DROBOTICS® ( \dro-‘bä-tiks\ )

: Technology used to design, build, and operate self-guided unmanned vehicles, with no single point of failure, and the highest priority possible for safety of human life within their area(s) of operation.

DROBOT® ( \dro-bot\ )

: A virtually autonomous vehicle, self-sufficient and self-guided, built on Drobotics technology.  Used primarily to distinguish from remotely piloted Unmanned Aerial Systems (UAS) or “drone”.


USDrobotics started with a simple question: “How can we create a UAS that is truly safe for almost any application?”  Our inescapable conclusion: Take the human pilot out of the equation. With that realization, our research has taken us down a fundamentally different R&D path from other companies, resulting in a completely new class of Unmanned Aircraft Systems. These systems have flight autonomy, yet are under complete system control and monitoring: the drobot. Drobotics technology is a major paradigm shift in how we think about UAS.

Along the way, we realized that these technologies, systems, and methods also provide for a safe and effective Air Traffic Control system (ATC) which can be utilized to automatically manage the UAS/drobotic air space, enforce registration and platform regulations, and provide safe monitoring of the air space to prevent offensive actions from UAS.

The FAA began its investigation of UAS in 2005, focusing on how to incorporate the new technology into the National Airspace System (NAS) starting in 2008.  It recently launched a registration program to facilitate the use of small UAS (under 55 lbs) for “non-hobby or non-recreational purposes”, in anticipation of a new Part 107 to be added to Title 14 Code of Federal Regulations (14 CFR), allowing routine civil operation of small UAS in the NAS.  Of the 19 limitations and risk mitigations noted in the proposed Part 107, the most constraining are: 1) restricted to daylight-only operations, 2) limited to confined areas of operation, and 3) a requirement for visual-line-of-sight operations.  These are based on the then industry consensus that there are no known technologies that could compensate for these mitigations.  However, the remainder of this document will show why we believe that this technology will solve for these three issues, and several more.

The Social Framework

An effective ATC must solve for all safety, operational and practical considerations surrounding UAS traffic.  If it does not, it will eventually fail, with potentially serious consequences.  In today’s world, it’s not an option for this new industry to be under-regulated when it comes to safety, yet at the same time not overregulated in terms of the rapidly evolving capabilities of the platforms and the explosion of applications. Imagine what would have happened to the growth of the microcomputer industry if the FCC had been required to approve all new applications to be run on the machine.

There are just a few critical factors for assuring safety and promoting overall consumer and business confidence in an expanded use of UAS:

  1. Reliable and safe avoidance of physical contact with people, objects or other UAS, and non-interference with traffic already in the NAS.
  2. Autonomy in both platforms and ATC processing. David Vos said at CES 2016 that the biggest limitation is “humans have to be involved. If it’s fully automated, it can happen at the speed of processing.”
  3. Personal Privacy Protection
  4. Integration of UAS technology into law enforcement and appropriate government agencies, with suitable protection for personal privacy
  5. Safe and effective commercial delivery and transport applications
  6. Regulation compliance and enforcement
  7. Mitigation of the potential for UAS to aid in criminal, destructive, or terrorist activity
  8. Simple, easy solutions that enable responsible hobbyists to enjoy flying their UAS

Hobbyists.  People in much of the free world believe they have the right to do almost anything, as long as they don’t infringe upon the safety and welfare of others.  This sometimes results in a resistance to compliance with regulations, bolstered by the belief that enforcement is just not possible or probable.

Commerce. The pending FAA rules are justifiably driven by the concern for safety of human life, damage to physical property, and avoidance of interference with the existing NAS. However, it will fall short of enabling businesses to fully realize the services and commercial success that could be achieved with  UAS, particularly those above the 55-lb small UAS category and soon above the 212-lb UAS limit. FAA Jumbled Airspace Board

Mitigating The Risks. Satisfaction of the considerations outlined above, with use of the right technologies, would enable legislation that would promote safe and successful commercial UAS traffic.  Such a technological solution would also bring resolution to the three chief risk mitigations noted under the FAA section above.  We know that it is unrealistic to expect total prevention of all serious misuse of UAS, but we can deter acts of intentional violence and destruction by making them more expensive and difficult to plan and execute.  We can also add predictability to, and increase the effectiveness of, law enforcement and government intelligence efforts to detect, forestall or prevent such behavior.  These objectives can be accomplished by the introduction of new types of vehicles, intelligent flight operations requirements, and new technical platforms for safety, privacy and increased forewarning systems, that have never before existed or been seriously considered.  Industry and government must move quickly to get ahead of the potential for serious criminal or subversive misuse of UAS.

We denote the two camps of thought on the UAS ATC as the Amazon “Avoidance” model (left) and the Google “Cooperative” model (below).

While they agree on many points, the largest division seems to be that Amazon feels the cooperative model is insufficient to take on all the possible obstructions that will exist in this low altitude environment, and Google believes that unless you can control all of the traffic it will quickly degenerate into chaos. The simple truth is that both are right. In an ATC that satisfies the above requirements industrial drones will have to follow tightly controlled flight paths and within given restrictions move independently to avoid transient obstructions.

FAA Organized Airspace BoardIf one looks ahead to an airspace crowded with many platforms of different origins and all flying just with avoidance control, it is similar to Newton’s Third Law: Every action has an opposite reaction. If a drone detects an imminent collision with another, its avoidance system will alter its course. The other drone, however, is also going to detect the collision and alter its course as well, both potentially now causing further interaction with other platforms in a chain reaction. We call this the “Pachinko Effect.”

For piloted systems, the total ATC system requires only a few fundamental considerations.

  • Block Reservations allow a user to request a block of space and time for recreation or commercial use. This has been suggested before, we agree with its utility, and it is fully supported by this ATC implementation.
  • Citizen “No Fly” Zones: Similar to the “no telemarketer” lists, concerned citizens can request limited overflight capabilities in their location, without cutting off their neighbors. This highlights one problem with the Geofencing paradigm, it requires high accuracy and if thousands of people request such a service the Geofence map quickly becomes larger than any drone could process internally in real time.
  • Inverse Geofencing: AKA Free Flight Corridors (FFC) or a Hard Fence. Piloted platforms would be provided with a set of 3-Dimensional waypoints and the times to hit them, along with an FFC that would limit the drone’s flight to within the corridor, not everywhere but the geofenced area. This is fundamentally necessary to protect the public and nation from offensive action and terrorism.
  • Platform Transponders: Legal transponders will be necessary for monitoring the ATC and enforcing regulations. Without this the regulations are unenforceable and the ATC system itself becomes meaningless, but more importantly the transponder allows us to detect an illegal and possibly offensive platform faster, providing essential warning time to high value targets and infrastructure.

The remainder of this document will focus on how a drobotics-based ATC system could satisfy all of the safety, commercial, and social concerns of UAS use, providing a safe, uniform and reliable framework for the expanding interest and reliance on UAS traffic.


The ATC System

Drobotic systems are specialized supercomputers built to do one thing very well:  follow a pre-designed path through space with exact timing and high accuracy.  It is how this path system is designed, implemented, and monitored that provides the functionality of our ATC.  We call this system a TrackPath®. In our technological paradigm shift, a TrackPath is a 4D mathematically defined spline governed by both space and time. Geofencing is simply inadequate to meet the safety concerns when the UAS can be flown anywhere with a gimmick as simple as covering the GPS receiver.  In contrast, Trackpaths define with high accuracy the free flight corridor within which the UAS is allowed to operate.  It cannot fly out of that corridor. If the GPS or other critical systems are disabled, it simply cannot fly. This difference is the fundamental basis for preventing and avoiding offensive action or unintended physical contact with people or objects.

Air Traffic Control. Any ATC system depends on platforms being compliant with current regulations.  Our proposed UAS ATC would propose the following foundation requirements:

  1. Load Capacity. No UAS with a load capacity of over 500 grams would be allowed to fly without an FAA-approved TrackPath   The primary reason the proposed FAA regulation (Part 107) addressing the weight of the vehicle is to attempt to protect general aviation and the public from a high mass object hurtling at them out of control.  Both of these audiences would be protected by other aspects of the Drobotics ATC. The focus on the load capacity allows us to mitigate the offensive capability of the platform, i.e. how much explosive can it carry? Or a combination of mass and load might be considered. Certainly if the whole platform plus load were less than 500 grams, both concerns are addressed.
  2. All vehicles in this class must support an FAA-required transponder. These are a critical element in monitoring and enforcing the regulations, and enforcement of the regulations is paramount to the success of the ATC.  We already have a working prototype that is lightweight, low cost, and fulfills the requirements of the system.
  3. Registration Required. This now becomes a requirement as part of the transponder process, and it’s imperative that the data be encrypted and protected. This is for the necessary protection of personal information to prevent criminal activity based on potential identity theft. Encryption is also necessary to prevent “hacking” of the trackpath which might allow for offensive capability.

The Trackpath

With these three foundations outlined above, the TrackPath is positioned to satisfy all safety and security concerns of UAS traffic.


UAS users would request a TrackPath through the ATC control station, where they are automatically generated by the ATC system utilizing a 4D Autorouter. This is a new technology similar to 3D autorouters which are used on a daily basis to design printed circuit boards. The 4D Autorouter calculates at high speed the optimum safe path for a vehicle through all known obstacles, taking all other vehicles into account in both space and time without human participation, but with the ability for oversight.  With this information, the system can quickly, safely, and effectively handle the workload of calculating and approving thousands to tens-of-thousands of air traffic requests per hour with no additional personnel requirements.

A TrackPath starts with a 3-dimensional model of the Area of Operation (AO) which includes the source and destination points.  This is then overlaid with a 3D grid structure, and the model is intersected with the grid to provide an area of computation that can be easily searched and manipulated in software. Through varying techniques the accuracy of this model can vary from tens of meters to centimeters depending on the requirements of the search and the density of AO structure. The key factor is that all known moving elements of the system can be included in this model as well as static obstructions, no fly zones, and citizen overflight restrictions. It can also consider the capabilities of the drone type and its relative accuracy in following the path (i.e. piloted vs autonomous).  It can even “learn” that a particular done is always fast or slow or just has a pilot that needs more room. This is the key to the overall control of thousands of UAS in the AO without human traffic controllers, planners, and technicians to check every flight plan. The autorouter can also be programmed to take into account moral decision criteria as defined by society, population density in areas at different times of day, shelter considerations, etc.


For all UAS within the AO, the autorouter also provides a Free Flight Corridor (FFC) 4D structure for autonomous systems, or a detailed Inverse Geofence for piloted platforms.

The FFC depicted left might be used in a block reservation sense for a drone theater at a theme park. At this level of complexity it is not very different from a Geofence, except it keeps the drones In instead of Out.

In the FFC structure below, however, no Geofence could adequately convey the information required.

The ATC System from the User’s Perspective

As outlined in ATC Recommendation #1, above, the UAS must load an approved TrackPath.  This would be done through the transponder, using three types of protocol:FIG 6

  1. Personal or Recreational Use. Using an FAA ATC mobile app, a user would request a “block  reservation” for a given ground space, altitude limitation and time frame e.g., an unused soccer field, or around a house for which he wishes to take pictures for a realtor. That “free fly” zone is noted in the 4D Autorouting system, which automatically prevents other craft from being routed through that area for that time. The zone is loaded into the user’s platform, and it is free to operate in real-time, but it cannot leave that zone. Certain block reservations for dedicated fly parks could be permanent and have higher than 200ft limitations, all supported in the ATC.
  2. Automated Delivery or Transport. Platforms used for all of these service types, e.g., Amazon, UPS, FedEx, or the US Postal Service, would require a designated TrackPath for the platform to get from point A to point B. Their internal automated systems would scan the package, and transmit the origin and destination to the local ATC control station.  The ATC system would take all other known traffic into account, and calculate a safe path for the requestor, and transmit the approved TrackPath and start time back to the shipping company.  The platform can then take off at the appointed time, using the calculated TrackPath. Obstacle avoidance would still be necessary for this class of UAS. The trackpath’s FFC provides it with sufficient room for obstacle avoidance without impacting other systems.  If the delivery vehicle is remotely piloted, the pilot would be given a set of waypoints and times with which to navigate, and the platform would be loaded with a detailed free-flight corridor or inverse geofence that it cannot leave.
  3. Law enforcement and other government agencies. Requests from these organizations would receive top-priority for free-flight zones when in authorized pursuit or tracking of a target (human, car, boat, etc.)  The 4D Autorouter provides the same functionality as the block reservation (Protocol #1, above) but with wider parameters.  The free-flight corridor may be more complex if the ATC system needs to negotiate through or around already-scheduled traffic.  Within moments, however, the interceptor (i.e., government UAS) is ready to launch. In addition communications links between first-responders and the ATC distributed by the monitoring system allow for emergency personnel and first-responders to quickly clear a given section of airspace when necessary.

With current technology and strategies, there is no way to discern any level of potential threat posed by any of the UAS which are rapidly filling the skies, since they all “look-alike” to the typical observer. With this tiered protocol approach, the ATC system can differentiate between approved platforms with designated TrackPaths, and those which might be unlicensed or “rogue”.    With the proposed FAA-issued TrackPaths and transponders, we can satisfy all of the considerations outlined above under the Social Framework section of this document.

Military Cockpit Board

NAS Integration

Because the trackpaths specify the location and time for each platform to operate, it can easily be integrated into the existing NAS providing the approximate location of any platform at a given time. This could be integrated into ADS-B or other instrumentation, particularly for disaster response, news helicopters and other aircraft which may be close to the UAS space. The monitoring system provides timely updates to the system to account for any deviations in time or space.


The System.  The monitoring system will provide two basic functions:

  • Scanning for targets that match UAS characteristics. (Several different technologies can be used to distinguish UAS from birds in flight, balloons, kites, etc.)
  • Receipt of transponder signals and correlation with the detected targets. When a transponder is not detected, a threat warning is raised which requires immediate evaluation and response.  Transponder tracking is the foundation of effective regulation enforcement and coordinating threat response.

This approach enables raising threat warnings with much more information and time than is currently possible. Countermeasures of various types would need to be considered and codified, both on the monitor tower and the interceptor platform. An immediate first option could include launching an interceptor UAS to take a closer look, make further threat assessments, and even follow the subject platform.

”The Bad Actor”:  A perpetrator who is intent on performing criminal or destructive action with a drone platform now has a much lower probability of success.  First, he has to get past the FAA and TrackPath restrictions.  With ATC monitoring, he can now be detected as unauthorized, and the radio signal controlling his device can be backtracked.  He’s also increased his risk:  possibly by purchasing an unlicensed drone from overseas and having to smuggle it into the country, or building his own drone possibly requiring additional conspirators or much more education, effort, and time – each step increasing the opportunities for law enforcement and government intelligence to intervene. Every level of protection that forces a higher level of education, cooperation, and logistics lowers the number of actors that can become real threats.

For the well-meaning but negligent drone-owner, knowing that detection and enforcement is reliable, there would likely be a renewed interest in drone registration and compliance with regulations.  A simple comparison can be made to toll booth cameras that record license tags to track down drivers who breeze through with an empty transponder account or the fact that almost everyone speeds 5 MPH over the limit because they know that that is the practical limit for enforcement.

Security.  The final security requirement is the intrinsic Security built into the TrackPath process:

  • TheTrackpath is loaded into the FAA transponder first, encrypted to prevent a hacker from transmitting an unapproved TrackPath to a platform. It is decrypted and checked for authenticity codes, then transferred to the platform’s controller. After the controller has validated authenticity, it reads the TrackPath back to the transponder to confirm it has not been compromised.  At this point, because it is hardware-based, the FAA-issued TrackPath cannot be altered within the platform without repeating the entire process.
  • There is a final Interlock Key which is encoded into the TrackPath data, which in a final check is sent to the FAA, and a confirmation code is received. The transponder then removes the final interlock and allows the platform to launch. This final Interlock Key prevents hacking and platform modifications that could circumvent FAA controls.