PRE2019 4 Group9

Group members

Name	Student ID	Department
Pim Claessen	0993712	Applied Physics
Bengt Frielinck	1269593	Automotive
Matthijs Marinus	1000921	Software Science
Max Opperman	1232427	Computer Science and Engineering
Thomas Willems	1022753	Software Science

Goedemorgen Lambert Rooijakkers

Problem Statement

From the beginning of mankind some 2 million years ago, humans have never lived in a more connected, safe world. People can travel the world by plane and car and we have a system to protect and help us from danger and misfortune. However this is modern way of live has not completely eliminated all dangers. Due to our connected world death by road accident is a common occurrence definitely under younger ages. In these accidents people can get stuck inside or under a car. The current tools used to free this people are hydraulic pumps, spreaders and cutters. While these can effectively help free people they also take quite some time to set up and use, time that isn't always there. This is why we propose the use of an actively powered exoskeleton. Firetrucks can be equipped with this exoskeleton and firemen can put it on while driving to the emergency. This will provide instant superhuman strength for any situation. In the case of a person being stuck under a car, the car can be lifted the moment the firemen arrive and valuable minutes are saved that are normally needed to set up a hydraulic jack. Firemen are only 1 example of the emergency workers benefiting from the super human strenght given by an active exoskeleton. The flexible design we propose can improve rescue workers effectiveness in all areas, for example disaster areas, where lifting rouble and carrying people all day puts a heavy strain on workers bodies. In this report a concept design for such a flexible, multipurpose, active exoskeleton will be given

User Group

We will be designing our exoskeleton for use by emergency responders. In most situations these will be firefighters. However we will keep other use cases in mind for example for police officers or search and recue operations. Firefighters have an incredibly difficult and dangerous job. Typical firefighter emergency scenario’s include medical emergencies, vehicle accidents, building collapse and of course putting out fires among others. These are difficult, strenuous activities often carried out in very adversarial conditions. It is then not surprising that one of the mayor causes of death for firefighters is overexertion, being struck by objects or getting caught/trapped . Our exoskeleton should help alleviate this group by reducing the amount of physical exertion firefighters have to undergo while performing our jobs. We also hope the exoskeleton can provide the firefighters with the extra boost in strength to free themselves or people they are helping in dangerous situation. The exoskeleton should also serve as a type of shield by taking some of the blows of various objects hitting the firemen since the exoskeleton will cover a large part of their bodies. It will also help them carry people much easier out of dangerous situations, or move heavy objects trapping people. You could also think about tall buildings which are on fire. Firemen have to carry equipment up a large set of stairs. Currently there is already an exoskeleton design who helps firemen carry up to 40kg of weight making this task much easier and faster . It should also be applicable in traffic accidents where victims are stuck in folded cars. Often firemen are called in these scenarios to cut open the car. This is a difficult process and having an exoskeleton to bend or break critical parts should be a tremendous help.

Another great user group are search and rescue workers. After natural disaster these people are deployed to find and help people who are in danger. This usually involves freeing people from under a large pile of debris from collapsed buildings or other items. These operations usually take a long time and a lot of equipment. Shows a company who has developed and exoskelton already for this case allowing the user to have extra power to move debris or objects for a long period of time under harsh conditions. These are defenitly some of the features we want to equip or exoskeleton with.

Police officers could also benefit from using this type of technoglogy. As explained in police officers often have to carry heavy equipment like gun vests or gun belts with them. This coupled with long standing hours causes a lot of police offers to eventually develop health problems in their back or legs causing them to become unemployed. If they were to carry and exoskelton during long work hours we could alleviate some of this repetetive strain.

State of the Art

We probably have to pull different innovations from all kinds of different types of exoskeletons. From different parts of the body to different types of exoskeletons (varying goals). shows that currently a problem many exoskeletons face is the tradeoff between rigidness and agility. Often a more rigid skeleton can provide more stability/force but in practice is quite cumbersome. The exoskeleton in is an example of an exoskeleton designed for firemen. It provides support for the back and shoulders and is a good example of something we would like to achieve, alleviate some of the heavy work. Discuses some positive/negatives of a back support exoskeleton mostly used in treatment of SCI (spinal cord injury). Interesting part of this article is that it also discusses some of the dangers involved in using an exoskeleton like bone fractures and skin shearing. Furthermore it also discuses how tailor made most exoskeletons are and that most take a lot of practice to get used to. The last problem it brings up is that they also take of lot of time to get into. These are all problems we are going to have to think about in our project.

Talks about the impact exoskeletons could have on police work. A lot of injuries over the long term are caused by repetitive strain from carrying gun belt, bullet resistant vests and long periods of standing. As is the case for firemen, who also carry a lot of gear and are likely to have to stand for long periods of time, our ES should alleviate this repetitive strain keeping the emergency responders in better health for a longer time. Displays another great possible use case exoskeletons, some of which we want to replicate in our model. It involves and exoskeleton designed for dangerous and heavy search and rescue work under extreme conditions. It allows the user to carry heavy object with greater ease and for longer periods of time helping with moving debris or heavy objects. This is also a functionality we want to have.

Requirements

Within the design of an exoskeleton, multiple required features should be present, depending on the user of the exoskeleton. As the user of the exoskeleton will be emergency services the exoskeleton should be flexible so as to not restrict the user because emergency responders need to be able to move in tight spots. The device should also be powered, this will allow the user to lift more than physically possible otherwise. To not restrict the movement, the exoskeleton should not just be flexible, but also lightweight. A lightweight and flexible design would help with the requirement of being able to operate the exoskeleton without power. It is important that the exoskeleton an be operated without power, as otherwise, the user could be put in a precarious situation if the device were to suddenly malfunction or power off. As the exoskeleton is going to be used by emergency services, the device should be transportable in a car used by the responders. Also, the exoskeleton has to be put on in a reasonable time, the exoskeleton cannot take more than 10 minutes to be put on. The final requirement is that a user with the exoskeleton should be able to lift x times as much, then a user without the exoskeleton, as the benefits from the exoskeleton should outway any negatives that a device such as this brings.

Max: Car weight: 1200kg (small) - 3000kg (large SUV) https://mechanicbase.com/cars/car-weight/ Size car: 4x1.7 (small) - 4.7x2 (large SUV) in meters. https://anewwayforward.org/average-car-length/ Uitgaande van 3000kg - Je tilt op de piek de helft want de andere helft staat op de grond

Exoskeleton: The measured contact pressure was highest on the trunk (91.7 kPa-93.8 kPa) and least on shoulders (47.6 kPa-51.7 kPa), whereas pressure was perceived highest on the thighs (35-44% of Max Local Perceived Pressure). Shoulders minimum: 47600 Pa = 47600 N / m^2 = 4853.8491737749kg / m^2 Trunk minimum: 91700 Pa = 91700 N / m^2 = 9350.7976730076kg / m^2 Note: 35-44% van “pijngrens” bereikt Pain Pressure Threshold (PPT) around 280 kPa - 480 kPa - as stated by the following source: https://www.mdpi.com/1424-8220/15/2/4550

https://reader.elsevier.com/reader/sd/pii/S0003687017302533?token=94793FB5658F55FC8368F7306DC3650F12CA6392036277749CED5F498D6E193E7F5BD19B8484454FFB4C457A0140D1FF

Requirements V2.0 Within the design of an exoskeleton, multiple required features should be present, depending on the user of the exoskeleton. Keeping in mind that the users of the exoskeleton will be emergency services we came up with the following requirements respecting the requirements ISO 29148 for systems (and software) engineering.

When in passive-mode, the exoskeleton shall carry at least its own weight. When in passive-mode, the exoskeleton shall move freely without restricting the movement of the user. When in passive-mode, the exoskeleton shall change to active-mode when the “change mode” button is pressed within 100ms. When in active-mode, the exoskeleton shall be powered by batteries. When in active-mode, the exoskeleton shall ensure that the user feels When in active-mode, the exoskeleton shall change to passive-mode when the “change mode” button is pressed within 100ms.

The exoskeleton shall resist heat up to 2300°C. Note: carbon melting point is 3550°C; approximately 2300°C is Acetylene fire The exoskeleton shall not limit the degrees of freedom of the user. The response time of the exoskeleton shall be no more than 0.1 seconds from user input to exoskeleton output. https://spectrum.ieee.org/automaton/robotics/industrial-robots/sarcos-guardian-xo-powered-exoskeleton The exoskeleton without batteries shall weigh at most 40 kg.

https://ieeexplore-ieee-org.dianus.libr.tue.nl/stamp/stamp.jsp?tp=&arnumber=8570092

https://ieeexplore-ieee-org.dianus.libr.tue.nl/stamp/stamp.jsp?tp=&arnumber=7992830

Basic form: Condition, Subject, Action, Object, Constraint of Action. Try to not use: negations, “shall be able to”, different forms than the basic form :)

Pim: When in active-mode, the exoskeleton shall be powered by batteries. (depending on required work needed and weight: remote batterypack in car with cable maybe option)

Prismatic lithium-Ion batteries have the highest energy density [Wh/Kg] of around 160 Wh/Kg and a volumetric energy density of around 360 Wh/L. epectec.com/batteries/cell-comparison.html

Weight car with hinge point (arm of force can be neglected in correct lift and with locking mechanism) Example SUV specs: 3000Kg 5m x 2m x 1.75m Force needed sideway tip = 14715N Energy needed sideway tip = (max 29430 J) → for 5min actief liftwerk +- 15kg batterijen

Approach, milestones & deliverables

Approach

Our current goal for the end deliverable is a model for an exoskeleton that helps emergency services. Due to the COVID-19 situation, the process of the actual building of the model will be difficult in the given time span. The aim is to have a full-body exoskeleton that has both a passive and active mode to preserve battery. We want to achieve this by reaching the milestones as mentioned below. In short, we want to do research on what has already been achieved in the field of exoskeletons and how they operate. After that, we want to start designing our model and elaborate on our design choices in a report. This model will be made using CAD software which we yet have to determine. Since we have plans for a full-body exoskeleton we will distribute this work amongst two of our group members. The rest of the group will work more on the research and design choices of the project. If we find out that this distribution of work is not working out for us, we will alter it accordingly.

Milestones

Week	Milestone
Week 1	Research on possible projects and prepare for the first meeting
Week 2	Summarize papers & more research First design decisions
Week 3	Learn CAD Elaborate research on design decisions
Week 4	First CAD concept designs Finish research & write the report
Week 5	Finalize design Elaborate design sections in the report
Week 6	Finalize CAD models Finish design sections in the report
Week 7	Finish video presentation Final report on the wiki page
Week 8	Video presentation and peer review

Deliverables

Our deliverables will be:

• A concept design for a flexible, multipurpose exoskeleton that uses passive and active technology for use by emergency services.
• A report on the wiki page containing a detailed description of the design as well as all of the research, findings, and results of the project.
• A video presentation presenting our research, findings, and design.

Task distributions

Bengt and Matthijs will focus on learning CAD and visualizing our designs. As mentioned before, there will be somebody (Max) who can help with this if there are too few group members assigned to this task. Max, Pim, and Thomas will do research on how the exoskeleton will be made. This consists of e.g. the materials, electronic circuits, and passive mechanisms.

Logbook

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Week 1:

Name (ID)	Hours	Work done
Matthijs Marinus (1000921)	8	Intro lecture[1h] Meetings [3h], Finding/Researching different topics [4h]
Bengt Frielinck (1269593)	8	Intro lecture[1h] Meetings [3h], Finding/Researching different topics [4h]
Pim Claessen (0993712)	7	Intro lecture[1h] Meetings [3h], Finding/Researching different topics [3h]
Max Opperman (1232427)	7	Intro lecture[1] Meetings [3h], Finding/Researching different topics [3h]
Thomas Willems (1022753)	7	Intro lecture[1] Meetings [3h], Finding/Researching different topics [3h]

Week 2:

Name (ID)	Hours	Work done
Matthijs Marinus (1000921)	6	Meetings[30m], Researching new topic for user groups [2h], Writing user groups/SoTA part/updating wiki page[3h30m], Installing CAD Fusion360/Doing tutorials on modelling[5h]
Bengt Frielinck (1269593)	5	Communications[30m],Researching[2h], Writing requirements and revision[2h30m]
Pim Claessen (0993712)	3.5	Meetings[2h], Writing Problem Statement [30m], Research [1h]
Max Opperman (1232427)	5	Meetings[2h], Writing Approach, Milestones and Deliverables/updating wiki page[3h]
Thomas Willems (1022753)	4	Meetings[2h], Writing Approach, Milestones and Deliverables/updating wiki page[2h]