Inceptors traditionally are connected to directional aircraft surfaces and power controls through mechanical linkages. On fly-by-wire aircraft, the inceptors transmit pilot inputs to the flight control computer, which translates them instantaneously to commands that adjust directional surfaces and power. Active inceptor systems feed information from the aircraft’s fly-by-wire system to the pilot through the inceptor (see diagram below). This “tactile cueing” is one of the many benefits of an active inceptor system. In an active inceptor system, two inceptors can be electronically coupled as if they were mechanically linked. Dual-pilot aircraft can thus benefit from the additional feel and cueing capabilities without the weight and through life cost penalties of actual mechanical linkages.
The difficulties for the pilots to maneuvers such a vehicle is in part covered by FCS and FCC and part by specific inceptor representing the final interface with the pilot. In particular the development of active inceptor should mimic a mechanical linkage, all physical parameters of which can be adjusted by the flight control computer in real-time, depending on the status of the aircraft. With having an active inceptor available, not only the disadvantages of the missing tactile feedback can be overcome, but also additional tactile cues can be added to improve the handling qualities and/or to reduce the workload further [Hosman1990]. The quality of the active inceptor is proportional to the amount of information that can be transferred to the pilot, which is equivalent to the tactile bandwidth [Einthoven2004].
The SMAR-TeR project intends to go beyond the state-of-the-art of civil tilt rotor inceptor concept, by fulfilling the following points.
The proposed inceptors is characterized by a simplified command logic, specifically tailored for a tiltrotor class vehicle and will result in a cheaper and lighter design, compared with current reference, represented by AW609 civil tiltrotor, which foresees mechanical linkage between pilot and co-pilot.
The SMAR-TeR project investigated all possible combinations of different existing and some novel concepts (subject of current analysis) mechanical control devices creating an analytical performance assessment matrix with the aim of predicting the inceptor configurations points of strengths and weaknesses in terms of easiness and intuitiveness of the command logic, effectiveness in the three flight phases (vertical flight, horizontal flight and transition), and relationship to fly-by-wire flight control system commands (including both simulated mechanical linkage, velocity, rate and position command modes).
Analytical and ergonomic assessment of each configuration was performed according to partners experience, Topic Leader support, key performance indicators and the use of virtual-reality tools with aircraft cockpit's representation. Thus, a conscious and performance-aware optimization first, and selection later was performed obtaining inceptor configurations with a high potentiality of innovation and effectiveness for the specific tiltrotor control application.
Since pilot loss of situational awareness is considered one of the major sources of flight accidents, the
proposed inceptors included haptic features in order to ease pilot situational awareness. Thanks to smart sensors and actuators the pilot commands can be translated to the vehicle’s FCS providing counter force feedback to the pilot.
Haptic shared control systems are support systems that share the control with the human operator by providing additional forces on the control device that show possible control strategies.
