A low-cost obstacle detection system suitable for civilian helicopter use is under study at Eurocopter. Using automotive radar sensors, the company is confident it can help helicopter pilots in the landing and takeoff phases.
The majority of obstacle warning systems for helicopters are expensive and often bulky, heavy and power-greedy, essentially limiting the market to military operators.
To find a technology with a price compatible with civil aviation, Eurocopter scoured the automotive industry. Mission system research engineer Tim Waanders and his teams turned to Astyx, a company specializing in millimeter-wave radar sensors for various automotive applications such as parking assistance. The sensors, which use the 76-GHz frequency, have to be modified to meet Eurocopter’s needs. For example, their field of view is limited and has to be extended.
With its lower-cost system, Eurocopter’s goal is to cover the hemisphere below the helicopter. This will be used in landing, takeoff and hover in confined areas. “We’ll give the pilot a surround view,” Waanders said.
The idea is to fit multiple sensors around the helicopter. Currently, each sensor has an 800-foot range. “What’s important is the warning time; at 45 knots, this range gives about 10 seconds of warning time,” Waanders said.
Also, the obstacle type will determine the detection range. For example, it is acceptable to see a small pole later than a larger pole, Waanders said. One configuration could be to have an 800-foot forward range and a 300-foot lateral range with increased resolution.
Astyx is responsible for sensor development. EADS Innovation Works (the research arm of Eurocopter’s parent company) is in charge of antenna design and data processing. Finally, Eurocopter is responsible for the overall system design and the human-machine interface.
One approach to integrating such an obstacle-detection system is the addition of a dedicated display in an existing cockpit. It could provide a two-dimensional top view of the obstacle environment, with color-coded height information. In addition, the company is considering an aural warning.
The second approach is integrating obstacles into the synthetic vision system that could be part of Eurocopter’s new Helionix avionics suite. Whatever the approach, Waanders wants the system to be as intuitive as possible. “No training required” is an objective.
What about certification? The 76-GHz frequency band would be new in aerospace. “This is a flight aid, not a flight guidance system,” Waanders emphasized, so the pilot remains responsible for visually checking the presence of the obstacle.
Waanders estimates that moving the technology from the feasibility stage to demonstration in an operational environment will take at least two years after which would come “the start of a real development program.”
Earlier this year, an EC145 flying testbed logged five hours assessing sensor performance using obstacles such as wind turbines, power lines and the edge of a forest.