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Iowa State University

Ames, Iowa

IE 571

Occupational Biomechanics

Single Hand Held Controller Ergonomic Evaluation

Final Exam

Thomas M. Schnieders

4 May 2015

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Table of Contents

Table of Contents..........................................................................................................................2

Table of Figures.............................................................................................................................3

List of Tables.................................................................................................................................3

List of Appendices.........................................................................................................................3

I. Executive Summary....................................................................................................................4

II. Introduction................................................................................................................................5

III. Schedule...................................................................................................................................6

IV. Customer Requirements Specification.....................................................................................7

Statement of Need.........................................................................................................................7

System Descriptions and Functions..............................................................................................8

Function Tree.................................................................................................................................8

Function Chart and Block Diagrams..............................................................................................9

Operating Environment................................................................................................................10

Deliverables.................................................................................................................................11

V. Market Research.....................................................................................................................11

VI. Global and Social Impacts.....................................................................................................11

VII. Recommendations and Design Concepts for the Redesign.................................................12

System specification....................................................................................................................12

Key Technical Challenges...........................................................................................................12

Ergonomic Evaluation..................................................................................................................13

Testing of controller.....................................................................................................................16

Ergonomic Improvements and Design Concepts........................................................................18

Mathematical Verification of the Redesign..................................................................................21

Trade Studies..............................................................................................................................22

VII. Future Work...........................................................................................................................23

VIII. References...........................................................................................................................24

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Table of FiguresFigure 1: CAD-model of the Single Hand Held Controller………………………………………7Figure 2: Function Tree of the Single Handle Controller…………………………………………8Figure 3: Functional Flow Chart for single hand held controller…………………………………9Figure 4: Muscles of the Back…………………………………………………………………...15Figure 5: Muscles of the Forearm………………………………………………………………..16Figure 6: How the test stand was assembled…………………………………………………….16Figure 7: The hand controller set together with the test stand…………………………………...17Figure 8: The pistol grip concept………………………………………………………………...19Figure 9: The forces affecting the arm from the existing model………………………………...20Figure 10: The extra handle to counteract torque in the body…………………………………...20

List of TablesTable 1: Classification of force/torque for selection of manual control actuators……………….14Table 2: Minimum recommended dimensions of manual control actuators……………………..14Table 3: Results from the calculations…………………………………………………………...22

List of AppendicesAppendix A: Customer Requirement BenchmarkingAppendix B: ISO 9355-3: 2006Appendix C: Matlab CodeAppendix D: Body Part Discomfort ChartAppendix E: Borg CR10 ScaleAppendix F: Force RecordingAppendix G: New HandleAppendix H: Extra HandleAppendix I: Part 00001Appendix J: Part 00002Appendix K: Part 00003Appendix L: Part 0004Appendix M: Part 0005Appendix N: Part 0006Appendix O: Part 0007Appendix P: Part 0008

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I. Executive SummaryIncluded in this report is a project plan for the project “Single Hand Held Controller,” for IE 571,

Occupational Biomechanics at Iowa State University. The project plan details statement of need,

customer requirements, and market research. The project is for by Altec, a leading provider of

products and services ranging from electric utility to contractor markets. Paul Zinnel and Chris

Barnes will be the team’s primary contacts at Altec. The team will be advised by Dr. Mani Mina.

The evaluation is on pilot pressure hand held controllers and will initially focus on the

ergonomic standards research and evaluation. The report ends with an evaluation on full pressure

hand held controllers, the design and building of a test platform, a redesign of the original

controller and other suggestions for Altec.

The purpose of this project is to find ergonomic standards that relate to single handle controllers

and aerial devices, design and develop a test platform and method for testing Altec’s iso grip

controllers, and evaluate if Altec’s controllers meet ergonomic standards. The reason for the

project comes from high strain in the shoulder and arm on operators during two and three

function movements. By analyzing, testing, and simulating these forces, an ergonomic evaluation

will be completed and suggestions and recommendations for a redesign will be proposed. A

redesigned prototype will be submitted which will meet the ergonomic standards.

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II. Introduction

Ergonomics has become a topic of larger importance over the recent decades and is a significant

aspect for individuals and companies in more than one way. Poor ergonomic conditions can

cause more severe issues than one might think. Many workers are injured in the workplace due

to incorrect ergonomic conditions, which usually consist of attritional wear due to incorrect

movements, strains, and lifts.

Ergonomics also affects the company in a larger degree, regarding the economic and productive

aspects. An injury caused by work related conditions is a cost for the injured employee,

company, and society. By reducing the risks for strain injury or attritional wear with better

ergonomic standards and conditions at the job site, savings of resources for the company,

employee, and society can occur. A company with good ergonomic conditions and products are

more competitive and are more attractive as an employer.

Altec, a company which was established over 80 years ago, delivers products and services in

more than 100 countries worldwide. Their core values include putting the customer first,

enjoyment of work, and quality. With this stated, their products need to meet good ergonomic

conditions since they are used daily by their customers. One subject of ergonomic discussion is

their single hand held controller used in aerial devices. Operators of the aerial devices use the

single hand held controller during a work day, which could range in length from 1-8 hours per

day. This requires that the controllers meet good ergonomic conditions in order to prevent

injuries caused by the controller and ease utilization.

In order to supply Altec an ergonomic evaluation of the single hand held controller and suggest a

redesign, specific requirements have to be met.

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IV. Customer Requirements SpecificationStatement of NeedAltec offers many different products such as digger derricks, pressure diggers, and ground pole

drivers. However, the focus of the MD5 team will be on the aerial trucks. The aerial trucks are

the units utilized for power line access. There are four main types of aerial trucks produced by

Altec: the Non-Overcenter, the Overcenter; the Telescopic; and the Telescopic Articulating. The

Non-Overcenter (Figure I) line of trucks has lift baskets that are capable of reaching up to 150

ft. The Overcenter can reach heights up to 93.3 ft. The Telescopic can reach heights up to 63 ft.

Lastly, the Telescopic Articulating line can reach heights up to 64.8 ft.

Figure 1: An example of a Non-Overcenter aerial truck

The controller utilized to operate the lift basket of the aerial trucks is a trademark patent of the

company. The controller is designed for one-arm operations, and there are two main types of

controllers: full-pressure (Figure 2) and pilot-pressure (team MD5 will work with the full-

pressure controller). Both controller types operate on a hydraulic system; however; the pilot-

pressure controller has a secondary pressure system that serves as median between the user and

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the main hydraulic system. Thus, the hydraulic system is more efficient in delivering power to

necessary functions.

Figure 2: Side view of the controller

Altec Industries have several different single hand held controllers to maneuver their products.

Over the last few years there have been customer complaints about fatigue caused by their iso

grip controllers, especially during two and three function movements that involve pulling the

controller backwards and upwards at the same time. Altec desires to investigate the ergonomics

surrounding the single handle controller and see whether it matches any ergonomic standards. If

it does not fit ergonomic standards, Altec would like to be provided with an alternative design or

improvements that could solve the problem and alleviate fatigue.

Figure 3: CAD-model of the Single Hand Held Controller

The problem is most prominent when operators use an upwards and backwards motion

simultaneously. Additionally, the slow movement of the boom leads to more time required to

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hold the controller using the safety interlock system. It is also very important that the

improvements do not include an electrical systems since the product is supposed to be used in an

environment where electricity is not suitable and could be fatal. Additionally, Altec’s controller

falls under the ANSI/SIA A92.2-2009 Vehicle-Mounted Elevating and Rotating Aerial Devices

standard. The improvements or new design must also fit the dimensions of the controller box

previously used.

To determine whether the controller fits the ergonomic standards there must be a method for

testing the forces on the controllers. This method will preferably be a physical model designed

and manufactured which should be suitable for the six different controls.

System Descriptions and Functions

Function TreeFigure 2, below, demonstrates the two different operating systems of the single handle controller.

The positioning system is the system causing fatigue, strain and uncomfortable movements of the

arm and shoulder. The safety system is an essential system for the single handle controller and

will have to have the same fundamental design in a redesign, due to its function and importance

during utilization of the single handle controller.

Figure 4: Function Tree of the Single Handle Controller

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Function Chart and Block DiagramsIn Figure 5, below, the specific functions of the single hand held controller are shown. For a

possible redesign and prototype, all these functions need to be considered, evaluated and

retained. The functions of positioning the cubicle, see figure 3 below, of the aerial device can be

divided in to the functions listed in Figure 4.

Figure 5: Functional Flow Chart for single hand held controller

The definitions of the functions are listed below:

Move Up/Down: Move and position the cubicle upwards and downwards in a vertical direction

by pulling/pushing the single hand held controller upwards/downwards.

Move Back and Forward: This function on the single hand held controller is interconnected with

the Move Up/Down function. While moving the cubicle from starting base position (horizontal

position) to an upright vertical position, the joint connecting the two shafts will force a motion

where the cubicle will move backwards and forwards while positioning into a vertical upright

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position. By pushing the single hand held controller forward/backward the cubicle will move

forwards/backwards.

Interlock: As a safety measure the single hand held controller has a lever which needs to be

pressed in while operating the cubicle of the aerial device. If the interlock is not pressed in it is

not possible to use the controller for any operations.

The Move Up/Down function and Move Back/Forward can be combined into a two-function

movement operation. This functionality is a customer requirement to retain during the project

and all functions listed above are necessary to retain for a redesign of the single hand held

controller.

All three functions can also be combined into a three-function operation. This report will not

focus on this.

A detailed breakdown of the control interface is featured in Figures 6 - 11. The interlock linkage

(Figure 7) is the safety feature that prevents the user from experiencing a self-induced controller

response. Essentially, this means that the lift arms (also known as booms) can only move while

the handle of the controller is squeezed. Pushing forward or backward on the controller activates

the linkages featured in Figure 8. These motions raise and lower the bottom boom of the aerial

truck. Pulling up and down on the controller activates the linkages featured in Figure 9. These

motions raise and lower the upper boom. Tilling and twisting the controller activates the linkages

in Figures 10& 11, respectively. These motions allow the user to rotate the lower boom in a

circular pattern. The controller is also capable of performing compound movements. For

example, the controller can be orientated so that the operator can raise the lower and upper

booms and rotate the lower boom.

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Figure 6: Linkages for motion Figure 7: Interlock linkage Figure 8: Forward/ Backward controlcontrol linkage

Figure 9: Up/ Down Control Figure 10: Tiller control Figure 11: Twist control linkage linkage linkage

Operating EnvironmentThe single hand held controllers are used in the cubicle of the skylift of the aerial devices. The

operators use the single hand held controllers during a work shift ranging from one to eight

hours. The major part of the work is performed in an outdoor environment and the operators

spend most of their shift in the cubicle. Depending on what type of work is performed, the single

handle controller is used a number of different ways and the operator’s arm can be in different

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positions. One operator might only use the single handle controller to position the cubicle to get

up to and down from the working site, while another operator might have a job which includes

needing to position the cubicle several times during one work shift. Hence, the usage of the

single handle controller differentiates depending on the tasks that need to be performed by the

operator, leading to different working conditions for each operator. Some of the aerial devices

are also used to work on power lines, which directly demands an isolated and non-electrical

controller.

DeliverablesAt the end of this project, a final report, recommendations, a set of ergonomic standards, and an

analysis of Altec’s controllers will be presented with notes on how to improve the ergonomics of

the controllers. A testing stand and testing procedure for force testing on the controllers will also

be delivered to Altec. Additionally, if time permits, a prototype of the improved handle will be

delivered either in CAD format or physical prototype. Force data and MATLAB calculations will

be performed for the original controller and presented in the final report, and MATLAB

estimations will be performed for the prototype.

V. Market ResearchThere are two primary systems to look at in the market – Altec’s ISO-Grip Control system and a

scissor lift controller. A breakdown of their benchmarking may be seen in Appendix A, attached.

Note that the customer requirement ranking is broken down as such: rank 9: “Very Important”,

rank 3: “Moderately Important”, Rank 1: “Minor Important”. The option preference ranking is as

follows: rank 9: Requirement “Strongly” Met, Rank 3: Requirement “Moderately” Met, and rank

1: Requirement “Barely” Met.

VI. Global and Social ImpactsThe ergonomic evaluation will supply Altec with recommendations regarding ergonomic

standards and suggestions for better ergonomic conditions for the single handle controller. With

this Altec can chose to use the evaluation and improve the ergonomic conditions of the single

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handle controller. By doing so, Altec will be more competitive in the market with supplying

aerial devices with better ergonomic controllers. Altec will be more attractive to customers, since

good ergonomic conditions will improve the work environment and productivity of any company

which is very beneficial for both Altec as for their customers who are leasing or buying the aerial

devices. Consequently, it might lead to Altec creating new relations and gaining more customers,

thus increasing its revenue and gaining a lead in the different markets Altec provides services

and products in.

An ergonomically improved single hand held controller also enables work possibilities and

opportunities for elder operators. Avoiding fatigue, strain issues and complications as the

operators get older allows them to work until retirement and the companies avoid having to pay

for medical expenses. A better ergonomic control invites for a more pleasant and work friendly

environment as an operator of the aerial devices. Operators will evade possible physical and

mental pain due to injuries caused by a less ergonomic controller.

In summary, more ergonomically fit single handle controllers and devices in general are

preferred due to the many benefits to employees, employers, and leasing companies.

VII. Recommendations and Design Concepts for the Redesign

System specificationThere are specific functional structures which need to be considered for a possible redesign of

the single hand held controller. Specific functions of the single hand held controller need to be

retained to meet Altec’s requirements for the project and the controller. As stated in the

Customer Requirement Specifications section, there are five main functions of the single hand

held controller, which are to be retained in any redesign.

Key Technical Challenges

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The key technical challenge for the design and function of the single hand held controller is that

it cannot be electrical. Due to the Customer Requirements, the hand held controller is acquired to

be entirely isolated and operated with nothing more than forces, torques, and hydraulics. For the

redesigned single hand held control the same requirements have to be met. The key challenge

would therefore be to design a hand held control with smoother operation without using

electronics.

Furthermore, the single hand held controller is to be locked and not moveable, therefore, another

technical challenge is to make the handheld controller more ergonomic without being able to

change the height of the control to suit the length of the operator. It is also to be fit into the box

where it is positioned in the cubicle, which constrains the size of the controller.

Ergonomic EvaluationThe team was only able to locate one ergonomic standard that relates to Altec’s iso grip handle --

ISO 9355-3:2006 Ergonomic requirements for the design of displays and control actuators --

Part 3: Control actuators. The standard’s abstract is as follows: ISO 9355-3:2006 gives

ergonomic requirements for, and guidance on, the selection, design and location of control

actuators adapted to the needs of the operator, suitable for the control task in question and

taking account of the circumstances of their use. It is applicable to manual control actuators

used in equipment for both occupational and private use. The 40 page standard can be seen in

Appendix B. Team MD 6 utilized four subject matter experts to locate the most relevant

standard.

Alex Renner, PhD candidate, was the team’s first point of contact. Thomas Schnieders worked

with Mr. Renner in the Virtual Reality Applications Center. Mr. Renner has many years of

experience in manufacturing and mechanical engineering working with ergonomics in the

workplace. Mr. Renner gave the team a number of textbooks to reference and facilitated the 3D

printing of the prototype handle.

Dr. Jason Gillette was the team’s second contact. Dr. Gillette received his masters and doctorate

at Iowa State University in Biomechanics and teaches courses on Biomechanics and injury

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prevention in the workplace. Dr. Gillette also gave the team a few text resources as well as a

short list of things to consider while re-designing the controller. Dr. Gillette pointed the team to

Dr. Gary Mirka and Dr. Rick Stone to help in the search of an ergonomic standard. Dr. Mirka

and Dr. Stone work with standards on a regular basis. Additionally, Dr. Stone does research in

ergonomics and biomechanics. Dr. Stone suggested the use of the ISO 9355-3:2006 standard and

the three other subject matter experts agreed on the decision.

The ISO standard details out suggestions for design and gives a standard of force values for

control actuators in section 5.2.3 Task requirement c) – Classification of force/torque (force)

(Table 1).

Table 1: Classification of force/torque for selection of manual control actuators

Additionally, the standard provides a listing for minimum dimensions of manual control

actuators (section 8.2 of the standard). A copy of that data can be seen in the table below. Altec’s

controller meets this standard.

Table 2: Minimum recommended dimensions of manual control actuators

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Guidelines for single handle controllers have been evaluated and applied on the Altec’s pilot

pressure single handle controller. The guidelines discuss size of handles, angles and positions of

arm and body and how to best reduce forces, strain and fatigue on the body.

There are some ergonomic standards and guidelines on how the handle should be modelled and

the current handle was within acceptable range. The most common problem with handles is that

they are either too big/small, stiff, awkwardly placed or slippery. The handle was at an

acceptable size and not slippery, thanks to the Altec logo, and not too stiff. There was, however,

a problem with the placement of the controller. Based on the ISO standard, as well as discussions

with Dr. Stone and Dr. Gillette, the placement of the controller creates an unnatural wrist angle

which can lead to strain and fatigue in the wrist, shoulder, and forearm.

From the team’s discussions with Dr. Stone, Dr. Mirka, and Dr. Gillette, as well as repeated

manual testing, the team noted that the stress and fatigue would be most prominent in the

following muscles: the latissimus dorsi, the trapezius, the levator scapulae, the flexor

retinaculum, the pronator quadratus, and the brachioradialis (see figures 4 & 5).

Figure 4: Muscles of the Back

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Figure 5: Muscles of the Forearm

Testing of controllerThe testing was done using a force gauge meter where strings were attached to the handle of the

controller. The controller was positioned in a test stand that was developed. The test stand was

then manufactured by Altec. The test stand consists of 4 parts that was assembled with bolts and

nuts. Then the hand controller was attached with bolts and nuts to the test stand, as seen in Figure

6. The drawing files for the test stand can be seen in Appendix I through P, attached.

Figure 6: How the test stand was assembled

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The test stand was then locked in position with c-clamps to make sure nothing but the controller

itself would be able to move during the testing. The final set up for testing should look like

figure 7, below. The test stand would be suitable for the EMG-testing as well as for the force

gauge testing.

Figure 7: The hand controller set together with the test stand

The strings were then connected to the gauge meter and pulled from the approximate center of

the controller’s handle until the controller reached its maximum movable distance. To make sure

the controller moved its full range of motion, the team first pushed or pulled the controller to its

full extent. The values the team were after were the minimum amount of force required for the

controller to reach its maximum distance in each of the primary directions. To normalize the

data, it was collected from three different individuals and an average was calculated. A larger

sample size would have been preferable, however, the team is confident that the data would still

average out to a very similar result.

The highest value was 10.2 lbs or 45.37 N and the lowest value was 4.2 lbs or 18.68 N. These

results made it possible to determine which of the controllers were the stiffest based on the

average values and it was controller 970042561. The least stiff was controller 716-61949. The

recorded forces may be seen in Appendix F. The accuracy of the measurements are not the best,

but the average gives somewhat of a correct estimate since all of the independent measured

forces was within an acceptable interval.

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Most of the forces fell within the average degree of requirements found in the ISO 9355-3

standard, this can also be seen in Table 2, above. For Altec’s iso-grip controller, the forces

should lie in the low to negligible range found in the table, indicating that the controller could

use a redesign to best fit within the ergonomic standard.

Additional EMG data was to be collected to show which muscles were experiencing the greatest

strain. EMG, or electromyography essentially measures the electrical impulses produced by

skeletal muscles as a result of movement. The higher the amount of electrical potential generated

by muscle cells, the higher the signal recorded. In other words, the more force required of the

muscles, which can indicate strain and load bearing, the higher the output. Every individual’s

musculature is essentially the same but there are slight differences. This difference can be

normalized by comparing an individual’s EMG data for the original controller, coupled with the

force data, against the same individual’s EMG and force data against the redesigned prototype.

With the help of their subject matter experts a hypothesize was formed about which muscles

would experience strain. Even though a total of fifteen user study participants were found, due to

time constraints and lack of availability with Dr. Stone, the data was unable to be collected. This

data would have shown clearer results, but since the mathematical model, see Mathematical

Verification of Redesign, and the measured forces gives an estimation regarding whether the

controllers fulfill the ergonomic standards or not.

Ergonomic Improvements and Design ConceptsTo be able to reduce the strain on the wrist, forearm, and shoulder the angle of the handle needed

to be changed. There were different design concepts that would have improved the angle, but the

final concept was to change the grip to a pistol grip, as seen in Figure 5. The redesigned handle

may also be seen in Appendix G, the relevant SolidWorks files may be seen in the relevant folder

on CyPoint. This design was chosen through the use of the ISO 9355-3 standard, the textbook

references on biomechanics, and the recommendations of Dr. Stone and Dr. Gillette.

Additionally, the team chose this concept because it would be the least expensive option,

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whereas other concepts involved replacing more than one part in each of the already existing

controllers.

Figure 8: The pistol grip concept

The pistol grip concept changes the force distribution in the arm and back reducing the strain.

The force required to hold in the interlock to be able to operate the controller is negligible and is

therefore not considered to be a problem.

In the original design for the iso grip controller, the wrist would be bent downward causing point

T2 (see Figure 9, below) to swing out away from the body creating a torque in the elbow joint as

well as in the wrist and shoulder. This created high strain in the levator scapulae and the

supraspinatus. Additionally, fatigue could result in the triceps and trapezius from repeated usage.

The pistol grip provides a much more natural movement reducing the strain in the levator

scapulae, the supraspinatus, the latissimus dorsi, the trapezius, the flexor retinaculum, the

pronator quadratus, and the brachioradialis. Furthermore, the fatigue in the triceps and trapezius

is also reduced. I was hoping to be able to further back its findings with relevant EMG data.

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Figure 9: The forces affecting the arm from the existing model

The second recommendation is an extra handle for the other arm, see Figure 10, attached to the

cubicle. The extra handle may be seen in Appendix H.. The extra handle would help counteract

the torque using the handheld controller which could potentially reduce strain and fatigue in the

internal and external obliques and the latissimus dorsi. When pulling with a force F1, for

example, there will be a clockwise torque in the body and this could be counteracted by applying

a counter torque via the extra grip.

Figure 10: The extra handle to counteract torque in the body

The twist motion is very non-ergonomic according to Dr. Stone, especially when using the

already existing grip. The best ergonomic solution would be to exclude the twist motion entirely.

The muscles of the human body are optimal when movements are in line with the body.

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A combination of the pistol grip and extra handle would, theoretically, reduce the forces and

torques applied on the joints and muscles to the low and negligible sections for degree of

requirements. This combination keeps the body’s limbs in line allowing for peak performance

with minimal force.

A model of the redesigned prototype with the pistol grip was 3D printed using the Virtual Reality

Applications Center’s Makerbot Replicator 2X to help affirm the change in ergonomics with a

change in grip style.

Mathematical Verification of the RedesignTo evaluate the redesigned prototype in an ergonomic point of view a mathematical model was

set up. The model is derived from Figure 9.

By calculating the torque in three joints of the arm; the wrist, the elbow, and the shoulder it

should be easy to see if the prototype has decreased the strain that is a result of the torque. It is

assumed that the forces that is needed to operate the existing joystick, is also needed to operate

the redesigned prototype. Meaning that the forces used in this model will be the measured forces

from the testing and they will be constant. The lengths l1, l2 and l3 will also be kept constant in

both cases. The input variables consists of the angles θ1, θ2 and θ3, which will vary between the

existing controller and the prototype and has been measured during operation of both of them.

The calculations were done in MatLab and may be seen in the attached Appendix C.

The results from the calculations is ambiguous and shows that the torque is reduced in some of

the joints with the redesign, but it also shows that it increases in some of the other joints, see

Table 3. These calculations doesn’t show which of the two designs is the most ergonomic.

However, Altec’s main customer complaints were about the two function movement that

included the Pull Up and the Pull Backward move. During this specific move the torque has

decreased with the redesign. The team still strongly believes the redesign is more ergonomic.

The EMG data would help show the ergonomic difference based on muscle activity.

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Table 3: Results from the calculations

Trade StudiesFor Altec, a new single handle control would certainly be a major investment with an uncertainty

in profitability. The current single handle controllers have been in utilization since 2001 and all

the aerial devices are equipped with either the pilot pressure single handle controller or a similar

controller. Thus, leading to a difficult decision making on which ways would be the better

balanced solutions for Altec and their customers.

An entirely redesigned single handle control would be a tremendous expense, even to an

established company like Altec. The time for redesigning, cost of production, replacing the

current controllers and to educate the operators in how to use the new single handle control

might be superfluous for Altec. Altec already has devoted and established customers, meaning

that Altec might not be in a need to execute such an extensive transformation for the single

handle controller used in the aerial devices. In order to pursue that kind of adjustment, the

customer complaints have to more extensive and larger in number to prove the necessity of a

redesign. An extended examination and complaint analysis has to be performed in order to

understand and assess the complaints on pain, fatigue and injuries after using the single handle

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controller. The team recommends that Altec has the companies who are filing complaints have

their workers fill out a Body Part Discomfort Chart (Appendix D) and a Borg CR10 Scale

(Appendix E).

One possibility for Altec and the customers is to apply some of the ergonomic recommendations

in this report, such as implementing a supportive handle. By doing so, Altec can examine if a

smaller adjustment can make a big difference for the operators without costing Altec a larger

amount of money. This way, the operating environment will be more ergonomically suited,

without major readjustments of the single handle controller and find out if any OSHA 200

(injury and illness record keeping) forms have been filed.

A balanced technical solution for Altec would be to implement the second handle and perform a

follow up evaluation. Ideally, Altec would implement both the second handle as well as the

pistol grip controller.

VII. Future WorkThere is still work to be done on the pistol grip design. The SolidWorks model presented by the

team does not fully take into account the interlock. It merely offers an ergonomic solution. Team

MD6 primarily focused on the ergonomics in terms of the controller and the force/strain loadings

on the muscles in this project. Additionally, EMG testing would vastly contribute to the validity

of the ergonomic solutions presented in this report.

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VIII. References

[1]"Altec ISO-Grip Control System." Altec News and Articles. 5 Oct. 2013

<http://info.altec.com/articles/bid/242179/Altec-ISO-Grip-Control-System>.

[2]"ANSI/SIA A92.2-2009 Vehicle Mounted Elevating and Rotating Aerial Devices."

ANSI eStandards Store. 5 Oct. 2013 <http://webstore.ansi.org/RecordDetail.aspx?

sku=ANSI%2FSIA+A92.2-2009>.

[3]Chaffin, Don B., Gunnar Andersson, and Bernard J. Martin. Occupational

biomechanics. New York: Wiley-Interscience Publication, 1999.

[4]Chaffin, Don B., Gunnar B. J. Andersson, and Bernard J. Martin. Occupational

biomechanics. New York: Wiley, 2006.

[5]"CSA C225-10 Vehicle-mounted Aerial Devices (Includes Update 1)." ANSI

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[16] Altec

[17] Dr. Jason Gillette, Associate Professor, Department of Kinesiology, Iowa State

University. Postdoctoral: University of Kentucky, Biomedical Engineering; Doctor of

Philosophy: Iowa State University, Biomedical Engineering, and Engineering Mechanics.

[18] Dr. Richard Stone, Associate Professor, Department of Industrial Manufacturing

Systems Engineering; Doctor of Philosophy: University of Buffalo – New York,

Industrial Engineering.

[19] Alex Renner, Doctor of Philosophy candidate, Iowa State University, Mechanical

Engineering and Human Computer Interaction.

[20] Dr. Gary Mirka, associate dean, Iowa State University. Doctor of Philosophy,

Industrial and Systems Engineering, Ohio State University.