means that MAVs are more fragile than other UAVs,and how they transported and deployed in unforgiving environments such as thebattlefield is worthy of consideration. Many MAVs are designed to fit into protectivebags and cases that can be attached to the warfighter’s loadout. Many MAVs aredesigned to be packable within the standard Modular Lightweight, Load-carryingEquipment (MOLLE) system.

Providing bags for compatibility with common equipment attachment methodsis desirable but does not guarantee the level of protection that may be necessaryto protect the smallest and most fragile MAVs. In the future, MAVs are going tocontinue to shrink in size, and it stands to reason that their fragility will continueto increase. This reality presents a challenge for the future as manufacturers ofmilitary components have had difficulty in the past keeping up with the speed ofthe evolution of commercial off-the-shelf components. Components get smaller,faster, and more rugged, while military systems can get bogged down in expensive

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and time-consuming tests to make sure they meet military standards (Military andAerospace Electronics 2004).

Applied Research Associates’ Tactical Mini-Unmanned Air Vehicle (TACMAV)was a novel approach to storage and carrying. TACMAV had a 20.9-in. wingspan,and its flexible wings folded up around its carbon fiber fuselage. The entire systemwas storable in a 22 � 5 in. tube that attached to a soldier’s backpack and weighed0.8 pounds (United States Department of Defense 2009).

Designers should consider not only the vehicle itself but its ground controlstation’s protection for harsh environments. The ruggedness of a MAV systemshould be driven by its intended use. Systems deployed inside of structures should beseen in contrast to those deployed outdoors. Standards and guidelines can be usefulto designers as they determine to what degree a system’s packaging needs to repelwater, heat, cold, or other elements. When examining ruggedization from an HSIperspective, one should consider the survivability domain and it’s interdependenceon the other HSI domains.

54.10 Conclusion

Remaining mindful of the distinction between Human Systems Integration andHuman Factors Engineering with regard to MAV development is pivotal to correctlyaccounting for the human in the design process. The uniqueness of MAVs andhow they are deployed is forging a new understanding of man-machine systemsas their intelligence expands the capabilities of humans in diverse operationalenvironments. Teamwork in the future among humans and MAVs will dependon systems appropriately accounting for operator-specific elements such as work-load, situational awareness, and training. Developing and implementing a HumanSystems Integration Plan throughout acquisition is part of a total systems ap-proach and will ensure that the human is considered throughout the entire designprocess.

While specific design choices regarding ground control station interfaces orruggedization will vary from system to system, one must remember that HumanFactors Engineering is comprised of a series of tradeoffs. The individual choicesmade should support the operational performance objectives set forth for a specificMAV system to accomplish its mission. The relative merits of the issues discussedin this work are driven by how a particular system is intended to be deployed. Forexample, MAVs intended for urban combat environments will require a different setof design criteria than ones intended for agricultural surveying.

As civilian and military operators continue to appreciate the valuable differ-ences MAVs can make in protecting human life and accomplishing formidablemissions, much of the focus moving forward will be on meeting the technical andpolitical challenges of achieving interoperability, enhancing communications, man-aging system affordability, furthering autonomous behavior, increasing endurance,and integrating into national airspace. MAVs will no doubt continue to be an

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increasingly popular solution for warfighters as they operate in dynamically chal-lenging environments, and therefore the means of further integrating MAVs at theplatoon level will be a concern. In a time when so much of the media attentionsurrounding MAVs is focused on advances in technical capability and policyconsiderations, one must not forget to pay attention to the needs, wants, and desiresof human operators within the design space. How well designers implement ahuman-centered approach to MAVs in the future will largely dictate the platform’ssuccess.

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