Bit by bit, drones can print structures made of foam and cement. The technique could transform future construction sites and post-disaster reconstruction.
TECHNOLOGY 21 September 2022
By Jeremy Hsu
**Disclaimer** We don't own this video
Drones working together can create large 3D-printed structures made of foam or cement. The experiments are paving the way for a future where swarms of drones could help construct extremely tall or intricate buildings and other structures like bridges without the need for support scaffolding or large construction machinery.
“We’re talking about being able to build something of limitless size, theoretically speaking,” says Robert Stuart-Smith at the University of Pennsylvania. Such creations would only be restricted by structural engineering constraints and factors like drone flight logistics.
The drone swarm construction takes inspiration from animals such as wasps and termites. “If you want to build something very large, typically in nature what happens is that many animals work together,” says Mirko Kovac at Imperial College London, who led the project.
Kovac and Stuart-Smith together with their colleagues showed how several drones could cooperatively build a 2-metre-tall cylinder made of insulation foam and a 0.18-metre-tall cylinder made of special cement. First, one of two builder drones flew around in a circle while squirting out a line of the quick-hardening foam or cement, building up the structures one layer at a time.
After each layer was printed, a third drone used a depth-sensing camera to capture a 3D map of the work in progress and allow the cooperative drone team to adjust construction steps as needed.
Each of the drones can operate for up to 10 minutes before needing to reload building materials and sometimes get a fresh battery.
Additional testing and simulations demonstrated how up to 15 drones could coordinate flight paths and work together to build a dome. The drones can make their own AI-guided decisions about where to fly and how to deposit building materials, but still require human supervision.
These 3D-printing drones could help with post-disaster reconstruction in remote areas, or even work on dangerous projects such as repairing the concrete sarcophagus at the Chernobyl nuclear plant.
A next big step involves moving the drone construction outdoors, says Vijay Pawar at University College London. That requires figuring out an efficient way to recharge the drones and load them up with fresh building materials, along with setting up the communication networks to safely supervise large numbers of drones.
The construction industry has already been using drones for inspection, but the concept of builder drones makes sense, says Masoud Gheisari at the University of Florida, who was not involved in the study. “I think this paper perfectly shows that it’s not science fiction anymore,” he says.
Drone Survey vs Traditional Survey The Main Differences from Cost efficiency through to reliability.
The Pros and Cons
What is Survey? As we are aware survey is a term used fairly loosely these days and in many different contexts but traditionally was a term that meant the gathering of sufficient data to allow for instant or prolonged decision making based on the results of that particular data capture and further analysis. For this particular post, we will concentrate on this instance.
We have included a snapshot of the term that was recently pulled from Google and their thoughts on the terminology meaning. Drone Survey What Does It Involve? Drone survey is to carry out the above method or methods utilising drone technology in place of manned survey techniques which were once commonplace. However, as drone survey becomes normality in the workplace manned survey techniques will eventually begin to reduce. Drone survey is what is known as disruptive innovation.
Disruptive innovation What Is It’s Meaning? Disruptive innovation or disruptive technology is a particular service or product that disrupts a product or service that was done differently in years previous, resulting in the end goal achieved with more economic results in terms of finances, More time efficient or with an improvement in safety. There are further cases of disruptive innovation but essentially the end result is achieved with a much greater all-around user experience, disrupting the traditional methods to the point of them no longer being relevant. What are Classed as Traditional Methods?
Rope Access Inspection Rope access inspection could be classed as traditional methods of survey, when compared to drone survey, as can several others, however, the difference being they all require a manned element. These might include scaffold access to the particular area or asset where the survey will be conducted or MEWP Hire to access the area from ground level etc. Rope access inspection is a service carried out by IRATA qualified rope access technicians IRATA being the qualification body that governs the individual’s certification based on their experience (Industrial Rope Access Trade Association) Rope access inspection is usually the preferred method of high-level survey in certain industries due to the fact that it’s less invasive than other methods despite the up close manned element. However, there is an element of risk to rope access inspection methods with potential for dropped objects from rope access personnel or equipment failure resulting in loss of life. Rope access inspection also has the potential flaw of the human element. We all make mistakes unfortunately and making mistakes, under those circumstances, can result in loss of life. Scaffolding
Inspection from Scaffolding is an idealistic solution to many industries due to the fact that scaffolding provides a work platform for any person or project decision-maker to access via ladders and perform their own unhindered survey of a particular asset or piece of equipment. This gives the opportunity to access the area as many times as necessary whilst providing a secure platform to work from. Scaffolding, however, requires many restrictive factors such as:
Lower level area restrictions whilst scaffolding erection is taking place
Prolonged shut down during scaffold erection and disassembly
Inefficient time scales during scaffold erection and disassembly
Requirement for a large team of personnel during scaffold erection/disassembly
Minimum spatial requirements surrounding asset
Scaffold erection also has several safety concerns in comparison to other survey methods:
High risk of dropped objects to lower levels
Risk of load bearing equipment failure
Risk of tools and equipment falls from height
As can be noted there are both pros and cons to scaffolding and area to be inspected but the decision on whether scaffold erection is the preferred method is situational and based on several factors. MEWP Hire / Access Platform Hire Inspection via MEWP or access platform can be beneficial if the conditions are appropriate as per other methods of survey such as rope access inspection methods or use of scaffolding, they all have their pro’s and cons. MEWP hire can be expensive and restrictive for one and also requires the usual manned element but also have many benefits. MEWP’s or Mobile Elevating Work Platforms can offer unrivaled access to difficult areas in comparison to the other methods previously mentioned. There are several varieties which can overcome most scenarios and terrain issues and are known as many different names much the same as our own primary business tools.
MEWP: Mobile Elevated Work Platform
EWP: Elevated Work Platform
AWP: Aerial Work Platform
MAWP: Mobile Aerial Work Platform
MAP: Mobile Access Platform
AP: Access Platform
MEWP hire for visual inspection can be a great way to access arduous areas at height but as aforementioned, there are still flaws and restrictions. Inspection from a MEWP is limited by reach although there are several variations around MEWP hire unfortunately, none have an infinite reach capacity. Also the longer reach capacity the higher the hire cost generally speaking. Second issue with MEWP hire for survey requirements are the usual safety concerns as per any of the other manned inspection methods. MEWPs must be operated by trained operators which adds to the cost but also have a habit of tipping over if operated incorrectly or abused. There are also instances where the operator is thrown from the basket whilst traveling. There are other issues with MEWPs such as working weight restrictions and terrain access, some are 4×4 but they still need to operate on stable ground. They also carry the same issues as the above two entries regarding catastrophic failure, there is always a risk of equipment failure and no matter how many secondary safety measures and how much mitigation is put in place there is always a risk of failure. Dropped objects and falls from height are also possible alongside human error. All factors that must be undertaken when considering MEWP hire for visual survey purposes. Drone Survey
Drone Survey is unique in terms of the only survey method that doesn’t require direct involvement from a manned perspective trumping all of the other visual inspection services such as rope access inspection, MEWP hire or scaffold in terms of health and safety.
Drone survey is the only method of visual survey where if a catastrophic failure were to occur resulting in complete equipment failure, the likelihood of fatality is none existent and injury to personnel slim to none if the correct risks have been mitigated in accordance with company operations manual and flight limitations.
Drone survey does not have limitations in terms of requirement for specific surroundings or need for idealistic logistics in terms of architectural style or shape providing highly detailed data.
Drone survey can provide highly detailed and live feedback to the ground station and connected devices or record directly to onboard SD card allowing for remote further analysis.
Drone survey can cover more ground in a time effective manner in comparison to rope access inspection methods which is, in turn, more time and cost-effective than any of the other methods listed.
Drone survey and the outputs that can be achieved scores highly over any of the other options used for instance a thermography scan can be produced of an entire building detecting for energy losses and heat signatures from an aerial perspective. Providing the data to analyse the building envelope efficiency.
Drone survey can provide point cloud data allowing the overlay of a HD mesh on top of the point cloud, providing a highly detailed 3D image providing the client the necessary means to navigate and orbit the model remotely and inspect in fine detail to analyse any specific fault or remedial requirement.
Drone survey can be optimised to produce highly detailed orthomosaic images and maps through an automated sequence called Photogrammetry again this orthomosaic or orthoimage can be rectified to sit perfectly on top of its relative OS grid providing a highly accurate map or orthorectified image.
There are other options that drone survey can be utilised for but the above items are the most common. Not one of the other options can produce or have a hand in producing the same level of data. The time taken to survey a 500sq/m building can be reduced from a week to a day. Or to produce land survey outputs an area of 60 Hectares can be reduced from 2 weeks to 2 days. Drone Safety Health and safety in the workplace is by far the most important factor in any industry when conducting not only survey but anything requiring manned intervention. This can be as basic as cleaning the workplace or as in-depth and intense as replacing a major component part on site. The HSE or Health and Safety Executive the UK’s goverment body for health and safety in the work place, provide reports and conduct random and spot checks in every industry regarding their compliance towards the Health and Saftey At Work Act. This is done to ensure these companies are not placing any unnecessary danger on their employees which could result in injury, fatality or illness. When an accident, fatality or illness occurs in the workplace it is documented and investigated and this data is the driving force behind the HSE annual documentation around accidents, injuries and fatalities in the workplace as per the below Infographic. RIDDOR: Fatalities In The Workplace 2018
Falls From Height
Struck By Moving Vehicle
Struck By Moving Object
Trapped By Something Collapsing
Contact With Moving Machinery
Falls From Height As can be clearly acknowledged although hard to swallow the biggest cause of fatality in the workplace is due to falls from height at least 25% of all work-related fatalities are down to this issue. In this day and age and with all of the education available to us we should not be seeing these figures. Drone survey for visual inspection should be considered in attempt to reduce the current statistics. Injuries due to falls from height are less than expected, however… if we are honest with ourselves. If an injury has taken place due to a fall from height then the victim of this injury is unlikely to admit that the fall from height is the contributing factor to those injuries or injury especially if time off work is required. The reason for this is down to the Risk Assessment and the requirement for use of Specialised personal protective equipment such as harness and fall arrest. Unfortunately, there are still personnel that prefer not to use the equipment as is intended. The recorded incidents around injury due to falls from height will no doubt relate to those that were using their PPE as per procedure and have been injured as a result of the fall from height but were working within the limits of their own risk assessment. Which does not breach any company safety policies and procedures allowing the victim to recover from the injury at home, without worrying about disciplinary proceedings or unpaid leave of absence. Irrespective of the above assumptions drone survey should definitely be the first consideration towards visual inspections in the first instance opposed to rope access inspection, scaffold or MEWP hire. Again there are many other methods of visual survey but these are the main and most popular methods. The Future of Traditional Methods Traditional methods of survey and inspection will always have their place in industry. Hands on inspection can occasionally be the only method that works and until remote technology is adapted and evolves to using tools and can be assigned to repair and maintain those hard to access areas at height then the requirement for traditional access methods such as rope access inspection or MEWP hire will continue. We at DJM Aerial Solutions have great relationships with several companies that specialise in the above access methods and we do on occasion call on them for assistance. But in the meantime please feel free to call us regarding your drone survey enquiries.