Sharp senses for industrial drones

Unmanned Aerial Vehicles (UAVs), also called drones, are going to be a big thing. Between drones for military reconnaissance and combat and the booming toy multicopter market there is a broad range of commercial UAV applications. A decisive factor for the quality and application possibilities of these drones is the built-in sensor technology and thus the know-how of specialists.

UAVs are an attractive growth market: The market research company Gartner predicts that more than 3 million drones will be delivered worldwide in 2017. Sales of UAVs are expected to increase by 34 percent to $ 6 billions, and to 11.2 billions by 2020. Market aresearchers expect significant growth, particularly in the field of aindustrial inspection (oil, gas, energy, infrastructure, transport). By 2020, this sector is expected to account for about 30 percent of the commercial drones market. Delivery drones on the other hand, though a popular daily press news topic, will stay a mere niche – the market researchers expect a market share of less than one percent by 2020.

Wide range of requirements
Sensors are vital components of any drone. Only sensor systems with suitable performance lend commercial drones the flight characteristics they need. Sensors also determine the application possibilities of commercial UAVs. Police surveys, traffic monitoring or searches for missing persons, reconnaissance flights in disaster control, the recording of geoinformation or the inspection of buildings and technical facilities: Different tasks require different sensors, or rather different sensor combinations.

While the hard price pressure in the hobby drone market does not leave leeway for cameras or motion sensors, the sensor equipment is an important distinguishing feature in professional target markets.

These sensor types are used in drones:

• LIDAR (light detection and ranging) for collision avoidance, navigation and as a 3D scanner
• Range finders for collision avoidance and navigation
• PIN diodes for motion detection
• Cameras for observation, data acquisition, navigation and collision avoidance
• RADAR for collision avoidance and navigation
• Inertial measuring units (IMU) for navigation
• Pressure gauges for data collection and navigation
• GPS for position determination

This listing shows that many special skills are required here. Drone manufacturers outside the defense industry rarely can offer these on their own. Companies wanting to conquer this growth market usually rely on partnerships with sensor manufacturers that are experienced in industry and aeronautics. But these partners have to offer additional skills apart from the pure sensor know-how. Customizing capabilities are just as much in demand as manufacturing according to industrial quality standards, and the ability to reliably supply small and medium quantities at reasonable prices and over a longer period of time. Even large sensor manufacturers often fail in this regard, so that medium-sized specialists for industrial sensors such as First Sensor can score points. Here are some examples:

LIDAR
LIDAR or LADAR (Light / Laser Detection And Ranging) systems serve as optical systems and determine the fields of applications of commercial drones. Like the radar systems in large flight systems, they measure distance, speed and partial atmospheric parameters. The essential components are avalanche photodiode arrays (APD). IR-APDs are used for long-range LIDAR systems. Integrating these components into the systems often requires customizing, and the APD supplier should be experienced in the aerospace industry.

Movement and location
The inertial measuring units that detect the direction of movement and the inclination angle are needed for controlling the UAV. These sensors are essential for the precise steering and the stabilization of the flight position for the actual measurement tasks. It is recommended to integrate high-quality HARMS microsystems (high aspect ratio microstructures) on the PCB of the UAV control system.

First Sensor offers an interesting technology platform with capacitive inclinometers and accelerometers based on single-crystal silicon sensor elements. They achieve a very good signal-to-noise ratio and a high temperature stability. Even the smallest changes in position or acceleration are detected which is a precondition for the use of drones in measurement applications. The high aspect ratio microstructures (HARMS) ensure lowest cross-sensitivity. In addition, the patented AIM technology (Air gap Insulated Microstructures) minimizes parasitic capacitances by insulating the active areas by air gaps. Overmore, the supplier should be experienced in the aviation industry, and able to adapt the sensor measuring ranges to the requirements of the UAV and the application.

Cameras
An exciting topic are cameras. Here it is necessary to distinguish between the real-time imaging which permits the remote-control operator to virtually sit in the "cockpit" of the drone, the digital imaging for automatic navigation, and optical data collection.

Robust high-quality camera systems are already widely used in the field of driver assistance systems. Suppliers to the automotive industry know how to build reliable systems and, above all, how to test their suitability. Developments and trends from this sector can be used to quickly achieve viable solutions by adapting proven standard sensors. Modular systems offer the flexibility to meet various requirements in user data collection, such as infrared, different resolutions and optics.

What is more, local intelligence can be employed as it is common with sensors for autonomous safety systems. Evaluating the images via nearby subsystems reduces the data volume that has to be processed by the computer of the drone or sent to the controller. So for example only the result of a pattern recognition has to be transmitted without burdening the system with unnecessary picture information.

Wanted: Suitable development partners
Commercial drones with observation and analysis functions are a growth market where, in contrast to the hobby sector, the price is not the primary factor. Drone suppliers who want to set themselves apart from their competitors have to earn credits for superior functionality and reliability.The quality of the "sensory perception" of a UAV enables a safe flight and justifies the deployment and its costs.

Manufacturers can shorten their time-to-market by looking for sensor suppliers who can also act as development partners. Ideal are partners who are experienced in demanding industries with high quality and function test standards, like Aerospace and Automotive. Such development partners are better suited to contribute to engineering tailored sensor systems than mere component suppliers. Moreover, manufacturers of often highly specialized commercial UAVs need partners who have the necessary supply flexibility due to the smaller number of items.