In order to be able to guarantee the reliability of such an infrastructure, all machines must be able to process deliveries without human intervention. The machines must therefore be able to carry out all the tasks that a person currently has to perform for a drone delivery themselves. The following requirements are divided into four levels: Must, Should, Can and May not.
Must is an absolutely necessary requirement with functional relevance. Neglection of such may result in dire effects on the whole system
Should is a recommended requirement, the implementation of which would improve the functionality of the system immensely.
Can is an eligible requirement the existence or non-existence of which has no directly identifiable effect on the functionality of the system.
May not or must at no time implies the prohibition of implementation of the matter mentioned in the context.
The drones must be able to take off completely autonomously in any weather condition from any machine and land on any machine. The landing sequence should take place via an interaction of GPS / GNSS and machine vision. RTK-GPS can be implemented as well to improve the accuracy of the GPS sensors. However, an RTK-GPS module would result in high additional costs per drone.
1. Take-off and landing
The drones may at no time cross no-fly zones such as nature reserves, highways or airports. When placing the machines, care should therefore be taken not to include no-fly zones in the operating area in order to prevent energy-consuming bypass routes. A machine must be able to store at least 10 drones. When dimensioning, however, care should be taken not to put drones out of range of people in the user target group. The machines represent the nodes for the telemetry of the drones. In order to make the communication fail-safe and redundant, there must be a connection to at least two machines for each drone in every operating area. In addition, the machines must be permanently connected to the Internet in order to upload and evaluate log data. Preferably by glass fiber connection. Alternatively, they can also communicate via the 4G or 5G network. The machines must have a camera pointing towards the sky in order to be able to verify a valid take-off situation, ergo a clear path upwards. The machines should have several of these cameras and recognize if one of them is covered or otherwise restricted.
The drone’s batteries must either be exchanged automatically by the machine or be able to be recharged during storage. Batteries that have several cells must be charged in such a way that each cell can be charged separately. Each cell should therefore have its own contact point. Otherwise, there would be an imbalance between the cells, which would severely limit their life-span. The drones can be equipped with a BMS3,which would enable the drones to be charged via just two contact points. It would add weight, however. The behavior of the batteries during the flight should be carefully monitored and documented by the drones. Drones must be able to detect dead cells and put themselves into a maintenance state that prevents them from taking off.
The goods to be transported by the drones must be housed in lockable containers. The containers must be constructed in such a way that only the maintenance personnel in addition to the respective transmitter and receiver are able to open them. The containers should be oriented approximately horizontally for the entire duration of the flight. Also, there can exist a mechanism (e.g. belt or airbag) that fixes the delivery inside the box for the entire duration of the flight
4. Loading and unloading
The drones must be able to transport packages of at least 20∗15∗8 cm. The drones must be able to carry an additional weight of at least 1,2kg over 30km. However, they should be dimensioned for at least an additional load of 2kg. All system-relevant components of the drones such as motors, flight controllers, onboard computers and power supplies must be designed redundantly in order to minimize the probability of failure. The drones must have a physical docking-structure that enables the machines to handle them safely every time. All drones should have a display that can communicate their battery level, availability and error messages. The displays can also convey messages that are related to the delivered goods (e.g. QR codes that lead to instructions or greetings).
Payments must work contactless at every machine. There should also be an app in which PayPal and certain cryptos are permitted as valid means of payment. There can be a subscription offer that promises users a certain delivery contingent at a fixed monthly price. This subscription model can be expanded into an enterprise solution. Companies would enable their employees to use all drone machines on their own company premises permanently free of charge in order to increase in-house connectivity.
If a drone loses contact with all of its machines, suffers an aerial collision (e.g. with a bird) or any other fatality, an emergency protocol must be in place to protect passers-by from falling debris. One way to do this would be to use a parachute system.