• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.10
• /
• pp.79-88
• /
• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The FBWA configurations are of the same generic form of the Korean advanced trainer. The normal acceleration (Nz) and pitch rate (q) feedback control system is employed for longitudinal axis and roll rate (p) and lateral acceleration (Ny) feedback flight control law is developed in lateral/ directional axis. The flight tests for the FBW A dynamics evaluation were executed for the target aircraft (FBWA) on the IFS (In-Flight-Simulator) aircraft . The test results showed that Level 1 handling qualities for the most unstable flight regime and Level 1/2 for the landing approach flight regime were achieved. And the designed FBWA flight control law has revealed acceptable CHR (Cooper-Harper handling qualities Ratings).

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.3
• /
• pp.509-520
• /
• 2023

In this paper, the structure and the characteristics of the Fly-By-Wire system applied to the civil aircraft was described. The development trend of the redundant method of the flight control system, data communication system, control surface actuation system and the control laws implemented by the Fly-By-Wire system of the civil aircraft are discussed. The Fly-By-Wire system was first applied to the fighter and its inherent advantages lead to the advent of the Fly-By-Wire civil aircraft. Recently even the small jet aircraft shows the trend of adopting the Fly-By-Wire system. In the future, most of the aircraft are expected to be the Fly-By-Wire type.

• Current Industrial and Technological Trends in Aerospace
• /
• v.7 no.2
• /
• pp.85-94
• /
• 2009

The Fly-By-Wire system was first applied to the fighter and its inherent advantages lead to the advent of the Fly-By-Wire civil aircraft. Recently even the small jet aircraft shows the trend of adopting the Fly-By-Wire system. In the future, most of the aircraft are expected to be the Fly-By-Wire type. In this paper, the structure and the characteristics of the Fly-By-Wire system applied to the civil aircraft was described. The development trend of the redundant method of the flight control system, data communication system, control surface actuation system and the control laws implemented by the Fly-By-Wire system of the civil aircraft are discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.8
• /
• pp.731-738
• /
• 2015

The rapid prototyping process and development tool which enable the control law evaluation efficiently are needed to minimize the development cycle, cost and risk of aircraft flight control system. This paper describes a development process that integrates the designed control law into HETLAS to evaluate simulation effectively using nonlinear mathematical models. The desktop engineering simulator was developed using HETLAS for the piloted simulation evaluation of a various control modes and the procedure was developed, which quickly integrates the HETLAS into HQS(Handling Quality Simulator) and HILS(Hardware In the Loop Simulation) environments. This paper presents a rapid prototyping process using HETLAS that significantly shortens the integration process of the control law into the nonlinear math model, HETLAS, and allows the control law designs to be quickly tested in the piloted simulation and HILS environments.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.10
• /
• pp.940-947
• /
• 2007

For the performance upgrade of a supersonic jet fighter, the processor and FLCC(Flight Control Computer) Architecture were upgraded from a baseline FLCC. Prior to the hardware implementation phase, the exact CPU throughput estimation is necessary. For this purpose, an experimental method for new FLCC throughput estimation was introduced in this study.　While baseline FLCC operating, the CPU address bus was collected with logic analyzer, and then decoded to get the exact access times to each memory-memory and the number of program Instruction branches. Based on these data, a throughput test in CPU demo-board of the new FLCC configuration was performed. From test results, the CPU-Memory architecture was design-changed before FLCC hardware implementation phase. To check the flight stability degradation due to power-interrupt problem due to CPU-Memory architecture change, the piloted HILS (Hardware-In-the Loop Simulator) test was conducted.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.8
• /
• pp.678-687
• /
• 2012

The Fly-By-Wire(FBW) flight control system is essential to improve the stability and flying quality of the helicopter. Advanced aerospace companies, such as Bell-Sikorsky (USA) and NHI (European Consortium), have already applied the FBW flight control system to manufacture V-22 and NH-90 helicopters, respectively. This paper addresses the development of control law design using model inversion method improve the hover and low speed handling qualities of helicopter based on BO-105 model in 'Day' and 'Degraded visual environments(DVEs)' in accordance with ADS-33E-PRF. Design parameters are optimized to satisfy the handling qualities specification using Control Designer's Unified Interface (CONDUIT) commercial control law software. The result of the analysis based on CONDUIT and non-real time simulation in-house software, HETLAS (HElicopter Trim Linearization And Simulation) reveals that the provides an efficient mean to achieve Level 1 handling qualities.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.1
• /
• pp.159-164
• /
• 2016

This paper reports the load factor logic design for a fly-by-wire helicopter flight envelope protection. As a helicopter is very complex system with a rotor, fuselage, engine, etc., there are many constraints on the flight region. Because of these constraints, pilots should consider them carefully and have a heavy workload, which causes controllability degradation. In this respect, automatic logic is needed to free the pilot from these considerations. As one of these logics, the flight envelope protection logic for the load factor of a FBW helicopter was designed. The flight to exceed the load factor is caused by an abrupt pitch cyclic stick change. In this scheme, the load factor limit logic was added between the pilot stick command block and pitch attitude command block. From the current load value, the available attitude range was calculated dynamically and simulated on the helicopter simulator model to verify the performance. A comparison of the simulation results at the hovering and forward speed region with and without applying the load limiting logic showed that the load factor limit was exceeded more than 20% when the logic was not applied, whereas with the load factor limit logic the load factor was within the limit. In conclusion, a dynamically allocated limitation logic to helicopter FBW controller was verified by simulation.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.12 no.4
• /
• pp.42-47
• /
• 2008

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot adjusts the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller rotational speed. The electronic engine controller(EEC) of PW206C engine developed for helicopter is not fit for the power control concept of Smart UAV, and therefore the manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever angle(PLA) according to the variation of engine output shaft speed, flight altitude and flight speed. These data provide a guide for the PLA control in manual mode operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.6
• /
• pp.488-494
• /
• 2013

The control law design and analysis environment of the FBW helicopter system have been developed using model base design method. The model based design is generally used in a aircraft, unmanned aerial system and automobile as well as rotorcraft development. The model based design provides many advantages such as development risk and schedule reduction using simulation and autocode generation. This paper describes a development of process for verification and validation of auto generated code for FBW helicopter flight control law. And this process is applied for Fly-By-Wire Helicopter Development Project. The results of functional test for auto generated code meet several specific requirements.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.339-342
• /
• 2007

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot inputs the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller RPM. The manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever arm(PLA) angle according to the variation of flight altitude and speed. These data provide a guide for the engine control in manual mode operation.