Quadcopter is slowly getting more and more involved in our daily lives. According to some recent researches reports, the commercial drone market is projected to grow at an average rate of 27% per year, until at least 2021. This market expansion was already noticed in the past 5 years, becoming more popular as affordable prices and a higher commercial availability facilitate the general public to buy one.
The possibilities of use are wide, as the consumer profiles. A quadcopter drone can perform functionalities such as high altitude photos, videos and mapping, for several segments such as agriculture, civil engineering, heavy commodities industry (oil, gas, and mining), public services in cities and for personal recreation.
With the increased number of drones flying, offering potential safety risks for users and others, requirements for manufactures became more austere and controlled.The European Union for example, in 2014 proposed a set of regulations to control the effects of drones on peoples’ safety, security and privacy.
The International Organization for Standardization also concerned about the situation, created a specific subcommittee (ISO/TC 20/SC 16) for unmanned aircraft systems.
This scenario, plus the high technology characteristic from the product, gives to manufacturers a quite challenger perspective regarding quality control.
Understanding What a Quadcopter Is Made Of
A typical unmanned quadcopter is made of light composite materials to reduce weight and increase maneuverability. This composite material strength for example, allows military drones to cruise at extremely high altitudes.
Drones are equipped with different state of the art technology such as video cameras, infra-red cameras and GPS. They can be controlled by remote control system or a ground cockpit. It come in a wide variety of sizes, with the larger models mostly used for military purposes, while smaller drones, which can be launched by hand, focused more on the general market for industries or personal recreation.
An unmanned aerial vehicle system has two parts, the drone itself and the control system. The nose is where all the sensors and navigational systems are present, while the rest of the body is most for structural and mechanical parts.
The engineering materials used to build some drones are highly complex composites which can absorb vibration which decreases the noise produced.
Characteristics to Verify for Quadcopter
1. Quadcopter Structure (Frame and Shell)
The frame can be made from different materials, most of them plastic or light metals (as aluminum). The main function is structural, both on the sense of keeping all parts together, and give some resistance for the aircraft. Facing this fact, manufacturers have to take special care regarding hardness and weight, in order to not compromise power requisitions.
The shell act as an esthetic / functional cover used to improve resistance to the elements and sometimes improve aerodynamics. It is usually made of a plastic material, but other materials can also be found.
Superficial imperfections or wrong dimensions (this one valid to frame as well) should be certified, as it may result in assembly issues with other parts, or even generate an inadequate aerodynamics, resulting in a bad flight performance.
Other physical characteristics such as resistance to corrosion or temperature variances, for example, is also recommended to be checked, in order to ensure the correct life cycle of the vehicle during its use, in terms of what is promised for the vehicle.
2. Drone’s Motors Type
Independent of the number required, quality parameters are the same, and this is a particularly important part facing the aircraft reliability and safety.
Most models available on market are offered with small electric motors, where a cylindrical shell of magnets rotates on precision bearings around a core of tightly and neatly coiled wire. The propeller is fastened atop.
Voltage, amperage, thrust, power and speed (in RPM) are the most critical controlled parameters to be inspected regarding the motor itself, while ensure a good surface material quality and the right dimensioning are critical parameters regarding the propeller.
This is a device that must be connected between a motor and a flight controller, and it is responsible for control the speed and to distribute the electric power for each motor. It is basically a small electronic part, but very important to the overall performance of the drone. Voltage, amperage and the quality of its connectors have to be checked in an inspection plan.
4. Flight Controller
The flight controller is the brain, the core chip required to build a quadcopter and to get it in the air. This connects your motors, your GPS (if any), with your battery and your receiver. The simple idea here is that the user, the UAV pilot, gives the drone some throttle from the ground via a transmitter.
The signal reaches the quadcopter via the receiver which then passes to the flight controller. It determines how much every motor must spin and passes some integer values to the ESC’s and lastly the ESC decides how much voltage must be sent to the motors.
This small electronic board has several features, and it´s function ability depends on its memory and processing capacities. Connectors must be reliable, as it can cause a general failure of the drone.
For a UAS the Shelf Life may be considered the most important one, as it is related to the capacity retention (the remaining capacity that a battery keeps during storage), and so will be determinant to the duration of flight time.
Premature failures, unexpected discharge for example, may cause serious damage during a flight. Because of that some aircrafts are equipped with more than one battery, in parallel.
There are several options of remote control for drones, and you may find different features and controlling options in all of them. But considering the basic and critical characteristics, it is the same for all different types. Functionalities should be perfectly working (buttons and sticks response), radio frequency should be reliable and correctly synchronized and the range of controlling adjusted according to the promise.
There are some basic items like antennas and transmitters that will be found in almost every quadcopter available in the market, and some others like GPS, altimeter, barometer, flight controller or video camera, will vary according the model and brand. For all cases it is important certify all features are correctly adjusted, connected and operating correctly.
Asia Quality Control at your service
On the manufacturing process there is a mix of parts acquired from suppliers and some that may be produced by the manufacturer, so it is important have a coherent strategy for quality control considering all stages and possibilities.
For those parts supplied from third parts, an Incoming Material Inspection strategy is essential to ensure quality items will be provided for the assembly line process.
In addition a Basic Supplier Audit also called Simple Factory Audit, Supplier Evaluation is an option for qualification operation which is performed during the sourcing phase.
During manufacturing and assembly visual inspection and the measure of some parameters may detect some defects, and a product monitoring service could be used on this purpose.
A Pre-Shipment Inspection in China and Asia also called Final Random Inspection, Pre-Shipment Check or even Final Quality Control (FQC) is performed when at least 80% of the production is over, and would be appropriate to certify Quadcopter Drones quality status before loading and shipment of the goods, ensuring this way a final security regarding defective products.